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Sample records for arengukeskkonna mju lapse

  1. AMS Time Lapse Installation

    NASA Video Gallery

    A time lapse video compilation of the installation of the Alpha Magnetic Spectrometer on the International Space Station’s starboard truss using the station’s robotic arm, Canadarm2, during the...

  2. A-3 Construction Time Lapse

    NASA Technical Reports Server (NTRS)

    2009-01-01

    A time lapse from start to finish of steel erection for the 235-foot tall A-3 Test Stand. Ground work for the stand was broken in August 2008 and the final structural steel beam was placed April 9, 2009.

  3. Drinking Trajectories Following an Initial Lapse

    PubMed Central

    Witkiewitz, Katie; Masyn, Katherine E.

    2008-01-01

    Relapse following alcohol treatment is a major problem for individuals who are alcohol dependent, yet little is known about the course of drinking after the initial lapse. In the current study, discrete-time survival analysis and latent growth mixture modeling were used to evaluate the time to first lapse and the trajectories of postlapse drinking in a sample of 563 individuals who received community alcohol treatment. Results showed a decreasing risk of lapsing over time. After the initial lapse, 3 trajectory subgroups provided a parsimonious representation of the heterogeneity in postlapse drinking frequency and quantity, with the majority of individuals reporting light, infrequent drinking. Covariate analyses incorporating demographics, distal risk factors, time to first lapse, and coping behavior as predictors of time to lapse and postlapse drinking trajectories indicated that alcohol dependence and coping behavior were the strongest predictors of lapsing and postlapse drinking behavior. PMID:18540713

  4. Rim Fire Time Lapse, August 2013

    NASA Video Gallery

    Time-lapse photography shows various perspectives of the 2013 Rim Fire, as viewed from Yosemite National Park. The first part of this video is from the Crane Flat Helibase. The fire is currently bu...

  5. Time-lapse camera for microscopy

    NASA Technical Reports Server (NTRS)

    Cook, J. E.

    1972-01-01

    Compact, lightweight camera which advances film frames without use of conventional sprockets and slip clutches obtains time lapse photomicrographs of human cell growth in a zero-G environment over a period of about a month.

  6. Crawler-Transporter Time-Lapse

    NASA Video Gallery

    Time-lapse video shows crawler-transporter No. 2 traveling from the Vehicle Assembly Building to Launch Pad 39A at NASA's Kennedy Space Center in Florida. The move was performed by the Ground Syste...

  7. Pupillary correlates of lapses of sustained attention.

    PubMed

    Unsworth, Nash; Robison, Matthew K

    2016-08-01

    The current study examined the extent to which pupillary responses (both pretrial baseline and phasic responses) would accurately track lapses of attention as predicted by theories of locus coeruleus norepinephrine (LC-NE) functioning. Participants performed a sustained attention task while pupil responses were continuously recorded. Periodically during the task, participants were presented with thought probes to determine if they were on or off task. The results suggested the pupillary responses accurately distinguished on from off-task states. Importantly, pretrial baseline pupil responses distinguished different types of lapses of attention, with inattentive and mind-wandering states being associated with small pretrial baseline pupil diameters on average and distracted states being associated with larger pretrial baseline pupil diameters on average compared to focused states. These results support the notion that pupil diameter is sensitive to different types of lapses of attention which may be associated with different LC-NE modes. PMID:27038165

  8. [Auditory evoked potentials under attentional lapses].

    PubMed

    Lazarev, I E; Bryzgalov, D V; Osokina, E S; Viazovtseva, A A; Antonenko, A S; Arkhipova, E A; Chernyshev, B V

    2014-01-01

    In order to study spontaneous attentional lapses the experimental task was used that created a moderately high attentional load and involved response choice based on stimulus feature conjunction. The participant's average correct response rate was 85.1%; they made errors in 9.6% trials and response omissions in 5.4% trials. Peak N1 of the evoked potential was consistent across all behavioral outcomes, while peak P2 amplitude was significantly greater before errors and response omissions compared to correct responses. The analysis of polygraphic indexes (ECG, EMG, SGR) did not reveal any arousal level reduction before attentional lapses. The proposed interpretation of the results obtained is based on the assumption that attentional lapses are mediated by the suppression of external stimuli information processing caused by the state of mind-wandering. PMID:25723016

  9. Predicting the Initial Lapse Using a Mobile Health Application after Alcohol Detoxification

    ERIC Educational Resources Information Center

    Chih, Ming-Yuan

    2013-01-01

    The prediction and prevention of the initial lapse--which is defined as the first lapse after a period of abstinence--is important because the initial lapse often leads to subsequent lapses (within the same lapse episode) or relapse. The prediction of the initial lapse may allow preemptive intervention to be possible. This dissertation reports on…

  10. MUSCLE: MUltiscale Spherical-ColLapse Evolution

    NASA Astrophysics Data System (ADS)

    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.

  11. Time-Lapse Imaging of Cell Death.

    PubMed

    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

  12. New Siemens Research Turbine - time lapse

    SciTech Connect

    2009-01-01

    The National Renewable Energy Laboratory (NREL) and Siemens Energy Inc. recently commissioned a new 2.3 megawatt Siemens wind turbine at NREL's National Wind Technology Center. This video shows a time lapse of the installation. The turbine is the centerpiece of a multi-year project to study the performance and aerodynamics of a new class of large, land-based machines — in what will be the biggest government-industry research partnership for wind power generation ever undertaken in the U.S.

  13. Lapse in Institutional Animal Care and Use Committee Continuing Reviews.

    PubMed

    Tsan, Min-Fu; Grabenbauer, Michael; Nguyen, Yen

    2016-01-01

    The United States federal animal welfare regulations and the Public Health Service Policy on Humane Care and Use of Laboratory Animals require that institutional animal care and use committees (IACUCs) conduct continuing reviews of all animal research activities. However, little is known about the lapse rate of IACUC continuing reviews, and how frequently investigators continue research activities during the lapse. It is also not clear what factors may contribute to an institution's lapse in IACUC continuing reviews. As part of the quality assurance program, the Department of Veterans Affairs (VA) has collected performance metric data for animal care and use programs since 2011. We analyzed IACUC continuing review performance data at 74-75 VA research facilities from 2011 through 2015. The IACUC continuing review lapse rates improved from 5.6% in 2011 to 2.7% in 2015. The rate of investigators continuing research activities during the lapse also decreased from 47.2% in 2012 to 7.4% in 2015. The type of IACUCs used and the size of animal research programs appeared to have no effect in facility's rates of lapse in IACUC continuing reviews. While approximately 80% of facilities reported no lapse in IACUC continuing reviews, approximately 14% of facilities had lapse rates of >10% each year. Some facilities appeared to be repeat offenders. Four facilities had IACUC lapse rates of >10% in at least 3 out of 5 years, suggesting a system problem in these facilities requiring remedial actions to improve their IACUC continuing review processes. PMID:27606820

  14. 26 CFR 25.2704-1 - Lapse of certain rights.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... GIFT TAXES GIFT TAX; GIFTS MADE AFTER DECEMBER 31, 1954 Special Valuation Rules § 25.2704-1 Lapse of... or a liquidation right may be conferred by and may lapse by reason of a State law, the corporate... the total voting power and the common stock had 40 percent. Under the corporate by-laws, the...

  15. 26 CFR 25.2704-1 - Lapse of certain rights.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... GIFT TAXES GIFT TAX; GIFTS MADE AFTER DECEMBER 31, 1954 Special Valuation Rules § 25.2704-1 Lapse of... or a liquidation right may be conferred by and may lapse by reason of a State law, the corporate... the total voting power and the common stock had 40 percent. Under the corporate by-laws, the...

  16. 30 CFR 256.55 - Lapse of bond.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Lapse of bond. 256.55 Section 256.55 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Bonding § 256.55 Lapse of...

  17. Time-Lapse Zirconography of Continental Growth

    NASA Astrophysics Data System (ADS)

    Parman, S. W.

    2014-12-01

    When did the continents form? Peaks in the distributions of zircon U-Pb ages around 2.7, 1.9 and 1.2 Ga have been used as evidence for increased crustal growth rates at these times (growth pulses). The pulses appear linked to the formation of super-continents, with fundamental implications for the thermal evolution of the mantle. However, the age peaks could also be produced by variations in preservation/destruction rates, in which case the implications for the deep Earth are less direct. Here I use the novel approach of examining U-Pb zircon age spectra as a function of the age of the sediment in which the zircons are preserved. This produces time-lapse sequences of zircon age distributions, and presumably, crustal evolution. The database [1] is large enough (n>200,000) that time-lapse sequences can be constructed for each continent. To my knowledge, this approach has only been applied to the Australian zircon record [2]. The results are quite clear (Figure 1; circles are positions of peaks (x-axis) in detrital zircon U-Pb age spectra in different age sediments (y-axis), size of circle is proportional to the height of the peak). There are no major zircon U-Pb age peaks in the ranges 2.2-2.4 Ga and 1.3-1.6 Ga in any sediment of any age on any continent. While some crust was produced at these times, there is no evidence in the zircon record that substantial amounts of crust of these ages ever existed, suggesting that the troughs in the age spectra are due to substantial decreases in (though not cessation of) crustal production. In contrast, U-Pb age peaks between 2.5 and 2.7 Ga appear in sediments immediately after these times and persist in subsequent sedimentary records. The peak heights decrease steadily through time, indicating that crustal destruction is a significant process in modifying the zircon record, but is not responsible for producing the peaks. The same pattern is seen for age peaks at 1.6-2.1 and 1.0-1.3 Ga. Comparing the time-lapse results with Hf

  18. Time-Lapsed Animation of a Mercury Day

    NASA Video Gallery

    Parts of Prokofiev crater (center) and Kandinsky crater (upper left side of Prokofiev) stay in darkness, making it possible for ice to persist on the surface. This time-lapsed animation represents ...

  19. Atlantis Time-Lapse Move to KSC Visitor Complex

    NASA Video Gallery

    Time-lapse cameras captured space shuttle Atlantis making a 10-mile trek from the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to the Kennedy Space Center Visitor Complex whe...

  20. NEA Scout Solar Sail: Half-scale Fold Time Lapse

    NASA Video Gallery

    In this time lapse, the Near-Earth Asteroid Scout (NEA Scout) CubeSat team rolls a half-scale prototype of the small satellite's solar sail in preparation for a deployment test. During its mission,...

  1. 77 FR 38396 - Agency Information Collection (Notice of Lapse-Government Life Insurance) Activities Under OMB...

    Federal Register 2010, 2011, 2012, 2013, 2014

    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...

  2. Temperature lapse rate as an adjunct to wind shear detection

    NASA Technical Reports Server (NTRS)

    Zweifil, Terry

    1991-01-01

    Several meteorological parameters were examined to determine if measurable atmospheric conditions can improve windshear detection devices. Lapse rate, the temperature change with altitude, shows promise as being an important parameter in the prediction of severe wind shears. It is easily measured from existing aircraft instrumentation, and it can be important indicator of convective activity including thunderstorms and microbursts. The meteorological theory behind lapse rate measurement is briefly reviewed, and and FAA certified system is described that is currently implemented in the Honeywell Wind Shear Detection and Guidance System.

  3. Negative Affect and Smoking Lapses: A Prospective Analysis

    ERIC Educational Resources Information Center

    Shiffman, Saul; Waters, Andrew J.

    2004-01-01

    Relapse is a central problem in smoking treatment. Data collected at the time of relapse episodes indicate that stress and negative affect (NA) promote relapse, but retrospective data are potentially biased. The authors performed a prospective analysis of stress and NA prior to initial lapses in smokers (N = 215). Day-to-day changes in stress…

  4. Lessons from NAEYC Accreditation: Avoiding Lapses in Supervision that Place Children at Risk

    ERIC Educational Resources Information Center

    Young Children, 2010

    2010-01-01

    Lapses in supervision of children can happen in all types of programs, and even a momentary lapse can have disastrous consequences. When a lapse occurs that affects program quality and puts children at risk, it is critical to consider the nature of the incident and its lessons for future risk management. Between September 2006 and September 2009,…

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

    SciTech Connect

    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.

  6. Use and effectiveness of lapse prevention strategies among pregnant smokers.

    PubMed

    Naughton, Felix; McEwen, Andy; Sutton, Stephen

    2015-11-01

    Little is known about the use of lapse prevention strategies to help smokers manage situation-triggered urges to smoke. Pregnant smokers (N = 174) participating in an intervention trial reported use of cognitive-behavioural lapse prevention strategies and smoking abstinence (biochemically verified). Participants typically enacted few strategies. Distraction strategies were most commonly used. Total number of strategies used did not predict abstinence. However, using 'self-talk' (odds ratio (OR) = 3.44, 95% confidence interval = 1.14-10.40) or 'avoiding spending time with other smokers' (OR = 4.01, 95% confidence interval = 1.34-11.95) independently increased the odds of abstinence. The promotion of these and other under-utilised evidence-based strategies warrants further attention. PMID:24296735

  7. Surface-consistent matching filters for time-lapse processing

    NASA Astrophysics Data System (ADS)

    Al Mutlaq, Mahdi H.

    The problem of mismatch between repeated time-lapse seismic surveys remains a challenge, particularly for land acquisition. In this dissertation, we present a new algorithm, which is an extension of the surface-consistent model, and which minimizes the mismatch between surveys, hence improving repeatability. We introduce the concept of surface-consistent matching filters (SCMF) for processing time-lapse seismic data, where matching filters are convolutional filters that minimize the sum-squared error between two signals. Since in the Fourier domain, a matching filter is the spectral ratio of the two signals, we extend the well known surface-consistent hypothesis such that the data term is a trace-by-trace spectral ratio of two datasets instead of only one (i.e. surface-consistent deconvolution). To avoid unstable division of spectra, we compute the spectral ratios in the time domain by first designing trace-sequential, least-squares matching filters, then Fourier transforming them. A subsequent least-squares solution then factors the trace-sequential matching filters into four operators: two surface-consistent (source and receiver), and two subsurface-consistent (offset and midpoint). We apply the algorithm to two datasets: a synthetic time-lapse model and field data from a CO2 monitoring site in Northern Alberta. In addition, two common time-lapse processing schemes (independent processing and simultaneous processing) are compared. We present a modification of the simultaneous processing scheme as a direct result of applying the new SCMF algorithm. The results of applying the SCMF together with the new modified simultaneous processing flow reveal the potential benefit of the method, however some challenges remain, specifically in the presence of random noise.

  8. Time-lapse Raman imaging of osteoblast differentiation

    NASA Astrophysics Data System (ADS)

    Hashimoto, Aya; Yamaguchi, Yoshinori; Chiu, Liang-Da; Morimoto, Chiaki; Fujita, Katsumasa; Takedachi, Masahide; Kawata, Satoshi; Murakami, Shinya; Tamiya, Eiichi

    2015-07-01

    Osteoblastic mineralization occurs during the early stages of bone formation. During this mineralization, hydroxyapatite (HA), a major component of bone, is synthesized, generating hard tissue. Many of the mechanisms driving biomineralization remain unclear because the traditional biochemical assays used to investigate them are destructive techniques incompatible with viable cells. To determine the temporal changes in mineralization-related biomolecules at mineralization spots, we performed time-lapse Raman imaging of mouse osteoblasts at a subcellular resolution throughout the mineralization process. Raman imaging enabled us to analyze the dynamics of the related biomolecules at mineralization spots throughout the entire process of mineralization. Here, we stimulated KUSA-A1 cells to differentiate into osteoblasts and conducted time-lapse Raman imaging on them every 4 hours for 24 hours, beginning 5 days after the stimulation. The HA and cytochrome c Raman bands were used as markers for osteoblastic mineralization and apoptosis. From the Raman images successfully acquired throughout the mineralization process, we found that β-carotene acts as a biomarker that indicates the initiation of osteoblastic mineralization. A fluctuation of cytochrome c concentration, which indicates cell apoptosis, was also observed during mineralization. We expect time-lapse Raman imaging to help us to further elucidate osteoblastic mineralization mechanisms that have previously been unobservable.

  9. Time-lapse Raman imaging of osteoblast differentiation

    PubMed Central

    Hashimoto, Aya; Yamaguchi, Yoshinori; Chiu, Liang-da; Morimoto, Chiaki; Fujita, Katsumasa; Takedachi, Masahide; Kawata, Satoshi; Murakami, Shinya; Tamiya, Eiichi

    2015-01-01

    Osteoblastic mineralization occurs during the early stages of bone formation. During this mineralization, hydroxyapatite (HA), a major component of bone, is synthesized, generating hard tissue. Many of the mechanisms driving biomineralization remain unclear because the traditional biochemical assays used to investigate them are destructive techniques incompatible with viable cells. To determine the temporal changes in mineralization-related biomolecules at mineralization spots, we performed time-lapse Raman imaging of mouse osteoblasts at a subcellular resolution throughout the mineralization process. Raman imaging enabled us to analyze the dynamics of the related biomolecules at mineralization spots throughout the entire process of mineralization. Here, we stimulated KUSA-A1 cells to differentiate into osteoblasts and conducted time-lapse Raman imaging on them every 4 hours for 24 hours, beginning 5 days after the stimulation. The HA and cytochrome c Raman bands were used as markers for osteoblastic mineralization and apoptosis. From the Raman images successfully acquired throughout the mineralization process, we found that β-carotene acts as a biomarker that indicates the initiation of osteoblastic mineralization. A fluctuation of cytochrome c concentration, which indicates cell apoptosis, was also observed during mineralization. We expect time-lapse Raman imaging to help us to further elucidate osteoblastic mineralization mechanisms that have previously been unobservable. PMID:26211729

  10. Time-lapse Raman imaging of osteoblast differentiation.

    PubMed

    Hashimoto, Aya; Yamaguchi, Yoshinori; Chiu, Liang-da; Morimoto, Chiaki; Fujita, Katsumasa; Takedachi, Masahide; Kawata, Satoshi; Murakami, Shinya; Tamiya, Eiichi

    2015-01-01

    Osteoblastic mineralization occurs during the early stages of bone formation. During this mineralization, hydroxyapatite (HA), a major component of bone, is synthesized, generating hard tissue. Many of the mechanisms driving biomineralization remain unclear because the traditional biochemical assays used to investigate them are destructive techniques incompatible with viable cells. To determine the temporal changes in mineralization-related biomolecules at mineralization spots, we performed time-lapse Raman imaging of mouse osteoblasts at a subcellular resolution throughout the mineralization process. Raman imaging enabled us to analyze the dynamics of the related biomolecules at mineralization spots throughout the entire process of mineralization. Here, we stimulated KUSA-A1 cells to differentiate into osteoblasts and conducted time-lapse Raman imaging on them every 4 hours for 24 hours, beginning 5 days after the stimulation. The HA and cytochrome c Raman bands were used as markers for osteoblastic mineralization and apoptosis. From the Raman images successfully acquired throughout the mineralization process, we found that β-carotene acts as a biomarker that indicates the initiation of osteoblastic mineralization. A fluctuation of cytochrome c concentration, which indicates cell apoptosis, was also observed during mineralization. We expect time-lapse Raman imaging to help us to further elucidate osteoblastic mineralization mechanisms that have previously been unobservable. PMID:26211729

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

    NASA Astrophysics Data System (ADS)

    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.

  12. The Attention-Lapse and Motor Decoupling accounts of SART performance are not mutually exclusive.

    PubMed

    Seli, Paul

    2016-04-01

    There is an ongoing debate about the mechanisms purported to underlie performance in the Sustained-Attention-to-Response Task (SART). Whereas the Attention-Lapse account posits that SART errors result from attentional disengagement, the Motor Decoupling account proposes that SART errors result from failures to inhibit a fast, prepotent motor response, despite adequate attention to the task. That SART performance might be fully accounted for by motor decoupling is problematic for a Attention-Lapse account, and for the use of the SART as an index of attention lapses. To test whether SART performance is in fact fully accounted for by motor decoupling, I examined the relation between SART performance and attention lapses while controlling for motor decoupling. The results were clear: The SART was associated with attention lapses independently of motor decoupling. Thus, the present study suggests that both accounts are correct and that the SART is a valid measure of attention lapses. PMID:26946296

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

    PubMed

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  15. Repeatability observations from a time-lapse seismic survey

    USGS Publications Warehouse

    Walters, S.L.; Miller, R.D.; Raef, A.E.

    2006-01-01

    Time-lapse seismic surveys have proven extremely valuable in recent years, having numerous economical and environmental applications. To fully utilize this monitoring technique, problems associated with recording repeatability must be minimized. Much work has been done to equalize data from one survey to the next via processing techniques (Huang et al., 1998). The purpose of this study is to investigate the potential for minimized processing, allowing study of extremely small changes in subsurface characteristics. The goal is to evaluate source and receiver terrain combination to optimize signal repeatability, and to improve deconvolution with the ground force to suppress different types of noise and increase repeatability. ?? 2005 Society of Exploration Geophysicists.

  16. Debye decomposition of time-lapse spectral induced polarisation data

    NASA Astrophysics Data System (ADS)

    Weigand, M.; Kemna, A.

    2016-01-01

    Spectral induced polarisation (SIP) measurements capture the low-frequency electrical properties of soils and rocks and provide a non-invasive means to access lithological, hydrogeological, and geochemical properties of the subsurface. The Debye decomposition (DD) approach is now increasingly being used to analyse SIP signatures in terms of relaxation time distributions due to its flexibility regarding the shape of the spectra. Imaging and time-lapse (monitoring) SIP measurements, capturing SIP variations in space and time, respectively, are now more and more conducted and lead to a drastic increase in the number of spectra considered, which prompts the need for robust and reliable DD tools to extract quantitative parameters from such data. We here present an implementation of the DD method for the analysis of a series of SIP data sets which are expected to only smoothly change in terms of spectral behaviour, such as encountered in many time-lapse applications where measurement geometry does not change. The routine is based on a non-linear least-squares inversion scheme with smoothness constraints on the spectral variation and in addition from one spectrum of the series to the next to deal with the inherent ill-posedness and non-uniqueness of the problem. By means of synthetic examples with typical SIP characteristics we elucidate the influence of the number and range of considered relaxation times on the inversion results. The source code of the presented routines is provided under an open source licence as a basis for further applications and developments.

  17. Temperature lapse rate and methane in Titan's troposphere.

    PubMed

    McKay, C P; Chau Martin, S; Griffith, C A; Keller, R M

    1997-10-01

    We have reanalyzed the Voyager radio occultation data for Titan, examining two alternative approaches to methane condensation. In one approach, methane condensation is facilitated by the presence of nitrogen because nitrogen lowers the condensation level of a methane/nitrogen mixture. The resulting enhancement in methane condensation lowers the upper limit on surface relative humidity of methane obtained from the Voyager occultation data from 0.7 to 0.6. We conclude that in this case the surface relative humidity of methane lies between 0.08 and 0.6, with values close to 0.6 indicated. In the other approach, methane is allowed to become supersaturated and reaches 1.4 times saturation in the troposphere. In this case, surface humidities up to 100% are allowed by the Voyager occultation data, and thus the upper limit must be set by other considerations. We conclude that if supersaturation is included, then the surface relative humidity of methane can be any value greater than 0.08--unless a deep ocean is present, in which case the surface relative humidity is limited to less than 0.85. Again, values close to 0.6 are indicated. Overall, the tropospheric lapse rate on Titan appears to be determined by radiative equilibrium. The lapse rate is everywhere stable against dry convection, but is unstable to moist convection. This finding is consistent with a supersaturated atmosphere in which condensation-and hence moist convection-is inhibited. PMID:11541736

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

    PubMed Central

    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 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

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

    PubMed

    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

  20. Time-lapse analysis of gravitropism in Ceratodon protonemata.

    PubMed

    Young, J C; Sack, F D

    1992-12-01

    The tip cell of the protonema of the moss Ceratodon purpureus (Hedw.) Brid. is negatively gravitropic when grown in the dark on supplemented agar. Gravitropism, plastid distribution, and plastid movement were studied in living cells using time-lapse video microscopy and infrared light. A wrong-way (downward) curvature preceded upward curvature and was detected as early as 2 minutes after reorientation. Upward curvature began 30-45 minutes after reorientation to the horizontal. Cell division temporarily reversed upward curvature, but did not inhibit wrong-way curvature. Since significant amyloplast sedimentation always occurred before the start of upward curvature, it is possible that these amyloplasts function as statoliths for upward curvature. However, no significant amyloplast sedimentation occurred before wrong-way curvature. Thus, this early phase of gravitropism cannot require plastid sedimentation for gravity sensing. Most plastids moved within and between zones, and plastid zonation was highly dynamic. Plastids moved toward the apex and toward the base of the cell at rates much slower than cytoplasmic streaming. Despite the dynamic nature of plastid movement and zonation, during upward curvature the distance between sedimented plastids and the apex stayed constant. Time-lapse analysis has revealed intriguing events not readily seen previously using destructive sampling. PMID:11537671

  1. Time-lapse analysis of gravitropism in Ceratodon protonemata

    NASA Technical Reports Server (NTRS)

    Young, J. C.; Sack, F. D.

    1992-01-01

    The tip cell of the protonema of the moss Ceratodon purpureus (Hedw.) Brid. is negatively gravitropic when grown in the dark on supplemented agar. Gravitropism, plastid distribution, and plastid movement were studied in living cells using time-lapse video microscopy and infrared light. A wrong-way (downward) curvature preceded upward curvature and was detected as early as 2 minutes after reorientation. Upward curvature began 30-45 minutes after reorientation to the horizontal. Cell division temporarily reversed upward curvature, but did not inhibit wrong-way curvature. Since significant amyloplast sedimentation always occurred before the start of upward curvature, it is possible that these amyloplasts function as statoliths for upward curvature. However, no significant amyloplast sedimentation occurred before wrong-way curvature. Thus, this early phase of gravitropism cannot require plastid sedimentation for gravity sensing. Most plastids moved within and between zones, and plastid zonation was highly dynamic. Plastids moved toward the apex and toward the base of the cell at rates much slower than cytoplasmic streaming. Despite the dynamic nature of plastid movement and zonation, during upward curvature the distance between sedimented plastids and the apex stayed constant. Time-lapse analysis has revealed intriguing events not readily seen previously using destructive sampling.

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

    ERIC Educational Resources Information Center

    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…

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

    PubMed Central

    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

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

    ERIC Educational Resources Information Center

    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…

  5. Relations among affect, abstinence motivation and confidence, and daily smoking lapse risk.

    PubMed

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

    2014-06-01

    This study tested the hypothesis that changes in momentary affect, abstinence motivation, and confidence would predict lapse risk over the next 12-24 hr using Ecological Momentary Assessment (EMA) data from smokers attempting to quit smoking. One hundred and three 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 postquit. 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, hr 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 although momentary changes in confidence did not predict lapse risk over 12 hr. 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

  6. The Development of an Aftermath of Dietary Lapses Coping Questionnaire for Weight Control

    ERIC Educational Resources Information Center

    Shimpo, Misa; Akamatsu, Rie

    2015-01-01

    Objective: This study was designed to develop the Aftermath of Dietary Lapses Coping Questionnaire (ADLCQ) for evaluating how people cope with the aftermath of dietary lapses during weight control. Method: Between June-July 2012, dieticians working in public health centres and city offices in Sizuoka, Japan, recruited 466 participants. They were…

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

    SciTech Connect

    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.

  8. Time-lapse video sysem used to study nesting gyrfalcons

    USGS Publications Warehouse

    Booms, Travis; Fuller, Mark R.

    2003-01-01

    We used solar-powered time-lapse video photography to document nesting Gyrfalcon (Falco rusticolus) food habits in central West Greenland from May to July in 2000 and 2001. We collected 2677.25 h of videotape from three nests, representing 94, 87, and 49% of the nestling period at each nest. The video recorded 921 deliveries of 832 prey items. We placed 95% of the items into prey categories. The image quality was good but did not reveal enough detail to identify most passerines to species. We found no evidence that Gyrfalcons were negatively affected by the video system after the initial camera set-up. The video system experienced some mechanical problems but proved reliable. The system likely can be used to effectively document the food habits and nesting behavior of other birds, especially those delivering large prey to a nest or other frequently used site.

  9. Dust Storm Time Lapse Shows Opportunity's Skies Darken

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Dust Storm Time Lapse Shows Opportunity's Skies Darken

    NASA's Opportunity rover is literally seeing some of its darkest days. Both Mars Exploration Rovers have been riding out a regional dust storm for several weeks. Conditions became particularly dreary in the Meridiani Planum region where Opportunity sits, perched on the edge of 'Victoria Crater.'

    This image is a time-lapse composite where each horizon-survey image has been compressed horizontally (but not vertically) to emphasize the sky. The relative brightness and darkness of the sky from sol to sol (over a 30-sol period beginning June 14, 2007) is depicted accurately in these images, which view roughly the same part of the plains southwest of the rover. The images are approximately true color composites, generated from calibrated radiance data files using the panoramic camera's 601-nanometer, 535-nanometer and 482-nanometer filters.

    The rovers' atmospheric science team is concerned that smaller, regional dust storms could expand into a larger, globe-encircling storm. That could extend the time the sun stays obscured, challenging the capability of Opportunity's solar panels to produce enough electricity for the rover to function.

    Fortunately, as of July 19, 2007, the Opportunity site is clearing slightly. When the storm ends, atmospheric scientists hope to review data from the rovers that will help them determine what sort of dust was being lifted and distributed.

    The numbers across the top of the image report a measurement of atmospheric opacity, called by the Greek letter tau. The lower the number, the clearer the sky. Both Opportunity and Spirit have been recording higher tau measurements in July 2007 than they had seen any time previously in their three and a half years on Mars. The five sol numbers across the bottom correspond (left to right) to June 14, June 30, July 5, July 13 and July 15, 2007.

  10. Cross-sectional and longitudinal analyses of everyday memory lapses in older adults.

    PubMed

    McAlister, Courtney; Schmitter-Edgecombe, Maureen

    2016-09-01

    Everyday memory lapses experienced by older adults (OAs) were examined using a daily-diary checklist and retrospective questionnaire. In Experiment 1, 138 younger and 138 OAs indicated the frequency of forgetting of 16 memory lapses, and whether each occurred daily during the course of a week. OAs reported more memory lapses on the questionnaire, but not the daily diary. OAs reported more frequently forgetting names and words, while younger adults had more difficulty with appointments and personal dates. Fewer memory lapses on the daily diary were related to better performance on a laboratory-memory measure for OAs. In Experiment 2, 62 OAs returned for a five-year follow-up and endorsed experiencing more memory lapses on the daily diary compared to baseline, specifically forgetting more names and words, but not the retrospective questionnaire. Daily checklist memory lapses again correlated with the laboratory-memory measure. A daily checklist may be a viable way to assess everyday memory lapses. PMID:26810777

  11. Biomarkers identified with time-lapse imaging: discovery, validation, and practical application

    PubMed Central

    Chen, Alice A.; Tan, Lei; Suraj, Vaishali; Pera, Renee Reijo; Shen, Shehua

    2014-01-01

    “Time-lapse markers,” which are defined by time-lapse imaging and correlated with clinical outcomes, may provide embryologists with new opportunities for improving embryo selection. This article provides an overview of noninvasive biomarkers defined by time-lapse imaging studies. In addition to comprehensively reviewing the discovery of each time-lapse marker, it focuses on the criteria necessary for their successful integration into clinical practice, including [1] statistical and biological significance, [2] validation through prospective clinical studies, and [3] development of reliable technology to measure and quantify the time-lapse marker. Because manual analysis of time-lapse images is labor intensive and limits the practical use of the image data in the clinic, automated image analysis software platforms may contribute substantially to improvements in embryo selection accuracy. Ultimately, time-lapse markers that are based on a foundation of basic research, validated through prospective clinical studies, and enabled by a reliable quantification technology may improve IVF success rates, encourage broader adoption of single-embryo transfer, and reduce the risks associated with multiple gestation pregnancies. PMID:23499001

  12. Work Predictors of Lapse in Patients under Treatment of Methadone Maintenance Therapy

    PubMed Central

    Mehrdad, Ramin; Zarbafi, Benafsheh; Pouryaghoub, Gholamreza; Saraeei, Maryam

    2015-01-01

    Background: Addiction to narcotics ‎can cause serious problems and ‎monetary losses. Therapeutic ‎success can be predicted ‎through identifying lapse risk ‎factors.‎ Objective: Determining Job Risk ‎Factor of Lapse.‎ Methods: This was a cross ‎sectional study on 351 addicts ‎visiting five methadone clinics. A ‎Data collection sheet consisting ‎of questions on demographic ‎and job information was filled up ‎through direct interviews. ‎Information relating to lapse in ‎the first month was analyzed.‎ Results: The mean (SD) age of ‎the participants was 40(12) ‎years; of them, 74% were ‎employed, of whom 34% had ‎lapsed. A relationship was ‎noticed between education ‎qualification (secondary school ‎compared with higher and lower ‎education) and lapse (p = .04), ‎and also between type of drug ‎abuse (amphetamine) and lapse ‎‎(p = .001).‎ Conclusion: ‎ ‏ ‏‎ Lapse was more ‎dependent on type of drug abused, ‎and employment had a protective role, ‎with no correlation with the type of ‎job and other job conditions. Non-‎work factors mediated/suppressed the ‎role of occupational conditions.‎ PMID:27006672

  13. Biomarkers identified with time-lapse imaging: discovery, validation, and practical application.

    PubMed

    Chen, Alice A; Tan, Lei; Suraj, Vaishali; Reijo Pera, Renee; Shen, Shehua

    2013-03-15

    "Time-lapse markers," which are defined by time-lapse imaging and correlated with clinical outcomes, may provide embryologists with new opportunities for improving embryo selection. This article provides an overview of noninvasive biomarkers defined by time-lapse imaging studies. In addition to comprehensively reviewing the discovery of each time-lapse marker, it focuses on the criteria necessary for their successful integration into clinical practice, including [1] statistical and biological significance, [2] validation through prospective clinical studies, and [3] development of reliable technology to measure and quantify the time-lapse marker. Because manual analysis of time-lapse images is labor intensive and limits the practical use of the image data in the clinic, automated image analysis software platforms may contribute substantially to improvements in embryo selection accuracy. Ultimately, time-lapse markers that are based on a foundation of basic research, validated through prospective clinical studies, and enabled by a reliable quantification technology may improve IVF success rates, encourage broader adoption of single-embryo transfer, and reduce the risks associated with multiple gestation pregnancies. PMID:23499001

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

    PubMed

    Verster, Joris C; Roth, Thomas

    2014-10-01

    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 18 adult ADHD patients performed a 100-km on-road driving test and were instructed to drive with a steady lateral position and constant speed. The SD of lateral position (SDLP), that is, the weaving of the car, lapses, and alertness, was assessed.Driving was significantly better (P = 0.006) with methylphenidate (SDLP, 18.8 cm) when compared with placebo (SDLP, 21.2 cm). Both the reduction in SDLP and the number of lapses (P = 0.003) confirm this significant improvement, which is further supported by subjective assessments of perceived driving performance. Although lapses were common in the placebo condition (11/18 patients), they were much less frequently observed (5/18 patients) after treatment with methylphenidate. Postdriving assessments suggest that lapses often go unnoticed by drivers.In conclusion, methylphenidate significantly improves driving of patients with ADHD by significantly reducing the number of lapses. PMID:24978156

  15. Relative influence of lapse rate and water vapor on the greenhouse effect

    SciTech Connect

    Sinha, A.

    1995-03-01

    Observational data are employed in a radiative transfer model to simulate the mean variation in normalized greenhouse effect (NGE) between January and July. This is performed at a variety of locations, and the mean local rate of change in NGE with surface temperature is determined. The result is 1.5 times larger than the variation of NGE with surface temperature obtained by spatially correlating the aggregated data. This disagreement is ascribed to systematic differences between the two approaches and is interpreted as indicating the significant role that large-scale circulations as well as surface temperatures have on determining local thermal and humidity structures. The separate effects of water vapor and lapse rate variations are estimated, by simulating the January-July changes in NGE with each process in turn held constant: beyond the tropics the lapse rate feedback is found to dominate over the water vapor feedback, particularly over land; in the inter-tropics, lapse rate variations account for about a third of the change in greenhouse trapping, contributing substantially to the `super-greenhouse effect.` Utilizing a radiative-convective model, the possible effects on climate change of both lapse rate changes and water vapor feedback are compared: a global mean model cliamte is perturbed by a doubling of atmospheric carbon dioxide and equilibrium surface temperatures obtained for a variety of lapse rates. If, under conditions of climate change, the global mean lapse rate varies with surface temperature in the same manner as in the present-day mean seasonal cycle (increasing the lapse rate magnitude by 6%), then the lapse rate feedback amplifies the modeled water vapor feedback by 40%; conversely, a 12% reduction in the magnitude of the lapse rate completely nullifies the water vapor feedback.

  16. Observation of infiltration experiments with time lapse electrical resistivity tomography

    NASA Astrophysics Data System (ADS)

    Noell, Ursula; Ganz, Christina; Altfelder, Sven; Günther, Thomas; Duijnisveld, Wilhelmus; Grissemann, Christoph

    2010-05-01

    Recent progress in the development of resistivity equipment enables the real time observation of infiltration processes through the vadose zone. In order to study the advantages and limitations of the method infiltration experiments are carried out for different soil types at various locations. All sites are subsequently excavated and investigated in detail. For an improved verification of the resistivity data the most recent experiment is conducted using a colour tracer. Two infiltration experiments are carried out in sandy soil. The location is Fuhrberg, close to Hannover, Germany. The area has been intensively studied for soil research purposes for more than 30 years. During both infiltration experiments water (110 l/80 l) is infiltrated for a period of 4.5 h and 8 h, respectively, and the infiltration process is observed by ERT. The resistivity measurements are conducted using a 3D-dipole-dipole configuration with electrode distances of 20 cm in the centre of the infiltration field. The whole resistivity array consists of 200 and 300 electrodes, respectively. The second experiment uses increased electrode spacing in the border area in order to enable the resolution of the deeper groundwater table (3.5 m during the second experiment compared to about 1.2 m for the first experiment). Immediately after completion of the resistivity measurements TDR and tensiometer measurements are carried out in 5-8 slices of the excavated infiltration area over a period of several days. The colour tracer used during the second experiment clearly outlines the infiltration plume with sharp outer limits. The ERT inversion depicts the shape of the plume successfully. Time lapse ERT interpretation reveals the development of the plume in time. The combination of ERT interpretation and TDR measurements enables the construction of the relationship between water content and resistivity as reconstructed by ERT using an Archie approach. By using this function water content changes can be

  17. Use of time-lapse video recording for the direct measurement of behavior in the mentally retarded.

    PubMed

    Linscheid, T R; Feiner, J; Sostek, A M

    1984-01-01

    In the present paper behaviors of mentally retarded children were recorded simultaneously on real time and time lapse video recorders. Behaviors on the time lapse recordings occurred at a rate 12 times faster than they actually occurred in real time resulting in a 92 percent reduction in the time required to score the tapes. Reliability estimates from real time and time lapse records were high and correspondence between the two methods was good. The limitations of time lapse and the feasibilities for the extended use of time lapse video recorders in behavioral and ecobehavioral assessment of mentally retarded individuals are discussed. PMID:6595965

  18. Time lapse gravity monitoring at Coso geothermal field

    NASA Astrophysics Data System (ADS)

    Woolf, Rachel Vest

    An extensive time lapse gravity data set was acquired over the Coso geothermal field near Ridgecrest, California starting in 1987, with the latest data set acquired in 2013. In this thesis I use these gravity data to obtain a better understanding of mass changes occurring within the geothermal field. Geothermal energy is produced by flashing naturally heated ground water into steam which is used to turn turbines. Brine and re-condensed steam are then re-injected into the reservoir. A percentage of the water removed from the system is lost to the process. The time lapse gravity method consists of gravity measurements taken at the same locations over time, capturing snap shots of the changing field. After careful processing, the final data are differenced to extract the change in gravity over time. This change in gravity can then be inverted to recover the change in density and therefore mass over time. The inversion process also produces information on the three dimensional locations of these mass changes. Thirty five gravity data sets were processed and a subsection were inverted with two different starting times, a sixteen point data set collected continuously between 1991 and 2005, and a thirty-eight point data set collected between 1996 and 2005. The maximum change in gravity in the 1991 data group was -350 microGal observed near station CSE2. For the 1996 data group the maximum gravity change observed over the nine year period was -248 microGal. The gravity data were then inverted using the surface inversion method. Three values of density contrast were used, -0.05 g/cm3, -0.10 g/cm3, and -0.20 g/cm3. The starting surface in 1991 was set to 2,500 ft above sea level. The changes in surfaces were then converted to mass changes. The largest total mass change recovered was -1.39x1011 kg. This mass value is of the same order of magnitude as published well production data for the field. Additionally, the gravity data produces a better understanding of the spatial

  19. Time-lapse ratios of cone excitations in natural scenes.

    PubMed

    Foster, David H; Amano, Kinjiro; Nascimento, Sérgio M C

    2016-03-01

    The illumination in natural environments varies through the day. Stable inferences about surface color might be supported by spatial ratios of cone excitations from the reflected light, but their invariance has been quantified only for global changes in illuminant spectrum. The aim here was to test their invariance under natural changes in both illumination spectrum and geometry, especially in the distribution of shadows. Time-lapse hyperspectral radiance images were acquired from five outdoor vegetated and nonvegetated scenes. From each scene, 10,000 pairs of points were sampled randomly and ratios measured across time. Mean relative deviations in ratios were generally large, but when sampling was limited to short distances or moderate time intervals, they fell below the level for detecting violations in ratio invariance. When illumination changes with uneven geometry were excluded, they fell further, to levels obtained with global changes in illuminant spectrum alone. Within sampling constraints, ratios of cone excitations, and also of opponent-color combinations, provide an approximately invariant signal for stable surface-color inferences, despite spectral and geometric variations in scene illumination. PMID:25847405

  20. Terahertz time-lapse imaging of hydration in physiological tissues

    NASA Astrophysics Data System (ADS)

    Bennett, David B.; Taylor, Zachary D.; Bajwa, Neha; Tewari, Priyamvada; Maccabi, Ashkan; Sung, Shijun; Singh, Rahul S.; Culjat, Martin O.; Grundfest, Warren S.; Brown, Elliott R.

    2011-02-01

    This study describes terahertz (THz) imaging of hydration changes in physiological tissues with high water concentration sensitivity. A fast-scanning, pulsed THz imaging system (centered at 525 GHz; 125 GHz bandwidth) was utilized to acquire a 35 mm x 35 mm field-of-view with 0.5 mm x 0.5 mm pixels in less than two minutes. THz time-lapsed images were taken on three sample systems: (1) a simple binary system of water evaporating from a polypropylene towel, (2) the accumulation of fluid at the site of a sulfuric acid burn on ex vivo porcine skin, and (3) the evaporative dehydration of an ex vivo porcine cornea. The diffusion-regulating behavior of corneal tissue is elucidated, and the correlation of THz reflectivity with tissue hydration is measured using THz spectroscopy on four ex vivo corneas. We conclude that THz imaging can discern small differences in the distribution of water in physiological tissues and is a good candidate for burn and corneal imaging.

  1. Patenting time-lapse microscopy: the European story.

    PubMed

    Sterckx, Sigrid; Cockbain, Julian; Pennings, Guido

    2014-02-01

    European Patent No. 2430454 of Stanford University is open to opposition before the European Patent Office if such opposition is filed by 23 October 2013. This is the European equivalent of the US Patent that raised such controversy in this journal in August 2013 as being a patent on time. The European Patent, which is directed to a method of selecting embryos for implantation using the results of time-lapse microscopy, should, in the present authors' opinion, be revoked as being directed to a method of medical diagnosis, which is unpatentable under European patent law. The only party currently opposing Stanford's patent is a competitor, Unisense FertiliTech A/S which is itself seeking to patent similar methods in Europe; the objection that Stanford has patented a method of diagnosis has not been raised by Unisense FertiliTech. We submit that Stanford's patent should be opposed to safeguard competition and to protect the freedom to operate of clinicians. In this paper we explain how Stanford's patent should fail under European law. PMID:24369922

  2. Time-lapse Geophysical Data from a Stressed Environment

    NASA Astrophysics Data System (ADS)

    Milkereit, B.; Tibbo, M.; Kassam, A.; Carey, A.; Schmitt, D. R.; Mohammed, T. E.; Malehmir, R.; Guo, K.

    2015-12-01

    A complication in geophysical monitoring of deep mines is the high-stress dependency of the physical properties of hard rocks. This project is part of a comprehensive, exploration geophysical study in a deep, highly stressed mine located in Sudbury, Ontario, Canada. Data from in situ monitoring of the mining induced seismicity, conductivity, and stress dependent physical properties have been obtained from two boreholes located in this mine. These borehole are approximately 400 m long with NQ diameters and depths of about 1300 - 1600 m and 1700 - 2000 m. Two borehole logging surveys were performed on both boreholes, October 2013 and July 2015, in order to perform a time-lapse analysis of the geophysical changes in the mine. These multi-parameter surveys include caliper, full waveform sonic, televiewer, chargeability (IP), and resistivity. Multi-electrode array DC/IP borehole and borehole-to-borehole surveys were also conducted in 2014, showing an increase in resistivity only in the 1300 m borehole near the active mining area, possibly due to stress induced closing of fractures. There is only exploration activity near the 1700 m borehole over this time period, and it therefore shows no changes in resistivity. Laboratory experiments have been performed on borehole core samples from each borehole. These experiments have measured the geophysical properties including elastic modulus, bulk modulus, P- and S-wave velocities, and density.

  3. Twelve tips for addressing medical student and resident physician lapses in professionalism.

    PubMed

    Rougas, Steven; Gentilesco, Bethany; Green, Emily; Flores, Libertad

    2015-01-01

    Medical educators have gained significant ground in the practical and scholarly approach to professionalism. When a lapse occurs, thoughtful remediation to address the underlying issue can have a positive impact on medical students and resident physicians, while failure to address lapses, or to do so ineffectively, can have long-term consequences for learners and potentially patients. Despite these high stakes, educators are often hesitant to address lapses in professionalism, possibly due to a lack of time and familiarity with the process. Attention must be paid to generalizable, hands-on recommendations for daily use so that clinicians and administrators feel well equipped to tackle this often difficult yet valuable task. This article reviews the literature related to addressing unprofessional behavior among trainees in medicine and connects it to the shared experience of medical educators at one institution. The framework presented aims to provide practical guidance and empowerment for educators responsible for addressing medical student and resident physician lapses in professionalism. PMID:25665630

  4. Poor sleep quality as a risk factor for lapse following a cannabis quit attempt.

    PubMed

    Babson, Kimberly A; Boden, Matthew Tyler; Harris, Alex H; Stickle, Timothy R; Bonn-Miller, Marcel O

    2013-04-01

    Treatments for cannabis dependence are associated with high rates of lapse/relapse, underscoring the importance of identifying malleable risk factors that are associated with quit failure. Whereas research has demonstrated that poor sleep quality following cannabis discontinuation is related to subsequent use, there has yet to be an examination of whether poor sleep quality prior to a quit attempt results in a similar pattern of lapse. The present study addressed this gap by examining the role of pre-quit sleep quality on early lapse to cannabis use following a self-guided quit attempt, among 55 cannabis dependent military veterans. Results indicated that participants who experienced poor pre-quit sleep quality had greater risk for lapse within the first 2 days (out of 7) following their quit attempt. Findings are discussed in terms of improving treatments for individuals who report poor sleep quality prior to a cannabis quit attempt. PMID:23098380

  5. Time-Lapse of Backplane of the JWST Being Moved Into Clean Room

    NASA Video Gallery

    This is a time-lapse video of the center section of the 'pathfinder' backplane for NASA's James Webb Space Telescope being moved into the clean room at NASA's Goddard Space Flight Center in Greenbe...

  6. Orb-2's Antares Rolls Out to Launch Pad (Time-Lapse)

    NASA Video Gallery

    This time-lapse video shows the roll out of the Orbital Sciences Corporation Antares rocket, with the Cygnus spacecraft aboard, from the Horizontal Integration Facility to the Mid-Atlantic Regional...

  7. NASA HS3 Mission Time Lapse Highlights Cameras Over Tropical Systems

    NASA Video Gallery

    This is a time-lapse video created with images recorded during a recent HS3 Science Missions with the NASA Global Hawk. Shown are the images from the Daylight, HDVis, and the Low-light Cameras on t...

  8. Feasibility of time-lapse AVO and AVOA analysis to monitor compaction-induced seismic anisotropy

    NASA Astrophysics Data System (ADS)

    He, Y.-X.; Angus, D. A.; Yuan, S. Y.; Xu, Y. G.

    2015-11-01

    Hydrocarbon reservoir production generally results in observable time-lapse physical property changes, such as velocity increases within a compacting reservoir. However, the physical property changes that lead to velocity changes can be difficult to isolate uniquely. Thus, integrated hydro-mechanical simulation, stress-sensitive rock physics models and time-lapse seismic modelling workflows can be employed to study the influence of velocity changes and induced seismic anisotropy due to reservoir compaction. We study the influence of reservoir compaction and compartmentalization on time-lapse seismic signatures for reflection amplitude variation with offset (AVO) and azimuth (AVOA). Specifically, the time-lapse AVO and AVOA responses are predicted for two models: a laterally homogeneous four-layer dipping model and a laterally heterogeneous graben structure reservoir model. Seismic reflection coefficients for different offsets and azimuths are calculated for compressional (P-P) and converted shear (P-S) waves using an anisotropic ray tracer as well as using approximate equations for AVO and AVOA. The simulations help assess the feasibility of using time-lapse AVO and AVOA signatures to monitor reservoir compartmentalization as well as evaluate induced stress anisotropy due to changes in the effective stress field. The results of this study indicate that time-lapse AVO and AVOA analysis can be applied as a potential means for qualitatively and semi-quantitatively linking azimuthal anisotropy changes caused by reservoir production to pressure/stress changes.

  9. Estimation of atmospheric parameters from time-lapse imagery

    NASA Astrophysics Data System (ADS)

    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.

  10. Variability of the isotopic lapse rate across the mountain ranges in Wyoming

    NASA Astrophysics Data System (ADS)

    Brian, H.; Fan, M.

    2012-12-01

    Stable isotope based paleoaltimetry studies require knowledge of the isotope-elevation gradient during the time of interest, but this information is rarely available. As a result, many studies often apply the modern local lapse rate or a global average lapse rate and assume these values are valid for the area of interest and that they hold through time. However, natural variability in local-scale climate and mountain geometry and morphology can influence the isotope-elevation (and temperature-elevation) gradient. We evaluate the inter- and intra-mountain range variability of modern climate and isotope values of stream water for three Laramide ranges in Wyoming (Wind River Range, Bighorn and Laramie Mountains), as well as for a regional elevation transect across the central Rocky mountain front. Samples of steam water were taken from major catchments across Wyoming in 2007, 2011, and 2012. We find that the modern lapse rate for these ranges is -1.7‰/km, -2.2‰/km and -1.8‰/km respectively. Although these values are very similar to one another and to the global isotopic lapse rate (-2.1‰/km), large variation (up to 6‰/km) exists among individual small river catchments of the Bighorn Mountains. The variability in catchment-scale lapse rate does not appear to be systematically related to annual, or seasonal surface air temperature, precipitation amount, or catchment area. However, the range-scale lapse rates may yet reflect the regional climate, which is generally coolest and driest in the Wind River Range (lowest lapse rate) and warmest and wettest in the Bighorn Mountains (highest lapse rate). Similar d-excess values exist across individual mountain ranges, but inter-mountain range differences indicate that the Laramie Mountains (and regions of western Nebraska) receive evaporatively enriched rainwater compared to those in the Wind River Range and Bighorn Mountains. These differences do not necessarily require separate vapor sources as the lower d

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

    PubMed Central

    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

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

    PubMed

    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

  13. Acoustic startle and prepulse inhibition predict smoking lapse in posttraumatic stress disorder.

    PubMed

    Vrana, Scott R; Calhoun, Patrick S; Dennis, Michelle F; Kirby, Angela C; Beckham, Jean C

    2015-10-01

    Most smokers who attempt to quit lapse within the first week and are ultimately unsuccessful in their quit attempt. Nicotine withdrawal exacerbates cognitive and attentional problems and may be one factor in smoking relapse. The startle reflex response and prepulse inhibition (PPI) of the response are sensitive to arousal and early attentional dysregulation. The current study examined whether startle response and PPI are related to early smoking lapse, and if this differs in people with and without posttraumatic stress disorder (PTSD). Participants with (N = 34) and without (N = 57) PTSD completed a startle reflex and PPI assessment during (1) ad lib smoking (2) on the first day of abstinence during a quit attempt. Most (88%) participants lapsed within the first week of the quit attempt. PTSD status predicted shorter time to lapse. Larger startle magnitude and greater PPI predicted a longer duration before smoking lapse. When diagnostic groups were examined separately, greater PPI predicted a longer successful quit attempt only in participants with a PTSD diagnosis. The startle reflex response and PPI may provide an objective, neurophysiological evaluation of regulation of arousal and early attentional processes by nicotine, which are important factors in smoking cessation success. PMID:26253620

  14. Climatological characteristics of high altitude wind shear and lapse rate layers

    NASA Technical Reports Server (NTRS)

    Ehernberger, L. J.; Guttman, N. B.

    1981-01-01

    Indications of the climatological distribution of wind shear and temperature lapse and inversion rates as observed by rawinsonde measurements over the western United States are recorded. Frequencies of the strongest shear, lapse rates, and inversion layer strengths were observed for a 1 year period of record and were tabulated for the lower troposphere, the upper troposphere, and five altitude intervals in the lower stratosphere. Selected bivariate frequencies were also tabulated. Strong wind shears, lapse rates, and inversion are observed less frequently as altitude increases from 175 millibars to 20 millibars. On a seasonal basis the frequencies were higher in winter than in summer except for minor influences due to increased tropopause altitude in summer and the stratospheric wind reversal in the spring and fall.

  15. Dynamic self-efficacy and outcome expectancies: prediction of smoking lapse and relapse.

    PubMed

    Gwaltney, Chad J; Shiffman, Saul; Balabanis, Mark H; Paty, Jean A

    2005-11-01

    According to social learning models of drug relapse, decreases in abstinence self-efficacy (ASE) and increases in positive smoking outcome expectancies (POEs) should foreshadow lapses and relapse. In this study, the authors examined this hypothesis by using ecological momentary assessment data from 305 smokers who achieved initial abstinence from smoking and monitored their smoking and their ASE and POEs by using palmtop computers. Daily ASE and POEs predicted the occurrence of a 1st lapse on the following day. Following a lapse, variations in daily ASE predicted the onset of relapse, even after controlling for concurrent smoking. ASE and POEs generally neither mediated nor moderated each other's effects. These data emphasize the role of dynamic factors in the relapse process. PMID:16351387

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

    PubMed

    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. PMID:24692183

  17. Psychological symptoms, smoking lapse behavior, and the mediating effects of nicotine withdrawal symptoms: A laboratory study.

    PubMed

    Ameringer, Katherine J; Leventhal, Adam M

    2015-03-01

    The influence of psychological symptoms on smoking-lapse behavior is critical to understand. However, this relationship is obscured by comorbidity across multiple forms of psychological symptoms and their overlap with nicotine withdrawal. To address these challenges, we constructed a structural model of latent factors underlying 9 manifest scales of affective and behavioral symptoms and tested relations between latent factors and manifest scale residuals with nicotine withdrawal and smoking lapse in a laboratory analog task. Adult daily smokers (N = 286) completed a baseline session at which several forms of affective and behavioral symptoms were assessed and 2 experimental sessions (i.e., following 16 hr of smoking abstinence and following regular smoking), during which withdrawal symptoms and delay of smoking in exchange for monetary reinforcement, as an analogue for lapse propensity, were measured. A single second-order factor of general psychological maladjustment associated with more severe withdrawal-like symptoms, which in turn associated with shorter delay of smoking. The first-order factors, which tapped qualitatively unique domains of psychological symptoms (low positive affect, negative affect, disinhibition), and the manifest scale residuals provided little predictive power beyond the second-order factor with regard to lapse behavior. Relations among general psychological maladjustment, withdrawal-like symptoms, and lapse were significant in both abstinent and nonabstinent conditions, suggesting that psychological maladjustment, and not nicotine withdrawal per se, accounted for the relation with lapse. These results highlight the potential for smoking-cessation strategies that target general psychological maladjustment processes and have implications for addressing withdrawal-like symptoms among individuals with psychological symptoms. PMID:25243836

  18. Psychological Symptoms, Smoking Lapse Behavior, and the Mediating Effects of Nicotine Withdrawal Symptoms: A Laboratory Study

    PubMed Central

    Ameringer, Katherine J.; Leventhal, Adam M.

    2015-01-01

    The influence of psychological symptoms on smoking-lapse behavior is critical to understand. However, this relationship is obscured by comorbidity across multiple forms of psychological symptoms and their overlap with nicotine withdrawal. To address these challenges, we constructed a structural model of latent factors underlying 9 manifest scales of affective and behavioral symptoms and tested relations between latent factors and manifest scale residuals with nicotine withdrawal and smoking lapse in a laboratory analog task. Adult daily smokers (N = 286) completed a baseline session at which several forms of affective and behavioral symptoms were assessed and 2 experimental sessions (i.e., following 16 hr of smoking abstinence and following regular smoking), during which withdrawal symptoms and delay of smoking in exchange for monetary reinforcement, as an analogue for lapse propensity, were measured. A single second-order factor of general psychological maladjustment associated with more severe withdrawal-like symptoms, which in turn associated with shorter delay of smoking. The first-order factors, which tapped qualitatively unique domains of psychological symptoms (low positive affect, negative affect, disinhibition), and the manifest scale residuals provided little predictive power beyond the second-order factor with regard to lapse behavior. Relations among general psychological maladjustment, withdrawal-like symptoms, and lapse were significant in both abstinent and nonabstinent conditions, suggesting that psychological maladjustment, and not nicotine withdrawal per se, accounted for the relation with lapse. These results highlight the potential for smoking-cessation strategies that target general psychological maladjustment processes and have implications for addressing withdrawal-like symptoms among individuals with psychological symptoms. PMID:25243836

  19. Lapse time dependence of coda wave attenuation in Central West Turkey

    NASA Astrophysics Data System (ADS)

    Akyol, Nihal

    2015-09-01

    The attenuation of coda waves has been inferred for Central West Turkey, which is characterized by a very complex tectonic evolution. The selected dataset is composed of 440 waveforms from 228 local earthquakes with a magnitude range of 2.9-4.9. The coda quality factor (Qc) was estimated for five central frequencies (fc = 1.5, 3, 5, 7, 10 Hz) and eight lapse times (tL, ranging from 25 to 60 s), based on the assumption of single isotropic scattering model. Estimated Qc values were strongly dependent on frequency and lapse time. The frequency dependence of Qc values for each lapse time was inferred from Qc(f) = Q0fn relationships. Q0 values change between 32.7 and 82.1, while n values changes between 0.91 and 0.79 for the lapse times of 25 and 60 s, respectively. The obtained low Q0 values show that the Central West Turkey region is characterized by a high seismic attenuation, in general. The whole region was divided into four subregions to examine spatial differences of attenuation characteristics. Obtained 1/Q0 and n values versus the lapse time for each subregion implies the tectonic complexity of the region. Lapse time dependencies of attenuation and n values were also examined for subdatasets from two different ranges of event depth (h < 10 km and h ≥ 10 km) and distance (r < 40 km and r ≥ 40 km). High attenuation and its high frequency dependence for long distances manifest the elevation of isotherms and increasing heterogeneity with depth. This could be associated with the extensional intra-continental plate setting, forming regional tectonics in the back-arc area.

  20. Photographer : JPL Range : 1 million kilometers Voyager 2 completed a dramatic 10 hour time lapse

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Photographer : JPL Range : 1 million kilometers Voyager 2 completed a dramatic 10 hour time lapse photo sequence to monitor the active volcanos on Jupiter's moon Io following the spacecraft's closest approach to Jupiter. This picture is one of about 200 images that will be used to generate a time lapse motion picture to illustrate Io's volcanic activity. On the bright limb, two of the plumes (P-5 & P-6) discovered in March by Voyager 1 are again visible. The plumes are spewing materials to a height of about 100 kilometers.

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

    SciTech Connect

    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.

  2. Lapses in Sustained Attention and Their Relation to Executive Control and Fluid Abilities: An Individual Differences Investigation

    ERIC Educational Resources Information Center

    Unsworth, Nash; Redick, Thomas S.; Lakey, Chad E.; Young, Diana L.

    2010-01-01

    A latent variable analysis was conducted to examine the nature of individual differences in lapses of attention and their relation to executive and fluid abilities. Participants performed a sustained attention task along with multiple measures of executive control and fluid abilities. Lapses of attention were indexed based on the slowest reaction…

  3. MathLTWA: Multiple lapse time window analysis using Wolfram Mathematica 7

    NASA Astrophysics Data System (ADS)

    Del Pezzo, Edoardo; Bianco, Francesca

    2010-10-01

    The MATHCAD 2000 professional code to perform the Multiple Lapse Time Analysis (MLTWA) has been revised and rewritten in MATHEMATICA 7. The new code contains two new procedures to find the minimum of the misfit function between observation and model and a new example of application to real data from Chamoli earthquake aftershock sequence.

  4. Probabilistic 3-D time-lapse inversion of magnetotelluric data: application to an enhanced geothermal system

    NASA Astrophysics Data System (ADS)

    Rosas-Carbajal, M.; Linde, N.; Peacock, J.; Zyserman, F. I.; Kalscheuer, T.; Thiel, S.

    2015-12-01

    Surface-based monitoring of mass transfer caused by injections and extractions in deep boreholes is crucial to maximize oil, gas and geothermal production. Inductive electromagnetic methods, such as magnetotellurics, are appealing for these applications due to their large penetration depths and sensitivity to changes in fluid conductivity and fracture connectivity. In this work, we propose a 3-D Markov chain Monte Carlo inversion of time-lapse magnetotelluric data to image mass transfer following a saline fluid injection. The inversion estimates the posterior probability density function of the resulting plume, and thereby quantifies model uncertainty. To decrease computation times, we base the parametrization on a reduced Legendre moment decomposition of the plume. A synthetic test shows that our methodology is effective when the electrical resistivity structure prior to the injection is well known. The centre of mass and spread of the plume are well retrieved. We then apply our inversion strategy to an injection experiment in an enhanced geothermal system at Paralana, South Australia, and compare it to a 3-D deterministic time-lapse inversion. The latter retrieves resistivity changes that are more shallow than the actual injection interval, whereas the probabilistic inversion retrieves plumes that are located at the correct depths and oriented in a preferential north-south direction. To explain the time-lapse data, the inversion requires unrealistically large resistivity changes with respect to the base model. We suggest that this is partly explained by unaccounted subsurface heterogeneities in the base model from which time-lapse changes are inferred.

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

    NASA Astrophysics Data System (ADS)

    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.

  6. Estimating topsoil water content of clay soils with data from time-lapse electrical conductivity surveys

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spatial estimation of soil water content (') at the field, hillslope, or catchment scale is required in numerous applications. Time-lapse electrical resistivity and electrical conductivity surveys were recognized as the useful source of information about both spatial variations in soil water conten...

  7. A Typology of University Ethical Lapses: Types, Levels of Seriousness, and Originating Location

    ERIC Educational Resources Information Center

    Kelley, Patricia C.; Chang, Pepe Lee

    2007-01-01

    Scandals ranging from National Collegiate Athletic Association (NCAA) violations to falsified research results have fueled criticism of America's universities. Sports violations, research manipulation, gender discrimination, and other ethical lapses affect an entire institution as they have a spillover effect on its reputation. The results of…

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

    SciTech Connect

    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.

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

    USGS Publications Warehouse

    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.

  10. 77 FR 22069 - Proposed Information Collection (Notice of Lapse-Government Life Insurance); Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    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...'s estimate of the burden of the proposed collection of information; (3) ways to enhance the...

  11. Automated time-lapse microscopy and high-resolution tracking of cell migration

    SciTech Connect

    Fotos, Joseph S.; Vivek, Patel P.; Karin, Norm J.; Temburni, Murali; Koh, John T.; Galileo, Deni S.

    2006-08-09

    The study of cell motility is greatly enhanced by using a fully-automated high-throughput time-lapse microscopy system that is capable of collecting and analyzing data (1) from closely-spaced time points (seconds to minutes), (2) over long periods (hours to days), (3) from multiple areas of interest, (4) under several different experimental conditions simultaneously. Time-lapse video images collected under phase contrast and fluorescent illumination were analyzed using parameters of migration velocity, total accumulated distance (path length), and directionality for individual cells or for averaged cell populations. Quantitation of ''scratch'' or ''wound healing'' assays revealed unique motility dynamics of drug-treated and adhesion molecule-transfected cells with high resolution and, thus, is a vast distinct improvement of current methods. Several fluorescent vital labeling methods commonly used for end-point analyses, including GFP expression, were evaluated and most were useful for time-lapse studies under specific conditions. For example, fluorescently-labeled tumor cells were seeded onto cell monolayers expressing ectopic adhesion molecules displayed altered migration velocities compared to tumor cells plated directly onto culture dishes. The techniques described here revealed cell motility behavior not discernable by previously-used methods. We propose that quantitative time-lapse video analysis will foster the creation new cell motility assays, and increase the resolution and accuracy of existing assays.

  12. 78 FR 53011 - Agency Information Collection (Application for Reinstatement (Insurance Lapsed More Than 6 Months...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-27

    ... comment. The PRA submission describes the nature of the information collection and its expected cost and... (Insurance Lapsed More than 6 Months), Government Life Insurance and/or Total Disability Income Provision, VA... Life Insurance, VA Form 29-353. OMB Control Number: 2900-0011. Type of Review: Extension of a...

  13. Knowledge of Ethical Lapses and Other Experiences on Clinical Licensure Examinations.

    ERIC Educational Resources Information Center

    Feil, Philip; Meeske, Jessica; Fortman, Jared

    1999-01-01

    A survey of 429 general dentists attempted to verify anecdotal reports of ethical lapses in clinical dental licensing examinations. It found significant occurrence of not arranging followup care for the patient even though indicated, intentional creation of lesions, premature treatment for the purpose of the examinations, coercing patients into…

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

    PubMed Central

    Faramarzi, Azita; Khalili, Mohammad Ali; Soleimani, Mehrdad

    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 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. PMID:26131014

  15. Dynamic Association between Negative Affect and Alcohol Lapses following Alcohol Treatment

    ERIC Educational Resources Information Center

    Witkiewitz, Katie; Villarroel, Nadia Aracelliz

    2009-01-01

    Clinical research has found a strong association between negative affect and returning to alcohol use after a period of abstinence. Yet little is known about the probability of a lapse given a particular level of negative affect or whether there is a reciprocal relationship between negative affect and alcohol use across time. The goal of the…

  16. 2D Time-lapse Seismic Tomography Using An Active Time Constraint (ATC) Approach

    EPA Science Inventory

    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...

  17. 37 CFR 1.317 - Lapsed patents; delayed payment of balance of issue fee.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 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...

  18. 37 CFR 1.317 - Lapsed patents; delayed payment of balance of issue fee.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 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...

  19. 37 CFR 1.317 - Lapsed patents; delayed payment of balance of issue fee.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 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...

  20. 37 CFR 1.317 - Lapsed patents; delayed payment of balance of issue fee.

    Code of Federal Regulations, 2010 CFR

    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...

  1. Diurnal Wind Regimes and Lapse-Rate Variability Over Clean and Debris-Covered Ice

    NASA Astrophysics Data System (ADS)

    Flowers, G. E.; Young, E.

    2015-12-01

    Near-surface winds and air temperature play an important role in the surface energy balance of glaciers and ice sheets, and can be highly variable in space and time. The increasing fraction of debris-covered ice observed in many retreating alpine glacier environments motivates the study of these variables, and the processes that control them, over both clean and debris-covered ice. We use meteorological data collected in the ablation zone of a ~ 5km-long valley glacier in Yukon, Canada, to analyze the diurnal variability of temperature and wind regimes over debris-covered and debris-free ice. Our data reveal pronounced diurnal cycles in temperature lapse rates, wind speeds, and wind directions. Common to both clean and debris-covered areas are: (1) a shallowing of lapse rates in the early morning from 6:00 to 9:00 and a steepening of lapse rates during the day from 9:00 to 16:00, (2) nearly identical lapse rates regardless of surface type between 15:00 and 19:00, and (3) a persistent diurnal wind regime in which up-valley winds occur from late morning to evening, peaking at 16:00-17:00, and relatively weaker down-valley winds occur overnight. Significant differences between the clean-ice and debris-covered sites are also evident in the data, namely: (1) much steeper night-time lapse rates over debris-covered ice than clean ice, (2) the occurrence of steepest lapse rates overnight for debris-covered ice and in late afternoon (around 16:00) for clean ice, and (3) a more pronounced diurnal cycle in windspeed over debris-covered ice than clean ice, despite all stations exhibiting evidence of the diurnal changes in wind direction. The patterns described above conform to a model of weak katabatic flow at night and relatively stronger up-valley winds during the day, peaking in late afternoon. Though absolute temperatures over clean and debris-covered ice are markedly different during the day, lapse rates over both surfaces evolve similarly through the day to achieve steep

  2. Time-Lapse inversion of EM Tomography data for polymer-injected hydrocarbon reservoirs

    NASA Astrophysics Data System (ADS)

    Cheon, Seiwook; Park, Chanho; Nam, Myung Jin; Son, Jeong-Sul

    2015-04-01

    Polymer flooding is a method to increase the production of hydrocarbon reservoir by injecting polymer solution into the reservoir. For a study on the monitoring fluid variation within the reservoir, we first make analysis on seismic- and electromagnetic (EM)- tomography responses for seismic and electrical-resistivity rock physics models (RPMs) of the reservoir considering polymer fluid. Constructing RPMs are dependent on not only geologic characteristics of reservoir but also reservoir parameters such as fluid-type, fluid saturation, pressure and temperature. When making RPM for monitoring analysis, we assume the geology does not changes while reservoir parameters change to affect responses of seismic and EM tomography data. Specifically when constructing electrical-resistivity RPM, we consider three different types of hydrocarbon reservoirs, which are clean sand, shaly sand, sand-shale lamination, while considering two different types of waters (fresh water and salt water) to make 2wt% polymer solution. To compute time lapse EM and seismic tomography responses for corresponding RPMs of polymer-injected reservoirs, we used 2.5D finite element EM modeling algorithm and staggered-grid finite difference elastic modeling algorithm, respectively. Comparison between sensitivities of seismic and EM tomography to polymer injection confirms that EM tomography is more sensitivity to the polymer injection. For the evaluation of the potential of EM tomography to monitor polymer flooding, this study subsequently develops an efficient time-lapse EM tomography inversion algorithm based on the 2.5D EM tomography modeling. Using the inversion algorithm, we inverted the time-lapse EM tomography data to construct true resistivity models of polymer-injected reservoirs and analyze differences between them. From the time-lapse inversion results, we can observe the differences in time lapse responses between using fresh water and salt water have been decreased in the inverted time-lapse

  3. Time-lapse monitoring of localized changes within heterogeneous media with scattered waves

    NASA Astrophysics Data System (ADS)

    Chinaemerem, Kanu

    Time-lapse monitoring of geological and mechanical media has been the focus of various studies over the past four decades because of the information that the inferred changes within the medium provides insight into the dynamic characteristics of the medium. Time-lapse changes within a medium can be used to characterize the temporal evolution of the medium, evaluate the forces driving the changes within the medium and make predictions on the future state of the monitored medium. The detectability of the changes within a material depends on the characteristics of the change to be imaged, the sensitivity of the monitoring data to the change, and the time-lapse monitoring parameters such as the monitoring source-receiver array and the spectral content of the monitoring waves. Various time-lapse monitoring tools have been used to monitor changes within media ranging from the earth's surface to tumors within the human body. These monitoring tools include the use of 4D active surveys were an imprint of the change within the medium is extracted from the time-lapse surveys and the use of interferometric techniques that use singly or multiply scattered waves. My major goal in this study is to image and localize changes present within a scattering medium using time-lapse multiply scattered waves generated within the monitored medium. The changes to be imaged are generally localized in space. This work is an extension of coda wave interferometry. Coda wave interferometry focuses on the identification and extraction of average velocity change occurring within a scattering medium. Due to the non-linear characteristics of multiply scattered waves and limited information of the origin of the multiply scattered waves, coda wave interferometry resolves the average velocity change within the scattering medium with no or limited indication of the location of the change. In this study, I demonstrate that time-lapse changes can be imaged and localized within scattering media using

  4. Developing an EEG-based on-line closed-loop lapse detection and mitigation system

    PubMed Central

    Wang, Yu-Te; Huang, Kuan-Chih; Wei, Chun-Shu; Huang, Teng-Yi; Ko, Li-Wei; Lin, Chin-Teng; Cheng, Chung-Kuan; Jung, Tzyy-Ping

    2014-01-01

    In America, 60% 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-reality environment. When the subjects experienced lapses or failed to respond to events during the experiment, auditory warning 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 warning to subjects suffering momentary cognitive lapses, and assess the efficacy of the warning 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. PMID:25352773

  5. Formation of medical student professional identity: categorizing lapses of professionalism, and the learning environment

    PubMed Central

    2014-01-01

    Background Acquiring the values of medical professionalism has become a critical issue in medical education. The purpose of this study was to identify lapses in professionalism witnessed by medical students during their four year MD curriculum, and to categorize, from the students’ perspective, who was responsible and the settings in which these occurred. Methods An electronic survey, developed by faculty and medical students, was sent to all students with two email reminders. It included quantitative responses and some open-ended opportunities for comments. All analyses were performed with SAS version 9.1. Results The response rate was 45.6% (255 of 559 students) for all four years of the medical school curriculum. Thirty six percent of students had witnessed or been part of an exemplary demonstration of professionalism; 64% responded that they had witnessed a lapse of professionalism. At the pre-clerkship level, the most frequent lapses involved students: arrogance (42.2%), impairment (24.2%), followed by cultural or religious insensitivity (20.5%). At the clerkship level of training, where students are exposed to real clinical situations, the lapses involved primarily faculty (including preceptor and clinician) or other staff; these included arrogance (55.3%), breach of confidentiality (28.3%), and cultural or religious insensitivity (26.6%); impairment involved mostly students (25.5%). These findings are analyzed from the perspective of role modeling by faculty and in the context of the learning environment. Conclusions Medical students witnessed a lapse of professionalism involving both fellow students as well as faculty and administrative staff, in several domains. Results from this study emphasize the importance of role modeling and the need for faculty development, to improve the learning environment. This study adds to the limited emerging literature on the forces that influence medical student professional identity formation. PMID:25004924

  6. Developing an EEG-based on-line closed-loop lapse detection and mitigation system.

    PubMed

    Wang, Yu-Te; Huang, Kuan-Chih; Wei, Chun-Shu; Huang, Teng-Yi; Ko, Li-Wei; Lin, Chin-Teng; Cheng, Chung-Kuan; Jung, Tzyy-Ping

    2014-01-01

    In America, 60% 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-reality environment. When the subjects experienced lapses or failed to respond to events during the experiment, auditory warning 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 warning to subjects suffering momentary cognitive lapses, and assess the efficacy of the warning 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. PMID:25352773

  7. The influence of surface characteristics on lapse rates and temperature profiles in areas of complex terrain

    NASA Astrophysics Data System (ADS)

    Pepin, N. C.; Pike, G.; Fower, D.; Schaefer, M.

    2012-12-01

    Temperatures near the ground are often decoupled from free-air equivalents, particularly in areas of complex relief and at high latitudes where cold air drainage occurs particularly when radiation balances become negative. This means that it is hard to predict spatial patterns of surface temperature in such regions. In this study several years of intensive field measurements in complex terrain in northern Finland (Kevo) and Sweden (Abisko) allow detailed examination of the interaction between land surface characteristics (including cryosphere), vegetation, and local/micro-climate in mountain basins. Temperature and vapour pressure were measured every 30 minutes for 5 years (2007-2012) at 60 sites at Kevo and for a winter season (September-June) at 52 sites in Abisko, ranging over 300/600 metres of elevation respectively. In Finland lapse rates vary considerably both seasonally and diurnally, the relative importance of seasonal and diurnal forcing changing throughout the year. The results show intense (up to +80 °C/km) and persistent inversion events during the winter months (NDJ) which are broken up by mechanical effects since there is no diurnal cycle. In the transition from winter into spring (FMA) these inversions still occur but increasing radiation imposes a diurnal pattern on their formation and destruction. As snow cover peaks in spring the interaction between surface albedo, land cover and radiation serves to amplify the diurnal cycle in lapse rates. Daytime lapse rates peak in spring because of an increase in albedo with elevation as dark trees give way to reflective snow. At night inversions rapidly reform. Summer lapse rates are modified (usually weakened) by the presence of open water at low elevations. In Abisko similar processes are shown to be at work, although since the valley system is more open and at a larger spatial scale, the range of lapse rate variability is slightly less and the influence of surface characteristics more subdued. Taken

  8. Volumetric monitoring of aqueous two phase system droplets using time-lapse optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Lee, J.; Bathany, C.; Ahn, Y.; Takayama, S.; Jung, W.

    2016-02-01

    We present a volumetric monitoring method to observe the morphological changes of aqueous two phase system (ATPS) droplets in a microfluidic system. Our method is based on time-lapse optical coherence tomography (OCT) which allows the study of the dynamics of ATPS droplets while visualizing their 3D structures and providing quantitative information on the droplets. In this study, we monitored the process of rehydration and deformation of an ATPS droplet in a microfluidic system and quantified the changes of its volume and velocity under both static and dynamic fluid conditions. Our results indicate that time-lapse OCT is a very promising tool to evaluate the unprecedented features of droplet-based microfluidics.

  9. Temperature lapse rates at restricted thermodynamic equilibrium. Part II: Saturated air and further discussions

    NASA Astrophysics Data System (ADS)

    Björnbom, Pehr

    2016-03-01

    In the first part of this work equilibrium temperature profiles in fluid columns with ideal gas or ideal liquid were obtained by numerically minimizing the column energy at constant entropy, equivalent to maximizing column entropy at constant energy. A minimum in internal plus potential energy for an isothermal temperature profile was obtained in line with Gibbs' classical equilibrium criterion. However, a minimum in internal energy alone for adiabatic temperature profiles was also obtained. This led to a hypothesis that the adiabatic lapse rate corresponds to a restricted equilibrium state, a type of state in fact discussed already by Gibbs. In this paper similar numerical results for a fluid column with saturated air suggest that also the saturated adiabatic lapse rate corresponds to a restricted equilibrium state. The proposed hypothesis is further discussed and amended based on the previous and the present numerical results and a theoretical analysis based on Gibbs' equilibrium theory.

  10. Time-lapse resistivity investigations for imaging saltwater transport in glaciofluvial deposits

    NASA Astrophysics Data System (ADS)

    Leroux, Virginie; Dahlin, Torleif

    2006-01-01

    Five intersecting resistivity sections have been measured in glaciofluvial deposits hosting an aquifer of regional importance situated along a heavy traffic highway in Sweden. The winter salt spreading has caused a regular salinity increase through the years. For imaging the transport of saltwater in the aquifer, the sections were measured exactly in the same location before and after winter, and interpreted using a time-lapse inverse procedure. Some auger drilling and RCPT data were available for correlation. After winter, the resistivity had generally decreased under the water table and increased above it. The decrease in resistivity in the saturated zone is interpreted as a plume of more saline groundwater created by de-icing salt from the road. The increase in the upper layer can be explained by changes in temperature and soil moisture. The study shows that time-lapse resistivity investigations has potential for imaging hydraulic pathways in complex hydrogeological environments.

  11. Capturing Tissue Repair in Zebrafish Larvae with Time-lapse Brightfield Stereomicroscopy

    PubMed Central

    Lisse, Thomas S.; Brochu, Elizabeth A.; Rieger, Sandra

    2015-01-01

    The zebrafish larval tail fin is ideal for studying tissue regeneration due to the simple architecture of the larval fin-fold, which comprises of two layers of skin that enclose undifferentiated mesenchyme, and because the larval tail fin regenerates rapidly within 2-3 days. Using this system, we demonstrate a method for capturing the repair dynamics of the amputated tail fin with time-lapse video brightfield stereomicroscopy. We demonstrate that fin amputation triggers a contraction of the amputation wound and extrusion of cells around the wound margin, leading to their subsequent clearance. Fin regeneration proceeds from proximal to distal direction after a short delay. In addition, developmental growth of the larva can be observed during all stages. The presented method provides an opportunity for observing and analyzing whole tissue-scale behaviors such as fin development and growth in a simple microscope setting, which is easily adaptable to any stereomicroscope with time-lapse capabilities. PMID:25742070

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

    NASA Astrophysics Data System (ADS)

    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

  13. TIME-LAPSE SEISMIC MODELING & INVERSION OF CO2 SATURATION FOR SEQUESTRATION AND ENHANCED OIL RECOVERY

    SciTech Connect

    Mark A. Meadows

    2006-03-31

    Injection of carbon dioxide (CO2) into subsurface aquifers for geologic storage/sequestration, and into subsurface hydrocarbon reservoirs for enhanced oil recovery, has become an important topic to the nation because of growing concerns related to global warming and energy security. In this project we developed new ways to predict and quantify the effects of CO2 on seismic data recorded over porous reservoir/aquifer rock systems. This effort involved the research and development of new technology to: (1) Quantitatively model the rock physics effects of CO2 injection in porous saline and oil/brine reservoirs (both miscible and immiscible). (2) Quantitatively model the seismic response to CO2 injection (both miscible and immiscible) from well logs (1D). (3) Perform quantitative inversions of time-lapse 4D seismic data to estimate injected CO2 distributions within subsurface reservoirs and aquifers. This work has resulted in an improved ability to remotely monitor the injected CO2 for safe storage and enhanced hydrocarbon recovery, predict the effects of CO2 on time-lapse seismic data, and estimate injected CO2 saturation distributions in subsurface aquifers/reservoirs. We applied our inversion methodology to a 3D time-lapse seismic dataset from the Sleipner CO2 sequestration project, Norwegian North Sea. We measured changes in the seismic amplitude and traveltime at the top of the Sleipner sandstone reservoir and used these time-lapse seismic attributes in the inversion. Maps of CO2 thickness and its standard deviation were generated for the topmost layer. From this information, we estimated that 7.4% of the total CO2 injected over a five-year period had reached the top of the reservoir. This inversion approach could also be applied to the remaining levels within the anomalous zone to obtain an estimate of the total CO2 injected.

  14. Probabilistic 3-D time-lapse inversion of magnetotelluric data: Application to an enhanced geothermal system

    USGS Publications Warehouse

    Rosas-Carbajal, Marina; Linde, Nicolas; Peacock, Jared R.; Zyserman, F. I.; Kalscheuer, Thomas; Thiel, Stephan

    2015-01-01

    Surface-based monitoring of mass transfer caused by injections and extractions in deep boreholes is crucial to maximize oil, gas and geothermal production. Inductive electromagnetic methods, such as magnetotellurics, are appealing for these applications due to their large penetration depths and sensitivity to changes in fluid conductivity and fracture connectivity. In this work, we propose a 3-D Markov chain Monte Carlo inversion of time-lapse magnetotelluric data to image mass transfer following a saline fluid injection. The inversion estimates the posterior probability density function of the resulting plume, and thereby quantifies model uncertainty. To decrease computation times, we base the parametrization on a reduced Legendre moment decomposition of the plume. A synthetic test shows that our methodology is effective when the electrical resistivity structure prior to the injection is well known. The centre of mass and spread of the plume are well retrieved.We then apply our inversion strategy to an injection experiment in an enhanced geothermal system at Paralana, South Australia, and compare it to a 3-D deterministic time-lapse inversion. The latter retrieves resistivity changes that are more shallow than the actual injection interval, whereas the probabilistic inversion retrieves plumes that are located at the correct depths and oriented in a preferential north-south direction. To explain the time-lapse data, the inversion requires unrealistically large resistivity changes with respect to the base model. We suggest that this is partly explained by unaccounted subsurface heterogeneities in the base model from which time-lapse changes are inferred.

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

    PubMed

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  17. Time-lapse AVO fluid inversion for dynamic reservoir characterization in Delhi Field, Louisiana

    NASA Astrophysics Data System (ADS)

    Putri, Indah Hermansyah

    In the development stage, CO2 injection is becoming more widely used in enhanced oil recovery (EOR). Delhi Oil Field is part of Phases XIII and XIV of the Reservoir Characterization Project (RCP) Colorado School of Mines. The focus of these phases is to monitor the effectiveness of the CO 2 injection in Delhi Field by using multicomponent time-lapse seismic data. In this study, I analyze the amplitude versus offset (AVO) response of the time-lapse P-wave seismic data in order to quantify the fluid probability in the field. RCP acquired four square miles of multicomponent time-lapse seismic in Delhi Field to characterize the field dynamically. RCP's two surveys, monitor 1 and monitor 2, were shot in 2010 and 2011 after the start of CO2 injection in November 2009. Time-lapse AVO modeling was performed. The modeling results show that both the top Tuscaloosa and Paluxy Formations are class III AVO, and change toward class IV AVO by increasing the CO2 saturation in the reservoir. In addition, the Paluxy Formation shows a consistent result between the synthetic and real data, however, the Tuscaloosa Formation is not consistent as it is affected by tuning. AVO fluid inversion (AFI) was performed on both the Tuscaloosa and Paluxy Formations in order to quantify the fluid probability in these formations. The inversion results are confirmed by the pseudo gamma ray model, the porosity model, the permeability model, the pressure model, and the production data. In the Tuscaloosa and Paluxy Formations, oil and CO2 are located in the good quality, high porosity, and high permeability sandstones. The presence of CO2 is also confirmed by the pressure interpretation. Furthermore, production data from both Tuscaloosa and Paluxy Formations confirm the fluid presence in the reservoir.

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

    USGS Publications Warehouse

    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.

  19. Time-lapse cross-hole electrical resistivity tomography monitoring effects of an urban tunnel

    NASA Astrophysics Data System (ADS)

    Bellmunt, F.; Marcuello, A.; Ledo, J.; Queralt, P.; Falgàs, E.; Benjumea, B.; Velasco, V.; Vázquez-Suñé, E.

    2012-12-01

    Tunnel construction in urban areas has recently become a topic of interest and has increased the use of tunnel boring machines. Monitoring subsurface effects due to tunnel building in urban areas with conventional surface geophysical techniques is not an easy task because of space constraints. Taking advantage of the construction of a new metro line in Barcelona (Spain), a geoelectrical experiment, which included borehole logging and time-lapse cross-hole measurements using permanent electrode deployments, was designed to characterise and to study the subsurface effects of the tunnel drilling in a test site. We present a case study in which the differences between time-lapse cross-hole resistivity measurements acquired before, during and after the tunnel drilling below the test site have been calculated using three different procedures: a constrained time-lapse inversion, a model subtraction and an inversion of the normalised data ratio. The three procedures have provided satisfactory images of the resistivity changes and tunnel geometry, but resistivity changes for the tunnel void were lower than predicted by modelling. This behaviour has been explained by considering a conductive zone around the tunnel. Further, an apparent resistivity pseudosection for the cross-hole data, equivalent to the case of the equatorial dipole-dipole on the surface, is introduced.

  20. Dynamic Association Between Negative Affect and Alcohol Lapses Following Alcohol Treatment

    PubMed Central

    Witkiewitz, Katie; Villarroel, Nadia Aracelliz

    2009-01-01

    Clinical research has found a strong association between negative affect and returning to alcohol use after a period of abstinence. Yet little is known about the probability of a lapse given a particular level of negative affect or whether there is a reciprocal relationship between negative affect and alcohol use across time. The goal of the current study was to examine the association between negative affect and drinking behavior in the 1st year following alcohol treatment. The authors applied an associative latent transition analysis to the Project MATCH outpatient data (n = 952) and then replicated the model in the Project MATCH aftercare data (n = 774). Changes in drinking following treatment were significantly associated with current and prior changes in negative affect, and changes in negative affect were related to prior changes in drinking (effect size range = 0.13–0.33). The results supported the hypothesis that negative affect and alcohol lapses are dynamically linked and suggest that targeting the relationship between negative affect and alcohol use could greatly decrease the probability of lapses and improve alcohol treatment outcomes. PMID:19634957

  1. Extended Time-lapse Intravital Imaging of Real-time Multicellular Dynamics in the Tumor Microenvironment

    PubMed Central

    Harney, Allison S.; Wang, Yarong; Condeelis, John S.; Entenberg, David

    2016-01-01

    In the tumor microenvironment, host stromal cells interact with tumor cells to promote tumor progression, angiogenesis, tumor cell dissemination and metastasis. Multicellular interactions in the tumor microenvironment can lead to transient events including directional tumor cell motility and vascular permeability. Quantification of tumor vascular permeability has frequently used end-point experiments to measure extravasation of vascular dyes. However, due to the transient nature of multicellular interactions and vascular permeability, the kinetics of these dynamic events cannot be discerned. By labeling cells and vasculature with injectable dyes or fluorescent proteins, high-resolution time-lapse intravital microscopy has allowed the direct, real-time visualization of transient events in the tumor microenvironment. Here we describe a method for using multiphoton microscopy to perform extended intravital imaging in live mice to directly visualize multicellular dynamics in the tumor microenvironment. This method details cellular labeling strategies, the surgical preparation of a mammary skin flap, the administration of injectable dyes or proteins by tail vein catheter and the acquisition of time-lapse images. The time-lapse sequences obtained from this method facilitate the visualization and quantitation of the kinetics of cellular events of motility and vascular permeability in the tumor microenvironment. PMID:27341448

  2. High-resolution imaging characterization of bladder dynamic morphophysiology by time-lapse optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Pan, Y. T.; Wu, Q.; Wang, Z. G.; Brink, P. R.; Du, C. W.

    2005-09-01

    We report an experimental study of the possibility of high-speed optical coherence tomography (OCT) for high-resolution imaging characterization of detrusor dynamic morphophysiology and analysis of the mechanisms that lead to geriatric incontinence (GI). The spontaneous contractility of intact fresh rabbit bladders was imaged with two-dimensional (2D) OCT ex vivo at up to 8frames/s. The time-lapse 2D OCT images were postprocessed by image segmentation and fast-Fourier-transform analysis to characterize the dynamic morphological changes of the bladder contractility. In addition, we studied young and aging rat bladders to analyze the differences in dynamics. Preliminary results of our ex vivo study reveal that time-lapse OCT can track the contractile waves of bladders at high spatial resolution and characterize their dynamic morphophysiology in terms of amplitude, phase, and frequency. The results suggest that time-lapse OCT has the potential to act as a detrusor optical biopsy to enhance the diagnosis of detrusor dysfunction and thus of the mechanisms that lead to GI.

  3. Extended Time-lapse Intravital Imaging of Real-time Multicellular Dynamics in the Tumor Microenvironment.

    PubMed

    Harney, Allison S; Wang, Yarong; Condeelis, John S; Entenberg, David

    2016-01-01

    In the tumor microenvironment, host stromal cells interact with tumor cells to promote tumor progression, angiogenesis, tumor cell dissemination and metastasis. Multicellular interactions in the tumor microenvironment can lead to transient events including directional tumor cell motility and vascular permeability. Quantification of tumor vascular permeability has frequently used end-point experiments to measure extravasation of vascular dyes. However, due to the transient nature of multicellular interactions and vascular permeability, the kinetics of these dynamic events cannot be discerned. By labeling cells and vasculature with injectable dyes or fluorescent proteins, high-resolution time-lapse intravital microscopy has allowed the direct, real-time visualization of transient events in the tumor microenvironment. Here we describe a method for using multiphoton microscopy to perform extended intravital imaging in live mice to directly visualize multicellular dynamics in the tumor microenvironment. This method details cellular labeling strategies, the surgical preparation of a mammary skin flap, the administration of injectable dyes or proteins by tail vein catheter and the acquisition of time-lapse images. The time-lapse sequences obtained from this method facilitate the visualization and quantitation of the kinetics of cellular events of motility and vascular permeability in the tumor microenvironment. PMID:27341448

  4. Automated time-lapse microscopy and high-resolution tracking of cell migration.

    PubMed

    Fotos, Joseph S; Patel, Vivek P; Karin, Norman J; Temburni, Murali K; Koh, John T; Galileo, Deni S

    2006-05-01

    We describe a novel fully automated high-throughput time-lapse microscopy system and evaluate its performance for precisely tracking the motility of several glioma and osteoblastic cell lines. Use of this system revealed cell motility behavior not discernable with conventional techniques by collecting data (1) from closely spaced time points (minutes), (2) over long periods (hours to days), (3) from multiple areas of interest, (4) in parallel under several different experimental conditions. Quantitation of true individual and average cell velocity and path length was obtained with high spatial and temporal resolution in "scratch" or "wound healing" assays. This revealed unique motility dynamics of drug-treated and adhesion molecule-transfected cells and, thus, this is a considerable improvement over current methods of measurement and analysis. Several fluorescent vital labeling methods commonly used for end-point analyses (GFP expression, DiO lipophilic dye, and Qtracker nanocrystals) were found to be useful for time-lapse studies under specific conditions that are described. To illustrate one application, fluorescently labeled tumor cells were seeded onto cell monolayers expressing ectopic adhesion molecules, and this resulted in consistently reduced tumor cell migration velocities. These highly quantitative time-lapse analysis methods will promote the creation of new cell motility assays and increase the resolution and accuracy of existing assays. PMID:19002890

  5. Dynamic association between negative affect and alcohol lapses following alcohol treatment.

    PubMed

    Witkiewitz, Katie; Villarroel, Nadia Aracelliz

    2009-08-01

    Clinical research has found a strong association between negative affect and returning to alcohol use after a period of abstinence. Yet little is known about the probability of a lapse given a particular level of negative affect or whether there is a reciprocal relationship between negative affect and alcohol use across time. The goal of the current study was to examine the association between negative affect and drinking behavior in the 1st year following alcohol treatment. The authors applied an associative latent transition analysis to the Project MATCH outpatient data (n = 952) and then replicated the model in the Project MATCH aftercare data (n = 774). Changes in drinking following treatment were significantly associated with current and prior changes in negative affect, and changes in negative affect were related to prior changes in drinking (effect size range = 0.13-0.33). The results supported the hypothesis that negative affect and alcohol lapses are dynamically linked and suggest that targeting the relationship between negative affect and alcohol use could greatly decrease the probability of lapses and improve alcohol treatment outcomes. PMID:19634957

  6. Can arousing feedback rectify lapses in driving? Prediction from EEG power spectra

    NASA Astrophysics Data System (ADS)

    Lin, Chin-Teng; Huang, Kuan-Chih; Chuang, Chun-Hsiang; Ko, Li-Wei; Jung, Tzyy-Ping

    2013-10-01

    Objective. This study explores the neurophysiological changes, measured using an electroencephalogram (EEG), in response to an arousing warning signal delivered to drowsy drivers, and predicts the efficacy of the feedback based on changes in the EEG. Approach. Eleven healthy subjects participated in sustained-attention driving experiments. The driving task required participants to maintain their cruising position and compensate for randomly induced lane deviations using the steering wheel, while their EEG and driving performance were continuously monitored. The arousing warning signal was delivered to participants who experienced momentary behavioral lapses, failing to respond rapidly to lane-departure events (specifically the reaction time exceeded three times the alert reaction time). Main results. The results of our previous studies revealed that arousing feedback immediately reversed deteriorating driving performance, which was accompanied by concurrent EEG theta- and alpha-power suppression in the bilateral occipital areas. This study further proposes a feedback efficacy assessment system to accurately estimate the efficacy of arousing warning signals delivered to drowsy participants by monitoring the changes in their EEG power spectra immediately thereafter. The classification accuracy was up 77.8% for determining the need for triggering additional warning signals. Significance. The findings of this study, in conjunction with previous studies on EEG correlates of behavioral lapses, might lead to a practical closed-loop system to predict, monitor and rectify behavioral lapses of human operators in attention-critical settings.

  7. Enhancing Monitoring of Recharge-Related Environmental Remediation Processes Using Time-Lapse Seismic Refraction

    NASA Astrophysics Data System (ADS)

    Gaines, D. P.; Baker, G. S.; Hubbard, S. S.; Watson, D. B.; Jardine, P. M.

    2008-12-01

    The application of time-lapse seismic methods has typically been constrained to large-scale geologic investigations associated with petroleum exploration and exploitation; however, there is growing interest in monitoring near-surface phenomena (e.g., fluid flow in fractured or karstic geologic media, hydraulic recharge, and near-surface anthropogenic manipulations) using time-lapse seismic methods. In order to demonstrate the feasibility of detailed time-lapse seismic refraction tomography (TLSRT), we have monitored a perched water table at Oak Ridge National Laboratory (ORNL) Y-12 site in conjunction with a multi- disciplinary investigation of the fate and transport of contaminants. Due to remnant anthropogenic alterations of the site (i.e., replacement of 0-7 meters of contaminated soil with poorly sorted limestone gravel fill during construction of a seepage basin cap), the near surface hydrology is extremely complex and is hypothesized to have a large influence on infiltration, contaminant distribution, and contaminant remobilization. Understanding the impact of recharge-related flow and transport processes is especially important in regions that are subjected to significant precipitation events, such as at the ORNL Y-12 site. Here, TLSRT techniques are used to monitor the changing geometry of a perched water table located near the covered seepage basin, while coincident time-lapse surface electrical resistivity (TLERT) measurements are used to monitor changes in total dissolved solids due to recharge-related dilution. Data are collected at multiple time intervals (i.e., daily, weekly, monthly, yearly) and at varying stages in the evolution of the perch zone. The resulting seismic data are processed using wavepath eikonal tomography (WET) and differenced to identify areas of variable velocity associated with a change in saturation. The differenced tomograms correlate with discrete point water table measurements; however, the highly variable water table at this

  8. Time-lapse borehole radar for monitoring rainfall infiltration through podosol horizons in a sandy vadose zone

    NASA Astrophysics Data System (ADS)

    Strobach, Elmar; Harris, B. D.; Dupuis, J. C.; Kepic, A. W.

    2014-03-01

    The shallow aquifer on the Gnangara Mound, north of Perth, Western Australia, is recharged by winter rainfall. Water infiltrates through a sandy Podosol where cemented accumulation (B-) horizons are common. They are water retentive and may impede recharge. To observe wetting fronts and the influence of soil horizons on unsaturated flow, we deployed time-lapse borehole radar techniques sensitive to soil moisture variations during an annual recharge cycle. Zero-offset crosswell profiling (ZOP) and vertical radar profiling (VRP) measurements were performed at six sites on a monthly basis before, during, and after annual rainfall in 2011. Water content profiles are derived from ZOP logs acquired in closely spaced wells. Sites with small separation between wells present potential repeatability and accuracy difficulties. Such problems could be lessened by (i) ZOP saturated zone velocity matching of time-lapse curves, and (ii) matching of ZOP and VRP results. The moisture contents for the baseline condition and subsequent observations are computed using the Topp relationship. Time-lapse moisture curves reveal characteristic vadose zone infiltration regimes. Examples are (I) full recharge potential after 200 mm rainfall, (II) delayed wetting and impeded recharge, and (III) no recharge below 7 m depth. Seasonal infiltration trends derived from long-term time-lapse neutron logging at several sites are shown to be comparable with infiltration trends recovered from time-lapse crosswell radar measurements. However, radar measurements sample a larger volume of earth while being safer to deploy than the neutron method which employs a radioactive source. For the regime (III) site, where time-lapse radar indicates no net recharge or zero flux to the water table, a simple water balance provides an evapotranspiration value of 620 mm for the study period. This value compares favorably to previous studies at similar test sites in the region. Our six field examples demonstrate

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

    SciTech Connect

    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

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

    SciTech Connect

    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.

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

    PubMed

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

    2015-01-01

    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 surface-based ERT in conjunction with limited field sampling to improve spatial

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

    NASA Astrophysics Data System (ADS)

    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.

  13. Fast and robust optical flow for time-lapse microscopy using super-voxels

    PubMed Central

    Amat, Fernando; Myers, Eugene W.; Keller, Philipp J.

    2013-01-01

    Motivation: Optical flow is a key method used for quantitative motion estimation of biological structures in light microscopy. It has also been used as a key module in segmentation and tracking systems and is considered a mature technology in the field of computer vision. However, most of the research focused on 2D natural images, which are small in size and rich in edges and texture information. In contrast, 3D time-lapse recordings of biological specimens comprise up to several terabytes of image data and often exhibit complex object dynamics as well as blurring due to the point-spread-function of the microscope. Thus, new approaches to optical flow are required to improve performance for such data. Results: We solve optical flow in large 3D time-lapse microscopy datasets by defining a Markov random field (MRF) over super-voxels in the foreground and applying motion smoothness constraints between super-voxels instead of voxel-wise. This model is tailored to the specific characteristics of light microscopy datasets: super-voxels help registration in textureless areas, the MRF over super-voxels efficiently propagates motion information between neighboring cells and the background subtraction and super-voxels reduce the dimensionality of the problem by an order of magnitude. We validate our approach on large 3D time-lapse datasets of Drosophila and zebrafish development by analyzing cell motion patterns. We show that our approach is, on average, 10 × faster than commonly used optical flow implementations in the Insight Tool-Kit (ITK) and reduces the average flow end point error by 50% in regions with complex dynamic processes, such as cell divisions. Availability: Source code freely available in the Software section at http://janelia.org/lab/keller-lab. Contact: amatf@janelia.hhmi.org or kellerp@janelia.hhmi.org Supplementary information: Supplementary data are available at Bioinformatics online. PMID:23242263

  14. The Contribution of Attentional Lapses to Individual Differences in Visual Working Memory Capacity

    PubMed Central

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

    2015-01-01

    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. PMID:25811710

  15. Time-lapse Measurements of Electrical Resistivities to Characterise Snowmelt Infiltration Patterns

    NASA Astrophysics Data System (ADS)

    French, H. K.; Du Saire, M.; Binley, A.; Baker, J.

    2006-12-01

    During snowmelt Oslo airport has on repeated occations experienced the formation of large meltwater ponds due to impermeable ice forming below the snowcover. The airport is situated on a large glacial outwash plane with coarse sandy gravely sediments, hence the area normaly has a high infiltration capacity. Focussed infiltration can cause fast transport of contaminants to the groundwater, hence improved understanding of the processes determining where and how the focussed infiltration takes place is important. Previously the melting process has been monitored successfully on a small scale (4 m2) using a two dimensional grid of permanently installed electrodes (French and Binley, 2004). In the present work snowmelt infiltration was monitored by time-lapse measurements of electrical resistivity using grounded electrodes on 4 and 20 m2 plots and a capacitively coupled resistivity system (Ohmmapper, Geometrics) on a larger scale. While the smaller scale systems provide 3D images the capacitively coupled system was used to monitor changes in two dimensional vertical sections in a retention pond adjacent to one of the runways. The area covered by 4 lines was 170 m by 340 m. The initial data were collected late in the spring (2006) during the final stages of the snowmelt. The lines were repeated later in the year when the soil profile was dryer. The lines show good consistency in the description of the general geology of the subsurface and the time-lapse changes describe the infiltration pattern that occurred during snowmelt and subsequent drainage. The surveys provide useful information about the differences in spatial distribution of snowmelt infiltration at different scales. And there are good indications that capacitively coupled resistivity surveys can be used to describe infiltration processes at relatively large spacio-temporal scales. References French, H. and A. Binley, 2004, Snowmelt infiltration: monitoring temporal and spatial variability using time- lapse

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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

  18. Time-lapse Imaging of Active Lava Flows at Mt. Etna, Sicily

    NASA Astrophysics Data System (ADS)

    James, M. R.; Pinkerton, H.; Applegarth, L. J.; Hancock, A.; Slatcher, N.; Owen, J.; Calvari, S.; Ganci, G.

    2014-12-01

    Over the last ~6 years, remote time-lapse cameras have been deployed on Mt. Etna, Sicily, with a view to capturing the emplacement of a substantial lava flow field. Initial deployment of wildlife trail-style cameras in 2008 acquired data on lava channel processes during the 2008-9 eruption. In 2009, just in time to capture the dying phases of the eruption, an upgraded network of dSLRs was installed. The network has subsequently captured the steady growth of the New South East crater and the rapid emplacement of short-lived sheet flows that have accompanied the recent paroxysmal fire fountaining events. Most of the imagery has been acquired over distances of multiple kilometres, but the portability of the time-lapse setup has also allowed several opportunistic close range (hundreds of metres or less) deployments, to observe near-vent processes or effusion inside the Bocca Nuova crater. Here, we provide an overview of the equipment, and the approaches used to georeference the monoscopic time-lapse imagery through integrating with 3D data (e.g. existing DEMs, or data simultaneously collected by terrestrial laser scanner or photogrammetric techniques). The acquired observations of flow front emplacement, flow inflation, channel breaching and effusion rate variations that provide insight into the processes involved in long lived flow fields will be presented. Significant opportunities remain, for example, in the near real-time derivation of bulk rheological parameters, and integration with numerical flow models, and the challenges involved in using such imagery will be discussed.

  19. A state-space Bayesian framework for estimating biogeochemical transformations using time-lapse geophysical data

    SciTech Connect

    Chen, J.; Hubbard, S.; Williams, K.; Pride, S.; Li, L.; Steefel, C.; Slater, L.

    2009-04-15

    We develop a state-space Bayesian framework to combine time-lapse geophysical data with other types of information for quantitative estimation of biogeochemical parameters during bioremediation. We consider characteristics of end-products of biogeochemical transformations as state vectors, which evolve under constraints of local environments through evolution equations, and consider time-lapse geophysical data as available observations, which could be linked to the state vectors through petrophysical models. We estimate the state vectors and their associated unknown parameters over time using Markov chain Monte Carlo sampling methods. To demonstrate the use of the state-space approach, we apply it to complex resistivity data collected during laboratory column biostimulation experiments that were poised to precipitate iron and zinc sulfides during sulfate reduction. We develop a petrophysical model based on sphere-shaped cells to link the sulfide precipitate properties to the time-lapse geophysical attributes and estimate volume fraction of the sulfide precipitates, fraction of the dispersed, sulfide-encrusted cells, mean radius of the aggregated clusters, and permeability over the course of the experiments. Results of the case study suggest that the developed state-space approach permits the use of geophysical datasets for providing quantitative estimates of end-product characteristics and hydrological feedbacks associated with biogeochemical transformations. Although tested here on laboratory column experiment datasets, the developed framework provides the foundation needed for quantitative field-scale estimation of biogeochemical parameters over space and time using direct, but often sparse wellbore data with indirect, but more spatially extensive geophysical datasets.

  20. Arctic sea-ice variations from time-lapse passive microwave imagery

    USGS Publications Warehouse

    Campbell, W.J.; Ramseier, R.O.; Zwally, H.J.; Gloersen, P.

    1980-01-01

    This paper presents: (1) a short historical review of the passive microwave research on sea ice which established the observational and theoretical base permitting the interpretation of the first passive microwave images of Earth obtained by the Nimbus-5 ESMR; (2) the construction of a time-lapse motion picture film of a 16-month set of serial ESMR images to aid in the formidable data analysis task; and (3) a few of the most significant findings resulting from an early analysis of these data, using selected ESMR images to illustrate these findings. ?? 1980 D. Reidel Publishing Co.

  1. When spacing out brings clarity. Mental lapses serve as diagnostic clue for type of dementia.

    PubMed

    Tuma, Rabiya S

    2004-01-28

    NEW YORK CITY--Everyone has slow-witted moments: entering a room only to forget why, putting ice cream into the fridge, or blanking out on how to use the microwave. Some clinicians think that periodic mental lapses might help diagnose dementia with Lewy bodies (DLB), a scourge that kills brain cells (see DLB Case Study), although not all experts agree. Now, scientists have found that some cognitive blunders crop up more frequently in patients with DLB than in those with Alzheimer's disease (AD) or in healthy elderly individuals, according to work presented here on 15 January 2004 at an American Medical Association briefing for media. PMID:14749519

  2. Time-lapse CCD imagery of plasma-tail motions in Comet Austin

    NASA Technical Reports Server (NTRS)

    Klinglesmith, Daniel A., III; Niedner, Malcolm B., Jr.; Oliversen, R. J.; Westpfahl, David J.

    1991-01-01

    The appearance of the bright comet Austin 1989c1 in April-May of 1990 allowed us to test a new imaging instrument at the Joint Observatory for Cometary Research (JOCR). It is a 300mm lens/charge coupled device (CCD) system with interference filters appropriate for cometary emissions. The 13 frames were made into a time-lapse movie showing the evolution of the plasma tail. We were able to follow at least two large-scale waves out through the main tail structure. During the sequence, we saw two new tail rays form and undergo similar wave motion.

  3. Live-streaming: Time-lapse video evidence of novel streamer formation mechanism and varying viscosity.

    PubMed

    Parvinzadeh Gashti, Mazeyar; Bellavance, Julien; Kroukamp, Otini; Wolfaardt, Gideon; Taghavi, Seyed Mohammad; Greener, Jesse

    2015-07-01

    Time-lapse videos of growing biofilms were analyzed using a background subtraction method, which removed camouflaging effects from the heterogeneous field of view to reveal evidence of streamer formation from optically dense biofilm segments. In addition, quantitative measurements of biofilm velocity and optical density, combined with mathematical modeling, demonstrated that streamer formation occurred from mature, high-viscosity biofilms. We propose a streamer formation mechanism by sudden partial detachment, as opposed to continuous elongation as observed in other microfluidic studies. Additionally, streamer formation occurred in straight microchannels, as opposed to serpentine or pseudo-porous channels, as previously reported. PMID:26339304

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

    NASA Astrophysics Data System (ADS)

    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

  5. Live-streaming: Time-lapse video evidence of novel streamer formation mechanism and varying viscosity

    PubMed Central

    Parvinzadeh Gashti, Mazeyar; Bellavance, Julien; Kroukamp, Otini; Wolfaardt, Gideon; Taghavi, Seyed Mohammad; Greener, Jesse

    2015-01-01

    Time-lapse videos of growing biofilms were analyzed using a background subtraction method, which removed camouflaging effects from the heterogeneous field of view to reveal evidence of streamer formation from optically dense biofilm segments. In addition, quantitative measurements of biofilm velocity and optical density, combined with mathematical modeling, demonstrated that streamer formation occurred from mature, high-viscosity biofilms. We propose a streamer formation mechanism by sudden partial detachment, as opposed to continuous elongation as observed in other microfluidic studies. Additionally, streamer formation occurred in straight microchannels, as opposed to serpentine or pseudo-porous channels, as previously reported. PMID:26339304

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

    NASA Astrophysics Data System (ADS)

    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

  7. Refinement of Eocene lapse rates, fossil-leaf altimetry, and North American Cordilleran surface elevation estimates

    NASA Astrophysics Data System (ADS)

    Feng, Ran; Poulsen, Christopher J.

    2016-02-01

    Estimates of continental paleoelevation using proxy methods are essential for understanding the geodynamic, climatic, and geomorphoric evolution of ancient orogens. Fossil-leaf paleoaltimetry, one of the few quantitative proxy approaches, uses fossil-leaf traits to quantify differences in temperature or moist enthalpy between coeval coastal and inland sites along latitudes. These environmental differences are converted to elevation differences using their rates of change with elevation (lapse rate). Here, we evaluate the uncertainty associated with this method using the Eocene North American Cordillera as a case study. To do so, we develop a series of paleoclimate simulations for the Early (∼55-49 Ma) and Middle Eocene (49-40 Ma) period using a range of elevation scenarios for the western North American Cordillera. Simulated Eocene lapse rates over western North America are ∼5 °C/km and 9.8 kJ/km, close to moist adiabatic rates but significantly different from modern rates. Further, using linear lapse rates underestimates high-altitude (>3 km) temperature variability and loss of moist enthalpy induced by non-linear circulation changes in response to increasing surface elevation. Ignoring these changes leads to kilometer-scale biases in elevation estimates. In addition to these biases, we demonstrate that previous elevation estimates of the western Cordillera are affected by local climate variability at coastal fossil-leaf sites of up to ∼8 °C in temperature and ∼20 kJ in moist enthalpy, a factor which further contributes to elevation overestimates of ∼1 km for Early Eocene floras located in the Laramide foreland basins and underestimates of ∼1 km for late Middle Eocene floras in the southern Cordillera. We suggest a new approach for estimating past elevations by comparing proxy reconstructions directly with simulated distributions of temperature and moist enthalpy under a range of elevation scenarios. Using this method, we estimate mean elevations for

  8. High Lapse Rates in AIRS Retrieved Temperatures in Cold Air Outbreaks

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.; Kahn, Brian; Olsen, Edward T.; Fishbein, Evan

    2004-01-01

    The Atmospheric Infrared Sounder (AIRS) experiment, on NASA's Aqua spacecraft, uses a combination of infrared and microwave observations to retrieve cloud and surface properties, plus temperature and water vapor profiles comparable to radiosondes throughout the troposphere, for cloud cover up to 70%. The high spectral resolution of AIRS provides sensitivity to important information about the near-surface atmosphere and underlying surface. A preliminary analysis of AIRS temperature retrievals taken during January 2003 reveals extensive areas of superadiabatic lapse rates in the lowest kilometer of the atmosphere. These areas are found predominantly east of North America over the Gulf Stream, and, off East Asia over the Kuroshio Current. Accompanying the high lapse rates are low air temperatures, large sea-air temperature differences, and low relative humidities. Imagery from a Visible / Near Infrared instrument on the AIRS experiment shows accompanying clouds. These lines of evidence all point to shallow convection in the bottom layer of a cold air mass overlying warm water, with overturning driven by heat flow from ocean to atmosphere. An examination of operational radiosondes at six coastal stations in Japan shows AIRS to be oversensitive to lower tropospheric lapse rates due to systematically warm near-surface air temperatures. The bias in near-surface air temperature is seen to be independent of sea surface temperature, however. AIRS is therefore sensitive to air-sea temperature difference, but with a warm atmospheric bias. A regression fit to radiosondes is used to correct AIRS near-surface retrieved temperatures, and thereby obtain an estimate of the true atmosphere-ocean thermal contrast in five subtropical regions across the north Pacific. Moving eastward, we show a systematic shift in this air-sea temperature differences toward more isothermal conditions. These results, while preliminary, have implications for our understanding of heat flow from ocean to

  9. Reconstructed imaging of acoustic cloak using time-lapse reversal method

    NASA Astrophysics Data System (ADS)

    Zhou, Chen; Cheng, Ying; Xu, Jian-yi; Li, Bo; Liu, Xiao-jun

    2014-08-01

    We proposed and investigated a solution to the inverse acoustic cloak problem, an anti-stealth technology to make cloaks visible, using the time-lapse reversal (TLR) method. The TLR method reconstructs the image of an unknown acoustic cloak by utilizing scattered acoustic waves. Compared to previous anti-stealth methods, the TLR method can determine not only the existence of a cloak but also its exact geometric information like definite shape, size, and position. Here, we present the process for TLR reconstruction based on time reversal invariance. This technology may have potential applications in detecting various types of cloaks with different geometric parameters.

  10. Time-Lapse Evaluation of Interactions Between Biodegradable Mg Particles and Cells.

    PubMed

    Alvarez, Florencia; Lozano Puerto, Rosa M; Pérez-Maceda, Blanca; Grillo, Claudia A; Fernández Lorenzo de Mele, Mónica

    2016-02-01

    Mg-based implants have promising applications as biodegradable materials in medicine for orthopedic, dental, and cardiovascular therapies. During wear and degradation microdebris are released. Time-lapse multidimensional microscopy (MM) is proposed here as a suitable tool to follow, in fixed intervals over 24-h periods, the interaction between cells and particles. Results of MM show interactions of macrophages (J774) with the magnesium particles (MgPa) that led to modifications of cell size and morphology, a decrease in duplication rate, and cell damage. Corrosion products were progressively formed on the surface of the particles and turbulence was generated due to hydrogen development. Changes were more significant after treating MgPa with potassium fluoride. In order to complement MM observations, membrane damage as detected by a lactase dehydrogenase (LDH) assay and mitochondrial activity as detected by a WST-1 assay with macrophages and osteoblasts (MC3T3-E1) were compared. A more significant concentration-dependent effect was detected for macrophages exposed to MgPa than for osteoblasts. Accordingly, complementary data showed that viability and cell cycle seem to be more altered in macrophages. In addition, protein profiles and expression of proteins associated with the adhesion process changed in the presence of MgPa. These studies revealed that time-lapse MM is a helpful tool for monitoring changes of biodegradable materials and the biological surrounding in real time and in situ. This information is useful in studies related to biodegradable biomaterials. PMID:26810154

  11. A study on quality-adjusted impact of time lapse on iris recognition

    NASA Astrophysics Data System (ADS)

    Sazonova, Nadezhda; Hua, Fang; Liu, Xuan; Remus, Jeremiah; Ross, Arun; Hornak, Lawrence; Schuckers, Stephanie

    2012-06-01

    Although human iris pattern is widely accepted as a stable biometric feature, recent research has found some evidences on the aging effect of iris system. In order to investigate changes in iris recognition performance due to the elapsed time between probe and gallery iris images, we examine the effect of elapsed time on iris recognition utilizing 7,628 iris images from 46 subjects with an average of ten visits acquired over two years from a legacy database at Clarkson University. Taken into consideration the impact of quality factors such as local contrast, illumination, blur and noise on iris recognition performance, regression models are built with and without quality metrics to evaluate the degradation of iris recognition performance based on time lapse factors. Our experimental results demonstrate the decrease of iris recognition performance along with increased elapsed time based on two iris recognition system (the modified Masek algorithm and a commercial software VeriEye SDK). These results also reveal the significance of quality factors in iris recognition regression indicating the variability in match scores. According to the regression analysis, our study in this paper helps provide the quantified decrease on match scores with increased elapsed time, which indicates the possibility to implement the prediction scheme for iris recognition performance based on learning of impact on time lapse factors.

  12. The Extreme Ice Survey: Capturing and Conveying Glacial Processes Through Time-Lapse Imagery and Narration

    NASA Astrophysics Data System (ADS)

    Balog, J. D.; Box, J. E.; Pfeffer, W. T.; Hood, E. W.; Fagre, D. B.; Anker, C.; O'Neel, S.

    2010-12-01

    The Extreme Ice Survey (EIS) uses time-lapse photography, conventional photography, and video to document rapid change in the Earth's glacial ice. The EIS team currently has 38 time-lapse cameras at sites in Greenland, Iceland, Alaska, the Rocky Mountains and Nepal. EIS supplements this ongoing record with annual repeat photography in British Columbia, Iceland, the Alps, and Bolivia. EIS imagery supplies basic knowledge in glacier dynamics to the science community, as well as compelling, engaging narratives to the general public about the immediacy of the Anthropocene and climate change. Visual materials from EIS have impacted more than 150 million people, ranging from White House staff, the U. S. Congress and government agency officials to globally influential corporate officers and all age strata of the general public. Media products include a National Geographic/NOVA special, two National Geographic magazine articles, a feature in Parade magazine (circulation 71 million), and numerous presentations on CNN, NBC, BBC and National Public Radio. Columbia Glacier, Alaska, June 2006, May 2007, June 2008 terminus indicated.

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

    PubMed

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

    PubMed Central

    Farooq, Muhammad; 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

  15. A Single-Cell Assay for Time Lapse Studies of Exosome Secretion and Cell Behaviors.

    PubMed

    Chiu, Yu-Jui; Cai, Wei; Shih, Yu-Ru V; Lian, Ian; Lo, Yu-Hwa

    2016-07-01

    To understand the inhomogeneity of cells in biological systems, there is a growing demand on the capability of characterizing the properties of individual single cells. Since single-cell studies require continuous monitoring of the cell behaviors, an effective single-cell assay that can support time lapsed studies in a high throughput manner is desired. Most currently available single-cell technologies cannot provide proper environments to sustain cell growth and, proliferation of single cells and convenient, noninvasive tests of single-cell behaviors from molecular markers. Here, a highly versatile single-cell assay is presented that can accommodate different cellular types, enable easy and efficient single-cell loading and culturing, and be suitable for the study of effects of in vitro environmental factors in combination with drug screening. One salient feature of the assay is the noninvasive collection and surveying of single-cell secretions at different time points, producing unprecedented insight of single-cell behaviors based on the biomarker signals from individual cells under given perturbations. Above all, the acquired information is quantitative, for example, measured by the number of exosomes each single-cell secretes for a given time period. Therefore, our single-cell assay provides a convenient, low-cost, and enabling tool for quantitative, time lapsed studies of single-cell properties. PMID:27254278

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

    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

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

    SciTech Connect

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

    2009-11-01

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

  19. Time-lapse nanoscopy of friction in the non-Amontons and non-Coulomb regime.

    PubMed

    Ishida, Tadashi; Sato, Takaaki; Ishikawa, Takahiro; Oguma, Masatsugu; Itamura, Noriaki; Goda, Keisuke; Sasaki, Naruo; Fujita, Hiroyuki

    2015-03-11

    Originally discovered by Leonard da Vinci in the 15th century, the force of friction is directly proportional to the applied load (known as Amontons' first law of friction). Furthermore, kinetic friction is independent of the sliding speed (known as Coulomb's law of friction). These empirical laws break down at high normal pressure (due to plastic deformation) and low sliding speed (in the transition regime between static friction and kinetic friction). An important example of this phenomenon is friction between the asperities of tectonic plates on the Earth. Despite its significance, little is known about the detailed mechanism of friction in this regime due to the lack of experimental methods. Here we demonstrate in situ time-lapse nanoscopy of friction between asperities sliding at ultralow speed (∼0.01 nm/s) under high normal pressure (∼GPa). This is made possible by compressing and rubbing a pair of nanometer-scale crystalline silicon anvils with electrostatic microactuators and monitoring its dynamical evolution with a transmission electron microscope. Our analysis of the time-lapse movie indicates that superplastic behavior is induced by decrystallization, plastic deformation, and atomic diffusion at the asperity-asperity interface. The results hold great promise for a better understanding of quasi-static friction under high pressure for geoscience, materials science, and nanotechnology. PMID:25330166

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

    PubMed

    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

  1. Time lapse seismic observations and effects of reservoir compressibility at Teal South oil field

    NASA Astrophysics Data System (ADS)

    Islam, Nayyer

    One of the original ocean-bottom time-lapse seismic studies was performed at the Teal South oil field in the Gulf of Mexico during the late 1990's. This work reexamines some aspects of previous work using modern analysis techniques to provide improved quantitative interpretations. Using three-dimensional volume visualization of legacy data and the two phases of post-production time-lapse data, I provide additional insight into the fluid migration pathways and the pressure communication between different reservoirs, separated by faults. This work supports a conclusion from previous studies that production from one reservoir caused regional pressure decline that in turn resulted in liberation of gas from multiple surrounding unproduced reservoirs. I also provide an explanation for unusual time-lapse changes in amplitude-versus-offset (AVO) data related to the compaction of the producing reservoir which, in turn, changed an isotropic medium to an anisotropic medium. In the first part of this work, I examine regional changes in seismic response due to the production of oil and gas from one reservoir. The previous studies primarily used two post-production ocean-bottom surveys (Phase I and Phase II), and not the legacy streamer data, due to the unavailability of legacy prestack data and very different acquisition parameters. In order to incorporate the legacy data in the present study, all three post-stack data sets were cross-equalized and examined using instantaneous amplitude and energy volumes. This approach appears quite effective and helps to suppress changes unrelated to production while emphasizing those large-amplitude changes that are related to production in this noisy (by current standards) suite of data. I examine the multiple data sets first by using the instantaneous amplitude and energy attributes, and then also examine specific apparent time-lapse changes through direct comparisons of seismic traces. In so doing, I identify time-delays that, when

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Automated identification of axonal growth cones in time-lapse image sequences.

    PubMed

    Keenan, Thomas M; Hooker, Andrew; Spilker, Mary E; Li, Nianzhen; Boggy, Gregory J; Vicini, Paolo; Folch, Albert

    2006-03-15

    The isolation and purification of axon guidance molecules has enabled in vitro studies of the effects of axon guidance molecule gradients on numerous neuronal cell types. In a typical experiment, cultured neurons are exposed to a chemotactic gradient and their growth is recorded by manual identification of the axon tip position from two or more micrographs. Detailed and statistically valid quantification of axon growth requires evaluation of a large number of neurons at closely spaced time points (e.g. using a time-lapse microscopy setup). However, manual tracing becomes increasingly impractical for recording axon growth as the number of time points and/or neurons increases. We present a software tool that automatically identifies and records the axon tip position in each phase-contrast image of a time-lapse series with minimal user involvement. The software outputs several quantitative measures of axon growth, and allows users to develop custom measurements. For, example analysis of growth velocity for a dissociated E13 mouse cortical neuron revealed frequent extension and retraction events with an average growth velocity of 0.05 +/- 0.14 microm/min. Comparison of software-identified axon tip positions with manually identified axon tip positions shows that the software's performance is indistinguishable from that of skilled human users. PMID:16174535

  4. Tracking tracer breakthrough in the hyporheic zone using time‐lapse DC resistivity, Crabby Creek, Pennsylvania

    USGS Publications Warehouse

    Nyquist, Jonathan E.; Toran, Laura; Fang, Allison C.; Ryan, Robert J.; Rosenberry, Donald O.

    2010-01-01

    Characterization of the hyporheic zone is of critical importance for understanding stream ecology, contaminant transport, and groundwater‐surface water interaction. A salt water tracer test was used to probe the hyporheic zone of a recently re‐engineered portion of Crabby Creek, a stream located near Philadelphia, PA. The tracer solution was tracked through a 13.5 meter segment of the stream using both a network of 25 wells sampled every 5–15 minutes and time‐lapse electrical resistivity tomographs collected every 11 minutes for six hours, with additional tomographs collected every 100 minutes for an additional 16 hours. The comparison of tracer monitoring methods is of keen interest because tracer tests are one of the few techniques available for characterizing this dynamic zone, and logistically it is far easier to collect resistivity tomographs than to install and monitor a dense network of wells. Our results show that resistivity monitoring captured the essential shape of the breakthrough curve and may indicate portions of the stream where the tracer lingered in the hyporheic zone. Time‐lapse resistivity measurements, however, represent time averages over the period required to collect a tomographic data set, and spatial averages over a volume larger than captured by a well sample. Smoothing by the resistivity data inversion algorithm further blurs the resulting tomograph; consequently resistivity monitoring underestimates the degree of fine‐scale heterogeneity in the hyporheic zone.

  5. Very-high-resolution time-lapse photography for plant and ecosystems research1

    PubMed Central

    Nichols, Mary H.; Steven, Janet C.; Sargent, Randy; Dille, Paul; Schapiro, Joshua

    2013-01-01

    • Premise of the study: Traditional photography is a compromise between image detail and area covered. We report a new method for creating time-lapse sequences of very-high-resolution photographs to produce zoomable images that facilitate observation across a range of spatial and temporal scales. • Methods and Results: A robotic camera mount and software were used to capture images of the growth and movement in Brassica rapa every 15 s in the laboratory. The resultant time-lapse sequence (http://timemachine.gigapan.org/wiki/Plant_Growth) captures growth detail such as circumnutation. A modified, solar-powered system was deployed at a remote field site in southern Arizona. Images were collected every 2 h over a 3-mo period to capture the response of vegetation to monsoon season rainfall (http://timemachine.gigapan.org/wiki/Arizona_Grasslands). • Conclusions: A technique for observing time sequences of both individual plant and ecosystem response at a range of spatial scales is available for use in the laboratory and in the field. PMID:25202588

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

    PubMed

    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 3D VSP monitoring of a carbon dioxide injection project at Delhi Field, Louisiana

    NASA Astrophysics Data System (ADS)

    Lubis, Muhammad Husni Mubarak

    Delhi Field is a producing oil field located in northeastern Louisiana. The estimated original oil in place (OOIP) is 357 mmbo and approximately 54% of OOIP has been produced through the primary production and water-flooding. A CO2-EOR program has been implemented since November 2009 to recover an additional 17% of OOIP. Reservoir surveillance using time-lapse 3D seismic data has been conducted to monitor the CO2 sweep efficiency. The goal of this study is to monitor the CO2 flow-path in the area around the injector using time-lapse 3D VSP data. For this purpose, two 3D VSPs acquired in June 2010 and again in August 2011 were processed together. Fluid substitution and VSP modeling were performed to understand the influence of pore-fluid saturation change on VSP records. A cross-equalization was performed to improve the similarity of the datasets. This step is important to reduce the ambiguity in time-lapse observation. The splice of a 3D VSP image into the surface seismic data becomes the key point in determining the reflector of the reservoir. By integrating the observation from the modeling and the splice of 3D VSP image to surface seismic, the CO2 flow-path from injector 164-3 can be identified from 3D time-lapse VSP data. The CO2 was not radially distributed around the injector, but moved toward southwest direction. This finding is also consistent with the flow-path interpreted from surface seismic. This consistency implies that time-lapse 3D VSP surveys at Delhi Field confirm and augment the time-lapse interpretation from surface seismic data.

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

    NASA Astrophysics Data System (ADS)

    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

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

    USGS Publications Warehouse

    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.

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

    NASA Astrophysics Data System (ADS)

    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

  11. Minds “At Attention”: Mindfulness Training Curbs Attentional Lapses in Military Cohorts

    PubMed Central

    Jha, Amishi P.; Morrison, Alexandra B.; Dainer-Best, Justin; Parker, Suzanne; Rostrup, Nina; Stanley, Elizabeth A.

    2015-01-01

    We investigated the impact of mindfulness training (MT) on attentional performance lapses associated with task-unrelated thought (i.e., mind wandering). Periods of persistent and intensive demands may compromise attention and increase off-task thinking. Here, we investigated if MT may mitigate these deleterious effects and promote cognitive resilience in military cohorts enduring a high-demand interval of predeployment training. To better understand which aspects of MT programs are most beneficial, three military cohorts were examined. Two of the three groups were provided MT. One group received an 8-hour, 8-week variant of Mindfulness-based Mind Fitness Training (MMFT) emphasizing engagement in training exercises (training-focused MT, n = 40), a second group received a didactic-focused variant emphasizing content regarding stress and resilience (didactic-focused MT, n = 40), and the third group served as a no-training control (NTC, n = 24). Sustained Attention to Response Task (SART) performance was indexed in all military groups and a no-training civilian group (CIV, n = 45) before (T1) and after (T2) the MT course period. Attentional performance (measured by A’, a sensitivity index) was lower in NTC vs. CIV at T2, suggesting that performance suffers after enduring a high-demand predeployment interval relative to a similar time period of civilian life. Yet, there were significantly fewer performance lapses in the military cohorts receiving MT relative to NTC, with training-focused MT outperforming didactic-focused MT at T2. From T1 to T2, A’ degraded in NTC and didactic-focused MT but remained stable in training-focused MT and CIV. In sum, while protracted periods of high-demand military training may increase attentional performance lapses, practice-focused MT programs akin to training-focused MT may bolster attentional performance more than didactic-focused programs. As such, training-focused MT programs should be further examined in cohorts experiencing

  12. Iceberg Calving and Flow Dynamics at Helheim Glacier, East Greenland, from Time-Lapse Photography

    NASA Astrophysics Data System (ADS)

    Hamilton, G. S.; Khan, S. A.; Schild, K. M.; Stearns, L. A.; Nettles, M.; Ahlstrøm, A. P.; Andersen, M. L.; Davis, J. L.; Ekström, G.; Elósegui, P.; Forsberg, R.; de Juan, J.; Larsen, T. B.; Stenseng, L.

    2008-12-01

    Helheim Glacier in East Greenland is the focus of coordinated studies aimed at understanding tidewater outlet-glacier dynamics and kinematics, and their link to glacial earthquakes. As part of this effort, we installed three time-lapse cameras overlooking the calving terminus of the glacier during the Arctic summer of 2008. Images were captured every five minutes during the mostly unattended period of operation. Several interesting aspects of the glacier's behavior are observed in the image sequences, including vertical displacement of the glacier terminus by ocean tides, and very large calving events. These observations, in combination with simultaneous measurements of ice flow, ocean tides (including tsunamis) and seismic activity, contribute to our understanding of the dynamics of Helheim Glacier and the source mechanism of glacial earthquakes.

  13. TRIIG - Time-lapse reproduction of images through interactive graphics. [digital processing of quality hard copy

    NASA Technical Reports Server (NTRS)

    Buckner, J. D.; Council, H. W.; Edwards, T. R.

    1974-01-01

    Description of the hardware and software implementing the system of time-lapse reproduction of images through interactive graphics (TRIIG). The system produces a quality hard copy of processed images in a fast and inexpensive manner. This capability allows for optimal development of processing software through the rapid viewing of many image frames in an interactive mode. Three critical optical devices are used to reproduce an image: an Optronics photo reader/writer, the Adage Graphics Terminal, and Polaroid Type 57 high speed film. Typical sources of digitized images are observation satellites, such as ERTS or Mariner, computer coupled electron microscopes for high-magnification studies, or computer coupled X-ray devices for medical research.

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

    SciTech Connect

    Hirano, Masahiko; Hoshida, Tetsushi; Sakaue-Sawano, Asako; Miyawaki, Atsushi

    2010-02-12

    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 CO{sub 2}-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.

  15. Time-lapse microscopy and image processing for stem cell research: modeling cell migration

    NASA Astrophysics Data System (ADS)

    Gustavsson, Tomas; Althoff, Karin; Degerman, Johan; Olsson, Torsten; Thoreson, Ann-Catrin; Thorlin, Thorleif; Eriksson, Peter

    2003-05-01

    This paper presents hardware and software procedures for automated cell tracking and migration modeling. A time-lapse microscopy system equipped with a computer controllable motorized stage was developed. The performance of this stage was improved by incorporating software algorithms for stage motion displacement compensation and auto focus. The microscope is suitable for in-vitro stem cell studies and allows for multiple cell culture image sequence acquisition. This enables comparative studies concerning rate of cell splits, average cell motion velocity, cell motion as a function of cell sample density and many more. Several cell segmentation procedures are described as well as a cell tracking algorithm. Statistical methods for describing cell migration patterns are presented. In particular, the Hidden Markov Model (HMM) was investigated. Results indicate that if the cell motion can be described as a non-stationary stochastic process, then the HMM can adequately model aspects of its dynamic behavior.

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

    PubMed

    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. PMID:26923765

  17. Absent minds and absent agents: attention-lapse induced alienation of agency.

    PubMed

    Cheyne, James Allan; Carriere, Jonathan S A; Smilek, Daniel

    2009-06-01

    We report a novel task designed to elicit transient attention-lapse induced alienation (ALIA) of agency experiences in normal participants. When attention-related action slips occur during the task, participants reported substantially decreased self control as well as a high degree of perceived agency attributed to the errant hand. In addition, participants reported being surprised by, and annoyed with, the actions of the errant hand. We argue that ALIA experiences occur because of constraints imposed by the close and precise temporal relations between intention formation and a contrary action employed in this paradigm. We note similarities between ALIA experiences and anarchic hand sign (AHS) and argue that, despite important differences, both ALIA experiences and AHS phenomenology reflect failures of executive control to intervene and cancel contrary affordance-driven habitual motor plans. PMID:19264515

  18. Early lens development in the zebrafish: a three-dimensional time-lapse analysis.

    PubMed

    Greiling, Teri M S; Clark, John I

    2009-09-01

    In vivo, high-resolution, time-lapse imaging characterized lens development in the zebrafish from 16 to 96 hr postfertilization (hpf). In zebrafish, the lens placode appeared in the head ectoderm, similar to mammals. Delamination of the surface ectoderm resulted in the formation of the lens mass, which progressed to a solid sphere of cells separating from the developing cornea at approximately 24 hpf. A lens vesicle was not observed and apoptosis was not a major factor in separation of the lens from the future cornea. Differentiation of primary fibers began in the lens mass followed by formation of the anterior epithelium after delamination was complete. Secondary fibers differentiated from elongating epithelial cells near the posterior pole. Quantification characterized three stages of lens growth. The study confirmed the advantages of live-cell imaging for three-dimensional quantitative structural characterization of the mechanism(s) responsible for cell differentiation in formation of a transparent, symmetric, and refractile lens. PMID:19504455

  19. Time-lapse cinematography of the capillary tube cell migration inhibition test.

    PubMed

    Bray, M A

    1980-01-01

    The kinetics of human and guinea pig cell migration inhibition have been studied using time-lapse cinematography of cells migrating from capillary tubes. Guinea pig and human cells exhibit markedly different kinetics in the absence of inhibitors. Specific antigen causes a dose-related inhibition of migration for up to 60 h using guinea pig cells and a peak of inhibition after 18 h using the human leucocyte system. The timing of measurement of maximum activity more critical for the latter test. The kinetics of lymphokine generation have been examined and the migration inhibitory activity of the plant mitogen (PHA), a Kurloff cell product and a continuous cell line supernatant have been compared with the inhibitory profiles of lymphokine preparations and specific antigen. PMID:7350125

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

    PubMed

    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

  1. Smoking Abstinence-Induced Changes in Resting State Functional Connectivity with Ventral Striatum Predict Lapse During a Quit Attempt.

    PubMed

    Sweitzer, Maggie M; Geier, Charles F; Addicott, Merideth A; Denlinger, Rachel; Raiff, Bethany R; Dallery, Jesse; McClernon, F Joseph; Donny, Eric C

    2016-09-01

    The ventral and dorsal striatum are critical substrates of reward processing and motivation and have been repeatedly linked to addictive disorders, including nicotine dependence. However, little is known about how functional connectivity between these and other brain regions is modulated by smoking withdrawal and may contribute to relapse vulnerability. In the present study, 37 smokers completed resting state fMRI scans during both satiated and 24-h abstinent conditions, prior to engaging in a 3-week quit attempt supported by contingency management. We examined the effects of abstinence condition and smoking outcome (lapse vs non-lapse) on whole-brain connectivity with ventral and dorsal striatum seed regions. Results indicated a significant condition by lapse outcome interaction for both right and left ventral striatum seeds. Robust abstinence-induced increases in connectivity with bilateral ventral striatum were observed across a network of regions implicated in addictive disorders, including insula, superior temporal gyrus, and anterior/mid-cingulate cortex among non-lapsers; the opposite pattern was observed for those who later lapsed. For dorsal striatum seeds, 24-h abstinence decreased connectivity across both groups with several regions, including medial prefrontal cortex, posterior cingulate cortex, hippocampus, and supplemental motor area. These findings suggest that modulation of striatal connectivity with the cingulo-insular network during early withdrawal may be associated with smoking cessation outcomes. PMID:27091382

  2. 37 CFR 1.137 - Revival of abandoned application, terminated or limited reexamination prosecution, or lapsed patent.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Revival of abandoned application, terminated or limited reexamination prosecution, or lapsed patent. 1.137 Section 1.137 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES...

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

    ERIC Educational Resources Information Center

    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…

  4. Updated Optimal Designs of Time-Lapse Seismic Surveys for Monitoring CO2 Leakage through Fault Zones

    NASA Astrophysics Data System (ADS)

    Liu, J.; Shang, X.; Sun, Y.; Chen, P.

    2012-12-01

    Cost-effective time-lapse seismic surveys are crucial for long-term monitoring of geologic carbon sequestration. Similar to Shang and Huang (2012), in this study we have numerically modeled time-lapse seismic surveys for monitoring CO2 leakage through fault zones, and designed updated optimal surveys for time-lapse seismic data acquisition using elastic-wave sensitivity analysis. When CO2 was confined in a relatively deep region, our results show that the most desired location for receivers at the surface is at the hanging-wall side of the two fault zones, of high-angle normal faults and reverse faults. The most sensitive places at the surface to the change of different P- and S-wave velocities and density are similar to each other, but are often not sensitive to the source location. When CO2 migrates close to the surface, our modeling suggests that the best region at the surface for time-lapse seismic surveys is very sensitive to the source location and the elastic parameter to be monitored.

  5. Time-Lapse Joint Inversion of Cross-Well DC Resistivity and Seismic Data: A Numerical Investigation

    EPA Science Inventory

    Time-lapse joint inversion of geophysical data is required to image the evolution of oil reservoirs during production and enhanced oil recovery, CO2 sequestration, geothermal fields during production, and to monitor the evolution of contaminant plumes. Joint inversion schemes red...

  6. Characterization of connective tissue progenitors through phase contrast and multicolor fluorescence time-lapse microscopy

    NASA Astrophysics Data System (ADS)

    Kwee, Edward; Powell, Kimerly; Muschler, George

    2015-03-01

    Connective tissue progenitors (CTPs) are defined as the heterogeneous population of tissue resident stem and progenitor cells capable of proliferating and differentiating into connective tissue phenotypes. The prevalence and variation in clonal progeny of CTPs can be characterized using a colony formation assay. However, colony assays do not directly assess the characteristics of the colony founding CTP. We developed a large field of view, time lapse microscopy system with phase contrast and fluorescence capabilities that enables tracking from seeding through colony formation. Cells derived from the trabecular surface of bone were prepared and seeded in an Ibidi-Ph+ chamber slide. Phase contrast images of the slide were obtained every hour using a DMI6000 Leica microscope, 10X objective, and Retiga 2000R camera. Cells were stained using fluorescent antibodies for multiple markers at the time of plating to determine marker expression on seeded cells and re-stained to determine expression on their progeny. Colonies were identified and characterized using automated image processing and quantitative analysis methods. Following colony identification, the time lapse was reversed to identify and characterize the colony founding CTP according to morphology and marker expression. As a representative example, a CD73+/CD90-/CD105- and a CD73+/CD90+/CD105- CTP resulted in a colony with an area of 3720826 microns2 and percent area expression of 2.98%, 3.62%, and 1.13% for CD73, CD90, and CD105, respectively. This method can be used to study CTPs and other stem and progenitor cell populations to benefit point-of-care methods for assay and isolation in cell based therapies.

  7. Time-lapse stereo-photogrammetry to monitor electrical sounding electrodes on an unstable slope

    NASA Astrophysics Data System (ADS)

    Gance, J.; Dewez, T.; Malet, J.-P.; Stumpf, A.

    2012-04-01

    Time-lapse electrical resistivity tomography (ERT) of landslides allows at characterizing the water flows inside the moving mass. Inversion of electrical measurements imposes to locate and track in time the positions of each electrode. The spacing of the electrodes is typically unknown if the electrodes are not equipped with a displacement monitoring system (total station, dGPS antennas, extensometers). Here we tackle this practical problem with time lapse stereo-photogrammetry. In the field, the electrodes were overlaid with white 10cm-diameter Styrofoam spheres and tracked in the stereophoto sequences through image processing of very-high resolution terrestrial photographs. The acquisition profile (114 m long) is located in the most active part of the Super-Sauze landslide which is experiencing average velocities of 2 to 3 cm.day-1 with possible sudden acceleration (0.4 m to 2.0 m.day-1 as observed in 2008). The two cameras are spaced by 75 m which leads to a B/h ratio ranging between 1.6 and 2.1 according to the distribution of electrodes within the image plane The image processing is composed of 4 stages: (i) removal of the slow camera motion, (ii) identification of the electrodes in the 2D image planes; (iii) correction of the lens distortion; (iv) computation of 3D electrode location for each image pair; (v) computation of ERT profile displacement. The method was applied on a serie of 17 photographs over a period of 29 days in June and July 2011. The displacements obtained from stereo-photogrammetry were compared to dGPS campaign measurements, and to the displacement monitored by a permanent GPS receiver.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Improving time-lapse seismic repeatability: CO2CRC Otway site permanent geophone array field trials

    NASA Astrophysics Data System (ADS)

    Pevzner, Roman; Dupuis, Christian; Shulakova, Valeriya; Urosevic, Milovan; Lumley, David

    2013-04-01

    The proposed Stage 2C of the CO2CRC Otway project involves injection of a small amount (around 15,000 tonnes) of CO2/CH4 gas mixture into saline acquifer (Paaratte formation) at the depth of ~1.5 km. The seismic time-lapse signal will depend largely on the formation properties and the injection scenario, but is likely to be relatively weak. In order to improve time-lapse seismic monitoring capabilities by decreasing the noise level, a buried receiver arrays can be used. A small-scale trial of such an array was conducted at Otway site in June 2012. A set of 25 geophones was installed in 3 m deep boreholes in parallel to the same number of surface geophones. In addition, four geophones were placed into boreholes of 1 to 12 m depth. In order to assess the gain in the signal-to-noise ratio and repeatability, both active and passive seismic surveys were carried out. The surveys were conducted in relatively poor weather conditions, with rain, strong wind and thunderstorms increasing the noise level. We found that noise level for buried geophones is on average 20 dB lower compared to the surface ones. Furthermore, the combination of active and passive experiments has allowed us to perform a detailed classification of various noise sources. Acknowledgement The authors acknowledge the funding provided by the Australian government through its CRC program to support this CO2CRC research project. We also acknowledge the CO2CRC's corporate sponsors and the financial assistance provided through Australian National Low Emissions Coal Research and Development (ANLEC R&D). ANLEC R&D is supported by Australian Coal Association Low Emissions Technology Limited and the Australian Government through the Clean Energy Initiative.

  10. Low-Cost Motility Tracking System (LOCOMOTIS) for Time-Lapse Microscopy Applications and Cell Visualisation

    PubMed Central

    Lynch, Adam E.; Triajianto, Junian; Routledge, Edwin

    2014-01-01

    Direct visualisation of cells for the purpose of studying their motility has typically required expensive microscopy equipment. However, recent advances in digital sensors mean that it is now possible to image cells for a fraction of the price of a standard microscope. Along with low-cost imaging there has also been a large increase in the availability of high quality, open-source analysis programs. In this study we describe the development and performance of an expandable cell motility system employing inexpensive, commercially available digital USB microscopes to image various cell types using time-lapse and perform tracking assays in proof-of-concept experiments. With this system we were able to measure and record three separate assays simultaneously on one personal computer using identical microscopes, and obtained tracking results comparable in quality to those from other studies that used standard, more expensive, equipment. The microscopes used in our system were capable of a maximum magnification of 413.6×. Although resolution was lower than that of a standard inverted microscope we found this difference to be indistinguishable at the magnification chosen for cell tracking experiments (206.8×). In preliminary cell culture experiments using our system, velocities (mean µm/min ± SE) of 0.81±0.01 (Biomphalaria glabrata hemocytes on uncoated plates), 1.17±0.004 (MDA-MB-231 breast cancer cells), 1.24±0.006 (SC5 mouse Sertoli cells) and 2.21±0.01 (B. glabrata hemocytes on Poly-L-Lysine coated plates), were measured and are consistent with previous reports. We believe that this system, coupled with open-source analysis software, demonstrates that higher throughput time-lapse imaging of cells for the purpose of studying motility can be an affordable option for all researchers. PMID:25121722

  11. Recreational use assessment of water-based activities, using time-lapse construction cameras.

    PubMed

    Sunger, Neha; Teske, Sondra S; Nappier, Sharon; Haas, Charles N

    2012-01-01

    Recreational exposure to surface waters during periods of increased pathogen concentration may lead to a significantly higher risk of illness. However, estimates of elementary exposure factors necessary to evaluate health risk (i.e., usage distributions and exposure durations) are not available for many non-swimming water-related activities. No prior studies have assessed non-swimming water exposure with respect to factors leading to impaired water quality from increased pathogen concentration, such as weather condition (rain events produce increased runoff and sewer overflows) and type of day (heavy recreational periods). We measured usage patterns and evaluated the effect of weather and type of day at eight water sites located within Philadelphia, by using a novel "time lapse photography" technology during three peak recreational seasons (May-September) 2008-2010. Camera observations validated with simultaneous in-person surveys exhibited a strong correlation (R(2)=0.81 to 0.96) between the two survey techniques, indicating that the application of remote photography in collecting human exposure data was appropriate. Recreational activities usage varied more on a temporal basis than due to inclement weather. Only 14% (6 out of 44) of the site-specific activity combinations showed dry weather preference, whereas 41.5% (17 out of 41) of the combinations indicated greater usage on weekends as compared with weekday. In general, the log normal distribution described the playing and wading duration distribution, while the gamma distribution was the best fit for fishing durations. Remote photography provided unbiased, real-time human exposure data and was less personnel intensive compared with traditional survey methods. However, there are potential limitations associated with remote surveillance data related to its limited view. This is the first study to report that time lapse cameras can be successfully applied to assess water-based human recreational patterns and can

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

    PubMed

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Time-lapse capacitive resistivity imaging: a new technology concept for the monitoring of permafrost

    NASA Astrophysics Data System (ADS)

    Kuras, O.; Krautblatter, M.; Murton, J.; Haslam, E.; Wilkinson, P.; Meldrum, P.

    2011-12-01

    We have investigated and sought to prove a new technology concept for the non-invasive volumetric imaging and routine temporal monitoring of the thermal state of permafrost, a key indicator of global climate change. Capacitive Resistivity Imaging (CRI), a technique based upon low-frequency, capacitively-coupled measurements across permanently installed multi-sensor arrays is applied in order to emulate Electrical Resistivity Tomography (ERT) methodology, but without the need for galvanic contact on frozen soils or rocks. Recent work has shown that temperature-calibrated ERT using galvanic sensors is capable of imaging recession and re-advance of rock permafrost in response to the ambient temperature regime. However, our own laboratory experiments on rock samples under simulated permafrost conditions have equally demonstrated that galvanic electrodes experience large variations in contact resistances between sensors and the host material as the active layer freezes and thaws, leading to a rapid deterioration of data quality over time. As the presence of systematic but uncontrolled sensor noise will reduce the value of time-lapse ERT datasets for monitoring permafrost, the use of galvanic sensors will invariably impose practical limitations on field measurements. The capacitive methodology we are presenting here overcomes this problem and provides a roadmap for making stable resistance measurements with permanently installed sensors over time. We report on our experience with designing, building, testing and validating a functional prototype time-lapse CRI measurement system. The practical system architecture draws upon conceptual ideas incorporated in existing, field-scale CRI instrumentation designed by BGS; however, the use of dense capacitive sensor networks at the laboratory scale and the need for collecting tomographic imaging data across multiple sensors in an automated fashion required a novel technical approach. Our research has applied 4D CRI as well as

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

    NASA Astrophysics Data System (ADS)

    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. Time-lapse electrical resistivity tomography: a powerful tool for landslide monitoring?

    NASA Astrophysics Data System (ADS)

    Perrone, A.

    2011-12-01

    The extreme rainfall events and the quick snowmelt occurrences play an important role in the triggering of the landslides. The occurrence of one of these factors can determine the variation of water content in the first layers of the subsoil and as a consequence a quick soil saturation inducing both an increase in pore-water pressures and the overloaded of the slopes progressively collapsing. The electrical resistivity, self-potential, electromagnetic induction and GPR methods can be considered as the most appropriate for assessing the presence of water in the underground. Such methods allow us to study the behavior of water content over much wider and deeper areas than those offered by traditional methods (thermo-gravimetric, tensiometric, TDR, etc) based on spot measures and concerning small volumes. In particular, the Electrical Resistivity Tomography (ERT), which has already proved to be a powerful tool both for the geometrical reconstruction of a landslide body (location of sliding surface, estimation of the thickness of the slide material) and the individuation of high water content areas, can be considered as an alternative tool to be employed for a qualitative and quantitative water content monitoring in the first layers of the subsoil. Indeed, time-lapse 2D ERT can be tested in order to gather information on the temporal and spatial patterns of water infiltration processes and water content variation. This work reports the preliminary results from a new prototype system planned to obtain time-lapse 2D ERTs, TDR and precipitation measurements in two landslide areas located in the Southern Apennine chain (Italy). The system was planned with the aim to estimate the variation of the resistivity parameter on a long period considering the water content variation, the rain water infiltration and the seasonal changes. The prototype system, linked to a pc used for storing data and managing the time interval acquisition, consists of: a resistivimeter connected to a

  17. Muscle satellite cell proliferation and association: new insights from myofiber time-lapse imaging

    PubMed Central

    2011-01-01

    Background As the resident stem cells of skeletal muscle, satellite cells are activated by extracellular cues associated with local damage. Once activated, satellite cells will re-enter the cell cycle to proliferate and supply a population of myoblasts, which will repair or replace damaged myofibers by differentiating and fusing either with an existing myofiber or with each other. There is also evidence that the orientation of cell division with respect to the myofiber may indicate or convey asymmetry in the two daughter cells. Our recent studies with time-lapse imaging of myofiber-associated satellite cells in vitro have yielded new data on the timing and orientation of satellite cell divisions, and revealed persistent differences in the behavior of daughter cells from planar versus vertical divisions. Results We analyzed 244 individual fiber-associated satellite cells in time-lapse video from 24 to 48 hours after myofiber harvest. We found that initial cell division in fiber culture is not synchronous, although presumably all cells were activated by the initial trauma of harvest; that cell cycling time is significantly shorter than previously thought (as short as 4.8 hours, averaging 10 hours between the first and second divisions and eight hours between the second and third); and that timing of subsequent divisions is not strongly correlated with timing of the initial division. Approximately 65% of first and 80% of second cell divisions occur parallel to the axis of the myofiber, whereas the remainder occur outside the plane of the fiber surface (vertical division). We previously demonstrated that daughter cells frequently remain associated with each other after division or reassociate after a brief separation, and that unrelated cells may also associate for significant periods of time. We show in this paper that daughter cells resulting from a vertical division remain associated with one another several times longer than do daughters from a horizontal division

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

    NASA Astrophysics Data System (ADS)

    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

  19. Fast history matching of time-lapse seismic and production data for high resolution models

    NASA Astrophysics Data System (ADS)

    Jimenez Arismendi, Eduardo Antonio

    Integrated reservoir modeling has become an important part of day-to-day decision analysis in oil and gas management practices. A very attractive and promising technology is the use of time-lapse or 4D seismic as an essential component in subsurface modeling. Today, 4D seismic is enabling oil companies to optimize production and increase recovery through monitoring fluid movements throughout the reservoir. 4D seismic advances are also being driven by an increased need by the petroleum engineering community to become more quantitative and accurate in our ability to monitor reservoir processes. Qualitative interpretations of time-lapse anomalies are being replaced by quantitative inversions of 4D seismic data to produce accurate maps of fluid saturations, pore pressure, temperature, among others. Within all steps involved in this subsurface modeling process, the most demanding one is integrating the geologic model with dynamic field data, including 4Dseismic when available. The validation of the geologic model with observed dynamic data is accomplished through a "history matching" (HM) process typically carried out with well-based measurements. Due to low resolution of production data, the validation process is severely limited in its reservoir areal coverage, compromising the quality of the model and any subsequent predictive exercise. This research will aim to provide a novel history matching approach that can use information from high-resolution seismic data to supplement the areally sparse production data. The proposed approach will utilize streamline-derived sensitivities as means of relating the forward model performance with the prior geologic model. The essential ideas underlying this approach are similar to those used for high-frequency approximations in seismic wave propagation. In both cases, this leads to solutions that are defined along "streamlines" (fluid flow), or "rays" (seismic wave propagation). Synthetic and field data examples will be used

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

    NASA Astrophysics Data System (ADS)

    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

  1. Morphokinetic behavior of euploid and aneuploid embryos analyzed by time-lapse in embryoscope

    PubMed Central

    Patel, Deven V.; Shah, Preeti B.; Kotdawala, Aditi P.; Herrero, Javier; Rubio, Irene; Banker, Manish R.

    2016-01-01

    BACKGROUND: Embryonic aneuploidy may result in miscarriage, implantation failure, or birth defects. Thus, it is clinically necessary to avoid the selection of aneuploid embryos during in vitro fertilization treatment. AIM: The aim of this study was to identify the morphokinetic differences by analyzing the development of euploid and aneuploid embryos using a time-lapse technology. We also checked the accuracy of a previously described model for selection of euploid embryos based on morphokinetics in our study population. MATERIALS AND METHODS: It is a retrospective study of 29 cycles undergoing preimplantation genetic screening from October 2013 to April 2015 at our center. Of 253 embryos, 167 suitable for biopsy embryos were analyzed for their chromosomal status using array-comparative genome hybridization (CGH). The morphokinetic behavior of these embryos was further analyzed in embryoscope using time-lapse technology. RESULTS: Among the analyzed embryos, 41 had normal and 126 had abnormal chromosome content. No significant difference in morphokinetics was found between euploid and aneuploid embryos. The percentage of embryos with blastulation was similar in the euploid (65.85%, 27/41) and aneuploid (60.31%, 76/126) embryos (P = 0.76). Although hard to define, majority of the chromosomal defects might be due to meiotic errors. On applying embryo selection model from Basile et al., embryos falling within optimal ranges for time to division to 5 cells (t5), time period of the third cell cycle (CC3), and time from 2 cell division to 5 cell division (t5-t2) exhibited greater proportion of normal embryos than those falling outside the optimal ranges (28.6%, 25.9%, and 26.7% vs. 17.5%, 20.8%, and 14.3%). CONCLUSION: Keeping a track of time interval between two stages can help us recognize aneuploid embryos at an earlier stage and prevent their selection of transfer. However, it cannot be used as a substitute for array CGH to select euploid embryos for transfer. PMID

  2. Acquisition of time-lapse, 6-component, P- and S-wave, crosswell seismic survey with orbital vibrator and of time-lapse VSP for CO2 injection monitoring

    SciTech Connect

    Daley, Tom; Daley, T.M.; Myer, L.R.; Majer, E.L.

    2004-07-15

    Using an orbital vibrator source (2-components), and a 40 level 3-component geophone string, a 6-component crosswell survey was acquired before and after a CO2 injection in a saline aquifer. Decomposition of the two source components and component rotation of both source and sensors created good separation of P- and S-wave energy allowing independent analysis of travel time and reflectivity. A time-lapse VSP was also acquired.

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

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Time lapse seismic signal analysis for Cranfield, MS, EOR and CCS site

    NASA Astrophysics Data System (ADS)

    Ditkof, J.; Caspari, E.; Pevzner, R.; Urosevic, M.; Meckel, T. A.; Hovorka, S. D.

    2012-12-01

    The Cranfield field located in Southwest Mississippi is an EOR and CCS project which has been under continuous CO2 injection by Denbury Onshore LLC since 2008. To date, more than 3 million tons of CO2 remain in the subsurface. In 2007 and 2010, 3D seismic surveys were shot and an initial 4D seismic response was characterized showing coherent amplitude anomalies in some areas which received large amounts of CO2, but not in others. Previous work used Gassmann fluid substitution at two different wells, 31F-2 observation well and the 28-1 injection well to predict a post-injection saturation curves and acoustic impedance change through the reservoir. Since this writing, a second injection well, the 44-2 well, was added to the analysis to improve the practically unconstrained inversion. The two seismic volumes were cross-equalized with an appropriate correlation coefficient through well ties. Acoustic impedance inversions were carried out on each survey resulting with higher acoustic impedance changes than predicted by Gassmann for the 28-1 and 44-2 injection wells. The time-lapse acoustic impedance however is similar to the difference calculated from a time-delay along a horizon below the reservoir.

  6. Quantitative comparison of multiframe data association techniques for particle tracking in time-lapse fluorescence microscopy.

    PubMed

    Smal, Ihor; Meijering, Erik

    2015-08-01

    Biological studies of intracellular dynamic processes commonly require motion analysis of large numbers of particles in live-cell time-lapse fluorescence microscopy imaging data. Many particle tracking methods have been developed in the past years as a first step toward fully automating this task and enabling high-throughput data processing. Two crucial aspects of any particle tracking method are the detection of relevant particles in the image frames and their linking or association from frame to frame to reconstruct the trajectories. The performance of detection techniques as well as specific combinations of detection and linking techniques for particle tracking have been extensively evaluated in recent studies. Comprehensive evaluations of linking techniques per se, on the other hand, are lacking in the literature. Here we present the results of a quantitative comparison of data association techniques for solving the linking problem in biological particle tracking applications. Nine multiframe and two more traditional two-frame techniques are evaluated as a function of the level of missing and spurious detections in various scenarios. The results indicate that linking techniques are generally more negatively affected by missing detections than by spurious detections. If misdetections can be avoided, there appears to be no need to use sophisticated multiframe linking techniques. However, in the practically likely case of imperfect detections, the latter are a safer choice. Our study provides users and developers with novel information to select the right linking technique for their applications, given a detection technique of known quality. PMID:26176413

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Metamorphosis revealed: time-lapse three-dimensional imaging inside a living chrysalis

    PubMed Central

    Lowe, Tristan; Garwood, Russell J.; Simonsen, Thomas J.; Bradley, Robert S.; Withers, Philip J.

    2013-01-01

    Studies of model insects have greatly increased our understanding of animal development. Yet, they are limited in scope to this small pool of model species: a small number of representatives for a hyperdiverse group with highly varied developmental processes. One factor behind this narrow scope is the challenging nature of traditional methods of study, such as histology and dissection, which can preclude quantitative analysis and do not allow the development of a single individual to be followed. Here, we use high-resolution X-ray computed tomography (CT) to overcome these issues, and three-dimensionally image numerous lepidopteran pupae throughout their development. The resulting models are presented in the electronic supplementary material, as are figures and videos, documenting a single individual throughout development. They provide new insight and details of lepidopteran metamorphosis, and allow the measurement of tracheal and gut volume. Furthermore, this study demonstrates early and rapid development of the tracheae, which become visible in scans just 12 h after pupation. This suggests that there is less remodelling of the tracheal system than previously expected, and is methodologically important because the tracheal system is an often-understudied character system in development. In the future, this form of time-lapse CT-scanning could allow faster and more detailed developmental studies on a wider range of taxa than is presently possible. PMID:23676900

  9. A time-lapse photography method for monitoring salmon (Oncorhynchus spp.) passage and abundance in streams.

    PubMed

    Deacy, William W; Leacock, William B; Eby, Lisa A; Stanford, Jack A

    2016-01-01

    Accurately estimating population sizes is often a critical component of fisheries research and management. Although there is a growing appreciation of the importance of small-scale salmon population dynamics to the stability of salmon stock-complexes, our understanding of these populations is constrained by a lack of efficient and cost-effective monitoring tools for streams. Weirs are expensive, labor intensive, and can disrupt natural fish movements. While conventional video systems avoid some of these shortcomings, they are expensive and require excessive amounts of labor to review footage for data collection. Here, we present a novel method for quantifying salmon in small streams (<15 m wide, <1 m deep) that uses both time-lapse photography and video in a model-based double sampling scheme. This method produces an escapement estimate nearly as accurate as a video-only approach, but with substantially less labor, money, and effort. It requires servicing only every 14 days, detects salmon 24 h/day, is inexpensive, and produces escapement estimates with confidence intervals. In addition to escapement estimation, we present a method for estimating in-stream salmon abundance across time, data needed by researchers interested in predator--prey interactions or nutrient subsidies. We combined daily salmon passage estimates with stream specific estimates of daily mortality developed using previously published data. To demonstrate proof of concept for these methods, we present results from two streams in southwest Kodiak Island, Alaska in which high densities of sockeye salmon spawn. PMID:27326378

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  12. Setting up a groundwater recharge model for an arid karst system using time lapse camera data

    NASA Astrophysics Data System (ADS)

    Schulz, Stephan; de Rooij, Gerrit H.; Michelsen, Nils; Rausch, Randolf; Siebert, Christian; Schüth, Christoph; Merz, Ralf

    2015-04-01

    Groundwater is the principal water resource in most dryland areas. Therefore, its replenishment rate is of great importance for water management. The amount of groundwater recharge depends on the climatic conditions, but also on the geological conditions, soil properties and vegetation. In dryland areas, outcrops of karst aquifers often receive enhanced recharge rates compared to other geological settings. Especially in areas with exposed karst features like sinkholes or open shafts rainfall accumulates in channels and discharges directly into the aquifer. Using the example of the As Sulb plateau in Saudi Arabia this study introduces a cost-effective and robust method for recharge monitoring and modelling in karst outcrops. The measurement of discharge of a small catchment (4.0 x 104 m2) into a sinkhole, and hence the direct recharge into the aquifer, was carried out with a time lapse camera observing a v-notch weir. During the monitoring period of two rainy seasons (autumn 2012 to spring 2014) four recharge events were recorded. Afterwards, recharge data as well as proxy data about the drying of the sediment cover are used to set up a conceptual water balance model. This model was run for 17 years (1971 to 1986 and 2012 to 2014). Simulation results show highly variable seasonal recharge-precipitation-ratios, which underlines the nonlinearity between recharge and precipitation in dryland areas. Besides the amount of precipitation this ratio is strongly influenced by the interannual distribution of rainfall events.

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

    NASA Astrophysics Data System (ADS)

    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%.

  14. Protein kinase A catalytic subunit primed for action: Time-lapse crystallography of Michaelis complex formation

    DOE PAGESBeta

    Das, Amit; Gerlits, Oksana O.; Parks, Jerry M.; Langan, Paul; Kovalevskyi, Andrey Y.; Heller, William T.

    2015-11-12

    The catalytic subunit of the cyclic AMP-dependent protein kinase A (PKAc) catalyzes the transfer of the γ-phosphate of bound Mg2ATP to a serine or threonine residue of a protein substrate. Here, time-lapse X-ray crystallography was used to capture a series of complexes of PKAc with an oligopeptide substrate and unreacted Mg2ATP, including the Michaelis complex, that reveal important geometric rearrangements in and near the active site preceding the phosphoryl transfer reaction. Contrary to the prevailing view, Mg2+ binds first to the M1 site as a complex with ATP and is followed by Mg2+ binding to the M2 site. Furthermore, themore » target serine hydroxyl of the peptide substrate rotates away from the active site toward the bulk solvent, which breaks the hydrogen bond with D166. In conclusion, the serine hydroxyl of the substrate rotates back toward D166 to form the Michaelis complex with the active site primed for phosphoryl transfer.« less

  15. Time-lapse ERT for the monitoring of soil-plant interactions in the root zone

    NASA Astrophysics Data System (ADS)

    Cassiani, G.; Boaga, J.; Rossi, M.; D'Alpaos, A.; Fadda, G.; Putti, M.; Marani, M.

    2013-12-01

    The application of time-lapse non invasive 3D micro-scale electrical resistivity tomography (ERT) has been proven to be an efficient tool to monitor the soil-plant interactions and particularly the root zone activity. This information can support water balance modeling in the upper subsoil critical zone. Here we present the results of two field experiments in very different environments: the case of a single apple tree in an orchard located in the Trentino region (Northern Italy), and the case of salt-marshes plants in the Venice Lagoon. The micro-scale ERT apparatus consists of buried electrodes installed on micro boreholes, plus mini-electrodes on the ground surface. We collected repeated ERT, TDR and tensiometer data. For the apple orchard site test we adopted controlled irrigation tests in different seasons, while in the lagoon salt-marshes we monitored the root-plant activity during tidal flooding. The results demonstrate that micro-scale ERT is a very effective tool to characterize subsoil conditions and monitor root zone activities, especially in terms of root zone suction regions. Micro-scale ERT can detect the main suction zones caused by the tree root activity, as demonstrated in the case of the apple orchard, while ERT and moisture measurements in the lagoon environment show a high resistivity suction layer located at root depth even during marsh flooding. Both observations will be important pieces of information for the comprehension of relevant eco- hydrological dynamics.

  16. Time-lapse ERT for the monitoring of soil-plant interactions in the root zone

    NASA Astrophysics Data System (ADS)

    Cassiani, G.; Boaga, J.; Rossi, M.; D'Alpaos, A.; Fadda, G.; Putti, M.; Marani, M.

    2011-12-01

    The application of time-lapse non invasive 3D micro-scale electrical resistivity tomography (ERT) has been proven to be an efficient tool to monitor the soil-plant interactions and particularly the root zone activity. This information can support water balance modeling in the upper subsoil critical zone. Here we present the results of two field experiments in very different environments: the case of a single apple tree in an orchard located in the Trentino region (Northern Italy), and the case of salt-marshes plants in the Venice Lagoon. The micro-scale ERT apparatus consists of buried electrodes installed on micro boreholes, plus mini-electrodes on the ground surface. We collected repeated ERT, TDR and tensiometer data. For the apple orchard site test we adopted controlled irrigation tests in different seasons, while in the lagoon salt-marshes we monitored the root-plant activity during tidal flooding. The results demonstrate that micro-scale ERT is a very effective tool to characterize subsoil conditions and monitor root zone activities, especially in terms of root zone suction regions. Micro-scale ERT can detect the main suction zones caused by the tree root activity, as demonstrated in the case of the apple orchard, while ERT and moisture measurements in the lagoon environment show a high resistivity suction layer located at root depth even during marsh flooding. Both observations will be important pieces of information for the comprehension of relevant eco- hydrological dynamics.

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    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 infiltration and flow within the landslide body. Combined with borehole data, inverted resistivity models accurately defined the interface between Quaternary sediments and bedrock. Preferential flow pathways attributed to fracture zones and fissures were also delineated. In addition, we found that surface water permeates through these pathways into the slipping mass and drains away as fissure 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.

  18. Study of traveltime and amplitude time-lapse tomography using physical model data

    SciTech Connect

    Leggett, M. . Dept. of Geological Sciences Univ. of Strathclyde, Glasgow . Dept. of Electron and Electric Engineering); Goulty, N.R. . Dept. of Geological Sciences); Kragh, J.E. . Dept. of Geological Sciences Schlumberger Cambridge Research )

    1993-07-01

    In seismic tomography the observed traveltimes or amplitudes of direct waves are inverted to obtain an estimate of seismic velocity or absorption of the section surveyed. There has been much recent interest in using cross-well traveltime tomography to observe the progress of fluids injected into the reservoir rocks during enhanced oil recovery (EOR) processes. If repeated surveys are carried out, then EOR processes may monitored over a period of time. This paper describe the results of simulated time-lapse tomography experiment to image the flood zone in an EOR process. Two physical models were made out of epoxy resins to simulate an essentially plane-layered sedimentary sequence containing a reservoir layer and simple geological structure. The models differed only in the reservoir layer, which was uniform in the pre-flood' model and contained a flood zone of known geometry in the post-flood' model. Data sets were acquired from each model using a cross-well survey geometry. Traveltime and amplitude tomographic imaging techniques have been applied to these data in an attempt to locate the extent of the flood zone. Traveltime tomography locates the flood zone quite accurately. Amplitude tomography shows the flood zone as a region of higher absorption, but does not image its boundaries as precisely. This is primarily because of multipathing and diffraction effects, which are not accounted for by the ray-based techniques for inverting seismic amplitudes.

  19. Protein Kinase A Catalytic Subunit Primed for Action: Time-Lapse Crystallography of Michaelis Complex Formation.

    PubMed

    Das, Amit; Gerlits, Oksana; Parks, Jerry M; Langan, Paul; Kovalevsky, Andrey; Heller, William T

    2015-12-01

    The catalytic subunit of the cyclic AMP-dependent protein kinase A (PKAc) catalyzes the transfer of the γ-phosphate of bound Mg2ATP to a serine or threonine residue of a protein substrate. Here, time-lapse X-ray crystallography was used to capture a series of complexes of PKAc with an oligopeptide substrate and unreacted Mg2ATP, including the Michaelis complex, that reveal important geometric rearrangements in and near the active site preceding the phosphoryl transfer reaction. Contrary to the prevailing view, Mg(2+) binds first to the M1 site as a complex with ATP and is followed by Mg(2+) binding to the M2 site. Concurrently, the target serine hydroxyl of the peptide substrate rotates away from the active site toward the bulk solvent, which breaks the hydrogen bond with D166. Lastly, the serine hydroxyl of the substrate rotates back toward D166 to form the Michaelis complex with the active site primed for phosphoryl transfer. PMID:26585512

  20. Segmentation Method of Time-Lapse Microscopy Images with the Focus on Biocompatibility Assessment.

    PubMed

    Soukup, Jindřich; Císař, Petr; Šroubek, Filip

    2016-06-01

    Biocompatibility testing of new materials is often performed in vitro by measuring the growth rate of mammalian cancer cells in time-lapse images acquired by phase contrast microscopes. The growth rate is measured by tracking cell coverage, which requires an accurate automatic segmentation method. However, cancer cells have irregular shapes that change over time, the mottled background pattern is partially visible through the cells and the images contain artifacts such as halos. We developed a novel algorithm for cell segmentation that copes with the mentioned challenges. It is based on temporal differences of consecutive images and a combination of thresholding, blurring, and morphological operations. We tested the algorithm on images of four cell types acquired by two different microscopes, evaluated the precision of segmentation against manual segmentation performed by a human operator, and finally provided comparison with other freely available methods. We propose a new, fully automated method for measuring the cell growth rate based on fitting a coverage curve with the Verhulst population model. The algorithm is fast and shows accuracy comparable with manual segmentation. Most notably it can correctly separate live from dead cells. PMID:27132464

  1. Time-lapse crosswell seismic and VSP monitoring of injected CO2 ina brine aquifer

    SciTech Connect

    Daley, Thomas M.; Myer, Larry R.; Peterson, J.E.; Majer, E.L.; Hoversten,G.M.

    2006-05-30

    Seismic surveys successfully imaged a small scale C02injection (1,600 tons) conducted in a brine aquifer of the Frio Formationnear Houston, Texas. These time-lapse bore-hole seismic surveys,crosswell and vertical seismic profile (VSP), were acquired to monitorthe C02 distribution using two boreholes (the new injection well and apre-existing well used for monitoring) which are 30 m apart at a depth of1500 m. The crosswell survey provided a high-resolution image of the C02distribution between the wells via tomographic imaging of the P-wavevelocity decrease (up to 500 mls). The simultaneously acquired S-wavetomography showed little change in S-wave velocity, as expected for fluidsubstitution. A rock physics model was used to estimate C02 saturationsof 10-20 percent from the P-wave velocity change. The VSP survey resolveda large (-70 percent) change in reflection amplitude for the Friohorizon. This C02 induced reflection amplitude change allowed estimationof the C02 extent beyond the monitor well and on 3 azimuths. The VSPresult is compared with numerical modeling of C02 saturations and isseismically modeled using the velocity change estimated in the crosswellsurvey.

  2. Time-lapse microscopy studies of bystander effects induced by photosensitization

    NASA Astrophysics Data System (ADS)

    Chen, Yin-Chu; Redmond, Robert W.

    2006-02-01

    Reactive oxygen species (ROS) are involved in the pathogenesis of many critical diseases and are also utilized as cytotoxic agents in a variety of treatments for eradication of diseased tissue, including cancer. Oxidative stress ensues when the level of ROS in a system exceeds the antioxidant capacity. Oxidative stress can have local (direct) and long-range (bystander) effects in cells and tissue and this research was carried out to determine the spatial and temporal nature of the photosensitized bystander effect using time-lapse fluorescence microscopy. By initiating photosensitization in only a portion of the microscopic imaging field it was possible to differentiate direct from bystander effects in EMT-6 murine breast cancer cells in 6-well plates. Elevated ROS levels are seen immediately following photodynamic treatment in direct cells with a delayed increase in oxidative stress observed in bystander cells. Cytotoxicity is also seen at earlier times in direct cells and occurs in bystander cells in a delayed fashion. These studies confirm the existence of a bystander effect following photosensitization and implicate mediators capable of diffusing in an intercellular manner from directly photosensitized cells to bystander cells and also implicate increased oxidative stress as a mechanistic factor in generating damage in bystander cells.

  3. Time-lapse geophysical investigations over a simulated urban clandestine grave.

    PubMed

    Pringle, Jamie K; Jervis, John; Cassella, John P; Cassidy, Nigel J

    2008-11-01

    A simulated clandestine shallow grave was created within a heterogeneous, made-ground, urban environment where a clothed, plastic resin, human skeleton, animal products, and physiological saline were placed in anatomically correct positions and re-covered to ground level. A series of repeat (time-lapse), near-surface geophysical surveys were undertaken: (1) prior to burial (to act as control), (2) 1 month, and (3) 3 months post-burial. A range of different geophysical techniques was employed including: bulk ground resistivity and conductivity, fluxgate gradiometry and high-frequency ground penetrating radar (GPR), soil magnetic susceptibility, electrical resistivity tomography (ERT), and self potential (SP). Bulk ground resistivity and SP proved optimal for initial grave location whilst ERT profiles and GPR horizontal "time-slices" showed the best spatial resolutions. Research suggests that in complex urban made-ground environments, initial resistivity surveys be collected before GPR and ERT follow-up surveys are collected over the identified geophysical anomalies. PMID:18808369

  4. Protein kinase A catalytic subunit primed for action: Time-lapse crystallography of Michaelis complex formation

    SciTech Connect

    Das, Amit; Gerlits, Oksana O.; Parks, Jerry M.; Langan, Paul; Kovalevskyi, Andrey Y.; Heller, William T.

    2015-11-12

    The catalytic subunit of the cyclic AMP-dependent protein kinase A (PKAc) catalyzes the transfer of the γ-phosphate of bound Mg2ATP to a serine or threonine residue of a protein substrate. Here, time-lapse X-ray crystallography was used to capture a series of complexes of PKAc with an oligopeptide substrate and unreacted Mg2ATP, including the Michaelis complex, that reveal important geometric rearrangements in and near the active site preceding the phosphoryl transfer reaction. Contrary to the prevailing view, Mg2+ binds first to the M1 site as a complex with ATP and is followed by Mg2+ binding to the M2 site. Furthermore, the target serine hydroxyl of the peptide substrate rotates away from the active site toward the bulk solvent, which breaks the hydrogen bond with D166. In conclusion, the serine hydroxyl of the substrate rotates back toward D166 to form the Michaelis complex with the active site primed for phosphoryl transfer.

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

    USGS Publications Warehouse

    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.

  6. Time lapse electrical resistivity and induced polarization monitoring of near-surface CO2 injection

    NASA Astrophysics Data System (ADS)

    Allègre, V.; Kremer, T.; Williard, E.; Schmutz, M.; Maineult, A. J.

    2013-12-01

    Field experiments were carried out to investigate the efficiency and the reliability of electrical geophysical methods to detect and monitor CO2 leakages at field scale. Each test consisted of injecting CO2 for approximately four hours at five meters depth, corresponding to a cumulative mass of gas of around six kilograms. Electrical resistivity tomography and temporal induced polarization were acquired at the surface before, during and after injections along profiles centered to the injection well. Time lapse measurements were compared to a reference acquisition performed before the injection. We observe that both methods are sensitive to variations in terms of gas saturation, the chargeability measurements being more sensitive to the presence of CO2 than electrical resistivity. During the injection, an increase of chargeability and a decrease of the measured resistivity are observed at depth in the vinicity of the injection well. Afterwards, the medium equilibrates and retrieves its original state, corresponding to the reference acquisition. The temporal variations of electrical resistivity and induced polarization responses are interpreted in terms of gas dissolution and water/gas saturation.

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

    PubMed Central

    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

  8. Cellular dynamics during early barley pollen embryogenesis revealed by time-lapse imaging

    PubMed Central

    Daghma, Diaa Eldin S.; Hensel, Goetz; Rutten, Twan; Melzer, Michael; Kumlehn, Jochen

    2014-01-01

    Plants display a remarkable capacity for cellular totipotency. An intriguing and useful example is that immature pollen cultured in vitro can pass through embryogenic development to form haploid or doubled haploid plants. However, a lack of understanding the initial mechanisms of pollen embryogenesis hampers the improvement and more effective and widespread employment of haploid technology in plant research and breeding. To investigate the cellular dynamics during the onset of pollen embryogenesis, we used time-lapse imaging along with transgenic barley expressing nuclear localized Green Fluorescent Protein. The results enabled us to identify nine distinct embryogenic and non-embryogenic types of pollen response to the culture conditions. Cell proliferation in embryogenic pollen normally started via a first symmetric mitosis (54.3% of pollen observed) and only rarely did so via asymmetric pollen mitosis I (4.3% of pollen observed). In the latter case, proliferation generally originated from the vegetative-like cell, albeit the division of the generative-like cell was observed in few types of pollen. Under the culture conditions used, fusion of cell nuclei was the only mechanism of genome duplication observed. PMID:25538715

  9. Segmenting time-lapse phase contrast images of adjacent NIH 3T3 cells.

    PubMed

    Chalfoun, J; Kociolek, M; Dima, A; Halter, M; Cardone, A; Peskin, A; Bajcsy, P; Brady, M

    2013-01-01

    We present a new method for segmenting phase contrast images of NIH 3T3 fibroblast cells that is accurate even when cells are physically in contact with each other. The problem of segmentation, when cells are in contact, poses a challenge to the accurate automation of cell counting, tracking and lineage modelling in cell biology. The segmentation method presented in this paper consists of (1) background reconstruction to obtain noise-free foreground pixels and (2) incorporation of biological insight about dividing and nondividing cells into the segmentation process to achieve reliable separation of foreground pixels defined as pixels associated with individual cells. The segmentation results for a time-lapse image stack were compared against 238 manually segmented images (8219 cells) provided by experts, which we consider as reference data. We chose two metrics to measure the accuracy of segmentation: the 'Adjusted Rand Index' which compares similarities at a pixel level between masks resulting from manual and automated segmentation, and the 'Number of Cells per Field' (NCF) which compares the number of cells identified in the field by manual versus automated analysis. Our results show that the automated segmentation compared to manual segmentation has an average adjusted rand index of 0.96 (1 being a perfect match), with a standard deviation of 0.03, and an average difference of the two numbers of cells per field equal to 5.39% with a standard deviation of 4.6%. PMID:23126432

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

    PubMed

    Fredborg, M; Rosenvinge, F S; Spillum, E; Kroghsbo, S; Wang, M; Sondergaard, T E

    2015-12-01

    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 oCelloScope 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 (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) and extended-spectrum β-lactamase (ESBL) profiles. The net average time-to-result was 108 min, with 95% of the results being available within 180 min. In conclusion, this study strongly indicates that the oCelloScope system holds considerable potential as an accurate and sensitive AST method with short time-to-result, enabling same-day targeted antimicrobial therapy, facilitating antibiotic stewardship and better patient management. A full-scale validation of the oCelloScope system including more isolates is necessary to assess the impact of using it for AST. PMID:26407621

  11. Adaptive time-lapse optimized survey design for electrical resistivity tomography monitoring

    NASA Astrophysics Data System (ADS)

    Wilkinson, Paul B.; Uhlemann, Sebastian; Meldrum, Philip I.; Chambers, Jonathan E.; Carrière, Simon; Oxby, Lucy S.; Loke, M. H.

    2015-10-01

    Adaptive optimal experimental design methods use previous data and results to guide the choice and design of future experiments. This paper describes the formulation of an adaptive survey design technique to produce optimal resistivity imaging surveys for time-lapse geoelectrical monitoring experiments. These survey designs are time-dependent and, compared to dipole-dipole or static optimized surveys that do not change over time, focus a greater degree of the image resolution on regions of the subsurface that are actively changing. The adaptive optimization method is validated using a controlled laboratory monitoring experiment comprising a well-defined cylindrical target moving along a trajectory that changes its depth and lateral position. The algorithm is implemented on a standard PC in conjunction with a modified automated multichannel resistivity imaging system. Data acquisition using the adaptive survey designs requires no more time or power than with comparable standard surveys, and the algorithm processing takes place while the system batteries recharge. The results show that adaptively designed optimal surveys yield a quantitative increase in image quality over and above that produced by using standard dipole-dipole or static (time-independent) optimized surveys.

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

    NASA Astrophysics Data System (ADS)

    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

    2016-02-01

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Lapses in skin conductance responding across anatomical sites: Comparison of fingers, feet, forehead, and wrist.

    PubMed

    Payne, Andrew F H; Schell, Anne M; Dawson, Michael E

    2016-07-01

    The fingers are widely accepted as the gold standard for skin conductance (SC) recording, with the feet as a strong alternative. However, there are gaps in the current literature comparing these sites. There is also a great deal of interest in alternative recording sites to permit mobility, but data evaluating these are few and inconsistent. The present report compared multiple sites (fingers, abductor hallucis of the foot, arch of the foot, toes, forehead, and wrist) from 45 college student participants in a short-term sedentary laboratory setting and found large variation in both tonic and phasic SC responses, as well as crucial lapses in responding at nonpalmar sites. Across-site correlations between participants and within participants were also examined. The present data show that, in the laboratory setting employing commonly used recording techniques and stimuli, the nonpalmar sites are generally less responsive than the fingers, and the wrist in particular is the lowest in responding, whereas the toes are most similar to the fingers in responding. Within-participant correlations between the fingers and other sites were greatest for the plantar sites and least for the forehead. PMID:27015847

  15. Estimation of soil hydraulic properties based on time-lapse Ground-Penetrating Radar (GPR) measurements

    NASA Astrophysics Data System (ADS)

    Jaumann, Stefan; Klenk, Patrick; Roth, Kurt

    2015-04-01

    Recent developments brought surface-based GPR measurements to a precision that make them useful for estimating soil hydraulic properties. For this study, we estimate Mualem-Brooks-Corey parameters for a layered subsurface material distribution employing the Levenberg-Marquardt inversion algorithm. The required measurement data were recorded at our artificial test site ASSESS, where we forced the hydraulic system with a fluctuating water table and observed the dynamic deformation of the capillary fringe with time-lapse GPR. Subsequently, these measurements were simulated based on a model comprising (i) the Richards equation describing the temporal evolution of the soil hydraulic system which was solved with MUPHI, (ii) the Complex Refractive Index Model (CRIM) serving as petrophysical relationship which links the soil hydraulic model to (iii) the electrodynamic model consisting of Maxwell's equations which are solved with MEEP. For the objective function of the optimization algorithm, both measured and simulated GPR data were evaluated with a semi-automated wavelet feature detection algorithm allowing to directly compare the travel time and amplitude of the GPR signal. In this presentation, we discuss the results of the inversion based on the inversion of GPR data and we also discuss how including Time Domain Reflectometry (TDR) measurement data influences the estimated parameters.

  16. A time-lapse photography method for monitoring salmon (Oncorhynchus spp.) passage and abundance in streams

    PubMed Central

    Leacock, William B.; Eby, Lisa A.; Stanford, Jack A.

    2016-01-01

    Accurately estimating population sizes is often a critical component of fisheries research and management. Although there is a growing appreciation of the importance of small-scale salmon population dynamics to the stability of salmon stock-complexes, our understanding of these populations is constrained by a lack of efficient and cost-effective monitoring tools for streams. Weirs are expensive, labor intensive, and can disrupt natural fish movements. While conventional video systems avoid some of these shortcomings, they are expensive and require excessive amounts of labor to review footage for data collection. Here, we present a novel method for quantifying salmon in small streams (<15 m wide, <1 m deep) that uses both time-lapse photography and video in a model-based double sampling scheme. This method produces an escapement estimate nearly as accurate as a video-only approach, but with substantially less labor, money, and effort. It requires servicing only every 14 days, detects salmon 24 h/day, is inexpensive, and produces escapement estimates with confidence intervals. In addition to escapement estimation, we present a method for estimating in-stream salmon abundance across time, data needed by researchers interested in predator--prey interactions or nutrient subsidies. We combined daily salmon passage estimates with stream specific estimates of daily mortality developed using previously published data. To demonstrate proof of concept for these methods, we present results from two streams in southwest Kodiak Island, Alaska in which high densities of sockeye salmon spawn. PMID:27326378

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

    SciTech Connect

    RUCKER DF; FINK JB; LOKE MH; MYERS DA

    2009-11-05

    Highly industrialized areas pose significant challenges for surface based electrical resistivity characterization and monitoring due to the high degree of metallic infrastructure. The infrastructure is typically several orders of magnitude more conductive than the desired targets, preventing the geophysicist from obtaining a clear picture of the subsurface. These challenges may be minimized if steel-cased wells are used as long electrodes. We demonstrate a method of using long electrodes in a complex nuclear waste facility to monitor a simulated leak from an underground storage tank. The leak was simulated by injecting high conductivity fluid in a perforated well and the resistivity measurements were made before and after the leak test. The data were processed in four dimensions, where a regularization procedure was applied in both the time and space domains. The results showed a lowered resistivity feature develop south of the injection site. The time lapsed regularization parameter had a strong influence on the differences in inverted resistivity between the pre and post datasets, potentially making calibration of the results to specific hydrogeologic parameters difficult.

  18. Designing genetic algorithm for efficient calculation of value encoding in time-lapse gravity inversion

    NASA Astrophysics Data System (ADS)

    Wahyudi, Eko Januari

    2013-09-01

    As advancing application of soft computation technique in oil and gas industry, Genetic Algorithm (GA) also shows contribution in geophysical inverse problems in order to achieve better results and efficiency in computational process. In this paper, I would like to show the progress of my work in inverse modeling of time-lapse gravity data uses value encoding with alphabet formulation. The alphabet formulation designed to provide solution of characterization positive density change (+Δρ) and negative density change (-Δρ) respect to reference value (0 gr/cc). The inversion that utilize discrete model parameter, computed with GA as optimization algorithm. The challenge working with GA is take long time computational process, so the step in designing GA in this paper described through evaluation on GA operators performance test. The performances of several combinations of GA operators (selection, crossover, mutation, and replacement) tested with synthetic model in single-layer reservoir. Analysis on sufficient number of samples shows combination of SUS-MPCO-QSA/G-ND as the most promising results. Quantitative solution with more confidence level to characterize sharp boundary of density change zones was conducted with average calculation of sufficient model samples.

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

    PubMed Central

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

    2012-01-01

    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. PMID:22482997

  20. ESIAC: A data products system for ERTS imagery (time-lapse viewing and measuring)

    NASA Technical Reports Server (NTRS)

    Evans, W. E.; Serebreny, S. M.

    1974-01-01

    An Electronic Satellite Image Analysis Console (ESIAC) has been developed for visual analysis and objective measurement of earth resources imagery. The system is being employed to process imagery for use by USGS investigators in several different disciplines studying dynamic hydrologic conditions. The ESIAC provides facilities for storing registered image sequences in a magnetic video disc memory for subsequent recall, enhancement, and animated display in monochrome or color. The unique feature of the system is the capability to time-lapse the ERTS imagery and/or analytic displays of the imagery. Data products have included quantitative measurements of distances and areas, brightness profiles, and movie loops of selected themes. The applications of these data products are identified and include such diverse problem areas as measurement of snowfield extent, sediment plumes from estuary dicharge, playa inventory, phreatophyte and other vegetation changes. A comparative ranking of the electronic system in terms of accuracy, cost effectiveness and data output shows it to be a viable means of data analysis.

  1. Deciphering the Receptor Repertoire Encoding Specific Odorants by Time-Lapse Single-Cell Array Cytometry

    PubMed Central

    Suzuki, Masato; Yoshimoto, Nobuo; Shimono, Ken; Kuroda, Shun’ichi

    2016-01-01

    Mammals can recognize a vast number of odorants by using olfactory receptors (ORs) known as G protein-coupled receptors. The OR gene family is one of the most diverse gene families in mammalian genomes. Because of the vast combinations of ORs and odorants, few ORs have thus far been linked to specific odorants. Here, we established a functional screening method for OR genes by using a microchamber array containing >5,400 single olfactory epithelium-derived cells from mice applied to time-lapse single-cell array cytometry. This method facilitated the prompt isolation of single olfactory sensory neurons (OSNs) responding to the odorant of interest. Subsequent single-cell RT-PCR allowed us to isolate the genes encoding respective ORs. By using volatile molecules recognized as biomarkers for lung cancers, this method could deorphanize ORs and thereby reconstitute the OR-mediated signaling cascade in HEK293T cells. Thus, our system could be applied to identify any receptor by using specific ligands in the fields of physiopathology and pharmacology. PMID:26832639

  2. Deciphering the Receptor Repertoire Encoding Specific Odorants by Time-Lapse Single-Cell Array Cytometry.

    PubMed

    Suzuki, Masato; Yoshimoto, Nobuo; Shimono, Ken; Kuroda, Shun'ichi

    2016-01-01

    Mammals can recognize a vast number of odorants by using olfactory receptors (ORs) known as G protein-coupled receptors. The OR gene family is one of the most diverse gene families in mammalian genomes. Because of the vast combinations of ORs and odorants, few ORs have thus far been linked to specific odorants. Here, we established a functional screening method for OR genes by using a microchamber array containing >5,400 single olfactory epithelium-derived cells from mice applied to time-lapse single-cell array cytometry. This method facilitated the prompt isolation of single olfactory sensory neurons (OSNs) responding to the odorant of interest. Subsequent single-cell RT-PCR allowed us to isolate the genes encoding respective ORs. By using volatile molecules recognized as biomarkers for lung cancers, this method could deorphanize ORs and thereby reconstitute the OR-mediated signaling cascade in HEK293T cells. Thus, our system could be applied to identify any receptor by using specific ligands in the fields of physiopathology and pharmacology. PMID:26832639

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Time-lapse imaging of human heart motion with switched array UWB radar.

    PubMed

    Brovoll, Sverre; Berger, Tor; Paichard, Yoann; Aardal, Øyvind; Lande, Tor Sverre; Hamran, Svein-Erik

    2014-10-01

    Radar systems for detection of human heartbeats have mostly been single-channel systems with limited spatial resolution. In this paper, a radar system for ultra-wideband (UWB) imaging of the human heart is presented. To make the radar waves penetrate the human tissue the antenna is placed very close to the body. The antenna is an array with eight elements, and an antenna switch system connects the radar to the individual elements in sequence to form an image. Successive images are used to build up time-lapse movies of the beating heart. Measurements on a human test subject are presented and the heart motion is estimated at different locations inside the body. The movies show rhythmic motion consistent with the beating heart, and the location and shape of the reflections correspond well with the expected response form the heart wall. The spatial dependent heart motion is compared to ECG recordings, and it is confirmed that heartbeat modulations are seen in the radar data. This work shows that radar imaging of the human heart may provide valuable information on the mechanical movement of the heart. PMID:25350945

  5. Attentional Lapses of Adults with Attention Deficit Hyperactivity Disorder in Tasks of Sustained Attention.

    PubMed

    Gmehlin, Dennis; Fuermaier, Anselm B M; Walther, Stephan; Tucha, Lara; Koerts, Janneke; Lange, Klaus W; Tucha, Oliver; Weisbrod, Matthias; Aschenbrenner, Steffen

    2016-06-01

    Adults with attention deficit hyperactivity disorder (ADHD) show attentional dysfunction such as distractibility and mind-wandering, especially in lengthy tasks. However, fundamentals of dysfunction are ambiguous and relationships of neuropsychological test parameters with self-report measures of ADHD symptoms are marginal. We hypothesize that basic deficits in sustaining attention explain more complex attentional dysfunction in persons with ADHD and relate to ADHD symptoms. Attentional function was analyzed by computing ex-Gaussian parameters for 3 time Blocks in a 20 min test of sustained alertness. Changes in performance across these blocks were analyzed by comparing adult persons with ADHD (n = 24) with healthy matched controls (n = 24) and correlated with neuropsychological measures of selective and divided attention as well as self-report measures of ADHD symptoms. We found a significantly steeper increase in the number of slow responses (ex-Gaussian parameter τ) in persons with ADHD with time on task in basic sustained alertness. They also performed significantly worse in tasks of sustained selective and divided attention. However, after controlling for an increase in τ during the alertness task, significant differences between groups disappeared for divided and partly selective attention. Increases in τ in the sustained alertness task correlated significantly with self-report measures of ADHD symptoms. Our results provide evidence that very basic deficits in sustaining attention in adults with ADHD are related to infrequent slow responses (=attentional lapses), with changes over time being relevant for more complex attentional function and experienced ADHD symptoms in everyday life. PMID:27193369

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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. Estimating the hydrogeological parameters with the time-lapse resistivity imaging method during the pumping test in the unconfined aquifer

    NASA Astrophysics Data System (ADS)

    Chang, P.; Chang, L.; Chen, W.; Lu, H.

    2013-12-01

    We have conducted the time-lapse monitoring study during a single-well pumping test at the Pengtsuo site in Pingtung, Taiwan. Water level gauges were installed in the four wells, including P1, W1, O1 and O2, at the Pengtsuo site with different screen depths for the observation. We designed the pumping test to be executed in three phases, including the background, the stepwise pumping, and the continuous pumping phases. The survey line is crossing the four wells in order to compare the resistivity measurements with the water level records. Although the inverted resistivity images the vertical resistivity structures also reveal that the influences from the steel well casing at the well positions, the resistivity differences to the pre-pumping background show that the electrical resistivity imaging is able to resolve the change due to the dewatering from the pumping activity. We have found that the maximum resistivity increase took place at the locations in the vadose zone instead of the groundwater surface in the time-lapse images. The variation of the maximum resistivity differences in the vadose zone is consistent to the change of the groundwater level during the pumping test. We tried to use the drawdown from the time-lapse resistivity differences and the Theis equation for estimating the hydraulic transmissivity and the specific yield at the Pentsuo site. The estimated transmissivity and the specific yield is 1.01 m^2/min and 0.11, respectively. These values are close to those calculated from the measured groundwater level variations in the multiple wells. Therefore we concluded that the time-lapse resistivity imaging methods is able to help estimating and verify the transmissivity and the specific yield for the pumping test in the unconfined aquifer.

  9. Time-lapse interpretation of p-wave data for a hydraulically fractured reservoir, Wattenberg Field, Colorado

    NASA Astrophysics Data System (ADS)

    White, Matthew D.

    Hydraulic fracturing technology has contributed to making production from low permeability source rocks economic for oil and gas companies. However, few direct observations have been made regarding the physical modifications of the reservoir resulting from the hydraulic fracturing process. This thesis investigates the time-lapse seismic response generated by hydraulically fracturing an unconventional reservoir. Compressional seismic data sets were acquired before and after completions in a single section in Wattenberg Field, CO. Cross-equalization of the time-lapse seismic data sets was required for the comparison of seismic amplitudes. A time-shift anomaly and amplitude anomaly were observed in the reservoir interval, and time-lapse changes are spatially aligned with the wellbores. To understand the physical change that caused this seismic anomaly, percentage change of acoustic P-impedance was calculated. A decrease in the acoustic P-impedance of up to 7% was observed from the baseline to the monitor survey in the reservoir interval. This observation was put into physical context through interpretation of a structural geologic model, and completions parameter and timing. An increase in pore pressure due to hydraulic fracturing was interpreted as the physical mechanism causing the change in P-impedance. Hydraulic fracturing is highly dependent on local geology, and the integration of geoscience with parameter design is necessary for optimization. Seismic monitoring can assist assist reservoir management of Wattenberg Field.

  10. puffMarker: A Multi-Sensor Approach for Pinpointing the Timing of First Lapse in Smoking Cessation

    PubMed Central

    Saleheen, Nazir; Ali, Amin Ahsan; Hossain, Syed Monowar; Sarker, Hillol; Chatterjee, Soujanya; Marlin, Benjamin; Ertin, Emre; al’Absi, Mustafa; Kumar, Santosh

    2015-01-01

    Recent researches have demonstrated the feasibility of detecting smoking from wearable sensors, but their performance on real-life smoking lapse detection is unknown. In this paper, we propose a new model and evaluate its performance on 61 newly abstinent smokers for detecting a first lapse. We use two wearable sensors — breathing pattern from respiration and arm movements from 6-axis inertial sensors worn on wrists. In 10-fold cross-validation on 40 hours of training data from 6 daily smokers, our model achieves a recall rate of 96.9%, for a false positive rate of 1.1%. When our model is applied to 3 days of post-quit data from 32 lapsers, it correctly pinpoints the timing of first lapse in 28 participants. Only 2 false episodes are detected on 20 abstinent days of these participants. When tested on 84 abstinent days from 28 abstainers, the false episode per day is limited to 1/6. PMID:26543927