WorldWideScience

Sample records for attention lapses

  1. Noradrenergic Genotype Predicts Lapses in Sustained Attention

    Science.gov (United States)

    Greene, Ciara M.; Bellgrove, Mark A.; Gill, Michael; Robertson, Ian H.

    2009-01-01

    Sustained attention is modulated by the neurotransmitter noradrenaline. The balance of dopamine and noradrenaline in the cortex is controlled by the DBH gene. The principal variant in this gene is a C/T change at position-1021, and the T allele at this locus is hypothesised to result in a slower rate of dopamine to noradrenaline conversion than…

  2. Methylphenidate significantly reduces lapses of attention during on-road highway driving in patients with ADHD

    NARCIS (Netherlands)

    Verster, Joris C; Roth, Thomas

    2014-01-01

    Lapses of attention are characteristic for attention-deficit/hyperactivity disorder (ADHD) and as such may impair performance of daily activities. Data from an on-road driving study were reanalyzed to determine lapses in patients with ADHD after treatment with methylphenidate and placebo.A total of

  3. Distinct neural correlates for attention lapses in patients with schizophrenia and healthy participants.

    OpenAIRE

    Phillips, Ryan C.; Taylor eSalo; Carter, Cameron S.

    2015-01-01

    Momentary lapses in attention are common in healthy populations. This phenomenon has recently received increased investigation, particularly in relationship to the default mode network (DMN). Previous research has suggested that these lapses may be due to intrusive task-irrelevant thoughts. The study of this phenomenon in schizophrenia, which is characterized by a wide variety of cognitive deficits including deficits in attention, has not previously been explored. We used the AX Continuous Pe...

  4. Distinct neural correlates for attention lapses in patients with schizophrenia and healthy participants

    OpenAIRE

    Phillips, Ryan C.; Salo, Taylor; Carter, Cameron S.

    2015-01-01

    Momentary lapses in attention are common in healthy populations. This phenomenon has recently received increased investigation, particularly in relationship to the default mode network (DMN). Previous research has suggested that these lapses may be due to intrusive task-irrelevant thoughts. The study of this phenomenon in schizophrenia, which is characterized by a wide variety of cognitive deficits including deficits in attention, has not previously been explored. We used the AX Continuous Pe...

  5. Distinct neural correlates for attention lapses in patients with schizophrenia and healthy participants.

    Science.gov (United States)

    Phillips, Ryan C; Salo, Taylor; Carter, Cameron S

    2015-01-01

    Momentary lapses in attention are common in healthy populations. This phenomenon has recently received increased investigation, particularly in relationship to the default mode network (DMN). Previous research has suggested that these lapses may be due to intrusive task-irrelevant thoughts. The study of this phenomenon in schizophrenia, which is characterized by a wide variety of cognitive deficits including deficits in attention, has not previously been explored. We used the AX Continuous Performance Task to investigate attention lapses in healthy participants as well as patients with schizophrenia. We found distinct patterns of network activation between these two groups. Lapses in healthy participants were associated with DMN activation, while in patients, the same behavioral phenomenon was associated with deactivations in frontal-parietal control network (FPCN) regions. When considered in contrast to the results observed in healthy participants, these results suggest an additional origin of attention lapses in patients derived from a loss of task-related context, rather than intrusive task-irrelevant thoughts. PMID:26500517

  6. Distinct neural correlates for attention lapses in patients with schizophrenia and healthy participants.

    Directory of Open Access Journals (Sweden)

    Ryan C. Phillips

    2015-10-01

    Full Text Available Momentary lapses in attention are common in healthy populations. This phenomenon has recently received increased investigation, particularly in relationship to the default mode network (DMN. Previous research has suggested that these lapses may be due to intrusive task-irrelevant thoughts. The study of this phenomenon in schizophrenia, which is characterized by a wide variety of cognitive deficits including deficits in attention, has not previously been explored. We used the AX Continuous Performance Task to investigate attention lapses in healthy participants as well as patients with schizophrenia. We found distinct patterns of network activation between these two groups. Lapses in healthy participants were associated with default mode network activation, while in patients, the same behavioral phenomenon was associated with deactivations in frontal-parietal control network (FPCN regions. When considered in contrast to the results observed in healthy participants, these results suggest an additional origin of attention lapses in patients derived from a loss of task context, rather than intrusive task-irrelevant thoughts.

  7. The contribution of attentional lapses to individual differences in visual working memory capacity.

    Science.gov (United States)

    Adam, Kirsten C S; Mance, Irida; Fukuda, Keisuke; Vogel, Edward K

    2015-08-01

    Attentional control and working memory capacity are important cognitive abilities that substantially vary between individuals. Although much is known about how attentional control and working memory capacity relate to each other and to constructs like fluid intelligence, little is known about how trial-by-trial fluctuations in attentional engagement impact trial-by-trial working memory performance. Here, we employ a novel whole-report memory task that allowed us to distinguish between varying levels of attentional engagement in humans performing a working memory task. By characterizing low-performance trials, we can distinguish between models in which working memory performance failures are caused by either (1) complete lapses of attention or (2) variations in attentional control. We found that performance failures increase with set-size and strongly predict working memory capacity. Performance variability was best modeled by an attentional control model of attention, not a lapse model. We examined neural signatures of performance failures by measuring EEG activity while participants performed the whole-report task. The number of items correctly recalled in the memory task was predicted by frontal theta power, with decreased frontal theta power associated with poor performance on the task. In addition, we found that poor performance was not explained by failures of sensory encoding; the P1/N1 response and ocular artifact rates were equivalent for high- and low-performance trials. In all, we propose that attentional lapses alone cannot explain individual differences in working memory performance. Instead, we find that graded fluctuations in attentional control better explain the trial-by-trial differences in working memory that we observe.

  8. Serotonergic neurotransmission and lapses of attention in children and adolescents with attention deficit hyperactivity disorder: availability of tryptophan influences attentional performance.

    Science.gov (United States)

    Zepf, Florian D; Gaber, Tilman J; Baurmann, David; Bubenzer, Sarah; Konrad, Kerstin; Herpertz-Dahlmann, Beate; Stadler, Christina; Poustka, Fritz; Wöckel, Lars

    2010-08-01

    Deficiencies in serotonergic (5-HT) neurotransmission have frequently been linked to altered attention and memory processes. With attention deficit hyperactivity disorder (ADHD) being associated with impaired attention and working memory, this study investigated the effects of a diminished 5-HT turnover achieved by rapid tryptophan depletion (RTD) on attentional performance in children and adolescents with ADHD. Twenty-two male patients with ADHD (aged 9-15 yr) received the RTD procedure Moja-De and a tryptophan (Trp)-balanced placebo (Pla) in a randomized, double-blind, within-subject crossover design on two separate study days. Lapses of attention (LA) and phasic alertness (PA) were assessed within the test battery for attentional performance under depleted and sham-depleted conditions 120 (T1), 220 (T2) and 300 (T3) min after intake of RTD/Pla. At T1 there was a significant main effect for RTD, indicating more LA under intake of a Trp-balanced Pla compared to diminished 5-HT neurotransmission. For T2/T3 there were no such effects. PA was not affected by the factors RTD/Pla and time. Interactions of 5-HT with other neurotransmitters as possible underlying neurochemical processes could be subject to further investigations involving healthy controls as regards altered attentional performance in children and adolescents.

  9. The Relation of Mild Traumatic Brain Injury to Chronic Lapses of Attention

    Science.gov (United States)

    Pontifex, Matthew B.; Broglio, Steven P.; Drollette, Eric S.; Scudder, Mark R.; Johnson, Chris R.; O'Connor, Phillip M.; Hillman, Charles H.

    2012-01-01

    We assessed the extent to which failures in sustained attention were associated with chronic mild traumatic brain injury (mTBI) deficits in cognitive control among college-age young adults with and without a history of sport-related concussion. Participants completed the ImPACT computer-based assessment and a modified flanker task. Results…

  10. Stimulant Treatment Reduces Lapses in Attention among Children with ADHD: The Effects of Methylphenidate on Intra-Individual Response Time Distributions

    Science.gov (United States)

    Spencer, Sarah V.; Hawk, Larry W., Jr.; Richards, Jerry B.; Shiels, Keri; Pelham, William E., Jr.; Waxmonsky, James G.

    2009-01-01

    Recent research has suggested that intra-individual variability in reaction time (RT) distributions of children with ADHD is characterized by a particularly large rightward skew that may reflect lapses in attention. The purpose of the study was to provide the first randomized, placebo-controlled test of the effects of the stimulant methylphenidate…

  11. Lapses in Learning Mathematics

    OpenAIRE

    Prem Shankar Srivastava

    2014-01-01

    The present conceptual study deals about lapses in learning mathematics of students in schools are a problem of serious academic significance. The present day situation of teaching-learning of mathematics is unsatisfactory as the results of mathematics in different classes show. In our country, there are many school-going-students cut a sorry figure in learning mathematics. The present paper identifies lapses in learning mathematics on the part of the students, teachers, institutions, parents...

  12. Lapse Rate Modeling

    DEFF Research Database (Denmark)

    De Giovanni, Domenico

    The surrender option embedded in many life insurance products is a clause that allows policyholders to terminate the contract early. Pricing techniques based on the American Contingent Claim (ACC) theory are often used, though the actual policyholders' behavior is far from optimal. Inspired by many...... prepayment models for mortgage backed securities, this paper builds a Rational Expectation (RE) model describing the policyholders' behavior in lapsing the contract. A market model with stochastic interest rates is considered, and the pricing is carried out through numerical approximation...

  13. Lapse rate modeling

    DEFF Research Database (Denmark)

    De Giovanni, Domenico

    2010-01-01

    The surrender option embedded in many life insurance products is a clause that allows policyholders to terminate the contract early. Pricing techniques based on the American Contingent Claim (ACC) theory are often used, though the actual policyholders' behavior is far from optimal. Inspired by many...... prepayment models for mortgage backed securities, this paper builds a Rational Expectation (RE) model describing the policyholders' behavior in lapsing the contract. A market model with stochastic interest rates is considered, and the pricing is carried out through numerical approximation...

  14. Things Forgotten: Simple Lapse or Serious Problem?

    Science.gov (United States)

    ... Version (PDF—401 kb) Keeping Bones Strong and Healthy Things Forgotten ... forgotten why you went there. And misplaced your keys or eyeglasses at least a few times. Many people worry about these memory lapses. They fear they’re ...

  15. Haridus - iga lapse õigus / Gerd Tarand

    Index Scriptorium Estoniae

    Tarand, Gerd, 1985-

    2009-01-01

    MTÜ Mondo alustas veebruaris maailmaharidusprojektiga „Haridus - iga lapse õigus“, mille üldine eesmärk on tõsta Eesti elanikkonna, eriti noorte huvi arengumaade vastu ning teadmisi ja arusaamist arengumaade haridusega seonduvatest probleemidest

  16. Nähtamatud lapsed / Margit Tõnson

    Index Scriptorium Estoniae

    Tõnson, Margit, 1978-

    2006-01-01

    UNICEFi palvel valmistasid kaheksa tuntud režissööri kassett-filmi maailma kannatavatest lastest "Kõik nähtamatud lapsed" ("All the Invisible Children") : Prantsusmaa - Itaalia 2005. Film on Sõpruse kino kavas

  17. Improved site contamination through time-lapse complex resistivity imaging

    Science.gov (United States)

    Flores Orozco, Adrian; Kemna, Andreas; Cassiani, Giorgio; Binley, Andrew

    2016-04-01

    In the framework of the EU FP7 project ModelPROBE, time-lapse complex resistivity (CR) measurements were conducted at a test site close to Trecate (NW Italy). The objective was to investigate the capabilities of the CR imaging method to delineate the geometry and dynamics of subsurface hydrocarbon contaminant plume which resulted from a crude oil spill in 1994. To achieve this it is required to discriminate the electrical signal associated to static (i.e., lithology) from dynamic changes in the subsurface, with the latter associated to significant seasonal groundwater fluctuations. Previous studies have demonstrated the benefits of the CR method to gain information which is not accessible with common electrical resistivity tomography. However field applications are still rarely and neither the analysis of the data error for CR time-lapse measurements, nor the inversion itself haven not received enough attention. While the ultimate objective at the site is to characterize, here we address the discrimination of the lithological and hydrological controls on the IP response by considering data collected in an uncontaminated area of the site. In this study we demonstrate that an adequate error description of CR measurements provides images free of artifacts and quantitative superior than previous approaches. Based on this approach, differential images computed for time-lapse data exhibited anomalies well correlated with spatiotemporal changes correlated to seasonal fluctuations in the groundwater level. The proposed analysis may be useful in the characterization of fate and transport of hydrocarbon contaminants relevant for the site, which presents areas contaminated with crude oil.

  18. How Long Can Students Pay Attention in Class? A Study of Student Attention Decline Using Clickers

    Science.gov (United States)

    Bunce, Diane M.; Flens, Elizabeth A.; Neiles, Kelly Y.

    2010-01-01

    Students enrolled in three levels of general chemistry self-reported their attention decline during both lecture and other teaching approaches via personal response devices (clickers). Students report attention declines of 1 min or less more often than longer attention lapses. The data suggest that student engagement alternates between attention…

  19. Jehoova tunnistajate lapse arstide kriminaalasjast / Ants Nõmper

    Index Scriptorium Estoniae

    Nõmper, Ants, 1977-

    2000-01-01

    Kriminaalasjast, kus süüdistati arste meditsiinilise abi osutamata jätmises lapsele, kelle vanemad ei nõustunud vereülekandega. Arsti ravikohustusest, lapse enesemääramisõigusest, vanemlike õiguste piiridest. Arstieetika koodeksitest. Arstiabi mitteandmise kriminaalmenetlusest Saksamaal

  20. Time-lapse seismic within reservoir engineering

    NARCIS (Netherlands)

    Oldenziel, T.

    2003-01-01

    Time-lapse 3D seismic is a fairly new technology allowing dynamic reservoir characterisation in a true volumetric sense. By investigating the differences between multiple seismic surveys, valuable information about changes in the oil/gas reservoir state can be captured. Its interpretation involves d

  1. 26 CFR 25.2704-1 - Lapse of certain rights.

    Science.gov (United States)

    2010-04-01

    ... GIFT TAXES GIFT TAX; GIFTS MADE AFTER DECEMBER 31, 1954 Special Valuation Rules § 25.2704-1 Lapse of certain rights. (a) Lapse treated as transfer—(1) In general. The lapse of a voting right or a liquidation right in a corporation or partnership (an “entity”) is a transfer by the individual directly...

  2. Lapse varajastest sotsialiseerumisvõimalustest / Inna Järva

    Index Scriptorium Estoniae

    Järva, Inna

    1998-01-01

    Suhtlemine oma ema või täiskasvanutega on lapse üldise psüühilise arengu tähtsaim faktor. Ema ja lapse suhted sotsiaalsete teooriate valguses, lapse varajased sotsialiseerumise võimalused väikelaste mängukoolide kaudu (Ave Kumpase väikelapse mängukool)

  3. Suhtlusstrateegiad eesti-soome kakskeelsust omandava lapse segakoodis

    Directory of Open Access Journals (Sweden)

    Kristiina Teiss

    2006-05-01

    Full Text Available Artiklis käsitletakse lapse lähedaste isikute suhtlusstrateegiaid lapse kahe keele (eesti, soome omandamises, samuti kakskeelse lapse keelevalikuid suhtlussituatsioonides. Uurimuse aluseks on helisalvestused ja päevikumärkmed lapse vanusest 2;4–2;10 eluaastat. Lapse kolmas eluaasta on mitmete autorite kakskeelsust ja keele omandamist käsitlevates töödes tõstetud esile olulise vanusena, mil laps hakkab keelte omandamist teadvustama ja kahte keelt eraldama (nt Vihman 1985, Lanza 1992.

  4. MUSCLE: MUltiscale Spherical-ColLapse Evolution

    Science.gov (United States)

    Neyrinck, Mark C.

    2016-05-01

    MUSCLE (MUltiscale Spherical ColLapse Evolution) produces low-redshift approximate N-body realizations accurate to few-Megaparsec scales. It applies a spherical-collapse prescription on multiple Gaussian-smoothed scales. It achieves higher accuracy than perturbative schemes (Zel'dovich and second-order Lagrangian perturbation theory - 2LPT), and by including the void-in-cloud process (voids in large-scale collapsing regions), solves problems with a single-scale spherical-collapse scheme.

  5. Explaining lapse in long-term care insurance markets.

    Science.gov (United States)

    Konetzka, R Tamara; Luo, Ye

    2011-10-01

    Expansion of private long-term care insurance (LTCI) is often posited as a potential mechanism to finance long-term care (LTC) for a growing elderly population in the US. One largely ignored issue is lapse or cancellation of policies. Individuals who let a LTCI policy lapse face resumed risk of LTC expenditures while suffering the financial loss of premiums paid. The motivation for lapse has been poorly understood, though some have hypothesized that improvements in health risk may be responsible. We use 1996-2006 Health and Retirement Study data from 3974 respondents who report having private LTCI to estimate baseline and dynamic predictors of lapse and test for ex post adverse selection. Individuals who lapse are generally poorer, less educated, less healthy, and more likely to be racial and ethnic minorities than those who retain their policies. Changes in health status play a relatively small role in lapse, and we find little evidence for adverse selection associated with lapse. We conclude that lapse of LTCI is more an issue of finances and alternatives than a reassessment of health risk. Because lapse rates are highest among the least healthy individuals, lapse should be considered explicitly in efforts to expand the LTCI market. PMID:20882573

  6. Time-Lapse Imaging of Cell Death.

    Science.gov (United States)

    Wallberg, Fredrik; Tenev, Tencho; Meier, Pascal

    2016-03-01

    The best approach to distinguish between necrosis and apoptosis is time-lapse video microscopy. This technique enables a biological process to be photographed at regular intervals over a period, which may last from a few hours to several days, and can be applied to cells in culture or in vivo. We have established two time-lapse microscopy methods based on different ways of calculating cell death: semiautomated and automated. In the semiautomated approach, cell death can be visualized by staining with combinations of Alexa Fluor 647-conjugated Annexin V and Sytox Green (SG), or Annexin V(FITC) and Propidium iodide (PI). The automated method is similar except that all cells are labeled with dyes. This allows faster quantification of data. To this end Cell Tracker Green is used to label all cells at time zero in combination with PI and Alexa Fluor 647-conjugated Annexin V. Necrotic cell death is accompanied by either simultaneous labeling with Annexin V and PI or SG (double-positive), or direct PI or SG staining. Additionally, necrotic cells display characteristic morphology, such as cytoplasmic swelling. In contrast to necrosis where membrane permeabilization is an early event, cells that die by apoptosis lose their membrane permeability relatively late. Therefore, the time between Annexin V staining and PI or SG uptake (double-positive) can be used to distinguish necrosis from apoptosis. This protocol describes the analysis of cell death by time-lapse imaging of HT1080 and L929 cells stained with these dyes, but it can be readily adapted to other cell types of interest. PMID:26933245

  7. Lapse ülalpidamise hind / Ene-Margit Tiit

    Index Scriptorium Estoniae

    Tiit, Ene-Margit, 1934-

    2005-01-01

    Tutvustav artikkel sotsiaalministeeriumi tellimusel läbiviidud uuringust, mille eesmärgiks oli välja töötada lapse kõikidest vajadustest lähtuv ühtne metoodika lapse ülalpidamiskulude arvutamiseks ühes kuus. Tabelid. Diagrammid. Vt. ka lk. 15-16: Kaplan, Signe. Metoodika kasutamisvõimalusi

  8. Purposeless repeated acquisition time-lapse seismic data processing

    Institute of Scientific and Technical Information of China (English)

    Li Jingye; Chen Xiaohong; Zhao Wei; Zhang Yunpeng

    2008-01-01

    In China, most oil fields are continental sedimentation with strong heterogeneity, which on one side makes the reservoir prospecting and development more difficult, but on the other side provides more space for searching residual oil in matured fields. Time-lapse seismic reservoir monitoring technique is one of most important techniques to define residual oil distribution. According to the demand for and development of time-lapse seismic reservoir monitoring in China, purposeless repeated acquisition time-lapse seismic data processing was studied. The four key steps in purposeless repeated acquisition time-lapse seismic data processing, including amplitude-preserved processing with relative consistency,rebinning, match filtering and difference calculation, were analyzed by combining theory and real seismic data processing. Meanwhile, quality control during real time-lapse seismic processing was emphasized.

  9. Attention to Attention

    DEFF Research Database (Denmark)

    Tække, Jesper; Paulsen, Michael Eric

    , but new expanded possibilities for teaching and learning provided by the new media. Our core postulate is that the teachers and pupils have to develop social reflexion on ‘the practice of attention’ in the class, both on a social and individual level; use the new media to facilitate this reflexion...... and simultaneously (based on the on-going reflexion) learn to cope better with the new attention-demanding medium milieu, which means both to restrict oneself and behave more socially responsible and to develop better awareness skills (e.g. multiplexing skills). Only this (and not prohibition against Facebook......, online games etc. neither unconcern and ignorance of the new media and their consequences for attention) - we argue - can generate adequate social norms regulating psychic awareness in the new digital learning environment....

  10. A NEW INVERSION METHOD OF TIME-LAPSE SEISMIC

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Time-Lapse Seismic improves oil recovery ratio by dynamic reservoir monitoring. Because of the large number of seismic explorations in the process of time-lapse seismic inversion, traditional methods need plenty of inversion calculations which cost high computational works. The method is therefore inefficient. In this paper, in order to reduce the repeating computations in traditional, a new time-lapse seismic inversion method is put forward. Firstly a homotopy-regularization method is proposed for the first time inversion. Secondly, with the first time inversion results as the initial value of following model, a model of the second time inversion is rebuilt by analyzing the characters of time-lapse seismic and localized inversion method is designed by using the model. Finally, through simulation, the comparison between traditional method and the new scheme is given. Our simulation results show that the new scheme could save the algorithm computations greatly.

  11. 77 FR 38396 - Agency Information Collection (Notice of Lapse-Government Life Insurance) Activities Under OMB...

    Science.gov (United States)

    2012-06-27

    ... AFFAIRS Agency Information Collection (Notice of Lapse--Government Life Insurance) Activities Under OMB... INFORMATION: Titles: a. Notice of Lapse--Government Life Insurance, VA Form 29-389. b. Application for... government life insurance has lapsed or will lapse due to nonpayment of premiums. The claimant must...

  12. Kohtu loal lapse nimel tehingute tegemine krediidiasutuses : [magistritöö] / Merily Saar ; Tartu Ülikool, õigusteaduskond ; juhendaja: Triin Göttig

    Index Scriptorium Estoniae

    Saar, Merily, 1987-

    2013-01-01

    Varahooldusõigusest tulenevast lapse vara säilitamise kohustusest, perekonnaseadusest tulenevatest piirangutest vanema poolt lapse esindajana tehingute tegemisel, lapse nimel väärtpaberitehingute tegemisest

  13. Calibrating vadose zone models with time-lapse gravity data

    DEFF Research Database (Denmark)

    Christiansen, Lars; Binning, Philip John; Rosbjerg, Dan;

    2011-01-01

    The vadose zone plays an important role in the hydrologic cycle. Various geophysical methods can determine soil water content variations in time and space in volumes ranging from a few cubic centimeters to several cubic meters. In contrast to the established methods, time-lapse gravity measurements...... hydrologic information. In this study, changes in the soil water content gave rise to a measurable signal in a forced infiltration experiment on a 107-m2 grassland area. Time-lapse gravity data were able to constrain the van Genuchten soil hydraulic parameters in both a synthetic example and a field...

  14. Attention Economies

    OpenAIRE

    Falkinger, Josef

    2003-01-01

    Attracting attention is a basic feature of economic life but no standard economic problem. A new theoretical model is developed which describes the general structure of competition for attention and characterizes equilibria. The exogenous fundamentals of an attention economy are the space of receiving subjects with their attention capacity, and the potential set of competing companies (senders) with their radiation technologies. The endogenous variables explained by the theory are equilibrium...

  15. Andeka lapse arengukeskkond ja toimetulek koolis / Helle Sikka

    Index Scriptorium Estoniae

    Sikka, Helle

    2001-01-01

    Andekuse mõistest ja selle arengust, andeka lapse isiksuseomadustest. 1998-2000.a. läbi viidud küsitlusuuringust, mille eesmärgiks oli selgitada andekate laste koolimeeldivust, hinnanguid õpetajatele, õpilaste asendit kaaslaste seas, õpilaste arvamusi oma isiksuseomaduste kohta ning andekate harrastusi ja huvisid

  16. Arengukeskkonna mõju lapse intelligentsuse arengule / Marika Veisson, Kristina Nugin

    Index Scriptorium Estoniae

    Veisson, Marika

    2002-01-01

    Uuringust, mille eesmärgiks oli määratleda 3-4-aastaste laste kasvukeskkonna faktorite mõju lapse intelligentsuse arengule, eraldi on vaadeldud intelligentsuse erinevaid komponente. Uuritavateks olid 1996-2002.a. longituuduuringus osalenud lapsed. Alates 1999.a. võrreldi nende laste arengu näitajaid kontrollgrupiga, mille moodustasid tavalasteaia ja Hea Alguse programmis osalenud lapsed

  17. TimeLapseAnalyzer: Multi-target analysis for live-cell imaging and time-lapse microscopy

    DEFF Research Database (Denmark)

    Huth, Johannes; Buchholz, Malte; Kraus, Johann M.;

    2011-01-01

    , we developed TimeLapseAnalyzer. Apart from general purpose image enhancements and segmentation procedures, this extensible, self-contained, modular cross-platform package provides dedicated modalities for fast and reliable analysis of multi-target cell tracking, scratch wound healing analysis, cell...

  18. Shifting Attention

    Science.gov (United States)

    Ingram, Jenni

    2014-01-01

    This article examines the shifts in attention and focus as one teacher introduces and explains an image that represents the processes involved in a numeric problem that his students have been working on. This paper takes a micro-analytic approach to examine how the focus of attention shifts through what the teacher and students do and say in the…

  19. Seismic imaging of reservoir flow properties: Time-lapse pressurechanges

    Energy Technology Data Exchange (ETDEWEB)

    Vasco, Don W.

    2003-04-08

    Time-lapse fluid pressure and saturation estimates are sensitive to reservoir flow properties such as permeability. In fact, given time-lapse estimates of pressure and saturation changes, one may define a linear partial differential equation for permeability variations within the reservoir. The resulting linear inverse problem can be solved quite efficiently using sparse matrix techniques. An application to a set of crosswell saturation and pressure estimates from a CO{sub 2} flood at the Lost Hills field in California demonstrates the utility of this approach. From the crosswell estimates detailed estimates of reservoir permeability are produced. The resulting permeability estimates agree with a permeability log in an adjacent well and are in accordance with water and CO{sub 2} saturation changes in the interwell region.

  20. Predictive Modeling of Addiction Lapses in a Mobile Health Application

    OpenAIRE

    Chih, Ming-Yuan; Patton, Timothy; McTavish, Fiona M.; Isham, Andrew; Judkins-Fisher, Chris L.; Atwood, Amy K.; Gustafson, David H.

    2013-01-01

    The chronically relapsing nature of alcoholism leads to substantial personal, family, and societal costs. Addiction-Comprehensive Health Enhancement Support System (A-CHESS) is a smartphone application that aims to reduce relapse. To offer targeted support to patients who are at risk of lapses within the coming week, a Bayesian network model to predict such events was constructed using responses on 2,934 weekly surveys (called the Weekly Check-in) from 152 alcohol-dependent individuals who re...

  1. Time-lapse seismic imaging of the Reykjanes geothermal reservoir

    Science.gov (United States)

    Weemstra, Cornelis; Obermann, Anne; Blanck, Hanna; Verdel, Arie; Paap, Bob; Árni Guðnason, Egill; Páll Hersir, Gylfi; Jousset, Philippe; Sigurðsson, Ómar

    2016-04-01

    We report on the results obtained from a dense seismic deployment over a geothermal reservoir. The reservoir has been producing continuously for almost a decade and is located on the tip of the Reykjanes peninsula, SW Iceland. The seismic stations on top of the reservoir have continuously recorded the ambient seismic wavefield between April 2014 and September 2015. The density of the seismic network makes the data well suited for time-lapse seismic imaging of the reservoir. To that end we compute time-lapse responses through the application of seismic interferometry. These interferometric lapse responses are obtained by simple crosscorrelation of the seismic noise recorded by the different seismic stations. We subsequently evaluate the temporal variation of the coda of these crosscorrelations. The term coda refers to the later arriving, multiple scattered waves. The multiple scattering implies that these waves have sampled the subsurface very densely and hence become highly sensitive to tiny mechanical and structural changes in that subsurface. This sensitivity allows one, in principle at least, to monitor the geothermal reservoir. Preliminary results indeed suggest a relation between the temporal variation of the coda waves and the reservoir. Ultimately, this method may lead to a means to monitor a geothermal reservoir in both space and time.

  2. Revealed Attention

    OpenAIRE

    Masatlioglu, Yusufcan; NAKAJIMA, Daisuke; Ozbay, Erkut Y

    2012-01-01

    The standard revealed preference argument relies on an implicit assumption that a decision maker considers all feasible alternatives. The marketing and psychology literatures, however, provide wellestablished evidence that consumers do not consider all brands in a given market before making a purchase (Limited Attention). In this paper, we illustrate how one can deduce both the decision maker's preference and the alternatives to which she pays attention and inattention from the observed behav...

  3. Revealed Attention

    OpenAIRE

    Yusufcan Masatlioglu; Daisuke Nakajima; Ozbay, Erkut Y

    2012-01-01

    The standard revealed preference argument relies on an implicit assumption that a decision maker considers all feasible alternatives. The marketing and psychology literatures, however, provide well-established evidence that consumers do not consider all brands in a given market before making a purchase (Limited Attention). In this paper, we illustrate how one can deduce both the decision maker's preference and the alternatives to which she pays attention and inattention from the observed beha...

  4. Shared Attention.

    Science.gov (United States)

    Shteynberg, Garriy

    2015-09-01

    Shared attention is extremely common. In stadiums, public squares, and private living rooms, people attend to the world with others. Humans do so across all sensory modalities-sharing the sights, sounds, tastes, smells, and textures of everyday life with one another. The potential for attending with others has grown considerably with the emergence of mass media technologies, which allow for the sharing of attention in the absence of physical co-presence. In the last several years, studies have begun to outline the conditions under which attending together is consequential for human memory, motivation, judgment, emotion, and behavior. Here, I advance a psychological theory of shared attention, defining its properties as a mental state and outlining its cognitive, affective, and behavioral consequences. I review empirical findings that are uniquely predicted by shared-attention theory and discuss the possibility of integrating shared-attention, social-facilitation, and social-loafing perspectives. Finally, I reflect on what shared-attention theory implies for living in the digital world. PMID:26385997

  5. Distinct coping strategies differentially predict urge levels and lapses in a smoking cessation attempt.

    Science.gov (United States)

    Brodbeck, Jeannette; Bachmann, Monica S; Znoj, Hansjörg

    2013-06-01

    This study analysed mechanisms through which stress-coping and temptation-coping strategies were associated with lapses. Furthermore, we explored whether distinct coping strategies differentially predicted reduced lapse risk, lower urge levels, or a weaker association between urge levels and lapses during the first week of an unassisted smoking cessation attempt. Participants were recruited via the internet and mass media in Switzerland. Ecological momentary assessment (EMA) with mobile devices was used to assess urge levels and lapses. Online questionnaires were used to measure smoking behaviours and coping variables at baseline, as well as smoking behaviour at the three-month follow-up. The sample consisted of 243 individuals, aged 20 to 40, who reported 4199 observations. Findings of multilevel regression analyses show that coping was mainly associated with a reduced lapse risk and not with lower urge levels or a weaker association between urge levels and lapses. 'Calming down' and 'commitment to change' predicted a lower lapse risk and also a weaker relation between urge levels and lapses. 'Stimulus control' predicted a lower lapse risk and lower urge levels. Conversely, 'task-orientation' and 'risk assessment' were related to higher lapse risk and 'risk assessment' also to higher urge levels. Disengagement coping i.e. 'eating or shopping', 'distraction', and 'mobilising social support' did not affect lapse risk. Promising coping strategies during the initial stage of smoking cessation attempt are targeted directly at reducing the lapse risk and are characterised by engagement with the stressor or one's reactions towards the stressor and a focus on positive consequences instead of health risks. PMID:23501139

  6. Attention Sensor

    NARCIS (Netherlands)

    Börner, Dirk; Kalz, Marco; Specht, Marcus

    2014-01-01

    This software sketch was used in the context of an experiment for the PhD project “Ambient Learning Displays”. The sketch comprises a custom-built attention sensor. The sensor measured (during the experiment) whether a participant looked at and thus attended a public display. The sensor was built us

  7. Monitoring of Shirase Glacier with time-lapse video recorder

    OpenAIRE

    齊藤, 隆志; 神山, 孝吉; 西尾, 文彦

    2010-01-01

    An observation had been carried out to monitor the flow condition and surficial change of Shirase Glacier, Lutzow-Holm bukt, East Antarctica in the summer of Japanese Antarctic Research Expedition 43rd. Time-lapse video camera was set on the rock in Instekleppane(70.05S, 38.8E) located at the right bank of Shirase Glacier between its grounding line and outlet to the Lutzow-Holm bukt.The view range was set in transverse direction from right bank to left bank of Shirase Glacier. The monitoring ...

  8. Lapsed, kes sünnivad südamest / Evar Post

    Index Scriptorium Estoniae

    Post, Evar, 1967-

    2008-01-01

    Lapsendamisest, hooldusperedest, hoolekandest ja tugiperedest. Lisatud: 2007. aastal oli Eestis... ; Eesti lapsed välismaale ; Petoffer, Sigrid. Lapsendamisest huvitatud koonduvad ühingusse ; aitamise mitu vormi

  9. Attention Sensor

    OpenAIRE

    Börner, Dirk; KALZ Marco; Specht, Marcus

    2014-01-01

    This software sketch was used in the context of an experiment for the PhD project “Ambient Learning Displays”. The sketch comprises a custom-built attention sensor. The sensor measured (during the experiment) whether a participant looked at and thus attended a public display. The sensor was built using the Processing 1.5.1 development environment and the open source computer vision library OpenCV for Processing. Available under the GNU LGPL licence version 3 or higher.

  10. Predictive modeling of addiction lapses in a mobile health application.

    Science.gov (United States)

    Chih, Ming-Yuan; Patton, Timothy; McTavish, Fiona M; Isham, Andrew J; Judkins-Fisher, Chris L; Atwood, Amy K; Gustafson, David H

    2014-01-01

    The chronically relapsing nature of alcoholism leads to substantial personal, family, and societal costs. Addiction-comprehensive health enhancement support system (A-CHESS) is a smartphone application that aims to reduce relapse. To offer targeted support to patients who are at risk of lapses within the coming week, a Bayesian network model to predict such events was constructed using responses on 2,934 weekly surveys (called the Weekly Check-in) from 152 alcohol-dependent individuals who recently completed residential treatment. The Weekly Check-in is a self-monitoring service, provided in A-CHESS, to track patients' recovery progress. The model showed good predictability, with the area under receiver operating characteristic curve of 0.829 in the 10-fold cross-validation and 0.912 in the external validation. The sensitivity/specificity table assists the tradeoff decisions necessary to apply the model in practice. This study moves us closer to the goal of providing lapse prediction so that patients might receive more targeted and timely support. PMID:24035143

  11. Separation of genetic influences on attention deficit hyperactivity disorder symptoms and reaction time performance from those on IQ

    NARCIS (Netherlands)

    Wood, A. C.; Asherson, P.; van der Meere, J. J.; Kuntsi, J.

    2010-01-01

    Background. Attention deficit hyperactivity disorder (ADHD) shows a strong phenotypic and genetic association with reaction time (RI) variability, considered to reflect lapses in attention. Yet we know little about whether this aetiological pathway is shared with other affected cognitive processes i

  12. 77 FR 22069 - Proposed Information Collection (Notice of Lapse-Government Life Insurance); Comment Request

    Science.gov (United States)

    2012-04-12

    ... AFFAIRS Proposed Information Collection (Notice of Lapse--Government Life Insurance); Comment Request... Life Insurance policy. DATES: Written comments and recommendations on the proposed collection of... use of other forms of information technology. Titles a. Notice of Lapse--Government Life Insurance,...

  13. Relations among Affect, Abstinence Motivation and Confidence, and Daily Smoking Lapse Risk

    Science.gov (United States)

    Minami, Haruka; Yeh, Vivian M.; Bold, Krysten W.; Chapman, Gretchen B.; McCarthy, Danielle E.

    2016-01-01

    Aims This study tested the hypothesis that changes in momentary affect, abstinence motivation, and confidence would predict lapse risk over the next 12–24 hours using Ecological Momentary Assessment (EMA) data from smokers attempting to quit smoking. Method 103 adult, daily, treatment-seeking smokers recorded their momentary affect, motivation to quit, abstinence confidence, and smoking behaviors in near real time with multiple EMA reports per day using electronic diaries post-quit. Results Multilevel models indicated that initial levels of negative affect were associated with smoking, even after controlling for earlier smoking status, and that short-term increases in negative affect predicted lapses up to 12, but not 24, hours later. Positive affect had significant effects on subsequent abstinence confidence, but not motivation to quit. High levels of motivation appeared to reduce increases in lapse risk that occur over hours while momentary changes in confidence did not predict lapse risk over 12 hours. Conclusion Negative affect had short-lived effects on lapse risk, whereas higher levels of motivation protected against the risk of lapsing that accumulates over hours. An increase in positive affect was associated with greater confidence to quit, but such changes in confidence did not reduce short-term lapse risk, contrary to expectations. Relations observed among affect, cognitions, and lapse seem to depend critically on the timing of assessments. PMID:24955665

  14. Exploring Time-Lapse Photography as a Means for Qualitative Data Collection

    Science.gov (United States)

    Persohn, Lindsay

    2015-01-01

    Collecting information via time-lapse photography is nothing new. Scientists and artists have been using this kind of data since the late 1800s. However, my research and experiments with time-lapse have shown that great potential may lie in its application to educational and social scientific research methods. This article is part history, part…

  15. Seismic time-lapse effects of solution salt mining - a feasibility study

    NARCIS (Netherlands)

    Arts, R.J.

    2012-01-01

    This article addresses the question whether time-lapse seismic reflection techniques can be used to follow and quantify the effects of solution salt mining. Specifically, the production of magnesium salts as mined in the north of the Netherlands is considered. The use of seismic time-lapse technique

  16. Distress Tolerance Treatment for Early-Lapse Smokers: Rationale, Program Description, and Preliminary Findings

    Science.gov (United States)

    Brown, Richard A.; Palm, Kathleen M.; Strong, David R.; Lejuez, Carl W.; Kahler, Christopher W.; Zvolensky, Michael J.; Hayes, Steven C.; Wilson, Kelly G.; Gifford, Elizabeth V.

    2008-01-01

    A significant percentage of individuals attempting smoking cessation lapse within a matter of days, and very few are able to recover to achieve long-term abstinence. This observation suggests that many smokers may have quit-attempt histories characterized exclusively by early lapses to smoking following quit attempts. Recent negative-reinforcement…

  17. Seismic imaging of reservoir flow properties: Time-lapse amplitude changes

    Energy Technology Data Exchange (ETDEWEB)

    Vasco, D.W.; Datta-Gupta, Akhil; Behrens, Ron; Condon, Pat; Rickett, Jame s

    2003-03-13

    Asymptotic methods provide an efficient means by which to infer reservoir flow properties, such as permeability, from time-lapse seismic data. A trajectory-based methodology, much like ray-based methods for medical and seismic imaging, is the basis for an iterative inversion of time-lapse amplitude changes. In this approach a single reservoir simulation is required for each iteration of the algorithm. A comparison between purely numerical and the trajectory-based sensitivities demonstrates their accuracy. An application to a set of synthetic amplitude changes indicates that they can recover large-scale reservoir permeability variations from time-lapse data. In an application of actual time-lapse amplitude changes from the Bay Marchand field in the Gulf of Mexico we are able to reduce the misfit by 81% in twelve iterations. The time-lapse observations indicate lower permeabilities are required in the central portion of the reservoir.

  18. Research Note:Derivation of temperature lapse rates in semi-arid south-eastern Arizona

    Directory of Open Access Journals (Sweden)

    R. C. Harlow

    2004-01-01

    Full Text Available Ecological and hydrological modelling at the regional scale requires distributed information on weather variables, and temperature is important among these. In an area of basin and range topography with a wide range of elevations, such as south-eastern Arizona, measurements are usually available only at a relatively small number of locations and elevations, and temperatures elsewhere must be estimated from atmospheric lapse rate. This paper derives the lapse rates to estimate maximum, minimum and mean daily temperatures from elevation. Lapse rates were calculated using air temperatures at 2 m collected during 2002 at 18 locations across south-eastern Arizona, with elevations from 779 to 2512 m. The lapse rate predicted for the minimum temperature was lower than the mean environmental lapse rate (MELR, i.e. 6 K km–1, whereas those predicted for the mean and maximum daily temperature were very similar to the MELR. Lapse rates were also derived from radiosonde data at 00 and 12 UTC (5 pm and 5 am local time, respectively. The lapse rates calculated from radiosonde data were greater than those from the 2 m measurements, presumably because the effect of the surface was less. Given temperatures measured at Tucson airport, temperatures at the other sites were predicted using the different estimates of lapse rates. The best predictions of temperatures used the locally predicted lapse rates. In the case of maximum and mean temperature, using the MELR also resulted in accurate predictions. Keywords: near surface lapse rates, semi-arid climate, mean minimum and maximum temperatures, basin and range topography

  19. A randomized clinical trial comparing embryo culture in a conventional incubator with a time-lapse incubator

    DEFF Research Database (Denmark)

    Kirkegaard, Kirstine; Hindkjaer, Johnny Juhl; Grøndahl, Marie Louise;

    2012-01-01

    Time-lapse monitoring allows for a flexible embryo evaluation and potentially provides new dynamic markers of embryo competence. Before introducing time-lapse monitoring in a clinical setting, the safety of the instrument must be properly documented. Accordingly, the aim of this study was to eval......Time-lapse monitoring allows for a flexible embryo evaluation and potentially provides new dynamic markers of embryo competence. Before introducing time-lapse monitoring in a clinical setting, the safety of the instrument must be properly documented. Accordingly, the aim of this study...... was to evaluate the safety of a commercially available time-lapse incubator....

  20. Network Analysis of Time-Lapse Microscopy Recordings

    Directory of Open Access Journals (Sweden)

    Erik eSmedler

    2014-09-01

    Full Text Available Multicellular organisms rely on intercellular communication to regulate important cellular processes critical to life. To further our understanding of those processes there is a need to scrutinize dynamical signaling events and their functions in both cells and organisms. Here, we report a method and provide MATLAB code that analyzes time-lapse microscopy recordings to identify and characterize network structures within large cell populations, such as interconnected neurons. The approach is demonstrated using intracellular calcium (Ca2+ recordings in neural progenitors and cardiac myocytes, but could be applied to a wide variety of biosensors employed in diverse cell types and organisms. In this method, network structures are analyzed by applying cross-correlation signal processing and graph theory to single-cell recordings. The goal of the analysis is to determine if the single cell activity constitutes a network of interconnected cells and to decipher the properties of this network. The method can be applied in many fields of biology in which biosensors are used to monitor signaling events in living cells. Analyzing intercellular communication in cell ensembles can reveal essential network structures that provide important biological insights.

  1. The state of the art in time-lapse seismic monitoring of heavy oil fields

    Energy Technology Data Exchange (ETDEWEB)

    Lines, Larry; Embleton, Joan [Chorus (Canada)

    2011-07-01

    Reservoir characterization is an essential tool for the maximization of heavy oil production. Characterization allows the changes occurring in the reservoir during production to be monitored. The current study demonstrates that time-lapse 3D seismology may be used to monitor these changes over time. When a reservoir change influences seismic velocity, changes in the subsurface may be assessed by time-lapse 3D seismology. Multiple factors (such as seismic noise, near-surface seasonal variations, or consistent acquisition and processing) affect the data acquired when using time-lapse 3D seismology to monitor heavy oil fields. The study shows how to circumvent these factors to obtain consistent and usable data. Using information such as well logs, Vp/Vs ratios from core samples and seismic data, it was demonstrated that time-lapse 3D seismology is a suitable characterization method for reservoir changes in heavy oil production.

  2. Lapse käsi Riigikogu käes / Aivar Jarne

    Index Scriptorium Estoniae

    Jarne, Aivar, 1965-

    2003-01-01

    Rahvastikuprobleemidega toimetulekuks peab kogu lääne kultuuripiirkond ja iga maa omaette mõtlema, kuidas stimuleerida sündimust, suurendada lapse väärtust perekonnas ja vanemate jaoks, tõdeb autor

  3. Construction of an 8-mm time-lapse camera for biological research

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the construction of an 8mm camera for biological research. A time-lapse camera for use in biological research can be constructed from a super...

  4. Discrimination between phase and amplitude attributes in time-lapse seismic streamer data

    NARCIS (Netherlands)

    Spetzler, J.; Kvam, O.

    2006-01-01

    Time-lapse seismic experiments aim to obtain information about production-related effects in hydrocarbon reservoirs to increase the recovery percentage. However, nonrepeatability problems such as acquisition differences, overburden effects, and noise are often significantly stronger than the imprint

  5. The issue of Time lapse in lawsuit Islamic Republic of Iran

    Directory of Open Access Journals (Sweden)

    Qaeme Naderi

    2013-02-01

    Full Text Available We know that between Workers and Employers claims are subject to the law Work, 1992 approved by the expediency council, according to Article 157 of the law above mentioned shall be investigated and resolved and specific and clarified administrative authorities called "delegations identify and resolve differences" as provided in the foregoing Articles, are assigned to handle such claims. But the question may be raised in this regards, Inclusion or exclusion time lapse is relative to is the above claims. Of this research can be very important in different directions and dimensions. In this research, first define the passage of time lapse and nature of the legal its and judicial and administrative enforcement of time lapse better investigated to improve the services we have. Then look at the importance of time lapse in the rules and regulations of Iran the legal system we have.

  6. Peeter Kreitzberg : võtame vaestelt lapsed ära! / Peeter Kreitzberg ; vahendas Helen Urbanik

    Index Scriptorium Estoniae

    Kreitzberg, Peeter, 1948-2011

    2001-01-01

    Intervjuu Keskerakonna presidendikandidaadi Peeter Kreitzbergiga : Peeter Kreitzbergi ettekanne konverentsil "Teine võimalus hariduses" sisaldas ettepanekut koguda probleemsete ja ebasoodsas keskkonnas elavate perekondade hooletusse jäetud lapsed riigi pansionidesse

  7. Coupled hydrogeophysical inversion using time-lapse magnetic resonance sounding and time-lapse gravity data for hydraulic aquifer testing: Will it work in practice?

    DEFF Research Database (Denmark)

    Herckenrath, Daan; Auken, Esben; Christiansen, Lars;

    2012-01-01

    Temporal changes in water content can be directly related to the time-lapse signals retrieved using magnetic resonance sounding (TL-MRS) and relative gravimetry (TL-RG). Previous studies suggest that TL-RG measurements can potentially provide accurate estimates of aquifer characteristics in an aq......Temporal changes in water content can be directly related to the time-lapse signals retrieved using magnetic resonance sounding (TL-MRS) and relative gravimetry (TL-RG). Previous studies suggest that TL-RG measurements can potentially provide accurate estimates of aquifer characteristics...

  8. History matching of time-lapse crosswell data using ensemble kalman filtering

    KAUST Repository

    de Matos Ravanelli, Fabio Miguel

    2015-09-03

    Data from crosswell seismic surveys is processed to provide crosswell time-lapse data to map fluid changes in a reservoir where time-lapse or 4D seismic data is unavailable or unreliable, such as in onshore reservoirs. The resultant processing results provide quantitative information for history matching purposes using a probabilistic approach to take in account uncertainties in the geological model and reduce uncertainties in reservoir production forecasts.

  9. First successful pregnancies following embryo selection using Time-lapse technology in Iran: Case report

    OpenAIRE

    Azita Faramarzi; Mohammad Ali Khalili; Mehrdad Soleimani

    2015-01-01

    Background: Embryo selection is a vital part of in vitro fertilization (IVF) programs, with morphology-based grading systems having been widely used for decades. Time-lapse imaging combined with embryo morph kinetics may proffer a non-invasive means for improving embryo selection. We report the first ongoing and chemical pregnancies using Time-lapse embryo scope to select best embryos for transfer in Iran. Cases: A case with tubal factor infertility was admitted to IVF program with normozo...

  10. Attention, Joint Attention, and Social Cognition

    OpenAIRE

    Mundy, Peter; Newell, Lisa

    2007-01-01

    Before social cognition there is joint processing of information about the attention of self and others. This joint attention requires the integrated activation of a distributed cortical network involving the anterior and posterior attention systems. In infancy, practice with the integrated activation of this distributed attention network is a major contributor to the development of social cognition. Thus, the functional neuroanatomies of social cognition and the anterior–posterior attention ...

  11. Estimation of atmospheric parameters from time-lapse imagery

    Science.gov (United States)

    McCrae, Jack E.; Basu, Santasri; Fiorino, Steven T.

    2016-05-01

    A time-lapse imaging experiment was conducted to estimate various atmospheric parameters for the imaging path. Atmospheric turbulence caused frame-to-frame shifts of the entire image as well as parts of the image. The statistics of these shifts encode information about the turbulence strength (as characterized by Cn2, the refractive index structure function constant) along the optical path. The shift variance observed is simply proportional to the variance of the tilt of the optical field averaged over the area being tracked. By presuming this turbulence follows the Kolmogorov spectrum, weighting functions can be derived which relate the turbulence strength along the path to the shifts measured. These weighting functions peak at the camera and fall to zero at the object. The larger the area observed, the more quickly the weighting function decays. One parameter we would like to estimate is r0 (the Fried parameter, or atmospheric coherence diameter.) The weighting functions derived for pixel sized or larger parts of the image all fall faster than the weighting function appropriate for estimating the spherical wave r0. If we presume Cn2 is constant along the path, then an estimate for r0 can be obtained for each area tracked, but since the weighting function for r0 differs substantially from that for every realizable tracked area, it can be expected this approach would yield a poor estimator. Instead, the weighting functions for a number of different patch sizes can be combined through the Moore-Penrose pseudo-inverse to create a new weighting function which yields the least-squares optimal linear combination of measurements for estimation of r0. This approach is carried out, and it is observed that this approach is somewhat noisy because the pseudo-inverse assigns weights much greater than one to many of the observations.

  12. How does blastomere removal affect embryonic development? : A time-lapse analysis

    DEFF Research Database (Denmark)

    Kirkegaard, Kirstine; Hindkjær, Johnny Juhl; Ingerslev, Hans Jakob

    of the 6-10 cell embryo. It has been argued that blastomere removal does not affect embryonic development, but few studies have focussed on safety of the procedure. Recently, time-lapse studies on mice have suggested that blastomere removal affects embryonic development. The present study was conducted...... to evaluate the effect of blastomere biopsy on early human embryonic development using time-lapse analysis. Materials and methods: Couples undergoing IVF treatment or PGD were requested permission to include embryos in the project. The diagnosis healthy/diseased was made by analysis of a single blastomere....... For PGD 56 human embryos were biopsied 68 hours after fertilisation, the majority at the eight cell stage. As controls 43 non-biopsied embryos at the 6-8 cell stage were selected. All embryos were cultured until 5 days after fertilisation in a time-lapse incubator (EmbryoScope™). Key events such as time...

  13. Using time-lapse gravity for groundwater model calibration: An application to alluvial aquifer storage

    DEFF Research Database (Denmark)

    Christiansen, Lars; Binning, Philip John; Rosbjerg, Dan;

    2011-01-01

    The estimation of hydrological model parameters by calibration to field data is a critical step in the modeling process. However, calibration often fails because of parameter correlation. Here it is shown that time-lapse gravity data can be combined with hydraulic head data in a coupled hydrogeop......The estimation of hydrological model parameters by calibration to field data is a critical step in the modeling process. However, calibration often fails because of parameter correlation. Here it is shown that time-lapse gravity data can be combined with hydraulic head data in a coupled...... shows that time-lapse gravity data are especially useful to constrain specific yield. Furthermore, we demonstrate that evapotranspiration, and riverbed conductance are better constrained by coupled inversion to gravity and head data than to head data alone. When estimating the four parameters...

  14. Physical activity adoption to adherence, lapse, and dropout: a self-determination theory perspective.

    Science.gov (United States)

    Kinnafick, Florence-Emilie; Thøgersen-Ntoumani, Cecilie; Duda, Joan L

    2014-05-01

    Grounded in Self-Determination Theory, we aimed to explore and identify key motivational processes involved in the transition from a physically inactive to an active lifestyle, and the processes involved in lapse and dropout behavior within a walking program. We implemented a qualitative, longitudinal case study method, using semistructured interviews and theoretical thematic analyses. Fifteen women were interviewed over 10 months and three profiles were generated: (a) nonadherence, (b) lapse/readoption of physical activity, and (c) adherence. Internalization of walking behavior was key to adherence. Satisfaction of the needs for competence and relatedness were central for participation during exercise at the adoption stages, and autonomy was particularly pertinent in facilitating adherence. Those who lapsed and restarted physical activity experienced feelings of autonomy at the point of readoption. Sources of support were driving forces in the adoption and adherence phases.

  15. Attention and Olfactory Consciousness

    OpenAIRE

    Keller, Andreas

    2011-01-01

    Understanding the relation between attention and consciousness is an important part of our understanding of consciousness. Attention, unlike consciousness, can be systematically manipulated in psychophysical experiments and a law-like relation between attention and consciousness is waiting to be discovered. Most attempts to discover the nature of this relation are focused on a special type of attention: spatial visual attention. In this review I want to introduce another type of attention to ...

  16. A non-strictly hyperbolic system for the Einstein equations with arbitrary lapse and shift

    CERN Document Server

    Abrahams, A M; Choquet-Bruhat, Y; York, J W; Abrahams, Andrew; Anderson, Arlen; Choquet-Bruhat, Yvonne; York, James W

    1996-01-01

    We obtain a system for the spatial metric and extrinsic curvature of a spacelike slice that is hyperbolic non-strict in the sense of Leray and Ohya and is equivalent to the Einstein equations. Its characteristics are the light cone and the normal to the slice for any choice of lapse and shift functions, and it admits a well-posed causal Cauchy problem in a Gevrey class of index \\alpha=2. The system becomes quasidiagonal hyperbolic if we posit a certain wave equation for the lapse function, and we can then relate the results to our previously obtained first order symmetric hyperbolic system for general relativity.

  17. Inter and intra-observer variability of time-lapse annotations

    DEFF Research Database (Denmark)

    Sundvall Germeys, Linda Karin M; Ingerslev, Hans Jakob; Knudsen, Ulla Breth;

    already: The commonly employed method used to assess embryos in IVF treatments is based on static evaluation of morphology in a microscope, but this is limited by substantial intra- and inter-observer variation. Time-lapse imaging has been proposed as a method to refine embryo selection by adding new......-lapse recordings. One observer performed the assessment twice. Twenty-five parameters were annotated and the inter- and intra-observer agreement was assessed by calculating Intra-class correlation coefficients (ICC). Main results and the role of chance: Extremely close agreement (ICC 0.99) was found for dynamic...

  18. Advances in interpretation of subsurface processes with time-lapse electrical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Singha, Kamini; Day-Lewis, Frederick D.; Johnson, Timothy C.; Slater, Lee D.

    2015-03-15

    Electrical geophysical methods, including electrical resistivity, time-domain induced polarization, and complex resistivity, have become commonly used to image the near subsurface. Here, we outline their utility for time-lapse imaging of hydrological, geochemical, and biogeochemical processes, focusing on new instrumentation, processing, and analysis techniques specific to monitoring. We review data collection procedures, parameters measured, and petrophysical relationships and then outline the state of the science with respect to inversion methodologies, including coupled inversion. We conclude by highlighting recent research focused on innovative applications of time-lapse imaging in hydrology, biology, ecology, and geochemistry, among other areas of interest.

  19. Determining changes in CO2 saturation from time-lapse measurements using ghost reflections retrieved by seismic interferometry

    NARCIS (Netherlands)

    Draganov, D.S.; Ghose, R.; Angelov, P.; Arts, R.

    2013-01-01

    One of the targets of time-lapse seismic monitoring of CO2 sequestration is to determine the parts of the reservoir reached by the injected CO2 and to estimate their saturation. Such information could be extracted from the time-lapse measurement using AVO or impedance information. But non-repeatabil

  20. Application of a linear finite-frequency theory to time-lapse crosswell tomography in ultrasonic and numerical experiments

    NARCIS (Netherlands)

    Spetzler, J.; Sijacic, D.; Wolf, K.H.A.A.

    2007-01-01

    Time-lapse seismic monitoring is the geophysical discipline whereby multiple data sets recorded at the same location but at different times are used to locate and quantify temporal changes in the elastic parameters of the subsurface. We validate a time-lapse monitoring method by crosswell tomography

  1. Snorre time-lapse feasibility study: increased repeatability through close co-operation between processing reservoir geophysicists

    NARCIS (Netherlands)

    Verhelst, F.J.P.C.M.G.; Smith, P.; Eidsvig, S.; Magnus, I.; Berg, J.I.; Helgesen, J.

    2002-01-01

    This paper discusses how an increased repeatability was obtained through a close co-operation between processing and reservoir geophysicists during the Snorre time-lapse feasibility study. Since the SG9701 dataset was not specifically designed for time-lapse purposes, the main aim of the "Full 4D" r

  2. Delayed Attentional Engagement in the Attentional Blink

    NARCIS (Netherlands)

    Nieuwenstein, Mark R.; Chun, Marvin M.; Lubbe, van der Rob H.J.; Hooge, Ignace T.C.

    2005-01-01

    Observers often miss the 2nd of 2 visual targets (first target [T1] and second target [T2]) when these targets are presented closely in time; the attentional blink (AB). The authors hypothesized that the AB occurs because the attentional response to T2 is delayed by T1 processing, causing T2 to lose

  3. 2D Time-lapse Seismic Tomography Using An Active Time Constraint (ATC) Approach

    Science.gov (United States)

    We propose a 2D seismic time-lapse inversion approach to image the evolution of seismic velocities over time and space. The forward modeling is based on solving the eikonal equation using a second-order fast marching method. The wave-paths are represented by Fresnel volumes rathe...

  4. Existence, uniqueness and other properties of the BCT (minimal strain lapse and shift) gauge

    CERN Document Server

    Garfinkle, D; Isenberg, J; Murchadha, N O; Garfinkle, David; Gundlach, Carsten; Isenberg, James; Murchadha, Niall O

    2000-01-01

    Brady, Creighton and Thorne have proposed a choice of the lapse and shift for numerical evolutions in general relativity that extremizes a measure of the rate of change of the three-metric (BCT gauge). We investigate existence and uniqueness of this gauge, and comment on its use in numerical time evolutions.

  5. Determination of Optimum Frame Rates for Observation of Construction Operations from Time-Lapse Movies

    Directory of Open Access Journals (Sweden)

    Y. M. Ibrahim

    2012-07-01

    Full Text Available Construction professionals have been using time-lapse movies in monitoring construction operations. However, some amount of detail is always lost in the interval between two consecutive frames in a time-lapse movie. This poses the question: By how much can the frame rate be lowered from the standard 30fps (frames per second to allow for the accurate observation of construction operations from a time-lapse movie? This paper addresses the problem by establishing the optimum frame rates for observation of activities related to mortar mixing and block handling. The activities were first recorded at the standard rate of 30fps. Using the Adobe Premier Pro video editing software, the records were then segregated into still images from which 15 different time-lapse movies of various time intervals were generated. The movies were then shown to 25 Construction Managers. A structured questionnaire was employed to capture the level of accuracy with which Construction Managers could interpret the job site situation from each movie. The results suggest that 1fpm (frame per minute is sufficient for the accurate tracking of labourers involved in mortar mixing while 1 frame in every 20 seconds is sufficient for accurate identification of number of cement bags used. However, for tracking number of blocks off-loaded, and those damaged, 1 frame in every 2 seconds is required.

  6. Lapse of time effects on tax evasion in an agent-based econophysics model

    Science.gov (United States)

    Seibold, Götz; Pickhardt, Michael

    2013-05-01

    We investigate an inhomogeneous Ising model in the context of tax evasion dynamics where different types of agents are parameterized via local temperatures and magnetic fields. In particular, we analyze the impact of lapse of time effects (i.e. backauditing) and endogenously determined penalty rates on tax compliance. Both features contribute to a microfoundation of agent-based econophysics models of tax evasion.

  7. First successful pregnancies following embryo selection using Time-lapse technology in Iran: Case report

    Directory of Open Access Journals (Sweden)

    Azita Faramarzi

    2015-03-01

    Full Text Available Background: Embryo selection is a vital part of in vitro fertilization (IVF programs, with morphology-based grading systems having been widely used for decades. Time-lapse imaging combined with embryo morph kinetics may proffer a non-invasive means for improving embryo selection. We report the first ongoing and chemical pregnancies using Time-lapse embryo scope to select best embryos for transfer in Iran. Cases: A case with tubal factor infertility was admitted to IVF program with normozoospermia. After ovarian hyper stimulation, 6 COCs were retrieved and inseminated with 25,000 progressive sperms/ oocyte. Five zygotes were placed individually into the micro wells of equilibrated embryo scope dish for Time-lapse observation, and incubated at 37°C, 5% CO2. On day 3, single embryo transfer (SET took place based on kinetic parameters of the embryos. Clinical pregnancy was confirmed 7 weeks after SET. The second case with history of previous ICSI failure was admitted with azoospermia. Nine MII oocytes underwent ICSI, and incubated in Time-lapse facilities. The rest of procedures were followed as described for case 1. Chemical pregnancy was confirmed 15 days after SET. Conclusion: This approach opens a way to select best embryo non-invasively for SET; thus, increasing implantation, while reducing multiple pregnancy complications.

  8. Calibrating vadose zone models with time-lapse gravity data: a forced infiltration experiment

    DEFF Research Database (Denmark)

    Christiansen, Lars; Hansen, Allan Bo; Zibar, Majken Caroline Looms;

    A change in soil water content is a change in mass stored in the subsurface, and when large enough, can be measured with a gravity meter. Over the last few decades there has been increased use of ground-based time-lapse gravity measurements to infer hydrogeological parameters. These studies have...

  9. Exploiting the airwave for time-lapse reservoir monitoring with CSEM on land

    NARCIS (Netherlands)

    Wirianto, M.; Mulder, W.A.; Slob, E.C.

    2011-01-01

    In the application of controlled source electromagnetics for reservoir monitoring on land, repeatability errors in the source will mask the time-lapse signal due to hydrocarbon production when recording surface data close to the source. We demonstrate that at larger distances, the airwave will still

  10. 37 CFR 1.317 - Lapsed patents; delayed payment of balance of issue fee.

    Science.gov (United States)

    2010-07-01

    ... payment of balance of issue fee. 1.317 Section 1.317 Patents, Trademarks, and Copyrights UNITED STATES... Processing Provisions Allowance and Issue of Patent § 1.317 Lapsed patents; delayed payment of balance of... is required at the time the issue fee is paid, any remaining balance of the issue fee is to be...

  11. Time-lapse misorientation maps for the analysis of electron backscatter diffraction data from evolving microstructures

    NARCIS (Netherlands)

    Wheeler, J.; Cross, A.; Drury, M.; Hough, R.M.; Mariani, E.; Piazolo, S.; Prior, D.J.

    2011-01-01

    A “time-lapse misorientation map” is defined here as a map which shows the orientation change at each point in an evolving crystalline microstructure between two different times. Electron backscatter diffraction data from in situ heating experiments can be used to produce such maps, which then highl

  12. Feasibility of monitoring gas hydrate production with time-lapse VSP

    Energy Technology Data Exchange (ETDEWEB)

    Kowalsky, M.B.; Nakagawa, S.; Moridis, G.J.

    2009-11-01

    In this work we begin to examine the feasibility of using time-lapse seismic methods-specifically the vertical seismic profiling (VSP) method-for monitoring changes in hydrate accumulations that are predicted to occur during production of natural gas.

  13. An Investigation of Relationships Among Question Level, Response Level and Lapse Time

    Science.gov (United States)

    Arnold, Daniel S.; And Others

    1973-01-01

    Studied relationships among questioning lapse time'' and the cognitive levels of teachers' questions and youngsters' responses, using Bloom's taxonomy and tape recordings in student teaching. Concluded that teachers' questions above the memory level could serve as a mechanism for promoting youngsters' learning at higher cognitive levels. (CC)

  14. Time-lapse motion picture technique applied to the study of geological processes

    Science.gov (United States)

    Miller, R.D.; Crandell, D.R.

    1959-01-01

    Light-weight, battery-operated timers were built and coupled to 16-mm motion-picture cameras having apertures controlled by photoelectric cells. The cameras were placed adjacent to Emmons Glacier on Mount Rainier. The film obtained confirms the view that exterior time-lapse photography can be applied to the study of slow-acting geologic processes.

  15. Developing an EEG based On-line Closed-loop Lapse Detection and Mitigation System

    Directory of Open Access Journals (Sweden)

    Yu-Te eWang

    2014-10-01

    Full Text Available In America, sixty percent of adults reported that they have driven a motor vehicle while feeling drowsy, and at least 15-20% of fatal car accidents are fatigue-related. This study translates previous laboratory-oriented neurophysiological research to design, develop, and test an On-line Closed-loop Lapse Detection and Mitigation (OCLDM System featuring a mobile wireless dry-sensor EEG headgear and a cell-phone based real-time EEG processing platform. Eleven subjects participated in an event-related lane-keeping task, in which they were instructed to manipulate a randomly deviated, fixed-speed cruising car on a 4-lane highway. This was simulated in a 1st person view with an 8-screen and 8-projector immersive virtual-realty environment. When the subjects experienced lapses or failed to respond to events during the experiment, auditory feedback was delivered to rectify the performance decrements. However, the arousing auditory signals were not always effective. The EEG spectra exhibited statistically significant differences between effective and ineffective arousing signals, suggesting that EEG spectra could be used as a countermeasure of the efficacy of arousing signals. In this on-line pilot study, the proposed OCLDM System was able to continuously detect EEG signatures of fatigue, deliver arousing feedback to subjects suffering momentary cognitive lapses, and assess the efficacy of the feedback in near real-time to rectify cognitive lapses. The on-line testing results of the OCLDM System validated the efficacy of the arousing signals in improving subjects' response times to the subsequent lane-departure events. This study may lead to a practical on-line lapse detection and mitigation system in real-world environments.

  16. EEG predictors of covert vigilant attention

    Science.gov (United States)

    Martel, Adrien; Dähne, Sven; Blankertz, Benjamin

    2014-06-01

    Objective. The present study addressed the question whether neurophysiological signals exhibit characteristic modulations preceding a miss in a covert vigilant attention task which mimics a natural environment in which critical stimuli may appear in the periphery of the visual field. Approach. Subjective, behavioural and encephalographic (EEG) data of 12 participants performing a modified Mackworth Clock task were obtained and analysed offline. The stimulus consisted of a pointer performing regular ticks in a clockwise sequence across 42 dots arranged in a circle. Participants were requested to covertly attend to the pointer and press a response button as quickly as possible in the event of a jump, a rare and random event. Main results. Significant increases in response latencies and decreases in the detection rates were found as a function of time-on-task, a characteristic effect of sustained attention tasks known as the vigilance decrement. Subjective sleepiness showed a significant increase over the duration of the experiment. Increased activity in the α-frequency range (8-14 Hz) was observed emerging and gradually accumulating 10 s before a missed target. Additionally, a significant gradual attenuation of the P3 event-related component was found to antecede misses by 5 s. Significance. The results corroborate recent findings that behavioural errors are presaged by specific neurophysiological activity and demonstrate that lapses of attention can be predicted in a covert setting up to 10 s in advance reinforcing the prospective use of brain-computer interface (BCI) technology for the detection of waning vigilance in real-world scenarios. Combining these findings with real-time single-trial analysis from BCI may pave the way for cognitive states monitoring systems able to determine the current, and predict the near-future development of the brain's attentional processes.

  17. Attention Mosaics: Studies of Organizational Attention

    OpenAIRE

    Carvalho de Mesquita Ferreira, Luciana

    2010-01-01

    textabstractOrganizational studies emphasizing the role of attention in organizational behavior depart from the idea that organizations, like individuals, have limited capacity to attend to environmental stimuli. The bounded capacity of the organizations to respond to stimuli is conditioned by the limited cognitions of individuals and by the limited capability of organizations to distribute, coordinate and integrate those cognitions. The cross-level nature of organizational attention, its dua...

  18. Visual attention capacity

    DEFF Research Database (Denmark)

    Habekost, Thomas; Starrfelt, Randi

    2009-01-01

    Psychophysical studies have identified two distinct limitations of visual attention capacity: processing speed and apprehension span. Using a simple test, these cognitive factors can be analyzed by Bundesen's Theory of Visual Attention (TVA). The method has strong specificity and sensitivity...

  19. Attention Breaks in Lectures

    Science.gov (United States)

    Johnstone, A. H.; Percival, F.

    1976-01-01

    Describes research into student attention patterns during lectures that suggests that student attention declines steadily during a lecture, and that the rate of decrease is dependent upon several variables including subject difficulty. (MLH)

  20. Using Digital Time-Lapse Videos to Teach Geomorphic Processes to Undergraduates

    Science.gov (United States)

    Clark, D. H.; Linneman, S. R.; Fuller, J.

    2004-12-01

    We demonstrate the use of relatively low-cost, computer-based digital imagery to create time-lapse videos of two distinct geomorphic processes in order to help students grasp the significance of the rates, styles, and temporal dependence of geologic phenomena. Student interviews indicate that such videos help them to understand the relationship between processes and landform development. Time-lapse videos have been used extensively in some sciences (e.g., biology - http://sbcf.iu.edu/goodpract/hangarter.html, meteorology - http://www.apple.com/education/hed/aua0101s/meteor/, chemistry - http://www.chem.yorku.ca/profs/hempsted/chemed/home.html) to demonstrate gradual processes that are difficult for many students to visualize. Most geologic processes are slower still, and are consequently even more difficult for students to grasp, yet time-lapse videos are rarely used in earth science classrooms. The advent of inexpensive web-cams and computers provides a new means to explore the temporal dimension of earth surface processes. To test the use of time-lapse videos in geoscience education, we are developing time-lapse movies that record the evolution of two landforms: a stream-table delta and a large, natural, active landslide. The former involves well-known processes in a controlled, repeatable laboratory experiment, whereas the latter tracks the developing dynamics of an otherwise poorly understood slope failure. The stream-table delta is small and grows in ca. 2 days; we capture a frame on an overhead web-cam every 3 minutes. Before seeing the video, students are asked to hypothesize how the delta will grow through time. The final time-lapse video, ca. 20-80 MB, elegantly shows channel migration, progradation rates, and formation of major geomorphic elements (topset, foreset, bottomset beds). The web-cam can also be "zoomed-in" to show smaller-scale processes, such as bedload transfer, and foreset slumping. Post-lab tests and interviews with students indicate that

  1. Attention Competition with Advertisement

    OpenAIRE

    Cetin, Uzay; Bingol, Haluk O.

    2012-01-01

    In the new digital age, information is available in large quantities. Since information consumes primarily the attention of its recipients, the scarcity of attention is becoming the main limiting factor. In this study, we investigate the impact of advertisement pressure on a cultural market where consumers have a limited attention capacity. A model of competition for attention is developed and investigated analytically and by simulation. Advertisement is found to be much more effective when a...

  2. Attention competition with advertisement

    Science.gov (United States)

    Cetin, Uzay; Bingol, Haluk O.

    2014-09-01

    In the new digital age, information is available in large quantities. Since information consumes primarily the attention of its recipients, the scarcity of attention is becoming the main limiting factor. In this study, we investigate the impact of advertisement pressure on a cultural market where consumers have a limited attention capacity. A model of competition for attention is developed and investigated analytically and by simulation. Advertisement is found to be much more effective when the attention capacity of agents is extremely scarce. We have observed that the market share of the advertised item improves if dummy items are introduced to the market while the strength of the advertisement is kept constant.

  3. Attention Alters Perceived Attractiveness.

    Science.gov (United States)

    Störmer, Viola S; Alvarez, George A

    2016-04-01

    Can attention alter the impression of a face? Previous studies showed that attention modulates the appearance of lower-level visual features. For instance, attention can make a simple stimulus appear to have higher contrast than it actually does. We tested whether attention can also alter the perception of a higher-order property-namely, facial attractiveness. We asked participants to judge the relative attractiveness of two faces after summoning their attention to one of the faces using a briefly presented visual cue. Across trials, participants judged the attended face to be more attractive than the same face when it was unattended. This effect was not due to decision or response biases, but rather was due to changes in perceptual processing of the faces. These results show that attention alters perceived facial attractiveness, and broadly demonstrate that attention can influence higher-level perception and may affect people's initial impressions of one another. PMID:26966228

  4. Time-lapse microgravity study of the Strengbach catchment (Vosges mountains, France)

    Science.gov (United States)

    Masson, Frédéric; Viville, Daniel; Pierret, Marie-Claire; Mouyen, Maxime; Hecker, Louis; Chabaux, François

    2012-06-01

    Time-lapse microgravity measurements can be used to monitor underground water storage changes. For the first time, this method has been applied to a relatively steeply sloped and forested watershed in a temperate climate. Spatial and temporal measurements were performed on the small granitic Strengbach catchment (Vosges Mountains, France) during the unusually dry spring of 2011. The survey consisted of 11 relative gravimeter measurements for 13 gravity stations from February to June 2011. Temporal variations are significantly different from one station to the other. Nevertheless, the variations have a clearly observable spatial consistency, which could be related to the climatology, the characteristics of the bedrocks and/or the topography. This preliminary result highlights the potential capacity of time-lapse microgravimetry in understanding and constraining the water mass movement within a complex watershed.

  5. Near-surface temperature lapse rates in a mountainous catchment in the Chilean Andes

    Science.gov (United States)

    Ayala; Schauwecker, S.; Pellicciotti, F.; McPhee, J. P.

    2011-12-01

    In mountainous areas, and in the Chilean Andes in particular, the irregular and sparse distribution of recording stations resolves insufficiently the variability of climatic factors such as precipitation, temperature and relative humidity. Assumptions about air temperature variability in space and time have a strong effect on the performance of hydrologic models that represent snow processes such as accumulation and ablation. These processes have large diurnal variations, and assumptions that average over longer time periods (days, weeks or months) may reduce the predictive capacity of these models under different climatic conditions from those for which they were calibrated. They also introduce large uncertainties when such models are used to predict processes with strong subdiurnal variability such as snowmelt dynamics. In many applications and modeling exercises, temperature is assumed to decrease linearly with elevation, using the free-air moist adiabatic lapse rate (MALR: 0.0065°C/m). Little evidence is provided for this assumption, however, and recent studies have shown that use of lapse rates that are uniform in space and constant in time is not appropriate. To explore the validity of this approach, near-surface (2 m) lapse rates were calculated and analyzed at different temporal resolution, based on a new data set of spatially distributed temperature sensors setup in a high elevation catchment of the dry Andes of Central Chile (approx. 33°S). Five minutes temperature data were collected between January 2011 and April 2011 in the Ojos de Agua catchment, using two Automatic Weather Stations (AWSs) and 13 T-loggers (Hobo H8 Pro Temp with external data logger), ranging in altitude from 2230 to 3590 m.s.l.. The entire catchment was snow free during our experiment. We use this unique data set to understand the main controls over temperature variability in time and space, and test whether lapse rates can be used to describe the spatial variations of air

  6. Attention Mosaics: Studies of Organizational Attention

    NARCIS (Netherlands)

    L. Carvalho de Mesquita Ferreira (Luciana)

    2010-01-01

    textabstractOrganizational studies emphasizing the role of attention in organizational behavior depart from the idea that organizations, like individuals, have limited capacity to attend to environmental stimuli. The bounded capacity of the organizations to respond to stimuli is conditioned by the l

  7. Analysis of the repeatability of time-lapse 3d vsp multicomponent surveys, delhi field

    Science.gov (United States)

    Carvalho, Mariana Fernandes de

    Delhi Field is a producing oil field located in northeastern Louisiana. In order to monitor the CO2 sweep efficiency, time-lapse 3D seismic data have been acquired in this area. Time-lapse studies are increasingly used to evaluate changes in the seismic response induced by the production of hydrocarbons or the injection of water, CO2 or steam into a reservoir. A 4D seismic signal is generated by a combination of production and injection effects within the reservoir as well as non-repeatability effects. In order to get reliable results from time-lapse seismic methods, it is important to distinguish the production and injection effects from the non-repeatability effects in the 4D seismic signal. Repeatability of 4D land seismic data is affected by several factors. The most significant of them are: source and receiver geometry inaccuracies, differences in seismic sources signatures, variations in the immediate near surface and ambient non-repeatable noise. In this project, two 3D multicomponent VSP surveys acquired in Delhi Field were used to quantify the relative contribution of each factor that can affect the repeatability in land seismic data. The factors analyzed in this study were: source and receiver geometry inaccura- cies, variations in the immediate near surface and ambient non-repeatable noise. This study showed that all these factors had a significant impact on the repeatability of the successive multicomponent VSP surveys in Delhi Field. This project also shows the advantages and disadvantages in the use of different repeata- bility metrics, normalized-root-mean-square (NRMS) difference and signal-to-distortion ratio (SDR) attribute, to evaluate the level of seismic repeatability between successive time-lapse seismic surveys. It is observed that NRMS difference is greatly influenced by time-shifts and that SDR attribute combined with the time-shift may give more distinct and representative repeatability information than the NRMS difference.

  8. Lapsed kapsapõldudel mehe eest väljas / Anne Oja

    Index Scriptorium Estoniae

    Oja, Anne, 1970-

    2006-01-01

    Kadarbiku talu peremees Ants Pak kasutab oma põldudel 8-12-aastaste laste tööd. Vt. samas: Vanemad tohivad lapsi tööle panna vaid oma tallu ja pereettevõttesse. Vt. samas Gert D Hankewitz interv. talu peremehe Ants Pakìga: Vanem ise sokutab lapse meile. Kommenteerivad Alar Tamm, Tarmo Kriis, Mailis Reps, Juhan Salum, Janno Järve, Aivo Tamm, Dmitri Jegorov ja Liivi Lents

  9. Evaluating four-dimensional time-lapse electrical resistivity tomography for monitoring DNAPL source zone remediation.

    Science.gov (United States)

    Power, Christopher; Gerhard, Jason I; Karaoulis, Marios; Tsourlos, Panagiotis; Giannopoulos, Antonios

    2014-07-01

    Practical, non-invasive tools do not currently exist for mapping the remediation of dense non-aqueous phase liquids (DNAPLs). Electrical resistivity tomography (ERT) exhibits significant potential but has not yet become a practitioner's tool due to challenges in interpreting the survey results at real sites. This study explores the effectiveness of recently developed four-dimensional (4D, i.e., 3D space plus time) time-lapse surface ERT to monitor DNAPL source zone remediation. A laboratory experiment demonstrated the approach for mapping a changing NAPL distribution over time. A recently developed DNAPL-ERT numerical model was then employed to independently simulate the experiment, providing confidence that the DNAPL-ERT model is a reliable tool for simulating real systems. The numerical model was then used to evaluate the potential for this approach at the field scale. Four DNAPL source zones, exhibiting a range of complexity, were initially simulated, followed by modeled time-lapse ERT monitoring of complete DNAPL remediation by enhanced dissolution. 4D ERT inversion provided estimates of the regions of the source zone experiencing mass reduction with time. Results show that 4D time-lapse ERT has significant potential to map both the outline and the center of mass of the evolving treated portion of the source zone to within a few meters in each direction. In addition, the technique can provide a reasonable, albeit conservative, estimate of the DNAPL volume remediated with time: 25% underestimation in the upper 2m and up to 50% underestimation at late time between 2 and 4m depth. The technique is less reliable for identifying cleanup of DNAPL stringers outside the main DNAPL body. Overall, this study demonstrates that 4D time-lapse ERT has potential for mapping where and how quickly DNAPL mass changes in real time during site remediation.

  10. Coupled Hydrogeophysical inversion for soil hydraulic property estimation from time-lapse geophysical data

    OpenAIRE

    Mboh, Cho Miltin

    2012-01-01

    Good knowledge of the hydraulic properties of the vadose zone is important for understanding water flow and solute transport processes therein. This can help to promote sustainable use and mitigate anthropogenic threats to soil and water resources. The use of time-lapse geophysical data to constrain our understanding of the flow and transport properties of the vadose zone is now well recognised. Conventional use of geophysical data to estimate the hydraulic properties of the vadose zone is ba...

  11. Calixarenes and cations: a time-lapse photography of the big-bang.

    Science.gov (United States)

    Casnati, Alessandro

    2013-08-01

    The outstanding cation complexation properties emerging from the pioneering studies on calixarene ligands during a five-year period in the early 1980s triggered a big-bang burst of publications on such macrocycles that is still lasting at a distance of more than 30 years. A time-lapse photography of this timeframe is proposed which allows the readers to pinpoint the contributions of the different research groups. PMID:23792898

  12. Time-lapse misorientation maps for the analysis of electron backscatter diffraction data from evolving microstructures

    International Nuclear Information System (INIS)

    A 'time-lapse misorientation map' is defined here as a map which shows the orientation change at each point in an evolving crystalline microstructure between two different times. Electron backscatter diffraction data from in situ heating experiments can be used to produce such maps, which then highlight areas of microstructural change and also yield statistics indicative of how far different types of boundary (with different misorientations) have moved.

  13. Convective damping of buoyancy anomalies and its effect on lapse rates in the tropical lower troposphere

    OpenAIRE

    Folkins, I.

    2005-01-01

    International audience In regions of the tropics undergoing active deep convection, the variation of lower tropospheric lapse rates (2.0 km to 5.2 km) with height is inconsistent with both reversible moist adiabatic and pseudoadiabatic assumptions. It is argued that this anomalous behavior arises from the tendency for the divergence of a convective buoyancy anomaly to be primarily offset by the collective divergence of other updrafts and downdrafts within one Rossby radius of deformation. ...

  14. Peeter Kreitzberg : võtame vaestelt lapsed ära! / Peeter Kreitzberg ; interv. Helen Urbanik

    Index Scriptorium Estoniae

    Kreitzberg, Peeter, 1948-2011

    2001-01-01

    Endine haridusminister tuli märtsi keskel konverentsil "Teine võimalus hariduses" välja ettepanekuga, et lastele peaks koolis käimine olema kohustuslik 18. eluaastani, riigi pansionidesse ja internaatidesse tuleks panna need lapsed, kelle pered ei jaksa neid üleval pidada. Autori täiendus 3. mai Eesti Ekspressi kirjade rubriigis (lk. A6) pealkirja all: Pakkusin vanematele võimalust, mitte vaeste laste konfiskeerimist. Autor: Keskerakond. Parlamendisaadik

  15. Principles of visual attention

    DEFF Research Database (Denmark)

    Bundesen, Claus; Habekost, Thomas

    The nature of attention is one of the oldest and most central problems in psychology. A huge amount of research has been produced on this subject in the last half century, especially on attention in the visual modality, but a general explanation has remained elusive. Many still view attention res....... The book explains the TVA model and shows how it accounts for attentional effects observed across all the research areas described. Principles of Visual Attention offers a uniquely integrated view on a central topic in cognitive neuroscience.......The nature of attention is one of the oldest and most central problems in psychology. A huge amount of research has been produced on this subject in the last half century, especially on attention in the visual modality, but a general explanation has remained elusive. Many still view attention...... research as a field that is fundamentally fragmented. This book takes a different perspective and presents a unified theory of visual attention: the TVA model. The TVA model explains the many aspects of visual attention by just two mechanisms for selection of information: filtering and pigeonholing...

  16. Confocal time lapse imaging as an efficient method for the cytocompatibility evaluation of dental composites.

    Science.gov (United States)

    Attik, Ghania Nina; Gritsch, Kerstin; Colon, Pierre; Grosgogeat, Brigitte

    2014-01-01

    It is generally accepted that in vitro cell material interaction is a useful criterion in the evaluation of dental material biocompatibility. The objective of this study was to use 3D CLSM time lapse confocal imaging to assess the in vitro biocompatibility of dental composites. This method provides an accurate and sensitive indication of viable cell rate in contact with dental composite extracts. The ELS extra low shrinkage, a dental composite used for direct restoration, has been taken as example. In vitro assessment was performed on cultured primary human gingival fibroblast cells using Live/Dead staining. Images were obtained with the FV10i confocal biological inverted system and analyzed with the FV10-ASW 3.1 Software. Image analysis showed a very slight cytotoxicity in the presence of the tested composite after 5 hours of time lapse. A slight decrease of cell viability was shown in contact with the tested composite extracts compared to control cells. The findings highlighted the use of 3D CLSM time lapse imaging as a sensitive method to qualitatively and quantitatively evaluate the biocompatibility behavior of dental composites.

  17. Efficiency of time-lapse intervals and simple baits for camera surveys of wild pigs

    Science.gov (United States)

    Williams, B.L.; Holtfreter, R.W.; Ditchkoff, S.S.; Grand, J.B.

    2011-01-01

    Growing concerns surrounding established and expanding populations of wild pigs (Sus scrofa) have created the need for rapid and accurate surveys of these populations. We conducted surveys of a portion of the wild pig population on Fort Benning, Georgia, to determine if a longer time-lapse interval than had been previously used in surveys of wild pigs would generate similar detection results. We concurrently examined whether use of soured corn at camera sites affected the time necessary for pigs to locate a new camera site or the time pigs remained at a site. Our results suggest that a 9-min time-lapse interval generated dependable detection results for pigs and that soured corn neither attracted pigs to a site any quicker than plain, dry, whole-kernel corn, nor held them at a site longer. Maximization of time-lapse interval should decrease data and processing loads, and use of a simple, available bait should decrease cost and effort associated with more complicated baits; combination of these concepts should increase efficiency of wild pig surveys. ?? 2011 The Wildlife Society.

  18. Aging, exercise, and attention.

    Science.gov (United States)

    Hawkins, H L; Kramer, A F; Capaldi, D

    1992-12-01

    The authors investigated the relationship among aging, attentional processes, and exercise in 2 experiments. First they examined age differences on 2 attentional tasks, a time-sharing task and an attentional flexibility task. Young adults alternated attention between 2 sequenced tasks more rapidly and time-shared the processing of 2 tasks more efficiently than older adults. They then investigated the effects of aerobic exercise on the same 2 attentional tasks in older adults. Following the 10-week exercise program, older exercisers showed substantially more improvement in alternation speed and time-sharing efficiency than older controls. Interestingly, this exercise effect was specific to dual-task processing. Both groups of subjects showed equivalent effects on single-task performance. These results indicate that aerobic exercise can exert a beneficial influence on the efficiency of at least 2 different attentional processes in older adults. PMID:1466833

  19. Dynamics of Media Attention

    CERN Document Server

    Traag, V A; Hicks, J; van Klinken, G

    2014-01-01

    Studies of human attention dynamics analyses how attention is focused on specific topics, issues or people. In online social media, there are clear signs of exogenous shocks, bursty dynamics, and an exponential or powerlaw lifetime distribution. We here analyse the attention dynamics of traditional media, focussing on co-occurrence of people in newspaper articles. The results are quite different from online social networks and attention. Different regimes seem to be operating at two different time scales. At short time scales we see evidence of bursty dynamics and fast decaying edge lifetimes and attention. This behaviour disappears for longer time scales, and in that regime we find Poissonian dynamics and slower decaying lifetimes. We propose that a cascading Poisson process may take place, with issues arising at a constant rate over a long time scale, and faster dynamics at a shorter time scale.

  20. Special Attention Network

    CERN Document Server

    Indekeu, J O

    2003-01-01

    In this Note a social network model for opinion formation is proposed in which a person connected to $q$ partners pays an {\\em attention} $1/q$ to each partner. The mutual attention between two connected persons $i$ and $j$ is taken equal to the geometric mean $1/\\sqrt{q_iq_j}$. Opinion is represented as usual by an Ising spin $s=\\pm 1$ and mutual attention is given through a two-spin coupling $J_{ij} = J Q/\\sqrt{q_iq_j}$, $Q$ being the average connectivity in the network. Connectivity diminishes attention and only persons with low connectivity can pay special attention to each other leading to a durable common (or opposing) opinion. The model is solved in "mean-field" approximation and a critical "temperature" $T_c$ proportional to $JQ$ is found, which is independent of the number of persons $N$, for large $N$.

  1. Attention and choice

    DEFF Research Database (Denmark)

    Orquin, Jacob Lund; Mueller Loose, Simone

    2013-01-01

    This paper reviews studies on eye movements in decision making, and compares their observations to theoretical predictions concerning the role of attention in decision making. Four decision theories are examined: rational models, bounded rationality, evidence accumulation, and parallel constraint...... satisfaction models. Although most theories were confirmed with regard to certain predictions, none of the theories adequately accounted for the role of attention during decision making. Several observations emerged concerning the drivers and down-stream effects of attention on choice, suggesting...... that these assumptions are implausible, and that more accurate assumptions could have been made based on prior attention and eye movement research. Future decision making research would benefit from greater integration with attention research....

  2. Attentional processes and meditation.

    Science.gov (United States)

    Hodgins, Holley S; Adair, Kathryn C

    2010-12-01

    Visual attentional processing was examined in adult meditators and non-meditators on behavioral measures of change blindness, concentration, perspective-shifting, selective attention, and sustained inattentional blindness. Results showed that meditators (1) noticed more changes in flickering scenes and noticed them more quickly, (2) counted more accurately in a challenging concentration task, (3) identified a greater number of alternative perspectives in multiple perspectives images, and (4) showed less interference from invalid cues in a visual selective attention task, but (5) did not differ on a measure of sustained inattentional blindness. Together, results show that regular meditation is associated with more accurate, efficient, and flexible visual attentional processing across diverse tasks that have high face validity outside of the laboratory. Furthermore, effects were assessed in a context separate from actual meditation practice, suggesting that meditators' better visual attention is not just immediate, but extends to contexts separate from meditation practice.

  3. Realtime infiltration process monitoring in macroporous soil - a plot-scale experiment accompanied by high-resolution time-lapse 3D GPR

    Science.gov (United States)

    Jackisch, Conrad; Allroggen, Niklas

    2016-04-01

    Infiltration and quick vertical redistribution of event water through rapid subsurface flow in soil structures is one of the key issues in hydrology. Although the importance of preferential flow is broadly recognised, our theories, observation techniques and modelling approaches lose grounds when the assumption of well-mixed states in REVs collapses. To characterise the combination of advective and diffusive flow is especially challenging. We have shown in earlier studies that a combination of TDR monitoring, dye- and salt-tracer recovery and time-lapse 3D GPR in irrigation experiments provides means to characterise infiltration dynamics at the plot- and hillslope-scale also in highly structured soils. We pinpointed that the spatial and temporal resolution requires special attention and improvement - particularly owing to the facts of high velocity (10‑3 ms‑1) of advective flow and small scale (10‑2 m) of the respective flow structures. We present insights from a novel technique of continuous high-resolution time-lapse 3D GPR measurements during and after a plot-scale (1 m x 1 m) irrigation experiment. Continuous TDR soil moisture measurements, dye tracer excavation and salt-tracer samples are used as qualitative and quantitative references. While classical infiltration experiments either look at spatial patterns or temporal dynamics at singular gauges, we highlight the advantage of combining both to achieve a more complete image of the infiltration process. Although operating at the limits of the techniques this setup enables non-invasive observation of preferential flow processes in the field and allows to explore and characterise macropore matrix exchange.

  4. Attention Deficit Hyperactivity Disorder

    Science.gov (United States)

    ... finish things? If so, your child may have attention deficit hyperactivity disorder (ADHD). Nearly everyone shows some of these behaviors at times, but ADHD lasts more than 6 months and causes problems ...

  5. Attention enhances feature integration.

    Science.gov (United States)

    Paul, Liza; Schyns, Philippe G

    2003-08-01

    Perceptual processing delays between attribute dimensions (e.g. color, form and motion) [Proceedings of the Royal Society of London Series B 264 (1997) 1407] have been attributed to temporal processing asynchronies resulting from functional segregation of visual information [Science 240 (1988) 740]. In addition, several lines of evidence converge to suggest that attention plays an important role in the integration of functionally processed information. However, exactly how attention modulates the temporal integration of information remains unclear. Here, we examined how attention modulates the integration of color and form into a unitary perception. Results suggest that attending to the location of an object enhances the integration of its defining attributes by speeding up the perceptual processing of each attribute dimension. Moreover, the perceptual asynchrony between attributes remains constant across attended and unattended conditions because attention seems to offer each processing dimension an equal processing advantage. PMID:12826102

  6. Lapsed, joonistama!

    Index Scriptorium Estoniae

    2003-01-01

    Päästeameti mõttest kutsuda kõiki päästeasutusi korraldama ühist laste loominguvõistlust. Konkursi eesmärk on anda lastele võimalus arutleda tuleohutuse üle ja propageerida päästetöötaja elukutset. Võistlustööd võivad olla joonistused, kollaazid, esseed või luuletused

  7. Time-lapse refraction seismic tomography for the detection of ground ice degradation

    Directory of Open Access Journals (Sweden)

    C. Hilbich

    2010-07-01

    Full Text Available The ice content of the subsurface is a major factor controlling the natural hazard potential of permafrost degradation in alpine terrain. Monitoring of changes in ice content is therefore similarly important as temperature monitoring in mountain permafrost. Although electrical resistivity tomography monitoring (ERTM proved to be a valuable tool for the observation of ice degradation, results are often ambiguous or contaminated by inversion artefacts. In theory, the sensitivity of P-wave velocity of seismic waves to phase changes between unfrozen water and ice is similar to the sensitivity of electric resistivity. Provided that the general conditions (lithology, stratigraphy, state of weathering, pore space remain unchanged over the observation period, temporal changes in the observed travel times of repeated seismic measurements should indicate changes in the ice and water content within the pores and fractures of the subsurface material. In this paper, a time-lapse refraction seismic tomography (TLST approach is applied as an independent method to ERTM at two test sites in the Swiss Alps. The approach was tested and validated based on a the comparison of time-lapse seismograms and analysis of reproducibility of the seismic signal, b the analysis of time-lapse travel time curves with respect to shifts in travel times and changes in P-wave velocities, and c the comparison of inverted tomograms including the quantification of velocity changes. Results show a high potential of the TLST approach concerning the detection of altered subsurface conditions caused by freezing and thawing processes. For velocity changes on the order of 3000 m/s even an unambiguous identification of significant ice loss is possible.

  8. Time-Lapse Electrical Geophysical Monitoring of Amendment-Based Biostimulation

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Timothy C.; Versteeg, Roelof; Day-Lewis, Frederick D.; Major, William; Lane, John W.

    2015-12-02

    Biostimulation is increasingly used to accelerate microbial remediation of recalcitrant groundwater contaminants. Effective application of biostimulation requires successful emplacement of amendment in the contaminant target zone. Verification of remediation performance requires postemplacement assessment and contaminant monitoring. Sampling based approaches are expensive and provide low-density spatial and temporal information. Time-lapse electrical resistivity tomography (ERT) is an effective geophysical method for determining temporal changes in subsurface electrical conductivity. Because remedial amendments and biostimulation-related biogeochemical processes often change subsurface electrical conductivity, ERT can complement and enhance sampling-based approaches for assessing emplacement and monitoring biostimulation-based remediation. Field studies demonstrating the ability of time-lapse ERT to monitor amendment emplacement and behavior were performed during a biostimulation remediation effort conducted at the Department of Defense Reutilization and Marketing Office (DRMO) Yard, in Brandywine, Maryland, United States. Geochemical fluid sampling was used to calibrate a petrophysical relation in order to predict groundwater indicators of amendment distribution. The petrophysical relations were field validated by comparing predictions to sequestered fluid sample results, thus demonstrating the potential of electrical geophysics for quantitative assessment of amendment-related geochemical properties. Crosshole radar zero-offset profile and borehole geophysical logging were also performed to augment the data set and validate interpretation. In addition to delineating amendment transport in the first 10 months after emplacement, the time-lapse ERT results show later changes in bulk electrical properties interpreted as mineral precipitation. Results support the use of more cost-effective surfacebased ERT in conjunction with limited field sampling to improve spatial

  9. Time-lapse 3D ground-penetrating radar during plot-scale infiltration experiments

    Science.gov (United States)

    Allroggen, Niklas; Jackisch, Conrad; Tronicke, Jens

    2016-04-01

    In electrical resistive soils, surface-based ground-penetrating radar (GPR) is known as the geophysical tool providing the highest spatial resolution. Thus, 2D and 3D GPR surveys are commonly used for imaging subsurface structures or estimating soil moisture content. Due to its sensitivity to soil moisture and its non-invasive character, GPR provides a large potential to monitor soil moisture variation at high temporal and spatial resolution. As shown in previous experiments, the acquisition of time-lapse GPR data under field conditions requires a high data quality in terms of repeatability as well as spatial and temporal resolution. We present hydrogeophysical field experiments at the plot scale (1m x 1m), during which we record time-lapse 3D GPR. For GPR data acquisition, we use a pulseEKKO PRO GPR system equipped with a pair of 500 MHz antennas in combination with a specially designed metal-free measuring platform. Additionally, we collect tracer and soil moisture data, which are used to improve the interpretation of the GPR data with special focus on preferential flow paths and their structured advective flow field. After an accurate time-lapse GPR data processing, we compare 3D reflection events before and after infiltration and quantitatively interpret their relative time-shift in terms of soil moisture variations. Thereby, we are able to account for basically all of the infiltrated water. The first experiments demonstrate the general applicability of our experimental approach but are limited by the number of acquired time steps and measurement during the sprinkling period (the time of the highest temporal dynamics) are not possible at all. Based on this experience we redesign our experimental setup to continuously collect GPR data during irrigation and infiltration. Thereby, we strongly increase the temporal resolution of our measurements, improve the interpretability of the GPR data, and monitor the temporal and spatial dynamics of shallow subsurface

  10. Time-lapse camera studies of sea-disposed chemical munitions in Hawaii

    Science.gov (United States)

    Edwards, Margo H.; Fornari, Daniel J.; Rognstad, Mark R.; Kelley, Christopher D.; Mah, Christopher L.; Davis, Logan K.; Flores, Kyle R. M.; Main, Erin L.; Bruso, Natalie L.

    2016-06-01

    The interactions between fauna and sea-disposed munitions provide important evidence regarding whether munitions constituents affect the health of the ocean environment and its inhabitants. To date few studies of these interactions have been conducted at deep-water disposal sites; typically observations of fauna in the vicinity of sea-disposed munitions are limited to the few minutes or hours required to collect physical samples at a specific location. During the 2012 Hawaii Undersea Military Munitions Assessment (HUMMA) field program we deployed two deep-sea time-lapse camera systems with the objectives of cataloging the diversity of fauna visiting sea-disposed chemical munitions and observing faunal behavior and physiology. Over the 1- and 3-day deployments we recorded 28 different species of fishes, crustaceans, mollusks, cnidarians, and echinoderms at the two sites. Both cameras captured the previously undocumented behavior of brisingid sea stars repositioning themselves along chemical munitions casings. Despite the fact that brisingid sea stars are able to move, for the duration of both time-lapse experiments they remained on chemical munitions casings. We interpret this result to indicate that the advantages of residing on a hard substrate slightly elevated above the seafloor outweigh the effects of chemical munitions constituents for brisingid sea stars. One type of physiological anomaly observed on several arms of the brisingid sea stars at the time-lapse sites led to the collection and examination of six specimens. As reported by Mah (2015. Deep Sea Res. II, 2015, XX-XX), these physiological features are the result of parasitic crustaceans and are not caused by chemical munitions constituents.

  11. High-Resolution Time-Lapse Monitoring of Unsaturated Flow using Automated GPR Data Collection

    Science.gov (United States)

    Mangel, A. R.; Moysey, S. M.; Lytle, B. A.; Bradford, J. H.

    2015-12-01

    High-resolution ground-penetrating radar (GPR) data provide the detailed information required to image subsurface structures. Recent advances in GPR monitoring now also make it possible to study transient hydrologic processes, but high-speed data acquisition is critical for this application. We therefore highlight the capabilities of our automated system to acquire time-lapse, high-resolution multifold GPR data during infiltration of water into soils. The system design allows for fast acquisition of constant-offset (COP) and common-midpoint profiles (CMP) to monitor unsaturated flow at multiple locations. Qualitative interpretation of the unprocessed COPs can provide substantial information regarding the hydrologic response of the system, such as the complexities of patterns associated with the wetting of the soil and geophysical evidence of non-uniform propagation of a wetting front. While we find that unprocessed images are informative, we show that the spatial variability of velocity introduced by infiltration events can complicate the images and that migration of the data is an effective tool to improve interpretability of the time-lapse images. The ability of the system to collect high density CMP data also introduces the potential for improving the velocity model along with the image via reflection tomography in the post-migrated domain. We show that for both simulated and empirical time-lapse GPR profiles we can resolve a propagating wetting front in the soil that is in good agreement with the response of in-situ soil moisture measurements. The data from these experiments illustrate the importance of high-speed, high-resolution GPR data acquisition for obtaining insight about the dynamics of hydrologic events. Continuing research is aimed at improving the quantitative analysis of surface-based GPR monitoring data for identifying preferential flow in soils.

  12. Sensitivity of MJO to the CAPE lapse time in the NCAR CAM3

    Energy Technology Data Exchange (ETDEWEB)

    LIU, P.; Wang, B.; Meehl, Gerald, A.

    2007-09-05

    Weak and irregular boreal winter MJO in the NCAR CAM3 corresponds to very low CAPE background, which is caused by easy-to-occur and over-dominant deep convection indicating the deep convective scheme uses either too low CAPE threshold as triggering function or too large consumption rate of CAPE to close the scheme. Raising the CAPE threshold from default 70 J/kg to ten times large only enhances the CAPE background while fails to noticeably improve the wind mean state and the MJO. However, lengthening the CAPE lapse time from one to eight hours significantly improved the background in CAPE and winds, and salient features of the MJO. Variances, dominant periods and zonal wave numbers, power spectra and coherent propagating structure in winds and convection associated with MJO are ameliorated and comparable to the observations. Lengthening the CAPE lapse time to eight hours reduces dramatically the cloud base mass flux, which prevents effectively the deep convection from occurring prematurely. In this case, partitioning of deep to shallow convection in MJO active area is about 5:4.5 compared to over 9:0.5 in the control run. Latent heat is significantly enhanced below 600 hPa over the central Indian Ocean and the western Pacific. Such partitioning of deep and shallow convection is argued necessary for simulating realistic MJO features. Although the universal eight hours lies in the upper limit of that required by the quasi-equilibrium theory, a local CAPE lapse time for the parameterized cumulus convection will be more realistic.

  13. Iconic memory requires attention

    OpenAIRE

    Persuh, Marjan; Genzer, Boris; Melara, Robert D.

    2012-01-01

    Two experiments investigated whether attention plays a role in iconic memory, employing either a change detection paradigm (Experiment 1) or a partial-report paradigm (Experiment 2). In each experiment, attention was taxed during initial display presentation, focusing the manipulation on consolidation of information into iconic memory, prior to transfer into working memory. Observers were able to maintain high levels of performance (accuracy of change detection or categorization) even when co...

  14. Switch Attention to Listen

    OpenAIRE

    Dhamani, Imran; Leung, Johahn; Carlile, Simon; Sharma, Mridula

    2013-01-01

    The aim of this research was to evaluate the ability to switch attention and selectively attend to relevant information in children (10–15 years) with persistent listening difficulties in noisy environments. A wide battery of clinical tests indicated that children with complaints of listening difficulties had otherwise normal hearing sensitivity and auditory processing skills. Here we show that these children are markedly slower to switch their attention compared to their age-matched peers. T...

  15. Adaptive visual attention model

    OpenAIRE

    Hügli, Heinz; Bur, Alexandre

    2009-01-01

    Visual attention, defined as the ability of a biological or artificial vision system to rapidly detect potentially relevant parts of a visual scene, provides a general purpose solution for low level feature detection in a vision architecture. Well considered for its universal detection behaviour, the general model of visual attention is suited for any environment but inferior to dedicated feature detectors in more specific environments. The goal of the development presented in this paper is t...

  16. Cognition, emotion, and attention.

    Science.gov (United States)

    Müller-Oehring, Eva M; Schulte, Tilman

    2014-01-01

    Deficits of attention, emotion, and cognition occur in individuals with alcohol abuse and addiction. This review elucidates the concepts of attention, emotion, and cognition and references research on the underlying neural networks and their compromise in alcohol use disorder. Neuroimaging research on adolescents with family history of alcoholism contributes to the understanding of pre-existing brain structural conditions and characterization of cognition and attention processes in high-risk individuals. Attention and cognition interact with other brain functions, including perceptual selection, salience, emotion, reward, and memory, through interconnected neural networks. Recent research reports compromised microstructural and functional network connectivity in alcoholism, which can have an effect on the dynamic tuning between brain systems, e.g., the frontally based executive control system, the limbic emotion system, and the midbrain-striatal reward system, thereby impeding cognitive flexibility and behavioral adaptation to changing environments. Finally, we introduce concepts of functional compensation, the capacity to generate attentional resources for performance enhancement, and brain structure recovery with abstinence. An understanding of the neural mechanisms of attention, emotion, and cognition will likely provide the basis for better treatment strategies for developing skills that enhance alcoholism therapy adherence and quality of life, and reduce the propensity for relapse. PMID:25307584

  17. Interocular conflict attracts attention.

    Science.gov (United States)

    Paffen, Chris L E; Hessels, Roy S; Van der Stigchel, Stefan

    2012-02-01

    During binocular rivalry, perception alternates.between dissimilar images presented dichoptically. Since.its discovery, researchers have debated whether the phenomenon is subject to attentional control. While it is now clear that attentional control over binocular rivalry is possible, the opposite is less evident: Is interocular conflict (i.e., the situation leading to binocular rivalry) able to attract attention?In order to answer this question, we used a change blindness paradigm in which observers looked for salient changes in two alternating frames depicting natural scenes. Each frame contained two images: one for the left and one for the right eye. Changes occurring in a single image (monocular) were detected faster than those occurring in both images (binocular). In addition,monocular change detection was also faster than detection in fused versions of the changed and unchanged regions. These results show that interocular conflict is capable of attracting attention, since it guides visual attention toward salient changes that otherwise would remain unnoticed for longer. The results of a second experiment indicated that interocular conflict attracts attention during the first phase of presentation, a phase during which the stimulus is abnormally fused [added]. PMID:22167536

  18. Using Student-Produced Time-Lapse Plant Movies to communicate concepts in Plant Biology †

    OpenAIRE

    Marcia Harrison-Pitaniello

    2013-01-01

    Why do students think plants are “boring”?  One factor may be that they do not see plant movement in real (i.e., their) time.  This attitude may negatively impact their understanding of plant biology.  Time-lapse movies of plants allow students to see the sophistication of movements involved in both organ development and orientation.  The objective of this project was to develop simple methods to capture image sequences for lab analysis and for converting into movies.  The technology for maki...

  19. A software solution for recording circadian oscillator features in time-lapse live cell microscopy

    Directory of Open Access Journals (Sweden)

    Salmon Patrick

    2010-07-01

    Full Text Available Abstract Background Fluorescent and bioluminescent time-lapse microscopy approaches have been successfully used to investigate molecular mechanisms underlying the mammalian circadian oscillator at the single cell level. However, most of the available software and common methods based on intensity-threshold segmentation and frame-to-frame tracking are not applicable in these experiments. This is due to cell movement and dramatic changes in the fluorescent/bioluminescent reporter protein during the circadian cycle, with the lowest expression level very close to the background intensity. At present, the standard approach to analyze data sets obtained from time lapse microscopy is either manual tracking or application of generic image-processing software/dedicated tracking software. To our knowledge, these existing software solutions for manual and automatic tracking have strong limitations in tracking individual cells if their plane shifts. Results In an attempt to improve existing methodology of time-lapse tracking of a large number of moving cells, we have developed a semi-automatic software package. It extracts the trajectory of the cells by tracking theirs displacements, makes the delineation of cell nucleus or whole cell, and finally yields measurements of various features, like reporter protein expression level or cell displacement. As an example, we present here single cell circadian pattern and motility analysis of NIH3T3 mouse fibroblasts expressing a fluorescent circadian reporter protein. Using Circadian Gene Express plugin, we performed fast and nonbiased analysis of large fluorescent time lapse microscopy datasets. Conclusions Our software solution, Circadian Gene Express (CGE, is easy to use and allows precise and semi-automatic tracking of moving cells over longer period of time. In spite of significant circadian variations in protein expression with extremely low expression levels at the valley phase, CGE allows accurate and

  20. Moist-entropic vertical adiabatic lapse rates: the standard cases and some lead towards inhomogeneous conditions

    CERN Document Server

    Geleyn, Jean-François

    2014-01-01

    Adiabatic lapse rates $\\Gamma_{ns}$ and $\\Gamma_{sw}$ are derived in Marquet and Geleyn (2013) for non-saturated ($\\Gamma_{ns}$) or saturated ($\\Gamma_{sw}$) parcel of moist-air. They are computed in terms of the vertical derivative of the moist-air entropy potential temperature $\\theta_s$ defined in Marquet (2011). The saturated value $\\Gamma_{sw}$ is rewritten in this note so that a more compact formulation is obtained. The new formulation for $\\Gamma_{sw}$ is expressed in term of a weighting factor $C$. This factor may represent the proportion of an air parcel being in saturated conditions.

  1. Quantification of erosion and sedimentation using time-lapse gravimetry and Lidar in southern Taiwan

    Science.gov (United States)

    Mouyen, Maxime; Steer, Philippe; Croissant, Thomas; Le Moigne, Nicolas; Hwang, Cheinway; Cheng, Ching-Chung; Masson, Frédéric; Davy, Philippe; Lague, Dimitri; Longuevergne, Laurent

    2016-04-01

    After the 2009 Morakot typhoon, which triggered numerous large landslides in Taiwan, Mouyen et al. (2013) showed for the first time the potential of time-lapse gravity survey to infer the mass of sediments transferring by landsliding or through rivers. By providing an integrated measurement of masses, gravimetry might thus be complementary to common methods used to assess the sediments discharge of rivers. But the masses of rocks displaced by Morakot were exceptionally large as a result of the record-breaking rainfalls brought by this typhoon and one might wonder to what extent time-lapse gravimetry could record such sediment transfers. In order to better assess the capabilities of this method, we set a time-lapse gravity network dedicated to the monitoring of such sediments transfers in Paolai village (south-central Taiwan). Paolai is located near the large Laonong river where temporary alluvial deposits of sediments exist and face steep mountain slopes likely to experience landslides. Both features are considered as potential source of mass transfers, and in turn of temporal gravity changes. The first base gravity measurements were done in November 2015, using absolute and relative gravimeters, and will be repeated every year, before and after the typhoon season. In the same time, we also use a terrestrial lidar to scan the geometry of both the river and the mountain slopes, hence providing a detailed topographical survey of the studied area. Adding Lidar measurements is an efficient strategy to solve for the non-uniqueness of gravity solutions. Meanwhile, we use the Eros morphodynamic model, that combine landsliding and flooding models, to investigate various scenarios of landsliding and subsequent sediment transport and compute the gravity changes on a virtual network of gravimeters. This gives us insights on the expected order of magnitudes for these surface sediment transfers, which are useful to unravel the induced gravity signal from others sources such as

  2. Sea-floor-mounted rotating side-scan sonar for making time-lapse sonographs

    Science.gov (United States)

    Rubin, David M.; McCulloch, David S.; Hill, H. R.

    1983-01-01

    A rotating side-scan sonar system was designed to make time-lapse sonographs of a circular area of the sea floor. To construct the system, the transducers of a commercial side-scan system (frequency 105 kHz; pulse length 0.1 ms; horizontal beam width 1°; vertical beam width 20°; beam depressed 10° with respect to horizontal) were mounted 2 m above the sea floor on a vertical shaft that had a rotation speed of 0.5 rpm.

  3. Soil Contamination, Advanced integrated characterisation and time-lapse Monitoring, SoilCAM project highlights

    Science.gov (United States)

    French, H. K.; Van Der Zee, S. E.; Wehrer, M.; Godio, A.; Pedersen, L. B.; Tsocano, G.

    2013-12-01

    The SoilCAM project (2008- 2012, EU-FP7-212663) aimed at improving methods for monitoring subsurace contaminant distribution and biodegradation. Two test sites were chosen, Oslo airport Gardermoen, Norway where de-icing agents infiltrate the soil during snowmelt and the Trecate site in Italy where an inland crude oil spill occurred in 1994. A number of geophysical investigation techniques were combined with soil and water sampling techniques. Data obtained from time-lapse measurements were further analysed by numerical modelling of flow and transport at different scales in order to characterise transport processes in the unsaturated and saturated zones. Laboratory experiments provided physical and biogeochemical data for model parameterisation and to select remediation methods. The geophysical techniques were used to map geological heterogeneities and to conduct time-lapse measurements of processes in the unsaturated zone. Both cross borehole and surface electrodes were used for electrical resistivity and induced polarisation surveys. Results showed clear indications of areas highly affected by de-icing chemicals along the runway at Oslo airport. The time lapse measurements along the runway at the airport showed infiltration patterns during snowmelt and were used to validate 2D unsaturated flow and transport simulations using SUTRA. The simulations illustrate the effect of layering geological structures and membranes, buried parallel to the runway, on the flow pattern. Complex interaction between bio-geo-chemical processes in a 1D vertical profile along the runway were described with the ORCHESTRA model. Smaller scale field site measurements revealed increase of iron and manganese during degradation of de-icing chemicals. At the Trecate site a combination of georadar, electrical resistivity and radio magneto telluric provided a broad outline of the geology down to 50 m. Anomalies in the Induced polarisation and electrical resistivity data from the cross borehole

  4. Selective Attention and Attention Switching: Towards a Unified Developmental Approach

    Science.gov (United States)

    Hanania, Rima; Smith, Linda B.

    2010-01-01

    We review and relate two literatures on the development of attention in children: one concerning flexible attention switching and the other concerning selective attention. The first is a growing literature on preschool children's performances in an attention-switching task indicating that children become more flexible in their attentional control…

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-11-01

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

  6. Fluorescence Time-lapse Imaging of the Complete S. venezuelae Life Cycle Using a Microfluidic Device.

    Science.gov (United States)

    Schlimpert, Susan; Flärdh, Klas; Buttner, Mark

    2016-01-01

    Live-cell imaging of biological processes at the single cell level has been instrumental to our current understanding of the subcellular organization of bacterial cells. However, the application of time-lapse microscopy to study the cell biological processes underpinning development in the sporulating filamentous bacteria Streptomyces has been hampered by technical difficulties. Here we present a protocol to overcome these limitations by growing the new model species, Streptomyces venezuelae, in a commercially available microfluidic device which is connected to an inverted fluorescence widefield microscope. Unlike the classical model species, Streptomyces coelicolor, S. venezuelae sporulates in liquid, allowing the application of microfluidic growth chambers to cultivate and microscopically monitor the cellular development and differentiation of S. venezuelae over long time periods. In addition to monitoring morphological changes, the spatio-temporal distribution of fluorescently labeled target proteins can also be visualized by time-lapse microscopy. Moreover, the microfluidic platform offers the experimental flexibility to exchange the culture medium, which is used in the detailed protocol to stimulate sporulation of S. venezuelae in the microfluidic chamber. Images of the entire S. venezuelae life cycle are acquired at specific intervals and processed in the open-source software Fiji to produce movies of the recorded time-series. PMID:26967231

  7. Time-Lapse Electrical Resistivity Investigations for Imaging the Grouting Injection in Shallow Subsurface Cavities

    Directory of Open Access Journals (Sweden)

    Muhammad Farooq

    2014-01-01

    Full Text Available The highway of Yongweol-ri, Muan-gun, south-western part of the South Korean Peninsula, is underlain by the abandoned of subsurface cavities, which were discovered in 2005. These cavities lie at shallow depths with the range of 5∼15 meters below the ground surface. Numerous subsidence events have repeatedly occurred in the past few years, damaging infrastructure and highway. As a result of continuing subsidence issues, the Korean Institute of Geosciences and Mineral Resources (KIGAM was requested by local administration to resolve the issue. The KIGAM used geophysical methods to delineate subsurface cavities and improve more refined understanding of the cavities network in the study area. Cement based grouting has been widely employed in the construction industry to reinforce subsurface ground. In this research work, time-lapse electrical resistivity surveys were accomplished to monitor the grouting injection in the subsurface cavities beneath the highway, which have provided a quasi-real-time monitoring for modifying the subsurface cavities related to ground reinforcement, which would be difficult with direct methods. The results obtained from time-lapse electrical resistivity technique have satisfactory imaged the grouting injection experiment in the subsurface cavities beneath the highway. Furthermore, the borehole camera confirmed the presence of grouting material in the subsurface cavities, and hence this procedure increases the mechanical resistance of subsurface cavities below the highway.

  8. Using a time lapse microgravity model for mapping seawater intrusion around Semarang

    Science.gov (United States)

    Supriyadi, Khumaedi, Yusuf, M.; Agung, W.

    2016-03-01

    A modeling of time-lapse microgravity anomaly due to sea water intrusion has been conducted. It used field data of aquifer cross section, aquifer thickness and lithology of research area. Those data were then processed using Grav3D and Surfer. Modeling results indicated that the intrusion of sea water resulting in a time-lapse microgravity anomalies of 0.12 to 0.18 mGal, at soil layer density of 0.15 g/cm3 to 0.3 g/cm3 and at depth of 30 to 100 m. These imply that the areas experiencing seawater intrusion were Tanjung Mas, SPBE Bandarharjo, Brass, Old Market Boom and Johar as the microgravity measured there were in the range of 0.12 to 0.18 mGal and the density contrast were at 0.15 g/cm3 to 0.28 g/cm3. Areas that experienced fluid reduction were Puri Anjasmoro, Kenconowungu and Puspowarno with microgravity changes from -0.06 mGal to -0.18 mGal.

  9. Numerical studies of imaging subsurface waterfloods using CSERT with time-lapse inversion

    Science.gov (United States)

    Zhang, Ying-Ying; Liu, De-Jun; Wang, Li-Yang; Ai, Qing-Hui; Qin, Min-Jun

    2015-12-01

    During the operation of the waterflooding technique, it is necessary to identify the waterflooding areas to enhance oil displacement efficiency. A casing-surface electrical resistivity tomography (CSERT) system using a well casing as a long electrode is able to detect a wide lateral scope, but its vertical resolution and ability to identify deep anomalies in the reservoir are limited, particularly for reservoirs with high-conductivity anomalies in the shallow subsurface, which disturb the response from the water floods at depth. In this study, we first simplified this kind of reservoir into a dual layered anomaly model. Then the log-inject-log method with time-lapse inversion was proposed and evaluated regarding its ability to improve the imaging of the deep waterflooding areas and the shallow anomaly. The results were compared with the commonly used static measurement with static inversion. In the static inversion results, the shallow anomaly was imaged well but the deep anomaly was unobservable. The results of the proposed log-inject-log method with time-lapse inversion showed that it is able to identify the shallow and deep anomalies better under various conditions, thus validating its ability to improve the vertical resolution of the CSERT system.

  10. Focused time-lapse inversion of radio and audio magnetotelluric data

    Science.gov (United States)

    Rosas Carbajal, Marina; Linde, Niklas; Kalscheuer, Thomas

    2012-09-01

    Geoelectrical techniques are widely used to monitor groundwater processes, while surprisingly few studies have considered audio (AMT) and radio (RMT) magnetotellurics for such purposes. In this numerical investigation, we analyze to what extent inversion results based on AMT and RMT monitoring data can be improved by (1) time-lapse difference inversion; (2) incorporation of statistical information about the expected model update (i.e., the model regularization is based on a geostatistical model); (3) using alternative model norms to quantify temporal changes (i.e., approximations of l1 and Cauchy norms using iteratively reweighted least-squares), (4) constraining model updates to predefined ranges (i.e., using Lagrange Multipliers to only allow either increases or decreases of electrical resistivity with respect to background conditions). To do so, we consider a simple illustrative model and a more realistic test case related to seawater intrusion. The results are encouraging and show significant improvements when using time-lapse difference inversion with non l2 model norms. Artifacts that may arise when imposing compactness of regions with temporal changes can be suppressed through inequality constraints to yield models without oscillations outside the true region of temporal changes. Based on these results, we recommend approximate l1-norm solutions as they can resolve both sharp and smooth interfaces within the same model.

  11. An Analytical Formula for Potential Water Vapor in an Atmosphere of Constant Lapse Rate

    Directory of Open Access Journals (Sweden)

    Ali Varmaghani

    2012-01-01

    Full Text Available Accurate calculation of precipitable water vapor (PWV in the atmosphere has always been a matter of importance for meteorologists. Potential water vapor (POWV or maximum precipitable water vapor can be an appropriate base for estimation of probable maximum precipitation (PMP in an area, leading to probable maximum flood (PMF and flash flood management systems. PWV and POWV have miscellaneously been estimated by means of either discrete solutions such as tables, diagrams or empirical methods; however, there is no analytical formula for POWV even in a particular atmospherical condition. In this article, fundamental governing equations required for analytical calculation of POWV are first introduced. Then, it will be shown that this POWV calculation relies on a Riemann integral solution over a range of altitude whose integrand is merely a function of altitude. The solution of the integral gives rise to a series function which is bypassed by approximation of saturation vapor pressure in the range of -55 to 55 degrees Celsius, and an analytical formula for POWV in an atmosphere of constant lapse rate is proposed. In order to evaluate the accuracy of the suggested equation, exact calculations of saturated adiabatic lapse rate (SALR at different surface temperatures were performed. The formula was compared with both the diagrams from the US Weather Bureau and SALR. The results demonstrated unquestionable capability of analytical solutions and also equivalent functions.

  12. Time-lapse electrical resistivity investigations for imaging the grouting injection in shallow subsurface cavities.

    Science.gov (United States)

    Farooq, Muhammad; Park, Samgyu; Kim, Jung Ho; Song, Young Soo; Amjad Sabir, Mohammad; Umar, Muhammad; Tariq, Mohammad; Muhammad, Said

    2014-01-01

    The highway of Yongweol-ri, Muan-gun, south-western part of the South Korean Peninsula, is underlain by the abandoned of subsurface cavities, which were discovered in 2005. These cavities lie at shallow depths with the range of 5∼15 meters below the ground surface. Numerous subsidence events have repeatedly occurred in the past few years, damaging infrastructure and highway. As a result of continuing subsidence issues, the Korean Institute of Geosciences and Mineral Resources (KIGAM) was requested by local administration to resolve the issue. The KIGAM used geophysical methods to delineate subsurface cavities and improve more refined understanding of the cavities network in the study area. Cement based grouting has been widely employed in the construction industry to reinforce subsurface ground. In this research work, time-lapse electrical resistivity surveys were accomplished to monitor the grouting injection in the subsurface cavities beneath the highway, which have provided a quasi-real-time monitoring for modifying the subsurface cavities related to ground reinforcement, which would be difficult with direct methods. The results obtained from time-lapse electrical resistivity technique have satisfactory imaged the grouting injection experiment in the subsurface cavities beneath the highway. Furthermore, the borehole camera confirmed the presence of grouting material in the subsurface cavities, and hence this procedure increases the mechanical resistance of subsurface cavities below the highway. PMID:24578621

  13. Long-term time-lapse microscopy of C. elegans post-embryonic development.

    Science.gov (United States)

    Gritti, Nicola; Kienle, Simone; Filina, Olga; van Zon, Jeroen Sebastiaan

    2016-01-01

    We present a microscopy technique that enables long-term time-lapse microscopy at single-cell resolution in moving and feeding Caenorhabditis elegans larvae. Time-lapse microscopy of C. elegans post-embryonic development is challenging, as larvae are highly motile. Moreover, immobilization generally leads to rapid developmental arrest. Instead, we confine larval movement to microchambers that contain bacteria as food, and use fast image acquisition and image analysis to follow the dynamics of cells inside individual larvae, as they move within each microchamber. This allows us to perform fluorescence microscopy of 10-20 animals in parallel with 20 min time resolution. We demonstrate the power of our approach by analysing the dynamics of cell division, cell migration and gene expression over the full ∼48 h of development from larva to adult. Our approach now makes it possible to study the behaviour of individual cells inside the body of a feeding and growing animal. PMID:27558523

  14. Noise-free accurate count of microbial colonies by time-lapse shadow image analysis.

    Science.gov (United States)

    Ogawa, Hiroyuki; Nasu, Senshi; Takeshige, Motomu; Funabashi, Hisakage; Saito, Mikako; Matsuoka, Hideaki

    2012-12-01

    Microbial colonies in food matrices could be counted accurately by a novel noise-free method based on time-lapse shadow image analysis. An agar plate containing many clusters of microbial colonies and/or meat fragments was trans-illuminated to project their 2-dimensional (2D) shadow images on a color CCD camera. The 2D shadow images of every cluster distributed within a 3-mm thick agar layer were captured in focus simultaneously by means of a multiple focusing system, and were then converted to 3-dimensional (3D) shadow images. By time-lapse analysis of the 3D shadow images, it was determined whether each cluster comprised single or multiple colonies or a meat fragment. The analytical precision was high enough to be able to distinguish a microbial colony from a meat fragment, to recognize an oval image as two colonies contacting each other, and to detect microbial colonies hidden under a food fragment. The detection of hidden colonies is its outstanding performance in comparison with other systems. The present system attained accuracy for counting fewer than 5 colonies and is therefore of practical importance.

  15. Attention in Urban Foraging

    Directory of Open Access Journals (Sweden)

    Malcolm McCullough

    2013-05-01

    Full Text Available This position paper argues how there has to be much more to smart city learning than just wayshowing, and something better as augmented reality than covering the world with instructions. Attention has become something for many people to know better in an age of information superabundance. Embodied cognition explains how the work-ings of attention are not solely a foreground task, as if attention is something to pay. As digital media appear in ever more formats and contexts, their hybrids with physical form increasing influence how habitual engagement with persistent situations creates learning. Ambient information can just add to the distraction by multitasking, or it can support more favorable processes of shifting among different kinds of information with a particular intent. As one word for this latter process, foraging deserves more consideration in smart city learning

  16. Time-lapse seismic waveform modelling and attribute analysis using hydromechanical models for a deep reservoir undergoing depletion

    Science.gov (United States)

    He, Y.-X.; Angus, D. A.; Blanchard, T. D.; Wang, G.-L.; Yuan, S.-Y.; Garcia, A.

    2016-04-01

    Extraction of fluids from subsurface reservoirs induces changes in pore pressure, leading not only to geomechanical changes, but also perturbations in seismic velocities and hence observable seismic attributes. Time-lapse seismic analysis can be used to estimate changes in subsurface hydromechanical properties and thus act as a monitoring tool for geological reservoirs. The ability to observe and quantify changes in fluid, stress and strain using seismic techniques has important implications for monitoring risk not only for petroleum applications but also for geological storage of CO2 and nuclear waste scenarios. In this paper, we integrate hydromechanical simulation results with rock physics models and full-waveform seismic modelling to assess time-lapse seismic attribute resolution for dynamic reservoir characterization and hydromechanical model calibration. The time-lapse seismic simulations use a dynamic elastic reservoir model based on a North Sea deep reservoir undergoing large pressure changes. The time-lapse seismic traveltime shifts and time strains calculated from the modelled and processed synthetic data sets (i.e. pre-stack and post-stack data) are in a reasonable agreement with the true earth models, indicating the feasibility of using 1-D strain rock physics transform and time-lapse seismic processing methodology. Estimated vertical traveltime shifts for the overburden and the majority of the reservoir are within ±1 ms of the true earth model values, indicating that the time-lapse technique is sufficiently accurate for predicting overburden velocity changes and hence geomechanical effects. Characterization of deeper structure below the overburden becomes less accurate, where more advanced time-lapse seismic processing and migration is needed to handle the complex geometry and strong lateral induced velocity changes. Nevertheless, both migrated full-offset pre-stack and near-offset post-stack data image the general features of both the overburden and

  17. Robust joint full-waveform inversion of time-lapse seismic data sets with total-variation regularization

    CERN Document Server

    Maharramov, Musa

    2014-01-01

    We present a technique for reconstructing subsurface velocity model changes from time-lapse seismic survey data using full-waveform inversion (FWI). The technique is based on simultaneously inverting multiple survey vintages, with model difference regularization using the total variation (TV) seminorm. We compare the new TV-regularized time-lapse FWI with the $L_2$-regularized joint inversion proposed in our earlier work, using synthetic data sets that exhibit survey repeatability issues. The results demonstrate clear advantages of the proposed TV-regularized joint inversion over alternatives methods for recovering production-induced model changes that are due to both fluid substitution and geomechanical effects.

  18. Bayesian Markov chain Monte Carlo Inversion of Time-Lapse Geophysical Data To Characterize the Vadose Zone

    DEFF Research Database (Denmark)

    Scholer, Marie; Irving, James; Zibar, Majken Caroline Looms;

    Geophysical methods have the potential to provide valuable information on hydrological properties in the unsaturated zone. In particular, time-lapse geophysical data, when coupled with a hydrological model and inverted stochastically, may allow for the effective estimation of subsurface hydraulic...... parameters and their corresponding uncertainties. In this study, we use a Bayesian Markov-chain-Monte-Carlo (MCMC) inversion approach to investigate how much information regarding vadose zone hydraulic properties can be retrieved from time-lapse crosshole GPR data collected at the Arrenaes field site...

  19. Selected time-lapse movies of the east rift zone eruption of KĪlauea Volcano, 2004–2008

    Science.gov (United States)

    Orr, Tim R.

    2011-01-01

    Since 2004, the U.S. Geological Survey's Hawaiian Volcano Observatory has used mass-market digital time-lapse cameras and network-enabled Webcams for visual monitoring and research. The 26 time-lapse movies in this report were selected from the vast collection of images acquired by these camera systems during 2004–2008. Chosen for their content and broad aesthetic appeal, these image sequences document a variety of flow-field and vent processes from Kīlauea's east rift zone eruption, which began in 1983 and is still (as of 2011) ongoing.

  20. Attention and Distraction

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    2010-01-01

    This article aims to examine the interrelationship between attention and distraction in the reception of video installation art, a genre which is commonly associated with "immersion" and an intensified feeling of presence in the discourses on new media art and installation art. This tends to veil...

  1. Phase lapses in open quantum systems and the non-Hermitian Hamilton operator

    International Nuclear Information System (INIS)

    We study transmission through a system with N=10 states coupled to K=2 continua of scattering wave functions in the framework of the S matrix theory by using the Feshbach projection operator formalism for open quantum systems. Due to the coupling of the system (being localized in space) to the (extended) continuum of scattering wave functions, the Hamilton operator Heff of the system is non-Hermitian. The numerical calculations are performed for different distributions of both the positions Ei0 (i=1,...,N) of the states of the isolated (closed) system and the elements of the coupling vectors Vc between system and continua (c=1,...,K). The overall coupling strength α simulating the degree of resonance overlapping, is used as a parameter. In all cases, the complex eigenvalues and eigenfunctions of Heff are controlled by α. In the regime of overlapping resonances, the well-known spectroscopic reordering processes (resonance trapping) take place because the phases of the eigenfunctions of Heff are not rigid in the neighborhood of singular points (being crossing points of eigenvalue trajectories). Finally, width bifurcation generates K=2 short-lived and N-K trapped long-lived states. Thus, narrow (Fano-like) resonances may appear in the transmission at high level density. They are similar to, but different from the Fano resonances in the scattering theory with K=1. Phase lapses are related to zeros in the transmission probability. Their number and position (in energy) are determined by the Vc and Ei0, but not by α. However, number and position of the resonance states depend on α due to resonance trapping occurring in the regime of overlapping resonances. As a consequence, universal phase lapses between every two resonances may appear at high level density while the system will show mesoscopic features at low level density. The phase lapses are not a single phenomenon. Due to their link to singularities in the continuum, they are related also to other 'puzzling

  2. Active and passive electrical and seismic time-lapse monitoring of earthen embankments

    Science.gov (United States)

    Rittgers, Justin Bradley

    In this dissertation, I present research involving the application of active and passive geophysical data collection, data assimilation, and inverse modeling for the purpose of earthen embankment infrastructure assessment. Throughout the dissertation, I identify several data characteristics, and several challenges intrinsic to characterization and imaging of earthen embankments and anomalous seepage phenomena, from both a static and time-lapse geophysical monitoring perspective. I begin with the presentation of a field study conducted on a seeping earthen dam, involving static and independent inversions of active tomography data sets, and self-potential modeling of fluid flow within a confined aquifer. Additionally, I present results of active and passive time-lapse geophysical monitoring conducted during two meso-scale laboratory experiments involving the failure and self-healing of embankment filter materials via induced vertical cracking. Identified data signatures and trends, as well as 4D inversion results, are discussed as an underlying motivation for conducting subsequent research. Next, I present a new 4D acoustic emissions source localization algorithm that is applied to passive seismic monitoring data collected during a full-scale embankment failure test. Acoustic emissions localization results are then used to help spatially constrain 4D inversion of collocated self-potential monitoring data. I then turn to time-lapse joint inversion of active tomographic data sets applied to the characterization and monitoring of earthen embankments. Here, I develop a new technique for applying spatiotemporally varying structural joint inversion constraints. The new technique, referred to as Automatic Joint Constraints (AJC), is first demonstrated on a synthetic 2D joint model space, and is then applied to real geophysical monitoring data sets collected during a full-scale earthen embankment piping-failure test. Finally, I discuss some non-technical issues related to

  3. Does attention exist?

    OpenAIRE

    Wilson, Keith

    2007-01-01

    In the introduction to the Phenomenology of Perception, Merleau-Ponty (2002: 34) states that ‘Attention, [...] as a general and formal activity, does not exist’. This paper examines the meaning and truth of this difficult and surprising statement, along with its implications for the account of perception given by theorists such as Dretske (1988) and Peacocke (1983). In order to elucidate Merleau-Ponty’s phenomenological account of human perception, I will present two alternative models1 of ho...

  4. Attention, communication, and schizophrenia.

    OpenAIRE

    Rund, B. R.

    1985-01-01

    The paper starts by drawing the historical lines for and giving an account of the main methods and results from an empirical investigation of cognitive disorders in schizophrenics and communication deviances in their parents. The focus of the report is on the significant correlations that were found between some aspects of parents' style of communication and offsprings' cognitive functioning. On the basis of the empirical study, the relationship between attention and communication is discusse...

  5. Well-posedness of formulations of the Einstein equations with dynamical lapse and shift conditions

    CERN Document Server

    Gundlach, C; Gundlach, Carsten; Martin-Garcia, Jose M.

    2006-01-01

    We prove that when the equations are restricted to the principal part the standard version of the BSSN formulation of the Einstein equations is equivalent to the NOR formulation for any gauge, and that the KST formulation is equivalent to NOR for a variety of gauges. We review a family of elliptic gauge conditions and the implicit parabolic and hyperbolic drivers that can be derived from them, and show how to make them symmetry-seeking. We investigate the hyperbolicity of ADM, NOR and BSSN with implicit hyperbolic lapse and shift drivers. We show that BSSN with the coordinate drivers used in recent ``moving puncture'' binary black hole evolutions is ill-posed at large shifts, and suggest how to make it strongly hyperbolic for arbitrary shifts. For ADM, NOR and BSSN with elliptic and parabolic gauge conditions, which cannot be hyperbolic, we investigate a necessary condition for well-posedness.

  6. Rapid antimicrobial susceptibility testing of clinical isolates by digital time-lapse microscopy

    DEFF Research Database (Denmark)

    Fredborg, M; Rosenvinge, F S; Spillum, E;

    2015-01-01

    (168 antimicrobial agent-organism combinations) demonstrated 3.6 % minor, no major and 1.2 % very major errors of the oCelloScope system compared to conventional susceptibility testing, as well as a rapid and correct phenotypic detection of strains with methicillin-resistant Staphylococcus aureus (MRSA......Rapid antimicrobial susceptibility testing (AST) is essential for early and appropriate therapy. Methods with short detection time enabling same-day treatment optimisation are highly favourable. In this study, we evaluated the potential of a digital time-lapse microscope system, the o......CelloScope system, to perform rapid AST. The oCelloScope system demonstrated a very high accuracy (96 % overall agreement) when determining the resistance profiles of four reference strains, nine clinical isolates, including multi-drug-resistant isolates, and three positive blood cultures. AST of clinical isolates...

  7. Time-lapse cinematographic analysis of beryllium--lung fibroblast interactions.

    Science.gov (United States)

    Absher, M; Sylwester, D; Hart, B A

    1983-02-01

    The proliferative response to beryllium chloride of cells in a population of human lung fibroblasts was quantitatively assessed using time-lapse cinematography. A dose of 0.02 microgram Be/ml, known to decrease the growth rate of fibroblasts, affects an estimated 75% of the cells in the population, increasing their interdivision time (IDT) by approximately 5 hr. The differences in mean 1n(IDT) between treated and control cells were essentially constant for comparable culture sizes ranging from 25 to 250 cells. There was no correlation between mother and daughter cell IDTs in control or treated culture at any culture size. IDTs of sister pairs were highly correlated in control cultures at selected culture sizes while sister pair IDTs of treated cultures were not. The data suggest that while beryllium alters the IDT of fibroblasts, an effect not related to culture size, any given cell affected by beryllium does not impart effects of the mineral to its progeny.

  8. A poly(dimethylsiloxane)-based device enabling time-lapse imaging with high spatial resolution

    International Nuclear Information System (INIS)

    We have developed a regulator-free device that enables long-term incubation of mammalian cells for epi-fluorescence imaging, based on a concept that the size of sample to be gassed and heated is reduced to observation scale. A poly(dimethylsiloxane) block stamped on a coverslip works as a long-lasting supplier of CO2-rich gas to adjust bicarbonate-containing medium in a tiny chamber at physiological pH, and an oil-immersion objective warms cells across the coverslip. A time-lapse imaging experiment using HeLa cells stably expressing fluorescent cell-cycle indicators showed that the cells in the chamber proliferated with normal cell-cycle period over 2 days.

  9. Optimal Estimation of Diffusion Coefficients from Noisy Time-Lapse-Recorded Single-Particle Trajectories

    DEFF Research Database (Denmark)

    Vestergaard, Christian Lyngby

    2012-01-01

    Optimal Estimation of Diusion Coecients from Noisy Time-Lapse- Measurements of Single-Particle Trajectories Single-particle tracking techniques allow quantitative measurements of diusion at the single-molecule level. Recorded time-series are mostly short and contain considerable measurement noise....... The standard method for estimating diusion coecients from single-particle trajectories is based on leastsquares tting to the experimentally measured mean square displacements. This method is highly inecient, since it ignores the high correlations inherent in these. We derive the exact maximum likelihood...... parameter values. We extend the methods to particles diusing on a uctuating substrate, e.g., exible or semi exible polymers such as DNA, and show that uctuations induce an important bias in the estimates of diusion coecients if they are not accounted for. We apply the methods to obtain precise estimates...

  10. 3-D time-lapse electrical resistivity monitoring of injected CO2 in a shallow aquifer

    DEFF Research Database (Denmark)

    Doetsch, Joseph A. J.A.; Auken, Esben; Christiansen, Anders Vest C A.V.C.;

    2013-01-01

    inversion reveals the geology at the site consisting of aeolian sands near the surface and glacial sands below 5 m depth. Time-lapse inversions clearly image the dissolved CO2 plume with decreased electrical resistivity values. We can follow the CO2 plume as it spreads and moves with the groundwater...... and 10 m and monitored its migration using 320 surface electrodes on a 126 m × 20 m grid. A fully automated acquisition system continuously collected data and uploaded it into an online database. The large amount of data allows for time-series analysis for data quality and noise estimation. A baseline......, and the spatial distribution of the plume agrees well with direct measurements of the groundwater resistivity. Future work will include improved time-series analyses and quantitative comparison with the groundwater resistivity measurements....

  11. Time-lapse seismic analysis of the North Sea Fulmar Field

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, David H.; McKenny, Robert S.; Burkhart, Tucker D.

    1998-12-31

    Time-lapse seismic analysis has been applied to two 3-D seismic surveys acquired over the central North Sea Fulmar field in a pre-production survey shot in 1977, reprocessed in 1987, and a survey in 1992. The Upper Jurassic reservoirs in the field have been under production since 1982. Differences in averaged impedance between the 1977 and 1992 surveys clearly show the effects of water influx and pressure decline. The changes observed in the seismic data are overall consistent with predictions obtained from a full-field, history-matched simulation. Differences in details may suggest areas of bypassed oil. Dta quality is not sufficient to serve as the sole basis for drilling decisions. 1 ref., 6 figs.

  12. Electron microscopic time-lapse visualization of surface pore filtration on particulate matter trapping process.

    Science.gov (United States)

    Sanui, Ryoko; Hanamura, Katsunori

    2016-09-01

    A scanning electron microscope (SEM) was used to dynamically visualize the particulate matter (PM) trapping process on diesel particulate filter (DPF) walls at a micro scale as 'time-lapse' images corresponding to the increase in pressure drop simultaneously measured through the DPF. This visualization and pressure drop measurement led to the conclusion that the PM trapping in surface pores was driven by PM bridging and stacking at constricted areas in porous channels. This caused a drastic increase in the pressure drop during PM accumulation at the beginning of the PM trapping process. The relationship between the porous structure of the DPF and the depth of the surface pore was investigated in terms of the porosity distribution and PM penetration depth near the wall surface with respect to depth. The pressure drop calculated with an assumed surface pore depth showed a good correspondence to the measured pressure drop.

  13. Time-lapse cinematography in living Drosophila tissues: preparation of material.

    Science.gov (United States)

    Davis, Ilan; Parton, Richard M

    2006-01-01

    The fruit fly, Drosophila melanogaster, has been an extraordinarily successful model organism for studying the genetic basis of development and evolution. It is arguably the best-understood complex multicellular model system, owing its success to many factors. Recent developments in imaging techniques, in particular sophisticated fluorescence microscopy methods and equipment, now allow cellular events to be studied at high resolution in living material. This ability has enabled the study of features that tend to be lost or damaged by fixation, such as transient or dynamic events. Although many of the techniques of live cell imaging in Drosophila are shared with the greater community of cell biologists working on other model systems, studying living fly tissues presents unique difficulties in keeping the cells alive, introducing fluorescent probes, and imaging through thick hazy cytoplasm. This protocol outlines the preparation of major tissue types amenable to study by time-lapse cinematography and different methods for keeping them alive. PMID:22485989

  14. In vivo amyloid aggregation kinetics tracked by time-lapse confocal microscopy in real-time.

    Science.gov (United States)

    Villar-Piqué, Anna; Espargaró, Alba; Ventura, Salvador; Sabate, Raimon

    2016-01-01

    Amyloid polymerization underlies an increasing number of human diseases. Despite this process having been studied extensively in vitro, aggregation is a difficult process to track in vivo due to methodological limitations and the slow kinetics of aggregation reactions in cells and tissues. Herein we exploit the amyloid properties of the inclusions bodies (IBs) formed by amyloidogenic proteins in bacteria to address the kinetics of in vivo amyloid aggregation. To this aim we used time-lapse confocal microscopy and a fusion of the amyloid-beta peptide (A β42) with a fluorescent reporter. This strategy allowed us to follow the intracellular kinetics of amyloid-like aggregation in real-time and to discriminate between variants exhibiting different in vivo aggregation propensity. Overall, the approach opens the possibility to assess the impact of point mutations as well as potential anti-aggregation drugs in the process of amyloid formation in living cells.

  15. Motivations for Giving of Alumni Donors, Lapsed Donors and Non-Donors: Implications for Christian Higher Education

    Science.gov (United States)

    Rugano, Emilio Kariuki

    2011-01-01

    This descriptive and causal comparative study sought to identify motivations for alumni donor acquisition and retention in Christian institutions of higher learning. To meet this objective, motivations for alumni donors, lapsed donors, and non-donors were analyzed and compared. Data was collected through an electronic survey of a stratified sample…

  16. Social Cognitive Analysis of Recovery from a Lapse after Smoking Cessation: Comment on Haaga and Stewart (1992).

    Science.gov (United States)

    Devins, Gerald M.

    1992-01-01

    Responds to previous article by Haaga and Stewart on perceived self-efficacy for recovery of abstinence from smoking after lapse and success in maintaining abstinence. Identifies and addresses issues regarding application of social cognitive theory to such areas as smoking cessation. Examines distinctions between efficacy and outcome beliefs,…

  17. In the heat of the moment: Alcohol consumption and smoking lapse and relapse among adolescents who have quit smoking

    NARCIS (Netherlands)

    Zundert, R.M.P. van; Kuntsche, E.N.; Engels, R.C.M.E.

    2012-01-01

    Background: The present study tested the co-occurrence of alcohol use and the first lapse and relapse into smoking among daily smoking adolescents who quit smoking. Methods: In this ecological momentary assessment study, participants completed web-based questionnaires three times a day during one we

  18. Micromechanical Time-Lapse X-ray CT Study of Fatigue Damage in Uni-Directional Fibre Composites

    DEFF Research Database (Denmark)

    Jespersen, Kristine Munk; Lowe, Tristan; Withers, Philip J.;

    2015-01-01

    . The geometry of the cut-out is similar to that which will be used in the time-lapse study. As the micro-mechanical damage mechanisms are small features, it is necessary to obtain a high scan resolution which sets a limit to how large the field of view can be. Therefore, it is necessary to perform several scans...

  19. Sensitivity of time-lapse changes in pressure and saturation to seismic AVO and time-shifts

    NARCIS (Netherlands)

    Trani, M.; Arts, R.; Leeuwenburgh, O.; Brouwer, J.

    2010-01-01

    An inversion scheme that solves for reservoir pressure and fluid saturation changes from time-lapse pre-stack seismic attributes and post-stack seismic time-shifts is presented. It makes use of four equations expressing the changes in zero-offset and gradient reflectivities, compressional and shear

  20. Generalized focusing of time-lapse changes with applications to direct current and time-domain induced polarization inversions

    Science.gov (United States)

    Fiandaca, Gianluca; Doetsch, Joseph; Vignoli, Giulio; Auken, Esben

    2015-11-01

    Often in geophysical monitoring experiments time-lapse inversion models vary too smoothly with time, owing to the strong imprint of regularization. Several methods have been proposed for focusing the spatiotemporal changes of the model parameters. In this study, we present two generalizations of the minimum support norm, which favour compact time-lapse changes and can be adapted to the specific problem requirements. Inversion results from synthetic direct current resistivity models that mimic developing plumes show that the focusing scheme significantly improves size, shape and magnitude estimates of the time-lapse changes. Inversions of the synthetic data also illustrate that the focused inversion gives robust results and that the focusing settings are easily chosen. Inversions of full-decay time-domain induced polarization (IP) field data from a CO2 monitoring injection experiment show that the focusing scheme performs well for field data and inversions for all four Cole-Cole polarization parameters. Our tests show that the generalized minimum support norms react in an intuitive and predictable way to the norm settings, implying that they can be used in time-lapse experiments for obtaining reliable and robust results.

  1. Mass conservative three-dimensional water tracer distribution from MCMC inversion of time-lapse GPR data

    NARCIS (Netherlands)

    E. Lalov; N. Linde; J.A. Vrugt

    2012-01-01

    Time-lapse geophysical measurements are widely used to monitor the movement of water and solutes through the subsurface. Yet commonly used deterministic least squares inversions typically suffer from relatively poor mass recovery, spread overestimation, and limited ability to appropriately estimate

  2. Time-lapse seismic AVP analysis on the sleipner C02 storage monitoring data using CFP processing

    NARCIS (Netherlands)

    Neele, F.P.; Arts, R.J.

    2010-01-01

    CO2 has been injected into the Utsira Sand at Sleipner since 1996, with more than 11 million tonnes currently in the reservoir. Six time-lapse seismic monitoring surveys to follow the migration of the CO2 in the reservoir have been carried out. This paper describes a pre-stack data analysis of the t

  3. Applicability of time-lapse refraction seismic tomography for the detection of ground ice degradation

    Directory of Open Access Journals (Sweden)

    C. Hilbich

    2010-01-01

    Full Text Available The ice content of the subsurface is a major factor controlling the natural hazard potential of permafrost degradation in alpine terrain. Monitoring of changes in ground ice content is therefore similarly important as temperature monitoring in mountain permafrost. Although electrical resistivity tomography monitoring (ERTM has proved to be a valuable tool for the observation of ground ice degradation, results are often ambiguous or contaminated by inversion artefacts. In theory, the P-wave velocity of seismic waves is similarly sensitive to phase changes between unfrozen water and ice. Provided that the general conditions (lithology, stratigraphy, state of weathering, pore space remain unchanged over the observation period, temporal changes in the observed travel times of repeated seismic measurements should indicate changes in the ice and water content within the pores and fractures of the subsurface material. In this paper, the applicability of refraction seismic tomography monitoring (RSTM as an independent and complementary method to ERTM is analysed for two test sites in the Swiss Alps. The development and validation of an appropriate RSTM approach involves a the comparison of time-lapse seismograms and analysis of reproducibility of the seismic signal, b the analysis of time-lapse travel time curves with respect to shifts in travel times and changes in P-wave velocities, and c the comparison of inverted tomograms including the quantification of velocity changes. Results show a high potential of the RSTM approach concerning the detection of altered subsurface conditions caused by freezing and thawing processes. For velocity changes on the order of 3000 m/s even an unambiguous identification of significant ground ice loss is possible.

  4. Quantifying Effusion Rates at Active Volcanoes through Integrated Time-Lapse Laser Scanning and Photography

    Directory of Open Access Journals (Sweden)

    Neil Slatcher

    2015-11-01

    Full Text Available During volcanic eruptions, measurements of the rate at which magma is erupted underpin hazard assessments. For eruptions dominated by the effusion of lava, estimates are often made using satellite data; here, in a case study at Mount Etna (Sicily, we make the first measurements based on terrestrial laser scanning (TLS, and we also include explosive products. During the study period (17–21 July 2012, regular Strombolian explosions were occurring within the Bocca Nuova crater, producing a ~50 m-high scoria cone and a small lava flow field. TLS surveys over multi-day intervals determined a mean cone growth rate (effusive and explosive products of ~0.24 m3·s−1. Differences between 0.3-m resolution DEMs acquired at 10-minute intervals captured the evolution of a breakout lava flow lobe advancing at 0.01–0.03 m3·s−1. Partial occlusion within the crater prevented similar measurement of the main flow, but integrating TLS data with time-lapse imagery enabled lava viscosity (7.4 × 105 Pa·s to be derived from surface velocities and, hence, a flux of 0.11 m3·s−1 to be calculated. Total dense rock equivalent magma discharge estimates are ~0.1–0.2 m3·s−1 over the measurement period and suggest that simultaneous estimates from satellite data are somewhat overestimated. Our results support the use of integrated TLS and time-lapse photography for ground-truthing space-based measurements and highlight the value of interactive image analysis when automated approaches, such as particle image velocimetry (PIV, fail.

  5. Gliding motility of Babesia bovis merozoites visualized by time-lapse video microscopy.

    Directory of Open Access Journals (Sweden)

    Masahito Asada

    Full Text Available BACKGROUND: Babesia bovis is an apicomplexan intraerythrocytic protozoan parasite that induces babesiosis in cattle after transmission by ticks. During specific stages of the apicomplexan parasite lifecycle, such as the sporozoites of Plasmodium falciparum and tachyzoites of Toxoplasma gondii, host cells are targeted for invasion using a unique, active process termed "gliding motility". However, it is not thoroughly understood how the merozoites of B. bovis target and invade host red blood cells (RBCs, and gliding motility has so far not been observed in the parasite. METHODOLOGY/PRINCIPAL FINDINGS: Gliding motility of B. bovis merozoites was revealed by time-lapse video microscopy. The recorded images revealed that the process included egress of the merozoites from the infected RBC, gliding motility, and subsequent invasion into new RBCs. The gliding motility of B. bovis merozoites was similar to the helical gliding of Toxoplasma tachyzoites. The trails left by the merozoites were detected by indirect immunofluorescence assay using antiserum against B. bovis merozoite surface antigen 1. Inhibition of gliding motility by actin filament polymerization or depolymerization indicated that the gliding motility was driven by actomyosin dependent process. In addition, we revealed the timing of breakdown of the parasitophorous vacuole. Time-lapse image analysis of membrane-stained bovine RBCs showed formation and breakdown of the parasitophorous vacuole within ten minutes of invasion. CONCLUSIONS/SIGNIFICANCE: This is the first report of the gliding motility of B. bovis. Since merozoites of Plasmodium parasites do not glide on a substrate, the gliding motility of B. bovis merozoites is a notable finding.

  6. Assessment of Saturation Patterns on Agricultural Land Using Time-lapse Photography

    Science.gov (United States)

    Silasari, R.; Bloeschl, G.

    2015-12-01

    Agricultural land generates overland flow differently from natural environment due to features from anthropogenic activities such as cultivated soil layer and tile drain pipe. During rainfall events, the formation of overland flow may happen from infiltration excess and/or saturation excess according to the threshold processes which are influenced by rainfall characteristics and soil hydraulic parameters. The dynamics of threshold processes in varying rainfall and soil hydraulic conditions will affect the surface runoff response which can be inversely analyzed by visually observing the generated saturation patterns. This study aims to explore the use of time-lapse photographs of saturated plot during rainfall events to observe and understand the threshold processes of overland flow generation. The observation was conducted at Hydrological Open Air Laboratory (HOAL) in Lower Austria with a 2 megapixels surveillance camera overlooking a 1.8 ha tile-drained agricultural field situated on a hillslope. The main tile drain pipe extends from the higher ground into the riparian area - creating a depression line which generates the main saturation track. The time-lapse photographs are able to capture the spatial and temporal dynamics of 0.1 ha saturated plot (117 m long and 10 m wide in average) during three big rainfall events in 2014 which produced measurable overland flow. The photographs also manage to capture the behavior of overland flow on tractor tracks which were generated faster than on the main saturated plot - due to the more compacted soil - and contribute significantly to the overall overland flow discharge and movements. Comparison of the photographs with on-field manual plotting shows good accuracy of the captured saturation plot and the possibility of calculating the plot area digitally. This method gives opportunity to observe overland flow generation on visual basis as a complement of the customary discharge measurements.

  7. Spectral-element simulations of carbon dioxide (CO2) sequestration time-lapse monitoring

    Science.gov (United States)

    Morency, C.; Luo, Y.; Tromp, J.

    2009-12-01

    Geologic sequestration of CO2, a green house gas, represents an effort to reduce the large amount of CO2 generated as a by-product of fossil fuels combustion and emitted into the atmosphere. This process of sequestration involves CO2 storage deep underground. There are three main storage options: injection into hydrocarbon reservoirs, injection into methane-bearing coal beds, or injection into deep saline aquifers, that is, highly permeable porous media. The key issues involve accurate monitoring of the CO2, from the injection stage to the prediction & verification of CO2 movement over time for environmental considerations. A natural non-intrusive monitoring technique is referred to as ``4D seismics'', which involves 3D time-lapse seismic surveys. The success of monitoring the CO2 movement is subject to a proper description of the physics of the problem. We propose to realize time-lapse migrations comparing acoustic, elastic, and poroelastic simulations of 4D seismic imaging to characterize the storage zone. This approach highlights the influence of using different physical theories on interpreting seismic data, and, more importantly, on extracting the CO2 signature from the seismic wave field. Our simulations are performed using a spectral-element method, which allows for highly accurate results. Biot's equations are implemented to account for poroelastic effects. Attenuation associated with the anelasticity of the rock frame and frequency-dependent viscous resistance of the pore fluid are accommodated based upon a memory variable approach. The sensitivity of observables to the model parameters is quantified based upon finite-frequency sensitivity kernels calculated using an adjoint method.

  8. Selective Attention and Attention Switching: Toward a Unified Developmental Approach

    OpenAIRE

    Hanania, Rima; Smith, Linda B.

    2010-01-01

    We review and relate two literatures on the development of attention in children: one concerning flexible attention switching and the other concerning selective attention. The first is a growing literature on preschool children’s performances in an attention switching task indicating that children become more flexible in their attentional control during the preschool years. The second literature encompasses a large and robust set of phenomena for the same developmental period that indicate a ...

  9. Monitoring channel head erosion processes in response to an artificially induced abrupt base level change using time-lapse photography

    Science.gov (United States)

    Nichols, M. H.; Nearing, M.; Hernandez, M.; Polyakov, V. O.

    2016-07-01

    Gullies that terminate at a vertical-wall are ubiquitous throughout arid and semiarid regions. Multi-year assessments of gully evolution and headcut advance are typically accomplished using traditional ground surveys and aerial photographs, with much recent research focused on integrating data collected at very high spatial resolutions using new techniques such as aerial surveys with blimps or kites and ground surveys with LiDar scanners. However, knowledge of specific processes that drive headcut advance is limited due to inadequate observation and documentation of flash floods and subsequent erosion that can occur at temporal resolutions not captured through repeat surveys. This paper presents a method for using very-high temporal resolution ground-based time-lapse photography to capture short-duration flash floods and gully head evolution in response. In 2004, a base level controlling concrete weir was removed from the outlet of a 1.29 ha semiarid headwater drainage on the Walnut Gulch Experimental Watershed in southeastern Arizona, USA. During the ten year period from 2004 to 2014 the headcut migrated upchannel a total of 14.5 m reducing the contributing area at the headwall by 9.5%. Beginning in July 2012, time-lapse photography was employed to observe event scale channel evolution dynamics. The most frequent erosion processes observed during three seasons of time-lapse photography were plunge pool erosion and mass wasting through sidewall or channel headwall slumping that occurred during summer months. Geomorphic change during the ten year period was dominated by a single piping event in August 2014 that advanced the channel head 7.4 m (51% of the overall advance) and removed 11.3 m3 of sediment. High temporal resolution time-lapse photography was critical for identifying subsurface erosion processes, in the absence of time-lapse images piping would not have been identified as an erosion mechanism responsible for advancing the gully headwall at this site.

  10. Time-Lapse Video Microscopy for Assessment of EYFP-Parkin Aggregation as a Marker for Cellular Mitophagy.

    Science.gov (United States)

    Di Sante, Gabriele; Casimiro, Mathew C; Pestell, Timothy G; Pestell, Richard G

    2016-01-01

    Time-lapse video microscopy can be defined as the real time imaging of living cells. This technique relies on the collection of images at different time points. Time intervals can be set through a computer interface that controls the microscope-integrated camera. This kind of microscopy requires both the ability to acquire very rapid events and the signal generated by the observed cellular structure during these events. After the images have been collected, a movie of the entire experiment is assembled to show the dynamic of the molecular events of interest. Time-lapse video microscopy has a broad range of applications in the biomedical research field and is a powerful and unique tool for following the dynamics of the cellular events in real time. Through this technique, we can assess cellular events such as migration, division, signal transduction, growth, and death. Moreover, using fluorescent molecular probes we are able to mark specific molecules, such as DNA, RNA or proteins and follow them through their molecular pathways and functions. Time-lapse video microscopy has multiple advantages, the major one being the ability to collect data at the single-cell level, that make it a unique technology for investigation in the field of cell biology. However, time-lapse video microscopy has limitations that can interfere with the acquisition of high quality images. Images can be compromised by both external factors; temperature fluctuations, vibrations, humidity and internal factors; pH, cell motility. Herein, we describe a protocol for the dynamic acquisition of a specific protein, Parkin, fused with the enhanced yellow fluorescent protein (EYFP) in order to track the selective removal of damaged mitochondria, using a time-lapse video microscopy approach. PMID:27168174

  11. Vanemate töötamine välismaal - kuidas see mõjutab lapse elu : laste ja spetsialistide tõlgendused / Helen Pärna, Karmen Lai, Taimi Tulva

    Index Scriptorium Estoniae

    Pärna, Helen, 1983-

    2008-01-01

    Artikkel tugineb Helen Pärna magistriuurimusele. Ülevaade uurimustulemustest, mis puudutavad välismaale tööle läinud lapsevanemate lapse toimetulekut argieluga ning arutletakse selle üle, kuidas lapse lahusolek vanematest võib mõjutada lapse ja vanema vahelisi suhteid

  12. The Normalization Model of Attention

    OpenAIRE

    Reynolds, John H.; Heeger, David J.

    2009-01-01

    Attention has been found to have a wide variety of effects on the responses of neurons in visual cortex. We describe a model of attention that exhibits each of these different forms of attentional modulation, depending on the stimulus conditions and the spread (or selectivity) of the attention field in the model. The model helps reconcile proposals that have been taken to represent alternative theories of attention. We argue that the variety and complexity of the results reported in the liter...

  13. Attention decay in science

    CERN Document Server

    Parolo, Pietro Della Briotta; Ghosh, Rumi; Huberman, Bernardo A; Kaski, Kimmo; Fortunato, Santo

    2015-01-01

    The exponential growth in the number of scientific papers makes it increasingly difficult for researchers to keep track of all the publications relevant to their work. Consequently, the attention that can be devoted to individual papers, measured by their citation counts, is bound to decay rapidly. In this work we make a thorough study of the life-cycle of papers in different disciplines. Typically, the citation rate of a paper increases up to a few years after its publication, reaches a peak and then decreases rapidly. This decay can be described by an exponential or a power law behavior, as in ultradiffusive processes, with exponential fitting better than power law for the majority of cases. The decay is also becoming faster over the years, signaling that nowadays papers are forgotten more quickly. However, when time is counted in terms of the number of published papers, the rate of decay of citations is fairly independent of the period considered. This indicates that the attention of scholars depends on th...

  14. Culture, attention, and emotion.

    Science.gov (United States)

    Grossmann, Igor; Ellsworth, Phoebe C; Hong, Ying-yi

    2012-02-01

    This research provides experimental evidence for cultural influence on one of the most basic elements of emotional processing: attention to positive versus negative stimuli. To this end, we focused on Russian culture, which is characterized by brooding and melancholy. In Study 1, Russians spent significantly more time looking at negative than positive pictures, whereas Americans did not show this tendency. In Study 2, Russian Latvians were randomly primed with symbols of each culture, after which we measured the speed of recognition for positive versus negative trait words. Biculturals were significantly faster in recognizing negative words (as compared with baseline) when primed with Russian versus Latvian cultural symbols. Greater identification with Russian culture facilitated this effect. We provide a theoretical discussion of mental processes underlying cultural differences in emotion research.

  15. Environmental monitoring of leaks using time-lapsed long electrode electrical resistivity

    Science.gov (United States)

    Rucker, Dale F.; Fink, James B.; Loke, Meng H.

    2011-08-01

    Highly industrialized areas pose challenges for surface electrical resistivity characterization due to metallic infrastructure. The infrastructure is typically more conductive than the desired targets and will mask the deeper subsurface information. The risk of this occurring may be minimized if steel-cased wells are used as long electrodes in the area near the target. We demonstrate a method of using long electrodes to electrically monitor a simulated leak from an underground storage tank with both synthetic examples and a field demonstration. Although the method of using long electrodes has been proposed by others, no time-lapse resistivity data have been collected, modeled, and analyzed within a nuclear waste tank farm environment. Therefore, the main objective of this work was to test whether the long electrode method using steel-cased wells can be employed to spatially and temporally track simulated leaks in a highly industrialized setting. A secondary objective was to apply a time-lapse regularization procedure in the inverse modeling code, similar to the 4D tomography approach by Kim et al. (2009), and to test the procedure's effect on the quality of the outcome regarding plume intensity and position. For the synthetic examples, a simple target of varying electrical properties was placed beneath different types of layers of low resistivity to simulate the effects of the infrastructure. Both surface and long electrodes were tested on the synthetic domain, and the test cases covered a variety of survey parameters including low and high electrode density, noise, array type, and the explicit location of the wells relative to the target. All data were processed in four dimensions, where the regularization procedure was applied in both the time and space domains. The synthetic test case showed that the long electrode resistivity method could detect relative changes in resistivity that was commensurate with the differing target properties. The surface electrodes

  16. Mindfulness training affects attention--or is it attentional effort?

    DEFF Research Database (Denmark)

    Jensen, Christian Gaden; Vangkilde, Signe Allerup; Frokjaer, Vibe;

    2012-01-01

    , the latter receiving a financial reward to improve attentional performance. Pre- and postintervention, 5 validated attention paradigms were employed along with self-report scales on mindfulness and perceived stress and saliva cortisol samples to measure physiological stress. Attentional effects of MBSR, NMSR...

  17. Monotoring of CO2 Sequestration at Sleipner Using Full Waveform Inversion in Time-lapse Mode.

    Science.gov (United States)

    Gosselet, A.; Singh, S. C.

    2007-12-01

    It is now widely admitted that recent increase of CO2 in the atmosphere is due to human activities. The consecutive greenhouse effect is a major ecological concern. Geological storage is one proposed way to reduce atmosphere CO2 emissions. The Sleipner methane field, North Sea, is the very first site where CO2 has been injected back into a deep saline aquifer. In 1996, the Norwegian company Statoil and its partners began the production of the methane. The extracted methane contains a relatively high ratio of CO2, between 4% and 9%, that has to be reduced below 2.5% before delivering into the pipeline. An environmental tax introduced in Norway as early as 1991 prompted the company to store the separated CO2 instead of releasing it into the atmosphere as usually done. The CO2 is injected at the base of the Utsira sands. This water bearing formation lies at a depth between 800 and 1000m and is sealed by a thick shale layer. Seismic monitoring is a key tool in this strategy from a security standpoint and for sequestration optimization itself. Consequently, 3D seismic data were acquired before injection in 1994 and after injection in 1999, 2001, 2002, 2004 and 2006. Well-log revealed that the reservoir is crossed by thin shale layers that are 1 to 10m thick. CO2 rises up and is confined vertically by the shale layers, favouring horizontal gas migration and creating gas bearing thin beds. Seismic imaging of the gas pockets is therefore a challenging problem because large velocity variations occur on very short distance. Classical processing of time-lapse data consists in subtracting repeated survey seismic traces from the pre- injection baseline traces to exhibit changes within the reservoir. This approach remains qualitative, providing only the shape and extent of the gas cloud. Instead, we propose to compare elastic models of the subsurface computed through 2D full wave form inversion, an advanced seismic imaging technique. This method is based on the wave equation

  18. Geoelectrical time-lapse analysis for improved interpretation of data in a contaminated area

    Science.gov (United States)

    Chitea, Florina; Serban, Adrian; Ioane, Dumitru; Georgescu, Paul

    2014-05-01

    Non invasive geoelectrical studies are useful in the preliminary assessment of areas suspected to be contaminated but also in the investigation stage. Correctly adapted to the site specific situation, they are used to detect and investigate buried sources of pollution, to characterize the geology of the area, to detect the contaminated plume or to study the attenuation of pollution in case the appliance of an site-specific remediation techniques. Despite the improved technological acquisition techniques and the optimized inversion data algorithms, interpretation of geoelectrical data in still a challenging task, especially in a contaminated hydrogeological context. Beside the soil physical properties (composition, porosity, texture, etc.), moisture content and chemical composition of the pollutant are also influencing the measured parameter. Apparent electrical resistivity method was use in an area located near an Oil Refinery. Electrical measurements performed on profiles (transverse and along the direction of water flow -according to hydrological data) revealed the presence of contaminants by means of high resistivity anomalies. Using the same acquisition technique (Schlumberger array, same VES points, injection - AB - and voltage - MN - lines extension), measurements were repeated during time, along the same profiles. On the resulted electrical sections from 2006 to 2013, a dynamic situation regarding the pollution plume was observed. Time - lapse analysis, based on the calculation of resistivity differences between sets of data acquired along the same profile was applied, and data interpretation was made using the resulted sections. Significant variation between data sets (> 17% of apparent resistivity normalized differences) observed along the main profile were mainly ranging from the near surface (1.5 m) to an approximated depth (AB/2) of 10m. Using the time-lapse method, changes in the lateral and in depth extension of polluted areas could be observed and

  19. Attentional Modulation of Binocular Rivalry

    OpenAIRE

    Chris ePaffen; David eAlais

    2011-01-01

    Ever since Wheatstone initiated the scientific study of binocular rivalry, it has been debated whether the phenomenon is under attentional control. In recent years, the issue of attentional modulation of binocular rivalry has seen a revival. Here we review the classical studies as well as recent advances in the study of attentional modulation of binocular rivalry. We show that (1) voluntary control over binocular rivalry is possible, yet limited, (2) both endogenous and exogenous attention in...

  20. Attentional networks in developmental dyscalculia

    OpenAIRE

    Henik Avishai; Askenazi Sarit

    2010-01-01

    Abstract Background Very little is known about attention deficits in developmental dyscalculia, hence, this study was designed to provide the missing information. We examined attention abilities of participants suffering from developmental dyscalculia using the attention networks test - interactions. This test was designed to examine three different attention networks--executive function, orienting and alerting--and the interactions between them. Methods Fourteen university students that were...

  1. Attention, Media and Fuel Efficiency

    OpenAIRE

    Thoenes, Stefan; Gores, Timo

    2012-01-01

    This study examines attention effects in the market for hybrid vehicles. We show that local media coverage, gasoline price changes and unprecedented record gasoline prices have a significant causal impact on the consumers’ attention. As attention is not directly observable, we analyze online search behavior as a proxy for the revealed consumer attention. Our study is based on weekly panel data of local newspaper coverage, gasoline prices and Google search trends for 19 metropolitan areas in the...

  2. Chewing and Attention: A Positive Effect on Sustained Attention

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Hirano

    2015-01-01

    Full Text Available Chewing is crushing food not only to aid swallowing and digestion, but also to help stress relief and regulate cognitive function, especially in attention. It is well known that chewing gum is used for sleepiness prevention during work, learning, and driving, suggesting a link between chewing and sustained attention. We hypothesized that chewing elevates attention and/or alertness, leading to improvements in cognitive performance. We carried out a systematic review of the PubMed database. We inspected the attributes of effects on attention in studies investigating the effects of chewing on attention or alertness conducted with pre-post design in healthy subjects, except elderly. We identified 151 references, 22 of which were included: 14 (64% showed positive attributes of effects on attention, 1 (5% showed negative attributes of effects on attention, 5 (23% showed both positive and negative attributes of effects on attention, and 2 (9% showed no significant attributes of effects on attention. Thus, positive attributes of effects of chewing on attention, especially on sustained attention, were shown in over half of the reports. These effects also appeared with improvement in mood and stress relief and were influenced by time-on-task effect. Further studies are needed, but chewing could be useful for modifying cognitive function.

  3. Assessment of attention in preschoolers.

    Science.gov (United States)

    Mahone, E M; Schneider, H E

    2012-12-01

    In the past two decades, there has been an increased interest in the assessment and treatment of preschool children presenting with concerns about attention problems. This article reviews the research and clinical literature involving assessment of attention and related skills in the preschool years. While inattention among preschoolers is common, symptoms alone do not necessarily indicate a disorder, and most often represent a normal variation in typical preschool child development. Thus, accurate identification of "disordered" attention in preschoolers can be challenging, and development of appropriate, norm-referenced tests of attention for preschoolers is also difficult. The current review suggests that comprehensive assessment of attention and related functions in the preschool child should include thorough review of the child's history, planned observations, and formal psychometric testing. The three primary methods of psychometric assessment that have been used to characterize attentional functioning in preschool children include performance-based tests, structured caregiver interviews, and rating scales (parent, teacher, and clinician). Among performance-based methods for measurement of attention in the preschool years, tests have been developed to assess sustained attention, selective (focused) attention, span of attention (encoding/manipulation), and (top-down) controlled attention--including freedom from distractibility and set shifting. Many of these tests remain experimental in nature, and review of published methods yields relatively few commercially available, nationally normed tests of attention for preschoolers, and an overall dearth of reliability and validity studies on the available measures.

  4. Time-lapse CO2 monitoring using ambient-noise seismic interferometry: a feasibility study from Ketzin, Germany

    Science.gov (United States)

    Boullenger, Boris; Verdel, Arie; Paap, Bob; Thorbecke, Jan; Draganov, Deyan

    2015-04-01

    Seismic interferometry applied to ambient-noise measurements allows retrieval of the Green's function between two seismic receivers, by cross-correlating their recordings, as if from a source at one of the receivers. We propose to use ambient-noise seismic interferometry (ANSI) to retrieve reflection data. The time-lapse differences between different vintages of the retrieved data may help characterize property changes within a geologic reservoir with varying CO2 saturation. We test the feasibility of this time-lapse passive seismic method with numerical experiments based on the CO2-storage site of Ketzin, Germany. Ambient-noise recordings from Ketzin exhibit significant passive body-wave energy (from natural tremors or induced seismicity in the vicinity of the reservoir), which is advantageous to retrieve reflections with ANSI. The ANSI numerical experiments aim to understand what the requirements are for the recorded body-wave noise to retrieve the time-lapse reflection signal caused by an increase of CO2 saturation in the reservoir. For this purpose, we design two velocity scenarios at Ketzin: a base scenario before the injection of CO2, and a repeat scenario corresponding to a P-wave velocity decline in the reservoir by 20 percent. For both scenarios, we simulate passive seismic experiments of body-wave noise recordings that may take several days or months to record in the field. The passive recordings are obtained by modelling global (direct wave, internal and surface multiples) transmission responses from band-limited subsurface noise sources, randomly triggered in space and time. The time-lapse reflection signal is obtained by taking the differences between the base and the repeat retrieved reflection data (virtual common-shot gathers). We found that the time-lapse signal is still recovered with ANSI even if the base and repeat retrieved reflection data are partially polluted with artifacts. This means that uneven illumination of the array does not

  5. Three dimensional time lapse imaging of live cell mitochondria with photothermal optical lock-in optical coherence microscopy (Conference Presentation)

    Science.gov (United States)

    Sison, Miguel; Chakrabortty, Sabyasachi; Extermann, Jerome; Nahas, Amir; Pache, Christophe; Weil, Tanja; Lasser, Theo

    2016-03-01

    The photothermal optical lock-in optical coherence microscope (poli-OCM) introduced molecular specificity to OCM imaging, which is conventionally, a label-free technique. Here we achieve three-dimensional live cell and mitochondria specific imaging using ~4nm protein-functionalized gold nanoparticles (AuNPs). These nanoparticles do not photobleach and we demonstrate they're suitability for long-term time lapse imaging. We compare the accuracy of labelling with these AuNPs using classical fluorescence confocal imaging with a standard mitochondria specific marker. Furthermore, time lapse poli-OCM imaging every 5 minutes over 1.5 hours period was achieved, revealing the ability for three-dimensional monitoring of mitochondria dynamics.

  6. Time lapse investigation of antibiotic susceptibility using a microfluidic linear gradient 3D culture device.

    Science.gov (United States)

    Hou, Zining; An, Yu; Hjort, Karin; Hjort, Klas; Sandegren, Linus; Wu, Zhigang

    2014-09-01

    This study reports a novel approach to quantitatively investigate the antibacterial effect of antibiotics on bacteria using a three-dimensional microfluidic culture device. In particular, our approach is suitable for studying the pharmacodynamics effects of antibiotics on bacterial cells temporally and with a continuous range of concentrations in a single experiment. The responses of bacterial cells to a linear concentration gradient of antibiotics were observed using time-lapse photography, by encapsulating bacterial cells in an agarose-based gel located in a commercially available microfluidics chamber. This approach generates dynamic information with high resolution, in a single operation, e.g., growth curves and antibiotic pharmacodynamics, in a well-controlled environment. No pre-labelling of the cells is needed and therefore any bacterial sample can be tested in this setup. It also provides static information comparable to that of standard techniques for measuring minimum inhibitory concentration (MIC). Five antibiotics with different mechanisms were analysed against wild-type Escherichia coli, Staphylococcus aureus and Salmonella Typhimurium. The entire process, including data analysis, took 2.5-4 h and from the same analysis, high-resolution growth curves were obtained. As a proof of principle, a pharmacodynamic model of streptomycin against Salmonella Typhimurium was built based on the maximal effect model, which agreed well with the experimental results. Our approach has the potential to be a simple and flexible solution to study responding behaviours of microbial cells under different selection pressures both temporally and in a range of concentrations.

  7. Traxtile: Interactive editing of cell tracks in time-lapse images.

    Science.gov (United States)

    Braun, Benjamin S

    2015-08-01

    Time-lapse imaging can be used to quantify how cells move, divide, and die over time and under defined culture conditions. Open source software packages such as CellProfiler, Icy, and Fiji provide robust and convenient interfaces for performing such analyses. However, object tracking algorithms are imperfect, and validation of significant events is often required. This is challenging, as CellProfiler produces only tabular data for object tracking, and the graphical tools in Icy and Fiji are not optimal for manual review of these events. Here we describe Traxtile, a program that allows interactive graphical review and revision of object tracking assignments. Traxtile imports initial assignments and automatically identifies events needing review (i.e., apparent creation of new objects, splits, merges, and losses). For each such event, the object track is displayed on a montage of images centered on the event and spanning the preceding and subsequent frames. Links between cells in successive frames can be reviewed and edited, yielding validated tracks for the image series. Reports summarize events from the validated tracks. Traxtile is implemented in Python version 2.7 using standard distribution libraries (available at www.python.org) and is freely available at https://github.com/braunb/traxtile-public. PMID:26260086

  8. Landslide monitoring in southwestern China via time-lapse electrical resistivity tomography

    Institute of Scientific and Technical Information of China (English)

    Xu Dong; Hu Xiang-Yun; Shan Chun-Ling; Li Rui-Heng

    2016-01-01

    The dynamic monitoring of landslides in engineering geology has focused on the correlation among landslide stability, rainwater infiltration, and subsurface hydrogeology. However, the understanding of this complicated correlation is still poor and inadequate. Thus, in this study, we investigated a typical landslide in southwestern China via time-lapse electrical resistivity tomography (TLERT) in November 2013 and August 2014. We studied landslide mechanisms based on the spatiotemporal characteristics of surface water infi ltration andfl ow within the landslide body. Combined with borehole data, inverted resistivity models accurately defined the interface between Quaternary sediments and bedrock. Preferential fl ow pathways attributed to fracture zones andfi ssures were also delineated. In addition, we found that surface water permeates through these pathways into the slipping mass and drains away asfi ssure water in the fractured bedrock, probably causing the weakly weathered layer to gradually soften and erode, eventually leading to a landslide. Clearly, TLERT dynamic monitoring can provide precursory information of critical sliding and can be used in landslide stability analysis and prediction.

  9. Non-rigid estimation of cell motion in calcium time-lapse images

    Science.gov (United States)

    Hachi, Siham; Lucumi Moreno, Edinson; Desmet, An-Sofie; Vanden Berghe, Pieter; Fleming, Ronan M. T.

    2016-03-01

    Calcium imaging is a widely used technique in neuroscience permitting the simultaneous monitoring of electro- physiological activity of hundreds of neurons at single cell resolution. Identification of neuronal activity requires rapid and reliable image analysis techniques, especially when neurons fire and move simultaneously over time. Traditionally, image segmentation is performed to extract individual neurons in the first frame of a calcium sequence. Thereafter, the mean intensity is calculated from the same region of interest in each frame to infer calcium signals. However, when cells move, deform and fire, this segmentation on its own generates artefacts and therefore biased neuronal activity. Therefore, there is a pressing need to develop a more efficient cell tracking technique. We hereby present a novel vision-based cell tracking scheme using a thin-plate spline deformable model. The thin-plate spline warping is based on control points detected using the Fast from Accelerated Segment Test descriptor and tracked using the Lucas-Kanade optical flow. Our method is able to track neurons in calcium time-series, even when there are large changes in intensity, such as during a firing event. The robustness and efficiency of the proposed approach is validated on real calcium time-lapse images of a neuronal population.

  10. Time-Lapse Dynamics of the Mouse Oocyte Chromatin Organisation during Meiotic Resumption

    Science.gov (United States)

    Redi, Carlo Alberto; Zuccotti, Maurizio

    2014-01-01

    In the mammalian oocyte, distinct patterns of centromeres and pericentromeric heterochromatin localisation correlate with the gamete's developmental competence. Mouse antral oocytes display two main types of chromatin organisation: SN oocytes, with a ring of Hoechst-positive chromatin surrounding the nucleolus, and NSN oocytes lacking this ring. When matured to MII and fertilised, only SN oocytes develop beyond the 2-cell, and reach full term. To give detailed information on the dynamics of the SN or NSN chromatin during meiosis resumption, we performed a 9 hr time-lapse observation. The main significant differences recorded are: (1) reduction of the nuclear area only in SN oocytes; (2) ~17 min delay of GVBD in NSN oocytes; (3) chromatin condensation, after GVBD, in SN oocytes; (4) formation of 4-5 CHCs in SN oocytes; (5) increase of the perivitelline space, ~57 min later in NSN oocytes; (6) formation of a rosette-like disposition of CHCs, ~84 min later in SN oocytes; (7) appearance of the MI plate ~40 min later in NSN oocytes. Overall, we described a pathway of transition from the GV to the MII stage that is punctuated of discrete recordable events showing their specificity and occurring with different time kinetics in the two types of oocytes. PMID:24864231

  11. Time-Lapse Dynamics of the Mouse Oocyte Chromatin Organisation during Meiotic Resumption

    Directory of Open Access Journals (Sweden)

    Martina Belli

    2014-01-01

    Full Text Available In the mammalian oocyte, distinct patterns of centromeres and pericentromeric heterochromatin localisation correlate with the gamete’s developmental competence. Mouse antral oocytes display two main types of chromatin organisation: SN oocytes, with a ring of Hoechst-positive chromatin surrounding the nucleolus, and NSN oocytes lacking this ring. When matured to MII and fertilised, only SN oocytes develop beyond the 2-cell, and reach full term. To give detailed information on the dynamics of the SN or NSN chromatin during meiosis resumption, we performed a 9 hr time-lapse observation. The main significant differences recorded are: (1 reduction of the nuclear area only in SN oocytes; (2 ~17 min delay of GVBD in NSN oocytes; (3 chromatin condensation, after GVBD, in SN oocytes; (4 formation of 4-5 CHCs in SN oocytes; (5 increase of the perivitelline space, ~57 min later in NSN oocytes; (6 formation of a rosette-like disposition of CHCs, ~84 min later in SN oocytes; (7 appearance of the MI plate ~40 min later in NSN oocytes. Overall, we described a pathway of transition from the GV to the MII stage that is punctuated of discrete recordable events showing their specificity and occurring with different time kinetics in the two types of oocytes.

  12. Convective damping of buoyancy anomalies and its effect on lapse rates in the tropical lower troposphere

    Directory of Open Access Journals (Sweden)

    I. Folkins

    2006-01-01

    Full Text Available In regions of the tropics undergoing active deep convection, the variation of lower tropospheric lapse rates (2.0 km to 5.2 km with height is inconsistent with both reversible moist adiabatic and pseudoadiabatic assumptions. It is argued that this anomalous behavior arises from the tendency for the divergence of a convective buoyancy anomaly to be primarily offset by the collective divergence of other updrafts and downdrafts within one Rossby radius of deformation. Ordinarily, convective mass flux divergences are at least partially offset by an induced radiative mass flux divergence in the background atmosphere. If mass flux divergences from lower tropospheric convection are balanced mainly by those of neighboring updrafts/downdrafts, it would force the vertical clear sky radiative mass flux of the background atmosphere to be weakly dependent on height. This is observed at several radiosonde locations in the Western Tropical Pacific between 2.0 and the 5.2 km melting level. At tropical locations where SST's exceed 27°C over a region whose horizontal extent exceeds the local Rossby radius, this condition on the vertical variation of the background radiative mass flux partially constrains the range of physically allowed mean temperature and moisture profiles in the lower troposphere.

  13. DIFFERENT SECURITY MECHANISMS FOR DIFFERENT TYPE OF SECURITY LAPSES IN WMN- A REVIEW

    Directory of Open Access Journals (Sweden)

    Narender Singh

    2012-02-01

    Full Text Available The wireless mesh network(WMN is a wide network over globe . It is a multi-hop network which is made of static as well as the Mobile nodes which are connected with each other via special node called routers and Backbone gateways. As the infrastructure of WMN is large and it is multi-hop . It is difficult to provide security easily at different communications links. WMN is made up of many type communication media such as wired such as co-axial cable to optical fiber and Wireless Media such as low length WI-FI to high range and capacity Wimax. So it is heterogonous in nature. Due to heterogeneity, security lapses are much more over WMN. There my be several type of attacks which affects the data unlawfully. There are many security mechanisms are deployed which according to transmission media provide adequate security and make WMN a safe network fordata transmission. We discussed threats and there possible solution using security mechanisms This paper serves a baseline for developing a secured, full-proof WMN which takes care of all types of attacks.

  14. Time-lapse characterization of hydrothermal seawater and microbial interactions with basaltic tephra at Surtsey Volcano

    Science.gov (United States)

    Jackson, M. D.; Gudmundsson, M. T.; Bach, W.; Cappelletti, P.; Coleman, N. J.; Ivarsson, M.; Jónasson, K.; Jørgensen, S. L.; Marteinsson, V.; McPhie, J.; Moore, J. G.; Nielson, D.; Rhodes, J. M.; Rispoli, C.; Schiffman, P.; Stefánsson, A.; Türke, A.; Vanorio, T.; Weisenberger, T. B.; White, J. D. L.; Zierenberg, R.; Zimanowski, B.

    2015-12-01

    A new International Continental Drilling Program (ICDP) project will drill through the 50-year-old edifice of Surtsey Volcano, the youngest of the Vestmannaeyjar Islands along the south coast of Iceland, to perform interdisciplinary time-lapse investigations of hydrothermal and microbial interactions with basaltic tephra. The volcano, created in 1963-1967 by submarine and subaerial basaltic eruptions, was first drilled in 1979. In October 2014, a workshop funded by the ICDP convened 24 scientists from 10 countries for 3 and a half days on Heimaey Island to develop scientific objectives, site the drill holes, and organize logistical support. Representatives of the Surtsey Research Society and Environment Agency of Iceland also participated. Scientific themes focus on further determinations of the structure and eruptive processes of the type locality of Surtseyan volcanism, descriptions of changes in fluid geochemistry and microbial colonization of the subterrestrial deposits since drilling 35 years ago, and monitoring the evolution of hydrothermal and biological processes within the tephra deposits far into the future through the installation of a Surtsey subsurface observatory. The tephra deposits provide a geologic analog for developing specialty concretes with pyroclastic rock and evaluating their long-term performance under diverse hydrothermal conditions. Abstracts of research projects are posted at http://surtsey.icdp-online.org.

  15. Time-lapse analysis of potential cellular responsiveness to Johrei, a Japanese healing technique

    Directory of Open Access Journals (Sweden)

    Moore Dan

    2005-01-01

    Full Text Available Abstract Background Johrei is an alternative healing practice which involves the channeling of a purported universal healing energy to influence the health of another person. Despite little evidence to support the efficacy of such practices the use of such treatments is on the rise. Methods We assessed cultured human cancer cells for potential responsiveness to Johrei treatment from a short distance. Johrei treatment was delivered by practitioners who participated in teams of two, alternating every half hour for a total of four hours of treatment. The practitioners followed a defined set of mental procedures to minimize variability in mental states between experiments. An environmental chamber maintained optimal growth conditions for cells throughout the experiments. Computerized time-lapse microscopy allowed documentation of cancer cell proliferation and cell death before, during and after Johrei treatments. Results Comparing eight control experiments with eight Johrei intervention experiments, we found no evidence of a reproducible cellular response to Johrei treatment. Conclusion Cell death and proliferation rates of cultured human cancer cells do not appear responsive to Johrei treatment from a short distance.

  16. High-resolution time-lapse tomography of rat vertebrae during compressive loading: deformation response analysis

    Science.gov (United States)

    Fíla, T.; Kytýř, D.; Zlámal, P.; Kumpová, I.; Doktor, T.; Koudelka, P.; Jiroušek, O.

    2014-05-01

    This paper is focused on investigation of mechanical properties of rat vertebrae during compressive loading in the longitudinal direction of rat's spine. High-resolution time-lapse micro-tomography was used as a tool to create models of the inner structure and deformed shape in pre-defined deformation steps. First, peripheral areas of vertebra specimen were embedded in polymethyl methacrylate to obtain proper boundary conditions of contact between specimen and loading plattens. Experimental loading device designed for application in X-ray setups was utilized to compress the vertebrae in several deformation steps. High-resolution micro-tomography scanning was carried out at each deformation step. Specimen was irradiated in tomography device equipped with microfocus X-ray tube with 5μm focal spot size and large area flat panel detector. Spatial resolution of reconstructed three-dimensional images was approximately 10μm. Digital volume correlation algorithm was utilized in order to assess displacements in the microstructure in every loading increment. Finite element model of vertebra was created from volumetric data reconstructed from tomography of the undeformed specimen. Simulated compressive test of the developed finite element model was performed in order to compare stiffness and displacements obtained by digital volume correlation and finite element simulation.

  17. Cell segmentation for division rate estimation in computerized video time-lapse microscopy

    Science.gov (United States)

    He, Weijun; Wang, Xiaoxu; Metaxas, Dimitris; Mathew, Robin; White, Eileen

    2007-02-01

    The automated estimation of cell division rate plays an important role in the evaluation of a gene function in high throughput biomedical research. Using Computerized Video Time-Lapse (CVTL) microcopy , it is possible to follow a large number of cells in their physiological conditions for several generations. However analysis of this large volume data is complicated due to cell to cell contacts in a high density population. We approach this problem by segmenting out cells or cell clusters through a learning method. The feature of a pixel is represented by the intensity and gradient information in a small surrounding sub-window. Curve evolution techniques are used to accurately find the cell or cell cluster boundary. With the assumption that the average cell size is the same in each frame, we can use the cell area to estimate the cell division rate. Our segmentation results are compared to manually-defined ground truth. Both recall and precision measures for segmentation accuracy are above 95%.

  18. Time-lapse-Embryomonitoring und Oozytenvitrifikation: Neue Verfahren in der Reproduktionsmedizin aus ethischer Sicht

    Directory of Open Access Journals (Sweden)

    Kreß H

    2013-01-01

    Full Text Available Zurzeit zeigt sich der stetige technische Fortschritt der Reproduktionsmedizin an zwei neuen Verfahren. Es geht um die Möglichkeit, außerkörperlich erzeugte Embryonen in neuartigen Inkubatorsystemen zu beobachten (Time-lapse-Monitoring, und um die Kryokonservierung von Eizellen (Oozytenvitrifikation. Das Einfrieren von Eizellen kann in Frage kommen, wenn eine Frau einen Kinderwunsch aus persönlichen oder sozialen Gründen auf einen späteren Zeitpunkt verschieben möchte („social egg freezing“ oder wenn sie sich aus Krankheitsgründen einer keimzellschädigenden Behandlung aussetzen lassen muss (medizinisch indizierte Vitrifikation. Der Artikel beleuchtet diese unterschiedlichen Handlungsoptionen unter ethischen Aspekten. Er wägt jeweils ihre normative Verträglichkeit, ihre Humanverträglichkeit und ihre Sozialverträglichkeit ab und hält sie – bei manchen Differenzen, die im Einzelnen bestehen – insgesamt für ethisch vertretbar. Für konkrete Entscheidungen kommt es auf den Einzelfall und auf die Einzelumstände an.

  19. Distortion effects in a switch array UWB radar for time-lapse imaging of human heartbeats

    Science.gov (United States)

    Brovoll, Sverre; Berger, Tor; Aardal, Åyvind; Lande, Tor S.; Hamran, Svein-Erik

    2014-05-01

    Cardiovascular diseases (CVD) are a major cause of deaths all over the world. Microwave radar can be an alternative sensor for heart diagnostics and monitoring in modern healthcare that aids early detection of CVD symptoms. In this paper measurements from a switch array radar system are presented. This UWB system operates below 3 GHz and does time-lapse imaging of the beating heart inside the human body. The array consists of eight fat dipole elements. With a switch system, every possible sequence of transmit/receive element pairs can be selected to build a radar image from the recordings. To make the radar waves penetrate the human tissue, the antenna array is placed in contact with the body. Removal of the direct signal leakage through the antennas and body surface are done by high-pass (HP) filtering of the data prior to image processing. To analyze the results, measurements of moving spheres in air and simulations are carried out. We see that removal of the direct signal introduces amplitude distortion in the images. In addition, the effect of small target motion between the collection times of data from the individual elements is analyzed. With low pulse repetition frequency (PRF) this motion will distort the image. By using data from real measurements of heart motion in simulations, we analyze how the PRF and the antenna geometry influence this distortions.

  20. Estimation of the path-averaged atmospheric refractive index structure constant from time-lapse imagery

    Science.gov (United States)

    Basu, Santasri; McCrae, Jack E.; Fiorino, Steven T.

    2015-05-01

    A time-lapse imaging experiment was conducted to monitor the effects of the atmosphere over some period of time. A tripod-mounted digital camera captured images of a distant building every minute. Correlation techniques were used to calculate the position shifts between the images. Two factors causing shifts between the images are: atmospheric turbulence, causing the images to move randomly and quickly, plus changes in the average refractive index gradient along the path which cause the images to move vertically, more slowly and perhaps in noticeable correlation with solar heating and other weather conditions. A technique for estimating the path-averaged C 2n from the random component of the image motion is presented here. The technique uses a derived set of weighting functions that depend on the size of the imaging aperture and the patch size in the image whose motion is being tracked. Since this technique is phase based, it can be applied to strong turbulence paths where traditional irradiance based techniques suffer from saturation effects.

  1. Imaging Rainfall Infiltration Processes with the Time-Lapse Electrical Resistivity Imaging Method

    Science.gov (United States)

    Zhang, Gang; Zhang, Gui-Bin; Chen, Chien-chih; Chang, Ping-Yu; Wang, Tzu-Pin; Yen, Horng-Yuan; Dong, Jia-Jyun; Ni, Chuen-Fa; Chen, Su-Chin; Chen, Chao-Wei; Jia, Zheng-yuan

    2016-06-01

    Electrical Resistivity Imaging (ERI) was carried out continuously for 10 days to map the subsurface resistivity distribution along a potentially hazardous hillslope at the Jieshou Junior High School in Taoyuan, Taiwan. The reliability of the inverted resistivity structures down to about 25 m depth was examined with synthetic modeling using the same electrode arrangements installed on land surface as in field surveys, together with a DOI (depth-of-investigation) index calculated from the ERI data. The subsurface resistivity distribution is consistent with results from well logging. These ERI recordings were taken daily and provided highly resolved imagery of the resistivity distribution underground and illustrated the dynamical fluid-flow behavior due to heavy rainfall infiltration. Using Archie's law, the resistivity distribution was transformed into a map of relative water saturation (RWS), which is strongly correlated with the rainfall infiltration process. We then found that the averaged RWS is significantly correlated with daily precipitation. Our observations indicate that time-lapse ERI is effective in monitoring subterraneous rainfall infiltration; moreover, the preferential flow paths can be delineated according to the changes in averaged RWS derived from the ERI data.

  2. Thermal erosion of a permafrost coastline: Improving process-based models using time-lapse photography

    Science.gov (United States)

    Wobus, C.; Anderson, R.; Overeem, I.; Matell, N.; Clow, G.; Urban, F.

    2011-01-01

    Coastal erosion rates locally exceeding 30 m y-1 have been documented along Alaska's Beaufort Sea coastline, and a number of studies suggest that these erosion rates have accelerated as a result of climate change. However, a lack of direct observational evidence has limited our progress in quantifying the specific processes that connect climate change to coastal erosion rates in the Arctic. In particular, while longer ice-free periods are likely to lead to both warmer surface waters and longer fetch, the relative roles of thermal and mechanical (wave) erosion in driving coastal retreat have not been comprehensively quantified. We focus on a permafrost coastline in the northern National Petroleum Reserve-Alaska (NPR-A), where coastal erosion rates have averaged 10-15 m y-1 over two years of direct monitoring. We take advantage of these extraordinary rates of coastal erosion to observe and quantify coastal erosion directly via time-lapse photography in combination with meteorological observations. Our observations indicate that the erosion of these bluffs is largely thermally driven, but that surface winds play a crucial role in exposing the frozen bluffs to the radiatively warmed seawater that drives melting of interstitial ice. To first order, erosion in this setting can be modeled using formulations developed to describe iceberg deterioration in the open ocean. These simple models provide a conceptual framework for evaluating how climate-induced changes in thermal and wave energy might influence future erosion rates in this setting.

  3. Image-based characterization of thrombus formation in time-lapse DIC microscopy.

    Science.gov (United States)

    Brieu, Nicolas; Navab, Nassir; Serbanovic-Canic, Jovana; Ouwehand, Willem H; Stemple, Derek L; Cvejic, Ana; Groher, Martin

    2012-05-01

    The characterization of thrombus formation in time-lapse DIC microscopy is of increased interest for identifying genes which account for atherothrombosis and coronary artery diseases (CADs). In particular, we are interested in large-scale studies on zebrafish, which result in large amount of data, and require automatic processing. In this work, we present an image-based solution for the automatized extraction of parameters quantifying the temporal development of thrombotic plugs. Our system is based on the joint segmentation of thrombotic and aortic regions over time. This task is made difficult by the low contrast and the high dynamic conditions observed in vivo DIC microscopic scenes. Our key idea is to perform this segmentation by distinguishing the different motion patterns in image time series rather than by solving standard image segmentation tasks in each image frame. Thus, we are able to compensate for the poor imaging conditions. We model motion patterns by energies based on the idea of dynamic textures, and regularize the model by two prior energies on the shape of the aortic region and on the topological relationship between the thrombus and the aorta. We demonstrate the performance of our segmentation algorithm by qualitative and quantitative experiments on synthetic examples as well as on real in vivo microscopic sequences.

  4. Attention Networks and Consciousness

    Directory of Open Access Journals (Sweden)

    Michael ePosner

    2012-03-01

    Full Text Available The term consciousness is an important one in the vernacular of the western literature in many fields. It is no wonder that scientists have assumed that consciousness will be found as a component of the human brain and that we will come to understand its neural basis. However, there is rather little in common between consciousness as the neurologist would use it to diagnose the vegetative state, how the feminist would use it to support raising male consciousness of the economic plight of women and as the philosopher would use it when defining the really hard question of the subjective state of awareness induced by sensory qualities. When faced with this kind of problem it is usual to subdivide the term into more manageable perhaps partly operational definitions. Three meanings that capture aspects of consciousness are: (1 the neurology of the state of mind allowing coherent orientation to time and place (2 the selection of sensory or memorial information for awareness and (3 the voluntary control over overt responses. In each of these cases the mechanisms of consciousness overlap with one or more of the attentional networks that have been studied with the methods of cognitive neuroscience. In this paper we explore t

  5. Time-lapse three-dimensional inversion of complex conductivity data using an active time constrained (ATC) approach

    Science.gov (United States)

    Karaoulis, M.; Revil, A.; Werkema, D.D.; Minsley, B.J.; Woodruff, W.F.; Kemna, A.

    2011-01-01

    Induced polarization (more precisely the magnitude and phase of impedance of the subsurface) is measured using a network of electrodes located at the ground surface or in boreholes. This method yields important information related to the distribution of permeability and contaminants in the shallow subsurface. We propose a new time-lapse 3-D modelling and inversion algorithm to image the evolution of complex conductivity over time. We discretize the subsurface using hexahedron cells. Each cell is assigned a complex resistivity or conductivity value. Using the finite-element approach, we model the in-phase and out-of-phase (quadrature) electrical potentials on the 3-D grid, which are then transformed into apparent complex resistivity. Inhomogeneous Dirichlet boundary conditions are used at the boundary of the domain. The calculation of the Jacobian matrix is based on the principles of reciprocity. The goal of time-lapse inversion is to determine the change in the complex resistivity of each cell of the spatial grid as a function of time. Each model along the time axis is called a 'reference space model'. This approach can be simplified into an inverse problem looking for the optimum of several reference space models using the approximation that the material properties vary linearly in time between two subsequent reference models. Regularizations in both space domain and time domain reduce inversion artefacts and improve the stability of the inversion problem. In addition, the use of the time-lapse equations allows the simultaneous inversion of data obtained at different times in just one inversion step (4-D inversion). The advantages of this new inversion algorithm are demonstrated on synthetic time-lapse data resulting from the simulation of a salt tracer test in a heterogeneous random material described by an anisotropic semi-variogram. ?? 2011 The Authors Geophysical Journal International ?? 2011 RAS.

  6. Time-lapse Imaging of Primary Preneoplastic Mammary Epithelial Cells Derived from Genetically Engineered Mouse Models of Breast Cancer

    OpenAIRE

    Nakles, Rebecca E.; Millman, Sarah L.; Cabrera, M. Carla; Johnson, Peter; Mueller, Susette; Hoppe, Philipp S.; Schroeder, Timm; Furth, Priscilla A.

    2013-01-01

    Time-lapse imaging can be used to compare behavior of cultured primary preneoplastic mammary epithelial cells derived from different genetically engineered mouse models of breast cancer. For example, time between cell divisions (cell lifetimes), apoptotic cell numbers, evolution of morphological changes, and mechanism of colony formation can be quantified and compared in cells carrying specific genetic lesions. Primary mammary epithelial cell cultures are generated from mammary glands without...

  7. A Versatile Time-Lapse Camera System Developed by the Hawaiian Volcano Observatory for Use at Kilauea Volcano, Hawaii

    Science.gov (United States)

    Orr, Tim R.; Hoblitt, Richard P.

    2008-01-01

    Volcanoes can be difficult to study up close. Because it may be days, weeks, or even years between important events, direct observation is often impractical. In addition, volcanoes are often inaccessible due to their remote location and (or) harsh environmental conditions. An eruption adds another level of complexity to what already may be a difficult and dangerous situation. For these reasons, scientists at the U.S. Geological Survey (USGS) Hawaiian Volcano Observatory (HVO) have, for years, built camera systems to act as surrogate eyes. With the recent advances in digital-camera technology, these eyes are rapidly improving. One type of photographic monitoring involves the use of near-real-time network-enabled cameras installed at permanent sites (Hoblitt and others, in press). Time-lapse camera-systems, on the other hand, provide an inexpensive, easily transportable monitoring option that offers more versatility in site location. While time-lapse systems lack near-real-time capability, they provide higher image resolution and can be rapidly deployed in areas where the use of sophisticated telemetry required by the networked cameras systems is not practical. This report describes the latest generation (as of 2008) time-lapse camera system used by HVO for photograph acquisition in remote and hazardous sites on Kilauea Volcano.

  8. A time-series method for automated measurement of changes in mitotic and interphase duration from time-lapse movies.

    Directory of Open Access Journals (Sweden)

    Frederic D Sigoillot

    Full Text Available BACKGROUND: Automated time-lapse microscopy can visualize proliferation of large numbers of individual cells, enabling accurate measurement of the frequency of cell division and the duration of interphase and mitosis. However, extraction of quantitative information by manual inspection of time-lapse movies is too time-consuming to be useful for analysis of large experiments. METHODOLOGY/PRINCIPAL FINDINGS: Here we present an automated time-series approach that can measure changes in the duration of mitosis and interphase in individual cells expressing fluorescent histone 2B. The approach requires analysis of only 2 features, nuclear area and average intensity. Compared to supervised learning approaches, this method reduces processing time and does not require generation of training data sets. We demonstrate that this method is as sensitive as manual analysis in identifying small changes in interphase or mitotic duration induced by drug or siRNA treatment. CONCLUSIONS/SIGNIFICANCE: This approach should facilitate automated analysis of high-throughput time-lapse data sets to identify small molecules or gene products that influence timing of cell division.

  9. Direct Two-Dimensional Access to the Spatial Location of Covert Attention in Macaque Prefrontal Cortex.

    Science.gov (United States)

    Astrand, Elaine; Wardak, Claire; Baraduc, Pierre; Ben Hamed, Suliann

    2016-07-11

    Direct access to motor cortical information now enables tetraplegic patients to precisely control neuroprostheses and recover some autonomy. In contrast, explicit access to higher cortical cognitive functions, such as covert attention, has been missing. Indeed, this cognitive information, known only to the subject, can solely be inferred by an observer from the subject's overt behavior. Here, we present direct two-dimensional real-time access to where monkeys are covertly paying attention, using machine-learning decoding methods applied to their ongoing prefrontal cortical activity. Decoded attention was highly predictive of overt behavior in a cued target-detection task. Indeed, monkeys had a higher probability of detecting a visual stimulus as the distance between decoded attention and stimulus location decreased. This was true whether the visual stimulus was presented at the cued target location or at another distractor location. In error trials, in which the animals failed to detect the cued target stimulus, both the locations of attention and visual cue were misencoded. This misencoding coincided with a specific state of the prefrontal cortical population in which the shared variability between its different neurons (or noise correlations) was high, even before trial onset. This observation strongly suggests a functional link between high noise-correlation states and attentional failure. Overall, this real-time access to the attentional spotlight, as well as the identification of a neural signature of attentional lapses, open new perspectives both to the study of the neural bases of attention and to the remediation or enhancement of the attentional function using neurofeedback. PMID:27238280

  10. Attention in a bayesian framework

    DEFF Research Database (Denmark)

    Whiteley, Louise Emma; Sahani, Maneesh

    2012-01-01

    The behavioral phenomena of sensory attention are thought to reflect the allocation of a limited processing resource, but there is little consensus on the nature of the resource or why it should be limited. Here we argue that a fundamental bottleneck emerges naturally within Bayesian models...... of perception, and use this observation to frame a new computational account of the need for, and action of, attention - unifying diverse attentional phenomena in a way that goes beyond previous inferential, probabilistic and Bayesian models. Attentional effects are most evident in cluttered environments......, and include both selective phenomena, where attention is invoked by cues that point to particular stimuli, and integrative phenomena, where attention is invoked dynamically by endogenous processing. However, most previous Bayesian accounts of attention have focused on describing relatively simple experimental...

  11. Chewing and Attention: A Positive Effect on Sustained Attention

    OpenAIRE

    Yoshiyuki Hirano; Minoru Onozuka

    2015-01-01

    Chewing is crushing food not only to aid swallowing and digestion, but also to help stress relief and regulate cognitive function, especially in attention. It is well known that chewing gum is used for sleepiness prevention during work, learning, and driving, suggesting a link between chewing and sustained attention. We hypothesized that chewing elevates attention and/or alertness, leading to improvements in cognitive performance. We carried out a systematic review of the PubMed database. We ...

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

    Science.gov (United States)

    Rahimi, H.; Hamzehloo, H.

    2008-06-01

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

  13. Enhanced imaging of CO2 at the Ketzin storage site: Inversion of 3D time-lapse seismic data

    Science.gov (United States)

    Gil, M.; Götz, J.; Ivanova, A.; Juhlin, C.; Krawczyk, C. M.; Lüth, S.; Yang, C.

    2012-04-01

    The Ketzin test site, located near Berlin, is Europe's longest-operating on-shore CO2 storage site. As of December 2011, more than 56,000 tons of food grade CO2 has been injected since June 2008 in an anticlinal structure of the Northeast German Basin. The target reservoir consists of porous, brine bearing sandstone units of the Upper Triassic Stuttgart Formation at approximately 630 to 650 m depth. In order to enhance the understanding of the structural geometry of the site and to investigate the extension of the CO2-plume, several geophysical monitoring methods are being applied at Ketzin, among these are active seismic measurements, geoelectrics and borehole measurements. Among the various seismic techniques (e.g. 2D reflection surveys, crosshole tomography, Vertical Seismic Profiling, 2D- and 3D-Moving Source Profiling) employed at this pilot site, 3D time-lapse reflection surveys are an important component. The baseline 3D survey was acquired in 2005 and the first repeat measurements were performed in 2009 after injection of about 22,000 tons of CO2. The second repeat survey is planned to be carried out in fall 2012. These measurements allow the time-lapse signature of the injected CO2 to be imaged. The time-lapse amplitude variation attributed to the injected CO2 in the reservoir matches, considering detection limits of seismic surface measurements, the expected distribution of the CO2 plume derived from reservoir simulations. Previous attempts towards a quantitative interpretation were based on integrative considerations of different types of geophysical measurements using strict assumptions and characterized by large error bars. In order to increase the resolution and reliability of the data and to improve estimation of rock properties and especially to enhance the imaging resolution of the CO2-plume, the time-lapse 3D seismic data have now been inverted for seismic impedances with different methods, which is the focus of this presentation. One difficulty

  14. STUDY OF TIME LAPSE IN FOREIGN BODY ASPIRATION IN RELATION TO CHEST X - RAY AND TYPE OF FOREIGN BODY

    Directory of Open Access Journals (Sweden)

    Salma

    2015-10-01

    Full Text Available INTRODUCTI ON: Foreign body aspiration in pediatrics is a potentially fatal accident which will continue until children explore their surroundings with their hand and mouth. Pediatric aspirations will persist until mankind exists. Not all foreign body aspirations are witnessed hence chances of delay in diagnosing an aspiration are high. Delay in diagnosis depends on site and character of foreign body aspirated. The chest x - ray findings and type of foreign body extracted vary depending on the duration the foreign body remains in airway . OBJECTIVE: To study the X - ray finding in pediatric airway aspiration and its relation to time lapse, the type and site of lodgment of foreign body extracted via bronchoscopy. The type of foreign body in relation to time lapse in aspiration. MATERIAL AND METHODS: This was a prospective study done in Bapuji child health institute and research center, JJM Medical College, Davangere . History and pre bronchoscopy x - Ray finding were noted for 65 children who were posted for suspicious bronchoscopy from August 2011 to September 2013. 11 children were excluded from study as they showed no foreign body on bronchoscopy. Time lapse in aspir ation and seeking medical care was noted. The bronchoscopic findings regarding site of foreign body lodgment and type of foreign body were recorded. The type of foreign body and variation of x - ray picture in relation to time lapse in aspiration were noted. Data collected was analyzed using descriptive statistics. RESULT: It was observed that mean age was 28 months. About 80% of the cases were between 1 to 3 years age. 82% (n=53/54 were radio lucent foreign body, only 1.5% (n=1/54 were radio o paque. Site of lodgment of foreign body was right main bronchus in 48% (n=26/54, left main bronchus 46% (n=25/54 , tracheal 1.85% (n=1/54, subglottic 1.85% (n=1/54, carinal 1.85% (n=1/54, multiple site i.e. left bronchus +right bronchus+ carinal 1.85% (n=1/54. Groundnut was most common

  15. Overland flow dynamics through visual observation using time-lapse photographs

    Science.gov (United States)

    Silasari, Rasmiaditya; Blöschl, Günter

    2016-04-01

    Overland flow process on agricultural land is important to be investigated as it affects the stream discharge and water quality assessment. During rainfall events the formation of overland flow may happen through different processes (i.e. Hortonian or saturation excess overland flow) based on the governing soil hydraulic parameters (i.e. soil infiltration rate, soil water capacity). The dynamics of the soil water state and the processes will affect the surface runoff response which can be analyzed visually by observing the saturation patterns with a camera. Although visual observation was proven useful in laboratory experiments, the technique is not yet assessed for natural rainfall events. The aim of this work is to explore the use of time-lapse photographs of naturally occurring-saturation patterns in understanding the threshold processes of overland flow generation. The image processing produces orthographic projection of the saturation patterns which will be used to assess the dynamics of overland flow formation in relation with soil moisture state and rainfall magnitude. The camera observation was performed at Hydrological Open Air Laboratory (HOAL) catchment at Petzenkirchen, Lower Austria. The catchment covers an area of 66 ha dominated with agricultural land (87%). The mean annual precipitation and mean annual flow at catchment outlet are 750 mm and 4 l/s, respectively. The camera was set to observe the overland flow along a thalweg on an arable field which was drained in 1950s and has advantages of: (1) representing agricultural land as the dominant part of the catchment, (2) adjacent to the stream with clear visibility (no obstructing objects, such as trees), (3) drained area provides extra cases in understanding the response of tile drain outflow to overland flow formation and vice versa, and (4) in the vicinity of TDT soil moisture stations. The camera takes a picture with 1280 x 720 pixels resolution every minute and sends it directly in a PC via fiber

  16. Using electromagnetic conductivity imaging to generate time-lapse soil moisture estimates.

    Science.gov (United States)

    Huang, Jingyi; Scuderio, Elia; Corwin, Dennis; Triantafilis, John

    2015-04-01

    Irrigated agriculture is crucial to the agricultural productivity of the Moreno valley. To maintain profitability, more will need to be done by irrigators with less water, owing to competing demands from rapidly expanding urbanisation in southern California. In this regard, irrigators need to understand the spatial and temporal variation of soil moisture to discern inefficiencies. However, soil moisture is difficult to measure and monitor, unless a large bank of soil sensors are installed and at various depths in the profile. In order to value add to the limited amount of information, geophysical techniques, such as direct current resisivity (DCR) arrays are used to develop electrical resistivity images (ERI). Whilst successful the approach is time consuming and labour intensive. In this research we describe how equivalent data can be collected using a proximal sensing electromagnetic (EM) induction instrument (i.e. DUALEM-421) and inversion software (EM4Soil) to generate EM conductivity images (EMCI). Figure 1 shows the EMCI generated from DUALEM-421 data acquired at various days of a time-lapse experiment and including; day a) 0, b) 1, c) 2, d) 3, e) 5, f) 7 and g) 11. We calibrate the estimates of true electrical conductivity (sigma - mS/m) with volumetric moisture content and show with good accuracy the spatial and temporal variation of soil moisture status and over 12 day period. The results show clearly that the pivot sprinkler irrigation system is effective at providing sufficient amounts of water to the top 0.5 m of a Lucerne crop (i.e. red shaded areas of high sigma). However, in some places faulty sprinklers are evident owing to the lack of wetting (i.e. blue shaded areas of low sigma). In addition, and over time, our approach shows clearly the effect the Lucerne crop has in drying the soil profile and using the soil moisture.

  17. Time Lapse Storey Building Early Monitoring Based on Rapid Seismic Response Analysis in Indonesia

    Science.gov (United States)

    Julius, A. M.

    2015-12-01

    Within the last decade, advances in the acquisition, processing and transmission of data from seismic monitoring has contributed to the growth in the number structures instrumented with such systems. An equally important factor for such growth can be attributed to the demands by stakeholders to find rapid answers to important questions related to the functionality or state of "health" of structures during and immediately of a seismic events. Consequently, this study aims to monitor the storey building based on seismic response i. e. earthquake and tremor analysis at short time lapse using accelerographs data. This study used one of storey building (X) in Jakarta city that suffered the effects of Kebumen earthquake January 25th 2014, Pandeglang earthquake July 9th 2014, and Lebak earthquake November 8th 2014. Tremors used in this study are tremors after the three following earthquakes. Data processing used to determine peak ground acceleration (PGA), peak ground velocity (PGV), peak ground displacement (PGD), spectral acceleration (SA), spectral velocity (SV), spectral displacement (SD), A/V ratio, acceleration amplification and effective duration (te). Then determine the natural frequency (f0) and peak of H/V ratio using H/V ratio method. The earthquakes data processing result shows the value of peak ground motion, spectrum response, A/V ratio and acceleration amplification increases with height, while the value of the effective duration decreases. Then, tremors data processing result one month after each earthquakes shows the natural frequency of building in constant value. Increasing of peak ground motion, spectrum response, A/V ratio, acceleration amplification, then decrease of effective duration following the increase of building floors shows that the building construction supports the increasing of shaking and strongly influenced by local site effect. The constant value of building natural frequency shows the building still in good performance. This

  18. Spatio-Temporal Variation and Monsoon Effect on the Temperature Lapse Rate of a Subtropical Island

    Directory of Open Access Journals (Sweden)

    Ching-An Chiu

    2014-01-01

    Full Text Available Temperature lapse rate (TLR has been widely used in the prediction of mountain climate and vegetation and in many ecological models. The aims of this paper are to explore the spatio-temporal variations and monsoon effects on the TLR in the subtropical island of Taiwan with its steep Central Mountain Region (CMR. A TLR analysis using the 32-year monthly mean air temperatures and elevations from 219 weather stations (sea level to 3852 m a.s.l. was performed based on different geographical regions and monsoon exposures. The results revealed that the average TLR for all of Taiwan is -5.17°C-5.17°C km-1, with a general tendency to be steeper in summer and shallower in winter. The results are also shallower than the typical or global average TLR of -6.5°C-6.5°C km-1. During the prevailing northeast monsoon season (winter, the TLR exhibits a contrast between the windward side (steeper, -5.97°C-5.97°C km-1 and the leeward side (shallower, -4.51°C-4.51°C km-1. From the diagnosis on spatial characteristics of monthly cloud amount and vertical atmospheric profiles, this contrasting phenomenon may be explained by the warming effect of onshore stratus clouds (500 - 2500 m depth on cold and dry Siberian monsoon air on the windward side of the CMR. On the southwestern leeward side of the CMR, the low-level (1500 m, the weak ventilation atmosphere and temperature inversion make the TLR shallower than on the windward side.

  19. Time lapse inversion of 2D ERT data for monitoring river water infiltration

    Science.gov (United States)

    Wallin, E. L.; Johnson, T. C.; Greenwood, W. J.

    2011-12-01

    Uranium transport in the 300 area is driven by both the chemical and physical effects of stage fluctuations in the Columbia River and resulting river water, ground water interaction. Because river water is less conductive than groundwater, it serves as a natural tracer that can be imaged using surface ERT. We've monitored 4 lines for 4 months over the high stage spring runoff interval to identify preferred flowpaths for river water intrusion. The four lines overlay former waste disposal sites including the processing ponds and sanitary leach trenches. We have used this ERT data set to investigate two methods of time lapse inversion, sequential and all-at-once. Each technique is a model difference approach as opposed to a data difference inversion approach. Both use a regularized inversion with model constraints that regularize spatially and temporally. For the sequential inversion, the starting and reference models are taken from the previous inversion. Both starting and reference models are taken from the first inversion for the all-at-once method. In either case an inversion is triggered if data misfit from the starting model exceeds the chi-squared convergence criteria. It was found that starting with a relatively smooth model provided better visualization of temporal conductivity changes when inverting all data sets with the same initial model, while an initial model exhibiting smaller data misfit may be used successfully as the starting point for sequential inversion. Inland conductivity changes within model cells were found to be highly correlated with river stage, and when paired with the characterization model, provide evidence of waste trenches, the processing pond, as well as the existence of a paleo-channel incised into the Ringold Formation and dipping structures on the Hanford-Ringold contact that provide preferred pathways for river water intrusion.

  20. Time Lapse Gravity and Seismic Monitoring of CO2 Injection at the West Hastings Field, Texas

    Science.gov (United States)

    Ferguson, J. F.; Richards, T.; Klopping, F.; MacQueen, J.; Hosseini, S. A.

    2015-12-01

    Time lapse or 4D gravity and seismic reflection surveys are being conducted at the West Hastings Field near Houston, Texas to monitor the progress of CO2 injection. This Department of Energy supported CO2 sequestration experiment is conducted in conjunction with a Denbury Onshore, LLC tertiary recovery project. The reservoir is at a depth of 1.8 km in the Oligocene Frio sands and has been produced since the 1930s. Goals are an accounting and mapping of the injected CO2 and to determine if migration occurs along intra-reservoir faults. An integrated interpretation of the geophysical surveys will be made together with well logs and engineering data. Gravity monitoring of water versus gas replacement has been very successful, but liquid phase CO2 monitoring is problematic due to the smaller density contrast with respect to oil and water. This reservoir has a small volume to depth ratio and hence only a small gravity difference signal is expected on the surface. New borehole gravity technology introduced by Micro-g-Lacoste can make gravity measurements at near reservoir depths with a much higher signal to noise ratio. This method has been successfully evaluated on a simulation of the Hastings project. Field operations have been conducted for repeated surface and borehole gravity surveys beginning in 2013. The surface survey of 95 stations covers an area of 3 by 5 km and 22 borehole gravity logs are run in the interval above the Frio formation. 4D seismic reflection surveys are being made at 6 month intervals on the surface and in 3 VSP wells. CO2 injection into the targeted portion of the reservoir only began in early 2015 and monitoring will continue into 2017. To date only the baseline reservoir conditions have been assessed. The overall success of the gravity monitoring will not be determined until 2017.

  1. ENVIRONMENTAL MONITORING OF LEAKS USING TIME LAPSED LONG ELECTRODE ELECTRICAL RESISTIVITY

    International Nuclear Information System (INIS)

    Highly industrialized areas pose challenges for surface electrical resistivity characterization due to metallic infrastructure. The infrastructure is typically more conductive than the desired targets and will mask the deeper subsurface information. These challenges may be minimized if steel-cased wells are used as long electrodes in the area near the target. We demonstrate a method of using long electrodes to electrically monitor a simulated leak from an underground storage tank with both synthetic examples and a field demonstration. The synthetic examples place a simple target of varying electrical properties beneath a very low resistivity layer. The layer is meant to replicate the effects of infrastructure. Both surface and long electrodes are tested on the synthetic domain. The leak demonstration for the field experiment is simulated by injecting a high conductivity fluid in a perforated well within the S tank farm at Hanford, and the resistivity measurements are made before and after the leak test. All data are processed in four dimensions, where a regularization procedure is applied in both the time and space domains. The synthetic test case shows that the long electrode ERM could detect relative changes in resistivity that are commensurate with the differing target properties. The surface electrodes, on the other hand, had a more difficult time matching the original target's footprint. The field results shows a lowered resistivity feature develop south of the injection site after cessation of the injections. The time lapsed regularization parameter has a strong influence on the differences in inverted resistivity between the pre and post injection datasets, but the interpretation of the target is consistent across all values of the parameter. The long electrode ERM method may provide a tool for near real-time monitoring of leaking underground storage tanks.

  2. ENTREPRENEURIAL ALERTNESS AND PAYING ATTENTION

    OpenAIRE

    DAVE VALLIERE

    2013-01-01

    This article uses theoretical approaches from cognitive psychology to examine the basis for entrepreneurial alertness and to connect it to existing theories of attention in strategic management and decision-making. It thereby provides a theoretical basis for understanding how entrepreneurial alertness leads the individual to pay attention to new opportunities. A model is developed to show how attention and entrepreneurial alertness work together to support the recognition or creation of oppor...

  3. Visual attention in Drosophila melanogaster

    OpenAIRE

    Sareen, Preeti

    2012-01-01

    There is such vast amount of visual information in our surroundings at any time that filtering out the important information for further processing is a basic requirement for any visual system. This is accomplished by deploying attention to focus on one source of sensory inputs to the exclusion of others (Luck and Mangun 2009). Attention has been studied extensively in humans and non human primates (NHPs). In Drosophila, visual attention was first demonstrated in 1980 (Wolf and Heisenberg 198...

  4. When sustained attention impairs perception

    OpenAIRE

    Ling, Sam; Carrasco, Marisa

    2006-01-01

    Virtually all behavioral and neurophysiological studies have shown that sustained (endogenous, conceptually driven) attention enhances perception. But can this enhancement be held indefinitely? We assessed the time course of attention’s effects on contrast sensitivity, reasoning that if attention does indeed boost stimulus strength, the strengthened representation could result in stronger adaptation over time. We found that attention initially enhances contrast sensitivity, but that over time...

  5. Advertising, Attention, and Financial Markets

    OpenAIRE

    Focke, Florens; Ruenzi, Stefan; Ungeheuer, Michael

    2015-01-01

    We investigate the impact of product market advertising on investor attention and financial market outcomes. Using daily advertising data allows us to identify short-term effects of advertising. We measure daily investor attention based the company's number of Wikipedia page views. We show that TV and newspaper advertising positively impacts short-term investor attention. It also positively impacts turnover and liquidity, but the effects are not economically significant. Most importantly, ass...

  6. Attention, Media, Value and Economics

    OpenAIRE

    Aigrain, Philippe

    1997-01-01

    Building on the debate about the "attention economy" initiated by Michael Goldhaber and Rishab Aiyer Ghosh, I introduce the notion of valuing process, i.e. the process by which potential value can be translated in an economy. I show that the valuing processes applicable to attention depend on the nature of the media through which attention can be given and looked for. From there, I claim that the integration between attention and action, and the creation of a related literacy are the keys to ...

  7. Limited Attention and Discourse Structure

    CERN Document Server

    Walker, M A

    1995-01-01

    This squib examines the role of limited attention in a theory of discourse structure and proposes a model of attentional state that relates current hierarchical theories of discourse structure to empirical evidence about human discourse processing capabilities. First, I present examples that are not predicted by Grosz and Sidner's stack model of attentional state. Then I consider an alternative model of attentional state, the cache model, which accounts for the examples, and which makes particular processing predictions. Finally I suggest a number of ways that future research could distinguish the predictions of the cache model and the stack model.

  8. Attentional networks in developmental dyscalculia

    Directory of Open Access Journals (Sweden)

    Henik Avishai

    2010-01-01

    Full Text Available Abstract Background Very little is known about attention deficits in developmental dyscalculia, hence, this study was designed to provide the missing information. We examined attention abilities of participants suffering from developmental dyscalculia using the attention networks test - interactions. This test was designed to examine three different attention networks--executive function, orienting and alerting--and the interactions between them. Methods Fourteen university students that were diagnosed as suffering from developmental dyscalculia--intelligence and reading abilities in the normal range and no indication of attention-deficit hyperactivity disorder--and 14 matched controls were tested using the attention networks test - interactions. All participants were given preliminary tests to measure mathematical abilities, reading, attention and intelligence. Results The results revealed deficits in the alerting network--a larger alerting effect--and in the executive function networks--a larger congruity effect in developmental dyscalculia participants. The interaction between the alerting and executive function networks was also modulated by group. In addition, developmental dyscalculia participants were slower to respond in the non-cued conditions. Conclusions These results imply specific attentional deficits in pure developmental dyscalculia. Namely, those with developmental dyscalculia seem to be deficient in the executive function and alertness networks. They suffer from difficulty in recruiting attention, in addition to the deficits in numerical processing.

  9. Unaware yet reliant on attention: Experience sampling reveals that mind-wandering impedes implicit learning.

    Science.gov (United States)

    Franklin, Michael S; Smallwood, Jonathan; Zedelius, Claire M; Broadway, James M; Schooler, Jonathan W

    2016-02-01

    Although implicit learning has been widely studied, controversy remains regarding its reliance on attentional resources. A central issue in this controversy is the question of how best to manipulate attention. The usual approach of comparing implicit learning in a serial reaction time (SRT) task under single- versus dual-task conditions is known to be problematic, because the secondary task may not only divert attention away from the primary task, but also interfere with the implicit-learning process itself. To address this confound, in the present study we used an experience-sampling instead of a dual-task approach. We assessed lapses of attention (mind-wandering) with experience-sampling thought probes during a standard implicit-learning SRT task. The results revealed a significant negative correlation between mind-wandering and implicit learning. Thus, greater task focus was associated with improved implicit sequence learning. This result suggests that, at least in the context of this SRT task, optimal implicit learning relies on attention.

  10. Visual attention: The past 25 years

    OpenAIRE

    Carrasco, Marisa

    2011-01-01

    This review focuses on covert attention and how it alters early vision. I explain why attention is considered a selective process, the constructs of covert attention, spatial endogenous and exogenous attention, and feature-based attention. I explain how in the last 25 years research on attention has characterized the effects of covert attention on spatial filters and how attention influences the selection of stimuli of interest. This review includes the effects of spatial attention on discrim...

  11. Visuospatial selective attention in chickens.

    Science.gov (United States)

    Sridharan, Devarajan; Ramamurthy, Deepa L; Schwarz, Jason S; Knudsen, Eric I

    2014-05-13

    Voluntary control of attention promotes intelligent, adaptive behaviors by enabling the selective processing of information that is most relevant for making decisions. Despite extensive research on attention in primates, the capacity for selective attention in nonprimate species has never been quantified. Here we demonstrate selective attention in chickens by applying protocols that have been used to characterize visual spatial attention in primates. Chickens were trained to localize and report the vertical position of a target in the presence of task-relevant distracters. A spatial cue, the location of which varied across individual trials, indicated the horizontal, but not vertical, position of the upcoming target. Spatial cueing improved localization performance: accuracy (d') increased and reaction times decreased in a space-specific manner. Distracters severely impaired perceptual performance, and this impairment was greatly reduced by spatial cueing. Signal detection analysis with an "indecision" model demonstrated that spatial cueing significantly increased choice certainty in localizing targets. By contrast, error-aversion certainty (certainty of not making an error) remained essentially constant across cueing protocols, target contrasts, and individuals. The results show that chickens shift spatial attention rapidly and dynamically, following principles of stimulus selection that closely parallel those documented in primates. The findings suggest that the mechanisms that control attention have been conserved through evolution, and establish chickens--a highly visual species that is easily trained and amenable to cutting-edge experimental technologies--as an attractive model for linking behavior to neural mechanisms of selective attention.

  12. Caffeine Modulates Attention Network Function

    Science.gov (United States)

    Brunye, Tad T.; Mahoney, Caroline R.; Lieberman, Harris R.; Taylor, Holly A.

    2010-01-01

    The present work investigated the effects of caffeine (0 mg, 100 mg, 200 mg, 400 mg) on a flanker task designed to test Posner's three visual attention network functions: alerting, orienting, and executive control [Posner, M. I. (2004). "Cognitive neuroscience of attention". New York, NY: Guilford Press]. In a placebo-controlled, double-blind…

  13. Combining segmentation and attention: a new foveal attention model

    Directory of Open Access Journals (Sweden)

    Rebeca eMarfil

    2014-08-01

    Full Text Available Artificial vision systems cannot process all the information that they receive from the world in real time because it is highly expensive and inefficient in terms of computational cost. Inspired by biological perception systems, articial attention models pursuit to select only the relevant part of the scene. Besides, it is well established that the units of attention on human vision are not merely spatial but closely related to perceptual objects (proto-objects. This implies a strong bidirectional relationship between segmentation and attention processes. Therefore, while the segmentation process is the responsible to extract the proto-objects from the scene, attention can guide segmentation, arising the concept of foveal attention. When the focus of attention is deployed from one visual unit to another, the rest of the scene is perceived but at a lower resolution that the focused object. The result is a multi-resolution visual perception in which the fovea, a dimple on the central retina, provides the highest resolution vision. In this paper, a bottom-up foveal attention model is presented. In this model the input image is a foveal image represented using a Cartesian Foveal Geometry (CFG, which encodes the field of view of the sensor as a fovea (placed in the focus of attention surrounded by a set of concentric rings with decreasing resolution. Then multirresolution perceptual segmentation is performed by building a foveal polygon using the Bounded Irregular Pyramid (BIP. Bottom-up attention is enclosed in the same structure, allowing to set the fovea over the most salient image proto-object. Saliency is computed as a linear combination of multiple low level features such us colour and intensity contrast, symmetry, orientation and roundness. Obtained results from natural images show that the performance of the combination of hierarchical foveal segmentation and saliency estimation is good in terms of accuracy and speed.

  14. Social reward shapes attentional biases.

    Science.gov (United States)

    Anderson, Brian A

    2016-01-01

    Paying attention to stimuli that predict a reward outcome is important for an organism to survive and thrive. When visual stimuli are associated with tangible, extrinsic rewards such as money or food, these stimuli acquire high attentional priority and come to automatically capture attention. In humans and other primates, however, many behaviors are not motivated directly by such extrinsic rewards, but rather by the social feedback that results from performing those behaviors. In the present study, I examine whether positive social feedback can similarly influence attentional bias. The results show that stimuli previously associated with a high probability of positive social feedback elicit value-driven attentional capture, much like stimuli associated with extrinsic rewards. Unlike with extrinsic rewards, however, such stimuli also influence task-specific motivation. My findings offer a potential mechanism by which social reward shapes the information that we prioritize when perceiving the world around us. PMID:25941868

  15. What Attracts Decision Makers' Attention?

    DEFF Research Database (Denmark)

    Bentzen, Eric; Christiansen, John K.; Varnes, Claus J.

    2011-01-01

    /methodology/approach – The present analysis draws on insights from previous research into decision making in product and portfolio management and studies on organizational decision making. The authors frame why the attention of decision makers is so critical in complex situations. Data for this study were collected through direct...... portfolio meetings. The study seeks to investigate how managers allocate their attention and the role of different factors for their attention. Observations also make it possible to compare prior research and expectations with the actual observed behavior of decision makers. Design......Purpose – Managers' attention is a scarce resource in complex innovation settings. Prior research on the factors to which managers pay attention is mostly based on surveys. The present study aims to address the need for knowledge about the behavior of decision makers based on observations from...

  16. Emotional distractors can enhance attention

    Science.gov (United States)

    Sussman, Tamara J.; Heller, Wendy; Miller, Gregory A.; Mohanty, Aprajita

    2015-01-01

    The deleterious effects of emotional distractors on attention are well demonstrated. However, it is unclear if emotional distractors inevitably disrupt task-relevant attention. Using multilevel modeling (MLM), the present study examined the impact of valence and arousal dimensions of distracting emotional stimuli and individual differences in anxiety on task-relevant processing. Consistent with prior literature, high-arousal negative distractors were associated with poor task-relevant attention compared to positive and neutral distractors. However, low-arousal negative distractors were associated with better task-relevant performance than were positive and neutral distractors. Furthermore, these effects were accentuated by individual differences in worry. These findings challenge assumptions that distraction and worry must be minimized for augmented attentional performance. Overall, these results emphasize the importance of taking into account emotional dimensions of arousal and valence as well as individual differences in anxiety when examining attention in the presence of emotional distractors. PMID:24058065

  17. Guiding Attention by Cooperative Cues

    Institute of Scientific and Technical Information of China (English)

    KangWoo Lee

    2008-01-01

    A common assumption in visual attention is based on the rationale of "limited capacity of information pro-ceasing". From this view point there is little consideration of how different information channels or modules are cooperating because cells in processing stages are forced to compete for the limited resource. To examine the mechanism behind the cooperative behavior of information channels, a computational model of selective attention is implemented based on two hypotheses. Unlike the traditional view of visual attention, the cooperative behavior is assumed to be a dynamic integration process between the bottom-up and top-down information. Furthermore, top-down information is assumed to provide a contextual cue during selection process and to guide the attentional allocation among many bottom-up candidates. The result from a series of simulation with still and video images showed some interesting properties that could not be explained by the competitive aspect of selective attention alone.

  18. Variogram-based inversion of time-lapse electrical resistivity data: development and application to a thermal tracing experiment

    Science.gov (United States)

    Hermans, Thomas; Nguyen, Frédéric

    2015-04-01

    Electrical resistivity tomography (ERT) has become a popular imaging methodology in a broad range of applications given its large sensitivity to subsurface parameters and its relative simplicity to implement. More particularly, time-lapse ERT is now increasingly used for monitoring purposes in many contexts such as water content, permafrost, landslide, seawater intrusion, solute transport or heat transport experiments. Specific inversion schemes have been developed for time-lapse data sets. However, in contrast with static inversions for which many techniques including geostatistical, minimum support or structural inversion are commonly applied, most of the methodologies for time-lapse inversion still rely on non-physically based spatial and/or temporal smoothing of the parameters or parameter changes. In this work, we propose a time-lapse ERT inversion scheme based on the difference inversion scheme. We replace the standard smoothness-constraint regularization operator by the parameter change covariance matrix. The objective function can be expressed as ψdiff(Δm ) = ||Wd [d - d0 + f(m0)- f(m )]||2 + λ ||||C-Δ0m.5Δm ||||2 where Wd is the data weighting matrix, d and d0 are the data sets corresponding to the considered time-step and to the background, f() is the forward operator, m and m0 are the models corresponding to the considered time-step and to the background, Δm is the parameter change (resistivity), CΔm is the parameter change covariance matrix and λ the regularization parameter. This operator takes into account the correlation between changes in resistivity at different locations through a variogram computed using independent data (e.g., electromagnetic logs). It may vary for subsequent time-steps if the correlation length is time-dependent. The methodology is first validated and compared to the standard smoothness-constraint inversion using a synthetic benchmark simulating the injection of a conductive tracer into a homogeneous aquifer inducing

  19. Near real-time imaging of molasses injections using time-lapse electrical geophysics at the Brandywine DRMO, Brandywine, Maryland

    Science.gov (United States)

    Versteeg, R. J.; Johnson, T.; Major, B.; Day-Lewis, F. D.; Lane, J. W.

    2010-12-01

    Enhanced bioremediation, which involves introduction of amendments to promote biodegradation, increasingly is used to accelerate cleanup of recalcitrant compounds and has been identified as the preferred remedial treatment at many contaminated sites. Although blind introduction of amendments can lead to sub-optimal or ineffective remediation, the distribution of amendment throughout the treatment zone is difficult to measure using conventional sampling. Because amendments and their degradation products commonly have electrical properties that differ from those of ambient soil, time-lapse electrical geophysical monitoring has the potential to verify amendment emplacement and distribution. In order for geophysical monitoring to be useful, however, results of the injection ideally should be accessible in near real time. In August 2010, we demonstrated the feasibility of near real-time, autonomous electrical geophysical monitoring of amendment injections at the former Defense Reutilization and Marketing Office (DRMO) in Brandywine, Maryland. Two injections of about 1000 gallons each of molasses, a widely used amendment for enhanced bioremediation, were monitored using measurements taken with borehole and surface electrodes. During the injections, multi-channel resistance data were recorded; data were transmitted to a server and processed using a parallel resistivity inversion code; and results in the form of time-lapse imagery subsequently were posted to a website. This process occurred automatically without human intervention. The resulting time-lapse imagery clearly showed the evolution of the molasses plume. The delay between measurements and online delivery of images was between 45 and 60 minutes, thus providing actionable information that could support decisions about field procedures and a check on whether amendment reached target zones. This experiment demonstrates the feasibility of using electrical imaging as a monitoring tool both during amendment emplacement

  20. Effect of Time Lapse on the Diagnostic Accuracy of Cone Beam Computed Tomography for Detection of Vertical Root Fractures.

    Science.gov (United States)

    Eskandarloo, Amir; Asl, Amin Mahdavi; Jalalzadeh, Mohsen; Tayari, Maryam; Hosseinipanah, Mohammad; Fardmal, Javad; Shokri, Abbas

    2016-01-01

    Accurate and early diagnosis of vertical root fractures (VRFs) is imperative to prevent extensive bone loss and unnecessary endodontic and prosthodontic treatments. The aim of this study was to assess the effect of time lapse on the diagnostic accuracy of cone beam computed tomography (CBCT) for VRFs in endodontically treated dog's teeth. Forty-eight incisors and premolars of three adult male dogs underwent root canal therapy. The teeth were assigned to two groups: VRFs were artificially induced in the first group (n=24) while the teeth in the second group remained intact (n=24). The CBCT scans were obtained by NewTom 3G unit immediately after inducing VRFs and after one, two, three, four, eight, 12 and 16 weeks. Three oral and maxillofacial radiologists blinded to the date of radiographs assessed the presence/absence of VRFs on CBCT scans. The sensitivity, specificity and accuracy values were calculated and data were analyzed using SPSS v.16 software and ANOVA. The total accuracy of detection of VRFs immediately after surgery, one, two, three, four, eight, 12 and 16 weeks was 67.3%, 68.7%, 66.6%, 64.6%, 64.5%, 69.4%, 68.7%, 68% respectively. The effect of time lapse on detection of VRFs was not significant (p>0.05). Overall sensitivity, specificity and accuracy of CBCT for detection of VRFs were 74.3%, 62.2%, 67.2% respectively. Cone beam computed tomography is a valuable tool for detection of VRFs. Time lapse (four months) had no effect on detection of VRFs on CBCT scans.

  1. Effect of time lapse on the diagnostic accuracy of cone beam computed tomography for detection of vertical root fractures

    International Nuclear Information System (INIS)

    Accurate and early diagnosis of vertical root fractures (VRFs) is imperative to prevent extensive bone loss and unnecessary endodontic and prosthodontic treatments. The aim of this study was to assess the effect of time lapse on the diagnostic accuracy of cone beam computed tomography (CBCT) for VRFs in endodontically treated dog’s teeth. Forty eight incisors and premolars of three adult male dogs underwent root canal therapy. The teeth were assigned to two groups: VRFs were artificially induced in the first group (n=24) while the teeth in the second group remained intact (n=24). The CBCT scans were obtained by NewTom 3G unit immediately after inducing VRFs and after one, two, three, four, eight, 12 and 16 weeks. Three oral and maxillofacial radiologists blinded to the date of radiographs assessed the presence/absence of VRFs on CBCT scans. The sensitivity, specificity and accuracy values were calculated and data were analyzed using SPSS v.16 software and ANOVA. The total accuracy of detection of VRFs immediately after surgery, one, two, three, four, eight, 12 and 16 weeks was 67.3%, 68.7%, 66.6%, 64.6%, 64.5%, 69.4%, 68.7%, 68% respectively. The effect of time lapse on detection of VRFs was not significant (p>0.05). Overall sensitivity, specificity and accuracy of CBCT for detection of VRFs were 74.3%, 62.2%, 67.2% respectively. Cone beam computed tomography is a valuable tool for detection of VRFs. Time lapse (four months) had no effect on detection of VRFs on CBCT scans. (author)

  2. Effect of time lapse on the diagnostic accuracy of cone beam computed tomography for detection of vertical root fractures

    Energy Technology Data Exchange (ETDEWEB)

    Eskandarloo, Amir; Shokri, Abbas, E-mail: Dr.a.shokri@gmail.com [Dental Research Center, Department of Oral and Maxillofacial Radiology, Hamadan University of Medical Sciences, Hamadan (Iran, Islamic Republic of); Asl, Amin Mahdavi [Department of Oral and Maxillofacial Radiology, Golestan University of Medical Sciences, Gorgan (Iran, Islamic Republic of); Jalalzadeh, Mohsen [Department of Endodontics, Hamadan University of Medical Sciences, Hamadan (Iran, Islamic Republic of); Tayari, Maryam [Department of Pedodontics, Golestan University of Medical Sciences, Gorgan (Iran, Islamic Republic of); Hosseinipanah, Mohammad [Department of Anatomy, School of Medicine, Hamadan University of Medical Sciences, Hamadan (Iran, Islamic Republic of); Fardmal, Javad [Research Center for Health Sciences and Department of Epidemiology and Biostatistics, School of Public Health, Hamadan University of Medical Sciences, Hamadan (Iran, Islamic Republic of)

    2016-01-15

    Accurate and early diagnosis of vertical root fractures (VRFs) is imperative to prevent extensive bone loss and unnecessary endodontic and prosthodontic treatments. The aim of this study was to assess the effect of time lapse on the diagnostic accuracy of cone beam computed tomography (CBCT) for VRFs in endodontically treated dog’s teeth. Forty eight incisors and premolars of three adult male dogs underwent root canal therapy. The teeth were assigned to two groups: VRFs were artificially induced in the first group (n=24) while the teeth in the second group remained intact (n=24). The CBCT scans were obtained by NewTom 3G unit immediately after inducing VRFs and after one, two, three, four, eight, 12 and 16 weeks. Three oral and maxillofacial radiologists blinded to the date of radiographs assessed the presence/absence of VRFs on CBCT scans. The sensitivity, specificity and accuracy values were calculated and data were analyzed using SPSS v.16 software and ANOVA. The total accuracy of detection of VRFs immediately after surgery, one, two, three, four, eight, 12 and 16 weeks was 67.3%, 68.7%, 66.6%, 64.6%, 64.5%, 69.4%, 68.7%, 68% respectively. The effect of time lapse on detection of VRFs was not significant (p>0.05). Overall sensitivity, specificity and accuracy of CBCT for detection of VRFs were 74.3%, 62.2%, 67.2% respectively. Cone beam computed tomography is a valuable tool for detection of VRFs. Time lapse (four months) had no effect on detection of VRFs on CBCT scans. (author)

  3. Penicillin induced persistence in Chlamydia trachomatis: high quality time lapse video analysis of the developmental cycle.

    Directory of Open Access Journals (Sweden)

    Rachel J Skilton

    Full Text Available BACKGROUND: Chlamydia trachomatis is a major human pathogen with a unique obligate intracellular developmental cycle that takes place inside a modified cytoplasmic structure known as an inclusion. Following entry into a cell, the infectious elementary body (EB differentiates into a non-infectious replicative form known as a reticulate body (RB. RBs divide by binary fission and at the end of the cycle they redifferentiate into EBs. Treatment of C.trachomatis with penicillin prevents maturation of RBs which survive and enlarge to become aberrant RBs within the inclusion in a non-infective persistent state. Persistently infected individuals may be a reservoir for chlamydial infection. The C.trachomatis genome encodes the enzymes for peptidoglycan (PG biosynthesis but a PG sacculus has never been detected. This coupled to the action of penicillin is known as the chlamydial anomaly. We have applied video microscopy and quantitative DNA assays to the chlamydial developmental cycle to assess the effects of penicillin treatment and establish a framework for investigating penicillin induced chlamydial persistence. PRINCIPAL FINDINGS: Addition of penicillin at the time of cell infection does not prevent uptake and the establishment of an inclusion. EB to RB transition occurs but bacterial cytokinesis is arrested by the second binary fission. RBs continue to enlarge but not divide in the presence of penicillin. The normal developmental cycle can be recovered by the removal of penicillin although the large, aberrant RBs do not revert to the normal smaller size but remain present to the completion of the developmental cycle. Chromosomal and plasmid DNA replication is unaffected by the addition of penicillin but the arrest of bacterial cytokinesis under these conditions results in RBs accumulating multiple copies of the genome. CONCLUSIONS: We have applied video time lapse microscopy to the study of the chlamydial developmental cycle. Linked with accurate

  4. Time-lapse Geophysical Monitoring of the Subsurface Hydrology at Kings Park, Western Australia

    Science.gov (United States)

    Adekoya, Tunde; McGrath, Gavan; Leopold, Matthias; Shragge, Jeffrey; Challis, Anthea; Stevens, Jason; Miller, Ben

    2015-04-01

    The increasing occurrence of drought stress throughout Southwestern Western Australia is postulated to have contributed to the decline of Banksia populations both in Kings Park, Perth, and in the Banksia woodlands in the greater Swan Coastal Plain region. To help quantify these assertions, there is an urgent need to better understand the base levels of soil moisture content - as well as seasonal variations thereof - in these geographical regions. We conducted time-lapse (TL) electrical resistivity tomography (ERT) and ground penetrating radar (GPR) methods on a monthly basis (May-August 2014). In addition, at each site we hand-augured test holes to a depth of 3-4 m and collected samples at 20-cm intervals to enable grain-size analysis, soil moisture content and water retention tests. PR2 capacitance probe measurements were also acquired when augering to enable a moisture content comparison study. The acquired TL ERT datasets were inverted using 2D EarthImager software and the temporal variations in resistivity were interpreted in terms of changes in moisture content. The TL ERT data reveal significant calendar variations in the spatial distribution of moisture content. The TL ERT inversions also detected isolated less resistive lithologies and the depth to groundwater. Processed TL GPR data were interpreted to show vertical variations in the vadose zone moisture content. The water content variations were consistent with the rainfall data. The grain-size distributions of the samples were analysed statistically. The apparent resistivity values from the analysed samples and observed volumetric water content are strongly correlated (R2=0.84) as may be expected from Archie's law. Soil moisture content analysis results including the PR2 probe measurements were plotted as a function of depth, the result shows vertical variations in moisture content with depth. The hydrological tests indicated the properties of the subsurface lithologies and confirm the responses of the

  5. Globally referenced real time monitoring of mass movements using monoscopic time-lapse photography.

    Science.gov (United States)

    Kenner, Robert; Phillips, Marcia; Buchroithner, Manfred

    2016-04-01

    The creep movement of a rock glacier was monitored in daily resolution using images of an automatic in-situ time-lapse camera (AC). Displacements were calculated between the images in 2D image coordinates using the imaging velocimetry algorithm of Roesgen and Totaro, 1995. To georeference and scale these displacements, a creep velocity field captured once by a terrestrial laser scan (TLS) repeat measurement was used. The laser scan point cloud and the creep velocity vector field were projected in image coordinates of the AC to obtain a georeferencing mask, a scale mask and an azimuth mask for the 2D displacements calculated between two images. The scale mask was obtained by comparing the TLS derived displacement vectors with those of the AC, referring to a common measurement period. The automatic procedure includes the following work steps: 1. Offsets between two images are identified and corrected based on image parts representing unchanged terrain. 2. 2D displacements are calculated between all chronological image sequences. 3. Faulty displacement vectors are eliminated based on a predefined threshold for spatial direction differences. 4. The remaining displacements are georeferenced, scaled and attributed with individual displacement directions (azimuths) in global coordinates. 5. In addition to the displacement values, displacement velocities and accelerations are calculated using the date of the images. 6. For chronologically successive displacement vector fields, the spatial mean of the relative velocity is defined and expressed as a percentage of the first displacement velocity in the series. The time series of the relative velocities is expressed in chart form. 7. The spatial resolution of all georeferenced output data sets is homogenized, as they were influenced by the central projection of the photos. The described procedure proved to be a reliable, low cost method to monitor mass wasting processes. Even under difficult conditions, like thin snow coverage

  6. Soundscape and Noise Exposure Monitoring in a Marine Protected Area Using Shipping Data and Time-Lapse Footage.

    Science.gov (United States)

    Merchant, Nathan D; Pirotta, Enrico; Barton, Tim R; Thompson, Paul M

    2016-01-01

    We review recent work that developed new techniques for underwater noise assessment that integrate acoustic monitoring with automatic identification system (AIS) shipping data and time-lapse video, meteorological, and tidal data. Two sites were studied within the Moray Firth Special Area of Conservation (SAC) for bottlenose dolphins, where increased shipping traffic is expected from construction of offshore wind farms outside the SAC. Noise exposure varied markedly between the sites, and natural and anthropogenic contributions were characterized using multiple data sources. At one site, AIS-operating vessels accounted for total cumulative sound exposure (0.1-10 kHz), suggesting that noise modeling using the AIS would be feasible.

  7. Characteristics of Lapsed German Whole Blood Donors and Barriers to Return Four Years after the Initial Donation

    OpenAIRE

    Weidmann, Christian; Müller-Steinhardt, Michael; Schneider, Sven; Weck, Eberhard; Klüter, Harald

    2011-01-01

    Background: The aim of the study was to identify characteristics of lapsed donors 4 years after the initial donation as well as self-reported barriers to return for further blood donations. Methods: A random number of 8,000 blood donors, donating for the German Red Cross Blood Service Baden-Wurttemberg - Hessen, were asked to fill in a self-administered questionnaire. The response rate was 38.5%. Donors were categorized as ”lapsed’ if they had not donated within the last 24 months. The odds o...

  8. Soundscape and Noise Exposure Monitoring in a Marine Protected Area Using Shipping Data and Time-Lapse Footage.

    Science.gov (United States)

    Merchant, Nathan D; Pirotta, Enrico; Barton, Tim R; Thompson, Paul M

    2016-01-01

    We review recent work that developed new techniques for underwater noise assessment that integrate acoustic monitoring with automatic identification system (AIS) shipping data and time-lapse video, meteorological, and tidal data. Two sites were studied within the Moray Firth Special Area of Conservation (SAC) for bottlenose dolphins, where increased shipping traffic is expected from construction of offshore wind farms outside the SAC. Noise exposure varied markedly between the sites, and natural and anthropogenic contributions were characterized using multiple data sources. At one site, AIS-operating vessels accounted for total cumulative sound exposure (0.1-10 kHz), suggesting that noise modeling using the AIS would be feasible. PMID:26611022

  9. The Potential Impact of Biofield Treatment on Human Brain Tumor Cells: A Time-Lapse Video Microscopy

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    Study background: Glioblastoma (GBM) is the most common subtype of primary brain tumor in adults. The aim was to evaluate the impact of biofield treatment potential on human GBM and non-GBM brain cells using two time-lapse video microscopy technique. Methods: The human brain tumor, GBM cultured cells were divided into two groups viz. GBM control and GBM treatment. Similarly, human normal brain cultured cells (non-GBM) were taken and divided into two groups viz. non- GBM control ...

  10. Capture of exogenous attention modulates the attentional blink

    DEFF Research Database (Denmark)

    Nielsen, Simon; Andersen, Tobias

    2011-01-01

    When two targets (T1 & T2) are presented in rapid succession, observers often fail to report T2 if they attend to T1. Bottleneck theories propose that this attentional blink (AB) is due to T1 occupying a slow processing stage when T2 is presented. Accordingly, if increasing T1 difficulty increases...... T1 processing time, this should cause a greater AB. Attention capture hypotheses suggest that T1 captures attention, which cannot be reallocated to T2 in time. Accordingly, if increasing T1 difficulty, decreases saliency, this should cause a smaller AB. Studies examining how T1 difficulty affects...... negatively with T1 contrast energy. Our results indicate that T1 capture modulates the AB. We suggest that this effect has confounded previous studies on the effect of T1 difficulty. In an electrophysiological version of the study we will further examine the implied relation between attention capture and the...

  11. [Neuropsychological approach to visual attention].

    Science.gov (United States)

    Suzuki, Kyoko

    2007-01-01

    Visual experience depends critically on visual attention, which selects a particular aspect of a visual display. Recent clinical, neuroimaging, and animal studies revealed that visual attention was divided into active and passive or top-down and bottom-up attention. Although these dichotomies are clear-cut in definition, visual attention could be modulated by many factors. Detailed observation of brain-injured patients provides with evidence for dynamic and fine control of visual attention. We observed patients with dorsal simultanagnosia and that with callosal disconnection syndrome. Patients with dorsal simultanagnosia demonstrated that extent of visual attention was dynamically changed depending on the level of visual processing. Despite the ability to read a kanji character and to describe its components correctly, a patient could not notice a component that he had just written and could not assemble individual components to make up a correct kanji character. He could point to an overlapping area of two figures. But once he started to color the overlapping area, he missed the margin of the area and colored much larger area. Another patient with dorsal simultanagnosia missed borderlines between columns of a newspaper and read letters continuously across columns. In contrast, he could point to lines between figures or meaningless patterns easily. These findings indicated that visual attention was directed automatically to meaningful characters. A patients with callosal disconnection syndrome demonstrated left unilateral spatial neglect only when he used his right hand to draw figures. Right hand movement, controlled by the left hemisphere, elicited visual attention to the right hemispace, resulting in the left unilateral spatial neglect. Thus visual attention is not simply top-down or bottom up, but is implicitly affected by the visual recognition as well as motor component of the task. PMID:17354375

  12. Early vision and visual attention

    Directory of Open Access Journals (Sweden)

    Gvozdenović Vasilije P.

    2003-01-01

    Full Text Available The question whether visual perception is spontaneous, sudden or is running through several phases, mediated by higher cognitive processes, was raised ever since the early work of Gestalt psychologists. In the early 1980s, Treisman proposed the feature integration theory of attention (FIT, based on the findings of neuroscience. Soon after publishing her theory a new scientific approach appeared investigating several visual perception phenomena. The most widely researched were the key constructs of FIT, like types of visual search and the role of the attention. The following review describes the main studies of early vision and visual attention.

  13. Attention and the Evolution of Intentional Communication

    OpenAIRE

    Brinck, Ingar

    2001-01-01

    Intentional communication is perceptually based and about attentional objects. Three attention mechanisms are distinguished: scanning, attention attraction, and attention-focusing. Attention-focusing directs the subject towards attentional objects. Attention-focusing is goal-governed (controlled by stimulus) or goal-intended (under the control of the subject). Attentional objects are perceptually categorised functional entities that emerge in the interaction between subjects and environment. ...

  14. Tips for Beginners: Attention Getters.

    Science.gov (United States)

    Moldavan, Carla

    1993-01-01

    Proposes the use of humor and the personalization of word problems by inserting students' names in the problem statement as methods of gaining students' attention. Illustrates their use in a mixture problem and the Tower of Hanoi problem. (MDH)

  15. Modelling of Attentional Dwell Time

    DEFF Research Database (Denmark)

    Petersen, Anders; Kyllingsbæk, Søren; Bundesen, Claus

    2009-01-01

    Studies of the time course of visual attention have identified a temporary functional blindness to the second of two spatially separated targets: attending to one visual stimulus may lead to impairments in identifying a second stimulus presented between 200 to 500 ms after the first...... of attentional dwell time extends these mechanisms by proposing that the processing resources (cells) already engaged in a feedback loop (i.e. allocated to an object) are locked in VSTM and therefore cannot be allocated to other objects in the visual field before the encoded object has been released....... This phenomenon is known as attentional dwell time (e.g. Duncan, Ward, Shapiro, 1994). All Previous studies of the attentional dwell time have looked at data averaged across subjects. In contrast, we have succeeded in running subjects for 3120 trials which has given us reliable data for modelling data from...

  16. Visual attention in posterior stroke

    DEFF Research Database (Denmark)

    Fabricius, Charlotte; Petersen, Anders; Iversen, Helle K;

    Objective: Impaired visual attention is common following strokes in the territory of the middle cerebral artery, particularly in the right hemisphere. However, attentional effects of more posterior lesions are less clear. The aim of this study was to characterize visual processing speed...... and apprehension span following posterior cerebral artery (PCA) stroke. We also relate these attentional parameters to visual word recognition, as previous studies have suggested that reduced visual speed and span may explain pure alexia. Methods: Nine patients with MR-verified focal lesions in the PCA......-territory (four left PCA; four right PCA; one bilateral, all >1 year post stroke) were compared to 25 controls using single case statistics. Visual attention was characterized by a whole report paradigm allowing for hemifield-specific speed and span measurements. We also characterized visual field defects...

  17. Mindfulness training affects attention--or is it attentional effort?

    Science.gov (United States)

    Jensen, Christian Gaden; Vangkilde, Signe; Frokjaer, Vibe; Hasselbalch, Steen G

    2012-02-01

    Improvements in attentional performance are at the core of proposed mechanisms for stress reduction in mindfulness meditation practices. However, this claim can be questioned because no previous studies have actively manipulated test effort in control groups and controlled for effects of stress reduction per se. In a blinded design, 48 young, healthy meditation novices were randomly assigned to a mindfulness-based stress reduction (MBSR), nonmindfulness stress reduction (NMSR), or inactive control group. At posttest, inactive controls were randomly split into nonincentive and incentive controls, the latter receiving a financial reward to improve attentional performance. Pre- and postintervention, 5 validated attention paradigms were employed along with self-report scales on mindfulness and perceived stress and saliva cortisol samples to measure physiological stress. Attentional effects of MBSR, NMSR, and the financial incentive were comparable or significantly larger in the incentive group on all reaction-time-based measures. However, selective attention in the MBSR group improved significantly more than in any other group. Similarly, only the MBSR intervention improved the threshold for conscious perception and visual working memory capacity. Furthermore, stress-reducing effects of MBSR were supported because those in the MBSR group showed significantly less perceived and physiological stress while increasing their mindfulness levels significantly. We argue that MBSR may contribute uniquely to attentional improvements but that further research focusing on non-reaction-time-based measures and outcomes less confounded by test effort is needed. Critically, our data demonstrate that previously observed improvements of attention after MBSR may be seriously confounded by test effort and nonmindfulness stress reduction.

  18. Emotional distractors can enhance attention

    OpenAIRE

    Sussman, Tamara J.; Heller, Wendy; Miller, Gregory A.; Mohanty, Aprajita

    2013-01-01

    The deleterious effects of emotional distractors on attention are well demonstrated. However, it is unclear if emotional distractors inevitably disrupt task-relevant attention. Using multilevel modeling (MLM), the present study examined the impact of valence and arousal dimensions of distracting emotional stimuli and individual differences in anxiety on task-relevant processing. Consistent with prior literature, high-arousal negative distractors were associated with poor task-relevant attenti...

  19. Attention modulates visual size adaptation.

    OpenAIRE

    Kreutzer, Sylvia; Fink, G R; R. Weidner

    2015-01-01

    The current study determined in healthy subjects (n = 16) whether size adaptation occurs at early, i.e., preattentive, levels of processing or whether higher cognitive processes such as attention can modulate the illusion. To investigate this issue, bottom-up stimulation was kept constant across conditions by using a single adaptation display containing both small and large adapter stimuli. Subjects' attention was directed to either the large or small adapter stimulus by means of a luminance ...

  20. Estimation of soil hydraulic parameters by integrated hydrogeophysical inversion of time-lapse GPR data measured at Selhausen, Germany

    KAUST Repository

    Jadoon, Khan

    2012-06-01

    We present an integrated hydrogeophysical inversion approach that uses time-lapse off-ground ground-penetrating radar (GPR) data to estimate soil hydraulic parameters, and apply it to a dataset collected in the field. Off-ground GPR data are mainly sensitive to the near-surface water content profile and dynamics, and are thus related to soil hydraulic parameters, such as the parameters of the hydraulic conductivity and water retention functions. The hydrological simulator HYDRUS 1-D was used with a two-layer single- and dual-porosity model. To monitor the soil water content dynamics, time-lapse GPR and time domain reflectometry (TDR) measurements were performed, whereby only GPR data was used in the inversion. The dual porosity model provided better results compared to the single porosity model for describing the soil water dynamics, which is supported by field observations of macropores. Furthermore, the GPR-derived water content profiles reconstructed from the integrated hydrogeophysical inversion were in good agreement with TDR observations. These results suggest that the proposed method is promising for non-invasive characterization of the shallow subsurface hydraulic properties and monitoring water dynamics at the field scale.

  1. High-resolution Time-lapse Imaging and Automated Analysis of Microtubule Dynamics in Living Human Umbilical Vein Endothelial Cells.

    Science.gov (United States)

    Braun, Alexander; Caesar, Nicole M; Dang, Kyvan; Myers, Kenneth A

    2016-01-01

    The physiological process by which new vasculature forms from existing vasculature requires specific signaling events that trigger morphological changes within individual endothelial cells (ECs). These processes are critical for homeostatic maintenance such as wound healing, and are also crucial in promoting tumor growth and metastasis. EC morphology is defined by the organization of the cytoskeleton, a tightly regulated system of actin and microtubule (MT) dynamics that is known to control EC branching, polarity and directional migration, essential components of angiogenesis. To study MT dynamics, we used high-resolution fluorescence microscopy coupled with computational image analysis of fluorescently-labeled MT plus-ends to investigate MT growth dynamics and the regulation of EC branching morphology and directional migration. Time-lapse imaging of living Human Umbilical Vein Endothelial Cells (HUVECs) was performed following transfection with fluorescently-labeled MT End Binding protein 3 (EB3) and Mitotic Centromere Associated Kinesin (MCAK)-specific cDNA constructs to evaluate effects on MT dynamics. PlusTipTracker software was used to track EB3-labeled MT plus ends in order to measure MT growth speeds and MT growth lifetimes in time-lapse images. This methodology allows for the study of MT dynamics and the identification of how localized regulation of MT dynamics within sub-cellular regions contributes to the angiogenic processes of EC branching and migration. PMID:27584860

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

    Science.gov (United States)

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

    2016-10-01

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

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

    Science.gov (United States)

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

    2016-07-01

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

  4. IP4DI: A software for time-lapse 2D/3D DC-resistivity and induced polarization tomography

    Science.gov (United States)

    Karaoulis, M.; Revil, A.; Tsourlos, P.; Werkema, D. D.; Minsley, B. J.

    2013-04-01

    We propose a 2D/3D forward modelling and inversion package to invert direct current (DC)-resistivity, time-domain induced polarization (TDIP), and frequency-domain induced polarization (FDIP) data. Each cell used for the discretization of the 2D/3D problems is characterized by a DC-resistivity value and a chargeability or complex conductivity for TDIP/FDIP problems, respectively. The governing elliptic partial differential equations are solved with the finite element method, which can be applied for both real and complex numbers. The inversion can be performed either for a single snapshot of data or for a sequence of snapshots in order to monitor a dynamic process such as a salt tracer test. For the time-lapse inversion, we have developed an active time constrained (ATC) approach that is very efficient in filtering out noise in the data that is not correlated over time. The forward algorithm is benchmarked with simple analytical solutions. The inversion package IP4DI is benchmarked with three tests, two including simple geometries. The last one corresponds to a time-lapse resistivity problem for cross-well tomography during enhanced oil recovery. The algorithms are based on MATLAB® code package and a graphical user interface (GUI).

  5. Optical Flow Applied to Time-Lapse Image Series to Estimate Glacier Motion in the Southern Patagonia Ice Field

    Science.gov (United States)

    Lannutti, E.; Lenzano, M. G.; Toth, C.; Lenzano, L.; Rivera, A.

    2016-06-01

    In this work, we assessed the feasibility of using optical flow to obtain the motion estimation of a glacier. In general, former investigations used to detect glacier changes involve solutions that require repeated observations which are many times based on extensive field work. Taking into account glaciers are usually located in geographically complex and hard to access areas, deploying time-lapse imaging sensors, optical flow may provide an efficient solution at good spatial and temporal resolution to describe mass motion. Several studies in computer vision and image processing community have used this method to detect large displacements. Therefore, we carried out a test of the proposed Large Displacement Optical Flow method at the Viedma Glacier, located at South Patagonia Icefield, Argentina. We collected monoscopic terrestrial time-lapse imagery, acquired by a calibrated camera at every 24 hour from April 2014 until April 2015. A filter based on temporal correlation and RGB color discretization between the images was applied to minimize errors related to changes in lighting, shadows, clouds and snow. This selection allowed discarding images that do not follow a sequence of similarity. Our results show a flow field in the direction of the glacier movement with acceleration in the terminus. We analyzed the errors between image pairs, and the matching generally appears to be adequate, although some areas show random gross errors related to the presence of changes in lighting. The proposed technique allowed the determination of glacier motion during one year, providing accurate and reliable motion data for subsequent analysis.

  6. Time-lapse geophysical technology-based study on overburden strata changes induced by modern coal mining

    Institute of Scientific and Technical Information of China (English)

    Wenfeng Du; Suping Peng; Guowei Zhu; Feng Yang

    2014-01-01

    To study the impact of modern coal mining on overlying strata and its water bearing conditions, integrated time-lapse geophysical prospecting integrating 3D seismic, electrical and ground penetrating radar method were used. Through observing and analyzing the geophysical data variations of all stages of pre-mining, mining and post-mining as well as post-mining deposition stable period, impacts of coal mining on stratigraphic structure and its water bearing were studied and modern coal mining induced stratigraphic change pattern was summarized. The research result shows that the stratigraphic structure and the water bearing of surface layer during modern coal mining have self-healing pattern with mining time;the self-healing capability of near-surface strata is relatively strong while the roof weak;water bearing self-healing of near-surface strata is relatively high while the roof strata adjacent to mined coal beds low. Due to integrated time-lapse geophysical prospecting technology has extra time dimension which makes up the deficiency of static analysis of conventional geophysical methods, it can better highlight the dynamic changes of modern coal mining induced over-burden strata and its water bearing conditions.

  7. Time-lapse imaging of primary preneoplastic mammary epithelial cells derived from genetically engineered mouse models of breast cancer.

    Science.gov (United States)

    Nakles, Rebecca E; Millman, Sarah L; Cabrera, M Carla; Johnson, Peter; Mueller, Susette; Hoppe, Philipp S; Schroeder, Timm; Furth, Priscilla A

    2013-01-01

    Time-lapse imaging can be used to compare behavior of cultured primary preneoplastic mammary epithelial cells derived from different genetically engineered mouse models of breast cancer. For example, time between cell divisions (cell lifetimes), apoptotic cell numbers, evolution of morphological changes, and mechanism of colony formation can be quantified and compared in cells carrying specific genetic lesions. Primary mammary epithelial cell cultures are generated from mammary glands without palpable tumor. Glands are carefully resected with clear separation from adjacent muscle, lymph nodes are removed, and single-cell suspensions of enriched mammary epithelial cells are generated by mincing mammary tissue followed by enzymatic dissociation and filtration. Single-cell suspensions are plated and placed directly under a microscope within an incubator chamber for live-cell imaging. Sixteen 650 μm x 700 μm fields in a 4x4 configuration from each well of a 6-well plate are imaged every 15 min for 5 days. Time-lapse images are examined directly to measure cellular behaviors that can include mechanism and frequency of cell colony formation within the first 24 hr of plating the cells (aggregation versus cell proliferation), incidence of apoptosis, and phasing of morphological changes. Single-cell tracking is used to generate cell fate maps for measurement of individual cell lifetimes and investigation of cell division patterns. Quantitative data are statistically analyzed to assess for significant differences in behavior correlated with specific genetic lesions. PMID:23425702

  8. Bayesian Markov-Chain-Monte-Carlo inversion of time-lapse crosshole GPR data to characterize the vadose zone at the Arrenaes Site, Denmark

    DEFF Research Database (Denmark)

    Scholer, Marie; Irving, James; Zibar, Majken Caroline Looms;

    2012-01-01

    We examined to what extent time-lapse crosshole ground-penetrating radar traveltimes, measured during a forced infiltration experiment at the Arreneas field site in Denmark, could help to quantify vadose zone hydraulic properties and their corresponding uncertainties using a Bayesian Markov......-state infiltration conditions, which represent only a small fraction of practically relevant scenarios. We explored in detail the dynamic infiltration case, specifically examining to what extent time-lapse crosshole GPR traveltimes, measured during a forced infiltration experiment at the Arreneas field site...... synthetic example before applying it to field measurements. In our analysis, we also considered different degrees of prior information. Our findings indicate that the stochastic inversion of the time-lapse GPR data does indeed allow for a substantial refinement in the inferred posterior VGM parameter...

  9. Real-time performance modelling of a Sustained Attention to Response Task.

    Science.gov (United States)

    Larue, Grégoire S; Rakotonirainy, Andry; Pettitt, Anthony N

    2010-10-01

    Vigilance declines when exposed to highly predictable and uneventful tasks. Monotonous tasks provide little cognitive and motor stimulation and contribute to human errors. This paper aims to model and detect vigilance decline in real time through participants' reaction times during a monotonous task. A laboratory-based experiment adapting the Sustained Attention to Response Task (SART) is conducted to quantify the effect of monotony on overall performance. Relevant parameters are then used to build a model detecting hypovigilance throughout the experiment. The accuracy of different mathematical models is compared to detect in real time - minute by minute - the lapses in vigilance during the task. It is shown that monotonous tasks can lead to an average decline in performance of 45%. Furthermore, vigilance modelling enables the detection of vigilance decline through reaction times with an accuracy of 72% and a 29% false alarm rate. Bayesian models are identified as a better model to detect lapses in vigilance as compared with neural networks and generalised linear mixed models. This modelling could be used as a framework to detect vigilance decline of any human performing monotonous tasks. STATEMENT OF RELEVANCE: Existing research on monotony is largely entangled with endogenous factors such as sleep deprivation, fatigue and circadian rhythm. This paper uses a Bayesian model to assess the effects of a monotonous task on vigilance in real time. It is shown that the negative effects of monotony on the ability to sustain attention can be mathematically modelled and predicted in real time using surrogate measures, such as reaction times. This allows the modelling of vigilance fluctuations.

  10. Intense dust episodes in the Mediterranean and possible effects on atmospheric lapse rates

    Science.gov (United States)

    Hatzianastassiou, Nikos; Gkikas, Antonis; Papadimas, Christos D.; Gavrouzou, Maria

    2016-04-01

    Dust aerosols are major contributor to the atmospheric particulate matter, having significant effects on climate and weather patterns as well as on human health, not to mention others like agriculture or ocean chlorophyll. Moreover, these effects are maximized under conditions of massive dust concentration in the atmosphere, namely dust episodes or events. Such events are caused by uplifting and transport of dust from arid and semi-arid areas under favorable synoptic conditions. The Mediterranean basin, nearby to the greatest world deserts of North Africa and Middle East, frequently undergoes dust episodes. During such Mediterranean episodes, the number and mass concentration of dust is high, due to the proximity of its source areas. The dust episodes, through the direct interaction of dust primarily withthe shortwave but also with longwave radiation can lead to strong local warming in the atmosphere, possibly causing temperature inversion during daytime. The existence of such temperature inversions, associated with intense dust episodes in the Mediterranean, is the focus in this study. The methodology followed to achieve the scientific goal of the study consists in the use of a synergy of different data. This synergy enables: (i) the determination of intense dust episodes over the Mediterranean, (ii) the investigation and specification of temperature lapse rates and inversions during the days of dust episodes and (iii) the identification of vertical distribution of aerosols in the atmosphere over specific locations during the days of the episodes. These objectives are achieved through the use of data from: (i) the AERosol Robotic NETwork (AERONET) network, (ii) the Upper Air Observations (radiosondes) database of the University of Wyoming (UoW) and (iii) the European Aerosol Research Lidar Network (EARLINET) database. The study period spans the years from 2000 to 2013, constrained by the data availability of the databases. A key element of the methodology is the

  11. Does mindfulness meditation improve attention in attention deficit hyperactivity disorder?

    Science.gov (United States)

    Modesto-Lowe, Vania; Farahmand, Pantea; Chaplin, Margaret; Sarro, Lauren

    2015-12-22

    Attention deficit hyperactivity disorder (ADHD) manifests by high levels of inattention, impulsiveness and hyperactivity. ADHD starts in childhood and results in impairments that continue into adulthood. While hyperactivity declines over time, inattention and executive function difficulties persist, leading to functional deficits. Adolescents and adults with ADHD have pervasive impairment in interpersonal and family relationships. They may develop addiction, delinquent behavior and comorbid psychiatric disorders. Despite advances in diagnosis and treatment, persistent residual symptoms are common, highlighting the need for novel treatment strategies. Mindfulness training, derived from Eastern meditation practices, may improve self-regulation of attention. It may also be a useful strategy to augment standard ADHD treatments and may be used as a potential tool to reduce impairments in patients with residual symptoms of ADHD. Clinically, this would manifest by an increased ability to suppress task-unrelated thoughts and distractions resulting in improved attention, completion of tasks and potential improvement in occupational and social function. PMID:26740931

  12. Attention trees and semantic paths

    Science.gov (United States)

    Giusti, Christian; Pieroni, Goffredo G.; Pieroni, Laura

    2007-02-01

    In the last few decades several techniques for image content extraction, often based on segmentation, have been proposed. It has been suggested that under the assumption of very general image content, segmentation becomes unstable and classification becomes unreliable. According to recent psychological theories, certain image regions attract the attention of human observers more than others and, generally, the image main meaning appears concentrated in those regions. Initially, regions attracting our attention are perceived as a whole and hypotheses on their content are formulated; successively the components of those regions are carefully analyzed and a more precise interpretation is reached. It is interesting to observe that an image decomposition process performed according to these psychological visual attention theories might present advantages with respect to a traditional segmentation approach. In this paper we propose an automatic procedure generating image decomposition based on the detection of visual attention regions. A new clustering algorithm taking advantage of the Delaunay- Voronoi diagrams for achieving the decomposition target is proposed. By applying that algorithm recursively, starting from the whole image, a transformation of the image into a tree of related meaningful regions is obtained (Attention Tree). Successively, a semantic interpretation of the leaf nodes is carried out by using a structure of Neural Networks (Neural Tree) assisted by a knowledge base (Ontology Net). Starting from leaf nodes, paths toward the root node across the Attention Tree are attempted. The task of the path consists in relating the semantics of each child-parent node pair and, consequently, in merging the corresponding image regions. The relationship detected in this way between two tree nodes generates, as a result, the extension of the interpreted image area through each step of the path. The construction of several Attention Trees has been performed and partial

  13. Attention Deficits, Attention-Deficit Hyperactivity Disorder, and Intellectual Disabilities

    Science.gov (United States)

    Deutsch, Curtis K.; Dube, William V.; McIlvane, William J.

    2008-01-01

    Attention-Deficit Hyperactivity Disorder (ADHD) and its earlier nosologic classifications have been extensively investigated since the 1960s, with PubMed listings alone exceeding 13,000 entries. Strides have been made in the diagnosis and treatment of ADHD in individuals with intellectual function in the normal range, as described in companion…

  14. Now, Pay Attention! The Effects of Instruction on Children's Attention

    Science.gov (United States)

    Kannass, Kathleen N.; Colombo, John; Wyss, Nancy

    2010-01-01

    We investigated the effects of instructions to "stay on task" on preschoolers' attention and cognitive performance in the face of either incomprehensible or comprehensible distraction. Three- and 4-year-olds completed problem-solving tasks while a distracting event played continuously in the background under conditions of (a) no instruction, (b)…

  15. Components of Attention in Synesthesia

    DEFF Research Database (Denmark)

    Sørensen, Thomas Alrik; Nordfang, Maria; Pedersen, Michael Nygaard;

    2013-01-01

    One of the most common forms of synesthesia is between colors and graphemes (Colizoli, Murre, & Rouw, 2012). Numerous studies have investigated different aspects of attention and synesthesia, e.g. effects of Stroop-like interference by colors that are incongruent with the synesthetic experience....... Here we attempt to isolate how specific components of attention are affected by grapheme-color synesthesia. Eight carefully screened healthy participants with synesthesia reported the letters in briefly presented, post-masked arrays of letters and digits. On half the trials, the letters and digits were...... presented in colors congruent with the synesthetic experience. On the other half of the trials, the letters and digits were presented in colors that were incongruent with the synesthetic experience. Components of attention were estimated separately for congruent and incongruent trials by fitting the data...

  16. Supramodal Executive Control of Attention

    Directory of Open Access Journals (Sweden)

    ALFREDO eSPAGNA

    2015-02-01

    Full Text Available The human attentional system can be subdivided into three functional networks of alerting, orienting, and executive control. Although these networks have been extensively studied in the visuospatial modality, whether the same mechanisms are deployed across different sensory modalities remains unclear. In this study we used the attention network test for visuospatial modality, in addition to two auditory variants with spatial and frequency manipulations to examine cross-modal correlations between network functions. Results showed that among the visual and auditory tasks the effects of executive control, but not effects of alerting and orienting were significantly correlated. These findings suggest that while alerting and orienting functions rely more upon modality specific processes, the executive control of attention coordinates complex behavior via supramodal mechanisms.

  17. Mindful Movement and Skilled Attention

    Directory of Open Access Journals (Sweden)

    Dav eClark

    2015-06-01

    Full Text Available Bodily movement has long been employed as a foundation for cultivating mental skills such as attention, self-control or mindfulness, with recent studies documenting the positive impacts of mindful movement training, such as yoga and tai chi. A parallel mind-body connection has also been observed in many developmental disorders. We elaborate a spectrum of mindfulness by considering ADHD, in which deficient motor control correlates with impaired (disinhibited behavioral control contributing to defining features of excessive distractibility and impulsivity. These data provide evidence for an important axis of variation for wellbeing, in which skillful cognitive control covaries with a capacity for skillful movement. We review empirical and theoretical literature on attention, cognitive control, mind wandering, mindfulness and skill learning, endorsing a model of skilled attention in which motor plans, attention, and executive goals are seen as mutually co-defining aspects of skilled behavior that are linked by reciprocal inhibitory and excitatory connections. Thus, any movement training should engage higher-order inhibition and selection and develop a repertoire of rehearsed procedures that coordinate goals, attention and motor plans. However, we propose that mindful movement practice may improve the functional quality of rehearsed procedures, cultivating a transferrable skill of attention. We adopt Langer’s spectrum of mindful learning that spans from mindlessness to engagement with the details of the present task and contrast this with the mental attitudes cultivated in standard mindfulness meditation. We particularly follow Feldenkrais’ suggestion that mindful learning of skills for organizing the body in movement might transfer to other forms of mental activity. The results of mindful movement training should be observed in multiple complementary measures, and may have tremendous potential benefit for individuals with ADHD and other

  18. Separating climate change signals into thermodynamic, lapse-rate and circulation effects: Theory and application to the European summer climate

    Science.gov (United States)

    Kroener, Nico; Kotlarski, Sven; Fischer, Erich; Lüthi, Daniel; Zubler, Elias; Schär, Christoph

    2016-04-01

    Climate models robustly project a strong overall summer warming across Europe showing a characteristic north-south gradient with enhanced warming and drying in southern Europe. However, the processes that are responsible for this pattern are not fully understood. We here employ an extended surrogate or pseudo-warming approach to disentangle the contribution of different mechanisms to this response pattern. The basic idea of the surrogate technique is to use a regional climate model and apply a large-scale warming to the lateral boundary conditions of a present-day reference simulation, while maintaining the relative humidity (and thus implicitly increasing the specific moisture content). In comparison to previous studies, our approach includes two important extensions: First, different vertical warming profiles are applied in order to separate the effects of a mean warming from lapse-rate effects. Second, a twin-design is used, in which the temperature change signal is not only added to present-day conditions, but also subtracted from a scenario experiment. We use the regional climate model COSMO-CLM with a grid spacing of approximately 50 km (EURO-CORDEX EUR-44 setup) using transient simulations (1950-2100) with the RCP8.5 emissions scenario. We demonstrate that the aforementioned extensions provide an elegant way to separate the full climate change signal into contributions from large-scale thermodynamics (LST), lapse-rate (LR) and large-scale circulation (LSC). In our framework the LSC effect also includes effects due to changes in land-sea contrast and the spatial variations of the SST warming pattern. We find that the LST effect yields a large-scale warming across Europe without any distinct latitudinal gradient. The LR effect, which is quantified for the first time in our study, leads to a stronger warming and some drying in Southern Europe. It explains about 50% of the warming amplification over the Iberian Peninsula, thus demonstrating the important role of

  19. Identifying unsaturated soil hydraulic parameters using integrated hydrogeophysical inversion approach on time-lapse ground-penetrating radar data

    Science.gov (United States)

    Jadoon, K. Z.; Weihermüller, L.; Scharnagl, B.; Kowalsky, M. B.; Bechtold, M.; Hubbard, S. S.; Vereecken, H.; Lambot, S.

    2012-04-01

    Recently, ground-penetrating radar (GPR) has proven to have a great potential for high resolution, non-invasive mapping of the soil hydrogeophysical properties at the scale of interest. Common GPR techniques are usually based on ray-based travel time or reflection analyses to retrieve soil dielectric permittivity, which is strongly correlated to soil water content. These methods suffer, however, from two major limitations. First, only a part of the information in the GPR signal is considered (e.g., propagation time). Second, the forward model describing the radar data is subject to relatively strong simplifications with respect to electromagnetic wave propagation phenomena. These limitations typically results in errors in the reconstructed water content images and, moreover, this does not permit to exploit all information contained in the radar data. We explored an alternative method by using full-waveform hydrogeophysical inversion of time-lapse, proximal GPR data to remotely estimate the unsaturated soil hydraulic properties. The radar system is based on international standard vector network analyzer technology and a full-waveform model is used to describe wave propagation in the antenna-air-soil system, including antenna-soil interactions. A hydrodynamic model is used to constrain the inverse electromagnetic problem in reconstructing continuous vertical water content profiles. In that case the estimated parameters reduce to the soil hydraulic properties, thereby strongly reducing the dimensionality of the inverse problem. In this study, we present an application of the proposed method to a data set collected in a field experiment. The GPR model involves a full-waveform frequency-domain solution of Maxwell's equations for wave propagation in three-dimensional multilayered media. The hydrodynamic model used in this work is based on a one-dimensional solution of Richards equation and the hydrological simulator HYDRUS 1-D was used with a single- and dual

  20. Entropy-Bayesian Inversion of Time-Lapse Tomographic GPR data for Monitoring Dielectric Permittivity and Soil Moisture Variations

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Zhangshuan; Terry, Neil C.; Hubbard, Susan S.

    2013-02-22

    In this study, we evaluate the possibility of monitoring soil moisture variation using tomographic ground penetrating radar travel time data through Bayesian inversion, which is integrated with entropy memory function and pilot point concepts, as well as efficient sampling approaches. It is critical to accurately estimate soil moisture content and variations in vadose zone studies. Many studies have illustrated the promise and value of GPR tomographic data for estimating soil moisture and associated changes, however, challenges still exist in the inversion of GPR tomographic data in a manner that quantifies input and predictive uncertainty, incorporates multiple data types, handles non-uniqueness and nonlinearity, and honors time-lapse tomograms collected in a series. To address these challenges, we develop a minimum relative entropy (MRE)-Bayesian based inverse modeling framework that non-subjectively defines prior probabilities, incorporates information from multiple sources, and quantifies uncertainty. The framework enables us to estimate dielectric permittivity at pilot point locations distributed within the tomogram, as well as the spatial correlation range. In the inversion framework, MRE is first used to derive prior probability density functions (pdfs) of dielectric permittivity based on prior information obtained from a straight-ray GPR inversion. The probability distributions are then sampled using a Quasi-Monte Carlo (QMC) approach, and the sample sets provide inputs to a sequential Gaussian simulation (SGSIM) algorithm that constructs a highly resolved permittivity/velocity field for evaluation with a curved-ray GPR forward model. The likelihood functions are computed as a function of misfits, and posterior pdfs are constructed using a Gaussian kernel. Inversion of subsequent time-lapse datasets combines the Bayesian estimates from the previous inversion (as a memory function) with new data. The memory function and pilot point design takes advantage of

  1. Entropy-Bayesian Inversion of Time-Lapse Tomographic GPR data for Monitoring Dielectric Permittivity and Soil Moisture Variations

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Z; Terry, N; Hubbard, S S; Csatho, B

    2013-02-12

    In this study, we evaluate the possibility of monitoring soil moisture variation using tomographic ground penetrating radar travel time data through Bayesian inversion, which is integrated with entropy memory function and pilot point concepts, as well as efficient sampling approaches. It is critical to accurately estimate soil moisture content and variations in vadose zone studies. Many studies have illustrated the promise and value of GPR tomographic data for estimating soil moisture and associated changes, however, challenges still exist in the inversion of GPR tomographic data in a manner that quantifies input and predictive uncertainty, incorporates multiple data types, handles non-uniqueness and nonlinearity, and honors time-lapse tomograms collected in a series. To address these challenges, we develop a minimum relative entropy (MRE)-Bayesian based inverse modeling framework that non-subjectively defines prior probabilities, incorporates information from multiple sources, and quantifies uncertainty. The framework enables us to estimate dielectric permittivity at pilot point locations distributed within the tomogram, as well as the spatial correlation range. In the inversion framework, MRE is first used to derive prior probability distribution functions (pdfs) of dielectric permittivity based on prior information obtained from a straight-ray GPR inversion. The probability distributions are then sampled using a Quasi-Monte Carlo (QMC) approach, and the sample sets provide inputs to a sequential Gaussian simulation (SGSim) algorithm that constructs a highly resolved permittivity/velocity field for evaluation with a curved-ray GPR forward model. The likelihood functions are computed as a function of misfits, and posterior pdfs are constructed using a Gaussian kernel. Inversion of subsequent time-lapse datasets combines the Bayesian estimates from the previous inversion (as a memory function) with new data. The memory function and pilot point design takes

  2. Separating climate change signals into thermodynamic, lapse-rate and circulation effects: theory and application to the European summer climate

    Science.gov (United States)

    Kröner, Nico; Kotlarski, Sven; Fischer, Erich; Lüthi, Daniel; Zubler, Elias; Schär, Christoph

    2016-07-01

    Climate models robustly project a strong overall summer warming across Europe showing a characteristic north-south gradient with enhanced warming and drying in southern Europe. However, the processes that are responsible for this pattern are not fully understood. We here employ an extended surrogate or pseudo-warming approach to disentangle the contribution of different mechanisms to this response pattern. The basic idea of the surrogate technique is to use a regional climate model and apply a large-scale warming to the lateral boundary conditions of a present-day reference simulation, while maintaining the relative humidity (and thus implicitly increasing the specific moisture content). In comparison to previous studies, our approach includes two important extensions: first, different vertical warming profiles are applied in order to separate the effects of a mean warming from lapse-rate effects. Second, a twin-design is used, in which the climate change signals are not only added to present-day conditions, but also subtracted from a scenario experiment. We demonstrate that these extensions provide an elegant way to separate the full climate change signal into contributions from large-scale thermodynamic (TD), lapse-rate (LR), and circulation and other remaining effects (CO). The latter in particular include changes in land-ocean contrast and spatial variations of the SST warming patterns. We find that the TD effect yields a large-scale warming across Europe with no distinct latitudinal gradient. The LR effect, which is quantified for the first time in our study, leads to a stronger warming and some drying in southern Europe. It explains about 50 % of the warming amplification over the Iberian Peninsula, thus demonstrating the important role of lapse-rate changes. The effect is linked to an extending Hadley circulation. The CO effect as inherited from the driving GCM is shown to further amplify the north-south temperature change gradient. In terms of mean summer

  3. Attention and the Testing Effect

    Science.gov (United States)

    Mulligan, Neil W.; Picklesimer, Milton

    2016-01-01

    Memory retrieval often enhances still later memory as evidenced by the testing effect. Divided attention (DA) is known to produce different effects on encoding and retrieval, substantially disrupting the former and often producing little effect on the latter. The present experiments examine whether the mnemonic consequences of retrieval are…

  4. Attentional bias in math anxiety

    Science.gov (United States)

    Rubinsten, Orly; Eidlin, Hili; Wohl, Hadas; Akibli, Orly

    2015-01-01

    Cognitive theory from the field of general anxiety suggests that the tendency to display attentional bias toward negative information results in anxiety. Accordingly, the current study aims to investigate whether attentional bias is involved in math anxiety (MA) as well (i.e., a persistent negative reaction to math). Twenty seven participants (14 with high levels of MA and 13 with low levels of MA) were presented with a novel computerized numerical version of the well established dot probe task. One of six types of prime stimuli, either math related or typically neutral, was presented on one side of a computer screen. The prime was preceded by a probe (either one or two asterisks) that appeared in either the prime or the opposite location. Participants had to discriminate probe identity (one or two asterisks). Math anxious individuals reacted faster when the probe was at the location of the numerical related stimuli. This suggests the existence of attentional bias in MA. That is, for math anxious individuals, the cognitive system selectively favored the processing of emotionally negative information (i.e., math related words). These findings suggest that attentional bias is linked to unduly intense MA symptoms. PMID:26528208

  5. Attentional Bias in Math Anxiety

    Directory of Open Access Journals (Sweden)

    Orly eRubinsten

    2015-10-01

    Full Text Available Cognitive theory from the field of general anxiety suggests that the tendency to display attentional bias toward negative information results in anxiety. Accordingly, the current study aims to investigate whether attentional bias is involved in math anxiety as well (i.e., a persistent negative reaction to math. Twenty seven participants (14 with high levels of math anxiety and 13 with low levels of math anxiety were presented with a novel computerized numerical version of the well established dot probe task. One of 6 types of prime stimuli, either math related or typically neutral, were presented on one side of a computer screen. The prime was preceded by a probe (either one or two asterisks that appeared in either the prime or the opposite location. Participants had to discriminate probe identity (one or two asterisks. Math anxious individuals reacted faster when the probe was at the location of the numerical related stimuli. This suggests the existence of attentional bias in math anxiety. That is, for math anxious individuals, the cognitive system selectively favored the processing of emotionally negative information (i.e., math related words. These findings suggest that attentional bias is linked to unduly intense math anxiety symptoms.

  6. Attention Deficit Hyperactivity Disorder (ADHD)

    Centers for Disease Control (CDC) Podcasts

    2014-04-10

    This podcast discusses Attention Deficit Hyperactivity Disorder, or ADHD, the most common behavioral disorder in children. Learn about symptoms, risk factors, and treatment.  Created: 4/10/2014 by National Center on Birth Defects and Developmental Disabilities (NCBDDD).   Date Released: 5/7/2014.

  7. Attention: A Machine Learning Perspective

    DEFF Research Database (Denmark)

    Hansen, Lars Kai

    2012-01-01

    We review a statistical machine learning model of top-down task driven attention based on the notion of ‘gist’. In this framework we consider the task to be represented as a classification problem with two sets of features — a gist of coarse grained global features and a larger set of low...

  8. Practicing the attentional Dwell Away?

    DEFF Research Database (Denmark)

    Petersen, Anders; Kyllingsbæk, Søren; Bundesen, Claus Mogens

    2007-01-01

    Studies of the time course of visual attention have identified a temporary functional blindness to the second of two spatially separated targets: attending to one visual stimulus may lead to impairments in identifying a second stimulus presented about 200-500 ms later than the first. The phenomen...

  9. Attentional episodes in visual perception

    NARCIS (Netherlands)

    Wyble, Brad; Potter, Mary C.; Bowman, Howard; Nieuwenstein, Mark

    2011-01-01

    Is one's temporal perception of the world truly as seamless as it appears? This article presents a computationally motivated theory suggesting that visual attention samples information from temporal episodes (episodic simultaneous type/serial token model; Wyble, Bowman, & Nieuwenstein, 2009). Breaks

  10. Attentional bias in math anxiety.

    Science.gov (United States)

    Rubinsten, Orly; Eidlin, Hili; Wohl, Hadas; Akibli, Orly

    2015-01-01

    Cognitive theory from the field of general anxiety suggests that the tendency to display attentional bias toward negative information results in anxiety. Accordingly, the current study aims to investigate whether attentional bias is involved in math anxiety (MA) as well (i.e., a persistent negative reaction to math). Twenty seven participants (14 with high levels of MA and 13 with low levels of MA) were presented with a novel computerized numerical version of the well established dot probe task. One of six types of prime stimuli, either math related or typically neutral, was presented on one side of a computer screen. The prime was preceded by a probe (either one or two asterisks) that appeared in either the prime or the opposite location. Participants had to discriminate probe identity (one or two asterisks). Math anxious individuals reacted faster when the probe was at the location of the numerical related stimuli. This suggests the existence of attentional bias in MA. That is, for math anxious individuals, the cognitive system selectively favored the processing of emotionally negative information (i.e., math related words). These findings suggest that attentional bias is linked to unduly intense MA symptoms.

  11. Attending at a Low Intensity Increases Impulsivity in an Auditory Sustained Attention to Response Task.

    Science.gov (United States)

    Roebuck, Hettie; Guo, Kun; Bourke, Patrick

    2015-12-01

    Why attention lapses during prolonged tasks is debated, specifically whether errors are a consequence of under-arousal or exerted effort. To explore this, we investigated whether increased impulsivity is associated with effortful processing by modifying the demand of a task by presenting it at a quiet intensity. Here, we consider whether attending at low but detectable levels affects impulsivity in a population with intact hearing. A modification of the Sustained Attention to Response Task was used with auditory stimuli at two levels: the participants' personal "lowest detectable" level and a "normal speaking" level. At the quiet intensity, we found that more impulsive responses were made compared with listening at a normal speaking level. These errors were not due to a failure in discrimination. The findings suggest an increase in processing time for auditory stimuli at low levels that exceeds the time needed to interrupt a planned habitual motor response. This leads to a more impulsive and erroneous response style. These findings have important implications for understanding the nature of impulsivity in relation to effortful processing. They may explain why a high proportion of individuals with hearing loss are also diagnosed with Attention Deficit Hyperactivity Disorder.

  12. Validation of snow depth reconstruction from lapse-rate webcam images against terrestrial laser scanner measurements in centrel Pyrenees

    Science.gov (United States)

    Revuelto, Jesús; Jonas, Tobias; López-Moreno, Juan Ignacio

    2015-04-01

    Snow distribution in mountain areas plays a key role in many processes as runoff dynamics, ecological cycles or erosion rates. Nevertheless, the acquisition of high resolution snow depth data (SD) in space-time is a complex task that needs the application of remote sensing techniques as Terrestrial Laser Scanning (TLS). Such kind of techniques requires intense field work for obtaining high quality snowpack evolution during a specific time period. Combining TLS data with other remote sensing techniques (satellite images, photogrammetry…) and in-situ measurements could represent an improvement of the available information of a variable with rapid topographic changes. The aim of this study is to reconstruct daily SD distribution from lapse-rate images from a webcam and data from two to three TLS acquisitions during the snow melting periods of 2012, 2013 and 2014. This information is obtained at Izas Experimental catchment in Central Spanish Pyrenees; a catchment of 33ha, with an elevation ranging from 2050 to 2350m a.s.l. The lapse-rate images provide the Snow Covered Area (SCA) evolution at the study site, while TLS allows obtaining high resolution information of SD distribution. With ground control points, lapse-rate images are georrectified and their information is rasterized into a 1-meter resolution Digital Elevation Model. Subsequently, for each snow season, the Melt-Out Date (MOD) of each pixel is obtained. The reconstruction increases the estimated SD lose for each time step (day) in a distributed manner; starting the reconstruction for each grid cell at the MOD (note the reverse time evolution). To do so, the reconstruction has been previously adjusted in time and space as follows. Firstly, the degree day factor (SD lose/positive average temperatures) is calculated from the information measured at an automatic weather station (AWS) located in the catchment. Afterwards, comparing the SD lose at the AWS during a specific time period (i.e. between two TLS

  13. Large-scale time-lapse microscopy of Oct4 expression in human embryonic stem cell colonies.

    Science.gov (United States)

    Bhadriraju, Kiran; Halter, Michael; Amelot, Julien; Bajcsy, Peter; Chalfoun, Joe; Vandecreme, Antoine; Mallon, Barbara S; Park, Kye-Yoon; Sista, Subhash; Elliott, John T; Plant, Anne L

    2016-07-01

    Identification and quantification of the characteristics of stem cell preparations is critical for understanding stem cell biology and for the development and manufacturing of stem cell based therapies. We have developed image analysis and visualization software that allows effective use of time-lapse microscopy to provide spatial and dynamic information from large numbers of human embryonic stem cell colonies. To achieve statistically relevant sampling, we examined >680 colonies from 3 different preparations of cells over 5days each, generating a total experimental dataset of 0.9 terabyte (TB). The 0.5 Giga-pixel images at each time point were represented by multi-resolution pyramids and visualized using the Deep Zoom Javascript library extended to support viewing Giga-pixel images over time and extracting data on individual colonies. We present a methodology that enables quantification of variations in nominally-identical preparations and between colonies, correlation of colony characteristics with Oct4 expression, and identification of rare events.

  14. Imaging subsurface migration of dissolved CO2 in a shallow aquifer using 3-D time-lapse electrical resistivity tomography

    DEFF Research Database (Denmark)

    Auken, Esben; Doetsch, Joseph; Fiandaca, Gianluca;

    2014-01-01

    of aeolian and glacial sands near the surface and marine sands below 10m depth. 3-D time-lapse ERT inversions clearly image the dissolved CO2 plume with decreased electrical resistivity values. We can image the geochemical changes induced by the dissolved CO2 until the end of the acquisition, 120days after......, we injected CO2 at a depth of 5 and 10m and monitored its migration using 320 electrodes on a 126m×25m surface grid. A fully automated acquisition system continuously collected data and uploaded it into an online database. The large amount of data allows for time-series analysis using geostatistical...... techniques for noise estimation and data interpolation to compensate for intermittent instrument failure. We estimate a time-dependent noise level for each ERT configuration, taking data variation and measurement frequency into account.A baseline inversion reveals the geology at the site consisting...

  15. Do animal models provide a valid analogue for human drug lapse and relapse? Comment on Leri and Stewart (2002).

    Science.gov (United States)

    Marlatt, G Alan

    2002-11-01

    Prior research on animal models of drug relapse has demonstrated that passive exposure to an addictive substance following acquisition and extinction of drug self-administration has a "priming effect" on subsequent drug use. The validity of this animal analogue of human relapse can be criticized, however, because most human drug relapses are precipitated by the user's voluntary self-administration of a substance. The results of the present study by F. Leri and J. Stewart (2002) clearly show that if the initial heroin lapse is self-administered by rats, subsequent heroin seeking during the relapse test is significantly greater than if the heroin is externally administered. These results help bridge the gap between animal and human models of drug use and highlight the significance of both behavioral and environmental determinants of relapse. PMID:12498331

  16. Human treadmill walking needs attention

    Directory of Open Access Journals (Sweden)

    Daniel Olivier

    2006-08-01

    Full Text Available Abstract Background The aim of the study was to assess the attentional requirements of steady state treadmill walking in human subjects using a dual task paradigm. The extent of decrement of a secondary (cognitive RT task provides a measure of the attentional resources required to maintain performance of the primary (locomotor task. Varying the level of difficulty of the reaction time (RT task is used to verify the priority of allocation of attentional resources. Methods 11 healthy adult subjects were required to walk while simultaneously performing a RT task. Participants were instructed to bite a pressure transducer placed in the mouth as quickly as possible in response to an unpredictable electrical stimulation applied on the back of the neck. Each subject was tested under five different experimental conditions: simple RT task alone and while walking, recognition RT task alone and while walking, walking alone. A foot switch system composed of a pressure sensitive sensor was placed under the heel and forefoot of each foot to determine the gait cycle duration. Results Gait cycle duration was unchanged (p > 0.05 by the addition of the RT task. Regardless of the level of difficulty of the RT task, the RTs were longer during treadmill walking than in sitting conditions (p 0.05 was found between the attentional demand of the walking task and the decrement of performance found in the RT task under varying levels of difficulty. This finding suggests that the healthy subjects prioritized the control of walking at the expense of cognitive performance. Conclusion We conclude that treadmill walking in young adults is not a purely automatic task. The methodology and outcome measures used in this study provide an assessment of the attentional resources required by walking on the treadmill at a steady state.

  17. Monitoring channel head erosion processes in response to an artificially induced abrupt base level change using time-lapse photography 2301

    Science.gov (United States)

    Headcut and channel extension in response to an abrupt base level change in 2004 of approximately 1m was studied in a 1.29 ha semiarid headwater drainage on the Walnut Gulch Experimental Watershed (WGEW) in southeastern Arizona, USA. Field observations and time-lapse photography were coupled with hy...

  18. Remote estimation of the hydraulic properties of a sand using full-waveform integrated hydrogeophysical inversion of time-lapse, off-ground GPR data

    NARCIS (Netherlands)

    Lambot, S.; Slob, E.; Rhebergen, J.B.; Lopera, O.; Jadoon, K.Z.; Vereecken, H.

    2009-01-01

    We used integrated hydrogeophysical inversion of time-lapse, proximal ground penetrating radar (GPR) data to remotely infer the unsaturated soil hydraulic properties of a laboratory sand during an infiltration event. The inversion procedure involved full-waveform modeling of the radar signal and one

  19. Time-lapse ERT and DTS for seasonal and short-term monitoring of an alpine river hyporheic zone

    Science.gov (United States)

    Boaga, Jacopo; Laura, Busato; Mariateresa, Perri; Giorgio, Cassiani

    2016-04-01

    The hyporheic zone (HZ) is the area located beneath and adjacent to rivers and streams, where the interactions between surface water and groundwater take place. This complex physical domain allows the transport of several substances from a stream to the unconfined aquifer below, and vice versa, thus playing a fundamental role in the river ecosystem. The importance of the hyporheic zone makes its characterization a goal shared by several disciplines, which range from applied geophysics to biogeochemistry, from hydraulics to ecology. The frontier field of HZ characterization stays in applied non-invasive methodologies as Electrical Resistivity Tomography - ERT - and Distributed Temperature Sensing - DTS. ERT is commonly applied in cross-well configuration or with a superficial electrodes deployment while DTS is used in hydro-geophysics in the last decade, revealing a wide applicability to the typical issues of this field of study. DTS for hydro-geophysics studies is based on Raman scattering and employs heat as tracer and uses a fiber-optic cable to acquire temperature values. We applied both techniques for an alpine river case studies located in Val di Sole, TN, Italy. The collected measurements allow high-resolution characterization of the hyporheic zone, overcoming the critical problem of invasive measurements under riverbeds. In this work, we present the preliminary results regarding the characterization of the hyporheic zone of the alpine river obtained combining ERT and DTS time-lapse measurements. The data collection benefits from an innovative instrumentation deployment, which consists of both an ERT multicore cable and a DTS fiber-optic located in two separated boreholes drilled 5m under the watercourse and perpendicular to it. In particular we present the first year monitoring results and a short time-lapse monitoring experiment conducted during summer 2015. The site and the results here described are part of the EU FP7 CLIMB (Climate Induced Changes on the

  20. Scattering and anelastic attenuation of seismic energy in Northeast India using the multiple lapse time window analysis

    Science.gov (United States)

    Padhy, S.

    2010-12-01

    We investigated the intrinsic dissipation and scattering properties of the lithosphere beneath the northeast India by using the seismic waves recorded by a network of ten broadband stations in the region with hypocentral distances ranging from 31 to 200 km. First, we determined coda Q from the amplitude decay rate of the S-wave coda envelopes in five frequency bands from 1.5 to 24 Hz based on single scattering theory and QS by means of the coda normalization method. Assuming a frequency dependent power-law of the form , we found a low Q0 (Q0 India is seismically active and heterogeneous. Then we applied the multiple lapse time window (MLTW) analysis in the hypothesis of velocity and scattering coefficients constant with depth. We calculated the variation of integrated spectral energy with hypocentral distance for three consecutive lapse time windows (0-15, 15-30, 30-45 sec), starting from the onset of the S-wave arrival. The spectral energies over an octave bandwidth with central frequencies at 1.5, 3, 6, 12 and 24 Hz were calculated to obtain the frequency dependence of attenuation parameters. The results show that intrinsic absorption dominates over scattering in the attenuation process at high frequencies. However, in the hypothesis of uniform medium, the estimates of scattering attenuations obtained by MLTW analysis are overestimated. So the present results are correct to a first order approximation. To obtain more reliable and unbiased estimates of the attenuation parameters and their frequency dependences by considering the probable influence of crustal-mantel heterogeneities, we analyze the events by using the depth dependent MLTW method.

  1. Time-lapse imaging of the dynamics of CNS glial-axonal interactions in vitro and ex vivo.

    Directory of Open Access Journals (Sweden)

    Kalliopi Ioannidou

    Full Text Available BACKGROUND: Myelination is an exquisite and dynamic example of heterologous cell-cell interaction, which consists of the concentric wrapping of multiple layers of oligodendrocyte membrane around neuronal axons. Understanding the mechanism by which oligodendrocytes ensheath axons may bring us closer to designing strategies to promote remyelination in demyelinating diseases. The main aim of this study was to follow glial-axonal interactions over time both in vitro and ex vivo to visualize the various stages of myelination. METHODOLOGY/PRINCIPAL FINDINGS: We took two approaches to follow myelination over time: i time-lapse imaging of mixed CNS myelinating cultures generated from mouse spinal cord to which exogenous GFP-labelled murine cells were added, and ii ex vivo imaging of the spinal cord of shiverer (Mbp mutant mice, transplanted with GFP-labelled murine neurospheres. We demonstrate that oligodendrocyte-axonal interactions are dynamic events with continuous retraction and extension of oligodendroglial processes. Using cytoplasmic and membrane-GFP labelled cells to examine different components of the myelin-like sheath, we provide evidence from time-lapse fluorescence microscopy and confocal microscopy that the oligodendrocytes' cytoplasm-filled processes initially spiral around the axon in a corkscrew-like manner. This is followed subsequently by focal expansion of the corkscrew process to form short cuffs, which then extend longitudinally along the axons. We predict from this model that these spiral cuffs must extend over each other first before extending to form internodes of myelin. CONCLUSION: These experiments show the feasibility of visualizing the dynamics of glial-axonal interaction during myelination over time. Moreover, these approaches complement each other with the in vitro approach allowing visualization of an entire internodal length of myelin and the ex vivo approach validating the in vitro data.

  2. Technical Note: Semi-automated effective width extraction from time-lapse RGB imagery of a remote, braided Greenlandic river

    Science.gov (United States)

    Gleason, C. J.; Smith, L. C.; Finnegan, D. C.; LeWinter, A. L.; Pitcher, L. H.; Chu, V. W.

    2015-06-01

    River systems in remote environments are often challenging to monitor and understand where traditional gauging apparatus are difficult to install or where safety concerns prohibit field measurements. In such cases, remote sensing, especially terrestrial time-lapse imaging platforms, offer a means to better understand these fluvial systems. One such environment is found at the proglacial Isortoq River in southwestern Greenland, a river with a constantly shifting floodplain and remote Arctic location that make gauging and in situ measurements all but impossible. In order to derive relevant hydraulic parameters for this river, two true color (RGB) cameras were installed in July 2011, and these cameras collected over 10 000 half hourly time-lapse images of the river by September of 2012. Existing approaches for extracting hydraulic parameters from RGB imagery require manual or supervised classification of images into water and non-water areas, a task that was impractical for the volume of data in this study. As such, automated image filters were developed that removed images with environmental obstacles (e.g., shadows, sun glint, snow) from the processing stream. Further image filtering was accomplished via a novel automated histogram similarity filtering process. This similarity filtering allowed successful (mean accuracy 79.6 %) supervised classification of filtered images from training data collected from just 10 % of those images. Effective width, a hydraulic parameter highly correlated with discharge in braided rivers, was extracted from these classified images, producing a hydrograph proxy for the Isortoq River between 2011 and 2012. This hydrograph proxy shows agreement with historic flooding observed in other parts of Greenland in July 2012 and offers promise that the imaging platform and processing methodology presented here will be useful for future monitoring studies of remote rivers.

  3. Modality-specificity of Selective Attention Networks

    OpenAIRE

    Stewart, Hannah J; Amitay, Sygal

    2015-01-01

    Objective: To establish the modality specificity and generality of selective attention networks. Method: Forty-eight young adults completed a battery of four auditory and visual selective attention tests based upon the Attention Network framework: the visual and auditory Attention Network Tests (vANT, aANT), the Test of Everyday Attention (TEA), and the Test of Attention in Listening (TAiL). These provided independent measures for auditory and visual alerting, orienting, and conflict resol...

  4. Media multitasking, attention, and distraction

    DEFF Research Database (Denmark)

    Aagaard, Jesper

    2015-01-01

    Students often multitask with technologies such as computers, laptops, tablets and smartphones during class. Unfortunately, numerous empirical studies firmly establish a significant drop in academic performance caused by this media multitasking. In this paper it is argued that cognitive studies may...... have clarified the negative consequences of this activity, yet they struggle to address the processes involved in it. A cognitive characterization of attention as a mental phenomenon neglects the interaction between bodies and technologies, and it is suggested that a postphenomenological understanding...

  5. Deployment of Attention on Handshakes

    OpenAIRE

    Shen, Mowei; Yin, Jun; Ding, Xiaowei; Shui, Rende; Zhou, Jifan

    2016-01-01

    Understanding the social structures between objects, organizing, and selecting them accordingly, is fundamental to social cognition. We report an example that demonstrates the object association learned from social interactions could impact visual attention. Particularly, when two hands approach each other to perform a handshake, they tend to be attended to as a unit because of the cooperative relationship exhibited in the action: even a cue presented on a non-target hand may facilitate a res...

  6. Attentional Networks and Biological Motion

    OpenAIRE

    Chandramouli Chandrasekaran; Lucy Turner; Heinrich H Bülthoff; Thornton, Ian M.

    2010-01-01

    Our ability to see meaningful actions when presented with pointlight traces of human movement is commonly referred to as the perception of biological motion. While traditionalexplanations have emphasized the spontaneous and automatic nature of this ability, morerecent findings suggest that attention may play a larger role than is typically assumed. Intwo studies we show that the speed and accuracy of responding to point-light stimuli is highly correlated with the ability to control selective ...

  7. Attention and Optimal Sensory Codes

    OpenAIRE

    Jaramillo, Santiago; Pearlmutter, Barak A.

    2004-01-01

    Neuronal activity can be modulated by attention even while the sensory stimulus is held fixed. This modulation implies changes in the tuning curve (or receptive field) of the neurons involved in sensory processing. We propose an information-theoretic hypothesis for the purpose of this modulation, and show using computer simulation that the similar modulation emerges in a system that is optimally encoding a sensory stimulus when the system is informed about the changing relevance of different ...

  8. A Real Attention-Getter

    Science.gov (United States)

    2003-01-01

    While most parents would agree that playing videos games is the antithesis of time well spent for their children, recent advances involving NASA biofeedback technology are proving otherwise. The same techniques used to measure brain activity in NASA pilots during flight simulation exercises are now a part of a revolutionary video game system that is helping to improve overall mental awareness for Americans of all ages, including those who suffer from Attention Deficit Hyperactivity Disorder (ADHD).

  9. 29 CFR 785.43 - Medical attention.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Medical attention. 785.43 Section 785.43 Labor Regulations..., Medical Attention, Civic and Charitable Work, and Suggestion Systems § 785.43 Medical attention. Time spent by an employee in waiting for and receiving medical attention on the premises or at the...

  10. Voluntary attention increases perceived spatial frequency

    OpenAIRE

    Abrams, Jared; Barbot, Antoine; Carrasco, Marisa

    2010-01-01

    Voluntary covert attention selects relevant sensory information for prioritized processing. The behavioral and neural consequences of such selection have been extensively documented, but its phenomenology has received little empirical investigation. Involuntary attention increases perceived spatial frequency (Gobell & Carrasco, 2005), but involuntary attention can differ from voluntary attention in its effects on performance in tasks mediated by spatial resolution (Yeshurun, Montagna, & Carra...

  11. 时移地震资料贝叶斯AVO波形反演%Time-lapse Bayesian AVO waveform inversion

    Institute of Scientific and Technical Information of China (English)

    王守东; 王波

    2012-01-01

    Aiming at the difference of time-lapse seismic data of different vintages, a Bayesian AVO waveform inversion method is given in this paper. This method can obtain the changes of compressional/shear impedance and density simultaneously using the pre-stack seismic data in different vintages. Because of the differences in the process of data acquisition and processing in the seismic data of different vintages, when the time-lapse seismic inversion is made, changes exist in the region where the process of injection and production does not have impacts, and these changes will lead to some obvious changes in the inversion results in this region. To solve the problem, in this paper, Bayesian theoretical framework is used to combine the prior information of the changes of the elastic parameters with information contained in the seismic data. We assume the changes of compressional/shear impedance and density follow the Gaussian distribution, whose expectation is the answer of time-lapse seismic uncoupled inversion. Meanwhile in order to better characterize the changes in reservoir properties and improve the resolution of the results and inhibit the artifacts in the non-production region, we also assume that the derivatives of changes of elastic parameters follow the improved Cauchy distribution. Tests on synthetic data and practical data show that the proposed inversion method can effectively inhibit the artifacts, highlight the changes of reservoir properties, get the changes of elastic parameters of high-resolution and provide more effective information for the study of reservoir properties and the optimization of recovery scheme.%针对时移地震差异数据,给出了一种基于贝叶斯理论的AVO波形反演方法.该方法可以利用时移地震差异数据同时反演出纵波阻抗、横波阻抗和密度的变化.利用时移地震资料进行反演,由于采集和处理过程中存在一定的差异,不同年份地震资料在非注采过程影响区域也

  12. 4D Time-Lapse Seismic Analysis of Active Gas Seepage Systems on the Vestnesa Ridge, Offshore W-Svalbard

    Science.gov (United States)

    Bunz, S.; Hurter, S.; Plaza-Faverola, A. A.; Mienert, J.

    2014-12-01

    Active gas venting occurs on the Vestnesa Ridge, an elongated sediment drift north of the Molloy Transform and just east of the Molloy Ridge, one of the shortest segments of the slow spreading North-Atlantic Ridge system. The crest of the Vestnesa Ridge at water depth between 1200-1300 m is pierced with fluid-flow features. Seafloor pockmarks vary in size up to 1 km in diameter with significant morphological features consisting of small ridges, diapiric structures and small pits. Detailed hydro-acoustic surveying shows that gas mostly emanates from the small-scale pits, where also hydrates have been recovered by sediment sampling. High-resolution P-Cable 3D seismic data acquired in 2012 show vertical focused fluid flow features beneath the seafloor pockmarks. These co-called chimneys extend down to the free-gas zone underneath a bottom-simulating reflection (BSR). Here, they link up with small fault systems that might provide pathways to the deeper subsurface. The chimney features show a high variability in their acoustic characteristics with alternating blanked or masked zones and high-amplitude anomalies scattered through the whole vertical extent of the chimneys. The amplitude anomalies indicate high-impedance contrasts due to the likely presence of gas or a high-velocity material like gas hydrates or carbonates. In most cases, the high-amplitude anomalies line up along specific vertical pathways that connect nicely with the small-scale pits at the surface where gas bubbles seep from the seafloor. We re-acquired the 3D seismic survey in 2013 for time-lapse seismic studies in order to better understand the origin of the amplitude anomalies and in order to track potentially migrating gas fronts up along the chimney structure. The time-lapse seismic analysis indicates several areas, where gas migration may have led to changes in acoustic properties of the subsurface. These areas are located along chimney structures and the BSR. This work provides a basis for better

  13. A STUDY OF SPATIAL DIFFERENCE CORRECTION FOR TIME-LAPSE SEISMIC DATA%时移地震数据空间偏差校正方法

    Institute of Scientific and Technical Information of China (English)

    李景叶; 张连群; 陈小宏

    2012-01-01

    Time-lapse seismic reservoir monitoring technology is one of the most important technologies that can determine the distribution of residual oil directly. Spatial difference correction for time-lapse seismic data was studied in this paper, aiming at solving the difficulties in the demand and application of time-lapse seismic reservoir monitoring technique in China. Spatial position difference for the same reflection point in different migrated sections caused by the differences in geometry and acquisition orientation results in unreasonable time-lapse seismic data difference, which increases the difficulty and risk of time-lapse seismic interpretation processing parameters. The optimal shifts in x, y and time directions are calculated by 3D cross-correlation between local data volumes from reference data and monitor data. And then the spatial position difference correction can be conducted for monitor seismic data. The comparison and analysis of real time-lapse seismic data indicate that time-lapse seismic spatial difference correction is effective in decreasing 3D nonlinear spatial difference of purposeless repeated acquisition time-lapse seismic data.%时移地震油藏监测技术是直接确定剩余油分布的关键技术之一.针对时移地震油藏监测在国内的需求及推广应用难点,研究了时移地震数据空间偏差校正处理方法.由于在观测系统、采集方向的处理参数等方面的差异,导致地下同一反射点在不同时移地震数据偏移后空间位置存在差异,产生与油藏变化无关的地震差异,增加数据解释的难度和风险.通过对参考数据与监测数据三维空间内的局部数据体的三维相关计算,确定监测数据体在x方向、y方向和时间方向上最佳移动量,从而实现两次地震数据空间位置差异校正.实际时移地震数据处理试验结果分析表明,空间偏差校正处理方法在消除时移地震数据三维空间非线性空间偏差方面是有效的.

  14. Automated segmentation and tracking of non-rigid objects in time-lapse microscopy videos of polymorphonuclear neutrophils.

    Science.gov (United States)

    Brandes, Susanne; Mokhtari, Zeinab; Essig, Fabian; Hünniger, Kerstin; Kurzai, Oliver; Figge, Marc Thilo

    2015-02-01

    Time-lapse microscopy is an important technique to study the dynamics of various biological processes. The labor-intensive manual analysis of microscopy videos is increasingly replaced by automated segmentation and tracking methods. These methods are often limited to certain cell morphologies and/or cell stainings. In this paper, we present an automated segmentation and tracking framework that does not have these restrictions. In particular, our framework handles highly variable cell shapes and does not rely on any cell stainings. Our segmentation approach is based on a combination of spatial and temporal image variations to detect moving cells in microscopy videos. This method yields a sensitivity of 99% and a precision of 95% in object detection. The tracking of cells consists of different steps, starting from single-cell tracking based on a nearest-neighbor-approach, detection of cell-cell interactions and splitting of cell clusters, and finally combining tracklets using methods from graph theory. The segmentation and tracking framework was applied to synthetic as well as experimental datasets with varying cell densities implying different numbers of cell-cell interactions. We established a validation framework to measure the performance of our tracking technique. The cell tracking accuracy was found to be >99% for all datasets indicating a high accuracy for connecting the detected cells between different time points. PMID:25465844

  15. Intracellular accumulation and dissolution of silver nanoparticles in L-929 fibroblast cells using live cell time-lapse microscopy.

    Science.gov (United States)

    Wildt, Bridget E; Celedon, Alfredo; Maurer, Elizabeth I; Casey, Brendan J; Nagy, Amber M; Hussain, Saber M; Goering, Peter L

    2016-08-01

    Cytotoxicity assessments of nanomaterials, such as silver nanoparticles, are challenging due to interferences with test reagents and indicators as well uncertainties in dosing as a result of the complex nature of nanoparticle intracellular accumulation. Furthermore, current theories suggest that silver nanoparticle cytotoxicity is a result of silver nanoparticle dissolution and subsequent ion release. This study introduces a novel technique, nanoparticle associated cytotoxicity microscopy analysis (NACMA), which combines fluorescence microscopy detection using ethidium homodimer-1, a cell permeability marker that binds to DNA after a cell membrane is compromised (a classical dead-cell indicator dye), with live cell time-lapse microscopy and image analysis to simultaneously investigate silver nanoparticle accumulation and cytotoxicity in L-929 fibroblast cells. Results of this method are consistent with traditional methods of assessing cytotoxicity and nanoparticle accumulation. Studies conducted on 10, 50, 100 and 200 nm silver nanoparticles reveal size dependent cytotoxicity with particularly high cytotoxicity from 10 nm particles. In addition, NACMA results, when combined with transmission electron microscopy imaging, reveal direct evidence of intracellular silver ion dissolution and possible nanoparticle reformation within cells for all silver nanoparticle sizes. PMID:26643278

  16. The Relationship between Cell Number, Division Behavior and Developmental Potential of Cleavage Stage Human Embryos: A Time-Lapse Study.

    Science.gov (United States)

    Kong, Xiangyi; Yang, Shuting; Gong, Fei; Lu, Changfu; Zhang, Shuoping; Lu, Guangxiu; Lin, Ge

    2016-01-01

    Day 3 cleavage embryo transfer is routine in many assisted reproductive technology centers today. Embryos are usually selected according to cell number, cell symmetry and fragmentation for transfer. Many studies have showed the relationship between cell number and embryo developmental potential. However, there is limited understanding of embryo division behavior and their association with embryo cell number and developmental potential. A retrospective and observational study was conducted to investigate how different division behaviors affect cell number and developmental potential of day 3 embryos by time-lapse imaging. Based on cell number at day 3, the embryos (from 104 IVF/intracytoplasmic sperm injection (ICSI) treatment cycles, n = 799) were classified as follows: less than 5 cells (10C; n = 42). Division behavior, morphokinetic parameters and blastocyst formation rate were analyzed in 5 groups of day 3 embryos with different cell numbers. In 10C embryos increased compared to 7-8C embryos (45.8%, 33.3% vs. 11.1%, respectively). In ≥5C embryos, FR and DC significantly reduced developmental potential, whereas division behaviors. In NB embryos, the blastocyst formation rate increased with cell number from 7.4% (10C). In NB embryos, the cell cycle elongation or shortening was the main cause for abnormally low or high cell number, respectively. After excluding embryos with abnormal division behaviors, the developmental potential, implantation rate and live birth rate of day 3 embryos increased with cell number.

  17. Rapid drug susceptibility test of Mycobacterium tuberculosis using microscopic time-lapse imaging in an agarose matrix.

    Science.gov (United States)

    Choi, Jungil; Yoo, Jungheon; Kim, Ki-Jung; Kim, Eun-Geun; Park, Kyung Ock; Kim, Hyejin; Kim, Haeun; Jung, Hyunju; Kim, Taeyoung; Choi, Myungjin; Kim, Hee Chan; Ryoo, Sungweon; Jung, Yong-Gyun; Kwon, Sunghoon

    2016-03-01

    Tuberculosis (TB) is a major global health problem, and multi-drug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) are spreading throughout the world. However, conventional drug susceptibility test (DST) methods, which rely on the detection of the colony formation on a solid medium, require 1-2 months to the result. A rapid and accurate DST is necessary to identify patients with drug-resistant TB and treat them with appropriate drugs. Here, we used microscopic imaging of Mycobacterium tuberculosis (MTB) immobilized in an agarose matrix for a rapid DST. The agarose matrix, which was molded in a microfluidic chip, was inoculated with MTB, and TB drugs in liquid culture medium diffused throughout the agarose to reach the MTB immobilized in the agarose matrix. After the responses of MTB to drugs were tracked with an automated microscopic system, an image-processing program automatically determined the susceptibility and resistance of MTB to specific doses of TB drugs. The automatic DST system was able to assess the drug susceptibility of various drug-resistant clinical TB strains within 9 days with an accuracy comparable to that of conventional method. Our rapid DST method based on microscopic time-lapse imaging greatly reduces the time required for a DST and can be used to rapidly and accurately treat TB patients. PMID:26754815

  18. A Sparse Bayesian Imaging Technique for Efficient Recovery of Reservoir Channels With Time-Lapse Seismic Measurements

    KAUST Repository

    Sana, Furrukh

    2016-06-01

    Subsurface reservoir flow channels are characterized by high-permeability values and serve as preferred pathways for fluid propagation. Accurate estimation of their geophysical structures is thus of great importance for the oil industry. The ensemble Kalman filter (EnKF) is a widely used statistical technique for estimating subsurface reservoir model parameters. However, accurate reconstruction of the subsurface geological features with the EnKF is challenging because of the limited measurements available from the wells and the smoothing effects imposed by the \\\\ell _{2} -norm nature of its update step. A new EnKF scheme based on sparse domain representation was introduced by Sana et al. (2015) to incorporate useful prior structural information in the estimation process for efficient recovery of subsurface channels. In this paper, we extend this work in two ways: 1) investigate the effects of incorporating time-lapse seismic data on the channel reconstruction; and 2) explore a Bayesian sparse reconstruction algorithm with the potential ability to reduce the computational requirements. Numerical results suggest that the performance of the new sparse Bayesian based EnKF scheme is enhanced with the availability of seismic measurements, leading to further improvement in the recovery of flow channels structures. The sparse Bayesian approach further provides a computationally efficient framework for enforcing a sparse solution, especially with the possibility of using high sparsity rates through the inclusion of seismic data.

  19. Lapses, infidelities, and creative adaptations: lessons from evaluation of a participatory market development approach in the Andes.

    Science.gov (United States)

    Horton, Douglas; Rotondo, Emma; Paz Ybarnegaray, Rodrigo; Hareau, Guy; Devaux, André; Thiele, Graham

    2013-08-01

    Participatory approaches are frequently recommended for international development programs, but few have been evaluated. From 2007 to 2010 the Andean Change Alliance evaluated an agricultural research and development approach known as the "Participatory Market Chain Approach" (PMCA). Based on a study of four cases, this paper examines the fidelity of implementation, the factors that influenced implementation and results, and the PMCA change model. We identify three types of deviation from the intervention protocol (lapses, creative adaptations, and true infidelities) and five groups of variables that influenced PMCA implementation and results (attributes of the macro context, the market chain, the key actors, rules in use, and the capacity development strategy). There was insufficient information to test the validity of the PMCA change model, but results were greatest where the PMCA was implemented with highest fidelity. Our analysis suggests that the single most critical component of the PMCA is engagement of market agents - not just farmers - throughout the exercise. We present four lessons for planning and evaluating participatory approaches related to the use of action and change models, the importance of monitoring implementation fidelity, the limits of baseline survey data for outcome evaluation, and the importance of capacity development for implementers. PMID:23619235

  20. Time-lapse analysis reveals different modes of primordial germ cell migration in the medaka Oryzias latipes.

    Science.gov (United States)

    Kurokawa, Hiromi; Aoki, Yumiko; Nakamura, Shuhei; Ebe, Youko; Kobayashi, Daisuke; Tanaka, Minoru

    2006-04-01

    Previous studies have shown that medaka primordial germ cells (PGC) are first distinguishable by olvas expression during late gastrulation, and that they migrate to the gonadal region through the lateral plate mesoderm. Here, we demonstrate that medaka nanos expression marks the germ line at early gastrulation stage. By marking the germ line with green fluorescent protein (GFP) fused to the nanos 3' untranslated region, we were able to visualize the behavior of PGC using time-lapse imaging. We show that there are three distinct modes of PGC migration that function at different stages of development. At early gastrulation stage, PGC actively migrate towards the marginal zone, a process that requires the function of a chemokine receptor, CXCR4. However, at late gastrulation stage, PGC change the mode and direction of their movement, as they are carried towards the midline along with somatic cells undergoing convergent movements. After aligning bilaterally, PGC actively migrate to the posterior end of the lateral plate mesoderm. This posterior movement depends on the activity of both HMGCoAR and a ligand of CXCR4, SDF-1a. These results demonstrate that PGC undergo different modes of migration to reach the prospective gonadal region of the embryo.

  1. Improved reservoir modelling with time-lapse seismic data in a Gulf of Mexico gas condensate reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Waggoner, J.R.; Seymour, R.H.; Cominelli, A. [ENI/Agip Div., Milan (Italy); Stradiotti, A. [Agip Petroleum, Houston, TX (United States)

    2003-07-01

    Time-lapse 3D- or 4D-seismic data have been tried in several fields to date, with some good case studies published to demonstrate the utility of the 4D seismic information. While another 4D case study would be useful, this paper describes two novel aspects of a recent application in the Gulf of Mexico. First, the target reservoir contains a gas condensate fluid under primary depletion, so pressure, rather than saturation, changes create the observed 4D acoustic response. Further, the primary impact of the pressure change is to the fluid composition as the initially dense gas phase lightens as condensate drops out below the dew point. The result was a 2.8% change in acoustic impedance predicted in the feasibility study. Second, the 4D seismic result was used to constrain an optimized history-matching procedure, along with the production data. After describing the method used, the paper will discuss the changes to the reservoir model that resulted. While the results should not be considered unique, they do give some insight into the structure of the reservoir that should be considered for optimal reservoir management. (Author)

  2. Analyse de "Time Lapse" optiques stéréo et d'images radar satellitaires : application à la mesure du déplacement de glaciers

    OpenAIRE

    Pham, Ha Thai

    2015-01-01

    Earth observation by image acquisition systems allows the survey of temporal evolution of natural phenomena such as earthquakes, volcanoes or gravitational movements. Various techniques exist including satellite imagery, terrestrial photogrammetry and in-situ measurements. Image time series from automatic cameras (Time Lapse) are a growing source of information since they offer an interesting compromise in terms of spatial coverage and observation frequency in order to measure surface motion ...

  3. In situ monitoring of corrosion mechanisms and phosphate inhibitor surface deposition during corrosion of zinc-magnesium-aluminium (ZMA) alloys using novel time-lapse microscopy.

    Science.gov (United States)

    Sullivan, James; Cooze, Nathan; Gallagher, Callum; Lewis, Tom; Prosek, Tomas; Thierry, Dominique

    2015-01-01

    In situ time-lapse optical microscopy was used to examine the microstructural corrosion mechanisms in three zinc-magnesium-aluminium (ZMA) alloy coated steels immersed in 1% NaCl pH 7. Preferential corrosion of MgZn(2) lamellae within the eutectic phases was observed in all the ZMA alloys followed by subsequent dissolution of Zn rich phases. The total extent and rate of corrosion, measured using time-lapse image analysis and scanning vibrating electrode technique (SVET) estimated mass loss, decreased as Mg and Al alloying additions were increased up to a level of 3 wt% Mg and 3.7 wt% Al. This was probably due to the increased presence of MgO and Al(2)O(3) at the alloy surface retarding the kinetics of cathodic oxygen reduction. The addition of 1 × 10(-2) mol dm(-3) Na(3)PO(4) to 1% NaCl pH 7 had a dramatic influence on the corrosion mechanism for a ZMA with passivation of anodic sites through phosphate precipitation observed using time-lapse image analysis. Intriguing rapid precipitation of filamentous phosphate was also observed and it is postulated that these filaments nucleate and grow due to super saturation effects. Polarisation experiments showed that the addition of 1 × 10(-2) mol dm(-3) Na(3)PO(4) to the 1% NaCl electrolyte promoted an anodic shift of 50 mV in open circuit potential for the ZMA alloy with a reduction in anodic current of 2.5 orders of magnitude suggesting that it was acting primarily as an anodic inhibitor supporting the inferences from the time-lapse investigations. These phosphate additions resulted in a 98% reduction in estimated mass loss as measured by SVET demonstrating the effectiveness of phosphate inhibitors for this alloy system.

  4. Spatial monitoring of groundwater drawdown and rebound associated with quarry dewatering using automated time-lapse electrical resistivity tomography and distribution guided clustering

    OpenAIRE

    Chambers, J. E.; Meldrum, P.I.; P. B. Wilkinson; Ward, W.; Jackson, C; Matthews, B.; Joel, P; Kuras, O.; Bai, L.; S. Uhlemann; Gunn, D

    2015-01-01

    Dewatering systems used for mining and quarrying operations often result in highly artificial and complex groundwater conditions, which can be difficult to characterise and monitor using borehole point sampling approaches. Here automated time-lapse electrical resistivity tomography (ALERT) is considered as a means of monitoring subsurface groundwater dynamics associated with changes in the dewatering regime in an operational sand and gravel quarry. We considered two scenarios: the first was u...

  5. THE KEY PROCESSING TECHNIQUES FOR MARINE TIME-LAPSE SEISMIC DATA%海上时移地震数据处理关键技术

    Institute of Scientific and Technical Information of China (English)

    丘斌煌; 李添才; 周家雄; 刘金朋; 晏红艳; 肖二莲

    2011-01-01

    This paper analyzed the geophysical mechanism of the time-lapse seisin and the non - geological factors responsible for the differences of the time-lapse seismic data, and dealt with the key processing technology for the marine time-lapse seismic data acquired on cable. Practical applications show that these technologies can improve the consistency of the seismic data processing results and improve the reliability of the difference profile, thus providing accurate information for the reservoir development monitoring.%分析了时移地震地球物理机制及造成时移地震数据差异的非地质因素,论述了海上拖缆采集的时移地震数据处理的关键技术.实例证明,这些技术可以改善时移地震资料处理结果的,致性,提高差异剖面的可靠性,为油气减开发过程的监测提供准确信息.

  6. A Reevaluation of the Attentional Inertia Concept

    NARCIS (Netherlands)

    W.J.M.I. Verbeke (Willem)

    1992-01-01

    textabstractAnderson's (1983) theory about children's attention behavior during television viewing hypothesizes that attention behavior is affected by positive feedback (the inertia hypothesis) and the degree to which a child understands the television program. During an experiment, neither componen

  7. Faststats: Attention Deficit Hyperactivity Disorder (ADHD)

    Science.gov (United States)

    ... this? Submit What's this? Submit Button NCHS Home Attention Deficit Hyperactivity Disorder (ADHD)* Recommend on Facebook Tweet ... physician offices, hospital outpatient and emergency departments) with attention deficit disorder as primary diagnosis: 9.0 million ( ...

  8. Infant Visual Attention and Object Recognition

    Science.gov (United States)

    Reynolds, Greg D.

    2015-01-01

    This paper explores the role visual attention plays in the recognition of objects in infancy. Research and theory on the development of infant attention and recognition memory are reviewed in three major sections. The first section reviews some of the major findings and theory emerging from a rich tradition of behavioral research utilizing preferential looking tasks to examine visual attention and recognition memory in infancy. The second section examines research utilizing neural measures of attention and object recognition in infancy as well as research on brain-behavior relations in the early development of attention and recognition memory. The third section addresses potential areas of the brain involved in infant object recognition and visual attention. An integrated synthesis of some of the existing models of the development of visual attention is presented which may account for the observed changes in behavioral and neural measures of visual attention and object recognition that occur across infancy. PMID:25596333

  9. The Role of Attention in Goal Setting

    OpenAIRE

    Meacham, Kristina A.

    2003-01-01

    This study examined the role of attention in goal setting theory, using techniques adapted from selective attention research. Specifically, it explored activation and suppression of goal related information in the presence of two conflicting assigned goals. Pre vs. post goal completion and goal commitment were examined as moderators of these attentional effects. In addition, exploratory analyses looked at the impact of individual differences on attention (goal preference & action-state orient...

  10. Higher Cortical Functions: Attention and Vigilance

    OpenAIRE

    Gillig, Paulette Marie; Sanders, Richard D.

    2011-01-01

    The ability to sustain attention over time (vigilance) is a cognitive function that often is impaired in patients with psychiatric disorders. Attention has been found to be disordered in a number of psychiatric conditions, including attention deficit disorder, schizophrenia, antisocial personality disorder, and the impulse control disorders. Less widely known is the finding that attention also is affected in patients suffering from anxiety disorders, posttraumatic stress disorder, mood disord...

  11. Dissociations between developmental dyslexias and attention deficits

    OpenAIRE

    Limor eLukov; Naama eFriedmann; Lilach eShalev; Lilach eKhentov-Kraus; Nir eShalev; Rakefet eLorber; Revital eGuggenheim

    2015-01-01

    We examine whether attention deficits underlie developmental dyslexia, or certain types of dyslexia, by presenting double dissociations between the two. We took into account the existence of distinct types of dyslexia and of attention deficits, and focused on dyslexias that may be thought to have an attentional basis: letter position dyslexia (LPD), in which letters migrate within words, attentional dyslexia (AD), in which letters migrate between words, neglect dyslexia, in which letters on o...

  12. Investor attention and FX market volatility

    OpenAIRE

    Goddard, John; Kita, Arben; Wang, Qingwei

    2015-01-01

    We study the relationship between investors’ active attention, measured by a Google search volume index (SVI), and the dynamics of currency prices. Investor attention is correlated with the trading activities of large FX market participants. Investor attention comoves with contemporaneous FX market volatility and predicts subsequent FX market volatility, after controlling for macroeconomic fundamentals. In addition, investor attention is related to the currency risk premium. Our results sugge...

  13. Mindfulness and Attention Deficit Hyperactivity Disorder

    OpenAIRE

    Smalley, Susan L; Loo, Sandra K.; Hale, T. Sigi; Shrestha, Anshu; Mcgough, James,; Flook, Lisa; Reise, Steven

    2009-01-01

    Attention Deficit Hyperactivity Disorder (ADHD) is a disorder characterized by attentional difficulties. Mindfulness is a receptive attention to present experience. Both ADHD and mindfulness are associated with attention and personality. This study tests whether individuals with ADHD have lower mindfulness scores than controls and, if true, whether personality contributes to these differences. 105 adults (half with ADHD) were assessed for mindfulness, using the Kentucky Inventory of Mindfulne...

  14. Spatial attention can modulate unconscious orientation processing

    OpenAIRE

    Bahrami, Bahador; Carmel, David; Walsh, Vincent; Rees, Geraint; Lavie, Nilli

    2008-01-01

    It has recently been suggested that visual spatial attention can only affect consciously perceived events. We measured the effects of sustained spatial attention oil orientation-selective adaptation to gratings, rendered invisible by prolonged interocular suppression. Spatial attention augmented the orientation-selective adaptation to invisible adaptor orientation. The effect of attention was clearest for test stimuli at peri-threshold, intermediate contrast levels, suggesting that previous n...

  15. Separable Attentional Predictors of Language Outcome

    Science.gov (United States)

    Salley, Brenda; Panneton, Robin K.; Colombo, John

    2013-01-01

    The aim of this study was to examine the combined influences of infants' attention and use of social cues in the prediction of their language outcomes. This longitudinal study measured infants' visual attention on a distractibility task (11 months), joint attention (14 months), and language outcomes (word-object association, 14 months;…

  16. Everyday Attention Failures: An Individual Differences Investigation

    Science.gov (United States)

    Unsworth, Nash; McMillan, Brittany D.; Brewer, Gene A.; Spillers, Gregory J.

    2012-01-01

    The present study examined individual differences in everyday attention failures. Undergraduate students completed various cognitive ability measures in the laboratory and recorded everyday attention failures in a diary over the course of a week. The majority of attention failures were failures of distraction or mind wandering in educational…

  17. An Operant Analysis of Joint Attention Skills

    Science.gov (United States)

    Holth, Per

    2005-01-01

    Joint attention, a synchronizing of the attention of two or more persons, has been an increasing focus of research in cognitive developmental psychology. Research in this area has progressed mainly outside of behavior analysis, and behavior-analytic research and theory has tended to ignore the work on joint attention. It is argued here, on the one…

  18. Attention to Faces in Williams Syndrome

    Science.gov (United States)

    Riby, Deborah M.; Jones, Nicola; Brown, Philippa H.; Robinson, Lucy J.; Langton, Stephen R. H.; Bruce, Vicki; Riby, Leigh M.

    2011-01-01

    Williams syndrome (WS) is associated with distinct social behaviours. One component of the WS social phenotype is atypically prolonged face fixation. This behaviour co-exists with attention difficulties. Attention is multi-faceted and may impact on gaze behaviour in several ways. Four experiments assessed (i) attention capture by faces, (ii)…

  19. Attention and the Art of Scientific Publishing

    NARCIS (Netherlands)

    A. Klamer (Arjo); H.P. van Dalen (Hendrik)

    2001-01-01

    textabstractAttention is the coordination device, which makes modern science work the way it does. A typical characteristic of attention in the scientific world is that those who seek attention are the same people who are giving it. Another important feature within groups is the skewed distribution

  20. Attention to Affect in Language Learning

    Science.gov (United States)

    Arnold, Jane

    2011-01-01

    As language teachers, we have to pay attention to many things in our work so why add "attention to affect"? Perhaps the simplest, most direct answer is that whatever we focus most on in our particular context, be it general English, morphosyntax, phonetics, literature, English for academic writing or any other special area, attention to affect…

  1. Exogenous spatial attention decreases audiovisual integration

    NARCIS (Netherlands)

    Van der Stoep, N.; Van der Stigchel, S.; Nijboer, T. C W

    2015-01-01

    Multisensory integration (MSI) and spatial attention are both mechanisms through which the processing of sensory information can be facilitated. Studies on the interaction between spatial attention and MSI have mainly focused on the interaction between endogenous spatial attention and MSI. Most of t

  2. Methylphenidate alters selective attention by amplifying salience

    NARCIS (Netherlands)

    Huurne, N.; Fallon, S.J.; Schouwenburg, M. van; Schaaf, M.; Buitelaar, J.; Jensen, O.; Cools, R.

    2015-01-01

    RATIONALE: Methylphenidate, the most common treatment of attention deficit hyperactivity disorder (ADHD), is increasingly used by healthy individuals as a "smart drug" to enhance cognitive abilities like attention. A key feature of (selective) attention is the ability to ignore irrelevant but salien

  3. Attentional bias predicts heroin relapse following treatment

    NARCIS (Netherlands)

    M.A.E. Marissen; I.H.A. Franken; A.J. Waters; P. Blanken; W. van den Brink; V.M. Hendriks

    2006-01-01

    Aims Previous studies have shown that abstinent heroin addicts exhibit an attentional bias to heroin-related stimuli. It has been suggested that attentional bias may represent a vulnerability to relapse into drug use. In the present study, the predictive value of pre-treatment attentional bias on re

  4. Effects of presession attention on the frequency of attention-maintained behavior.

    OpenAIRE

    O'Reilly, M F

    1999-01-01

    The effect of prior attention was systematically manipulated to study its influence on rates of yelling and head hitting, both maintained by positive reinforcement in the form of attention. Higher levels of head hitting occurred in analogue attention conditions when the person was deprived of attention (no social interactions for 1 hr) prior to the analysis in comparison to when the person received high levels of attention (attention delivered on a fixed-time 30-s schedule for 1 hr) prior to ...

  5. Are seismic velocity time-lapse changes due to fluid substitution or matrix dissolution? A CO2 sequestration study at Pohokura Field, New Zealand

    Science.gov (United States)

    Adam, L.; Sim, C. Y.; Macfarlane, J.; van Wijk, K.; Shragge, J. C.; Higgs, K.

    2015-12-01

    Time-lapse seismic signatures can be used to quantify fluid saturation and pressure changes in a reservoir undergoing CO2 sequestration. However, the injection of CO2 acidifies the water, which may dissolve and/or precipitate minerals. Understanding the impact on the rock frame from field seismic time-lapse changes remains an outstanding challenge. Here, we study the effects of carbonate-CO2-water reactions on the physical and elastic properties of rock samples with variable volumes of carbonate cementation. The effects of fluid substitution alone (brine to CO2) and those due to the combination of fluid substitution and mineral dissolution on time-lapse seismic signatures are studied by combining laboratory data, geophysical well-log data and 1-D seismic modeling. Nine rocks from Pohokura Field (New Zealand) are reacted with carbonic acid. The elastic properties are measured using a high-density laser-ultrasonic setup. We observe that P-wave velocity changes up to -19% and correlate with sandstone grain size. Coarse-grained sandstones show greater changes in elastic wave velocities due to dissolution than fine-grained sandstones. To put this in perspective, this velocity change is comparable to the effect of fluid substitution from brine to CO2. This can potentially create an ambiguity in the interpretation of the physical processes responsible for time-lapse signatures in a CO2injection scenario. The laboratory information is applied onto well-log data to model changes in elastic properties of sandstones at the well-log scale. Well-logs and core petrographic analyses are used to find an elastic model that best describes the observed elastic waves velocities in the cemented reservoir sandstones. The Constant-cement rock physics model is found to predict the elastic behaviour of the cemented sandstones. A possible late-time sequestration scenario is that both mineral dissolution and fluid substitution occur in the reservoir. 1-D synthetic seismograms show that

  6. Attention deficit and attention training in early twentieth-century Japan.

    Science.gov (United States)

    Takeda, Toshinobu; Ando, Mizuho; Kumagai, Keiko

    2015-06-01

    Yuzero Motora (1856-1912), regarded as the first professional Japanese psychologist, tried to address students' attention difficulties through attention training methods of his own design. His reports contain the first description of ADHD-like symptoms in the history of Japan. Motora viewed "distractibility" as the irregular transition of attention. Students with low scores and attention difficulties who participated in Motora's exercises showed improvement in arithmetic, psychological testing, and certain aspects of daily life. This article describes Motora's theoretical conception of attention and attention training methodology, the history of attention deficit and attention training, and the significance of Motora's experiments.

  7. Early vision and focal attention

    Science.gov (United States)

    Julesz, Bela

    1991-07-01

    At the thirty-year anniversary of the introduction of the technique of computer-generated random-dot stereograms and random-dot cinematograms into psychology, the impact of the technique on brain research and on the study of artificial intelligence is reviewed. The main finding-that stereoscopic depth perception (stereopsis), motion perception, and preattentive texture discrimination are basically bottom-up processes, which occur without the help of the top-down processes of cognition and semantic memory-greatly simplifies the study of these processes of early vision and permits the linking of human perception with monkey neurophysiology. Particularly interesting are the unexpected findings that stereopsis (assumed to be local) is a global process, while texture discrimination (assumed to be a global process, governed by statistics) is local, based on some conspicuous local features (textons). It is shown that the top-down process of "shape (depth) from shading" does not affect stereopsis, and some of the models of machine vision are evaluated. The asymmetry effect of human texture discrimination is discussed, together with recent nonlinear spatial filter models and a novel extension of the texton theory that can cope with the asymmetry problem. This didactic review attempts to introduce the physicist to the field of psychobiology and its problems-including metascientific problems of brain research, problems of scientific creativity, the state of artificial intelligence research (including connectionist neural networks) aimed at modeling brain activity, and the fundamental role of focal attention in mental events.

  8. Feature- and category-specific attentional control settings are differently affected by attentional engagement in contingent attentional capture.

    Science.gov (United States)

    Wu, Xia; Liu, Xiaoyue; Fu, Shimin

    2016-07-01

    A distractor can capture attention and impair target processing when it shares a target-defining property and matches specific attentional control settings (ACS). We studied how feature-specific ACS (fACS) and category-specific ACS (cACS) operate in a conjunction search task and how they are influenced by attentional engagement. The feature- and category-matching level and temporal lags between the distractor and target were manipulated in a rapid serial visual presentation (RSVP) task. The N2pc component and impairment of target identification, which are associated with attentional allocation at an earlier stage and response selection at a later stage, respectively, were measured as markers of attentional capture. The interaction of two ACSs was observed in behavioral data, but disappeared in N2pc data, suggesting two-stage processing of multiple ACSs during a conjunction search, including an early independent and a late integrated stage. Moreover, a reliable N2pc was observed for fACS regardless of the sufficiency of attentional engagement, whereas the N2pc for cACS was only observed with sufficient attentional engagement, but disappeared when the attentional engagement was insufficient. This suggests that cACS demands sufficient attentional engagement, while fACS does not. In conclusion, fACS and cACS can be activated independently at an earlier stage, but they are integrated at a later stage during a conjunction search task and are differently influenced by attentional engagement.

  9. A study on 4D inversion of time-lapse magnetotelluric data sets for monitoring geothermal reservoir

    Science.gov (United States)

    Jang, H.; Nam, M. J.; Song, Y.

    2015-12-01

    The productivity of geothermal reservoir, which is function of pore-space and fluid-flow path of the reservoir, varies since the properties of reservoir changes with geothermal electricity generation. The variation in the reservoir properties causes changes in electrical resistivity, time-lapse (TL) three-dimensional (3D) magnetotelluric (MT) methods can be applied to monitor the productivity variation of geothermal reservoir thanks to its sensitive to the electrical resistivity of deep subsurface. For an accurate interpretation of TL 3D MT data, a 4D MT inversion algorithm has been developed to simultaneously invert all vintage data in a time-coupled way. However, the changes in electrical resistivity of deep geothermal reservoirs are usually small generating minimum variation in TL MT responses. In order to reduce TL inversion artifacts emphasizing the TL changes, we upgrade the TL coupling of the original 4D inversion algorithm with active time constraint (ATC), which has been verified to be efficient for resistivity monitoring based on TL electrical resistivity surveys. In order to maximize the sensitivity to reservoir-region resistivity changes, we further developed a focused 4D MT inversion method by considering the distribution of reservoir fractures. To analyze the validity of the 4D algorithms, we make 4D MT inversion of synthetic TL data sets applying ATC and focusing methods, respectively, and compare their results those from the original 4D algorithm. The numerical tests find that ATC 4D inversion can be useful for conventional geothermal reservoirs, while the focused inversion algorithm can be better for monitoring engineering geothermal system (EGS) reservoir, within which new fracture can be actively developed by fluid circulation during production. This work is supported by KETEP granted by MOTIE, KOREA (NO. 20133030000220).

  10. Application of time-lapse ERT to Characterize Soil-Water-Disease Interactions of Citrus Orchard - Case Study

    Science.gov (United States)

    Peddinti, S. R.; Kbvn, D. P.; Ranjan, S.; Suradhaniwar, S.; J, P. A.; R M, G.

    2015-12-01

    Vidarbha region in Maharashtra, India (home for mandarin Orange) experience severe climatic uncertainties resulting in crop failure. Phytopthora are the soil-borne fungal species that accumulate in the presence of moisture, and attack the root / trunk system of Orange trees at any stage. A scientific understanding of soil-moisture-disease relations within the active root zone under different climatic, irrigation, and crop cycle conditions can help in practicing management activities for improved crop yield. In this study, we developed a protocol for performing 3-D time-lapse electrical resistivity tomography (ERT) at micro scale resolution to monitor the changes in resistivity distribution within the root zone of Orange trees. A total of 40 electrodes, forming a grid of 3.5 m x 2 m around each Orange tree were used in ERT survey with gradient and Wenner configurations. A laboratory test on un-disturbed soil samples of the region was performed to plot the variation of electrical conductivity with saturation. Curve fitting techniques were applied to get the modified Archie's model parameters. The calibrated model was further applied to generate the 3-D soil moisture profiles of the study area. The point estimates of soil moisture were validated using TDR probe measurements at 3 different depths (10, 20, and 40 cm) near to the root zone. In order to understand the effect of soil-water relations on plant-disease relations, we performed ERT analysis at two locations, one at healthy and other at Phytopthora affected Orange tree during the crop cycle, under dry and irrigated conditions. The degree to which an Orange tree is affected by Phytopthora under each condition is evaluated using 'grading scale' approach following visual inspection of the canopy features. Spatial-temporal distribution of moisture profiles is co-related with grading scales to comment on the effect of climatic and irrigation scenarios on the degree and intensity of crop disease caused by Phytopthora.

  11. In vivo time-lapse imaging of skin burn wound healing using second-harmonic generation microscopy

    Science.gov (United States)

    Yasui, Takeshi; Tanaka, Ryosuke; Hase, Eiji; Fukushima, Shu-ichiro; Araki, Tsutomu

    2014-02-01

    Wound healing is a process to repair the damaged tissue caused by thermal burn, incised wound, or stab wound. Although the wound healing has many aspects, it is common for dynamics of collagen fiber, such as decomposition, production, or growth, to be closely related with wound healing. If such the healing process can be visualized as a timelapse image of the collagen fiber in the same subject, one may obtain new findings regarding biological repairing mechanisms in the healing process. In this article, to investigate the temporal modoification of dermal collagen fiber in the burn wound healing, we used second-harmonic-generation (SHG) microscopy, showing high selectivity and good image contrast to collagen molecules as well as high spatial resolution, optical three-dimensional sectioning, minimal invasiveness, deep penetration, the absence of interference from background light, and in vivo measurement without additional staining. Since SHG light arises from a non-centrosymmetric triple helix of three polypeptide chains in the collagen molecule, SHG intensity sensitively reflects the structure maturity of collagen molecule and its aggregates. A series of time-lapse SHG images during the wound healing process of 2 weeks clearly indicated that condensation and melting of dermal collagen fibers by the deep dermal burn, decomposition of the damaged collagen fibers in the inflammation phase, production of new collagen fibers in the proliferation phase, and the growth of the new collagen fibers in the remodeling phase. These results show a high potential of SHG microscopy for optical assessment of the wound healing process in vivo.

  12. 2D Time-lapse Resistivity Monitoring of an Organic Produced Gas Plume in a Landfill using ERT.

    Science.gov (United States)

    Amaral, N. D.; Mendonça, C. A.; Doherty, R.

    2014-12-01

    This project has the objective to study a landfill located on the margins of Tietê River, in São Paulo, Brazil, using the electroresistivity tomography method (ERT). Due to huge organic matter concentrations in the São Paulo Basin quaternary sediments, there is subsurface depth related biogas accumulation (CH4 and CO2), induced by anaerobic degradation of the organic matter. 2D resistivity sections were obtained from a test area since March 2012, a total of 7 databases, being the last one dated from October 2013. The studied line has the length of 56m, the electrode interval is of 2m. In addition, there are two boreholes along the line (one with 3 electrodes and the other one with 2) in order to improve data quality and precision. The boreholes also have a multi-level sampling system that indicates the fluid (gas or water) presence in relation to depth. With our results it was possible to map the gas plume position and its area of extension in the sections as it is a positive resistivity anomaly, with the gas level having approximately 5m depth. With the time-lapse analysis (Matlab script) between the obtained 2D resistivity sections from the site, it was possible to map how the biogas volume and position change in the landfill in relation to time. Our preliminary results show a preferential gas pathway through the subsurface studied area. A consistent relation between the gas depth and obtained microbiological data from archea and bacteria population was also observed.

  13. Single-cell time-lapse analysis of depletion of the universally conserved essential protein YgjD

    Directory of Open Access Journals (Sweden)

    Ackermann Martin

    2011-05-01

    Full Text Available Abstract Background The essential Escherichia coli gene ygjD belongs to a universally conserved group of genes whose function has been the focus of a number of recent studies. Here, we put ygjD under control of an inducible promoter, and used time-lapse microscopy and single cell analysis to investigate the phenotypic consequences of the depletion of YgjD protein from growing cells. Results We show that loss of YgjD leads to a marked decrease in cell size and termination of cell division. The transition towards smaller size occurs in a controlled manner: cell elongation and cell division remain coupled, but cell size at division decreases. We also find evidence that depletion of YgjD leads to the synthesis of the intracellular signaling molecule (pppGpp, inducing a cellular reaction resembling the stringent response. Concomitant deletion of the relA and spoT genes - leading to a strain that is uncapable of synthesizing (pppGpp - abrogates the decrease in cell size, but does not prevent termination of cell division upon YgjD depletion. Conclusions Depletion of YgjD protein from growing cells leads to a decrease in cell size that is contingent on (pppGpp, and to a termination of cell division. The combination of single-cell timelapse microscopy and statistical analysis can give detailed insights into the phenotypic consequences of the loss of essential genes, and can thus serve as a new tool to study the function of essential genes.

  14. Attentional modulation of motion-induced blindness

    Institute of Scientific and Technical Information of China (English)

    GENG HaiYan; SONG QianLan; LI YunFeng; XU Shan; ZHU Ying

    2007-01-01

    When a global moving pattern is superimposed on high-contrast stationary or slowly moving stimuli,the stimuli can be perceived as disappearing and reappearing alternately for periods of several seconds. This visual illusory phenomenon was named "motion-induced blindness" (MIB) in recent literature. So far there is no consensus on the mechanism of MIB, especially on the role of attention in this phenomenon. To examine the effect of spatial attention on MIB, the present study manipulated the participants' spatial attention by asking them to respond to two targets simultaneously presented in bilateral visual fields (the divided-attention condition) or only respond to one of them (the focused-attention condition). A central arrow was presented as an endogenous cue to index the target visual field in the focused-attention condition, while a point was presented instead in the divided-attention condition. The results show that the percentage of accumulated invisibility period was larger for the targets in the focused-attention condition than for those in the divided-attention condition.This effect of attentionis significant in upper visual field (UVF) and left lower visual field (left LVF); that is, this effect shows a hemispheric asymmetry in LVF but not in UVF. Furthermore, the percentage of accumulated invisibility period was larger for targets in left LVF than for those in right LVF in the focused-attention condition, but no hemispheric asymmetry was found in the divided-attention condition.In addition, the increased percentage of accumulated invisibility period in the focused-attention condition originated merely in the enhancement of the mean phase duration of disappearance in LVF, while the disappearance occurred more frequently and lasted longer for each occurrence, which led to an increase in the total invisibility period, in the focused- than divided-attention condition in UVF. These results suggest that the modulation of spatial attention on MIB has different

  15. Voluntary attention increases perceived spatial frequency.

    Science.gov (United States)

    Abrams, Jared; Barbot, Antoine; Carrasco, Marisa

    2010-08-01

    Voluntary covert attention selects relevant sensory information for prioritized processing. The behavioral and neural consequences of such selection have been extensively documented, but its phenomenology has received little empirical investigation. Involuntary attention increases perceived spatial frequency (Gobell & Carrasco, 2005), but involuntary attention can differ from voluntary attention in its effects on performance in tasks mediated by spatial resolution (Yeshurun, Montagna, & Carrasco, 2008). Therefore, we ask whether voluntary attention affects the subjective appearance of spatial frequency--a fundamental dimension of visual perception underlying spatial resolution. We used a demanding rapid serial visual presentation task to direct voluntary attention and measured perceived spatial frequency at the attended and unattended locations. Attention increased the perceived spatial frequency of suprathreshold stimuli and also improved performance on a concurrent orientation discrimination task. In the control experiment, we ruled out response bias as an alternative account by using a lengthened interstimulus interval, which allows observers to disengage attention from the cued location. In contrast to the main experiment, the observers showed neither increased perceived spatial frequency nor improved orientation discrimination at the attended location. Thus, this study establishes that voluntary attention increases perceived spatial frequency. This phenomenological consequence links behavioral and neurophysiological studies on the effects of attention.

  16. Low attentional engagement makes attention network activity susceptible to emotional interference.

    Science.gov (United States)

    Mäki-Marttunen, Verónica; Pickard, Natasha; Solbakk, Anne-Kristin; Ogawa, Keith H; Knight, Robert T; Hartikainen, Kaisa M

    2014-09-10

    The aim of this study was to investigate whether emotion-attention interaction depends on attentional engagement. To investigate emotional modulation of attention network activation, we used a functional MRI paradigm consisting of a visuospatial attention task with either frequent (high-engagement) or infrequent (low-engagement) targets and intermittent emotional or neutral distractors. The attention task recruited a bilateral frontoparietal network with no emotional interference on network activation when the attentional engagement was high. In contrast, when the attentional engagement was low, the unpleasant stimuli interfered with the activation of the frontoparietal attention network, especially in the right hemisphere. This study provides novel evidence for low attentional engagement making attention control network activation susceptible to emotional interference.

  17. Saccade preparation is required for exogenous attention but not endogenous attention or IOR

    OpenAIRE

    Smith, D. T.; Schenk, T.; Rorden, C.

    2012-01-01

    Covert attention is tightly coupled with the control of eye-movements but there is controversy about how tight this coupling is. The Premotor theory of attention proposes that activation of the eye-movement system is necessary to produce shifts of attention. In this study we experimentally prevented healthy participants from planning or executing eye-movements and observed the effect on exogenous attention, Inhibition of Return (IOR) and endogenous attention. The participants experienced a de...

  18. Attention alters the appearance of motion coherence.

    Science.gov (United States)

    Liu, Taosheng; Fuller, Stuart; Carrasco, Marisa

    2006-12-01

    Selective attention enhances visual information processing, as measured by behavioral performance and neural activity. However, little is known about its effects on subjective experience. Here, we investigated the effect of transient (exogenous) attention on the appearance of visual motion, using a psychophysical procedure that directly measures appearance and controls for response bias. Observers viewed pairs of moving dot patterns and reported the motion direction of the more coherent pattern. Directing attention (via a peripheral precue) to a stimulus location increased its perceived coherence level and improved performance on a direction discrimination task. In a control experiment, we ruled out response bias by lengthening the time interval between the cue and the stimuli, so that the effect of transient attention could no longer be exerted. Our results are consistent with those of neurophysiological studies showing that attention modulates motion processing and provide evidence of a subjective perceptual correlate of attention, with a concomitant effect on performance.

  19. Attention in schizophrenia and in epileptic psychosis

    Directory of Open Access Journals (Sweden)

    I.C.J Kairalla

    2008-01-01

    Full Text Available The adaptive behavior of human beings is usually supported by rapid monitoring of outstanding events in the environment. Some investigators have suggested that a primary attention deficit might trigger symptoms of schizophrenia. In addition, researchers have long discussed the relationship between schizophrenia and the schizophrenia-like psychosis of epilepsy (SLPE. On the basis of these considerations, the objective of the present study was to investigate attention performance of patients with both disorders. Patient age was 18 to 60 years, and all patients had received formal schooling for at least four years. Patients were excluded if they had any systemic disease with neurologic or psychiatric comorbidity, or a history of brain surgery. The computer-assisted TAVIS-2R test was applied to all patients and to a control group to evaluate and discriminate between selective, alternating and sustained attention. The TAVIS-2R test is divided into three parts: one for selective attention (5 min, the second for alternating attention (5 min, and the third for the evaluation of vigilance or sustained attention (10 min. The same computer software was used for statistical analysis of reaction time, omission errors, and commission errors. The sample consisted of 36 patients with schizophrenia, 28 with interictal SLPE, and 47 healthy controls. The results of the selective attention tests for both patient groups were significantly lower than that for controls. The patients with schizophrenia and SLPE performed differently in the alternating and sustained attention tests: patients with SLPE had alternating attention deficits, whereas patients with schizophrenia showed deficits in sustained attention. These quantitative results confirmed the qualitative clinical observations for both patient groups, that is, that patients with schizophrenia had difficulties in focusing attention, whereas those with epilepsy showed perseveration in attention focus.

  20. Race Guides Attention in Visual Search

    OpenAIRE

    Marte Otten

    2016-01-01

    It is known that faces are rapidly and even unconsciously categorized into social groups (black vs. white, male vs. female). Here, I test whether preferences for specific social groups guide attention, using a visual search paradigm. In Experiment 1 participants searched displays of neutral faces for an angry or frightened target face. Black target faces were detected more efficiently than white targets, indicating that black faces attracted more attention. Experiment 2 showed that attention ...

  1. The allocation of attention: theory and evidence

    OpenAIRE

    Gabaix, Xavier; Laibson, David Isaac; Moloche, Guillermo; Stephen, Weinberg

    2003-01-01

    A host of recent studies show that attention allocation has important economic consequences. This paper reports the first empirical test of a cost-benefit model of the endogenous allocation of attention. The model assumes that economic agents have finite mental processing speeds and cannot analyze all of the elements in complex problems. The model makes tractable predictions about attention allocation, despite the high level of complexity in our environment. The model successfully predicts th...

  2. Investor Attention: Overconfidence and Category Learning

    OpenAIRE

    Lin Peng; Wei Xiong

    2005-01-01

    Motivated by psychological evidence that attention is a scarce cognitive resource, we model investors' attention allocation in learning and study the effects of this on asset-price dynamics. We show that limited investor attention leads to ``category-learning" behavior, i.e., investors tend to process more market and sector-wide information than firm-specific information. This endogenous structure of information, when combined with investor overconfidence, generates important features observe...

  3. Remediation of attention deficits in head injury.

    OpenAIRE

    Nag S; Rao S

    1999-01-01

    Head injury is associated with psychological sequelae which impair the patient′s psychosocial functioning. Information processing, attention and memory deficits are seen in head injuries of all severity. We attempted to improve deficits of focused, sustained and divided attention. The principle of overlapping sources of attention resource pools was utilised in devising the remediation programme. Tasks used simple inexpensive materials. Four head injured young adult males with post conc...

  4. Cross-modal links in spatial attention.

    OpenAIRE

    Driver, J; Spence, C.

    1998-01-01

    A great deal is now known about the effects of spatial attention within individual sensory modalities, especially for vision and audition. However, there has been little previous study of possible cross-modal links in attention. Here, we review recent findings from our own experiments on this topic, which reveal extensive spatial links between the modalities. An irrelevant but salient event presented within touch, audition, or vision, can attract covert spatial attention in the other modaliti...

  5. Developing Attention: Behavioral and Brain Mechanisms

    OpenAIRE

    Posner, Michael I.; Rothbart, Mary K.; Sheese, Brad E.; Pascale Voelker

    2014-01-01

    Brain networks underlying attention are present even during infancy and are critical for the developing ability of children to control their emotions and thoughts. For adults, individual differences in the efficiency of attentional networks have been related to neuromodulators and to genetic variations. We have examined the development of attentional networks and child temperament in a longitudinal study from infancy (7 months) to middle childhood (7 years). Early temperamental differences am...

  6. Attention Stabilizes Representations in the Human Hippocampus.

    Science.gov (United States)

    Aly, Mariam; Turk-Browne, Nicholas B

    2016-02-01

    Attention and memory are intricately linked, but how attention modulates brain areas that subserve memory, such as the hippocampus, is unknown. We hypothesized that attention may stabilize patterns of activity in human hippocampus, resulting in distinct but reliable activity patterns for different attentional states. To test this prediction, we utilized high-resolution functional magnetic resonance imaging and a novel "art gallery" task. On each trial, participants viewed a room containing a painting, and searched a stream of rooms for a painting from the same artist (art state) or a room with the same layout (room state). Bottom-up stimulation was the same in both tasks, enabling the isolation of neural effects related to top-down attention. Multivariate analyses revealed greater pattern similarity in all hippocampal subfields for trials from the same, compared with different, attentional state. This stability was greater for the room than art state, was unrelated to univariate activity, and, in CA2/CA3/DG, was correlated with behavior. Attention therefore induces representational stability in the human hippocampus, resulting in distinct activity patterns for different attentional states. Modulation of hippocampal representational stability highlights the far-reaching influence of attention outside of sensory systems.

  7. Lapsed teatrisse! / Kairi Prints

    Index Scriptorium Estoniae

    Prints, Kairi

    2009-01-01

    Kahest lastele mõeldud lavastusest: Tartu Vanemuise teatris Uku Uusbergi lavastus "Kuidas kuningas kuu peale kippus". Teksti autor Strisdanddolia Vai. Eesti Draamateatris "Piparkoogimehike", autor David Wood, lavastaja Ivo Eensalu

  8. Erivajadustega lapsed / Marika Veisson

    Index Scriptorium Estoniae

    Veisson, Marika, 1949-

    2008-01-01

    Vaimupuudega laste arengu ja kasvatuse iseärasustest, ülevaade ka lastest, kellele on pandud Downi sündroomi ja autismi diagnoos ning tserebraalparalüüsi, tähelepanupuudulikkuse ja hüperaktiivsusega lastest

  9. Integrating Terrestrial Time-Lapse Photography with Laser Scanning to Distinguish the Drivers of Movement at Sólheimajökull, Iceland

    Science.gov (United States)

    How, P.; James, M. R.; Wynn, P.

    2014-12-01

    Glacier movement is attributed to a sensitive configuration of driving forces. Here, we present an approach designed to evaluate the drivers of movement at Sólheimajökull, an outlet glacier from the Myrdalsjökull ice cap, Iceland, through combining terrestrial time-lapse photography and laser scanning (TLS). A time-lapse camera (a dSLR with intervalometer and solar-recharged battery power supply) collected hourly data over the summer of 2013. The data are subject to all the difficulties that are usually present in long time-lapse sequences, such as highly variable illumination and visibility conditions, evolving surfaces, and camera instabilities. Feature-tracking software [1] was used to: 1) track regions of static topography (e.g. the skyline) from which camera alignment could be continuously updated throughout the sequence; and 2) track glacial surface features for velocity estimation. Absolute georeferencing of the image sequence was carried out by registering the camera to a TLS survey acquired at the beginning of the monitoring period. A second TLS survey (July 2013) provided an additional 3D surface. By assuming glacial features moved in approximately planimetrically straight lines between the two survey dates, combining the two TLS surfaces with the monoscopic feature tracking allows 3D feature tracks to be derived. Such tracks will enable contributions from different drivers (e.g. surface melting) to be extracted, even in imagery that is acquired not perpendicular to glacier motion. At Sólheimajökull, our aim is to elucidate any volcanic contribution to the observed movement.[1] http://www.lancaster.ac.uk/staff/jamesm/software/pointcatcher.htm

  10. Roles of inter-individual differences and intra-individual acute elevations in early smoking lapse in people with posttraumatic stress disorder.

    Science.gov (United States)

    Dedert, Eric A; Hicks, Terrell A; Dennis, Paul A; Calhoun, Patrick S; Beckham, Jean C

    2016-09-01

    Existing models of the role of posttraumatic stress disorder (PTSD) symptoms and smoking have almost exclusively examined mean symptom levels, rather than the acute elevations that might trigger smoking lapse immediately or increase risk of a smoking lapse in the next few hours. We examined ecological momentary assessments (EMA) of PTSD symptom clusters and smoking in the first week of a quit attempt in 52 people with PTSD. In multilevel models including PTSD symptom means, acute elevations, and lagged acute elevations together as simultaneous predictors of odds of smoking in the same models, pre-quit smoking occasions were significantly related to acute elevations in symptoms, including PTSD totals (OR=1.20; 95% CI, 1.10 to 1.31), PTSD re-experiencing symptoms (OR=1.16; 95% CI, 1.06 to 1.27), PTSD avoidance symptoms (OR=1.20; 95% CI, 1.10 to 1.31), PTSD numbing symptoms (OR=1.14; 95% CI, 1.04 to 1.24), and PTSD hyperarousal symptoms (OR=1.20; 95% CI, 1.09 to 1.31). In contrast, post-quit smoking was related to lagged acute elevations in PTSD re-experiencing (OR=1.24, 95% CI, 1.03 to 1.50) avoidance (OR=1.27, 95% CI, 1.05 to 1.53), and numbing symptoms (OR=1.24, 95% CI, 1.02 to 1.51). During a quit attempt, individuals with PTSD delayed smoking in response to acute elevations in PTSD re-experiencing and Avoidance. This period presents an opportunity to use mobile health interventions to prevent smoking lapse and to use coping skills acquired in trauma-focused therapy to respond to acute PTSD symptom elevation. PMID:27155244

  11. Estimation of soil hydraulic parameters in the field by integrated hydrogeophysical inversion of time-lapse ground-penetrating radar data

    KAUST Repository

    Jadoon, Khan

    2012-01-01

    An integrated hydrogeophysical inversion approach was used to remotely infer the unsaturated soil hydraulic parameters from time-lapse ground-penetrating radar (GPR) data collected at a fixed location over a bare agricultural field. The GPR model combines a full-waveform solution of Maxwell\\'s equations for three-dimensional wave propaga- tion in planar layered media together with global reflection and transmission functions to account for the antenna and its interactions with the medium. The hydrological simu- lator HYDRUS-1D was used with a two layer single- and dual-porosity model. The radar model was coupled to the hydrodynamic model, such that the soil electrical properties (permitivity and conductivity) that serve as input to the GPR model become a function of the hydrodynamic model output (water content), thereby permiting estimation of the soil hydraulic parameters from the GPR data in an inversion loop. To monitor the soil water con- tent dynamics, time-lapse GPR and time domain reflectometry (TDR) measurements were performed, whereby only GPR data was used in the inversion. Significant effects of water dynamics were observed in the time-lapse GPR data and in particular precipitation and evaporation events were clearly visible. The dual porosity model provided betier results compared to the single porosity model for describing the soil water dynamics, which is sup- ported by field observations of macropores. Furthermore, the GPR-derived water content profiles reconstructed from the integrated hydrogeophysical inversion were in good agree- ment with TDR observations. These results suggest that the proposed method is promising for non-invasive characterization of the shallow subsurface hydraulic properties and moni- toring water dynamics at the field scale. © Soil Science Society of America.

  12. Modeling and mapping the effects of heat and pressure outside a SAGD steam chamber using time-lapse multicomponent seismic data, Athabasca oil sands, Alberta

    Science.gov (United States)

    Zeigler, Loren Michelle

    The field of study is a bitumen producing reservoir within the McMurray Formation. The deposit is a part of the Athabasca oil sands trend in Northeastern Alberta, Canada. This field contains 16 well pads that are, combined, producing more than 41,000 BOPD. Bitumen reservoirs are unique as a result of their high viscosity, low API gravity oil. This oil in this field has been produced by means of a method called Steam Assisted Gravity Drainage (SAGD), since 2007. In this method, two vertically stacked, horizontal wells are drilled. The upper well injects high temperature, high pressure steam and as the viscosity of the bitumen decreases it will begin to flow, via gravity, down to the lower producing well. Reservoir monitoring in this field is very important for multiple reasons, including the shallow depth and the large velocity changes that result from SAGD production. In order to map these changes, time-lapse multicomponent data were incorporated with rock physics modeling in order to map and interpret changes in Vp/Vs with production. When fluid substitution results and pressure estimations are combined, the resulting velocities are consistent with the core sample modeling done by Kato et al. (2008). These results were then compared with the seismic data in order to identify areas affected by steam, heat, and pressure within the reservoir through time-lapse Vp/Vs. PP time-lapse results show the location of the steam chamber within the reservoir, however these data do not give any information about the effects of pressure or heat. Converted-wave (PS) data can be used to image pressure and viscosity changes in the reservoir. When these data are combined into a Vp/Vs volume, the effects of steam, heat and pressure can be identified. Vp/Vs areas of little to no difference indicate steamed zones while the surrounding areas with large differences indicate heated and pressured zones.

  13. 电阻率法监测地下地质变化的数值模拟%NUMERICAL MODELING OF GEOELECTRICAL TIME-LAPSE MONITORING SUBSURFACE

    Institute of Scientific and Technical Information of China (English)

    罗维斌; 李庆春

    2011-01-01

    通过有限元数值模拟方法,研究了电阻率法监测地下地质变化的可行性,提出了基于多期次观测的地下电阻率监测方法,应用二维电阻率正、反演程序对模型进行了数值模拟.结果表明,电阻率相对变化率可以较好地指示电阻率变化的区域和位置.高精度、大数据量的地电阻率观测,以及基于2D或3D的电阻率正、反演计算使得应用电阻率法监测地下地质变化成为可能.%Based on finite-element numerical modeling, the authors studied the feasibility of applying the resistivity method to monitoring underground geological variations. A time-lapse subsurface monitoring method based on geoelectrical observations is proposed in this paper. The numerical modeling result using 2D resistivity forward and inversion program shows that the relative variation of resistivity can serve as a good indicator for resistivity changes both regionally and locally. High-precision and large quantities of data observations of earth resistivity constitute the foundation of time-lapse subsurface monitoring. With the well-performed 2D or 3D resistivity modeling and inversion, this technique makes geo-electrical survey a useful time-lapse monitoring subsurface method.

  14. Analysis of one year time-lapse electrical data to unravel hydrological processes acting on a clayey landslide

    Science.gov (United States)

    Gance, J.; Sailhac, P.; Malet, J.; Supper, R.; Jochum, B.; Ottowitz, D.; Grandjean, G.

    2013-12-01

    Movements of water in the topsoil (infiltration, run-off and evaporation) influence changes in slope stability which is the main controlling factor of landslide triggering (e.g. van Asch et al., 1999). Among the petrophysical parameters that can provide time-lapse sections of the topsoil, we consider the electrical conductivity for its sensitivity to soil water contents. Based on recent works which showed the possibility of monitoring the hydrological response of a clay-shale slope to a controlled rainfall experiment (Travelletti et al., 2012), we installed a permanent electrical monitoring experiment at the Super-Sauze landslide for long-term monitoring (one year) of natural meteorological events. We used the GEOMON4D resistivimeter, developed by the Austrian Geological Survey (Vienna, Austria) for experiments needing high rate of data acquisition, records of full signal samples for noise detection, remote controlled management and automatic data transfer (Supper et al., 2002, 2003 & 2004). The electrode positions varying with time, we installed two terrestrial optical cameras to characterize the changes in dipole geometry. Several hydrological sensors were installed along the profile to measure soil temperature, water temperature and conductivity, ground water level and soil humidity in the vadose zone. The main challenge is the processing of ca. 4.2 million of electrical resistivity data. In this difficult context, the potential factors influencing electrical resistivity with time without modification of soil saturation are the relative changes in the dipole geometry (linked to the displacement of the electrodes), changes in soil and water temperature, change in material porosity due to compaction/dilatation caused by the landslide movement. Therefore, before any inversion of data, we verify the presence of possible 3D effects, and assess the measurement accuracy and uncertainty. An apparent resistivity variation threshold, from which a modification of the

  15. Time lapse imaging of water content with geoelectrical methods: on the interest of working with absolute water content data

    Science.gov (United States)

    Dumont, Gaël; Pilawski, Tamara; Robert, Tanguy; Hermans, Thomas; Garré, Sarah; Nguyen, Frederic

    2016-04-01

    The electrical resistivity tomography is a suitable method to estimate the water content of a waste material and detect changes in water content. Various ERT profiles, both static data and time-lapse, where acquired on a landfill during the Minerve project. In the literature, the relative change of resistivity (Δρ/ρ) is generally computed. For saline or heat tracer tests in the saturated zone, the Δρ/ρ can be easily translated into pore water conductivity or underground temperature changes (provided that the initial salinity or temperature condition is homogeneous over the ERT panel extension). For water content changes in the vadose zone resulting of an infiltration event or injection experiment, many authors also work with the Δρ/ρ or relative changes of water content Δθ/θ (linked to the change of resistivity through one single parameter: the Archie's law exponent "m"). This parameter is not influenced by the underground temperature and pore fluid conductivity (ρ¬w) condition but is influenced by the initial water content distribution. Therefore, you never know if the loss of Δθ/θ signal is representative of the limit of the infiltration front or more humid initial condition. Another approach for the understanding of the infiltration process is the assessment of the absolute change of water content (Δθ). This requires the direct computation of the water content of the waste from the resistivity data. For that purpose, we used petrophysical laws calibrated with laboratory experiments and our knowledge of the in situ temperature and pore fluid conductivity parameters. Then, we investigated water content changes in the waste material after a rainfall event (Δθ= Δθ/θ* θ). This new observation is really representatives of the quantity of water infiltrated in the waste material. However, the uncertainty in the pore fluid conductivity value may influence the computed water changes (Δθ=k*m√(ρw) ; where "m" is the Archie's law exponent

  16. Oriented cell divisions and cellular morphogenesis in the zebrafish gastrula and neurula: a time-lapse analysis.

    Science.gov (United States)

    Concha, M L; Adams, R J

    1998-03-01

    We have taken advantage of the optical transparency of zebrafish embryos to investigate the patterns of cell division, movement and shape during early stages of development of the central nervous system. The surface-most epiblast cells of gastrula and neurula stage embryos were imaged and analysed using a computer-based, time-lapse acquisition system attached to a differential interference contrast (DIC) microscope. We find that the onset of gastrulation is accompanied by major changes in cell behaviour. Cells collect into a cohesive sheet, apparently losing independent motility and integrating their behaviour to move coherently over the yolk in a direction that is the result of two influences: towards the vegetal pole in the movements of epiboly and towards the dorsal midline in convergent movements that strengthen throughout gastrulation. Coincidentally, the plane of cell division becomes aligned to the surface plane of the embryo and oriented in the anterior-posterior (AP) direction. These behaviours begin at the blastoderm margin and propagate in a gradient towards the animal pole. Later in gastrulation, cells undergo increasingly mediolateral-directed elongation and autonomous convergence movements towards the dorsal midline leading to an enormous extension of the neural axis. Around the equator and along the dorsal midline of the gastrula, persistent AP orientation of divisions suggests that a common mechanism may be involved but that neither oriented cell movements nor shape can account for this alignment. When the neural plate begins to differentiate, there is a gradual transition in the direction of cell division from AP to the mediolateral circumference (ML). ML divisions occur in both the ventral epidermis and dorsal neural plate. In the neural plate, ML becomes the predominant orientation of division during neural keel and nerve rod stages and, from late neural keel stage, divisions are concentrated at the dorsal midline and generate bilateral progeny

  17. Acute sleep deprivation and circadian misalignment associated with transition onto the first night of work impairs visual selective attention.

    Directory of Open Access Journals (Sweden)

    Nayantara Santhi

    Full Text Available BACKGROUND: Overnight operations pose a challenge because our circadian biology promotes sleepiness and dissipates wakefulness at night. Since the circadian effect on cognitive functions magnifies with increasing sleep pressure, cognitive deficits associated with night work are likely to be most acute with extended wakefulness, such as during the transition from a day shift to night shift. METHODOLOGY/PRINCIPAL FINDINGS: To test this hypothesis we measured selective attention (with visual search, vigilance (with Psychomotor Vigilance Task [PVT] and alertness (with a visual analog scale in a shift work simulation protocol, which included four day shifts followed by three night shifts. There was a nocturnal decline in cognitive processes, some of which were most pronounced on the first night shift. The nighttime decrease in visual search sensitivity was most pronounced on the first night compared with subsequent nights (p = .04, and this was accompanied by a trend towards selective attention becoming 'fast and sloppy'. The nighttime increase in attentional lapses on the PVT was significantly greater on the first night compared to subsequent nights (p<.05 indicating an impaired ability to sustain focus. The nighttime decrease in subjective alertness was also greatest on the first night compared with subsequent nights (p<.05. CONCLUSIONS/SIGNIFICANCE: These nocturnal deficits in attention and alertness offer some insight into why occupational errors, accidents, and injuries are pronounced during night work compared to day work. Examination of the nighttime vulnerabilities underlying the deployment of attention can be informative for the design of optimal work schedules and the implementation of effective countermeasures for performance deficits during night work.

  18. Joint attention by gaze interpolation and saliency

    NARCIS (Netherlands)

    Z. Yücel; A.A. Salah; C. Meriçli; T. Meriçli; R. Valenti; T. Gevers

    2013-01-01

    Joint attention, which is the ability of coordination of a common point of reference with the communicating party, emerges as a key factor in various interaction scenarios. This paper presents an image-based method for establishing joint attention between an experimenter and a robot. The precise ana

  19. Attention and Communication in Rett Syndrome

    Science.gov (United States)

    Fabio, Rosa Angela; Antonietti, Alessandro; Castelli, Ilaria; Marchetti, Antonella

    2009-01-01

    The study of selective attention and its influence on communication in patients with Rett Syndrome (RS), in which communication abilities are impaired is particularly relevant. The aim of this study was to analyse attention and communication abilities in RS. A sample of 20 children (10 girls with RS and 10 control girls, matched on mental age)…

  20. Interactions between working memory and selective attention

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Event-related potential (ERP) was used to examine the interactions between working memory and selective attention. We combined two unrelated tasks, one requiring working memory and the other selective attention, which were performed by some undergraduates. The ERP results revealed that both congruent and incongruent stimuli in the selective attention task evoked an N400 component, reaching the peak point at around 500 ms. The N400 evoked by incongruent stimuli was more negative than that of congruent, which indicated the difference of semantic N400. Furthermore, working memory load had a significant influence on the N400 evoked by selective attention task in parietal region. And working memory load showed difference in the ERPs of working memory retrieval in central and parietal regions. The ERPs of probe under high working memory load were more positive from 350 to 550 ms post-stimulus; however, stimulus type of selective attention had no influence on working memory retrieval. The present study shows that working memory does not play a major role in the selective attention, especially in ignoring distracter, but it influences the performance of the selective attention as the background. The congruency of target and distracter in the selective attention task does not influence the working memory retrieval.

  1. Attention modeling for video quality assessment

    DEFF Research Database (Denmark)

    You, Junyong; Korhonen, Jari; Perkis, Andrew

    2010-01-01

    averaged spatiotemporal pooling. The local quality is derived from visual attention modeling and quality variations over frames. Saliency, motion, and contrast information are taken into account in modeling visual attention, which is then integrated into IQMs to calculate the local quality of a video frame...

  2. Ambiguity Produces Attention Shifts in Category Learning

    Science.gov (United States)

    Vadillo, Miguel A.; Orgaz, Cristina; Luque, David; Nelson, James Byron

    2016-01-01

    It has been suggested that people and nonhuman animals protect their knowledge from interference by shifting attention toward the context when presented with information that contradicts their previous beliefs. Despite that suggestion, no studies have directly measured changes in attention while participants are exposed to an interference…

  3. 34 CFR 300.606 - Public attention.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Public attention. 300.606 Section 300.606 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND..., and Enforcement § 300.606 Public attention. Whenever a State receives notice that the Secretary...

  4. 28 CFR 301.104 - Medical attention.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Medical attention. 301.104 Section 301.104 Judicial Administration FEDERAL PRISON INDUSTRIES, INC., DEPARTMENT OF JUSTICE INMATE ACCIDENT COMPENSATION General § 301.104 Medical attention. Whenever an inmate worker is injured while in the...

  5. The Attentional Boost Effect and Context Memory

    Science.gov (United States)

    Mulligan, Neil W.; Smith, S. Adam; Spataro, Pietro

    2016-01-01

    Stimuli co-occurring with targets in a detection task are better remembered than stimuli co-occurring with distractors--the attentional boost effect (ABE). The ABE is of interest because it is an exception to the usual finding that divided attention during encoding impairs memory. The effect has been demonstrated in tests of item memory but it is…

  6. The lasting memory enhancements of retrospective attention.

    Science.gov (United States)

    Reaves, Sarah; Strunk, Jonathan; Phillips, Shekinah; Verhaeghen, Paul; Duarte, Audrey

    2016-07-01

    Behavioral research has shown that spatial cues that orient attention toward task relevant items being maintained in visual short-term memory (VSTM) enhance item memory accuracy. However, it is unknown if these retrospective attentional cues ("retro-cues") enhance memory beyond typical short-term memory delays. It is also unknown whether retro-cues affect the spatial information associated with VSTM representations. Emerging evidence suggests that processes that affect short-term memory maintenance may also affect long-term memory (LTM) but little work has investigated the role of attention in LTM. In the current event-related potential (ERP) study, we investigated the duration of retrospective attention effects and the impact of retrospective attention manipulations on VSTM representations. Results revealed that retro-cueing improved both VSTM and LTM memory accuracy and that posterior maximal ERPs observed during VSTM maintenance predicted subsequent LTM performance. N2pc ERPs associated with attentional selection were attenuated by retro-cueing suggesting that retrospective attention may disrupt maintenance of spatial configural information in VSTM. Collectively, these findings suggest that retrospective attention can alter the structure of memory representations, which impacts memory performance beyond short-term memory delays. PMID:27038756

  7. A specific attentional bias in suicide attempters

    NARCIS (Netherlands)

    Becker, E.S.; Strohbach, D.; Rinck, M.

    1999-01-01

    Selective attention in patients after an attempted suicide was investigated to find out whether a specific attentional bias for suicide-related materials exists and to clarify the possible role of emotions in the bias. Thirty-one patients who had previously attempted to commit suicide and 31 control

  8. Do social utility judgments influence attentional processing?

    Science.gov (United States)

    Shore, Danielle M; Heerey, Erin A

    2013-10-01

    Research shows that social judgments influence decision-making in social environments. For example, judgments about an interaction partners' trustworthiness affect a variety of social behaviors and decisions. One mechanism by which social judgments may influence social decisions is by biasing the automatic allocation of attention toward certain social partners, thereby shaping the information people acquire. Using an attentional blink paradigm, we investigate how trustworthiness judgments alter the allocation of attention to social stimuli in a set of two experiments. The first experiment investigates trustworthiness judgments based solely on a social partner's facial appearance. The second experiment examines the effect of trustworthiness judgments based on experienced behavior. In the first, strong appearance-based judgments (positive and negative) enhanced stimulus recognizability but did not alter the size of the attentional blink, suggesting that appearance-based social judgments enhance face memory but do not affect pre-attentive processing. However, in the second experiment, in which judgments were based on behavioral experience rather than appearance, positive judgments enhanced pre-attentive processing of trustworthy faces. This suggests that a stimulus's potential benefits, rather than its disadvantages, shape the automatic distribution of attentional resources. These results have implications for understanding how appearance- and behavior-based social cues shape attention distribution in social environments. PMID:23887150

  9. Exogenous spatial attention decreases audiovisual integration.

    Science.gov (United States)

    Van der Stoep, N; Van der Stigchel, S; Nijboer, T C W

    2015-02-01

    Multisensory integration (MSI) and spatial attention are both mechanisms through which the processing of sensory information can be facilitated. Studies on the interaction between spatial attention and MSI have mainly focused on the interaction between endogenous spatial attention and MSI. Most of these studies have shown that endogenously attending a multisensory target enhances MSI. It is currently unclear, however, whether and how exogenous spatial attention and MSI interact. In the current study, we investigated the interaction between these two important bottom-up processes in two experiments. In Experiment 1 the target location was task-relevant, and in Experiment 2 the target location was task-irrelevant. Valid or invalid exogenous auditory cues were presented before the onset of unimodal auditory, unimodal visual, and audiovisual targets. We observed reliable cueing effects and multisensory response enhancement in both experiments. To examine whether audiovisual integration was influenced by exogenous spatial attention, the amount of race model violation was compared between exogenously attended and unattended targets. In both Experiment 1 and Experiment 2, a decrease in MSI was observed when audiovisual targets were exogenously attended, compared to when they were not. The interaction between exogenous attention and MSI was less pronounced in Experiment 2. Therefore, our results indicate that exogenous attention diminishes MSI when spatial orienting is relevant. The results are discussed in terms of models of multisensory integration and attention. PMID:25341648

  10. Early attention processes and anxiety in children

    NARCIS (Netherlands)

    Kallen, V. L.; Ferdinand, R. F.; Tulen, J. H. M.

    2007-01-01

    It has been hypothesized that anxiety in children is associated with attentional bias in the early stages of information processing. Bias towards threat indicates the tendency of an individual to direct attention towards threatening information. The airn of the present study was to investigate wheth

  11. Application of Time-Lapse Seismic Monitoring for the Control and Optimization of CO2 Enhanced Oil Recovery Operations

    Energy Technology Data Exchange (ETDEWEB)

    Brian Toelle

    2008-11-30

    This project, 'Application of Time-Lapse Seismic Monitoring for the Control and Optimization of CO{sub 2} Enhanced Oil Recovery Operations', investigated the potential for monitoring CO{sub 2} floods in carbonate reservoirs through the use of standard p-wave seismic data. This primarily involved the use of 4D seismic (time lapse seismic) in an attempt to observe and map the movement of the injected CO{sub 2} through a carbonate reservoir. The differences between certain seismic attributes, such as amplitude, were used for this purpose. This technique has recently been shown to be effective in CO{sub 2} monitoring in Enhanced Oil Recovery (EOR) projects, such as Weyborne. This study was conducted in the Charlton 30/31 field in the northern Michigan Basin, which is a Silurian pinnacle reef that completed its primary production in 1997 and was scheduled for enhanced oil recovery using injected CO{sub 2}. Prior to injection an initial 'Base' 3D survey was obtained over the field and was then processed and interpreted. CO{sub 2} injection within the main portion of the reef was conducted intermittently during 13 months starting in August 2005. During this time, 29,000 tons of CO{sub 2} was injected into the Guelph formation, historically known as the Niagaran Brown formation. By September 2006, the reservoir pressure within the reef had risen to approximately 2000 lbs and oil and water production from the one producing well within the field had increased significantly. The determination of the reservoir's porosity distribution, a critical aspect of reservoir characterization and simulation, proved to be a significant portion of this project. In order to relate the differences observed between the seismic attributes seen on the multiple 3D seismic surveys and the actual location of the CO{sub 2}, a predictive reservoir simulation model was developed based on seismic attributes obtained from the base 3D seismic survey and available well data. This

  12. Race Guides Attention in Visual Search.

    Science.gov (United States)

    Otten, Marte

    2016-01-01

    It is known that faces are rapidly and even unconsciously categorized into social groups (black vs. white, male vs. female). Here, I test whether preferences for specific social groups guide attention, using a visual search paradigm. In Experiment 1 participants searched displays of neutral faces for an angry or frightened target face. Black target faces were detected more efficiently than white targets, indicating that black faces attracted more attention. Experiment 2 showed that attention differences between black and white faces were correlated with individual differences in automatic race preference. In Experiment 3, using happy target faces, the attentional preference for black over white faces was eliminated. Taken together, these results suggest that automatic preferences for social groups guide attention to individuals from negatively valenced groups, when people are searching for a negative emotion such as anger or fear. PMID:26900957

  13. Unimodal and crossmodal gradients of spatial attention

    DEFF Research Database (Denmark)

    Föcker, J.; Hötting, K.; Gondan, Matthias;

    2010-01-01

    Behavioral and event-related potential (ERP) studies have shown that spatial attention is gradually distributed around the center of the attentional focus. The present study compared uni- and crossmodal gradients of spatial attention to investigate whether the orienting of auditory and visual...... spatial attention is based on modality specific or supramodal representations of space. Auditory and visual stimuli were presented from five speaker locations positioned in the right hemifield. Participants had to attend to the innermost or outmost right position in order to detect either visual...... or auditory deviant stimuli. Detection rates and event-related potentials (ERPs) indicated that spatial attention is distributed as a gradient. Unimodal spatial ERP gradients correlated with the spatial resolution of the modality. Crossmodal spatial gradients were always broader than the corresponding...

  14. Attentional mechanisms in the generation of sympathy

    Directory of Open Access Journals (Sweden)

    Stephan Dickert

    2009-06-01

    Full Text Available Empathic responses, such as sympathy towards others, are a key ingredient in the decision to provide help to those in need. The determinants of empathic responses are usually thought to be the vividness, similarity, and proximity of the victim. However, recent research highlights the role that attention plays in the generation of feelings. We expanded on this idea by investigating whether sympathy depends on cognitive mechanisms such as attention. In two studies we found that sympathy responses were lower and reaction times were longer when targets were presented with distractors. In addition, online sympathy judgments that allow attentional focusing on a target lead to greater affective responses than judgments made from memory. We conclude that attention is an ingredient in the generation of sympathy, and discuss implications for research on prosocial behaviour and the interaction between attention and emotions.

  15. Race Guides Attention in Visual Search.

    Directory of Open Access Journals (Sweden)

    Marte Otten

    Full Text Available It is known that faces are rapidly and even unconsciously categorized into social groups (black vs. white, male vs. female. Here, I test whether preferences for specific social groups guide attention, using a visual search paradigm. In Experiment 1 participants searched displays of neutral faces for an angry or frightened target face. Black target faces were detected more efficiently than white targets, indicating that black faces attracted more attention. Experiment 2 showed that attention differences between black and white faces were correlated with individual differences in automatic race preference. In Experiment 3, using happy target faces, the attentional preference for black over white faces was eliminated. Taken together, these results suggest that automatic preferences for social groups guide attention to individuals from negatively valenced groups, when people are searching for a negative emotion such as anger or fear.

  16. The dynamic pattern of human attention

    CERN Document Server

    Zhao, Zhi-Dan; Cai, Shi-Min

    2013-01-01

    A mass of traces of human activities show diverse dynamic patterns. In this paper, we comprehensively investigate the dynamic pattern of human attention defined by the quantity of interests on subdisciplines in an online academic communication forum. Both the expansion and exploration of human attention have a power-law scaling relation with browsing actions, of which the exponent is close to that in one-dimension random walk. Furthermore, the memory effect of human attention is characterized by the power-law distributions of both the return interval time and return interval steps, which is reinforced by studying the attention shift that monotonically increase with the interval order between pairs of continuously segmental sequences of expansion. At last, the observing dynamic pattern of human attention in the browsing process is analytically described by a dynamic model whose generic mechanism is analogy to that of human spatial mobility. Thus, our work not only enlarges the research scope of human dynamics,...

  17. Attention Supports Verbal Short-Term Memory via Competition between Dorsal and Ventral Attention Networks.

    OpenAIRE

    Majerus, Steve; Attout, Lucie; D'Argembeau, Arnaud; Degueldre, Christian; Fias, W.; Maquet, Pierre; Martinez Perez, Trecy; Stawarczyk, David; Salmon, Eric; Van der Linden, Martial; Phillips, Christophe; Balteau, Evelyne

    2012-01-01

    Interactions between the neural correlates of short-term memory (STM) and attention have been actively studied in the visual STM domain but much less in the verbal STM domain. Here we show that the same attention mechanisms that have been shown to shape the neural networks of visual STM also shape those of verbal STM. Based on previous research in visual STM, we contrasted the involvement of a dorsal attention network centered on the intraparietal sulcus supporting task-related attention and ...

  18. Separation of the lapse rate and the cold point tropopauses in the tropics and the resulting impact on cloud top-tropopause relationships

    Science.gov (United States)

    Munchak, Leigh A.; Pan, Laura L.

    2014-07-01

    Four years of temperature profiles from Constellation Observing System for Meteorology, Ionosphere, and Climate GPS satellite retrievals are used to examine the difference between the World Meteorological Organization lapse rate definition and the cold point definition of the tropopause in the tropics. The separation between the cold point tropopause (CPT) and lapse rate tropopause (LRT) heights is quantified in seasonal averages and with the frequency of occurrence. In seasonal averages, small separations, structures in the December-January-February (DJF) and June-July-August (JJA) seasons. Case studies indicate that breaking Rossby waves and their effects extending into the equatorial region are responsible for the longitudinal structure in the DJF season. The seasonal average CPT-LRT separation therefore identifies the regions of the tropical upper troposphere-lower stratosphere that are controlled by extratropical forcing. Examination of individual profiles shows that a small yet significant fraction (~12%) of temperature profiles has CPT-LRT separations of 1 km or larger in the region of small seasonal average separation. These large separations are produced by wave perturbations of the upper tropospheric temperature structure. The impact of tropopause separation on the cloud top-tropopause relationship is examined using colocated CALIPSO cloud top data. We find that the frequency of clouds above the tropopause is reduced by approximately 50% if the CPT is used instead of LRT. The occurrence of clouds above the CPT is nevertheless significant, especially over the western Pacific in the DJF season and over the Asian monsoon region in the JJA season.

  19. 基于岩石物理实验的时移地震研究%A study of time-lapse seismic based on rock physics experiment

    Institute of Scientific and Technical Information of China (English)

    周水生; 刘洪; 王冲

    2013-01-01

    时移地震技术是油田开发阶段动态检测的一个重要手段.岩石物理实验室能实现模拟油气田在开采过程中其储层参数变化对岩石弹性参数的影响.本文基于岩石物理实验及地震正演模拟,分析了X气田在开采过程中其孔隙压力下降及水不断侵入情况下,进行时移地震监测的可行性及其主要影响因素.%Time-lapse seismic is an important means of oilfield dynamic detection.Rock physics laboratory can simulate how change of the reservoir parameters influences seismic attributes in the process of oil and gas field exploitation.The paper,based on rock physics experiment and seismic forward simulation,analysizes the feasibility of time-lapse seismic and main influencing factors of X gas field.

  20. 延时摄影--高效且艺术的拍摄手法%Time-lapse Photography---Efficient and Artistic Photography Style

    Institute of Scientific and Technical Information of China (English)

    苏文锋

    2015-01-01

    As a Emerging Photography style, Time-lapse photography is more and more interested by Photogra-phers No matter they are Professional or not.The style can affect viewer in deep and efficient in spread, and very aestheticism also.It very fits to film advertising video and documentary and so on.This text will discuss Time-lapse photography characteristic and the production process.%作为一种新兴的摄影手法,延时摄影受到越来越多专业和非专业摄影者的关注,这是一种能够深深打动受众、具有很高传播效率并且非常唯美的一种拍摄手法,适合拍摄宣传片、纪录片等,浅述延时摄影手法的特性以及拍摄制作的流程。

  1. Preschool teacher attachment and attention skills.

    Science.gov (United States)

    Commodari, Elena

    2013-01-01

    Attention underlies and energizes all cognitive and behavioral activities. Many studies showed that the quality of child attachment (both to parental and non parental figures) influences cognitive functions and attention. This study aimed to investigate the relationships among attachment to preschool teachers and attention in a sample of preschoolers. In particular, the study analyzed whether child attachment security to preschool teachers influences the different aspects of their attention skills. In addition, gender- and age-related differences in attention and teacher attachment were explored. Research was conducted using two standardized instruments: the Attention and Concentration Battery, and the Attachment Q Sort. Participants were 279 children (147 male, 132 female) who attended two preschools in a town in Southern Italy. Descriptive analyses, t-tests analyses, and correlation and regression analyses were carried out. Findings highlighted several interesting points concerning the relationships that occur among attachment to preschool teachers and attention. Children with secure attachments presented higher reaction time and better auditory, visual, and visual spatial selectivity and maintenance.

  2. Can Rhesus Monkey Learn Executive Attention?

    Science.gov (United States)

    Bramlett-Parker, Jessica; Washburn, David A

    2016-01-01

    A growing body of data indicates that, compared to humans, rhesus monkeys perform poorly on tasks that assess executive attention, or voluntary control over selection for processing, particularly under circumstances in which attention is attracted elsewhere by competing stimulus control. In the human-cognition literature, there are hotly active debates about whether various competencies such as executive attention, working memory capacity, and fluid intelligence can be improved through training. In the current study, rhesus monkeys (Macaca mulatta) completed an attention-training intervention including several inhibitory-control tasks (a Simon task, numerical Stroop task, global/local interference task, and a continuous performance task) to determine whether generalized improvements would be observed on a version of the Attention Network Test (ANT) of controlled attention, which was administered before and after the training intervention. Although the animals demonstrated inhibition of prepotent responses and improved in executive attention with practice, this improvement did not generalize to the ANT at levels consistently better than were observed for control animals. Although these findings fail to encourage the possibility that species differences in cognitive competencies can be ameliorated through training, they do advance our understanding of the competition between stimulus-control and cognitive-control in performance by nonhuman and human primates. PMID:27304969

  3. Socially guided attention influences infants' communicative behavior.

    Science.gov (United States)

    Miller, Jennifer L; Gros-Louis, Julie

    2013-12-01

    For effective prelinguistic communication, infants must be able to direct their attention, vocalizations, and nonverbal gestures in social interactions. The purpose of our study was to examine how different styles of caregiver responses influenced infant attentional and communicative behavior in social interactions, based on prior studies that have shown influences of responsiveness on attention, language and cognitive outcomes. Infants were exposed to redirective and sensitive behavior systematically using an ABA design to examine real-time changes in infants' behavior as a function of caregiver responses. During the two baseline "A" periods, caregivers were instructed to play as they would at home. During the social response "B" period, caregivers were instructed to respond sensitively to infants' behavior on one visit and redirectively on the other visit. Results demonstrated that when caregivers behaved redirectively, infants shifted their attention more frequently and decreased the duration of their visual attention. Caregiver responses also resulted in changes in vocal and gesture production. Infants decreased their production of caregiver-directed vocalizations, gestures, and gesture-vocal combinations during in the redirective condition. Results suggest that caregiver sensitive responding to infants' attentional focus may be one influence on infants' attentional and prelinguistic communicative behavior. PMID:23906941

  4. Vision in Flies: Measuring the Attention Span.

    Science.gov (United States)

    Koenig, Sebastian; Wolf, Reinhard; Heisenberg, Martin

    2016-01-01

    A visual stimulus at a particular location of the visual field may elicit a behavior while at the same time equally salient stimuli in other parts do not. This property of visual systems is known as selective visual attention (SVA). The animal is said to have a focus of attention (FoA) which it has shifted to a particular location. Visual attention normally involves an attention span at the location to which the FoA has been shifted. Here the attention span is measured in Drosophila. The fly is tethered and hence has its eyes fixed in space. It can shift its FoA internally. This shift is revealed using two simultaneous test stimuli with characteristic responses at their particular locations. In tethered flight a wild type fly keeps its FoA at a certain location for up to 4s. Flies with a mutation in the radish gene, that has been suggested to be involved in attention-like mechanisms, display a reduced attention span of only 1s.

  5. Vision in Flies: Measuring the Attention Span.

    Directory of Open Access Journals (Sweden)

    Sebastian Koenig

    Full Text Available A visual stimulus at a particular location of the visual field may elicit a behavior while at the same time equally salient stimuli in other parts do not. This property of visual systems is known as selective visual attention (SVA. The animal is said to have a focus of attention (FoA which it has shifted to a particular location. Visual attention normally involves an attention span at the location to which the FoA has been shifted. Here the attention span is measured in Drosophila. The fly is tethered and hence has its eyes fixed in space. It can shift its FoA internally. This shift is revealed using two simultaneous test stimuli with characteristic responses at their particular locations. In tethered flight a wild type fly keeps its FoA at a certain location for up to 4s. Flies with a mutation in the radish gene, that has been suggested to be involved in attention-like mechanisms, display a reduced attention span of only 1s.

  6. Neurophysical substrates of arousal and attention.

    Science.gov (United States)

    Pop-Jordanov, Jordan; Pop-Jordanova, Nada

    2009-02-01

    The study of arousal and attention could be of prominent importance for elucidating both fundamental and practical aspects of the mind-brain puzzle. Defined as "general activation of mind" (Kahnemann in Attention and effort. Prentice-Hall, New Jersey, 1973), or "general operation of consciousness" (Thacher and John in Functional neuroscience: foundations of cognitive processing. Erlbaum, Hillsdale, 1977), arousal can be considered as a starting point of fundamental research on consciousness. Similar role could be assigned to attention, which can be defined by substituting the attributes "general" with "focused". Concerning the practical applications, the empirically established correlation between neuronal oscillations and arousal/attention levels is widely used in research and clinics, including neurofeedback, brain-computer communication, etc. However, the neurophysical mechanism underlying this correlation is still not clear enough. In this paper, after reviewing some present classical and quantum approaches, a transition probability concept of arousal based on field-dipole quantum interactions and information entropy is elaborated. The obtained analytical expressions and numerical values correspond to classical empirical results for arousal and attention, including the characteristic frequency dependence and intervals. Simultaneously, the fundamental (substrate) role of EEG spectrum has been enlightened, whereby the attention appears to be a bridge between arousal and the content of consciousness. Finally, some clinical implications, including the brain-rate parameter as an indicator of arousal and attention levels, are provided. PMID:18975019

  7. Can Rhesus Monkey Learn Executive Attention?

    Directory of Open Access Journals (Sweden)

    Jessica Bramlett-Parker

    2016-06-01

    Full Text Available A growing body of data indicates that, compared to humans, rhesus monkeys perform poorly on tasks that assess executive attention, or voluntary control over selection for processing, particularly under circumstances in which attention is attracted elsewhere by competing stimulus control. In the human-cognition literature, there are hotly active debates about whether various competencies such as executive attention, working memory capacity, and fluid intelligence can be improved through training. In the current study, rhesus monkeys (Macaca mulatta completed an attention-training intervention including several inhibitory-control tasks (a Simon task, numerical Stroop task, global/local interference task, and a continuous performance task to determine whether generalized improvements would be observed on a version of the Attention Network Test (ANT of controlled attention, which was administered before and after the training intervention. Although the animals demonstrated inhibition of prepotent responses and improved in executive attention with practice, this improvement did not generalize to the ANT at levels consistently better than were observed for control animals. Although these findings fail to encourage the possibility that species differences in cognitive competencies can be ameliorated through training, they do advance our understanding of the competition between stimulus-control and cognitive-control in performance by nonhuman and human primates.

  8. Hierarchical nonlinear dynamics of human attention.

    Science.gov (United States)

    Rabinovich, Mikhail I; Tristan, Irma; Varona, Pablo

    2015-08-01

    Attention is the process of focusing mental resources on a specific cognitive/behavioral task. Such brain dynamics involves different partially overlapping brain functional networks whose interconnections change in time according to the performance stage, and can be stimulus-driven or induced by an intrinsically generated goal. The corresponding activity can be described by different families of spatiotemporal discrete patterns or sequential dynamic modes. Since mental resources are finite, attention modalities compete with each other at all levels of the hierarchy, from perception to decision making and behavior. Cognitive activity is a dynamical process and attention possesses some universal dynamical characteristics. Thus, it is time to apply nonlinear dynamical theory for the description and prediction of hierarchical attentional tasks. Such theory has to include the analyses of attentional control stability, the time cost of attention switching, the finite capacity of informational resources in the brain, and the normal and pathological bifurcations of attention sequential dynamics. In this paper we have integrated today's knowledge, models and results in these directions. PMID:25869439

  9. Joint Attention in Autism: Teaching Smiling Coordinated with Gaze to Respond to Joint Attention Bids

    Science.gov (United States)

    Krstovska-Guerrero, Ivana; Jones, Emily A.

    2013-01-01

    Children with autism demonstrate early deficits in joint attention and expressions of affect. Interventions to teach joint attention have addressed gaze behavior, gestures, and vocalizations, but have not specifically taught an expression of positive affect such as smiling that tends to occur during joint attention interactions. Intervention was…

  10. Saccade Preparation Is Required for Exogenous Attention but Not Endogenous Attention or IOR

    Science.gov (United States)

    Smith, Daniel T.; Schenk, Thomas; Rorden, Chris

    2012-01-01

    Covert attention is tightly coupled with the control of eye movements, but there is controversy about how tight this coupling is. The premotor theory of attention proposes that activation of the eye movement system is necessary to produce shifts of attention. In this study, we experimentally prevented healthy participants from planning or…

  11. Sustained Attention at Age 5 Predicts Attention-Related Problems at Age 9

    Science.gov (United States)

    Martin, Anne; Razza, Rachel A.; Brooks-Gunn, Jeanne

    2012-01-01

    This study tested whether two aspects of sustained attention (focused attention and lack of impulsivity) measured at child age 5 predicted attention problems reported by mothers and teachers at age 9. Because lack of impulsivity reflects the executive control network, and ADHD is commonly characterized as a deficit in executive function, it was…

  12. Visual Field Asymmetries in Attention Vary with Self-Reported Attention Deficits

    Science.gov (United States)

    Poynter, William; Ingram, Paul; Minor, Scott

    2010-01-01

    The purpose of this study was to determine whether an index of self-reported attention deficits predicts the pattern of visual field asymmetries observed in behavioral measures of attention. Studies of "normal" subjects do not present a consistent pattern of asymmetry in attention functions, with some studies showing better left visual field (LVF)…

  13. Visual Attentional Deficits in Reading Disability

    Directory of Open Access Journals (Sweden)

    Vandana Rajaram, OD, PhD

    2013-07-01

    Full Text Available Background: Dyslexia, also referred to as specific reading disability, is a condition where an individual demonstrates a level of reading that is significantly below what may be expected for his age or intelligence. Although the phonological deficit theory of dyslexia is widely accepted, there is accumulating evidence suggesting that at least a subset of dyslexic subjects demonstrate distinct visual attentional deficits. However, it is unclear if the magnitude of visual attention at attended and unattended locations is equivalent in poor and normal readers. The aim of the present study was to examine differences in the magnitude of attentional facilitation (benefits and inhibition (costs in response to an abrupt onset spatial cue in children with reading disabilities in comparison to controls. Methods: A group of impaired readers (n=15, ages nine to 12 years, reading at a level at least 1.5 years below grade level and with average mathematics scores, were included in this study. The control group included an age-matched sample of normal readers (n=20. An adaptation of the covert orienting paradigm was used to investigate differences in magnitude of visual spatial attention between groups.Results: Poor readers demonstrated smaller costs (t=2.07, p<0.02 at unattended locations in comparison to their normal counterparts. Additionally, poor readers were significantly slower (F(1,32 = 14.17, p<0.001 in moving spatial attention in response to an abrupt onset peripheral cue when compared to controls.Conclusion: The poor readers in the current study were slower in shifting spatial attention in comparison to their normal counterparts. They also demonstrated smaller costs at unattended locations,providing indirect evidence for a diffuse attentional field in this group. Consistent with many studies in the literature, we have presented evidence for spatial attentional deficits in impaired readers, the implications of which are discussed within the context

  14. Conscious attention, meditation, and bilateral information transfer.

    Science.gov (United States)

    Bob, Petr; Zimmerman, Elizabeth M; Hamilton, Elizabeth A; Sheftel, Jenna G; Bajo, Stephanie D; Raboch, Jiri; Golla, Megan; Konopka, Lukasz M

    2013-01-01

    Recent findings indicate that conscious attention is related to large-scale information integration of various brain regions, including both hemispheres, that enables integration of parallel distributed modalities of processed information. There is also evidence that the level of information transference related to integration or splitting among brain regions, and between hemispheres, establishes a certain level of efficiency of the information processing. The level of information transference also may have modulatory influences on attentional capacity that are closely linked to the emotional arousal and autonomic response related to a stimulus. These findings suggest a hypothesis that changes in conscious attention, specifically during meditation could be reflected in the autonomic activity as the left-right information transference calculated from bilateral electrodermal activity (EDA). With the aim to compare conscious attention during meditation with other attentional states (resting state, Stroop task, and memory task), we performed bilateral EDA measurement in 7 healthy persons during resting state, Stroop task, neurofeedback memory test, and meditation. The results indicate that the information transference (ie, transinformation) is able to distinguish those attentional states, and that the highest level of the transinformation has been found during attentional processing related to meditation, indicating higher level of connectivity between left and right sides. Calculations other than pointwise transinformation (PTI) performed on EDA records, such as mean skin conductance level or laterality index, were not able to distinguish attentional states. The results suggest that PTI may present an interesting method useful for the assessment of information flow, related to neural functioning, that in the case of meditation may reflect typical integrative changes in the autonomic nervous system related to brain functions and focused attentional processing.

  15. The role of divided attention and selective attention in time perception deficit of children with attention deficit hyperactivity disorder (ADHD)

    OpenAIRE

    Choi, Poi-ki; 蔡博麒

    2012-01-01

    Time deficit in people with ADHD has been consistently found, but the underlying mechanism remains unclear. The present study aimed to investigate whether divided attention and selective attention are the causes for the deficit; and whether duration judgment performance was related to everyday temporal behaviour. 20 children with ADHD and 23 control children (mean age = 9 years 5 months) matched on age and IQ with no significant difference in working memory were tested. Experiment 1 used retr...

  16. Single-Trial Inference on Visual Attention

    DEFF Research Database (Denmark)

    Dyrholm, Mads; Kyllingsbæk, Søren; Vangkilde, Signe Allerup;

    2011-01-01

    In this paper we take a step towards single-trial behavioral modeling within a Theory of Visual Attention (TVA). In selective attention tasks, such as the Partial Report paradigm, the subject is asked to ignore distractors and only report stimuli that belong to the target class. Nothing about...... Report trial. This result retrodicts a latent attentional state of the subject using the observed response from that particular trial and thus differs from other predictions made with TVA which are based on expected values of observed variables. We show an example of the result in single-trial analysis...

  17. Single-Trial Inference on Visual Attention

    DEFF Research Database (Denmark)

    Dyrholm, Mads; Kyllingsbæk, Søren; Vangkilde, Signe Allerup;

    In this paper we take a step towards single-trial behavioral modeling within a Theory of Visual Attention (TVA). In selective attention tasks, such as the Partial Report paradigm, the subject is asked to ignore distractors and only report stimuli that belong to the target class. Nothing about...... Report trial. This result retrodicts a latent attentional state of the subject using the observed response from that particular trial and thus differs from other predictions made with TVA which are based on expected values of observed variables. We show an example of the result in single-trial analysis...

  18. Attention Modifies Gender Differences in Face Recognition

    OpenAIRE

    Lovén, Johanna

    2007-01-01

    Gender differences favoring women have been found in face recognition, and in addition to this, it has been shown that women remember more female than male faces. This own-gender effect may be a result of women directing more attention towards female faces, resulting in a better memory. The aim of this study was to assess the role of attention for gender differences in face recognition and women’s own-gender bias by dividing attention at encoding of faces. Thirty-two participants completed tw...

  19. Lateralization of visual hemifield attention across development.

    Science.gov (United States)

    Nieves, N; Linz, T D; Hynd, G W; Connor, R T; Shapiro, M S

    1987-01-01

    Heilman and Valenstein (Clinical Neuropsychology, 1979, Oxford University Press, New York) have hypothesized a right hemispheric mechanism which mediates attention bilaterally. Shapiro and Hynd ("The development of functional lateralization in visual hemifield attention." Developmental Neuropsychology, Vol. 1, pp 67-80, 1985) examined the developmental validity of this model and their findings did not provide evidence for a lateralized mechanism for visual hemifield attention in 9, 13, and 18 year olds. However, length of foreperiod and gender effects were noted. This study attempted to compare these groups with a group of normal adults (ages 25-35) using the same reaction time paradigm. The study demonstrated support for the length of foreperiod effect found by Shapiro and Hynd. Hand effects were also found. However, these results do not lend support to either the model proposed by Heilman and Valenstein (1979) or Shapiro and Hynd's (1985) notion of developmental differences across age groups with respect to right hemisphere dominance for mediating attention. PMID:14591140

  20. Attractive faces temporally modulate visual attention

    Directory of Open Access Journals (Sweden)

    Koyo eNakamura

    2014-06-01

    Full Text Available Facial attractiveness is an important biological and social signal on social interaction. Recent research has demonstrated that an attractive face captures greater spatial attention than an unattractive face does. Little is known, however, about the temporal characteristics of visual attention for facial attractiveness. In this study, we investigated the temporal modulation of visual attention induced by facial attractiveness by using a rapid serial visual presentation (RSVP. Fourteen male faces and two female faces were successively presented for 160 ms respectively, and participants were asked to identify two female faces embedded among a series of multiple male distractor faces. Identification of a second female target (T2 was impaired when a first target (T1 was attractive compared to neutral or unattractive faces, at 320 ms SOA; identification was improved when T1 was attractive compared to unattractive faces at 640 ms SOA. These findings suggest that the spontaneous appraisal of facial attractiveness modulates temporal attention.

  1. Attention and Neurocognitive Impairment in ADHD

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2007-07-01

    Full Text Available Specific executive functions (EFs and attention deficit patterns in ADHD subtypes were studied in 50 boys (ages 8-14 years, mean 10.42 with ADHD and 44 controls, at the University of Rome, Italy.

  2. Fundamentals of Agent Perception and Attention Modelling

    DEFF Research Database (Denmark)

    Peters, Christopher; Castellano, Ginevra; Rehm, Matthias;

    2011-01-01

    Perception and attention mechanisms are of great importance for entities situated within complex dynamic environments. With roles extending greatly beyond passive information services about the external environment, such mechanisms actively prioritise, augment and expedite information to ensure t...

  3. Neural evidence that suspense narrows attentional focus.

    Science.gov (United States)

    Bezdek, M A; Gerrig, R J; Wenzel, W G; Shin, J; Pirog Revill, K; Schumacher, E H

    2015-09-10

    The scope of visual attention changes dynamically over time. Although previous research has reported conditions that suppress peripheral visual processing, no prior work has investigated how attention changes in response to the variable emotional content of audiovisual narratives. We used fMRI to test for the suppression of spatially peripheral stimuli and enhancement of narrative-relevant central stimuli at moments when suspense increased in narrative film excerpts. Participants viewed films presented at fixation, while flashing checkerboards appeared in the periphery. Analyses revealed that increasing narrative suspense caused reduced activity in peripheral visual processing regions in the anterior calcarine sulcus and in default mode network nodes. Concurrently, activity increased in central visual processing regions and in frontal and parietal regions recruited for attention and dynamic visual processing. These results provide evidence, using naturalistic stimuli, of dynamic spatial tuning of attention in early visual processing areas due to narrative context. PMID:26143014

  4. Growth hormone and selective attention : A review

    NARCIS (Netherlands)

    Quik, Elise H.; van Dam, P. Sytze; Kenemans, J. Leon

    2010-01-01

    Introduction: The relation between growth hormone (GH) secretion and general cognitive function has been established. General cognitive functioning depends on core functions including selective attention, which have not been addressed specifically in relation to GH. The present review addresses curr

  5. Attention deficit in children: a multiprofessional approach

    Directory of Open Access Journals (Sweden)

    Sangeetha Thirumazhisi Sachithanandam

    2015-02-01

    Full Text Available Attention Deficit Hyperactivity Disorder (ADHD is the most common behavior disorder in children characterized by attention deficit, overactivity and impulsivity, which may persist into adolescence and adulthood. It is often complicated with multiple comorbid disorders which when undiagnosed or untreated significantly affects the children on aspects like academic skills, peer relationship, social life and difficulty in leading productive lives. This report presents a case of 12 year old male child with attention deficit and poor academic performance, diagnosed and treated for ADHD with a complex array of coexisting disorders untreated. An attempt is made to highlight the differential diagnosis for attention deficit in children, comorbid disorders, and the necessity for a multiprofessional approach in complete evaluation and comprehensive management of the same. [Int J Res Med Sci 2015; 3(2.000: 502-505

  6. Visual attention capacity after right hemisphere lesions

    DEFF Research Database (Denmark)

    Habekost, Thomas; Rostrup, Egill

    2007-01-01

    for both VSTM capacity and ipsilesional processing speed. The study also showed that lesions in a large region of the right hemisphere, including the putamen, insula, and inferior frontal cortex, do not lead to general deficits in the capacity of visual attention. Udgivelsesdato: 2007-Apr-8......Recently there has been a growing interest in visual short-term memory (VSTM) including the neural basis of the function. Processing speed, another main aspect of visual attention capacity, has received less investigation. For both cognitive functions human lesion studies are sparse. We used...... a whole report experiment for estimation of these two parameters in 22 patients with right side stroke. Psychophysical performance was analyzed using Bundesen's [Bundesen, C. (1990). A theory of visual attention. Psychological Review, 97, 523-547] Theory of Visual Attention (TVA) and compared...

  7. Attentive Turkers: MTurk participants perform better on online attention checks than do subject pool participants.

    Science.gov (United States)

    Hauser, David J; Schwarz, Norbert

    2016-03-01

    Participant attentiveness is a concern for many researchers using Amazon's Mechanical Turk (MTurk). Although studies comparing the attentiveness of participants on MTurk versus traditional subject pool samples have provided mixed support for this concern, attention check questions and other methods of ensuring participant attention have become prolific in MTurk studies. Because MTurk is a population that learns, we hypothesized that MTurkers would be more attentive to instructions than are traditional subject pool samples. In three online studies, participants from MTurk and collegiate populations participated in a task that included a measure of attentiveness to instructions (an instructional manipulation check: IMC). In all studies, MTurkers were more attentive to the instructions than were college students, even on novel IMCs (Studies 2 and 3), and MTurkers showed larger effects in response to a minute text manipulation. These results have implications for the sustainable use of MTurk samples for social science research and for the conclusions drawn from research with MTurk and college subject pool samples.

  8. Selective Attention and Drug Related Attention Bias in Methadone Maintenance Patients

    Directory of Open Access Journals (Sweden)

    Majid Nejati

    2011-12-01

    Full Text Available One of the main problems of the drug abusers is drug related attention bias, which causes craving, and as a result drive the drug abusers to take narcotics. Methadone is used as a maintenance treatment for drug abusers. The purpose of this study is evaluation of the effect of Methadone maintenance therapy (MMT on selective attention and drug related attention bias. This study investigated drug cue-related attention bias and selective attention in 16 methadone-maintained patients before and 45 days after methadone therapy period. Stroop color-word test and addiction Stroop test were used as measurement methods. Results show less reaction time and higher accuracy in Color-Word Stroop Test after MMT and less delay for addict related word in addiction Stroop test. It is concluded that methadone can improve selective attention capability and reduce drug related attention bias.

  9. Measuring Auditory Selective Attention using Frequency Tagging

    Directory of Open Access Journals (Sweden)

    Hari M Bharadwaj

    2014-02-01

    Full Text Available Frequency tagging of sensory inputs (presenting stimuli that fluctuate periodically at rates to which the cortex can phase lock has been used to study attentional modulation of neural responses to inputs in different sensory modalities. For visual inputs, the visual steady-state response (VSSR at the frequency modulating an attended object is enhanced, while the VSSR to a distracting object is suppressed. In contrast, the effect of attention on the auditory steady-state response (ASSR is inconsistent across studies. However, most auditory studies analyzed results at the sensor level or used only a small number of equivalent current dipoles to fit cortical responses. In addition, most studies of auditory spatial attention used dichotic stimuli (independent signals at the ears rather than more natural, binaural stimuli. Here, we asked whether these methodological choices help explain discrepant results. Listeners attended to one of two competing speech streams, one simulated from the left and one from the right, that were modulated at different frequencies. Using distributed source modeling of magnetoencephalography results, we estimate how spatially directed attention modulates the ASSR in neural regions across the whole brain. Attention enhances the ASSR power at the frequency of the attended stream in the contralateral auditory cortex. The attended-stream modulation frequency also drives phase-locked responses in the left (but not right precentral sulcus (lPCS, a region implicated in control of eye gaze and visual spatial attention. Importantly, this region shows no phase locking to the distracting stream suggesting that the lPCS in engaged in an attention-specific manner. Modeling results that take account of the geometry and phases of the cortical sources phase locked to the two streams (including hemispheric asymmetry of lPCS activity help partly explain why past ASSR studies of auditory spatial attention yield seemingly contradictory

  10. Neural mechanisms of attention to motion

    OpenAIRE

    Furlan, Michele

    2011-01-01

    Attention is thought to alter appearance by intensifying the sensory impression of the attended stimulus. Current debates are about how this increases might operate and what are the underlying neural mechanisms. Three mechanisms have been proposed to account the effect of attention: contrast gain, response gain and baseline shift. However, psychophysical and neuroimaging studies produced results that are not always consistent. We used the functional magnetic resonance imaging (fMRI) to explor...

  11. Economic principles motivating social attention in humans

    OpenAIRE

    Hayden, Benjamin Y.; Parikh, Purak C.; Deaner, Robert O.; Platt, Michael L.

    2007-01-01

    We know little about the processes by which we evaluate the opportunity to look at another person. We propose that behavioural economics provides a powerful approach to understanding this basic aspect of social attention. We hypothesized that the decision process culminating in attention to another person follows the same economic principles that govern choices about rewards such as food, drinks and money. Specifically, such rewards are discounted as a function of time, are tradable for other...

  12. Toddlers’ Duration of Attention towards Putative Threat

    OpenAIRE

    Kiel, Elizabeth J.; Buss, Kristin A.

    2011-01-01

    Although individual differences in reactions to novelty in the toddler years have been consistently linked to risk for developing anxious behavior, toddlers’ attention towards a novel, putatively threatening stimulus while in the presence of other enjoyable activities has rarely been examined as a precursor to such risk. The current study examined how attention towards an angry-looking gorilla mask in a room with alternative opportunities for play in 24-month-old toddlers predicted social inh...

  13. Attention deficit in children: a multiprofessional approach

    OpenAIRE

    Sangeetha Thirumazhisi Sachithanandam

    2015-01-01

    Attention Deficit Hyperactivity Disorder (ADHD) is the most common behavior disorder in children characterized by attention deficit, overactivity and impulsivity, which may persist into adolescence and adulthood. It is often complicated with multiple comorbid disorders which when undiagnosed or untreated significantly affects the children on aspects like academic skills, peer relationship, social life and difficulty in leading productive lives. This report presents a case of 12 year old male ...

  14. Attention regulation and monitoring in meditation

    OpenAIRE

    Lutz, Antoine; Slagter, Heleen A.; Dunne, John D.; Davidson, Richard J.

    2008-01-01

    This article explores initial findings and the implications of neuroscientific research on meditation. Meditation is conceptualized here as a family of complex emotional and attentional regulatory training regimes developed for various ends, including the cultivation of well-being and emotional balance. The review focuses on the mental processes and the underlying neural circuitry that are critically involved in two styles of meditation. One style, Focused Attention (FA) meditation, entails t...

  15. Spatial attention in written word perception

    Directory of Open Access Journals (Sweden)

    Veronica eMontani

    2014-02-01

    Full Text Available The role of attention in visual word recognition and reading aloud is a long debated issue. Studies of both developmental and acquired reading disorders provide growing evidence that spatial attention is critically involved in word reading, in particular for the phonological decoding of unfamiliar letter strings. However, studies on healthy participants have produced contrasting results. The aim of this study was to investigate how the allocation of spatial attention may influence the perception of letter strings in skilled readers. High frequency words, low frequency words and pseudowords were briefly and parafoveally presented either in the left or the right visual field. Attentional allocation was modulated by the presentation of a spatial cue before the target string. Accuracy in reporting the target string was modulated by the spatial cue but this effect varied with the type of string. For unfamiliar strings, processing was facilitated when attention was focused on the string location and hindered when it was diverted from the target. This finding is consistent the assumptions of the CDP+ model of reading aloud, as well as with familiarity sensitivity models that argue for a flexible use of attention according with the specific requirements of the string. Moreover, we found that processing of high-frequency words was facilitated by an extra-large focus of attention. The latter result is consistent with the hypothesis that a broad distribution of attention is the default mode during reading of familiar words because it might optimally engage the broad receptive fields of the highest detectors in the hierarchical system for visual word recognition.

  16. Multisensory attention training for treatment of tinnitus

    OpenAIRE

    Spiegel D. P.; Linford T.; Thompson B; Petoe M. A.; Kobayashi K; Stinear C. M.; Searchfield G. D.

    2015-01-01

    Tinnitus is the conscious perception of sound with no physical sound source. Some models of tinnitus pathophysiology suggest that networks associated with attention, memory, distress and multisensory experience are involved in tinnitus perception. The aim of this study was to evaluate whether a multisensory attention training paradigm which used audio, visual, and somatosensory stimulation would reduce tinnitus. Eighteen participants with predominantly unilateral chronic tinnitus were randomi...

  17. Interactions of attention, emotion and motivation.

    Science.gov (United States)

    Raymond, Jane

    2009-01-01

    Although successful visually guided action begins with sensory processes and ends with motor control, the intervening processes related to the appropriate selection of information for processing are especially critical because of the brain's limited capacity to handle information. Three important mechanisms--attention, emotion and motivation--contribute to the prioritization and selection of information. In this chapter, the interplay between these systems is discussed with emphasis placed on interactions between attention (or immediate task relevance of stimuli) and emotion (or affective evaluation of stimuli), and between attention and motivation (or the predicted value of stimuli). Although numerous studies have shown that emotional stimuli modulate mechanisms of selective attention in humans, little work has been directed at exploring whether such interactions can be reciprocal, that is, whether attention can influence emotional response. Recent work on this question (showing that distracting information is typically devalued upon later encounters) is reviewed in the first half of the chapter. In the second half, some recent experiments exploring how prior value-prediction learning (i.e., learning to associate potential outcomes, good or bad, with specific stimuli) plays a role in visual selection and conscious perception. The results indicate that some aspects of motivation act on selection independently of traditionally defined attention and other aspects interact with it.

  18. Attentional Set-Shifting Across Species.

    Science.gov (United States)

    Brown, Verity J; Tait, David S

    2016-01-01

    Attentional set-shifting, as a measure of executive flexibility, has been a staple of investigations into human cognition for over six decades. Mediated by the frontal cortex in mammals, the cognitive processes involved in forming, maintaining and shifting an attentional set are vulnerable to dysfunction arising from a number of human neurodegenerative diseases (such as Alzheimer's, Parkinson's and Huntington's diseases) and other neurological disorders (such as schizophrenia, depression, and attention deficit/hyperactivity disorder). Our understanding of these diseases and disorders, and the cognitive impairments induced by them, continues to advance, in tandem with an increasing number of tools at our disposal. In this chapter, we review and compare commonly used attentional set-shifting tasks (the Wisconsin Card Sorting Task and Intradimensional/Extradimensional tasks) and their applicability across species. In addition to humans, attentional set-shifting has been observed in a number of other animals, with a substantial body of literature describing performance in monkeys and rodents. We consider the task designs used to investigate attentional set-shifting in these species and the methods used to model human diseases and disorders, and ultimately the comparisons and differences between species-specific tasks, and between performance across species. PMID:26873018

  19. There Is No Such Thing As Attention

    Directory of Open Access Journals (Sweden)

    Britt eAnderson

    2011-09-01

    Full Text Available Given that the core issues of attention research have been recognized for millenia, we do not know as much about attention as we should. I argue that the reasons for this failure are 1 we create spurious dichotomies, 2 we reify attention, treating it as a cause, when it is an effect, and 3 we equate a collection of facts with a theory. In order to correct these errors, we need a new technical vocabulary that allows for attentional effects to be continuously distributed, rather than merelypresent or absent, and that provides a basis for quantitative behavioral predictions that map onto neural substrates. The terminology of the Bayesian Decision Process has already proved useful for structuring conceptual discussions in other psychological domains, such as perception and decision making under uncertainty, and it had demonstrated early success in the domain of attention. By rejecting a reified, causal conception of attention, in favor of theories that produce attentionaleffects as consequences, psychologists will be able to conduct more definitive experiments. Such conceptual advances will then enhance the productivity of neuroscientists by allowing them to concentrate their data collection efforts on the richest soil.

  20. A Neurodynamical Model for Selective Visual Attention

    Institute of Scientific and Technical Information of China (English)

    QU Jing-Yi; WANG Ru-Bin; ZHANG Yuan; DU Ying

    2011-01-01

    A neurodynamical model for selective visual attention considering orientation preference is proposed. Since orientation preference is one of the most important properties of neurons in the primary visual cortex, it should be fully considered besides external stimuli intensity. By tuning the parameter of orientation preference, the regimes of synchronous dynamics associated with the development of the attention focus are studied. The attention focus is represented by those peripheral neurons that generate spikes synchronously with the central neuron while the activity of other peripheral neurons is suppressed. Such dynamics correspond to the partial synchronization mode. Simulation results show that the model can sequentially select objects with different orientation preferences and has a reliable shift of attention from one object to another, which are consistent with the experimental results that neurons with different orientation preferences are laid out in pinwheel patterns.%A neurodynamical model for selective visual attention considering orientation preference is proposed.Since orientation preference is one of the most important properties of neurons in the primary visual cortex,it should be fully considered besides external stimuli intensity.By tuning the parameter of orientation preference,the regimes of synchronous dynamics associated with the development of the attention focus are studied.The attention focus is represented by those peripheral neurons that generate spikes synchronously with the central neuron while the activity of other peripheral neurons is suppressed.Such dynamics correspond to the partial synchronization mode.Simulation results show that the model can sequentially select objects with different orientation preferences and has a reliable shift of attention from one object to another,which are consistent with the experimental results that neurons with different orientation preferences are laid out in pinwheel patterns.Selective visual

  1. STATIC CORRECTION IN TIME-LAPSE SEISMIC DATA PROCESSING%时延地震处理中的近地表静校正技术

    Institute of Scientific and Technical Information of China (English)

    尚新民

    2014-01-01

    Time shift,amplitude,frequency and phase difference are main factors influencing time-lapse seismic data processing. The elimination of the time difference is the primary step in non-repeatable time-lapse data processing.Based on the acquisition parameter a-nalysis of two seismic data,the authors have solved the static correction problem caused by the absence of measured elevation in old seismic data.Joint tomographic inversion of the two time-lapse data is used to obtain an uniform near surface model.As a result,the ap-plication of calculated statics removes the time shift of the two data effectively,which has laid a good foundation for the subsequent pro-cessing.%时差、振幅、频率、相位差异是影响时延地震处理的主要因素。非一致性重复地震资料进行时延处理时,消除两期资料时差影响是做好后续处理工作的基础。在分析不同时期地震资料施工参数差异的基础上,解决了老资料未测地表高程对静校正的影响,利用初至层析反演技术,通过优选参与反演的偏移距,利用新、老资料初至共同反演得到了统一的近地表速度、厚度模型,在此基础上优化得到的静校正量最大程度地消除了两期资料时差的影响,为后续时延地震处理、分析工作奠定了基础。

  2. Time-lapse Data Oriented Infrared Face Recognition Using Block-PCA%面向时延数据的分块PCA红外人脸识别

    Institute of Scientific and Technical Information of China (English)

    谢志华; 伍世虔; 方志军; 卢宇

    2012-01-01

    The good performance of face recognition system under time-lapse data is the foundation of practical applications. This paper presents a time-lapse data oriented infrared face recognition method using block-PCA (Principal Component Analysis). Firstly, to take full advantage of the local characteristics of images, the infrared face images are partitioned into several blocks and FCA are performed on those blocks. Then, in order to lessen the influence of ambient temperature on the performance of infrared face recognition, those components of PCA that are affected greatly by ambient temperature are discarded to get the robust local features based on training of infrared face images in different ambient temperatures. Finally, the remained components from all blocks are combined to represent global facial features for final recognition. Experimental results on time-lapse data illustrate that the new block-PCA can get robust local features in variable ambient temperatures, and the proposed infrared face recognition method outperforms the traditional method based on PCA.%时延数据下的高识别性能是红外人脸识别系统应用的基础,提出一种基于分块PCA的红外人脸识别方法,提高红外人脸识别系统对时延数据识别率.为了充分利用图像的局部特征,对图像进行大小分块,并对各分块图像进行主成分分析;然后,为了缓解外部环境温度对识别的影响,通过训练学习不同温度下的红外人脸数据,去除每个图像块受环境温度影响较大的特征值.最后,为了结合整体特征,并将余下的特征值组合成特征向量用于识别.实验结果表明,本文提出的方法可以提高红外人脸识别系统对时延数据的识别率.

  3. A Geometric Representation of Collective Attention Flows.

    Directory of Open Access Journals (Sweden)

    Peiteng Shi

    Full Text Available With the fast development of Internet and WWW, "information overload" has become an overwhelming problem, and collective attention of users will play a more important role nowadays. As a result, knowing how collective attention distributes and flows among different websites is the first step to understand the underlying dynamics of attention on WWW. In this paper, we propose a method to embed a large number of web sites into a high dimensional Euclidean space according to the novel concept of flow distance, which both considers connection topology between sites and collective click behaviors of users. With this geometric representation, we visualize the attention flow in the data set of Indiana university clickstream over one day. It turns out that all the websites can be embedded into a 20 dimensional ball, in which, close sites are always visited by users sequentially. The distributions of websites, attention flows, and dissipations can be divided into three spherical crowns (core, interim, and periphery. 20% popular sites (Google.com, Myspace.com, Facebook.com, etc. attracting 75% attention flows with only 55% dissipations (log off users locate in the central layer with the radius 4.1. While 60% sites attracting only about 22% traffics with almost 38% dissipations locate in the middle area with radius between 4.1 and 6.3. Other 20% sites are far from the central area. All the cumulative distributions of variables can be well fitted by "S"-shaped curves. And the patterns are stable across different periods. Thus, the overall distribution and the dynamics of collective attention on websites can be well exhibited by this geometric representation.

  4. When can attention influence binocular rivalry?

    Science.gov (United States)

    Dieter, Kevin C; Melnick, Michael D; Tadin, Duje

    2015-08-01

    Attentional influence over perception is particularly pronounced when sensory stimulation is ambiguous, where attention can reduce stimulus uncertainty and promote a stable interpretation of the world. However, binocular rivalry, an extensively studied visual ambiguity, has proved to be comparatively resistant to attentional modulation. We hypothesize that this apparent inconsistency reflects fluctuations in the degree of unresolved competition during binocular rivalry. Namely, attentional influence over rivalry dynamics should be limited to phases of relatively unresolved stimulus competition, such as ends of individual dominance periods. We found that transient, feature-based cues congruent with the dominant stimulus prolonged dominance durations, while cues matching the suppressed stimulus hastened its return to dominance. Notably, the effect of cues depended on when the cues are presented. Cues presented late, but not early, during a given episode of perceptual dominance influenced rivalry dynamics. This temporal pattern mirrors known changes in the relative competitive dynamics of rival stimuli, revealing that selective effects occur only during temporal windows containing weak resolution of visual competition. In conclusion, these findings reveal that unresolved competition, which gates attention across a variety of domains, is also crucial in determining the susceptibility of binocular rivalry to selective influences. PMID:25898898

  5. Attentional Modulation of Eye Torsion Responses

    Science.gov (United States)

    Stevenson, Scott B.; Mahadevan, Madhumitha S.; Mulligan, Jeffrey B.

    2016-01-01

    Eye movements generally have both reflexive and voluntary aspects, but torsional eye movements are usually thought of as a reflexive response to image rotation around the line of sight (torsional OKN) or to head roll (torsional VOR). In this study we asked whether torsional responses could be modulated by attention in a case where two stimuli rotated independently, and whether attention would influence the latency of responses. The display consisted of rear-projected radial "pinwheel" gratings, with an inner annulus segment extending from the center to 22 degrees eccentricity, and an outer annulus segment extending from 22 degrees out to 45 degrees eccentricity. The two segments rotated around the center in independent random walks, stepping randomly 4 degrees clockwise or counterclockwise at 60 Hz. Subjects were asked to attend to one or the other while keeping fixation steady at the center of the display. To encourage attention on one or the other segment of the display, subjects were asked to move a joystick in synchrony with the back and forth rotations of one part of the image while ignoring the other. Eye torsion was recorded with the scleral search coil technique, sampled at 500 Hz. All four subjects showed roughly 50% stronger torsion responses to the attended compared to unattended segments. Latency varied from 100 to 150 msec across subjects and was unchanged by attention. These findings suggest that attention can influence eye movement responses that are not typically under voluntary control.

  6. MAOA Influences the Trajectory of Attentional Development

    Science.gov (United States)

    Lundwall, Rebecca A.; Rasmussen, Claudia G.

    2016-01-01

    Attention is vital to success in all aspects of life (Meck and Benson, 2002; Erickson et al., 2015), hence it is important to identify biomarkers of later attentional problems early enough to intervene. Our objective was to determine if any of 11 genes (APOE, BDNF, HTR4, CHRNA4, COMT, DRD4, IGF2, MAOA, SLC5A7, SLC6A3, and SNAP25) predicted the trajectory of attentional development within the same group of children between infancy and childhood. We recruited follow up participants from children who participated as infants in visual attention studies and used a similar task at both time points. Using multilevel modeling, we associated changes in the participant’s position in the distribution of scores in infancy to his/her position in childhood with genetic markers on each of 11 genes. While all 11 genes predicted reaction time (RT) residual scores, only Monoamine oxidase A (MAOA) had a significant interaction including time point. We conclude that the MAOA single nucleotide polymorphism (SNP) rs1137070 is useful in predicting which girls are likely to develop slower RTs on an attention task between infancy and childhood. This early identification is likely to be helpful in early intervention. PMID:27610078

  7. Developing Attention: Behavioral and Brain Mechanisms.

    Science.gov (United States)

    Posner, Michael I; Rothbart, Mary K; Sheese, Brad E; Voelker, Pascale

    2014-05-01

    Brain networks underlying attention are present even during infancy and are critical for the developing ability of children to control their emotions and thoughts. For adults, individual differences in the efficiency of attentional networks have been related to neuromodulators and to genetic variations. We have examined the development of attentional networks and child temperament in a longitudinal study from infancy (7 months) to middle childhood (7 years). Early temperamental differences among infants, including smiling and laughter and vocal reactivity, are related to self-regulation abilities at 7 years. However, genetic variations related to adult executive attention, while present in childhood, are poor predictors of later control, in part because individual genetic variationmay have many small effects and in part because their influence occurs in interaction with caregiver behavior and other environmental influences. While brain areas involved in attention are present during infancy, their connectivity changes and leads to improvement in control of behavior. It is also possible to influence control mechanisms through training later in life. The relation between maturation and learning may allow advances in our understanding of human brain development. PMID:25110757

  8. Assessing the heritability of attentional networks

    Directory of Open Access Journals (Sweden)

    Fossella John A

    2001-09-01

    Full Text Available Abstract Background Current efforts to study the genetics of higher functions have been lacking appropriate phenotypes to describe cognition. One of the problems is that many cognitive concepts for which there is a single word (e.g. attention have been shown to be related to several anatomical networks. Recently we have developed an Attention Network Test (ANT that provides a separate measure for each of three anatomically defined attention networks. In this small scale study, we ran 26 pairs of MZ and DZ twins in an effort to determine if any of these networks show sufficient evidence of heritability to warrant further exploration of their genetic basis. Results The efficiency of the executive attention network, that mediates stimulus and response conflict, shows sufficient heritability to warrant further study. Alerting and overall reaction time show some evidence for heritability and in our study the orienting network shows no evidence of heritability. Conclusions These results suggest that genetic variation contributes to normal individual differences in higher order executive attention involving dopamine rich frontal areas including the anterior cingulate. At least the executive portion of the ANT may serve as a valid endophenotype for larger twin studies and subsequent molecular genetic analysis in normal subject populations.

  9. Age trends for failures of sustained attention.

    Science.gov (United States)

    Carriere, Jonathan S A; Cheyne, J Allan; Solman, Grayden J F; Smilek, Daniel

    2010-09-01

    Recent research has revealed an age-related reduction in errors in a sustained attention task, suggesting that sustained attention abilities improve with age. Such results seem paradoxical in light of the well-documented age-related declines in cognitive performance. In the present study, performance on the sustained attention to response task (SART) was assessed in a supplemented archival sample of 638 individuals between 14 and 77 years old. SART errors and response speed appeared to decline in a linear fashion as a function of age throughout the age span studied. In contrast, other measures of sustained attention (reaction time coefficient of variation), anticipation, and omissions) showed a decrease early in life and then remained unchanged for the rest of the life span. Thus, sustained attention shows improvements with maturation in early adulthood but then does not change with aging in older adults. On the other hand, aging across the entire life span leads to a more strategic (i.e., slower) response style that reduces the overt and critical consequences (i.e., SART errors) of momentary task disengagement.

  10. Developing Attention: Behavioral and Brain Mechanisms

    Directory of Open Access Journals (Sweden)

    Michael I. Posner

    2014-01-01

    Full Text Available Brain networks underlying attention are present even during infancy and are critical for the developing ability of children to control their emotions and thoughts. For adults, individual differences in the efficiency of attentional networks have been related to neuromodulators and to genetic variations. We have examined the development of attentional networks and child temperament in a longitudinal study from infancy (7 months to middle childhood (7 years. Early temperamental differences among infants, including smiling and laughter and vocal reactivity, are related to self-regulation abilities at 7 years. However, genetic variations related to adult executive attention, while present in childhood, are poor predictors of later control, in part because individual genetic variation may have many small effects and in part because their influence occurs in interaction with caregiver behavior and other environmental influences. While brain areas involved in attention are present during infancy, their connectivity changes and leads to improvement in control of behavior. It is also possible to influence control mechanisms through training later in life. The relation between maturation and learning may allow advances in our understanding of human brain development.

  11. Does attention redirection contribute to the effectiveness of attention bias modification on social anxiety?

    Science.gov (United States)

    Yao, Nisha; Yu, Hongyu; Qian, Mingyi; Li, Songwei

    2015-12-01

    Attention bias modification (ABM) is designed to modify threat-related attention bias and thus alleviate anxiety. The current research examined whether consistently directing attention towards targeted goals per se contributes to ABM efficacy. We randomly assigned 68 non-clinical college students with elevated social anxiety to non-valence-specific attend-to-geometrics (AGC), attention modification (AMC), or attention control (ACC) conditions. We assessed subjective, behavioral, and physiological reactivity to a speech task and self-reported social anxiety symptoms. After training, participants in the AMC exhibited an attention avoidance from threat, and those in the AGC responded more rapidly toward targeted geometrics. There was a significant pre- to post-reduction in subjective speech distress across groups, but behavioral and physiological reactivity to speech, as well as self-report social anxiety symptoms, remained unchanged. These results lead to questions concerning effectiveness of ABM training for reducing social anxiety. Further examination of the current ABM protocol is required.

  12. Attention and Implicit Memory: Priming-Induced Benefits and Costs Have Distinct Attentional Requirements

    OpenAIRE

    Keane, Margaret M.; Cruz, Matt E.; Verfaellie, Mieke

    2015-01-01

    Attention at encoding plays a critical and ubiquitous role in explicit memory performance, but its role in implicit memory performance (i.e., priming) is more variable: Some, but not all, priming effects are reduced by division of attention at encoding. A wealth of empirical and theoretical work has aimed to define the critical features of priming effects that do or do not require attention at encoding. This work, however, has focused exclusively on priming effects that are beneficial in natu...

  13. Defining the Focus of Attention: Effects of Attention on Perceived Exertion and Fatigue.

    OpenAIRE

    Keith eLohse; SHERWOOD, DAVID E.

    2011-01-01

    This manuscript presents two experiments designed to explore the effects of attention on perceived exertion and time to failure in a fatiguing athletic task. There were two major motivating factors for these experiments. First, there are few studies evaluating attentional focus effects in endurance tasks and, second, there is a lack of integration between studies of attentional focus as external/internal (e.g., Wulf, 2007a) compared to associative/dissociative (e.g., Stevinson and Biddle, 199...

  14. Antecedent acute cycling exercise affects attention control: an ERP study using attention network test

    OpenAIRE

    Yu-Kai eChang; Caterina ePesce; Yi-Te eChiang; Cheng-Yuh eKuo; Dong-Yang eFong

    2015-01-01

    The purpose of this study was to investigate the after-effects of an acute bout of moderate intensity aerobic cycling exercise on neuroelectric and behavioral indices of efficiency of three attentional networks: alerting, orienting, and executive (conflict) control. Thirty young, highly fit amateur basketball players performed a multifunctional attentional reaction time task, the attention network test (ANT), with a two-group randomized experimental design after an acute bout of moderate inte...

  15. Design on Injection Mold demolding by Time-lapse Parting of Slide%滑块延时分型脱模的注塑模设计

    Institute of Scientific and Technical Information of China (English)

    周铭杰

    2012-01-01

    分析了套管塑件的结构特点,介绍了套管注塑模的结构与工作过程.采用滑块延时分型实现塑件的脱模,在型芯中开设隔片式冷却回路加强对型芯的冷却,保证了塑件的质量.%Based on the analysis of the structure characteristics of the casing pipe, the structure and working process of an injection mold for the casing pipe were introduced. The time-lapse parting mechanism was used for demolding of the molded part. The cooling waterline with baffle was set in core insert to reinforce the cooling effect.

  16. Scope of Attention, Control of Attention, and Intelligence in Children and Adults

    OpenAIRE

    Cowan, Nelson; Fristoe, Nathanael M.; Elliott, Emily M.; Brunner, Ryan P.; Saults, J. Scott

    2006-01-01

    Recent experimentation has shown that cognitive aptitude measures are predicted by tests of the scope of an individual’s attention or capacity in simple working-memory tasks, and also by the ability to control attention. However, these experiments do not indicate how separate or related the scope and control of attention are. An experiment with 52 children 10 to 11 years old and 52 college students included measures of the scope and control of attention as well as verbal and nonverbal aptitud...

  17. Mindfulness Meditation Improves Mood, Quality of Life, and Attention in Adults with Attention Deficit Hyperactivity Disorder

    Directory of Open Access Journals (Sweden)

    Viviane Freire Bueno

    2015-01-01

    Full Text Available Objective. Adults with attention deficit hyperactivity disorder (ADHD display affective problems and impaired attention. Mood in ADHD can be improved by mindful awareness practices (MAP, but results are mixed regarding the enhancement of attentional performance. Here we evaluated MAP-induced changes in quality of life (QoL, mood, and attention in adult ADHD patients and controls using more measures of attention than prior studies. Methods. Twenty-one ADHD patients and 8 healthy controls underwent 8 weekly MAP sessions; 22 similar patients and 9 controls did not undergo the intervention. Mood and QoL were assessed using validated questionnaires, and attention was evaluated using the Attentional Network Test (ANT and the Conners Continuous Performance Test (CPT II, before and after intervention. Results. MAP enhanced sustained attention (ANT and detectability (CPT II and improved mood and QoL of patients and controls. Conclusion. MAP is a complementary intervention that improves affect and attention of adults with ADHD and controls.

  18. Mindfulness Meditation Improves Mood, Quality of Life, and Attention in Adults with Attention Deficit Hyperactivity Disorder

    Science.gov (United States)

    Bueno, Viviane Freire; Kozasa, Elisa H.; da Silva, Maria Aparecida; Alves, Tânia Maria; Louzã, Mario Rodrigues; Pompéia, Sabine

    2015-01-01

    Objective. Adults with attention deficit hyperactivity disorder (ADHD) display affective problems and impaired attention. Mood in ADHD can be improved by mindful awareness practices (MAP), but results are mixed regarding the enhancement of attentional performance. Here we evaluated MAP-induced changes in quality of life (QoL), mood, and attention in adult ADHD patients and controls using more measures of attention than prior studies. Methods. Twenty-one ADHD patients and 8 healthy controls underwent 8 weekly MAP sessions; 22 similar patients and 9 controls did not undergo the intervention. Mood and QoL were assessed using validated questionnaires, and attention was evaluated using the Attentional Network Test (ANT) and the Conners Continuous Performance Test (CPT II), before and after intervention. Results. MAP enhanced sustained attention (ANT) and detectability (CPT II) and improved mood and QoL of patients and controls. Conclusion. MAP is a complementary intervention that improves affect and attention of adults with ADHD and controls. PMID:26137496

  19. Moving to Capture Children’s Attention: Developing a Methodology for Measuring Visuomotor Attention

    Science.gov (United States)

    Coats, Rachel O.; Mushtaq, Faisal; Williams, Justin H. G.; Aucott, Lorna S.; Mon-Williams, Mark

    2016-01-01

    Attention underpins many activities integral to a child’s development. However, methodological limitations currently make large-scale assessment of children’s attentional skill impractical, costly and lacking in ecological validity. Consequently we developed a measure of ‘Visual Motor Attention’ (VMA)—a construct defined as the ability to sustain and adapt visuomotor behaviour in response to task-relevant visual information. In a series of experiments, we evaluated the capability of our method to measure attentional processes and their contributions in guiding visuomotor behaviour. Experiment 1 established the method’s core features (ability to track stimuli moving on a tablet-computer screen with a hand-held stylus) and demonstrated its sensitivity to principled manipulations in adults’ attentional load. Experiment 2 standardised a format suitable for use with children and showed construct validity by capturing developmental changes in executive attention processes. Experiment 3 tested the hypothesis that children with and without coordination difficulties would show qualitatively different response patterns, finding an interaction between the cognitive and motor factors underpinning responses. Experiment 4 identified associations between VMA performance and existing standardised attention assessments and thereby confirmed convergent validity. These results establish a novel approach to measuring childhood attention that can produce meaningful functional assessments that capture how attention operates in an ecologically valid context (i.e. attention's specific contribution to visuomanual action). PMID:27434198

  20. Adapting the Theory of Visual Attention (TVA) to model auditory attention

    DEFF Research Database (Denmark)

    Roberts, Katherine L.; Andersen, Tobias; Kyllingsbæk, Søren;

    2014-01-01

    Mathematical and computational models have provided useful insights into normal and impaired visual attention, but less progress has been made in modelling auditory attention. We are developing a Theory of Auditory Attention (TAA), based on an influential visual model, the Theory of Visual...... the auditory data, producing good estimates of the rate at which information is encoded (C), the minimum exposure duration required for processing to begin (t0), and the relative attentional weight to targets versus distractors (α). Future work will address the issue of target-distractor confusion, and extend...

  1. Raputatud lapse sündroomi mõiste, olemus, tuvastamine ja ennetamine : [bakalaureusetöö] / Hettel Varik ; Tartu Ülikooli Õigusinstituut ; juhendaja: Endla Ülviste

    Index Scriptorium Estoniae

    Varik, Hettel

    2006-01-01

    Raputatud lapse sündroomi (RLS) mõiste, olemus ja probleemi teadvustamine, RLS-i põhjustanud tegevuse kui kuriteo tuvastamine, süüteo subjektiivse koosseisu sisustamine, kohtulahendid, RLS-i vältimise võimalikkusest, RLS-i tekitaja karistamine

  2. Components of attention modulated by temporal expectation

    DEFF Research Database (Denmark)

    Sørensen, Thomas Alrik; Vangkilde, Signe Allerup; Bundesen, Claus

    2015-01-01

    By varying the probabilities that a stimulus would appear at particular times after the presentation of a cue and modeling the data by the theory of visual attention (Bundesen, 1990), Vangkilde, Coull, and Bundesen (2012) provided evidence that the speed of encoding a singly presented stimulus...... conditions. In line with the Easterbrook (1959) hypothesis, under high temporal expectancy, the processing was also more focused (selective). First, the storage capacity of VSTM was lower, so that fewer stimuli were encoded into VSTM. Second, the distribution of attentional weights across stimuli was less...... even: The efficiency of selecting targets rather than distractors for encoding into VSTM was higher, as was the spread of the attentional weights of the target letters....

  3. Reduced attentional scope in cocaine polydrug users.

    Directory of Open Access Journals (Sweden)

    Lorenza S Colzato

    Full Text Available Cocaine is Europe's second preferred recreational drug after cannabis but very little is known about possible cognitive impairments in the upcoming type of recreational cocaine user (monthly consumption. We asked whether recreational use of cocaine impacts early attentional selection processes. Cocaine-free polydrug controls (n = 18 and cocaine polydrug users (n = 18 were matched on sex, age, alcohol consumption, and IQ (using the Raven's progressive matrices, and were tested by using the Global-Local task to measure the scope of attention. Cocaine polydrug users attended significantly more to local aspects of attended events, which fits with the idea that a reduced scope of attention may be associated with the perpetuation of the use of the drug.

  4. Visual attention capacity after right hemisphere lesions

    DEFF Research Database (Denmark)

    Habekost, Thomas; Rostrup, Egill

    2007-01-01

    a whole report experiment for estimation of these two parameters in 22 patients with right side stroke. Psychophysical performance was analyzed using Bundesen's [Bundesen, C. (1990). A theory of visual attention. Psychological Review, 97, 523-547] Theory of Visual Attention (TVA) and compared...... to damage in the right middle frontal gyrus or leukoaraiosis. The storage capacity of VSTM was also normal for most patients, but deficits were found after severe leukoaraiosis or large strokes extending deep into white matter. Thus, the study demonstrated the importance of white-matter connectivity...... for both VSTM capacity and ipsilesional processing speed. The study also showed that lesions in a large region of the right hemisphere, including the putamen, insula, and inferior frontal cortex, do not lead to general deficits in the capacity of visual attention. Udgivelsesdato: 2007-Apr-8...

  5. Effectiveness of attention training in schizophrenia.

    Science.gov (United States)

    Medalia, A; Aluma, M; Tryon, W; Merriam, A E

    1998-01-01

    This study assessed the impact of attention training on information processing in schizophrenia. Fifty-four inpatients with chronic schizophrenia were randomly assigned to two groups after baseline assessment with the Continuous Performance Test (CPT). Patients in the experimental group participated in individual sessions of computerized attention remediation, while patients in the control group participated in individual sessions during which they viewed video documentaries. After 18 sessions, reassessment with the CPT showed that patients in the experimental group had made significantly more improvement than the control group, which made no significant change. Brief Psychiatric Rating Scale assessments before and after the study phase indicated that both groups improved on the total score but the experimental group made significantly more improvement. These results suggest that it is feasible to use practice and behavioral learning to remediate a core attention deficit in chronic schizophrenia. PMID:9502552

  6. A neural theory of visual attention

    DEFF Research Database (Denmark)

    Bundesen, Claus; Habekost, Thomas; Kyllingsbæk, Søren

    2005-01-01

    A neural theory of visual attention (NTVA) is presented. NTVA is a neural interpretation of C. Bundesen's (1990) theory of visual attention (TVA). In NTVA, visual processing capacity is distributed across stimuli by dynamic remapping of receptive fields of cortical cells such that more processing...... resources (cells) are devoted to behaviorally important objects than to less important ones. By use of the same basic equations used in TVA, NTVA accounts for a wide range of known attentional effects in human performance (reaction times and error rates) and a wide range of effects observed in firing rates...... of single cells in the primate visual system. NTVA provides a mathematical framework to unify the 2 fields of research--formulas bridging cognition and neurophysiology....

  7. Time-lapse imaging as a tool to investigate contractility of the epididymal duct--effects of cGMP signaling.

    Directory of Open Access Journals (Sweden)

    Andrea Mietens

    Full Text Available The well orchestrated function of epididymal smooth muscle cells ensures transit of spermatozoa through the epididymal duct during which spermatozoa acquire motility and fertilizing capacity. Relaxation of smooth muscle cells is mediated by cGMP signaling and components of this pathway are found within the male reproductive tract. Whereas contractile function of caudal parts of the rat epididymal duct can be examined in organ bath studies, caput and corpus regions are fragile and make it difficult to mount them in an organ bath. We developed an ex vivo time-lapse imaging-based approach to investigate the contractile pattern in these parts of the epididymal duct. Collagen-embedding allowed immobilization without impeding contractility or diffusion of drugs towards the duct and therefore facilitated subsequent movie analyses. The contractile pattern was made visible by placing virtual sections through the acquired image stack to track wall movements over time. By this, simultaneous evaluation of contractile activity at different positions of the observed duct segment was possible. With each contraction translating into a spike, drug-induced alterations in contraction frequency could be assessed easily. Peristaltic contractions were also detectable and throughout all regions in the proximal epididymis we found regular spontaneous contractile activity that elicited movement of intraluminal contents. Stimulating cGMP production by natriuretic peptide ANP or inhibiting degradation of cGMP by the phosphodiesterase 5 inhibitor sildenafil significantly reduced contractile frequency in isolated duct segments from caput and corpus. RT-PCR analysis after laser-capture microdissection localized the corresponding molecules to the smooth muscle layer of the duct. Our time-lapse imaging approach proved to be feasible to assess contractile function in all regions of the epididymal duct under near physiological conditions and provides a tool to evaluate acute

  8. Preliminary Seismic Time-lapse Results of the First Post-injection Monitoring at the Ketzin Pilot Site for CO2 Storage

    Science.gov (United States)

    Huang, Fei; Monika, Ivandic; Julin, Christopher; Lüth, Stefan; Bergmann, Peter

    2016-04-01

    Time-lapse surface seismic monitoring methods have proven to be notably successful in imaging the development of the CO2 plume injected into the 630-650 meters deep saline aquifer at the Ketzin pilot site. A 3D baseline survey was acquired in the autumn of 2005 prior to CO2 injection, followed by two 3D repeat surveys conducted in the same season of 2009 and 2012 after injection of about 22 and 61 kt of CO2, respectively. These repeat surveys showed that the CO2 plume was concentrated around the injection well with a preferred WNW propagating trend due to reservoir heterogeneity. The CO2 induced amplitude anomaly continued to grow with more CO2 injected into the reservoir. The CO2 injection ended on August 29, 2013 after a total of about 67 kt injected CO2. In the autumn of 2015, a third 3D repeat survey with a nominal fold of 25 was acquired during the post-injection phase. The acquisition was implemented with an identical template scheme and acquisition parameters as in the previous surveys. About 5500 source points were acquired during the 57 days of active acquisition. The same processing steps as used before were carried out from pre-stack to post-stack. In order to minimize changes unrelated to the site operations, cross-calibration was applied to the data. Preliminary results of the time-lapse analysis show that the obtained amplitude anomaly at the reservoir level is smaller in size than the one observed at the time of the second repeat survey. This may indicate that CO2 dissolution is active, especially east of the injection site, where permeability and flow rate appear to be lower. In comparison to the previous surveys, the maximum amplitude anomaly has moved towards the west, which is consistent with the previously observed propagating tendency of the CO2 plume within the reservoir. No CO2 leakage is observed within the overburden.

  9. Improvements of a COMS Land Surface Temperature Retrieval Algorithm Based on the Temperature Lapse Rate and Water Vapor/Aerosol Effect

    Directory of Open Access Journals (Sweden)

    A-Ra Cho

    2015-02-01

    Full Text Available The National Meteorological Satellite Center in Korea retrieves land surface temperature (LST by applying the split-window LST algorithm (CSW_v1.0 to Communication, Ocean, and Meteorological Satellite (COMS data. Considerable errors were detected under conditions of high water vapor content or temperature lapse rates during validation with Moderate Resolution Imaging Spectroradiometer (MODIS LST because of the too simplified LST algorithm. In this study, six types of LST retrieval equations (CSW_v2.0 were developed to upgrade the CSW_v1.0. These methods were developed by classifying “dry,” “normal,” and “wet” cases for day and night and considering the relative sizes of brightness temperature difference (BTD values. Similar to CSW_v1.0, the LST retrieved by CSW_v2.0 had a correlation coefficient of 0.99 with the prescribed LST and a slightly larger bias of −0.03 K from 0.00K; the root mean square error (RMSE improved from 1.41 K to 1.39 K. In general, CSW_v2.0 improved the retrieval accuracy compared to CSW_v1.0, especially when the lapse rate was high (mid-day and dawn and the water vapor content was high. The spatial distributions of LST retrieved by CSW_v2.0 were found to be similar to the MODIS LST independently of the season, day/night, and geographic locations. The validation using one year’s MODIS LST data showed that CSW_v2.0 improved the retrieval accuracy of LST in terms of correlations (from 0.988 to 0.989, bias (from −1.009 K to 0.292 K, and RMSEs (from 2.613 K to 2.237 K.

  10. An efficient method of 3-D elastic full waveform inversion using a finite-difference injection method for time-lapse imaging

    Science.gov (United States)

    Borisov, Dmitry; Singh, Satish C.; Fuji, Nobuaki

    2015-09-01

    Seismic full waveform inversion is an objective method to estimate elastic properties of the subsurface and is an important area of research, particularly in seismic exploration community. It is a data-fitting approach, where the difference between observed and synthetic data is minimized iteratively. Due to a very high computational cost, the practical implementation of waveform inversion has so far been restricted to a 2-D geometry with different levels of physics incorporated in it (e.g. elasticity/viscoelasticity) or to a 3-D geometry but using an acoustic approximation. However, the earth is three-dimensional, elastic and heterogeneous and therefore a full 3-D elastic inversion is required in order to obtain more accurate and valuable models of the subsurface. Despite the recent increase in computing power, the application of 3-D elastic full waveform inversion to real-scale problems remains quite challenging on the current computer architecture. Here, we present an efficient method to perform 3-D elastic full waveform inversion for time-lapse seismic data using a finite-difference injection method. In this method, the wavefield is computed in the whole model and is stored on a surface above a finite volume where the model is perturbed and localized inversion is performed. Comparison of the final results using the 3-D finite-difference injection method and conventional 3-D inversion performed within the whole volume shows that our new method provides significant reductions in computational time and memory requirements without any notable loss in accuracy. Our approach shows a big potential for efficient reservoir monitoring in real time-lapse experiments.

  11. Attentional Processing of Letter Strings by Children.

    Science.gov (United States)

    Leclercq, Virginie; Siéroff, Eric

    2016-01-01

    Reading a letter string requires attentional orienting toward the beginning of the string (left-dominant orientation), followed by orienting along the string. These attentional-orienting processes differ according to the lexicality of the letter string: Sequential processes apply when reading nonwords or pseudowords, while words can be processed more globally. The aim of this study was to evaluate the development of these attentional processes involved in reading. We conducted two experiments in 6- (first grade), 7- (second grade), and 9-year-old (fourth grade) children, using a procedure that required the detection of a letter (Experiment 1) or a nonletter (Experiment 2) target in a string of five characters. The target character could occur in the second (left) or fourth (right) position in the string. Results showed an advantage for left nonletter targets as early as age 6 and of left letter targets as early as age 7. In 6-year-olds, only good readers detected a left letter target faster than a right letter target; others detected a right letter target faster. Thus, dominant orienting toward the beginning of the letter string is not fully developed in children before the second year of reading. A possibility is that beginning readers have difficulties inhibiting an attention-orienting bias toward the right visual field in linguistic tasks. The results also showed that the lexicality effect on these attentional processes develops gradually until the fourth year of reading. We believe that the procedure used in this study will be very valuable for evaluating attentional difficulties during reading acquisition. PMID:25386702

  12. Deep Attention Recurrent Q-Network

    OpenAIRE

    Sorokin, Ivan; Seleznev, Alexey; Pavlov, Mikhail; Fedorov, Aleksandr; Ignateva, Anastasiia

    2015-01-01

    A deep learning approach to reinforcement learning led to a general learner able to train on visual input to play a variety of arcade games at the human and superhuman levels. Its creators at the Google DeepMind's team called the approach: Deep Q-Network (DQN). We present an extension of DQN by "soft" and "hard" attention mechanisms. Tests of the proposed Deep Attention Recurrent Q-Network (DARQN) algorithm on multiple Atari 2600 games show level of performance superior to that of DQN. Moreov...

  13. Components of attentional set-switching.

    Science.gov (United States)

    Rushworth, M F S; Passingham, R E; Nobre, A C

    2005-01-01

    A series of distinct event-related potentials (ERPs) have been recorded from the scalp of human subjects as they switch from one task to another. It is possible that task switching may depend on different mechanisms depending on whether the switch requires a change in attentional set, in other words the redirecting of attention to different aspects of a sensory stimulus, or whether it requires a change in intentional set, in others words a change in the way that responses are selected. To address this issue, the current study recorded ERPs while subjects switched between attentional sets and the results were compared with those of a previous investigation in which subjects switched between intentional sets. Subjects selected stimuli according to two conflicting attentional sets, each emphasizing one visual stimulus dimension (colour, shape). Pairs of stimuli, only one of which was to be attended, were presented for between eight and seventeen trials then either a switch or a stay cue was shown. The switch cue instructed subjects to switch from the current attentional set to the other set, while the stay cue instructed subjects to maintain the current set. Comparing ERPs time-locked to the switch and stay cues revealed neural correlates of the initiation of a task switch. Comparing the ERPs time locked to the first stimuli after either stay or switch cues identified neural correlates of the implementation of a task switch. A similar modulation over parietal electrodes was seen when subjects were switching between either attentional or intentional sets. While an intentional set switch began with a medial frontal modulation, attentional set switching began with a lateral frontal modulation. Implementing a new attentional set was associated with modulation of relatively early visual potentials, while implementing a new intentional set was associated with modulation of later response-related potentials. The results confirm that task switching consists of a number of

  14. How Attention Modulates Encoding of Dynamic Stimuli

    Science.gov (United States)

    Oren, Noga; Shapira-Lichter, Irit; Lerner, Yulia; Tarrasch, Ricardo; Hendler, Talma; Giladi, Nir; Ash, Elissa L.

    2016-01-01

    When encoding a real-life, continuous stimulus, the same neural circuits support processing and integration of prior as well as new incoming information. This ongoing interplay is modulated by attention, and is evident in regions such as the prefrontal cortex section of the task positive network (TPN), and in the posterior cingulate cortex (PCC), a hub of the default mode network (DMN). Yet the exact nature of such modulation is still unclear. To investigate this issue, we utilized an fMRI task that employed movies as the encoded stimuli and manipulated attentional load via an easy or hard secondary task that was performed simultaneously with encoding. Results showed increased intersubject correlation (inter-SC) levels when encoding movies in a condition of high, as compared to low attentional load. This was evident in bilateral ventrolateral and dorsomedial prefrontal cortices and the dorsal PCC (dPCC). These regions became more attuned to the combination of the movie and the secondary task as the attentional demand of the latter increased. Activation analyses revealed that at higher load the prefrontal TPN regions were more activated, whereas the dPCC was more deactivated. Attentional load also influenced connectivity within and between the networks. At high load the dPCC was anti-correlated to the prefrontal regions, which were more functionally coherent amongst themselves. Finally and critically, greater inter-SC in the dPCC at high load during encoding predicted lower memory strength when that information was retrieved. This association between inter-SC levels and memory strength suggest that as attentional demands increased, the dPCC was more attuned to the secondary task at the expense of the encoded stimulus, thus weakening memory for the encoded stimulus. Together, our findings show that attentional load modulated the function of core TPN and DMN regions. Furthermore, the observed relationship between memory strength and the modulation of the dPCC points

  15. Object based attention and visual area LO.

    OpenAIRE

    de-Wit, L.; Kentridge, R. W.; Milner, A D

    2009-01-01

    We investigated the neural basis of so-called “object-based attention” by examining patient D.F., who has visual form agnosia caused by bilateral damage to the lateral occipital (LO) area of the ventral visual stream. We tested D.F.’s object-based attention in two ways. In the first experiment, we used a spatial cueing procedure to compare the costs associated with shifting attention within versus between two separate outline figures. D.F. did not show the normal advantage of within-object ov...

  16. Attention Dysfunction Subtypes of Developmental Dyslexia

    OpenAIRE

    Lewandowska, Monika; Milner, Rafał; Ganc, Małgorzata; Włodarczyk, Elżbieta; Skarżyński, Henryk

    2014-01-01

    Background Previous studies indicate that many different aspects of attention are impaired in children diagnosed with developmental dyslexia (DD). The objective of the present study was to identify cognitive profiles of DD on the basis of attentional test performance. Material/Methods 78 children with DD (30 girls, 48 boys, mean age of 12 years ±8 months) and 32 age- and sex-matched non-dyslexic children (14 girls, 18 boys) were examined using a battery of standardized tests of reading, phono...

  17. Medical Comorbidities in Attention Deficit Hyperactivity Disorder

    OpenAIRE

    Irem Yalug; Ali Evren Tufan

    2009-01-01

    Attention Deficit Hyperactivity Disorder is one of the most common developmental disorders of childhood with a reported world-wide prevalence of 8 to 12 %. In studies conducted in our country the prevalence rates in community were reported to vary between 8.6 to 8.1 % while clinical prevalence rates were reported to vary between 8.6 to 29.44 %. Fifty to eighty percent of cases were reported to continue into adolescence while thirty to fifty percent may continue into adulthood. Attention defic...

  18. Control of Auditory Attention in Children with Specific Language Impairment

    Science.gov (United States)

    Victorino, Kristen R.; Schwartz, Richard G.

    2015-01-01

    Purpose: Children with specific language impairment (SLI) appear to demonstrate deficits in attention and its control. Selective attention involves the cognitive control of attention directed toward a relevant stimulus and simultaneous inhibition of attention toward irrelevant stimuli. The current study examined attention control during a…

  19. Audiovisual semantic interference and attention : Evidence from the attentional blink paradigm

    NARCIS (Netherlands)

    Van der Burg, Erik; Brederoo, Sanne G.; Nieuwenstein, Mark R.; Theeuwes, Jan; Olivers, Christian N. L.

    2010-01-01

    In the present study we investigate the role of attention in audiovisual semantic interference, by using an attentional blink paradigm. Participants were asked to make an unspeeded response to the identity of a visual target letter. This target letter was preceded at various SOAs by a synchronized a

  20. Differentiating Attention Deficits in Children with Fetal Alcohol Spectrum Disorder or Attention-Deficit-Hyperactivity Disorder

    Science.gov (United States)

    Kooistra, Libbe; Crawford, Susan; Gibbard, Ben; Ramage, Barbara; Kaplan, Bonnie J

    2010-01-01

    Aim: The attention and inhibition problems found in children with attention-deficit-hyperactivity disorder (ADHD) are also common in children with fetal alcohol spectrum disorders (FASDs). Attempts to distinguish ADHD from FASDs in terms of these deficits are rare and were pursued in this study. Method: A total of 116 children (47 with ADHD, 31…