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Sample records for passive localization processing

  1. Passive localization processing for tactical unattended ground sensors

    SciTech Connect

    Ng, L.C.; Breitfeller, E.F.

    1995-09-01

    This report summarizes our preliminary results of a development effort to assess the potential capability of a system of unattended ground sensors to detect, classify, and localize underground sources. This report also discusses the pertinent signal processing methodologies, demonstrates the approach with computer simulations, and validates the simulations with experimental data. Specific localization methods discussed include triangulation and measurement of time difference of arrival from multiple sensor arrays.

  2. Integration Processes Compared: Cortical Differences for Consistency Evaluation and Passive Comprehension in Local and Global Coherence.

    PubMed

    Egidi, Giovanna; Caramazza, Alfonso

    2016-10-01

    This research studies the neural systems underlying two integration processes that take place during natural discourse comprehension: consistency evaluation and passive comprehension. Evaluation was operationalized with a consistency judgment task and passive comprehension with a passive listening task. Using fMRI, the experiment examined the integration of incoming sentences with more recent, local context and with more distal, global context in these two tasks. The stimuli were stories in which we manipulated the consistency of the endings with the local context and the relevance of the global context for the integration of the endings. A whole-brain analysis revealed several differences between the two tasks. Two networks previously associated with semantic processing and attention orienting showed more activation during the judgment than the passive listening task. A network previously associated with episodic memory retrieval and construction of mental scenes showed greater activity when global context was relevant, but only during the judgment task. This suggests that evaluation, more than passive listening, triggers the reinstantiation of global context and the construction of a rich mental model for the story. Finally, a network previously linked to fluent updating of a knowledge base showed greater activity for locally consistent endings than inconsistent ones, but only during passive listening, suggesting a mode of comprehension that relies on a local scope approach to language processing. Taken together, these results show that consistency evaluation and passive comprehension weigh differently on distal and local information and are implemented, in part, by different brain networks. PMID:27243613

  3. Integration Processes Compared: Cortical Differences for Consistency Evaluation and Passive Comprehension in Local and Global Coherence.

    PubMed

    Egidi, Giovanna; Caramazza, Alfonso

    2016-10-01

    This research studies the neural systems underlying two integration processes that take place during natural discourse comprehension: consistency evaluation and passive comprehension. Evaluation was operationalized with a consistency judgment task and passive comprehension with a passive listening task. Using fMRI, the experiment examined the integration of incoming sentences with more recent, local context and with more distal, global context in these two tasks. The stimuli were stories in which we manipulated the consistency of the endings with the local context and the relevance of the global context for the integration of the endings. A whole-brain analysis revealed several differences between the two tasks. Two networks previously associated with semantic processing and attention orienting showed more activation during the judgment than the passive listening task. A network previously associated with episodic memory retrieval and construction of mental scenes showed greater activity when global context was relevant, but only during the judgment task. This suggests that evaluation, more than passive listening, triggers the reinstantiation of global context and the construction of a rich mental model for the story. Finally, a network previously linked to fluent updating of a knowledge base showed greater activity for locally consistent endings than inconsistent ones, but only during passive listening, suggesting a mode of comprehension that relies on a local scope approach to language processing. Taken together, these results show that consistency evaluation and passive comprehension weigh differently on distal and local information and are implemented, in part, by different brain networks.

  4. Passive Acoustic Vessel Localization

    NASA Astrophysics Data System (ADS)

    Suwal, Pasang Sherpa

    This thesis investigates the development of a low-cost passive acoustic system for localizing moving vessels to monitor areas where human activities such as fishing, snorkeling and poaching are restricted. The system uses several off-the-shelf sensors with unsynchronized clocks where the Time Difference of Arrival (TDOA) or time delay is extracted by cross-correlation of the signal between paired sensors. The cross-correlation function uses phase correlation or Phase Transform (PHAT) which whitens the cross-spectrum in order to de-emphasize dominant frequency components. Using the locations of pairs of sensors as foci, hyperbolic equations can be defined using the time delay between them. With three or more sensors, multiple hyperbolic functions can be calculated which intersect at a unique point: the boat's location. It is also found that increasing separation distances between sensors decreased the correlation between the signals. However larger separation distances have better localization capability than with small distances. Experimental results from the Columbia and Willamette Rivers are presented to demonstrate performance.

  5. Strong local passivity in finite quantum systems.

    PubMed

    Frey, Michael; Funo, Ken; Hotta, Masahiro

    2014-07-01

    Passive states of quantum systems are states from which no system energy can be extracted by any cyclic (unitary) process. Gibbs states of all temperatures are passive. Strong local (SL) passive states are defined to allow any general quantum operation, but the operation is required to be local, being applied only to a specific subsystem. Any mixture of eigenstates in a system-dependent neighborhood of a nondegenerate entangled ground state is found to be SL passive. In particular, Gibbs states are SL passive with respect to a subsystem only at or below a critical system-dependent temperature. SL passivity is associated in many-body systems with the presence of ground state entanglement in a way suggestive of collective quantum phenomena such as quantum phase transitions, superconductivity, and the quantum Hall effect. The presence of SL passivity is detailed for some simple spin systems where it is found that SL passivity is neither confined to systems of only a few particles nor limited to the near vicinity of the ground state.

  6. Adaptive passive fathometer processing.

    PubMed

    Siderius, Martin; Song, Heechun; Gerstoft, Peter; Hodgkiss, William S; Hursky, Paul; Harrison, Chris

    2010-04-01

    Recently, a technique has been developed to image seabed layers using the ocean ambient noise field as the sound source. This so called passive fathometer technique exploits the naturally occurring acoustic sounds generated on the sea-surface, primarily from breaking waves. The method is based on the cross-correlation of noise from the ocean surface with its echo from the seabed, which recovers travel times to significant seabed reflectors. To limit averaging time and make this practical, beamforming is used with a vertical array of hydrophones to reduce interference from horizontally propagating noise. The initial development used conventional beamforming, but significant improvements have been realized using adaptive techniques. In this paper, adaptive methods for this process are described and applied to several data sets to demonstrate improvements possible as compared to conventional processing.

  7. Model-based ocean acoustic passive localization. Revision 1

    SciTech Connect

    Candy, J.V.; Sullivan, E.J.

    1994-06-01

    A model-based approach is developed (theoretically) to solve the passive localization problem. Here the authors investigate the design of a model-based identifier for a shallow water ocean acoustic problem characterized by a normal-mode model. In this problem they show how the processor can be structured to estimate the vertical wave numbers directly from measured pressure-field and sound speed measurements thereby eliminating the need for synthetic aperture processing or even a propagation model solution. Finally, they investigate various special cases of the source localization problem, designing a model-based localizer for each and evaluating the underlying structure with the expectation of gaining more and more insight into the general problem.

  8. Passive versus active local microrheology in mammalian cells and amoebae

    NASA Astrophysics Data System (ADS)

    Riviere, C.; Gazeau, F.; Marion, S.; Bacri, J.-C.; Wilhelm, C.

    2004-12-01

    We compare in this paper the rotational magnetic microrheology detailed by Marion et al [18] and Wilhelm et al [19] to the passive tracking microrheology. The rotational microrheology has been designed to explore, using magnetic rotating probes, the local intracellular microenvironment of living cells in terms of viscoelasticity. Passive microrheology techniques is based on the analysis of spontaneous diffusive motions of Brownian probes. The dependence of mean square displacement (MSD) with the time then directly reflects the type of movement (sub-, hyper- or diffusive motions). Using the same intracellular probes, we performed two types of measurements (active and passive). Based on the fluctuation-dissipation theorem, one should obtain the same information from the both techniques in a thermally equilibrium system. Interestingly, our measurements differ, and the discordances directly inform on active biological processes, which add to thermally activated fluctuations in our out-of equilibrium systems. In both cell models used, mammalian Hela cells and amoebae Entamoeba Histolytica, a hyper-diffusive regime at a short time is observed, which highlights the presence of an active non-thermal driving force, acting on the probe. However, the nature of this active force in mammalian cells and amoebae is different, according to their different phenotypes. In mammalian cells active processes are governed by the transport, via molecular motors, on the microtubule network. In amoebae, which are highly motile cells free of microtubule network, the active processes are dominated by strong fluxes of cytoplasm driven by extension of pseudopodia, in random directions, leading to an amplitude of motion one order of magnitude higher than for mammalian cells. Figs 7, Refs 32.

  9. Optimization of receiver arrangements for passive emitter localization methods.

    PubMed

    Flückiger, M; Neild, A; Nelson, B J

    2012-03-01

    Passive localization of an object from its emission can be based on time difference of arrival or phase shift measurements for different receiver groups in sensor arrays. The accuracy of the localization primarily depends on accurate time and/or phase measurements. The frequency of the emission and the number and arrangement of the receivers mainly effect the resolution of the emitter localization. In this paper optimal receiver positions for passive localization methods are proposed, resulting in a maximal resolution for the emitter location estimate. The optimization is done by analyzing the uncertainty of the emitted signal, including its frequency. The technique has been developed specifically for ultrasound signals obtained from omnidirectional transducers, although the results apply for other application using passive localization techniques.

  10. Stable surface passivation process for compound semiconductors

    DOEpatents

    Ashby, Carol I. H.

    2001-01-01

    A passivation process for a previously sulfided, selenided or tellurated III-V compound semiconductor surface. The concentration of undesired mid-gap surface states on a compound semiconductor surface is reduced by the formation of a near-monolayer of metal-(sulfur and/or selenium and/or tellurium)-semiconductor that is effective for long term passivation of the underlying semiconductor surface. Starting with the III-V compound semiconductor surface, any oxidation present thereon is substantially removed and the surface is then treated with sulfur, selenium or tellurium to form a near-monolayer of chalcogen-semiconductor of the surface in an oxygen-free atmosphere. This chalcogenated surface is then contacted with a solution of a metal that will form a low solubility chalcogenide to form a near-monolayer of metal-chalcogen-semiconductor. The resulting passivating layer provides long term protection for the underlying surface at or above the level achieved by a freshly chalcogenated compound semiconductor surface in an oxygen free atmosphere.

  11. Human sperm rheotaxis: a passive physical process.

    PubMed

    Zhang, Zhuoran; Liu, Jun; Meriano, Jim; Ru, Changhai; Xie, Shaorong; Luo, Jun; Sun, Yu

    2016-01-01

    A long-standing question in natural reproduction is how mammalian sperm navigate inside female reproductive tract and finally reach the egg cell, or oocyte. Recently, fluid flow was proposed as a long-range guidance cue for sperm navigation. Coitus induces fluid flow from oviduct to uterus, and sperm align themselves against the flow direction and swim upstream, a phenomenon termed rheotaxis. Whether sperm rheotaxis is a passive process dominated by fluid mechanics, or sperm actively sense and adapt to fluid flow remains controversial. Here we report the first quantitative study of sperm flagellar motion during human sperm rheotaxis and provide direct evidence indicating that sperm rheotaxis is a passive process. Experimental results show that there is no significant difference in flagellar beating amplitude and asymmetry between rheotaxis-turning sperm and those sperm swimming freely in the absence of fluid flow. Additionally, fluorescence image tracking shows no Ca(2+) influx during sperm rheotaxis turning, further suggesting there is no active signal transduction during human sperm rheotaxis. PMID:27005727

  12. Human sperm rheotaxis: a passive physical process

    NASA Astrophysics Data System (ADS)

    Zhang, Zhuoran; Liu, Jun; Meriano, Jim; Ru, Changhai; Xie, Shaorong; Luo, Jun; Sun, Yu

    2016-03-01

    A long-standing question in natural reproduction is how mammalian sperm navigate inside female reproductive tract and finally reach the egg cell, or oocyte. Recently, fluid flow was proposed as a long–range guidance cue for sperm navigation. Coitus induces fluid flow from oviduct to uterus, and sperm align themselves against the flow direction and swim upstream, a phenomenon termed rheotaxis. Whether sperm rheotaxis is a passive process dominated by fluid mechanics, or sperm actively sense and adapt to fluid flow remains controversial. Here we report the first quantitative study of sperm flagellar motion during human sperm rheotaxis and provide direct evidence indicating that sperm rheotaxis is a passive process. Experimental results show that there is no significant difference in flagellar beating amplitude and asymmetry between rheotaxis-turning sperm and those sperm swimming freely in the absence of fluid flow. Additionally, fluorescence image tracking shows no Ca2+ influx during sperm rheotaxis turning, further suggesting there is no active signal transduction during human sperm rheotaxis.

  13. Human sperm rheotaxis: a passive physical process

    PubMed Central

    Zhang, Zhuoran; Liu, Jun; Meriano, Jim; Ru, Changhai; Xie, Shaorong; Luo, Jun; Sun, Yu

    2016-01-01

    A long-standing question in natural reproduction is how mammalian sperm navigate inside female reproductive tract and finally reach the egg cell, or oocyte. Recently, fluid flow was proposed as a long–range guidance cue for sperm navigation. Coitus induces fluid flow from oviduct to uterus, and sperm align themselves against the flow direction and swim upstream, a phenomenon termed rheotaxis. Whether sperm rheotaxis is a passive process dominated by fluid mechanics, or sperm actively sense and adapt to fluid flow remains controversial. Here we report the first quantitative study of sperm flagellar motion during human sperm rheotaxis and provide direct evidence indicating that sperm rheotaxis is a passive process. Experimental results show that there is no significant difference in flagellar beating amplitude and asymmetry between rheotaxis-turning sperm and those sperm swimming freely in the absence of fluid flow. Additionally, fluorescence image tracking shows no Ca2+ influx during sperm rheotaxis turning, further suggesting there is no active signal transduction during human sperm rheotaxis. PMID:27005727

  14. Localization of acoustic sensors from passive Green's function estimation.

    PubMed

    Nowakowski, Thibault; Daudet, Laurent; de Rosny, Julien

    2015-11-01

    A number of methods have recently been developed for passive localization of acoustic sensors, based on the assumption that the acoustic field is diffuse. This article presents the more general case of equipartition fields, which takes into account reflections off boundaries and/or scatterers. After a thorough discussion on the fundamental differences between the diffuse and equipartition models, it is shown that the method is more robust when dealing with wideband noise sources. Finally, experimental results show, for two types of boundary conditions, that this approach is especially relevant when acoustic sensors are close to boundaries.

  15. Local suppression of turbulent noise by passively inducing relaminarization

    NASA Astrophysics Data System (ADS)

    Kirkman, Richard; Metzger, Meredith

    2010-11-01

    Direct numerical simulations of turbulent channel flow were performed to study potential means of locally suppressing wall pressure noise by passively driving the flow towards relaminarization. The noise reduction is achieved by altering the surface geometry along a wall of the channel. Two separate geometries were investigated, namely a wedge-shaped protrusion and an inverted wedge-shaped depression. In both configurations, the wedge remains stationary and spans the width of the channel. The flow tends toward relaminarization due to local convective acceleration along the upslope of the wedge (in the case of the protrusion) and due to the gradual unstalled expansion along the downslope of the wedge (in the case of the depression). Simulations were performed at a Reynolds number based on friction velocity of 180. The no-slip condition along the surface of the protrusion/depression was enforced using an immersed boundary method. Profiles of turbulence statistics and wall- pressure intensity, as well as the wall-pressure spectra along the front face of the two different wedges are compared in relation to those of the undisturbed approach boundary layer.

  16. Comparative evaluation of passive, active, and passive-active distraction techniques on pain perception during local anesthesia administration in children.

    PubMed

    Abdelmoniem, Soad A; Mahmoud, Sara A

    2016-05-01

    Local anesthesia forms the backbone of pain control techniques and is necessary for a painless dental procedure. Nevertheless, administering a local anesthetic injection is among the most anxiety-provoking procedures to children. This study was performed to compare the efficacy of different distraction techniques (passive, active, and passive-active) on children's pain perception during local anesthesia administration. A total of 90 children aged four to nine years, requiring inferior alveolar nerve block for primary molar extraction, were included in this study and randomly divided into three groups according to the distraction technique employed during local anesthesia administration. Passive distraction group: the children were instructed to listen to a song on headphones; Active distraction group: the children were instructed to move their legs up and down alternatively; and Passive-active distraction group: this was a combination between both techniques. Pain perception during local anesthesia administration was evaluated by the Sounds, Eyes, and Motor (SEM) scale and Wong Baker FACES® Pain Rating Scale. There was an insignificant difference between the three groups for SEM scale and Wong Baker FACES Pain Rating Scale at P = 0.743 and P = 0.112 respectively. The examined distraction techniques showed comparable results in reducing pain perception during local anesthesia administration.

  17. Comparative evaluation of passive, active, and passive-active distraction techniques on pain perception during local anesthesia administration in children

    PubMed Central

    Abdelmoniem, Soad A.; Mahmoud, Sara A.

    2015-01-01

    Local anesthesia forms the backbone of pain control techniques and is necessary for a painless dental procedure. Nevertheless, administering a local anesthetic injection is among the most anxiety-provoking procedures to children. This study was performed to compare the efficacy of different distraction techniques (passive, active, and passive-active) on children’s pain perception during local anesthesia administration. A total of 90 children aged four to nine years, requiring inferior alveolar nerve block for primary molar extraction, were included in this study and randomly divided into three groups according to the distraction technique employed during local anesthesia administration. Passive distraction group: the children were instructed to listen to a song on headphones; Active distraction group: the children were instructed to move their legs up and down alternatively; and Passive-active distraction group: this was a combination between both techniques. Pain perception during local anesthesia administration was evaluated by the Sounds, Eyes, and Motor (SEM) scale and Wong Baker FACES® Pain Rating Scale. There was an insignificant difference between the three groups for SEM scale and Wong Baker FACES Pain Rating Scale at P = 0.743 and P = 0.112 respectively. The examined distraction techniques showed comparable results in reducing pain perception during local anesthesia administration. PMID:27222759

  18. Enhanced Passive and Active Processing of Syllables in Musician Children

    ERIC Educational Resources Information Center

    Chobert, Julie; Marie, Celine; Francois, Clement; Schon, Daniele; Besson, Mireille

    2011-01-01

    The aim of this study was to examine the influence of musical expertise in 9-year-old children on passive (as reflected by MMN) and active (as reflected by discrimination accuracy) processing of speech sounds. Musician and nonmusician children were presented with a sequence of syllables that included standards and deviants in vowel frequency,…

  19. Passive localization in the deep ocean based on cross-correlation function matching.

    PubMed

    Lei, Zhixiong; Yang, Kunde; Ma, Yuanliang

    2016-06-01

    Passive localization of a sound source in the deep ocean is investigated in this study. The source can be localized by taking advantage of a cross-correlation function matching technique. When a two-sensor vertical array is used in the deep ocean, two types of side lobe curves appear in the ambiguity surface of the localization. The side lobe curves are analytically expressed and they are then used as indicators of the localization result instead of the scanning point with the maximum power. Simulation and experiment demonstrate the performance of the proposed passive localization method. PMID:27369172

  20. Catalytic cracking process with vanadium passivation

    SciTech Connect

    Kennedy, J.V.; Jossens, L.W.

    1991-03-26

    This paper discusses a process for the catalytic cracking of metal-containing hydrocarbonaceous feedstock. It comprises contacting the feedstock under cracking conditions with a dual component catalyst composition. The catalyst composition comprises a first component comprising an active cracking catalyst; and a second component, as a separate and distinct entity, the second component comprising the following materials: a calcium and magnesium containing material selected from the group consisting of dolomite, substantially amorphous calcium magnesium silicate, calcium magnesium oxide, calcium magnesium acetate, calcium magnesium carbonate, and calcium magnesium subcarbonate; a magnesium containing material comprising a hydrous magnesium silicate; and a binder selected from the group consisting of kaolin, bentonite, montmorillonite, saponite, hectorite, alumina, silica, titania, zirconia, silica-alumina, and combinations thereof.

  1. Passive electrical monitoring and localization of fluid leakages from wells

    NASA Astrophysics Data System (ADS)

    Revil, A.; Mao, D.; Haas, A. K.; Karaoulis, M.; Frash, L.

    2015-02-01

    Electrokinetic phenomena are a class of cross-coupling phenomena involving the relative displacement between the pore water (together with the electrical diffuse layer) with respect to the solid phase of a porous material. We demonstrate that electrical fields of electrokinetic nature can be associated with fluid leakages from wells. These leakages can be remotely monitored and the resulting signals used to localize their causative source distribution both in the laboratory and in field conditions. The first laboratory experiment (Experiment #1) shows how these electrical fields can be recorded at the surface of a cement block during the leakage of a brine from a well. The measurements were performed with a research-grade medical electroencephalograph and were inverted using a genetic algorithm to localize the causative source of electrical current and therefore, localize the leak in the block. Two snapshots of electrical signals were used to show how the leak evolved over time. The second experiment (Experiment #2) was performed to see if we could localize a pulse water injection from a shallow well in field conditions in the case of a heterogeneous subsurface. We used the same equipment as in Experiment #1 and processed the data with a trend removal algorithm, picking the amplitude from 24 receiver channels just after the water injection. The amplitude of the electric signals changed from the background level indicating that a volume of water was indeed flowing inside the well into the surrounding soil and then along the well. We used a least-square inversion algorithm to invert a snapshot of the electrical potential data at the injection time to localize the source of the self-potential signals. The inversion results show positive potential anomalies in the vicinity of the well. For both experiments, forward numerical simulations of the problem using a finite element package were performed in order to assess the underlying physics of the causative source of the

  2. Non-invasive Technology to Study Local Passivity Breakdown of Metal Alloys in Aqueous Media

    SciTech Connect

    Alan M. Shipley

    2005-03-09

    Little is known about the basic mechanisms of passive oxide breakdown, repair, and localized corrosion of metals. A non-invasive instrument and methods have been developed to study local events and mechanisms that initiate passivity breakdown and subsequent corrosion of metals in aqueous media. The ''difference viewer imaging technique'' (DVIT) is a rapid, real time, non-invasive assay to study metal surfaces in corrosive solutions. It has a spatial resolution of less than 10.0 ?m (1cm x 1cm sample, 1000 x 1000 pixel CCD) to observe initial corrosion processes of the order of seconds. DVIT is a software-controlled video microscopy system and methods to collect and analyze pixel changes in video images. These images are recorded from a digital CCD video camera and frame grabber package using visible light for illumination. The DVIT system detects changes in video images that represent initial corrosive events that lead to passivity breakdown and re-passivation on metal surfaces in situ. This visual technique is easy to use and apply. It compliments other metal surface measurement techniques and can be used simultaneously with them. DVIT has proven to be more sensitive in detecting changes than scanning microelectrode techniques. DVIT is also much easier than other methods to apply and operate. It has the further advantage of providing a real time image of the entire metal surface under study instead of waiting for a microelectrode to scan a number of data points over a sample then plot the results. This project has fulfilled all specifications as outlined in the Department of Energy solicitation responsible for this grant application and award and exceeded a number of the specifications. Applicable Electronics, Inc. now has a marketable instrument and software package available for sale now. Further development of the system will be ongoing as driven by customer needs and discoveries. This technology has immediate applications in corrosion labs to further study

  3. Passive silicon photonic devices for microwave photonic signal processing

    NASA Astrophysics Data System (ADS)

    Wu, Jiayang; Peng, Jizong; Liu, Boyu; Pan, Ting; Zhou, Huanying; Mao, Junming; Yang, Yuxing; Qiu, Ciyuan; Su, Yikai

    2016-08-01

    We present our recent progress on microwave signal processing (MSP) using on-chip passive silicon photonic devices, including tunable microwave notch filtering/millimeter-wave (MMW) signal generation based on self-coupled micro-resonators (SCMRs), and tunable radio-frequency (RF) phase shifting implemented by a micro-disk resonator (MDR). These schemes can provide improved flexibility and performances of MSP. The experimental results are in good agreement with theoretical predictions, which validate the effectiveness of the proposed schemes.

  4. Is Children's Acquisition of the Passive a Staged Process? Evidence from Six- and Nine-Year-Olds' Production of Passives

    ERIC Educational Resources Information Center

    Messenger, Katherine; Branigan, Holly P.; McLean, Janet F.

    2012-01-01

    We report a syntactic priming experiment that examined whether children's acquisition of the passive is a staged process, with acquisition of constituent structure preceding acquisition of thematic role mappings. Six-year-olds and nine-year-olds described transitive actions after hearing active and passive prime descriptions involving the same or…

  5. Local-Level Prognostics Health Management Systems Framework for Passive AdvSMR Components. Interim Report

    SciTech Connect

    Ramuhalli, Pradeep; Roy, Surajit; Hirt, Evelyn H.; Pardini, Allan F.; Jones, Anthony M.; Deibler, John E.

    2014-09-12

    This report describes research results to date in support of the integration and demonstration of diagnostics technologies for prototypical AdvSMR passive components (to establish condition indices for monitoring) with model-based prognostics methods. The focus of the PHM methodology and algorithm development in this study is at the localized scale. Multiple localized measurements of material condition (using advanced nondestructive measurement methods), along with available measurements of the stressor environment, enhance the performance of localized diagnostics and prognostics of passive AdvSMR components and systems.

  6. Solution-processed amorphous silicon surface passivation layers

    SciTech Connect

    Mews, Mathias Sontheimer, Tobias; Korte, Lars; Rech, Bernd; Mader, Christoph; Traut, Stephan; Wunnicke, Odo

    2014-09-22

    Amorphous silicon thin films, fabricated by thermal conversion of neopentasilane, were used to passivate crystalline silicon surfaces. The conversion is investigated using X-ray and constant-final-state-yield photoelectron spectroscopy, and minority charge carrier lifetime spectroscopy. Liquid processed amorphous silicon exhibits high Urbach energies from 90 to 120 meV and 200 meV lower optical band gaps than material prepared by plasma enhanced chemical vapor deposition. Applying a hydrogen plasma treatment, a minority charge carrier lifetime of 1.37 ms at an injection level of 10{sup 15}/cm{sup 3} enabling an implied open circuit voltage of 724 mV was achieved, demonstrating excellent silicon surface passivation.

  7. Delivery of video-on-demand services using local storages within passive optical networks.

    PubMed

    Abeywickrama, Sandu; Wong, Elaine

    2013-01-28

    At present, distributed storage systems have been widely studied to alleviate Internet traffic build-up caused by high-bandwidth, on-demand applications. Distributed storage arrays located locally within the passive optical network were previously proposed to deliver Video-on-Demand services. As an added feature, a popularity-aware caching algorithm was also proposed to dynamically maintain the most popular videos in the storage arrays of such local storages. In this paper, we present a new dynamic bandwidth allocation algorithm to improve Video-on-Demand services over passive optical networks using local storages. The algorithm exploits the use of standard control packets to reduce the time taken for the initial request communication between the customer and the central office, and to maintain the set of popular movies in the local storage. We conduct packet level simulations to perform a comparative analysis of the Quality-of-Service attributes between two passive optical networks, namely the conventional passive optical network and one that is equipped with a local storage. Results from our analysis highlight that strategic placement of a local storage inside the network enables the services to be delivered with improved Quality-of-Service to the customer. We further formulate power consumption models of both architectures to examine the trade-off between enhanced Quality-of-Service performance versus the increased power requirement from implementing a local storage within the network. PMID:23389189

  8. Localized ohmic contact through a passivation dielectric for solar cell rear surface design

    NASA Astrophysics Data System (ADS)

    Western, Ned J.; Sung, Andrew; Wenham, Stuart R.; Bremner, Stephen P.

    2013-06-01

    We report the demonstration of a method for forming localized ohmic contact through dielectric passivation layers, via a laser doped region, with no etching prior to metal deposition. A simple bench top voltage source contacted to the gate and bulk of a test Metal-Insulator-Semiconductor device facilitates localized heating leading to ohmic contact formation. The surface passivation qualities of the dielectrics are preserved away from the contact region using this method, as hard dielectric breakdown is restricted to the laser doped region. This is a potential technique for precisely contacting rear surface of high efficiency solar cells.

  9. Passive acoustic source localization using sources of opportunity.

    PubMed

    Verlinden, Christopher M A; Sarkar, J; Hodgkiss, W S; Kuperman, W A; Sabra, K G

    2015-07-01

    The feasibility of using data derived replicas from ships of opportunity for implementing matched field processing is demonstrated. The Automatic Identification System (AIS) is used to provide the library coordinates for the replica library and a correlation based processing procedure is used to overcome the impediment that the replica library is constructed from sources with different spectra and will further be used to locate another source with its own unique spectral structure. The method is illustrated with simulation and then verified using acoustic data from a 2009 experiment for which AIS information was retrieved from the United States Coast Guard Navigation Center Nationwide AIS database.

  10. Passive acoustic source localization using sources of opportunity.

    PubMed

    Verlinden, Christopher M A; Sarkar, J; Hodgkiss, W S; Kuperman, W A; Sabra, K G

    2015-07-01

    The feasibility of using data derived replicas from ships of opportunity for implementing matched field processing is demonstrated. The Automatic Identification System (AIS) is used to provide the library coordinates for the replica library and a correlation based processing procedure is used to overcome the impediment that the replica library is constructed from sources with different spectra and will further be used to locate another source with its own unique spectral structure. The method is illustrated with simulation and then verified using acoustic data from a 2009 experiment for which AIS information was retrieved from the United States Coast Guard Navigation Center Nationwide AIS database. PMID:26233061

  11. Surface passivation process of compound semiconductor material using UV photosulfidation

    DOEpatents

    Ashby, Carol I. H.

    1995-01-01

    A method for passivating compound semiconductor surfaces by photolytically disrupting molecular sulfur vapor with ultraviolet radiation to form reactive sulfur which then reacts with and passivates the surface of compound semiconductors.

  12. Local Fine Structural Insight into Mechanism of Electrochemical Passivation of Titanium.

    PubMed

    Wang, Lu; Yu, Hongying; Wang, Ke; Xu, Haisong; Wang, Shaoyang; Sun, Dongbai

    2016-07-20

    Electrochemically formed passive film on titanium in 1.0 M H2SO4 solution and its thickness, composition, chemical state, and local fine structure are examined by Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), and X-ray absorption fine structure. AES analysis reveals that the thickness and composition of oxide film are proportional to the reciprocal of current density in potentiodynamic polarization. XPS depth profiles of the chemical states of titanium exhibit the coexistence of various valences cations in the surface. Quantitative X-ray absorption near edge structure analysis of the local electronic structure of the topmost surface (∼5.0 nm) shows that the ratio of [TiO2]/[Ti2O3] is consistent with that of passivation/dissolution of electrochemical activity. Theoretical calculation and analysis of extended X-ray absorption fine structure spectra at Ti K-edge indicate that both the structures of passivation and dissolution are distorted caused by the appearance of two different sites of Ti-O and Ti-Ti. And the bound water in the topmost surface plays a vital role in structural disorder confirmed by XPS. Overall, the increase of average Ti-O coordination causes the electrochemical passivation, and the dissolution is due to the decrease of average Ti-Ti coordination. The structural variations of passivation in coordination number and interatomic distance are in good agreement with the prediction of point defect model. PMID:27355902

  13. Apparatus and process for passivating an SRF cavity

    DOEpatents

    Myneni, Ganapati Rao; Wallace, John P

    2014-12-02

    An apparatus and process for the production of a niobium cavity exhibiting high quality factors at high gradients is provided. The apparatus comprises a first chamber positioned within a second chamber, an RF generator and vacuum pumping systems. The process comprises placing the niobium cavity in a first chamber of the apparatus; thermally treating the cavity by high temperature in the first chamber while maintaining high vacuum in the first and second chambers; and applying a passivating thin film layer to a surface of the cavity in the presence of a gaseous mixture and an RF field. Further a niobium cavity exhibiting high quality factors at high gradients produced by the method of the invention is provided.

  14. Systematic Satellite Observations of the Impact of Aerosols from Passive Volcanic Degassing on Local Cloud Properties

    NASA Technical Reports Server (NTRS)

    Ebmeier, S.K.; Sayer, Andrew M.; Grainger, R. G.; Mather, T. A.; Carboni, E.

    2014-01-01

    The impact of volcanic emissions, especially from passive degassing and minor explosions, is a source of uncertainty in estimations of aerosol indirect effects. Observations of the impact of volcanic aerosol on clouds contribute to our understanding of both present-day atmospheric properties and of the pre-industrial baseline necessary to assess aerosol radiative forcing. We present systematic measurements over several years at multiple active and inactive volcanic islands in regions of low present-day aerosol burden. The timeaveraged indirect aerosol effects within 200 kilometers downwind of island volcanoes are observed using Moderate Resolution Imaging Spectroradiometer (MODIS, 2002-2013) and Advanced Along-Track Scanning Radiometer (AATSR, 2002- 2008) data. Retrievals of aerosol and cloud properties at Kilauea (Hawaii), Yasur (Vanuatu) and Piton de la Fournaise (la Reunion) are rotated about the volcanic vent to be parallel to wind direction, so that upwind and downwind retrievals can be compared. The emissions from all three volcanoes - including those from passive degassing, Strombolian activity and minor explosions - lead to measurably increased aerosol optical depth downwind of the active vent. Average cloud droplet effective radius is lower downwind of the volcano in all cases, with the peak difference ranging from 2 - 8 micrometers at the different volcanoes in different seasons. Estimations of the difference in Top of Atmosphere upward Short Wave flux upwind and downwind of the active volcanoes from NASA's Clouds and the Earth's Radiant Energy System (CERES) suggest a downwind elevation of between 10 and 45 Watts per square meter at distances of 150 - 400 kilometers from the volcano, with much greater local (less than 80 kilometers) effects. Comparison of these observations with cloud properties at isolated islands without degassing or erupting volcanoes suggests that these patterns are not purely orographic in origin. Our observations of unpolluted

  15. Physical processes impacting passive particle dispersal in the Upper Florida Keys

    NASA Astrophysics Data System (ADS)

    Fiechter, Jerome; Haus, Brian K.; Melo, Nelson; Mooers, Christopher N. K.

    2008-06-01

    Physical processes affecting the dispersion of passive particles (e.g., coral larvae, pollutants) in the Upper Florida Keys are investigated through in situ observations (acoustic Doppler current profilers and surface drifters) and numerical ocean circulation modeling (horizontal resolution: 800 m, vertical resolution: 0.1-1 m). During the study period in August 2006 (set to coincide with an annual coral spawning event), Lagrangian trajectories in the vicinity of the reef tract indicate that alongshelf advection was mainly poleward and due to the subtidal flow of the Florida Current, while cross-shelf advection was mainly onshore and due to wind-driven currents. Tidal currents resulted in predominantly alongshelf displacements, but did not contribute significantly to net passive particle transport on a weekly timescale. Typical advection distances were of the order of 10 to 50 km for pelagic durations of 1 week, with significant variability linked to geographical location. In contrast, the direction of transport from the offshore reefs remained essentially constant (i.e., potential dispersion pathways were limited). In addition, Lagrangian trajectories and progressive vector diagrams in the vicinity of the reef tract indicate that alongshelf variations in the cross-shelf velocity gradient associated with the FC are relatively weak on an alongshore scale of ca. 50 km. For August 2006, the highest particle concentrations typically occur inshore of the reef tract, thereby suggesting that onshore transport associated with wind-driven currents contributes significantly to the local retention of passive organisms (and other tracers) in the Upper Florida Keys. Overall, the results illustrate the necessity of conducting targeted in situ observations and numerical model predictions to quantify the physical processes affecting reef-scale advection, especially in an effort to understand local retention and dispersion mechanisms for larval marine organisms.

  16. Effects of passive heat stress on human somatosensory processing.

    PubMed

    Nakata, Hiroki; Oshiro, Misaki; Namba, Mari; Shibasaki, Manabu

    2015-12-01

    Herein, we investigated the effects of passive heat stress on human somatosensory processing recorded by somatosensory-evoked potentials (SEPs). Fifteen healthy subjects received a median nerve stimulation at the left wrist under two thermal conditions: Heat Stress and normothermic Time Control. The latencies and amplitudes of P14, N20, P25, N35, P45, and N60 at C4' and P14, N18, P22, and N30 at Fz were evaluated. Under the Heat Stress condition, SEPs were recorded at normothermic baseline (1st), early in heat stress (2nd), when esophageal temperature had increased by ~1.0°C (3rd) and ~2.0°C (4th), and after heat stress (5th). In the Time Control condition, SEPs were measured at the same time intervals as those in the Heat Stress condition. The peak latencies and amplitudes of SEPs did not change early in heat stress. However, the latencies of P14, N20, and N60 at C4' and P14, N18, and P22 at Fz were significantly shorter in the 4th session than in the 1st session. Furthermore, the peak amplitudes of P25 and N60 at C4', and P22 and N30 at Fz decreased with increases in body temperature. On the other hand, under the Time Control condition, no significant differences were observed in the amplitudes or latencies of any component of SEPs. These results suggested that the conduction velocity of the ascending somatosensory input was accelerated by increases in body temperature, and hyperthermia impaired the neural activity of cortical somatosensory processing. PMID:26468258

  17. Local oscillator induced degradation of medium-term stability in passive atomic frequency standards

    NASA Technical Reports Server (NTRS)

    Dick, G. John; Prestage, John D.; Greenhall, Charles A.; Maleki, Lute

    1990-01-01

    As the performance of passive atomic frequency standards improves, a new limitation is encountered due to frequency fluctuations in an ancillary local oscillator (L.O.). The effect is due to time variation in the gain of the feedback which compensates L.O. frequency fluctuations. The high performance promised by new microwave and optical trapped ion standards may be severely compromised by this effect. Researchers present an analysis of this performance limitation for the case of sequentially interrogated standards. The time dependence of the sensitivity of the interrogation process to L.O. frequency fluctuations is evaluated for single-pulse and double-pulse Ramsey RF interrogation and for amplitude modulated pulses. The effect of these various time dependencies on performance of the standard is calculated for an L.O. with frequency fluctuations showing a typical 1/f spectral density. A limiting 1/sq. root gamma dependent deviation of frequency fluctuations is calculated as a function of pulse lengths, dead time, and pulse overlap. Researchers also present conceptual and hardware-oriented solutions to this problem which achieve a much more nearly constant sensitivity to L.O. fluctuations. Solutions involve use of double-pulse interrogation; alternate interrogation of multiple traps so that the dead time of one trap can be covered by operation of the other; and the use of double-pulse interrogation for two traps, so that during the time of the RF pulses, the increasing sensitivity of one trap tends to compensate for the decreasing sensitivity of the other. A solution making use of amplified-modulated pulses is also presented which shows nominally zero time variation.

  18. 43 CFR 2806.43 - How does BLM calculate rent for passive reflectors and local exchange networks?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... electric power; and (2) Local exchange network means radio service which provides basic telephone service... reflectors and local exchange networks? 2806.43 Section 2806.43 Public Lands: Interior Regulations Relating...-Of-Way § 2806.43 How does BLM calculate rent for passive reflectors and local exchange networks?...

  19. Localized electrical fine tuning of passive microwave and radio frequency devices

    DOEpatents

    Findikoglu, Alp T.

    2001-04-10

    A method and apparatus for the localized electrical fine tuning of passive multiple element microwave or RF devices in which a nonlinear dielectric material is deposited onto predetermined areas of a substrate containing the device. An appropriate electrically conductive material is deposited over predetermined areas of the nonlinear dielectric and the signal line of the device for providing electrical contact with the nonlinear dielectric. Individual, adjustable bias voltages are applied to the electrically conductive material allowing localized electrical fine tuning of the devices. The method of the present invention can be applied to manufactured devices, or can be incorporated into the design of the devices so that it is applied at the time the devices are manufactured. The invention can be configured to provide localized fine tuning for devices including but not limited to coplanar waveguides, slotline devices, stripline devices, and microstrip devices.

  20. Effect of excimer laser annealing on a-InGaZnO thin-film transistors passivated by solution-processed hybrid passivation layers

    NASA Astrophysics Data System (ADS)

    Bermundo, Juan Paolo; Ishikawa, Yasuaki; Fujii, Mami N.; Nonaka, Toshiaki; Ishihara, Ryoichi; Ikenoue, Hiroshi; Uraoka, Yukiharu

    2016-01-01

    We demonstrate the use of excimer laser annealing (ELA) as a low temperature annealing alternative to anneal amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) passivated by a solution-processed hybrid passivation layer. Usually, a-IGZO is annealed using thermal annealing at high temperatures of up to 400 °C. As an alternative to high temperature thermal annealing, two types of ELA, XeCl (308 nm) and KrF (248 nm) ELA, are introduced. Both ELA types enhanced the electrical characteristics of a-IGZO TFTs leading to a mobility improvement of ~13 cm2 V-1 s-1 and small threshold voltage which varied from ~0-3 V. Furthermore, two-dimensional heat simulation using COMSOL Multiphysics was used to identify possible degradation sites, analyse laser heat localization, and confirm that the substrate temperature is below 50 °C. The two-dimensional heat simulation showed that the substrate temperature remained at very low temperatures, less than 30 °C, during ELA. This implies that any flexible material can be used as the substrate. These results demonstrate the large potential of ELA as a low temperature annealing alternative for already-passivated a-IGZO TFTs.

  1. Local and global processing in savant artists with autism.

    PubMed

    Pring, Linda; Ryder, Nicola; Crane, Laura; Hermelin, Beate

    2010-01-01

    We explored the hypothesis that an enhanced local processing style is characteristic of both art and autism spectrum disorder (ASD) by examining local and global processing in savant artists with ASD. Specifically, savant artists were compared against non-talented individuals with ASD or mild/moderate learning difficulties (MLD), as well as artistically talented or nontalented students, on the block-design task and meaningful and abstract versions of the embedded figures test (EFT). Results demonstrated that there were no significant differences between the meaningful and abstract versions of the EFT, in any of the groups. This suggests that the primary process governing performance on this task was perceptual (local), rather than conceptual (global). More interestingly, the savant artists performed above the level of the ASD and MLD groups on the block-design test, but not the EFT. Despite both the block-design task and the EFT measuring local processing abilities, we suggest that this result is due to the block-design task being an active construction task (requiring the conversion of a visual input into a motor output), whereas the EFT is a passive recognition task. Therefore, although an enhanced local processing style is an important aspect of savant artistic talent, motor control also appears to be a necessary skill.

  2. Local and global visual processing.

    PubMed

    Burr, D C; Morrone, M C; Ross, J

    1986-01-01

    The fundamental sinusoidal components of a chequerboard pattern are oriented at 45 degrees to the orientation of the chequerboard edges. Removal of one of the fundamental sinusoids (at +45 degrees) creates a useful pattern for studying the mechanisms of visual analysis. Close up, the pattern appears to be oriented +45 degrees, although there is no global energy at that orientation, implying local analysis. At a distance, the perceived diagonality switches to -45 degrees implying access to global information. Measurements show that contrast thresholds for seeing diagonality at +45 degrees follow closely those for detecting the 5th harmonic component of the pattern, over a wide range of spatial frequencies and luminances. Low pass filtering also causes the pattern to be perceived according to its global energy, provided that the cutoff frequency is set to remove the fifth harmonic. We conclude that, at least for this particular stimulus, the visual system performs a local analysis if the fifth harmonic is visible and a global analysis if not.

  3. Numerical simulation study on active and passive hydroforming process optimization of box shaped part

    NASA Astrophysics Data System (ADS)

    Zeng, Y. P.; Dong, J. L.; He, T. D.; Wang, B.

    2016-08-01

    Low qualified rate and inferior quality frequently occurring in the general deep drawing process of a certain box-shaped part, now use hydroforming to optimize forming process, in order to study the effect of hydroforming for improving the quality and formability, purposed five process schemes: general deep drawing, active hydroforming, passive hydroforming, general deep drawing combined with active hydroforming, passive combined with active hydroforming. Each process was simulated by finite element simulation and results were analysed. The results indicate the passive combined with active hydroforming is the best scheme which can obtain smallest thickness thinning and satisfactory formability, then optimized hydroforming pressure, blank holder force subsequently by adjust the simulation parameters. Research result proves that active/passive hydroforming is a new method for complex parts forming.

  4. Efficient support of best-effort traffic in passive tree local loops

    NASA Astrophysics Data System (ADS)

    Angelopoulos, John D.; Fragoulopoulos, Stratos K.; Protonotarios, E. N.

    1995-11-01

    For an expeditious and successful penetration of broadband services to residential and other small traffic subscribers, cost-efficiency by means of investment sharing and partial re-use of existing infrastructure are imperative. Employment of passive optical technology to feed subscriber clusters while maintaining the copper in the last drop is a promising strategy. To achieve traffic concentration and high utilization, a MAC protocol designed for low CDV is essential. A TDMA protocol based on ATM cells suitable for upgrading both twisted pair and coaxial based access networks creating hybrid solutions is presented. This protocol offers a dynamic response at cell level to the bursty traffic expected in B-ISDN using the reservation method to sample by periodic requests the arrival rate. No resort to signalling related information is required. Differentiating the handling between delay tolerant and non-tolerant traffic can offer significantly higher exploitation and a cost effective solution for the local loop.

  5. Starting a local conservation and passive solar retrofit program: an energy planning sourcebook

    SciTech Connect

    Barber, V; Mathews, R

    1982-02-01

    A city planner or a neighborhood activist may wish to initiate a local conservation and passive solar retrofit program but may not have previous experience in doing so. This sourcebook is designed to assist interested individuals with their energy planning efforts, from determining retrofit potential, to financing and implementing the program. An approach or methodology is provided which can be applied to determine retrofit potential in single-family residences, mobile homes, multifamily residences, and nonresidential buildings. Case studies in Albuquerque, New Mexico, are given as examples. Guidelines are provided for evaluating the economic benefits of a retrofit program through benefit-cost analysis and economic base studies at the city and neighborhood levels. Also included are approaches to community outreach, detailing how to get started, how to gain local support, and examples of successful programs throughout the US. The need for financing, the development of a local strategy, public and private financing techniques, and community energy service organizations are examined. In addition to the Albuquerque case studies, a brief technology characterization, heat-loss calculations, economic tools, and a list of resources are appended.

  6. Passive Sensor Integration for Vehicle Self-Localization in Urban Traffic Environment.

    PubMed

    Gu, Yanlei; Hsu, Li-Ta; Kamijo, Shunsuke

    2015-12-03

    This research proposes an accurate vehicular positioning system which can achieve lane-level performance in urban canyons. Multiple passive sensors, which include Global Navigation Satellite System (GNSS) receivers, onboard cameras and inertial sensors, are integrated in the proposed system. As the main source for the localization, the GNSS technique suffers from Non-Line-Of-Sight (NLOS) propagation and multipath effects in urban canyons. This paper proposes to employ a novel GNSS positioning technique in the integration. The employed GNSS technique reduces the multipath and NLOS effects by using the 3D building map. In addition, the inertial sensor can describe the vehicle motion, but has a drift problem as time increases. This paper develops vision-based lane detection, which is firstly used for controlling the drift of the inertial sensor. Moreover, the lane keeping and changing behaviors are extracted from the lane detection function, and further reduce the lateral positioning error in the proposed localization system. We evaluate the integrated localization system in the challenging city urban scenario. The experiments demonstrate the proposed method has sub-meter accuracy with respect to mean positioning error.

  7. Passive Sensor Integration for Vehicle Self-Localization in Urban Traffic Environment †

    PubMed Central

    Gu, Yanlei; Hsu, Li-Ta; Kamijo, Shunsuke

    2015-01-01

    This research proposes an accurate vehicular positioning system which can achieve lane-level performance in urban canyons. Multiple passive sensors, which include Global Navigation Satellite System (GNSS) receivers, onboard cameras and inertial sensors, are integrated in the proposed system. As the main source for the localization, the GNSS technique suffers from Non-Line-Of-Sight (NLOS) propagation and multipath effects in urban canyons. This paper proposes to employ a novel GNSS positioning technique in the integration. The employed GNSS technique reduces the multipath and NLOS effects by using the 3D building map. In addition, the inertial sensor can describe the vehicle motion, but has a drift problem as time increases. This paper develops vision-based lane detection, which is firstly used for controlling the drift of the inertial sensor. Moreover, the lane keeping and changing behaviors are extracted from the lane detection function, and further reduce the lateral positioning error in the proposed localization system. We evaluate the integrated localization system in the challenging city urban scenario. The experiments demonstrate the proposed method has sub-meter accuracy with respect to mean positioning error. PMID:26633420

  8. Passive Sensor Integration for Vehicle Self-Localization in Urban Traffic Environment.

    PubMed

    Gu, Yanlei; Hsu, Li-Ta; Kamijo, Shunsuke

    2015-01-01

    This research proposes an accurate vehicular positioning system which can achieve lane-level performance in urban canyons. Multiple passive sensors, which include Global Navigation Satellite System (GNSS) receivers, onboard cameras and inertial sensors, are integrated in the proposed system. As the main source for the localization, the GNSS technique suffers from Non-Line-Of-Sight (NLOS) propagation and multipath effects in urban canyons. This paper proposes to employ a novel GNSS positioning technique in the integration. The employed GNSS technique reduces the multipath and NLOS effects by using the 3D building map. In addition, the inertial sensor can describe the vehicle motion, but has a drift problem as time increases. This paper develops vision-based lane detection, which is firstly used for controlling the drift of the inertial sensor. Moreover, the lane keeping and changing behaviors are extracted from the lane detection function, and further reduce the lateral positioning error in the proposed localization system. We evaluate the integrated localization system in the challenging city urban scenario. The experiments demonstrate the proposed method has sub-meter accuracy with respect to mean positioning error. PMID:26633420

  9. Fabrication process of carbon nanotube field effect transistors using atomic layer deposition passivation for biosensors.

    PubMed

    Nakashima, Yasuhiro; Ohno, Yutaka; Kishimoto, Shigeru; Okochi, Mina; Honda, Hiroyuki; Mizutani, Takashi

    2010-06-01

    Fabrication process of the carbon nanotube (CNT) field effect transistors (FETs) for biosensors was studied. Atomic layer deposition (ALD) of HfO2 was applied to the deposition of the passivation/gate insulator film. The CNT-FETs did not show the drain current degradation after ALD passivation even though the passivation by Si3N4 deposited by plasma-enhanced chemical vapor deposition (PECVD) resulted in a significant drain current decrease. This indicates the advantage of the present ALD technique in terms of the damage suppression. The biosensing operation was confirmed using thus fabricated CNT-FETs. PMID:20355371

  10. Passivation process for superfine aluminum powders obtained by electrical explosion of wires

    NASA Astrophysics Data System (ADS)

    Kwon, Young-Soon; Gromov, Alexander A.; Ilyin, Alexander P.; Rim, Geun-Hie

    2003-04-01

    The process of passivation of superfine aluminum powders (SFAPs) ( as≤100 nm), obtained with the electrical explosion of wires (EEW) method, has been studied. The passivation coatings of different nature (oxides, stearic acid and aluminum diboride) were covered on the particle surface. The process of passivation and analysis of passivated powders was studied by X-ray photoelectron spectroscopy (XPS), XRD, TEM, infrared spectroscopy (IR), mass spectrometry (MS), thermocouple method and bomb calorimetry. After the comprehensive testing of coatings, a model of stabilization of the superfine aluminum particles was suggested, explaining the anomalous high content of aluminum metal in the electroexplosive powders. The main characteristic of the model is a formation of charged structures, which prevent metal oxidation.

  11. Passivation Behavior of Ultrafine-Grained Pure Copper Fabricated by Accumulative Roll Bonding (ARB) Process

    NASA Astrophysics Data System (ADS)

    Fattah-alhosseini, Arash; Imantalab, Omid

    2016-01-01

    In this study, passivation behavior of ultrafine-grained (UFG) pure copper fabricated by ARB process in 0.01 M borax solution has been investigated. Before any electrochemical measurements, evaluation of microstructure was obtained by transmission electron microscopy (TEM). TEM observations revealed that with increasing the number of ARB passes, the grain size of specimens decrease. Also, TEM images showed that UFGs with average size of below 100 nm appeared after 7 passes of ARB. To investigate the passivation behavior of the specimens, electrochemical impedance spectroscopy (EIS) and Mott-Schottky analysis was carried out. For this purpose, three potentials within the passive region were chosen for potentiostatic passive film growth. EIS results showed that both passive film and charge-transfer resistance increases with increasing the number of ARB passes. Moreover, Mott-Schottky analysis revealed that with increasing the number of ARB passes, the acceptor density of the passive films decreased. In conclusion, increasing the number of ARB passes offers better conditions for forming the passive films with higher protection behavior, due to the growth of a much thicker and less defective films.

  12. Coexistence of passive and carrier-mediated processes in drug transport.

    PubMed

    Sugano, Kiyohiko; Kansy, Manfred; Artursson, Per; Avdeef, Alex; Bendels, Stefanie; Di, Li; Ecker, Gerhard F; Faller, Bernard; Fischer, Holger; Gerebtzoff, Grégori; Lennernaes, Hans; Senner, Frank

    2010-08-01

    The permeability of biological membranes is one of the most important determinants of the pharmacokinetic processes of a drug. Although it is often accepted that many drug substances are transported across biological membranes by passive transcellular diffusion, a recent hypothesis speculated that carrier-mediated mechanisms might account for the majority of membrane drug transport processes in biological systems. Based on evidence of the physicochemical characteristics and of in vitro and in vivo findings for marketed drugs, as well as results from real-life discovery and development projects, we present the view that both passive transcellular processes and carrier-mediated processes coexist and contribute to drug transport activities across biological membranes.

  13. Combining Radiography and Passive Measurements for Radiological Threat Localization in Cargo

    SciTech Connect

    Miller, Erin A.; White, Timothy A.; Jarman, Kenneth D.; Kouzes, Richard T.; Kulisek, Jonathan A.; Robinson, Sean M.; Wittman, Richard A.

    2015-10-01

    Detecting shielded special nuclear material (SNM) in a cargo container is a difficult problem, since shielding reduces the amount of radiation escaping the container. Radiography provides information that is complementary to that provided by passive gamma-ray detection systems: while not directly sensitive to radiological materials, radiography can reveal highly shielded regions that may mask a passive radiological signal. Combining these measurements has the potential to improve SNM detection, either through improved sensitivity or by providing a solution to the inverse problem to estimate source properties (strength and location). We present a data-fusion method that uses a radiograph to provide an estimate of the radiation-transport environment for gamma rays from potential sources. This approach makes quantitative use of radiographic images without relying on image interpretation, and results in a probabilistic description of likely source locations and strengths. We present results for this method for a modeled test case of a cargo container passing through a plastic-scintillator-based radiation portal monitor and a transmission-radiography system. We find that a radiograph-based inversion scheme allows for localization of a low-noise source placed randomly within the test container to within 40 cm, compared to 70 cm for triangulation alone, while strength estimation accuracy is improved by a factor of six. Improvements are seen in regions of both high and low shielding, but are most pronounced in highly shielded regions. The approach proposed here combines transmission and emission data in a manner that has not been explored in the cargo-screening literature, advancing the ability to accurately describe a hidden source based on currently-available instrumentation.

  14. Industry-Grade Seismic Processing System for Controlled- (and Passive-) Source Research in Seismology

    NASA Astrophysics Data System (ADS)

    Chubak, G.; Morozov, I.

    2004-05-01

    to be initiated and controlled from a single interface. Jobs may be executed either locally or on a single or multiple remote systems in a heterogeneous computing environment. The GUI includes tools for run-time control of both local and remote processes.. The GUI also includes provisions for cluster scheduling, allowing processes to be executed on Beowulf clusters. Depending on their design, individual tools or flows can be parallelized using either PVM or MPI (Message Passing Interface). With the decentralized processing concept implemented in SIA, grid computing and seamless data exchange could become a reality without any effort from the users. In passive-source work, which is quickly adopting reflection processing techniques, this industry-style processing could provide sophisticated, inexpensive, and high performance approaches to data retrieval and access to hundreds of signal enhancement tools developed in reflection seismics.

  15. DHOFAR Seismic Experiment: First results to understand the breakup processes in a passive margin context

    NASA Astrophysics Data System (ADS)

    Tiberi, C.; Leroy, S.; D'Acremont, E.; Pointu, A.; Ebinger, C.; Brisbourne, A.; Denton, P.; Al-Lazki, A.; Al-Azri, H.; Bin Monshir Bahlaf, S.; Brunet, C.; Famin, V.; Labrousse, L.

    2004-12-01

    The process of strain localisation preceding the onset of seafloor spreading is still poorly understood, though extensively studied. The reason is the differences in lithospheric properties, proximity to hot spot(s) and melt generation and extraction that lead to a variety of structural styles with major differences. The eastern Gulf of Aden represents a natural laboratory to study passive continental margins for many reasons: post-rift sedimentary strata are relatively thin, both onshore and nearshore structures are well-exposed, and conjugate margins can be precisely reconstructed. A first cruise (ENCENS-SHEBA), in 2000, has established the structural and geophysical framework using bathymetric swath mapping and underway geophysics. Later on, the Dhofar seismic experiment consisted in the deployment of a network of 11 broadband seismic stations from March 2003 to March 2004 on the northern margin, in the Dhofar area, southern Oman. This experiment was dedicated to the detailed study of the crust and upper mantle beneath the northern passive margin. CMG40TD 3-components seismometers from SEIS-UK network were used. We have recorded hundreds of teleseismic events with a good azimuthal coverage. Three main studies are then attempted. First, a teleseismic image of the first 200 km depth will be established using the P- and PKP-phases. This will allow a 3D representation of crustal and upper mantle velocity structures. We present here the preliminary results from the study of the traveltime residuals. The image resolution shall be enhanced by combining gravity data. Second, a receiver function analysis will locally determine the depth of the main interfaces (eg, Moho boundary). Finally, events recorded within the 1000-6000 km distance range will improve the regional S-wave velocity structure in this area and will help to locate the main regional wide structures related to this extended area.

  16. Systematic Satellite Observations of the Impact of Aerosols from Passive Volcanic Degassing on Local Cloud Properties

    NASA Technical Reports Server (NTRS)

    Ebmeier, S. K.; Sayer, A. M.; Grainger, R. G.; Mather, T. A.; Carboni, E.

    2014-01-01

    The impact of volcanic emissions is a significant source of uncertainty in estimations of aerosol indirect radiative forcing, especially with respect to emissions from passive de-gassing and minor explosions. Understanding the impact of volcanic emissions on indirect radiative forcing is important assessing present day atmospheric properties and also to define the pre-industrial baseline to assess anthropogenic perturbations. We present observations of the time-averaged indirect aerosol effect within 200 km downwind of isolated island volcanoes in regions of low present-day aerosol burden using MODIS and AATSR data. Retrievals of aerosol and cloud properties at Kilauea (Hawaii), Yasur (Vanuatu) and Piton de la Fournaise (Reunion) are rotated about the volcanic vent according to wind direction, so that retrievals downwind of the volcano can be averaged to improve signal to noise ratio. The emissions from all three volcanoes, including those from passive degassing, strombolian activity and minor explosions lead to measurably increased aerosol optical depth downwind of the active vent. Average cloud droplet effective radius is lower downwind of the volcano in all cases, with the peak difference in effective radius ranging from 48 microns at the different volcanoes. A comparison of these observations with cloud properties at isolated islands with no significant source of aerosol suggests that these patterns are not purely orographic in origin. This approach sets out a first step for the systematic measurement of the effects of present day low altitude volcanic emissions on cloud properties, and our observations of unpolluted, isolated marine settings may capture processes similar to those in the preindustrial marine atmosphere.

  17. On the Design of Passive Resonant Circuits to Measure Local Pulse Wave Velocity in a Stent.

    PubMed

    Schächtele, Jonathan

    2016-06-01

    In-stent restenosis is a frequent complication after stent implantation. This article investigates the design of a passive sensor system to be integrated into a stent for the detection of an in-stent restenosis by measuring the local pulse wave velocity (PWV). The proposed system uses two resonant circuits consisting of a capacitive pressure sensor and a coil as transponders. The pressure sensors are located at the proximal and distal end of the stent. An alternating external magnetic field with a constant frequency is applied such that the resonance frequencies of the transponders cross the excitation frequency when the pulse wave passes. The time delay between the resonances at the transponders can be captured to obtain the PWV. A model for the measurement system and a correlation between transponder design parameters and minimal resolvable time delay are derived. This correlation is based on the criterion that the 3 dB bandwidth of the transponder resonances may not overlap in the measurement time interval. This correlation can be used to design and analyze a transponder system for the proposed measurement system. In an experiment, in which the pressure sensors have been emulated by varactor diodes, it could be shown that the model is valid and that the criterion is suitable. Finally, the relevant design parameters of the transponders have been identified and their limitations investigated. PMID:26800547

  18. On the Design of Passive Resonant Circuits to Measure Local Pulse Wave Velocity in a Stent.

    PubMed

    Schächtele, Jonathan

    2016-06-01

    In-stent restenosis is a frequent complication after stent implantation. This article investigates the design of a passive sensor system to be integrated into a stent for the detection of an in-stent restenosis by measuring the local pulse wave velocity (PWV). The proposed system uses two resonant circuits consisting of a capacitive pressure sensor and a coil as transponders. The pressure sensors are located at the proximal and distal end of the stent. An alternating external magnetic field with a constant frequency is applied such that the resonance frequencies of the transponders cross the excitation frequency when the pulse wave passes. The time delay between the resonances at the transponders can be captured to obtain the PWV. A model for the measurement system and a correlation between transponder design parameters and minimal resolvable time delay are derived. This correlation is based on the criterion that the 3 dB bandwidth of the transponder resonances may not overlap in the measurement time interval. This correlation can be used to design and analyze a transponder system for the proposed measurement system. In an experiment, in which the pressure sensors have been emulated by varactor diodes, it could be shown that the model is valid and that the criterion is suitable. Finally, the relevant design parameters of the transponders have been identified and their limitations investigated.

  19. Passive localization of noise-producing targets using a compact volumetric array.

    PubMed

    Gebbie, John; Siderius, Martin; Nielsen, Peter L; Miller, James

    2014-07-01

    A technique is presented for passively localizing multiple noise-producing targets by cross-correlating the elevation beams of a compact volumetric array on separate bearings. A target's multipath structure inherently contains information about its range; however, unknown, random noise waveforms make time separation of individual arrivals difficult. Ocean ambient noise has previously been used to measure multipath delays to the seabed by cross-correlating the beams of a vertical line array [Siderius, Song, Gerstoft, Hodgkiss, Hursky, and Harrison, J. Acoust. Soc. Am. 127, 2193-2200 (2010)], but this methodology has not been applied to distant noise sources having non-vertical arrivals. The technique presented in this paper uses a compact volumetric array mounted to an autonomous underwater vehicle to measure the three-dimensional directionality and time delays of multipath arrivals, while adaptively rejecting clutter and multi-target interference. This is validated with experimental results in a shallow ocean environment in which a small workboat maneuvered in the vicinity. Short ranges could be estimated reliably using straight ray paths, but longer ranges required accounting for ray refraction. PMID:24993197

  20. Passive localization of noise-producing targets using a compact volumetric array.

    PubMed

    Gebbie, John; Siderius, Martin; Nielsen, Peter L; Miller, James

    2014-07-01

    A technique is presented for passively localizing multiple noise-producing targets by cross-correlating the elevation beams of a compact volumetric array on separate bearings. A target's multipath structure inherently contains information about its range; however, unknown, random noise waveforms make time separation of individual arrivals difficult. Ocean ambient noise has previously been used to measure multipath delays to the seabed by cross-correlating the beams of a vertical line array [Siderius, Song, Gerstoft, Hodgkiss, Hursky, and Harrison, J. Acoust. Soc. Am. 127, 2193-2200 (2010)], but this methodology has not been applied to distant noise sources having non-vertical arrivals. The technique presented in this paper uses a compact volumetric array mounted to an autonomous underwater vehicle to measure the three-dimensional directionality and time delays of multipath arrivals, while adaptively rejecting clutter and multi-target interference. This is validated with experimental results in a shallow ocean environment in which a small workboat maneuvered in the vicinity. Short ranges could be estimated reliably using straight ray paths, but longer ranges required accounting for ray refraction.

  1. Three-dimensional velocity structure of the Galeras volcano (Colombia) from passive local earthquake tomography

    NASA Astrophysics Data System (ADS)

    Vargas, Carlos Alberto; Torres, Roberto

    2015-08-01

    A three-dimensional estimation of the Vp, Vs and Vp/Vs ratio structure at Galeras volcano was conducted by means of passive local earthquake tomography. 14,150 volcano-tectonic events recorded by 58 stations in the seismological network established for monitoring the volcanic activity by the Colombian Geological Survey - Pasto Volcano Observatory between the years 1989 and 2015, were inverted by using the LOTOS code. The seismic events are associated with shear-stress fractures in solid rock as a response to pressure induced by magma flow. Tomography resolution tests suggest a depth of imaging that yield 10 km from the summit of the main crater, illuminating a large portion of the volcanic structure and the interaction of tectonic features like the Buesaco and Silvia-Pijao faults. Full catalog tomographic inversion, that represents the stacked image of the volcanic structure or the most permanent features underneath the volcano, shows vertical structures aligned with seismicity beneath the main crater. We hypothesize that these structures correspond to a system of ducts or fractures through which magma and fluid phases flow up from deeper levels toward the top and related with the intersection of the surface traces of the Silvia-Pijao and Buesaco faults.

  2. Methodology for the passive control of orbital inclination and mean local time to meet sun-synchronous orbit requirements

    NASA Technical Reports Server (NTRS)

    Folta, David; Kraft, Lauri

    1992-01-01

    The mean local time (MLT) of equatorial crossing of a sun-synchronous Earth-observing spacecraft orbit drifts with inclination; therefore, in order to maintain the MLT, the inclination must be controlled. Inclination may be maintained actively by costly out-of-plane maneuvers or passively by using the perturbing forces due to the sun and moon. This paper examines the passive control approach using the Earth Observing System (EOS) as a basis for the discussion. Applications to Landsat and National Oceanic and Atmospheric Administration (NOAA) spacecraft are presented for comparison. This technique is especially beneficial to spacecraft lacking propulsion systems. The results indicate that passive inclination control appears to be the preferable maintenance method when spacecraft weight restrictions, operational considerations, and scientific requirements apply.

  3. DEMONSTRATION OF AN INTEGRATED, PASSIVE BIOLOGICAL TREATMENT PROCESS FOR AMD

    EPA Science Inventory

    An innovative, cost-effective, biological treatment process has been designed by MSE Technology Applications, Inc. to treat acid mine drainage (AMD). A pilot-scale demonstration is being conducted under the Mine Waste Technology Program using water flowing from an abandoned mine ...

  4. Modeling hydrogen diffusion for solar cell passivation and process optimization

    NASA Astrophysics Data System (ADS)

    Zhang, Yi

    A diffusion model for hydrogen (H) in crystalline silicon was established which takes into account the charged state conversion, junction field, mobile traps, and complex formation and dissociation at dopant and trap sites. Carrier exchange among the various charged species is a "fast" process compared to the diffusion process. A numerical method was developed to solve the densities of various charged species from the Poisson's equation that involves shallow-level dopants and one "negative U" impurity, e.g., H. Time domain implicit method was adopted in finite difference scheme to solve the fully coupled equations. Limiting versions of the model were applied to the problems that are of interest to photovoltaics. Simplified trap-limited model was used to describe the low temperature diffusion profiles, assuming process-induced traps, a constant bulk trap level, and trapping/detrapping mechanisms. The results of the simulation agreed with those obtained from experiments. The best fit yielded a low surface free H concentration, Cs, (˜10 14 cm-3) from high temperature extrapolated diffusivity value. In the case of ion beam hydrogenation, mobile traps needed to be considered. PAS analysis showed the existence of vacancy-type defects in implanted Si substrates. Simulation of hydrogen diffusion in p-n junction was first attempted in this work. The order of magnitude of Cs (˜10 14 cm-3) was confirmed. Simulation results showed that the preferred charged state of H is H- (H +) in n- (p-) side of the junction. The accumulation of H- (H+) species on n+ (p+) side of the n+-p (p+-n) junction was observed, which could retard the diffusion in junction. The diffusion of hydrogen through heavily doped region in a junction is trap-limited. Several popular hydrogenation techniques were evaluated by means of modeling and experimental observations. In particular, PECVD followed by RTP hydrogenation was found to be two-step process: PECVD deposition serves as a predeposition step of H

  5. Semantic Processing Persists despite Anomalous Syntactic Category: ERP Evidence from Chinese Passive Sentences

    PubMed Central

    Yang, Yang; Wu, Fuyun; Zhou, Xiaolin

    2015-01-01

    The syntax-first model and the parallel/interactive models make different predictions regarding whether syntactic category processing has a temporal and functional primacy over semantic processing. To further resolve this issue, an event-related potential experiment was conducted on 24 Chinese speakers reading Chinese passive sentences with the passive marker BEI (NP1 + BEI + NP2 + Verb). This construction was selected because it is the most-commonly used Chinese passive and very much resembles German passives, upon which the syntax-first hypothesis was primarily based. We manipulated semantic consistency (consistent vs. inconsistent) and syntactic category (noun vs. verb) of the critical verb, yielding four conditions: CORRECT (correct sentences), SEMANTIC (semantic anomaly), SYNTACTIC (syntactic category anomaly), and COMBINED (combined anomalies). Results showed both N400 and P600 effects for sentences with semantic anomaly, with syntactic category anomaly, or with combined anomalies. Converging with recent findings of Chinese ERP studies on various constructions, our study provides further evidence that syntactic category processing does not precede semantic processing in reading Chinese. PMID:26125621

  6. The Effect of Processing Instruction and Dictogloss Tasks on Acquisition of the English Passive Voice

    ERIC Educational Resources Information Center

    Qin, Jingjing

    2008-01-01

    This study was intended to compare processing instruction (VanPatten, 1993, 1996, 2000), an input-based focus on form technique, to dictogloss tasks, an output-oriented focus-on-form type of instruction to assess their effects in helping beginning-EFL (English as a Foreign Language) learners acquire the simple English passive voice. Two intact…

  7. Anisotropic Elastography for Local Passive Properties and Active Contractility of Myocardium from Dynamic Heart Imaging Sequence

    PubMed Central

    Wang, Ge; Sun, L. Z.

    2006-01-01

    Major heart diseases such as ischemia and hypertrophic myocardiopathy are accompanied with significant changes in the passive mechanical properties and active contractility of myocardium. Identification of these changes helps diagnose heart diseases, monitor therapy, and design surgery. A dynamic cardiac elastography (DCE) framework is developed to assess the anisotropic viscoelastic passive properties and active contractility of myocardial tissues, based on the chamber pressure and dynamic displacement measured with cardiac imaging techniques. A dynamic adjoint method is derived to enhance the numerical efficiency and stability of DCE. Model-based simulations are conducted using a numerical left ventricle (LV) phantom with an ischemic region. The passive material parameters of normal and ischemic tissues are identified during LV rapid/reduced filling and artery contraction, and those of active contractility are quantified during isovolumetric contraction and rapid/reduced ejection. It is found that quasistatic simplification in the previous cardiac elastography studies may yield inaccurate material parameters. PMID:23165032

  8. Children’s assignment of grammatical roles in the online processing of Mandarin passive sentences

    PubMed Central

    Huang, Yi Ting; Zheng, Xiaobei; Meng, Xiangzhi; Snedeker, Jesse

    2013-01-01

    Children’s difficulty understanding passives in English has been attributed to the syntactic complexity, overall frequency, cue reliability, and/or incremental processing of this construction. To understand the role of these factors, we used the visual-world paradigm to examine comprehension in Mandarin Chinese where passives are infrequent but signaled by a highly valid marker (BEI). Eye-movements during sentences indicated that these markers triggered incremental role assignments in adults and 5-year-olds. Actions after sentences indicated that passives were often misinterpreted as actives when markers appeared after the referential noun (“Seal BEI it eat” → The seal is eaten by it). However, they were more likely to be interpreted correctly when markers appeared before (“It BEI seal eat” → It is eaten by the seal). The actions and the eye-movements suggest that for both adults and children, interpretations of passive are easier when they do not require revision of an earlier role assignment. PMID:24376303

  9. Advanced information processing system: Local system services

    NASA Technical Reports Server (NTRS)

    Burkhardt, Laura; Alger, Linda; Whittredge, Roy; Stasiowski, Peter

    1989-01-01

    The Advanced Information Processing System (AIPS) is a multi-computer architecture composed of hardware and software building blocks that can be configured to meet a broad range of application requirements. The hardware building blocks are fault-tolerant, general-purpose computers, fault-and damage-tolerant networks (both computer and input/output), and interfaces between the networks and the computers. The software building blocks are the major software functions: local system services, input/output, system services, inter-computer system services, and the system manager. The foundation of the local system services is an operating system with the functions required for a traditional real-time multi-tasking computer, such as task scheduling, inter-task communication, memory management, interrupt handling, and time maintenance. Resting on this foundation are the redundancy management functions necessary in a redundant computer and the status reporting functions required for an operator interface. The functional requirements, functional design and detailed specifications for all the local system services are documented.

  10. Lexically Specific Knowledge and Individual Differences in Adult Native Speakers' Processing of the English Passive

    ERIC Educational Resources Information Center

    Street, James A.; Dabrowska, Ewa

    2014-01-01

    This article provides experimental evidence for the role of lexically specific representations in the processing of passive sentences and considerable education-related differences in comprehension of the passive construction. The experiment measured response time and decision accuracy of participants with high and low academic attainment using an…

  11. Application of a passive electrochemical noise technique to localized corrosion of candidate radioactive waste container materials

    SciTech Connect

    Korzan, M.A.

    1994-05-01

    One of the key engineered barriers in the design of the proposed Yucca Mountain repository is the waste canister that encapsulates the spent fuel elements. Current candidate metals for the canisters to be emplaced at Yucca Mountain include cast iron, carbon steel, Incoloy 825 and titanium code-12. This project was designed to evaluate passive electrochemical noise techniques for measuring pitting and corrosion characteristics of candidate materials under prototypical repository conditions. Experimental techniques were also developed and optimized for measurements in a radiation environment. These techniques provide a new method for understanding material response to environmental effects (i.e., gamma radiation, temperature, solution chemistry) through the measurement of electrochemical noise generated during the corrosion of the metal surface. In addition, because of the passive nature of the measurement the technique could offer a means of in-situ monitoring of barrier performance.

  12. Ataxin-1 oligomers induce local spread of pathology and decreasing them by passive immunization slows Spinocerebellar ataxia type 1 phenotypes.

    PubMed

    Lasagna-Reeves, Cristian A; Rousseaux, Maxime Wc; Guerrero-Munoz, Marcos J; Vilanova-Velez, Luis; Park, Jeehye; See, Lauren; Jafar-Nejad, Paymaan; Richman, Ronald; Orr, Harry T; Kayed, Rakez; Zoghbi, Huda Y

    2015-12-17

    Previously, we reported that ATXN1 oligomers are the primary drivers of toxicity in Spinocerebellar ataxia type 1 (SCA1; Lasagna-Reeves et al., 2015). Here we report that polyQ ATXN1 oligomers can propagate locally in vivo in mice predisposed to SCA1 following intracerebral oligomeric tissue inoculation. Our data also show that targeting these oligomers with passive immunotherapy leads to some improvement in motor coordination in SCA1 mice and to a modest increase in their life span. These findings provide evidence that oligomer propagation is regionally limited in SCA1 and that immunotherapy targeting extracellular oligomers can mildly modify disease phenotypes.

  13. Modeling aerosol processes at the local scale

    SciTech Connect

    Lazaridis, M.; Isukapalli, S.S.; Georgopoulos, P.G.

    1998-12-31

    This work presents an approach for modeling photochemical gaseous and aerosol phase processes in subgrid plumes from major localized (e.g. point) sources (plume-in-grid modeling), thus improving the ability to quantify the relationship between emission source activity and ambient air quality. This approach employs the Reactive Plume Model (RPM-AERO) which extends the regulatory model RPM-IV by incorporating aerosol processes and heterogeneous chemistry. The physics and chemistry of elemental carbon, organic carbon, sulfate, sodium, chloride and crustal material of aerosols are treated and attributed to the PM size distribution. A modified version of the Carbon Bond IV chemical mechanism is included to model the formation of organic aerosol, and the inorganic multicomponent atmospheric aerosol equilibrium model, SEQUILIB is used for calculating the amounts of inorganic species in particulate matter. Aerosol dynamics modeled include mechanisms of nucleation, condensation and gas/particle partitioning of organic matter. An integrated trajectory-in-grid modeling system, UAM/RPM-AERO, is under continuing development for extracting boundary and initial conditions from the mesoscale photochemical/aerosol model UAM-AERO. The RPM-AERO is applied here to case studies involving emissions from point sources to study sulfate particle formation in plumes. Model calculations show that homogeneous nucleation is an efficient process for new particle formation in plumes, in agreement with previous field studies and theoretical predictions.

  14. Real-time image processing for passive mmW imagery

    NASA Astrophysics Data System (ADS)

    Kozacik, Stephen; Paolini, Aaron; Bonnett, James; Harrity, Charles; Mackrides, Daniel; Dillon, Thomas E.; Martin, Richard D.; Schuetz, Christopher A.; Kelmelis, Eric; Prather, Dennis W.

    2015-05-01

    The transmission characteristics of millimeter waves (mmWs) make them suitable for many applications in defense and security, from airport preflight scanning to penetrating degraded visual environments such as brownout or heavy fog. While the cold sky provides sufficient illumination for these images to be taken passively in outdoor scenarios, this utility comes at a cost; the diffraction limit of the longer wavelengths involved leads to lower resolution imagery compared to the visible or IR regimes, and the low power levels inherent to passive imagery allow the data to be more easily degraded by noise. Recent techniques leveraging optical upconversion have shown significant promise, but are still subject to fundamental limits in resolution and signal-to-noise ratio. To address these issues we have applied techniques developed for visible and IR imagery to decrease noise and increase resolution in mmW imagery. We have developed these techniques into fieldable software, making use of GPU platforms for real-time operation of computationally complex image processing algorithms. We present data from a passive, 77 GHz, distributed aperture, video-rate imaging platform captured during field tests at full video rate. These videos demonstrate the increase in situational awareness that can be gained through applying computational techniques in real-time without needing changes in detection hardware.

  15. Electrochemical and Passive Behaviors of Pure Copper Fabricated by Accumulative Roll-Bonding (ARB) Process

    NASA Astrophysics Data System (ADS)

    Imantalab, O.; Fattah-alhosseini, A.

    2015-07-01

    In the present work, electrochemical and passive behaviors of pure copper fabricated by accumulative roll-bonding (ARB) process in 0.01 M borax solution (pH = 9.1) have been studied. Before any electrochemical measurements, evaluation of microstructure was obtained by Vickers microhardness, x-ray diffraction (XRD), and transmission electron microscopy. The results of microhardness tests revealed that microhardness values increased with the increasing number of ARB cycles. Also a sharp increase was seen in microhardness after the first ARB cycle, whereas mediocre additional increases were observed afterward up to the seven cycles. Moreover, XRD patterns showed that the mean crystallite size values decrease with the increasing number of ARB cycles. To investigate the electrochemical and passive behaviors of the samples, the potentiodynamic polarization, Mott-Schottky analysis and electrochemical impedance spectroscopy (EIS) were carried out. Polarization plots revealed that as a result of ARB, the corrosion behavior of the specimens improves compared with the annealed pure copper. Also, the Mott-Schottky analysis and EIS measurements showed that the increasing number of ARB cycles offer better conditions for forming the passive films with higher protection behavior, due to the growth of less-defective films.

  16. Comparing passive source localization and tracking approaches with a towed horizontal receiver array in an ocean waveguide.

    PubMed

    Gong, Zheng; Tran, Duong D; Ratilal, Purnima

    2013-11-01

    Approaches for instantaneous passive source localization using a towed horizontal receiver array in a random range-dependent ocean waveguide are examined. They include: (1) Moving array triangulation, (2) array invariant, (3) bearings-only target motion analysis in modified polar coordinates via the extended Kalman filter, and (4) bearings-migration minimum mean-square error. These methods are applied to localize and track a vertical source array deployed in the far-field of a towed horizontal receiver array during the Gulf of Maine 2006 Experiment. The source transmitted intermittent broadband pulses in the 300 to 1200 Hz frequency range. A nonlinear matched-filter kernel designed to replicate the acoustic signal measured by the receiver array is applied to enhance the signal-to-noise ratio. The source localization accuracy is found to be highly dependent on source-receiver geometry and the localization approach. For a relatively stationary source drifting at speeds much slower than the receiver array tow-speed, the mean source position can be estimated by moving array triangulation with less than 3% error near broadside direction. For a moving source, the Kalman filter method gives the best performance with 5.5% error. The array invariant is the best approach for localizing sources within the endfire beam of the receiver array with 7% error.

  17. Sulfur passivated reforming process lowers syngas H sub 2 /CO ratio

    SciTech Connect

    Udengaard, N.R. )

    1992-03-09

    This paper reports that a decision by Sterling Chemicals Inc. to exit the methanol business in 1980 created a product slate that favored a decrease in the molar H{sub 2}.CO ratio from 2.7 to 1.8 in synthesis gas produced there. This paper reports that this made it necessary eventually to develop an economical way of achieving the changed product slate without hurting the economics of carbon monoxide, blend gas, and hydrogen production. The answer was the sulfur passivated reforming (Sparg) process. It was first commercialized at Sterling's Texas City, Tex., plant in 1987. In the years since, it has proven to be both economical and reliable.

  18. Passivity and Localized Corrosion of AZ31 Magnesium Alloy in High pH Electrolytes

    NASA Astrophysics Data System (ADS)

    Alsagabi, Sultan; Ninlachart, Jakraphan; Raja, Krishnan S.; Charit, Indrajit

    2016-06-01

    Electrochemical corrosion tests were carried out on AZ31 magnesium alloy specimens in pH: 4.5, 9.5, and 13.0 solutions with 0-2000 ppm of chloride additions at room temperature. No passivity breakdown was observed during cyclic polarization in pH:13 solutions containing up to 1500 ppm of chloride. Addition of sodium sulfate and sodium dihydrogen phosphate as supporting electrolytes offset the chloride effect on the corrosion of AZ31 in pH 4.5 and 9.5 solutions. The Mott-Schottky analysis showed the presence of a duplex surface layer consisting of an n-type MgO1- x inner layer ( x = 0.024-0.05), and a p-type outer layer which thickened with time at the expense of the inner layer.

  19. Study of passive and active optical waveguides: Synthesis, processing and characterization of materials

    NASA Astrophysics Data System (ADS)

    Yoshida, Makoto

    Photonics uses photons for information and image processing, and has been touted as the technology of the 21 st century. An optical waveguide is a key component of an optical integrated circuit which is the optical analog of an electrical integrated circuit (IC). Electrical transistor IC technology resulted in an enormous impact on society, and it changed our life styles from the age of the vacuum tube. The advent of the optical integrated circuit is expected to have the same impact on society as the electronic IC. Various optical circuit elements are interrelated to materials, therefore, the study and the better understanding of materials and processing have been receiving a great deal of attention. My research focuses on the study of optical waveguide materials and their processings in terms of passive and active optical waveguides. The first target was to establish a method for measuring the refractive index and optical propagation loss of optical waveguides. The second target was to develop passive waveguide materials which can route, split and combine optical signals on a substrate. There are several requirements for waveguiding, such as high optical transparency, proper refractive index, and proper thickness. The sol-gel technique was used to meet the requirements, and several types of organic: inorganic composite materials were developed. The third target involved the development of processing methods to fabricate channel waveguides using the above-mentioned passive and active waveguide materials. Selective laser densification was developed for sol-gel composite materials. Use of trenched substrates and photobleaching were also studied. The last target was to develop an active material which could process optical signals using the electrooptic effect. A crosslinked urethane polymer with a newly synthesized chromophore was used due to its high thermal stability and optical transparency. In order to obtain second order nonlinearity, macroscopic molecular

  20. "Active" and "Passive" Lava Resurfacing Processes on Io: A Comparative Study of Loki Patera and Prometheus

    NASA Technical Reports Server (NTRS)

    Davies, A. G.; Matson, D. L.; Leone, G.; Wilson, L.; Keszthelyi, L. P.

    2004-01-01

    Studies of Galileo Near Infrared Mapping Spectrometer (NIMS) data and ground based data of volcanism at Prometheus and Loki Patera on Io reveal very different mechanisms of lava emplacement at these two volcanoes. Data analyses show that the periodic nature of Loki Patera s volcanism from 1990 to 2001 is strong evidence that Loki s resurfacing over this period resulted from the foundering of a crust on a lava lake. This process is designated passive , as there is no reliance on sub-surface processes: the foundering of the crust is inevitable. Prometheus, on the other hand, displays an episodicity in its activity which we designate active . Like Kilauea, a close analog, Prometheus s effusive volcanism is dominated by pulses of magma through the nearsurface plumbing system. Each system affords views of lava resurfacing processes through modelling.

  1. Sensitivity of passive microwave sea ice concentration algorithms to the selection of locally and seasonally adjusted tie points

    NASA Technical Reports Server (NTRS)

    Steffen, Konrad; Schweiger, Axel

    1989-01-01

    The sensitivity of passive microwave sea-ice concentration (SIC) algorithms to the selection of tie points was analyzed. SICs were derived with the NASA Team ice algorithm for global tie points and for locally and seasonally adjusted tie points. The SSM/I SIC was then compared to Landsat-MSS-derived SICs. Preliminary results show a mean difference of SSM/I- and Landsat-derived SICs for 50 x 50 km grid cells of 2.7 percent along the ice edge of the Beaufort Sea during fall with local tie points. The accuracy decreased to 9.7 percent when global tie points were used. During freeze-up in the Beaufort Sea, with grey ice and nilas as dominant ice cover, the mean difference was 4.3 percent for local tie points and 13.9 percent for global tie points. For the spring ice cover in the Bering Sea a mean difference of 4.4 percent for local tie points and 15.7 percent for global tie points was found. This large difference reveals some limitations of the NASA-Team algorithm under freeze-up and spring conditions (thin ice areas).

  2. Morphotectonic evolution of passive margins undergoing active surface processes: large-scale experiments using numerical models.

    NASA Astrophysics Data System (ADS)

    Beucher, Romain; Huismans, Ritske S.

    2016-04-01

    Extension of the continental lithosphere can lead to the formation of a wide range of rifted margins styles with contrasting tectonic and geomorphological characteristics. It is now understood that many of these characteristics depend on the manner extension is distributed depending on (among others factors) rheology, structural inheritance, thermal structure and surface processes. The relative importance and the possible interactions of these controlling factors is still largely unknown. Here we investigate the feedbacks between tectonics and the transfers of material at the surface resulting from erosion, transport, and sedimentation. We use large-scale (1200 x 600 km) and high-resolution (~1km) numerical experiments coupling a 2D upper-mantle-scale thermo-mechanical model with a plan-form 2D surface processes model (SPM). We test the sensitivity of the coupled models to varying crust-lithosphere rheology and erosional efficiency ranging from no-erosion to very efficient erosion. We discuss how fast, when and how the topography of the continents evolves and how it can be compared to actual passive margins escarpment morphologies. We show that although tectonics is the main factor controlling the rift geometry, transfers of masses at the surface affect the timing of faulting and the initiation of sea-floor spreading. We discuss how such models may help to understand the evolution of high-elevated passive margins around the world.

  3. Amorphous Silicon Carbide Passivating Layers to Enable Higher Processing Temperature in Crystalline Silicon Heterojunction Solar Cells

    SciTech Connect

    Boccard, Mathieu; Holman, Zachary

    2015-04-06

    "Very efficient crystalline silicon (c-Si) solar cells have been demonstrated when thin layers of intrinsic and doped hydrogenated amorphous silicon (a-Si:H) are used for passivation and carrier selectivity in a heterojunction device. One limitation of this device structure is the (parasitic) absorption in the front passivation/collection a-Si:H layers; another is the degradation of the a-Si:H-based passivation upon temperature, limiting the post-processes to approximately 200°C thus restricting the contacting possibilities and potential tandem device fabrication. To alleviate these two limitations, we explore the potential of amorphous silicon carbide (a-SiC:H), a widely studied material in use in standard a-Si:H thin-film solar cells, which is known for its wider bandgap, increased hydrogen content and stronger hydrogen bonding compared to a-Si:H. We study the surface passivation of solar-grade textured n-type c-Si wafers for symmetrical stacks of 10-nm-thick intrinsic a-SiC:H with various carbon content followed by either p-doped or n-doped a-Si:H (referred to as i/p or i/n stacks). For both doping types, passivation (assessed through carrier lifetime measurements) is degraded by increasing the carbon content in the intrinsic a-SiC:H layer. Yet, this hierarchy is reversed after annealing at 350°C or more due to drastic passivation improvements upon annealing when an a-SiC:H layer is used. After annealing at 350°C, lifetimes of 0.4 ms and 2.0 ms are reported for i/p and i/n stacks, respectively, when using an intrinsic a-SiC:H layer with approximately 10% of carbon (initial lifetimes of 0.3 ms and 0.1 ms, respectively, corresponding to a 30% and 20-fold increase, respectively). For stacks of pure a-Si:H material the lifetimes degrade from 1.2 ms and 2.0 ms for i/p and i/n stacks, respectively, to less than 0.1 ms and 1.1 ms (12-fold and 2-fold decrease, respectively). For complete solar cells using pure a-Si:H i/p and i/n stacks, the open-circuit voltage (Voc

  4. Effect of temperature and active biogas process on passive separation of digested manure.

    PubMed

    Kaparaju, P; Angelidaki, I

    2008-03-01

    The objective of the study was to identify the optimum time interval for effluent removal after temporarily stopping stirring in otherwise continuously stirred tank reactors. Influence of temperature (10 and 55 degrees C) and active biogas process on passive separation of digested manure, where no outside mechanical or chemical action was used, within the reactor was studied in three vertical settling columns (100 cm deep). Variations in solids and microbial distribution at top, middle and bottom layers of column were assessed over a 15 day settling period. Results showed that best solids separation was achieved when digested manure was allowed to settle at 55 degrees C with active biogas process (pre-incubated at 55 degrees C) compared to separation at 55 degrees C without active biogas process (autoclaved at 120 degrees C, for 20 min) or at 10 degrees C with active biogas process. Maximum solids separation was noticed 24h after settling in column incubated at 55 degrees C, with active biogas process. Microbiological analyses revealed that proportion of Archaea and Bacteria, absent in the autoclaved material, varied with incubation temperature, time and sampling depth. Short rod shaped bacteria dominated at 55 degrees C, while long rod shaped bacteria dominated at 10 degrees C. Methanosarcinaceae were seen more abundant in the surface layer at 55 degrees C while it was seen more common in the top and bottom layers at 10 degrees C. Thus, passive separation of digester contents within the reactor can be used effectively as an operating strategy to optimize biogas production by increasing the solids and biomass retention times. A minimum of 1-2h "non-stirring" period appears to be optimal time before effluent removal in plants where extraction is batch-wise 2-4 times a day.

  5. Application of XAD-resin based passive air samplers to assess local (roadside) and regional patterns of persistent organic pollutants.

    PubMed

    Barthel, Paul; Thuens, Sabine; Shunthirasingham, Chubashini; Westgate, John N; Wania, Frank; Radke, Michael

    2012-07-01

    We used XAD-resin based passive air samplers (PAS) to measure atmospheric levels of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) at five ombrotrophic bogs in Eastern Canada. The aims of our study were to investigate the influence of local roads on contaminant levels in the bogs, to derive the regional pattern of atmospheric concentrations, and to assess the uncertainties of the method. Expanded uncertainties based on the duplicate PAS deployed at 24 sites were good for the PAHs, while the deployment period of approx. 100 days was too short to yield acceptable uncertainties for PCBs. The regional PAH distribution was in good agreement with the calculated source proximity of the sampled bogs. We conclude that XAD-resin based PAS deployed for comparatively short periods are well suited for measuring atmospheric concentrations of volatile PAHs, while in remote regions longer deployment is necessary for less volatile PAHs and for PCBs. PMID:22516712

  6. Moving source localization using seismic signal processing

    NASA Astrophysics Data System (ADS)

    Asgari, Shadnaz; Stafsudd, Jing Z.; Hudson, Ralph E.; Yao, Kung; Taciroglu, Ertugrul

    2015-01-01

    Accurate localization of a seismic source in a near-field scenario where the distances between sensors and the source are less than a few wavelengths of the generated signal has shown to be a challenging task. Conventional localization algorithms often prove to be ineffective, as near-field seismic signals exhibit characteristics different from the well-studied far-field signals. The current work is aimed at the employment of a seismic sensor array for the localization and tracking of a near-field wideband moving source. In this paper, the mathematical derivation of a novel DOA estimation algorithm-dubbed the Modified Kirlin Method-has been presented in details. The estimated DOAs are then combined using a least-squares optimization method for source localization. The performance of the proposed method has been evaluated in a field experiment to track a moving truck. We also compare the DOA estimation and source localization results of the proposed method with those of two other existing methods originally developed for localization of a stationary wideband source; Covariance Matrix Analysis and the Surface Wave Analysis. Our results indicate that both the Surface Wave Analysis and the Modified Kirlin Methods are effective in locating and tracking a moving truck.

  7. Local Ownership of Education Policies at the Crossroads between the Active Participation and the Passive Compliance to International Goals

    ERIC Educational Resources Information Center

    Imaniriho, Dan

    2015-01-01

    Over the past three decades, perceptions about the role of local population in policy development process have deeply changed. This change is related to the idea promoted by international institutions that the development actions cannot succeed without a strong local ownership and a broad approach that guarantee active participation of local…

  8. Passive ranging errors due to multipath distortion of deterministic transient signals with application to the localization of small arms fire

    NASA Astrophysics Data System (ADS)

    Ferguson, Brian G.; Lo, Kam W.

    2002-01-01

    A passive ranging technique based on wavefront curvature is used to estimate the ranges and bearings of impulsive sound sources represented by small arms fire. The discharge of a firearm results in the generation of a transient acoustic signal whose energy propagates radially outwards from the omnidirectional source. The radius of curvature of the spherical wavefront at any instant is equal to the instantaneous range from the source. The curvature of the acoustic wavefront is sensed with a three-microphone linear array by first estimating the differential time of arrival (or time delay) of the acoustic wavefront at each of the two adjacent sensor pairs and then processing the time-delay information to extract the range and bearing of the source. However, modeling the passive ranging performance of the wavefront curvature method for a deterministic transient signal source in a multipath environment shows that when the multipath and direct path arrivals are unresolvable, the time-delay estimates are biased which, in turn, biases the range estimates. The model explains the observed under-ranging of small arms firing positions during a field experiment.

  9. Passive ranging errors due to multipath distortion of deterministic transient signals with application to the localization of small arms fire.

    PubMed

    Ferguson, Brian G; Lo, Kam W

    2002-01-01

    A passive ranging technique based on wavefront curvature is used to estimate the ranges and bearings of impulsive sound sources represented by small arms fire. The discharge of a firearm results in the generation of a transient acoustic signal whose energy propagates radially outwards from the omnidirectional source. The radius of curvature of the spherical wavefront at any instant is equal to the instantaneous range from the source. The curvature of the acoustic wavefront is sensed with a three-microphone linear array by first estimating the differential time of arrival (or time delay) of the acoustic wavefront at each of the two adjacent sensor pairs and then processing the time-delay information to extract the range and bearing of the source. However, modeling the passive ranging performance of the wavefront curvature method for a deterministic transient signal source in a multipath environment shows that when the multipath and direct path arrivals are unresolvable, the time-delay estimates are biased which, in turn, biases the range estimates. The model explains the observed under-ranging of small arms firing positions during a field experiment. PMID:11831787

  10. High purity chemical etching and thermal passivation process for Ge(001) as nanostructure template.

    PubMed

    Blumenstein, Christian; Meyer, Sebastian; Ruff, Andreas; Schmid, Benjamin; Schäfer, Jörg; Claessen, Ralph

    2011-08-14

    An advanced two-step cleaning process of the Ge(001) surface for nanoscience requirements is presented. First, wet-chemical etching with a variant of the Piranha solution (H(2)SO(4), H(2)O(2), H(2)O) is used to remove contaminants as well as the native oxide layer. Second, passivation of the surface is achieved by a rapid thermal oxidation step, leading to a homogeneous protective oxide layer. The thickness of the oxide layer is tuned to be thick enough to protect the surface, yet thin enough to be completely removed by thermal treatment in ultra-high vacuum. The application of this recipe results in an outstandingly clean and atomically flat surface, with carbon contamination at the detection limit of x-ray photoelectron spectroscopy. Scanning tunneling microscopy and electron diffraction reveal a long range ordered surface with typical terrace diameters of ~100 nm, suitable for the growth of atomic-scale nanostructures.

  11. High Accuracy Passive Magnetic Field-Based Localization for Feedback Control Using Principal Component Analysis.

    PubMed

    Foong, Shaohui; Sun, Zhenglong

    2016-01-01

    In this paper, a novel magnetic field-based sensing system employing statistically optimized concurrent multiple sensor outputs for precise field-position association and localization is presented. This method capitalizes on the independence between simultaneous spatial field measurements at multiple locations to induce unique correspondences between field and position. This single-source-multi-sensor configuration is able to achieve accurate and precise localization and tracking of translational motion without contact over large travel distances for feedback control. Principal component analysis (PCA) is used as a pseudo-linear filter to optimally reduce the dimensions of the multi-sensor output space for computationally efficient field-position mapping with artificial neural networks (ANNs). Numerical simulations are employed to investigate the effects of geometric parameters and Gaussian noise corruption on PCA assisted ANN mapping performance. Using a 9-sensor network, the sensing accuracy and closed-loop tracking performance of the proposed optimal field-based sensing system is experimentally evaluated on a linear actuator with a significantly more expensive optical encoder as a comparison. PMID:27529253

  12. Underwater passive acoustic localization of Pacific walruses in the northeastern Chukchi Sea.

    PubMed

    Rideout, Brendan P; Dosso, Stan E; Hannay, David E

    2013-09-01

    This paper develops and applies a linearized Bayesian localization algorithm based on acoustic arrival times of marine mammal vocalizations at spatially-separated receivers which provides three-dimensional (3D) location estimates with rigorous uncertainty analysis. To properly account for uncertainty in receiver parameters (3D hydrophone locations and synchronization times) and environmental parameters (water depth and sound-speed correction), these quantities are treated as unknowns constrained by prior estimates and prior uncertainties. Unknown scaling factors on both the prior and arrival-time uncertainties are estimated by minimizing Akaike's Bayesian information criterion (a maximum entropy condition). Maximum a posteriori estimates for sound source locations and times, receiver parameters, and environmental parameters are calculated simultaneously using measurements of arrival times for direct and interface-reflected acoustic paths. Posterior uncertainties for all unknowns incorporate both arrival time and prior uncertainties. Monte Carlo simulation results demonstrate that, for the cases considered here, linearization errors are small and the lack of an accurate sound-speed profile does not cause significant biases in the estimated locations. A sequence of Pacific walrus vocalizations, recorded in the Chukchi Sea northwest of Alaska, is localized using this technique, yielding a track estimate and uncertainties with an estimated speed comparable to normal walrus swim speeds. PMID:23968051

  13. High Accuracy Passive Magnetic Field-Based Localization for Feedback Control Using Principal Component Analysis

    PubMed Central

    Foong, Shaohui; Sun, Zhenglong

    2016-01-01

    In this paper, a novel magnetic field-based sensing system employing statistically optimized concurrent multiple sensor outputs for precise field-position association and localization is presented. This method capitalizes on the independence between simultaneous spatial field measurements at multiple locations to induce unique correspondences between field and position. This single-source-multi-sensor configuration is able to achieve accurate and precise localization and tracking of translational motion without contact over large travel distances for feedback control. Principal component analysis (PCA) is used as a pseudo-linear filter to optimally reduce the dimensions of the multi-sensor output space for computationally efficient field-position mapping with artificial neural networks (ANNs). Numerical simulations are employed to investigate the effects of geometric parameters and Gaussian noise corruption on PCA assisted ANN mapping performance. Using a 9-sensor network, the sensing accuracy and closed-loop tracking performance of the proposed optimal field-based sensing system is experimentally evaluated on a linear actuator with a significantly more expensive optical encoder as a comparison. PMID:27529253

  14. High Accuracy Passive Magnetic Field-Based Localization for Feedback Control Using Principal Component Analysis.

    PubMed

    Foong, Shaohui; Sun, Zhenglong

    2016-08-12

    In this paper, a novel magnetic field-based sensing system employing statistically optimized concurrent multiple sensor outputs for precise field-position association and localization is presented. This method capitalizes on the independence between simultaneous spatial field measurements at multiple locations to induce unique correspondences between field and position. This single-source-multi-sensor configuration is able to achieve accurate and precise localization and tracking of translational motion without contact over large travel distances for feedback control. Principal component analysis (PCA) is used as a pseudo-linear filter to optimally reduce the dimensions of the multi-sensor output space for computationally efficient field-position mapping with artificial neural networks (ANNs). Numerical simulations are employed to investigate the effects of geometric parameters and Gaussian noise corruption on PCA assisted ANN mapping performance. Using a 9-sensor network, the sensing accuracy and closed-loop tracking performance of the proposed optimal field-based sensing system is experimentally evaluated on a linear actuator with a significantly more expensive optical encoder as a comparison.

  15. Underwater passive acoustic localization of Pacific walruses in the northeastern Chukchi Sea.

    PubMed

    Rideout, Brendan P; Dosso, Stan E; Hannay, David E

    2013-09-01

    This paper develops and applies a linearized Bayesian localization algorithm based on acoustic arrival times of marine mammal vocalizations at spatially-separated receivers which provides three-dimensional (3D) location estimates with rigorous uncertainty analysis. To properly account for uncertainty in receiver parameters (3D hydrophone locations and synchronization times) and environmental parameters (water depth and sound-speed correction), these quantities are treated as unknowns constrained by prior estimates and prior uncertainties. Unknown scaling factors on both the prior and arrival-time uncertainties are estimated by minimizing Akaike's Bayesian information criterion (a maximum entropy condition). Maximum a posteriori estimates for sound source locations and times, receiver parameters, and environmental parameters are calculated simultaneously using measurements of arrival times for direct and interface-reflected acoustic paths. Posterior uncertainties for all unknowns incorporate both arrival time and prior uncertainties. Monte Carlo simulation results demonstrate that, for the cases considered here, linearization errors are small and the lack of an accurate sound-speed profile does not cause significant biases in the estimated locations. A sequence of Pacific walrus vocalizations, recorded in the Chukchi Sea northwest of Alaska, is localized using this technique, yielding a track estimate and uncertainties with an estimated speed comparable to normal walrus swim speeds.

  16. Passive acoustic detection and localization of whales: effects of shipping noise in Saguenay-St. Lawrence Marine Park.

    PubMed

    Simard, Yvan; Roy, Nathalie; Gervaise, Cédric

    2008-06-01

    The performance of large-aperture hydrophone arrays to detect and localize blue and fin whales' 15-85 Hz signature vocalizations under ocean noise conditions was assessed through simulations from a normal mode propagation model combined to noise statistics from 15 960 h of recordings in Saguenay-St. Lawrence Marine Park. The probability density functions of 2482 summer noise level estimates in the call bands were used to attach a probability of detection/masking to the simulated call levels as a function of whale depth and range for typical environmental conditions. Results indicate that call detection was modulated by the calling depth relative to the sound channel axis and by modal constructive and destructive interferences with range. Masking of loud infrasounds could reach 40% at 30 km for a receiver at the optimal depth. The 30 dB weaker blue whale D-call were subject to severe masking. Mapping the percentages of detection and localization allowed assessing the performance of a six-hydrophone array under mean- and low-noise conditions. This approach is helpful for optimizing hydrophone configuration in implementing passive acoustic monitoring arrays and building their detection function for whale density assessment, as an alternative to or in combination with the traditional undersampling visual methods. PMID:18537362

  17. Passive acoustic detection and localization of whales: effects of shipping noise in Saguenay-St. Lawrence Marine Park.

    PubMed

    Simard, Yvan; Roy, Nathalie; Gervaise, Cédric

    2008-06-01

    The performance of large-aperture hydrophone arrays to detect and localize blue and fin whales' 15-85 Hz signature vocalizations under ocean noise conditions was assessed through simulations from a normal mode propagation model combined to noise statistics from 15 960 h of recordings in Saguenay-St. Lawrence Marine Park. The probability density functions of 2482 summer noise level estimates in the call bands were used to attach a probability of detection/masking to the simulated call levels as a function of whale depth and range for typical environmental conditions. Results indicate that call detection was modulated by the calling depth relative to the sound channel axis and by modal constructive and destructive interferences with range. Masking of loud infrasounds could reach 40% at 30 km for a receiver at the optimal depth. The 30 dB weaker blue whale D-call were subject to severe masking. Mapping the percentages of detection and localization allowed assessing the performance of a six-hydrophone array under mean- and low-noise conditions. This approach is helpful for optimizing hydrophone configuration in implementing passive acoustic monitoring arrays and building their detection function for whale density assessment, as an alternative to or in combination with the traditional undersampling visual methods.

  18. Effects of Active and Passive Hearing Protection Devices on Sound Source Localization, Speech Recognition, and Tone Detection

    PubMed Central

    Brown, Andrew D.; Beemer, Brianne T.; Greene, Nathaniel T.; Argo, Theodore; Meegan, G. Douglas; Tollin, Daniel J.

    2015-01-01

    Hearing protection devices (HPDs) such as earplugs offer to mitigate noise exposure and reduce the incidence of hearing loss among persons frequently exposed to intense sound. However, distortions of spatial acoustic information and reduced audibility of low-intensity sounds caused by many existing HPDs can make their use untenable in high-risk (e.g., military or law enforcement) environments where auditory situational awareness is imperative. Here we assessed (1) sound source localization accuracy using a head-turning paradigm, (2) speech-in-noise recognition using a modified version of the QuickSIN test, and (3) tone detection thresholds using a two-alternative forced-choice task. Subjects were 10 young normal-hearing males. Four different HPDs were tested (two active, two passive), including two new and previously untested devices. Relative to unoccluded (control) performance, all tested HPDs significantly degraded performance across tasks, although one active HPD slightly improved high-frequency tone detection thresholds and did not degrade speech recognition. Behavioral data were examined with respect to head-related transfer functions measured using a binaural manikin with and without tested HPDs in place. Data reinforce previous reports that HPDs significantly compromise a variety of auditory perceptual facilities, particularly sound localization due to distortions of high-frequency spectral cues that are important for the avoidance of front-back confusions. PMID:26313145

  19. Effects of Active and Passive Hearing Protection Devices on Sound Source Localization, Speech Recognition, and Tone Detection.

    PubMed

    Brown, Andrew D; Beemer, Brianne T; Greene, Nathaniel T; Argo, Theodore; Meegan, G Douglas; Tollin, Daniel J

    2015-01-01

    Hearing protection devices (HPDs) such as earplugs offer to mitigate noise exposure and reduce the incidence of hearing loss among persons frequently exposed to intense sound. However, distortions of spatial acoustic information and reduced audibility of low-intensity sounds caused by many existing HPDs can make their use untenable in high-risk (e.g., military or law enforcement) environments where auditory situational awareness is imperative. Here we assessed (1) sound source localization accuracy using a head-turning paradigm, (2) speech-in-noise recognition using a modified version of the QuickSIN test, and (3) tone detection thresholds using a two-alternative forced-choice task. Subjects were 10 young normal-hearing males. Four different HPDs were tested (two active, two passive), including two new and previously untested devices. Relative to unoccluded (control) performance, all tested HPDs significantly degraded performance across tasks, although one active HPD slightly improved high-frequency tone detection thresholds and did not degrade speech recognition. Behavioral data were examined with respect to head-related transfer functions measured using a binaural manikin with and without tested HPDs in place. Data reinforce previous reports that HPDs significantly compromise a variety of auditory perceptual facilities, particularly sound localization due to distortions of high-frequency spectral cues that are important for the avoidance of front-back confusions. PMID:26313145

  20. Public Participation in the Process of Local Public Health Policy, Using Policy Network Analysis

    PubMed Central

    Park, Yukyung; Kim, Chang-yup; You, Myoung Soon; Lee, Kun Sei; Park, Eunyoung

    2014-01-01

    Objectives: To assess the current public participation in-local health policy and its implications through the analysis of policy networks in health center programs. Methods: We examined the decision-making process in sub-health center installations and the implementation process in metabolic syndrome management program cases in two districts (‘gu’s) of Seoul. Participants of the policy network were selected by the snowballing method and completed self-administered questionnaires. Actors, the interactions among actors, and the characteristics of the network were analyzed by Netminer. Results: The results showed that the public is not yet actively participating in the local public health policy processes of decision-making and implementation. In the decision-making process, most of the network actors were in the public sector, while the private sector was a minor actor and participated in only a limited number of issues after the major decisions were made. In the implementation process, the program was led by the health center, while other actors participated passively. Conclusions: Public participation in Korean public health policy is not yet well activated. Preliminary discussions with various stakeholders, including civil society, are needed before making important local public health policy decisions. In addition, efforts to include local institutions and residents in the implementation process with the public officials are necessary to improve the situation. PMID:25475197

  1. Comparison of Sedimentary Processes on Adjacent Passive and Active Continental Margins Offshore of Southwest Taiwan Based on Echo Character Studies

    NASA Astrophysics Data System (ADS)

    Liu, C.; Chiu, J.

    2008-12-01

    Echo character recorded on Chirp sub-bottom sonar data from offshore area of southwest Taiwan were analyzed to examine and compare the sedimentary processes of adjacent passive and active continental margin settings. Seafloor echoes in the study area are classified into four types: (1) distinct echoes, (2) indistinct echoes, (3) hyperbolic echoes, and (4) irregular echoes. Based on the mapped distribution of the echo types, the sedimentary processes offshore of southwest Taiwan are different in the two tectonic settings. On the passive South China Sea margin, slope failure is the main process on the upper continental slope, whereas turbidite deposits accumulate in the lower continental slope. In contrast, the submarine Taiwan orogenic wedge is characterized by fill-and-spill processes in the intraslope basins of the upper slope, and mass-transport deposits are observed in the canyons and on the lower Kaoping slope. This difference is largely caused by the huge influx of terrigenous sediments into the submarine Taiwan orogenic wedge province compared to the passive South China Sea continental margin. In the passive South China Sea margin, loading and movement of the Taiwan orogenic wedge has had significant effect on the seafloor morphology, and triggered retrogressive failures. Gas hydrate dissociation may have enhanced the slope failure processes at some locations.

  2. Fluid transport processes in the passive margins of the Eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Bertoni, Claudia; Foschi, Martino; Cartwright, Joe; Levell, Bruce

    2015-04-01

    We analyse and produce a synoptic model of the different styles of fluid transport occurring in the various passive margin settings in the Eastern Mediterranean. The common tectonic-stratigraphic setting is dominated, from the Mesozoic, by the interaction of the Tethyan platforms with Cenozoic to recent, mainly clastic, deposits interacting with the ubiquitous thick late Miocene (Messinian) evaporitic sediments. This created different specific modes of fluid-lithology coupling behaviours, and generated an extraordinary suite of seismically resolvable fluid flow phenomena, including mud volcanoes, pockmarks, dissolution/collapse structures, chimneys and pipes. We integrate this evidence with the analysis of the regional pressure/temperature gradient, and with published hydrocarbon generation models, to propose a regional synthesis of all fluid transport processes in a specific basinal context. We place the fluid flow evidence observed in the Eastern Mediterranean in the framework of the three main fluid flow settings, which are typically defined in sedimentary basins, in terms of depth: 1) A thermobaric fluid regime, where fluid transport is limited and convection can be the dominant transport mechanism, 2) A thermogenic regime, where fluids supplied by hydrocarbon generation can migrate by hydraulic fracturing and advection (along open faults/conduits), by matrix flow and in the longer term, by diffusion processes, 3) A shallow compactional regime, where the fluids are generated by sediment dewatering and shallow diagenesis, and the main transport mechanism is characterised by vertical fluid flow, either through advection and hydrofracturing along faults, or matrix flow. In the Eastern Mediterranean passive margins, this depth-related subdivision needs to be modified in order to accommodate the influence of the laterally and vertically extensive evaporitic series, which acts as a regional aquitard/aquiclude to water or a seal to hydrocarbon flow. The presence of

  3. Asymmetrical hemisphere activation enhances global-local processing.

    PubMed

    Gable, Philip A; Poole, Bryan D; Cook, Mary S

    2013-12-01

    Decades of research focusing on the neurophysiological underpinnings related to global-local processing of hierarchical stimuli have associated global processing with the right hemisphere and local processing with the left hemisphere. The current experiment sought to expand this research by testing the causal contributions of hemisphere activation to global-local processing. To manipulate hemisphere activation, participants engaged in contralateral hand contractions. Then, EEG activity and attentional scope were measured. Right-hand contractions caused greater relative left-cortical activity than left-hand contractions. Participants were more narrowly focused after left-hemisphere activation than after right-hemisphere activation. Moreover, N1 amplitudes to local targets in the left hemisphere were larger after left-hemisphere activation than after right-hemisphere activation. Consistent with past research investigating hemispheric asymmetry and attentional scope, the current results suggest that manipulating left (right) hemisphere activity enhanced local (global) attentional processing.

  4. The Comparative Effects of Processing Instruction and Dictogloss on the Acquisition of the English Passive by Speakers of Turkish

    ERIC Educational Resources Information Center

    Uludag, Onur; Vanpatten, Bill

    2012-01-01

    The current study presents the results of an experiment investigating the effects of processing instruction (PI) and dictogloss (DG) on the acquisition of the English passive voice. Sixty speakers of Turkish studying English at university level were assigned to three groups: one receiving PI, the other receiving DG and the third serving as a…

  5. Is Broca's Area Involved in the Processing of Passive Sentences? An Event-Related fMRI Study

    ERIC Educational Resources Information Center

    Yokoyama, Satoru; Watanabe, Jobu; Iwata, Kazuki; Ikuta, Naho; Haji, Tomoki; Usui, Nobuo; Taira, Masato; Miyamoto, Tadao; Nakamura, Wataru; Sato, Shigeru; Horie, Kaoru; Kawashima, Ryuta

    2007-01-01

    We used functional magnetic resonance imaging (fMRI) to investigate whether activation in Broca's area is greater during the processing of passive versus active sentences in the brains of healthy subjects. Twenty Japanese native speakers performed a visual sentence comprehension task in which they were asked to read a visually presented sentence…

  6. A PROPOSED METHOD FOR ESTIMATING FAILURE RATES OF DEGRADED PASSIVE COMPONENTS IN THE NRC SIGNIFICANCE DETERMINATION PROCESS

    SciTech Connect

    Unwin, Stephen D.; Johnson, Kenneth I.; Ivans, William J.; Lowry, Peter P.

    2013-11-01

    This paper outlines a methodology for estimation of the incremental core damage frequency associated with the degradation of passive components with a view to its application in the US Nuclear Regulatory Commission's significance determination process. The method involves use of simplified physics-based models of materials degradation and the probabilistic comparison of transient loads with deteriorating system capacities.

  7. Update on scribe-cleave-passivate (SCP) slim edge technology for silicon sensors: Automated processing and radiation resistance

    NASA Astrophysics Data System (ADS)

    Fadeyev, V.; Ely, S.; Galloway, Z.; Ngo, J.; Parker, C.; Sadrozinski, H. F.-W.; Christophersen, M.; Phlips, B. F.; Pellegrini, G.; Rafi, J. M.; Quirion, D.; Dalla Betta, G.-F.; Boscardin, M.; Casse, G.; Gorelov, I.; Hoeferkamp, M.; Metcalfe, J.; Seidel, S.; Gaubas, E.; Ceponis, T.; Vaitkus, J. V.

    2014-11-01

    We pursue scribe-cleave-passivate (SCP) technology for making "slim edge" sensors. The goal is to reduce the inactive region at the periphery of the devices while maintaining their performance. In this paper we report on two aspects of the current efforts. The first one involves fabrication options for mass production. We describe the automated cleaving tests and a simplified version of SCP post-processing of n-type devices. Another aspect is the radiation resistance of the passivation. We report on the radiation tests of n- and p-type devices with protons and neutrons.

  8. Localized rapid heating process for precision chalcogenide glass molding

    NASA Astrophysics Data System (ADS)

    Li, Hui; He, Peng; Yu, Jianfeng; Lee, L. James; Yi, Allen Y.

    2015-10-01

    Precision glass molding is an important process for high volume optical fabrication. However, conventional glass molding is a bulk heating process that usually requires a long thermal cycle, where molding assembly and other mechanical parts are heated and cooled together. This often causes low efficiency and other heating and cooling related problems, such as large thermal expansion in both the molds and molded optics. To cope with this issue, we developed a localized rapid heating process to effectively heat only very small part of the glass. This localized rapid heating study utilized a fused silica wafer coated with a thin graphene layer to heat only the surface of the glass. The graphene coating functions as an electrical resistant heater when a power source was applied across the thin film coating, generating heat on and near the coating. The feasibility of this process was validated by both experiments and numerical simulation. To demonstrate the advantages of the localized rapid heating, both localized rapid heating process and bulk heating process were performed and carefully compared. The uniformity and quality of the molded sample by localized rapid heating process was also demonstrated. In summary, localized rapid heating process by using graphene coated fused silica wafer was characterized and can be readily implemented in replication of micro scale chalcogenide glasses. A fused silica wafer coated with a thin graphene layer was utilized for localized rapid heating only the surface of the glass. The graphene coating functions as an electrical resistant heater when a power source was applied across the thin film coating, generating high temperature on and near the coating. This process is fast and efficient since only interested areas are heated without affecting the entire glass substrate or the mold assembly. The uniformity and quality of the molded sample by localized rapid heating process was demonstrated by comparing both localized rapid heating

  9. Quality of Life and Toxicity From Passively Scattered and Spot-Scanning Proton Beam Therapy for Localized Prostate Cancer

    SciTech Connect

    Pugh, Thomas J.; Munsell, Mark F.; Choi, Seungtaek; Nguyen, Quyhn Nhu; Mathai, Benson; Zhu, X. Ron; Sahoo, Narayan; Gillin, Michael; Johnson, Jennifer L.; Amos, Richard A.; Dong, Lei; Mahmood, Usama; Kuban, Deborah A.; Frank, Steven J.; Hoffman, Karen E.; McGuire, Sean E.; Lee, Andrew K.

    2013-12-01

    Purpose: To report quality of life (QOL)/toxicity in men treated with proton beam therapy for localized prostate cancer and to compare outcomes between passively scattered proton therapy (PSPT) and spot-scanning proton therapy (SSPT). Methods and Materials: Men with localized prostate cancer enrolled on a prospective QOL protocol with a minimum of 2 years' follow-up were reviewed. Comparative groups were defined by technique (PSPT vs SSPT). Patients completed Expanded Prostate Cancer Index Composite questionnaires at baseline and every 3-6 months after proton beam therapy. Clinically meaningful differences in QOL were defined as ≥0.5 × baseline standard deviation. The cumulative incidence of modified Radiation Therapy Oncology Group grade ≥2 gastrointestinal (GI) or genitourinary (GU) toxicity and argon plasma coagulation were determined by the Kaplan-Meier method. Results: A total of 226 men received PSPT, and 65 received SSPT. Both PSPT and SSPT resulted in statistically significant changes in sexual, urinary, and bowel Expanded Prostate Cancer Index Composite summary scores. Only bowel summary, function, and bother resulted in clinically meaningful decrements beyond treatment completion. The decrement in bowel QOL persisted through 24-month follow-up. Cumulative grade ≥2 GU and GI toxicity at 24 months were 13.4% and 9.6%, respectively. There was 1 grade 3 GI toxicity (PSPT group) and no other grade ≥3 GI or GU toxicity. Argon plasma coagulation application was infrequent (PSPT 4.4% vs SSPT 1.5%; P=.21). No statistically significant differences were appreciated between PSPT and SSPT regarding toxicity or QOL. Conclusion: Both PSPT and SSPT confer low rates of grade ≥2 GI or GU toxicity, with preservation of meaningful sexual and urinary QOL at 24 months. A modest, yet clinically meaningful, decrement in bowel QOL was seen throughout follow-up. No toxicity or QOL differences between PSPT and SSPT were identified. Long-term comparative results in a

  10. Hydrogen passivation of defects and rapid thermal processing for high-efficiency silicon ribbon solar cells

    NASA Astrophysics Data System (ADS)

    Jeong, Ji-Weon

    2002-01-01

    The use of photovoltaic (PV) system offers a unique opportunity to solve the energy and the environmental problems simultaneously because solar energy is free and can be directly converted into electrical energy by solar cells without any undesirable impact on the environment. In spite of the many advantages, PV still accounts for less than 0.05% of the current U.S. energy portfolio. This is mainly because PV is 2-4 times more expensive than traditional energy sources. PV modules should cost about $1/W to produce electricity at a rate of 6¢/kWh and to compete with fossil fuels. Since Si material accounts for ˜40% of the cost of current Si PV modules, the use of low-cost Si substrate is critical for cost reduction. Edge-defined film-fed grown (EFG) Si ribbon is the focus as substrate materials for this research because it is one of the most promising for low-cost PV. However, as-grown EFG Si has a lot of impurities and crystal defects resulted from the Si feedstock and its growth system, which reduce the bulk lifetime of less than 3 ms. In this research, first, the requirements for achieving 16% efficiency have been established using computer model simulations. To improve the bulk lifetime, manufacturable P and Al gettering techniques are developed to remove the lifetime-killing impurities from the active to inactive device regions. PECVD SiN-induced hydrogen defect passivation is investigated and maximized through the fundamental understanding of the role of Al, the impact of RTP firing, and the difference between two PECVD SiN films. For low-cost contact formation, a novel RTP firing process is developed for high-quality screen-printed contacts and Al-BSF. Finally, a complete process sequence that involves the optimal conditions for defect passivation and contacts is developed to produce ˜16% efficiency on screen-printed EFG Si solar cells, which is the highest efficiency for any screen-printed Si ribbon solar cells to date.

  11. Effects of obesity and mild hypohydration on local sweating and cutaneous vascular responses during passive heat stress in females.

    PubMed

    Moyen, Nicole E; Burchfield, Jenna M; Butts, Cory L; Glenn, Jordan M; Tucker, Matthew A; Treece, Keeley; Smith, Amber J; McDermott, Brendon P; Ganio, Matthew S

    2016-08-01

    The purpose of this study was to evaluate the effect of obesity and mild hypohydration on local sweating (LSR) and cutaneous vascular conductance (CVC) responses during passive heat stress in females. Thirteen obese (age, 24 ± 4 years; 45.4% ± 5.2% body fat) and 12 nonobese (age, 22 ± 2 years; 25.1% ± 3.9% body fat) females were passively heated (1.0 °C rectal temperature increase) while either euhydrated (EUHY) or mildly hypohydrated (HYPO; via fluid restriction). Chest and forearm LSR (ventilated capsule) and CVC (Laser Doppler flowmetry) onset, sensitivity, and plateau/steady state were recorded as mean body temperature increased (ΔTb). Participants began trials EUHY (urine specific gravity, Usg = 1.009 ± 0.006) or HYPO (Usg = 1.025 ± 0.004; p < 0.05), and remained EUHY or HYPO. Independent of obesity, HYPO decreased sweat sensitivity at the chest (HYPO = 0.79 ± 0.35, EUHY = 0.95 ± 0.39 Δmg·min(-1)·cm(-2)/°C ΔTb) and forearm (HYPO = 0.82 ± 0.39, EUHY = 1.06 ± 0.34 Δmg·min(-1)·cm(-2)/°C ΔTb); forearm LSR plateau was also decreased (HYPO = 0.66 ± 0.19, EUHY = 0.78 ± 0.23 mg·min(-1)·cm(-2); all p < 0.05). Overall, obese females had lower chest-sweat sensitivity (0.72 ± 0.35 vs. 1.01 ± 0.33 Δmg·min(-1)·cm(-2)/°C ΔTb) and plateau (0.55 ± 0.27 vs. 0.80 ± 0.25 mg·min(-1)·cm(-2); p < 0.05). While hypohydrated, obese females had a lower chest LSR (p < 0.05) versus nonobese females midway (0.45 ± 0.26 vs. 0.73 ± 0.23 mg·min(-1)·cm(-2)) and at the end (0.53 ± 0.27 vs. 0.81 ± 0.24 mg·min(-1)·cm(-2)) of heating. Furthermore, HYPO (relative to the EUHY trials) led to a greater decrease in CVC sensitivity in obese (-28 ± 27 Δ% maximal CVC/°C ΔTb) versus nonobese females (+9.2 ± 33 Δ% maximal CVC/°C ΔTb; p < 0.05). In conclusion, mild hypohydration impairs females' sweating responses during passive heat stress, and this effect is exacerbated when obese. PMID:27455036

  12. Signal processing for passive detection and classification of underwater acoustic signals

    NASA Astrophysics Data System (ADS)

    Chung, Kil Woo

    2011-12-01

    This dissertation examines signal processing for passive detection, classification and tracking of underwater acoustic signals for improving port security and the security of coastal and offshore operations. First, we consider the problem of passive acoustic detection of a diver in a shallow water environment. A frequency-domain multi-band matched-filter approach to swimmer detection is presented. The idea is to break the frequency contents of the hydrophone signals into multiple narrow frequency bands, followed by time averaged (about half of a second) energy calculation over each band. Then, spectra composed of such energy samples over the chosen frequency bands are correlated to form a decision variable. The frequency bands with highest Signal/Noise ratio are used for detection. The performance of the proposed approach is demonstrated for experimental data collected for a diver in the Hudson River. We also propose a new referenceless frequency-domain multi-band detector which, unlike other reference-based detectors, does not require a diver specific signature. Instead, our detector matches to a general feature of the diver spectrum in the high frequency range: the spectrum is roughly periodic in time and approximately flat when the diver exhales. The performance of the proposed approach is demonstrated by using experimental data collected from the Hudson River. Moreover, we present detection, classification and tracking of small vessel signals. Hydroacoustic sensors can be applied for the detection of noise generated by vessels, and this noise can be used for vessel detection, classification and tracking. This dissertation presents recent improvements aimed at the measurement and separation of ship DEMON (Detection of Envelope Modulation on Noise) acoustic signatures in busy harbor conditions. Ship signature measurements were conducted in the Hudson River and NY Harbor. The DEMON spectra demonstrated much better temporal stability compared with the full ship

  13. Surface Passivation for 3-5 Semiconductor Processing: Stable Gallium Sulphide Films by MOCVD

    NASA Technical Reports Server (NTRS)

    Macinnes, Andrew N.; Jenkins, Phillip P.; Power, Michael B.; Kang, Soon; Barron, Andrew R.; Hepp, Aloysius F.; Tabib-Azar, Massood

    1994-01-01

    Gallium sulphide (GaS) has been deposited on GaAs to form stable, insulating, passivating layers. Spectrally resolved photoluminescence and surface recombination velocity measurements indicate that the GaS itself can contribute a significant fraction of the photoluminescence in GaS/GaAs structures. Determination of surface recombination velocity by photoluminescence is therefore difficult. By using C-V analysis of metal-insulator-semiconductor structures, passivation of the GaAs with GaS films is quantified.

  14. Local infiltration of rabies immunoglobulins without systemic intramuscular administration: An alternative cost effective approach for passive immunization against rabies

    PubMed Central

    Bharti, Omesh Kumar; Madhusudana, Shampur Narayan; Gaunta, Pyare Lal; Belludi, Ashwin Yajaman

    2016-01-01

    ABSTRACT Presently the dose of rabies immunoglobulin (RIG) which is an integral part of rabies post exposure prophylaxis (PEP) is calculated based on body weight though the recommendation is to infiltrate the wound(s). This practice demands large quantities of RIG which may be unaffordable to many patients. In this background, we conducted this study to know if the quantity and cost of RIG can be reduced by restricting passive immunization to local infiltration alone and avoiding systemic intramuscular administration based on the available scientific evidence. Two hundred and sixty nine category III patients bitten by suspect or confirmed rabid dogs/animals were infiltrated with equine rabies immunoglobulin (ERIGs) in and around the wound. The quantity of ERIG used was proportionate to the size and number of wounds irrespective of their body weight. They were followed with a regular course of rabies vaccination by intra-dermal route. As against 363 vials of RIGs required for all these cases as per current recommendation based on body weight, they required only 42 vials of 5ml RIG. Minimum dose of RIGs given was 0.25 ml and maximum dose given was 8 ml. On an average 1.26 ml of RIGs was required per patient that costs Rs. 150 ($3). All the patients were followed for 9 months and they were healthy and normal at the end of observation period. With local infiltration, that required small quantities of RIG, the RIGs could be made available to all patients in times of short supply in the market. A total of 30 (11%) serum samples of patients were tested for rabies virus neutralizing antibodies by the rapid fluorescent focus inhibition test (RFFIT) and all showed antibody titers >0.5 IU/mL by day 14. In no case the dose was higher than that required based on body weight and no immunosuppression resulted. To conclude, this pilot study shows that local infiltration of RIG need to be considered in times of non-availability in the market or unaffordability by poor patients

  15. Fundamental studies on passivity and passivity breakdown

    SciTech Connect

    Macdonald, D.D.; Urquidi-Macdonald, M.

    1993-06-01

    Using photoelectrochemical impedance and admittance spectroscopies, a fundamental and quantitative understanding of the mechanisms for the growth and breakdown of passive films on metal and alloy surfaces in contact with aqueous environments is being developed. A point defect model has been extended to explain the breakdown of passive films, leading to pitting and crack growth and thus development of damage due to localized corrosion.

  16. Geothermal policy development program: expediting the local geothermal permitting process

    SciTech Connect

    Not Available

    1981-07-01

    For a number of years, concerns have been raised about the length of time and the complexity involved in obtaining required permits in order to develop the geothermal resource at the Geysers. Perhaps the most important factor is jurisdiction. At the Geysers, all three levels of government - local, state, and federal - exercise significant authority over various aspects of geothermal development. In addition, several agencies within each governmental level play an active role in the permitting process. The present study is concerned primarily with the local permitting process, and the ways in which this process could be expedited. This report begins by looking at the local role in the overall permitting process, and then reviews the findings and conclusions that have been reached in other studies of the problem. This is followed by a case study evaluation of recent permitting experience in the four Geysers-Calistoga KGRA counties, and the report concludes by outlining several approaches to expediting the local permitting process.

  17. Passivation process and the mechanism of packing particles in the Fe0/GAC system during the treatment of ABS resin wastewater.

    PubMed

    Lai, Bo; Zhou, Yuexi; Wang, Juling; Zhang, Yunhong; Chen, Zhiqiang

    2014-01-01

    This study provides mechanistic insights into the passivation of the packing particles during the treatment of acrylonitrile-butadiene-styrene (ABS) resin wastewater by the Fe0/GAC system. The granular-activated carbon (GAC) and iron chippings (Fe0) were mixed together with a volumetric ratio of 1:1. GAC has a mean particle size of approximately 3-5 mm, a specific surface of 748 m2 g(-1), a total pore volume of 0.48 mL g(-1) and a bulk density of 0.49 g cm(-3). The iron chippings have a compact and non-porous surface morphology. The results show that the packing particles in the Fe0/GAC system would lose their activity because the removal of TOC and PO4(3-) for ABS resin wastewater could not carried out by the Fe0/GAC system after 40 days continuous running. Meanwhile, the availability of O2 and intrinsic reactivity of Fe0 play a key role on the form of passive film with different iron oxidation states. The passive film on the surface of iron chippings was formed by two phases: (a) local corrosion phase (0-20 d) and (b) co-precipitation phase (20-40 d), while that of GAC was mainly formed by the co-precipitation of corrosion products with SO4(2-) and PO4(3-) because SO4(2-) and PO4(3-) would not easily reach the Fe0 surface. Therefore, in order to avoid the occurrence of filler passivation, high concentrations of SO4(2-) and PO4(3-) in wastewater should be removed before the treatment process of the Fe/GAC system.

  18. Deciphering the influence of the thermal processes on the early passive margins formation

    NASA Astrophysics Data System (ADS)

    Bousquet, Romain; Nalpas, Thierry; Ballard, Jean-François; Ringenbach, Jean-Claude; Chelalou, Roman; Clerc, Camille

    2015-04-01

    Many large-scale dynamic processes, from continental rifting to plate subduction, are intimately linked to metamorphic reactions. This close relation between geodynamic processes and metamorphic reactions is, in spite of appearances, yet poorly understood. For example, during extension processes, rocks will be exposed to important temperature, pressures and stress changes. Meanwhile less attention has been paid to other important aspects of the metamorphic processes. When reacting rocks expand and contract, density and volume changes will set up in the surrounding material. While several tectonic models are proposed to explain the formation of extensive basins and passive margins ( simple shear detachment mantle exhumation .... ) a single thermal model (McKenzie , 1978), as a dogma, is used to understanding and modeling the formation and evolution of sedimentary basins . This model is based on the assumption that the extension is only by pure shear and it is instantaneous. Under this approach, the sedimentary deposits occur in two stages. i) A short step , 1 to 10 Ma , controlled by tectonics. ii) A longer step , at least 50 Ma as a result of the thermal evolution of the lithosphere.
However, most stratigraphic data indicate that less thermal model can account for documented vertical movements. The study of the thermal evolution , coupled with other tectonic models , and its consequences have never been studied in detail , although the differences may be significant and it is clear that the petrological changes associated with changes in temperature conditions , influence changes reliefs.
In addition, it seems that the relationship between basin formation and thermal evolution is not always the same:
- Sometimes the temperature rise above 50 to 100 Ma tectonic extension. In the Alps, a significant rise in geothermal gradient Permo -Triassic followed by a "cold" extension , leading to the opening of the Ligurian- Piedmont ocean, from the Middle Jurassic .

  19. A sequential method for passive detection, characterization, and localization of multiple low probability of intercept LFMCW signals

    NASA Astrophysics Data System (ADS)

    Hamschin, Brandon M.

    A method for passive Detection, Characterization, and Localization (DCL) of multiple low power, Linear Frequency Modulated Continuous Wave (LFMCW) (i.e., Low Probability of Intercept (LPI)) signals is proposed. We demonstrate, via simulation, laboratory, and outdoor experiments, that the method is able to detect and correctly characterize the parameters that define two simultaneous LFMCW signals with probability greater than 90% when the signal to noise ratio is -10 dB or greater. While this performance is compelling, it is far from the Cramer-Rao Lower Bound (CRLB), which we derive, and the performance of the Maximum Likelihood Estimator (MLE), whose performance we simulate. The loss in performance relative to the CRLB and the MLE is the price paid for computational tractability. The LFMCW signal is the focus of this work because of its common use in modern, low-cost radar systems. In contrast to other detection and characterization approaches, such as the MLE and those based on the Wigner-Ville Transform (WVT) or the Wigner-Ville Hough Transform (WVHT), our approach does not begin with a parametric model of the received signal that is specified directly in terms of its LFMCW constituents. Rather, we analyze the signal over time intervals that are short, non-overlapping, and contiguous by modeling it within these intervals as a sum of a small number sinusoidal (i.e., harmonic) components with unknown frequencies, deterministic but unknown amplitudes, unknown order (i.e., number of harmonic components), and unknown noise autocorrelation function. It is this model of the data that makes the solution computationally feasible, but also what leads to a degradation in performance since estimates are not based on the full time series. By modeling the signal in this way, we reliably detect the presence of multiple LFMCW signals in colored noise without the need for prewhitening, efficiently estimate (i.e. , characterize) their parameters, provide estimation error

  20. Passive versus active operator work in automated process control--a job design case study in a control centre.

    PubMed

    Persson, A; Wanek, B; Johansson, A

    2001-10-01

    Methods of avoiding common problems associated with operator work in automated process control, such as understimulation and difficulties in achieving and maintaining necessary skills and competence, are addressed in this paper. The source of these problems is deduced here to be that monitoring tasks are a predominant part of the job. This case study shows how work in a highly automated process can be designed not only to avoid the traditional problems, but also provide a stimulating job within a good work situation at the same time as fulfilling efficiency demands. A new definition of active/passive operator jobs is made which is based on a categorisation of the types of work tasks that make up the job. The definition gives an explanation of how different designs of operator jobs result in more or less active/passive work situations.

  1. Cultural Variations in Global versus Local Processing: A Developmental Perspective

    ERIC Educational Resources Information Center

    Oishi, Shigehiro; Jaswal, Vikram K.; Lillard, Angeline S.; Mizokawa, Ai; Hitokoto, Hidefumi; Tsutsui, Yoshiro

    2014-01-01

    We conducted 3 studies to explore cultural differences in global versus local processing and their developmental trajectories. In Study 1 ("N" = 363), we found that Japanese college students were less globally oriented in their processing than American or Argentine participants. We replicated this effect in Study 2 ("N" =…

  2. Change Processes and Strategies at the Local Level.

    ERIC Educational Resources Information Center

    Fullan, Michael

    Change processes at the school building level are considered in order to formulate a number of locally based strategies, derived from research, for significantly improving schools and classrooms. Part I of the three-part analysis examines, through illustration, what is known about successful change processes at the school and classroom levels.…

  3. Local Conjecturing Process in the Solving of Pattern Generalization Problem

    ERIC Educational Resources Information Center

    Sutarto; Nusantara, Toto; Subanji; Sisworo

    2016-01-01

    This aim of this study is to describe the process of local conjecturing in generalizing patterns based on Action, Process, Object, Schema (APOS) theory. The subjects were 16 grade 8 students from a junior high school. Data collection used Pattern Generalization Problem (PGP) and interviews. In the first stage, students completed PGP; in the second…

  4. Molecular kinetic theory of strongly nonequilibrium processes of mass, momentum, and energy transfer: Local equilibrium criteria

    NASA Astrophysics Data System (ADS)

    Tovbin, Yu. K.

    2015-09-01

    Consequences of the complete system of transfer equations of the properties (momentum, energy, and mass) of particles and their pairs are considered under local equilibrium conditions with regard to the Bogoliubov hierarchy of relaxation times between the first and second distribution functions (DFs) and distinctions in the characteristic relaxation times of particle momentum, energy, and mass. It is found that even under the local equilibrium condition in the Bogoliubov hierarchy of relaxation times between the first and second DFs, pair correlations are maintained between all dynamic variables (velocity, temperature, and density) whose values are proportional to the gradients of transferable properties. A criterion is introduced requiring there be no local equilibrium condition upon reaching the critical value at which the description of the transfer process becomes incorrect in classical nonequilibrium thermodynamics. External forces are considered in the equations for strongly nonequilibrium processes. Along with allowing for intermolecular potentials, it becomes possible to discuss the concept of passive forces (introduced in thermodynamics by Gibbs) from the standpoint of the kinetic theory. It is shown that use of this concept does not reflect modern representations of real processes.

  5. Effect of Film Formation Potential on Passive Behavior of Ultra-Fine-Grained 1050 Al Alloy Fabricated via ARB Process

    NASA Astrophysics Data System (ADS)

    Fattah-alhosseini, A.; Gashti, S. O.; Keshavarz, M. K.

    2016-04-01

    In this work, the effect of film formation potential on the passive behavior of ultra-fine-grained 1050 Al alloy in a borate buffer solution is investigated. For this purpose, the specimens were fabricated via accumulative roll bonding (ARB) process up to 1, 3, 5, and 7 passes. To determine the evolution of microstructure as a function of ARB process, atomic force microscopy (AFM) and transmission electron microscopy (TEM) were used. AFM images revealed that the grain size values decreased as the number of ARB passes increased. Moreover, TEM micrograph showed that mean grain size of the sample reached to about 340 nm after applying 7 passes of ARB. Potentiodynamic polarization plots indicated that, as the number of ARB passes increased, the corrosion and passive current densities decreased. Also, electrochemical impedance spectroscopy measurements showed that at selected applied potential above open circuit potential, the corrosion resistance of the 1050 Al alloy was systematically increased by applying further ARB passes. It was found that passive behavior of the ARBed 1050 Al alloy specimens were improved by reducing the grain size.

  6. Snap Your Fingers! An ERP/sLORETA Study Investigating Implicit Processing of Self- vs. Other-Related Movement Sounds Using the Passive Oddball Paradigm

    PubMed Central

    Justen, Christoph; Herbert, Cornelia

    2016-01-01

    So far, neurophysiological studies have investigated implicit and explicit self-related processing particularly for self-related stimuli such as the own face or name. The present study extends previous research to the implicit processing of self-related movement sounds and explores their spatio-temporal dynamics. Event-related potentials (ERPs) were assessed while participants (N = 12 healthy subjects) listened passively to previously recorded self- and other-related finger snapping sounds, presented either as deviants or standards during an oddball paradigm. Passive listening to low (500 Hz) and high (1000 Hz) pure tones served as additional control. For self- vs. other-related finger snapping sounds, analysis of ERPs revealed significant differences in the time windows of the N2a/MMN and P3. An subsequent source localization analysis with standardized low-resolution brain electromagnetic tomography (sLORETA) revealed increased cortical activation in distinct motor areas such as the supplementary motor area (SMA) in the N2a/mismatch negativity (MMN) as well as the P3 time window during processing of self- and other-related finger snapping sounds. In contrast, brain regions associated with self-related processing [e.g., right anterior/posterior cingulate cortex (ACC/PPC)] as well as the right inferior parietal lobule (IPL) showed increased activation particularly during processing of self- vs. other-related finger snapping sounds in the time windows of the N2a/MMN (ACC/PCC) or the P3 (IPL). None of these brain regions showed enhanced activation while listening passively to low (500 Hz) and high (1000 Hz) pure tones. Taken together, the current results indicate (1) a specific role of motor regions such as SMA during auditory processing of movement-related information, regardless of whether this information is self- or other-related, (2) activation of neural sources such as the ACC/PCC and the IPL during implicit processing of self-related movement stimuli, and (3

  7. On non-local transport processes in the solar atmosphere

    NASA Technical Reports Server (NTRS)

    Macneice, P.

    1992-01-01

    We review two mechanisms which can lend a non-local character to energy transport in the solar atmosphere, heat flux propagating in the form of collisionless electrons, and non-equilibrium ionization of hydrogen driven by ambipolar diffusion. Application of these processes to modelling of the lower transition region and upper chromosphere is considered.

  8. A Model Using Local Weather Data to Determine the Effective Sampling Volume for PCB Congeners Collected on Passive Air Samplers.

    PubMed

    Herkert, Nicholas J; Martinez, Andres; Hornbuckle, Keri C

    2016-07-01

    We have developed and evaluated a mathematical model to determine the effective sampling volumes (Veff) of PCBs and similar compounds captured using polyurethane foam passive air samplers (PUF-PAS). We account for the variability in wind speed, air temperature, and equilibrium partitioning over the course of the deployment of the samplers. The model, provided as an annotated Matlab script, predicts the Veff as a function of physical-chemical properties of each compound and meteorology from the closest Integrated Surface Database (ISD) data set obtained through NOAA's National Centers for Environmental Information (NCEI). The model was developed to be user-friendly, only requiring basic Matlab knowledge. To illustrate the effectiveness of the model, we evaluated three independent data sets of airborne PCBs simultaneously collected using passive and active samplers: at sites in Chicago, Lancaster, UK, and Toronto, Canada. The model provides Veff values comparable to those using depuration compounds and calibration against active samplers, yielding an average congener specific concentration method ratio (active/passive) of 1.1 ± 1.2. We applied the model to PUF-PAS samples collected in Chicago and show that previous methods can underestimate concentrations of PCBs by up to 40%, especially for long deployments, deployments conducted under warming conditions, and compounds with log Koa values less than 8.

  9. A Model Using Local Weather Data to Determine the Effective Sampling Volume for PCB Congeners Collected on Passive Air Samplers.

    PubMed

    Herkert, Nicholas J; Martinez, Andres; Hornbuckle, Keri C

    2016-07-01

    We have developed and evaluated a mathematical model to determine the effective sampling volumes (Veff) of PCBs and similar compounds captured using polyurethane foam passive air samplers (PUF-PAS). We account for the variability in wind speed, air temperature, and equilibrium partitioning over the course of the deployment of the samplers. The model, provided as an annotated Matlab script, predicts the Veff as a function of physical-chemical properties of each compound and meteorology from the closest Integrated Surface Database (ISD) data set obtained through NOAA's National Centers for Environmental Information (NCEI). The model was developed to be user-friendly, only requiring basic Matlab knowledge. To illustrate the effectiveness of the model, we evaluated three independent data sets of airborne PCBs simultaneously collected using passive and active samplers: at sites in Chicago, Lancaster, UK, and Toronto, Canada. The model provides Veff values comparable to those using depuration compounds and calibration against active samplers, yielding an average congener specific concentration method ratio (active/passive) of 1.1 ± 1.2. We applied the model to PUF-PAS samples collected in Chicago and show that previous methods can underestimate concentrations of PCBs by up to 40%, especially for long deployments, deployments conducted under warming conditions, and compounds with log Koa values less than 8. PMID:26963482

  10. A Model Using Local Weather Data to Determine the Effective Sampling Volume for PCB Congeners Collected on Passive Air Samplers

    PubMed Central

    2016-01-01

    We have developed and evaluated a mathematical model to determine the effective sampling volumes (Veff) of PCBs and similar compounds captured using polyurethane foam passive air samplers (PUF–PAS). We account for the variability in wind speed, air temperature, and equilibrium partitioning over the course of the deployment of the samplers. The model, provided as an annotated Matlab script, predicts the Veff as a function of physical-chemical properties of each compound and meteorology from the closest Integrated Surface Database (ISD) data set obtained through NOAA’s National Centers for Environmental Information (NCEI). The model was developed to be user-friendly, only requiring basic Matlab knowledge. To illustrate the effectiveness of the model, we evaluated three independent data sets of airborne PCBs simultaneously collected using passive and active samplers: at sites in Chicago, Lancaster, UK, and Toronto, Canada. The model provides Veff values comparable to those using depuration compounds and calibration against active samplers, yielding an average congener specific concentration method ratio (active/passive) of 1.1 ± 1.2. We applied the model to PUF–PAS samples collected in Chicago and show that previous methods can underestimate concentrations of PCBs by up to 40%, especially for long deployments, deployments conducted under warming conditions, and compounds with log Koa values less than 8. PMID:26963482

  11. Can clouds dance? Neural correlates of passive conceptual expansion using a metaphor processing task: Implications for creative cognition.

    PubMed

    Rutter, Barbara; Kröger, Sören; Stark, Rudolf; Schweckendiek, Jan; Windmann, Sabine; Hermann, Christiane; Abraham, Anna

    2012-03-01

    Creativity has emerged in the focus of neurocognitive research in the past decade. However, a heterogeneous pattern of brain areas has been implicated as underpinning the neural correlates of creativity. One explanation for these divergent findings lies in the fact that creativity is not usually investigated in terms of its many underlying cognitive processes. The present fMRI study focuses on the neural correlates of conceptual expansion, a central component of all creative processes. The study aims to avoid pitfalls of previous fMRI studies on creativity by employing a novel paradigm. Participants were presented with phrases and made judgments regarding both the unusualness and the appropriateness of the stimuli, corresponding to the two defining criteria of creativity. According to their respective evaluation, three subject-determined experimental conditions were obtained. Phrases judged as both unusual and appropriate were classified as indicating conceptual expansion in participants. The findings reveal the involvement of frontal and temporal regions when engaging in passive conceptual expansion as opposed to the information processing of mere unusualness (novelty) or appropriateness (relevance). Taking this new experimental approach to uncover specific processes involved in creative cognition revealed that frontal and temporal regions known to be involved in semantic cognition and relational reasoning play a role in passive conceptual expansion. Adopting a different vantage point on the investigation of creativity would allow for critical advances in future research on this topic.

  12. Synergistic Use of Passive and Active Data for Cloud Process Studies: Examples from the A-Train Constellation

    NASA Astrophysics Data System (ADS)

    Luo, Z. J.

    2013-05-01

    Clouds play a critical role in regulating the energy budget and water cycle of our planet. Developing a global observation and understanding of clouds requires space-borne remote sensing systems. Through internationally coordinated efforts, various observation systems and cloud products have been developed over the past 30 years. An especially fruitful area involves the synergy between passive and active sensing. Since a number of textbooks and review articles have been published on the remote sensing techniques of these systems, we do not intend to repeat them. Rather, the focus of this paper is on the application side, that is, we illustrate how synergistic use of passive and active observations can be employed to study cloud microphysical and dynamical processes using examples from recent studies that utilized the A-Train data, including a short study of warm cloud droplet growth mechanisms using CloudSat, MODIS and AMSR-E, and a series of studies of tropical convective dynamics using CloudSat and MODIS. Compared to cloud retrieval algorithm development, synergistic use of passive and active data for cloud process studies is a relatively new area. Strictly speaking, it may not be proper to classify it as an "area" because there is no clear roadmap to guide its development, nor any well defined envelop to contain it. Most such studies appear ad hoc in nature and almost always have a certain innovative touch that defies any rigid a priori framework. Yet, it is through these novel studies that cloud processes are systematically investigated from a global perspective. Conclusions drawn from them can thus be generalized that will help evaluate and improve cloud parameterizations in global climate models. It is our hope that more of this kind of studies will blossom out in the future. Finally, from a satellite mission development perspective, these applications will feed back to the design of the observation systems so that guidance can be provided to help define the

  13. Evaluation of active and passive transport processes in corneas extracted from preserved rabbit eyes.

    PubMed

    Majumdar, Soumyajit; Hingorani, Tushar; Srirangam, Ramesh

    2010-04-01

    In vitro transcorneal permeability studies are an important screening tool in drug development. The objective of this research is to examine the feasibility of using corneas isolated from preserved rabbit eyes as a model for permeability evaluation. Eyes from male New Zealand White rabbits were used immediately or were stored overnight in phosphate-buffered saline (PBS) or Hanks balanced salt solution (HBSS) over wet ice. Integrity of isolated corneas was evaluated by measuring the TEER and by determining the permeability of paracellular and transcellular markers. Active transport was assessed by measuring transcorneal permeability of selected amino acids. Esterase activity was estimated using p-nitrophenyl assay. In all cases, corneas from freshly enucleated eyes were compared to those isolated from the day-old preserved eyes. Transcellular and paracellular passive diffusion was not affected by the storage medium and observed to be similar in the fresh and preserved eye models. However, amino acid transporters demonstrated lower functional activity in corneas excised from eyes preserved in PBS. Moreover, preserved eyes displayed almost 1.5-fold lower esterase activity in the corneal tissue. Thus, corneas isolated from day-old eyes, preserved in HBSS, closely mimics freshly excised rabbit corneas in terms of both active and passive transport characteristics but possesses slightly reduced enzymatic activity.

  14. The challenge of localizing vehicle backup alarms: effects of passive and electronic hearing protectors, ambient noise level, and backup alarm spectral content.

    PubMed

    Alali, Khaled A; Casali, John G

    2011-01-01

    A human factors experiment employed a hemi-anechoic sound field in which listeners were required to localize a vehicular backup alarm warning signal (both a standard and a frequency-augmented alarm) in 360-degrees azimuth in pink noise of 60 dBA and 90 dBA. Measures of localization performance included: (1) percentage correct localization, (2) percentage of right--left localization errors, (3) percentage of front-rear localization errors, and (4) localization absolute deviation in degrees from the alarm's actual location. In summary, the data demonstrated that, with some exceptions, normal hearing listeners' ability to localize the backup alarm in 360-degrees azimuth did not improve when wearing augmented hearing protectors (including dichotic sound transmission earmuffs, flat attenuation earplugs, and level-dependent earplugs) as compared to when wearing conventional passive earmuffs or earplugs of the foam or flanged types. Exceptions were that in the 90 dBA pink noise, the flat attenuation earplug yielded significantly better accuracy than the polyurethane foam earplug and both the dichotic and the custom-made diotic electronic sound transmission earmuffs. However, the flat attenuation earplug showed no benefit over the standard pre-molded earplug, the arc earplug, and the passive earmuff. Confusions of front-rear alarm directions were most significant in the 90 dBA noise condition, wherein two types of triple-flanged earplugs exhibited significantly fewer front-rear confusions than either of the electronic muffs. On all measures, the diotic sound transmission earmuff resulted in the poorest localization of any of the protectors due to the fact that its single-microphone design did not enable interaural cues to be heard. Localization was consistently more degraded in the 90 dBA pink noise as compared with the relatively quiet condition of the 60 dBA pink noise. A frequency-augmented backup alarm, which incorporated 400 Hz and 4000 Hz components to exploit the

  15. Design of an HF-Band RFID System with Multiple Readers and Passive Tags for Indoor Mobile Robot Self-Localization.

    PubMed

    Mi, Jian; Takahashi, Yasutake

    2016-01-01

    Radio frequency identification (RFID) technology has already been explored for efficient self-localization of indoor mobile robots. A mobile robot equipped with RFID readers detects passive RFID tags installed on the floor in order to locate itself. The Monte-Carlo localization (MCL) method enables the localization of a mobile robot equipped with an RFID system with reasonable accuracy, sufficient robustness and low computational cost. The arrangements of RFID readers and tags and the size of antennas are important design parameters for realizing accurate and robust self-localization using a low-cost RFID system. The design of a likelihood model of RFID tag detection is also crucial for the accurate self-localization. This paper presents a novel design and arrangement of RFID readers and tags for indoor mobile robot self-localization. First, by considering small-sized and large-sized antennas of an RFID reader, we show how the design of the likelihood model affects the accuracy of self-localization. We also design a novel likelihood model by taking into consideration the characteristics of the communication range of an RFID system with a large antenna. Second, we propose a novel arrangement of RFID tags with eight RFID readers, which results in the RFID system configuration requiring much fewer readers and tags while retaining reasonable accuracy of self-localization. We verify the performances of MCL-based self-localization realized using the high-frequency (HF)-band RFID system with eight RFID readers and a lower density of RFID tags installed on the floor based on MCL in simulated and real environments. The results of simulations and real environment experiments demonstrate that our proposed low-cost HF-band RFID system realizes accurate and robust self-localization of an indoor mobile robot. PMID:27483279

  16. Design of an HF-Band RFID System with Multiple Readers and Passive Tags for Indoor Mobile Robot Self-Localization.

    PubMed

    Mi, Jian; Takahashi, Yasutake

    2016-01-01

    Radio frequency identification (RFID) technology has already been explored for efficient self-localization of indoor mobile robots. A mobile robot equipped with RFID readers detects passive RFID tags installed on the floor in order to locate itself. The Monte-Carlo localization (MCL) method enables the localization of a mobile robot equipped with an RFID system with reasonable accuracy, sufficient robustness and low computational cost. The arrangements of RFID readers and tags and the size of antennas are important design parameters for realizing accurate and robust self-localization using a low-cost RFID system. The design of a likelihood model of RFID tag detection is also crucial for the accurate self-localization. This paper presents a novel design and arrangement of RFID readers and tags for indoor mobile robot self-localization. First, by considering small-sized and large-sized antennas of an RFID reader, we show how the design of the likelihood model affects the accuracy of self-localization. We also design a novel likelihood model by taking into consideration the characteristics of the communication range of an RFID system with a large antenna. Second, we propose a novel arrangement of RFID tags with eight RFID readers, which results in the RFID system configuration requiring much fewer readers and tags while retaining reasonable accuracy of self-localization. We verify the performances of MCL-based self-localization realized using the high-frequency (HF)-band RFID system with eight RFID readers and a lower density of RFID tags installed on the floor based on MCL in simulated and real environments. The results of simulations and real environment experiments demonstrate that our proposed low-cost HF-band RFID system realizes accurate and robust self-localization of an indoor mobile robot.

  17. Design of an HF-Band RFID System with Multiple Readers and Passive Tags for Indoor Mobile Robot Self-Localization

    PubMed Central

    Mi, Jian; Takahashi, Yasutake

    2016-01-01

    Radio frequency identification (RFID) technology has already been explored for efficient self-localization of indoor mobile robots. A mobile robot equipped with RFID readers detects passive RFID tags installed on the floor in order to locate itself. The Monte-Carlo localization (MCL) method enables the localization of a mobile robot equipped with an RFID system with reasonable accuracy, sufficient robustness and low computational cost. The arrangements of RFID readers and tags and the size of antennas are important design parameters for realizing accurate and robust self-localization using a low-cost RFID system. The design of a likelihood model of RFID tag detection is also crucial for the accurate self-localization. This paper presents a novel design and arrangement of RFID readers and tags for indoor mobile robot self-localization. First, by considering small-sized and large-sized antennas of an RFID reader, we show how the design of the likelihood model affects the accuracy of self-localization. We also design a novel likelihood model by taking into consideration the characteristics of the communication range of an RFID system with a large antenna. Second, we propose a novel arrangement of RFID tags with eight RFID readers, which results in the RFID system configuration requiring much fewer readers and tags while retaining reasonable accuracy of self-localization. We verify the performances of MCL-based self-localization realized using the high-frequency (HF)-band RFID system with eight RFID readers and a lower density of RFID tags installed on the floor based on MCL in simulated and real environments. The results of simulations and real environment experiments demonstrate that our proposed low-cost HF-band RFID system realizes accurate and robust self-localization of an indoor mobile robot. PMID:27483279

  18. Local and global processing: observations from a remote culture.

    PubMed

    Davidoff, Jules; Fonteneau, Elisabeth; Fagot, Joel

    2008-09-01

    In Experiment 1, a normal adult population drawn from a remote culture (Himba) in northern Namibia made similarity matches to [Navon, D. (1977). Forest before trees: The precedence of global features in visual perception. Cognitive Psychology, 9, 353-383] hierarchical figures. The Himba showed a local bias stronger than that has been previously observed in any other non-clinical human population. However, in Experiment 2, their recognition of normal or distorted ("Thatcherized") faces did not appear to have been affected by their attention to detail as has been suggested for autistic populations. The data are consistent with a cultural/experiential origin for population differences in local processing and suggest that attention to the local and global properties of stimuli may differ for hierarchical figures and faces. PMID:18662813

  19. Method for localizing and isolating an errant process step

    DOEpatents

    Tobin, Jr., Kenneth W.; Karnowski, Thomas P.; Ferrell, Regina K.

    2003-01-01

    A method for localizing and isolating an errant process includes the steps of retrieving from a defect image database a selection of images each image having image content similar to image content extracted from a query image depicting a defect, each image in the selection having corresponding defect characterization data. A conditional probability distribution of the defect having occurred in a particular process step is derived from the defect characterization data. A process step as a highest probable source of the defect according to the derived conditional probability distribution is then identified. A method for process step defect identification includes the steps of characterizing anomalies in a product, the anomalies detected by an imaging system. A query image of a product defect is then acquired. A particular characterized anomaly is then correlated with the query image. An errant process step is then associated with the correlated image.

  20. The Effect of Active versus Passive Recovery Periods during High Intensity Intermittent Exercise on Local Tissue Oxygenation in 18 – 30 Year Old Sedentary Men

    PubMed Central

    Kerhervé, Hugo A.; Askew, Christopher D.; Solomon, Colin

    2016-01-01

    Purpose High intensity interval training (HIIT) has been proposed as a time-efficient format of exercise to reduce the chronic disease burden associated with sedentary behaviour. Changes in oxygen utilisation at the local tissue level during an acute session of HIIT could be the primary stimulus for the health benefits associated with this format of exercise. The recovery periods of HIIT effect the physiological responses that occur during the session. It was hypothesised that in sedentary individuals, local and systemic oxygen utilisation would be higher during HIIT interspersed with active recovery periods, when compared to passive recovery periods. Methods Twelve sedentary males (mean ± SD; age 23 ± 3 yr) completed three conditions on a cycle ergometer: 1) HIIT with passive recovery periods between four bouts (HIITPASS) 2) HIIT with active recovery periods between four bouts (HIITACT) 3) HIITACT with four HIIT bouts replaced with passive periods (REC). Deoxygenated haemoglobin (HHb) in the vastus lateralis (VL) and gastrocnemius (GN) muscles and the pre-frontal cortex (FH), oxygen consumption (VO2), power output and heart rate (HR) were measured continuously during the three conditions. Results There was a significant increase in HHb at VL during bouts 2 (p = 0.017), 3 (p = 0.035) and 4 (p = 0.035) in HIITACT, compared to HIITPASS. Mean power output was significantly lower in HIITACT, compared to HIITPASS (p < 0.001). There was a significant main effect for site in both HIITPASS (p = 0.029) and HIITACT (p = 0.005). There were no significant differences in VO2 and HR between HIITPASS and HIITACT. Conclusions The increase in HHb at VL and the lower mean power output during HIITACT could indicate that a higher level of deoxygenation contributes to decreased mechanical power in sedentary participants. The significant differences in HHb between sites indicates the specificity of oxygen utilisation. PMID:27677081

  1. Exciton localization in solution-processed organolead trihalide perovskites

    NASA Astrophysics Data System (ADS)

    He, Haiping; Yu, Qianqian; Li, Hui; Li, Jing; Si, Junjie; Jin, Yizheng; Wang, Nana; Wang, Jianpu; He, Jingwen; Wang, Xinke; Zhang, Yan; Ye, Zhizhen

    2016-03-01

    Organolead trihalide perovskites have attracted great attention due to the stunning advances in both photovoltaic and light-emitting devices. However, the photophysical properties, especially the recombination dynamics of photogenerated carriers, of this class of materials are controversial. Here we report that under an excitation level close to the working regime of solar cells, the recombination of photogenerated carriers in solution-processed methylammonium-lead-halide films is dominated by excitons weakly localized in band tail states. This scenario is evidenced by experiments of spectral-dependent luminescence decay, excitation density-dependent luminescence and frequency-dependent terahertz photoconductivity. The exciton localization effect is found to be general for several solution-processed hybrid perovskite films prepared by different methods. Our results provide insights into the charge transport and recombination mechanism in perovskite films and help to unravel their potential for high-performance optoelectronic devices.

  2. Exciton localization in solution-processed organolead trihalide perovskites

    PubMed Central

    He, Haiping; Yu, Qianqian; Li, Hui; Li, Jing; Si, Junjie; Jin, Yizheng; Wang, Nana; Wang, Jianpu; He, Jingwen; Wang, Xinke; Zhang, Yan; Ye, Zhizhen

    2016-01-01

    Organolead trihalide perovskites have attracted great attention due to the stunning advances in both photovoltaic and light-emitting devices. However, the photophysical properties, especially the recombination dynamics of photogenerated carriers, of this class of materials are controversial. Here we report that under an excitation level close to the working regime of solar cells, the recombination of photogenerated carriers in solution-processed methylammonium–lead–halide films is dominated by excitons weakly localized in band tail states. This scenario is evidenced by experiments of spectral-dependent luminescence decay, excitation density-dependent luminescence and frequency-dependent terahertz photoconductivity. The exciton localization effect is found to be general for several solution-processed hybrid perovskite films prepared by different methods. Our results provide insights into the charge transport and recombination mechanism in perovskite films and help to unravel their potential for high-performance optoelectronic devices. PMID:26996605

  3. Modeling Structural and Mechanical Responses to Localized Erosional Processes on a Bivergent Orogenic Wedge

    NASA Astrophysics Data System (ADS)

    Marzen, R.; Morgan, J. K.

    2014-12-01

    Critical Coulomb wedge theory established that orogenic and accretionary wedges should develop self-similarly and maintain a critical taper that reflects the balance of strength of the wedge material and a basal décollement. However, a variety of geological processes can perturb that balance, forcing readjustment of the wedge. For example, glacial erosion and landsliding can concentrate erosion on a localized portion of the wedge slope, leaving that portion of the wedge with an out-of-equilibrium slope that would need to re-develop for the wedge to resume self-similar growth. We use the discrete element method to analyze how growing bivergent wedges with different cohesive strengths respond structurally and mechanically to erosional events localized along upper, middle, and lower segments of the pro-wedge. Mechanically, pro-wedge erosion results in a sudden decrease followed by a quick recovery of the mean stress and maximum shear stress throughout the pro-wedge. However, when erosion is localized in the mid- to lower portions of the pro-wedge, a zone of increased mean stress develops where the wedge is concentrating deformation to recover its taper. In contrast, when erosion is localized in the upper axial zone, there is almost no recovery of the wedge taper, reflecting the fact that the material at the top of the wedge is being carried passively in a transition zone between the pro-wedge and retro-wedge. Structurally, wedges composed of lower cohesion material recover their critical taper almost immediately through distributed deformation, while wedges of higher-cohesion material recover more slowly, and incompletely, by concentrating deformation along existing fault surfaces. As a result, localized erosional episodes can have a lasting effect on the wedge morphology when the wedge is composed of higher cohesion material.

  4. Applicability of radio astronomy techniques to the processing and interpretation of aperture synthesis passive millimetre-wave applications

    NASA Astrophysics Data System (ADS)

    Taylor, Christopher T.; Wilkinson, Peter N.; Salmon, Neil A.; Cameron, Colin D.

    2012-06-01

    This PhD programme is contributing to the development of Passive Millimetre-Wave Imagers (PMMWI) using the principles of interferometric aperture synthesis and digital signal processing. The principal applications are security screening, all-weather flight aids and earth observation. To enhance the cost-effectiveness of PMMWI systems the number of collecting elements must be minimised whilst maintaining adequate image fidelity. A wide range of techniques have been developed by the radio astronomy community for improving the fidelity of sparse interferometric array imagery. This paper brings to the attention of readers these techniques and discusses how they may be applied to imaging using software packages publicly available from the radio astronomy community. The intention of future work is to adapt these algorithms to process experimental data from a range of realistic simulations and real-world targets.

  5. Passive signal processing for a miniature Fabry-Perot interferometric sensor with a multimode laser-diode source

    NASA Astrophysics Data System (ADS)

    Ezbiri, A.; Tatam, R. P.

    1995-09-01

    A passive signal-processing technique for addressing a miniature low-finesse fiber Fabry-Perot interferometric sensor with a multimode laser diode is reported. Two modes of a multimode laser diode separated by 3 nm are used to obtain quadrature outputs from an \\similar 20 - mu m cavity. Wavelength-division demultiplexing combined with digital signal processing is used to recover the measurand-induced phase change. The technique is demonstrated for the measurement of vibration. The signal-to-noise ratio is \\similar 70 dB at 500 Hz for \\similar pi /2 rad displacement of the mirror, which results in a minimum detectable signal of \\similar 200 mu rad H z-1/2 . A quantitative discussion of miscalibration and systematic errors is presented.

  6. Global processing takes time: A meta-analysis on local-global visual processing in ASD.

    PubMed

    Van der Hallen, Ruth; Evers, Kris; Brewaeys, Katrien; Van den Noortgate, Wim; Wagemans, Johan

    2015-05-01

    What does an individual with autism spectrum disorder (ASD) perceive first: the forest or the trees? In spite of 30 years of research and influential theories like the weak central coherence (WCC) theory and the enhanced perceptual functioning (EPF) account, the interplay of local and global visual processing in ASD remains only partly understood. Research findings vary in indicating a local processing bias or a global processing deficit, and often contradict each other. We have applied a formal meta-analytic approach and combined 56 articles that tested about 1,000 ASD participants and used a wide range of stimuli and tasks to investigate local and global visual processing in ASD. Overall, results show no enhanced local visual processing nor a deficit in global visual processing. Detailed analysis reveals a difference in the temporal pattern of the local-global balance, that is, slow global processing in individuals with ASD. Whereas task-dependent interaction effects are obtained, gender, age, and IQ of either participant groups seem to have no direct influence on performance. Based on the overview of the literature, suggestions are made for future research.

  7. RANS Simulation of Passive Scalar Residence Times and Exchange Processes in Idealized and Natural Stream Systems

    NASA Astrophysics Data System (ADS)

    Drost, Kevin; Jackson, Tracie; Haggerty, Roy; Apte, Sourabh

    2011-11-01

    Natural stream systems contain a variety of dead zones characterized by flow separation, a mixing layer, and a recirculation zone. These dead zones play an important role in stream solute transport studies. Previous published work has focused on idealized storage zone geometries studied in laboratory flumes. Using RANS simulations, this study first examines these idealized geometries to determine the appropriate scaling relationships between idealized dead zone geometries and the residence times of a passive scalar. These scaling relationships are then applied to measurements from natural systems. The field-measured geometries are located in Oak and Soap creeks near Corvallis, Oregon. Field measurements for the natural systems included: (a) survey measurements to delineate storage zone morphologies; (b) Marsh-McBirney and acoustic Doppler velocimetry measurements for model boundary conditions and computation of turbulence parameters; and (c) continuous salt injections within storage zones and electrical conductivity measurements at point locations in the main channel and storage zones to quantify exchange rates and residence times. This work is sponsored by NSF-EAR project #0943570.

  8. Qualia Could Arise from Information Processing in Local Cortical Networks

    PubMed Central

    Orpwood, Roger

    2013-01-01

    Re-entrant feedback, either within sensory cortex or arising from prefrontal areas, has been strongly linked to the emergence of consciousness, both in theoretical and experimental work. This idea, together with evidence for local micro-consciousness, suggests the generation of qualia could in some way result from local network activity under re-entrant activation. This paper explores the possibility by examining the processing of information by local cortical networks. It highlights the difference between the information structure (how the information is physically embodied), and the information message (what the information is about). It focuses on the network’s ability to recognize information structures amongst its inputs under conditions of extensive local feedback, and to then assign information messages to those structures. It is shown that if the re-entrant feedback enables the network to achieve an attractor state, then the message assigned in any given pass of information through the network is a representation of the message assigned in the previous pass-through of information. Based on this ability the paper argues that as information is repeatedly cycled through the network, the information message that is assigned evolves from a recognition of what the input structure is, to what it is like, to how it appears, to how it seems. It could enable individual networks to be the site of qualia generation. The paper goes on to show networks in cortical layers 2/3 and 5a have the connectivity required for the behavior proposed, and reviews some evidence for a link between such local cortical cyclic activity and conscious percepts. It concludes with some predictions based on the theory discussed. PMID:23504586

  9. Contribution of active and passive acoustics to study oceanographic processes feeding whales in a critical habitat of the St. Lawrence Estuary

    NASA Astrophysics Data System (ADS)

    Simard, Yvan; Roy, Nathalie; Simard, Yvan; Cotté, Cédric

    2001-05-01

    The head of the main channel of the continent in eastern Canada is the site of particular oceanographic processes that are responsible for the creation of a persistent feeding ground regularly visited by baleen whales from the Atlantic for centuries. Multifrequency acoustics coupled with ADCP and hydrographic measurements has been used to map the krill and capelin aggregations in 3D and visualize their local concentration process under tidal forcing and upwelling at the channel head. The krill scattering layers, pumped into the area by the strong two-layer estuarine circulation, appear to be concentrated during flood by tidal currents forced against the slopes and upwelling, to which depth-keeping krill is reacting by swimming down. Capelin also tends to concentrate on slopes and neighboring shallows. This highly recurrent process generates rich patches that are contributing with the mean circulation to make this area the richest krill aggregation in Northwest Atlantic. This critical habitat is located in a major continental seaway. Passive acoustics techniques are explored to locate whale calls and map the use of this area in continuing months, especially by blue and fin whales, with the aim of understanding their movements to improve their protection.

  10. Gaussian process regression for sensor networks under localization uncertainty

    USGS Publications Warehouse

    Jadaliha, M.; Xu, Yunfei; Choi, Jongeun; Johnson, N.S.; Li, Weiming

    2013-01-01

    In this paper, we formulate Gaussian process regression with observations under the localization uncertainty due to the resource-constrained sensor networks. In our formulation, effects of observations, measurement noise, localization uncertainty, and prior distributions are all correctly incorporated in the posterior predictive statistics. The analytically intractable posterior predictive statistics are proposed to be approximated by two techniques, viz., Monte Carlo sampling and Laplace's method. Such approximation techniques have been carefully tailored to our problems and their approximation error and complexity are analyzed. Simulation study demonstrates that the proposed approaches perform much better than approaches without considering the localization uncertainty properly. Finally, we have applied the proposed approaches on the experimentally collected real data from a dye concentration field over a section of a river and a temperature field of an outdoor swimming pool to provide proof of concept tests and evaluate the proposed schemes in real situations. In both simulation and experimental results, the proposed methods outperform the quick-and-dirty solutions often used in practice.

  11. Scalable Indoor Localization via Mobile Crowdsourcing and Gaussian Process

    PubMed Central

    Chang, Qiang; Li, Qun; Shi, Zesen; Chen, Wei; Wang, Weiping

    2016-01-01

    Indoor localization using Received Signal Strength Indication (RSSI) fingerprinting has been extensively studied for decades. The positioning accuracy is highly dependent on the density of the signal database. In areas without calibration data, however, this algorithm breaks down. Building and updating a dense signal database is labor intensive, expensive, and even impossible in some areas. Researchers are continually searching for better algorithms to create and update dense databases more efficiently. In this paper, we propose a scalable indoor positioning algorithm that works both in surveyed and unsurveyed areas. We first propose Minimum Inverse Distance (MID) algorithm to build a virtual database with uniformly distributed virtual Reference Points (RP). The area covered by the virtual RPs can be larger than the surveyed area. A Local Gaussian Process (LGP) is then applied to estimate the virtual RPs’ RSSI values based on the crowdsourced training data. Finally, we improve the Bayesian algorithm to estimate the user’s location using the virtual database. All the parameters are optimized by simulations, and the new algorithm is tested on real-case scenarios. The results show that the new algorithm improves the accuracy by 25.5% in the surveyed area, with an average positioning error below 2.2 m for 80% of the cases. Moreover, the proposed algorithm can localize the users in the neighboring unsurveyed area. PMID:26999139

  12. Scalable Indoor Localization via Mobile Crowdsourcing and Gaussian Process.

    PubMed

    Chang, Qiang; Li, Qun; Shi, Zesen; Chen, Wei; Wang, Weiping

    2016-01-01

    Indoor localization using Received Signal Strength Indication (RSSI) fingerprinting has been extensively studied for decades. The positioning accuracy is highly dependent on the density of the signal database. In areas without calibration data, however, this algorithm breaks down. Building and updating a dense signal database is labor intensive, expensive, and even impossible in some areas. Researchers are continually searching for better algorithms to create and update dense databases more efficiently. In this paper, we propose a scalable indoor positioning algorithm that works both in surveyed and unsurveyed areas. We first propose Minimum Inverse Distance (MID) algorithm to build a virtual database with uniformly distributed virtual Reference Points (RP). The area covered by the virtual RPs can be larger than the surveyed area. A Local Gaussian Process (LGP) is then applied to estimate the virtual RPs' RSSI values based on the crowdsourced training data. Finally, we improve the Bayesian algorithm to estimate the user's location using the virtual database. All the parameters are optimized by simulations, and the new algorithm is tested on real-case scenarios. The results show that the new algorithm improves the accuracy by 25.5% in the surveyed area, with an average positioning error below 2.2 m for 80% of the cases. Moreover, the proposed algorithm can localize the users in the neighboring unsurveyed area. PMID:26999139

  13. High-efficiency screen-printed silicon ribbon solar cells by effective defect passivation and rapid thermal processing

    NASA Astrophysics Data System (ADS)

    Rohatgi, Ajeet; Jeong, Ji-Weon

    2003-01-01

    A conversion efficiency of 15.9% has been achieved on low-cost edge-defined film-fed grown silicon ribbon solar cells. This represents an improvement over the previously reported efficiencies for silicon ribbon solar cells with manufacturable screen-printed contacts and single layer silicon nitride (SiNx) antireflection coating. Two separate rapid thermal processing cycles with fast ramp-up and cooling rates contributed to the enhancement in cell efficiency. The fast ramp-up rate improved the quality of back surface field and contacts; and a short firing time with a fast cooling rate improved contacts and the SiNx-induced hydrogen passivation of defects, resulting in bulk lifetime enhancement from ˜2 to ˜50 μs.

  14. Three-dimensional line interpretation via local processing

    NASA Astrophysics Data System (ADS)

    Pentland, Alexander P.; Kuo, Jeff

    1990-10-01

    The interpretation of line drawings is known to be very difficult, and has a long history in vision research. However for certain restricted but important types of drawings we have been able to produce good 3-D interpretations quite efficiently using only local image-plane computations. The types of drawings we can handle are line drawings of 3-D space curves, for instance, a drawing of the 3-D path followed by a butterfly or a line drawing of a potato chip. Such line drawings are, of course, intrinsically ambiguous - there is simply not enough information in the 2-D image to arrive at a unique 3-D interpretation. Despite this difficulty, there remains the fact that for any given image all people see pretty much exactly the same 3-D interpretation (or sometimes a small number of interpretations). People, therefore, must be bringing additional knowledge or assumptions to the problem. In this paper we show that by picking the smoothest 3-D space curve that is consistent with the image data we can obtain a 3-D interpretation which is very similar to the people's interpretation. The teleological motivation for selecting the smoothest 3-D space curve is that it is the most stable 3-D interpretation, and thus in one sense the most likely 3-D interpretation. The process of computing the smoothest 3-D space curve is carried out by simple, local processing that can be implemented by a neural network.

  15. Passive Localization of Mixed Far-Field and Near-Field Sources without Estimating the Number of Sources

    PubMed Central

    Xie, Jian; Tao, Haihong; Rao, Xuan; Su, Jia

    2015-01-01

    This paper presents a novel algorithm for the localization of mixed far-field sources (FFSs) and near-field sources (NFSs) without estimating the source number. Firstly, the algorithm decouples the direction-of-arrival (DOA) estimation from the range estimation by exploiting fourth-order spatial-temporal cumulants of the observed data. Based on the joint diagonalization structure of multiple spatial-temporal cumulant matrices, a new one-dimensional (1-D) spatial spectrum function is derived to generate the DOA estimates of both FFSs and NFSs. Then, the FFSs and NFSs are identified and the range parameters of NFSs are determined via beamforming technique. Compared with traditional mixed sources localization algorithms, the proposed algorithm avoids the performance deterioration induced by erroneous source number estimation. Furthermore, it has a higher resolution capability and improves the estimation accuracy. Computer simulations are implemented to verify the effectiveness of the proposed algorithm. PMID:25668212

  16. Substrate patterning for passive matrix organic light-emitting devices by photolithography processing

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Yu, Jun-sheng; Lin, Hui; Lou, Shuang-ling; Jiang, Ya-dong

    2007-12-01

    The fabrication technology of high resolution substrate pattern for organic light-emitting devices (OLEDs) was discussed in the paper. Surface morphology and crystallization properties of ITO films and the shape of photolithography pattern were investigated. Experimental results show that three factors including deposition pressure, flow ratio of argon to oxygen and annealing temperature greatly influence the conductance of ITO film.. Some attempts about designing photomask were enumerated and the reverse taper angle separator was successfully fabricated with image reversal process.

  17. Method of drying passivated micromachines by dewetting from a liquid-based process

    DOEpatents

    Houston, Michael R.; Howe, Roger T.; Maboudian, Roya; Srinivasan, Uthara

    2000-01-01

    A method of fabricating a micromachine includes the step of constructing a low surface energy film on the micromachine. The micromachine is then rinsed with a rinse liquid that has a high surface energy, relative to the low surface energy film, to produce a contact angle of greater than 90.degree. between the low surface energy film and the rinse liquid. This relatively large contact angle causes any rinse liquid on the micromachine to be displaced from the micromachine when the micromachine is removed from the rinse liquid. In other words, the micromachine is dried by dewetting from a liquid-based process. Thus, a separate evaporative drying step is not required, as the micromachine is removed from the liquid-based process in a dry state. The relatively large contact angle also operates to prevent attractive capillary forces between micromachine components, thereby preventing contact and adhesion between adjacent microstructure surfaces. The low surface energy film may be constructed with a fluorinated self-assembled monolayer film. The processing of the invention avoids the use of environmentally harmful, health-hazardous chemicals.

  18. On sequential observation processing in localized ensemble Kalman filters

    NASA Astrophysics Data System (ADS)

    Nerger, Lars

    2014-05-01

    The different variants of current ensemble square-root Kalman filters assimilate either all observations at once or perform a sequence in which batches of observations or each single observation is assimilated. The sequential observation processing is used in filter algorithms like the ensemble adjustment Kalman filter (EAKF) and the ensemble square-root filter (EnSRF) and can result in computationally efficient algorithms because matrix inversions in the observation space are reduced to the inversion of single numbers. For large scale applications, ensemble filter algorithms require typically the application of localization. The necessary modification of the algorithm leads to an inconsistency of the update equation for the state error covariance matrix as was noted by Whitaker and Hamill (Mon. Wea. Rev. 130 (2002) 1913). Often, this inconsistency does not lead to a significant impact on the assimilation performance. However, using a simple model, it is demonstrated with the EnSRF algorithm that the sequential observation processing can significantly deteriorate the assimilation performance under some circumstances. The deterioration can reach a level at which intermediate state realizations in the assimilation sequence over all observation can have a larger root-mean square error than the state estimate without assimilating any observations. This effect can be characterized to appear for small ensembles and a rather strong assimilation impact.

  19. Local permeability changes, passive degassing and related gas hazard at the Baia di Levante area (Vulcano island, Italy)

    NASA Astrophysics Data System (ADS)

    Diliberto, Iole Serena; Cangemi, Marianna; Gagliano, Antonina Lisa; Inguaggiato, Salvatore; Madonia, Paolo; Pedone, Maria; Fabio Pisciotta, Antonino

    2016-04-01

    Vulcano, the southernmost island of the Aeolian archipelago (Italy), is presently characterized by active fumarolic fields located along the rim of La Fossa cone and the shoreline of the Baia di Levante beach, in the northern portion of the island.The Baia di Levante fumarolic vents are fed by a shallow hydrothermal aquifer heated by magmatic gases rising from the deep down, with a spatial distribution strongly affected by the local fracture network. These fractures are the expression of a deformation field, dominated by a northward motion to Lipari, abruptly decaying to the Vulcanello peninsula, immediately northward of the Baia di Levante beach. Variable rates of fluid transfer to the surface, following permeability changes affecting the fracture network are among the results of stress field variations over time which induce fluctuations in the pressure state of the hydrothermal system. Under these conditions, increments in hydrothermal gas flow, able to cause an increase of gas hazard, could be determined by a rearrangement of the shallow permeability distribution induced by changes in the deformation field. In this case not associated to any variation in the volcanic activity state. Since 2009 an huge gas flow increment has been noticed in some undersea vents of the Baia di Levante area, leading to increase of gas hazard in their immediate surroundings. On the contrary, the acquired data from the INGV volcanic surveillance program didn't suggest any correlated increase of the magmatic fluid component in the degassing activity.In July 2015, we carried out multi-parametric geochemical surveys in this area, based on direct (thermocouple) and indirect (thermal infrared camera and pyrometer) soil temperature, soil CO2 flux, atmospheric concentration of CO2 and H2S measurements at low elevation (one meter a.s.l.). The chemical and isotopic composition of low temperature fumarole gases was determined too.The comparison of the new data with previous surveys carried out

  20. Do you want to see the tree? Ignore the forest: inhibitory control during local processing: a negative priming study of local-global processing.

    PubMed

    Poirel, Nicolas; Krakowski, Claire Sara; Sayah, Sabrina; Pineau, Arlette; Houdé, Olivier; Borst, Grégoire

    2014-01-01

    The visual environment consists of global structures (e.g., a forest) made up of local parts (e.g., trees). When compound stimuli are presented (e.g., large global letters composed of arrangements of small local letters), the global unattended information slows responses to local targets. Using a negative priming paradigm, we investigated whether inhibition is required to process hierarchical stimuli when information at the local level is in conflict with the one at the global level. The results show that when local and global information is in conflict, global information must be inhibited to process local information, but that the reverse is not true. This finding has potential direct implications for brain models of visual recognition, by suggesting that when local information is conflicting with global information, inhibitory control reduces feedback activity from global information (e.g., inhibits the forest) which allows the visual system to process local information (e.g., to focus attention on a particular tree).

  1. Rise of dinosaurs reveals major body-size transitions are driven by passive processes of trait evolution.

    PubMed

    Sookias, Roland B; Butler, Richard J; Benson, Roger B J

    2012-06-01

    A major macroevolutionary question concerns how long-term patterns of body-size evolution are underpinned by smaller scale processes along lineages. One outstanding long-term transition is the replacement of basal therapsids (stem-group mammals) by archosauromorphs, including dinosaurs, as the dominant large-bodied terrestrial fauna during the Triassic (approx. 252-201 million years ago). This landmark event preceded more than 150 million years of archosauromorph dominance. We analyse a new body-size dataset of more than 400 therapsid and archosauromorph species spanning the Late Permian-Middle Jurassic. Maximum-likelihood analyses indicate that Cope's rule (an active within-lineage trend of body-size increase) is extremely rare, despite conspicuous patterns of body-size turnover, and contrary to proposals that Cope's rule is central to vertebrate evolution. Instead, passive processes predominate in taxonomically and ecomorphologically more inclusive clades, with stasis common in less inclusive clades. Body-size limits are clade-dependent, suggesting intrinsic, biological factors are more important than the external environment. This clade-dependence is exemplified by maximum size of Middle-early Late Triassic archosauromorph predators exceeding that of contemporary herbivores, breaking a widely-accepted 'rule' that herbivore maximum size greatly exceeds carnivore maximum size. Archosauromorph and dinosaur dominance occurred via opportunistic replacement of therapsids following extinction, but were facilitated by higher archosauromorph growth rates.

  2. Toxicological evaluation of some Malaysian locally processed raw food products.

    PubMed

    Sharif, R; Ghazali, A R; Rajab, N F; Haron, H; Osman, F

    2008-01-01

    Malaysian locally processed raw food products are widely used as main ingredients in local cooking. Previous studies showed that these food products have a positive correlation with the incidence of cancer. The cytotoxicity effect was evaluated using MTT assay (3-(4,5-dimetil-2-thiazolil)-2,5-diphenyl-2H-tetrazolium bromide) against Chang liver cells at 2000 microg/ml following 72 h incubation. Findings showed all methanol extracts caused a tremendous drop in the percentage of cell viability at 2000 microg/ml (shrimp paste - 41.69+/-3.36%, salted fish - 37.2+/-1.06%, dried shrimp - 40.32+/-1.8%, p<0.05). To detect DNA damage in a single cell, alkaline Comet Assay was used. None of the extracts caused DNA damage to the Chang liver cells at 62.5 microg/ml following 24 h incubation, as compared to the positive control, hydrogen peroxide (tail moment - 9.50+/-1.50; tail intensity - 30.50+/-2.50). Proximate analysis which was used for the evaluation of macronutrients in food showed that shrimp paste did not comply with the protein requirement (<25%) as in Food Act 1983. Salt was found in every sample with the highest percentage being detected in shrimp paste which exceeded 20%. Following heavy metal analysis (arsenic, cadmium, lead and mercury), arsenic was found in every sample with dried shrimps showing the highest value as compared to the other samples (6.16 mg/kg). In conclusion, several food extracts showed cytotoxic effect but did not cause DNA damage against Chang liver cells. Salt was found as the main additive and arsenic was present in every sample, which could be the probable cause of the toxicity effects observed.

  3. Influence of Second Language Proficiency and Syntactic Structure Similarities on the Sensitivity and Processing of English Passive Sentence in Late Chinese-English Bilinguists: An ERP Study

    ERIC Educational Resources Information Center

    Chang, Xin; Wang, Pei

    2016-01-01

    To investigate the influence of L2 proficiency and syntactic similarity on English passive sentence processing, the present ERP study asked 40 late Chinese-English bilinguals (27 females and 13 males, mean age = 23.88) with high or intermediate L2 proficiency to read the sentences carefully and to indicate for each sentence whether or not it was…

  4. Linking margin morphology to sedimentary processes along the US East Coast passive continental margin

    NASA Astrophysics Data System (ADS)

    Brothers, D. S.; ten Brink, U. S.; Andrews, B.; Twichell, D.

    2010-12-01

    The morphology of the US East Coast continental slope and rise has a surprising amount of along-margin variation. Multibeam bathymetry datasets that cover the slope and rise from Cape Hatteras to Georges Bank provide a unique opportunity to analyze both first-order and higher-order morphologies, including submarine canyons, landslides, slumps and sedimentary bedforms. Using the morphological characterization coupled with seismic and core data, we hope to better understand how ancient and modern sedimentary processes control the shape of the margin. As a first step, the margin bathymetry was subdivided into 20 shelf-perpendicular regions from which several statistical parameters were analyzed. Within each region, the slope gradient was computed separately for down-slope and across-slope aspect directions. Distribution curves in each region for down- and across-slope gradients and seafloor roughness as functions of depth were grouped according to their statistical similarities. Four basic groups emerge and each approximately corresponds to known regions of Quaternary glacial, fluvial, current-controlled and gravity-driven sedimentary transport. In the second part of the study, published lithologic and chronostratigraphic frameworks of this margin were used to examine the relationship between seafloor morphology and the underlying geology. Along the upper continental rise, thick Quaternary deposits appear to have a strong influence on the short- and long-wavelength variation in rise topography, revealing a complex interplay between down-slope and along-slope sediment transport. Despite the close correlation between continental slope morphology and Quaternary environmental conditions, initial results suggest that the underlying, older, stratigraphy also plays a primary role. Along the continental slope, Quaternary processes appear to control the relief of slope-confined canyons and other short-wavelength (<5 km) topography, but the first order morphology of the slope

  5. Investigation of radio astronomy image processing techniques for use in the passive millimetre-wave security screening environment

    NASA Astrophysics Data System (ADS)

    Taylor, Christopher T.; Hutchinson, Simon; Salmon, Neil A.; Wilkinson, Peter N.; Cameron, Colin D.

    2014-06-01

    Image processing techniques can be used to improve the cost-effectiveness of future interferometric Passive MilliMetre Wave (PMMW) imagers. The implementation of such techniques will allow for a reduction in the number of collecting elements whilst ensuring adequate image fidelity is maintained. Various techniques have been developed by the radio astronomy community to enhance the imaging capability of sparse interferometric arrays. The most prominent are Multi- Frequency Synthesis (MFS) and non-linear deconvolution algorithms, such as the Maximum Entropy Method (MEM) and variations of the CLEAN algorithm. This investigation focuses on the implementation of these methods in the defacto standard for radio astronomy image processing, the Common Astronomy Software Applications (CASA) package, building upon the discussion presented in Taylor et al., SPIE 8362-0F. We describe the image conversion process into a CASA suitable format, followed by a series of simulations that exploit the highlighted deconvolution and MFS algorithms assuming far-field imagery. The primary target application used for this investigation is an outdoor security scanner for soft-sided Heavy Goods Vehicles. A quantitative analysis of the effectiveness of the aforementioned image processing techniques is presented, with thoughts on the potential cost-savings such an approach could yield. Consideration is also given to how the implementation of these techniques in CASA might be adapted to operate in a near-field target environment. This may enable a much wider usability by the imaging community outside of radio astronomy and thus would be directly relevant to portal screening security systems in the microwave and millimetre wave bands.

  6. Effect of passivation layer grown by atomic layer deposition and sputtering processes on Si quantum dot superlattice to generate high photocurrent for high-efficiency solar cells

    NASA Astrophysics Data System (ADS)

    Maksudur Rahman, Mohammad; Higo, Akio; Sekhar, Halubai; Erman Syazwan, Mohd; Hoshi, Yusuke; Usami, Noritaka; Samukawa, Seiji

    2016-03-01

    The effect of passivation films on a Si quantum dot superlattice (QDSL) was investigated to generate high photocurrent in solar-cell applications. Three types of passivation films, sputter-grown amorphous silicon carbide (a-SiC), hydrogenated a-SiC (a-SiC:H), and atomic-layer-deposited aluminum oxide (ALD-Al2O3), were used to passivate the Si QDSLs containing a stack of four 4 nm Si nanodisks (NDs) and 2 nm silicon carbide (SiC) films fabricated by neutral beam etching (NBE). Because of the high surface-to-volume ratio typically present in quantum Si-NDs formed in the top-down NBE process, there is a tendency to form larger surface dangling bonds on untreated Si-ND surfaces as well as to have short distance (<10 nm) between high-aspect-ratio nanopillars of stacked 4 nm Si-NDs/2 nm SiC films, which conventionally sputter SiC films cannot uniformly cover. Therefore, we optimized the passivation techniques with an ALD-Al2O3 film. Scanning electron microscopy (SEM) analysis helped to explain the surface morphology before and after the passivation of the QDSLs. After the completion of the passivation process, the quality of the top surface films of the QDSLs was analyzed from the surface roughness by atomic force microscopy (AFM) analysis, which revealed that ALD-Al2O3 passivated films had the smallest roughness (RMS) of 1.09 nm with respect to sputter-grown a-SiC (RMS: 1.75 nm) and a-SiC:H (RMS: 1.54 nm) films. Conductive atomic force microscopy (CAFM) revealed that ALD-Al2O3 passivation decreased the surface-leakage current as a result of proper passivation of side-wall surface defects in the QDSLs. The carrier transport characteristics were extracted from the QDSLs using the photovoltaic (PV) properties of p++/i/n+ solar cells, where the QDSLs consisted of different passivation layers acting as intermediate layers (i-layers) between the high-doping-density p++ Si (1 × 1020 cm-3) and n+ Si (1 × 1019 cm-3) substrates. High-doping-density p++ Si acted as a hole

  7. Fundamental studies of passivity and passivity breakdown. Final report, [September 1993--September 1994

    SciTech Connect

    Macdonald, D.D.; Urquidi-Macdonald, M.

    1994-02-21

    Purpose is to understand the mechanisms for growth and breakdown of passive films on metal and alloy surfaces in aqueous medium; a secondary goal is to devise methods for predicting localized corrosion damage in industrial systems. Tasks currently being studied are: formation of bilayer structures in passive films on metals and alloys; passivity breakdown on solid vs. liquid gallium; roles of alloying elements in passivity breakdown; electrochemical impedance spectroscopy of passive films; electronic structure of passive oxide films; photoelectrochemical impedance spectroscopy of passive films; and kinetics of localized attack.

  8. A novel local anti-colorectal cancer drug delivery system: negative lipidoid nanoparticles with a passive target via a size-dependent pattern

    NASA Astrophysics Data System (ADS)

    Ding, Weifeng; Wang, Feng; Zhang, Jianfeng; Guo, Yibing; Ju, Shaoqing; Wang, Huimin

    2013-09-01

    The nontoxic, targeted and effective delivery of nucleic acid drugs remains an important challenge for clinical development. Here, we describe a novel negative lipidoid nanoparticle delivery system, providing entrapment-based transfection agents for local delivery of siRNA to the colorectal cancer focus. The delivery system was synthesized with lipidoid material 98N12-5(1), mPEG2000-C12/C14 glyceride and cholesterol at a desired molar ratio to realize the anionic surface charge of particles, which could alleviate to a larger degree the inflammatory response and immune stimulation of the organism, embodying dramatic biocompatibility. In particular, mPEG2000-C12/C14 glyceride was selected to ameliorate the stability of the delivery system and protection of nucleic acids by extending the tail length of the carbons, crucial also to neutralize the positive charge of 98N12-5(1) to form a resultant anionic particle. In vivo experiments revealed that a particle size of 90 nm perfectly realized a passive target in a size-dependent manner and did not affect the function of the liver and kidneys by a local delivery method, enema. We clarified that the uptake of negative lipidoid nanoparticles internalized through a lipid raft endocytotic pathway with low cytotoxicity, strong biocompatibility and high efficacy. This study suggests that negative lipidoid nanoparticles with enema delivery costitute, uniquely and appropriately, a local anti-colorectal cancer nucleic acid drug delivery platform, and the application of similar modes may be feasible in other therapeutic settings.

  9. County Scale Distribution of Amblyomma americanum (Ixodida: Ixodidae) in Oklahoma: Addressing Local Deficits in Tick Maps Based on Passive Reporting.

    PubMed

    Barrett, Anne W; Noden, Bruce H; Gruntmeir, Jeff M; Holland, Taylor; Mitcham, Jessica R; Martin, Jaclyn E; Johnson, Eileen M; Little, Susan E

    2015-03-01

    Geographic distribution records for the lone star tick [Amblyomma americanum (L.)] in the peer-reviewed literature are incomplete for Oklahoma, preventing accurate disease risk assessments. To address this issue and document the presence of A. americanum in available habitats throughout the state, county-scale tick records published in U.S. Department of Agriculture-Cooperative Economic Insect Reports and specimens maintained at the K.C. Emerson Entomology Museum, Oklahoma State University, were reviewed. In addition, dry ice traps and tick drags were used to collect adult and nymphal A. americanum from throughout the state. Review of published USDA reports and the local museum collection documented A. americanum in 49 total counties (35 and 35, respectively). Active surveillance efforts confirmed the presence of this tick in 50 counties from which this species had not been previously reported to be established, documenting A. americanum is established in 68 of the 77 (88.3%) counties in Oklahoma. Taken together, these data verify that A. americanum ticks are much more widespread in Oklahoma than reflected in the literature, a phenomenon likely repeated throughout the geographic range of this tick in the eastern half of North America. PMID:26336311

  10. The factor of local cultural specificity and process of globalization.

    PubMed

    Rudnev, Viacheslav

    2012-12-01

    is important today. Actually, Glocalization can assist in adaptation process of harmonizing local and global needs to a way of Sustainability. Glocalization puts globalization problems down to the human scale. The age of Globalization has made the problem of cultural dialog extra actual, otherwise the Mankind has no chance to survive. The Glocalization is the process of creation of a harmony in Nature, Society and Humans system in the context of Sustainability.

  11. Deep Reactive Ion Etching (DRIE) of High Aspect Ratio SiC Microstructures using a Time-Multiplexed Etch-Passivate Process

    NASA Technical Reports Server (NTRS)

    Evans, Laura J.; Beheim, Glenn M.

    2006-01-01

    High aspect ratio silicon carbide (SiC) microstructures are needed for microengines and other harsh environment micro-electro-mechanical systems (MEMS). Previously, deep reactive ion etching (DRIE) of low aspect ratio (AR less than or = 1) deep (greater than 100 micron) trenches in SiC has been reported. However, existing DRIE processes for SiC are not well-suited for definition of high aspect ratio features because such simple etch-only processes provide insufficient control over sidewall roughness and slope. Therefore, we have investigated the use of a time-multiplexed etch-passivate (TMEP) process, which alternates etching with polymer passivation of the etch sidewalls. An optimized TMEP process was used to etch high aspect ratio (AR greater than 5) deep (less than 100 micron) trenches in 6H-SiC. Power MEMS structures (micro turbine blades) in 6H-SiC were also fabricated.

  12. Antarctic snow and sea ice processes: Effects on passive microwave emissions and AMSR-E sea ice products

    NASA Astrophysics Data System (ADS)

    Lewis, Michael John, Jr.

    In this research, passive microwave remote sensing products generated for the Antarctic sea ice zone from the Advance Microwave Scanning Radiometer-Earth Observing System (AMSR-E) sensor were compared with various in situ field measurements, both from previous Antarctic campaigns in the published literature and as obtained during the Sea Ice Mass Balance in the Antarctic (SIMBA) project during the International Polar Year (IPY) 2007--2008. Data gathered during the SIMBA project was used to understand the geophysical processes occurring in the sea ice and snow cover of the Bellingshausen Sea and to provide a physical basis for modeling of microwave emissions. In Chapter 2, the AMSR-E sea ice temperature product was compared with AMSR-E snow depth product and previous in situ field measurements. The comparisons were not intended to provide a strict validation of remote sensing products, but to evaluate the physical context of the remotely sensed data and examine potential trends. From examination of the data, it was found that the AMSR-E sea ice temperature product conflicted with several generally observed sea ice properties. The apparent contradictory behavior of the satellite data product is indicative of radiative temperature behavior related to changes in emissivity within the ice pack. Further comparisons of the AMSR-E sea ice temperature product with in situ temperature data from Ice Mass-balance Buoys (IMB) from two Antarctic field programs showed no correlation. However, apparent response of sea ice temperature product to snow/ice interface flooding events was noted. In Chapter 3, an important sea ice process related to the formation of "gap layers" within Antarctic sea ice was examined and modeled. Gap layers are horizontal voids that develop internally within the sea ice structure, often filled with decaying sea ice, saline slush, and a microbial biological community that thrives on the available nutrients. Gap layers are commonly observed in summer melt

  13. Local Risk-Minimization for Defaultable Claims with Recovery Process

    SciTech Connect

    Biagini, Francesca; Cretarola, Alessandra

    2012-06-15

    We study the local risk-minimization approach for defaultable claims with random recovery at default time, seen as payment streams on the random interval [0,{tau} Logical-And T], where T denotes the fixed time-horizon. We find the pseudo-locally risk-minimizing strategy in the case when the agent information takes into account the possibility of a default event (local risk-minimization with G-strategies) and we provide an application in the case of a corporate bond. We also discuss the problem of finding a pseudo-locally risk-minimizing strategy if we suppose the agent obtains her information only by observing the non-defaultable assets.

  14. Realistic Modeling of Local Dynamo Processes on the Sun

    NASA Astrophysics Data System (ADS)

    Kitiashvili, I. N.; Kosovichev, A. G.; Mansour, N. N.; Wray, A. A.

    2015-08-01

    Magnetic fields are usually observed in the quiet Sun as small-scale elements that cover the entire solar surface (the “salt-and-pepper” patterns in line-of-sight magnetograms). By using 3D radiative MHD numerical simulations, we find that these fields result from a local dynamo action in the top layers of the convection zone, where extremely weak “seed” magnetic fields (e.g., from a 10‑6 G) can locally grow above the mean equipartition field to a stronger than 2000 G field localized in magnetic structures. Our results reveal that the magnetic flux is predominantly generated in regions of small-scale helical downflows. We find that the local dynamo action takes place mostly in a shallow, about 500 km deep, subsurface layer, from which the generated field is transported into the deeper layers by convective downdrafts. We demonstrate that the observed dominance of vertical magnetic fields at the photosphere and horizontal fields above the photosphere can be explained by small-scale magnetic loops produced by the dynamo. Such small-scale loops play an important role in the structure and dynamics of the solar atmosphere and their detection in observations is critical for understanding the local dynamo action on the Sun.

  15. Realistic Modeling of Local Dynamo Processes on the Sun

    NASA Astrophysics Data System (ADS)

    Kitiashvili, I. N.; Kosovichev, A. G.; Mansour, N. N.; Wray, A. A.

    2015-08-01

    Magnetic fields are usually observed in the quiet Sun as small-scale elements that cover the entire solar surface (the “salt-and-pepper” patterns in line-of-sight magnetograms). By using 3D radiative MHD numerical simulations, we find that these fields result from a local dynamo action in the top layers of the convection zone, where extremely weak “seed” magnetic fields (e.g., from a 10-6 G) can locally grow above the mean equipartition field to a stronger than 2000 G field localized in magnetic structures. Our results reveal that the magnetic flux is predominantly generated in regions of small-scale helical downflows. We find that the local dynamo action takes place mostly in a shallow, about 500 km deep, subsurface layer, from which the generated field is transported into the deeper layers by convective downdrafts. We demonstrate that the observed dominance of vertical magnetic fields at the photosphere and horizontal fields above the photosphere can be explained by small-scale magnetic loops produced by the dynamo. Such small-scale loops play an important role in the structure and dynamics of the solar atmosphere and their detection in observations is critical for understanding the local dynamo action on the Sun.

  16. REALISTIC MODELING OF LOCAL DYNAMO PROCESSES ON THE SUN

    SciTech Connect

    Kitiashvili, I. N.; Mansour, N. N.; Wray, A. A.; Kosovichev, A. G.

    2015-08-10

    Magnetic fields are usually observed in the quiet Sun as small-scale elements that cover the entire solar surface (the “salt-and-pepper” patterns in line-of-sight magnetograms). By using 3D radiative MHD numerical simulations, we find that these fields result from a local dynamo action in the top layers of the convection zone, where extremely weak “seed” magnetic fields (e.g., from a 10{sup −6} G) can locally grow above the mean equipartition field to a stronger than 2000 G field localized in magnetic structures. Our results reveal that the magnetic flux is predominantly generated in regions of small-scale helical downflows. We find that the local dynamo action takes place mostly in a shallow, about 500 km deep, subsurface layer, from which the generated field is transported into the deeper layers by convective downdrafts. We demonstrate that the observed dominance of vertical magnetic fields at the photosphere and horizontal fields above the photosphere can be explained by small-scale magnetic loops produced by the dynamo. Such small-scale loops play an important role in the structure and dynamics of the solar atmosphere and their detection in observations is critical for understanding the local dynamo action on the Sun.

  17. Passive-solar homes for Texas

    NASA Astrophysics Data System (ADS)

    Garrison, M. L.

    1982-06-01

    Acceptance of passive solar technologies has been slow within the conventional building trades in Texas because it is a common misconception that solar is expensive, and data on local applications is severely limited or nonexistent. It is the purpose of this solar development to move passive solar design into the mainstream of public acceptance by helping to overcome and eliminate these barriers. Specifically, the goal is to develop a set of regional climatic building standards to help guide the conventional building trade toward the utilization of soft energy systems which will reduce overall consumption at a price and convenience most Texans can afford. To meet this objective, eight sample passive design structures are presented. These designs represent state of the art regional applications of passive solar space conditioning. The methodology used in the passive solar design process included: analysis of regional climatic data; analysis of historical regional building prototypes; determination of regional climatic design priorities and assets; prototypical design models for the discretionary housing market; quantitative thermal analysis of prototypical designs; and construction drawings of building prototypes.

  18. Experimental investigations of thermal-hydraulic processes arising during operation of the passive safety systems used in new projects of nuclear power plants equipped with VVER reactors

    NASA Astrophysics Data System (ADS)

    Morozov, A. V.; Remizov, O. V.; Kalyakin, D. S.

    2014-05-01

    The results obtained from experimental investigations into thermal-hydraulic processes that take place during operation of the passive safety systems used in new-generation reactor plants constructed on the basis of VVER technology are presented. The experiments were carried out on the model rigs available at the Leipunskii Institute for Physics and Power Engineering. The processes through which interaction occurs between the opposite flows of saturated steam and cold water moving in the vertical steam line of the additional system for passively flooding the core from the second-stage hydro accumulators are studied. The specific features pertinent to undeveloped boiling of liquid on a single horizontal tube heated by steam and steam-gas mixture that is typical for of the condensing operating mode of a VVER reactor steam generator are investigated.

  19. Local and Global Processing: Observations from a Remote Culture

    ERIC Educational Resources Information Center

    Davidoff, Jules; Fonteneau, Elisabeth; Fagot, Joel

    2008-01-01

    In Experiment 1, a normal adult population drawn from a remote culture (Himba) in northern Namibia made similarity matches to [Navon, D. (1977). Forest before trees: The precedence of global features in visual perception. "Cognitive Psychology", 9, 353-383] hierarchical figures. The Himba showed a local bias stronger than that has been previously…

  20. Applying Psychology in Local Authority Emergency Planning Processes

    ERIC Educational Resources Information Center

    Posada, Susan E.

    2006-01-01

    This article describes the work of two EPs involved in a multi-agency project to produce Local Authority (LA) guidelines on psycho/social support following critical incidents and disasters. EPs were involved as participant observers during a simulation of setting up and running a LA reception centre for evacuees. A questionnaire was then…

  1. Challenges of Engaging Local Stakeholders for Statewide Program Development Process

    ERIC Educational Resources Information Center

    Martin, Michael J.; Leuci, Mary; Stewart, Mark

    2014-01-01

    The University of Missouri Extension needed to develop an annual program review process that collaboratively engaged county-level stakeholders. The results from the first 2 years highlight the results, challenges, and implications of the design process. The annual review process needs to be adaptive, responsive, and reflective from year to year…

  2. The rhetoric and realities of integrating air quality into the local transport planning process in English local authorities.

    PubMed

    Olowoporoku, Dotun; Hayes, Enda; Longhurst, James; Parkhurst, Graham

    2012-06-30

    Regardless of its intent and purposes, the first decade of the Local Air Quality Management (LAQM) framework had little or no effect in reducing traffic-related air pollution in the UK. Apart from the impact of increased traffic volumes, the major factor attributed to this failure is that of policy disconnect between the process of diagnosing air pollution and its management, thereby limiting the capability of local authorities to control traffic-related sources of air pollution. Integrating air quality management into the Local Transport Plan (LTP) process therefore presents opportunities for enabling political will, funding and joined-up policy approach to reduce this limitation. However, despite the increased access to resources for air quality measures within the LTP process, there are local institutional, political and funding constraints which reduce the impact of these policy interventions on air quality management. This paper illustrate the policy implementation gaps between central government policy intentions and the local government process by providing evidence of the deprioritisation of air quality management compared to the other shared priorities in the LTP process. We draw conclusions on the policy and practice of integrating air quality management into transport planning. The evidence thereby indicate the need for a policy shift from a solely localised hotspot management approach, in which the LAQM framework operates, to a more holistic management of vehicular emissions within wider spatial administrative areas.

  3. Local and global visual processing and eating disorder traits: An event-related potential study.

    PubMed

    Moynihan, Jennifer; Rose, Mark; van Velzen, Jose; de Fockert, Jan

    2016-03-01

    Recent studies have suggested that individuals with eating disorders show a stronger local processing bias and/or a weaker global bias in visual processing than typical individuals. In this study, healthy participants with varying scores on the Eating Disorder Examination Questionnaire (EDE-Q) performed the Navon task, a standard task of local and global visual processing, whilst electrophysiological measures were recorded. Global stimuli were presented that were made up of many local parts, and the information between levels was either compatible or incompatible. Participants were instructed to report the identity of either a global or a local target shape, while ignoring the other level. Higher EDE-Q scores were associated with enhanced amplitude of the P3 component during local visual processing, as well as greater P1 amplitude during local incompatible trials. These findings support the claim that eating disorders are associated with differences in local and global visual processing.

  4. Local and global visual processing and eating disorder traits: An event-related potential study.

    PubMed

    Moynihan, Jennifer; Rose, Mark; van Velzen, Jose; de Fockert, Jan

    2016-03-01

    Recent studies have suggested that individuals with eating disorders show a stronger local processing bias and/or a weaker global bias in visual processing than typical individuals. In this study, healthy participants with varying scores on the Eating Disorder Examination Questionnaire (EDE-Q) performed the Navon task, a standard task of local and global visual processing, whilst electrophysiological measures were recorded. Global stimuli were presented that were made up of many local parts, and the information between levels was either compatible or incompatible. Participants were instructed to report the identity of either a global or a local target shape, while ignoring the other level. Higher EDE-Q scores were associated with enhanced amplitude of the P3 component during local visual processing, as well as greater P1 amplitude during local incompatible trials. These findings support the claim that eating disorders are associated with differences in local and global visual processing. PMID:26777337

  5. Investigation of the surface passivation mechanism through an Ag-doped Al-rich film using a solution process.

    PubMed

    Khan, Firoz; Baek, Seong-Ho; Kim, Jae Hyun

    2016-01-14

    Electronic recombination loss is an important issue for photovoltaic (PV) devices. While it can be reduced by using a passivating layer, most of the techniques used to prepare passivating layers are either not cost effective or not applicable for device applications. Previously, it was reported that a low cost sol-gel derived Al-rich zinc oxide (ZnO:Al) film serves as an effective passivating layer for p-type silicon but is not effective for n-type silicon. Herein, we studied the elemental composition of the film and the interfacial structure of ZnO:Al:Ag/n-Si using TEM, XPS, FTIR, and SIMS analyses. The XPS analysis revealed that Ag-rich zones randomly formed in the film near the ZnO:Al:Ag//n-Si interface, which induced a positive charge at the interface. The maximal value of the effective minority carrier lifetime (τeff ≈ 1581 μs) is obtained for a wafer using the ZnO:Al:Ag passivating layer with RAg/Zn = 2%. The corresponding limiting surface recombination velocity is ∼16 cm s(-1). The FTIR absorption area of Si-H bonds is used to calculate the hydrogen content in the film. The hydrogen content is increased with increasing Ag content up to RAg/Zn = 2% to a maximal value of 3.89 × 10(22) atoms per cm(3) from 3.03 × 10(22) atoms per cm(3) for RAg/Zn = 0%. The positive charge induced at the interface may cause band bending, which would produce an electric field that repels the minority charge carriers from the interface to the bulk of n-Si. Two basic phenomena, chemical passivation due to Si-H bonding and field effect passivation due to the charge induced at the interface, have been observed for effective passivation of the n-Si surface. An implied Voc of 688.1 mV is obtained at an illumination intensity of 1 sun. PMID:26661502

  6. Local pattern classification differentiates processes of economic valuation.

    PubMed

    Clithero, John A; Carter, R McKell; Huettel, Scott A

    2009-05-01

    For effective decision making, individuals must be able to form subjective values from many types of information. Yet, the neural mechanisms that underlie potential differences in value computation across different decision scenarios are incompletely understood. Here, we used functional magnetic resonance imaging (fMRI), in conjunction with the machine learning technique of support vector machines (SVM), to identify brain regions that contain unique local information associated with different types of valuation. We used a combinatoric approach that evaluated the unique contributions of different brain regions to model generalization strength. Local voxel patterns in left posterior parietal cortex contained unique information differentiating probabilistic and intertemporal valuation, a result that was not accessible using standard fMRI analyses. We conclude that the early valuation phases for these reward types differ on a fine spatial scale, suggesting the existence of computational topographies along the value construction pathway.

  7. Investigation of the surface passivation mechanism through an Ag-doped Al-rich film using a solution process

    NASA Astrophysics Data System (ADS)

    Khan, Firoz; Baek, Seong-Ho; Kim, Jae Hyun

    2015-12-01

    Electronic recombination loss is an important issue for photovoltaic (PV) devices. While it can be reduced by using a passivating layer, most of the techniques used to prepare passivating layers are either not cost effective or not applicable for device applications. Previously, it was reported that a low cost sol-gel derived Al-rich zinc oxide (ZnO:Al) film serves as an effective passivating layer for p-type silicon but is not effective for n-type silicon. Herein, we studied the elemental composition of the film and the interfacial structure of ZnO:Al:Ag/n-Si using TEM, XPS, FTIR, and SIMS analyses. The XPS analysis revealed that Ag-rich zones randomly formed in the film near the ZnO:Al:Ag//n-Si interface, which induced a positive charge at the interface. The maximal value of the effective minority carrier lifetime (τeff ~ 1581 μs) is obtained for a wafer using the ZnO:Al:Ag passivating layer with RAg/Zn = 2%. The corresponding limiting surface recombination velocity is ~16 cm s-1. The FTIR absorption area of Si-H bonds is used to calculate the hydrogen content in the film. The hydrogen content is increased with increasing Ag content up to RAg/Zn = 2% to a maximal value of 3.89 × 1022 atoms per cm3 from 3.03 × 1022 atoms per cm3 for RAg/Zn = 0%. The positive charge induced at the interface may cause band bending, which would produce an electric field that repels the minority charge carriers from the interface to the bulk of n-Si. Two basic phenomena, chemical passivation due to Si-H bonding and field effect passivation due to the charge induced at the interface, have been observed for effective passivation of the n-Si surface. An implied Voc of 688.1 mV is obtained at an illumination intensity of 1 sun.Electronic recombination loss is an important issue for photovoltaic (PV) devices. While it can be reduced by using a passivating layer, most of the techniques used to prepare passivating layers are either not cost effective or not applicable for device

  8. Fast contactless vibrating structure characterization using real time field programmable gate array-based digital signal processing: demonstrations with a passive wireless acoustic delay line probe and vision.

    PubMed

    Goavec-Mérou, G; Chrétien, N; Friedt, J-M; Sandoz, P; Martin, G; Lenczner, M; Ballandras, S

    2014-01-01

    Vibrating mechanical structure characterization is demonstrated using contactless techniques best suited for mobile and rotating equipments. Fast measurement rates are achieved using Field Programmable Gate Array (FPGA) devices as real-time digital signal processors. Two kinds of algorithms are implemented on FPGA and experimentally validated in the case of the vibrating tuning fork. A first application concerns in-plane displacement detection by vision with sampling rates above 10 kHz, thus reaching frequency ranges above the audio range. A second demonstration concerns pulsed-RADAR cooperative target phase detection and is applied to radiofrequency acoustic transducers used as passive wireless strain gauges. In this case, the 250 ksamples/s refresh rate achieved is only limited by the acoustic sensor design but not by the detection bandwidth. These realizations illustrate the efficiency, interest, and potentialities of FPGA-based real-time digital signal processing for the contactless interrogation of passive embedded probes with high refresh rates. PMID:24517814

  9. Fast contactless vibrating structure characterization using real time field programmable gate array-based digital signal processing: Demonstrations with a passive wireless acoustic delay line probe and vision

    NASA Astrophysics Data System (ADS)

    Goavec-Mérou, G.; Chrétien, N.; Friedt, J.-M.; Sandoz, P.; Martin, G.; Lenczner, M.; Ballandras, S.

    2014-01-01

    Vibrating mechanical structure characterization is demonstrated using contactless techniques best suited for mobile and rotating equipments. Fast measurement rates are achieved using Field Programmable Gate Array (FPGA) devices as real-time digital signal processors. Two kinds of algorithms are implemented on FPGA and experimentally validated in the case of the vibrating tuning fork. A first application concerns in-plane displacement detection by vision with sampling rates above 10 kHz, thus reaching frequency ranges above the audio range. A second demonstration concerns pulsed-RADAR cooperative target phase detection and is applied to radiofrequency acoustic transducers used as passive wireless strain gauges. In this case, the 250 ksamples/s refresh rate achieved is only limited by the acoustic sensor design but not by the detection bandwidth. These realizations illustrate the efficiency, interest, and potentialities of FPGA-based real-time digital signal processing for the contactless interrogation of passive embedded probes with high refresh rates.

  10. Passive Accelerometer

    NASA Technical Reports Server (NTRS)

    Naumann, Robert J.; Baugher, Charles; Alexander, Iwan

    1992-01-01

    Motion of ball in liquid indicates acceleration. Passive accelerometer measures small accelerations along cylindrical axis. Principle of operation based on Stokes' law. Provides accurate measurements of small quasi-steady accelerations. Additional advantage, automatically integrates out unwanted higher-frequency components of acceleration.

  11. Tunneling Processes into Localized Subgap States in Superconductors.

    PubMed

    Ruby, Michael; Pientka, Falko; Peng, Yang; von Oppen, Felix; Heinrich, Benjamin W; Franke, Katharina J

    2015-08-21

    We combine scanning-tunneling-spectroscopy experiments probing magnetic impurities on a superconducting surface with a theoretical analysis of the tunneling processes between (superconducting) tip and substrate. We show that the current through impurity-induced Shiba bound states is carried by single-electron tunneling at large tip-substrate distances and Andreev reflections at smaller distances. The single-electron current requires relaxation processes, allowing us to extract information on quasiparticle transitions and lifetimes. PMID:26340200

  12. Rapid communication: Global-local processing affects recognition of distractor emotional faces.

    PubMed

    Srinivasan, Narayanan; Gupta, Rashmi

    2011-03-01

    Recent studies have shown links between happy faces and global, distributed attention as well as sad faces to local, focused attention. Emotions have been shown to affect global-local processing. Given that studies on emotion-cognition interactions have not explored the effect of perceptual processing at different spatial scales on processing stimuli with emotional content, the present study investigated the link between perceptual focus and emotional processing. The study investigated the effects of global-local processing on the recognition of distractor faces with emotional expressions. Participants performed a digit discrimination task with digits at either the global level or the local level presented against a distractor face (happy or sad) as background. The results showed that global processing associated with broad scope of attention facilitates recognition of happy faces, and local processing associated with narrow scope of attention facilitates recognition of sad faces. The novel results of the study provide conclusive evidence for emotion-cognition interactions by demonstrating the effect of perceptual processing on emotional faces. The results along with earlier complementary results on the effect of emotion on global-local processing support a reciprocal relationship between emotional processing and global-local processing. Distractor processing with emotional information also has implications for theories of selective attention.

  13. Study of surface passivation as a function of InP closed-ampoule solar cell fabrication processing variables

    NASA Technical Reports Server (NTRS)

    Faur, Mircea; Faur, Maria; Jenkins, Phillip; Goradia, Manju; Goradia, Chandra; Bailey, Sheila; Weinberg, Irving; Jayne, Douglas

    1990-01-01

    The effects of various surface preparation procedures, including chemical treatment and anodic or chemical oxidation, closed-ampoule diffusion conditions, and post-diffusion surface preparation and annealing conditions, on the passivating properties of InP have been investigated in order to optimize the fabrication procedures of n(+)p InP solar cells made by closed-ampoule diffusion of sulfur into p-type InP. The InP substrates used were p-type Cd-doped to a level of 1.7 x 10 to the 16th/cu cm, Zn-doped to levels of 2.2 x 10 to the 16th and 1.2 x 10 to the 18th/cu cm, and n-type S-doped to 4.4 x 10 to the 18th/cu cm. The passivating properties have been evaluated from photoluminescence (PL) and conductance-voltage (G-V) data. Good agreement was found between the level of surface passivation and the composition of different surface layers as revealed by X-ray photoelectron spectroscopy (XPS) analysis.

  14. Global Impacts of the Bologna Process: International Perspectives, Local Particularities

    ERIC Educational Resources Information Center

    Zmas, Aristotelis

    2015-01-01

    The paper examines the transfer of the Bologna Process (BP) outside Europe, focusing on its "external dimension" and dynamics in global settings. It argues that the BP impacts on the internationalisation activities of universities, especially with regard to cross-border transparency of qualifications, transnational improvement of quality…

  15. The Influence of Local Geometric Effects on Mars Polar Processes

    NASA Technical Reports Server (NTRS)

    Hecht, M. H.

    2005-01-01

    Using simple, qualitative heat balance models, this paper addresses textures and structures that will result from the evolution of volatile layers by accretion and by ablation. Such phenomena may have global implications that are not apparent when only flat or sloped surfaces are modeled. In general, structures such as mounds or depressions formed out of volatile materials will evolve in shape such that the growth or retreat of any particular surface will be maximized. It can be shown that the local radius of curvature is proportional to the growth or retreat rate. For example, icy surfaces will tend to form facets that face the dominant sun direction. Two such cases are evaluated: a) Features associated with condensation of volatiles, include cold-trapping and redistribution, such as the concentration of frost around the Viking 2 lander [1]. Here I will focus on textures that likely result from the formation of seasonal CO2 deposits. b) Features associated with sublimation of volatiles, such as those described by Ingersoll et. al. [2] result in textured surfaces that affect both the apparent emissivity and albedo. Similar calculations have been performed with respect to the "Swiss cheese" features on the South Polar Cap [3]. Here, I evaluate the likely sublimation rates from optimal ice scarp structures and their implications for the long-term evolution of the polar caps and formation of layered terrain.

  16. Local adaptation in Trinidadian guppies alters ecosystem processes.

    PubMed

    Bassar, Ronald D; Marshall, Michael C; López-Sepulcre, Andrés; Zandonà, Eugenia; Auer, Sonya K; Travis, Joseph; Pringle, Catherine M; Flecker, Alexander S; Thomas, Steven A; Fraser, Douglas F; Reznick, David N

    2010-02-23

    Theory suggests evolutionary change can significantly influence and act in tandem with ecological forces via ecological-evolutionary feedbacks. This theory assumes that significant evolutionary change occurs over ecologically relevant timescales and that phenotypes have differential effects on the environment. Here we test the hypothesis that local adaptation causes ecosystem structure and function to diverge. We demonstrate that populations of Trinidadian guppies (Poecilia reticulata), characterized by differences in phenotypic and population-level traits, differ in their impact on ecosystem properties. We report results from a replicated, common garden mesocosm experiment and show that differences between guppy phenotypes result in the divergence of ecosystem structure (algal, invertebrate, and detrital standing stocks) and function (gross primary productivity, leaf decomposition rates, and nutrient flux). These phenotypic effects are further modified by effects of guppy density. We evaluated the generality of these effects by replicating the experiment using guppies derived from two independent origins of the phenotype. Finally, we tested the ability of multiple guppy traits to explain observed differences in the mesocosms. Our findings demonstrate that evolution can significantly affect both ecosystem structure and function. The ecosystem differences reported here are consistent with patterns observed across natural streams and argue that guppies play a significant role in shaping these ecosystems. PMID:20133670

  17. Behavioral and Physiological Findings of Gender Differences in Global-Local Visual Processing

    ERIC Educational Resources Information Center

    Roalf, David; Lowery, Natasha; Turetsky, Bruce I.

    2006-01-01

    Hemispheric asymmetries in global-local visual processing are well-established, as are gender differences in cognition. Although hemispheric asymmetry presumably underlies gender differences in cognition, the literature on gender differences in global-local processing is sparse. We employed event related brain potential (ERP) recordings during…

  18. "Autistic" Local Processing Bias Also Found in Children Gifted in Realistic Drawing

    ERIC Educational Resources Information Center

    Drake, Jennifer E.; Redash, Amanda; Coleman, Katelyn; Haimson, Jennifer; Winner, Ellen

    2010-01-01

    We investigated whether typically-developing children with a gift for drawing realistically show the local processing bias seen in individuals with autism spectrum disorder (ASD). Twenty-seven 6-12 year-olds made an observational drawing (scored for level of realism) and completed three local processing tasks, and parents completed the Childhood…

  19. Enhanced Local Processing of Dynamic Visual Information in Autism: Evidence from Speed Discrimination

    ERIC Educational Resources Information Center

    Chen, Y.; Norton, D. J.; McBain, R.; Gold, J.; Frazier, J. A.; Coyle, J. T.

    2012-01-01

    An important issue for understanding visual perception in autism concerns whether individuals with this neurodevelopmental disorder possess an advantage in processing local visual information, and if so, what is the nature of this advantage. Perception of movement speed is a visual process that relies on computation of local spatiotemporal signals…

  20. Local Authorities' Experiences of Improving Parental Confidence in the Special Educational Needs Process. LGA Research Report

    ERIC Educational Resources Information Center

    White, Richard; Macleod, Shona; Jeffes, Jennifer; Atkinson, Mary

    2010-01-01

    How can we help parents to understand the special educational needs (SEN) process? What sort of information and support do they need? This report details the results of research with SEN officers (or their equivalent) in 26 local authorities, covering: (1) the referral process; (2) early identification and intervention; (3) local authority and…

  1. Localization of Impaired Kinesthetic Processing Post-stroke

    PubMed Central

    Kenzie, Jeffrey M.; Semrau, Jennifer A.; Findlater, Sonja E.; Yu, Amy Y.; Desai, Jamsheed A.; Herter, Troy M.; Hill, Michael D.; Scott, Stephen H.; Dukelow, Sean P.

    2016-01-01

    Kinesthesia is our sense of limb motion, and allows us to gauge the speed, direction, and amplitude of our movements. Over half of stroke survivors have significant impairments in kinesthesia, which leads to greatly reduced recovery and function in everyday activities. Despite the high reported incidence of kinesthetic deficits after stroke, very little is known about how damage beyond just primary somatosensory areas affects kinesthesia. Stroke provides an ideal model to examine structure-function relationships specific to kinesthetic processing, by comparing lesion location with behavioral impairment. To examine this relationship, we performed voxel-based lesion-symptom mapping and statistical region of interest analyses on a large sample of sub-acute stroke subjects (N = 142) and compared kinesthetic performance with stroke lesion location. Subjects with first unilateral, ischemic stroke underwent neuroimaging and a comprehensive robotic kinesthetic assessment (~9 days post-stroke). The robotic exoskeleton measured subjects' ability to perform a kinesthetic mirror-matching task of the upper limbs without vision. The robot moved the stroke-affected arm and subjects' mirror-matched the movement with the unaffected arm. We found that lesions both within and outside primary somatosensory cortex were associated with significant kinesthetic impairments. Further, sub-components of kinesthesia were associated with different lesion locations. Impairments in speed perception were primarily associated with lesions to the right post-central and supramarginal gyri whereas impairments in amplitude of movement perception were primarily associated with lesions in the right pre-central gyrus, anterior insula, and superior temporal gyrus. Impairments in perception of movement direction were associated with lesions to bilateral post-central and supramarginal gyri, right superior temporal gyrus and parietal operculum. All measures of impairment shared a common association with

  2. [Passive smoking].

    PubMed

    Grandjean, E; Weber, A; Fischer, T

    1979-03-01

    Passive smoking is the involuntary inspiration of smoky indoor air. Based on the information available today, it may be assumed that passive smoking normally is no health hazard as far as the classical smoker's diseases (lung cancer, myocardial infarct, etc.) are concerned. Nevertheless, it is probable that irritations caused by tobacco smoke have an unfavorable influence on the health of small children and that of already sick persons. The main problem of passive smoking is annoyance due to odor and irritations of eyes and respiratory organs. Our investigations in a climatic chamber with healthy subjects show that air pollution caused by tobacco smoke as indicated by 5 ppm CO leads to marked eye irritations--objectively as well as subjectively--in 15 to 20% of the subjects. This corresponds to smoking 10 cigarettes per hour in a small room with an air ventilation rate of four times per hour. If air pollution caused by tobacco smoke lies below the level of 2 ppm CO, irritations and annoyance for healthy persons are regarded as low and tolerable. This corresponds to about four cigarettes per hour under the same circumstances.

  3. Active and Passive Surveillance and Phylogenetic Analysis of Borrelia burgdorferi Elucidate the Process of Lyme Disease Risk Emergence in Canada

    PubMed Central

    Ogden, Nicholas H.; Bouchard, Catherine; Kurtenbach, Klaus; Margos, Gabriele; Lindsay, L. Robbin; Trudel, Louise; Nguon, Soulyvane; Milord, François

    2010-01-01

    Background Northward expansion of the tick Ixodes scapularis is driving Lyme disease (LD) emergence in Canada. Information on mechanisms involved is needed to enhance surveillance and identify where LD risk is emerging. Objectives We used passive and active surveillance and phylogeographic analysis of Borrelia burgdorferi to investigate LD risk emergence in Quebec. Methods In active surveillance, we collected ticks from the environment and from captured rodents. B. burgdorferi transmission was detected by serological analysis of rodents and by polymerase chain reaction assays of ticks. Spatiotemporal trends in passive surveillance data assisted interpretation of active surveillance. Multilocus sequence typing (MLST) of B. burgdorferi in ticks identified likely source locations of B. burgdorferi. Results In active surveillance, we found I. scapularis at 55% of sites, and we were more likely to find them at sites with a warmer climate. B. burgdorferi was identified at 13 I. scapularis–positive sites, but infection prevalence in ticks and animal hosts was low. Low infection prevalence in ticks submitted in passive surveillance after 2004—from the tick-positive regions identified in active surveillance—coincided with an exponential increase in tick submissions during this time. MLST analysis suggested recent introduction of B. burgdorferi from the northeastern United States. Conclusions These data are consistent with I. scapularis ticks dispersed from the United States by migratory birds, founding populations where the climate is warmest, and then establishment of B. burgdorferi from the United States several years after I. scapularis have established. These observations provide vital information for public health to minimize the impact of LD in Canada. PMID:20421192

  4. Deconfounding the effects of local element spatial heterogeneity and sparsity on processing dominance.

    PubMed

    Montoro, Pedro R; Luna, Dolores

    2009-10-01

    Previous studies on the processing of hierarchical patterns (Luna & Montoro, 2008) have shown that altering the spatial relationships between the local elements affected processing dominance by decreasing global advantage. In the present article, the authors examine whether heterogeneity or a sparse distribution of the local elements was the responsible factor for this effect. In Experiments 1 and 2, the distance between the local elements was increased in a similar way, but between-element distance was homogeneous in Experiment 1 and heterogeneous in Experiment 2. In Experiment 3, local elements' size was varied by presenting global patterns composed of similar large or small local elements and of different large and small sizes. The results of the present research showed that, instead of element sparsity, spatial heterogeneity that could change the appearance of the global form as well as the salience of the local elements was the main determiner of impairing global processing.

  5. Effect of flexible vegetation on localized erosion processes

    NASA Astrophysics Data System (ADS)

    Termini, Donatella

    2013-04-01

    The knowledge of the hydraulic characteristics of flow over vegetation is very important to support the management of fluvial processes. The effects of vegetation on flow velocity are significant and of crucial importance for stabilizing sediments and reducing erosion along the channel. But, because of the temporal changing of roughness due to natural vegetative growth, the response of vegetation to the flow can change in time. Thus, vegetation has a complex effect on walls roughness and the study of the hydrodynamic conditions of flow is difficult. Many theoretical and experimental investigations have been performed in order to analyze both the mean flow and turbulence structure of open-channel flow (Nezu and Rodi 1986; Ghisalberti and Nepf, 2002). Recent experimental runs carried out in laboratory channels with flexible vegetation, realized by using artificial filaments (Kutija and Hong 1996; Ikeda and Kanazawa 1996), investigated some peculiar characteristics of flow turbulence structure and revealed the generation of periodic organized vortices whose center is located slightly above the top of the vegetation layer. Ghisalberti and Nepf (2002) confirmed the formation of such vortices, highlighting that, in the case of flexible vegetation, the vortex-driven oscillation of velocity drives coherent vegetation waving, producing a spatially and temporally variable drag force. In this paper, attention is paid to the influence of vegetation on the erosion processes both on the bed and on the channel banks. Experiments were carried out both in a straight channel and in a meandering channel, both constructed at the Department of Civil, Environmental, Aerospatial and of Materials (DICAM) - University of Palermo (Italy). The formation of turbulence structures inside the vegetated layer is verified, providing some insight into the mechanisms of sediment transport. Nezu, I. & Rodi, W. 1986. Open-channel flow measurements with a Laser Doppler Anemometer. Journal of Hydraulic

  6. Passivation process in quasi-continuous laser derusting with intermediate pulse width and line-scanning method.

    PubMed

    Li, Wei; Du, Peng; Zhang, Jun; Shi, Shudong; Liu, Shujing; Chen, Nianjiang; Zhao, Hong; Song, Feng

    2014-02-20

    Floating rust composed of particles and aggregates is the primary product of iron or steel corrosion. Because the floating rust has a porous structure and small thickness, part of the irradiating laser energy can be transmitted through the rust layer and be absorbed by the iron substrate. The adherent force between the floating rust and the metal substrate is weak. In this paper we carried out a series of experiments on this specific rust type to achieve laser derusting and passivating simultaneously. We used a line-scanning method (50% overlapping ratio between adjacent laser spots) to get the nearly average uniform distribution of laser fluence in a large cleaning area. The laser irradiation can directly heat a metal surface to cause thermo-elastic vibration to shake off the rust layer and to cause oxidization to form a protective layer. The most important factor of laser passivating is that the iron surface must be heated to the melting point of iron but not much higher. During this short melting period, on the one hand the iron surface could be oxidized completely; on the other hand the melting of the iron surface could make uniform the oxygen concentration and temperature in the molten iron bath. PMID:24663308

  7. Passivation process in quasi-continuous laser derusting with intermediate pulse width and line-scanning method.

    PubMed

    Li, Wei; Du, Peng; Zhang, Jun; Shi, Shudong; Liu, Shujing; Chen, Nianjiang; Zhao, Hong; Song, Feng

    2014-02-20

    Floating rust composed of particles and aggregates is the primary product of iron or steel corrosion. Because the floating rust has a porous structure and small thickness, part of the irradiating laser energy can be transmitted through the rust layer and be absorbed by the iron substrate. The adherent force between the floating rust and the metal substrate is weak. In this paper we carried out a series of experiments on this specific rust type to achieve laser derusting and passivating simultaneously. We used a line-scanning method (50% overlapping ratio between adjacent laser spots) to get the nearly average uniform distribution of laser fluence in a large cleaning area. The laser irradiation can directly heat a metal surface to cause thermo-elastic vibration to shake off the rust layer and to cause oxidization to form a protective layer. The most important factor of laser passivating is that the iron surface must be heated to the melting point of iron but not much higher. During this short melting period, on the one hand the iron surface could be oxidized completely; on the other hand the melting of the iron surface could make uniform the oxygen concentration and temperature in the molten iron bath.

  8. Physically secured orthogonal frequency division multiplexing-passive optical network employing noise-based encryption and signal recovery process

    NASA Astrophysics Data System (ADS)

    Jin, Wei; Zhang, Chongfu; Yuan, Weicheng

    2016-02-01

    We propose a physically enhanced secure scheme for direct detection-orthogonal frequency division multiplexing-passive optical network (DD-OFDM-PON) and long reach coherent detection-orthogonal frequency division multiplexing-passive optical network (LRCO-OFDM-PON), by employing noise-based encryption and channel/phase estimation. The noise data generated by chaos mapping are used to substitute training sequences in preamble to realize channel estimation and frame synchronization, and also to be embedded on variable number of key-selected randomly spaced pilot subcarriers to implement phase estimation. Consequently, the information used for signal recovery is totally hidden as unpredictable noise information in OFDM frames to mask useful information and to prevent illegal users from correctly realizing OFDM demodulation, and thereby enhancing resistance to attackers. The levels of illegal-decryption complexity and implementation complexity are theoretically discussed. Through extensive simulations, the performances of the proposed channel/phase estimation and the security introduced by encrypted pilot carriers have been investigated in both DD-OFDM and LRCO-OFDM systems. In addition, in the proposed secure DD-OFDM/LRCO-OFDM PON models, both legal and illegal receiving scenarios have been considered. These results show that, by utilizing the proposed scheme, the resistance to attackers can be significantly enhanced in DD-OFDM-PON and LRCO-OFDM-PON systems without performance degradations.

  9. Gaussian Process Regression Plus Method for Localization Reliability Improvement.

    PubMed

    Liu, Kehan; Meng, Zhaopeng; Own, Chung-Ming

    2016-01-01

    Location data are among the most widely used context data in context-aware and ubiquitous computing applications. Many systems with distinct deployment costs and positioning accuracies have been developed over the past decade for indoor positioning. The most useful method is focused on the received signal strength and provides a set of signal transmission access points. However, compiling a manual measuring Received Signal Strength (RSS) fingerprint database involves high costs and thus is impractical in an online prediction environment. The system used in this study relied on the Gaussian process method, which is a nonparametric model that can be characterized completely by using the mean function and the covariance matrix. In addition, the Naive Bayes method was used to verify and simplify the computation of precise predictions. The authors conducted several experiments on simulated and real environments at Tianjin University. The experiments examined distinct data size, different kernels, and accuracy. The results showed that the proposed method not only can retain positioning accuracy but also can save computation time in location predictions.

  10. Gaussian Process Regression Plus Method for Localization Reliability Improvement.

    PubMed

    Liu, Kehan; Meng, Zhaopeng; Own, Chung-Ming

    2016-01-01

    Location data are among the most widely used context data in context-aware and ubiquitous computing applications. Many systems with distinct deployment costs and positioning accuracies have been developed over the past decade for indoor positioning. The most useful method is focused on the received signal strength and provides a set of signal transmission access points. However, compiling a manual measuring Received Signal Strength (RSS) fingerprint database involves high costs and thus is impractical in an online prediction environment. The system used in this study relied on the Gaussian process method, which is a nonparametric model that can be characterized completely by using the mean function and the covariance matrix. In addition, the Naive Bayes method was used to verify and simplify the computation of precise predictions. The authors conducted several experiments on simulated and real environments at Tianjin University. The experiments examined distinct data size, different kernels, and accuracy. The results showed that the proposed method not only can retain positioning accuracy but also can save computation time in location predictions. PMID:27483276

  11. Gaussian Process Regression Plus Method for Localization Reliability Improvement

    PubMed Central

    Liu, Kehan; Meng, Zhaopeng; Own, Chung-Ming

    2016-01-01

    Location data are among the most widely used context data in context-aware and ubiquitous computing applications. Many systems with distinct deployment costs and positioning accuracies have been developed over the past decade for indoor positioning. The most useful method is focused on the received signal strength and provides a set of signal transmission access points. However, compiling a manual measuring Received Signal Strength (RSS) fingerprint database involves high costs and thus is impractical in an online prediction environment. The system used in this study relied on the Gaussian process method, which is a nonparametric model that can be characterized completely by using the mean function and the covariance matrix. In addition, the Naive Bayes method was used to verify and simplify the computation of precise predictions. The authors conducted several experiments on simulated and real environments at Tianjin University. The experiments examined distinct data size, different kernels, and accuracy. The results showed that the proposed method not only can retain positioning accuracy but also can save computation time in location predictions. PMID:27483276

  12. Which way is which? Examining global/local processing with symbolic cues.

    PubMed

    Mills, Mark; Dodd, Michael D

    2014-08-01

    A new method combining spatial-cueing and compound-stimulus paradigms draws on involuntary attentional orienting elicited by a spatially uninformative central arrow cue to investigate global/local processing under incidental processing conditions, wherein global/local levels were uninformative (do not aid performance) and task-irrelevant (need not be processed to perform the task). The task was peripheral target detection. Cues were compound arrows, which were either consistent (global/local arrows oriented in same direction) or inconsistent (global/local arrows oriented in opposite directions). Global/local processing was measured by spatial-cueing effects (response time [RT] difference between target locations validly cued by an arrow and targets at different locations), with the test of global/local advantage represented by the effect of cue-level for inconsistent cues (RT difference between global-valid and local-valid cues). Cue-target interval (stimulus-onset-asynchrony [SOA]) was manipulated to test whether global/local advantage varied with relative stimulus availability. Experiment 1 observed a Cue-Level × SOA interaction such that an early, large global cueing effect was followed by a later, smaller local cueing effect, indicative of a global-to-local shift in advantage. This occurred despite knowledge that global/local arrows were uninformative and task-irrelevant and could therefore be ignored, thus displaying key properties of an involuntary process. Experiment 2 added neutral cues (arrow at one level, rectangle at the other) and determined that the reversal was not due to inhibition of the globally cued location or to attenuation of global information but rather to the presence of conflicting spatial information. Experiments 3 and 4 ruled out alternative accounts for these results. These data indicate global precedence in attended but incidentally processed objects.

  13. Cellular growth defects triggered by an overload of protein localization processes

    PubMed Central

    Kintaka, Reiko; Makanae, Koji; Moriya, Hisao

    2016-01-01

    High-level expression of a protein localized to an intracellular compartment is expected to cause cellular defects because it overloads localization processes. However, overloads of localization processes have never been studied systematically. Here, we show that the expression levels of green fluorescent proteins (GFPs) with localization signals were limited to the same degree as a toxic misfolded GFP in budding yeast cells, and that their high-level expression caused cellular defects associated with localization processes. We further show that limitation of the exportin Crm1 determined the expression limit of GFP with a nuclear export signal. Although misfolding of GFP with a vesicle-mediated transport signal triggered endoplasmic reticulum stress, it was not the primary determinant of its expression limit. The precursor of GFP with a mitochondrial targeting signal caused a cellular defect. Finally, we estimated the residual capacities of localization processes. High-level expression of a localized protein thus causes cellular defects by overloading the capacities of localization processes. PMID:27538565

  14. Cellular growth defects triggered by an overload of protein localization processes.

    PubMed

    Kintaka, Reiko; Makanae, Koji; Moriya, Hisao

    2016-01-01

    High-level expression of a protein localized to an intracellular compartment is expected to cause cellular defects because it overloads localization processes. However, overloads of localization processes have never been studied systematically. Here, we show that the expression levels of green fluorescent proteins (GFPs) with localization signals were limited to the same degree as a toxic misfolded GFP in budding yeast cells, and that their high-level expression caused cellular defects associated with localization processes. We further show that limitation of the exportin Crm1 determined the expression limit of GFP with a nuclear export signal. Although misfolding of GFP with a vesicle-mediated transport signal triggered endoplasmic reticulum stress, it was not the primary determinant of its expression limit. The precursor of GFP with a mitochondrial targeting signal caused a cellular defect. Finally, we estimated the residual capacities of localization processes. High-level expression of a localized protein thus causes cellular defects by overloading the capacities of localization processes. PMID:27538565

  15. The State and Local Curriculum Approval Process in Illinois Community and Junior Colleges.

    ERIC Educational Resources Information Center

    Parcells, Frank E.

    The program approval process of the Illinois Community College Board (ICCB) and the local process of course and program approval used by Illinois community colleges are detailed in this report. Following an introduction and study overview, course and program approval processes at John A. Logan College and Shawnee College are described and…

  16. Global/Local Processing in Autism: Not a Disability, but a Disinclination

    ERIC Educational Resources Information Center

    Koldewyn, Kami; Jiang, Yuhong V.; Weigelt, Sarah; Kanwisher, Nancy

    2013-01-01

    It is widely suggested that ASD is characterized by atypical local/global processing, but the published findings are contradictory. In an effort to resolve this question, we tested a large group of children on both a free-choice task and an instructed task using hierarchical local-global stimuli. We find that although children with autism showed a…

  17. Global-Local Visual Processing in High Functioning Children with Autism: Structural vs. Implicit Task Biases

    ERIC Educational Resources Information Center

    Iarocci, Grace; Burack, Jacob A.; Shore, David I.; Mottron, Laurent; Enns, James T.

    2006-01-01

    Global-local processing was examined in high-functioning children with autism and in groups of typically developing children. In experiment 1, the effects of structural bias were tested by comparing visual search that favored access to either local or global targets. The children with autism were not unusually sensitive to either level of visual…

  18. The Development of Global and Local Processing: A Comparison of Children to Adults

    ERIC Educational Resources Information Center

    Peterson, Eric; Peterson, Robin L.

    2014-01-01

    In light of the adult model of a hemispheric asymmetry of global and local processing, we compared children (M [subscript age] = 8.4 years) to adults in a global-local reaction time (RT) paradigm. Hierarchical designs (large shapes made of small shapes) were presented randomly to each visual field, and participants were instructed to identify…

  19. Managed Moves: School and Local Authority Staff Perceptions of Processes, Success and Challenges

    ERIC Educational Resources Information Center

    Bagley, Christopher; Hallam, Susan

    2015-01-01

    The current research aimed to increase understanding of the processes of managed moves for children at risk of exclusion from school, particularly exploring what contributed to success and the nature of the challenges experienced. The study was conducted in one English local authority where 11 school staff and 5 local authority staff were…

  20. Adaptation to Leftward-shifting Prisms Enhances Local Processing in Healthy Individuals

    PubMed Central

    Reed, Scott A.; Dassonville, Paul

    2014-01-01

    In healthy individuals, adaptation to left-shifting prisms has been shown to simulate the symptoms of hemispatial neglect, including a reduction in global processing that approximates the local bias observed in neglect patients. The current study tested whether leftward prism adaptation can more specifically enhance local processing abilities. In three experiments, the impact of local and global processing was assessed through tasks that measure susceptibility to illusions that are known to be driven by local or global contextual effects. Susceptibility to the rod-and-frame illusion – an illusion disproportionately driven by both local and global effects depending on frame size – was measured before and after adaptation to left- and right-shifting prisms. A significant increase in rod-and-frame susceptibility was found for the left-shifting prism group, suggesting that adaptation caused an increase in local processing effects. The results of a second experiment confirmed that leftward prism adaptation enhances local processing, as assessed with susceptibility to the simultaneous-tilt illusion. A final experiment employed a more specific measure of the global effect typically associated with the rod-andframe illusion, and found that although the global effect was somewhat diminished after leftward prism adaptation, the trend failed to reach significance (p = .078). Rightward prism adaptation had no significant effects on performance in any of the experiments. Combined, these findings indicate that leftward prism adaptation in healthy individuals can simulate the local processing bias of neglect patients primarily through an increased sensitivity to local visual cues, and confirm that prism adaptation not only modulates lateral shifts of attention, but also prompts shifts from one level of processing to another. PMID:24560913

  1. Adaptation to leftward-shifting prisms enhances local processing in healthy individuals.

    PubMed

    Reed, Scott A; Dassonville, Paul

    2014-04-01

    In healthy individuals, adaptation to left-shifting prisms has been shown to simulate the symptoms of hemispatial neglect, including a reduction in global processing that approximates the local bias observed in neglect patients. The current study tested whether leftward prism adaptation can more specifically enhance local processing abilities. In three experiments, the impact of local and global processing was assessed through tasks that measure susceptibility to illusions that are known to be driven by local or global contextual effects. Susceptibility to the rod-and-frame illusion - an illusion disproportionately driven by both local and global effects depending on frame size - was measured before and after adaptation to left- and right-shifting prisms. A significant increase in rod-and-frame susceptibility was found for the left-shifting prism group, suggesting that adaptation caused an increase in local processing effects. The results of a second experiment confirmed that leftward prism adaptation enhances local processing, as assessed with susceptibility to the simultaneous-tilt illusion. A final experiment employed a more specific measure of the global effect typically associated with the rod-and-frame illusion, and found that although the global effect was somewhat diminished after leftward prism adaptation, the trend failed to reach significance (p=.078). Rightward prism adaptation had no significant effects on performance in any of the experiments. Combined, these findings indicate that leftward prism adaptation in healthy individuals can simulate the local processing bias of neglect patients primarily through an increased sensitivity to local visual cues, and confirm that prism adaptation not only modulates lateral shifts of attention, but also prompts shifts from one level of processing to another.

  2. Passivated niobium cavities

    SciTech Connect

    Myneni, Ganapati Rao; Hjorvarsson, Bjorgvin; Ciovati, Gianluigi

    2006-12-19

    A niobium cavity exhibiting high quality factors at high gradients is provided by treating a niobium cavity through a process comprising: 1) removing surface oxides by plasma etching or a similar process; 2) removing hydrogen or other gases absorbed in the bulk niobium by high temperature treatment of the cavity under ultra high vacuum to achieve hydrogen outgassing; and 3) assuring the long term chemical stability of the niobium cavity by applying a passivating layer of a superconducting material having a superconducting transition temperature higher than niobium thereby reducing losses from electron (cooper pair) scattering in the near surface region of the interior of the niobium cavity. According to a preferred embodiment, the passivating layer comprises niobium nitride (NbN) applied by reactive sputtering.

  3. Management of local economic and ecological system of coal processing company

    NASA Astrophysics Data System (ADS)

    Kiseleva, T. V.; Mikhailov, V. G.; Karasev, V. A.

    2016-10-01

    The management issues of local ecological and economic system of coal processing company - coal processing plant - are considered in the article. The objectives of the research are the identification and the analysis of local ecological and economic system (coal processing company) performance and the proposals for improving the mechanism to support the management decision aimed at improving its environmental safety. The data on the structure of run-of-mine coal processing products are shown. The analysis of main ecological and economic indicators of coal processing enterprises, characterizing the state of its environmental safety, is done. The main result of the study is the development of proposals to improve the efficiency of local enterprise ecological and economic system management, including technical, technological and business measures. The results of the study can be recommended to industrial enterprises to improve their ecological and economic efficiency.

  4. Passive fetal monitoring sensor

    NASA Technical Reports Server (NTRS)

    Zuckerwar, Allan J. (Inventor); Hall, Earl T. (Inventor); Baker, Donald A. (Inventor); Bryant, Timothy D. (Inventor)

    1992-01-01

    An ambulatory, passive sensor for use in a fetal monitoring system is discussed. The invention is comprised of a piezoelectric polymer film, combined with a metallic mounting plate fastened to a belt, and electrically connected to a signal processing unit by means of a shielded cable. The purpose of the sensor is to receive pressure pulses emitted by a fetus inside an expectant mother. Additionally, the monitor will filter out pressure pulses arising from other sources, such as the maternal heart.

  5. Use of phenomena identification and ranking (PIRT) process in research related to design certification of the AP600 advanced passive light water reactor (LWR)

    SciTech Connect

    Wilson, G.E.; Fletcher, C.D.; Eltawila, F.

    1996-07-01

    The AP600 LWR is a new advanced passive design that has been submitted to the USNRC for design certification. Within the certification process the USNRC will perform selected system thermal hydraulic response audit studies to help confirm parts of the vendor`s safety analysis submittal. Because of certain innovative design features of the safety systems, new experimental data and related advances in the system thermal hydraulic analysis computer code are being developed by the USNRC. The PIRT process is being used to focus the experimental and analytical work to obtain a sufficient and cost effective research effort. The objective of this paper is to describe the application and most significant results of the PIRT process, including several innovative features needed in the application to accommodate the short design certification schedule. The short design certification schedule has required that many aspects of the USNRC experimental and analytical research be performed in parallel, rather than in series as was normal for currently operating LWRS. This has required development and use of management techniques that focus and integrate the various diverse parts of the research. The original PIRTs were based on inexact knowledge of an evolving reactor design, and concentrated on the new passive features of the design. Subsequently, the PIRTs have evolved in two more stages as the design became more firm and experimental and analytical data became available. A fourth and final stage is planned and in progress to complete the PIRT development. The PIRTs existing at the end of each development stage have been used to guide the experimental program, scaling analyses and code development supporting the audit studies.

  6. Coexistence of passive and proton antiporter-mediated processes in nicotine transport at the mouse blood-brain barrier.

    PubMed

    Cisternino, Salvatore; Chapy, Hélène; André, Pascal; Smirnova, Maria; Debray, Marcel; Scherrmann, Jean-Michel

    2013-04-01

    Nicotine, the main tobacco alkaloid leading to smoking dependence, rapidly crosses the blood-brain barrier (BBB) to become concentrated in the brain. Recently, it has been shown that nicotine interacts with some organic cation transporters (OCT), but their influence at the BBB has not yet been assessed in vivo. In this study, we characterized the transport of nicotine at the mouse luminal BBB by in situ brain perfusion. Its influx was saturable and followed the Michaelis-Menten kinetics (K(m)=2.60 mM, V(max)=37.60 nmol/s/g at pH 7.40). At its usual micromolar concentrations in the plasma, most (79%) of the net transport of nicotine at the BBB was carrier-mediated, while passive diffusion accounted for 21%. Studies on knockout mice showed that the OCT Oct1-3, P-gp, and Bcrp did not alter [(3)H]-nicotine transport at the BBB. Neither did inhibiting the transporters Mate1, Octn, or Pmat. The in vivo manipulation of intracellular and/or extracellular pH, the chemical inhibition profile, and the trans-stimulation experiments demonstrated that the nicotine transporter at the BBB shared the properties of the clonidine/proton antiporter. The molecular features of this proton-coupled antiporter have not yet been identified, but it also transports diphenhydramine and tramadol and helps nicotine cross the BBB at a faster rate and to a greater extent. The pharmacological inhibition of this nicotine/proton antiporter could represent a new strategy to reduce nicotine uptake by the brain and thus help curb addiction to smoking. PMID:23212563

  7. Coexistence of passive and proton antiporter-mediated processes in nicotine transport at the mouse blood-brain barrier.

    PubMed

    Cisternino, Salvatore; Chapy, Hélène; André, Pascal; Smirnova, Maria; Debray, Marcel; Scherrmann, Jean-Michel

    2013-04-01

    Nicotine, the main tobacco alkaloid leading to smoking dependence, rapidly crosses the blood-brain barrier (BBB) to become concentrated in the brain. Recently, it has been shown that nicotine interacts with some organic cation transporters (OCT), but their influence at the BBB has not yet been assessed in vivo. In this study, we characterized the transport of nicotine at the mouse luminal BBB by in situ brain perfusion. Its influx was saturable and followed the Michaelis-Menten kinetics (K(m)=2.60 mM, V(max)=37.60 nmol/s/g at pH 7.40). At its usual micromolar concentrations in the plasma, most (79%) of the net transport of nicotine at the BBB was carrier-mediated, while passive diffusion accounted for 21%. Studies on knockout mice showed that the OCT Oct1-3, P-gp, and Bcrp did not alter [(3)H]-nicotine transport at the BBB. Neither did inhibiting the transporters Mate1, Octn, or Pmat. The in vivo manipulation of intracellular and/or extracellular pH, the chemical inhibition profile, and the trans-stimulation experiments demonstrated that the nicotine transporter at the BBB shared the properties of the clonidine/proton antiporter. The molecular features of this proton-coupled antiporter have not yet been identified, but it also transports diphenhydramine and tramadol and helps nicotine cross the BBB at a faster rate and to a greater extent. The pharmacological inhibition of this nicotine/proton antiporter could represent a new strategy to reduce nicotine uptake by the brain and thus help curb addiction to smoking.

  8. From Local to Global Processing: The Development of Illusory Contour Perception

    PubMed Central

    Nayar, Kritika; Franchak, John; Adolph, Karen; Kiorpes, Lynne

    2015-01-01

    Global visual processing is important for segmenting scenes, extracting form from background, and recognizing objects. Local processing involves attention to the local elements, contrast, and boundaries of an image at the expense of extracting a global percept. Previous work is inconclusive regarding the relative development of local and global processing. Some studies suggest that global perception is already present by 8 months of age, whereas others suggest that the ability arises in childhood and continues to develop in adolescence. We used a novel method to assess the development of global processing in 3- to 10-year-old children and an adult comparison group. We used Kanizsa illusory contours as an assay of global perception and measured responses on a touch screen while monitoring eye position with a head-mounted eye tracker. Participants were tested using a similarity match-to-sample paradigm. Using converging measures, we found a clear developmental progression with age such that the youngest children performed near chance on the illusory contour discrimination whereas 7- to 8-year-olds performed nearly perfectly, as did adults. There was clear evidence of a gradual shift from a local to a global processing strategy: Young children looked predominantly at and touched the pacman inducers of the illusory form, whereas older children and adults looked predominantly at and touched the middle of the form. These data show a prolonged developmental trajectory in appreciation of global form, with a transition from local to global visual processing between 4 and 7 years of age. PMID:25514785

  9. Auditory global-local processing: effects of attention and musical experience.

    PubMed

    Ouimet, Tia; Foster, Nicholas E V; Hyde, Krista L

    2012-10-01

    In vision, global (whole) features are typically processed before local (detail) features ("global precedence effect"). However, the distinction between global and local processing is less clear in the auditory domain. The aims of the present study were to investigate: (i) the effects of directed versus divided attention, and (ii) the effect musical training on auditory global-local processing in 16 adult musicians and 16 non-musicians. Participants were presented with short nine-tone melodies, each comprised of three triplet sequences (three-tone units). In a "directed attention" task, participants were asked to focus on either the global or local pitch pattern and had to determine if the pitch pattern went up or down. In a "divided attention" task, participants judged whether the target pattern (up or down) was present or absent. Overall, global structure was perceived faster and more accurately than local structure. The global precedence effect was observed regardless of whether attention was directed to a specific level or divided between levels. Musicians performed more accurately than non-musicians overall, but non-musicians showed a more pronounced global advantage. This study provides evidence for an auditory global precedence effect across attention tasks, and for differences in auditory global-local processing associated with musical experience. PMID:23039447

  10. Auditory global-local processing: effects of attention and musical experience.

    PubMed

    Ouimet, Tia; Foster, Nicholas E V; Hyde, Krista L

    2012-10-01

    In vision, global (whole) features are typically processed before local (detail) features ("global precedence effect"). However, the distinction between global and local processing is less clear in the auditory domain. The aims of the present study were to investigate: (i) the effects of directed versus divided attention, and (ii) the effect musical training on auditory global-local processing in 16 adult musicians and 16 non-musicians. Participants were presented with short nine-tone melodies, each comprised of three triplet sequences (three-tone units). In a "directed attention" task, participants were asked to focus on either the global or local pitch pattern and had to determine if the pitch pattern went up or down. In a "divided attention" task, participants judged whether the target pattern (up or down) was present or absent. Overall, global structure was perceived faster and more accurately than local structure. The global precedence effect was observed regardless of whether attention was directed to a specific level or divided between levels. Musicians performed more accurately than non-musicians overall, but non-musicians showed a more pronounced global advantage. This study provides evidence for an auditory global precedence effect across attention tasks, and for differences in auditory global-local processing associated with musical experience.

  11. Influence of focal point properties on energy transfer and plasma evolution during laser ignition process with a passively q-switched laser.

    PubMed

    Bärwinkel, Mark; Lorenz, Sebastian; Stäglich, Robert; Brüggemann, Dieter

    2016-07-11

    Miniaturized passively q-switched laser ignition systems are a promising alternative to conventional ignition sources to ensure a reliable ignition under difficult conditions. In this study the influences of focal point properties on energy transfer from laser to plasma as well as plasma formation and propagation are investigated as the first steps of the laser induced ignition process. Maximum fluence and fluence volume are introduced to characterize focal point properties for varying laser pulse energies and focusing configurations. The results show that the transferred laser energy increases with increasing maximum fluence. During laser emission plasma propagates along the beam path of the focused laser beam. Rising maximum fluence results in increased plasma volume, but expansion saturates when fluence volume reaches its maximum. PMID:27410797

  12. Influence of focal point properties on energy transfer and plasma evolution during laser ignition process with a passively q-switched laser.

    PubMed

    Bärwinkel, Mark; Lorenz, Sebastian; Stäglich, Robert; Brüggemann, Dieter

    2016-07-11

    Miniaturized passively q-switched laser ignition systems are a promising alternative to conventional ignition sources to ensure a reliable ignition under difficult conditions. In this study the influences of focal point properties on energy transfer from laser to plasma as well as plasma formation and propagation are investigated as the first steps of the laser induced ignition process. Maximum fluence and fluence volume are introduced to characterize focal point properties for varying laser pulse energies and focusing configurations. The results show that the transferred laser energy increases with increasing maximum fluence. During laser emission plasma propagates along the beam path of the focused laser beam. Rising maximum fluence results in increased plasma volume, but expansion saturates when fluence volume reaches its maximum.

  13. Localization in covariance matrices of coupled heterogenous Ornstein-Uhlenbeck processes

    NASA Astrophysics Data System (ADS)

    Barucca, Paolo

    2014-12-01

    We define a random-matrix ensemble given by the infinite-time covariance matrices of Ornstein-Uhlenbeck processes at different temperatures coupled by a Gaussian symmetric matrix. The spectral properties of this ensemble are shown to be in qualitative agreement with some stylized facts of financial markets. Through the presented model formulas are given for the analysis of heterogeneous time series. Furthermore evidence for a localization transition in eigenvectors related to small and large eigenvalues in cross-correlations analysis of this model is found, and a simple explanation of localization phenomena in financial time series is provided. Finally we identify both in our model and in real financial data an inverted-bell effect in correlation between localized components and their local temperature: high- and low-temperature components are the most localized ones.

  14. Feature binding and the processing of global-local shapes in bilingual and monolingual children.

    PubMed

    Cottini, Milvia; Pieroni, Laura; Spataro, Pietro; Devescovi, Antonella; Longobardi, Emiddia; Rossi-Arnaud, Clelia

    2015-04-01

    In the present study, we examined the effects of bilingualism and age on a color-shape binding task (assessing visual working memory) and a global-local task (assessing inhibitory processes) in a sample of 55 bilingual and 49 monolingual children 8 and 10 years old. In the color-shape binding task, corrected recognition scores increased in older children; bilingual children performed better than monolinguals in the shape-only condition, but the two groups were equally accurate in the color-only and combination conditions. In the global-local task, accuracy was higher in bilingual than in monolingual children, particularly on incongruent trials; monolingual children showed a strong global precedence effect (higher accuracy in the global than in the local conditions and greater global-to-local interference), whereas bilingual children exhibited a small, but significant, local precedence effect (higher accuracy in the local than in the global conditions and greater local-to-global interference). These findings confirm and extend previous evidence indicating that the bilingualism advantage is more pronounced in working memory tasks involving inhibitory processes.

  15. Examining local processes when applying a cumulative impact policy to address harms of alcohol outlet density.

    PubMed

    Grace, Daniel; Egan, Matt; Lock, Karen

    2016-07-01

    One approach to addressing the negative health and social harms of excessive drinking has been to attempt to limit alcohol availability in areas of high outlet density. The Licensing Act (2003) enables English local authorities the power to implement a Cumulative Impact Policy (CIP) in order to tackle alcohol challenges. More than 100 English local authorities have implemented a CIP in one or more designated areas. We examined local licence decision-making in the context of implementing CIPs. Specifically, we explored the activities involved in alcohol licensing in one London local authority in order to explicate how local decision-making processes regarding alcohol outlet density occur. Institutional ethnographic research revealed that CIPs were contested on multiple grounds within the statutory licensing process of a local authority with this policy in place. CIPs are an example of multi-level governance in which national and local interests, legal powers and alcohol licensing priorities interface. Public health priorities can be advanced in the delivery of CIPs, but those priorities can at times be diluted by those of other stakeholders, both public sector and commercial. PMID:27197092

  16. Differences in global and local level information processing in autism: an fMRI investigation

    PubMed Central

    Gadgil, Milind; Peterson, Eric; Tregellas, Jason; Hepburn, Susan; Rojas, Donald

    2013-01-01

    People with autism spectrum disorders (ASD) have atypical visual perception of global and local information. Previous neuroimaging studies have examined the functional anatomy of locally-directed attention during visual processing in ASD, but few have examined differences in both globally-and locally-directed attention. We performed functional magnetic resonance imaging (fMRI) in 17 adults with ASD and 16 typically developing (TD) subjects to examine the neurobiology of both global- and local- level information processing in ASD using an abstract hierarchical design task. TD subjects showed no regions of increased brain activation relative to subjects with ASD using whole brain analysis. Subjects with ASD exhibited greater activation in right superior frontal gyrus during locally directed attention. During globally directed attention, the ASD group showed greater right lateral occipital activation. Additionally, subjects with ASD showed less deactivation in medial prefrontal cortex (part of the default mode network) in the globally directed attention condition. Our findings help elucidate networks of brain activation related to atyipcal global and local feature processing in ASD. PMID:23768913

  17. The role of local and global processing in the recognition of living and nonliving things.

    PubMed

    Thomas, Richard; Forde, Emer

    2006-01-01

    We report a study on a patient (DW) with integrative visual agnosia and a category-specific recognition impairment for living things. We assessed DW's local and global processing and tested if his integrative agnosia could have led directly to his category-specific impairment. The main findings were: (i) DW was faster at identifying local compared to global letters. (ii) DW showed no local-to-global (or global-to-local) interference effects in selective attention tasks. (iii) DW showed a congruency effect in a divided attention task, suggesting that, when his attention was cued to both levels, he could process information simultaneously and integrate local and global information. (iv) Controls were poorer at naming nonliving compared to living things when presented with silhouettes. These data suggest that local and global information are differentially weighted in the visual recognition of living and nonliving things, and that an impairment in processing the overall shape of an object can lead to a category-specific deficit for living things. Crucially, this implies that category-specific impairments do not necessarily reflect damage to the semantic system, and models of semantic memory based on this assumption need to be revised. PMID:16253294

  18. Alerting enhances attentional bias for salient stimuli: evidence from a global/local processing task.

    PubMed

    Weinbach, Noam; Henik, Avishai

    2014-11-01

    The present study examined the role of alerting in modulating attentional bias to salient events. In a global/local processing task, participants were presented with a large arrow (global level) comprised of smaller arrows (local level) pointing in the same or opposite directions and had to indicate the direction of the large or small arrows in different blocks. Saliency of the global and local levels was manipulated, creating global-salient and local-salient conditions. Alerting signals were presented in half of the trials prior to the target. Results revealed a double dissociation in the effects of alerting on global/local interference effects. In a global salient condition, alerting increased global interference and decreased local interference. In a local salient condition, alerting reduced global interference and increased local interference. We demonstrate that within a single task, alerting can increase and reduce conflict based on perceptual saliency. These findings help to better understand disorders like hemispatial neglect in which both arousal and attention to salient events are impaired. These results also challenge previous theories suggesting that alerting acts to increase conflict interference. We argue that alerting is an adaptive mechanism that diverts attention to salient events, but comes at a cost when selective attention to less salient details is required.

  19. Volcanic passive margins

    NASA Astrophysics Data System (ADS)

    Geoffroy, Laurent

    2005-12-01

    Compared to non-volcanic ones, volcanic passive margins mark continental break-up over a hotter mantle, probably subject to small-scale convection. They present distinctive genetic and structural features. High-rate extension of the lithosphere is associated with catastrophic mantle melting responsible for the accretion of a thick igneous crust. Distinctive structural features of volcanic margins are syn-magmatic and continentward-dipping crustal faults accommodating the seaward flexure of the igneous crust. Volcanic margins present along-axis a magmatic and tectonic segmentation with wavelength similar to adjacent slow-spreading ridges. Their 3D organisation suggests a connection between loci of mantle melting at depths and zones of strain concentration within the lithosphere. Break-up would start and propagate from localized thermally-softened lithospheric zones. These 'soft points' could be localized over small-scale convection cells found at the bottom of the lithosphere, where adiabatic mantle melting would specifically occur. The particular structure of the brittle crust at volcanic passive margins could be interpreted by active and sudden oceanward flow of both the unstable hot mantle and the ductile part of the lithosphere during the break-up stage. To cite this article: L. Geoffroy, C. R. Geoscience 337 (2005).

  20. Impairment in local and global processing and set-shifting in body dysmorphic disorder.

    PubMed

    Kerwin, Lauren; Hovav, Sarit; Hellemann, Gerhard; Feusner, Jamie D

    2014-10-01

    Body dysmorphic disorder (BDD) is characterized by distressing and often debilitating preoccupations with misperceived defects in appearance. Research suggests that aberrant visual processing may contribute to these misperceptions. This study used two tasks to probe global and local visual processing as well as set-shifting in individuals with BDD. Eighteen unmedicated individuals with BDD and 17 non-clinical controls completed two global-local tasks. The embedded figures task requires participants to determine which of three complex figures contains a simpler figure embedded within it. The Navon task utilizes incongruent stimuli comprised of a large letter (global level) made up of smaller letters (local level). The outcome measures were response time and accuracy rate. On the embedded figures task, BDD individuals were slower and less accurate than controls. On the Navon task, BDD individuals processed both global and local stimuli slower and less accurately than controls, and there was a further decrement in performance when shifting attention between the different levels of stimuli. Worse insight correlated with poorer performance on both tasks. Taken together, these results suggest abnormal global and local processing for non-appearance related stimuli among BDD individuals, in addition to evidence of poor set-shifting abilities. Moreover, these abnormalities appear to relate to the important clinical variable of poor insight. Further research is needed to explore these abnormalities and elucidate their possible role in the development and/or persistence of BDD symptoms.

  1. Gestalt perception and local-global processing in high-functioning autism.

    PubMed

    Bölte, Sven; Holtmann, Martin; Poustka, Fritz; Scheurich, Armin; Schmidt, Lutz

    2007-09-01

    This study examined gestalt perception in high-functioning autism (HFA) and its relation to tasks indicative of local visual processing. Data on of gestalt perception, visual illusions (VI), hierarchical letters (HL), Block Design (BD) and the Embedded Figures Test (EFT) were collected in adult males with HFA, schizophrenia, depression and normative controls. Individuals with HFA processed gestalt stimuli less in accord with gestalt laws, particularly regarding the principle of similarity. Gestalt processing correlated positively with global processing of the HL. EFT and BD performance correlated negatively with VI susceptibility in HFA. All clinical groups succumbed less to VI than the normative sample. Results suggest decreased gestalt perception in HFA, being associated with a more general local visual processing bias.

  2. Evaluation of Alternate Surface Passivation Methods (U)

    SciTech Connect

    Clark, E

    2005-05-31

    Stainless steel containers were assembled from parts passivated by four commercial vendors using three passivation methods. The performance of these containers in storing hydrogen isotope mixtures was evaluated by monitoring the composition of initially 50% H{sub 2} 50% D{sub 2} gas with time using mass spectroscopy. Commercial passivation by electropolishing appears to result in surfaces that do not catalyze hydrogen isotope exchange. This method of surface passivation shows promise for tritium service, and should be studied further and considered for use. On the other hand, nitric acid passivation and citric acid passivation may not result in surfaces that do not catalyze the isotope exchange reaction H{sub 2} + D{sub 2} {yields} 2HD. These methods should not be considered to replace the proprietary passivation processes of the two current vendors used at the Savannah River Site Tritium Facility.

  3. The discriminability of local cues determines the strength of holistic face processing.

    PubMed

    Goffaux, Valerie

    2012-07-01

    Face perception is thought to result from the dynamic interplay between holistic and featural modes of processing. What determines the engagement of each mode is currently unknown. Here, we investigated whether the discriminability of local feature cues is a critical determinant of holistic/featural processing engagement. We estimated the strength of holistic processing based on observers' failure to discriminate target features independently of the context of distracter features in a congruency paradigm. Feature discriminability was manipulated by varying the dissimilarity of target features parametrically, using morphing. We observed that the size of the congruency effect decayed monotonically as a function of the dissimilarity of the target features. In other words, the more similar the target features the stronger the holistic processing. A correlation analysis confirmed that local feature discriminability reliably predicted holistic engagement at upright orientation. In contrast, when a clear local feature difference was detected, perceptual contamination by the other surrounding features was prevented. This evidence firmly suggests that the interplay between holistic/featural processing depends on the discriminability of the signal provided at the local featural level.

  4. Enhanced Carrier Collection from CdS Passivated Grains in Solution-Processed Cu2ZnSn(S,Se)4 Solar Cells.

    PubMed

    Werner, Melanie; Keller, Debora; Haass, Stefan G; Gretener, Christina; Bissig, Benjamin; Fuchs, Peter; La Mattina, Fabio; Erni, Rolf; Romanyuk, Yaroslav E; Tiwari, Ayodhya N

    2015-06-10

    Solution processing of Cu2ZnSn(S,Se)4 (CZTSSe)-kesterite solar cells is attractive because of easy manufacturing using readily available metal salts. The solution-processed CZTSSe absorbers, however, often suffer from poor morphology with a bilayer structure, exhibiting a dense top crust and a porous bottom layer, albeit yielding efficiencies of over 10%. To understand whether the cell performance is limited by this porous layer, a systematic compositional study using (scanning) transmission electron microscopy ((S)TEM) and energy-dispersive X-ray spectroscopy of the dimethyl sulfoxide processed CZTSSe absorbers is presented. TEM investigation revealed a thin layer of CdS that is formed around the small CZTSSe grains in the porous bottom layer during the chemical bath deposition step. This CdS passivation is found to be beneficial for the cell performance as it increases the carrier collection and facilitates the electron transport. Electron-beam-induced current measurements reveal an enhanced carrier collection for this buried region as compared to reference cells with evaporated CdS. PMID:25985349

  5. Global interference during early visual processing: ERP evidence from a rapid global/local selective task.

    PubMed

    Beaucousin, Virginie; Simon, Grégory; Cassotti, Mathieu; Pineau, Arlette; Houdé, Olivier; Poirel, Nicolas

    2013-01-01

    Visual perception depends on the integration of local elements of a visual scene into a global frame. Evidence from behavioral studies shows that (1) the detection of the global frame is faster than the detection of the local parts, a phenomenon called the global advantage, and that (2) an interference of the global shape is also present during local processing. Together, these effects are called the global precedence effect (GPE). Even if the global advantage appears to impact neural processing as early as the first 100 ms post-stimulus, previous studies failed to find a global interference effect before 200 ms post-stimulus. Using for the first time a rapid display of letter component stimuli during a global/local selective task in which conditions with perceptual conflict, congruent and incongruent conditions were considered, the present event-related potential (ERP) study shows a global interference effect occurring as early as the time range of the N1 component. In particular, only congruent stimuli elicited similar N1 amplitude during the global and local tasks, whereas an increased of the N1 amplitude during the global task was observed (as compared to the local task) for both stimuli with perceptual conflict and incongruent stimuli. This finding corroborates the recent neural models of human visual perception.

  6. Zinc recovery and waste sludge minimization from chromium passivation baths.

    PubMed

    Diban, Nazely; Mediavilla, Rosa; Urtiaga, Ane; Ortiz, Inmaculada

    2011-08-30

    This work reports the feasibility of applying emulsion pertraction technology (EPT) aiming at zinc recovery and waste minimization in the zinc electroplating processes that include Cr (III) passivation. The assessment consists of firstly the lifetime extension of the passivation baths by selective removal of the tramp ions zinc and iron, and secondly, the recovery of zinc for further reuse. Spent passivation baths from a local industry were tested, being the major metallic content: Cr(3+) 9000mg L(-1), Zn(2+) 12,000mg L(-1), Fe(3+) 100mg L(-1). Working in a Liqui-Cel hollow fiber membrane contactor and using the extractant bis(2,4,4-trimethylpentyl) phosphinic acid, reduction of zinc and iron concentrations below 60mg L(-1) and 2mg L(-1), respectively were obtained, while trivalent chromium, the active metal that generates the passivation layer, was retained in the baths. Zinc was selectively transferred to an acidic stripping phase that in the experimental time reached a concentration of 157,000mg L(-1). Zinc recovery by electrowinning from the acidic stripping phase without any pretreatment of the electrolyte solution provided a purity of 98.5%, matching the lower commercial zinc grade. As a result of the extension of the life time of the passivation bath, significant environmental advantages are derived such as minimization of the volume of hazardous wastes and savings in the consumption of raw materials. PMID:21704452

  7. Permeability Reduction in Passively Degassing Seawater-dominated Volcanic-hydrothermal systems: Processes and Perils on Raoul Island, Kermadecs (NZ)

    NASA Astrophysics Data System (ADS)

    Christenson, B. W.; Reyes, A. G.

    2014-12-01

    The 2006 eruption from Raoul Island occurred apparently in response to local tectonic swarm activity, but without any precursory indication of volcanic unrest within the hydrothermal system on the island. The eruption released some 200 T of SO2, implicating the involvement of a deep magmatic vapor input into the system during/prior to the event. In the absence of any recognized juvenile material in the eruption products, previous explanations for this eruptive event focused on this vapor being a driving force for the eruption. In 2004, at least 80 T/d of CO2 was escaping from the hydrothermal system, but mainly through areas that did not correspond to the 2006 eruption vents. The lack of a pre-eruptive hydrothermal system response related to the seismic event in 2006 can be explained by the presence of a hydrothermal mineralogic seal in the vent area of the volcano. Evidence for the existence of such a seal was found in eruption deposits in the form of massive fracture fillings of aragonite, calcite and anhydrite. Fluid inclusion homogenization temperatures in these phases range from ca. 140 °C to 220 °C which, for pure water indicate boiling point depths of between 40 and 230 m assuming a cold hydrostatic pressure constraint. Elevated pressures behind this seal are consistent with the occurrence of CO2 clathrates in some inclusion fluids, indicating CO2 concentrations approaching 1 molal in the parent fluids. Reactive transport modeling of magmatic volatile inputs into what is effectively a seawater-dominated hydrothermal system provide valuable insights into seal formation. Carbonate mineral phases ultimately come to saturation along this flow path, but we suggest that focused deposition of the observed massive carbonate seal is facilitated by near-surface boiling of these CO2-enriched altered seawaters, leading to large degrees of supersaturation which are required for the formation of aragonite. As the seal grew and permeability declined, pore pressures

  8. From local to global processing: the development of illusory contour perception.

    PubMed

    Nayar, Kritika; Franchak, John; Adolph, Karen; Kiorpes, Lynne

    2015-03-01

    Global visual processing is important for segmenting scenes, extracting form from background, and recognizing objects. Local processing involves attention to the local elements, contrast, and boundaries of an image at the expense of extracting a global percept. Previous work is inconclusive regarding the relative development of local and global processing. Some studies suggest that global perception is already present by 8 months of age, whereas others suggest that the ability arises during childhood and continues to develop during adolescence. We used a novel method to assess the development of global processing in 3- to 10-year-old children and an adult comparison group. We used Kanizsa illusory contours as an assay of global perception and measured responses on a touch-sensitive screen while monitoring eye position with a head-mounted eye tracker. Participants were tested using a similarity match-to-sample paradigm. Using converging measures, we found a clear developmental progression with age such that the youngest children performed near chance on the illusory contour discrimination, whereas 7- and 8-year-olds performed nearly perfectly, as did adults. There was clear evidence of a gradual shift from a local processing strategy to a global one; young children looked predominantly at and touched the "pacman" inducers of the illusory form, whereas older children and adults looked predominantly at and touched the middle of the form. These data show a prolonged developmental trajectory in appreciation of global form, with a transition from local to global visual processing between 4 and 7 years of age.

  9. Kinect Posture Reconstruction Based on a Local Mixture of Gaussian Process Models.

    PubMed

    Liu, Zhiguang; Zhou, Liuyang; Leung, Howard; Shum, Hubert P H

    2016-11-01

    Depth sensor based 3D human motion estimation hardware such as Kinect has made interactive applications more popular recently. However, it is still challenging to accurately recognize postures from a single depth camera due to the inherently noisy data derived from depth images and self-occluding action performed by the user. In this paper, we propose a new real-time probabilistic framework to enhance the accuracy of live captured postures that belong to one of the action classes in the database. We adopt the Gaussian Process model as a prior to leverage the position data obtained from Kinect and marker-based motion capture system. We also incorporate a temporal consistency term into the optimization framework to constrain the velocity variations between successive frames. To ensure that the reconstructed posture resembles the accurate parts of the observed posture, we embed a set of joint reliability measurements into the optimization framework. A major drawback of Gaussian Process is its cubic learning complexity when dealing with a large database due to the inverse of a covariance matrix. To solve the problem, we propose a new method based on a local mixture of Gaussian Processes, in which Gaussian Processes are defined in local regions of the state space. Due to the significantly decreased sample size in each local Gaussian Process, the learning time is greatly reduced. At the same time, the prediction speed is enhanced as the weighted mean prediction for a given sample is determined by the nearby local models only. Our system also allows incrementally updating a specific local Gaussian Process in real time, which enhances the likelihood of adapting to run-time postures that are different from those in the database. Experimental results demonstrate that our system can generate high quality postures even under severe self-occlusion situations, which is beneficial for real-time applications such as motion-based gaming and sport training. PMID:26701789

  10. 43 CFR 44.20 - How does the Department process payments to local governments whose jurisdictions contain...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... to local governments whose jurisdictions contain entitlement lands? 44.20 Section 44.20 Public Lands: Interior Office of the Secretary of the Interior FINANCIAL ASSISTANCE, LOCAL GOVERNMENTS Payments to Local Governments Containing Entitlement Lands § 44.20 How does the Department process payments to local...

  11. Global-National-Local Dynamics in Policy Processes: A Case of 'Quality' Policy in Higher Education

    ERIC Educational Resources Information Center

    Vidovich, Lesley

    2004-01-01

    This paper moves beyond a conceptualization of globalization as a top-down imposition of policy directions 'from above' to focus on the active two-way dynamics between global, national and local levels of policy processes. Arguably, the particular 'case' examined here of 'quality' policy is especially appropriate as quality policy and…

  12. Effects of Local and Global Context on Processing Sentences with Subject and Object Relative Clauses

    ERIC Educational Resources Information Center

    Yang, Fang; Mo, Lun; Louwerse, Max M.

    2013-01-01

    An eye tracking study investigated the effects of local and global discourse context on the processing of subject and object relative clauses, whereby the contexts favored either a subject relative clause interpretation or an object relative clause interpretation. The fixation data replicated previous studies showing that object relative clause…

  13. Local and Topological Processing in Sentence Comprehension by French and Spanish Children.

    ERIC Educational Resources Information Center

    Kail, Michele; Charvillat, Agnes

    1988-01-01

    Cross-linguistic investigation of the importance of syntactic cues and cue processing cost in French and Spanish four through six-year-olds' sentence comprehension revealed that topological cues helped French subjects most, while local cues helped Spanish subjects most. (Author/CB)

  14. Preparing for Novel versus Familiar Events: Shifts in Global and Local Processing

    ERIC Educational Resources Information Center

    Forster, Jens; Liberman, Nira; Shapira, Oren

    2009-01-01

    Six experiments examined whether novelty versus familiarity influences global versus local processing styles. Novelty and familiarity were manipulated by either framing a task as new versus familiar or by asking participants to reflect upon novel versus familiar events prior to the task (i.e., procedural priming). In Experiments 1-3, global…

  15. Gestalt Perception and Local-Global Processing in High-Functioning Autism

    ERIC Educational Resources Information Center

    Bolte, Sven; Holtmann, Martin; Poustka, Fritz; Scheurich, Armin; Schmidt, Lutz

    2007-01-01

    This study examined gestalt perception in high-functioning autism (HFA) and its relation to tasks indicative of local visual processing. Data on of gestalt perception, visual illusions (VI), hierarchical letters (HL), Block Design (BD) and the Embedded Figures Test (EFT) were collected in adult males with HFA, schizophrenia, depression and…

  16. Are the Autism and Positive Schizotypy Spectra Diametrically Opposed in Local versus Global Processing?

    ERIC Educational Resources Information Center

    Russell-Smith, Suzanna N.; Maybery, Murray T.; Bayliss, Donna M.

    2010-01-01

    Crespi and Badcock (2008) proposed that autism and psychosis represent two extremes on a cognitive spectrum with normality at its center. Their specific claim that autistic and positive schizophrenia traits contrastingly affect preference for local versus global processing was investigated by examining Embedded Figures Test performance in two…

  17. Material Processing Handbook. The Wisconsin Guide to Local Curriculum Improvement in Industrial Education K-12.

    ERIC Educational Resources Information Center

    Wisconsin State Dept. of Public Instruction, Madison. Div. of Instructional Services.

    This handbook is intended to aid industrial educators in developing material processing activities for their programs; it is especially designed to aid educators in implementing "The Wisconsin Guide to Local Curriculum Improvement in Industrial Education, K-12." The guide provides suggested outlines and models that could be used to structure a…

  18. Visual Search in ASD: Instructed versus Spontaneous Local and Global Processing

    ERIC Educational Resources Information Center

    Van der Hallen, Ruth; Evers, Kris; Boets, Bart; Steyaert, Jean; Noens, Ilse; Wagemans, Johan

    2016-01-01

    Visual search has been used extensively to investigate differences in mid-level visual processing between individuals with ASD and TD individuals. The current study employed two visual search paradigms with Gaborized stimuli to assess the impact of task distractors (Experiment 1) and task instruction (Experiment 2) on local-global visual…

  19. Curvature instability in passive diffractive resonators.

    PubMed

    Tlidi, M; Vladimirov, A G; Mandel, Paul

    2002-12-01

    We study the stability of localized structures in a passive optical bistable system. We show that there is a critical value of the input field intensity above which localized structures are unstable with respect to a curvature instability. Beyond this instability boundary, a transition from the localized branch of solutions to stable hexagons is found. PMID:12485009

  20. Gibbs free energy assisted passivation layers

    NASA Astrophysics Data System (ADS)

    Salihoglu, Omer; Tansel, T.; Hostut, M.; Ergun, Y.; Aydinli, A.

    2016-05-01

    Reduction of surface leakage is a major challenge in most photodetectors that requires the elimination of surface oxides on etched mesas during passivation. Engineering the passivation requires close attention to chemical reactions that take place at the interface during the process. In particular, removal of surface oxides may be controlled via Gibbs reactivity. We have compared electrical performance of type-II superlattice photodetectors, designed for MWIR operation, passivated by different passivation techniques. We have used ALD deposited Al2O3, HfO2, TiO2, ZnO, PECVD deposited SiO2, Si3N4 and sulphur containing octadecanethiol (ODT) selfassembled monolayers (SAM) passivation layers on InAs/GaSb p-i-n superlattice photodetectors with cutoff wavelength at 5.1 μm. In this work, we have compared the result of different passivation techniques which are done under same conditions, same epitaxial structure and same fabrication processes. We have found that ALD deposited passivation is directly related to the Gibbs free energy of the passivation material. Gibbs free energies of the passivation layer can directly be compared with native surface oxides to check the effectiveness of the passivation layer before the experimental study.

  1. Influence of Second Language Proficiency and Syntactic Structure Similarities on the Sensitivity and Processing of English Passive Sentence in Late Chinese-English Bilinguists: An ERP Study.

    PubMed

    Chang, Xin; Wang, Pei

    2016-02-01

    To investigate the influence of L2 proficiency and syntactic similarity on English passive sentence processing, the present ERP study asked 40 late Chinese-English bilinguals (27 females and 13 males, mean age = 23.88) with high or intermediate L2 proficiency to read the sentences carefully and to indicate for each sentence whether or not it was correct. Sentences were classified into literal translation sentences with the similar structure between the two languages and free translation sentences with the different structure. Behavioral data showed: shorter reaction times and higher accuracy rates occurred in the high-proficient group than those in the intermediate-proficient group; shorter reaction times and higher accuracy rates were observed in literal translation sentences than those in free translation sentences. ERP results showed literal translation sentences elicited an enhanced P200 and P600 while free translation sentences elicited a larger N400. The high-proficient group showed a larger P600 in syntactic violations and double violations while the intermediate-proficient group evoked an enhanced N400 in semantic violations and double violations. Literal translation sentences caused a larger P200 while free translation sentences elicited more negative-going N400. Behavioral and ERP data revealed the influence of L2 proficiency and syntactic similarity on L2 sentence processing, and L2 proficiency played a predominate role.

  2. An improved solution of local window parameters setting for local singularity analysis based on Excel VBA batch processing technology

    NASA Astrophysics Data System (ADS)

    Zhang, Daojun; Cheng, Qiuming; Agterberg, Frits; Chen, Zhijun

    2016-03-01

    In this paper Excel VBA is used for batch calculation in Local Singularity Analysis (LSA), which is for the information extracting from different kinds of geoscience data. Capabilities and advantages of a new module called Batch Tool for Local Singularity Index Mapping (BTLSIM) are: (1) batch production of series of local singularity maps with different settings of local window size, shape and orientation parameters; (2) local parameter optimization based on statistical tests; and (3) provision of extra output layers describing how spatial changes induced by parameter optimization are related to spatial structure of the original input layers.

  3. Effects of Local and Non-Local Processes on the Aging of the Tropopause Layer and the Lower Stratosphere

    NASA Astrophysics Data System (ADS)

    Pittman, J. V.; Wofsy, S. C.; Daube, B. C.; Smith, J. B.; Anderson, J. G.; Gao, R. S.; Rollins, A. W.; Thornberry, T. D.; Watts, L. A.; Hintsa, E. J.; Moore, F. L.; Elkins, J. W.; Dlugokencky, E. J.; Andrews, A. E.; Atlas, E. L.; Navarro, M. A.; Schauffler, S.; Bui, T. V.; Pfister, L.; Liang, Q.; Wang, T.

    2015-12-01

    As concentrations of greenhouse gases continue to increase in the troposphere, general circulation models predict an acceleration in the Brewer-Dobson circulation (BDC). A common diagnostic used to evaluate this change in circulation is age of air, which is defined as the time elapsed since stratospheric air was last in contact with the troposphere. An acceleration in the BDC can lead to shorter residence times and hence younger age of air. This change would affect the chemical distribution of pollutants and ozone-depleting substances in the stratosphere and potentially impact the recovery of the stratospheric ozone layer. In this study, we use in-situ measurements and model outputs to derive and compare vertical profiles of age of air and to assess the impact of various dynamical processes on age of air over the tropics and Northern Hemisphere midlatitudes. We focus on measurements of winds and several tracers with varying atmospheric lifetimes recently obtained in the tropopause region and lower stratosphere during the NASA ATTREX and NASA SEAC4RS campaigns between Jan 2013 and Mar 2014. We derive age of air using CO2 measurements at the surface and at altitude. This tracer is nearly chemically inert in the atmosphere and has well-known sources at the surface: an increasing trend over time resulting from anthropogenic activity and a superimposed seasonal cycle resulting from photosynthesis and respiration by the biosphere. During the field deployments, we encountered episodes of contrasting transport and mixing processes compared to background conditions, namely local and non-local convection as identified by trajectories and distinct chemical signatures, nearby typhoons, wave activity, and shifts in large-scale circulation. In addition to aircraft measurements, we also examine data from earlier high-altitude balloon flights, which allowed us to sample deeper into the stratosphere. We complement the observations with model outputs from the NASA GEOS-5 atmospheric

  4. Fundamental studies of passivity and passivity breakdown

    SciTech Connect

    Macdonald, D.D.; Urquidi-Macdonald, M.; Song, H.; Biaggio-Rocha, S.; Searson, P.

    1991-11-01

    This report summarizes the findings of our fundamental research program on passivity and passivity breakdown. During the past three and one half years in this program (including the three year incrementally-funded grant prior to the present grant), we developed and experimentally tested various physical models for the growth and breakdown of passive films on metal surfaces. These models belong to a general class termed point defects models'' (PDMs), in which the growth and breakdown of passive films are described in terms of the movement of anion and cation vacancies.

  5. Understanding the local socio-political processes affecting conservation management outcomes in Corbett Tiger Reserve, India.

    PubMed

    Rastogi, Archi; Hickey, Gordon M; Badola, Ruchi; Hussain, Syed Ainul

    2014-05-01

    Several measures have been recommended to guarantee a sustainable population of tigers: sufficient inviolate spaces for a viable population, sufficient prey populations, trained and skilled manpower to guard against poaching and intrusion, banning trade in tiger products to reduce poaching, and importantly, the political will to precipitate these recommendations into implementation. Of these, the creation of sufficient inviolate spaces (generally in the form of protected areas) has created the most issues with local resource-dependent communities, often resulting in significant challenges for tiger conservation policy and management. Very little empirical research has, however, been done to understand and contextualize the local-level socio-political interactions that may influence the efficacy of tiger conservation in India. In this paper, we present the results of exploratory research into the ways in which local-stakeholder groups affect the management of Corbett Tiger Reserve (CTR). Using a combined grounded theory-case study research design, and the Institutional Analysis and Development framework for analysis, we identify the socio-political processes through which local-stakeholder groups are able to articulate their issues and elicit desirable actions from the management of CTR. Increasing our awareness of these processes can help inform the design and implementation of more effective tiger conservation management and policy strategies that have the potential to create more supportive coalitions of tiger conservation stakeholders at the local level.

  6. Understanding the Local Socio-political Processes Affecting Conservation Management Outcomes in Corbett Tiger Reserve, India

    NASA Astrophysics Data System (ADS)

    Rastogi, Archi; Hickey, Gordon M.; Badola, Ruchi; Hussain, Syed Ainul

    2014-05-01

    Several measures have been recommended to guarantee a sustainable population of tigers: sufficient inviolate spaces for a viable population, sufficient prey populations, trained and skilled manpower to guard against poaching and intrusion, banning trade in tiger products to reduce poaching, and importantly, the political will to precipitate these recommendations into implementation. Of these, the creation of sufficient inviolate spaces (generally in the form of protected areas) has created the most issues with local resource-dependent communities, often resulting in significant challenges for tiger conservation policy and management. Very little empirical research has, however, been done to understand and contextualize the local-level socio-political interactions that may influence the efficacy of tiger conservation in India. In this paper, we present the results of exploratory research into the ways in which local-stakeholder groups affect the management of Corbett Tiger Reserve (CTR). Using a combined grounded theory-case study research design, and the Institutional Analysis and Development framework for analysis, we identify the socio-political processes through which local-stakeholder groups are able to articulate their issues and elicit desirable actions from the management of CTR. Increasing our awareness of these processes can help inform the design and implementation of more effective tiger conservation management and policy strategies that have the potential to create more supportive coalitions of tiger conservation stakeholders at the local level.

  7. Understanding the local socio-political processes affecting conservation management outcomes in Corbett Tiger Reserve, India.

    PubMed

    Rastogi, Archi; Hickey, Gordon M; Badola, Ruchi; Hussain, Syed Ainul

    2014-05-01

    Several measures have been recommended to guarantee a sustainable population of tigers: sufficient inviolate spaces for a viable population, sufficient prey populations, trained and skilled manpower to guard against poaching and intrusion, banning trade in tiger products to reduce poaching, and importantly, the political will to precipitate these recommendations into implementation. Of these, the creation of sufficient inviolate spaces (generally in the form of protected areas) has created the most issues with local resource-dependent communities, often resulting in significant challenges for tiger conservation policy and management. Very little empirical research has, however, been done to understand and contextualize the local-level socio-political interactions that may influence the efficacy of tiger conservation in India. In this paper, we present the results of exploratory research into the ways in which local-stakeholder groups affect the management of Corbett Tiger Reserve (CTR). Using a combined grounded theory-case study research design, and the Institutional Analysis and Development framework for analysis, we identify the socio-political processes through which local-stakeholder groups are able to articulate their issues and elicit desirable actions from the management of CTR. Increasing our awareness of these processes can help inform the design and implementation of more effective tiger conservation management and policy strategies that have the potential to create more supportive coalitions of tiger conservation stakeholders at the local level. PMID:24522894

  8. Impaired Global, and Compensatory Local, Biological Motion Processing in People with High Levels of Autistic Traits

    PubMed Central

    van Boxtel, Jeroen J. A.; Lu, Hongjing

    2013-01-01

    People with Autism Spectrum Disorder (ASD) are hypothesized to have poor high-level processing but superior low-level processing, causing impaired social recognition, and a focus on non-social stimulus contingencies. Biological motion perception provides an ideal domain to investigate exactly how ASD modulates the interaction between low and high-level processing, because it involves multiple processing stages, and carries many important social cues. We investigated individual differences among typically developing observers in biological motion processing, and whether such individual differences associate with the number of autistic traits. In Experiment 1, we found that individuals with fewer autistic traits were automatically and involuntarily attracted to global biological motion information, whereas individuals with more autistic traits did not show this pre-attentional distraction. We employed an action adaptation paradigm in the second study to show that individuals with more autistic traits were able to compensate for deficits in global processing with an increased involvement in local processing. Our findings can be interpreted within a predictive coding framework, which characterizes the functional relationship between local and global processing stages, and explains how these stages contribute to the perceptual difficulties associated with ASD. PMID:23630514

  9. [Effect of conflict frequency associated with presentation hemifield on global/local processing].

    PubMed

    Kuratomi, Kei; Yoshizaki, Kazuhito

    2013-12-01

    We used a global/local processing task with hierarchically structured visual stimuli to investigate whether each hemisphere independently modulates visual selectivity depending on conflict frequency. In both of the present experiments, a hierarchical pattern consisting of large (global) letter made up of small (local) letters was briefly presented to unilateral visual-field (LVF/RVF) and the congruency between the local and global levels was manipulated. An important manipulation was that the congruency ratio in a given block differed between the two visual-fields (80% and 20%). We required right-handed participants to identify the global (Experiment 1) and local level (Experiment 2) of the hierarchical stimulus. The results showed that when the stimuli were projected to the nondominant hemisphere for the task demand (left hemisphere in the global task and right hemisphere in the local task) the size of the interference (local interference in Experiment 1 and global interference in Experiment 2) was larger in the 80% congruent condition than in the 20% congruent condition, whereas it was invariant when the stimuli were projected to the dominant hemisphere. These results demonstrate that each hemisphere independently works cognitive control.

  10. Visual Search in ASD: Instructed Versus Spontaneous Local and Global Processing.

    PubMed

    Van der Hallen, Ruth; Evers, Kris; Boets, Bart; Steyaert, Jean; Noens, Ilse; Wagemans, Johan

    2016-09-01

    Visual search has been used extensively to investigate differences in mid-level visual processing between individuals with ASD and TD individuals. The current study employed two visual search paradigms with Gaborized stimuli to assess the impact of task distractors (Experiment 1) and task instruction (Experiment 2) on local-global visual processing in ASD versus TD children. Experiment 1 revealed both groups to be equally sensitive to the absence or presence of a distractor, regardless of the type of target or type of distractor. Experiment 2 revealed a differential effect of task instruction for ASD compared to TD, regardless of the type of target. Taken together, these results stress the importance of task factors in the study of local-global visual processing in ASD.

  11. The cold land processes experiment (CLPX) local scale observatin site (LSOS)

    NASA Technical Reports Server (NTRS)

    McDonald, K. C.; Hardy, J. P.; Cline, D.; Elder, K.; Davis, R.; Pomeroy, J.; Koh, G.; Armstrong, R.; Koike, T.

    2002-01-01

    The Local Scale Observation Site (LSOS) is the smallest study site of the Cold LandProcesses Experiment (CLPX) and is located within the Fraser Meso-cell Study Area (MSA), near the Fraser Experimental Forest Headquarters Facility, in Fraser, CO USA.The 100-m x 100-m site consists of a small open field, a managed dense canopy and an open, mixed age canopy. Unlike the other components of the experiment, which focus on spatial distributions at relatively brief snapshots in time, measurements at the local scale site focused on the temporal domain.

  12. Processing advances for localization of beaked whales using time difference of arrival.

    PubMed

    Baggenstoss, Paul M

    2013-06-01

    This paper is concerned with the localization of clicking Blainville's beaked whales (Mesoplodon densirostris) using an array of widely spaced bottom-mounted hydrophones. A set of signal and data processing advances are presented that together make reliable tracking a possibility. These advances include a species-specific detector, elimination of spurious time-difference-of-arrival (TDOA) estimates, improved tracking of TDOA estimates, positive association of TDOA estimates using different hydrophone pairs, and joint localization of multiple whales. A key innovation in three of these advances is the principle of click-matching. The methods are demonstrated using real data.

  13. An eigenvector-based test for local stationarity applied to array processing.

    PubMed

    Quijano, Jorge E; Zurk, Lisa M

    2014-06-01

    In sonar array processing, a challenging problem is the estimation of the data covariance matrix in the presence of moving targets in the water column, since the time interval of data local stationarity is limited. This work describes an eigenvector-based method for proper data segmentation into intervals that exhibit local stationarity, providing data-driven higher bounds for the number of snapshots available for computation of time-varying sample covariance matrices. Application of the test is illustrated with simulated data in a horizontal array for the detection of a quiet source in the presence of a loud interferer.

  14. Global-local visual processing impacts risk taking behaviors, but only at first.

    PubMed

    Lim, Stephen Wee Hun; Yuen, Alexander Y L; Tong, Eddie M W

    2015-01-01

    We investigated the impact of early visual processing on decision-making during unpredictable, risky situations. Participants undertook Navon's (1977) task and attended to either global letters or local letters only, following which they completed the Balloon Analogue Risk Task (BART). It was observed that global-focused individuals made more balloon pumps during the BART (i.e., took more risk), whereas local-focused individuals took less risk, albeit only initially. The theory of predictive and reactive control systems (PARCS) provides an excellent account of the data. Implications and future directions are discussed. PMID:26379586

  15. Turboprop and rotary-wing aircraft flight parameter estimation using both narrow-band and broadband passive acoustic signal-processing methods.

    PubMed

    Ferguson, B G; Lo, K W

    2000-10-01

    Flight parameter estimation methods for an airborne acoustic source can be divided into two categories, depending on whether the narrow-band lines or the broadband component of the received signal spectrum is processed to estimate the flight parameters. This paper provides a common framework for the formulation and test of two flight parameter estimation methods: one narrow band, the other broadband. The performances of the two methods are evaluated by applying them to the same acoustic data set, which is recorded by a planar array of passive acoustic sensors during multiple transits of a turboprop fixed-wing aircraft and two types of rotary-wing aircraft. The narrow-band method, which is based on a kinematic model that assumes the source travels in a straight line at constant speed and altitude, requires time-frequency analysis of the acoustic signal received by a single sensor during each aircraft transit. The broadband method is based on the same kinematic model, but requires observing the temporal variation of the differential time of arrival of the acoustic signal at each pair of sensors that comprises the planar array. Generalized cross correlation of each pair of sensor outputs using a cross-spectral phase transform prefilter provides instantaneous estimates of the differential times of arrival of the signal as the acoustic wavefront traverses the array.

  16. Investigating the stability of and relationships among global/local processing measures.

    PubMed

    Dale, Gillian; Arnell, Karen M

    2013-04-01

    Global/local stimuli have been used to estimate global processing biases in individuals and groups, as well as in response to various manipulations. Throughout the literature, multiple different versions of global/local stimuli have been used, such as traditional hierarchical letters and numbers (i.e., Navon letters), abstract hierarchical shapes, and high- and low-spatial-frequency gratings and faces. However, currently it is unclear how reliable or stable performance is on these measures within individuals over time, and whether these seemingly different measures are tapping into the same underlying process. As such, the purpose of the present study was to examine the stability of individual performance on three distinct global/local measures over time and to examine the relationships among the measures. In two studies, we examined the reliability of the biases within, and the relationships among, standard Navon letters in a traditional interference task, hierarchical shapes in a forced choice task, and superimposed high- and low-pass spatial frequency faces in a forced choice task. In both studies, participants completed all three of the tasks, and then returned 7-10 days later to again complete the same tasks. The degree of global/local bias within an individual was found to be highly reliable in the hierarchical shape task and the spatial frequency face task, but less reliable in the traditional Navon letter task. Interestingly, in both studies we found that none of the three measures of global bias were related to each other. Therefore, while these measures do appear to be reliable over time, they may be tapping into distinct aspects of global/local processing.

  17. Place as a social space: fields of encounter relating to the local sustainability process.

    PubMed

    Dumreicher, Heidi; Kolb, Bettina

    2008-04-01

    The paper shows how sustainability questions relate to the local space. The local place is not a static entity, but a dynamic one, undergoing constant changes, and it is the rapid social and material processes within the given local situation that is a challenge for the Chinese villages and their integrity. The following article considers the cohesion between the dwellers' emotional co-ownership of their local space and the sustainability process as a driving force in social, economic and ecological development. We bring together the classification of the seven fields of encounter, which were developed out of the empirical data of the Chinese case study villages, and sustainability oriented management considerations for all levels of this concept. We do not pretend to know the solutions, but describe a set of interrelated fields that can be anchor points for placing the solutions and show in which fields action and intervention is possible. In our concept of sustainability, every spatial field has its special meaning, needs special measures and policies and has different connotations to concepts like responsibility, family values or communication systems. We see the social sustainability process as a support for the empowerment of the local dwellers, and the SUCCESS research has encouraged the villages to find suitable sustainability oriented solutions for their natural and societal situation. Before entering the discussion about the chances and potential of a sustainability approach for the Chinese villages, it is first necessary to accept the fact that rural villages play a primordial role in Chinese society and that their potential can strengthen future pathways for China.

  18. Place as a social space: fields of encounter relating to the local sustainability process.

    PubMed

    Dumreicher, Heidi; Kolb, Bettina

    2008-04-01

    The paper shows how sustainability questions relate to the local space. The local place is not a static entity, but a dynamic one, undergoing constant changes, and it is the rapid social and material processes within the given local situation that is a challenge for the Chinese villages and their integrity. The following article considers the cohesion between the dwellers' emotional co-ownership of their local space and the sustainability process as a driving force in social, economic and ecological development. We bring together the classification of the seven fields of encounter, which were developed out of the empirical data of the Chinese case study villages, and sustainability oriented management considerations for all levels of this concept. We do not pretend to know the solutions, but describe a set of interrelated fields that can be anchor points for placing the solutions and show in which fields action and intervention is possible. In our concept of sustainability, every spatial field has its special meaning, needs special measures and policies and has different connotations to concepts like responsibility, family values or communication systems. We see the social sustainability process as a support for the empowerment of the local dwellers, and the SUCCESS research has encouraged the villages to find suitable sustainability oriented solutions for their natural and societal situation. Before entering the discussion about the chances and potential of a sustainability approach for the Chinese villages, it is first necessary to accept the fact that rural villages play a primordial role in Chinese society and that their potential can strengthen future pathways for China. PMID:17766035

  19. Angioedema attacks in patients with hereditary angioedema: Local manifestations of a systemic activation process.

    PubMed

    Hofman, Zonne L M; Relan, Anurag; Zeerleder, Sacha; Drouet, Christian; Zuraw, Bruce; Hack, C Erik

    2016-08-01

    Hereditary angioedema (HAE) caused by a deficiency of functional C1-inhibitor (C1INH) becomes clinically manifest as attacks of angioedema. C1INH is the main inhibitor of the contact system. Poor control of a local activation process of this system at the site of the attack is believed to lead to the formation of bradykinin (BK), which increases local vasopermeability and mediates angioedema on interaction with BK receptor 2 on the endothelium. However, several observations in patients with HAE are difficult to explain from a pathogenic model claiming a local activation process at the site of the angioedema attack. Therefore we postulate an alternative model for angioedema attacks in patients with HAE, which assumes a systemic, fluid-phase activation of the contact system to generate BK and its breakdown products. Interaction of these peptides with endothelial receptors that are locally expressed in the affected tissues rather than with receptors constitutively expressed by the endothelium throughout the whole body explains that such a systemic activation process results in local manifestations of an attack. In particular, BK receptor 1, which is induced on the endothelium by inflammatory stimuli, such as kinins and cytokines, meets the specifications of the involved receptor. The pathogenic model discussed here also provides an explanation for why angioedema can occur at multiple sites during an attack and why HAE attacks respond well to modest increases of circulating C1INH activity levels because inhibition of fluid-phase Factor XIIa and kallikrein requires lower C1INH levels than inhibition of activator-bound factors. PMID:27246526

  20. Angioedema attacks in patients with hereditary angioedema: Local manifestations of a systemic activation process.

    PubMed

    Hofman, Zonne L M; Relan, Anurag; Zeerleder, Sacha; Drouet, Christian; Zuraw, Bruce; Hack, C Erik

    2016-08-01

    Hereditary angioedema (HAE) caused by a deficiency of functional C1-inhibitor (C1INH) becomes clinically manifest as attacks of angioedema. C1INH is the main inhibitor of the contact system. Poor control of a local activation process of this system at the site of the attack is believed to lead to the formation of bradykinin (BK), which increases local vasopermeability and mediates angioedema on interaction with BK receptor 2 on the endothelium. However, several observations in patients with HAE are difficult to explain from a pathogenic model claiming a local activation process at the site of the angioedema attack. Therefore we postulate an alternative model for angioedema attacks in patients with HAE, which assumes a systemic, fluid-phase activation of the contact system to generate BK and its breakdown products. Interaction of these peptides with endothelial receptors that are locally expressed in the affected tissues rather than with receptors constitutively expressed by the endothelium throughout the whole body explains that such a systemic activation process results in local manifestations of an attack. In particular, BK receptor 1, which is induced on the endothelium by inflammatory stimuli, such as kinins and cytokines, meets the specifications of the involved receptor. The pathogenic model discussed here also provides an explanation for why angioedema can occur at multiple sites during an attack and why HAE attacks respond well to modest increases of circulating C1INH activity levels because inhibition of fluid-phase Factor XIIa and kallikrein requires lower C1INH levels than inhibition of activator-bound factors.

  1. An image processing application for the localization and segmentation of lymphoblast cell using peripheral blood images.

    PubMed

    Madhloom, Hayan T; Kareem, Sameem Abdul; Ariffin, Hany

    2012-08-01

    An important preliminary step in the diagnosis of leukemia is the visual examination of the patient's peripheral blood smear under the microscope. Morphological changes in the white blood cells can be an indicator of the nature and severity of the disease. Manual techniques are labor intensive, slow, error prone and costly. A computerized system can be used as a supportive tool for the specialist in order to enhance and accelerate the morphological analysis process. This research present a new method that integrates color features with the morphological reconstruction to localize and isolate lymphoblast cells from a microscope image that contains many cells. The localization and segmentation are conducted using a proposed method that consists of an integration of several digital image processing techniques. 180 microscopic blood images were tested, and the proposed framework managed to obtain 100% accuracy for the localization of the lymphoblast cells and separate it from the image scene. The results obtained indicate that the proposed method can be safely used for the purpose of lymphoblast cells localization and segmentation and subsequently, aiding the diagnosis of leukemia.

  2. Local Versus Global Effects of Isoflurane Anesthesia on Visual Processing in the Fly Brain.

    PubMed

    Cohen, Dror; Zalucki, Oressia H; van Swinderen, Bruno; Tsuchiya, Naotsugu

    2016-01-01

    What characteristics of neural activity distinguish the awake and anesthetized brain? Drugs such as isoflurane abolish behavioral responsiveness in all animals, implying evolutionarily conserved mechanisms. However, it is unclear whether this conservation is reflected at the level of neural activity. Studies in humans have shown that anesthesia is characterized by spatially distinct spectral and coherence signatures that have also been implicated in the global impairment of cortical communication. We questioned whether anesthesia has similar effects on global and local neural processing in one of the smallest brains, that of the fruit fly (Drosophila melanogaster). Using a recently developed multielectrode technique, we recorded local field potentials from different areas of the fly brain simultaneously, while manipulating the concentration of isoflurane. Flickering visual stimuli ('frequency tags') allowed us to track evoked responses in the frequency domain and measure the effects of isoflurane throughout the brain. We found that isoflurane reduced power and coherence at the tagging frequency (13 or 17 Hz) in central brain regions. Unexpectedly, isoflurane increased power and coherence at twice the tag frequency (26 or 34 Hz) in the optic lobes of the fly, but only for specific stimulus configurations. By modeling the periodic responses, we show that the increase in power in peripheral areas can be attributed to local neuroanatomy. We further show that the effects on coherence can be explained by impacted signal-to-noise ratios. Together, our results show that general anesthesia has distinct local and global effects on neuronal processing in the fruit fly brain. PMID:27517084

  3. Structural damage localization by outlier analysis of signal-processed mode shapes - Analytical and experimental validation

    NASA Astrophysics Data System (ADS)

    Ulriksen, M. D.; Damkilde, L.

    2016-02-01

    Contrary to global modal parameters such as eigenfrequencies, mode shapes inherently provide structural information on a local level. Therefore, this particular modal parameter and its derivatives are utilized extensively for damage identification. Typically, more or less advanced mathematical methods are employed to identify damage-induced discontinuities in the spatial mode shape signals, hereby, potentially, facilitating damage detection and/or localization. However, by being based on distinguishing damage-induced discontinuities from other signal irregularities, an intrinsic deficiency in these methods is the high sensitivity towards measurement noise. In the present paper, a damage localization method which, compared to the conventional mode shape-based methods, has greatly enhanced robustness towards measurement noise is proposed. The method is based on signal processing of a spatial mode shape by means of continuous wavelet transformation (CWT) and subsequent application of a generalized discrete Teager-Kaiser energy operator (GDTKEO) to identify damage-induced mode shape discontinuities. In order to evaluate whether the identified discontinuities are in fact damage-induced, outlier analysis is conducted by applying the Mahalanobis metric to major principal scores of the sensor-located bands of the signal-processed mode shape. The method is tested analytically and benchmarked with other mode shape-based damage localization approaches on the basis of a free-vibrating beam and validated experimentally in the context of a residential-sized wind turbine blade subjected to an impulse load.

  4. Local Versus Global Effects of Isoflurane Anesthesia on Visual Processing in the Fly Brain

    PubMed Central

    2016-01-01

    Abstract What characteristics of neural activity distinguish the awake and anesthetized brain? Drugs such as isoflurane abolish behavioral responsiveness in all animals, implying evolutionarily conserved mechanisms. However, it is unclear whether this conservation is reflected at the level of neural activity. Studies in humans have shown that anesthesia is characterized by spatially distinct spectral and coherence signatures that have also been implicated in the global impairment of cortical communication. We questioned whether anesthesia has similar effects on global and local neural processing in one of the smallest brains, that of the fruit fly (Drosophila melanogaster). Using a recently developed multielectrode technique, we recorded local field potentials from different areas of the fly brain simultaneously, while manipulating the concentration of isoflurane. Flickering visual stimuli (‘frequency tags’) allowed us to track evoked responses in the frequency domain and measure the effects of isoflurane throughout the brain. We found that isoflurane reduced power and coherence at the tagging frequency (13 or 17 Hz) in central brain regions. Unexpectedly, isoflurane increased power and coherence at twice the tag frequency (26 or 34 Hz) in the optic lobes of the fly, but only for specific stimulus configurations. By modeling the periodic responses, we show that the increase in power in peripheral areas can be attributed to local neuroanatomy. We further show that the effects on coherence can be explained by impacted signal-to-noise ratios. Together, our results show that general anesthesia has distinct local and global effects on neuronal processing in the fruit fly brain. PMID:27517084

  5. GWM-2005 - A Groundwater-Management Process for MODFLOW-2005 with Local Grid Refinement (LGR) Capability

    USGS Publications Warehouse

    Ahlfeld, David P.; Baker, Kristine M.; Barlow, Paul M.

    2009-01-01

    This report describes the Groundwater-Management (GWM) Process for MODFLOW-2005, the 2005 version of the U.S. Geological Survey modular three-dimensional groundwater model. GWM can solve a broad range of groundwater-management problems by combined use of simulation- and optimization-modeling techniques. These problems include limiting groundwater-level declines or streamflow depletions, managing groundwater withdrawals, and conjunctively using groundwater and surface-water resources. GWM was initially released for the 2000 version of MODFLOW. Several modifications and enhancements have been made to GWM since its initial release to increase the scope of the program's capabilities and to improve its operation and reporting of results. The new code, which is called GWM-2005, also was designed to support the local grid refinement capability of MODFLOW-2005. Local grid refinement allows for the simulation of one or more higher resolution local grids (referred to as child models) within a coarser grid parent model. Local grid refinement is often needed to improve simulation accuracy in regions where hydraulic gradients change substantially over short distances or in areas requiring detailed representation of aquifer heterogeneity. GWM-2005 can be used to formulate and solve groundwater-management problems that include components in both parent and child models. Although local grid refinement increases simulation accuracy, it can also substantially increase simulation run times.

  6. Low-Temperature Process for Atomic Layer Chemical Vapor Deposition of an Al2O3 Passivation Layer for Organic Photovoltaic Cells.

    PubMed

    Kim, Hoonbae; Lee, Jihye; Sohn, Sunyoung; Jung, Donggeun

    2016-05-01

    Flexible organic photovoltaic (OPV) cells have drawn extensive attention due to their light weight, cost efficiency, portability, and so on. However, OPV cells degrade quickly due to organic damage by water vapor or oxygen penetration when the devices are driven in the atmosphere without a passivation layer. In order to prevent damage due to water vapor or oxygen permeation into the devices, passivation layers have been introduced through methods such as sputtering, plasma enhanced chemical vapor deposition, and atomic layer chemical vapor deposition (ALCVD). In this work, the structural and chemical properties of Al2O3 films, deposited via ALCVD at relatively low temperatures of 109 degrees C, 200 degrees C, and 300 degrees C, are analyzed. In our experiment, trimethylaluminum (TMA) and H2O were used as precursors for Al2O3 film deposition via ALCVD. All of the Al2O3 films showed very smooth, featureless surfaces without notable defects. However, we found that the plastic flexible substrate of an OPV device passivated with 300 degrees C deposition temperature was partially bended and melted, indicating that passivation layers for OPV cells on plastic flexible substrates need to be formed at temperatures lower than 300 degrees C. The OPV cells on plastic flexible substrates were passivated by the Al2O3 film deposited at the temperature of 109 degrees C. Thereafter, the photovoltaic properties of passivated OPV cells were investigated as a function of exposure time under the atmosphere. PMID:27483916

  7. Low-Temperature Process for Atomic Layer Chemical Vapor Deposition of an Al2O3 Passivation Layer for Organic Photovoltaic Cells.

    PubMed

    Kim, Hoonbae; Lee, Jihye; Sohn, Sunyoung; Jung, Donggeun

    2016-05-01

    Flexible organic photovoltaic (OPV) cells have drawn extensive attention due to their light weight, cost efficiency, portability, and so on. However, OPV cells degrade quickly due to organic damage by water vapor or oxygen penetration when the devices are driven in the atmosphere without a passivation layer. In order to prevent damage due to water vapor or oxygen permeation into the devices, passivation layers have been introduced through methods such as sputtering, plasma enhanced chemical vapor deposition, and atomic layer chemical vapor deposition (ALCVD). In this work, the structural and chemical properties of Al2O3 films, deposited via ALCVD at relatively low temperatures of 109 degrees C, 200 degrees C, and 300 degrees C, are analyzed. In our experiment, trimethylaluminum (TMA) and H2O were used as precursors for Al2O3 film deposition via ALCVD. All of the Al2O3 films showed very smooth, featureless surfaces without notable defects. However, we found that the plastic flexible substrate of an OPV device passivated with 300 degrees C deposition temperature was partially bended and melted, indicating that passivation layers for OPV cells on plastic flexible substrates need to be formed at temperatures lower than 300 degrees C. The OPV cells on plastic flexible substrates were passivated by the Al2O3 film deposited at the temperature of 109 degrees C. Thereafter, the photovoltaic properties of passivated OPV cells were investigated as a function of exposure time under the atmosphere.

  8. Tropospheric Passive Remote Sensing

    NASA Technical Reports Server (NTRS)

    Keafer, L. S., Jr. (Editor)

    1982-01-01

    The long term role of airborne/spaceborne passive remote sensing systems for tropospheric air quality research and the identification of technology advances required to improve the performance of passive remote sensing systems were discussed.

  9. Interlanguage Passive Construction

    ERIC Educational Resources Information Center

    Simargool, Nirada

    2008-01-01

    Because the appearance of the passive construction varies cross linguistically, differences exist in the interlanguage (IL) passives attempted by learners of English. One such difference is the widely studied IL pseudo passive, as in "*new cars must keep inside" produced by Chinese speakers. The belief that this is a reflection of L1 language…

  10. Defining the face processing network: optimization of the functional localizer in fMRI.

    PubMed

    Fox, Christopher J; Iaria, Giuseppe; Barton, Jason J S

    2009-05-01

    Functional localizers that contrast brain signal when viewing faces versus objects are commonly used in functional magnetic resonance imaging studies of face processing. However, current protocols do not reliably show all regions of the core system for face processing in all subjects when conservative statistical thresholds are used, which is problematic in the study of single subjects. Furthermore, arbitrary variations in the applied thresholds are associated with inconsistent estimates of the size of face-selective regions-of-interest (ROIs). We hypothesized that the use of more natural dynamic facial images in localizers might increase the likelihood of identifying face-selective ROIs in individual subjects, and we also investigated the use of a method to derive the statistically optimal ROI cluster size independent of thresholds. We found that dynamic facial stimuli were more effective than static stimuli, identifying 98% (versus 72% for static) of ROIs in the core face processing system and 69% (versus 39% for static) of ROIs in the extended face processing system. We then determined for each core face processing ROI, the cluster size associated with maximum statistical face-selectivity, which on average was approximately 50 mm(3) for the fusiform face area, the occipital face area, and the posterior superior temporal sulcus. We suggest that the combination of (a) more robust face-related activity induced by a dynamic face localizer and (b) a cluster-size determination based on maximum face-selectivity increases both the sensitivity and the specificity of the characterization of face-related ROIs in individual subjects.

  11. Defining the face processing network: optimization of the functional localizer in fMRI.

    PubMed

    Fox, Christopher J; Iaria, Giuseppe; Barton, Jason J S

    2009-05-01

    Functional localizers that contrast brain signal when viewing faces versus objects are commonly used in functional magnetic resonance imaging studies of face processing. However, current protocols do not reliably show all regions of the core system for face processing in all subjects when conservative statistical thresholds are used, which is problematic in the study of single subjects. Furthermore, arbitrary variations in the applied thresholds are associated with inconsistent estimates of the size of face-selective regions-of-interest (ROIs). We hypothesized that the use of more natural dynamic facial images in localizers might increase the likelihood of identifying face-selective ROIs in individual subjects, and we also investigated the use of a method to derive the statistically optimal ROI cluster size independent of thresholds. We found that dynamic facial stimuli were more effective than static stimuli, identifying 98% (versus 72% for static) of ROIs in the core face processing system and 69% (versus 39% for static) of ROIs in the extended face processing system. We then determined for each core face processing ROI, the cluster size associated with maximum statistical face-selectivity, which on average was approximately 50 mm(3) for the fusiform face area, the occipital face area, and the posterior superior temporal sulcus. We suggest that the combination of (a) more robust face-related activity induced by a dynamic face localizer and (b) a cluster-size determination based on maximum face-selectivity increases both the sensitivity and the specificity of the characterization of face-related ROIs in individual subjects. PMID:18661501

  12. [Fundamental studies of passivity and passivity breakdown

    SciTech Connect

    Macdonald, D.D.

    1993-07-01

    We developed and experimentally tested physical models for growth and breakdown of passive films on metal surfaces. These models are ``point defect models,`` in which the growth and breakdown are described in terms of movement of anion and cation vacancies. The work during the past 5 years resulted in: theory of growth and breakdown of passive films, theory of corrosion-resistant alloys, electronic structure of passive films, and estimation of damage functions for energy systems. Proposals are give for the five ongoing tasks. 10 figs.

  13. Tracking marine mammals using passive acoustics

    NASA Astrophysics Data System (ADS)

    Nosal, Eva-Marie

    2007-12-01

    It is difficult to study the behavior and physiology of marine mammals or to understand and mitigate human impact on them because much of their lives are spent underwater. Since sound propagates for long distances in the ocean and since many cetaceans are vocal, passive acoustics is a valuable tool for studying and monitoring their behavior. After a brief introduction to and review of passive acoustic tracking methods, this dissertation develops and applies two new methods. Both methods use widely-spaced (tens of kilometers) bottom-mounted hydrophone arrays, as well as propagation models that account for depth-dependent sound speed profiles. The first passive acoustic tracking method relies on arrival times of direct and surface-reflected paths. It is used to track a sperm whale using 5 at the Atlantic Undersea Test and Evaluation Center (AUTEC) and gives position estimates that are accurate to within 10 meters. With such accuracy, the whale's pitch and yaw are estimated by assuming that its main axis (which points from the tail to the rostrum) is parallel to its velocity. Roll is found by fitting the details of the pulses within each sperm whale click to the so-called bent horn model of sperm whale sound production. Finally, given the position and orientation of the whale, its beam pattern is reconstructed and found to be highly directional with an intense forward directed component. Pair-wise spectrogram (PWS) processing is the second passive acoustic tracking method developed in this dissertation. Although it is computationally more intensive, PWS has several advantages over arrival-time tracking methods, especially in shallow water environments, for long duration calls, and for multiple-animal datasets, as is the case for humpback whales on Hawaiian breeding grounds. Results of simulations with realistic noise conditions and environmental mismatch are given and compared to other passive localization techniques. When applied to the AUTEC sperm whale dataset, PWS

  14. Self-Orientation Modulates the Neural Correlates of Global and Local Processing.

    PubMed

    Liddell, Belinda J; Das, Pritha; Battaglini, Eva; Malhi, Gin S; Felmingham, Kim L; Whitford, Thomas J; Bryant, Richard A

    2015-01-01

    Differences in self-orientation (or "self-construal") may affect how the visual environment is attended, but the neural and cultural mechanisms that drive this remain unclear. Behavioral studies have demonstrated that people from Western backgrounds with predominant individualistic values are perceptually biased towards local-level information; whereas people from non-Western backgrounds that support collectivist values are preferentially focused on contextual and global-level information. In this study, we compared two groups differing in predominant individualistic (N = 15) vs collectivistic (N = 15) self-orientation. Participants completed a global/local perceptual conflict task whilst undergoing functional Magnetic Resonance Imaging (fMRI) scanning. When participants high in individualistic values attended to the global level (ignoring the local level), greater activity was observed in the frontoparietal and cingulo-opercular networks that underpin attentional control, compared to the match (congruent) baseline. Participants high in collectivistic values activated similar attentional control networks o only when directly compared with global processing. This suggests that global interference was stronger than local interference in the conflict task in the collectivistic group. Both groups showed increased activity in dorsolateral prefrontal regions involved in resolving perceptual conflict during heightened distractor interference. The findings suggest that self-orientation may play an important role in driving attention networks to facilitate interaction with the visual environment. PMID:26270820

  15. Self-Orientation Modulates the Neural Correlates of Global and Local Processing.

    PubMed

    Liddell, Belinda J; Das, Pritha; Battaglini, Eva; Malhi, Gin S; Felmingham, Kim L; Whitford, Thomas J; Bryant, Richard A

    2015-01-01

    Differences in self-orientation (or "self-construal") may affect how the visual environment is attended, but the neural and cultural mechanisms that drive this remain unclear. Behavioral studies have demonstrated that people from Western backgrounds with predominant individualistic values are perceptually biased towards local-level information; whereas people from non-Western backgrounds that support collectivist values are preferentially focused on contextual and global-level information. In this study, we compared two groups differing in predominant individualistic (N = 15) vs collectivistic (N = 15) self-orientation. Participants completed a global/local perceptual conflict task whilst undergoing functional Magnetic Resonance Imaging (fMRI) scanning. When participants high in individualistic values attended to the global level (ignoring the local level), greater activity was observed in the frontoparietal and cingulo-opercular networks that underpin attentional control, compared to the match (congruent) baseline. Participants high in collectivistic values activated similar attentional control networks o only when directly compared with global processing. This suggests that global interference was stronger than local interference in the conflict task in the collectivistic group. Both groups showed increased activity in dorsolateral prefrontal regions involved in resolving perceptual conflict during heightened distractor interference. The findings suggest that self-orientation may play an important role in driving attention networks to facilitate interaction with the visual environment.

  16. Gaussian Process Regression-Based Video Anomaly Detection and Localization With Hierarchical Feature Representation.

    PubMed

    Cheng, Kai-Wen; Chen, Yie-Tarng; Fang, Wen-Hsien

    2015-12-01

    This paper presents a hierarchical framework for detecting local and global anomalies via hierarchical feature representation and Gaussian process regression (GPR) which is fully non-parametric and robust to the noisy training data, and supports sparse features. While most research on anomaly detection has focused more on detecting local anomalies, we are more interested in global anomalies that involve multiple normal events interacting in an unusual manner, such as car accidents. To simultaneously detect local and global anomalies, we cast the extraction of normal interactions from the training videos as a problem of finding the frequent geometric relations of the nearby sparse spatio-temporal interest points (STIPs). A codebook of interaction templates is then constructed and modeled using the GPR, based on which a novel inference method for computing the likelihood of an observed interaction is also developed. Thereafter, these local likelihood scores are integrated into globally consistent anomaly masks, from which anomalies can be succinctly identified. To the best of our knowledge, it is the first time GPR is employed to model the relationship of the nearby STIPs for anomaly detection. Simulations based on four widespread datasets show that the new method outperforms the main state-of-the-art methods with lower computational burden. PMID:26394423

  17. Self-Orientation Modulates the Neural Correlates of Global and Local Processing

    PubMed Central

    Liddell, Belinda J.; Das, Pritha; Battaglini, Eva; Malhi, Gin S.; Felmingham, Kim L.; Whitford, Thomas J.; Bryant, Richard A.

    2015-01-01

    Differences in self-orientation (or “self-construal”) may affect how the visual environment is attended, but the neural and cultural mechanisms that drive this remain unclear. Behavioral studies have demonstrated that people from Western backgrounds with predominant individualistic values are perceptually biased towards local-level information; whereas people from non-Western backgrounds that support collectivist values are preferentially focused on contextual and global-level information. In this study, we compared two groups differing in predominant individualistic (N = 15) vs collectivistic (N = 15) self-orientation. Participants completed a global/local perceptual conflict task whilst undergoing functional Magnetic Resonance Imaging (fMRI) scanning. When participants high in individualistic values attended to the global level (ignoring the local level), greater activity was observed in the frontoparietal and cingulo-opercular networks that underpin attentional control, compared to the match (congruent) baseline. Participants high in collectivistic values activated similar attentional control networks o only when directly compared with global processing. This suggests that global interference was stronger than local interference in the conflict task in the collectivistic group. Both groups showed increased activity in dorsolateral prefrontal regions involved in resolving perceptual conflict during heightened distractor interference. The findings suggest that self-orientation may play an important role in driving attention networks to facilitate interaction with the visual environment. PMID:26270820

  18. Techniques for Processing Eyes Implanted With a Retinal Prosthesis for Localized Histopathological Analysis

    PubMed Central

    Nayagam, David A. X.; McGowan, Ceara; Villalobos, Joel; Williams, Richard A.; Salinas-LaRosa, Cesar; McKelvie, Penny; Lo, Irene; Basa, Meri; Tan, Justin; Williams, Chris E.

    2013-01-01

    With the recent development of retinal prostheses, it is important to develop reliable techniques for assessing the safety of these devices in preclinical studies. However, the standard fixation, preparation, and automated histology procedures are not ideal. Here we describe new procedures for evaluating the health of the retina directly adjacent to an implant. Retinal prostheses feature electrode arrays in contact with eye tissue. Previous methods have not been able to spatially localize the ocular tissue adjacent to individual electrodes within the array. In addition, standard histological processing often results in gross artifactual detachment of the retinal layers when assessing implanted eyes. Consequently, it has been difficult to assess localized damage, if present, caused by implantation and stimulation of an implanted electrode array. Therefore, we developed a method for identifying and localizing the ocular tissue adjacent to implanted electrodes using a (color-coded) dye marking scheme, and we modified an eye fixation technique to minimize artifactual retinal detachment. This method also rendered the sclera translucent, enabling localization of individual electrodes and specific parts of an implant. Finally, we used a matched control to increase the power of the histopathological assessments. In summary, this method enables reliable and efficient discrimination and assessment of the retinal cytoarchitecture in an implanted eye. PMID:23963336

  19. Impacts of tropical deforestation. Part I: Process analysis of local climatic change

    SciTech Connect

    Zhang, H.; Henderson-Sellers, A.; McGuffie, K.

    1996-07-01

    The potential impacts of deforestation in the humid Tropics are examined using a version of the National Center for Atmospheric Research`s CCM1 coupled with the Biosphere-Atmosphere Transfer Scheme package. Tropical deforestation in South America, Africa, and Southeast Asia is studied using the results from an 11-yr deforestation experiment and a 25-yr control integration. It is found that the local-scale impact (here defined as within the area deforested) varies greatly between the three deforested regions due to the differing controls on the local atmospheric circulation: the Southeast Asian monsoon is much less sensitive to deforestation than the low-level flow over South America. The analysis of the changes in cloud radiative forcing suggests that reduction in cloud amount can significantly mitigate the imposed increases in surface albedo. The importance of water recycling by the forest canopy is stressed in the simulation of local precipitation changes. Correlation analysis of the changes resulting from the deforestation has been used to determine the nature of the processes that follow from the removal of the forest canopy and to suggest the important processes. The role of large-scale dynamics is explored in a companion paper. 44 refs., 9 figs., 5 tabs.

  20. Interhemispheric cooperation in global-local visual processing in pediatric multiple sclerosis.

    PubMed

    Todorow, Michelle; DeSouza, Joseph F; Banwell, Brenda L; Till, Christine

    2014-01-01

    Impairments in visuospatial abilities are commonly reported in children and adolescents with multiple sclerosis (MS). Corpus callosum (CC) pathology occurs in patients with MS and may contribute to impairment in visuospatial perception, particularly when interhemispheric information transfer is required. This study used a global-local hierarchical letter paradigm to examine the relationship between interhemispheric information transfer and white matter integrity in the CC assessed using diffusion tensor imaging. Thirteen cognitively preserved pediatric-onset MS patients and 15 age-matched healthy controls were asked to determine whether a target letter E appeared at the attended level of the stimulus. As expected, both groups processed global and local information more slowly under divided than selective attention conditions. The MS group performed similarly to the control group with respect to reaction time and accuracy on selective and divided attention conditions, with one exception. Specifically, the presence of a global target when attending to a local target caused greater response conflict in the MS group than in controls (p = .01). Pooling both the patient and control data, greater response conflict was associated with reduced white matter integrity as indicated by lower fractional anisotropy in the anterior body of the CC (r = -.33, p < .05). Results suggest that reduced white matter integrity in anterior regions of the CC may lead to less efficient inhibition of task-irrelevant global information in the hierarchal processing of visual information.

  1. High frequency source localization in a shallow ocean sound channel using frequency difference matched field processing.

    PubMed

    Worthmann, Brian M; Song, H C; Dowling, David R

    2015-12-01

    Matched field processing (MFP) is an established technique for source localization in known multipath acoustic environments. Unfortunately, in many situations, particularly those involving high frequency signals, imperfect knowledge of the actual propagation environment prevents accurate propagation modeling and source localization via MFP fails. For beamforming applications, this actual-to-model mismatch problem was mitigated through a frequency downshift, made possible by a nonlinear array-signal-processing technique called frequency difference beamforming [Abadi, Song, and Dowling (2012). J. Acoust. Soc. Am. 132, 3018-3029]. Here, this technique is extended to conventional (Bartlett) MFP using simulations and measurements from the 2011 Kauai Acoustic Communications MURI experiment (KAM11) to produce ambiguity surfaces at frequencies well below the signal bandwidth where the detrimental effects of mismatch are reduced. Both the simulation and experimental results suggest that frequency difference MFP can be more robust against environmental mismatch than conventional MFP. In particular, signals of frequency 11.2 kHz-32.8 kHz were broadcast 3 km through a 106-m-deep shallow ocean sound channel to a sparse 16-element vertical receiving array. Frequency difference MFP unambiguously localized the source in several experimental data sets with average peak-to-side-lobe ratio of 0.9 dB, average absolute-value range error of 170 m, and average absolute-value depth error of 10 m. PMID:26723312

  2. Insights to caving processes from localization of microseismic swarms induced by salt solution mining

    NASA Astrophysics Data System (ADS)

    Lennart Kinscher, Jannes; Bernard, Pascal; Contrucci, Isabelle; Mangeney, Anne; Piguet, Jack Pierre; Bigarre, Pascal

    2014-05-01

    In order to improve our understanding of hazardous ground failures, caving processes, and collapses of large natural or man-made underground cavities, we studied microseismicity induced by the development and collapse of a salt solution mining cavity with a diameter of ~ 200 m at Cerville-Buissoncourt in Lorraine, France. Microseismicity was recorded as part of a large geophysical, multi-parameter monitoring research project (GISOS) by a local, high resolution, triggered 40 Hz geophone monitoring system consisting of five one-component and four three-component borehole stations located around and in the center of the cavity. The recorded microseismic events are very numerous (~ 50.000 recorded event files) where the major portion (~ 80 %) appear in unusual swarming sequences constituted by complex clusters of superimposed microseismic events. Body wave phase based routine tools for microseismic event detection and localization face strong limitations in the treatment of these signals. To overcome these shortcomings, we developed two probabilistic methods being able to assess the spatio-temporal characteristics in a semi-automatic manner. The first localization approach uses simple signal amplitude estimates on different frequency bands, and an attenuation model to constrain hypocenter source location. The second approach was designed to identify significantly polarized P wave energies and the associated polarization angles. Both approaches and its probabilistic conjunction were applied to the data of a two months lasting microseismic crisis occurring one year before the final collapse that was related to caving processes leading to a maximal growth of ~ 50 m of the cavity roof. The obtained epicenter locations show systematic spatio-temporal migration trends observed for different time scales. During three phases of major swarming activity, epicenter migration trends appear in the order of several seconds to minutes, are spatially constrained, and show partially a

  3. Local Competition and Metapopulation Processes Drive Long-Term Seagrass-Epiphyte Population Dynamics

    PubMed Central

    Lobelle, Delphine; Kenyon, Emma J.; Cook, Kevan J.; Bull, James C.

    2013-01-01

    It is well known that ecological processes such as population regulation and natural enemy interactions potentially occur over a range of spatial scales, and there is a substantial body of literature developing theoretical understanding of the interplay between these processes. However, there are comparatively few studies quantifying the long-term effects of spatial scaling in natural ecosystems. A key challenge is that trophic complexity in real-world biological communities quickly obscures the signal from a focal process. Seagrass meadows provide an excellent opportunity in this respect: in many instances, seagrasses effectively form extensive natural monocultures, in which hypotheses about endogenous dynamics can be formulated and tested. We present amongst the longest unbroken, spatially explict time series of seagrass abundance published to date. Data include annual measures of shoot density, total above-ground abundance, and associated epiphyte cover from five Zostera marina meadows distributed around the Isles of Scilly, UK, from 1996 to 2011. We explore empirical patterns at the local and metapopulation scale using standard time series analysis and develop a simple population dynamic model, testing the hypothesis that both local and metapopulation scale feedback processes are important. We find little evidence of an interaction between scales in seagrass dynamics but that both scales contribute approximately equally to observed local epiphyte abundance. By quantifying the long-term dynamics of seagrass-epiphyte interactions we show how measures of density and extent are both important in establishing baseline information relevant to predicting responses to environmental change and developing management plans. We hope that this study complements existing mechanistic studies of physiology, genetics and productivity in seagrass, whilst highlighting the potential of seagrass as a model ecosystem. More generally, this study provides a rare opportunity to test

  4. Early vestibular processing does not discriminate active from passive self-motion if there is a discrepancy between predicted and actual proprioceptive feedback.

    PubMed

    Brooks, Jessica X; Cullen, Kathleen E

    2014-06-15

    Most of our sensory experiences are gained by active exploration of the world. While the ability to distinguish sensory inputs resulting of our own actions (termed reafference) from those produced externally (termed exafference) is well established, the neural mechanisms underlying this distinction are not fully understood. We have previously proposed that vestibular signals arising from self-generated movements are inhibited by a mechanism that compares the internal prediction of the proprioceptive consequences of self-motion to the actual feedback. Here we directly tested this proposal by recording from single neurons in monkey during vestibular stimulation that was externally produced and/or self-generated. We show for the first time that vestibular reafference is equivalently canceled for self-generated sensory stimulation produced by activation of the neck musculature (head-on-body motion), or axial musculature (combined head and body motion), when there is no discrepancy between the predicted and actual proprioceptive consequences of self-motion. However, if a discrepancy does exist, central vestibular neurons no longer preferentially encode vestibular exafference. Specifically, when simultaneous active and passive motion resulted in activation of the same muscle proprioceptors, neurons robustly encoded the total vestibular input (i.e., responses to vestibular reafference and exafference were equally strong), rather than exafference alone. Taken together, our results show that the cancellation of vestibular reafference in early vestibular processing requires an explicit match between expected and actual proprioceptive feedback. We propose that this vital neuronal computation, necessary for both accurate sensory perception and motor control, has important implications for a variety of sensory systems that suppress self-generated signals.

  5. Evaluating the implementation of environmental review mitigation in local planning and development processes

    SciTech Connect

    Slotterback, Carissa Schively

    2008-11-15

    The implementation of mitigation strategies and outcomes of environmental review remains a challenge for planners and regulators. While the process and content of environmental review is clearly defined, there is often little attention to what happens after the review is completed. This paper presents the results of an evaluation of the implementation of the outcomes of environmental review, specifically mitigation measures designed to respond to environmental impacts identified in the environmental impact analysis. Drawing on previous evaluations of environmental review outcomes and plan implementation, the research provides a methodology for evaluating the implementation of mitigation efforts, points to the challenges associated with implementing the mitigation outcomes of local environmental review in planning and development processes, and identifies opportunities to integrate planning and environmental review processes.

  6. Chlorination processing of local planetary ores for oxygen and metallurgically important metals

    NASA Technical Reports Server (NTRS)

    Lynch, D. C.

    1989-01-01

    The use of chlorine to extract, reclaim, and purify metals has attractive possibilities for extraterrestrial processing of local planetary resources. While a complete cyclic process has been proposed for the recovery of metallurgically significant metals and oxygen, herein the chlorination step of the cycle is examined. An experimental apparatus for reacting refractory materials, such as ilmenite, in a microwave induced plasma is being built. Complex equilibria calculations reveal that stable refractory materials can, under the influence of a plasma, undergo chlorination and yield oxygen as a by-product. These issues and the potential advantages for plasma processing in space are reviewed. Also presented is a discussion of the complex equilibria program used in the analysis.

  7. A Sagnac-Michelson fibre optic interferometer: Signal processing for disturbance localization

    NASA Astrophysics Data System (ADS)

    Kondrat, M.; Szustakowski, M.; Pałka, N.; Ciurapiński, W.; Życzkowski, M.

    2007-09-01

    We present numerical and experimental results on a new generation fibre optic perimeter sensor based on a Sagnac and Michelson interferometers configuration. In particular, an original signal processing scheme is presented. The sensor can detect a potential intruder and determine its position along a protected zone. We propose a localization method that offers the inherent properties of both interferometers. After demodulation of the signals from both interferometers, the obtained amplitude characteristic of the Sagnac interferometer depends on a position of a disturbance along the interferometer, while amplitude characteristic of the Michelson interferometer does not depend on this position. So, quotient of both demodulated characteristics makes it possible to localize the disturbance. During investigations of a laboratory model of the sensor, it was possible to detect the position of the disturbance with a resolution of about 40 m along the 6-km-long sensor.

  8. Non-Local Damage Modelling of Sheet Metal Forming Processes with ALE Formulation

    NASA Astrophysics Data System (ADS)

    Adetoro, O. B.; Cardoso, Rui P. R.

    2016-08-01

    The modelling of material degradation due to nucleation, growth and coalescence of micro-voids is vital in sheet metal forming process due to the large deformation typically experienced by the part. Nonlocal damage modelling or nonlocal continuum is gaining a lot of interest because it is an effective approach to modelling the strain-softening, whilst avoiding the spurious localization that gives rise to strong mesh sensitivity in numerical computations. However to accurately resolve the evolving narrow bands of highly localised strain, it is necessary to use sufficient computational grids. In this paper an ALE formulation is used for modelling the localization pattern. An approach for relocating the node points is presented and explored.

  9. γ-Glutamyl Transpeptidase in Transgenic Tobacco Plants. Cellular Localization, Processing, and Biochemical Properties1

    PubMed Central

    Storozhenko, Sergei; Belles-Boix, Enric; Babiychuk, Elena; Hérouart, Didier; Davey, Mark W.; Slooten, Luit; Van Montagu, Marc; Inzé, Dirk; Kushnir, Sergei

    2002-01-01

    γ-Glutamyl transpeptidase (γ-GT) is a ubiquitous enzyme that catalyzes the first step of glutathione (GSH) degradation in the γ-glutamyl cycle in mammals. A cDNA encoding an Arabidopsis homolog for γ-GT was overexpressed in tobacco (Nicotiana tabacum) plants. A high level of the membrane-bound γ-GT activity was localized outside the cell in transgenic plants. The overproduced enzyme was characterized by a high affinity to GSH and was cleaved post-translationally in two unequal subunits. Thus, Arabidopsis γ-GT is similar to the mammalian enzymes in enzymatic properties, post-translational processing, and cellular localization, suggesting analogous biological functions as a key enzyme in the catabolism of GSH. PMID:11891265

  10. [Passive smoking--active killer].

    PubMed

    Palavra, Irena Rojnić; Franelić, Iva Pejnović; Milanović, Sanja Musić; Puljić, Kresimir

    2013-01-01

    Although still not perceived in this way, passive smoking is a public health issue of great importance. World Health Organization estimates that as a result of passive exposure to tobacco smoke each year 600,000 people die, of which 165,000 children. There are 33% of men, 35% of women and 40% of children who do not smoke, but are exposed to second hand smoke, and still only 11% of the world population is protected by adequate smoke-free legislation. Scientific literature provides evidence that passive exposure to tobacco smoke can result in numerous adverse health effects: asthma and allergies, respiratory infections and (middle) ear infections, cancers of various localization, accelerated atherosclerosis and cardiovascular diseases, retardation of growth and development in children, and in pregnancy it can lead to congenital anomalies and premature birth as well as lower body weight and length of the child. Certainly, the scariest consequence of all is sudden infant death syndrome, also called "death in the crib". Smoke-free policies have proven their effectiveness, but while implementing the laws, it is necessary to raise public awareness of the hazards of, both active and passive, exposure to tobacco smoke. PMID:24490334

  11. Relations between Perceptual and Conceptual Scope: How Global versus Local Processing Fits a Focus on Similarity versus Dissimilarity

    ERIC Educational Resources Information Center

    Forster, Jens

    2009-01-01

    Nine studies showed a bidirectional link (a) between a global processing style and generation of similarities and (b) between a local processing style and generation of dissimilarities. In Experiments 1-4, participants were primed with global versus local perception styles and then asked to work on an allegedly unrelated generation task. Across…

  12. Switching between forest and trees: opposite relationship of progesterone and testosterone to global-local processing.

    PubMed

    Pletzer, Belinda; Petasis, Ourania; Cahill, Larry

    2014-07-01

    Sex differences in attentional selection of global and local components of stimuli have been hypothesized to underlie sex differences in cognitive strategy choice. A Navon figure paradigm was employed in 32 men, 41 naturally cycling women (22 follicular, 19 luteal) and 19 users of oral contraceptives (OCs) containing first to third generation progestins in their active pill phase. Participants were first asked to detect targets at any level (divided attention) and then at either the global or the local level only (focused attention). In the focused attention condition, luteal women showed reduced global advantage (i.e. faster responses to global vs. local targets) compared to men, follicular women and OC users. Accordingly, global advantage during the focused attention condition related significantly positively to testosterone levels and significantly negatively to progesterone, but not estradiol levels in a multiple regression model including all naturally cycling women and men. Interference (i.e. delayed rejection of stimuli displaying targets at the non-attended level) was significantly enhanced in OC users as compared to naturally cycling women and related positively to testosterone levels in all naturally cycling women and men. Remarkably, when analyzed separately for each group, the relationship of testosterone to global advantage and interference was reversed in women during their luteal phase as opposed to men and women during their follicular phase. As global processing is lateralized to the right and local processing to the left hemisphere, we speculate that these effects stem from a testosterone-mediated enhancement of right-hemisphere functioning as well as progesterone-mediated inter-hemispheric decoupling.

  13. Macroscopic fluxes and local reciprocal relation in second-order stochastic processes far from equilibrium

    NASA Astrophysics Data System (ADS)

    Ge, Hao

    2015-01-01

    A stochastic process is an essential tool for the investigation of the physical and life sciences at nanoscale. In the first-order stochastic processes widely used in chemistry and biology, only the flux of mass rather than that of heat can be well defined. Here we investigate the two macroscopic fluxes in second-order stochastic processes driven by position-dependent forces and temperature gradient. We prove that the thermodynamic equilibrium defined through the vanishing of macroscopic fluxes is equivalent to that defined via time reversibility at mesoscopic scale. In the small noise limit, we find that the entropy production rate, which has previously been defined by the mesoscopic irreversible fluxes on the phase space, matches the classic macroscopic expression as the sum of the products of macroscopic fluxes and their associated thermodynamic forces. Further we show that the two pairs of forces and fluxes in such a limit follow a linear phenomenonical relation and the associated scalar coefficients always satisfy the reciprocal relation for both transient and steady states. The scalar coefficient is proportional to the square of local temperature divided by the local frictional coefficient and originated from the second moment of velocity distribution along each dimension. This result suggests the very close connection between the Soret effect (thermal diffusion) and Dufour effect at nanoscale even far from equilibrium.

  14. Generation of spatiotemporally correlated spike trains and local field potentials using a multivariate autoregressive process.

    PubMed

    Gutnisky, Diego A; Josić, Kresimir

    2010-05-01

    Experimental advances allowing for the simultaneous recording of activity at multiple sites have significantly increased our understanding of the spatiotemporal patterns in neural activity. The impact of such patterns on neural coding is a fundamental question in neuroscience. The simulation of spike trains with predetermined activity patterns is therefore an important ingredient in the study of potential neural codes. Such artificially generated spike trains could also be used to manipulate cortical neurons in vitro and in vivo. Here, we propose a method to generate spike trains with given mean firing rates and cross-correlations. To capture this statistical structure we generate a point process by thresholding a stochastic process that is continuous in space and discrete in time. This stochastic process is obtained by filtering Gaussian noise through a multivariate autoregressive (AR) model. The parameters of the AR model are obtained by a nonlinear transformation of the point-process correlations to the continuous-process correlations. The proposed method is very efficient and allows for the simulation of large neural populations. It can be optimized to the structure of spatiotemporal correlations and generalized to nonstationary processes and spatiotemporal patterns of local field potentials and spike trains. PMID:20032244

  15. Local contextual processing of abstract and meaningful real-life images in professional athletes.

    PubMed

    Fogelson, Noa; Fernandez-Del-Olmo, Miguel; Acero, Rafael Martín

    2012-05-01

    We investigated the effect of abstract versus real-life meaningful images from sports on local contextual processing in two groups of professional athletes. Local context was defined as the occurrence of a short predictive series of stimuli occurring before delivery of a target event. EEG was recorded in 10 professional basketball players and 9 professional athletes of individual sports during three sessions. In each session, a different set of visual stimuli were presented: triangles facing left, up, right, or down; four images of a basketball player throwing a ball; four images of a baseball player pitching a baseball. Stimuli consisted of 15 % targets and 85 % of equal numbers of three types of standards. Recording blocks consisted of targets preceded by randomized sequences of standards and by sequences including a predictive sequence signaling the occurrence of a subsequent target event. Subjects pressed a button in response to targets. In all three sessions, reaction times and peak P3b latencies were shorter for predicted targets compared with random targets, the last most informative stimulus of the predictive sequence induced a robust P3b, and N2 amplitude was larger for random targets compared with predicted targets. P3b and N2 peak amplitudes were larger in the professional basketball group in comparison with professional athletes of individual sports, across the three sessions. The findings of this study suggest that local contextual information is processed similarly for abstract and for meaningful images and that professional basketball players seem to allocate more attentional resources in the processing of these visual stimuli.

  16. Processing local pragmatic anomalies in fictional contexts: evidence from the N400.

    PubMed

    Filik, Ruth; Leuthold, Hartmut

    2008-07-01

    Readers typically experience processing difficulty when they encounter a word that is anomalous within the local context, such as "The cat picked up the chainsaw." In an ERP study, we demonstrate that by placing such a sentence in a fictional scenario that is well known to the reader (e.g., a Tom and Jerry cartoon), the N400 effect usually associated with these pragmatic anomalies can be eliminated. This finding suggests that readers can rapidly integrate information from their common ground while interpreting incoming text and provides further evidence that incoming words are immediately evaluated within the global discourse.

  17. Subcellular localization of glycosidases and glycosyltransferases involved in the processing of N-linked oligosaccharides

    SciTech Connect

    Sturm, A.; Johnson, K.D.; Szumilo, T.; Elbein, A.D.; Chrispeels, M.J.

    1987-11-01

    Using isopycnic sucrose gradients, we have ascertained the subcellular location of several enzymes involved in the processing of the N-linked oligosaccharides of glycoproteins in developing cotyledons of the common bean, Phaseolus vulgaris. All are localized in the endoplasmic reticulum (ER) or Golgi complex as determined by co-sedimentation with the ER marker, NADH-cytochrome c reductase, or the Golgi marker, glucan synthase I. Glucosidase activity, which removes glucose residues from Glc/sub 3/Man/sub 9/(GlcNAc)/sub 2/, was found exclusively in the ER. All other processing enzymes, which act subsequent to the glucose trimming steps, are associates with Golgi. These include mannosidase I (removes 1-2 mannose residues from Man/sub 6-9/(GlcNAc)/sub 2/), mannosidase II (removes mannose residues from GlcNAcMan/sub 5/(GlcNAc)/sub 2/), and fucosyltransferase (transfers a fucose residue to the Asn-linked GlcNAc of appropriate glycans). The authors have previously reported the localization of two other glycan modifying enzymes (GlcNAc-transferase and xylosyltranferase activities) in the Golgi complex. Attempts at subfractionation of the Golgi fraction on shallow sucrose gradients yielded similar patterns of distribution for all the Golgi processing enzymes. Subfractionation on Percoll gradients resulted in two peaks of the Golgi marker enzyme inosine diphosphatase, whereas the glycan processing enzymes were all enriched in the peak of lower density. These results do not lend support to the hypothesis that N-linked oligosaccharide processing enzymes are associated with Golgi cisternae of different densities.

  18. Improvement of bias-stability in amorphous-indium-gallium-zinc-oxide thin-film transistors by using solution-processed Y{sub 2}O{sub 3} passivation

    SciTech Connect

    An, Sungjin; Mativenga, Mallory; Kim, Youngoo; Jang, Jin

    2014-08-04

    We demonstrate back channel improvement of back-channel-etch amorphous-indium-gallium-zinc-oxide (a-IGZO) thin-film transistors by using solution-processed yttrium oxide (Y{sub 2}O{sub 3}) passivation. Two different solvents, which are acetonitrile (35%) + ethylene glycol (65%), solvent A and deionized water, solvent B are investigated for the spin-on process of the Y{sub 2}O{sub 3} passivation—performed after patterning source/drain (S/D) Mo electrodes by a conventional HNO{sub 3}-based wet-etch process. Both solvents yield devices with good performance but those passivated by using solvent B exhibit better light and bias stability. Presence of yttrium at the a-IGZO back interface, where it occupies metal vacancy sites, is confirmed by X-ray photoelectron spectroscopy. The passivation effect of yttrium is more significant when solvent A is used because of the existence of more metal vacancies, given that the alcohol (65% ethylene glycol) in solvent A may dissolve the metal oxide (a-IGZO) through the formation of alkoxides and water.

  19. Prediction Of Formability In Sheet Metal Forming Processes Using A Local Damage Model

    SciTech Connect

    Teixeira, P.; Santos, Abel; Cesar Sa, J.; Andrade Pires, F.; Barata da Rocha, A.

    2007-05-17

    The formability in sheet metal forming processes is mainly conditioned by ductile fracture resulting from geometric instabilities due to necking and strain localization. The macroscopic collapse associated with ductile failure is a result of internal degradation described throughout metallographic observations by the nucleation, growth and coalescence of voids and micro-cracks. Damage influences and is influenced by plastic deformation and therefore these two dissipative phenomena should be coupled at the constitutive level. In this contribution, Lemaitre's ductile damage model is coupled with Hill's orthotropic plasticity criterion. The coupling between damaging and material behavior is accounted for within the framework of Continuum Damage Mechanics (CDM). The resulting constitutive equations are implemented in the Abaqus/Explicit code, for the prediction of fracture onset in sheet metal forming processes. The damage evolution law takes into account the important effect of micro-crack closure, which dramatically decreases the rate of damage growth under compressive paths.

  20. Neural Processes in the Human Temporoparietal Cortex Separated by Localized Independent Component Analysis.

    PubMed

    Igelström, Kajsa M; Webb, Taylor W; Graziano, Michael S A

    2015-06-24

    The human temporoparietal junction (TPJ) is a topic of intense research. Imaging studies have identified TPJ activation in association with many higher-order functions such as theory-of-mind, episodic memory, and attention, causing debate about the distribution of different processes. One major challenge is the lack of consensus about the anatomical location and extent of the TPJ. Here, we address this problem using data-driven analysis to test the hypothesis that the bilateral TPJ can be parcellated into subregions. We applied independent component analysis (ICA) to task-free fMRI data within a local region around the bilateral TPJ, iterating the ICA at multiple model orders and in several datasets. The localized analysis allowed finer separation of processes and the use of multiple dimensionalities provided qualitative information about lateralization. We identified four subdivisions that were bilaterally symmetrical and one that was right biased. To test whether the independent components (ICs) reflected true subdivisions, we performed functional connectivity analysis using the IC coordinates as seeds. This confirmed that the subdivisions belonged to distinct networks. The right-biased IC was connected with a network often associated with attentional processing. One bilateral subdivision was connected to sensorimotor regions and another was connected to auditory regions. One subdivision that presented as distinct left- and right-biased ICs was connected to frontoparietal regions. Another subdivision that also had left- and right-biased ICs was connected to social or default mode networks. Our results show that the TPJ in both hemispheres hosts multiple neural processes with connectivity patterns consistent with well developed specialization and lateralization. PMID:26109666

  1. The bud break process and its variation among local populations of boreal black spruce

    PubMed Central

    Rossi, Sergio; Bousquet, Jean

    2014-01-01

    Phenology of local populations can exhibit adaptations to the current environmental conditions resulting from a close interaction between climate and genotype. The bud break process and its variations among populations were analyzed in greenhouse by monitoring the growth resumption in black spruce [Picea mariana (Mill.) BSP] seedlings originating from seeds of five stands across the closed boreal forest in Quebec, Canada. Bud break lasted 15 days and occurred earlier and quicker in northern provenances. Provenance explained between 10.2 and 32.3% of the variance in bud break, while the families accounted for a smaller but still significant part of the variance. The late occurrence of one phenological phase corresponded to a delayed occurrence of the others according to linear relationships. A causal model was proposed in the form of a chain of events with each phase of bud break being related to the previous and successive one, while no link was observed between non-adjacent phases. The adaptation of black spruce populations along the latitudinal gradient points toward a strategy based on rapid physiological processes triggered by temperature increase inducing high metabolic activity. The variation observed in bud break reflects an evolutionary trade-off between maximization of security and taking advantage of the short growing season. This work provides evidence of the phenological adaptations of black spruce to its local environmental conditions while retaining sizeable genetic diversity within populations. Because of the multigenic nature of phenology, this diversity should provide some raw material for adaptation to changing local environmental conditions. PMID:25389430

  2. Localized Ni deposition improved by saccharin sodium in the intermittent MAGE process

    NASA Astrophysics Data System (ADS)

    Yang, J. H.; Lin, J. C.; Chang, T. K.; You, X. B.; Jiang, S. B.

    2009-02-01

    Localized Ni deposition improved by saccharin sodium (SS) in the intermittent microanode guided electroplating (intermittent MAGE) process has been investigated. This effect is more complicated than conventional planar electroplating. If there was an insignificant amount of SS in the bath (i.e. less than 1.0 mM), then the radius of the fabricated nodular columns would range from 37.5 to 42.5 µm cyclically along the axis and the surface would be covered with a homogeneous layer of 3-8 µm Ni particles. In the presence of an optimal amount of SS (i.e. around 1.0-3.0 mM), columns with uniform radius (around 42.5 µm) were fabricated and the surface was covered by a homogeneous layer of fine Ni particles (i.e. diameter 1 µm). With higher SS (4.0-6.0 mM in the bath), columns were constructed with uniform radius but the surface was covered by alternating zones of coarse and fine Ni particles. For SS beyond critical concentrations (8.0 mM at 4.0 V and 10.0 mM at 4.5 and 5.0 V), no microcolumn could be constructed and a universal planar Ni deposition on the substrate was formed instead. SS is an absorbent and it leads to cathodic polarization in the electroplating process. The influence of SS on the asymmetrical electric field distributed in the local area and formed by localized electrochemical deposition (LECD) has been studied by the use of the proposed model in this work and commercial finite element software.

  3. The bud break process and its variation among local populations of boreal black spruce.

    PubMed

    Rossi, Sergio; Bousquet, Jean

    2014-01-01

    Phenology of local populations can exhibit adaptations to the current environmental conditions resulting from a close interaction between climate and genotype. The bud break process and its variations among populations were analyzed in greenhouse by monitoring the growth resumption in black spruce [Picea mariana (Mill.) BSP] seedlings originating from seeds of five stands across the closed boreal forest in Quebec, Canada. Bud break lasted 15 days and occurred earlier and quicker in northern provenances. Provenance explained between 10.2 and 32.3% of the variance in bud break, while the families accounted for a smaller but still significant part of the variance. The late occurrence of one phenological phase corresponded to a delayed occurrence of the others according to linear relationships. A causal model was proposed in the form of a chain of events with each phase of bud break being related to the previous and successive one, while no link was observed between non-adjacent phases. The adaptation of black spruce populations along the latitudinal gradient points toward a strategy based on rapid physiological processes triggered by temperature increase inducing high metabolic activity. The variation observed in bud break reflects an evolutionary trade-off between maximization of security and taking advantage of the short growing season. This work provides evidence of the phenological adaptations of black spruce to its local environmental conditions while retaining sizeable genetic diversity within populations. Because of the multigenic nature of phenology, this diversity should provide some raw material for adaptation to changing local environmental conditions. PMID:25389430

  4. Revisiting Gaussian Process Regression Modeling for Localization in Wireless Sensor Networks.

    PubMed

    Richter, Philipp; Toledano-Ayala, Manuel

    2015-01-01

    Signal strength-based positioning in wireless sensor networks is a key technology for seamless, ubiquitous localization, especially in areas where Global Navigation Satellite System (GNSS) signals propagate poorly. To enable wireless local area network (WLAN) location fingerprinting in larger areas while maintaining accuracy, methods to reduce the effort of radio map creation must be consolidated and automatized. Gaussian process regression has been applied to overcome this issue, also with auspicious results, but the fit of the model was never thoroughly assessed. Instead, most studies trained a readily available model, relying on the zero mean and squared exponential covariance function, without further scrutinization. This paper studies the Gaussian process regression model selection for WLAN fingerprinting in indoor and outdoor environments. We train several models for indoor/outdoor- and combined areas; we evaluate them quantitatively and compare them by means of adequate model measures, hence assessing the fit of these models directly. To illuminate the quality of the model fit, the residuals of the proposed model are investigated, as well. Comparative experiments on the positioning performance verify and conclude the model selection. In this way, we show that the standard model is not the most appropriate, discuss alternatives and present our best candidate. PMID:26370996

  5. A Multi-Objective Compounded Local Mobile Cloud Architecture Using Priority Queues to Process Multiple Jobs.

    PubMed

    Wei, Xiaohui; Sun, Bingyi; Cui, Jiaxu; Xu, Gaochao

    2016-01-01

    As a result of the greatly increased use of mobile devices, the disadvantages of portable devices have gradually begun to emerge. To solve these problems, the use of mobile cloud computing assisted by cloud data centers has been proposed. However, cloud data centers are always very far from the mobile requesters. In this paper, we propose an improved multi-objective local mobile cloud model: Compounded Local Mobile Cloud Architecture with Dynamic Priority Queues (LMCpri). This new architecture could briefly store jobs that arrive simultaneously at the cloudlet in different priority positions according to the result of auction processing, and then execute partitioning tasks on capable helpers. In the Scheduling Module, NSGA-II is employed as the scheduling algorithm to shorten processing time and decrease requester cost relative to PSO and sequential scheduling. The simulation results show that the number of iteration times that is defined to 30 is the best choice of the system. In addition, comparing with LMCque, LMCpri is able to effectively accommodate a requester who would like his job to be executed in advance and shorten execution time. Finally, we make a comparing experiment between LMCpri and cloud assisting architecture, and the results reveal that LMCpri presents a better performance advantage than cloud assisting architecture. PMID:27419854

  6. A Multi-Objective Compounded Local Mobile Cloud Architecture Using Priority Queues to Process Multiple Jobs.

    PubMed

    Wei, Xiaohui; Sun, Bingyi; Cui, Jiaxu; Xu, Gaochao

    2016-01-01

    As a result of the greatly increased use of mobile devices, the disadvantages of portable devices have gradually begun to emerge. To solve these problems, the use of mobile cloud computing assisted by cloud data centers has been proposed. However, cloud data centers are always very far from the mobile requesters. In this paper, we propose an improved multi-objective local mobile cloud model: Compounded Local Mobile Cloud Architecture with Dynamic Priority Queues (LMCpri). This new architecture could briefly store jobs that arrive simultaneously at the cloudlet in different priority positions according to the result of auction processing, and then execute partitioning tasks on capable helpers. In the Scheduling Module, NSGA-II is employed as the scheduling algorithm to shorten processing time and decrease requester cost relative to PSO and sequential scheduling. The simulation results show that the number of iteration times that is defined to 30 is the best choice of the system. In addition, comparing with LMCque, LMCpri is able to effectively accommodate a requester who would like his job to be executed in advance and shorten execution time. Finally, we make a comparing experiment between LMCpri and cloud assisting architecture, and the results reveal that LMCpri presents a better performance advantage than cloud assisting architecture.

  7. Tissue distribution, intracellular localization and proteolytic processing of rat 4-hydroxyphenylpyruvate dioxygenase.

    PubMed

    Neve, Søren; Aarenstrup, Lene; Tornehave, Ditte; Rahbek-Nielsen, Henrik; Corydon, Thomas Juhl; Roepstorff, Peter; Kristiansen, Karsten

    2003-01-01

    4-hydroxyphenylpyruvate dioxygenase (HPD) is an important enzyme involved in tyrosine catabolism. HPD was shown to be identical to a protein named the F-antigen, exploited by immunologists because of its unique immunological properties. Congenital HPD deficiency is a rare, relatively benign condition known as hereditary type III tyrosinemia. Decreased expression of HPD is often observed in association with the severe type I tyrosinemia, and interestingly, inhibition of HPD activity seems to ameliorate the clinical symptoms of type I tyrosinemia. In this study we present a comprehensive analysis of tissue specific expression and intracellular localization of HPD in the rat. By combined use of in situ hybridization and immunohistochemistry we confirm previously known sites of expression in liver and kidney. In addition, we show that HPD is abundantly expressed in neurons in the cortex, cerebellum and hippocampus. By using immunoelectron microscopy and confocal laser scanning microscopy, we provide evidence that HPD contrary to earlier assumptions specifically localizes to membranes of the endoplasmic reticulum and the Golgi apparatus. Detailed mass spectrometric analyses of HPD purified from rat liver revealed N-terminal and C-terminal processing of HPD, and expression of recombinant HPD suggested that C-terminal processing enhances the enzymatic activity.

  8. Revisiting Gaussian Process Regression Modeling for Localization in Wireless Sensor Networks

    PubMed Central

    Richter, Philipp; Toledano-Ayala, Manuel

    2015-01-01

    Signal strength-based positioning in wireless sensor networks is a key technology for seamless, ubiquitous localization, especially in areas where Global Navigation Satellite System (GNSS) signals propagate poorly. To enable wireless local area network (WLAN) location fingerprinting in larger areas while maintaining accuracy, methods to reduce the effort of radio map creation must be consolidated and automatized. Gaussian process regression has been applied to overcome this issue, also with auspicious results, but the fit of the model was never thoroughly assessed. Instead, most studies trained a readily available model, relying on the zero mean and squared exponential covariance function, without further scrutinization. This paper studies the Gaussian process regression model selection for WLAN fingerprinting in indoor and outdoor environments. We train several models for indoor/outdoor- and combined areas; we evaluate them quantitatively and compare them by means of adequate model measures, hence assessing the fit of these models directly. To illuminate the quality of the model fit, the residuals of the proposed model are investigated, as well. Comparative experiments on the positioning performance verify and conclude the model selection. In this way, we show that the standard model is not the most appropriate, discuss alternatives and present our best candidate. PMID:26370996

  9. Effects of local electric surface potential on holes charging process in uncapped germanium nanocrystal

    SciTech Connect

    Marchand, Aude; El Hdiy, Abdelillah

    2015-04-21

    The charging kinetics of holes are investigated in an uncapped Ge nanocrystal by the use of the nano-electron beam induced current technique. The charging process is studied under zero volt or under an appropriate electric field. The investigation is repeated many times on the same nanocrystal and on others in the same sample to attest of the reproducibility of the results. At 0 V, the cycles of charging kinetics are superimposed and are in a steady state, but an instantaneous local and negative surface potential, established in the nanocrystal at the beginning of the kinetics, slows down the holes charging process. Under an external field, the energy band bending accentuation affects the holes charging time constants. As a result, the holes charging cycles weakly affect the electrical performance of the thin oxide as is indicated by the value of the measured local resistivity of 6 × 10{sup 10}–10{sup 11} Ω cm, which is relatively lower than that of the thick thermal oxide.

  10. A Multi-Objective Compounded Local Mobile Cloud Architecture Using Priority Queues to Process Multiple Jobs

    PubMed Central

    Wei, Xiaohui; Sun, Bingyi; Cui, Jiaxu; Xu, Gaochao

    2016-01-01

    As a result of the greatly increased use of mobile devices, the disadvantages of portable devices have gradually begun to emerge. To solve these problems, the use of mobile cloud computing assisted by cloud data centers has been proposed. However, cloud data centers are always very far from the mobile requesters. In this paper, we propose an improved multi-objective local mobile cloud model: Compounded Local Mobile Cloud Architecture with Dynamic Priority Queues (LMCpri). This new architecture could briefly store jobs that arrive simultaneously at the cloudlet in different priority positions according to the result of auction processing, and then execute partitioning tasks on capable helpers. In the Scheduling Module, NSGA-II is employed as the scheduling algorithm to shorten processing time and decrease requester cost relative to PSO and sequential scheduling. The simulation results show that the number of iteration times that is defined to 30 is the best choice of the system. In addition, comparing with LMCque, LMCpri is able to effectively accommodate a requester who would like his job to be executed in advance and shorten execution time. Finally, we make a comparing experiment between LMCpri and cloud assisting architecture, and the results reveal that LMCpri presents a better performance advantage than cloud assisting architecture. PMID:27419854

  11. A functional magnetic resonance imaging study of local/global processing with stimulus presentation in the peripheral visual hemifields.

    PubMed

    Lux, S; Marshall, J C; Ritzl, A; Weiss, P H; Pietrzyk, U; Shah, N J; Zilles, K; Fink, G R

    2004-01-01

    When stimuli are presented in the left or right visual fields, hemispheric specialization for global and local processing in occipital areas is attenuated. Using functional magnetic resonance imaging, we investigated how this attenuation is compensated for when information must cross the corpus callosum to reach the areas specialized for global and local processing. We presented hierarchically nested letters (e.g. a large E made of smaller E's) to the right or the left visual hemifield while subjects fixated centrally. In half the trials, subjects indicated whether the global aspect and in the other half whether the local aspect of the stimulus matched a pre-specified target letter. Visual hemifield presentations showed the expected contralateral activations of occipital cortex. The main effects of locally or globally directed attention did not show any differential occipital activations, but the right anterior cingulate cortex was activated differentially during local processing. Region-of-interest-based analyses showed increased neural activity in left posterior occipital cortex during local processing when stimuli were presented in the left hemifield. During global processing with stimulus presentation to the right hemifield, the right posterior occipital cortex was activated. Activation of right anterior cingulate cortex during local processing is likely to reflect the suppression of global processing precedence in order to select correctly the local stimulus level. The activations in left (local) and right (global) occipital areas are likely to reflect the top-down augmentation of stimulus information that has been degraded by callosal crossing in order to access the hemisphere specialized for local or global processing. PMID:14960344

  12. Tracking Passive Sentence Comprehension in Agrammatic Aphasia

    PubMed Central

    Meyer, Aaron M.; Mack, Jennifer E.; Thompson, Cynthia K.

    2011-01-01

    People with agrammatic aphasia often experience greater difficulty comprehending passive compared to active sentences. The Trace Deletion Hypothesis (TDH; Grodzinsky, 2000) proposes that aphasic individuals cannot generate accurate syntactic representations of passive sentences and, hence, use an agent-first processing strategy which leads to at-chance performance. We tested this claim using the eyetracking-while-listening paradigm in order to reveal online processing routines. Ten agrammatic aphasic participants and 10 age-matched controls listened to passive and active sentences and performed a sentence-picture matching task (i.e., selecting between two pictures with reversed thematic roles), while their eye movements were monitored. Control participants’ performance was at ceiling, whereas accuracy for the aphasic participants was above chance for active sentences and at chance for passive sentences. Further, for the control participants, the eye movement data showed an initial agent-first processing bias, followed by fixation on the correct picture in the vicinity of the verb in both active and passive sentences. However, the aphasic participants showed no evidence of agent-first processing, counter the predictions of the TDH. In addition, in active sentences, they reliably fixated the correct picture only at sentence offset, reflecting slowed processing. During passive sentence processing, fixations were at chance throughout the sentence, but different patterns were noted for correct and incorrect trials. These results are consistent with the proposal that agrammatic sentence comprehension failure involves lexical processing and/or lexical integration deficits. PMID:22043134

  13. The forest or the trees: preference for global over local image processing is reversed by prior experience in honeybees.

    PubMed

    Avarguès-Weber, Aurore; Dyer, Adrian G; Ferrah, Noha; Giurfa, Martin

    2015-01-22

    Traditional models of insect vision have assumed that insects are only capable of low-level analysis of local cues and are incapable of global, holistic perception. However, recent studies on honeybee (Apis mellifera) vision have refuted this view by showing that this insect also processes complex visual information by using spatial configurations or relational rules. In the light of these findings, we asked whether bees prioritize global configurations or local cues by setting these two levels of image analysis in competition. We trained individual free-flying honeybees to discriminate hierarchical visual stimuli within a Y-maze and tested bees with novel stimuli in which local and/or global cues were manipulated. We demonstrate that even when local information is accessible, bees prefer global information, thus relying mainly on the object's spatial configuration rather than on elemental, local information. This preference can be reversed if bees are pre-trained to discriminate isolated local cues. In this case, bees prefer the hierarchical stimuli with the local elements previously primed even if they build an incorrect global configuration. Pre-training with local cues induces a generic attentional bias towards any local elements as local information is prioritized in the test, even if the local cues used in the test are different from the pre-trained ones. Our results thus underline the plasticity of visual processing in insects and provide new insights for the comparative analysis of visual recognition in humans and animals.

  14. Occupancy mapping and surface reconstruction using local Gaussian processes with Kinect sensors.

    PubMed

    Kim, Soohwan; Kim, Jonghyuk

    2013-10-01

    Although RGB-D sensors have been successfully applied to visual SLAM and surface reconstruction, most of the applications aim at visualization. In this paper, we propose a noble method of building continuous occupancy maps and reconstructing surfaces in a single framework for both navigation and visualization. Particularly, we apply a Bayesian nonparametric approach, Gaussian process classification, to occupancy mapping. However, it suffers from high-computational complexity of O(n(3))+O(n(2)m), where n and m are the numbers of training and test data, respectively, limiting its use for large-scale mapping with huge training data, which is common with high-resolution RGB-D sensors. Therefore, we partition both training and test data with a coarse-to-fine clustering method and apply Gaussian processes to each local clusters. In addition, we consider Gaussian processes as implicit functions, and thus extract iso-surfaces from the scalar fields, continuous occupancy maps, using marching cubes. By doing that, we are able to build two types of map representations within a single framework of Gaussian processes. Experimental results with 2-D simulated data show that the accuracy of our approximated method is comparable to previous work, while the computational time is dramatically reduced. We also demonstrate our method with 3-D real data to show its feasibility in large-scale environments. PMID:23893758

  15. Locality-Aware Parallel Process Mapping for Multi-Core HPC Systems

    SciTech Connect

    Hursey, Joshua J; Squyres, Jeffrey M.; Dontje, Terry

    2011-01-01

    High Performance Computing (HPC) systems are composed of servers containing an ever-increasing number of cores. With such high processor core counts, non-uniform memory access (NUMA) architectures are almost universally used to reduce inter-processor and memory communication bottlenecks by distributing processors and memory throughout a server-internal networking topology. Application studies have shown that the tuning of processes placement in a server s NUMA networking topology to the application can have a dramatic impact on performance. The performance implications are magnified when running a parallel job across multiple server nodes, especially with large scale HPC applications. This paper presents the Locality-Aware Mapping Algorithm (LAMA) for distributing the individual processes of a parallel application across processing resources in an HPC system, paying particular attention to the internal server NUMA topologies. The algorithm is able to support both homogeneous and heterogeneous hardware systems, and dynamically adapts to the available hardware and user-specified process layout at run-time. As implemented in Open MPI, the LAMA provides 362,880 mapping permutations and is able to naturally scale out to additional hardware resources as they become available in future architectures.

  16. [Anti-doping policy development process in the sports world (1968~1999): focusing on IOC activities and passive response from Korea].

    PubMed

    Hwang, Eui-Ryong; Kim, Tae-Young

    2014-08-01

    athletes experienced doping test directly, yet education about doping was limited. However, some national team level athletes tested positive on the doping test and underwent disciplinary action. In addition, athletic federation or leaders acquiesced athletes doping made secretly; this indicated that South Korea was also not free from doping. It was found that Korea world of sports showed very passive countermeasures and development process. PMID:25223222

  17. [Anti-doping policy development process in the sports world (1968~1999): focusing on IOC activities and passive response from Korea].

    PubMed

    Hwang, Eui-Ryong; Kim, Tae-Young

    2014-08-01

    athletes experienced doping test directly, yet education about doping was limited. However, some national team level athletes tested positive on the doping test and underwent disciplinary action. In addition, athletic federation or leaders acquiesced athletes doping made secretly; this indicated that South Korea was also not free from doping. It was found that Korea world of sports showed very passive countermeasures and development process.

  18. The impact of local-scale processes on solubility and capillary trapping of injected CO2

    NASA Astrophysics Data System (ADS)

    Gasda, S. E.; Nordbotten, J. M.; Celia, M. A.

    2010-12-01

    Storage security of injected carbon dioxide (CO2) is an essential component of risk management for geological carbon sequestration operations. In the post-injection phase, the mobile CO2 plume migrates in large part due to buoyancy forces, following the natural topography of the geological formation, and may travel over very large distances before eventually being trapped by different physical and chemical processes. The primary trapping mechanisms are capillary and solubility trapping, which evolve over hundreds to thousands of years and can immobilize a significant portion of the mobile, free-phase CO2 plume. However, both the migration and trapping processes are inherently complex, involving a combination of small and large spatial scales and acting over a range of time scales. Solubility trapping is a good example of this complexity, where small-scale density instabilities in the dissolved CO2 region leads to convective mixing that has that has a significant effect on the large-scale dissolution process over very long time scales. Another example is the effect of capillary forces on the evolution of mobile CO2, where local capillary effects acting at the CO2-brine interface lead to a transition zone that may have a significant impact on large-scale plume migration dynamics. Appropriate modeling tools need to be developed that can capture both large and small-scale trapping effects in a practical way. We present a modeling approach that combines vertically-averaged governing equations with upscaled representations of the dissolution-convective mixing process and the local capillary transition zone or fringe. In this model, large-scale CO2 migration is captured numerically, while the small-scale dissolution-convection and capillary fringe effects are included using sub-grid corrections. In this way, we can eliminate the need for expensive grid refinement to capture the subscale instabilities associated with convective mixing or the details of the capillary

  19. Citric Acid Passivation of Stainless Steel

    NASA Technical Reports Server (NTRS)

    Yasensky, David; Reali, John; Larson, Chris; Carl, Chad

    2009-01-01

    Passivation is a process for cleaning and providing corrosion protection for stainless steel. Currently, on Kennedy Space Center (KSC), only parts passivated with nitric acid are acceptable for use. KSC disposes of approximately 125gal of concentrated nitric acid per year, and receives many parts from vendors who must also dispose of used nitric acid. Unfortunately, nitric acid presents health and environmental hazards. As a result, several recent industry studies have examined citric acid as an alternative. Implementing a citric acid-based passivation procedure would improve the health and environmental safety aspects of passivation process. However although there is a lack of published studies that conclusively prove citric acid is a technically sound passivation agent. In 2007, NASA's KSC Materials Advisory Working Group requested the evaluation of citric acid in place of nitric acid for passivation of parts at KSC. United Space Alliance Materials & Processes engineers have developed a three-phase test plan to evaluate citric acid as an alternative to nitric acid on three stainless steels commonly used at KSC: UNS S30400, S41000, and S17400. Phases 1 and 2 will produce an optimized citric acid treatment based on results from atmospheric exposure at NASA's Beach Corrosion Facility. Phase 3 will compare the optimized solution(s) with nitric acid treatments. If the results indicate that citric acid passivates as well or better than nitric acid, NASA intends to approve this method for parts used at the Kennedy Space Center.

  20. How to bridge the gap between local root water uptake processes and macroscopic hydrological models?

    NASA Astrophysics Data System (ADS)

    Javaux, M.; Couvreur, V.; Vereecken, H.; Vanderborght, J.

    2013-12-01

    Modeling root water uptake in hydrological models remains challenging given the scale gap between the local uptake processes and the model resolutions. When Richards equation is used, root water uptake is modeled with a sink-term spatially resolved at the grid element scale (~cm...m), much larger than the root segment scale (~mm). Typically this sink-term contains four functions: (i) a root resistance function, (ii) a soil resistance function, (iii) a stress function and (iv) a compensation function. Thanks to novel detailed 3-D and 1-D models that contain the current knowledge on soil and root water flow, we propose improvements for the four functions used in macroscopic sink terms, which respect biophysical principles. We show that (1) root resistance may be well defined by the root length density but only for relatively wet soil and no limiting xylem conductance; (2) soil resistance cannot be neglected, in particular in the rhizosphere where specific process may occur, which alter the soil hydraulic properties and thereby affect uptake and the stress functions; (3) stress and compensation are two different processes not linked to each other; (4) compensation occurs as soon as there is a heterogeneous distribution of the soil water potential around the root system; (5) stress function should be defined as a maximal actual transpiration in function of an integrated or root-sensed averaged water head rather than in terms of local water heads; and (6) non linearity in the stress function is expected to arise from evolution with pressure heads or time of the hydraulic resistances in the soil-plant system.

  1. Going beyond exposure to local news media: an information-processing examination of public perceptions of food safety.

    PubMed

    Fleming, Kenneth; Thorson, Esther; Zhang, Yuyan

    2006-12-01

    The relationship between local news media and public perceptions of food safety was examined in a statewide telephone survey (n = 524). The theoretical framework of the study was based on a review of the social and psychological factors that affect public concerns about food safety, the relationship between mass communication and risk perception, and the thesis of information-processing strategies and its impact on learning from the news. The results show that information-processing strategies substantially mediated the relationship between local news media and public perceptions of food safety, with elaborative processing being more influential than active reflection in people's learning from the news media. Attention to local television had an independent effect, after demographics, awareness of food safety problems, and perceived safety of local food supply were statistically controlled. Other important predictors included gender, education, ethnicity, and perceived safety of local food supply.

  2. 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.

  3. Endosomal localization of TLR8 confers distinctive proteolytic processing on human myeloid cells.

    PubMed

    Ishii, Noriko; Funami, Kenji; Tatematsu, Megumi; Seya, Tsukasa; Matsumoto, Misako

    2014-11-15

    Nucleic acid-sensing TLRs are involved in both antimicrobial immune responses and autoimmune inflammation. TLR8 is phylogenetically and structurally related to TLR7 and TLR9, which undergo proteolytic processing in the endolysosomes to generate functional receptors. Recent structural analyses of human TLR8 ectodomain and its liganded form demonstrated that TLR8 is also cleaved, and both the N- and C-terminal halves contribute to ligand binding. However, the structures and ssRNA recognition mode of endogenous TLR8 in human primary cells are largely unknown. In this study, we show that proteolytic processing of TLR8 occurs in human monocytes and macrophages in a different manner compared with TLR7/9 cleavage. The insertion loop between leucine-rich repeats 14 and 15 in TLR8 is indispensable for the cleavage and stepwise processing that occurs in the N-terminal fragment. Both furin-like proprotein convertase and cathepsins contribute to TLR8 cleavage in the early/late endosomes. TLR8 recognizes viral ssRNA and endogenous RNA, such as microRNAs, resulting in the production of proinflammatory cytokines. Hence, localization sites of the receptors are crucial for the nucleic acid-sensing mode and downstream signaling. PMID:25297876

  4. Judging sound rotation when listeners and sounds rotate: Sound source localization is a multisystem process.

    PubMed

    Yost, William A; Zhong, Xuan; Najam, Anbar

    2015-11-01

    In four experiments listeners were rotated or were stationary. Sounds came from a stationary loudspeaker or rotated from loudspeaker to loudspeaker around an azimuth array. When either sounds or listeners rotate the auditory cues used for sound source localization change, but in the everyday world listeners perceive sound rotation only when sounds rotate not when listeners rotate. In the everyday world sound source locations are referenced to positions in the environment (a world-centric reference system). The auditory cues for sound source location indicate locations relative to the head (a head-centric reference system), not locations relative to the world. This paper deals with a general hypothesis that the world-centric location of sound sources requires the auditory system to have information about auditory cues used for sound source location and cues about head position. The use of visual and vestibular information in determining rotating head position in sound rotation perception was investigated. The experiments show that sound rotation perception when sources and listeners rotate was based on acoustic, visual, and, perhaps, vestibular information. The findings are consistent with the general hypotheses and suggest that sound source localization is not based just on acoustics. It is a multisystem process.

  5. Rendering high dynamic range images by using integrated global and local processing

    NASA Astrophysics Data System (ADS)

    Shin, Hyunchul; Yu, Teng; Ismail, Yasir; Saeed, Bilal

    2011-11-01

    We propose a new and effective tone reproduction technique that preserves the visibility, contrast, and natural impression of scenes when rendering high dynamic range images on conventional low dynamic range display devices. The method is simple and easy to implement. Our new approach uses a modified mapping function that takes into account the block-level log-average, as well as the log-average of the whole image. This allows for increased visibility in dark regions. For those images with sharp edges that may cause a halo effect, the halo effect can be reduced by using bilateral filtering when the block-level log-average is computed. Furthermore, the local details of the image can be enhanced by using a median filter. Experimental results show that the technique gives satisfactory results for a variety of images and avoids common artefacts, such as halos, gradient reversals, and the loss of local contrast. In particular, our method produces excellent results when an image has both dark and bright regions due to new block-level processing during tone mapping.

  6. Judging sound rotation when listeners and sounds rotate: Sound source localization is a multisystem process.

    PubMed

    Yost, William A; Zhong, Xuan; Najam, Anbar

    2015-11-01

    In four experiments listeners were rotated or were stationary. Sounds came from a stationary loudspeaker or rotated from loudspeaker to loudspeaker around an azimuth array. When either sounds or listeners rotate the auditory cues used for sound source localization change, but in the everyday world listeners perceive sound rotation only when sounds rotate not when listeners rotate. In the everyday world sound source locations are referenced to positions in the environment (a world-centric reference system). The auditory cues for sound source location indicate locations relative to the head (a head-centric reference system), not locations relative to the world. This paper deals with a general hypothesis that the world-centric location of sound sources requires the auditory system to have information about auditory cues used for sound source location and cues about head position. The use of visual and vestibular information in determining rotating head position in sound rotation perception was investigated. The experiments show that sound rotation perception when sources and listeners rotate was based on acoustic, visual, and, perhaps, vestibular information. The findings are consistent with the general hypotheses and suggest that sound source localization is not based just on acoustics. It is a multisystem process. PMID:26627802

  7. Small deviations from local equilibrium for a process which exhibits hydrodynamical behavior. I

    NASA Astrophysics Data System (ADS)

    de Masi, A.; Ianiro, N.; Presutti, E.

    1982-09-01

    The symmetric simple exclusion process where infinitely many particles move randomly on ℤ, jump with equal probability on nearest-neighbor sites, and interact by simple exclusion is considered. It is known that the only extremal invariant measures are Bernoulli, that each measure, in a suitable class, after a "macroscopic" time is locally described, at a zero-order approximation, by a Bernoulli measure with parameter depending on macroscopic space and time, and that the so-defined equilibrium profile satisfies the heat equation. Small deviations from local equilibrium in the hydrodynamical limit are investigated. It is proven, under suitable assumptions, that at first order the state is Gibbs with one- and two-body potentials whose strength depends only on macroscopic space and time and on the equilibrium profile. More precisely, the one-body potential is linear (on the microscopic positions of the particles) and proportional to the macroscopic space gradient of the equilibrium parameter at that time, so that Fourier law holds. The two-body potential varies on a macroscopic scale and does not depend on the microscopic positions of the particles; it is given by the value of the covariance of the Gaussian "macroscopic density fluctuation field."

  8. Hi-fidelity multi-scale local processing for visually optimized far-infrared Herschel images

    NASA Astrophysics Data System (ADS)

    Li Causi, G.; Schisano, E.; Liu, S. J.; Molinari, S.; Di Giorgio, A.

    2016-07-01

    In the context of the "Hi-Gal" multi-band full-plane mapping program for the Galactic Plane, as imaged by the Herschel far-infrared satellite, we have developed a semi-automatic tool which produces high definition, high quality color maps optimized for visual perception of extended features, like bubbles and filaments, against the high background variations. We project the map tiles of three selected bands onto a 3-channel panorama, which spans the central 130 degrees of galactic longitude times 2.8 degrees of galactic latitude, at the pixel scale of 3.2", in cartesian galactic coordinates. Then we process this image piecewise, applying a custom multi-scale local stretching algorithm, enforced by a local multi-scale color balance. Finally, we apply an edge-preserving contrast enhancement to perform an artifact-free details sharpening. Thanks to this tool, we have thus produced a stunning giga-pixel color image of the far-infrared Galactic Plane that we made publicly available with the recent release of the Hi-Gal mosaics and compact source catalog.

  9. Passive magnetic bearing configurations

    DOEpatents

    Post, Richard F.

    2011-01-25

    A journal bearing provides vertical and radial stability to a rotor of a passive magnetic bearing system when the rotor is not rotating and when it is rotating. In the passive magnetic bearing system, the rotor has a vertical axis of rotation. Without the journal bearing, the rotor is vertically and radially unstable when stationary, and is vertically stable and radially unstable when rotating.

  10. Overcoming Passive Behavior.

    ERIC Educational Resources Information Center

    Kay, Marilyn

    1986-01-01

    Passivity in learning disabled children is identified as either inborn or as "learned helplessness," and the role of the teacher in overcoming passivity is noted. Teachers can help students understand themselves, become active agents in learning, and use self monitoring devices. (CL)

  11. Geothermal energy development in Washington State. A guide to the federal, state and local regulatory process

    SciTech Connect

    Bloomquist, R.G.; Simpson, S.J.

    1986-03-01

    Washington State's geothermal potential is wide spread. Hot springs and five strato volcanoes existing throughout the Cascade Range, limited hot spring activity on the Olympic Peninsula, and broad reaching, low temperature geothermal resources found in the Columbia Basin comprise the extent of Washington's known geothermal resources. Determination of resource ownership is the first step in proceeding with geothermal exploration and development activities. The federal and state processes are examined from pre-lease activity through leasing and post-lease development concerns. Plans, permits, licenses, and other requirements are addressed for the federal, state, and local level. Lease, permit, and other forms for a number of geothermal exploration and development activities are included. A map of public lands and another displaying the measured geothermal resources throughout the state are provided.

  12. Non-Local Means Inpainting of MS Lesions in Longitudinal Image Processing.

    PubMed

    Guizard, Nicolas; Nakamura, Kunio; Coupé, Pierrick; Fonov, Vladimir S; Arnold, Douglas L; Collins, D Louis

    2015-01-01

    In medical imaging, multiple sclerosis (MS) lesions can lead to confounding effects in automatic morphometric processing tools such as registration, segmentation and cortical extraction, and subsequently alter individual longitudinal measurements. Multiple magnetic resonance imaging (MRI) inpainting techniques have been proposed to decrease the impact of MS lesions in medical image processing, however, most of these methods make the assumption that lesions only affect white matter. Here, we propose a method to fill lesion regions using the patch-based non-local mean (NLM) strategy. The method consists of a hierarchical concentric filling strategy after identification of the lesion region. The lesion is filled iteratively, based on the surrounding tissue intensity, using an onion peel strategy. This concentric technique presents the advantage of preserving the local information and therefore the continuity of the anatomy and does not require identification of any a priori normal brain tissues. The method is first evaluated on 20 healthy subjects with simulated artificial MS lesions where we assessed our technique by measuring the peak signal-to-noise ratio (PSNR) of the images with inpainted lesion and the original healthy images. Second, in order to assess the impact of lesion filling on longitudinal image analyses, we performed a power analysis with sample size estimation to evaluate brain atrophy and ventricular growth in patients with MS. The method was compared to two different publicly available methods (FSL lesion fill and Lesion LEAP) and a more classic method, which fills the region with intensities similar to that of the surrounding healthy white matter tissue or mask the lesions. The proposed method was shown to exceed the other methods in reproducing the fidelity of healthy subject images where the lesions were inpainted. The method also improved the power to detect brain atrophy or ventricular growth by decreasing the sample size by 25% in the presence

  13. Non-Local Means Inpainting of MS Lesions in Longitudinal Image Processing

    PubMed Central

    Guizard, Nicolas; Nakamura, Kunio; Coupé, Pierrick; Fonov, Vladimir S.; Arnold, Douglas L.; Collins, D. Louis

    2015-01-01

    In medical imaging, multiple sclerosis (MS) lesions can lead to confounding effects in automatic morphometric processing tools such as registration, segmentation and cortical extraction, and subsequently alter individual longitudinal measurements. Multiple magnetic resonance imaging (MRI) inpainting techniques have been proposed to decrease the impact of MS lesions in medical image processing, however, most of these methods make the assumption that lesions only affect white matter. Here, we propose a method to fill lesion regions using the patch-based non-local mean (NLM) strategy. The method consists of a hierarchical concentric filling strategy after identification of the lesion region. The lesion is filled iteratively, based on the surrounding tissue intensity, using an onion peel strategy. This concentric technique presents the advantage of preserving the local information and therefore the continuity of the anatomy and does not require identification of any a priori normal brain tissues. The method is first evaluated on 20 healthy subjects with simulated artificial MS lesions where we assessed our technique by measuring the peak signal-to-noise ratio (PSNR) of the images with inpainted lesion and the original healthy images. Second, in order to assess the impact of lesion filling on longitudinal image analyses, we performed a power analysis with sample size estimation to evaluate brain atrophy and ventricular growth in patients with MS. The method was compared to two different publicly available methods (FSL lesion fill and Lesion LEAP) and a more classic method, which fills the region with intensities similar to that of the surrounding healthy white matter tissue or mask the lesions. The proposed method was shown to exceed the other methods in reproducing the fidelity of healthy subject images where the lesions were inpainted. The method also improved the power to detect brain atrophy or ventricular growth by decreasing the sample size by 25% in the presence

  14. Passive solar heating

    NASA Astrophysics Data System (ADS)

    Claridge, David E.; Mowris, Robert J.

    1985-11-01

    Buildings have been designed to use solar gains for winter heating for several millenia, but the quantitative basis for passive solar design has only been developed in the last decade. A simplified lumped capacitance model is used to provide insight into the physics of passive building behavior. Three passive design methods are described: the Solar Load Ratio (SLR) method based on correlations to simulation results; the Gordon/Zarmi closed form analytical mode;; and the ``unutilizability'' model of Monsen and Klein. Model predictions are compared with measured results; agreement is good if measured building characteristics are used. Numerous passive houses use less than 2 Btu/ft2-DD for auxiliary heating and consensus is developing that modest levels of passive glazing combined with superinsulation techniques can provide the best feature of both approaches.

  15. Passive solar construction handbook

    SciTech Connect

    Levy, E.; Evans, D.; Gardstein, C.

    1981-08-01

    Many of the basic elements of passive solar design are reviewed. The unique design constraints presented in passive homes are introduced and many of the salient issues influencing design decisions are described briefly. Passive solar construction is described for each passive system type: direct gain, thermal storage wall, attached sunspace, thermal storage roof, and convective loop. For each system type, important design and construction issues are discussed and case studies illustrating designed and built examples of the system type are presented. Construction details are given and construction and thermal performance information is given for the materials used in collector components, storage components, and control components. Included are glazing materials, framing systems, caulking and sealants, concrete masonry, concrete, brick, shading, reflectors, and insulators. The Load Collector Ratio method for estimating passive system performance is appended, and other analysis methods are briefly summarized. (LEW)

  16. Electrophysiological correlates of local-global visual processing in college students with schizotypal traits: an event-related potential study.

    PubMed

    Choi, Eun-Jung; Jang, Kyoung-Mi; Kim, Myung-Sun

    2014-02-01

    We examined local-global visual processing in college students with schizotypal traits using event-related potentials (ERPs). Local-global processing was assessed using a divided-attention task, in which large numbers (global level) composed of small numbers (local level) were presented. The control group had faster response time (RT) and more accurate responses to global-level than to local-level stimuli, whereas RT and accuracy did not differ between levels in the schizotypal-trait group. N150 amplitudes for local stimuli were larger than those for global stimuli in the schizotypal-trait group, whereas N150 amplitudes did not differ between levels in the control group. P300 amplitudes for local stimuli were larger relative to global stimuli in the control group, whereas P300 amplitudes did not differ between levels in the schizotypal-trait group. These results indicate that the global precedence effect was reduced in the schizotypal-trait group, possibly because of local-biased visual processing or difficulty in global processing.

  17. Local Dynamics of Chemical Kinetics at Different Phases of Nitriding Process

    NASA Astrophysics Data System (ADS)

    Özdemir, İ. Bedii; Akar, Firat

    2015-08-01

    The local dynamics of chemical kinetics at different phases of the nitriding process have been studied. The calculations are performed under the conditions where the temperature and composition data are provided experimentally from an in-service furnace. Results are presented in temporal variations of gas concentrations and the nitrogen coverage on the surface. It is shown that if it is available in the furnace, the adsorption of the N2 gas can seemingly start at temperatures as low as 200 °C. However, at such low temperatures, as the diffusion into the material is very unlikely, this results in the surface poisoning. It becomes clear that, contrary to common knowledge, the nitriding heat treatment with ammonia as a nitrogen-providing medium is possible at temperatures like 400 °C. Under these conditions, however, the presence of excess amounts of product gas N2 in the furnace atmosphere suppresses the forward kinetics in the nitriding process. It seems that the best operating point in the nitriding heat treatment is achieved with a mixture of 6% N2. When the major nitriding species NH3 is substituted by N2 and the N2 fraction increases above 30%, the rate of the forward reaction decreases drastically, so that there is no point to continue the furnace operation any further. Hence, during the initial heating phase, the N2 gas must be purged from the furnace to keep its fraction less than 30% before the furnace reaches the temperature where the reaction starts.

  18. Selectiveness of laser processing due to energy coupling localization: case of thin film solar cell scribing

    NASA Astrophysics Data System (ADS)

    Račiukaitis, G.; Grubinskas, S.; Gečys, P.; Gedvilas, M.

    2013-07-01

    Selectiveness of the laser processing is the top-most important for applications of the processing technology in thin-film electronics, including photovoltaics. Coupling of laser energy in multilayered thin-film structures, depending on photo-physical properties of the layers and laser wavelength was investigated experimentally and theoretically. Energy coupling within thin films highly depends on the film structure. The finite element and two-temperature models were applied to simulate the energy and temperature distributions inside the stack of different layers of a thin-film solar cell during a picosecond laser irradiation. Reaction of the films to the laser irradiation was conditioned by optical properties of the layers at the wavelength of laser radiation. Simulation results are consistent with the experimental data achieved in laser scribing of copper-indium-gallium diselenide (CIGS) solar cells on a flexible polymer substrate using picosecond-pulsed lasers. Selection of the right laser wavelength (1064 nm or 1572 nm) enabled keeping the energy coupling in a well-defined volume at the interlayer interface. High absorption at inner interface of the layers triggered localized temperature increase. Transient stress caused by the rapid temperature rise facilitating peeling of the films rather than evaporation. Ultra-short pulses ensured high energy input rate into absorbing material permitting peeling of the layers with no influence on the remaining material.

  19. Expression and subcellular localization of Ewing sarcoma (EWS) protein is affected by the methylation process.

    PubMed

    Belyanskaya, Larisa L; Delattre, Olivier; Gehring, Heinz

    2003-08-15

    Ewing sarcoma (EWS) protein contains an N-terminal transcriptional activation domain (EAD) and a C-terminal RNA-binding domain (RBD). Recently, we had shown that EWS protein is not only localized in the nucleus and cytosol, but also on the surface of T cells and that its RBD is extensively asymmetrically dimethylated on arginine residues. Here we show that stimulation of T cells with phytohemagglutinin (PHA) caused a time-dependent 10-fold increase in expression of methylated EWS protein on the cell surface and a sixfold increase in the nuclei of peripheral blood mononuclear cells (PBMC). Mitogenic stimulation of malignant T cell lines, however, did not increase their inherently high expression of EWS protein. This expression seemed to correlate with methionine adenosyltransferase activity and S-adenosyl-L-methionine (AdoMet) utilization in PBMC and tumor cells and thus indicates dependence on the methylation process. Inhibition of methylation in normal and malignant cells with the methylation inhibitor adenosine dialdehyde (AdOx) resulted in a three to fivefold decreased expression of EWS protein not only in the nucleus but also on the cell surface. The inhibitory effect of AdOx was compensated and negligible in PBMC, but not in tumor cells if they were treated simultaneously with mitogenic PHA concentrations. The present findings indicate that expression of EWS protein in the various subcellular compartments is affected by the methylation process, in particular by the availability of intracellular AdoMet.

  20. A program for passively tracking a target using an array of sensors

    SciTech Connect

    Buhl, M.R.

    1993-01-01

    The problem of passively tracking a moving signal source has importance in a variety of applications such as radar, sonar, seismology, and radio astronomy. In many applications, only limited information is available about the signal source. It will be assumed here that only the signals which are detected by the sensors and the velocity of the source signal are known. The objective of this document is to present a program which passively tracks a target using an array of sensors. This program is available in MATLAB, version 3.5. The algorithm which is implemented consists of three main parts: time delay estimation, passive localization, and data post processing. Each of these parts are discussed, and the mathematical foundation for their solution given. Following, this the organization of the program is presented, and an example of its usage is given.

  1. A program for passively tracking a target using an array of sensors

    NASA Astrophysics Data System (ADS)

    Buhl, M. R.

    1993-01-01

    The problem of passively tracking a moving signal source has importance in a variety of applications such as radar, sonar, seismology, and radio astronomy. In many applications, only limited information is available about the signal source. It will be assumed here that only the signals which are detected by the sensors and the velocity of the source signal are known. The objective of this document is to present a program which passively tracks a target using an array of sensors. This program is available in MATLAB, version 3.5. The algorithm which is implemented consists of three main parts: time delay estimation, passive localization, and data post processing. Each of these parts are discussed, and the mathematical foundation for their solution given. Following this, the organization of the program is presented, and an example of its usage is given.

  2. Adapted waveform analysis, wavelet packets, and local cosine libraries as a tool for image processing

    NASA Astrophysics Data System (ADS)

    Coifman, Ronald R.; Woog, Lionel J.

    1995-09-01

    Adapted wave form analysis, refers to a collection of FFT like adapted transform algorithms. Given an image these methods provide special matched collections of templates (orthonormal bases) enabling an efficient coding of the image. Perhaps the closest well known example of such coding method is provided by musical notation, where each segment of music is represented by a musical score made up of notes (templates) characterised by their duration, pitch, location and amplitude, our method corresponds to transcribing the music in as few notes as possible. The extension to images and video is straightforward we describe the image by collections of oscillatory patterns (paint brush strokes)of various sizes locations and amplitudes using a variety of orthogonal bases. These selected basis functions are chosen inside predefined libraries of oscillatory localized functions (trigonometric and wavelet-packets waveforms) so as to optimize the number of parameters needed to describe our object. These algorithms are of complexity N log N opening the door for a large range of applications in signal and image processing, such as compression, feature extraction denoising and enhancement. In particular we describe a class of special purpose compressions for fingerprint irnages, as well as denoising tools for texture and noise extraction. We start by relating traditional Fourier methods to wavelet, wavelet-packet based algorithms using a recent refinement of the windowed sine and cosine transforms. We will then derive an adapted local sine transform show it's relation to wavelet and wavelet-packet analysis and describe an analysis toolkit illustrating the merits of different adaptive and nonadaptive schemes.

  3. Benthic processes and coastal aquaculture: merging models and field data at a local scale

    NASA Astrophysics Data System (ADS)

    Brigolin, Daniele; Rabouille, Christophe; Bombled, Bruno; Colla, Silvia; Pastres, Roberto; Pranovi, Fabio

    2016-04-01

    Shellfish farming is regarded as an organic extractive aquaculture activity. However, the production of faeces and pseudofaeces, in fact, leads to a net transfer of organic matter from the water column to the surface sediment. This process, which is expected to locally affect the sediment biogeochemistry, may also cause relevant changes in coastal areas characterized by a high density of farms. In this paper, we present the result of a study recently carried out in the Gulf of Venice (northern Adriatic sea), combining mathematical modelling and field sampling efforts. The work aimed at using a longline mussel farm as an in-situ test-case for modelling the differences in soft sediments biogeochemical processes along a gradient of organic deposition. We used an existing integrated model, allowing to describe biogeochemical fluxes towards the mussel farm and to predict the extent of the deposition area underneath it. The model framework includes an individual-based population dynamic model of the Mediterranean mussel coupled with a Lagrangian deposition model and a 1D benthic model of early diagenesis. The work was articulated in 3 steps: 1) the integrated model allowed to simulate the downward fluxes of organic matter originated by the farm, and the extent of its deposition area; 2) based on the first model application, two stations were localized, at which sediment cores were collected during a field campaign, carried out in June 2015. Measurements included O2 and pH microprofiling, porosity and micro-porosity, Total Organic Carbon, and pore waters NH4, PO4, SO4, Alkalinity, and Dissolved Inorganic Carbon; 3) two distinct early diagenesis models were set-up, reproducing observed field data in the sampled cores. Observed oxygen microprofiles showed a different behavior underneath the farm with respect to the outside reference station. In particular, a remarkable decrease in the oxygen penetration depth, and an increase in the O2 influx calculated from the

  4. Functional Hemispheric Asymmetries of Global/Local Processing Mirrored by the Steady-State Visual Evoked Potential

    ERIC Educational Resources Information Center

    Martens, Ulla; Hubner, Ronald

    2013-01-01

    While hemispheric differences in global/local processing have been reported by various studies, it is still under dispute at which processing stage they occur. Primarily, it was assumed that these asymmetries originate from an early perceptual stage. Instead, the content-level binding theory (Hubner & Volberg, 2005) suggests that the hemispheres…

  5. Efficacy of identifying neural components in the face and emotion processing system in schizophrenia using a dynamic functional localizer.

    PubMed

    Arnold, Aiden E G F; Iaria, Giuseppe; Goghari, Vina M

    2016-02-28

    Schizophrenia is associated with deficits in face perception and emotion recognition. Despite consistent behavioural results, the neural mechanisms underlying these cognitive abilities have been difficult to isolate, in part due to differences in neuroimaging methods used between studies for identifying regions in the face processing system. Given this problem, we aimed to validate a recently developed fMRI-based dynamic functional localizer task for use in studies of psychiatric populations and specifically schizophrenia. Previously, this functional localizer successfully identified each of the core face processing regions (i.e. fusiform face area, occipital face area, superior temporal sulcus), and regions within an extended system (e.g. amygdala) in healthy individuals. In this study, we tested the functional localizer success rate in 27 schizophrenia patients and in 24 community controls. Overall, the core face processing regions were localized equally between both the schizophrenia and control group. Additionally, the amygdala, a candidate brain region from the extended system, was identified in nearly half the participants from both groups. These results indicate the effectiveness of a dynamic functional localizer at identifying regions of interest associated with face perception and emotion recognition in schizophrenia. The use of dynamic functional localizers may help standardize the investigation of the facial and emotion processing system in this and other clinical populations. PMID:26792586

  6. Efficacy of identifying neural components in the face and emotion processing system in schizophrenia using a dynamic functional localizer.

    PubMed

    Arnold, Aiden E G F; Iaria, Giuseppe; Goghari, Vina M

    2016-02-28

    Schizophrenia is associated with deficits in face perception and emotion recognition. Despite consistent behavioural results, the neural mechanisms underlying these cognitive abilities have been difficult to isolate, in part due to differences in neuroimaging methods used between studies for identifying regions in the face processing system. Given this problem, we aimed to validate a recently developed fMRI-based dynamic functional localizer task for use in studies of psychiatric populations and specifically schizophrenia. Previously, this functional localizer successfully identified each of the core face processing regions (i.e. fusiform face area, occipital face area, superior temporal sulcus), and regions within an extended system (e.g. amygdala) in healthy individuals. In this study, we tested the functional localizer success rate in 27 schizophrenia patients and in 24 community controls. Overall, the core face processing regions were localized equally between both the schizophrenia and control group. Additionally, the amygdala, a candidate brain region from the extended system, was identified in nearly half the participants from both groups. These results indicate the effectiveness of a dynamic functional localizer at identifying regions of interest associated with face perception and emotion recognition in schizophrenia. The use of dynamic functional localizers may help standardize the investigation of the facial and emotion processing system in this and other clinical populations.

  7. Hood River Passive House

    SciTech Connect

    Hales, D.

    2013-03-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project.

  8. Passive CO2 concentration in higher plants.

    PubMed

    Sage, Rowan F; Khoshravesh, Roxana

    2016-06-01

    Photorespiratory limitations on C3 photosynthesis are substantial in warm, low CO2 conditions. To compensate, certain plants evolved mechanisms to actively concentrate CO2 around Rubisco using ATP-supported CO2 pumps such as C4 photosynthesis. Plants can also passively accumulate CO2 without additional ATP expenditure by localizing the release of photorespired and respired CO2 around Rubisco that is diffusively isolated from peripheral air spaces. Passive accumulation of photorespired CO2 occurs when glycine decarboxylase is localized to vascular sheath cells in what is termed C2 photosynthesis, and through forming sheaths of chloroplasts around the periphery of mesophyll cells. The peripheral sheaths require photorespired CO2 to re-enter chloroplasts where it can be refixed. Passive accumulation of respiratory CO2 is common in organs such as stems, fruits and flowers, due to abundant heterotrophic tissues and high diffusive resistance along the organ periphery. Chloroplasts within these organs are able to exploit this high CO2 to reduce photorespiration. CO2 concentration can also be enhanced passively by channeling respired CO2 from roots and rhizomes into photosynthetic cells of stems and leaves via lacunae, aerenchyma and the xylem stream. Through passive CO2 concentration, C3 species likely improved their carbon economy and maintained fitness during episodes of low atmospheric CO2.

  9. Same, same—but different: on the use of Navon derived measures of global/local processing in studies of face processing.

    PubMed

    Gerlach, Christian; Krumborg, Julie R

    2014-11-01

    Some studies have reported a significant correlation between face discrimination/recognition ability and indexes of global/local processing derived from the Navon paradigm. Other studies, however, have failed to find such a relationship. In this paper we examine three aspects related to the Navon paradigm that may have contributed to this discrepancy but which have been largely neglected: (i) the use of different types of compound stimuli across studies, (ii) differences between studies in the type of index derived from the Navon paradigm, and (iii) the reliability of these indexes. In a Navon experiment comparing performance with compound letters and compound shapes in normal participants, we find little consistency both within and across participants in how they perform with these stimulus types, despite the fact that both stimulus types give rise to the typical effects. In addition we find that many of the Navon derived indexes of global/local effects used in studies examining face processing have low reliability and do not measure the same aspects of global/local processing. Echoing the results from the normal participants, we also find little consistency in how a congenital prosopagnosic performs in the Navon paradigm. With compound letters, she responds much faster to local than to global aspects of the stimuli; a pattern not seen in a single of the normal participants. With compound shapes, however, she exhibits no such abnormality. These findings question the validity of the conclusions in studies relating Navon derived indexes of global/local processing to face processing.

  10. Visualization of Neuregulin 1 ectodomain shedding reveals its local processing in vitro and in vivo

    PubMed Central

    Kamezaki, Aosa; Sato, Fuminori; Aoki, Kazuhiro; Asakawa, Kazuhide; Kawakami, Koichi; Matsuzaki, Fumio; Sehara-Fujisawa, Atsuko

    2016-01-01

    Neuregulin1 (NRG1) plays diverse developmental roles and is likely involved in several neurological disorders including schizophrenia. The transmembrane NRG1 protein is proteolytically cleaved and released as a soluble ligand for ErbB receptors. Such post-translational processing, referred to as ‘ectodomain shedding’, is thought to be crucial for NRG1 function. However, little is known regarding the regulatory mechanism of NRG1 cleavage in vivo. Here, we developed a fluorescent probe, NRG1 Cleavage Indicating SenSOR (N-CISSOR), by fusing mCherry and GFP to the extracellular and intracellular domains of NRG1, respectively. N-CISSOR mimicked the subcellular localization and biochemical properties of NRG1 including cleavage dynamics and ErbB phosphorylation in cultured cells. mCherry/GFP ratio imaging of phorbol-12-myristate-13-acetate-stimulated N-CISSOR-expressing HEK293T cells enabled to monitor rapid ectodomain shedding of NRG1 at the subcellular level. Utilizing N-CISSOR in zebrafish embryos revealed preferential axonal NRG1 ectodomain shedding in developing motor neurons, demonstrating that NRG1 ectodomain shedding is spatially regulated at the subcellular level. Thus, N-CISSOR will be a valuable tool for elucidating the spatiotemporal regulation of NRG1 ectodomain shedding, both in vitro and in vivo. PMID:27364328

  11. Combining the pressure effect with local heat treatment for improving the sheet metal forming process

    NASA Astrophysics Data System (ADS)

    Palumbo, G.; Piccininni, A.; Guglielmi, P.; Sorgente, D.; Tricarico, L.

    2016-08-01

    The present work deals with the advantages in the Hydromechanical Deep Drawing (HDD) when AA5754 Tailored Heat Treated Blanks (THTBs) are adopted. It is well known that the creation of a suitable distribution of material properties increases the process performance. When non heat-treatable alloys are considered, the THTB approach can be successfully applied to increase the Limit Drawing Ratio (LDR) by changing the peripheral zone into the annealed state starting from a cold-worked blank. If this approach is combined with the advantages of a counterpressure, even more remarkable improvements can be achieved. Due to the large number of involved parameters, the optimized design of both the local treatment and the pressure profile were investigated coupling an axial symmetric Finite Element model with the integration platform modeFRONTIER. Results confirmed the possibility of increasing the LDR from 2.0 (Deep Drawing using a blank in the annealed state) up to about 3.0 if combining the adoption of a THTB with the optimal pressure profile.

  12. Automated global structure extraction for effective local building block processing in XCS.

    PubMed

    Butz, Martin V; Pelikan, Martin; Llorà, Xavier; Goldberg, David E

    2006-01-01

    Learning Classifier Systems (LCSs), such as the accuracy-based XCS, evolve distributed problem solutions represented by a population of rules. During evolution, features are specialized, propagated, and recombined to provide increasingly accurate subsolutions. Recently, it was shown that, as in conventional genetic algorithms (GAs), some problems require efficient processing of subsets of features to find problem solutions efficiently. In such problems, standard variation operators of genetic and evolutionary algorithms used in LCSs suffer from potential disruption of groups of interacting features, resulting in poor performance. This paper introduces efficient crossover operators to XCS by incorporating techniques derived from competent GAs: the extended compact GA (ECGA) and the Bayesian optimization algorithm (BOA). Instead of simple crossover operators such as uniform crossover or one-point crossover, ECGA or BOA-derived mechanisms are used to build a probabilistic model of the global population and to generate offspring classifiers locally using the model. Several offspring generation variations are introduced and evaluated. The results show that it is possible to achieve performance similar to runs with an informed crossover operator that is specifically designed to yield ideal problem-dependent exploration, exploiting provided problem structure information. Thus, we create the first competent LCSs, XCS/ECGA and XCS/BOA, that detect dependency structures online and propagate corresponding lower-level dependency structures effectively without any information about these structures given in advance.

  13. Integrative processing of perception and reward in an auditory localization paradigm.

    PubMed

    Maiworm, Mario; König, Peter; Röder, Brigitte

    2011-01-01

    Under natural conditions, human beings routinely have to choose among multiple alternatives which are associated with specific outcomes of varying desirability. Typically, decisions are based upon the processing of perceptual input, which introduces additional noise to the system. Bayesian decision theory (BDT) allows us to formalize decision under risk and to predict statistically optimal choice behavior. In the present study, human observers performed a classification task characterized by an extensive amount of perceptual uncertainty (auditory localization). In addition, a spatial reward function was imposed on the task. We set up a BDT model with no free parameters to serve as a benchmark for statistically optimal choices, and tested it against a purely perceptual model and a hybrid, heuristic model. In addition, we tested these three models with free rather than fixed parameters for the perceptual uncertainty and the peak of the reward function. The log likelihoods of the models given the empirical data were determined by means of Monte Carlo simulations. Bayesian model comparison (BMC) revealed that the BDT model with two free parameters was the most plausible among the tested models. The fitted parameter values for the peak of the reward function were consistently smaller than the actual peak reward communicated to the participants. The results are discussed in the context of an internal underweighting of the reward function.

  14. Underwater Threat Source Localization: Processing Sensor Network TDOAs with a Terascale Optical Core Device

    SciTech Connect

    Barhen, Jacob; Imam, Neena

    2007-01-01

    Revolutionary computing technologies are defined in terms of technological breakthroughs, which leapfrog over near-term projected advances in conventional hardware and software to produce paradigm shifts in computational science. For underwater threat source localization using information provided by a dynamical sensor network, one of the most promising computational advances builds upon the emergence of digital optical-core devices. In this article, we present initial results of sensor network calculations that focus on the concept of signal wavefront time-difference-of-arrival (TDOA). The corresponding algorithms are implemented on the EnLight processing platform recently introduced by Lenslet Laboratories. This tera-scale digital optical core processor is optimized for array operations, which it performs in a fixed-point-arithmetic architecture. Our results (i) illustrate the ability to reach the required accuracy in the TDOA computation, and (ii) demonstrate that a considerable speed-up can be achieved when using the EnLight 64a prototype processor as compared to a dual Intel XeonTM processor.

  15. Neuro-computational processing of moving sonar echoes classifies and localizes foliage

    NASA Astrophysics Data System (ADS)

    Kuc, Roman

    2004-09-01

    Echoes from in situ tree trunks, similar to those observed by flying bats, are processed. A moving sonar converts echoes into spike sequences and applies neural-computational methods to classify objects and estimate passing range. Two classes of tree trunks act as retro-reflectors that generate strong echoes (SEs), identified by a locally dense spike pattern. Linear drive-by sonar trajectories cause SEs to follow hyperbolic curves specified by passing range. A glint is a collection of consecutive range readings matching expected values on a specific hyperbolic curve. Passing-range detectors compare successive SE data with expected values in a table and tally coincidences. Counters increment when coincidences occur and decrement when they do not. A glint terminates after tallying a sufficient number of coincidences and coincidence failure occurs in the maximum-count detector. Reflector roughness, deviations in sonar trajectory, and echo jitter necessitate a coincidence window to define matches. Short windows identify small glints over piecewise linear sonar trajectories, while long windows accommodate deviations in sonar speed and trajectory, and associate multiple glints observed with shorter windows. The minimum coincidence window size yielding glints classify smooth and rough retro-reflectors.

  16. Power spectra in totally asymmetric simple exclusion process (TASEP) with local inhomogeneity

    NASA Astrophysics Data System (ADS)

    Dong, Jiajia; Zia, Royce K. P.

    2010-03-01

    As a paradigmatic system in non-equilibrium statistical mechanics, TASEP has been extensively studied in the abstract and also applied to model many complex phenomena such as traffic flow and protein synthesis. We focus on a rather less studied aspect of TASEP: the total number of particles on a one-dimension open TASEP at time t, N(t), and its power spectra I(φ), especially when there are local inhomogeneities. Motivated by the protein synthesis process where messenger RNA, codons and ribosomes are associated with the underlying lattice, sites and particles transported in TASEP, we investigate the effect on the power spectrum due to one defect (slower hopping rate) at different positions along the lattice. Using Monte Carlo simulation, we measure I(φ) for both the entire system and the subsystems separated by the defect. As in previous studies, oscillations are found. Here, however, more interesting characteristics emerge, depending on the location and the ``strength'' of the slow site. The biological implication of these results is also discussed.

  17. Neuro-computational processing of moving sonar echoes classifies and localizes foliage.

    PubMed

    Kuc, Roman

    2004-09-01

    Echoes from in situ tree trunks, similar to those observed by flying bats, are processed. A moving sonar converts echoes into spike sequences and applies neural-computational methods to classify objects and estimate passing range. Two classes of tree trunks act as retro-reflectors that generate strong echoes (SEs), identified by a locally dense spike pattern. Linear drive-by sonar trajectories cause SEs to follow hyperbolic curves specified by passing range. A glint is a collection of consecutive range readings matching expected values on a specific hyperbolic curve. Passing-range detectors compare successive SE data with expected values in a table and tally coincidences. Counters increment when coincidences occur and decrement when they do not. A glint terminates after tallying a sufficient number of coincidences and coincidence failure occurs in the maximum-count detector. Reflector roughness, deviations in sonar trajectory, and echo jitter necessitate a coincidence window to define matches. Short windows identify small glints over piecewise linear sonar trajectories, while long windows accommodate deviations in sonar speed and trajectory, and associate multiple glints observed with shorter windows. The minimum coincidence window size yielding glints classify smooth and rough retro-reflectors.

  18. Small deviations from local equilibrium for a process which exhibits hydrodynamical behavior

    NASA Astrophysics Data System (ADS)

    Demasi, A.; Ianiro, N.; Presutti, E.

    1981-11-01

    Deviations from local equilibrium in a symmetric simple exclusion process are studied. Properties which mimic the hydrodynamical behavior of real physical systems are underlined. The only extremal invariant measures are the Bernoulli measures. Each measure in a suitable class, after a macroscopic time, at a zero order approximation, by a Bernoulli measure with parameter depending on macroscopic space and time. The so defined equilibrium profile satisfies the heat equation. It is proven that at first order, the state is the Gibbs phenomenon with one and two body potentials. Potential strength depends only on macroscopic space and time and on the equilibrium profile. The one body potential is linear (on the microscopic positions of the particles) and proportional to the macroscopic space gradient of the equilibrium parameter at that time, so that Fourier law holds. The two body potential varies on a macroscopic scale and is not dependent on the microscopic positions of the particles, which is given by the value of the covariance of the Gaussian macroscopic density fluctuation field.

  19. Signal/Image Processing of Acoustic Flaw Signatures for Detection and Localization

    SciTech Connect

    Candy, J V; Meyer, A W

    2001-06-01

    The timely, nondestructive evaluation (NDE) of critical optics in high energy, pulsed laser experiments is a crucial analysis that must be performed for the experiment to be successful. Failure to detect flaws of critical sizes in vacuum-loaded optical windows can result in a catastrophic failure jeopardizing the safety of both personnel and costly equipment. We discuss the development of signal/image processing techniques to both detect critical flaws and locate their position on the window. The data measured from two Orthogonal arrays of narrow beamwidth ultrasonic transducers are preprocessed using a model-based scheme based on the Green's function of the medium providing individual channel signatures. These signatures are then transformed to the two-dimensional image space using a power-based estimator. A 2D-replicant is then constructed based on the underlying physics of the material along with the geometry of the window. Correlating the replicant with the enhanced power image leads to the optimal 2D-matched filter solution detecting and localizing the flaw. Controlled experimental results on machined flaws are discussed.

  20. The role of local versus biogeographical processes in influencing diversity and body-size variation in mammal assemblages.

    PubMed

    Lopez, Luiz Carlos S; Figueiredo, Marcos S L; Fracasso, Maria Paula de Aguiar; Mesquita, Daniel Oliveira; Anjos, Ulisses Umbelino; Grelle, Carlos Eduardo Viveiros

    2016-03-01

    Our objective was to estimate and analyze the body-size distribution parameters of terrestrial mammal assemblages at different spatial scales, and to determine whether these parameters are controlled by local ecological processes or by larger-scale ones. Based on 93 local assemblages, plus the complete mammal assemblage from three continents (Africa, North, and South America), we estimated three key distribution parameters (diversity/size slope, skewness, and modal size) and compared the values to those expected if size distributions are mainly controlled by local interactions. Mammal diversity decreased much faster as body size increased than predicted by fractal niche theory, both at continental and at local scales, with continental distributions showing steeper slopes than the localities within them. South America showed a steeper slope (after controlling for species diversity), compared to Africa and North America, at local and continental scales. We also found that skewness and modal body size can show strikingly different correlations with predictor variables, such as species richness and median size, depending on the use of untransformed versus log-transformed data, due to changes in the distribution density generated by log-transformation. The main differences in slope, skewness, and modal size between local and continental scales appear to arise from the same biogeographical process, where small-sized species increase in diversity much faster (due to higher spatial turnover rates) than large-sized species. This process, which can operate even in the absence of competitive saturation at local scales, generates continental assemblages with steeper slopes, smaller modal sizes, and higher right skewness (toward small-sized species) compared to local communities. In addition, historical factors can also affect the size distribution slopes, which are significantly steeper, in South American mammal assemblages (probably due to stronger megafauna extinction events

  1. The role of local versus biogeographical processes in influencing diversity and body-size variation in mammal assemblages.

    PubMed

    Lopez, Luiz Carlos S; Figueiredo, Marcos S L; Fracasso, Maria Paula de Aguiar; Mesquita, Daniel Oliveira; Anjos, Ulisses Umbelino; Grelle, Carlos Eduardo Viveiros

    2016-03-01

    Our objective was to estimate and analyze the body-size distribution parameters of terrestrial mammal assemblages at different spatial scales, and to determine whether these parameters are controlled by local ecological processes or by larger-scale ones. Based on 93 local assemblages, plus the complete mammal assemblage from three continents (Africa, North, and South America), we estimated three key distribution parameters (diversity/size slope, skewness, and modal size) and compared the values to those expected if size distributions are mainly controlled by local interactions. Mammal diversity decreased much faster as body size increased than predicted by fractal niche theory, both at continental and at local scales, with continental distributions showing steeper slopes than the localities within them. South America showed a steeper slope (after controlling for species diversity), compared to Africa and North America, at local and continental scales. We also found that skewness and modal body size can show strikingly different correlations with predictor variables, such as species richness and median size, depending on the use of untransformed versus log-transformed data, due to changes in the distribution density generated by log-transformation. The main differences in slope, skewness, and modal size between local and continental scales appear to arise from the same biogeographical process, where small-sized species increase in diversity much faster (due to higher spatial turnover rates) than large-sized species. This process, which can operate even in the absence of competitive saturation at local scales, generates continental assemblages with steeper slopes, smaller modal sizes, and higher right skewness (toward small-sized species) compared to local communities. In addition, historical factors can also affect the size distribution slopes, which are significantly steeper, in South American mammal assemblages (probably due to stronger megafauna extinction events

  2. Evaluation of Alternate Stainless Steel Surface Passivation Methods

    SciTech Connect

    Clark, Elliot A.

    2005-05-31

    Stainless steel containers were assembled from parts passivated by four commercial vendors using three passivation methods. The performance of these containers in storing hydrogen isotope mixtures was evaluated by monitoring the composition of initially 50% H{sub 2} 50% D{sub 2} gas with time using mass spectroscopy. Commercial passivation by electropolishing appears to result in surfaces that do not catalyze hydrogen isotope exchange. This method of surface passivation shows promise for tritium service, and should be studied further and considered for use. On the other hand, nitric acid passivation and citric acid passivation may not result in surfaces that do not catalyze the isotope exchange reaction H{sub 2} + D{sub 2} {yields} 2HD. These methods should not be considered to replace the proprietary passivation processes of the two current vendors used at the Savannah River Site Tritium Facility.

  3. Passive and iontophoretic permeation of glipizide.

    PubMed

    Jain, Ashish; Ghosh, Bijaya; Rajgor, Naresh; Desai, B G

    2008-08-01

    In vitro iontophoretic delivery of glipizide across the pigskin was investigated. The experiment was carried out at three different donor drug concentrations using cathodal iontophoresis (current density 0.5 mA cm(-2)) with corresponding passive controls. At all concentration levels, iontophoresis showed enhanced permeation rate compared to passive controls (P<0.01). For passive permeation, the steady-state flux significantly increased with the increase in donor drug concentration (P<0.01). Passive process followed zero-order profile while the profile was nonlinear in iontophoresis. Competition by chloride ions released in the cathode compartment could be the reason. Flux enhancement was highest at the lowest drug load and lowest at the highest drug load. The target flux of glipizide was calculated to be 0. 4147 micromol h(-1). As the highest flux obtained was 0.2727 micromol cm(-2) h(-1), it can be said that glipizide is a promising candidate for iontophoretic delivery.

  4. The interference of local over global information processing in children with attention deficit hyperactivity disorder of the inattentive type.

    PubMed

    Song, Yongning; Hakoda, Yuji

    2012-04-01

    A classic finding in perception of compound patterns is normal individuals cannot skip global analysis in local-oriented processing, but they can successfully resist local analysis in global-oriented processing-the so-called global interference [1]. Recently, studies examining the role of brain hemisphere activity in the Navon task have indicated that the processing of global and local information can be, respectively, attributed to the right and left hemispheres. Moreover, many neuroimaging researches have revealed that certain core symptoms of attention deficit hyperactivity disorder (ADHD) are related to dysfunction of right hemisphere. These findings imply that global interference will be substantially less evident, and possibly even replaced by local interference in ADHD. The present study compared the performance of children with and without attention deficit hyperactivity disorder of the inattentive type (ADHD-I) in the processing of global and local information to examine the local interference hypothesis in ADHD. An ADHD-I group (n=15) and a paired control group (n=19) completed tasks using two versions of the Navon task, one requiring divided attention, in which no information was given to participants regarding the level at which a target would appear, and the other requiring selective attention, in which participants were instructed to attend to either the local or the global level. The results showed that children with ADHD-I exhibited local interference, regardless of which attention procedure was used. These results support the weak right hemisphere hypothesis in ADHD, and provide evidence against the deficit hypotheses for ADHD in the DSM-IV criteria [29], which postulates that inattention symptoms may manifest as a failure to provide close attention to details.

  5. Monitoring Coastal Processes at Local and Regional Geographic Scales with UAS

    NASA Astrophysics Data System (ADS)

    Starek, M. J.; Bridges, D.; Prouty, D.; Berryhill, J.; Williams, D.; Jeffress, G.

    2014-12-01

    Unmanned Aerial Systems (UAS) provide a powerful tool for coastal mapping due to attractive features such as low cost data acquisition, flexibility in data capture and resolution, rapid response, and autonomous flight. We investigate two different scales of UAS platforms for monitoring coastal processes along the central Texas Gulf coast. Firstly, the eBee is a small-scale UAS weighing ~0.7 kg designed for localized mapping. The imaging payload consists of a hand held RGB digital camera and NIR digital camera, both with 16.1 megapixel resolutions. The system can map up to 10 square kilometers on a single flight and is capable of acquiring imagery down to 1.5 cm ground sample distance. The eBee is configured with a GPS receiver, altitude sensor, gyroscope and a radio transmitter enabling autonomous flight. The system has a certificate of authorization (COA) from the FAA to fly over the Ward Island campus of Texas A&M University-Corpus Christi (TAMUCC). The campus has an engineered beach, called University Beach, located along Corpus Christi Bay. A set of groins and detached breakwaters were built in an effort to protect the beach from erosive wave action. The eBee is being applied to periodically survey the beach (Figure 1A). Through Structure from Motion (SfM) techniques, eBee-derived image sequences are post-processed to extract 3D topography and measure volumetric change. Additionally, when water clarity suffices, this approach enables the extraction of shallow-water bathymetry. Results on the utilization of the eBee to monitor beach morphodynamics will be presented including a comparison of derived estimates to RTK GPS and airborne lidar. Secondly, the RS-16 UAS has a 4 m wingspan and 11 kg sensor payload. The system is remotely piloted and has a flight endurance of 12 to 16 hours making it suitable for regional scale coastal mapping. The imaging payload consists of a multispectral sensor suite measuring in the visible, thermal IR, and ultraviolet ranges of the

  6. Electrical stability enhancement of GeInGaO thin-film transistors by solution-processed Li-doped yttrium oxide passivation

    NASA Astrophysics Data System (ADS)

    Choi, U. H.; Yoon, S.; Yoon, D. H.; Tak, Y. J.; Kim, Y.-G.; Ahn, B. D.; Park, J.; Kim, H. J.

    2016-07-01

    In this study, we investigated a method of enhancing the electrical stability of GeInGaO thin-film transistors (TFTs) using a Li-doped Y2O3 (YO) passivation layer (PVL). Li reduced metal hydroxide groups in the PVL, and diffused into the channel layer and reduced the oxygen vacancy at the top surface of the channel layer, which is the origin of the defect state and electrical instability. In addition, the negative-bias temperature stress (NBTS) for 3600 s improved for Li-doped YO (LYO) PVL. The threshold voltage shift decreased from  -10.3 V for the YO PVL to  -4.8 V for the LYO PVL, a 54% improvement.

  7. Exposure of lima bean leaves to volatiles from herbivore-induced conspecific plants results in emission of carnivore attractants: active or passive process?

    PubMed

    Choh, Yasuyuki; Shimoda, Takeshi; Ozawa, Rika; Dicke, Marcel; Takabayashi, Junji

    2004-07-01

    There is increasing evidence that volatiles emitted by herbivore-damaged plants can cause responses in downwind undamaged neighboring plants, such as the attraction of carnivorous enemies of herbivores. One of the open questions is whether this involves an active (production of volatiles) or passive (adsorption of volatiles) response of the uninfested downwind plant. This issue is addressed in the present study. Uninfested lima bean leaves that were exposed to volatiles from conspecific leaves infested with the spider mite Tetranychus urticae, emitted very similar blends of volatiles to those emitted from infested leaves themselves. Treating leaves with a protein-synthesis inhibitor prior to infesting them with spider mites completely suppressed the production of herbivore-induced volatiles in the infested leaves. Conversely, inhibitor treatment to uninfested leaves prior to exposure to volatiles from infested leaves did not affect the emission of volatiles from the exposed, uninfested leaves. This evidence supports the hypothesis that response of the exposed downwind plant is passive. T. urticae-infested leaves that had been previously exposed to volatiles from infested leaves emitted more herbivore-induced volatiles than T. urticae-infested leaves previously exposed to volatiles from uninfested leaves. The former leaves were also more attractive to the predatory mite, Phytoseiulus persimilis, than the latter. This shows that previous exposure of plants to volatiles from herbivore-infested neighbors results in a stronger response of plants in terms of predator attraction when herbivores damage the plant. This supports the hypothesis that the downwind uninfested plant is actively involved. Both adsorption and production of volatiles can mediate the attraction of carnivorous mites to plants that have been exposed to volatiles from infested neighbors.

  8. Reversible long-term changes in auditory processing in mature auditory cortex in the absence of hearing loss induced by passive, moderate-level sound exposure.

    PubMed

    Pienkowski, Martin; Eggermont, Jos J

    2012-01-01

    It has become increasingly clear that even occasional exposure to loud sounds in occupational or recreational settings can cause irreversible damage to the hair cells of the cochlea and the auditory nerve fibers, even if the resulting partial loss of hearing sensitivity, usually accompanied by tinnitus, disappears within hours or days of the exposure. Such exposure may explain at least some cases of poor speech intelligibility in noise in the face of a normal or near-normal audiogram. Recent findings from our laboratory suggest that long-term changes to auditory brain function-potentially leading to problems with speech intelligibility-can be effected by persistent, passive exposure to more moderate levels of noise (in the 70 dB SPL range) in the apparent absence of damage to the auditory periphery (as reflected in normal distortion product otoacoustic emissions and auditory brainstem responses). Specifically, passive exposure of adult cats to moderate levels of band-pass-filtered noise, or to band-limited ensembles of dense, random tone pips, can lead to a profound decrease of neural activity in the auditory cortex roughly in the exposure frequency range, and to an increase of activity outside that range. This can progress to an apparent reorganization of the cortical tonotopic map, which is reminiscent of the reorganization resulting from hearing loss restricted to a part of the hearing frequency range, although again, no hearing loss was apparent after our moderate-level sound exposure. Here, we review this work focusing specifically on the potential hearing problems that may arise despite a normally functioning auditory periphery.

  9. Local Authority Approaches to the School Admissions Process. LG Group Research Report

    ERIC Educational Resources Information Center

    Rudd, Peter; Gardiner, Clare; Marson-Smith, Helen

    2010-01-01

    What are the challenges, barriers and facilitating factors connected to the various school admissions approaches used by local authorities? This report gathers the views of local authority admissions officers on the strengths and weaknesses of different approaches, as well as the issues and challenges they face in this important area. It covers:…

  10. Trait inferences in goal-directed behavior: ERP timing and localization under spontaneous and intentional processing

    PubMed Central

    Van den Eede, Sofie; Baetens, Kris; Vandekerckhove, Marie

    2009-01-01

    This study measured event-related potentials (ERPs) during multiple goal and trait inferences, under spontaneous or intentional instructions. Participants read sentences describing several goal-implying behaviors of a target person from which also a strong trait could be inferred or not. The last word of each sentence determined the consistency with the inference induced during preceding sentences. In comparison with behaviors that implied only a goal, stronger waveforms beginning at ∼150 ms were obtained when the behaviors additionally implied a trait. These ERPs showed considerable parallels between spontaneous and intentional inferences. This suggests that traits embedded in a stream of goal-directed behaviors were detected more rapidly and automatically than mere goals, irrespective of the participants’ spontaneous or intentional instructions. In line with this, source localization (LORETA) of the ERPs show predominantly activation in the temporo-parietal junction (TPJ) during 150–200 ms, suggesting that goals were detected at that time interval. During 200–300 ms, activation was stronger at the medial prefrontal cortex (mPFC) for multiple goals and traits as opposed to goals only, suggesting that traits were inferred during this time window. A cued recall measure taken after the presentation of the stimulus material support the occurrence of goal and trait inferences and shows significant correlations with the neural components, indicating that these components are valid neural indices of spontaneous and intentional social inferences. The early detection of multiple goal and trait inferences is explained in terms of their greater social relevance, leading to privileged attention allocation and processing in the brain. PMID:19270041

  11. Nucleolar localization elements in U8 snoRNA differ from sequences required for rRNA processing.

    PubMed Central

    Lange, T S; Borovjagin, A V; Gerbi, S A

    1998-01-01

    U8 small nucleolar RNA (snoRNA) is essential for metazoan ribosomal RNA (rRNA) processing in nucleoli. The sequences and structural features in Xenopus U8 snoRNA that are required for its nucleolar localization were analyzed. Fluorescein-labeled U8 snoRNA was injected into Xenopus oocyte nuclei, and fluorescence microscopy of nucleolar preparations revealed that wild-type Xenopus U8 snoRNA localized to nucleoli, regardless of the presence or nature of the 5' cap on the injected U8 snoRNA. Nucleolar localization was observed when loops or stems in the 5' portion of U8 that are critical for U8 snoRNA function in rRNA processing were mutated. Therefore, sites of interaction in U8 snoRNA that potentially tether it to pre-rRNA are not essential for nucleolar localization of U8. Boxes C and D are known to be nucleolar localization elements (NoLEs) for U8 snoRNA and other snoRNAs of the Box C/D family. However, the spatial relationship of Box C to Box D was not crucial for U8 nucleolar localization, as demonstrated here by deletion of sequences in the two stems that separate them. These U8 mutants can localize to nucleoli and function in rRNA processing as well. The single-stranded Cup region in U8, adjacent to evolutionarily conserved Box C, functions as a NoLE in addition to Boxes C and D. Cup is unique to U8 snoRNA and may help bind putative protein(s) needed for nucleolar localization. Alternatively, Cup may help to retain U8 snoRNA within the nucleolus. PMID:9671052

  12. Processing and lysosomal localization of a glycoprotein whose secretion is transformation stimulated

    PubMed Central

    1985-01-01

    The major excreted protein (MEP) of transformed mouse fibroblasts is a mannose 6-phosphate-containing glycoprotein whose synthesis and secretion are increased in malignantly transformed 3T3 cells and whose synthesis is increased by treatment of 3T3 cells with tumor promoters or growth factors. When pulse-labeled extracts from Kirsten virus- transformed NIH 3T3 (KNIH) cells were immunoprecipitated using an antibody against secreted MEP, one cellular protein was immunoprecipitated that had the same molecular weight and tryptic peptide map as the secreted protein. Pulse-chase labeling experiments showed that 50-60% of this 39,000-mol-wt form was secreted in transformed cells. Of the 40-50% remaining, approximately 5% was processed into two lower molecular weight forms (29,000 and 20,000) which are sequestered within the cell. Similar processing of these proteins was observed in the nontransformed parent NIH 3T3 (NIH) cells. However, in NIH cells, much less of the synthesized MEP was secreted. Measurements of steady-state levels of these three forms of cellular MEP by Western blot immunolocalization revealed approximately fourfold more MEP in KNIH cells than in NIH cells as well as differences in the relative distribution of MEP forms in transformed and nontransformed cells. Subcellular fractionation of KNIH cells on a Percoll gradient demonstrated a distribution of total MEP similar to that of several lysosomal enzymes. The light lysosomal/Golgi peak from these gradients contained both the precursor 39,000-mol-wt form of MEP and the 20,000- mol-wt form, whereas the heavy lysosomal peak was enriched in the 20,000-mol-wt form. The distribution of MEP forms was found to be similar in NIH cells except that the 29,000-mol-wt form was also seen to be enriched in the heavy lysosomal peak. This biochemical localization of MEP was confirmed by immunolocalization with light and electron microscopy. These data support the hypothesis that MEP is a lysosomal protein that is

  13. A novel low-complexity post-processing algorithm for precise QRS localization.

    PubMed

    Fonseca, Pedro; Aarts, Ronald M; Foussier, Jérôme; Long, Xi

    2014-01-01

    Precise localization of QRS complexes is an essential step in the analysis of small transient changes in instant heart rate and before signal averaging in QRS morphological analysis. Most localization algorithms reported in literature are either not robust to artifacts, depend on the sampling rate of the ECG recordings or are too computationally expensive for real-time applications, especially in low-power embedded devices. This paper proposes a localization algorithm based on the intersection of tangents fitted to the slopes of R waves detected by any QRS detector. Despite having a lower complexity, this algorithm achieves comparable trigger jitter to more complex localization methods without requiring the data to first be upsampled. It also achieves high localization precision regardless of which QRS detector is used as input. It is robust to clipping artifacts and to noise, achieving an average localization error below 2 ms and a trigger jitter below 1 ms on recordings where no additional artifacts were added, and below 8 ms for recordings where the signal was severely degraded. Finally, it increases the accuracy of template-based false positive rejection, allowing nearly all mock false positives added to a set of QRS detections to be removed at the cost of a very small decrease in sensitivity. The localization algorithm proposed is particularly well-suited for implementation in embedded, low-power devices for real-time applications. PMID:26034664

  14. Spared and Impaired Spoken Discourse Processing in Schizophrenia: Effects of Local and Global Language Context

    PubMed Central

    Boudewyn, Megan A.; Long, Debra L.; Luck, Steve J.; Kring, Ann M.; Ragland, J. Daniel; Ranganath, Charan; Lesh, Tyler; Niendam, Tara; Solomon, Marjorie; Mangun, George R.; Carter, Cameron S.

    2013-01-01

    Individuals with schizophrenia are impaired in a broad range of cognitive functions, including impairments in the controlled maintenance of context-relevant information. In this study, we used ERPs in human subjects to examine whether impairments in the controlled maintenance of spoken discourse context in schizophrenia lead to overreliance on local associations among the meanings of individual words. Healthy controls (n = 22) and patients (n = 22) listened to short stories in which we manipulated global discourse congruence and local priming. The target word in the last sentence of each story was globally congruent or incongruent and locally associated or unassociated. ERP local association effects did not significantly differ between control participants and schizophrenia patients. However, in contrast to controls, patients only showed effects of discourse congruence when targets were primed by a word in the local context. When patients had to use discourse context in the absence of local priming, they showed impaired brain responses to the target. Our findings indicate that schizophrenia patients are impaired during discourse comprehension when demands on controlled maintenance of context are high. We further found that ERP measures of increased reliance on local priming predicted reduced social functioning, suggesting that alterations in the neural mechanisms underlying discourse comprehension have functional consequences in the illness. PMID:24068824

  15. A novel low-complexity post-processing algorithm for precise QRS localization.

    PubMed

    Fonseca, Pedro; Aarts, Ronald M; Foussier, Jérôme; Long, Xi

    2014-01-01

    Precise localization of QRS complexes is an essential step in the analysis of small transient changes in instant heart rate and before signal averaging in QRS morphological analysis. Most localization algorithms reported in literature are either not robust to artifacts, depend on the sampling rate of the ECG recordings or are too computationally expensive for real-time applications, especially in low-power embedded devices. This paper proposes a localization algorithm based on the intersection of tangents fitted to the slopes of R waves detected by any QRS detector. Despite having a lower complexity, this algorithm achieves comparable trigger jitter to more complex localization methods without requiring the data to first be upsampled. It also achieves high localization precision regardless of which QRS detector is used as input. It is robust to clipping artifacts and to noise, achieving an average localization error below 2 ms and a trigger jitter below 1 ms on recordings where no additional artifacts were added, and below 8 ms for recordings where the signal was severely degraded. Finally, it increases the accuracy of template-based false positive rejection, allowing nearly all mock false positives added to a set of QRS detections to be removed at the cost of a very small decrease in sensitivity. The localization algorithm proposed is particularly well-suited for implementation in embedded, low-power devices for real-time applications.

  16. Global and local processing of incidental information and memory retrieval at 6 months.

    PubMed

    Bhatt, R S; Rovee-Collier, C; Shyi, G C

    1994-04-01

    In five experiments, we examined the role of global and local cues in memory retrieval in infancy. Six-month-old infants were trained at home in a distinctive context (playpen liner) to kick to move a mobile. The liners were yellow and displayed either green stripes, green squares aligned vertically in stripe-like columns, or green squares in a grid pattern. The stripes and columns liners had a similar global configuration but different local components; the columns and grid liners had identical local components but different global configurations. When infants were tested 24 h after training in the presence of context liners that differed from the training context in either global configurations or local features, their memory retrieval was disrupted (Experiments 1 and 2). However, a change from stripes to columns failed to disrupt memory retrieval, even though the reverse change, from columns to stripes, did. Experiments 3, 4, and 5 revealed that this asymmetry was due to the fact that, when discriminative local information is not directly associated with training, a postperceptual strategy enables infants to disregard a mismatch in local information between training and test contexts and to generalize on the basis of a match in global information during the 24-h retention test. Thus, infants encode and remember for substantial periods of time both global configuration information and local component information in the incidental context in which an event occurs and flexibly utilize this information when responding to new events. PMID:8169579

  17. Spared and impaired spoken discourse processing in schizophrenia: effects of local and global language context.

    PubMed

    Swaab, Tamara Y; Boudewyn, Megan A; Long, Debra L; Luck, Steve J; Kring, Ann M; Ragland, J Daniel; Ranganath, Charan; Lesh, Tyler; Niendam, Tara; Solomon, Marjorie; Mangun, George R; Carter, Cameron S

    2013-09-25

    Individuals with schizophrenia are impaired in a broad range of cognitive functions, including impairments in the controlled maintenance of context-relevant information. In this study, we used ERPs in human subjects to examine whether impairments in the controlled maintenance of spoken discourse context in schizophrenia lead to overreliance on local associations among the meanings of individual words. Healthy controls (n = 22) and patients (n = 22) listened to short stories in which we manipulated global discourse congruence and local priming. The target word in the last sentence of each story was globally congruent or incongruent and locally associated or unassociated. ERP local association effects did not significantly differ between control participants and schizophrenia patients. However, in contrast to controls, patients only showed effects of discourse congruence when targets were primed by a word in the local context. When patients had to use discourse context in the absence of local priming, they showed impaired brain responses to the target. Our findings indicate that schizophrenia patients are impaired during discourse comprehension when demands on controlled maintenance of context are high. We further found that ERP measures of increased reliance on local priming predicted reduced social functioning, suggesting that alterations in the neural mechanisms underlying discourse comprehension have functional consequences in the illness.

  18. Wireless passive radiation sensor

    SciTech Connect

    Pfeifer, Kent B; Rumpf, Arthur N; Yelton, William G; Limmer, Steven J

    2013-12-03

    A novel measurement technique is employed using surface acoustic wave (SAW) devices, passive RF, and radiation-sensitive films to provide a wireless passive radiation sensor that requires no batteries, outside wiring, or regular maintenance. The sensor is small (<1 cm.sup.2), physically robust, and will operate unattended for decades. In addition, the sensor can be insensitive to measurement position and read distance due to a novel self-referencing technique eliminating the need to measure absolute responses that are dependent on RF transmitter location and power.

  19. Processing of Basic Speech Acts Following Localized Brain Damage: A New Light on the Neuroanatomy of Language

    ERIC Educational Resources Information Center

    Soroker, N.; Kasher, A.; Giora, R.; Batori, G.; Corn, C.; Gil, M.; Zaidel, E.

    2005-01-01

    We examined the effect of localized brain lesions on processing of the basic speech acts (BSAs) of question, assertion, request, and command. Both left and right cerebral damage produced significant deficits relative to normal controls, and left brain damaged patients performed worse than patients with right-sided lesions. This finding argues…

  20. A Spatial Frequency Account of the Detriment that Local Processing of Navon Letters Has on Face Recognition

    ERIC Educational Resources Information Center

    Hills, Peter J.; Lewis, Michael B.

    2009-01-01

    Five minutes of processing the local features of a Navon letter causes a detriment in subsequent face-recognition performance (Macrae & Lewis, 2002). We hypothesize a perceptual after effect explanation of this effect in which face recognition is less accurate after adapting to high-spatial frequencies at high contrasts. Five experiments were…

  1. Visual Local and Global Processing in Low-Functioning Deaf Individuals with and without Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Maljaars, J. P. W.; Noens, I. L. J.; Scholte, E. M.; Verpoorten, R. A. W.; van Berckelaer-Onnes, I. A.

    2011-01-01

    Background: The ComFor study has indicated that individuals with intellectual disability (ID) and autism spectrum disorder (ASD) show enhanced visual local processing compared with individuals with ID only. Items of the ComFor with meaningless materials provided the best discrimination between the two samples. These results can be explained by the…

  2. The Broader Cognitive Phenotype of Autism in Parents: How Specific Is the Tendency for Local Processing and Executive Dysfunction?

    ERIC Educational Resources Information Center

    Bolte, Sven; Poustka, Fritz

    2006-01-01

    Background: The objective of this study was to investigate the tendency for local processing style ("weak central coherence") and executive dysfunction in parents of subjects with an autism spectrum disorder (ASD) compared with parents of individuals with early onset schizophrenia (EOS) and mental retardation (MR). Method: Sixty-two parents of…

  3. Chemo-dynamical evolution of the Local Group dwarf galaxies: The origin of r-process elements

    NASA Astrophysics Data System (ADS)

    Hirai, Y.; Ishimaru, Y.; Saitoh, T. R.; Fujii, M. S.; Hidaka, J.; Kajino, T.

    2016-06-01

    The r-process elements such as Au, Eu, and U are observed in the extremely metal-poor stars in the Milky Way halo and the Local Group dwarf galaxies. However, the origin of r-process elements has not yet been identified. The abundance of r-process elements of stars in the Local Group galaxies provides clues to clarify early evolutionary history of galaxies. It is important to understand the chemical evolution of the Local Group dwarf galaxies which would be building blocks of the Milky Way. In this study, we perform a series of N-body/smoothed particle hydrodynamic simulations of dwarf galaxies. We show that neutron star mergers can reproduce the observation of r-process elements. We find that the effects of gas mixing processes including metals in the star-forming region of a typical scale of giant molecular clouds ¥sim 10-100 pc play significant roles in the early chemical enrichment of dwarf galaxies. We also find that the star formation rate of ˜ 10^{-3} M_{⊙}yr^{-1} in early epoch (<1 Gyr) of galactic halo evolution is necessary for these results. Our results suggest that neutron star mergers are a major site of r-process.

  4. An all-silicon passive optical diode.

    PubMed

    Fan, Li; Wang, Jian; Varghese, Leo T; Shen, Hao; Niu, Ben; Xuan, Yi; Weiner, Andrew M; Qi, Minghao

    2012-01-27

    A passive optical diode effect would be useful for on-chip optical information processing but has been difficult to achieve. Using a method based on optical nonlinearity, we demonstrate a forward-backward transmission ratio of up to 28 decibels within telecommunication wavelengths. Our device, which uses two silicon rings 5 micrometers in radius, is passive yet maintains optical nonreciprocity for a broad range of input power levels, and it performs equally well even if the backward input power is higher than the forward input. The silicon optical diode is ultracompact and is compatible with current complementary metal-oxide semiconductor processing.

  5. Passive perception system for day/night autonomous off-road navigation

    NASA Astrophysics Data System (ADS)

    Rankin, Arturo L.; Bergh, Charles F.; Goldberg, Steven B.; Bellutta, Paolo; Huertas, Andres; Matthies, Larry H.

    2005-05-01

    Passive perception of terrain features is a vital requirement for military related unmanned autonomous vehicle operations, especially under electromagnetic signature management conditions. As a member of Team Raptor, the Jet Propulsion Laboratory developed a self-contained passive perception system under the DARPA funded PerceptOR program. An environmentally protected forward-looking sensor head was designed and fabricated in-house to straddle an off-the-shelf pan-tilt unit. The sensor head contained three color cameras for multi-baseline daytime stereo ranging, a pair of cooled mid-wave infrared cameras for nighttime stereo ranging, and supporting electronics to synchronize captured imagery. Narrow-baseline stereo provided improved range data density in cluttered terrain, while wide-baseline stereo provided more accurate ranging for operation at higher speeds in relatively open areas. The passive perception system processed stereo images and outputted over a local area network terrain maps containing elevation, terrain type, and detected hazards. A novel software architecture was designed and implemented to distribute the data processing on a 533MHz quad 7410 PowerPC single board computer under the VxWorks real-time operating system. This architecture, which is general enough to operate on N processors, has been subsequently tested on Pentium-based processors under Windows and Linux, and a Sparc based-processor under Unix. The passive perception system was operated during FY04 PerceptOR program evaluations at Fort A. P. Hill, Virginia, and Yuma Proving Ground, Arizona. This paper discusses the Team Raptor passive perception system hardware and software design, implementation, and performance, and describes a road map to faster and improved passive perception.

  6. Method of passivating semiconductor surfaces

    DOEpatents

    Wanlass, Mark W.

    1990-01-01

    A method of passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

  7. Method of passivating semiconductor surfaces

    DOEpatents

    Wanlass, M.W.

    1990-06-19

    A method is described for passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

  8. Spatial control of chemical processes on nanostructures through nano-localized water heating.

    PubMed

    Jack, Calum; Karimullah, Affar S; Tullius, Ryan; Khorashad, Larousse Khosravi; Rodier, Marion; Fitzpatrick, Brian; Barron, Laurence D; Gadegaard, Nikolaj; Lapthorn, Adrian J; Rotello, Vincent M; Cooke, Graeme; Govorov, Alexander O; Kadodwala, Malcolm

    2016-01-01

    Optimal performance of nanophotonic devices, including sensors and solar cells, requires maximizing the interaction between light and matter. This efficiency is optimized when active moieties are localized in areas where electromagnetic (EM) fields are confined. Confinement of matter in these 'hotspots' has previously been accomplished through inefficient 'top-down' methods. Here we report a rapid 'bottom-up' approach to functionalize selective regions of plasmonic nanostructures that uses nano-localized heating of the surrounding water induced by pulsed laser irradiation. This localized heating is exploited in a chemical protection/deprotection strategy to allow selective regions of a nanostructure to be chemically modified. As an exemplar, we use the strategy to enhance the biosensing capabilities of a chiral plasmonic substrate. This novel spatially selective functionalization strategy provides new opportunities for efficient high-throughput control of chemistry on the nanoscale over macroscopic areas for device fabrication. PMID:26961708

  9. Processing hazardous materials: Risk information at the local level. Final report on Phase 1

    SciTech Connect

    Conn, W.D.; Owens, W.L.; Rich, R.C.; Manheim, J.B.

    1988-12-01

    The pilot study examines the role of Local Emergency Planning Committees (LEPCs, set up under Title III of the Superfund Amendments and Reauthorization Act) in communicating about the risks from hazardous wastes in Superfund or RCRA sites as well as the risks from hazardous substances covered under the Community Right-to-know Law. This phase evaluated the usefulness of certain hazard analysis materials to the LEPCs. Eighty LEPCs in Virginia were surveyed about their activities and their perceptions of their responsibilities for communicating to their communities about Title III risks. The major conclusion for Phase I is that LEPCs were emphasizing the development of their local emergency plans. Communicating with the local citizenry was a secondary concern at that time. Phase II is examining how things have changed across 10 states.

  10. Spatial control of chemical processes on nanostructures through nano-localized water heating

    PubMed Central

    Jack, Calum; Karimullah, Affar S.; Tullius, Ryan; Khorashad, Larousse Khosravi; Rodier, Marion; Fitzpatrick, Brian; Barron, Laurence D.; Gadegaard, Nikolaj; Lapthorn, Adrian J.; Rotello, Vincent M.; Cooke, Graeme; Govorov, Alexander O.; Kadodwala, Malcolm

    2016-01-01

    Optimal performance of nanophotonic devices, including sensors and solar cells, requires maximizing the interaction between light and matter. This efficiency is optimized when active moieties are localized in areas where electromagnetic (EM) fields are confined. Confinement of matter in these ‘hotspots' has previously been accomplished through inefficient ‘top-down' methods. Here we report a rapid ‘bottom-up' approach to functionalize selective regions of plasmonic nanostructures that uses nano-localized heating of the surrounding water induced by pulsed laser irradiation. This localized heating is exploited in a chemical protection/deprotection strategy to allow selective regions of a nanostructure to be chemically modified. As an exemplar, we use the strategy to enhance the biosensing capabilities of a chiral plasmonic substrate. This novel spatially selective functionalization strategy provides new opportunities for efficient high-throughput control of chemistry on the nanoscale over macroscopic areas for device fabrication. PMID:26961708

  11. Do local processes scale to global patterns? The role of drought and the species pool in determining treehole insect diversity.

    PubMed

    Srivastava, Diane S

    2005-09-01

    Global patterns in community species richness may represent limitations operating at the local scale, such as competitive exclusion and habitat suitability, or, in the case of unsaturated communities, limitations to the species pool of biogeographic regions. Separating the effects of local and regional processes on community richness requires combining small-scale experiments with broad surveys. I examine limitations to the number of aquatic insect species per treehole at the scale of a single woodland, and between eight biogeographic regions. Variation in species richness at the woodland scale can largely be explained by small-scale differences between treeholes in drought disturbance, as shown for British treehole insects for 2 years. At the global scale, drought disturbance is a relatively poor predictor of patterns in the local richness of treehole mosquitoes. Instead, regional differences in the species pool explain most of the variation in local mosquito richness. Treeholes in at least the most species-poor regions appear to be unsaturated with mosquito species. In this system, therefore, local processes do not necessarily scale to global patterns.

  12. Hood River Passive House

    SciTech Connect

    Hales, David

    2014-01-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to "reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project. The design includes high R-Value assemblies, extremely tight construction, high performance doors and windows, solar thermal DHW, heat recovery ventilation, moveable external shutters and a high performance ductless mini-split heat pump. Cost analysis indicates that many of the measures implemented in this project did not meet the BA standard for cost neutrality. The ductless mini-split heat pump, lighting and advanced air leakage control were the most cost effective measures. The future challenge will be to value engineer the performance levels indicated here in modeling using production based practices at a significantly lower cost.

  13. Hood River Passive House

    SciTech Connect

    Hales, D.

    2014-01-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project. The design includes high R-Value assemblies, extremely tight construction, high performance doors and windows, solar thermal DHW, heat recovery ventilation, moveable external shutters and a high performance ductless mini-split heat pump. Cost analysis indicates that many of the measures implemented in this project did not meet the BA standard for cost neutrality. The ductless mini-split heat pump, lighting and advanced air leakage control were the most cost effective measures. The future challenge will be to value engineer the performance levels indicated here in modeling using production based practices at a significantly lower cost.

  14. Electrophysiological Indices of Spatial Attention during Global/Local Processing in Good and Poor Phonological Decoders

    ERIC Educational Resources Information Center

    Matthews, Allison Jane; Martin, Frances Heritage

    2009-01-01

    Previous research suggests a relationship between spatial attention and phonological decoding in developmental dyslexia. The aim of this study was to examine differences between good and poor phonological decoders in the allocation of spatial attention to global and local levels of hierarchical stimuli. A further aim was to investigate the…

  15. Local and Global Processing in Blind and Sighted Children in a Naming and Drawing Task

    ERIC Educational Resources Information Center

    Puspitawati, Ira; Jebrane, Ahmed; Vinter, Annie

    2014-01-01

    This study investigated the spatial analysis of tactile hierarchical patterns in 110 early-blind children aged 6-8 to 16-18 years, as compared to 90 blindfolded sighted children, in a naming and haptic drawing task. The results revealed that regardless of visual status, young children predominantly produced local responses in both tasks, whereas…

  16. Effects of the Global and Local Attention on the Processing of Categorical and Coordinate Spatial Relations

    ERIC Educational Resources Information Center

    Michimata, Chikashi; Saneyoshi, Ayako; Okubo, Matia; Laeng, Bruno

    2011-01-01

    Participants made categorical or coordinate spatial judgments on the global or local elements of shapes. Stimuli were composed of a horizontal line and two dots. In the Categorical task, participants judged whether the line was above or below the dots. In the Coordinate task, they judged whether the line would fit between the dots. Stimuli were…

  17. Building the Capacity of Local Education Authorities in Wales: Context, Processes and Developments

    ERIC Educational Resources Information Center

    Avery, Graham; Colebourne, David; James, Chris; Florek, Anton

    2004-01-01

    Recent policy developments are requiring local education authorities (LEAs) in Wales to undertake a more significant role in improving the Welsh education service. This article reports some of the outcomes of a Welsh Assembly government-funded initiative that addressed aspects of the development of the capacity of LEAs in Wales to fulfil this…

  18. A theory of local and global processes which affect solar wind electrons. 2: Experimental support

    NASA Technical Reports Server (NTRS)

    Scudder, J. D.; Olbert, S.

    1979-01-01

    The microscopic characteristics of the Coulomb cross section show that there are three natural subpopulations for plasma electrons: the subthermals with local kinetic energy E kT sub c; the transthermals with kT sub c E 7 kT sub c and the extrathermals E 7 kT sub c. Data from three experimental groups on three different spacecraft in the interplanetary medium over a radial range are presented to support the five interrelations projected between solar wind electron properties and changes in the interplanetary medium: (1) subthermals respond primarily to local changes (compression and rarefactions) in stream dynamics; (2) the extrathermal fraction of the ambient electron density should be anti-correlated with the asymptotic bulk speed; (3) the extrathermal "temperature" should be anti-correlated with the local wind speed at 1 AU; (4) the heat flux carried by electrons should be anti-correlated with the local bulk speed; and (5) the extrathermal differential 'temperature' should be nearly independent of radius within 1 AU.

  19. Evaluating potential indicators of ecosystem processes across local gradients in a temperate grassland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Science-based information is needed to identify indicators of ecosystem services that may then be used to monitor natural resources and quantify effects of management. Here our aim was to perform a local gradient study to elucidate correlative associations between vegetation and multiple soil prope...

  20. Educational Organization, School Localization and the Process of Urbanization in Sweden.

    ERIC Educational Resources Information Center

    Andrae, Annika

    Traditionally Sweden's educational system has been highly centralized; physical characteristics, administrative factors, and teacher qualifications have been generally standardized as have curriculums, though local implementation has been afforded considerable freedom. In 1971 the upper secondary school (9-12) consolidated three previously…

  1. Processes governing phytoplankton blooms in estuaries. I: The local production-loss balance

    USGS Publications Warehouse

    Lucas, L.V.; Koseff, Jeffrey R.; Cloern, J.E.; Monismith, Stephen G.; Thompson, J.K.

    1999-01-01

    The formation and spatial distribution of phytoplankton blooms in estuaries are controlled by (1) local mechanisms, which determine the production-loss balance for a water column at a particular spatial location (i.e. control if a bloom is possible), and (2) transport-related mechanisms, which govern biomass distribution (i.e. control if and where a bloom actually occurs). In this study, the first of a 2-paper series, we use a depth-averaged numerical model as a theoretical tool to describe how interacting local conditions (water column height, light availability, benthic grazing) influence the local balance between phytoplankton sources and sinks. We also explore trends in the spatial variability of the production-loss balance across the topographic gradients between deep channels and lateral shoals which are characteristic of shallow estuaries. For example, under conditions of high turbidity and slow benthic grazing the highest rates of phytoplankton population growth are found in the shallowest regions. On the other hand, with low turbidity and rapid benthic grazing the highest growth rates occur in the deeper areas. We also explore the effects of semidiurnal tidal variation in water column height, as well as spring-neap variability. Local population growth in the shallowest regions is very sensitive to tidal-scale shallowing and deepening of the water column, especially in the presence of benthic grazing. A spring-neap signal in population growth rate is also prominent in the shallow areas. Population growth in deeper regions is less sensitive to temporal variations in tidal elevation. These results show that both shallow and deep regions of estuaries can act as sources or sinks for phytoplankton biomass, depending on the local conditions of mean water column height, tidal amplitude, light-limited growth rate, and consumption by grazers.

  2. Passive scalar transport in peripheral regions of random flows

    SciTech Connect

    Chernykh, A.; Lebedev, V.

    2011-08-15

    We investigate statistical properties of the passive scalar mixing in random (turbulent) flows assuming its diffusion to be weak. Then at advanced stages of the passive scalar decay, its unmixed residue is primarily concentrated in a narrow diffusive layer near the wall and its transport to the bulk goes through the peripheral region (laminar sublayer of the flow). We conducted Lagrangian numerical simulations of the process for different space dimensions d and revealed structures responsible for the transport, which are passive scalar tongues pulled from the diffusive boundary layer to the bulk. We investigated statistical properties of the passive scalar and of the passive scalar integrated along the wall. Moments of both objects demonstrate scaling behavior outside the diffusive boundary layer. We propose an analytic scheme for the passive scalar statistics, explaining the features observed numerically.

  3. Desynchronization and rebound of beta oscillations during conscious and unconscious local neuronal processing in the macaque lateral prefrontal cortex.

    PubMed

    Panagiotaropoulos, Theofanis I; Kapoor, Vishal; Logothetis, Nikos K

    2013-01-01

    Accumulating evidence indicates that control mechanisms are not tightly bound to conscious perception since both conscious and unconscious information can trigger control processes, probably through the activation of higher-order association areas like the prefrontal cortex. Studying the modulation of control-related prefrontal signals in a microscopic, neuronal level during conscious and unconscious neuronal processing, and under control-free conditions could provide an elementary understanding of these interactions. Here we performed extracellular electrophysiological recordings in the macaque lateral prefrontal cortex (LPFC) during monocular physical alternation (PA) and binocular flash suppression (BFS) and studied the local scale relationship between beta (15-30 Hz) oscillations, a rhythmic signal believed to reflect the current sensory, motor, or cognitive state (status-quo), and conscious or unconscious neuronal processing. First, we show that beta oscillations are observed in the LPFC during resting state. Both PA and BFS had a strong impact on the power of this spontaneous rhythm with the modulation pattern of beta power being identical across these two conditions. Specifically, both perceptual dominance and suppression of local neuronal populations in BFS were accompanied by a transient beta desynchronization followed by beta activity rebound, a pattern also observed when perception occurred without any underlying visual competition in PA. These results indicate that under control-free conditions, at least one rhythmic signal known to reflect control processes in the LPFC (i.e., beta oscillations) is not obstructed by local neuronal, and accordingly perceptual, suppression, thus being independent from temporally co-existing conscious and unconscious local neuronal representations. Future studies could reveal the additive effects of motor or cognitive control demands on prefrontal beta oscillations during conscious and unconscious processing.

  4. Autowave process of the localized plastic deformation of high-chromium steel saturated with hydrogen

    NASA Astrophysics Data System (ADS)

    Bochkareva, A. V.; Barannikova, S. A.; Li, Yu V.; Lunev, A. G.; Zuev, L. B.

    2016-06-01

    The deformation behavior of high-chromium stainless steel of sorbitic structure upon high-temperature tempering and of electrically saturated with hydrogen in the electrochemical cell during 12 hours is investigated. The stress-strain curves for each state were obtained. From the stress-strain curves, one can conclude that hydrogen markedly reduces the elongation to the fracture of specimen. Using double-exposed speckle photography method it was found that the plastic flow of the material is of a localized character. The pattern distribution of localized plastic flow domains at the linear hardening stage was investigated. Comparative study of autowave parameters was carried out for the tempered steel as well as the electrically saturated with hydrogen steel.

  5. Probing local pH-based precipitation processes in self-assembled silica-carbonate hybrid materials.

    PubMed

    Opel, Julian; Hecht, Mandy; Rurack, Knut; Eiblmeier, Josef; Kunz, Werner; Cölfen, Helmut; Kellermeier, Matthias

    2015-11-01

    Crystallisation of barium carbonate in the presence of silica can lead to the spontaneous assembly of highly complex superstructures, consisting of uniform and largely co-oriented BaCO3 nanocrystals that are interspersed by a matrix of amorphous silica. The formation of these biomimetic architectures (so-called silica biomorphs) is thought to be driven by a dynamic interplay between the components, in which subtle changes of conditions trigger ordered mineralisation at the nanoscale. In particular, it has been proposed that local pH gradients at growing fronts play a crucial role in the process of morphogenesis. In the present work, we have used a special pH-sensitive fluorescent dye to directly trace these presumed local fluctuations by means of confocal laser scanning microscopy. Our data demonstrate the existence of an active region near the growth front, where the pH is locally decreased with respect to the alkaline bulk solution on a length scale of few microns. This observation provides fundamental and, for the first time, direct experimental support for the current picture of the mechanism underlying the formation of these peculiar materials. On the other hand, the absence of any temporal oscillations in the local pH - another key feature of the envisaged mechanism - challenges the notion of autocatalytic phenomena in such systems and raises new questions about the actual role of silica as an additive in the crystallisation process. PMID:26439927

  6. Ways of making-sense: Local gamma synchronization reveals differences between semantic processing induced by music and language.

    PubMed

    Barraza, Paulo; Chavez, Mario; Rodríguez, Eugenio

    2016-01-01

    Similar to linguistic stimuli, music can also prime the meaning of a subsequent word. However, it is so far unknown what is the brain dynamics underlying the semantic priming effect induced by music, and its relation to language. To elucidate these issues, we compare the brain oscillatory response to visual words that have been semantically primed either by a musical excerpt or by an auditory sentence. We found that semantic violation between music-word pairs triggers a classical ERP N400, and induces a sustained increase of long-distance theta phase synchrony, along with a transient increase of local gamma activity. Similar results were observed after linguistic semantic violation except for gamma activity, which increased after semantic congruence between sentence-word pairs. Our findings indicate that local gamma activity is a neural marker that signals different ways of semantic processing between music and language, revealing the dynamic and self-organized nature of the semantic processing.

  7. Ways of making-sense: Local gamma synchronization reveals differences between semantic processing induced by music and language.

    PubMed

    Barraza, Paulo; Chavez, Mario; Rodríguez, Eugenio

    2016-01-01

    Similar to linguistic stimuli, music can also prime the meaning of a subsequent word. However, it is so far unknown what is the brain dynamics underlying the semantic priming effect induced by music, and its relation to language. To elucidate these issues, we compare the brain oscillatory response to visual words that have been semantically primed either by a musical excerpt or by an auditory sentence. We found that semantic violation between music-word pairs triggers a classical ERP N400, and induces a sustained increase of long-distance theta phase synchrony, along with a transient increase of local gamma activity. Similar results were observed after linguistic semantic violation except for gamma activity, which increased after semantic congruence between sentence-word pairs. Our findings indicate that local gamma activity is a neural marker that signals different ways of semantic processing between music and language, revealing the dynamic and self-organized nature of the semantic processing. PMID:26734990

  8. Submerged passively-safe power plant

    SciTech Connect

    Herring, J.S.

    1991-12-31

    The invention as presented consists of a submerged passively-safe power station including a pressurized water reactor capable of generating at least 600 MW of electricity, encased in a double hull vessel, and provides fresh water by using the spent thermal energy in a multistage flash desalination process.

  9. Submerged passively-safe power plant

    DOEpatents

    Herring, J.S.

    1993-09-21

    The invention as presented consists of a submerged passively-safe power station including a pressurized water reactor capable of generating at least 600 MW of electricity, encased in a double hull vessel, and provides fresh water by using the spent thermal energy in a multistage flash desalination process. 8 figures.

  10. Submerged passively-safe power plant

    DOEpatents

    Herring, J. Stephen

    1993-01-01

    The invention as presented consists of a submerged passively-safe power station including a pressurized water reactor capable of generating at least 600 MW of electricity, encased in a double hull vessel, and provides fresh water by using the spent thermal energy in a multistage flash desalination process.

  11. Passive broadband acoustic thermometry

    NASA Astrophysics Data System (ADS)

    Anosov, A. A.; Belyaev, R. V.; Klin'shov, V. V.; Mansfel'd, A. D.; Subochev, P. V.

    2016-04-01

    The 1D internal (core) temperature profiles for the model object (plasticine) and the human hand are reconstructed using the passive acoustothermometric broadband probing data. Thermal acoustic radiation is detected by a broadband (0.8-3.5 MHz) acoustic radiometer. The temperature distribution is reconstructed using a priori information corresponding to the experimental conditions. The temperature distribution for the heated model object is assumed to be monotonic. For the hand, we assume that the temperature distribution satisfies the heat-conduction equation taking into account the blood flow. The average error of reconstruction determined for plasticine from the results of independent temperature measurements is 0.6 K for a measuring time of 25 s. The reconstructed value of the core temperature of the hand (36°C) generally corresponds to physiological data. The obtained results make it possible to use passive broadband acoustic probing for measuring the core temperatures in medical procedures associated with heating of human organism tissues.

  12. Passively actuated valve

    DOEpatents

    Modro, S. Michael; Ougouag, Abderrafi M.

    2005-09-20

    A passively actuated valve for isolating a high pressure zone from a low pressure zone and discontinuing the isolation when the pressure in the high pressure zone drops below a preset threshold. If the pressure in the high pressure zone drops below the preset threshold, the valve opens and allows flow from the high pressure zone to the low pressure zone. The valve remains open allowing pressure equalization and back-flow should a pressure inversion between the two pressure zone occur.

  13. Rayleigh-Taylor Instability in Elastoplastic Solids: A Local Catastrophic Process.

    PubMed

    Maimouni, I; Goyon, J; Lac, E; Pringuey, T; Boujlel, J; Chateau, X; Coussot, P

    2016-04-15

    We show that the Rayleigh-Taylor instability in elastoplastic solids takes the form of local perturbations penetrating the material independently of the interface size, in contrast with the theory for simple elastic materials. Then, even just beyond the stable domain, the instability abruptly develops as bursts rapidly moving through the other medium. We show that this is due to the resistance to penetration of a finger which is minimal for a specific finger size and drops to a much lower value beyond a small depth (a few millimeters). PMID:27127971

  14. Alternative to Nitric Acid Passivation Project Overview

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie L.

    2013-01-01

    The standard practice for protection of stainless steel is a process called passivation. This procedure results in the formation of a metal oxide layer to prevent corrosion. Typical passivation procedures call for the use of nitric acid which exhibits excellent corrosion performance; however, there are a number of environmental, worker safety, and operational issues associated with its use. The longtime military specification for the passivation of stainless steel was cancelled in favor of newer specifications which allow for the use of citric acid in place of nitric acid. Citric acid offers a variety of benefits that include increased safety for personnel, reduced environmental impact, and reduced operational costs. There have been few studies, however, to determine whether citric acid is an acceptable alternative for NASA and DoD. This paper details activities to date including development of the joint test plan, on-going and planned testing, and preliminary results.

  15. Active colloids that slosh through passive matrices

    NASA Astrophysics Data System (ADS)

    Zhang, Jie; Granick, Steve

    Studies of natural and artificial active matter have focused on systems with a large mismatch of the time and length scales for active and passive elements, but in a variety of non-equilibrium condensed matter systems, including numerous biological processes, actively driven elements have a crowded environment of surrounding passive ``solvent'' elements of comparable size. Here we study self-propelled colloidal particles in a passive matrix of comparable size. Particles with high activity take straight lines and sharp turns through the soft 2-D crystal matrix to ensure rapid healing of the crystal structure. Effective attraction between active particles arises when the concentration of active particles or the hardness of the matrix increases; active particles tend to segregate in the grain boundaries of the crystal matrix.

  16. Generating passive NIR images from active LIDAR

    NASA Astrophysics Data System (ADS)

    Hagstrom, Shea; Broadwater, Joshua

    2016-05-01

    Many modern LIDAR platforms contain an integrated RGB camera for capturing contextual imagery. However, these RGB cameras do not collect a near-infrared (NIR) color channel, omitting information useful for many analytical purposes. This raises the question of whether LIDAR data, collected in the NIR, can be used as a substitute for an actual NIR image in this situation. Generating a LIDAR-based NIR image is potentially useful in situations where another source of NIR, such as satellite imagery, is not available. LIDAR is an active sensing system that operates very differently from a passive system, and thus requires additional processing and calibration to approximate the output of a passive instrument. We examine methods of approximating passive NIR images from LIDAR for real-world datasets, and assess differences with true NIR images.

  17. Passive Grubenwasserreinigung als Alternative zu aktiven Systemen

    NASA Astrophysics Data System (ADS)

    Wolkersdorfer, Christian; Younger, Paul L.

    2002-06-01

    For the treatment of contaminated mine waters reliable treatment methods with low investment and operational costs are essential. Therefore, passive treatment systems recently have been installed in Great Britain and in Germany (e. g. anoxic limestone drains, constructed wetlands, reactive barriers, roughing filters) and during the last eight years such systems successfully treated mine waters, using up to 6 ha of space. In some cases with highly contaminated mine water, a combination of active and passive systems should be applied, as in any case the water quality has to reach the limits. Because not all the processes of passive treatment systems are understood in detail, current research projects (e. g. EU-project PIRAMID) were established to clarify open questions.

  18. Quality improvement of fingerprints of decayed corpses by local thanatopractical processing (Thanatoprint).

    PubMed

    Gahr, Britta; Drewitz, M; Vöth, R; Ritz-Timme, S

    2013-01-01

    Thanatopractical processing allows morphological reconstruction of even advanced decayed bodies. By extracting fluids from the body's tissue antemortem tenseness and volume can be restored. If bodies are partly subject to thanatopractical processing in the hand region ("Thanatoprint"), fingerprints of high quality can be gathered even in cases of advanced decay. Without this treatment fingerprinting can be extremely difficult, if not impossible. Thanatopractical processing could be applied successfully in cases of partial to subtotal detachment of the epidermis as well. In an interdisciplinary study 400 fingerprints of bodies in various states of decay were examined after application of Thanatoprint. In 76.75% fingerprints were applicable for data entry into AFIS (Automated Fingerprint Identification System); another 11.00% of the fingerprints could be used for the process of non-elimination. Further advantages of the method are low invasivity while maintaining the integrity of the corpse, less time- and material requirement as well as its long-lasting effect. PMID:26504706

  19. [Why must we ‘master’ trust between all parties, in order to cultivate a process of sustainable local development?].

    PubMed

    Decoster, Dominique-Paule

    2014-03-01

    A sustainable territorial development process represents a society characterized by its uniqueness to the territory of implementation. This notion of territory constitutes a fact of human nature, the development of which integrates collective and individual wellbeing through an intersectoral and multidisciplinary process. When carrying out joint projects, the partnership dynamic can transform interpersonal relationships and encourage the development of trust at the very core of the sustainable local development process. This trust enables the creation of a collective territorial intelligence, based on individual and sectoral knowledge and on know-how that form a shared, intangible heritage for each of the stakeholders in the sustainable territorial development process; however, as a fact of human nature, this trust remains fragile.

  20. [Why must we ‘master’ trust between all parties, in order to cultivate a process of sustainable local development?].

    PubMed

    Decoster, Dominique-Paule

    2014-03-01

    A sustainable territorial development process represents a society characterized by its uniqueness to the territory of implementation. This notion of territory constitutes a fact of human nature, the development of which integrates collective and individual wellbeing through an intersectoral and multidisciplinary process. When carrying out joint projects, the partnership dynamic can transform interpersonal relationships and encourage the development of trust at the very core of the sustainable local development process. This trust enables the creation of a collective territorial intelligence, based on individual and sectoral knowledge and on know-how that form a shared, intangible heritage for each of the stakeholders in the sustainable territorial development process; however, as a fact of human nature, this trust remains fragile. PMID:24737811

  1. Demonstration of Passive Fuel Cell Thermal Management Technology

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.; Jakupca, Ian; Colozza, Anthony; Wynne, Robert; Miller, Michael; Meyer, Al; Smith, William

    2012-01-01

    The NASA Glenn Research Center is developing advanced passive thermal management technology to reduce the mass and improve the reliability of space fuel cell systems for the NASA Exploration program. The passive thermal management system relies on heat conduction within highly thermally conductive cooling plates to move the heat from the central portion of the cell stack out to the edges of the fuel cell stack. Using the passive approach eliminates the need for a coolant pump and other cooling loop components within the fuel cell system which reduces mass and improves overall system reliability. Previous development demonstrated the performance of suitable highly thermally conductive cooling plates and integrated heat exchanger technology to collect the heat from the cooling plates (Ref. 1). The next step in the development of this passive thermal approach was the demonstration of the control of the heat removal process and the demonstration of the passive thermal control technology in actual fuel cell stacks. Tests were run with a simulated fuel cell stack passive thermal management system outfitted with passive cooling plates, an integrated heat exchanger and two types of cooling flow control valves. The tests were run to demonstrate the controllability of the passive thermal control approach. Finally, successful demonstrations of passive thermal control technology were conducted with fuel cell stacks from two fuel cell stack vendors.

  2. First Came the Trees, Then the Forest: Developmental Changes during Childhood in the Processing of Visual Local-Global Patterns According to the Meaningfulness of the Stimuli

    ERIC Educational Resources Information Center

    Poirel, Nicolas; Mellet, Emmanuel; Houde, Olivier; Pineau, Arlette

    2008-01-01

    This study investigated how global and local perceptual processes evolve during childhood according to the meaningfulness of the stimuli. Children had to decide whether visually presented pairs of items were identical or not. Items consisted of global forms made up of local forms. Both global and local forms could represent either objects or…

  3. The Contribution of Local Experiments and Negotiation Processes to Field-Level Learning in Emerging (Niche) Technologies: Meta-Analysis of 27 New Energy Projects in Europe

    ERIC Educational Resources Information Center

    Raven, Rob P. J. M.; Heiskanen, Eva; Lovio, Raimo; Hodson, Mike; Brohmann, Bettina

    2008-01-01

    This article examines how local experiments and negotiation processes contribute to social and field-level learning. The analysis is framed within the niche development literature, which offers a framework for analyzing the relation between projects in local contexts and the transfer of local experiences into generally applicable rules. The…

  4. Are the satellite-observed narrow, streaky chlorophyll filaments locally intensified by the submesoscale processes?

    NASA Astrophysics Data System (ADS)

    Shulman, Igor; Penta, Bradley; Richman, James; Jacobs, Gregg; Anderson, Stephanie; Sakalaukus, Peter

    2015-05-01

    Based on observations and modeling studies we have evaluated the impact of submesoscale processes on the development and intensification of offshore narrow (5-10km wide) phytoplankton filaments during summer time in the Monterey Bay, CA. We have demonstrated that, submesoscale processes (surface frontogenesis and nonlinear Ekman transport) lead to the development of very productive phytoplankton patches along the edges between the cold jet and warm anticyclonic eddy. Our results illustrate that during persistent upwelling favorable winds, submesoscale processes can modulate the development and intensification of offshore narrow (5-10km wide) phytoplankton filaments. These processes can incubate the phytoplankton population offshore (as for example, bioluminescent dinoflagellates during August 2003). These offshore phytoplankton filaments can migrate onshore during relaxed winds following the upwelling, and be an additional source of phytoplankton bloom development in and around Monterey Bay. Therefore, the discussed offshore phytoplankton filaments may be a factor in the Bay ecosystem health, as for example, in the development of such events as harmful algae blooms (HABs). All these emphasize the importance of further observational and modeling studies of these submesoscale processes which impact the development and intensification of offshore phytoplankton filaments.

  5. Wave systems with direct processes and localized losses or gains: The nonunitary Poisson kernel

    NASA Astrophysics Data System (ADS)

    Martínez-Argüello, A. M.; Méndez-Sánchez, R. A.; Martínez-Mares, M.

    2012-07-01

    We study the scattering of waves in systems with losses or gains simulated by imaginary potentials. This is done for a complex delta potential that corresponds to a spatially localized absorption or amplification. In the Argand plane the scattering matrix moves on a circle C centered on the real axis, but not at the origin, that is tangent to the unit circle. From the numerical simulations it is concluded that the distribution of the scattering matrix, when measured from the center of the circle C, agrees with the nonunitary Poisson kernel. This result is also obtained analytically by extending the analyticity condition, of unitary scattering matrices, to the no-unitary ones. We use this nonunitary Poisson kernel to obtain the distribution of nonunitary scattering matrices when measured from the origin of the Argand plane. The obtained marginal distributions have excellent agreement with the numerical results.

  6. Fluvial processes and local lithology controlling abundance, structure, and composition of mussel beds

    PubMed Central

    Vannote, Robin L.; Minshall, G. Wayne

    1982-01-01

    In the Salmon River Canyon, Idaho, the fresh-water pearl mussel, Margaritifera falcata, attains maximum density and age in river reaches where large block-boulders structurally stabilize cobbles and interstitial gravels. We hypothesize that block-boulders prevent significant bed scour during major floods, and these boulder-sheltered mussel beds, although rare, may be critical for population recruitment elsewhere within the river, especially after periodic flood scour of less protected mussel habitat. Mussel shells in Indian middens adjacent to these boulder-stabilized areas suggest that prehistoric tribes selectively exploited the high-density old-aged mussel beds. Locally, canyon reaches are aggrading with sand and gravel, and M. falcata is being replaced by Gonidea angulata. PMID:16593208

  7. Triple Recycling Processes Impact Systemic and Local Bioavailability of Orally Administered Flavonoids.

    PubMed

    Dai, Peimin; Zhu, Lijun; Luo, Feifei; Lu, Linlin; Li, Qiang; Wang, Liping; Wang, Ying; Wang, Xinchun; Hu, Ming; Liu, Zhongqiu

    2015-05-01

    Triple recycling (i.e., enterohepatic, enteric and local recycling) plays a central role in governing the disposition of phenolics such as flavonoids, resulting in low systemic bioavailability but higher gut bioavailability and longer than expected apparent half-life. The present study aims to investigate the coexistence of these recycling schemes using model bioactive flavonoid tilianin and a four-site perfused rat intestinal model in the presence or absence of a lactase phlorizin hydrolase (LPH) inhibitor gluconolactone and/or a glucuronidase inhibitor saccharolactone. The result showed that tilianin could be metabolized into tilianin glucuronide, acacetin, and acacetin glucuronide, which are excreted into the bile and luminal perfusate (highest in the duodenum and lowest in the colon). Gluconolactone (20 mM) significantly reduced the absorption of tilianin and the enteric and biliary excretion of acacetin glucuronide. Saccharolactone (0.1 mM) alone or in combination of gluconolactone also remarkably reduced the biliary and intestinal excretion of acacetin glucuronide. Acacetin glucuronides from bile or perfusate were rapidly hydrolyzed by bacterial β-glucuronidases to acacetin, enabling enterohepatic and enteric recycling. Moreover, saccharolactone-sensitive tilianin disposition and glucuronide deconjugation, which was more active in the small intestine than the colon, points to the small intestinal origin of the deconjugation enzyme and supports the presence of local recycling scheme. In conclusion, our studies have demonstrated triple recycling of a bioactive phenolic (i.e., a model flavonoid), and this recycling may have an impact on the site and duration of polyphenols pharmacokinetics in vivo.

  8. Population response to natural images in the primary visual cortex encodes local stimulus attributes and perceptual processing.

    PubMed

    Ayzenshtat, Inbal; Gilad, Ariel; Zurawel, Guy; Slovin, Hamutal

    2012-10-01

    The primary visual cortex (V1) is extensively studied with a large repertoire of stimuli, yet little is known about its encoding of natural images. Using voltage-sensitive dye imaging in behaving monkeys, we measured neural population response evoked in V1 by natural images presented during a face/scramble discrimination task. The population response showed two distinct phases of activity: an early phase that was spread over most of the imaged area, and a late phase that was spatially confined. To study the detailed relation between the stimulus and the population response, we used a simple encoding model to compute a continuous map of the expected neural response based on local attributes of the stimulus (luminance and contrast), followed by an analytical retinotopic transformation. Then, we computed the spatial correlation between the maps of the expected and observed response. We found that the early response was highly correlated with the local luminance of the stimulus and was sufficient to effectively discriminate between stimuli at the single trial level. The late response, on the other hand, showed a much lower correlation to the local luminance, was confined to central parts of the face images, and was highly correlated with the animal's perceptual report. Our study reveals a continuous spatial encoding of low- and high-level features of natural images in V1. The low level is directly linked to the stimulus basic local attributes and the high level is correlated with the perceptual outcome of the stimulus processing.

  9. Quality improvement of fingerprints of decayed corpses by local thanatopractical processing (Thanatoprint)

    PubMed Central

    Gahr, Britta; Drewitz, M.; Vöth, R.; Ritz-Timme, S.

    2013-01-01

    Thanatopractical processing allows morphological reconstruction of even advanced decayed bodies. By extracting fluids from the body’s tissue antemortem tenseness and volume can be restored. If bodies are partly subject to thanatopractical processing in the hand region (“Thanatoprint”), fingerprints of high quality can be gathered even in cases of advanced decay. Without this treatment fingerprinting can be extremely difficult, if not impossible. Thanatopractical processing could be applied successfully in cases of partial to subtotal detachment of the epidermis as well. In an interdisciplinary study 400 fingerprints of bodies in various states of decay were examined after application of Thanatoprint. In 76.75% fingerprints were applicable for data entry into AFIS (Automated Fingerprint Identification System); another 11.00% of the fingerprints could be used for the process of non-elimination. Further advantages of the method are low invasivity while maintaining the integrity of the corpse, less time- and material requirement as well as its long-lasting effect. PMID:26504706

  10. Appointing Senior Managers in Education: Homosociability, Local Logics and Authenticity in the Selection Process

    ERIC Educational Resources Information Center

    Grummell, Bernie; Devine, Dympna; Lynch, Kathleen

    2009-01-01

    While there is extensive research on educational leadership and management, the selection of leaders has received comparatively little attention. This article examines how educational leadership is constructed through the selection process in the context of a qualitative study of Irish education. It highlights the tensions that can exist for…

  11. Manipulation of Length and Lexicality Localizes the Functional Neuroanatomy of Phonological Processing in Adult Readers

    PubMed Central

    Church, Jessica A.; Balota, David A.; Petersen, Steven E.; Schlaggar, Bradley L.

    2010-01-01

    In a previous study of single word reading, regions in the left supramarginal gyrus and left angular gyrus showed positive BOLD activity in children but significantly less activity in adults for high-frequency words. This developmental decrease may reflect decreased reliance on phonological processing for familiar stimuli in adults. Therefore, in the present study, variables thought to influence phonological demand (string length and lexicality) were manipulated. Length and lexicality effects in the brain were explored using both ROI and whole-brain approaches. In the ROI analysis, the supramarginal and angular regions from the previous study were applied to this study. The supramarginal region showed a significant positive effect of length, consistent with a role in phonological processing, whereas the angular region showed only negative deflections from baseline with a strong effect of lexicality and other weaker effects. At the whole-brain level, varying effects of length and lexicality and their interactions were observed in 85 regions throughout the brain. The application of hierarchical clustering analysis to the BOLD time course data derived from these regions revealed seven clusters, with potentially revealing anatomical locations. Of note, a left angular gyrus region was the sole constituent of one cluster. Taken together, these findings in adult readers (1) provide support for a widespread set of brain regions affected by lexical variables, (2) corroborate a role for phonological processing in the left supramarginal gyrus, and (3) do not support a strong role for phonological processing in the left angular gyrus. PMID:20433237

  12. Sex-specific strategy use and global-local processing: a perspective toward integrating sex differences in cognition.

    PubMed

    Pletzer, Belinda

    2014-01-01

    This article reviews the literature on sex-specific strategy use in cognitive tasks with the aim to carve out a link between sex differences in different cognitive tasks. I conclude that male strategies are commonly holistic and oriented toward global stimulus aspects, while female strategies are commonly decomposed and oriented toward local stimulus aspects. Thus, the strategies observed in different tasks, may depend on sex differences in attentional focus and hence sex differences in global-local processing. I hypothesize that strategy use may be sex hormone dependent and hence subject to change over the menstrual cycle as evidenced by findings in global-local processing and emotional memory. Furthermore, I propose sex hormonal modulation of hemispheric asymmetries as one possible neural substrate for this theory, thereby building on older theories, emphasizing the importance of sex differences in brain lateralization. The ideas described in the current article represent a perspective toward a unifying approach to the study of sex differences in cognition and their neural correlates.

  13. Investigation of model based beamforming and Bayesian inversion signal processing methods for seismic localization of underground sources.

    PubMed

    Oh, Geok Lian; Brunskog, Jonas

    2014-08-01

    Techniques have been studied for the localization of an underground source with seismic interrogation signals. Much of the work has involved defining either a P-wave acoustic model or a dispersive surface wave model to the received signal and applying the time-delay processing technique and frequency-wavenumber processing to determine the location of the underground tunnel. Considering the case of determining the location of an underground tunnel, this paper proposed two physical models, the acoustic approximation ray tracing model and the finite difference time domain three-dimensional (3D) elastic wave model to represent the received seismic signal. Two localization algorithms, beamforming and Bayesian inversion, are developed for each physical model. The beam-forming algorithms implemented are the modified time-and-delay beamformer and the F-K beamformer. Inversion is posed as an optimization problem to estimate the unknown position variable using the described physical forward models. The proposed four methodologies are demonstrated and compared using seismic signals recorded by geophones set up on ground surface generated by a surface seismic excitation. The examples show that for field data, inversion for localization is most advantageous when the forward model completely describe all the elastic wave components as is the case of the FDTD 3D elastic model.

  14. Assessing local population vulnerability to wind energy development with branching process models: an application to wind energy development

    USGS Publications Warehouse

    Erickson, Richard A.; Eager, Eric A.; Stanton, Jessica C.; Beston, Julie A.; Diffendorfer, James E.; Thogmartin, Wayne E.

    2015-01-01

    Quantifying the impact of anthropogenic development on local populations is important for conservation biology and wildlife management. However, these local populations are often subject to demographic stochasticity because of their small population size. Traditional modeling efforts such as population projection matrices do not consider this source of variation whereas individual-based models, which include demographic stochasticity, are computationally intense and lack analytical tractability. One compromise between approaches is branching process models because they accommodate demographic stochasticity and are easily calculated. These models are known within some sub-fields of probability and mathematical ecology but are not often applied in conservation biology and applied ecology. We applied branching process models to quantitatively compare and prioritize species locally vulnerable to the development of wind energy facilities. Specifically, we examined species vulnerability using branching process models for four representative species: A cave bat (a long-lived, low fecundity species), a tree bat (short-lived, moderate fecundity species), a grassland songbird (a short-lived, high fecundity species), and an eagle (a long-lived, slow maturation species). Wind turbine-induced mortality has been observed for all of these species types, raising conservation concerns. We simulated different mortality rates from wind farms while calculating local extinction probabilities. The longer-lived species types (e.g., cave bats and eagles) had much more pronounced transitions from low extinction risk to high extinction risk than short-lived species types (e.g., tree bats and grassland songbirds). High-offspring-producing species types had a much greater variability in baseline risk of extinction than the lower-offspring-producing species types. Long-lived species types may appear stable until a critical level of incidental mortality occurs. After this threshold, the risk of

  15. Using GIBS and Worldview to Connect Global Processes to Local Events

    NASA Astrophysics Data System (ADS)

    Meyer, D. J.

    2015-12-01

    The NASA Worldview client and undelrying Global Image Browse Service (GIBS) are powerful tools for visualizing dynamic global processes in a clear and understandable manner. Currently viewable data layers, such as sea surface temperature, cloud and aersol parameters, snow cover and sea ice, and fires can be observed over time to gain a better understanding of the interrleationship between land, ocean and atmospheric processes, and how these relationships evolve over time. This presentation demonstrates the use of these tools to visualize (for example) relationships between fire and air quality over North America, the evolution of the recent El Nino, and changes in sea ice extent, using Worldview directly, and GIBS through both open source and commercial applications. The presentation also discusses visualizations that will be possible with anticipated new data layers.

  16. Probing local pH-based precipitation processes in self-assembled silica-carbonate hybrid materials

    NASA Astrophysics Data System (ADS)

    Opel, Julian; Hecht, Mandy; Rurack, Knut; Eiblmeier, Josef; Kunz, Werner; Cölfen, Helmut; Kellermeier, Matthias

    2015-10-01

    Crystallisation of barium carbonate in the presence of silica can lead to the spontaneous assembly of highly complex superstructures, consisting of uniform and largely co-oriented BaCO3 nanocrystals that are interspersed by a matrix of amorphous silica. The formation of these biomimetic architectures (so-called silica biomorphs) is thought to be driven by a dynamic interplay between the components, in which subtle changes of conditions trigger ordered mineralisation at the nanoscale. In particular, it has been proposed that local pH gradients at growing fronts play a crucial role in the process of morphogenesis. In the present work, we have used a special pH-sensitive fluorescent dye to directly trace these presumed local fluctuations by means of confocal laser scanning microscopy. Our data demonstrate the existence of an active region near the growth front, where the pH is locally decreased with respect to the alkaline bulk solution on a length scale of few microns. This observation provides fundamental and, for the first time, direct experimental support for the current picture of the mechanism underlying the formation of these peculiar materials. On the other hand, the absence of any temporal oscillations in the local pH - another key feature of the envisaged mechanism - challenges the notion of autocatalytic phenomena in such systems and raises new questions about the actual role of silica as an additive in the crystallisation process.Crystallisation of barium carbonate in the presence of silica can lead to the spontaneous assembly of highly complex superstructures, consisting of uniform and largely co-oriented BaCO3 nanocrystals that are interspersed by a matrix of amorphous silica. The formation of these biomimetic architectures (so-called silica biomorphs) is thought to be driven by a dynamic interplay between the components, in which subtle changes of conditions trigger ordered mineralisation at the nanoscale. In particular, it has been proposed that local

  17. What Can Be Learned from X-Ray Spectroscopy Concerning Hot Gas in the Local Bubble and Charge Exchange Processes?

    NASA Technical Reports Server (NTRS)

    Snowden, S. L.

    2008-01-01

    Both solar wind charge exchange emission and diffuse thermal emission from the Local Bubble are strongly dominated in the soft X-ray band by lines from highly ionized elements. While both processes share many of the same lines, the spectra should differ significantly due to the different production mechanisms, abundances, and ionization states. Despite their distinct spectral signatures, current and past observatories have lacked the spectral resolution to adequately distinguish between the two sources. High-resolution X-ray spectroscopy instrumentation proposed for future missions has the potential to answer fundamental questions such as whether there is any hot plasma in the Local Hot Bubble, and if so, what are the abundances of the emitting plasma and whether the plasma is in equilibrium. Such instrumentation will provide dynamic information about the solar wind including data on ion species which are currently difficult to track. It will also make possible remote sensing of the solar wind.

  18. Institutions and Cultural Diversity: Effects of Democratic and Propaganda Processes on Local Convergence and Global Diversity.

    PubMed

    Ulloa, Roberto; Kacperski, Celina; Sancho, Fernando

    2016-01-01

    In a connected world where people influence each other, what can cause a globalized monoculture, and which measures help to preserve the coexistence of cultures? Previous research has shown that factors such as homophily, population size, geography, mass media, and type of social influence play important roles. In the present paper, we investigate for the first time the impact that institutions have on cultural diversity. In our first three studies, we extend existing agent-based models and explore the effects of institutional influence and agent loyalty. We find that higher institutional influence increases cultural diversity, while individuals' loyalty to their institutions has a small, preserving effect. In three further studies, we test how bottom-up and top-down processes of institutional influence impact our model. We find that bottom-up democratic practices, such as referenda, tend to produce convergence towards homogeneity, while top-down information dissemination practices, such as propaganda, further increase diversity. In our last model--an integration of bottom-up and top-down processes into a feedback loop of information--we find that when democratic processes are rare, the effects of propaganda are amplified, i.e., more diversity emerges; however, when democratic processes are common, they are able to neutralize or reverse this propaganda effect. Importantly, our models allow for control over the full spectrum of diversity, so that a manipulation of our parameters can result in preferred levels of diversity, which will be useful for the study of other factors in the future. We discuss possible mechanisms behind our results, applications, and implications for political and social sciences. PMID:27058247

  19. Institutions and Cultural Diversity: Effects of Democratic and Propaganda Processes on Local Convergence and Global Diversity.

    PubMed

    Ulloa, Roberto; Kacperski, Celina; Sancho, Fernando

    2016-01-01

    In a connected world where people influence each other, what can cause a globalized monoculture, and which measures help to preserve the coexistence of cultures? Previous research has shown that factors such as homophily, population size, geography, mass media, and type of social influence play important roles. In the present paper, we investigate for the first time the impact that institutions have on cultural diversity. In our first three studies, we extend existing agent-based models and explore the effects of institutional influence and agent loyalty. We find that higher institutional influence increases cultural diversity, while individuals' loyalty to their institutions has a small, preserving effect. In three further studies, we test how bottom-up and top-down processes of institutional influence impact our model. We find that bottom-up democratic practices, such as referenda, tend to produce convergence towards homogeneity, while top-down information dissemination practices, such as propaganda, further increase diversity. In our last model--an integration of bottom-up and top-down processes into a feedback loop of information--we find that when democratic processes are rare, the effects of propaganda are amplified, i.e., more diversity emerges; however, when democratic processes are common, they are able to neutralize or reverse this propaganda effect. Importantly, our models allow for control over the full spectrum of diversity, so that a manipulation of our parameters can result in preferred levels of diversity, which will be useful for the study of other factors in the future. We discuss possible mechanisms behind our results, applications, and implications for political and social sciences.

  20. Manipulation of length and lexicality localizes the functional neuroanatomy of phonological processing in adult readers.

    PubMed

    Church, Jessica A; Balota, David A; Petersen, Steven E; Schlaggar, Bradley L

    2011-06-01

    In a previous study of single word reading, regions in the left supramarginal gyrus and left angular gyrus showed positive BOLD activity in children but significantly less activity in adults for high-frequency words [Church, J. A., Coalson, R. S., Lugar, H. M., Petersen, S. E., & Schlaggar, B. L. A developmental fMRI study of reading and repetition reveals changes in phonological and visual mechanisms over age. Cerebral Cortex, 18, 2054-2065, 2008]. This developmental decrease may reflect decreased reliance on phonological processing for familiar stimuli in adults. Therefore, in the present study, variables thought to influence phonological demand (string length and lexicality) were manipulated. Length and lexicality effects in the brain were explored using both ROI and whole-brain approaches. In the ROI analysis, the supramarginal and angular regions from the previous study were applied to this study. The supramarginal region showed a significant positive effect of length, consistent with a role in phonological processing, whereas the angular region showed only negative deflections from baseline with a strong effect of lexicality and other weaker effects. At the whole-brain level, varying effects of length and lexicality and their interactions were observed in 85 regions throughout the brain. The application of hierarchical clustering analysis to the BOLD time course data derived from these regions revealed seven clusters, with potentially revealing anatomical locations. Of note, a left angular gyrus region was the sole constituent of one cluster. Taken together, these findings in adult readers (1) provide support for a widespread set of brain regions affected by lexical variables, (2) corroborate a role for phonological processing in the left supramarginal gyrus, and (3) do not support a strong role for phonological processing in the left angular gyrus.

  1. Institutions and Cultural Diversity: Effects of Democratic and Propaganda Processes on Local Convergence and Global Diversity

    PubMed Central

    Ulloa, Roberto; Kacperski, Celina; Sancho, Fernando

    2016-01-01

    In a connected world where people influence each other, what can cause a globalized monoculture, and which measures help to preserve the coexistence of cultures? Previous research has shown that factors such as homophily, population size, geography, mass media, and type of social influence play important roles. In the present paper, we investigate for the first time the impact that institutions have on cultural diversity. In our first three studies, we extend existing agent-based models and explore the effects of institutional influence and agent loyalty. We find that higher institutional influence increases cultural diversity, while individuals' loyalty to their institutions has a small, preserving effect. In three further studies, we test how bottom-up and top-down processes of institutional influence impact our model. We find that bottom-up democratic practices, such as referenda, tend to produce convergence towards homogeneity, while top-down information dissemination practices, such as propaganda, further increase diversity. In our last model—an integration of bottom-up and top-down processes into a feedback loop of information—we find that when democratic processes are rare, the effects of propaganda are amplified, i.e., more diversity emerges; however, when democratic processes are common, they are able to neutralize or reverse this propaganda effect. Importantly, our models allow for control over the full spectrum of diversity, so that a manipulation of our parameters can result in preferred levels of diversity, which will be useful for the study of other factors in the future. We discuss possible mechanisms behind our results, applications, and implications for political and social sciences. PMID:27058247

  2. Small deviations from local equilibrium for a process which exhibits hydrodynamical behavior. II

    NASA Astrophysics Data System (ADS)

    de Masi, A.; Ferrari, P.; Ianiro, N.; Presutti, E.

    1982-09-01

    The symmetric simple exclusion process on ℤ with sources at ± L, L ɛ ℕ is considered. The stationary measure μL is studied in the limit as L diverges. The first order correction to its limit is proven to be of order 1 / L and it is explicitly computed. The result is in agreement with the analysis of the model from the hydrodynamical point of view initiated in Ref.1.

  3. Local Navon letter processing affects skilled behavior: a golf-putting experiment.

    PubMed

    Lewis, Michael B; Dawkins, Gemma

    2015-04-01

    Expert or skilled behaviors (for example, face recognition or sporting performance) are typically performed automatically and with little conscious awareness. Previous studies, in various domains of performance, have shown that activities immediately prior to a task demanding a learned skill can affect performance. In sport, describing the to-be-performed action is detrimental, whereas in face recognition, describing a face or reading local Navon letters is detrimental. Two golf-putting experiments are presented that compare the effects that these three tasks have on experienced and novice golfers. Experiment 1 found a Navon effect on golf performance for experienced players. Experiment 2 found, for experienced players only, that performance was impaired following the three tasks described above, when compared with reading or global Navon tasks. It is suggested that the three tasks affect skilled performance by provoking a shift from automatic behavior to a more analytic style. By demonstrating similarities between effects in face recognition and sporting behavior, it is hoped to better understand concepts in both fields. PMID:25102927

  4. How interactions between animal movement and landscape processes modify local range dynamics and extinction risk

    PubMed Central

    Fordham, Damien A.; Shoemaker, Kevin T.; Schumaker, Nathan H.; Akçakaya, H. Reşit; Clisby, Nathan; Brook, Barry W.

    2014-01-01

    Forecasts of range dynamics now incorporate many of the mechanisms and interactions that drive species distributions. However, connectivity continues to be simulated using overly simple distance-based dispersal models with little consideration of how the individual behaviour of dispersing organisms interacts with landscape structure (functional connectivity). Here, we link an individual-based model to a niche-population model to test the implications of this omission. We apply this novel approach to a turtle species inhabiting wetlands which are patchily distributed across a tropical savannah, and whose persistence is threatened by two important synergistic drivers of global change: predation by invasive species and overexploitation. We show that projections of local range dynamics in this study system change substantially when functional connectivity is modelled explicitly. Accounting for functional connectivity in model simulations causes the estimate of extinction risk to increase, and predictions of range contraction to slow. We conclude that models of range dynamics that simulate functional connectivity can reduce an important source of bias in predictions of shifts in species distributions and abundances, especially for organisms whose dispersal behaviours are strongly affected by landscape structure. PMID:24806426

  5. Local Navon letter processing affects skilled behavior: a golf-putting experiment.

    PubMed

    Lewis, Michael B; Dawkins, Gemma

    2015-04-01

    Expert or skilled behaviors (for example, face recognition or sporting performance) are typically performed automatically and with little conscious awareness. Previous studies, in various domains of performance, have shown that activities immediately prior to a task demanding a learned skill can affect performance. In sport, describing the to-be-performed action is detrimental, whereas in face recognition, describing a face or reading local Navon letters is detrimental. Two golf-putting experiments are presented that compare the effects that these three tasks have on experienced and novice golfers. Experiment 1 found a Navon effect on golf performance for experienced players. Experiment 2 found, for experienced players only, that performance was impaired following the three tasks described above, when compared with reading or global Navon tasks. It is suggested that the three tasks affect skilled performance by provoking a shift from automatic behavior to a more analytic style. By demonstrating similarities between effects in face recognition and sporting behavior, it is hoped to better understand concepts in both fields.

  6. How interactions between animal movement and landscape processes modify local range dynamics and extinction risk.

    PubMed

    Fordham, Damien A; Shoemaker, Kevin T; Schumaker, Nathan H; Akçakaya, H Reşit; Clisby, Nathan; Brook, Barry W

    2014-05-01

    Forecasts of range dynamics now incorporate many of the mechanisms and interactions that drive species distributions. However, connectivity continues to be simulated using overly simple distance-based dispersal models with little consideration of how the individual behaviour of dispersing organisms interacts with landscape structure (functional connectivity). Here, we link an individual-based model to a niche-population model to test the implications of this omission. We apply this novel approach to a turtle species inhabiting wetlands which are patchily distributed across a tropical savannah, and whose persistence is threatened by two important synergistic drivers of global change: predation by invasive species and overexploitation. We show that projections of local range dynamics in this study system change substantially when functional connectivity is modelled explicitly. Accounting for functional connectivity in model simulations causes the estimate of extinction risk to increase, and predictions of range contraction to slow. We conclude that models of range dynamics that simulate functional connectivity can reduce an important source of bias in predictions of shifts in species distributions and abundances, especially for organisms whose dispersal behaviours are strongly affected by landscape structure. PMID:24806426

  7. Reconstructing Past Admixture Processes from Local Genomic Ancestry Using Wavelet Transformation

    PubMed Central

    Sanderson, Jean; Sudoyo, Herawati; Karafet, Tatiana M.; Hammer, Michael F.; Cox, Murray P.

    2015-01-01

    Admixture between long-separated populations is a defining feature of the genomes of many species. The mosaic block structure of admixed genomes can provide information about past contact events, including the time and extent of admixture. Here, we describe an improved wavelet-based technique that better characterizes ancestry block structure from observed genomic patterns. principal components analysis is first applied to genomic data to identify the primary population structure, followed by wavelet decomposition to develop a new characterization of local ancestry information along the chromosomes. For testing purposes, this method is applied to human genome-wide genotype data from Indonesia, as well as virtual genetic data generated using genome-scale sequential coalescent simulations under a wide range of admixture scenarios. Time of admixture is inferred using an approximate Bayesian computation framework, providing robust estimates of both admixture times and their associated levels of uncertainty. Crucially, we demonstrate that this revised wavelet approach, which we have released as the R package adwave, provides improved statistical power over existing wavelet-based techniques and can be used to address a broad range of admixture questions. PMID:25852078

  8. Similar Local and Landscape Processes Affect Both a Common and a Rare Newt Species

    PubMed Central

    Denoël, Mathieu; Perez, Amélie; Cornet, Yves; Ficetola, Gentile Francesco

    2013-01-01

    Although rare species are often the focus of conservation measures, more common species may experience similar decline and suffer from the same threatening processes. We tested this hypothesis by examining, through an information-theoretic approach, the importance of ecological processes at multiple scales in the great crested newt Triturus cristatus, regionally endangered and protected in Europe, and the more common smooth newt, Lissotriton vulgaris. Both species were similarly affected by the same processes, i.e. suitability of aquatic and terrestrial components of their habitat at different scales, connectivity among breeding sites, and the presence of introduced fish. T. cristatus depended more on water depth and aquatic vegetation than L. vulgaris. The results show that environmental pressures threaten both common and rare species, and therefore the more widespread species should not be neglected in conservation programs. Because environmental trends are leading to a deterioration of aquatic and terrestrial habitat features required by newt populations, populations of the common species may follow the fate of the rarest species. This could have substantial conservation implications because of the numerical importance of common species in ecosystems and because commonness could be a transient state moving towards rarity. On the other hand, in agreement with the umbrella species concept, targeting conservation efforts on the most demanding species would also protect part of the populations of the most common species. PMID:23658765

  9. Passive Tracking System and Method

    NASA Technical Reports Server (NTRS)

    Arndt, G. Dickey (Inventor); Ngo, Phong H. (Inventor); Chen, Henry A. (Inventor); Phan, Chau T. (Inventor); Bourgeois, Brian A. (Inventor); Dusl, Jon (Inventor); Hill, Brent W. (Inventor)

    2003-01-01

    Systems and methods are disclosed for passively determining the location of a moveable transmitter utilizing a pair of phase shifts at a receiver for extracting a direction vector from a receiver to the transmitter. In a preferred embodiment, a phase difference between the transmitter and receiver is extracted utilizing a noncoherent demodulator in the receiver. The receiver includes an antenna array with three antenna elements, which preferably are patch antenna elements spaced apart by one-half wavelength. Three receiver channels are preferably utilized for simultaneously processing the received signal from each of the three antenna elements. Multipath transmission paths for each of the three receiver channels are indexed so that comparisons of the same multipath component are made for each of the three receiver channels. The phase difference for each received signal is determined by comparing only the magnitudes of received and stored modulation signals to determine a winning modulation symbol.

  10. Passive adaptive imaging through turbulence

    NASA Astrophysics Data System (ADS)

    Tofsted, David

    2016-05-01

    Standard methods for improved imaging system performance under degrading optical turbulence conditions typically involve active adaptive techniques or post-capture image processing. Here, passive adaptive methods are considered where active sources are disallowed, a priori. Theoretical analyses of short-exposure turbulence impacts indicate that varying aperture sizes experience different degrees of turbulence impacts. Smaller apertures often outperform larger aperture systems as turbulence strength increases. This suggests a controllable aperture system is advantageous. In addition, sub-aperture sampling of a set of training images permits the system to sense tilts in different sub-aperture regions through image acquisition and image cross-correlation calculations. A four sub-aperture pattern supports corrections involving five realizable operating modes (beyond tip and tilt) for removing aberrations over an annular pattern. Progress to date will be discussed regarding development and field trials of a prototype system.

  11. Visual Search Targeting Either Local or Global Perceptual Processes Differs as a Function of Autistic-Like Traits in the Typically Developing Population

    ERIC Educational Resources Information Center

    Almeida, Renita A.; Dickinson, J. Edwin; Maybery, Murray T.; Badcock, Johanna C.; Badcock, David R.

    2013-01-01

    Relative to low scorers, high scorers on the Autism-Spectrum Quotient (AQ) show enhanced performance on the Embedded Figures Test and the Radial Frequency search task (RFST), which has been attributed to both enhanced local processing and differences in combining global percepts. We investigate the role of local and global processing further using…

  12. Realistic Drawing Talent in Typical Adults Is Associated with the Same Kind of Local Processing Bias Found in Individuals with ASD

    ERIC Educational Resources Information Center

    Drake, Jennifer E.; Winner, Ellen

    2011-01-01

    A local processing bias has been found in individuals with autism as well as in typical children with a gift for drawing realistically. This study investigated whether a local processing bias in typical adults is more strongly associated with drawing realism or autistic-like traits. Forty-two adults made an observational drawing (scored for…

  13. The sub-nucleolar localization of PHF6 defines its role in rDNA transcription and early processing events.

    PubMed

    Todd, Matthew A M; Huh, Michael S; Picketts, David J

    2016-10-01

    Ribosomal RNA synthesis occurs in the nucleolus and is a tightly regulated process that is targeted in some developmental diseases and hyperactivated in multiple cancers. Subcellular localization and immunoprecipitation coupled mass spectrometry demonstrated that a proportion of plant homeodomain (PHD) finger protein 6 (PHF6) protein is localized within the nucleolus and interacts with proteins involved in ribosomal processing. PHF6 sequence variants cause Börjeson-Forssman-Lehmann syndrome (BFLS, MIM#301900) and are also associated with a female-specific phenotype overlapping with Coffin-Siris syndrome (MIM#135900), T-cell acute lymphoblastic leukemia (MIM#613065), and acute myeloid leukemia (MIM#601626); however, very little is known about its cellular function, including its nucleolar role. HEK 293T cells were treated with RNase A, DNase I, actinomycin D, or 5,6-dichloro-β-D-ribofuranosylbenzimadole, followed by immunocytochemistry to determine PHF6 sub-nucleolar localization. We observed RNA-dependent localization of PHF6 to the sub-nucleolar fibrillar center (FC) and dense fibrillar component (DFC), at whose interface rRNA transcription occurs. Subsequent ChIP-qPCR analysis revealed strong enrichment of PHF6 across the entire rDNA-coding sequence but not along the intergenic spacer (IGS) region. When rRNA levels were quantified in a PHF6 gain-of-function model, we observed an overall decrease in rRNA transcription, accompanied by a modest increase in repressive promoter-associated RNA (pRNA) and a significant increase in the expression levels of the non-coding IGS36RNA and IGS39RNA transcripts. Collectively, our results demonstrate a role for PHF6 in carefully mediating the overall levels of ribosome biogenesis within a cell.

  14. The sub-nucleolar localization of PHF6 defines its role in rDNA transcription and early processing events

    PubMed Central

    Todd, Matthew A M; Huh, Michael S; Picketts, David J

    2016-01-01

    Ribosomal RNA synthesis occurs in the nucleolus and is a tightly regulated process that is targeted in some developmental diseases and hyperactivated in multiple cancers. Subcellular localization and immunoprecipitation coupled mass spectrometry demonstrated that a proportion of plant homeodomain (PHD) finger protein 6 (PHF6) protein is localized within the nucleolus and interacts with proteins involved in ribosomal processing. PHF6 sequence variants cause Börjeson–Forssman–Lehmann syndrome (BFLS, MIM#301900) and are also associated with a female-specific phenotype overlapping with Coffin–Siris syndrome (MIM#135900), T-cell acute lymphoblastic leukemia (MIM#613065), and acute myeloid leukemia (MIM#601626); however, very little is known about its cellular function, including its nucleolar role. HEK 293T cells were treated with RNase A, DNase I, actinomycin D, or 5,6-dichloro-β-D-ribofuranosylbenzimadole, followed by immunocytochemistry to determine PHF6 sub-nucleolar localization. We observed RNA-dependent localization of PHF6 to the sub-nucleolar fibrillar center (FC) and dense fibrillar component (DFC), at whose interface rRNA transcription occurs. Subsequent ChIP-qPCR analysis revealed strong enrichment of PHF6 across the entire rDNA-coding sequence but not along the intergenic spacer (IGS) region. When rRNA levels were quantified in a PHF6 gain-of-function model, we observed an overall decrease in rRNA transcription, accompanied by a modest increase in repressive promoter-associated RNA (pRNA) and a significant increase in the expression levels of the non-coding IGS36RNA and IGS39RNA transcripts. Collectively, our results demonstrate a role for PHF6 in carefully mediating the overall levels of ribosome biogenesis within a cell. PMID:27165002

  15. Fundamental studies of passivity and passivity breakdown. Final report

    SciTech Connect

    Macdonald, D.D.; Urquidi-Macdonald, M.; Song, H.; Biaggio-Rocha, S.; Searson, P.

    1991-11-01

    This report summarizes the findings of our fundamental research program on passivity and passivity breakdown. During the past three and one half years in this program (including the three year incrementally-funded grant prior to the present grant), we developed and experimentally tested various physical models for the growth and breakdown of passive films on metal surfaces. These models belong to a general class termed ``point defects models`` (PDMs), in which the growth and breakdown of passive films are described in terms of the movement of anion and cation vacancies.

  16. Passive film growth on titanium alloys: physicochemical and biologic considerations.

    PubMed

    Eliades, T

    1997-01-01

    The role of reactive oxygen derivatives (hydroxy peroxide, hydroxyl radical, and singlet oxygen) on the precipitation of inorganic and organic complexes onto the surface of titanium implant alloys is discussed in this review. In addition, the effect of possible implication of several biologic entities surrounding the implant on the implant-tissue interface constituents is described. Evidence from relevant studies suggests that local microenvironmental byproducts and factors associated with the inflammatory response resulting from the implant-induced tissue insult may enhance the expressivity of the inherent, clinically important property of titanium to form oxides. Growth of titanium oxide may be explained through several processes derived from biologic, thermodynamic, and electrochemical approaches. The models proposed to interpret this phenomenon are often contradictory, demonstrating inward or outward from the bulk material passive film growth, with increasing or self-limiting levels of oxide formation as a function of time. However, in vivo observations are consistent with aging-induced thickening of the complexes precipitated on the implant material surface. This review attempts to clarify several critical issues pertaining to passive film formation and kinetics on titanium-alloy surfaces.

  17. Motorcycle suspension design using matrix inequalities and passivity constraints

    NASA Astrophysics Data System (ADS)

    Sharma, Amrit; Limebeer, David J. N.

    2012-03-01

    This paper presents a design methodology for the suspension system of a novel aerodynamically efficient motorcycle. Since the machine's layout and the rider's seating position are unconventional, several aspects of the machine design, including the suspension, must be reviewed afresh. The design process is based on matrix inequalities that are used to optimise a road-grip objective function - others could be used equally well. The design problem is cast as the minimisation of an H 2 cost with passivity constraints imposed on the suspension transference. The resulting bilinear matrix inequality problem is solved using a locally optimal iterative algorithm. The matrix inequality-type characterisation of positive real functions permits the optimisation of the suspension system over an entire class of passive admittances. Torsional springs, dampers and inerters are then used to construct networks corresponding to the optimal (positive real) admittances. Networks of first, second, third and fourth orders are considered, and an argument based on the compromise between complexity and improved grip is made for the most suitable suspension configuration. Finally, the effects of improved road grip on the stability of the vehicle's lateral dynamics are analysed.

  18. Passive drainage and biofiltration of landfill gas: Australian field trial

    SciTech Connect

    Dever, S.A. . E-mail: stuart_dever@ghd.com.au; Swarbrick, G.E. . E-mail: g.swarbrick@unsw.edu.au; Stuetz, R.M. . E-mail: r.stuetz@unsw.edu.au

    2007-07-01

    In Australia a significant number of landfill waste disposal sites do not incorporate measures for the collection and treatment of landfill gas. This includes many old/former landfill sites, rural landfill sites, non-putrescible solid waste and inert waste landfill sites, where landfill gas generation is low and it is not commercially viable to extract and beneficially utilize the landfill gas. Previous research has demonstrated that biofiltration has the potential to degrade methane in landfill gas, however, the microbial processes can be affected by many local conditions and factors including moisture content, temperature, nutrient supply, including the availability of oxygen and methane, and the movement of gas (oxygen and methane) to/from the micro-organisms. A field scale trial is being undertaken at a landfill site in Sydney, Australia, to investigate passive drainage and biofiltration of landfill gas as a means of managing landfill gas emissions at low to moderate gas generation landfill sites. The design and construction of the trial is described and the experimental results will provide in-depth knowledge on the application of passive gas drainage and landfill gas biofiltration under Sydney (Australian) conditions, including the performance of recycled materials for the management of landfill gas emissions.

  19. Shell model of optimal passive-scalar mixing

    NASA Astrophysics Data System (ADS)

    Miles, Christopher; Doering, Charles

    2015-11-01

    Optimal mixing is significant to process engineering within industries such as food, chemical, pharmaceutical, and petrochemical. An important question in this field is ``How should one stir to create a homogeneous mixture while being energetically efficient?'' To answer this question, we consider an initially unmixed scalar field representing some concentration within a fluid on a periodic domain. This passive-scalar field is advected by the velocity field, our control variable, constrained by a physical quantity such as energy or enstrophy. We consider two objectives: local-in-time (LIT) optimization (what will maximize the mixing rate now?) and global-in-time (GIT) optimization (what will maximize mixing at the end time?). Throughout this work we use the H-1 mix-norm to measure mixing. To gain a better understanding, we provide a simplified mixing model by using a shell model of passive-scalar advection. LIT optimization in this shell model gives perfect mixing in finite time for the energy-constrained case and exponential decay to the perfect-mixed state for the enstrophy-constrained case. Although we only enforce that the time-average energy (or enstrophy) equals a chosen value in GIT optimization, interestingly, the optimal control keeps this value constant over time.

  20. An ultra-low-power area-efficient non-volatile memory in a 0.18 μm single-poly CMOS process for passive RFID tags

    NASA Astrophysics Data System (ADS)

    Xiaoyun, Jia; Peng, Feng; Shengguang, Zhang; Nanjian, Wu; Baiqin, Zhao; Su, Liu

    2013-08-01

    This paper presents an ultra-low-power area-efficient non-volatile memory (NVM) in a 0.18 μm single-poly standard CMOS process for passive radio frequency identification (RFID) tags. In the memory cell, a novel low-power operation method is proposed to realize bi-directional Fowler—Nordheim tunneling during write operation. Furthermore, the cell is designed with PMOS transistors and coupling capacitors to minimize its area. In order to improve its reliability, the cell consists of double floating gates to store the data, and the 1 kbit NVM was implemented in a 0.18 μm single-poly standard CMOS process. The area of the memory cell and 1 kbit memory array is 96 μm2 and 0.12 mm2, respectively. The measured results indicate that the program/erase voltage ranges from 5 to 6 V The power consumption of the read/write operation is 0.19 μW/0.69 μW at a read/write rate of (268 kb/s)/(3.0 kb/s).

  1. Processing and Breakdown Localization Rresults For an L-Band Standing-Wave Cavity

    SciTech Connect

    Wang, Faya; Adolphsen, Chris; /SLAC

    2009-08-03

    An L-band (1.3 GHz), normal-conducting, 5-cell, standing-wave cavity that was built as a prototype capture accelerator for the ILC is being high-power processed at SLAC. The goal is to demonstrate stable operation at 15 MV/m with 1 msec, 5 Hz pulses and the cavity immersed in a 0.5 Telsa solenoidal magnetic field. This paper summarizes the performance that was ultimately achieved and describes a novel analysis of the modal content of the stored energy in the cavity after a breakdown to determine on which iris it occurred.

  2. Minkowski space is locally the Noldus limit of Poisson process causets

    NASA Astrophysics Data System (ADS)

    Cristina, Jan

    2016-09-01

    A Poisson process {P}λ on {{{R}}}d with causal structure inherited from the the usual Minkowski metric on {{{R}}}d has a normalised discrete causal distance {D}λ (x,y) given by the height of the longest causal chain normalised by {λ }1/d{c}d. We prove that {P}λ restricted to a compact set Q converges in probability in the sense of Noldus (2004 Class. Quantum Grav. 21 839-50) to Q with the Minkowski metric.

  3. Minkowski space is locally the Noldus limit of Poisson process causets

    NASA Astrophysics Data System (ADS)

    Cristina, Jan

    2016-09-01

    A Poisson process {P}λ on {{{R}}}d with causal structure inherited from the the usual Minkowski metric on {{{R}}}d has a normalised discrete causal distance {D}λ (x,y) given by the height of the longest causal chain normalised by {λ }1/d{c}d. We prove that {P}λ restricted to a compact set Q converges in probability in the sense of Noldus (2004 Class. Quantum Grav. 21 839–50) to Q with the Minkowski metric.

  4. NMDA-dependent mechanisms only affect the BOLD response in the rat dentate gyrus by modifying local signal processing.

    PubMed

    Tiede, Regina; Krautwald, Karla; Fincke, Anja; Angenstein, Frank

    2012-03-01

    The role of N-methyl-D-aspartate (NMDA) receptor-mediated mechanisms in the formation of a blood oxygen level-dependent (BOLD) response was studied using electrical stimulation of the right perforant pathway. Stimulation of this fiber bundle triggered BOLD responses in the right hippocampal formation and in the left entorhinal cortex. The perforant pathway projects to and activates the dentate gyrus monosynaptically, activation in the contralateral entorhinal cortex is multisynaptic and requires forwarding and processing of signals. Application of the NMDA receptor antagonist MK801 during stimulation had no effect on BOLD responses in the right dentate gyrus, but reduced the BOLD responses in the left entorhinal cortex. In contrast, application of MK801 before the first stimulation train reduced the BOLD response in both regions. Electrophysiological recordings revealed that the initial stimulation trains changed the local processing of the incoming signals in the dentate gyrus. This altered electrophysiological response was not further changed by a subsequent application of MK801, which is in agreement with an unchanged BOLD response. When MK801 was present during the first stimulation train, a dissimilar electrophysiological response pattern was observed and corresponds to an altered BOLD response, indicating that NMDA-dependent mechanisms indirectly affect the BOLD response, mainly via modifying local signal processing and subsequent propagation. PMID:22167232

  5. NMDA-dependent mechanisms only affect the BOLD response in the rat dentate gyrus by modifying local signal processing

    PubMed Central

    Tiede, Regina; Krautwald, Karla; Fincke, Anja; Angenstein, Frank

    2012-01-01

    The role of N-methyl--aspartate (NMDA) receptor-mediated mechanisms in the formation of a blood oxygen level-dependent (BOLD) response was studied using electrical stimulation of the right perforant pathway. Stimulation of this fiber bundle triggered BOLD responses in the right hippocampal formation and in the left entorhinal cortex. The perforant pathway projects to and activates the dentate gyrus monosynaptically, activation in the contralateral entorhinal cortex is multisynaptic and requires forwarding and processing of signals. Application of the NMDA receptor antagonist MK801 during stimulation had no effect on BOLD responses in the right dentate gyrus, but reduced the BOLD responses in the left entorhinal cortex. In contrast, application of MK801 before the first stimulation train reduced the BOLD response in both regions. Electrophysiological recordings revealed that the initial stimulation trains changed the local processing of the incoming signals in the dentate gyrus. This altered electrophysiological response was not further changed by a subsequent application of MK801, which is in agreement with an unchanged BOLD response. When MK801 was present during the first stimulation train, a dissimilar electrophysiological response pattern was observed and corresponds to an altered BOLD response, indicating that NMDA-dependent mechanisms indirectly affect the BOLD response, mainly via modifying local signal processing and subsequent propagation. PMID:22167232

  6. Chemo-dynamical evolution model: Enrichment of r-process elements in the Local Group dwarf galaxies

    NASA Astrophysics Data System (ADS)

    Hirai, Yutaka; Ishimaru, Yuhri; Saitoh, Takayuki R.; Fujii, Michiko S.; Hidaka, Jun; Kajino, Toshitaka

    2016-08-01

    Neutron star mergers are one of the candidate astrophysical site(s) of r-process. Several chemical evolution studies however pointed out that the observed abundance of r-process is difficult to reproduce by neutron star mergers. In this study, we aim to clarify the enrichment of r-process elements in the Local Group dwarf galaxies. We carry out numerical simulations of galactic chemo-dynamical evolution using an N-body/smoothed particle hydrodynamics code, ASURA. We construct a chemo-dynamical evolution model for dwarf galaxies assuming that neutron star mergers are the major source of r-process elements. Our models reproduce the observed dispersion in [Eu/Fe] as a function of [Fe/H] with neutron star mergers with a merger time of 100 Myr. We find that star formation efficiency and metal mixing processes during the first <~ 300 Myr of galaxy evolution are important to reproduce the observations. This study supports that neutron star mergers are a major site of r-process.

  7. [Investigation on remote measurement of air pollution by a method of infrared passive scanning imaging].

    PubMed

    Jiao, Yang; Xu, Liang; Gao, Min-Guang; Feng, Ming-Chun; Jin, Ling; Tong, Jing-Jing; Li, Sheng

    2012-07-01

    Passive remote sensing by Fourier-transform infrared (FTIR) spectrometry allows detection of air pollution. However, for the localization of a leak and a complete assessment of the situation in the case of the release of a hazardous cloud, information about the position and the distribution of a cloud is essential. Therefore, an imaging passive remote sensing system comprising an interferometer, a data acquisition and processing software, scan system, a video system, and a personal computer has been developed. The remote sensing of SF6 was done. The column densities of all directions in which a target compound has been identified may be retrieved by a nonlinear least squares fitting algorithm and algorithm of radiation transfer, and a false color image is displayed. The results were visualized by a video image, overlaid by false color concentration distribution image. The system has a high selectivity, and allows visualization and quantification of pollutant clouds.

  8. Synergistic Effect of Sodium Chlorite and Edible Coating on Quality Maintenance of Minimally Processed Citrus grandis under Passive and Active MAP.

    PubMed

    Ban, Zhaojun; Feng, Jianhua; Wei, Wenwen; Yang, Xiangzheng; Li, Jilan; Guan, Junfeng; Li, Jiang

    2015-08-01

    Edible coating has been an innovation within the bioactive packaging concept. The comparative analysis upon the effect of edible coating, sodium chlorite (SC) and their combined application on quality maintenance of minimally processed pomelo (Citrus grandis) fruits during storage at 4 °C was conducted. Results showed that the combination of edible coating and SC dipping delayed the microbial development whereas the sole coating or dipping treatment was less efficient. The synergetic application of edible coating and SC treatment under modified atmosphere packaging (MAP, 10% O2 , 10% CO2 ) was able to maintain the total soluble solids level and ascorbic acid content, while reduce the weight loss as well as development of mesophiles and psychrotrophs. Nonetheless, the N, O-carboxymethyl chitosan solely coated samples showed significantly higher level of weight loss during storage with comparison to the untreated sample. Furthermore, the combined application of edible coating and SC dipping under active MAP best maintained the sensory quality of minimally processed pomelo fruit during storage.

  9. Epileptic Pattern Recognition and Discovery of the Local Field Potential in Amygdala Kindling Process.

    PubMed

    Wang, Yu-Lin; Chen, Yin-Lin; Su, Alvin Wen-Yu; Shaw, Fu-Zen; Liang, Sheng-Fu

    2016-03-01

    Epileptogenesis, which occurs in an epileptic brain, is an important focus for epilepsy. The spectral analysis has been popularly applied to study the electrophysiological activities. However, the resolution is dominated by the window function of the algorithm used and the sample size. In this report, a temporal waveform analysis method is proposed to investigate the relationship of electrophysiological discharges and motor outcomes with a kindling process. Wistar rats were subjected to electrical amygdala kindling to induce temporal lobe epilepsy. During the kindling process, different morphologies of afterdischarges (ADs) were found and a recognition method, using template matching techniques combined with morphological comparators, was developed to automatically detect the epileptic patterns. The recognition results were compared to manually labeled results, and 79%-91% sensitivity was found. In addition, the initial ADs (the first 10 s) of different seizure stages were specifically utilized for recognition, and an average of 85% sensitivity was achieved. Our study provides an alternative viewpoint away from frequency analysis and time-frequency analysis to investigate epileptogenesis in an epileptic brain. The recognition method can be utilized as a preliminary inspection tool to identify remarkable changes in a patient's electrophysiological activities for clinical use. Moreover, we demonstrate the feasibility of predicting behavioral seizure stages from the early epileptiform discharges.

  10. Numerical experiments on the influence of melt and serpentinization on passive margin structure

    NASA Astrophysics Data System (ADS)

    Tetreault, Joya; Buiter, Susanne

    2014-05-01

    Passive margins are often classified as magma-rich or magma-poor, with distinctly different crustal architectures. For example, end-member magma-rich margins have thick sequences of seaward-dipping reflectors, short necking zones, and thick oceanic crusts, whereas many magma-poor margins have wide necking zones, hyper-extended crust, and exhumed serpentinized mantle. Melt and magmatic processes can strongly affect the mantle and crust during various stages of extension. At late stages of extension, serpentinization of upper mantle rocks will also affect crustal strength. We aim to study the influence of melt and serpentinization on structures developed during passive margin formation. Melt and serpentinization are two processes that can alter crust and mantle rheologic properties during different stages of extension. Introducing melt into a rift system will alter the thermal field, rheology, and density of crust and lithosphere. The presence of large amounts of melt (7-8%) in upper mantle rocks will significantly lower the viscosity. In addition, depleted mantle rocks can have significant loss of water that would result in raising the viscosity by about a factor of 100. Intrusion and underplating of magma to the lower crust can cause metamorphism and thus density and rheological changes of the surrounding crust. Furthermore, analogue experiments have shown that magmatic underplating will induce strain localization in the crust during extension. In regions such as the magma-poor margins of the North Atlantic, the serpentinization of mantle peridotites after sufficient thinning of continental crust can lead to strain localization that will subsequently affect the margin architecture. Upper mantle rocks become serpentinized at temperatures lower than 400 degrees when seawater infiltrates. The lower frictional properties that serpentinized peridotites have at these temperatures work to localize strain and allow detachment faults to form. We use 2D numerical experiments

  11. An approach for assessing ALWR passive safety system reliability

    SciTech Connect

    Hake, T M

    1991-01-01

    Many advanced light water reactor designs incorporate passive rather than active safety features for front-line accident response. A method for evaluating the reliability of these passive systems in the context of probabilistic risk assessment has been developed at Sandia National Laboratories. This method addresses both the component (e.g. valve) failure aspect of passive system failure, and uncertainties in system success criteria arising from uncertainties in the system's underlying physical processes. These processes provide the system's driving force; examples are natural circulation and gravity-induced injection. This paper describes the method, and provides some preliminary results of application of the approach to the Westinghouse AP600 design.

  12. What can be Learned from X-ray Spectroscopy Concerning Hot Gas in Local Bubble and Charge Exchange Processes?

    NASA Technical Reports Server (NTRS)

    Snowden, Steve

    2007-01-01

    What can be learned from x-ray spectroscopy in observing hot gas in local bubble and charge exchange processes depends on spectral resolution, instrumental grasp, instrumental energy band, signal-to-nose, field of view, angular resolution and observatory location. Early attempts at x-ray spectroscopy include ROSAT; more recently, astronomers have used diffuse x-ray spectrometers, XMM Newton, sounding rocket calorimeters, and Suzaku. Future observations are expected with calorimeters on the Spectrum Roentgen Gamma mission, and the Solar Wind Charge Exchange (SWCX). The Geospheric SWCX may provide remote sensing of the solar wind and magnetosheath and remote observations of solar CMEs moving outward from the sun.

  13. Passive bistatic radar analysis

    NASA Astrophysics Data System (ADS)

    O'Hagan, Daniel W.; Kuschel, H.; Schiller, Joachim

    2009-06-01

    Passive Bistatic Radar (PBR) research is at its zenith with several notable PBR systems currently operational, or available for deployment. Such PBRs include the Manastash Ridge Radar (MRR) developed for and by academia; Silent Sentry developed as a commercial concern by Lockheed Martin; and Homeland Alerter (HA100) also a commercial system developed by Thales. However at present, despite the existence of numerous PBR prototypes, take up of commercial passive radar technology remains slow. This is due in part to technology immaturity, in part to politics, and particularly due to the fact that monostatic radars perform so well. If PBRs are to enjoy longevity as a viable technology then it is imperative that they address certain niche application areas, with the aforementioned MRR being one prime example of this. The focus of this paper will be an analysis of a PBR system that utilised FM radio signals of opportunity to detect aircraft targets with an RCS generally not lower than 20 m2. The paper will demonstrate the theoretical detection coverage of an FM based PBR operating in a severe interference environment.

  14. Fly ash carbon passivation

    DOEpatents

    La Count, Robert B; Baltrus, John P; Kern, Douglas G

    2013-05-14

    A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

  15. Passive damping technology demonstration

    NASA Astrophysics Data System (ADS)

    Holman, Robert E.; Spencer, Susan M.; Austin, Eric M.; Johnson, Conor D.

    1995-05-01

    A Hughes Space Company study was undertaken to (1) acquire the analytical capability to design effective passive damping treatments and to predict the damped dynamic performance with reasonable accuracy; (2) demonstrate reasonable test and analysis agreement for both baseline and damped baseline hardware; and (3) achieve a 75% reduction in peak transmissibility and 50% reduction in rms random vibration response. Hughes Space Company teamed with CSA Engineering to learn how to apply passive damping technology to their products successfully in a cost-effective manner. Existing hardware was selected for the demonstration because (1) previous designs were lightly damped and had difficulty in vibration test; (2) multiple damping concepts could be investigated; (3) the finite element model, hardware, and test fixture would be available; and (4) damping devices could be easily implemented. Bracket, strut, and sandwich panel damping treatments that met the performance goals were developed by analysis. The baseline, baseline with damped bracket, and baseline with damped strut designs were built and tested. The test results were in reasonable agreement with the analytical predictions and demonstrated that the desired reduction in dynamic response could be achieved. Having successfully demonstrated this approach, it can now be used with confidence for future designs as a means for reducing weight and enhancing reliability.

  16. Single-thread channels resulting from a localization process driven by vegetation

    NASA Astrophysics Data System (ADS)

    Narteau, C.; Tal, M.

    2009-12-01

    The unpredictable manner in which braided rivers evolve is in stark contrast to the orderly migration pattern of meandering rivers driven by erosion along outer bends and deposition along inner banks. Braided channels are the default pattern that develops when an unbounded water flow interacts with noncohesive sediment. A series of laboratory experiments demonstrated that plants alone are able to achieve the two key mechanisms to developing meandering: slowing the rate of widening and discouraging channel cutoffs. Plants initially colonized braid-bars that were emergent during low flow. By adding cohesion to the sediment and increasing roughness, vegetation deterred the flow from reoccupying areas which were colonized. By decreasing erosion rates, plants made it possible for deposition along the inner bank to match the rate of erosion along the outer bank. This enabled the channel to develop sinuosity and migrate laterally while suppressing channel splitting and the creation of new channel width. Areas with established vegetation provided stable conditions which promoted new seedling establishment and expansion of the vegetated area. A generic mechanism of width production in the braided state is the opportunistic creation of new channels. As existing flow paths become slightly less favorable, for example by bar deposition or an increase in sinuosity, new ones are readily created in areas that are not currently occupied by flow. By making it more difficult for flow to occupy vegetated areas, plants in effect decouple the transition between wet and dry areas, making it harder for areas that are dry (vegetated) to turn wet (reoccupied by flow) and less likely for areas that are wet to become dry. The net effect is localization of the flow into a single-thread channel with transitions between wet and dry occurring predominantly along the channel margin and driving lateral migration while a single-thread channel remains intact. We are using a 1D cellular automata model

  17. An assessment of the impact of local processes on dust lifting in martian climate models

    NASA Astrophysics Data System (ADS)

    Mulholland, David P.; Spiga, Aymeric; Listowski, Constantino; Read, Peter L.

    2015-05-01

    Simulation of the lifting of dust from the planetary surface is of substantially greater importance on Mars than on Earth, due to the fundamental role that atmospheric dust plays in the former's climate, yet the dust emission parameterisations used to date in martian global climate models (MGCMs) lag, understandably, behind their terrestrial counterparts in terms of sophistication. Recent developments in estimating surface roughness length over all martian terrains and in modelling atmospheric circulations at regional to local scales (less than O(100 km)) presents an opportunity to formulate an improved wind stress lifting parameterisation. We have upgraded the conventional scheme by including the spatially varying roughness length in the lifting parameterisation in a fully consistent manner (thereby correcting a possible underestimation of the true threshold level for wind stress lifting), and used a modification to account for deviations from neutral stability in the surface layer. Following these improvements, it is found that wind speeds at typical MGCM resolution never reach the lifting threshold at most gridpoints: winds fall particularly short in the southern midlatitudes, where mean roughness is large. Sub-grid scale variability, manifested in both the near-surface wind field and the surface roughness, is then considered, and is found to be a crucial means of bridging the gap between model winds and thresholds. Both forms of small-scale variability contribute to the formation of dust emission 'hotspots': areas within the model gridbox with particularly favourable conditions for lifting, namely a smooth surface combined with strong near-surface gusts. Such small-scale emission could in fact be particularly influential on Mars, due both to the intense positive radiative feedbacks that can drive storm growth and a strong hysteresis effect on saltation. By modelling this variability, dust lifting is predicted at the locations at which dust storms are frequently

  18. Localized surface plasmon for enhanced lasing performance in solution-processed perovskites.

    PubMed

    Kao, Tsung Sheng; Hong, Kuo-Bin; Chou, Yu-Hsun; Huang, Jiong-Fu; Chen, Fang-Chung; Lu, Tien-Chang

    2016-09-01

    A promising method to promote the lasing performance of solution-processed organic-inorganic lead-halide perovskites has been demonstrated. With the adding Ag and PMMA thin films, the threshold excitation power for low-temperature lasing action in perovskites can be greatly reduced by over two orders of magnitude than that acquired in bare perovskite layers, ascribing to the strong exciton-plasmon coupling between the Ag and perovskite films. Also, the PMMA layer can be exploited to prevent the perovskite degradation from the hydrolysis in ambient environment, achieving long-lasting light-emitting performance. The advantages exhibited by the hybrid perovskite configuration would be very promising in making practical laser devices. PMID:27607673

  19. Processing and intracellular localization of rice stripe virus Pc2 protein in insect cells

    SciTech Connect

    Zhao, Shuling; Zhang, Gaozhan; Dai, Xuejuan; Hou, Yanling; Li, Min; Liang, Jiansheng; Liang, Changyong

    2012-08-01

    Rice stripe virus (RSV) belongs to the genus Tenuivirus and its genome consists of four single-stranded RNAs encoding seven proteins. Here, we have analyzed the processing and membrane association of Pc2 encoded by vcRNA2 in insect cells. The enhanced green fluorescent protein (eGFP) was fused to the Pc2 and used for the detection of Pc2 fusion proteins. The results showed that Pc2 was cleaved to produce two proteins named Pc2-N and Pc2-C. When expressed alone, either Pc2-N or Pc2-C could transport to the Endoplasmic reticulum (ER) membranes independently. Further mutagenesis studies revealed that Pc2 contained three ER-targeting domains. The results led us to propose a model for the topology of the Pc2 in which an internal signal peptide immediately followed a cleavage site, and two transmembrane regions are contained.

  20. Matrix metalloproteinase expression and localization in turkey (Meleagris gallopavo) during the endochondral ossification process.

    PubMed

    Simsa, S; Genina, O; Ornan, E Monsonego

    2007-06-01

    Vertebrate long bones are formed by endochondral ossification, a process accompanied by changes in extracellular matrix synthesis and remodeling, performed mainly by the matrix metalloproteinases (MMP). The temporal/spatial expression patterns of 5 members of the MMP family known to be important for endochondral ossification were studied, for the first time, in the turkey growth plate during embryonic and juvenile stages. The expression of MMP-2 was detected in the proliferative zone, MMP-3, MMP-9, and MMP-13 in cells lining the blood vessels; MMP-13 was also detected in hypertrophic chondrocytes. The MMP-16 expression was detected in the reserve zone of the growth plate. These results present a detailed survey of turkey MMP, serving as a data source (atlas) for further studies in this subject.