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Sample records for measures blinks utilizing

  1. Detecting false intent using eye blink measures

    PubMed Central

    Marchak, Frank M.

    2013-01-01

    Eye blink measures have been shown to be diagnostic in detecting deception regarding past acts. Here we examined—across two experiments with increasing degrees of ecological validity—whether changes in eye blinking can be used to determine false intent regarding future actions. In both experiments, half of the participants engaged in a mock crime and then transported an explosive device with the intent of delivering it to a “contact” that would use it to cause a disturbance. Eye blinking was measured for all participants when presented with three types of questions: relevant to intent to transport an explosive device, relevant to intent to engage in an unrelated illegal act, and neutral questions. Experiment 1 involved standing participants watching a video interviewer with audio presented ambiently. Experiment 2 involved standing participants questioned by a live interviewer. Across both experiments, changes in blink count during and immediately following individual questions, total number of blinks, and maximum blink time length differentiated those with false intent from truthful intent participants. In response to questions relevant to intent to deliver an explosive device vs. questions relevant to intent to deliver illegal drugs, those with false intent showed a suppression of blinking during the questions when compared to the 10 s period after the end of the questions, a lower number of blinks, and shorter maximum blink duration. The results are discussed in relation to detecting deception about past activities as well as to the similarities and differences to detecting false intent as described by prospective memory and arousal. PMID:24130546

  2. Combining Blink, Pupil, and Response Time Measures in a Concealed Knowledge Test

    PubMed Central

    Seymour, Travis L.; Baker, Christopher A.; Gaunt, Joshua T.

    2013-01-01

    The response time (RT) based Concealed Knowledge Test (CKT) has been shown to accurately detect participants’ knowledge of mock-crime-related information. Tests based on ocular measures such as pupil-size and blink-rate have sometimes resulted in poor classification, or lacked detailed classification analyses. The present study examines the fitness of multiple pupil and blink related responses in the CKT paradigm. To maximize classification efficiency, participants’ concealed knowledge was assessed using both individual test measures and combinations of test measures. Results show that individual pupil-size, pupil-slope, and pre-response blink-rate measures produce efficient classifications. Combining pupil and blink measures yielded more accuracy classifications than individual ocular measures. Although RT-based tests proved efficient, combining RT with ocular measures had little incremental benefit. It is argued that covertly assessing ocular measures during RT-based tests may guard against effective countermeasure use in applied settings. A compound classification procedure was used to categorize individual participants and yielded high hit rates and low false-alarm rates without the need for adjustments between test paradigms and subject populations. We conclude that with appropriate test paradigms and classification analyses, ocular measures may prove as effective as other indices, though additional research is needed. PMID:23382718

  3. Detection and correction of blinking bias in image correlation transport measurements of quantum dot tagged macromolecules.

    PubMed

    Durisic, Nela; Bachir, Alexia I; Kolin, David L; Hebert, Benedict; Lagerholm, B Christoffer; Grutter, Peter; Wiseman, Paul W

    2007-08-15

    Semiconductor nanocrystals or quantum dots (QDs) are becoming widely used as fluorescent labels for biological applications. Here we demonstrate that fluorescence fluctuation analysis of their diffusional mobility using temporal image correlation spectroscopy is highly susceptible to systematic errors caused by fluorescence blinking of the nanoparticles. Temporal correlation analysis of fluorescence microscopy image time series of streptavidin-functionalized (CdSe)ZnS QDs freely diffusing in two dimensions shows that the correlation functions are fit well to a commonly used diffusion decay model, but the transport coefficients can have significant systematic errors in the measurements due to blinking. Image correlation measurements of the diffusing QD samples measured at different laser excitation powers and analysis of computer simulated image time series verified that the effect we observe is caused by fluorescence intermittency. We show that reciprocal space image correlation analysis can be used for mobility measurements in the presence of blinking emission because it separates the contributions of fluctuations due to photophysics from those due to transport. We also demonstrate application of the image correlation methods for measurement of the diffusion coefficient of glycosyl phosphatidylinositol-anchored proteins tagged with QDs as imaged on living fibroblasts. PMID:17526586

  4. A multi level system design for vigilance measurement based on head posture estimation and eyes blinking

    NASA Astrophysics Data System (ADS)

    Teyeb, Ines; Jemai, Olfa; Zaied, Mourad; ben Amar, Chokri

    2015-12-01

    Driving security is an important task for human society. The major challenge in the field of accident avoidance systems is the driver vigilance monitoring. The lack of vigilance can be noticed by various ways, such as, fatigue, drowsiness and distraction. Hence, the need of a reliable driver's vigilance decrease detection system which can alert drivers before a mishap happens. In this paper, we present a novel approach for vigilance estimation based on multilevel system by combining head movement analysis and eyes blinking. We have used Viola and Jones algorithm to analyse head movement and a classification system using wavelet networks for eyelid closure measuring. The contribution of our application is classifiying the vigilance state at multi level. This is different from the binary-class (awakening or hypovigilant state) existing in most popular systems.

  5. [Utility of electrophysiologic study using the blink reflex and brainstem evoked potentials for the evaluation of the course of uremic polyneuropathy].

    PubMed

    Baldini, S; Radicioni, R; Melappioni, M; Baldassari, M; Panichi, N; Pelliccioni, G; Guidi, M; Rosa, L; Magnaterra, R; Scarpino, O

    1995-03-01

    On the present study the authors evaluate the utility of electrophysiologic examination in uraemic polyneuropathy. A group of 19 uraemic patients in chronic dialysis underwent the Blink reflex and BAEPSs study to evaluate the alterations of nervous pathways. The results obtained were compared with those of a group of 10 healthy patients comparable for age and sex. The electrophysiologic parameters have been statistically compared with the plasma levels of vit. B12. folic acid, PTH and beta-2-microglobulin. The results show a significant difference of uremic patients compared with the healthy ones for the Blink reflex (ipsilateral and contralateral R2 responses). Also BAEPSs show significant alterations in the uraemic group (latencies of the III, V components). A statistically significantly inverse correlation is present between folic acid values and blink reflex R1 and R2 responses. Therefore our study shows the existence of a combined degeneration of central and peripheral nervous pathways in chronic uraemic patients. We believe that the decrease in folic acid concentration found in our study may be one of the causes of the beginning and then of the worsening of neurologic damage. PMID:7570255

  6. The effects of lubricant eye drops on visual function as measured by the Inter-blink interval Visual Acuity Decay test

    PubMed Central

    Torkildsen, Gail

    2009-01-01

    Objective: The purpose of the current study was to evaluate the effects of two marketed ocular lubricants on the visual decay in dry eye patients using the Inter-blink interval Visual Acuity Decay (IVAD) test. Methods: This controlled, randomized, double-masked crossover study compared the effects of a polyethylene glycol/propylene glycol-based (PEG/PG) tear and a carboxymethylcellulose sodium (CMC)/glycerin tear on the visual acuity decay between blinks of dry eye patients. At visit 1 (Day 0), baseline IVAD measurements were recorded prior to instillation of a single drop of randomized study medication. IVAD testing was repeated at 15-, 45-, and 90-minutes post-instillation. Reading rate and functional blink rate were also evaluated. At the second visit (Day 7 ± 3), study procedures were repeated using crossover treatment. Results: Forty-eight (48) subjects with dry eye (61.1 ± 14.8 years old, 79.2% female, 95.8% white) completed the study. Treatment with the PEG/PG-based tear demonstrated statistically significantly longer time to one-line loss of best-corrected visual acuity (BCVA) as determined by the IVAD test at 90 minutes post-instillation compared to the CMC/glycerin tear (P = 0.0365). Measurements of median time at BCVA, reading rate, and functional blink rate were similar for both treatments. Both formulations were well tolerated in the population studied. Conclusions: Treatment with the PEG/PG-based tear demonstrated statistically significant improved maintenance of visual acuity between blinks at 90 minutes post-instillation compared to the CMC/glycerin tear. This is the first study to demonstrate the ability of an artificial tear to extend visual acuity maintenance between blinks, as measured by the IVAD test. PMID:19789659

  7. Eye-Blink Behaviors in 71 Species of Primates

    PubMed Central

    Tada, Hideoki; Omori, Yasuko; Hirokawa, Kumi; Ohira, Hideki; Tomonaga, Masaki

    2013-01-01

    The present study was performed to investigate the associations between eye-blink behaviors and various other factors in primates. We video-recorded 141 individuals across 71 primate species and analyzed the blink rate, blink duration, and “isolated” blink ratio (i.e., blinks without eye or head movement) in relation to activity rhythms, habitat types, group size, and body size factors. The results showed close relationships between three types of eye-blink measures and body size factors. All of these measures increased as a function of body weight. In addition, diurnal primates showed more blinks than nocturnal species even after controlling for body size factors. The most important findings were the relationships between eye-blink behaviors and social factors, e.g., group size. Among diurnal primates, only the blink rate was significantly correlated even after controlling for body size factors. The blink rate increased as the group size increased. Enlargement of the neocortex is strongly correlated with group size in primate species and considered strong evidence for the social brain hypothesis. Our results suggest that spontaneous eye-blinks have acquired a role in social communication, similar to grooming, to adapt to complex social living during primate evolution. PMID:23741522

  8. Capturing and evaluating blinks from video-based eyetrackers.

    PubMed

    Jiang, Xianta; Tien, Geoffrey; Huang, Da; Zheng, Bin; Atkins, M Stella

    2013-09-01

    Blinks are related to several emotional states, and the present report describes a simple, reliable way to measure blinks from the video stream of an eye obtained during eyetracking, where the source of the eye video is a video camera attached to a head-mounted eyetracker. Computer vision techniques are employed to determine the moments that a blink starts and ends, for the purpose of calculating blink frequency and duration. The video is first processed to show blocks of eyelid and pupil movements, and is then analyzed for blink starts and ends. The moment of a blink start is reported when the eyelid starts to move quickly, exceeding a predetermined threshold. The end of a blink arises when the pupil size increases by less than a separate threshold. We observed several different blink patterns from different subjects, and our algorithm was designed to work for all of these patterns. We evaluated our algorithm by manually measuring the true blinks of five different subjects while they were eyetracked. To test the sensitivity and specificity of the algorithm, we employed a series of threshold values to plot the receiver operating characteristic curves. Using the best thresholds, we achieved excellent sensitivity (>90 %) and specificity (>99 %) over the five subjects. Potential applications of this research include real-time, nonintrusive, continuous and automated measurements of mental workload and other emotional states related to blink rates and durations. PMID:23271154

  9. Inhibition of eye blinking reveals subjective perceptions of stimulus salience.

    PubMed

    Shultz, Sarah; Klin, Ami; Jones, Warren

    2011-12-27

    Spontaneous eye blinking serves a critical physiological function, but it also interrupts incoming visual information. This tradeoff suggests that the inhibition of eye blinks might constitute an adaptive reaction to minimize the loss of visual information, particularly information that a viewer perceives to be important. To test this hypothesis, we examined whether the timing of blink inhibition, during natural viewing, is modulated between as well as within tasks, and also whether the timing of blink inhibition varies as a function of viewer engagement and stimulus event type. While viewing video scenes, we measured the timing of blinks and blink inhibition, as well as visual scanning, in a group of typical two-year-olds, and in a group of two-year-olds known for attenuated reactivity to affective stimuli: toddlers with Autism Spectrum Disorders (ASD). Although both groups dynamically adjusted the timing of their blink inhibition at levels greater than expected by chance, they inhibited their blinking and shifted visual fixation differentially with respect to salient onscreen events. Moreover, typical toddlers inhibited their blinking earlier than toddlers with ASD, indicating active anticipation of the unfolding of those events. These findings indicate that measures of blink inhibition can serve as temporally precise markers of perceived stimulus salience and are useful quantifiers of atypical processing of social affective signals in toddlers with ASD. PMID:22160686

  10. Blink and you’ll miss it: the role of blinking in the perception of magic tricks

    PubMed Central

    Nakano, Tamami

    2016-01-01

    Magicians use several techniques to deceive their audiences, including, for example, the misdirection of attention and verbal suggestion. We explored another potential stratagem, namely the relaxation of attention. Participants watched a video of a highly skilled magician whilst having their eye-blinks recorded. The timing of spontaneous eye-blinks was highly synchronized across participants. In addition, the synchronized blinks frequency occurred immediately after a seemingly impossible feat, and often coincided with actions that the magician wanted to conceal from the audience. Given that blinking is associated with the relaxation of attention, these findings suggest that blinking plays an important role in the perception of magic, and that magicians may utilize blinking and the relaxation of attention to hide certain secret actions. PMID:27069808

  11. Eye Movements Blink the Attentional Blink

    ERIC Educational Resources Information Center

    Kamienkowski, Juan E.; Navajas, Joaquin; Sigman, Mariano

    2012-01-01

    When presented with a sequence of visual stimuli in rapid succession, participants often fail to detect a second salient target, a phenomenon referred as the attentional blink (AB; Raymond, Shapiro, & Arnell, 1992; Shapiro, Raymond, & Arnell, 1997). On the basis of a vast corpus of experiments, several cognitive theories suggest that the blink…

  12. Excessive Blinking in Children

    MedlinePlus

    ... scratch on the front surface of the eye), conjunctivitis (pink eye), foreign body in the eye, or ... is excessive blinking treated? If an abrasion or conjunctivitis is diagnosed, eye drops or ointment may be ...

  13. Did Lavoisier Blink?

    ERIC Educational Resources Information Center

    Jensen, William B.

    2004-01-01

    A question and answer session on whether Lavoisier made an agreement with the French mathematician, Comte Joseph-Louis Lagrange shortly before being beheaded that he would blink his eyes if he retained consciousness after being beheaded and that he was executed because of his revolutionary scientific views is described. The circumstances…

  14. Electrothermal blinking vortices for chaotic mixing

    NASA Astrophysics Data System (ADS)

    Loire, Sophie; Kauffmann, Paul; Gimenez, Paul; Meinhart, Carl; Mezic, Igor

    2012-11-01

    We present an experimental and theoretical study of electrothermal chaotic mixing using blinking of asymmetric 2D electrothermal vortices. Electrothermal flows are modelled with 2D finite element method using COMSOL software based on an enhanced electrothermal model. Velocities in top-view and side-view devices are measured by micro particle image velocimetry (μPIV). The experimentally reconstructed velocity profile shows a dramatic asymmetry between the two vortices, in good agreement with the FEM model. The separation line between the two vortices is shifted and tilted making the blinking vortices overlap. We use the mix-variance coefficient (MVC) on experimental particle detection data and numerical trajectory simulations to evaluate mixing at different scales including the layering of fluid interfaces by the flow, a keypoint for efficient mixing. The blinking vortices method greatly improve mixing efficiency. Theoretical, experimental and simulation results of the mixing process will be presented.

  15. Trigeminal high-frequency stimulation produces short- and long-term modification of reflex blink gain

    PubMed Central

    Ryan, Michael; Kaminer, Jaime; Enmore, Patricia

    2013-01-01

    Reflex blinks provide a model system for investigating motor learning in normal and pathological states. We investigated whether high-frequency stimulation (HFS) of the supraorbital branch of the trigeminal nerve before the R2 blink component (HFS-B) decreases reflex blink gain in alert rats. As with humans (Mao JB, Evinger C. J Neurosci 21: RC151, 2001), HFS-B significantly reduced blink size in the first hour after treatment for rats. Repeated days of HFS-B treatment produced long-term depression of blink circuits. Blink gain decreased exponentially across days, indicating a long-term depression of blink circuits. Additionally, the HFS-B protocol became more effective at depressing blink amplitude across days of treatment. This depression was not habituation, because neither long- nor short-term blink changes occurred when HFS was presented after the R2. To investigate whether gain modifications produced by HFS-B involved cerebellar networks, we trained rats in a delay eyelid conditioning paradigm using HFS-B as the unconditioned stimulus and a tone as the conditioned stimulus. As HFS-B depresses blink circuits and delay conditioning enhances blink circuit activity, occlusion should occur if they share neural networks. Rats acquiring robust eyelid conditioning did not exhibit decreases in blink gain, whereas rats developing low levels of eyelid conditioning exhibited weak, short-term reductions in blink gain. These results suggested that delay eyelid conditioning and long-term HFS-B utilize some of the same cerebellar circuits. The ability of repeated HFS-B treatment to depress trigeminal blink circuit activity long term implied that it may be a useful protocol to reduce hyperexcitable blink circuits that underlie diseases like benign essential blepharospasm. PMID:24285868

  16. Electron transition pathways of photoluminescence from 3C-SiC nanocrystals unraveled by steady-state, blinking and time-resolved photoluminescence measurements

    NASA Astrophysics Data System (ADS)

    Gan, Zhixing; Wu, Xinglong; Xu, Hao; Zhang, Ning; Nie, Shouping; Fu, Ying

    2016-07-01

    The cubic phase SiC nanocrystals (3C-SiC NCs) have been extensively studied for electronics and photonics applications. In this work we study the electron transition pathways of photoluminescence (PL) from 3C-SiC NCs. It is found through measuring the steady-state, blinking and time-resolved PL spectra that surface passivation by glycerol improved the steady-state PL intensity (it does not modify the emission wavelength) and the NCs fluoresced more steadily. The PL decay lifetimes are shown to be the same when the detection wavelength is modified to scan the broad PL peak, implying that the broad PL peak is originated from the distribution of NCs’ sizes. Furthermore, the PL decay lifetimes are not modified by the surface passivation. It is concluded that for PL, the electron is photoexcited from the ground state in the NC to a high-energy excited state, relaxes to the first excited state then radiatively recombines to the ground state to emit a photon. The photoexcited electron at the high-energy excited state could transit to the surface state, resulting in a reduced PL intensity and a decreased on-state dwell time in the blinking trajectory. The PL decay lifetime data implies that the two principal electron transition pathways of (a) high-energy excited state \\Rightarrow the first excited state \\Rightarrow the ground state, and (b) high-energy excited state \\Rightarrow surface state \\Rightarrow the ground state are independent from each other. We strongly believe that such a deep knowledge about 3C-SiC NCs will open new doors to harness them for novel applications.

  17. The Attentional Blink Does Not Prevent Character Identification

    NASA Technical Reports Server (NTRS)

    Ruthruff, Eric; Johnston, James C.; McCann, Robert; Reington, Roger W. (Technical Monitor)

    1998-01-01

    The standard RSVP Attentional Blink (AB) paradigm was modified so that RT to the second target could be measured. Character distortion, intended to prolong the letter-identification processing stage, had a marked effect at long lags (baseline condition), but virtually no effect at short lags where AB interference occurred. According to locus-of-slack logic, this pattern of results indicates that the attentional blink causes a processing bottleneck at some stage subsequent to letter identification.

  18. BLINK: Billion Lines INdexing in a clicK

    NASA Astrophysics Data System (ADS)

    Kamennoff, N.; Foucaud, S.; Reybier, S.; Tsai, M.-F.; Tang, C.-H.

    2012-09-01

    The coming generation of sky surveys are going to provide measurements for properties of a number of objects like never have been reached before. Astronomical databases will have to deal with requests on several billions of entries at once, and therefore a new computational framework is vital for the next generation of Data-Centers. As part of the efforts linked to the setting up of the Taiwan Extragalactic Astronomical Data Center (TWEA-DC), Billion Lines INdexing in a clicK (BLINK) is developed to satisfy this role. BLINK is a framework that aims to ease access to large amount of data and share analysis software amongst users. BLINK is also designed to be parallelized and distributed on large amount of heterogeneous resources. BLINK will propose at first a very fast indexing algorithm and cross-matching capability, enabling to gather multiwavelength information of large chunk of the sky in a very limited period of time.

  19. Eye-blinks in choice response tasks uncover hidden aspects of information processing

    PubMed Central

    Wascher, Edmund; Heppner, Holger; Möckel, Tina; Kobald, Sven Oliver; Getzmann, Stephan

    2015-01-01

    Spontaneous eye-blinks occur much more often than it would be necessary to maintain the tear film on the eyes. Various factors like cognitive demand, task engagement, or fatigue are influencing spontaneous blink rate. During cognitive information processing there is evidence that blinks occur preferably at moments that can be assigned to input stream segmentation. We investigated blinking behavior in three different visual choice response experiments (Experiment 1: spatial Stimulus-Response correspondence, Experiment 2: Change Detection, Experiment 3: Continuous performance Test - AX version). Blinks during the experimental tasks were suppressed when new information was expected, as well as during cognitive processing until the response was executed. Blinks in go trials occurred within a short and relatively constant interval after manual responses. However, blinks were not a side effect of manual behavior, as they occurred in a similar manner in no-go trials in which no manual response was executed. In these trials, blinks were delayed when a prepared response had to be inhibited, compared to trials in which no response was intended. Additionally, time on task effects for no-go blinks mirrored those obtained in go trials. Thus, blinks seem to provide a reliable measure for cognitive processing beyond (or rather additional to) manual responses. PMID:27152110

  20. Eye-blinks in choice response tasks uncover hidden aspects of information processing.

    PubMed

    Wascher, Edmund; Heppner, Holger; Möckel, Tina; Kobald, Sven Oliver; Getzmann, Stephan

    2015-01-01

    Spontaneous eye-blinks occur much more often than it would be necessary to maintain the tear film on the eyes. Various factors like cognitive demand, task engagement, or fatigue are influencing spontaneous blink rate. During cognitive information processing there is evidence that blinks occur preferably at moments that can be assigned to input stream segmentation. We investigated blinking behavior in three different visual choice response experiments (Experiment 1: spatial Stimulus-Response correspondence, Experiment 2: Change Detection, Experiment 3: Continuous performance Test - AX version). Blinks during the experimental tasks were suppressed when new information was expected, as well as during cognitive processing until the response was executed. Blinks in go trials occurred within a short and relatively constant interval after manual responses. However, blinks were not a side effect of manual behavior, as they occurred in a similar manner in no-go trials in which no manual response was executed. In these trials, blinks were delayed when a prepared response had to be inhibited, compared to trials in which no response was intended. Additionally, time on task effects for no-go blinks mirrored those obtained in go trials. Thus, blinks seem to provide a reliable measure for cognitive processing beyond (or rather additional to) manual responses. PMID:27152110

  1. Evidence for a diffusion-controlled mechanism for fluorescence blinking of colloidal quantum dots.

    SciTech Connect

    Pelton, M.; Smith, G.; Scherer, N. F.; Marcus, R. A.; Univ. of Chicago; California Inst. of Tech.

    2007-09-04

    Fluorescence blinking in nanocrystal quantum dots is known to exhibit power-law dynamics, and several different mechanisms have been proposed to explain this behavior. We have extended the measurement of quantum-dot blinking by characterizing fluctuations in the fluorescence of single dots over time scales from microseconds to seconds. The power spectral density of these fluctuations indicates a change in the power-law statistics that occurs at a time scale of several milliseconds, providing an important constraint on possible mechanisms for the blinking. In particular, the observations are consistent with the predictions of models wherein blinking is controlled by diffusion of the energies of electron or hole trap states.

  2. INFRARED- BASED BLINK DETECTING GLASSES FOR FACIAL PACING: TOWARDS A BIONIC BLINK

    PubMed Central

    Frigerio, Alice; Hadlock, Tessa A; Murray, Elizabeth H; Heaton, James T

    2015-01-01

    IMPORTANCE Facial paralysis remains one of the most challenging conditions to effectively manage, often causing life-altering deficits in both function and appearance. Facial rehabilitation via pacing and robotic technology has great yet unmet potential. A critical first step towards reanimating symmetrical facial movement in cases of unilateral paralysis is the detection of healthy movement to use as a trigger for stimulated movement. OBJECTIVE To test a blink detection system that can be attached to standard eyeglasses and used as part of a closed-loop facial pacing system. DESIGN Standard safety glasses were equipped with an infrared (IR) emitter/detector pair oriented horizontally across the palpebral fissure, creating a monitored IR beam that became interrupted when the eyelids closed. SETTING Tertiary care Facial Nerve Center. PARTICIPANTS 24 healthy volunteers. MAIN OUTCOME MEASURE Video-quantified blinking was compared with both IR sensor signal magnitude and rate of change in healthy participants with their gaze in repose, while they shifted gaze from central to far peripheral positions, and during the production of particular facial expressions. RESULTS Blink detection based on signal magnitude achieved 100% sensitivity in forward gaze, but generated false-detections on downward gaze. Calculations of peak rate of signal change (first derivative) typically distinguished blinks from gaze-related lid movements. During forward gaze, 87% of detected blink events were true positives, 11% were false positives, and 2% false negatives. Of the 11% false positives, 6% were associated with partial eyelid closures. During gaze changes, false blink detection occurred 6.3% of the time during lateral eye movements, 10.4% during upward movements, 46.5% during downward movements, and 5.6% for movements from an upward or downward gaze back to the primary gaze. Facial expressions disrupted sensor output if they caused substantial squinting or shifted the glasses. CONCLUSION

  3. Infrared-based blink-detecting glasses for facial pacing: toward a bionic blink.

    PubMed

    Frigerio, Alice; Hadlock, Tessa A; Murray, Elizabeth H; Heaton, James T

    2014-01-01

    IMPORTANCE Facial paralysis remains one of the most challenging conditions to effectively manage, often causing life-altering deficits in both function and appearance. Facial rehabilitation via pacing and robotic technology has great yet unmet potential. A critical first step toward reanimating symmetrical facial movement in cases of unilateral paralysis is the detection of healthy movement to use as a trigger for stimulated movement. OBJECTIVE To test a blink detection system that can be attached to standard eyeglasses and used as part of a closed-loop facial pacing system. DESIGN, SETTING, AND PARTICIPANTS Standard safety glasses were equipped with an infrared (IR) emitter-detector unit, oriented horizontally across the palpebral fissure, creating a monitored IR beam that became interrupted when the eyelids closed, and were tested in 24 healthy volunteers from a tertiary care facial nerve center community. MAIN OUTCOMES AND MEASURES Video-quantified blinking was compared with both IR sensor signal magnitude and rate of change in healthy participants with their gaze in repose, while they shifted their gaze from central to far-peripheral positions, and during the production of particular facial expressions. RESULTS Blink detection based on signal magnitude achieved 100% sensitivity in forward gaze but generated false detections on downward gaze. Calculations of peak rate of signal change (first derivative) typically distinguished blinks from gaze-related eyelid movements. During forward gaze, 87% of detected blink events were true positives, 11% were false positives, and 2% were false negatives. Of the 11% false positives, 6% were associated with partial eyelid closures. During gaze changes, false blink detection occurred 6% of the time during lateral eye movements, 10% of the time during upward movements, 47% of the time during downward movements, and 6% of the time for movements from an upward or downward gaze back to the primary gaze. Facial expressions

  4. Spontaneous Eye-Blinking and Stereotyped Behavior in Older Persons with Mental Retardation

    ERIC Educational Resources Information Center

    Roebel, Amanda M.; MacLean, William E., Jr.

    2007-01-01

    Previous research indicates that abnormal stereotyped movements are associated with central dopamine dysfunction and that eye-blink rate is a noninvasive, in vivo measure of dopamine function. We measured the spontaneous eye-blinking and stereotyped behavior of older adults with severe/profound mental retardation living in a state mental…

  5. Blink Rate in Boys with Fragile X Syndrome: Preliminary Evidence for Altered Dopamine Function

    ERIC Educational Resources Information Center

    Roberts, J. E.; Symons, F. J.; Johnson, A.-M.; Hatton, D. D.; Boccia, M. L.

    2005-01-01

    Background: Dopamine, a neurotransmitter involved in motor and cognitive functioning, can be non-invasively measured via observation of spontaneous blink rates. Blink rates have been studied in a number of clinical conditions including schizophrenia, autism, Parkinsons, and attention deficit/hyperactivity disorder with results implicating either…

  6. Spectrally resolved analysis of fluorescence blinking of single dye molecules in polymers at low temperatures

    NASA Astrophysics Data System (ADS)

    Orlov, S. V.; Naumov, A. V.; Vainer, Yu. G.; Kador, Lothar

    2012-11-01

    We present a method for the spectrally resolved analysis of fluorescence blinking of single quantum emitters. It is based on the well-known technique of repeated recording of single-molecule (SM) fluorescence excitation spectra. The potential of our approach is presented for the example of single tetra-tert-butylterrylene molecules in an amorphous polymer matrix (polyisobutylene), which exhibit fluorescence blinking at cryogenic temperatures. Measuring the spectral dependence of the blinking statistics improves the possibility to clarify the microscopic nature of the dark state(s) of the emitters. We demonstrate how the blinking statistics can be definitely attributed to conformational changes in the local environment of a SM and how the parameters of the corresponding elementary excitations can be measured. The analysis of the blinking statistics as a function of the optical excitation frequency allows us to discriminate between photo-induced and spontaneous transitions into a dark state.

  7. Capturing Attention When Attention "Blinks"

    ERIC Educational Resources Information Center

    Wee, Serena; Chua, Fook K.

    2004-01-01

    Four experiments addressed the question of whether attention may be captured when the visual system is in the midst of an attentional blink (AB). Participants identified 2 target letters embedded among distractor letters in a rapid serial visual presentation sequence. In some trials, a square frame was inserted between the targets; as the only…

  8. Photoluminescence Blinking of Single-Crystal Methylammonium Lead Iodide Perovskite Nanorods Induced by Surface Traps

    PubMed Central

    2016-01-01

    Photoluminescence (PL) of organometal halide perovskite materials reflects the charge dynamics inside of the material and thus contains important information for understanding the electro-optical properties of the material. Interpretation of PL blinking of methylammonium lead iodide (MAPbI3) nanostructures observed on polycrystalline samples remains puzzling owing to their intrinsic disordered nature. Here, we report a novel method for the synthesis of high-quality single-crystal MAPbI3 nanorods and demonstrate a single-crystal study on MAPbI3 PL blinking. At low excitation power densities, two-state blinking was found on individual nanorods with dimensions of several hundred nanometers. A super-resolution localization study on the blinking of individual nanorods showed that single crystals of several hundred nanometers emit and blink as a whole, without showing changes in the localization center over the crystal. Moreover, both the blinking ON and OFF times showed power-law distributions, indicating trapping–detrapping processes. This is further supported by the PL decay times of the individual nanorods, which were found to correlate with the ON/OFF states. Furthermore, a strong environmental dependence of the nanorod PL blinking was revealed by comparing the measurements in vacuum, nitrogen, and air, implying that traps locate close to crystal surfaces. We explain our observations by proposing surface charge traps that are likely related to under-coordinated lead ions and methylammonium vacancies to result in the PL blinking observed here. PMID:27617323

  9. Compact and blinking-suppressed quantum dots for single-particle tracking in live cells.

    PubMed

    Lane, Lucas A; Smith, Andrew M; Lian, Tianquan; Nie, Shuming

    2014-12-11

    Quantum dots (QDs) offer distinct advantages over organic dyes and fluorescent proteins for biological imaging applications because of their brightness, photostability, and tunability. However, a major limitation is that single QDs emit fluorescent light in an intermittent on-and-off fashion called "blinking". Here we report the development of blinking-suppressed, relatively compact QDs that are able to maintain their favorable optical properties in aqueous solution. Specifically, we show that a linearly graded alloy shell can be grown on a small CdSe core via a precisely controlled layer-by-layer process, and that this graded shell leads to a dramatic suppression of QD blinking in both organic solvents and water. A substantial portion (>25%) of the resulting QDs does not blink (more than 99% of the time in the bright or "on" state). Theoretical modeling studies indicate that this type of linearly graded shell not only can minimize charge carrier access to surface traps but also can reduce lattice defects, both of which are believed to be responsible for carrier trapping and QD blinking. Further, we have evaluated the biological utility of blinking-suppressed QDs coated with polyethylene glycol (PEG)-based ligands and multidentate ligands. The results demonstrate that their optical properties are largely independent of surface coatings and solvating media, and that the blinking-suppressed QDs can provide continuous trajectories in live-cell receptor tracking studies. PMID:25157589

  10. Looking at a blinking quantum emitter through time slots: The effect of blind times

    NASA Astrophysics Data System (ADS)

    Shchukina, A. L.; Eremchev, I. Yu.; Naumov, A. V.

    2015-09-01

    Most experimental observations of physical processes are naturally accompanied by "blind" ("dead") times, which in principle can distort the result of measurements. Here we analyze how the presence of blind times in measurements changes the measured statistics of blinking fluorescence of single quantum dots. We show that information can be extracted even for blinking processes with characteristic times longer than both blind times and time slots between them.

  11. Postural and eye-blink indices of the defensive startle reflex.

    PubMed

    Hillman, Charles H; Hsiao-Wecksler, Elizabeth T; Rosengren, Karl S

    2005-01-01

    Postural and eye-blink reactions to acoustic startle probes were examined in 24 volunteers, who completed two blocked conditions (baseline, startle). A postural reaction during the startle condition demonstrated a reflexive movement in the anterior-posterior direction, which was not observed during the baseline condition. This reflexive response was positively associated with the eye-blink reflex, such that larger blink magnitude related to greater posterior movement. These findings were not observed for postural movements in the medial-lateral direction. The results suggest that a measurable postural reaction may be observed following a startling acoustic stimulus, which may reflect generalized bodily flexion associated with a preparatory behavioral response. PMID:15598515

  12. Compact and Blinking-Suppressed Quantum Dots for Single-Particle Tracking in Live Cells

    PubMed Central

    2015-01-01

    Quantum dots (QDs) offer distinct advantages over organic dyes and fluorescent proteins for biological imaging applications because of their brightness, photostability, and tunability. However, a major limitation is that single QDs emit fluorescent light in an intermittent on-and-off fashion called “blinking”. Here we report the development of blinking-suppressed, relatively compact QDs that are able to maintain their favorable optical properties in aqueous solution. Specifically, we show that a linearly graded alloy shell can be grown on a small CdSe core via a precisely controlled layer-by-layer process, and that this graded shell leads to a dramatic suppression of QD blinking in both organic solvents and water. A substantial portion (>25%) of the resulting QDs does not blink (more than 99% of the time in the bright or “on” state). Theoretical modeling studies indicate that this type of linearly graded shell not only can minimize charge carrier access to surface traps but also can reduce lattice defects, both of which are believed to be responsible for carrier trapping and QD blinking. Further, we have evaluated the biological utility of blinking-suppressed QDs coated with polyethylene glycol (PEG)-based ligands and multidentate ligands. The results demonstrate that their optical properties are largely independent of surface coatings and solvating media, and that the blinking-suppressed QDs can provide continuous trajectories in live-cell receptor tracking studies. PMID:25157589

  13. Suppressing the Fluorescence Blinking of Single Quantum Dots Encased in N-type Semiconductor Nanoparticles

    PubMed Central

    Li, Bin; Zhang, Guofeng; Wang, Zao; Li, Zhijie; Chen, Ruiyun; Qin, Chengbing; Gao, Yan; Xiao, Liantuan; Jia, Suotang

    2016-01-01

    N-type semiconductor indium tin oxide (ITO) nanoparticles are used to effectively suppress the fluorescence blinking of single near-infrared-emitting CdSeTe/ZnS core/shell quantum dots (QDs), where the ITO could block the electron transfer from excited QDs to trap states and facilitate more rapid regeneration of neutral QDs by back electron transfer. The average blinking rate of QDs is significantly reduced by more than an order of magnitude and the largest proportion of on-state is 98%, while the lifetime is not considerably reduced. Furthermore, an external electron transfer model is proposed to analyze the possible effect of radiative, nonradiative, and electron transfer pathways on fluorescence blinking. Theoretical analysis based on the model combined with measured results gives a quantitative insight into the blinking mechanism. PMID:27605471

  14. Suppressing the Fluorescence Blinking of Single Quantum Dots Encased in N-type Semiconductor Nanoparticles.

    PubMed

    Li, Bin; Zhang, Guofeng; Wang, Zao; Li, Zhijie; Chen, Ruiyun; Qin, Chengbing; Gao, Yan; Xiao, Liantuan; Jia, Suotang

    2016-01-01

    N-type semiconductor indium tin oxide (ITO) nanoparticles are used to effectively suppress the fluorescence blinking of single near-infrared-emitting CdSeTe/ZnS core/shell quantum dots (QDs), where the ITO could block the electron transfer from excited QDs to trap states and facilitate more rapid regeneration of neutral QDs by back electron transfer. The average blinking rate of QDs is significantly reduced by more than an order of magnitude and the largest proportion of on-state is 98%, while the lifetime is not considerably reduced. Furthermore, an external electron transfer model is proposed to analyze the possible effect of radiative, nonradiative, and electron transfer pathways on fluorescence blinking. Theoretical analysis based on the model combined with measured results gives a quantitative insight into the blinking mechanism. PMID:27605471

  15. Evidence for a diffusion-controlled mechanism for fluorescence blinking of colloidal quantum dots

    PubMed Central

    Pelton, Matthew; Smith, Glenna; Scherer, Norbert F.; Marcus, Rudolph A.

    2007-01-01

    Fluorescence blinking in nanocrystal quantum dots is known to exhibit power-law dynamics, and several different mechanisms have been proposed to explain this behavior. We have extended the measurement of quantum-dot blinking by characterizing fluctuations in the fluorescence of single dots over time scales from microseconds to seconds. The power spectral density of these fluctuations indicates a change in the power-law statistics that occurs at a time scale of several milliseconds, providing an important constraint on possible mechanisms for the blinking. In particular, the observations are consistent with the predictions of models wherein blinking is controlled by diffusion of the energies of electron or hole trap states. PMID:17720807

  16. Blinking

    MedlinePlus Videos and Cool Tools

    ... to prevent harmful substances from getting in the eyes. During the normal course of a day, a ... of 15 times a minute to keep the eyes healthy. The lacrimal gland provides lubricating fluid for ...

  17. Blinking

    MedlinePlus Videos and Cool Tools

    ... the eyes healthy. The lacrimal gland provides lubricating fluid for the eyes. The eyelid moves fluid from the lacrimal gland and across the eye. ... produces extra tears to wash out impurities. Excess fluid drains through the tear ducts and into the ...

  18. Electroencephalographic topography measures of experienced utility.

    PubMed

    Pedroni, Andreas; Langer, Nicolas; Koenig, Thomas; Allemand, Michael; Jäncke, Lutz

    2011-07-20

    Economic theory distinguishes two concepts of utility: decision utility, objectively quantifiable by choices, and experienced utility, referring to the satisfaction by an obtainment. To date, experienced utility is typically measured with subjective ratings. This study intended to quantify experienced utility by global levels of neuronal activity. Neuronal activity was measured by means of electroencephalographic (EEG) responses to gain and omission of graded monetary rewards at the level of the EEG topography in human subjects. A novel analysis approach allowed approximating psychophysiological value functions for the experienced utility of monetary rewards. In addition, we identified the time windows of the event-related potentials (ERP) and the respective intracortical sources, in which variations in neuronal activity were significantly related to the value or valence of outcomes. Results indicate that value functions of experienced utility and regret disproportionally increase with monetary value, and thus contradict the compressing value functions of decision utility. The temporal pattern of outcome evaluation suggests an initial (∼250 ms) coarse evaluation regarding the valence, concurrent with a finer-grained evaluation of the value of gained rewards, whereas the evaluation of the value of omitted rewards emerges later. We hypothesize that this temporal double dissociation is explained by reward prediction errors. Finally, a late, yet unreported, reward-sensitive ERP topography (∼500 ms) was identified. The sources of these topographical covariations are estimated in the ventromedial prefrontal cortex, the medial frontal gyrus, the anterior and posterior cingulate cortex and the hippocampus/amygdala. The results provide important new evidence regarding "how," "when," and "where" the brain evaluates outcomes with different hedonic impact. PMID:21775593

  19. The attentional blink provides episodic distinctiveness

    PubMed Central

    Wyble, Brad; Bowman, Howard; Nieuwenstein, Mark

    2009-01-01

    The attentional blink (Raymond et al 1992) refers to an apparent gap in perception that can be elicited when a second target follows a first at a temporal lag of several hundred milliseconds. . Theoretical and computational work have provided a variety of explanations for early sets of blink data, but more recent data have challenged these accounts by showing that the blink is attenuated when subjects encode entire strings of stimuli (Nieuwenstein & Potter, 2006, Olivers et al 2007, Kawahara et al 2007), are distracted (Olivers & Nieuwenhuis 2005) or are provided with irrelevant motion cues (Arend, Johnston, & Shapiro 2006) while viewing the RSVP stream. In this paper, we describe the Episodic Simultaneous Type Serial Token model (eSTST), a computational account of encoding visual stimuli into working memory which suggests that the attentional blink is a cognitive strategy rather than a resource limitation. This model is composed of neurobiologically plausible neural elements and simulates the attentional blink with a competitive attentional mechanism facilitates the formation of episodically distinct representations within working memory. In addition to the blink, the model addresses the phenomena of repetition blindness and whole report superiority, producing predictions which are supported by experimental work. PMID:19485692

  20. Characterizing the spontaneous blink generator: an animal model.

    PubMed

    Kaminer, Jaime; Powers, Alice S; Horn, Kyle G; Hui, Channing; Evinger, Craig

    2011-08-01

    Although spontaneous blinking is one of the most frequent human movements, little is known about its neural basis. We developed a rat model of spontaneous blinking to identify and better characterize the spontaneous blink generator. We monitored spontaneous blinking for 55 min periods in normal conditions and after the induction of mild dry eye or dopaminergic drug challenges. The normal spontaneous blink rate was 5.3 ± 0.3 blinks/min. Dry eye or 1 mg/kg apomorphine significantly increased and 0.1 mg/kg haloperidol significantly decreased the blink rate. Additional analyses revealed a consistent temporal organization to spontaneous blinking with a median 750 s period that was independent of the spontaneous blink rate. Dry eye and dopaminergic challenges significantly modified the regularity of the normal pattern of episodes of frequent blinking interspersed with intervals having few blinks. Dry eye and apomorphine enhanced the regularity of this pattern, whereas haloperidol reduced its regularity. The simplest explanation for our data is that the spinal trigeminal complex is a critical element in the generation of spontaneous blinks, incorporating reflex blinks from dry eye and indirect basal ganglia inputs into the blink generator. Although human subjects exhibited a higher average blink rate (17.6 ± 2.4) than rats, the temporal pattern of spontaneous blinking was qualitatively similar for both species. These data demonstrate that rats are an appropriate model for investigating the neural basis of human spontaneous blinking and suggest that the spinal trigeminal complex is a major element in the spontaneous blink generator. PMID:21813686

  1. Blink and Shrink: The Effect of the Attentional Blink on Spatial Processing

    ERIC Educational Resources Information Center

    Olivers, Christian N. L.

    2004-01-01

    The detection or discrimination of the second of 2 targets in a rapid serial visual presentation (RSVP) task is often temporarily impaired-a phenomenon termed the attentional blink. This study demonstrated that the attentional blink also affects localization performance. Spatial cues pointed out the possible target positions in a subsequent visual…

  2. Simultaneous Eye Tracking and Blink Detection with Interactive Particle Filters

    NASA Astrophysics Data System (ADS)

    Wu, Junwen; Trivedi, Mohan M.

    2007-12-01

    We present a system that simultaneously tracks eyes and detects eye blinks. Two interactive particle filters are used for this purpose, one for the closed eyes and the other one for the open eyes. Each particle filter is used to track the eye locations as well as the scales of the eye subjects. The set of particles that gives higher confidence is defined as the primary set and the other one is defined as the secondary set. The eye location is estimated by the primary particle filter, and whether the eye status is open or closed is also decided by the label of the primary particle filter. When a new frame comes, the secondary particle filter is reinitialized according to the estimates from the primary particle filter. We use autoregression models for describing the state transition and a classification-based model for measuring the observation. Tensor subspace analysis is used for feature extraction which is followed by a logistic regression model to give the posterior estimation. The performance is carefully evaluated from two aspects: the blink detection rate and the tracking accuracy. The blink detection rate is evaluated using videos from varying scenarios, and the tracking accuracy is given by comparing with the benchmark data obtained using the Vicon motion capturing system. The setup for obtaining benchmark data for tracking accuracy evaluation is presented and experimental results are shown. Extensive experimental evaluations validate the capability of the algorithm.

  3. Spontaneous eye blinks during creative task correlate with divergent processing.

    PubMed

    Ueda, Yoshiyuki; Tominaga, Atsuko; Kajimura, Shogo; Nomura, Michio

    2016-07-01

    Creativity consists of divergent and convergent thinking, with both related to individual eye blinks at rest. To assess underlying mechanisms between eye blinks and traditional creativity tasks, we investigated the relationship between creativity performance and eye blinks at rest and during tasks. Participants performed an alternative uses and remote association task while eye blinks were recorded. Results showed that the relationship between eye blinks at rest and creativity performance was compatible with those of previous research. Interestingly, we found that the generation of ideas increased as a function of eye blink number during the alternative uses task. On the other hand, during the remote association task, accuracy was independent of eye blink number during the task, but response time increased with it. Moreover, eye blink changes in participants who responded quickly during the remote association task were different depending on their resting state eye blinks; that is, participants with many eye blinks during rest showed little increasing eye blinks and achieved solutions quickly. Positive correlations between eye blinks during creative tasks and yielding ideas on the alternative uses task and response time on the remote association task suggest that eye blinks during creativity tasks relate to divergent thinking processes such as conceptual reorganization. PMID:25863791

  4. Blinking supervision in a working environment

    NASA Astrophysics Data System (ADS)

    Morcego, Bernardo; Argilés, Marc; Cabrerizo, Marc; Cardona, Genís; Pérez, Ramon; Pérez-Cabré, Elisabet; Gispets, Joan

    2016-02-01

    The health of the ocular surface requires blinks of the eye to be frequent in order to provide moisture and to renew the tear film. However, blinking frequency has been shown to decrease in certain conditions such as when subjects are conducting tasks with high cognitive and visual demands. These conditions are becoming more common as people work or spend their leisure time in front of video display terminals. Supervision of blinking frequency in such environments is possible, thanks to the availability of computer-integrated cameras. Therefore, the aim of the present study is to develop an algorithm for the detection of eye blinks and to test it, in a number of videos captured, while subjects are conducting a variety of tasks in front of the computer. The sensitivity of the algorithm for blink detection was found to be of 87.54% (range 30% to 100%), with a mean false-positive rate of 0.19% (range 0% to 1.7%), depending on the illumination conditions during which the image was captured and other computer-user spatial configurations. The current automatic process is based on a partly modified pre-existing eye detection and image processing algorithms and consists of four stages that are aimed at eye detection, eye tracking, iris detection and segmentation, and iris height/width ratio assessment.

  5. Lifetime blinking in nonblinking nanocrystal quantum dots.

    PubMed

    Galland, Christophe; Ghosh, Yagnaseni; Steinbrück, Andrea; Hollingsworth, Jennifer A; Htoon, Han; Klimov, Victor I

    2012-01-01

    Nanocrystal quantum dots are attractive materials for applications as nanoscale light sources. One impediment to these applications is fluctuations of single-dot emission intensity, known as blinking. Recent progress in colloidal synthesis has produced nonblinking nanocrystals; however, the physics underlying blinking suppression remains unclear. Here we find that ultra-thick-shell CdSe/CdS nanocrystals can exhibit pronounced fluctuations in the emission lifetimes (lifetime blinking), despite stable nonblinking emission intensity. We demonstrate that lifetime variations are due to switching between the neutral and negatively charged state of the nanocrystal. Negative charging results in faster radiative decay but does not appreciably change the overall emission intensity because of suppressed nonradiative Auger recombination for negative trions. The Auger process involving excitation of a hole (positive trion pathway) remains efficient and is responsible for charging with excess electrons, which occurs via Auger-assisted ionization of biexcitons accompanied by ejection of holes. PMID:22713750

  6. Erosive Burning Study Utilizing Ultrasonic Measurement Techniques

    NASA Technical Reports Server (NTRS)

    Furfaro, James A.

    2003-01-01

    A 6-segment subscale motor was developed to generate a range of internal environments from which multiple propellants could be characterized for erosive burning. The motor test bed was designed to provide a high Mach number, high mass flux environment. Propellant regression rates were monitored for each segment utilizing ultrasonic measurement techniques. These data were obtained for three propellants RSRM, ETM- 03, and Castor@ IVA, which span two propellant types, PBAN (polybutadiene acrylonitrile) and HTPB (hydroxyl terminated polybutadiene). The characterization of these propellants indicates a remarkably similar erosive burning response to the induced flow environment. Propellant burnrates for each type had a conventional response with respect to pressure up to a bulk flow velocity threshold. Each propellant, however, had a unique threshold at which it would experience an increase in observed propellant burn rate. Above the observed threshold each propellant again demonstrated a similar enhanced burn rate response corresponding to the local flow environment.

  7. The Attention Cascade Model and Attentional Blink

    ERIC Educational Resources Information Center

    Shih, Shui-I

    2008-01-01

    An attention cascade model is proposed to account for attentional blinks in rapid serial visual presentation (RSVP) of stimuli. Data were collected using single characters in a single RSVP stream at 10 Hz [Shih, S., & Reeves, A. (2007). "Attentional capture in rapid serial visual presentation." "Spatial Vision", 20(4), 301-315], and single words,…

  8. Biology Today: Of Wishbones, Beavers & Blinking.

    ERIC Educational Resources Information Center

    Flannery, Maura, Ed.

    1989-01-01

    Provided is a discussion of items covering a variety of fascinating biological topics which include: the elasticity of the furcula of starlings in flight, beavers increasing the greenhouse effect, effective invaders, traveling birds, the cuckoo deception, competitive sperm, hearing springs, heat and sight, blinking as punctuation, mutations, and…

  9. Utilization of Mobile VLBI for Geodetic Measurements

    NASA Technical Reports Server (NTRS)

    Davidson, J. M.; Trask, D. W.

    1985-01-01

    Three mobile very long base interferometry (VLBI) systems were fabricated for the NASA Crustal Dynamics Project. These systems include the 9-meter-diameter MV-3 telescope. Since 1980, mobile systems operated in conjunction with several fixed base stations in the western United States as part of a geodetic survey program to determine relative motions and regional strain fields near the tectonic plate boundaries in California and Alaska. A description is given of the three mobile systems and the environment in which they must function. The inherent accuracy of mobile VLBI measurements is assessed, based on a consideration of major sources of error. Some recent results are presented which serve to illustrate various aspects of the error model and are of geodetic interest as they span the broad region surrounding the surface trace of the San Andreas Fault. These results indicate that baseline measurements utilizing the current mobile VLBI systems attained an accuracy of 2 cm or better in the horizontal plane. It is likely that crustal motions will be detected within the next few years, provided they are presently occurring at the geological rates.

  10. Utilization of mobile VLBI for geodetic measurements

    NASA Technical Reports Server (NTRS)

    Davidson, J. M.; Trask, D. W.

    1985-01-01

    Three mobile very long base interferometry (VLBI) systems were fabricated for the NASA Crustal Dynamics Project. These systems include the 9-meter-diameter MV-3 telescope. Since 1980, mobile systems operated in conjunction with several fixed base stations in the western United States as part of a geodetic survey program to determine relative motions and regional strain fields near the tectonic plate boundaries in California and Alaska. A description is given of the three mobile systems and the environment in which they must function. The inherent accuracy of mobile VLBI measurements is assessed, based on a consideration of major sources of error. Some recent results are presented which serve to illustrate various aspects of the error model and are of geodetic interest as they span the broad region surrounding the surface trace of the San Andreas Fault. These results indicate that baseline measurements utilizing the current mobile VLBI systems attained an accuracy of 2 cm or better in the horizontal plane. It is likely that crustal motions will be detected within the next few years, provided they are presently occurring at the geological rates.

  11. The Modified Blink Reflex and individual Differences in Speed of Processing.

    ERIC Educational Resources Information Center

    Smyth, Mary; Anderson, Mike; Hammond, Geoff

    1999-01-01

    Studied a new method of measuring speed of processing, the modified blink reflex (MBR), in 2 experiments involving 57 adults. Findings are consistent with the view that interconnecting pathways allow higher level processing of a tone to prime the lower-level reflex pathway. Discusses implications for MBR and measurement of speed of processing.…

  12. Blinking triggered by the change in the solvent accessibility of a fluorescent molecule.

    PubMed

    Kawai, Kiyohiko; Koshimo, Takeshi; Maruyama, Atsushi; Majima, Tetsuro

    2014-09-18

    The more a fluorescent molecule is exposed to a solvent, the faster its triplet excited state is quenched by molecular oxygen. The changes in the solvent accessibility of a fluorescent molecule were probed by measuring the duration of the off time during the blinking of the fluorescence, which enabled analysis of the function of a molecular beacon-type probe. PMID:25068376

  13. Compulsive Behavior and Eye Blink in Prader-Willi Syndrome: Neurochemical Implications

    ERIC Educational Resources Information Center

    Holsen, Laura; Thompson, Travis

    2004-01-01

    Compulsive behavior in Prader-Willi syndrome is well-documented, though the neurochemical basis of these behaviors remains unknown. We studied a group of 16 people with Prader-Willi syndrome and a comparison group of 19 people with intellectual disability. Using eye-blink rate as an indirect measure of central nervous system dopamine, we found a…

  14. Labeling Cytosolic Targets in Live Cells with Blinking Probes

    PubMed Central

    Xu, Jianmin; Chang, Jason; Yan, Qi; Dertinger, Thomas; Bruchez, Marcel; Weiss, Shimon

    2013-01-01

    With the advent of superresolution imaging methods, fast dynamic imaging of biological processes in live cells remains a challenge. A subset of these methods requires the cellular targets to be labeled with spontaneously blinking probes. The delivery and specific targeting of cytosolic targets and the control of the probes’ blinking properties are reviewed for three types of blinking probes: quantum dots, synthetic dyes, and fluorescent proteins. PMID:23930154

  15. MEASUREMENT OF MERCURY IN CHINESE UTILITY COAL

    EPA Science Inventory

    The paper gives results of analyzing representative samples of 20 Chinese utility coals for mercury content, and proximate, ultimate, and heating values. The data for these bituminous coals, obtained from China with the cooperation of the Chinese University of Mining Technology,...

  16. Are Purkinje Cell Pauses Drivers of Classically Conditioned Blink Responses?

    PubMed

    Jirenhed, Dan-Anders; Hesslow, Germund

    2016-08-01

    Several lines of evidence show that classical or Pavlovian conditioning of blink responses depends on the cerebellum. Recordings from cerebellar Purkinje cells that control the eyelid and the conditioned blink show that during training with a conditioning protocol, a Purkinje cell develops a pause response to the conditional stimulus. This conditioned cellular response has many of the properties that characterise the overt blink. The present paper argues that the learned Purkinje cell pause response is the memory trace and main driver of the overt conditioned blink and that it explains many well-known behavioural phenomena. PMID:26400585

  17. Blinking correlation in nanocrystal quantum dots probed with novel laser scanning confocal microscopy methods

    NASA Astrophysics Data System (ADS)

    Hefti, Ryan Alf

    Semiconductor quantum dots have a vast array of applications: as fluorescent labels in biological systems, as physical or chemical sensors, as components in photovoltaic technology, and in display devices. An attribute of nearly every quantum dot is its blinking, or fluorescence intermittency, which tends to be a disadvantage in most applications. Despite the fact that blinking has been a nearly universal phenomenon among all types of fluorescent constructs, it is more prevalent in quantum dots than in traditional fluorophores. Furthermore, no unanimously accepted model of quantum dot blinking yet exists. The work encompassed by this dissertation began with an in-depth study of molecular motor protein dynamics in a variety of environments using two specially developed techniques, both of which feature applicability to live cell systems. Parked-beam confocal microscopy was utilized to increase temporal resolution of molecular motor motion dynamics by an order of magnitude over other popular methods. The second technique, fast-scanning confocal microscopy (FSCM), was used for long range observation of motor proteins. While using FSCM on motor protein assays, we discovered an unusual phenomenon. Single quantum dots seemingly communicated with neighboring quantum dots, indicated by a distinct correlation in their blinking patterns. In order to explain this novel correlation phenomenon, the majority of blinking models developed thus far would suggest a dipole-dipole interaction or a Coulomb interaction between singly charged quantum dots. However, our results indicate that the interaction energy is higher than supported by current models, thereby prompting a renewed examination. We propose that the blinking correlation we observed is due to a Coulomb interaction on the order of 3-4 elementary charges per quantum dot and that multiple charging of individual quantum dots may be required to plunge them into a non-emissive state. As a result of charging, charge carriers are

  18. The experiential blink: Mapping the cost of working memory encoding onto conscious perception in the attentional blink.

    PubMed

    Pincham, Hannah L; Bowman, H; Szucs, D

    2016-08-01

    The attentional blink (AB) represents a cognitive deficit in reporting the second of two targets (T2), when that second target appears 200-600 msec after the first (T1). However, it is unclear how this paradigm impacts the subjective visibility (that is, the conscious perception) of T2, and whether the temporal profile of T2 report accuracy matches the temporal profile of subjective visibility. In order to compare report accuracy and subjective visibility, we asked participants to identify T1 and T2, and to rate the subjective visibility of T2 across two experiments. Event-related potentials were also measured. The results revealed different profiles for the report of T2 versus the subjective visibility of T2, particularly when T1 and T2 appeared within 200 msec of one another. Specifically, T2 report accuracy was high but T2 visibility was low when the two targets appeared in close temporal succession, suggesting what we call the Experiential Blink is different from the classic AB. Electrophysiologically, at lag-1, the P3 component was modulated more by subjective visibility than by report accuracy. Collectively, the data indicate that the deficit in accurately reporting T2 is not the same as the deficit in subjectively experiencing T2. This suggests that traditional understandings of the AB may require adjustment and that, consistent with other findings, working memory (WM) encoding and conscious perception may not be synonymous. PMID:27176633

  19. The predictive validity of prospect theory versus expected utility in health utility measurement.

    PubMed

    Abellan-Perpiñan, Jose Maria; Bleichrodt, Han; Pinto-Prades, Jose Luis

    2009-12-01

    Most health care evaluations today still assume expected utility even though the descriptive deficiencies of expected utility are well known. Prospect theory is the dominant descriptive alternative for expected utility. This paper tests whether prospect theory leads to better health evaluations than expected utility. The approach is purely descriptive: we explore how simple measurements together with prospect theory and expected utility predict choices and rankings between more complex stimuli. For decisions involving risk prospect theory is significantly more consistent with rankings and choices than expected utility. This conclusion no longer holds when we use prospect theory utilities and expected utilities to predict intertemporal decisions. The latter finding cautions against the common assumption in health economics that health state utilities are transferable across decision contexts. Our results suggest that the standard gamble and algorithms based on, should not be used to value health. PMID:19833400

  20. An absolute scale for measuring the utility of money

    NASA Astrophysics Data System (ADS)

    Thomas, P. J.

    2010-07-01

    Measurement of the utility of money is essential in the insurance industry, for prioritising public spending schemes and for the evaluation of decisions on protection systems in high-hazard industries. Up to this time, however, there has been no universally agreed measure for the utility of money, with many utility functions being in common use. In this paper, we shall derive a single family of utility functions, which have risk-aversion as the only free parameter. The fact that they return a utility of zero at their low, reference datum, either the utility of no money or of one unit of money, irrespective of the value of risk-aversion used, qualifies them to be regarded as absolute scales for the utility of money. Evidence of validation for the concept will be offered based on inferential measurements of risk-aversion, using diverse measurement data.

  1. Blink reflex latency after exposure to trichloroethylene in well water

    SciTech Connect

    Feldman, R.G.; Chirico-Post, J.; Proctor, S.P.

    1988-03-01

    The electrophysiological measurement of the blink reflex (BR) can quantify the conduction latency in the reflex arc involving the Vth (trigeminal) and VIIth (facial) cranial nerves. We measured the electrophysiological BR in a population (N = 21), which had alleged chronic exposure to trichloroethylene (TCE) through the public drinking water at levels 30-80 times higher than the Environmental Protection Agency (EPA) Maximum Contamination Level (MCL). A highly significant difference was observed in the conduction latency means of the BR components (p less than .0001), when the study population was compared with laboratory controls (N = 27). This difference suggests a subclinical alteration of the Vth cranial nerve function due to chronic, environmental exposure to TCE.

  2. Viscous drag measurements utilizing microfabricated cantilevers

    SciTech Connect

    Oden, P.I.; Chen, G.Y.; Steele, R.A.; Warmack, R.J.; Thundat, T.

    1996-06-01

    The influence of viscous drag forces on cantilevers is investigated using standard atomic force microscope (AFM) cantilevers. Viscosity effects on several geometrically different cantilevers manifest themselves as variations in resonance frequencies, quality factors, and cantilever response amplitudes. With this novel measurement, a single cantilever can be used to measure viscosities ranging from {eta}=10{sup {minus}2} to 10{sup 2} g/cms. {copyright} {ital 1996 American Institute of Physics.}

  3. Surface area measurement utilizing an acoustic bridge

    PubMed

    Torigoe; Ishii

    2000-05-01

    A new method is proposed for measuring the surface area of an object. The acoustic conductance of a cavity is proportional to the surface area of the cavity inner wall. The surface area of an object thus can be known from the measurement of the acoustic impedance of a chamber in which the object is placed. In order to measure the acoustic impedance accurately; the proposed method employs the acoustic bridge technique. The experimental device is composed of the following elements so arranged that their electric equivalents form a bridge circuit: a measuring chamber in which an object under test is placed and whose volume can be adjusted; a reference chamber whose inner surface area can be varied; a loudspeaker (the signal source) mounted between the two chambers; and a bypass channel at the midpoint of which a microphone (the null detector) is installed. This bridge balances when the volume and the inner surface area of each chamber become equal. The surface area of the object can then be known from the inner surface area of the reference chamber. Several experiments were performed with this device and the success of the proposed method was verified. PMID:10830378

  4. Utilization of lasers for air data measurements

    NASA Astrophysics Data System (ADS)

    Hammer, J.

    1991-05-01

    The operating principles of the ALEV3 three axis laser Doppler anemometer, which was designed for flight tests with the A-320 and A-340 aircraft, are depicted. If mounted on the aircraft center of gravity, the ALEV-3 allows true flight velocity in three directions and angles of attack and sideslip to be directly measured with a very good accuracy, in particular flight areas such as limit buffeting, stall, high Mach numbers, or sideslip flights. Aircraft parameter estimation, calculation, and calibration results are presented. The accuracies of velocity, static pressure and aerodynamic angle measurements were compared with classical anemometers precisions. Flight tests results of the ALEV-1 one axis laser anemometer for A-320 are given as a reference.

  5. Blinking suppression of single quantum dots in agarose gel

    SciTech Connect

    Ko, H. C.; Yuan, C. T.; Tang, Jau; Lin, S. H.

    2010-01-04

    Fluorescence blinking is commonly observed in single molecule/particle spectroscopy, but it is an undesirable feature in many applications. We demonstrated that single CdSe/ZnS quantum dots in agarose gel exhibited suppressed blinking behavior. In addition, the long-time exponential bending tail of the power-law blinking statistics was found to be influenced by agarose gel concentration. We suggest that electron transfer from the light state to the dark state might be blocked due to electrostatic surrounding of gel with inherent negatively charged fibers.

  6. Synthesis of Non-blinking Semiconductor Quantum Dots Emitting in the Near-Infrared

    SciTech Connect

    Dennis, Allison M.; Mangum, Benjamin D.; Piryatinski, Andrei; Park, Young-Shin; Htoon, Han; Hollingsworth, Jennifer A.

    2012-06-21

    Our previous work demonstrates that Quasi-Type II CdSe/CdS core-shell quantum dots with thick shells (3-5 nm) exhibit unique photophysical characteristics, including improved chemical robustness over typical thin-shelled core/shell systems and the elimination of blinking through suppression of nonradiative Auger recombination. Here we describe a new thick-shelled heterostructure, InP/CdS, which exhibits a Type II bandgap alignment producing near-infrared (NIR) emission. Samples with a range of shell thicknesses were synthesized, enabling shell-thickness-dependent study of the absorbance and emission spectra, fluorescence lifetimes, and quantum yields. InP/CdS/ZnS core/shell/shell structures were also synthesized to reduce cadmium exposure for applications in the biological environment. Single particle spectroscopy indicates reduced blinking and improved photostability with increasing shell thickness, resulting in thick-shelled dots that are appropriate for single-particle tracking measurements with NIR emission.

  7. Diurnal rhythms of visual accommodation and blink responses - Implication for flight-deck visual standards

    NASA Technical Reports Server (NTRS)

    Murphy, M. R.; Randle, R. J.; Williams, B. A.

    1977-01-01

    Possible 24-h variations in accommodation responses were investigated. A recently developed servo-controlled optometer and focus stimulator were used to obtain monocular accommodation response data on four college-age subjects. No 24-h rhythm in accommodation was shown. Heart rate and blink rate also were measured and periodicity analysis showed a mean 24-h rhythm for both; however, blink rate periodograms were significant for only two of the four subjects. Thus, with the qualifications that college students were tested instead of pilots and that they performed monocular laboratory tasks instead of binocular flight-deck tasks, it is concluded that 24-h rhythms in accommodation responses need not be considered in setting visual standards for flight-deck tasks.

  8. Unilateral Eye Blinking Arising From the Ictal Ipsilateral Occipital Area.

    PubMed

    Falsaperla, Raffaele; Perciavalle, Valentina; Pavone, Piero; Praticò, Andrea Domenico; Elia, Maurizio; Ruggieri, Martino; Caraballo, Roberto; Striano, Pasquale

    2016-07-01

    We report on an 18-month-old boy with unilateral left eye blinking as a single ictal manifestation without facial twitching. The clinical onset of this phenomenon was first recorded (as an occasional event) at age 3 months, and it was overlooked. By age 6 months, the child's blinking increased to almost daily occurrence in clusters: during blinking the infant showed intact awareness and occasional jerks in the upper limbs and right leg. A video-electroencephalography (video-EEG) documented clinical correlation with a focal pattern arising from the left occipital region, and brain magnetic resonance imaging (MRI) revealed severe brain damage, consisting in poroencephalic hollows and increased spaces in the convexities involving a large area of the left cerebral hemisphere. The boy was prescribed sodium valproate (30 mg/kg/d), resulting in drastic reduction of his clinical seizures. Follow-up to his current age documented good general status, with persistent partial right hemilateral seizures. The blinking progressively disappeared, and is no longer recorded. The pathogenic hypotheses of the unilateral ictal blinking include involvement of the ipsilateral cerebral hemisphere and/or the cerebellar pathways. Review of previous reports of unilateral eye blinking, arising from the ictal ipsilateral brain, revealed that different damaged regions may give rise to blinking ictal phenomena, likely via the trigeminal fibres innervating the subdural intracranial structures and the pial vessels in the ipsilateral affected brain. The eye blinking in the present child represents a further example of an ictal phenomenon, which is predictive of the damaged brain region. PMID:25179638

  9. Estimating an Evaluation Utilization Model Using Conjoint Measurement and Analysis.

    ERIC Educational Resources Information Center

    Johnson, R. Burke

    1995-01-01

    The conjoint approach to measurement and analysis is demonstrated with a test of an evaluation utilization process-model that includes two endogenous variables (predicted participation and predicted instrumental evaluation). Conjoint measurement involves having respondents rate profiles that are analogues to concepts based on cells in a factorial…

  10. Eye blinking in an avian species is associated with gaze shifts.

    PubMed

    Yorzinski, Jessica L

    2016-01-01

    Even when animals are actively monitoring their environment, they lose access to visual information whenever they blink. They can strategically time their blinks to minimize information loss and improve visual functioning but we have little understanding of how this process operates in birds. This study therefore examined blinking in freely-moving peacocks (Pavo cristatus) to determine the relationship between their blinks, gaze shifts, and context. Peacocks wearing a telemetric eye-tracker were exposed to a taxidermy predator (Vulpes vulpes) and their blinks and gaze shifts were recorded. Peacocks blinked during the majority of their gaze shifts, especially when gaze shifts were large, thereby timing their blinks to coincide with periods when visual information is already suppressed. They inhibited their blinks the most when they exhibited high rates of gaze shifts and were thus highly alert. Alternative hypotheses explaining the link between blinks and gaze shifts are discussed. PMID:27572457

  11. Eye blinking in an avian species is associated with gaze shifts

    PubMed Central

    Yorzinski, Jessica L.

    2016-01-01

    Even when animals are actively monitoring their environment, they lose access to visual information whenever they blink. They can strategically time their blinks to minimize information loss and improve visual functioning but we have little understanding of how this process operates in birds. This study therefore examined blinking in freely-moving peacocks (Pavo cristatus) to determine the relationship between their blinks, gaze shifts, and context. Peacocks wearing a telemetric eye-tracker were exposed to a taxidermy predator (Vulpes vulpes) and their blinks and gaze shifts were recorded. Peacocks blinked during the majority of their gaze shifts, especially when gaze shifts were large, thereby timing their blinks to coincide with periods when visual information is already suppressed. They inhibited their blinks the most when they exhibited high rates of gaze shifts and were thus highly alert. Alternative hypotheses explaining the link between blinks and gaze shifts are discussed. PMID:27572457

  12. The Effects of Increasing Ocular Surface Stimulation on Blinking and Tear Secretion

    PubMed Central

    Wu, Ziwei; Begley, Carolyn G.; Port, Nicholas; Bradley, Arthur; Braun, Richard; King-Smith, Ewen

    2015-01-01

    Purpose. To investigate the effect of varying levels of ocular surface stimulation on the timing and amplitude of the blink and tear secretion. Methods. Following instillation of fluorescein dye, increasing levels of air flow were directed toward the central corneas of 10 healthy subjects. Interblink interval (IBI), tear meniscus height (TMH), and fluorescence intensity were measured simultaneously. Because blinking can obscure changes in TMH, we developed novel measures of tear secretion by calculating tear meniscus fluorescein concentration (TMFC) from intensity using a mathematical model. The change of TMH and TMFC over trials and the slope of the TMFC within each IBI (IBI-TTR) were further calculated. Results. The mean IBI was decreased by 8.08 ± 8.54 seconds from baseline to maximum air stimulation. The TMH increase was highly variable (0.41 ± 0.39 mm) among subjects, compared to the fluorescence tear turnover metrics: decrease in TMFC of 2.84 ± 0.98 natural logarithm or ln(%) and IBI-TTR of 0.065 ± 0.032 ln(%)/sec. Ocular surface stimulation was highly correlated with the TMFC and IBI-TTR, but less so with TMH (Pearson's r = 0.71, 0.69, and 0.40, P < 0.01, respectively). Blinking and tearing were significantly correlated with each other (Pearson's r = 0.56, P < 0.01), but tearing lagged behind by an average of 6.54 ± 4.07 seconds. Conclusions. Blinking and tearing share a common origin with sensory stimulation at the ocular surface. Both showed a dose–response increase with surface stimulation and were correlated with each other. These methods can potentially be used to understand alterations in ocular surface sensory function and associated protective responses in dry eye and other disorders of the ocular surface. PMID:26132780

  13. Emotional modulation of the attentional blink and the relation to interpersonal reactivity

    PubMed Central

    Kanske, Philipp; Schönfelder, Sandra; Wessa, Michèle

    2013-01-01

    The extent of the attentional blink effect on detection rates in rapid serial visual presentations is modulated by the emotionality of the stimuli. Emotionally salient stimuli are detected more often, even if presented in the attentional blink period, and elicit an enlarged P3 response, which has been interpreted as enhanced consolidation. This effect correlates with individual differences in trait affectivity such as anxiety or dysphoria. Here, we ask if it is also related to the capacity to detect emotions in others, i.e., to interpersonal social traits. We therefore presented emotional and neutral images depicting social scenes as targets in an attentional blink design and measured detection rates and event-related potentials. In addition, we recorded self-reports of empathy as measured by the Interpersonal Reactivity Index. The results show enhanced performance for emotional stimuli and increased P3 amplitudes, which correlated with individual differences in empathy. The data suggest that self-reported empathy goes along with enhanced processing of emotion in social stimuli, even under stimulus conditions that are suboptimal for conscious target detection. PMID:24130525

  14. Dynamics and function of the tear film in relation to the blink cycle

    PubMed Central

    Braun, R.J.; King-Smith, P.E.; Begley, C.G.; Li, Longfei; Gewecke, N.R.

    2014-01-01

    Great strides have recently been made in quantitative measurements of tear film thickness and thinning, mathematical modeling thereof and linking these to sensory perception. This paper summarizes recent progress in these areas and reports on new results. The complete blink cycle is used as a framework that attempts to unify the results that are currently available. Understanding of tear film dynamics is aided by combining information from different imaging methods, including fluorescence, retroillumination and a new high-speed stroboscopic imaging system developed for studying the tear film during the blink cycle. During the downstroke of the blink, lipid is compressed as a thick layer just under the upper lid which is often released as a narrow thick band of lipid at the beginning of the upstroke. “Rippling” of the tear film/air interface due to motion of the tear film over the corneal surface, somewhat like the flow of water in a shallow stream over a rocky streambed, was observed during lid motion and treated theoretically here. New mathematical predictions of tear film osmolarity over the exposed ocular surface and in tear breakup are presented; the latter is closely linked to new in vivo observations. Models include the effects of evaporation, osmotic flow through the cornea and conjunctiva, quenching of fluorescence, tangential flow of aqueous tears and diffusion of tear solutes and fluorescein. These and other combinations of experiment and theory increase our understanding of the fluid dynamics of the tear film and its potential impact on the ocular surface. PMID:25479602

  15. Defensive eye-blink startle responses in a human experimental model of anxiety

    PubMed Central

    Pinkney, Verity; Wickens, Robin; Bamford, Susan; Baldwin, David S; Garner, Matthew

    2014-01-01

    Inhalation of low concentrations of carbon dioxide (CO2) triggers anxious behaviours in rodents via chemosensors in the amygdala, and increases anxiety, autonomic arousal and hypervigilance in healthy humans. However, it is not known whether CO2 inhalation modulates defensive behaviours coordinated by this network in humans. We examined the effect of 7.5% CO2 challenge on the defensive eye-blink startle response. A total of 27 healthy volunteers completed an affective startle task during inhalation of 7.5% CO2 and air. The magnitude and latency of startle eye-blinks were recorded whilst participants viewed aversive and neutral pictures. We found that 7.5% CO2 increased state anxiety and raised concurrent measures of skin conductance and heart rate (HR). CO2 challenge did not increase startle magnitude, but slowed the onset of startle eye-blinks. The effect of CO2 challenge on HR covaried with its effects on both subjective anxiety and startle latency. Our findings are discussed with reference to startle profiles during conditions of interoceptive threat, increased cognitive load and in populations characterised by anxiety, compared with acute fear and panic. PMID:24899597

  16. Relieving the attentional blink in the amblyopic brain with video games.

    PubMed

    Li, Roger W; Ngo, Charlie V; Levi, Dennis M

    2015-01-01

    Video game play induces a generalized recovery of a range of spatial visual functions in the amblyopic brain. Here we ask whether video game play also alters temporal processing in the amblyopic brain. When visual targets are presented in rapid succession, correct identification of the first target (T1) can interfere with identification of the second (T2). This is known as the "attentional blink". We measured the attentional blink in each eye of adults with amblyopia before and after 40 hours of active video game play, using a rapid serial visual presentation technique. After videogame play, we observed a ~40% reduction in the attentional blink (identifying T2 200 ms after T1) seen through the amblyopic eye and this improvement in performance transferred substantially to the untrained fellow sound eye. Our experiments show that the enhanced performance cannot be simply explained by eye patching alone, or to improved visual acuity, but is specific to videogame experience. Thus, videogame training might have important therapeutic applications for amblyopia and other visual brain disorders. PMID:25715870

  17. Dynamics and function of the tear film in relation to the blink cycle.

    PubMed

    Braun, R J; King-Smith, P E; Begley, C G; Li, Longfei; Gewecke, N R

    2015-03-01

    Great strides have recently been made in quantitative measurements of tear film thickness and thinning, mathematical modeling thereof and linking these to sensory perception. This paper summarizes recent progress in these areas and reports on new results. The complete blink cycle is used as a framework that attempts to unify the results that are currently available. Understanding of tear film dynamics is aided by combining information from different imaging methods, including fluorescence, retroillumination and a new high-speed stroboscopic imaging system developed for studying the tear film during the blink cycle. During the downstroke of the blink, lipid is compressed as a thick layer just under the upper lid which is often released as a narrow thick band of lipid at the beginning of the upstroke. "Rippling" of the tear film/air interface due to motion of the tear film over the corneal surface, somewhat like the flow of water in a shallow stream over a rocky streambed, was observed during lid motion and treated theoretically here. New mathematical predictions of tear film osmolarity over the exposed ocular surface and in tear breakup are presented; the latter is closely linked to new in vivo observations. Models include the effects of evaporation, osmotic flow through the cornea and conjunctiva, quenching of fluorescence, tangential flow of aqueous tears and diffusion of tear solutes and fluorescein. These and other combinations of experiment and theory increase our understanding of the fluid dynamics of the tear film and its potential impact on the ocular surface. PMID:25479602

  18. Adjusting capitation rates using objective health measures and prior utilization

    PubMed Central

    Newhouse, Joseph P.; Manning, Willard G.; Keeler, Emmett B.; Sloss, Elizabeth M.

    1989-01-01

    Several analysts have proposed adding adjusters based on health status and prior utilization to the adjusted average per capita cost formula. The authors estimate how well such adjusters predict annual medical expenditures among non-elderly adults. Both measures substantially improve on the variables currently used. If only health measures are added, 20-30 percent of the predictable variance is explained; if only prior use is added, more than 40 percent is explained; if both are added, about 60 percent is explained. The results support including some measure of use in the formula until better health measures are developed. PMID:10313096

  19. Attention "blinks" differently for plants and animals.

    PubMed

    Balas, Benjamin; Momsen, Jennifer L

    2014-01-01

    Plants, to many, are simply not as interesting as animals. Students typically prefer to study animals rather than plants and recall plants more poorly, and plants are underrepresented in the classroom. The observed paucity of interest for plants has been described as plant blindness, a term that is meant to encapsulate both the tendency to neglect plants in the environment and the lack of appreciation for plants' functional roles. While the term plant blindness suggests a perceptual or attentional component to plant neglect, few studies have examined whether there are real differences in how plants and animals are perceived. Here, we use an established paradigm in visual cognition, the "attentional blink," to compare the extent to which images of plants and animals capture attentional resources. We find that participants are better able to detect animals than plants in rapid image sequences and that visual attention has a different refractory period when a plant has been detected. These results suggest there are fundamental differences in how the visual system processes plants that may contribute to plant blindness. We discuss how perceptual and physiological constraints on visual processing may suggest useful strategies for characterizing and overcoming zoocentrism. PMID:25185227

  20. A moving overlay shrinks the attentional blink.

    PubMed

    Chua, Fook K

    2015-01-01

    This report describes a study examining the effects of overlaying a veil of spots on the letters in a central rapid serial visual presentation stream. Observers identified two target letters (T1 and T2, respectively) embedded in a stream of distractor letters printed in a different color. In Experiment 1, the attentional blink (AB) diminished when a different overlay veiled each letter, such that the spots appeared to move as the letters changed. Experiment 2 concerned whether the performance enhancement occurred because the overlay hampered processing of the lag 1 distractor, thus weakening the distractor's interference with T1. Experiment 3 focused on how changing the overlay at or around T1 affected the AB. The attention disengagement hypothesis was proposed to explain the common theme in the results-that performance was only enhanced when different overlays were applied to the T1 and lag 1 frames. The claim is that the AB reflects a failure of prompt attentional disengagement from T1, which, in turn, delays reengagement when T2 appears shortly thereafter. When T1's disappearance is accompanied by an overlay change, the perceptual system gets an additional cue signaling that the visual scene has changed, thereby inducing attentional disengagement. Apart from facilitating prompt reengagement at the next target, earlier disengagement also improves target recovery by excluding features of the trailing item, likely to be a distractor, from working memory. PMID:25245077

  1. Sleep after practice reduces the attentional blink

    PubMed Central

    Cellini, Nicola; Goodbourn, Patrick T.; McDevitt, Elizabeth A.; Martini, Paolo; Holcombe, Alex O.

    2015-01-01

    The attentional blink (AB) is an impairment in detecting the second of two targets that appear in close temporal succession. We investigated the effect of practice and a nap on the magnitude of the AB deficit. We found evidence that sleep boosts practice-dependent reduction of the AB. Participants reported two target letters embedded in a rapid serial visual presentation display. After two morning sessions, half the participants took a polysomnographically recorded nap, while the others remained awake. Comparing two afternoon sessions to the two morning sessions, we observed a decreased AB only within the group who napped. The improvement was due to increased efficacy of the attentional selection of T2 (the probability of reporting a T2-relevant item). There was no change in selection’s latency or temporal precision. The magnitude of improvement was positively associated with the duration of N2 sleep and the number of N2 sleep spindles. Our results suggest that sleep, particularly N2 sleep and sleep spindles, improves attentional selection in time. PMID:25911156

  2. Electrically induced blink reflex in horses.

    PubMed

    Añor, S; Espadaler, J M; Monreal, L; Mayhew, I G

    The electrically induced blink reflex was studied electromyographically in 21 healthy adult, detomidine-sedated horses. Using surface electrodes, the supraorbital nerve was electrically stimulated at the supraorbital foramen. The responses were recorded from the ipsilateral and contralateral orbicularis oculi muscles with concentric needle electrodes inserted in the lateral aspect of the ventral eyelids. Ipsilateral and contralateral recordings were made on successive stimulations of the same side of the face, maintaining a constant stimulus intensity. The electromyographically recorded responses consisted of an early R1 response in the orbicularis oculi muscle ipsilateral to the side of stimulation, a bilateral late response (ipsilateral R2 and contralateral Rc) and a third, R3 response, in the ipsilateral orbicularis oculi muscle. All the responses were polyphasic muscle potentials of variable duration and peak to peak amplitudes. The reflex latency of the R1 response was, as in man, fairly stable. The R2 response showed greater variability both within and between individual horses. The Rc response was recorded in only 13 of the 21 horses and showed a slightly longer latency than the corresponding R2. The R3 response, which is significantly related to pain sensation in man, appeared in 19 horses and showed the greatest variability in latency. PMID:9123787

  3. Measuring equity in disability and healthcare utilization in Afghanistan.

    PubMed

    Trani, Jean-Francois; Barbou-des-Courieres, Cecile

    2012-01-01

    This paper analyses equity in health and healthcare utilization in Afghanistan based on a representative national household survey. Equitable access is a cornerstone of the Afghan health policy. We measured socioeconomic-related equity in access to public health care, using disability--because people with disabilities are poorer and more likely to use health care--and a concentration index (CI) and its decomposition. The socioeconomic-related equity in healthcare utilization was measured using a probit model and compared with an OLS model providing the horizontal inequity index (HI). We found a low rate of healthcare facilities utilization (25%). Disabled persons are using more healthcare facilities and have higher medical expenses. Disability is more frequently associated with older age, unemployed heads of household and lower education. The Cl of disability is 0.0221 indicating a pro-rich distribution of health. This pro-rich effect is higher in small households (CI decreases with size of the household, -0.0048) and safe (0.0059) areas. The CI of healthcare utilization is -0.0159 indicating a slightly pro-poor distribution of healthcare utilization but, overall, there is no difference in healthcare utilization by wealth status. Our study does not show major socioeconomic related inequity in disability and healthcare utilization in Afghanistan. This is due to the extreme and pervasive poverty found in Afghanistan. The absence of inequity in health access is explained by the uniform poverty of the population and the difficulty of accessing BPHS facilities (a basic package of health services), despite alarming health indicators. PMID:23189589

  4. Evidence for the role of holes in blinking: negative and oxidized CdSe/CdS dots.

    PubMed

    Qin, Wei; Guyot-Sionnest, Philippe

    2012-10-23

    Thin shell CdSe/CdS colloidal quantum dots with a small 3 nm core diameter exhibit typical blinking and a binary PL intensity distribution. Electrochemical charging with one electron suppresses the blinking. With a larger core of 5 nm, the blinking statistics of on and off states is identical to that of a smaller core but the dots also display a grey state with a finite duration time (~6 ms) on glass. However, the grey state disappears on the electron-accepting ZnO nanocrystals film. In addition, the grey state PL lifetime on glass is similar to the trion lifetime measured from electrochemically charged dots. Therefore, the grey state is assigned to the photocharged negative dots. It is concluded that a grey state is always present as the dots get negatively photocharged even though it might not be observed due to the brightness of the trion and/or the duration time of the negative charge. With thick shell CdSe/CdS dots under electrochemical control, multiple charging, up to four electrons per dot, is observed as sequential changes in the photoluminescence lifetime which can be described by the Nernst equation. The small potential increment confirms the weak electron confinement with the thick CdS shell. Finally, the mechanism of hole-trapping and surface oxidation by the hole is proposed to account for the grey state and off state in the blinking. PMID:23006012

  5. Automatic and Direct Identification of Blink Components from Scalp EEG

    PubMed Central

    Kong, Wanzeng; Zhou, Zhanpeng; Hu, Sanqing; Zhang, Jianhai; Babiloni, Fabio; Dai, Guojun

    2013-01-01

    Eye blink is an important and inevitable artifact during scalp electroencephalogram (EEG) recording. The main problem in EEG signal processing is how to identify eye blink components automatically with independent component analysis (ICA). Taking into account the fact that the eye blink as an external source has a higher sum of correlation with frontal EEG channels than all other sources due to both its location and significant amplitude, in this paper, we proposed a method based on correlation index and the feature of power distribution to automatically detect eye blink components. Furthermore, we prove mathematically that the correlation between independent components and scalp EEG channels can be translating directly from the mixing matrix of ICA. This helps to simplify calculations and understand the implications of the correlation. The proposed method doesn't need to select a template or thresholds in advance, and it works without simultaneously recording an electrooculography (EOG) reference. The experimental results demonstrate that the proposed method can automatically recognize eye blink components with a high accuracy on entire datasets from 15 subjects. PMID:23959240

  6. Detection of eye blink artifacts from single prefrontal channel electroencephalogram.

    PubMed

    Chang, Won-Du; Cha, Ho-Seung; Kim, Kiwoong; Im, Chang-Hwan

    2016-02-01

    Eye blinks are one of the most influential artifact sources in electroencephalogram (EEG) recorded from frontal channels, and thereby detecting and rejecting eye blink artifacts is regarded as an essential procedure for improving the quality of EEG data. In this paper, a novel method to detect eye blink artifacts from a single-channel frontal EEG signal was proposed by combining digital filters with a rule-based decision system, and its performance was validated using an EEG dataset recorded from 24 healthy participants. The proposed method has two main advantages over the conventional methods. First, it uses single-channel EEG data without the need for electrooculogram references. Therefore, this method could be particularly useful in brain-computer interface applications using headband-type wearable EEG devices with a few frontal EEG channels. Second, this method could estimate the ranges of eye blink artifacts accurately. Our experimental results demonstrated that the artifact range estimated using our method was more accurate than that from the conventional methods, and thus, the overall accuracy of detecting epochs contaminated by eye blink artifacts was markedly increased as compared to conventional methods. The MATLAB package of our library source codes and sample data, named Eyeblink Master, is open for free download. PMID:26560852

  7. Pre-target oscillatory brain activity and the attentional blink.

    PubMed

    Petro, Nathan M; Keil, Andreas

    2015-12-01

    Reporting the second of two targets within a stream of distracting words during rapid serial visual presentation (RSVP) is impaired when the targets are separated by a single distractor word, a deficit in temporal attention that has been referred to as the attentional blink (AB). Recent conceptual and empirical work has pointed to pre-target brain states as potential mediators of the AB effect. The current study examined differences in pre-target electrophysiology between correctly and incorrectly reported trials, considering amplitude and phase measures of alpha oscillations as well as the steady-state visual evoked potential (ssVEP) evoked by the RSVP stream. For incorrectly reported trials, relatively lower alpha-band power and greater ssVEP inter-trial phase locking were observed during extended time periods preceding presentation of the first target. These results suggest that facilitated processing of the pre-target distracter stream indexed by reduced alpha and heightened phase locking characterizes a dynamic brain state that predicts lower accuracy in terms of reporting the second target under strict temporal constraints. Findings align with hypotheses in which the AB effect is attributed to neurocognitive factors such as fluctuations in pre-target attention or to cognitive strategies applied at the trial level. PMID:26341931

  8. The Sparing Is Far from Spurious: Reevaluating Within-Trial Contingency Effects in the Attentional Blink

    ERIC Educational Resources Information Center

    Olivers, Christian N. L.; Hulleman, Johan; Spalek, Thomas; Kawahara, Jun-ichiro; Di Lollo, Vincent

    2011-01-01

    The attentional blink is the marked deficit in awareness of a 2nd target (T2) when it is presented shortly after the 1st target (T1) in a stream of distractors. When the distractors between T1 and T2 are replaced by even more targets, the attentional blink is reduced or absent, indicating that the attentional blink results from online selection…

  9. A novel approach to Hugoniot measurements utilizing transparent crystals

    SciTech Connect

    Fratanduono, D. E.; Eggert, J. H.; Akin, M. C.; Chau, R.; Holmes, N. C.

    2013-01-01

    A new absolute equation of state measurement technique is described and demonstrated measuring the shock state and the refractive index of MgO up to 226GPa. This technique utilizes steady shock waves and the high-pressure transparency of MgO under dynamic shock compression and release. Hugoniot measurements performed using this technique are consistent with the previous measurements. A linear dependence of the shocked refractive index and density is observed up to 226GPa, over a magnitude greater in pressure that previous studies. The transparency of MgO along the principal Hugoniot is higher than any other material reported to date. We observe a significant change in the refractive index of MgO as the Hugoniot elastic limit is exceeded due to the transition from uniaxial to hydrostatic strain. Measurements of the elastic-plastic two-wave structure in MgO indicate a nucleation time for plastic deformation.

  10. Startle and blink reflex in high functioning autism.

    PubMed

    Erturk, Ozdem; Korkmaz, Baris; Alev, Gulce; Demirbilek, Veysi; Kiziltan, Meral

    2016-06-01

    An important clinical feature of autism is the presence of atypical responses to sensory stimuli. In this study, we investigated if high functioning autistic patients had abnormalities in the blink reflex and the startle reaction to auditory or somatosensory stimuli. Fourteen patients aged between 7 and 16 years were included in the study. We found a longer latency of the blink reflex, an increased duration and amplitude of the auditory startle reaction and a lower presence rate of the somatosensorial startle reaction in autistic patients. To better define the sensorial characteristics of the disease could improve the therapeutic management of children with autism spectrum disorder. PMID:26997128

  11. Utility of de-escalatory confidence-building measures

    SciTech Connect

    Nation, J.

    1989-06-01

    This paper evaluates the utility of specific confidence-building de-escalatory measures and pays special attention to the evaluation of measures which place restrictions on or establish procedures for strategic forces. Some measures appear more promising than others. Potentially useful confidence-building measures largely satisfy defined criteria and include the phased return of strategic nuclear forces to peacetime bases and operations, the termination of interference with communications and NTMs (National Technical Means) and the termination of civil defense preparations. Less-promising CBMs include the standing down of supplemental early warning systems, the establishment of SSBN keep-out zones, and decreases in bomber alert rates. Establishment of SSBN keep-out zones and reduction in bomber rates are difficult to verify, while the standing-down of early warning systems provides little benefit at potentially large costs. Particular confidence-building measures (CBMs) may be most useful in building superpower confidence at specific points in the crisis termination phase. For example, a decrease in strategic bomber alert rates may provide some decrease in perception of the likelihood of war, but its potential costs, particularly in increasing bomber vulnerability, may limit its utility and implementation to the final crisis stages when the risks of re-escalation and surprise attack are lower.

  12. Minds on the blink: the relationship between inattentional blindness and attentional blink.

    PubMed

    Beanland, Vanessa; Pammer, Kristen

    2012-02-01

    Failures of conscious visual awareness occur when specific task demands prevent an observer from detecting a stimulus that would otherwise be clearly visible. Two examples are inattentional blindness (IB) and attentional blink (AB). IB is the failure to detect an unexpected stimulus when attention is otherwise engaged. AB describes the inability to detect a second target that is presented within 180-500 ms of the first target. Previous research has suggested that similar cognitive processes underlie both IB and AB; however, they are distinct phenomena, and no evidence has directly linked the two. We tested the same group of observers on an IB task and an AB task. Consistent with our hypotheses, we found that "non-noticers" who failed to detect an unexpected stimulus in the IB task also demonstrated a larger AB effect. This suggests that some observers may be more generally susceptible to failures of conscious visual awareness, regardless of specific context. PMID:22086482

  13. Religion and the Attentional Blink: Depth of Faith Predicts Depth of the Blink

    PubMed Central

    Colzato, Lorenza S.; Hommel, Bernhard; Shapiro, Kimron L.

    2010-01-01

    Religion is commonly defined as a set of rules, developed as part of a culture. Here we provide evidence that practice in following these rules systematically changes the way people allocate their attention, as indicated by the attentional blink (AB), a deficit in reporting the second of two target stimuli presented in close succession in a rapid sequence of distracters. We provide evidence that Dutch Calvinists and Atheists, brought up in the same country and culture and controlled for race, intelligence, mood, personality traits, and age, differ with respect to the amount of resources invested into processing AB targets. Calvinists showed a larger AB than Atheists, which is consistent with the notion that people's attentional processing style reflects biases rewarded by their religious beliefs. PMID:21833216

  14. Temporal cuing modulates alpha oscillations during auditory attentional blink.

    PubMed

    Shen, Dawei; Ross, Bernhard; Alain, Claude

    2016-07-01

    Attentional blink (AB) refers to the phenomenon whereby the correct identification of a visual or auditory target impairs processing of a subsequent probe. Although it has been shown that knowing in advance, when the probe would be presented, reduces the attentional blink and increases the amplitude of event-related potential (ERP) elicited by the probe, the neural mechanism by which attention mitigates the AB remains unclear. Here, we used time-frequency analysis to further explore the mechanism of the auditory attentional blink. Participants were presented a series of rapid auditory stimuli and asked to indicate whether a target and a probe were present in the sequence. In half of the trials, participants were cued to the probe position relative to the target ('Early' or 'Late'). Probe detection and ERP amplitude elicited by the probe decreased when the probe was presented shortly after the target compared to when it was presented later after the target. Importantly, the behavioral and ERP correlates of probe discrimination significantly improved when the 'Early' cue was presented. The improvement in processing the probe in the cued condition was accompanied by the decrease in alpha activity (8-13 Hz) after the time when the probe was expected; suggesting that successfully directing attention to time window where the probe would likely occur reduces the processing resources needed to suppress distractors. This in turn freed up available processing resources for the target and probe at the short-term consolidation stage, which ultimately reduced the auditory attentional blink. PMID:27152668

  15. Masking T1 Difficulty: Processing Time and the Attentional Blink

    ERIC Educational Resources Information Center

    Visser, Troy A. W.

    2007-01-01

    When observers are presented with 2 targets in rapid succession, identification of the 1st is highly accurate, whereas identification of the 2nd is impaired at brief intertarget intervals (i.e., 200-500 ms). This 2nd-target deficit is known as the attentional blink (AB). According to bottleneck models, the AB arises because attending to the 1st…

  16. When Do Additional Distractors Reduce the Attentional Blink?

    ERIC Educational Resources Information Center

    Kawahara, Jun-ichiro

    2009-01-01

    When 2 targets are embedded in a rapid serial visual presentation stream of distractors, perception of the second target is impaired when the intertarget lag is relatively short (less than 500 ms). Stimuli concurrently presented with the stream can affect this phenomenon, which is called attentional blink (AB). Previous studies have yielded…

  17. Delocalized and localized charged excitons in single CdSe/CdS dot-in-rods revealed by polarized photoluminescence blinking

    NASA Astrophysics Data System (ADS)

    Ihara, Toshiyuki; Sato, Ryota; Teranishi, Toshiharu; Kanemitsu, Yoshihiko

    2014-07-01

    CdSe/CdS heterostructured nanocrystals with quasi-type-II band alignments provide an interesting platform for studying the photoluminescence (PL) blinking associated with their unique morphologies. By using simultaneous measurements of the PL intensity, lifetime, and polarization anisotropy, we reveal the role of the electron delocalization during the blinking of single CdSe/CdS dot-in-rods. We found that a significant change in the PL polarization anisotropy distinguishes between two kinds of charged excitons with different electron delocalizations. We report our observation of unique polarized PL blinking governed by the band alignments and the Coulomb interactions between the charges inside and outside the dot-in-rod.

  18. Fixations and eye-blinks allow for detecting concealed crime related memories.

    PubMed

    Peth, Judith; Kim, Johann S C; Gamer, Matthias

    2013-04-01

    The Concealed Information Test (CIT) is a method of forensic psychophysiology that allows for revealing concealed crime related knowledge. Such detection is usually based on autonomic responses but there is a huge interest in other measures that can be acquired unobtrusively. Eye movements and blinks might be such measures but their validity is unclear. Using a mock crime procedure with a manipulation of the arousal during the crime as well as the delay between crime and CIT, we tested whether eye tracking measures allow for detecting concealed knowledge. Guilty participants showed fewer but longer fixations on central crime details and this effect was even present after stimulus offset and accompanied by a reduced blink rate. These ocular measures were partly sensitive for induction of emotional arousal and time of testing. Validity estimates were moderate but indicate that a significant differentiation between guilty and innocent subjects is possible. Future research should further investigate validity differences between gaze measures during a CIT and explore the underlying mechanisms. PMID:23511446

  19. The (B)link Between Creativity and Dopamine: Spontaneous Eye Blink Rates Predict and Dissociate Divergent and Convergent Thinking

    ERIC Educational Resources Information Center

    Chermahini, Soghra Akbari; Hommel, Bernhard

    2010-01-01

    Human creativity has been claimed to rely on the neurotransmitter dopamine, but evidence is still sparse. We studied whether individual performance (N=117) in divergent thinking (alternative uses task) and convergent thinking (remote association task) can be predicted by the individual spontaneous eye blink rate (EBR), a clinical marker of…

  20. Musical Minds: Attentional Blink Reveals Modality-Specific Restrictions

    PubMed Central

    Martens, Sander; Wierda, Stefan M.; Dun, Mathijs; de Vries, Michal; Smid, Henderikus G. O. M.

    2015-01-01

    Background Formal musical training is known to have positive effects on attentional and executive functioning, processing speed, and working memory. Consequently, one may expect to find differences in the dynamics of temporal attention between musicians and non-musicians. Here we address the question whether that is indeed the case, and whether any beneficial effects of musical training on temporal attention are modality specific or generalize across sensory modalities. Methodology/Principal Findings When two targets are presented in close temporal succession, most people fail to report the second target, a phenomenon known as the attentional blink (AB). We measured and compared AB magnitude for musicians and non-musicians using auditory or visually presented letters and digits. Relative to non-musicians, the auditory AB was both attenuated and delayed in musicians, whereas the visual AB was larger. Non-musicians with a large auditory AB tended to show a large visual AB. However, neither a positive nor negative correlation was found in musicians, suggesting that at least in musicians, attentional restrictions within each modality are completely separate. Conclusion/Significance AB magnitude within one modality can generalize to another modality, but this turns out not to be the case for every individual. Formal musical training seems to have a domain-general, but modality-specific beneficial effect on selective attention. The results fit with the idea that a major source of attentional restriction as reflected in the AB lies in modality-specific, independent sensory systems rather than a central amodal system. The findings demonstrate that individual differences in AB magnitude can provide important information about the modular structure of human cognition. PMID:25714836

  1. Enhancing quantum Fisher information by utilizing uncollapsing measurements

    NASA Astrophysics Data System (ADS)

    He, Juan; Ding, Zhi-Yong; Ye, Liu

    2016-09-01

    As an indicator of estimation precision, quantum Fisher information (QFI) lies at the heart of quantum metrology theory. In this work, an effective scheme for enhancing QFI is proposed by utilizing quantum uncollapsing measurements. Two kinds of strategies for the arbitrary two-qubit pure state with weight parameter and phase parameter are implemented under different situations, respectively. We derive the explicit conditions for the optimal measurement strengths, and verify that the QFI can be improved quite well. Meanwhile, due to the relation of quantum correlation and QFI, the maximal value of QFI associated with phase parameter for pure state is always equal to 1. It is worth noting that the optimal measurement strength is only related to the weight parameter, as uncollapsing measurements operation does not induce any disturbance on the value of phase parameter. The scheme also can be extended to improve the parameter estimation precision for an N-qubit pure state. In addition, as an example, the situation of an arbitrary single-qubit state under amplitude damping channel is investigated. It is shown that our scheme also works well for enhancing QFI under decoherence.

  2. Semantic and repetition priming within the attentional blink: an event-related brain potential (ERP) investigation study.

    PubMed

    Pesciarelli, F; Kutas, M; Dell'acqua, R; Peressotti, F; Job, R; Urbach, T P

    2007-09-01

    An attentional blink (AB) paradigm was used to directly compare semantic and repetition priming for reported words versus missed words. Three target words (T1, T2, T3) were embedded in a rapidly presented stream of non-word distractors for report at the end of each trial. Whereas T1 was not related to either T2 or T3, T2 and T3 could be unrelated words, semantically related words, or identical. Semantic and repetition priming effects were evident in both behavioral and electrophysiological measures on T3, whether T2 was accurately reported or 'blinked'. These results suggest that semantic and repetition priming effects, under rapid serial visual presentation conditions, are modulated by at least partially overlapping neural mechanisms. PMID:17611011

  3. The Attentional Blink Is Not Affected by Backward Masking of T2, T2-Mask SOA, or Level of T2 Impoverishment

    ERIC Educational Resources Information Center

    Jannati, Ali; Spalek, Thomas M.; Lagroix, Hayley E. P.; Di Lollo, Vincent

    2012-01-01

    Identification of the second of two targets (T2) is impaired when presented shortly after the first (T1). This "attentional blink" (AB) is thought to arise from a delay in T2 processing during which T2 is vulnerable to masking. Conventional studies have measured T2 accuracy which is constrained by the 100% ceiling. We avoided this problem by using…

  4. Development of a Neutron Spectroscopic System Utilizing Compressed Sensing Measurements

    NASA Astrophysics Data System (ADS)

    Vargas, Danilo; Cable Kurwitz, R.; Carron, Igor; DePriest, K. Russell

    2016-02-01

    A new approach to neutron detection capable of gathering spectroscopic information has been demonstrated. The approach relies on an asymmetrical arrangement of materials, geometry, and an ability to change the orientation of the detector with respect to the neutron field. Measurements are used to unfold the energy characteristics of the neutron field using a new theoretical framework of compressed sensing. Recent theoretical results show that the number of multiplexed samples can be lower than the full number of traditional samples while providing the ability to have some super-resolution. Furthermore, the solution approach does not require a priori information or inclusion of physics models. Utilizing the MCNP code, a number of candidate detector geometries and materials were modeled. Simulations were carried out for a number of neutron energies and distributions with preselected orientations for the detector. The resulting matrix (A) consists of n rows associated with orientation and m columns associated with energy and distribution where n < m. The library of known responses is used for new measurements Y (n × 1) and the solver is able to determine the system, Y = Ax where x is a sparse vector. Therefore, energy spectrum measurements are a combination of the energy distribution information of the identified elements of A. This approach allows for determination of neutron spectroscopic information using a single detector system with analog multiplexing. The analog multiplexing allows the use of a compressed sensing solution similar to approaches used in other areas of imaging. A single detector assembly provides improved flexibility and is expected to reduce uncertainty associated with current neutron spectroscopy measurement.

  5. Contingent negative variation indicates phasic arousal for externally cued unilateral eye blink in human subjects.

    PubMed

    Strenge, H; Kropp, P; Hoffmeister, J; Verri, A; Galli, C; Gerber, W D

    1999-04-30

    The contingent negative variation (CNV) as a slow cortical potential was used to investigate cortical processing of externally cued, voluntary unilateral eye blink. Probands blinked as a response within a modified two-stimulus reaction time paradigm. Reaction time and amplitudes of CNV were determined. The activity of the orbicularis oculi muscles (OO) was registered by surface electromyography (EMG). Probands who performed unilateral eye blinks with accurately inhibiting contralateral OO activity showed a significantly higher negativity of the early CNV component compared with the bilateral eye blink condition. This effect was confined to the beginning of unilateral blinking performance. It is suggested that the unilateral eye blink is a challenging motor task, initially requiring an increased cortically driven arousal and attention as revealed by increased early CNV components. PMID:10336183

  6. Tear lipid layer deficiency associated with incomplete blinking: A case report

    PubMed Central

    2013-01-01

    Background Meibomian gland obstruction induces hyposecretion of tear film lipids, which results in lipid layer deficiency and evaporative dry eye. Unfortunately, the importance of blinking in meibomian gland dysfunction has been largely overlooked, and it is not known whether incomplete blinking causes tear lipid deficiency, even in the unobstructed meibomian glands. Case presentation A 38-year-old woman suffering from foreign body sensations in her eyes was examined. The cornea was clear and tear secretion was normal. Lid margin abnormalities were not observed and the meibum was clear. However, the lipid layer was very thin, and the patient was given a diagnosis of incomplete blinking. The patient was made aware of her condition and asked to blink consciously and completely. After that, an immediate increase in lipid flow was observed. Conclusion Tear lipid layer deficiency can occur with incomplete blinking, even though meibomian gland structures are intact. This case highlights the importance of complete blinking. PMID:23855887

  7. Jaw, blink and corneal reflex latencies in multiple sclerosis.

    PubMed Central

    Sanders, E A; Ongerboer de Visser, B W; Barendswaard, E C; Arts, R J

    1985-01-01

    Jaw, blink and corneal reflexes, which all involve the trigeminal system, were recorded in 54 patients with multiple sclerosis; thirty-seven of these patients were classified as having definite multiple sclerosis and 17 as indefinite multiple sclerosis, according to Schumacher's criteria. The jaw reflex was abnormal less frequently than either of the other two reflexes, but in four cases it was the only abnormal reflex found. Testing a combination of two or three trigeminal reflexes did not yield a higher incidence of abnormalities than testing the blink or corneal reflex alone. Nine patients showed abnormal reflexes which were unexpected on the basis of clinical symptoms. The combined recordings demonstrate at least one abnormal reflex in 74% of the patients. The various types of reflex abnormalities reflect major damage to different parts of the trigeminal system and may therefore make an important contribution to the diagnosis of multiple sclerosis. PMID:4087004

  8. Apomorphine-induced blinking and yawning in healthy volunteers.

    PubMed Central

    Blin, O; Masson, G; Azulay, J P; Fondarai, J; Serratrice, G

    1990-01-01

    Yawning and spontaneous blink rate (SBR) are two physiological reflexes which have been incompletely examined but one neurobiological step of these two behaviours seems, at least in part, dopamine-dependent. The reference dopaminergic agonist, apomorphine hydrochloride (0.5, 1, and 2 micrograms kg-1 s.c.), was compared with a placebo in a double-blind latin-square design, and was shown to induce yawning and increase SBR in a population of eight healthy volunteers. These two behavioral effects were not dose-related. The individual SBR differences were correlated with the individual number of yawns for all the four treatments at the 10-30 min interval. Thus, parallel yawning and SBR behaviour suggests a similar pharmacological mechanism. Apomorphine-induced yawning and blinking may be therefore of use in the evaluation of central dopaminergic pathways in man. PMID:2271377

  9. Children Induce an Enhanced Attentional Blink in Child Molesters

    ERIC Educational Resources Information Center

    Beech, Anthony R.; Kalmus, Ellis; Tipper, Steven P.; Baudouin, Jean-Yves; Flak, Vanja; Humphreys, Glyn W.

    2008-01-01

    The attentional blink (AB) is a robust phenomenon that has been consistently reported in the cognitive literature. The AB is found when two target images (T1, T2) are presented within 500 ms of each other and errors are induced on the perceptual report of T2. The AB may increase when T1 has some salience to the viewer. This study examined the…

  10. CdSeS/ZnS alloyed nanocrystal lifetime and blinking studies under electrochemical control.

    PubMed

    Qin, Wei; Shah, Raman A; Guyot-Sionnest, Philippe

    2012-01-24

    Alloyed CdSeS nanocrystals allow tuning between the CdSe and CdS band edges while remaining relatively small. The CdSeS cores also lead to a reduced electron confinement energy and a slower biexciton decay rate compared to CdSe cores of similar sizes. A ZnS shell synthesis procedure allows stable CdSeS/ZnS colloidal quantum dots (QDs) suitable for single dot imaging. These are compared to CdSe/ZnS of similar core size. The blinking off-exponents of the CdSeS/ZnS dots in air and on a glass substrate were slightly larger. Using electrochemistry with ensemble and single dot measurements, the trion lifetime of CdSeS/ZnS dot is resolved to be ~0.75 ns, while it is about 0.15 ns for CdSe/ZnS. In addition, the blinking behavior of single CdSeS/ZnS QDs is largely suppressed when in the trion state. PMID:22191620

  11. Blink reflex in subjects with different hypnotizability: New findings for an old debate.

    PubMed

    Santarcangelo, Enrica L; Briscese, Lucia; Capitani, Simone; Orsini, Paolo; Varanini, Maurizio; Rossi, Bruno; Carboncini, Maria C

    2016-09-01

    Hypnotizability is associated with attentional characteristics whose neurophysiological bases are still under debate. Aim of the study was the assessment of possible hypnotizability-related differences in blink reflex (BR) which has a nociceptive component, is sensitive to attentional-emotional traits and states and is modulated by the brain dopamine content. In 10 high (highs) and 10 low hypnotizable participants (lows) BR was induced by electrical nociceptive stimulation of the right supraorbital nerve in the absence (noW) and in the presence of a visual cue preceding the electrical stimulation by 0.1ms (W01) and by 1ms (W1). The studied variables were: the amplitude of BR components (R1, R2, R3), the amplitude of the quick change (TO) of heart rate ("turbulence") induced by stimulation and its recovery slope (TS), the role of the Behavioral Inhibition/Activation System (BIS/BAS) in the variability BR and cardiac turbulence. Repeated measures ANOVA did not show any significant difference between highs and lows in blink reflex. TO indicated stimulation related HR increase in highs and decrease in lows, TS was larger in highs. BIS and BAS accounted for the warning effects on the BR amplitude and modulated the hypnotizability and warning effects on TO and TS. Findings do not support dopamine based hypnotizability-related attentional abilities. In contrast, they indicate that hypnotizability modulates the short-lasting cardiac response to electrical nociceptive stimulation. PMID:27184234

  12. Blinking Phase-Change Nanocapsules Enable Background-Free Ultrasound Imaging

    PubMed Central

    Hannah, Alexander S.; Luke, Geoffrey P.; Emelianov, Stanislav Y.

    2016-01-01

    Microbubbles are widely used as contrast agents to improve the diagnostic capability of conventional, highly speckled, low-contrast ultrasound imaging. However, while microbubbles can be used for molecular imaging, these agents are limited to the vascular space due to their large size (> 1 μm). Smaller microbubbles are desired but their ultrasound visualization is limited due to lower echogenicity or higher resonant frequencies. Here we present nanometer scale, phase changing, blinking nanocapsules (BLInCs), which can be repeatedly optically triggered to provide transient contrast and enable background-free ultrasound imaging. In response to irradiation by near-infrared laser pulses, the BLInCs undergo cycles of rapid vaporization followed by recondensation into their native liquid state at body temperature. High frame rate ultrasound imaging measures the dynamic echogenicity changes associated with these controllable, periodic phase transitions. Using a newly developed image processing algorithm, the blinking particles are distinguished from tissue, providing a background-free image of the BLInCs while the underlying B-mode ultrasound image is used as an anatomical reference of the tissue. We demonstrate the function of BLInCs and the associated imaging technique in a tissue-mimicking phantom and in vivo for the identification of the sentinel lymph node. Our studies indicate that BLInCs may become a powerful tool to identify biological targets using a conventional ultrasound imaging system. PMID:27570556

  13. Relieving the Attentional Blink in the Amblyopic Brain with Video Games

    PubMed Central

    Li, Roger W.; Ngo, Charlie V.; Levi, Dennis M.

    2015-01-01

    Video game play induces a generalized recovery of a range of spatial visual functions in the amblyopic brain. Here we ask whether video game play also alters temporal processing in the amblyopic brain. When visual targets are presented in rapid succession, correct identification of the first target (T1) can interfere with identification of the second (T2). This is known as the “attentional blink”. We measured the attentional blink in each eye of adults with amblyopia before and after 40 hours of active video game play, using a rapid serial visual presentation technique. After videogame play, we observed a ~40% reduction in the attentional blink (identifying T2 200 ms after T1) seen through the amblyopic eye and this improvement in performance transferred substantially to the untrained fellow sound eye. Our experiments show that the enhanced performance cannot be simply explained by eye patching alone, or to improved visual acuity, but is specific to videogame experience. Thus, videogame training might have important therapeutic applications for amblyopia and other visual brain disorders. PMID:25715870

  14. Blinking Phase-Change Nanocapsules Enable Background-Free Ultrasound Imaging.

    PubMed

    Hannah, Alexander S; Luke, Geoffrey P; Emelianov, Stanislav Y

    2016-01-01

    Microbubbles are widely used as contrast agents to improve the diagnostic capability of conventional, highly speckled, low-contrast ultrasound imaging. However, while microbubbles can be used for molecular imaging, these agents are limited to the vascular space due to their large size (> 1 μm). Smaller microbubbles are desired but their ultrasound visualization is limited due to lower echogenicity or higher resonant frequencies. Here we present nanometer scale, phase changing, blinking nanocapsules (BLInCs), which can be repeatedly optically triggered to provide transient contrast and enable background-free ultrasound imaging. In response to irradiation by near-infrared laser pulses, the BLInCs undergo cycles of rapid vaporization followed by recondensation into their native liquid state at body temperature. High frame rate ultrasound imaging measures the dynamic echogenicity changes associated with these controllable, periodic phase transitions. Using a newly developed image processing algorithm, the blinking particles are distinguished from tissue, providing a background-free image of the BLInCs while the underlying B-mode ultrasound image is used as an anatomical reference of the tissue. We demonstrate the function of BLInCs and the associated imaging technique in a tissue-mimicking phantom and in vivo for the identification of the sentinel lymph node. Our studies indicate that BLInCs may become a powerful tool to identify biological targets using a conventional ultrasound imaging system. PMID:27570556

  15. Origin and control of blinking in quantum dots.

    PubMed

    Efros, Alexander L; Nesbitt, David J

    2016-08-01

    Semiconductor nanocrystals offer an enormous diversity of potential device applications, based on their size-tunable photoluminescence, high optical stability and 'bottom-up' chemical approaches to self-assembly. However, the promise of such applications can be seriously limited by photoluminescence intermittency in nanocrystal emission, that is, 'blinking', arising from the escape of either one or both of the photoexcited carriers to the nanocrystal surface. In the first scenario, the remaining nanocrystal charge quenches photoluminescence via non-radiative Auger recombination, whereas for the other, the exciton is thought to be intercepted before thermalization and does not contribute to the photoluminescence. This Review summarizes the current understanding of the mechanisms responsible for nanocrystal blinking kinetics as well as core-shell engineering efforts to control such phenomena. In particular, 'softening' of the core-shell confinement potential strongly suppresses non-radiative Auger processes in charged nanocrystals, with successful non-blinking implementations demonstrated in CdSe-CdS core-thick-shell nanocrystals and their modifications. PMID:27485584

  16. Origin and control of blinking in quantum dots

    NASA Astrophysics Data System (ADS)

    Efros, Alexander L.; Nesbitt, David J.

    2016-08-01

    Semiconductor nanocrystals offer an enormous diversity of potential device applications, based on their size-tunable photoluminescence, high optical stability and 'bottom-up' chemical approaches to self-assembly. However, the promise of such applications can be seriously limited by photoluminescence intermittency in nanocrystal emission, that is, 'blinking', arising from the escape of either one or both of the photoexcited carriers to the nanocrystal surface. In the first scenario, the remaining nanocrystal charge quenches photoluminescence via non-radiative Auger recombination, whereas for the other, the exciton is thought to be intercepted before thermalization and does not contribute to the photoluminescence. This Review summarizes the current understanding of the mechanisms responsible for nanocrystal blinking kinetics as well as core-shell engineering efforts to control such phenomena. In particular, 'softening' of the core-shell confinement potential strongly suppresses non-radiative Auger processes in charged nanocrystals, with successful non-blinking implementations demonstrated in CdSe-CdS core-thick-shell nanocrystals and their modifications.

  17. The dopamine D1 receptor agonist SKF-82958 effectively increases eye blinking count in common marmosets.

    PubMed

    Kotani, Manato; Kiyoshi, Akihiko; Murai, Takeshi; Nakako, Tomokazu; Matsumoto, Kenji; Matsumoto, Atsushi; Ikejiri, Masaru; Ogi, Yuji; Ikeda, Kazuhito

    2016-03-01

    Eye blinking is a spontaneous behavior observed in all mammals, and has been used as a well-established clinical indicator for dopamine production in neuropsychiatric disorders, including Parkinson's disease and Tourette syndrome [1,2]. Pharmacological studies in humans and non-human primates have shown that dopamine agonists/antagonists increase/decrease eye blinking rate. Common marmosets (Callithrix jacchus) have recently attracted a great deal of attention as suitable experimental animals in the psychoneurological field due to their more developed prefrontal cortex than rodents, easy handling compare to other non-human primates, and requirement for small amounts of test drugs. In this study, we evaluated the effects of dopamine D1-4 receptors agonists on eye blinking in common marmosets. Our results show that the dopamine D1 receptor agonist SKF-82958 and the non-selective dopamine receptor agonist apomorphine significantly increased common marmosets eye blinking count, whereas the dopamine D2 agonist (+)-PHNO and the dopamine D3 receptor agonist (+)-PD-128907 produced somnolence in common marmosets resulting in a decrease in eye blinking count. The dopamine D4 receptor agonists PD-168077 and A-41297 had no effect on common marmosets' eye blinking count. Finally, the dopamine D1 receptor antagonist SCH 39166 completely blocked apomorphine-induced increase in eye blinking count. These results indicate that eye blinking in common marmosets may be a useful tool for in vivo screening of novel dopamine D1 receptor agonists as antipsychotics. PMID:26675887

  18. The Role of the Magnocellular and Parvocellular Pathways in the Attentional Blink

    ERIC Educational Resources Information Center

    Nieuwenhuis, Sander; Jepma, Marieke; La Fors, Sabrina; Olivers, Christian N. L.

    2008-01-01

    The attentional blink refers to the transient impairment in perceiving the 2nd of two targets presented in close temporal proximity in a rapid serial visual presentation (RSVP) stream. The purpose of this study was to examine the effect on human attentional-blink performance of disrupting the function of the magnocellular pathway--a major…

  19. Exploring the characteristics of the attentional blink paradigm when used to discover concealed knowledge.

    PubMed

    Niziurski, Julie; Andre, Jeffrey

    2015-12-01

    Ganis and Patnaik (Appl Psychophysiol Biofeedback 34:189-196, 2009) reported that the attentional blink paradigm using faces could be used to detect the presence of concealed knowledge. The attentional blink is defined as the inability to successfully detect the second of two target items presented within a short inter-stimulus interval. The present study tested the use of the attentional blink paradigm in a concealed knowledge test by investigating the effect that familiar faces may have on the attentional blink. Participants completed 200 trials where they were told to look for the same familiar target (Target 2; actor Brad Pitt) that was intermixed with neutral face stimuli and one other familiar face (Target 1; actor George Clooney). Target 1 was to act as the concealed knowledge as participants familiar with Target 1 would be distracted by his unannounced presence and report not seeing Target 2 thereby showing an attentional blink. Despite all participants being familiar with Target 2, an attentional blink still occurred, but with higher than normal Target 2 accuracy rates. Overall, we found support for using the AB paradigm with the concealed knowledge test; however, a possible countermeasure to the attentional blink is familiarity with Target 2 as eight of 21 participants who recognized Target 1 (the concealed knowledge) were also able to detect Target 2 on 100 % of the trials where Target 1's presence should have created an attentional blink. PMID:26162299

  20. Blink reflexes and magnetic resonance imaging in focal unilateral central trigeminal pathway demyelination.

    PubMed Central

    Kiers, L; Carroll, W M

    1990-01-01

    The electrically elicited blink reflex allows quantitative analysis of the corneal reflex which traverses the trigeminal and facial nerves and the brainstem. Two patients presenting with symptomatic unilateral trigeminal lesions are described, in whom the blink reflexes showed conduction block and slowing at predictable sites in the central pathways, and magnetic resonance imaging confirmed precisely the clinical and electrophysiological localisation. Images PMID:2380735

  1. Evaluation of the somatosensory evoked blink response in patients with neurological disorders.

    PubMed Central

    Miwa, H; Yamaji, Y; Abe, H; Mizuno, Y

    1996-01-01

    BACKGROUND--The somatosensory evoked blink response (SBR) is a characteristic reflex blink elicited by electrical stimulation of peripheral nerves or other anatomical sites. METHODS--139 patients with neurological disorders were examined for presence of the SBR. Although the SBR was not usually elicitable, it was present in a subset of patients with Parkinson's disease and with hemifacial spasm. It was also present in a patient with Guillain-Barré syndrome before the recovery phase. The latency of the EMG activities responsible for the SBR was significantly shorter than that of the startle blink. CONCLUSIONS--The SBR is not a variant of the startle blink, but is a release phenomenon transmitted via the brainstem reticular formation. This response may be clinically relevant in disorders associated with brainstem lesions and abnormal blinking. PMID:8778259

  2. Design of virtual keyboard using blink control method for the severely disabled.

    PubMed

    Yang, Shih-Wei; Lin, Chern-Sheng; Lin, Shir-Kuan; Lee, Chi-Hung

    2013-08-01

    In this paper, a human-machine interface with the concept of "blink control" is proposed. The human-machine interface is applied to an assistive device, namely "blink scanning keyboard", which is designed specifically for the severely physical disabled and people suffering from motor neuron diseases or severe cerebral palsy. The pseudo electromyography (EMG) signal of blinking eyes could be acquired by wearing a Bluetooth headset with one sensor on the forehead and the other three on the left ear of the user. Through a conscious blink, a clear and immediate variation will be formed in the pseudo EMG signal from the users' forehead. The occurrence of this variation in pseudo EMG signal could be detected and filtered by the algorithms proposed in this paper, acting like a trigger to activate the functions integrated in the scanning keyboard. The severely physical and visual disabled then can operate the proposed design by simply blinking their eyes, thus communicating with outside world. PMID:23702128

  3. Signal detection methods for measurement of utility in animals1

    PubMed Central

    Wright, Anthony A.; Nevin, John A.

    1974-01-01

    Analytic methods of signal detection theory were employed to assess the utility of reinforcers. Four pigeons were trained to detect the presence or absence of a stimulus by pecking one of two side keys in a trial-by-trial choice paradigm. The relative rate of positive reinforcement for correct choices was varied to offset the biasing effects of electric shock for incorrect right side-key choices. The effects of relative rate of reinforcement on bias were similar at all shock intensities even though the subjects' sensitivity changed during the course of the experiment. The relative rate of reinforcement required to produce equal bias was calculated and plotted against shock intensity to generate utility functions. The relative rate of reinforcement necessary to offset the bias induced by shock was an increasing function of shock intensity. PMID:16811750

  4. A Utility-Based Approach to Some Information Measures

    NASA Astrophysics Data System (ADS)

    Friedman, Craig; Huang, Jinggang; Sandow, Sven

    2007-03-01

    We review a decision theoretic, i.e., utility-based, motivation for entropy and Kullback-Leibler relative entropy, the natural generalizations that follow, and various properties of thesegeneralized quantities. We then consider these generalized quantities in an easily interpreted spe-cial case. We show that the resulting quantities, share many of the properties of entropy andrelative entropy, such as the data processing inequality and the second law of thermodynamics.We formulate an important statistical learning problem - probability estimation - in terms of ageneralized relative entropy. The solution of this problem reflects general risk preferences via theutility function; moreover, the solution is optimal in a sense of robust absolute performance.

  5. Determination of measurement uncertainty on coordinate measurement machines by measurement decomposition and utilization of canonical artifacts

    SciTech Connect

    Rasnick, B.; Cox, B.; Sherrill, M.

    1996-08-01

    The requirement for primary-level calibration of complex forms, e.g., gear profiles, has led to development of a method for quantifying the measurement uncertainty on the artifact being calibrated that does not rely on a transfer comparison. This method, developed jointly by National Institute of Standards and Technology (NIST) and Oak Ridge Metrology Center (ORMC) personnel, consists of breaking down the measurement method into simpler components and quantifying these components using generally accepted artifacts with low uncertainties (gage blocks, ring gages, spheres, etc.). Once quantified, these components are added vectorially according to NIST Technical Note 1297, 1994 Edition. Verification of this method can be accomplished by intercomparisons with other methods and laboratories.

  6. Aircraft water vapor measurements utilizing an aluminum oxide hygrometer

    NASA Technical Reports Server (NTRS)

    Hilsenrath, E.

    1973-01-01

    A hygrometer for water vapor measurements from an aircraft has been developed. An aluminum oxide hygrometer mounted in an aircraft Rosemount air temperature scoop was flown on NASA and USAF aircraft. Water vapor measurements were conducted up to 40,000 feet with penetration into the stratosphere. Good agreement was obtained with simultaneously flown remote sounders of water vapor. During transcontinental flights the hygrometer demonstrated adequate response to measure the natural variability of water vapor near the tropopause. Rapid response was demonstrated in pursuit of the jet wake of an F-104 at 35,000 feet.

  7. Aircraft water vapor measurements utilizing an aluminum oxide hygrometer

    NASA Technical Reports Server (NTRS)

    Hilsenrath, E.

    1974-01-01

    A hygrometer for water vapor measurements from an aircraft was developed. An aluminum oxide hygrometer mounted in an aircraft Rosemount air temperature scoop was flown on the NASA Convair 990 and on a USAF B-57 aircraft. Water vapor measurements from the Convair 990 were conducted up to 40,000 ft with penetration into the stratosphere. Good agreement was obtained with simultaneously flown remote sounders of water vapor. During transcontinental flights the hygrometer demonstrated adequate response to measure the natural variability of water vapor near the tropopause. Rapid response was demonstrated in pursuit of the jet wake of an F-104 at 35,000 ft.

  8. Nondestructive measurement of esophageal biaxial mechanical properties utilizing sonometry.

    PubMed

    Aho, Johnathon M; Qiang, Bo; Wigle, Dennis A; Tschumperlin, Daniel J; Urban, Matthew W

    2016-07-01

    Malignant esophageal pathology typically requires resection of the esophagus and reconstruction to restore foregut continuity. Reconstruction options are limited and morbid. The esophagus represents a useful target for tissue engineering strategies based on relative simplicity in comparison to other organs. The ideal tissue engineered conduit would have sufficient and ideally matched mechanical tolerances to native esophageal tissue. Current methods for mechanical testing of esophageal tissues both in vivo and ex vivo are typically destructive, alter tissue conformation, ignore anisotropy, or are not able to be performed in fluid media. The aim of this study was to investigate biomechanical properties of swine esophageal tissues through nondestructive testing utilizing sonometry ex vivo. This method allows for biomechanical determination of tissue properties, particularly longitudinal and circumferential moduli and strain energy functions. The relative contribution of mucosal-submucosal layers and muscular layers are compared to composite esophagi. Swine thoracic esophageal tissues (n  =  15) were tested by pressure loading using a continuous pressure pump system to generate stress. Preconditioning of tissue was performed by pressure loading with the pump system and pre-straining the tissue to in vivo length before data was recorded. Sonometry using piezocrystals was utilized to determine longitudinal and circumferential strain on five composite esophagi. Similarly, five mucosa-submucosal and five muscular layers from thoracic esophagi were tested independently. This work on esophageal tissues is consistent with reported uniaxial and biaxial mechanical testing and reported results using strain energy theory and also provides high resolution displacements, preserves native architectural structure and allows assessment of biomechanical properties in fluid media. This method may be of use to characterize mechanical properties of tissue engineered esophageal

  9. Nondestructive measurement of esophageal biaxial mechanical properties utilizing sonometry

    NASA Astrophysics Data System (ADS)

    Aho, Johnathon M.; Qiang, Bo; Wigle, Dennis A.; Tschumperlin, Daniel J.; Urban, Matthew W.

    2016-07-01

    Malignant esophageal pathology typically requires resection of the esophagus and reconstruction to restore foregut continuity. Reconstruction options are limited and morbid. The esophagus represents a useful target for tissue engineering strategies based on relative simplicity in comparison to other organs. The ideal tissue engineered conduit would have sufficient and ideally matched mechanical tolerances to native esophageal tissue. Current methods for mechanical testing of esophageal tissues both in vivo and ex vivo are typically destructive, alter tissue conformation, ignore anisotropy, or are not able to be performed in fluid media. The aim of this study was to investigate biomechanical properties of swine esophageal tissues through nondestructive testing utilizing sonometry ex vivo. This method allows for biomechanical determination of tissue properties, particularly longitudinal and circumferential moduli and strain energy functions. The relative contribution of mucosal–submucosal layers and muscular layers are compared to composite esophagi. Swine thoracic esophageal tissues (n  =  15) were tested by pressure loading using a continuous pressure pump system to generate stress. Preconditioning of tissue was performed by pressure loading with the pump system and pre-straining the tissue to in vivo length before data was recorded. Sonometry using piezocrystals was utilized to determine longitudinal and circumferential strain on five composite esophagi. Similarly, five mucosa–submucosal and five muscular layers from thoracic esophagi were tested independently. This work on esophageal tissues is consistent with reported uniaxial and biaxial mechanical testing and reported results using strain energy theory and also provides high resolution displacements, preserves native architectural structure and allows assessment of biomechanical properties in fluid media. This method may be of use to characterize mechanical properties of tissue engineered

  10. Hot spot assisted blinking suppression of CdSe quantum dots

    NASA Astrophysics Data System (ADS)

    Lu, Liu; Tong, Xuan; Zhang, Xu; Ren, Naifei; Jiang, Bo; Lu, Haifei

    2016-05-01

    This work compares the blinking of CdSe QDs on glass, single silver nanowire, and double aligned nanowires. The corresponding on-time fractions of these three cases are 50%, 70% and 85% respectively, which indicates that aligned double nanowires shows more efficient suppression than that of single nanowire. This phenomenon is attributed to the higher concentration of hot electron from hot spot between nanowires. Occupation of the non-radiative recombination centers by hot electrons from silver nanowires can be explained for the suppressed blinking behavior. The result has provided a novel pathway of suppressing the blinking behavior of QDs through plasmonic hot spot.

  11. UTILITY OF SURROGATES FOR MEASURING CRYPTOSPORIDIUM OOCYST INFECTIVITY

    EPA Science Inventory

    The water industry must assess whether Cryptosporidium oocysts detected in source and finished water are viable and/or infectious. Initial approaches measuring the infectious nature of C. parvum oocysts have focused on in vitro excystation and in vitro vital dye staining. Recen...

  12. UTILITY OF SURROGATES FOR MEASURING CRYPTOSPORIDIUM OOCYSTS INFECTIVITY

    EPA Science Inventory

    The water industry must assess whether Cryptosporidium oocysts detected in source and finished water are viable and/or infectious. Initial approaches measuring the infectious nature of C. parvum oocysts have focused on in vitro excystation and in vitro vital dye staining. Recen...

  13. Outcome measures for palliative oxygen therapy: relevance and practical utility.

    PubMed

    Antoniu, Sabina; Mihaltan, Florin

    2014-06-01

    Dyspnea is a common symptom in many advanced malignant and non-malignant diseases and often is refractory to the usual therapies. In such circumstances palliative care approaches are necessary and among them palliative care oxygen therapy can be applied although currently its effectiveness is rather uncertain. Palliative oxygen therapy can be given on either continuous basis or on demand. Often the continuous palliative oxygen therapy is seen as long-term oxygen therapy although their aims are rather different. Palliative oxygen therapy was evaluated in populations with mixed underlying diseases, with outcome measures not only the most appropriate for the setting and therefore these limitations might have influenced the overall perceived therapeutic benefit. Therefore an evaluation of this method in subsets defined based on the etiology and pathogenic mechanisms and with appropriate outcome measures would help to better define the criteria for its indication and would increase its acceptability. PMID:24741999

  14. Emotional Modulation of the Attentional Blink Is Awareness-Dependent

    PubMed Central

    Qian, Wenli; Meng, Qianli; Chen, Lin; Zhou, Ke

    2012-01-01

    It is well known that emotion can modulate attentional processes. Previous studies have shown that even under restricted awareness, emotional facial expressions (especially threat-related) can guide the direction of spatial attention. However, it remains unclear whether emotional facial expressions under restricted awareness can affect temporal attention. To address this issue, we used a modified attentional blink (AB) paradigm in which masked (Experiment 1) or unmasked (Experiment 2) emotional faces (fearful or neutral) were presented before the AB sequence. We found that, in comparison with neutral faces, masked fearful faces significantly decreased the AB magnitude (Experiment 1), whereas unmasked fearful faces significantly increased the AB magnitude (Experiment 2). These results indicate that effects of emotional expression on the AB are modulated by the level of awareness. PMID:23029507

  15. Non-blinking single-photon emitters in silica

    DOE PAGESBeta

    Rabouw, Freddy T.; Cogan, Nicole M. B.; Berends, Anne C.; Stam, Ward van der; Vanmaekelbergh, Daniel; Koenderink, A. Femius; Krauss, Todd D.; Donega, Celso de Mello

    2016-02-19

    Samples for single-emitter spectroscopy are usually prepared by spin-coating a dilute solution of emitters on a microscope cover slip of silicate based glass (such as quartz). Here, we show that both borosilicate glass and quartz contain intrinsic defect colour centres that fluoresce when excited at 532 nm. In a microscope image the defect emission is indistinguishable from spin-coated emitters. The emission spectrum is characterised by multiple peaks with the main peak between 2.05 and 2.20 eV, most likely due to coupling to a silica vibration with an energy that varies between 160 and 180 meV. The defects are single-photon emitters,more » do not blink, and have photoluminescence lifetimes of a few nanoseconds. Furthermore, photoluminescence from such defects may previously have been misinterpreted as originating from single nanocrystal quantum dots.« less

  16. Non-blinking single-photon emitters in silica.

    PubMed

    Rabouw, Freddy T; Cogan, Nicole M B; Berends, Anne C; Stam, Ward van der; Vanmaekelbergh, Daniel; Koenderink, A Femius; Krauss, Todd D; Donega, Celso de Mello

    2016-01-01

    Samples for single-emitter spectroscopy are usually prepared by spin-coating a dilute solution of emitters on a microscope cover slip of silicate based glass (such as quartz). Here, we show that both borosilicate glass and quartz contain intrinsic defect colour centres that fluoresce when excited at 532 nm. In a microscope image the defect emission is indistinguishable from spin-coated emitters. The emission spectrum is characterised by multiple peaks with the main peak between 2.05 and 2.20 eV, most likely due to coupling to a silica vibration with an energy that varies between 160 and 180 meV. The defects are single-photon emitters, do not blink, and have photoluminescence lifetimes of a few nanoseconds. Photoluminescence from such defects may previously have been misinterpreted as originating from single nanocrystal quantum dots. PMID:26892489

  17. Non-blinking single-photon emitters in silica

    PubMed Central

    Rabouw, Freddy T.; Cogan, Nicole M. B.; Berends, Anne C.; Stam, Ward van der; Vanmaekelbergh, Daniel; Koenderink, A. Femius; Krauss, Todd D.; Donega, Celso de Mello

    2016-01-01

    Samples for single-emitter spectroscopy are usually prepared by spin-coating a dilute solution of emitters on a microscope cover slip of silicate based glass (such as quartz). Here, we show that both borosilicate glass and quartz contain intrinsic defect colour centres that fluoresce when excited at 532 nm. In a microscope image the defect emission is indistinguishable from spin-coated emitters. The emission spectrum is characterised by multiple peaks with the main peak between 2.05 and 2.20 eV, most likely due to coupling to a silica vibration with an energy that varies between 160 and 180 meV. The defects are single-photon emitters, do not blink, and have photoluminescence lifetimes of a few nanoseconds. Photoluminescence from such defects may previously have been misinterpreted as originating from single nanocrystal quantum dots. PMID:26892489

  18. Emotional modulation of the attentional blink is awareness-dependent.

    PubMed

    Qian, Wenli; Meng, Qianli; Chen, Lin; Zhou, Ke

    2012-01-01

    It is well known that emotion can modulate attentional processes. Previous studies have shown that even under restricted awareness, emotional facial expressions (especially threat-related) can guide the direction of spatial attention. However, it remains unclear whether emotional facial expressions under restricted awareness can affect temporal attention. To address this issue, we used a modified attentional blink (AB) paradigm in which masked (Experiment 1) or unmasked (Experiment 2) emotional faces (fearful or neutral) were presented before the AB sequence. We found that, in comparison with neutral faces, masked fearful faces significantly decreased the AB magnitude (Experiment 1), whereas unmasked fearful faces significantly increased the AB magnitude (Experiment 2). These results indicate that effects of emotional expression on the AB are modulated by the level of awareness. PMID:23029507

  19. Memory reloaded: memory load effects in the attentional blink.

    PubMed

    Visser, Troy A W

    2010-06-01

    When two targets are presented in rapid succession, identification of the first is nearly perfect, while identification of the second is impaired when it follows the first by less than about 700 ms. According to bottleneck models, this attentional blink (AB) occurs because the second target is unable to gain access to capacity-limited working memory processes already occupied by the first target. Evidence for this hypothesis, however, has been mixed, with recent reports suggesting that increasing working memory load does not affect the AB. The present paper explores possible reasons for failures to find a link between memory load and the AB and shows that a reliable effect of load can be obtained when the item directly after T1 (Target 1) is omitted. This finding provides initial evidence that working memory load can influence the AB and additional evidence for a link between T1 processing time and the AB predicted by bottleneck models. PMID:19787551

  20. Non-blinking quantum dot with a plasmonic nanoshell resonator

    NASA Astrophysics Data System (ADS)

    Ji, Botao; Giovanelli, Emerson; Habert, Benjamin; Spinicelli, Piernicola; Nasilowski, Michel; Xu, Xiangzhen; Lequeux, Nicolas; Hugonin, Jean-Paul; Marquier, Francois; Greffet, Jean-Jacques; Dubertret, Benoit

    2015-02-01

    Colloidal semiconductor quantum dots are fluorescent nanocrystals exhibiting exceptional optical properties, but their emission intensity strongly depends on their charging state and local environment. This leads to blinking at the single-particle level or even complete fluorescence quenching, and limits the applications of quantum dots as fluorescent particles. Here, we show that a single quantum dot encapsulated in a silica shell coated with a continuous gold nanoshell provides a system with a stable and Poissonian emission at room temperature that is preserved regardless of drastic changes in the local environment. This novel hybrid quantum dot/silica/gold structure behaves as a plasmonic resonator with a strong Purcell factor, in very good agreement with simulations. The gold nanoshell also acts as a shield that protects the quantum dot fluorescence and enhances its resistance to high-power photoexcitation or high-energy electron beams. This plasmonic fluorescent resonator opens the way to a new family of plasmonic nanoemitters with robust optical properties.

  1. Non-blinking single-photon emitters in silica

    NASA Astrophysics Data System (ADS)

    Rabouw, Freddy T.; Cogan, Nicole M. B.; Berends, Anne C.; Stam, Ward Van Der; Vanmaekelbergh, Daniel; Koenderink, A. Femius; Krauss, Todd D.; Donega, Celso De Mello

    2016-02-01

    Samples for single-emitter spectroscopy are usually prepared by spin-coating a dilute solution of emitters on a microscope cover slip of silicate based glass (such as quartz). Here, we show that both borosilicate glass and quartz contain intrinsic defect colour centres that fluoresce when excited at 532 nm. In a microscope image the defect emission is indistinguishable from spin-coated emitters. The emission spectrum is characterised by multiple peaks with the main peak between 2.05 and 2.20 eV, most likely due to coupling to a silica vibration with an energy that varies between 160 and 180 meV. The defects are single-photon emitters, do not blink, and have photoluminescence lifetimes of a few nanoseconds. Photoluminescence from such defects may previously have been misinterpreted as originating from single nanocrystal quantum dots.

  2. Utilizing nitrogen-vacancy centers to measure oscillating magnetic fields

    NASA Astrophysics Data System (ADS)

    Chaudhry, Adam Zaman

    2014-10-01

    We show how nitrogen-vacancy centers can be used to determine the amplitude, phase, and frequency of unknown weak monochromatic and multichromatic oscillating magnetic fields using only the periodic dynamical decoupling and Carr-Purcell-Meiboom-Gill sequences. The effect of decoherence on the measurement of the magnetic field parameters is explicitly analyzed, and we take into account the fact that different pulse sequences suppress decoherence to different extents. Since the sensitivity increases with increasing sensing time while it decreases due to decoherence and limited photon detection efficiency, we use the Fisher information matrix in order to optimize the number of pulses that should be used.

  3. Efficient and robust pupil size and blink estimation from near-field video sequences for human-machine interaction.

    PubMed

    Chen, Siyuan; Epps, Julien

    2014-12-01

    Monitoring pupil and blink dynamics has applications in cognitive load measurement during human-machine interaction. However, accurate, efficient, and robust pupil size and blink estimation pose significant challenges to the efficacy of real-time applications due to the variability of eye images, hence to date, require manual intervention for fine tuning of parameters. In this paper, a novel self-tuning threshold method, which is applicable to any infrared-illuminated eye images without a tuning parameter, is proposed for segmenting the pupil from the background images recorded by a low cost webcam placed near the eye. A convex hull and a dual-ellipse fitting method are also proposed to select pupil boundary points and to detect the eyelid occlusion state. Experimental results on a realistic video dataset show that the measurement accuracy using the proposed methods is higher than that of widely used manually tuned parameter methods or fixed parameter methods. Importantly, it demonstrates convenience and robustness for an accurate and fast estimate of eye activity in the presence of variations due to different users, task types, load, and environments. Cognitive load measurement in human-machine interaction can benefit from this computationally efficient implementation without requiring a threshold calibration beforehand. Thus, one can envisage a mini IR camera embedded in a lightweight glasses frame, like Google Glass, for convenient applications of real-time adaptive aiding and task management in the future. PMID:24691198

  4. Assessing the utility of visual acuity measures in visual prostheses.

    PubMed

    Caspi, Avi; Zivotofsky, Ari Z

    2015-03-01

    There are presently several ongoing clinical trials to provide usable sight to profoundly visually impaired patients by means of electrical stimulation of the retina. Some of the blind patients implanted with retinal prosthesis reported un-patterned perception and yet benefit from the device in many activities of daily living, seemingly because they adopt active scanning strategies. The aim of the present work is to evaluate if and under what conditions a measured visual acuity level is truly an indication that the brain perceived a patterned image from the electrical stimulation of the visual prosthesis. Sighted subjects used a pixelized simulator in which they perceived either a low resolution sub-sampling of the original image ("normal mode"--patterned vision) or an image that was solely a function of the brightness and size of the original image ("brightness mode"--no patterned vision). Results show that subjects were able to adopt a head scanning strategy that enabled acuity beyond the resolution set by a static view of the stimulus. In brightness mode, i.e. without patterned vision, most subjects achieved a measurable acuity level better than the limit set by the geometrical resolution of the entire array but worse than the limit set by the distance between neighboring simulated pixels. In normal mode all subject achieved acuity level that is better than the geometrical resolution of the simulated pixels. Thus, visual acuity levels comparable with the electrodes/pixels resolution implies that the patient perceives an image with spatial patterns. PMID:25637855

  5. Crop identification and acreage measurement utilizing ERTS imagery

    NASA Technical Reports Server (NTRS)

    Vonsteen, D. H. (Principal Investigator)

    1972-01-01

    There are no author-identified significant results in this report. The microdensitometer will be used to analyze data acquired by ERTS-1 imagery. The classification programs and software packages have been acquired and are being prepared for use with the information as it is received. Photo and digital tapes have been acquired for coverage of virtually 100 percent of the test site areas. These areas are located in South Dakota, Idaho, Missouri, and Kansas. Hass 70mm color infrared, infrared, black and white high altitude aerial photography of the test sites is available. Collection of ground truth for updating the data base has been completed and a computer program written to count the number of fields and give total acres by size group for the segments in each test site. Results are given of data analysis performed on digitized data from densitometer measurements of fields of corn, sugar, beets, and alfalfa in Kansas.

  6. Moire technique utilization for detection and measurement of scoliosis

    NASA Astrophysics Data System (ADS)

    Zawieska, Dorota; Podlasiak, Piotr

    1993-02-01

    Moire projection method enables non-contact measurement of the shape or deformation of different surfaces and constructions by fringe pattern analysis. The fringe map acquisition of the whole surface of the object under test is one of the main advantages compared with 'point by point' methods. The computer analyzes the shape of the whole surface and next user can selected different points or cross section of the object map. In this paper a few typical examples of an application of the moire technique in solving different medical problems will be presented. We will also present to you the equipment the moire pattern analysis is done in real time using the phase stepping method with CCD camera.

  7. Study: Trained Experts Can Spot Breast Cancer in 'Blink of An Eye'

    MedlinePlus

    ... fullstory_160675.html Study: Trained Experts Can Spot Breast Cancer in 'Blink of an Eye' Skilled radiologists see ... these results suggest there are detectable signs of breast cancer that radiologists notice immediately, the study authors said. " ...

  8. Effect of Seated Trunk Posture on Eye Blink Startle and Subjective Experience: Comparing Flexion, Neutral Upright Posture, and Extension of Spine

    PubMed Central

    Ceunen, Erik; Zaman, Jonas; Vlaeyen, Johan W. S.; Dankaerts, Wim; Van Diest, Ilse

    2014-01-01

    Postures are known to be able to affect emotion and motivation. Much less is known about whether (affective) modulation of eye blink startle occurs following specific postures. The objective of the current study was to explore this. Participants in the present study were requested to assume three different sitting postures: with the spine flexed (slouched), neutral upright, and extended. Each posture was assumed for four minutes, and was followed by the administration of brief self-report questionnaires before proceeding to the next posture. The same series of postures and measures were repeated prior to ending the experiment. Results indicate that, relative to the other postures, the extended sitting posture was associated with an increased startle, was more unpleasant, arousing, had smaller levels of dominance, induced more discomfort, and was perceived as more difficult. The upright and flexed sitting postures differed in the level of self-reported positive affect, but not in eye blink startle amplitudes. PMID:24516664

  9. Long-term depression-like plasticity of the blink reflex for the treatment of blepharospasm.

    PubMed

    Kranz, Gottfried; Shamim, Ejaz A; Lin, Peter T; Kranz, George S; Hallett, Mark

    2013-04-01

    Our previous work showed a beneficial therapeutic effect on blepharospasm using slow repetitive transcranial magnetic stimulation, which produces a long-term depression (LTD)-like effect. High-frequency supraorbital electrical stimulation, asynchronous with the R2 component of the blink reflex, can also induce LTD-like effects on the blink reflex circuit in healthy subjects. Patients with blepharospasm have reduced inhibition of their blink recovery curves; therefore, a LTD-like intervention might normalize the blink reflex recovery (BRR) and have a favorable therapeutic effect. This is a randomized, sham-controlled, observer-blinded prospective study. In 14 blepharospasm patients, we evaluated the effects of high-frequency supraorbital stimulation on three separate treatment days. We applied 28 trains of nine stimuli, 400 Hz, either before or after the R2 or used sham stimulation. The primary outcome was the blink rate, number of spasms rated by a blinded physician and patient rating before, immediately after and 1 hour after stimulation while resting, reading, and talking; secondary outcome was the BRR. Stimulation "before" and "after" the R2 both showed a similar improvement as sham stimulation in physician rating, but patients felt significantly better with the before condition. Improvement in recovery of the blink reflex was noted only in the before condition. Clinical symptoms differed in the three baseline conditions (resting, reading, and talking). Stimulation before R2 increased inhibition in trigeminal blink reflex circuits in blepharospasm toward normal values and produced subjective, but not objective, improvement. Inhibition of the blink reflex pathway by itself appeared to be insufficient for a useful therapeutic effect. PMID:23401198

  10. Bilingualism and the increased attentional blink effect: evidence that the difference between bilinguals and monolinguals generalizes to different levels of second language proficiency.

    PubMed

    Khare, Vatsala; Verma, Ark; Kar, Bhoomika; Srinivasan, Narayanan; Brysbaert, Marc

    2013-11-01

    The attentional blink task involves rapid serial presentation of visual stimuli, two of which the participants have to report. The usual finding is that participants are impaired at reporting the second target if it appears in close temporal proximity to the first target. Previous research has shown that the effect is stronger in bilinguals than monolinguals. We investigated whether the difference between monolinguals and proficient bilinguals can be extended to bilinguals of different proficiency levels. Therefore, we replicated the paradigm in a large sample of Hindi-English bilinguals with different proficiency levels of English, as measured with a validated vocabulary test. We additionally measured the participants' intelligence with the raven progressive matrices. We found that the size of the attentional blink effect correlates with the degree of second language proficiency and not with the degree of intelligence. This indicates that research on executive control functions can be done with bilinguals of different proficiency levels. Our results are also in line with recent findings showing that the attentional blink effect is not primarily due to limited processing resources. PMID:23196431

  11. Two types of photoluminescence blinking revealed by single quantum dot spectroelectrochemistry

    PubMed Central

    Galland, Christophe; Ghosh, Yagnaseni; Steinbrück, Andrea; Sykora, Milan; Hollingsworth, Jennifer A.; Klimov, Victor I.; Htoon, Han

    2012-01-01

    Photoluminescence (PL) intermittency (blinking), or random switching between states of high- (ON) and low (OFF) emissivities, is a universal property of molecular emitters exhibited by dyes1, polymers2, biological molecules3 and artificial nanostructures such as nanocrystal quantum dots, carbon nanotubes, and nanowires4,5,6. For the past fifteen years, colloidal nanocrystals have been used as a model system for studies of this phenomenon.5,6 The occurrence of OFF periods in nanocrystal emission has been commonly attributed to the presence of an additional charge7, which leads to PL quenching by nonradiative Auger recombination.8 However, the “charging” model was recently challenged in several reports.9,10 Here, to clarify the role of charging in PL intermittency, we perform time-resolved PL studies of individual nanocrystals while controlling electrochemically the degree of their charging. We find that two distinct mechanisms can lead to PL intermittency. We identify conventional blinking (A-type) due to charging/discharging of the nanocrystal core when lower PL intensities correlate with shorter PL lifetimes. Importantly, we observe a different blinking (B-type), when large changes in the PL intensity are not accompanied by significant changes in PL dynamics. We attribute this blinking behavior to charge fluctuations in the electron-accepting surface sites. When unoccupied, these sites intercept hot electrons before they relax into emitting core states. Both blinking mechanisms can be controlled electrochemically and under appropriate potential blinking can be completely suppressed. PMID:22071764

  12. Suppressed blinking behavior of CdSe/CdS QDs by polymer coating.

    PubMed

    Zhang, Aidi; Bian, Yannan; Wang, Jinjie; Chen, Kuiyong; Dong, Chaoqing; Ren, Jicun

    2016-03-01

    Semiconductor quantum dots (QDs) are very important fluorescent nanocrystals with excellent optical properties. However, QDs, at the single-particle level, show severe fluorescence intermittency (or blinking) on a wide time scale from milliseconds to minutes, which limits certain optical and biological applications. Generally, blinking behavior of QDs strongly depends on their surface state and surrounding environment. Therefore, current blinking suppression approaches are mostly focused on the introduction of an inorganic shell and organic small molecule compounds. In this study, we described a "bottom up" approach for the synthesis of CdSe/CdS/polymer core/shell/shell QDs via the in situ one-pot polymerization approach in order to control the blinking behavior of QDs. Three monomers (dithiothreitol (DTT), phenylenediamine (PDA), and hexamethylenediamine (HDA)) were respectively used to polymerize with hexachlorocyclotriphosphazene (HCCP), and then the polyphosphazene polymers were obtained with cyclotriphosphazene as the basic macromolecular backbone. By regulating the molar ratios of the activated comonomers, we can control the blinking behavior of CdSe/CdS/polymer QDs. Under the optimal conditions, the percentage of "non-blinking" CdSe/CdS/polymer QDs (the "on time" fraction > 99% of the overall observation time) was up to 78%. The suppression mechanism was attributed to the efficient passivation of QD surface traps by the sulfhydryl or phenyl groups in the polyphosphazene polymers. PMID:26865498

  13. Repeated measurements of respiratory mechanics in developing rats utilizing a forced oscillation technique.

    PubMed

    Heulitt, Mark J; Jones, Stacie M; Holt, Shirley J; Thurman, Tracy L; Jo, Chan-Hee; Simpson, Pippa M

    2008-09-01

    The ability to successfully intubate the trachea of rats repeatedly over time, recover them, and perform repeated measures of changes in respiratory mechanics is important. The authors performed experiments utilizing 2 groups of rats at various ages in their development. Rats in the single-measurement group were studied at 1 age only. Rats in the repeated-measurement group were studied at each age point over time. Measurements of respiratory mechanics were made utilizing a forced-oscillation technique. We found no differences in respiratory mechanics between the 2 groups. Our results demonstrate that developing rats can be studied longitudinally to illustrate maturational changes in respiratory mechanics. PMID:18716927

  14. Sequential utilization of substrates by Pseudomonas putida CSV86: signatures of intermediate metabolites and online measurements.

    PubMed

    Basu, Aditya; Das, Debasish; Bapat, Prashant; Wangikar, Pramod P; Phale, Prashant S

    2009-01-01

    Pseudomonas putida CSV86 preferentially utilizes aromatics over glucose and co-metabolizes them with organic acids. On aromatics plus glucose, CSV86 utilized aromatics first with concomitant appearance of transient metabolites such as salicylate, benzaldehyde and benzoate. Citrate was the main extracellular metabolite observed during glucose uptake. The strain showed simultaneous utilization of organic acids and aromatic compounds. Based on the metabolite analysis and growth profiles, we hypothesize that the repression of glucose utilization could be due to organic acid intermediates generated from aromatic compound metabolism. The online measurements indicate the instantaneous metabolic state of the culture. For example, the CO(2) evolution and agitation speed show peak values during the two growth phases in the diauxic growth while dissolved oxygen values show decrease at the corresponding durations. These measurements correlated well with the offline measurements but provided a better time resolution of the process. PMID:17467253

  15. Measuring contour degradation in natural image utility assessment: methods and analysis

    NASA Astrophysics Data System (ADS)

    Pinto, Guilherme O.; Rouse, David M.; Hemami, Sheila S.

    2011-03-01

    Utility estimators predict the usefulness or utility of a distorted natural image when used as a surrogate for a reference image. They differ from quality estimators in that they should provide accurate estimates even when images are extremely visibly distorted relative to the original, yet are still sufficient for the task. Our group has previously proposed the Natural Image Contour Evaluation (NICE) utility estimator. NICE estimates perceived utility by comparing morphologically dilated binary edge maps of the reference and distorted images using the Hamming distance. This paper investigates perceptually inspired approaches to evaluating the degradation of image contours in natural images for utility estimation. First, the distance transform is evaluated as an alternative to the Hamming distance measure in NICE. Second, we introduce the image contour fidelity (ICF) computational model that is compatible with any block-based quality estimator. The ICF pools weighted fidelity degradations across image blocks with weights based on the local contour strength of an image block, and allows quality estimators to be repurposed as utility estimators. The performances of these approaches were evaluated on the CU-Nantes and CU-ObserverCentric databases, which provide perceived utility scores for a collection of distorted images. While the distance transform provides an improvement over the Hamming distance, the ICF model shows greater promise. The performances of common fidelity estimators for utility estimation are substantially improved when they are used in ICF computational model. This suggests that the utility estimation problem can be recast as a problem of fidelity estimation on image contours.

  16. Utilizing Photogrammetry and Strain Gage Measurement to Characterize Pressurization of an Inflatable Module

    NASA Technical Reports Server (NTRS)

    Valle, Gerard D.; Selig, Molly; Litteken, Doug; Oliveras, Ovidio

    2012-01-01

    This paper documents the integration of a large hatch penetration into an inflatable module. This paper also documents the comparison of analytical load predictions with measured results utilizing strain measurement. Strain was measured by utilizing photogrammetric measurement and through measurement obtained from strain gages mounted to selected clevises that interface with the structural webbings. Bench testing showed good correlation between strain measurement obtained from an extensometer and photogrammetric measurement especially after the fabric has transitioned through the low load/high strain region of the curve. Test results for the full-scale torus showed mixed results in the lower load and thus lower strain regions. Overall strain, and thus load, measured by strain gages and photogrammetry tracked fairly well with analytical predictions. Methods and areas of improvements are discussed.

  17. Distortion of power law blinking with binning and thresholding

    SciTech Connect

    Amecke, Nicole; Heber, André; Cichos, Frank

    2014-03-21

    Fluorescence intermittency is a random switching between emitting (on) and non-emitting (off) periods found for many single chromophores such as semiconductor quantum dots and organic molecules. The statistics of the duration of on- and off-periods are commonly determined by thresholding the emission time trace of a single chromophore and appear to be power law distributed. Here we test with the help of simulations if the experimentally determined power law distributions can actually reflect the underlying statistics. We find that with the experimentally limited time resolution real power law statistics with exponents α{sub on/off} ≳ 1.6, especially if α{sub on} ≠ α{sub off} would not be observed as such in the experimental data after binning and thresholding. Instead, a power law appearance could simply be obtained from the continuous distribution of intermediate intensity levels. This challenges much of the obtained data and the models describing the so-called power law blinking.

  18. Non-blinking quantum dot with a plasmonic nanoshell resonator.

    PubMed

    Ji, Botao; Giovanelli, Emerson; Habert, Benjamin; Spinicelli, Piernicola; Nasilowski, Michel; Xu, Xiangzhen; Lequeux, Nicolas; Hugonin, Jean-Paul; Marquier, Francois; Greffet, Jean-Jacques; Dubertret, Benoit

    2015-02-01

    Colloidal semiconductor quantum dots are fluorescent nanocrystals exhibiting exceptional optical properties, but their emission intensity strongly depends on their charging state and local environment. This leads to blinking at the single-particle level or even complete fluorescence quenching, and limits the applications of quantum dots as fluorescent particles. Here, we show that a single quantum dot encapsulated in a silica shell coated with a continuous gold nanoshell provides a system with a stable and Poissonian emission at room temperature that is preserved regardless of drastic changes in the local environment. This novel hybrid quantum dot/silica/gold structure behaves as a plasmonic resonator with a strong Purcell factor, in very good agreement with simulations. The gold nanoshell also acts as a shield that protects the quantum dot fluorescence and enhances its resistance to high-power photoexcitation or high-energy electron beams. This plasmonic fluorescent resonator opens the way to a new family of plasmonic nanoemitters with robust optical properties. PMID:25581887

  19. Eye Blink Rate as a biological marker of Mild Cognitive Impairment.

    PubMed

    Ladas, Aristea; Frantzidis, Christos; Bamidis, Panagiotis; Vivas, Ana B

    2014-07-01

    We investigated the relationship between dopamine activity (DA), as measured by Eye Blink Rate (EBR), and cognitive function in old adults with Mild Cognitive Impairment (MCI) and healthy controls. Research has been inconclusive so far about the factors responsible for the transition from MCI to dementia. However, some studies suggest that cortical hyperexcitability in very early stages of pathological aging may progressively lead to cell death, and thus to Alzheimer's disease. Hence, we speculated that a dysfunction of DA activity, as measured by EBR, may characterize people with MCI, and account for their poor cognitive function. Thirty three (33) healthy and thirty six (36) old adults with MCI (Mean age = 67.52 y.o.) participated in this study. The EBR was recorded under resting conditions, using two gold skin electrodes above and below the left eye. Cognitive function was assessed with a battery of neuropsychological tests. Participants with MCI showed significantly higher EBR than the healthy controls. Also, EBR was negatively related to scores on the Montreal Cognitive Assessment test (MoCA) test. We propose that abnormally increased dopamine activity, as indexed by relatively high EBR, may be partially responsible for the neurotransmitter imbalance in the central nervous system of people with MCI, and the overall impaired cognitive performance. In addition, this finding suggests that an abnormally high EBR may be a potential biomarker of the transition from healthy aging to dementia. PMID:23912068

  20. 43 CFR 3272.12 - What environmental protection measures must I include in my utilization plan?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false What environmental protection measures... What environmental protection measures must I include in my utilization plan? (a) Describe, at a... resources; (6) Minimize air and noise pollution; and (7) Minimize hazards to public health and safety...

  1. 43 CFR 3272.12 - What environmental protection measures must I include in my utilization plan?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false What environmental protection measures... What environmental protection measures must I include in my utilization plan? (a) Describe, at a... resources; (6) Minimize air and noise pollution; and (7) Minimize hazards to public health and safety...

  2. 43 CFR 3275.15 - How accurately must I measure my production and utilization?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... production and utilization? It depends on whether you use a meter to calculate Federal production or royalty, and what quantity of resource you are measuring. (a) For meters that you use to calculate Federal royalty: (1) If the meter measures electricity, it must have an accuracy of ±0.25% or better of...

  3. 43 CFR 3275.15 - How accurately must I measure my production and utilization?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... production and utilization? It depends on whether you use a meter to calculate Federal production or royalty, and what quantity of resource you are measuring. (a) For meters that you use to calculate Federal royalty: (1) If the meter measures electricity, it must have an accuracy of ±0.25% or better of...

  4. 43 CFR 3275.15 - How accurately must I measure my production and utilization?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... production and utilization? It depends on whether you use a meter to calculate Federal production or royalty, and what quantity of resource you are measuring. (a) For meters that you use to calculate Federal royalty: (1) If the meter measures electricity, it must have an accuracy of ±0.25% or better of...

  5. Utilizing Curriculum-Based Measurements of Writing in Third and Fifth Grade

    ERIC Educational Resources Information Center

    Dombek, Jennifer Lucas

    2013-01-01

    The purpose of this study was to address the utility of curriculum-based measurements of written expression (CBM-W) for predicting writing growth longitudinally and address the extent to which CBM-W relate to other academic and behavior measures. CBM-W has been shown to be an appropriate and useful method for assessing and monitoring writing skill…

  6. Two types of luminescence blinking revealed by spectroelectrochemistry of single quantum dots

    SciTech Connect

    Galland, Christophe; Ghosh, Yagnaseni; Steinbruck, Andrea; Sykora, Milan; Hollingsworth, Jennifer A.; Klimov, Victor I.; Htoon, Han

    2011-11-09

    Photoluminescence blinking—random switching between states of high (ON) and low (OFF) emissivities—is a universal property of molecular emitters found in dyes, polymers, biological molecules and artificial nanostructures such as nanocrystal quantum dots, carbon nanotubes and nanowires. For the past 15 years, colloidal nanocrystals have been used as a model system to study this phenomenon. The occurrence of OFF periods in nanocrystal emission has been commonly attributed to the presence of an additional charge, which leads to photoluminescence quenching by non-radiative recombination (the Auger mechanism). However, this ‘charging’ model was recently challenged in several reports. Here we report time-resolved photoluminescence studies of individual nanocrystal quantum dots performed while electrochemically controlling the degree of their charging, with the goal of clarifying the role of charging in blinking. We find that two distinct types of blinking are possible: conventional (A-type) blinking due to charging and discharging of the nanocrystal core, in which lower photoluminescence intensities correlate with shorter photoluminescence lifetimes; and a second sort (B-type), in which large changes in the emission intensity are not accompanied by significant changes in emission dynamics. We attribute B-type blinking to charge fluctuations in the electron-accepting surface sites. When unoccupied, these sites intercept ‘hot’ electrons before they relax into emitting core states. Both blinking mechanisms can be electrochemically controlled and completely suppressed by application of an appropriate potential.

  7. Blinking effect and the use of quantum dots in single molecule spectroscopy

    SciTech Connect

    Rombach-Riegraf, Verena; Oswald, Peter; Bienert, Roland; Petersen, Jan; Domingo, M.P.; Pardo, Julian; Graeber, P.; Galvez, E.M.

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer It is possible to eliminate the blinking effect of a water-soluble QD. Black-Right-Pointing-Pointer We provide a direct method to study protein function and dynamics at the single level. Black-Right-Pointing-Pointer QD, potent tool for single molecule studies of biochemical and biological processes. -- Abstract: Luminescent semiconductor nanocrystals (quantum dots, QD) have unique photo-physical properties: high photostability, brightness and narrow size-tunable fluorescence spectra. Due to their unique properties, QD-based single molecule studies have become increasingly more popular during the last years. However QDs show a strong blinking effect (random and intermittent light emission), which may limit their use in single molecule fluorescence studies. QD blinking has been widely studied and some hypotheses have been done to explain this effect. Here we summarise what is known about the blinking effect in QDs, how this phenomenon may affect single molecule studies and, on the other hand, how the 'on'/'off' states can be exploited in diverse experimental settings. In addition, we present results showing that site-directed binding of QD to cysteine residues of proteins reduces the blinking effect. This option opens a new possibility of using QDs to study protein-protein interactions and dynamics by single molecule fluorescence without modifying the chemical composition of the solution or the QD surface.

  8. An investigation into the temporal dimension of the Mozart effect: evidence from the attentional blink task.

    PubMed

    Ho, Cristy; Mason, Oliver; Spence, Charles

    2007-05-01

    In the present study, we examined whether the 'Mozart effect' would influence participants' temporal attention using a visual attentional blink (AB) task that provides a reliable measure of the temporal dynamics of visual attention. The 'Mozart effect' refers to the specific claim that listening to Mozart's Sonata for Two Pianos in D Major, K.448 can improve the performance in spatio-temporal tasks. Participants had to try and identify two target digits (in their correct order of presentation) presented amongst a stream of distractor letters in three different conditions (presented in separate blocks of trials): while listening to the Mozart sonata played normally, while listening to the same Mozart sonata played in reverse, and while in silence. The results showed that the participants were able to detect the second target (T2) significantly more accurately (given the correct detection of the first target, T1) in the AB stream when the Mozart sonata was played normally than in either of the other two conditions. Possible explanations for the differential effects of Mozart's music being played normally and in reverse and potential confounds in previous studies reporting a facilitatory 'Mozart effect' are discussed. Our results therefore provide the first empirical demonstration supporting the existence of a purely temporal component to the 'Mozart effect' using a non-spatial visual AB task. PMID:16942739

  9. Blink rate during tests of executive performance after nocturnal traffic noise.

    PubMed

    Breimhorst, Markus; Marks, Anke; Robens, Sibylle; Griefahn, Barbara

    2009-01-01

    This analysis is on the hypothesis that nocturnal traffic noise affects sleep quality whereas performance decrement is avoided by increased effort expressed by a decrease in blink rates (BRs) during a visual task. Twenty-four persons (12 women, 12 men; 19-28 years, 23.56+/-2.49 years) slept during three consecutive weeks in the laboratory while exposed to road, rail, or aircraft noise with weekly permuted changes. Each week consisted of a random sequence of a quiet night (32 dBA) and three nights with equivalent noise levels of 39, 44 and 50 dBA respectively. The polysomnogram was recorded during all nights. Every morning the participants rated their sleep quality and then completed two executive tasks (Go/Nogo-, Switch-task). Neither of the two performance tests was affected by nocturnal noise. Sleep efficiency and subjective sleep quality decreased with increasing noise levels but were not associated with the type of noise. In contrast, BRs were associated with the type of noise, not with noise levels. The results do not support the hypothesis concerning the BR. The possible reasons are discussed. However, the results do not exclude that other physiological parameters such as heart rate or brain potentials measured during the tests might have revealed alterations associated with nocturnal noise exposure. PMID:19805931

  10. The more your mind wanders, the smaller your attentional blink: an individual differences study.

    PubMed

    Thomson, David R; Ralph, Brandon C W; Besner, Derek; Smilek, Daniel

    2015-01-01

    The present studies investigate the hypothesis that individuals who frequently report experiencing episodes of mind wandering do so because they under-invest attentional/executive resources in the external environment. Here we examined whether self-reported instances of mind wandering predict the magnitude of the "attentional blink" (AB) in a rapid serial visual presentation (RSVP) task, since a prominent view is that the AB derives from an over-investment of attention in the information stream. Study 1 demonstrates that subjective reports of mind wandering in a sustained attention task have a negative predictive relation with respect to the magnitude of the AB measured in a subsequent RSVP task. In addition, using the Spontaneous and Deliberate Mind Wandering Questionnaire in Study 2, we were again able to show that trait-level mind wandering in everyday life negatively predicts AB magnitude. We suggest that mind wandering may be the behavioural outcome of an adaptive cognitive style intended to maximize the efficient processing of dynamic and temporally unpredictable events. PMID:25203499

  11. Plasmonic effect on photon antibunching and blinking behavior of single quantum dots near gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Dey, Swayandipta; Zhou, Yadong; Tian, Xiangdong; Jenkins, Julie A.; Chen, Ou; Zou, Shengli; Zhao, Jing

    2015-02-01

    In this work, we investigated how the blinking statistics and the photon antibunching behavior of single CdSe/CdS core/shell quantum dots(QDs) get modified in the presence of gold nanoparticles(Au NPs) overcoated with a silica shell of varying thickness.(Au@SiO2). The Au@SiO2 NPs have distinct plasmon resonance peaks which overlap with the absorption and emission of QDs, thereby effectively increasing the mutual plasmon-exciton interactions between them. From the second-order photoluminescence intensity cross-correlation measurements, we observed that in the regime of low excitation power, the relative ratio of the biexciton/exciton (BX/X) quantum yield (QY) and lifetimes of the single QDs in presence of the plasmonic substrates get significantly modified as compared to the QDs on glass. An electrodynamics model was developed to further quantify the effect of plasmons on the emission intensity, QY and lifetimes of X and BX of single QDs. The theoretical studies also indicated that the relative position of the QDs and orientation of the electric field are the critical factors regulating the emission properties of Xs and BXs.

  12. Measuring Resource Utilization: A Systematic Review of Validated Self-Reported Questionnaires.

    PubMed

    Leggett, Laura E; Khadaroo, Rachel G; Holroyd-Leduc, Jayna; Lorenzetti, Diane L; Hanson, Heather; Wagg, Adrian; Padwal, Raj; Clement, Fiona

    2016-03-01

    A variety of methods may be used to obtain costing data. Although administrative data are most commonly used, the data available in these datasets are often limited. An alternative method of obtaining costing is through self-reported questionnaires. Currently, there are no systematic reviews that summarize self-reported resource utilization instruments from the published literature.The aim of the study was to identify validated self-report healthcare resource use instruments and to map their attributes.A systematic review was conducted. The search identified articles using terms like "healthcare utilization" and "questionnaire." All abstracts and full texts were considered in duplicate. For inclusion, studies had to assess the validity of a self-reported resource use questionnaire, to report original data, include adult populations, and the questionnaire had to be publically available. Data such as type of resource utilization assessed by each questionnaire, and validation findings were extracted from each study.In all, 2343 unique citations were retrieved; 2297 were excluded during abstract review. Forty-six studies were reviewed in full text, and 15 studies were included in this systematic review. Six assessed resource utilization of patients with chronic conditions; 5 assessed mental health service utilization; 3 assessed resource utilization by a general population; and 1 assessed utilization in older populations. The most frequently measured resources included visits to general practitioners and inpatient stays; nonmedical resources were least frequently measured. Self-reported questionnaires on resource utilization had good agreement with administrative data, although, visits to general practitioners, outpatient days, and nurse visits had poorer agreement.Self-reported questionnaires are a valid method of collecting data on healthcare resource utilization. PMID:26962773

  13. Non-blinking single-photon generation with anisotropic colloidal nanocrystals: towards room-temperature, efficient, colloidal quantum sources.

    PubMed

    Pisanello, Ferruccio; Leménager, Godefroy; Martiradonna, Luigi; Carbone, Luigi; Vezzoli, Stefano; Desfonds, Pascal; Cozzoli, Pantaleo Davide; Hermier, Jean-Pierre; Giacobino, Elisabeth; Cingolani, Roberto; De Vittorio, Massimo; Bramati, Alberto

    2013-04-11

    Blinking and single-photon emission can be tailored in CdSe/CdS core/shell colloidal dot-in-rods. By increasing the shell thickness it is possible to obtain almost non-blinking nanocrystals, while the shell length can be used to control single-photon emission probability. PMID:23334905

  14. Low Dimensional Temporal Organization of Spontaneous Eye Blinks in Adults with Developmental Disabilities and Stereotyped Movement Disorder

    ERIC Educational Resources Information Center

    Lee, Mei-Hua; Bodfish, James W.; Lewis, Mark H.; Newell, Karl M.

    2010-01-01

    This study investigated the mean rate and time-dependent sequential organization of spontaneous eye blinks in adults with intellectual and developmental disability (IDD) and individuals from this group who were additionally categorized with stereotypic movement disorder (IDD + SMD). The mean blink rate was lower in the IDD + SMD group than the IDD…

  15. Detection of single-nucleotide variations by monitoring the blinking of fluorescence induced by charge transfer in DNA.

    PubMed

    Kawai, Kiyohiko; Majima, Tetsuro; Maruyama, Atsushi

    2013-08-19

    Charge transfer dynamics in DNA: Photo-induced charge separation and charge-recombination dynamics in DNA was assessed by monitoring the blinking of fluorescence. Single nucleotide variations, mismatch and one base deletion, were differentiated based on the length of the off-time of the blinking, which corresponds to the lifetime of the charge-separated state. PMID:23846860

  16. Measuring Health Utilities in Children and Adolescents: A Systematic Review of the Literature

    PubMed Central

    Thorrington, Dominic; Eames, Ken

    2015-01-01

    Background The objective of this review was to evaluate the use of all direct and indirect methods used to estimate health utilities in both children and adolescents. Utilities measured pre- and post-intervention are combined with the time over which health states are experienced to calculate quality-adjusted life years (QALYs). Cost-utility analyses (CUAs) estimate the cost-effectiveness of health technologies based on their costs and benefits using QALYs as a measure of benefit. The accurate measurement of QALYs is dependent on using appropriate methods to elicit health utilities. Objective We sought studies that measured health utilities directly from patients or their proxies. We did not exclude those studies that also included adults in the analysis, but excluded those studies focused only on adults. Methods and Findings We evaluated 90 studies from a total of 1,780 selected from the databases. 47 (52%) studies were CUAs incorporated into randomised clinical trials; 23 (26%) were health-state utility assessments; 8 (9%) validated methods and 12 (13%) compared existing or new methods. 22 unique direct or indirect calculation methods were used a total of 137 times. Direct calculation through standard gamble, time trade-off and visual analogue scale was used 32 times. The EuroQol EQ-5D was the most frequently-used single method, selected for 41 studies. 15 of the methods used were generic methods and the remaining 7 were disease-specific. 48 of the 90 studies (53%) used some form of proxy, with 26 (29%) using proxies exclusively to estimate health utilities. Conclusions Several child- and adolescent-specific methods are still being developed and validated, leaving many studies using methods that have not been designed or validated for use in children or adolescents. Several studies failed to justify using proxy respondents rather than administering the methods directly to the patients. Only two studies examined missing responses to the methods administered with

  17. COMMUNALITIES AND DIFFERENCES IN FEAR POTENTIATION BETWEEN CARDIAC DEFENSE AND EYE-BLINK STARTLE

    PubMed Central

    Sánchez, María B.; Guerra, Pedro; Muñoz, Miguel A.; Mata, José Luís; Bradley, Margaret M.; Lang, Peter J.; Vila, Jaime

    2009-01-01

    This study examines similarities and differences in fear potentiation between two protective reflexes: cardiac defense and eye-blink startle. Women reporting intense fear of animals but low fear of blood or intense fear of blood but low fear of animals viewed pictures depicting blood or the feared animal for 6 s in 2 separate trials in counterbalanced order. An intense burst of white noise, able to elicit both a cardiac defense response and a reflexive startle blink, was presented 3.5 s after picture onset. Both cardiac and blink responses were potentiated when highly fearful individuals viewed fearful pictures. However, differences appeared concerning picture order. This pattern of results indicates communalities and differences among protective reflexes that are relevant for understanding the dynamics of emotional reflex modulation. PMID:19572906

  18. Quantitative evaluation of blinking in surface enhanced resonance Raman scattering and fluorescence by electromagnetic mechanism

    NASA Astrophysics Data System (ADS)

    Itoh, Tamitake; Iga, Mitsuhiro; Tamaru, Hiroharu; Yoshida, Ken-ichi; Biju, Vasudevanpillai; Ishikawa, Mitsuru

    2012-01-01

    We analyze blinking in surface enhanced resonance Raman scattering (SERRS) and surface enhanced fluorescence (SEF) of rhodamine 6G molecules as intensity and spectral instability by electromagnetic (EM) mechanism. We find that irradiation of intense NIR laser pulses induces blinking in SERRS and SEF. Thanks to the finding, we systematically analyze SERRS and SEF from stable to unstable using single Ag nanoparticle (NP) dimers. The analysis reveals two physical insights into blinking as follows. (1) The intensity instability is inversely proportional to the enhancement factors of decay rate of molecules. The estimation using the proportionality suggests that separation of the molecules from Ag NP surfaces is several angstroms. (2) The spectral instability is induced by blueshifts in EM enhancement factors, which have spectral shapes similar to the plasmon resonance. This analysis provides us with a quantitative picture for intensity and spectral instability in SERRS and SEF within the framework of EM mechanism.

  19. Suppressed blinking behavior of CdSe/CdS QDs by polymer coating

    NASA Astrophysics Data System (ADS)

    Zhang, Aidi; Bian, Yannan; Wang, Jinjie; Chen, Kuiyong; Dong, Chaoqing; Ren, Jicun

    2016-02-01

    Semiconductor quantum dots (QDs) are very important fluorescent nanocrystals with excellent optical properties. However, QDs, at the single-particle level, show severe fluorescence intermittency (or blinking) on a wide time scale from milliseconds to minutes, which limits certain optical and biological applications. Generally, blinking behavior of QDs strongly depends on their surface state and surrounding environment. Therefore, current blinking suppression approaches are mostly focused on the introduction of an inorganic shell and organic small molecule compounds. In this study, we described a ``bottom up'' approach for the synthesis of CdSe/CdS/polymer core/shell/shell QDs via the in situ one-pot polymerization approach in order to control the blinking behavior of QDs. Three monomers (dithiothreitol (DTT), phenylenediamine (PDA), and hexamethylenediamine (HDA)) were respectively used to polymerize with hexachlorocyclotriphosphazene (HCCP), and then the polyphosphazene polymers were obtained with cyclotriphosphazene as the basic macromolecular backbone. By regulating the molar ratios of the activated comonomers, we can control the blinking behavior of CdSe/CdS/polymer QDs. Under the optimal conditions, the percentage of ``non-blinking'' CdSe/CdS/polymer QDs (the ``on time'' fraction > 99% of the overall observation time) was up to 78%. The suppression mechanism was attributed to the efficient passivation of QD surface traps by the sulfhydryl or phenyl groups in the polyphosphazene polymers.Semiconductor quantum dots (QDs) are very important fluorescent nanocrystals with excellent optical properties. However, QDs, at the single-particle level, show severe fluorescence intermittency (or blinking) on a wide time scale from milliseconds to minutes, which limits certain optical and biological applications. Generally, blinking behavior of QDs strongly depends on their surface state and surrounding environment. Therefore, current blinking suppression approaches are

  20. Fixational Eye Movement Correction of Blink-Induced Gaze Position Errors

    PubMed Central

    Costela, Francisco M.; Otero-Millan, Jorge; McCamy, Michael B.; Macknik, Stephen L.; Troncoso, Xoana G.; Jazi, Ali Najafian; Crook, Sharon M.; Martinez-Conde, Susana

    2014-01-01

    Our eyes move continuously. Even when we attempt to fix our gaze, we produce “fixational” eye movements including microsaccades, drift and tremor. The potential role of microsaccades versus drifts in the control of eye position has been debated for decades and remains in question today. Here we set out to determine the corrective functions of microsaccades and drifts on gaze-position errors due to blinks in non-human primates (Macaca mulatta) and humans. Our results show that blinks contribute to the instability of gaze during fixation, and that microsaccades, but not drifts, correct fixation errors introduced by blinks. These findings provide new insights about eye position control during fixation, and indicate a more general role of microsaccades in fixation correction than thought previously. PMID:25333481

  1. Fabry-Perot interferometer utilized for displacement measurement in a large measuring range

    SciTech Connect

    Wang, Yung-Cheng; Shyu, Lih-Horng; Chang, Chung-Ping

    2010-09-15

    The optical configuration of a Fabry-Perot interferometer is uncomplicated. This has already been applied in different measurement systems. For the displacement measurement with the Fabry-Perot interferometer, the result is significantly influenced by the tilt angles of the measurement mirror in the interferometer. Hence, only for the rather small measuring range, the Fabry-Perot interferometer is available. The goal of this investigation is to enhance the measuring range of Fabry-Perot interferometer by compensating the tilt angles. To verify the measuring characteristic of the self-developed Fabry-Perot interferometer, some comparison measurements with a reference standard have been performed. The maximum deviation of comparison experiments is less than 0.3 {mu}m in the traveling range of 30 mm. The experimental results show that the Fabry-Perot interferometer is highly stable, insensitive to environment effects, and can meet the measuring requirement of the submicrometer order.

  2. Three dimensional time-gated tracking of non-blinking quantum dots in live cells

    DOE PAGESBeta

    DeVore, Matthew S.; Werner, James H.; Goodwin, Peter M.; Keller, Aaron M.; Hollingsworth, Jennifer A.; Wilson, Bridget S.; Cleyrat, Cedric; Lidke, Diane S.; Ghosh, Yagnaseni; Stewart, Michael H.; et al

    2015-12-03

    Single particle tracking has provided a wealth of information about biophysical processes such as motor protein transport and diffusion in cell membranes. However, motion out of the plane of the microscope or blinking of the fluorescent probe used as a label generally limits observation times to several seconds. Here, we overcome these limitations by using novel non-blinking quantum dots as probes and employing a custom 3D tracking microscope to actively follow motion in three dimensions (3D) in live cells. As a result, signal-to-noise is improved in the cellular milieu through the use of pulsed excitation and time-gated detection.

  3. Three dimensional time-gated tracking of non-blinking quantum dots in live cells

    SciTech Connect

    DeVore, Matthew S.; Werner, James H.; Goodwin, Peter M.; Keller, Aaron M.; Hollingsworth, Jennifer A.; Wilson, Bridget S.; Cleyrat, Cedric; Lidke, Diane S.; Ghosh, Yagnaseni; Stewart, Michael H.; Stich, Dominik G.; Phipps, Mary E.

    2015-03-12

    Single particle tracking has provided a wealth of information about biophysical processes such as motor protein transport and diffusion in cell membranes. However, motion out of the plane of the microscope or blinking of the fluorescent probe used as a label generally limits observation times to several seconds. Here, we overcome these limitations by using novel non-blinking quantum dots as probes and employing a custom 3D tracking microscope to actively follow motion in three dimensions (3D) in live cells. As a result, signal-to-noise is improved in the cellular milieu through the use of pulsed excitation and time-gated detection.

  4. Three dimensional time-gated tracking of non-blinking quantum dots in live cells

    PubMed Central

    DeVore, Matthew S.; Stich, Dominik G.; Keller, Aaron M.; Ghosh, Yagnaseni; Goodwin, Peter M.; Phipps, Mary E.; Stewart, Michael H.; Cleyrat, Cédric; Wilson, Bridget S.; Lidke, Diane S.; Hollingsworth, Jennifer A.; Werner, James H.

    2015-01-01

    Single particle tracking has provided a wealth of information about biophysical processes such as motor protein transport and diffusion in cell membranes. However, motion out of the plane of the microscope or blinking of the fluorescent probe used as a label generally limits observation times to several seconds. Here, we overcome these limitations by using novel non-blinking quantum dots as probes and employing a custom 3D tracking microscope to actively follow motion in three dimensions (3D) in live cells. Signal-to-noise is improved in the cellular milieu through the use of pulsed excitation and time-gated detection. PMID:25932286

  5. Analyzing blinking effects in super resolution localization microscopy with single-photon SPAD imagers

    NASA Astrophysics Data System (ADS)

    Antolovic, Ivan Michel; Burri, Samuel; Bruschini, Claudio; Hoebe, Ron; Charbon, Edoardo

    2016-02-01

    For many scientific applications, electron multiplying charge coupled devices (EMCCDs) have been the sensor of choice because of their high quantum efficiency and built-in electron amplification. Lately, many researchers introduced scientific complementary metal-oxide semiconductor (sCMOS) imagers in their instrumentation, so as to take advantage of faster readout and the absence of excess noise. Alternatively, single-photon avalanche diode (SPAD) imagers can provide even faster frame rates and zero readout noise. SwissSPAD is a 1-bit 512×128 SPAD imager, one of the largest of its kind, featuring a frame duration of 6.4 μs. Additionally, a gating mechanism enables photosensitive windows as short as 5 ns with a skew better than 150 ps across the entire array. The SwissSPAD photon detection efficiency (PDE) uniformity is very high, thanks on one side to a photon-to-digital conversion and on the other to a reduced fraction of "hot pixels" or "screamers", which would pollute the image with noise. A low native fill factor was recovered to a large extent using a microlens array, leading to a maximum PDE increase of 12×. This enabled us to detect single fluorophores, as required by ground state depletion followed by individual molecule return imaging microscopy (GSDIM). We show the first super resolution results obtained with a SPAD imager, with an estimated localization uncertainty of 30 nm and resolution of 100 nm. The high time resolution of 6.4 μs can be utilized to explore the dye's photophysics or for dye optimization. We also present the methodology for the blinking analysis on experimental data.

  6. Blinking suppression and biexcitonic emission in thick-shell CdSe/CdS nanocrystals at cryogenic temperature

    NASA Astrophysics Data System (ADS)

    Canneson, D.; Biadala, L.; Buil, S.; Quélin, X.; Javaux, C.; Dubertret, B.; Hermier, J.-P.

    2014-01-01

    The fluorescence of single colloidal thick-shell CdSe/CdS nanocrystals (NCs), at cryogenic temperature (4 K) and room temperature (RT), is studied using the intensity autocorrelation function (ACF) and lifetime measurements. The radiative and Auger decay rates corresponding to the desexcitation of the charged biexcitonic state are determined through an original method of photon postselection. Especially, the charged biexciton quantum yield increases from about 15% at RT to 60% at 4 K. The high inhibition of Auger recombination already observed for the trion state of CdSe/CdS NCs at low temperature is also demonstrated for the charged biexcitonic state. At 4 K, the ACF is equal to 1 for time scales ranging from 50 ns to 200 ms. In contrast with RT operation, the intensity of the trion emission is then perfectly stable and no blinking is observed. All the results highlight the strong confinement of the charge carriers in the CdSe core.

  7. On the blink: the importance of target-distractor similarity in eliciting an attentional blink with faces.

    PubMed

    Müsch, Kathrin; Engel, Andreas K; Schneider, Till R

    2012-01-01

    Temporal allocation of attention is often investigated with a paradigm in which two relevant target items are presented in a rapid sequence of irrelevant distractors. The term Attentional Blink (AB) denotes a transient impairment of awareness for the second of these two target items when presented close in time. Experimental studies reported that the AB is reduced when the second target is emotionally significant, suggesting a modulation of attention allocation. The aim of the present study was to systematically investigate the influence of target-distractor similarity on AB magnitude for faces with emotional expressions under conditions of limited attention in a series of six rapid serial visual presentation experiments. The task on the first target was either to discriminate the gender of a neutral face (Experiments 1, 3-6) or an indoor/outdoor visual scene (Experiment 2). The task on the second target required either the detection of emotional expressions (Experiments 1-5) or the detection of a face (Experiment 6). The AB was minimal or absent when targets could be easily discriminated from each other. Three successive experiments revealed that insufficient masking and target-distractor similarity could account for the observed immunity of faces against the AB in the first two experiments. An AB was present but not increased when the facial expression was irrelevant to the task suggesting that target-distractor similarity plays a more important role in eliciting an AB than the attentional set demanded by the specific task. In line with previous work, emotional faces were less affected by the AB. PMID:22815982

  8. The utility of curriculum-based measurement for evaluating the effects of methylphenidate on academic performance.

    PubMed Central

    Stoner, G; Carey, S P; Ikeda, M J; Shinn, M R

    1994-01-01

    Two case studies were conducted to investigate the utility of curriculum-based measurement of math and reading for evaluating the effects of methylphenidate on the academic performance of 2 students diagnosed with attention deficit hyperactivity disorder. Following baseline measurement, double-blind placebo-controlled procedures were employed to evaluate each student's response to three levels (5 mg, 10 mg, and 15 mg) of the medication. Results of the first study suggest that the curriculum-based measures were sensitive indicators of the student's response to medication. This finding was replicated in the second study. In the second study, when the student's follow-up dose of medication was based on trial-phase data, follow-up performance was improved compared to baseline performance. These case studies suggest that further research is warranted on the utility of curriculum-based measurements for monitoring and evaluating stimulant medication interventions with children with this disorder. PMID:8188554

  9. 43 CFR 3272.12 - What environmental protection measures must I include in my utilization plan?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false What environmental protection measures must I include in my utilization plan? 3272.12 Section 3272.12 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) GEOTHERMAL RESOURCE...

  10. Utility of Clinical Swallowing Examination Measures for Detecting Aspiration Post-Stroke

    ERIC Educational Resources Information Center

    McCullough, G. H.; Rosenbek, J. C.; Wertz, R. T.; McCoy, S.; Mann, G.; McCullough, K.

    2005-01-01

    The purpose of this investigation was to determine the utility of clinical swallowing examination (CSE) measures for detecting aspiration as defined by videofluoroscopic swallowing examination (VFSE). This study, involving 165 participants, is a follow-up to a previously published investigation of 60 participants. Findings are compared with that…

  11. REVIEW OF CONCURRENT MASS EMISSION AND OPACITY MEASUREMENTS FOR COAL-BURNING UTILITY AND INDUSTRIAL BOILERS

    EPA Science Inventory

    The report gives results of concurrent particulate emissions and opacity measurements based on visual observations and/or in-stack transmissometry for more than 400 compliance, acceptance, or experimental tests on coal-fired utility and industrial boilers. The sampling, which inc...

  12. A structured review of health utility measures and elicitation in advanced/metastatic breast cancer

    PubMed Central

    Hao, Yanni; Wolfram, Verena; Cook, Jennifer

    2016-01-01

    Background Health utilities are increasingly incorporated in health economic evaluations. Different elicitation methods, direct and indirect, have been established in the past. This study examined the evidence on health utility elicitation previously reported in advanced/metastatic breast cancer and aimed to link these results to requirements of reimbursement bodies. Methods Searches were conducted using a detailed search strategy across several electronic databases (MEDLINE, EMBASE, Cochrane Library, and EconLit databases), online sources (Cost-effectiveness Analysis Registry and the Health Economics Research Center), and web sites of health technology assessment (HTA) bodies. Publications were selected based on the search strategy and the overall study objectives. Results A total of 768 publications were identified in the searches, and 26 publications, comprising 18 journal articles and eight submissions to HTA bodies, were included in the evidence review. Most journal articles derived utilities from the European Quality of Life Five-Dimensions questionnaire (EQ-5D). Other utility measures, such as the direct methods standard gamble (SG), time trade-off (TTO), and visual analog scale (VAS), were less frequently used. Several studies described mapping algorithms to generate utilities from disease-specific health-related quality of life (HRQOL) instruments such as European Organization for Research and Treatment of Cancer Quality of Life Questionnaire – Core 30 (EORTC QLQ-C30), European Organization for Research and Treatment of Cancer Quality of Life Questionnaire – Breast Cancer 23 (EORTC QLQ-BR23), Functional Assessment of Cancer Therapy – General questionnaire (FACT-G), and Utility-Based Questionnaire-Cancer (UBQ-C); most used EQ-5D as the reference. Sociodemographic factors that affect health utilities, such as age, sex, income, and education, as well as disease progression, choice of utility elicitation method, and country settings, were identified

  13. Method of utility-system source-impedance measurement for the industrial power engineer

    SciTech Connect

    Corvin, W C

    1982-05-24

    In general, the power company that delivers energy to an industrial power system will supply, upon request, information describing the utility source impedance at the point of interconnection with the industrial customer. this information is usually expressed as the maximum available short-circuit MVA (megavolt amperes) that the utility can deliver at some nominal voltage. For sizing the interrupting ratings of protective equipment, this number is important. However, better information is required for modeling the utility system under all conditions of system switching, generation, and loading. In this paper a method is described for measuring the utility source impedance that gives a more realistic representation of the utility at the point of interconnection. It is increasingly important that the industrial power engineer accurately view the power company as a power source of variable impedance. Industrial loads may operate and interact differently, depending on the relative stiffness of their power source. Electric utilities increasingly experience planned voltage reductions, brownouts, and temporary line-switching configurations that can leave the industrial customer with a power source far different from the one normally expected.

  14. A comparison of four different approaches to measuring health utility in depressed patients

    PubMed Central

    2013-01-01

    Background A variety of instruments are used to measure health related quality of life. Few data exist on the performance and agreement of different instruments in a depressed population. The aim of this study was to investigate agreement between, and suitability of, the EQ-5D-3L, EQ-5D Visual Analogue Scale (EQ-5D VAS), SF-6D and SF-12 new algorithm for measuring health utility in depressed patients. Methods The intraclass correlation coefficient (ICC) and Bland and Altman approaches were used to assess agreement. Instrument sensitivity was analysed by: (1) plotting utility scores for the instruments against one another; (2) correlating utility scores and depressive symptoms (Beck Depression Inventory (BDI)); and (3) using Tukey’s procedure. Receiver Operating Characteristic (ROC) analysis assessed instrument responsiveness to change. Acceptability was assessed by comparing instrument completion rates. Results The overall ICC was 0.57. Bland and Altman plots showed wide limits of agreement for each pair wise comparison, except between the SF-6D and SF-12 new algorithm. Plots of utility scores displayed ’ceiling effects’ in the EQ-5D-3L index and ’floor effects’ in the SF-6D and SF-12 new algorithm. All instruments showed a negative monotonic relationship with BDI, but the EQ-5D-3L index and EQ-5D VAS could not differentiate between depression severity sub-groups. The SF-based instruments were better able to detect changes in health state over time. There was no difference in completion rates of the four instruments. Conclusions There was a lack of agreement between utility scores generated by the different instruments. According to the criteria of sensitivity, responsiveness and acceptability that we applied, the SF-6D and SF-12 may be more suitable for the measurement of health related utility in a depressed population than the EQ-5D-3L, which is the instrument currently recommended by NICE. PMID:23659557

  15. Too Much Control Can Hurt: A Threaded Cognition Model of the Attentional Blink

    ERIC Educational Resources Information Center

    Taatgen, Niels A.; Juvina, Ion; Schipper, Marc; Borst, Jelmer P.; Martens, Sander

    2009-01-01

    Explanations for the attentional blink (AB; a deficit in identifying the second of two targets when presented 200-500ms after the first) have recently shifted from limitations in memory consolidation to disruptions in cognitive control. With a new model based on the threaded cognition theory of multi-tasking we propose a different explanation: the…

  16. Resting EEG in Alpha and Beta Bands Predicts Individual Differences in Attentional Blink Magnitude

    ERIC Educational Resources Information Center

    MacLean, Mary H.; Arnell, Karen M.; Cote, Kimberly A.

    2012-01-01

    Accuracy for a second target (T2) is reduced when it is presented within 500 ms of a first target (T1) in a rapid serial visual presentation (RSVP)--an attentional blink (AB). There are reliable individual differences in the magnitude of the AB. Recent evidence has shown that the attentional approach that an individual typically adopts during a…

  17. Evidence against a Central Bottleneck during the Attentional Blink: Multiple Channels for Configural and Featural Processing

    ERIC Educational Resources Information Center

    Awh, Edward; Serences, John; Laurey, Paul; Dhaliwal, Harpreet; van der Jagt, Thomas; Dassonville, Paul

    2004-01-01

    When a visual target is identified, there is a period of several hundred milliseconds when the processing of subsequent targets is impaired, a phenomenon labeled the attentional blink (AB). The emerging consensus is that the identification of a visual target temporarily occupies a limited attentional resource that is essential for all visual…

  18. Cardiac Modulation of Startle: Effects on Eye Blink and Higher Cognitive Processing

    ERIC Educational Resources Information Center

    Schulz, Andre; Reichert, Carolin F.; Richter, Steffen; Lass-Hennemann, Johanna; Blumenthal, Terry D.; Schachinger, Hartmut

    2009-01-01

    Cardiac cycle time has been shown to affect pre-attentive brainstem startle processes, such as the magnitude of acoustically evoked reflexive startle eye blinks. These effects were attributed to baro-afferent feedback mechanisms. However, it remains unclear whether cardiac cycle time plays a role in higher startle-related cognitive processes, as…

  19. Perception of Temporal Order Is Impaired during the Time Course of the Attentional Blink

    ERIC Educational Resources Information Center

    Spalek, Thomas M.; Lagroix, Hayley E. P.; Yanko, Matthew R.; Di Lollo, Vincent

    2012-01-01

    Identification accuracy for the second of two target (T2) is impaired when presented shortly after the first (T1). Does this attentional blink (AB) also impair the perception of the order of presentation? In four experiments, three letter targets (T1, T2, T3) were inserted in a stream of digit distractors displayed in rapid serial visual…

  20. Different Attentional Blink Tasks Reflect Distinct Information Processing Limitations: An Individual Differences Approach

    ERIC Educational Resources Information Center

    Kelly, Ashleigh J.; Dux, Paul E.

    2011-01-01

    To study the temporal dynamics and capacity-limits of attentional selection and encoding, researchers often employ the attentional blink (AB) phenomenon: subjects' impaired ability to report the second of two targets in a rapid serial visual presentation (RSVP) stream that appear within 200-500 ms of one another. The AB has now been the subject of…

  1. Attentional Blink in Young People with High-Functioning Autism and Asperger's Disorder

    ERIC Educational Resources Information Center

    Rinehart, Nicole; Tonge, Bruce; Brereton, Avril; Bradshaw, John

    2010-01-01

    The aim of the study was to examine the temporal characteristics of information processing in individuals with high-functioning autism and Asperger's disorder using a rapid serial visual presentation paradigm. The results clearly showed that such people demonstrate an attentional blink of similar magnitude to comparison groups. This supports the…

  2. Attentional and Perceptual Factors Affecting the Attentional Blink for Faces and Objects

    ERIC Educational Resources Information Center

    Landau, Ayelet N.; Bentin, Shlomo

    2008-01-01

    When 2 different visual targets presented among different distracters in a rapid serial visual presentation (RSVP) are separated by 400 ms or less, detection and identification of the 2nd targets are reduced relative to longer time intervals. This phenomenon, termed the "attentional blink" (AB), is attributed to the temporary engagement of a…

  3. The timing and temporal patterns of eye blinking are dynamically modulated by attention.

    PubMed

    Oh, Jihoon; Jeong, So-Yeong; Jeong, Jaeseung

    2012-12-01

    A number of human behaviors and movements show self-similar temporal patterns in their occurrence over time. Human walking, finger tapping and heartbeat intervals have fluctuations that are statistically similar at multiple time scales. However, whether eye blinking, which is a unique human behavior that occurs spontaneously, embeds a similar temporal structure within other types of movements is largely unknown. In this study, we used attention-requiring tasks to assess how the temporal pattern of eye blinking is altered in both the second and sub-second time scales. Our results showed that eyeblink activity was more suppressed as the task difficulty level increased and was facilitated immediately after exposure to auditory stimuli, which were presented for 6 to 14s. Moreover, similar transient suppressive and facilitative patterns were observed in the response period, which lasted for less than one second. Furthermore, we found that spontaneous eye blinking intervals fluctuated according to an 1/f scaling property, which is widely observed in various human movements. These results suggest that the dynamics of eye blinking under specific cognitive tasks exhibit a similar temporal structure at multiple time scales. PMID:22877514

  4. Correlation between Inter-Blink Interval and Episodic Encoding during Movie Watching.

    PubMed

    Shin, Young Seok; Chang, Won-du; Park, Jinsick; Im, Chang-Hwan; Lee, Sang In; Kim, In Young; Jang, Dong Pyo

    2015-01-01

    Human eye blinking is cognitively suppressed to minimize loss of visual information for important real-world events. Despite the relationship between eye blinking and cognitive state, the effect of eye blinks on cognition in real-world environments has received limited research attention. In this study, we focused on the temporal pattern of inter-eye blink interval (IEBI) during movie watching and investigated its relationship with episodic memory. As a control condition, 24 healthy subjects watched a nature documentary that lacked a specific story line while electroencephalography was performed. Immediately after viewing the movie, the subjects were asked to report its most memorable scene. Four weeks later, subjects were asked to score 32 randomly selected scenes from the movie, based on how much they were able to remember and describe. The results showed that the average IEBI was significantly longer during the movie than in the control condition. In addition, the significant increase in IEBI when watching a movie coincided with the most memorable scenes of the movie. The results suggested that the interesting episodic narrative of the movie attracted the subjects' visual attention relative to the documentary clip that did not have a story line. In the episodic memory test executed four weeks later, memory performance was significantly positively correlated with IEBI (p<0.001). In summary, IEBI may be a reliable bio-marker of the degree of concentration on naturalistic content that requires visual attention, such as a movie. PMID:26529091

  5. Alteration of Attentional Blink in High Functioning Autism: A Pilot Study

    ERIC Educational Resources Information Center

    Amirault, Marion; Etchegoyhen, Kattalin; Delord, Sandrine; Mendizabal, Sandrine; Kraushaar, Caroline; Hesling, Isabelle; Allard, Michele; Bouvard, Manuel; Mayo, Willy

    2009-01-01

    Autism is characterized by deficits in attention. However, no study has investigated the dynamics of attentional processes in autistic patients yet. The attentional blink (AB) paradigm provides information about the temporal dynamics of attention in particular about the allocation and the duration of an attentional episode. We compared 11 high…

  6. The Role of the Locus Coeruleus in Mediating the Attentional Blink: A Neurocomputational Theory

    ERIC Educational Resources Information Center

    Nieuwenhuis, Sander; Gilzenrat, Mark S.; Holmes, Benjamin D.; Cohen, Jonathan D.

    2005-01-01

    The attentional blink refers to the transient impairment in perceiving the 2nd of 2 targets presented in close temporal proximity. In this article, the authors propose a neurobiological mechanism for this effect. The authors extend a recently developed computational model of the potentiating influence of the locus coeruleus-norepinephrine system…

  7. Visual Search Is Postponed during the Attentional Blink until the System Is Suitably Reconfigured

    ERIC Educational Resources Information Center

    Ghorashi, S. M. Shahab; Smilek, Daniel; Di Lollo, Vincent

    2007-01-01

    J. S. Joseph, M. M. Chun, and K. Nakayama (1997) found that pop-out visual search was impaired as a function of intertarget lag in an attentional blink (AB) paradigm in which the 1st target was a letter and the 2nd target was a search display. In 4 experiments, the present authors tested the implication that search efficiency should be similarly…

  8. Attention Blinks for Selection, Not Perception or Memory: Reading Sentences and Reporting Targets

    ERIC Educational Resources Information Center

    Potter, Mary C.; Wyble, Brad; Olejarczyk, Jennifer

    2011-01-01

    In whole report, a sentence presented sequentially at the rate of about 10 words/s can be recalled accurately, whereas if the task is to report only two target words (e.g., red words), the second target suffers an attentional blink if it appears shortly after the first target. If these two tasks are carried out simultaneously, is there an…

  9. Individuals Differ in the Attentional Blink: Mental Speed and Intra-Subject Stability Matter

    ERIC Educational Resources Information Center

    Klein, Christoph; Arend, Isabel C.; Beauducel, Andre; Shapiro, Kimron L.

    2011-01-01

    The failure to correctly report two targets ("T[subscript 1]", "T[subscript 2]") that follow each other in close temporal proximity has been called the "attentional blink" (AB). The AB has, so far, mainly been studied using experimental approaches. The present studies investigated individual differences in AB performance, revealing (among further…

  10. Eye-Blink Conditioning Is Associated with Changes in Synaptic Ultrastructure in the Rabbit Interpositus Nuclei

    ERIC Educational Resources Information Center

    Weeks, Andrew C. W.; Connor, Steve; Hinchcliff, Richard; LeBoutillier, Janelle C.; Thompson, Richard F.; Petit, Ted L.

    2007-01-01

    Eye-blink conditioning involves the pairing of a conditioned stimulus (usually a tone) to an unconditioned stimulus (air puff), and it is well established that an intact cerebellum and interpositus nucleus, in particular, are required for this form of classical conditioning. Changes in synaptic number or structure have long been proposed as a…

  11. The Role of the Magnocellular Visual Pathway in the Attentional Blink

    ERIC Educational Resources Information Center

    Stuart, Geoffrey W.; Lambeth, Sandra E.; Day, Ross H.; Gould, Ian C.; Castles, Anne E.

    2012-01-01

    Visual attention has temporal limitations. In the attentional blink (AB) a stream of stimuli such as letters or digits are presented to a participant on a computer monitor at a rapid rate. Embedded in the stream are two targets that the participant must try to identify. Identification of the second target is severely impaired if it is presented…

  12. Correlation between Inter-Blink Interval and Episodic Encoding during Movie Watching

    PubMed Central

    Shin, Young Seok; Chang, Won-du; Park, Jinsick; Im, Chang-Hwan; Lee, Sang In; Kim, In Young; Jang, Dong Pyo

    2015-01-01

    Human eye blinking is cognitively suppressed to minimize loss of visual information for important real-world events. Despite the relationship between eye blinking and cognitive state, the effect of eye blinks on cognition in real-world environments has received limited research attention. In this study, we focused on the temporal pattern of inter-eye blink interval (IEBI) during movie watching and investigated its relationship with episodic memory. As a control condition, 24 healthy subjects watched a nature documentary that lacked a specific story line while electroencephalography was performed. Immediately after viewing the movie, the subjects were asked to report its most memorable scene. Four weeks later, subjects were asked to score 32 randomly selected scenes from the movie, based on how much they were able to remember and describe. The results showed that the average IEBI was significantly longer during the movie than in the control condition. In addition, the significant increase in IEBI when watching a movie coincided with the most memorable scenes of the movie. The results suggested that the interesting episodic narrative of the movie attracted the subjects’ visual attention relative to the documentary clip that did not have a story line. In the episodic memory test executed four weeks later, memory performance was significantly positively correlated with IEBI (p<0.001). In summary, IEBI may be a reliable bio-marker of the degree of concentration on naturalistic content that requires visual attention, such as a movie. PMID:26529091

  13. Modulation of Attentional Blink with Emotional Faces in Typical Development and in Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Yerys, Benjamin E.; Ruiz, Ericka; Strang, John; Sokoloff, Jennifer; Kenworthy, Lauren; Vaidya, Chandan J.

    2013-01-01

    Background: The attentional blink (AB) phenomenon was used to assess the effect of emotional information on early visual attention in typically developing (TD) children and children with autism spectrum disorders (ASD). The AB effect is the momentary perceptual unawareness that follows target identification in a rapid serial visual processing…

  14. Electrically induced blink reflex and facial motor nerve stimulation in beagles.

    PubMed

    Añor, S; Espadaler, J M; Pastor, J; Pumarola, M

    2000-01-01

    Electrophysiologic assessment of the blink reflex test and the muscle-evoked potentials evoked by stimulation of the facial nerve were performed in 15 healthy adult Beagles before and after supraorbital (trigeminal) and facial anesthetic nerve blocks performed by lidocaine injections. Unilateral electrical stimulation of the supraorbital nerve elicited 2 ipsilateral (R1 and R2) and a contralateral (Rc) reflex muscle potential in orbicularis oculi muscles. Electrical stimulation of the facial nerve elicited 2 muscle potentials (a direct response [D] and a reflex faciofacial response [RF]) in the ipsilateral orbicularis oculi muscle. Anesthetic block of the left supraorbital nerve resulted in bilateral lack of responses upon left supraorbital nerve stimulation, but normal responses in right and left orbicularis oculi muscles upon right supraorbital stimulation. Right facial anesthetic block produced lack of responses in the right orbicularis oculi muscle regardless the side of supraorbital nerve stimulation. Results of this study demonstrate that the blink reflex can be electrically elicited and assessed in dogs. Reference values for the blink reflex responses and for the muscle potentials evoked by direct facial nerve stimulation in dogs are provided. The potential usefulness of the electrically elicited blink reflex test in the diagnosis of peripheral facial and trigeminal dysfunction in dogs was demonstrated. PMID:10935892

  15. Bleaching/blinking assisted localization microscopy for superresolution imaging using standard fluorescent molecules.

    PubMed

    Burnette, Dylan T; Sengupta, Prabuddha; Dai, Yuhai; Lippincott-Schwartz, Jennifer; Kachar, Bechara

    2011-12-27

    Superresolution imaging techniques based on the precise localization of single molecules, such as photoactivated localization microscopy (PALM) and stochastic optical reconstruction microscopy (STORM), achieve high resolution by fitting images of single fluorescent molecules with a theoretical Gaussian to localize them with a precision on the order of tens of nanometers. PALM/STORM rely on photoactivated proteins or photoswitching dyes, respectively, which makes them technically challenging. We present a simple and practical way of producing point localization-based superresolution images that does not require photoactivatable or photoswitching probes. Called bleaching/blinking assisted localization microscopy (BaLM), the technique relies on the intrinsic bleaching and blinking behaviors characteristic of all commonly used fluorescent probes. To detect single fluorophores, we simply acquire a stream of fluorescence images. Fluorophore bleach or blink-off events are detected by subtracting from each image of the series the subsequent image. Similarly, blink-on events are detected by subtracting from each frame the previous one. After image subtractions, fluorescence emission signals from single fluorophores are identified and the localizations are determined by fitting the fluorescence intensity distribution with a theoretical Gaussian. We also show that BaLM works with a spectrum of fluorescent molecules in the same sample. Thus, BaLM extends single molecule-based superresolution localization to samples labeled with multiple conventional fluorescent probes. PMID:22167805

  16. Comprehensive description of blinking-dynamics regimes in single direct-band-gap silicon nanocrystals

    NASA Astrophysics Data System (ADS)

    Kůsová, Kateřina; Pelant, Ivan; Humpolíčková, Jana; Hof, Martin

    2016-01-01

    Blinking dynamics of strain-engineered direct-band-gap Si nanocrystals is measured over a broad interval of time scales and excitation intensities. The measured data are at first described using the autocorrelation function approach. Then, the relationship between the shape of the autocorrelation function and the distributions of on and off times is discussed. An original numerical approach allowing us to deduce and quantify the corresponding on- and off-times distributions is proposed. Both the autocorrelation function and the distribution of on and off times are observed to follow a broken-power-law function, for which we introduce an analytical formula. The broken-power-law function signifies a change in the power-law dynamics at short time scales (the power-law exponent changes on the time scale of 1-20 ms). Under the lowest excitation intensities, both the autocorrelation function and the distribution of on times are flat, implying the existence of a nonblinking regime. In addition to the broken-power-law dynamics, the end of the on-times distribution is also cut off by an exponential tail. All these temporal regimes are observed to be independent of excitation intensity for the lowest excitation intensities, whereas at higher excitation intensities, excitation intensity dependence appears. The distribution of off times is observed to be more robust, with changes occurring at higher excitation intensity than in the case of the on-times distribution. The different observed regimes are discussed in detail and a qualitative model including the emission of a trion is proposed.

  17. Estimation of utility values from visual analog scale measures of health in patients undergoing cardiac surgery

    PubMed Central

    Oddershede, Lars; Andreasen, Jan Jesper; Ehlers, Lars

    2014-01-01

    Introduction In health economic evaluations, mapping can be used to estimate utility values from other health outcomes in order to calculate quality adjusted life-years. Currently, no methods exist to map visual analog scale (VAS) scores to utility values. This study aimed to develop and propose a statistical algorithm for mapping five dimensions of health, measured on VASs, to utility scores in patients suffering from cardiovascular disease. Methods Patients undergoing coronary artery bypass grafting at Aalborg University Hospital in Denmark were asked to score their health using the five VAS items (mobility, self-care, ability to perform usual activities, pain, and presence of anxiety or depression) and the EuroQol 5 Dimensions questionnaire. Regression analysis was used to estimate four mapping models from patients’ age, sex, and the self-reported VAS scores. Prediction errors were compared between mapping models and on subsets of the observed utility scores. Agreement between predicted and observed values was assessed using Bland–Altman plots. Results Random effects generalized least squares (GLS) regression yielded the best results when quadratic terms of VAS scores were included. Mapping models fitted using the Tobit model and censored least absolute deviation regression did not appear superior to GLS regression. The mapping models were able to explain approximately 63%–65% of the variation in the observed utility scores. The mean absolute error of predictions increased as the observed utility values decreased. Conclusion We concluded that it was possible to predict utility scores from VAS scores of the five dimensions of health used in the EuroQol questionnaires. However, the use of the mapping model may be inappropriate in more severe conditions. PMID:24453497

  18. Utilizing Photogrammetry and Strain Gage Measurement to Characterize Pressurization of Inflatable Modules

    NASA Technical Reports Server (NTRS)

    Mohammed, Anil

    2011-01-01

    This paper focuses on integrating a large hatch penetration into inflatable modules of various constructions. This paper also compares load predictions with test measurements. The strain was measured by utilizing photogrammetric methods and strain gages mounted to select clevises that interface with the structural webbings. Bench testing showed good correlation between strain data collected from an extensometer and photogrammetric measurements, even when the material transitioned from the low load to high load strain region of the curve. The full-scale torus design module showed mixed results as well in the lower load and high strain regions. After thorough analysis of photogrammetric measurements, strain gage measurements, and predicted load, the photogrammetric measurements seem to be off by a factor of two.

  19. Simultaneous measurement of glucose transport and utilization in the human brain

    PubMed Central

    Shestov, Alexander A.; Emir, Uzay E.; Kumar, Anjali; Henry, Pierre-Gilles; Seaquist, Elizabeth R.

    2011-01-01

    Glucose is the primary fuel for brain function, and determining the kinetics of cerebral glucose transport and utilization is critical for quantifying cerebral energy metabolism. The kinetic parameters of cerebral glucose transport, KMt and Vmaxt, in humans have so far been obtained by measuring steady-state brain glucose levels by proton (1H) NMR as a function of plasma glucose levels and fitting steady-state models to these data. Extraction of the kinetic parameters for cerebral glucose transport necessitated assuming a constant cerebral metabolic rate of glucose (CMRglc) obtained from other tracer studies, such as 13C NMR. Here we present new methodology to simultaneously obtain kinetic parameters for glucose transport and utilization in the human brain by fitting both dynamic and steady-state 1H NMR data with a reversible, non-steady-state Michaelis-Menten model. Dynamic data were obtained by measuring brain and plasma glucose time courses during glucose infusions to raise and maintain plasma concentration at ∼17 mmol/l for ∼2 h in five healthy volunteers. Steady-state brain vs. plasma glucose concentrations were taken from literature and the steady-state portions of data from the five volunteers. In addition to providing simultaneous measurements of glucose transport and utilization and obviating assumptions for constant CMRglc, this methodology does not necessitate infusions of expensive or radioactive tracers. Using this new methodology, we found that the maximum transport capacity for glucose through the blood-brain barrier was nearly twofold higher than maximum cerebral glucose utilization. The glucose transport and utilization parameters were consistent with previously published values for human brain. PMID:21791622

  20. Target Cueing Provides Support for Target- and Resource-Based Models of the Attentional Blink

    PubMed Central

    Pincham, Hannah L.; Szűcs, Dénes

    2012-01-01

    The attentional blink (AB) describes a time-based deficit in processing the second of two masked targets. The AB is attenuated if successive targets appear between the first and final target, or if a cueing target is positioned before the final target. Using various speeds of stimulus presentation, the current study employed successive targets and cueing targets to confirm and extend an understanding of target-target cueing in the AB. In Experiment 1, three targets were presented sequentially at rates of 30 msec/item or 90 msec/item. Successive targets presented at 90 msec improved performance compared with non-successive targets. However, accuracy was equivalently high for successive and non-successive targets presented at 30 msec/item, suggesting that–regardless of whether they occurred consecutively–those items fell within the temporally defined attentional window initiated by the first target. Using four different presentation speeds, Experiment 2 confirmed the time-based definition of the AB and the success of target-cueing at 30 msec/item. This experiment additionally revealed that cueing was most effective when resources were not devoted to the cue, thereby implicating capacity limitations in the AB. Across both experiments, a novel order-error measure suggested that errors tend to decrease with an increasing duration between the targets, but also revealed that certain stimulus conditions result in stable order accuracy. Overall, the results are best encapsulated by target-based and resource-sharing theories of the AB, which collectively value the contributions of capacity limitations and optimizing transient attention in time. PMID:22629426

  1. Post-perceptual processing during the attentional blink is modulated by inter-trial task expectancies

    PubMed Central

    Sy, Jocelyn L.; Elliott, James C.; Giesbrecht, Barry

    2013-01-01

    The selective processing of goal-relevant information depends on an attention system that can flexibly adapt to changing task demands and expectations. Evidence from visual search tasks indicates that the perceptual selectivity of attention increases when the bottom-up demands of the task increase and when the expectations about task demands engendered by trial history are violated. Evidence from studies of the attentional blink (AB), which measures the temporal dynamics of attention, also indicates that perceptual selectivity during the AB is increased if the bottom-up task demands are increased. The present work tested whether expectations about task demands engendered by trial history also modulate perceptual selectivity during the AB. Two experiments tested the extent to which inter-trial switches in task demands reduced post-perceptual processing of targets presented during the AB. Experiment 1 indexed post-perceptual processing using the event-related potential (ERP) technique to isolate the context sensitive N400 ERP component evoked by words presented during the AB. Experiment 2 indexed post-perceptual processing using behavioral performance to determine the extent to which personal names survive the AB. The results of both experiments revealed that both electrophysiological (Exp. 1) and behavioral (Exp. 2) indices of post-perceptual processing were attenuated when consecutive trials differed in terms of their perceptual demands. The results are consistent with the notion that the selectivity of attention during the AB is modulated not only by within-trial task demands, but also can be flexibly determined by trial-by-trial expectations. PMID:24115924

  2. PET evidence for a role for striatal dopamine in the attentional blink: functional implications.

    PubMed

    Slagter, Heleen A; Tomer, Rachel; Christian, Bradley T; Fox, Andrew S; Colzato, Lorenza S; King, Carlye R; Murali, Dhanabalan; Davidson, Richard J

    2012-09-01

    Our outside world changes continuously, for example, when driving through traffic. An important question is how our brain deals with this constant barrage of rapidly changing sensory input and flexibly selects only newly goal-relevant information for further capacity-limited processing in working memory. The challenge our brain faces is experimentally captured by the attentional blink (AB): an impairment in detecting the second of two target stimuli presented in close temporal proximity among distracters. Many theories have been proposed to explain this deficit in processing goal-relevant information, with some attributing the AB to capacity limitations related to encoding of the first target and others assigning a critical role to on-line selection mechanisms that control access to working memory. The current study examined the role of striatal dopamine in the AB, given its known role in regulating the contents of working memory. Specifically, participants performed an AB task and their basal level of dopamine D2-like receptor binding was measured using PET and [F-18]fallypride. As predicted, individual differences analyses showed that greater D2-like receptor binding in the striatum was associated with a larger AB, implicating striatal dopamine and mechanisms that control access to working memory in the AB. Specifically, we propose that striatal dopamine may determine the AB by regulating the threshold for working memory updating, providing a testable physiological basis for this deficit in gating rapidly changing visual information. A challenge for current models of the AB lies in connecting more directly to these neurobiological data. PMID:22663253

  3. Utility of ketone measurement in the prevention, diagnosis and management of diabetic ketoacidosis.

    PubMed

    Misra, S; Oliver, N S

    2015-01-01

    Ketone measurement is advocated for the diagnosis of diabetic ketoacidosis and assessment of its severity. Assessing the evidence base for ketone measurement in clinical practice is challenging because multiple methods are available but there is a lack of consensus about which is preferable. Evaluating the utility of ketone measurement is additionally problematic because of variability in the biochemical definition of ketoacidosis internationally and in the proposed thresholds for ketone measures. This has led to conflicting guidance from expert bodies on how ketone measurement should be used in the management of ketoacidosis. The development of point-of-care devices that can reliably measure the capillary blood ketone β-hydroxybutyrate (BOHB) has widened the spectrum of applications of ketone measurement, but whether the evidence base supporting these applications is robust enough to warrant their incorporation into routine clinical practice remains unclear. The imprecision of capillary blood ketone measures at higher values, the lack of availability of routine laboratory-based assays for BOHB and the continued cost-effectiveness of urine ketone assessment prompt further discussion on the role of capillary blood ketone assessment in ketoacidosis. In the present article, we review the various existing methods of ketone measurement, the precision of capillary blood ketone as compared with other measures, its diagnostic accuracy in predicting ketoacidosis and other clinical applications including prevention, assessment of severity and resolution of ketoacidosis. PMID:25307274

  4. Responsiveness of health status measures and utility-based methods in patients with rheumatoid arthritis.

    PubMed

    Salaffi, F; Stancati, A; Carotti, M

    2002-11-01

    The aim of the study was to compare the responsiveness of disease-specific (Arthritis Impact Measurement Scale 2, AIMS2), generic (Medical Outcome Study Short Form Health Survey, SF-36) and preference-based instruments (rating scale, RS and time tradeoff, TTO) to changes in articular status and perceived health in patients with rheumatoid arthritis (RA). Seventy-eight consecutive patients with RA, attending the care facilities of the Department of Rheumatology of Ancona, were recruited in this longitudinal study. In order to assess the responsiveness three strategies were used: effect size (ES), standardised response mean (SRM) and receiver operating characteristic (ROC). There were 55 women and 23 men with a mean age of 56 years (range 19-78) and arthritis duration of 7.1 years (range 6 months to 24 years). Using three-category EULAR criteria as external indicators of improvement/response, 21 patients (27%) reported a significant improvement, 23 (29.5%) moderate improvement, and 34 (43.5%) no change over the 12-month period. The mean change scores in generic and specific health status instruments and utility measures were significantly related to response category. The AIMS2 subscales (physical function, pain, psychological function and social interaction) were slightly more responsive than those of SF-36. The physical and pain dimensions were most sensitive for measuring change over a 12-month period, followed by psychological and social dimensions. For the utility measurement, RS scores were found to be significantly more responsive in detecting changes in preferences than TTO scores. These results may have implications for the application of the health status and utility measures in clinical trials in patients with RA. PMID:12447631

  5. Utilizing Optical Coherence Tomography in the Nondestructive and Noncontact Measurement of Egg Shell Thickness

    PubMed Central

    2014-01-01

    The goal of this study was to measure the thickness of egg shells without any contact and by utilizing a nondestructive method that sends infrared light beam on the egg. We obtain measurement resolutions on the order of 7 μm up to a penetration depth of 1.7 mm from the actual surface of the egg shell. The measurement results we obtained show that optical coherence tomography can be used to accurately determine the egg shell thickness. Scanning the light beam over the surface allows for measuring the egg profile and monitoring the variations of shell thickness. Since this information gives a quantitative value for the uniformity of the egg shell structure, we anticipate that optical coherence tomography may be used in the quantitative evaluation of egg quality in in-line automated inspection systems. PMID:25133208

  6. A Review of Acculturation Measures and Their Utility in Studies Promoting Latino Health

    PubMed Central

    Wallace, Phyllis M.; Pomery, Elizabeth A.; Latimer, Amy E.; Martinez, Josefa L.; Salovey, Peter

    2010-01-01

    The authors reviewed the acculturation literature with the goal of identifying measures used to assess acculturation in Hispanic populations in the context of studies of health knowledge, attitudes, and behavior change. Twenty-six acculturation measures were identified and summarized. As the Hispanic population continues to grow in the United States, there is a need to develop rigorous acculturation measures that include health indicators. Findings suggest that multidimensional acculturation scales are robust measurement tools when assessing nationality, cultural awareness, media and language preferences, and health status. Furthermore, aspects of Hispanic cultural lifestyle, such as beliefs about nutrition and physical activity, affect health care utilization, treatment, and prevention. Health communication researchers should consider aspects of cultural values and beliefs, and their impact on health status, for future research and health promotion interventions. PMID:20582238

  7. Three-Dimensional Shape Measurement Method for Micro Droplet Utilizing Micro LIF Technique

    NASA Astrophysics Data System (ADS)

    Sugii, Yasuhiko; Horita, Ryo

    This paper describes a novel measurement technique for three-dimensional shape of micro droplet utilizing micro LIF (Laser Induced Fluorescence) technique. A measurement system consisted of microscope equipped with 10x lens, high sensitive CCD camera, mercury lamp, optical filters and so on. Calibration curve between thickness of micro droplet and emission of fluorescence dye solution was obtained by the use of the PDMS (polydimethylsiloxane) microchip, whose depth varied from 10 to 95 μm fabricated using photo lithography technique. The microchip based calibration method provides high measurement accuracy and eliminate photobleaching effect. Measurement accuracy of the present method in depth direction was about 0.57 μm assessed using laser con-focal microscope and the spatial resolution in the horizontal plane became 6.7 μm. The technique is useful to investigate a gas-liquid two-phase flow in micro scale.

  8. Utilization of coincidence criteria in absolute length measurements by optical interferometry in vacuum and air

    NASA Astrophysics Data System (ADS)

    Schödel, R.

    2015-08-01

    Traceability of length measurements to the international system of units (SI) can be realized by using optical interferometry making use of well-known frequencies of monochromatic light sources mentioned in the Mise en Pratique for the realization of the metre. At some national metrology institutes, such as Physikalisch-Technische Bundesanstalt (PTB) in Germany, the absolute length of prismatic bodies (e.g. gauge blocks) is realized by so-called gauge-block interference comparators. At PTB, a number of such imaging phase-stepping interference comparators exist, including specialized vacuum interference comparators, each equipped with three highly stabilized laser light sources. The length of a material measure is expressed as a multiple of each wavelength. The large number of integer interference orders can be extracted by the method of exact fractions in which the coincidence of the lengths resulting from the different wavelengths is utilized as a criterion. The unambiguous extraction of the integer interference orders is an essential prerequisite for correct length measurements. This paper critically discusses coincidence criteria and their validity for three modes of absolute length measurements: 1) measurements under vacuum in which the wavelengths can be identified with the vacuum wavelengths, 2) measurements under air in which the air refractive index is obtained from environmental parameters using an empirical equation, and 3) measurements under air in which the air refractive index is obtained interferometrically by utilizing a vacuum cell placed along the measurement pathway. For case 3), which corresponds to PTB’s Kösters-Comparator for long gauge blocks, the unambiguous determination of integer interference orders related to the air refractive index could be improved by about a factor of ten when an ‘overall dispersion value,’ suggested in this paper, is used as coincidence criterion.

  9. Ultimate Heat Sink Thermal Performance and Water Utilization: Measurements on Cooling and Spray Ponds

    SciTech Connect

    Athey, G. F.; Hadlock, R. K.; Abbey, O. B.

    1982-02-01

    A data acquisition research program, entitled "Ultimate Heat Sink Performance Field Experiments," has been brought to completion. The primary objective is to obtain the requisite data to characterize thermal performance and water utilization for cooling ponds and spray ponds at elevated temperature. Such data are useful for modeling purposes, but the work reported here does not contain modeling efforts within its scope. The water bodies which have been studied are indicative of nuclear reactor ultimate heat sinks, components of emergency core cooling systems. The data reflect thermal performance and water utilization for meteorological and solar influences which are representative of worst-case combinations of conditions. Constructed water retention ponds, provided with absolute seals against seepage, have been chosen as facilities for the measurement programs; the first pond was located at Raft River, Idaho, and the second at East Mesa, California. The data illustrate and describe, for both cooling ponds and spray ponds, thermal performance and water utilization as the ponds cool from an initially elevated temperature. To obtain the initial elevated temperature, it has been convenient to conduct the measurements at geothermal sites having large supplies and delivery rates of hot geothermal fluid. The data are described and discussed in the text, and presented in the form of data volumes as appendices.

  10. Can we understand, control and use the blinking of quantum dots in biological surroundings?

    NASA Astrophysics Data System (ADS)

    Durisic, Nela

    Semiconductor nanocrystals, also known as quantum dots (QDs), are evoking remarkable technological and scientific interest due to their fascinating size-dependent electronic and optical properties. Many biophysical studies to date have used effectively as brighter and more photostable replacement of organic dyes. In this thesis we focus on the most prominent feature of their photophysical properties, a random switching between emitting and non-emitting states, also known as fluorescence intermittency, or "blinking," in order to better understand the mechanism of quantum dot emission and how it reflects interaction with their immediate environment. We first designed and built a total internal reflection florescent microscope (TIRFM) with single molecule detection capabilities and determined optimal conditions for single QD studies. We then used image correlation techniques to show that the change in blinking dynamics could be detected and that it could complicate interpretation of the commonly used analytical techniques that rely on intensity fluctuations as reporters of particle mobility. In particular, we demonstrated that the transport coefficients recovered from fluorescence fluctuation analysis of diffusional mobility using temporal image correlation spectroscopy (TICS) had significant systematic errors due to blinking of the nanoparticles. We then performed a thorough, systematic study of the effects of protons on QDs' photochemical stability by varying the pH of their aqueous environment and related the single particle properties to properties of an ensemble of QDs. As pH was lowered, shorter "on" times and longer "off" times were observed, brightness of single QDs decreased and the number of permanently non-emitting QDs (dark fraction) increased. Based on these results, we proposed a coupled role for H+ ions by which they first reduced the intensity of the emitting state as well as affected probabilities of the QD to switch between the "on" and "off" states

  11. Edge Length and Surface Area of a Blank: Experimental Assessment of Measures, Size Predictions and Utility

    PubMed Central

    Dogandžić, Tamara; Braun, David R.; McPherron, Shannon P.

    2015-01-01

    Blank size and form represent one of the main sources of variation in lithic assemblages. They reflect economic properties of blanks and factors such as efficiency and use life. These properties require reliable measures of size, namely edge length and surface area. These measures, however, are not easily captured with calipers. Most attempts to quantify these features employ estimates; however, the efficacy of these estimations for measuring critical features such as blank surface area and edge length has never been properly evaluated. In addition, these parameters are even more difficult to acquire for retouched implements as their original size and hence indication of their previous utility have been lost. It has been suggested, in controlled experimental conditions, that two platform variables, platform thickness and exterior platform angle, are crucial in determining blank size and shape meaning that knappers can control the interaction between size and efficiency by selecting specific core angles and controlling where fracture is initiated. The robustness of these models has rarely been tested and confirmed in context other than controlled experiments. In this paper, we evaluate which currently employed caliper measurement methods result in the highest accuracy of size estimations of blanks, and we evaluate how platform variables can be used to indirectly infer aspects of size on retouched artifacts. Furthermore, we investigate measures of different platform management strategies that control the shape and size of artifacts. To investigate these questions, we created an experimental lithic assemblage, we digitized images to calculate 2D surface area and edge length, which are used as a point of comparison for the caliper measurements and additional analyses. The analysis of aspects of size determinations and the utility of blanks contributes to our understanding of the technological strategies of prehistoric knappers and what economic decisions they made

  12. Electric Field Measurements of the Capacitively Coupled Magnetized RF Sheath Utilizing Passive Optical Emission Spectroscopy

    NASA Astrophysics Data System (ADS)

    Martin, Elijah Henry

    A major challenge facing magnetic confinement fusion is the implementation of reliable plasma heating systems. Ion cyclotron resonance heating (ICRH) is a key technique utilized to achieve the ion temperatures necessary for desirable fusion reaction rates. ICRH systems are designed to couple energy into the core plasma ions through a resonant interaction with an electromagnetic wave in the radio frequency range. The interaction of the wave with the scrape off layer plasma establishes an electric field which terminates directly on the plasma facing surfaces and is referred to as the near-field. In order to bridge the gap between the theoretical and actual performance of ICRF antennas, experimental measurement of this electric field is highly desired. However, due to the large amount of power launched by ICRF antennas only non-local measurements have thus far been obtained. The research presented in this dissertation is centered on the development of a non-perturbative diagnostic to locally measure the near-field with high spatial and temporal resolution. The main objective of the research presented in this dissertation is to develop and validate a spectroscopic diagnostic capable of measuring local time periodic electric fields. The development phase of the diagnostic consisted of atomic physics formulation and was carried out in two steps. The first involved the calculation of the electronic structure of the one and two-electron atom utilizing the hydrogenic wave function. The second involved the calculation of the spectral line profile based on the electric dipole connection operator. The validate phase of the diagnostic consisted of implementation of the atomic physics to measure the electric field topology associated with the capacitively coupled magnetized RF sheath using passive OES. The experimental measurements are then compared to a simple one-dimensional analytical model providing the validation of the developed atomic physics.

  13. Utility and limitations of measures of health inequities: a theoretical perspective

    PubMed Central

    Alonge, Olakunle; Peters, David H.

    2015-01-01

    Summary box What is already known on this subject? Various measures have been used in quantifying health inequities among populations in recent times; most of these measures were derived to capture the socioeconomic inequalities in health. These different measures do not always lend themselves to common interpretation by policy makers and health managers because they each reflect limited aspects of the concept of health inequities. What does this study add? To inform a more appropriate application of the different measures currently used in quantifying health inequities, this article explicates common theories underlying the definition of health inequities and uses this understanding to show the utility and limitations of these different measures. It also suggests some key features of an ideal indicator based on the conceptual understanding, with the hope of influencing future efforts in developing more robust measures of health inequities. The article also provides a conceptual ‘product label’ for the common measures of health inequities to guide users and ‘consumers’ in making more robust inferences and conclusions. This paper examines common approaches for quantifying health inequities and assesses the extent to which they incorporate key theories necessary for explicating the definition of health inequity. The first theoretical analysis examined the distinction between inter-individual and inter-group health inequalities as measures of health inequities. The second analysis considered the notion of fairness in health inequalities from different philosophical perspectives. To understand the extent to which different measures of health inequities incorporate these theoretical explanations, four criteria were used to assess each measure: 1) Does the indicator demonstrate inter-group or inter-individual health inequalities or both; 2) Does it reflect health inequalities in relation to socioeconomic position; 3) Is it sensitive to the absolute transfer of

  14. About the parametrizations utilized to perform magnetic moments measurements using the transient field technique

    NASA Astrophysics Data System (ADS)

    Gómez, A. M.; Torres, D. A.

    2016-07-01

    The experimental study of nuclear magnetic moments, using the Transient Field technique, makes use of spin-orbit hyperfine interactions to generate strong magnetic fields, above the kilo-Tesla regime, capable to create a precession of the nuclear spin. A theoretical description of such magnetic fields is still under theoretical research, and the use of parametrizations is still a common way to address the lack of theoretical information. In this contribution, a review of the main parametrizations utilized in the measurements of Nuclear Magnetic Moments will be presented, the challenges to create a theoretical description from first principles will be discussed.

  15. Impaired Eye-Blink Conditioning in waggler, a Mutant Mouse With Cerebellar BDNF Deficiency

    PubMed Central

    Bao, Shaowen; Chen, Lu; Qiao, Xiaoxi; Knusel, Beat; Thompson, Richard F.

    1998-01-01

    In addition to their trophic functions, neurotrophins are also implicated in synaptic modulation and learning and memory. Although gene knockout techniques have been used widely in studying the roles of neurotrophins at molecular and cellular levels, behavioral studies using neurotrophin knockouts are limited by the early-onset lethality and various sensory deficits associated with the gene knockout mice. In the present study, we found that in a spontaneous mutant mouse, waggler, the expression of brain-derived neurotrophic factor (BDNF) was selectively absent in the cerebellar granule cells. The cytoarchitecture of the waggler cerebellum appeared to be normal at the light microscope level. The mutant mice exhibited no sensory deficits to auditory stimuli or heat-induced pain. However, they were massively impaired in classic eye-blink conditioning. These results suggest that BDNF may have a role in normal cerebellar neuronal function, which, in turn, is essential for classic eye-blink conditioning. PMID:10454360

  16. Single-molecule redox blinking of perylene diimide derivatives in water.

    PubMed

    Cordes, Thorben; Vogelsang, Jan; Anaya, Milena; Spagnuolo, Carla; Gietl, Andreas; Summerer, Wolfram; Herrmann, Andreas; Müllen, Klaus; Tinnefeld, Philip

    2010-02-24

    Dynamic developments in ultrasensitive and superresolution fluorescence microscopy call for improved fluorescence markers with increased photostability and new functionalities. We used single-molecule spectroscopy to study water-soluble perylene dicarboximide fluorophores (PDI), which were immobilized in aqueous buffer by attaching the fluorophore to DNA. Under these conditions bright fluorescence, comparable to that of single-molecule compatible organic fluorophores, is observed with homogeneous spectral and fluorescence decay time distributions. We additionally show how the fluorescence of the PDI can be controlled through photoinduced electron-transfer reactions by using different concentrations of reductants and oxidants, yielding either blinking or stable emission. We explain these properties by the redox potentials of PDI and the recently introduced ROXS (reducing and oxidizing system) concept. Finally, we evaluate how this fluorescence control of PDIs can be used for superresolution "Blink-Microscopy" in aqueous or organic media and more generally for single-molecule spectroscopy. PMID:20121094

  17. Quantum-confined emission and fluorescence blinking of individual exciton complexes in CdSe nanowires.

    PubMed

    Franz, Dennis; Reich, Aina; Strelow, Christian; Wang, Zhe; Kornowski, Andreas; Kipp, Tobias; Mews, Alf

    2014-11-12

    One-dimensional semiconductor nanostructures combine electron mobility in length direction with the possibility of tailoring the physical properties by confinement effects in radial direction. Here we show that thin CdSe quantum nanowires exhibit low-temperature fluorescence spectra with a specific universal structure of several sharp lines. The structure strongly resembles the pattern of bulk spectra but show a diameter-dependent shift due to confinement effects. Also the fluorescence shows a pronounced complex blinking behavior with very different blinking dynamics of different emission lines in one and the same spectrum. Time- and space-resolved optical spectroscopy are combined with high-resolution transmission electron microscopy of the very same quantum nanowires to establish a detailed structure-property relationship. Extensive numerical simulations strongly suggest that excitonic complexes involving donor and acceptor sites are the origin of the feature-rich spectra. PMID:25343231

  18. Eliminating the Attentional Blink through Binaural Beats: A Case for Tailored Cognitive Enhancement

    PubMed Central

    Reedijk, Susan A.; Bolders, Anne; Colzato, Lorenza S.; Hommel, Bernhard

    2015-01-01

    Enhancing human cognitive performance is a topic that continues to spark scientific interest. Studies into cognitive-enhancement techniques often fail to take inter-individual differences into account, however, which leads to underestimation of the effectiveness of these techniques. The current study investigated the effect of binaural beats, a cognitive-enhancement technique, on attentional control in an attentional blink (AB) task. As predicted from a neurocognitive approach to cognitive control, high-frequency binaural beats eliminated the AB, but only in individuals with low spontaneous eye-blink rates (indicating low striatal dopamine levels). This suggests that the way in which cognitive-enhancement techniques, such as binaural beats, affect cognitive performance depends on inter-individual differences. PMID:26089802

  19. Results from two research projects concerning aversion responses including the blink reflex

    NASA Astrophysics Data System (ADS)

    Reidenbach, Hans-Dieter; Dollinger, Klaus; Hofmann, Joachim

    2005-04-01

    In order to examine the safety philosophy for laser classes 2 and 2M according to the international laser standard IEC 60825-1, which is based on the existence of aversion responses including the blink reflex, two research projects have been funded by the Federal Institute of Occupational Safety and Health (FIOSH) in Germany. In total, 2,250 volunteers have been investigated in the blink-reflex study in various test situations, where a collimated beam, a divergent beam, a scanned laser line or LED irradiation have been used as a bright optical stimulus. The various test situations included, for example, a free laser beam (like that used in the case of laser adjustment), an eye-tracking system, in which visual tasks have been performed, or LEDs used as single elements or in a cluster. 796 volunteers took part in the aversion response study. Concerning the blink reflex, the mean value of the frequency has been estimated to be 18.36 % within a range extending from 13.8 % up to 36.1 % depending on various parameters and applied optical sources. Their respective influences will be explained. Aversion responses, like head and eye movements, have been found to be relatively seldom events, since only 4.65 % of volunteers showed a reaction which belonged to this category of inherent, physiological, protection reactions. The different parameters which are mainly responsible for the respective results concerning the blink reflex and aversion responses will be dealt with and explained, as they have been experimentally achieved up to now.

  20. Multimodality evoked potentials and electrically elicited blink reflex in optic neuritis.

    PubMed

    Tackmann, W; Ettlin, T; Strenge, H

    1982-01-01

    Pattern shift visual evoked potentials, brain stem auditory evoked potentials, spinal and scalp recorded somatosensory evoked potentials, and electrically elicited blink reflexes were investigated in 32 patients with isolated optic neuritis. Eleven patients were shown to have one additional lesion in the central nervous system outside the optic nerve. Therefore, cases with optic neuritis of unknown origin should be considered as possible cases of multiple sclerosis. PMID:6181223

  1. The Effects of Increasing Ocular Surface Stimulation on Blinking and Sensation

    PubMed Central

    Wu, Ziwei; Begley, Carolyn G.; Situ, Ping; Simpson, Trefford

    2014-01-01

    Purpose. The purpose of this study was to determine how increasing ocular surface stimulation affected blinking and sensation, while controlling task concentration. Methods. Ten healthy subjects concentrated on a task while a custom pneumatic device generated air flow toward the central cornea. Six flow rates (FRs) were randomly presented three times each and subjects used visual analog scales to record their sensory responses. The interblink interval (IBI) and the FR were recorded simultaneously and the IBI, sensory response, and corresponding FR were determined for each trial. The FR associated with a statistically significant decrease in IBI, the blink increase threshold (BIT), was calculated for each subject. Results. Both the mean and SD of IBI were decreased with increasing stimulation, from 5.69 ± 3.96 seconds at baseline to 1.02 ± 0.37 seconds at maximum stimulation. The average BIT was 129 ± 20 mL/min flow rate with an IBI of 2.33 ± 1.10 seconds (permutation test, P < 0.001). After log transformation, there was a significant linear function between increasing FR and decreasing IBI within each subject (Pearson's r ≤ −0.859, P < 0.05). The IBI was highly correlated with wateriness, discomfort, and cooling ratings (Pearson's r ≤ −0.606, P < 0.001). Conclusions. There was a dose-response–like relationship between increased surface stimulation and blinking in healthy subjects, presumably for protection of the ocular surface. The blink response was highly correlated with ocular surface sensation, which is not surprising given their common origins. The BIT, a novel metric, may provide an additional end point for studies on dry eye or other conditions. PMID:24557346

  2. Task-Set Reconfiguration Suspends Perceptual Processing: Evidence from Semantic Priming during the Attentional Blink

    ERIC Educational Resources Information Center

    Vachon, Francois; Tremblay, Sebastien; Jones, Dylan M.

    2007-01-01

    When two visual targets, Target 1 (T1) and Target 2 (T2), are presented among a rapid sequence of distractors, processing of T1 produces an attentional blink. Typically, processing of T2 is markedly impaired, except when T1 and T2 are adjacent (Lag 1 sparing). However, if a shift of task set--a change in task requirements from T1 to T2--occurs,…

  3. Disruption reduces accuracy and P3b amplitudes in the attentional blink.

    PubMed

    Pincham, Hannah L; Szücs, Dénes

    2014-10-01

    In everyday life, distracting stimuli often interfere with daily tasks, and disrupt successful task performance. The attentional blink paradigm (a deficit in reporting the second target (T2) in a rapid stream of visual stimuli) allows for an investigation of disruption by rapidly appearing stimuli. Specifically, the magnitude of the attentional blink deficit can be manipulated by positioning relevant stimuli at strategic locations within the visual stream. The current study therefore designed and tested a disruption paradigm that aimed to reduce T2 accuracy using a disruptor stimulus. Electroencephalography was used to reveal the neural correlates of the effect. To that end, targets were defined by task-set colours. The item immediately preceding T2 appeared in a task-set colour (disrupted trials) or a different colour (non-disrupted trials). The results revealed that T2 accuracy was reduced on disrupted trials, and disruption appeared to be worse when T2 appeared inside the attentional blink window. The behavioural data were paralleled by the neural results. On trials where T2 appeared within the AB window and was correctly reported, T2-P3b amplitude (a neural correlate of working memory consolidation) was significantly depressed on disrupted trials compared with non-disrupted trials. Single trial plots of P3b amplitude confirmed a weaker neural trace for T2 on disrupted trials. These data indicate that the magnitude and neural signature of the attentional blink deficit is malleable, and can be influenced by non-target, task-relevant stimuli. PMID:25139528

  4. The attentional blink freezes spatial attention allocation to targets, not distractors: evidence from human electrophysiology.

    PubMed

    Pomerleau, Vincent Jetté; Fortier-Gauthier, Ulysse; Corriveau, Isabelle; McDonald, John J; Dell'Acqua, Roberto; Jolicœur, Pierre

    2014-04-22

    Previous work found a significant reduction of the amplitude of the N2pc ERP component during the attentional blink in response to lateral visual targets, suggesting that the allocation of attention to visual targets is impaired during the attentional blink. Recent theorizing on the processes reflected by the N2pc suggests the possibility of distinct sets of neural mechanisms underlying its generation, one responsible for target activation, and one for distractor inhibition. To disentangle whether either or both of these mechanisms are impaired during the attentional blink, an RSVP sequence of circles, equidistant from fixation was used. The first target frame (T1) contained the same repeated target colour circle and target whereas the second target frame (T2) contained a distractor colour singleton as well as a target colour singleton. Only the target or only the distractor was presented at a lateral position; the other singleton was presented on the vertical midline so as not to elicit any event-related lateralization. Impaired T2 report accuracy at a short stimulus-onset asynchrony (SOA) was accompanied by a significant delay of the N2pc to lateral T2 targets when compared to a long SOA condition. No such delay was found when the lateralized stimulus was a distractor, suggesting that the attentional blink impacts attention allocation to targets, not distractors. We also observed a lateralized component earlier than the N2pc, a posterior contralateral positivity (Ppc) that did not depend on T1-T2 SOA and that was elicited by both lateral targets and distractors. We conclude that, contrary to N2pc, the Ppc likely reflects activity of bottom-up mechanisms responding unselectively to asymmetrical visual displays. PMID:24607298

  5. Utilization of Software Tools for Uncertainty Calculation in Measurement Science Education

    NASA Astrophysics Data System (ADS)

    Zangl, Hubert; Zine-Zine, Mariam; Hoermaier, Klaus

    2015-02-01

    Despite its importance, uncertainty is often neglected by practitioners in the design of system even in safety critical applications. Thus, problems arising from uncertainty may only be identified late in the design process and thus lead to additional costs. Although there exists numerous tools to support uncertainty calculation, reasons for limited usage in early design phases may be low awareness of the existence of the tools and insufficient training in the practical application. We present a teaching philosophy that addresses uncertainty from the very beginning of teaching measurement science, in particular with respect to the utilization of software tools. The developed teaching material is based on the GUM method and makes use of uncertainty toolboxes in the simulation environment. Based on examples in measurement science education we discuss advantages and disadvantages of the proposed teaching philosophy and include feedback from students.

  6. Method and apparatus for measuring gravitational acceleration utilizing a high temperature superconducting bearing

    DOEpatents

    Hull, John R.

    2000-01-01

    Gravitational acceleration is measured in all spatial dimensions with improved sensitivity by utilizing a high temperature superconducting (HTS) gravimeter. The HTS gravimeter is comprised of a permanent magnet suspended in a spaced relationship from a high temperature superconductor, and a cantilever having a mass at its free end is connected to the permanent magnet at its fixed end. The permanent magnet and superconductor combine to form a bearing platform with extremely low frictional losses, and the rotational displacement of the mass is measured to determine gravitational acceleration. Employing a high temperature superconductor component has the significant advantage of having an operating temperature at or below 77K, whereby cooling may be accomplished with liquid nitrogen.

  7. Method and Apparatus for measuring Gravitational Acceleration Utilizing a high Temperature Superconducting Bearing

    SciTech Connect

    Hull, John R.

    1998-11-06

    Gravitational acceleration is measured in all spatial dimensions with improved sensitivity by utilizing a high temperature superconducting (HTS) gravimeter. The HTS gravimeter is comprised of a permanent magnet suspended in a spaced relationship from a high temperature superconductor, and a cantilever having a mass at its free end is connected to the permanent magnet at its fixed end. The permanent magnet and superconductor combine to form a bearing platform with extremely low frictional losses, and the rotational displacement of the mass is measured to determine gravitational acceleration. Employing a high temperature superconductor component has the significant advantage of having an operative temperature at or below 77K, whereby cooling maybe accomplished with liquid nitrogen.

  8. Does Repeated Ticking Maintain Tic Behavior? An Experimental Study of Eye Blinking in Healthy Individuals

    PubMed Central

    Beetsma, Daniel J. V.; van den Hout, Marcel A.; Engelhard, Iris M.; Rijkeboer, Marleen M.; Cath, Danielle C.

    2014-01-01

    Tics in Tourette syndrome (TS) are often preceded by “premonitory urges”: annoying feelings or bodily sensations. We hypothesized that, by reducing annoyance of premonitory urges, tic behaviour may be reinforced. In a 2 × 2 experimental design in healthy participants, we studied the effects of premonitory urges (operationalized as air puffs on the eye) and tic behaviour (deliberate eye blinking after a puff or a sound) on changes in subjective evaluation of air puffs and EMG responses on the m. orbicularis oculi. The experimental group with air puffs + blinking experienced a decrease in subjective annoyance of the air puff, but habituation of the EMG response was blocked and length of EMG response increased. In the control groups (air puffs without instruction to blink, no air puffs), these effects were absent. When extrapolating to the situation in TS patients, these findings suggest that performance of tics is reinforced by reducing the subjective annoyance of premonitory urges, while simultaneously preventing habituation or even inducing sensitisation of the physiological motor response. PMID:24899785

  9. Effects of visual cortex activation on the nociceptive blink reflex in healthy subjects.

    PubMed

    Sava, Simona L; de Pasqua, Victor; Magis, Delphine; Magis, Delphine; Schoenen, Jean; Schoenen, Jean

    2014-01-01

    Bright light can cause excessive visual discomfort, referred to as photophobia. The precise mechanisms linking luminance to the trigeminal nociceptive system supposed to mediate this discomfort are not known. To address this issue in healthy human subjects we modulated differentially visual cortex activity by repetitive transcranial magnetic stimulation (rTMS) or flash light stimulation, and studied the effect on supraorbital pain thresholds and the nociceptive-specific blink reflex (nBR). Low frequency rTMS that inhibits the underlying cortex, significantly decreased pain thresholds, increased the 1st nBR block ipsi- and contralaterally and potentiated habituation contralaterally. After high frequency or sham rTMS over the visual cortex, and rMS over the right greater occipital nerve we found no significant change. By contrast, excitatory flash light stimulation increased pain thresholds, decreased the 1st nBR block of ipsi- and contralaterally and increased habituation contralaterally. Our data demonstrate in healthy subjects a functional relation between the visual cortex and the trigeminal nociceptive system, as assessed by the nociceptive blink reflex. The results argue in favour of a top-down inhibitory pathway from the visual areas to trigemino-cervical nociceptors. We postulate that in normal conditions this visuo-trigeminal inhibitory pathway may avoid disturbance of vision by too frequent blinking and that hypoactivity of the visual cortex for pathological reasons may promote headache and photophobia. PMID:24936654

  10. TRPM8 is a neuronal osmosensor that regulates eye blinking in mice

    PubMed Central

    Quallo, Talisia; Vastani, Nisha; Horridge, Elisabeth; Gentry, Clive; Parra, Andres; Moss, Sian; Viana, Felix; Belmonte, Carlos; Andersson, David A.; Bevan, Stuart

    2015-01-01

    Specific peripheral sensory neurons respond to increases in extracellular osmolality but the mechanism responsible for excitation is unknown. Here we show that small increases in osmolality excite isolated mouse dorsal root ganglion (DRG) and trigeminal ganglion (TG) neurons expressing the cold-sensitive TRPM8 channel (transient receptor potential channel, subfamily M, member 8). Hyperosmotic responses were abolished by TRPM8 antagonists, and were absent in DRG and TG neurons isolated from Trpm8−/− mice. Heterologously expressed TRPM8 was activated by increased osmolality around physiological levels and inhibited by reduced osmolality. Electrophysiological studies in a mouse corneal preparation demonstrated that osmolality regulated the electrical activity of TRPM8-expressing corneal afferent neurons. Finally, the frequency of eye blinks was reduced in Trpm8−/− compared with wild-type mice and topical administration of a TRPM8 antagonist reduced blinking in wild-type mice. Our findings identify TRPM8 as a peripheral osmosensor responsible for the regulation of normal eye-blinking in mice. PMID:25998021

  11. The Effect of Geographic Units of Analysis on Measuring Geographic Variation in Medical Services Utilization

    PubMed Central

    Park, Jong Heon; Hwang, Kyosang; Lee, Taesik

    2016-01-01

    Objectives: We aimed to evaluate the effect of geographic units of analysis on measuring geographic variation in medical services utilization. For this purpose, we compared geographic variations in the rates of eight major procedures in administrative units (districts) and new areal units organized based on the actual health care use of the population in Korea. Methods: To compare geographic variation in geographic units of analysis, we calculated the age–sex standardized rates of eight major procedures (coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, surgery after hip fracture, knee-replacement surgery, caesarean section, hysterectomy, computed tomography scan, and magnetic resonance imaging scan) from the National Health Insurance database in Korea for the 2013 period. Using the coefficient of variation, the extremal quotient, and the systematic component of variation, we measured geographic variation for these eight procedures in districts and new areal units. Results: Compared with districts, new areal units showed a reduction in geographic variation. Extremal quotients and inter-decile ratios for the eight procedures were lower in new areal units. While the coefficient of variation was lower for most procedures in new areal units, the pattern of change of the systematic component of variation between districts and new areal units differed among procedures. Conclusions: Geographic variation in medical service utilization could vary according to the geographic unit of analysis. To determine how geographic characteristics such as population size and number of geographic units affect geographic variation, further studies are needed. PMID:27499165

  12. Measuring and utilizing the hydrogen isotopic composition of deep-sea corals

    NASA Astrophysics Data System (ADS)

    Davin, Samuel; Hillaire-Marcel, Claude; Edinger, Evan; Gelinas, Yves

    2016-04-01

    Despite the widespread use of hydrogen isotopic analysis of bioarchives in paleoenvironmental reconstructions, no previously-published work has yet attempted to measure or utilize the hydrogen isotopic composition (δD) of deep-sea corals. Geographically ubiquitous and with lifespans on the scale of hundreds of years, δD measurements of deep-sea corals have the potential to elucidate physical paleoceanographic parameters at well-resolved spatial and temporal resolutions. We present a method for the determination of annually-resolved δD from deep-sea corals measured from gorgonin, a complex proteinaceous material making up the horny skeleton of gorgonian corals. We address the issue of exchangeable hydrogen in gorgonin by controlling the isotopic composition of exchangeable hydrogen using a heated batch dual-equilibration technique. Coupled with δ15N measurements, we attempt to identify the relationships between trophic feeding levels, physical oceanographic parameters, and the δD of gorgonin from corals collected from chemically distinct ocean basins. Preliminary results from 43 samples indicate reproducible measurements on coral species Primnoa pacifica, Primnoa resedaeformis, and Keratoisis grayii with bulk δD values ranging from -40‰ to -110‰ and bulk δ15N values ranging from +13‰ to +17‰. Final results will include a full suite of non-exchangeable δD values and δ15N of corals from the Labrador Sea and from the Gulf of Alaska.

  13. UTILIZATION OF MULTIPLE MEASUREMENTS FOR GLOBAL THREE-DIMENSIONAL MAGNETOHYDRODYNAMIC SIMULATIONS

    SciTech Connect

    Wang, A. H.; Wu, S. T.; Tandberg-Hanssen, E.; Hill, Frank

    2011-05-01

    Magnetic field measurements, line of sight (LOS) and/or vector magnetograms, have been used in a variety of solar physics studies. Currently, the global transverse velocity measurements near the photosphere from the Global Oscillation Network Group (GONG) are available. We have utilized these multiple observational data, for the first time, to present a data-driven global three-dimensional and resistive magnetohydrodynamic (MHD) simulation, and to investigate the energy transport across the photosphere to the corona. The measurements of the LOS magnetic field and transverse velocity reflect the effects of convective zone dynamics and provide information from the sub-photosphere to the corona. In order to self-consistently include the observables on the lower boundary as the inputs to drive the model, a set of time-dependent boundary conditions is derived by using the method of characteristics. We selected GONG's global transverse velocity measurements of synoptic chart CR2009 near the photosphere and SOLIS full-resolution LOS magnetic field maps of synoptic chart CR2009 on the photosphere to simulate the equilibrium state and compute the energy transport across the photosphere. To show the advantage of using both observed magnetic field and transverse velocity data, we have studied two cases: (1) with the inputs of the LOS magnetic field and transverse velocity measurements, and (2) with the input of the LOS magnetic field and without the input of transverse velocity measurements. For these two cases, the simulation results presented here are a three-dimensional coronal magnetic field configuration, density distributions on the photosphere and at 1.5 solar radii, and the solar wind in the corona. The deduced physical characteristics are the total current helicity and the synthetic emission. By comparing all the physical parameters of case 1 and case 2 and their synthetic emission images with the EIT image, we find that using both the measured magnetic field and the

  14. Evidence evaluation: measure Z corresponds to human utility judgments better than measure L and optimal-experimental-design models.

    PubMed

    Rusconi, Patrice; Marelli, Marco; D'Addario, Marco; Russo, Selena; Cherubini, Paolo

    2014-05-01

    Evidence evaluation is a crucial process in many human activities, spanning from medical diagnosis to impression formation. The present experiments investigated which, if any, normative model best conforms to people's intuition about the value of the obtained evidence. Psychologists, epistemologists, and philosophers of science have proposed several models to account for people's intuition about the utility of the obtained evidence with respect either to a focal hypothesis or to a constellation of hypotheses. We pitted against each other the so-called optimal-experimental-design models (i.e., Bayesian diagnosticity, log₁₀ diagnosticity, information gain, Kullback-Leibler distance, probability gain, and impact) and measures L and Z to compare their ability to describe humans' intuition about the value of the obtained evidence. Participants received words-and-numbers scenarios concerning 2 hypotheses and binary features. They were asked to evaluate the utility of "yes" and "no" answers to questions about some features possessed in different proportions (i.e., the likelihoods) by 2 types of extraterrestrial creatures (corresponding to 2 mutually exclusive and exhaustive hypotheses). Participants evaluated either how an answer was helpful or how an answer decreased/increased their beliefs with respect either to a single hypothesis or to both hypotheses. We fitted mixed-effects models and used the Akaike information criterion and the Bayesian information criterion values to compare the competing models of the value of the obtained evidence. Overall, the experiments showed that measure Z was the best fitting model of participants' judgments of the value of obtained answers. We discussed the implications for the human hypothesis-evaluation process. PMID:24446753

  15. Factors Impacting Student Service Utilization at Ontario Colleges: Key Performance Indicators as a Measure of Success: A Niagara College View

    ERIC Educational Resources Information Center

    Veres, David

    2015-01-01

    Student success in Ontario College is significantly influenced by the utilization of student services. At Niagara College there has been a significant investment in student services as a strategy to support student success. Utilizing existing KPI data, this quantitative research project is aimed at measuring factors that influence both the use of…

  16. A Hardened CARS System Utilized for Temperature Measurements in a Supersonic Combustor

    NASA Technical Reports Server (NTRS)

    Antcliff, Richard R.; Smith, Michael W.; Jarret, Olin, Jr.; Northam, G. Burton; Cutler, Andrew D.; Taylor, David J.

    1990-01-01

    A coherent anti-Stokes Raman scattering (CARS) system has been hardened for use in a NASA Langley supersonic combustion test cell. The system can obtain temperature cross sections of the flow at three locations. The system is environmentally protected and remotely operated. Measurements were made in a scram-jet combustor model consisting of a rear- ward-facing step, followed by an expansion duct. The duct is nominally 4 feet in length. The free stream conditions were Mach 2, with static pressure which ranged from 0.8 to 1.9 atm, and a static temperature of approximately 800K. Three vertical slots were machined into each side of the duct to allow optical access. The CARS system utilized a planar BOXCARS beam arrangement. This arrangement allowed the laser beams to pass through the vertical slots in the tunnel. Translation stages were utilized to move the focussing volume within the tunnel. These stages allowed complete cross sections to be obtained at each slot location. A fiber optic carried the signal to a remotely located monochrometer and reticon detector.Data for two different flow conditions were taken at each of the three slot locations. These two conditions provided a comparison between reacting and non-reacting mixing of injected hydrogen fuel with the combustion heated supersonic stream.

  17. Potential Clinical Utility of Copeptin (C-terminal provasopressin) measurements in clinical medicine.

    PubMed

    Lewandowski, K C; Brabant, G

    2016-03-01

    Copeptin is a 39-amino-acids containing glycosylated peptide derived from the C-terminal part of the arginine vasopressin (AVP) precursor. In the process of proteolysis the AVP precursor is processed to AVP, neurophysin II, and copeptin in equimolar amounts. In contrast to AVP, copeptin remains stable for several days at room temperature in serum or plasma. Hence, copeptin serves as a bona fide biomarker of AVP release. We briefly summarise clinical utility of copeptin in the diagnosis of diabetes insipidus. We also discuss potential applications of copeptin measurements in hyponatraemic states, assessment of an anterior pituitary function, as well as a wide range of several acute and chronic medical conditions, such as myocardial infarction, stroke or diabetes mellitus. PMID:27008633

  18. A hardened CARS system utilized for temperature measurements in a supersonic combustor

    NASA Technical Reports Server (NTRS)

    Antcliff, Richard R.; Smith, Michael W.; Jarrett, Olin, Jr.; Northam, G. Burton; Cutler, Andrew D.

    1991-01-01

    A coherent anti-Stokes Raman scattering (CARS) system has been hardened for utilization in a NASA Langley supersonic combustion test cell that can obtain temperature cross sections of the flow at three locations. This system is remotely operated and environmentally protected. Measurements were obtained in a scramjet combustor model consisting of a rearward-facing step, followed by an expansion duct. The freestream conditions were Mach 2, with static pressure that ranged from 0.8 to 1.9 atm, and a static temperature of about 800 K. Data for two different flow conditions were obtained that provided a comparison between reacting and nonreacting mixing of injected hydrogen fuel with the combustion-heated supersonic stream.

  19. Environmental chamber measurements of mercury flux from coal utilization by-products

    SciTech Connect

    Pekney, N.J.; Martello, D.V.; Schroeder, K.T.; Granite, E.J.

    2009-05-01

    An environmental chamber was constructed to measure the mercury flux from coal utilization by-product (CUB) samples. Samples of fly ash, FGD gypsum, and wallboard made from FGD gypsum were tested under both dark and illuminated conditions with or without the addition of water to the sample. Mercury releases varied widely, with 7-day experiment averages ranging from -6.8 to 73 ng/m2 h for the fly ash samples and -5.2 to 335 ng/m2 h for the FGD/wallboard samples. Initial mercury content, fly ash type, and light exposure had no observable consistent effects on the mercury flux. For the fly ash samples, the effect of a mercury control technology was to decrease the emission. For three of the four pairs of FGD gypsum and wallboard samples, the wallboard sample released less (or absorbed more) mercury than the gypsum.

  20. Environmental chamber measurements of mercury flux from coal utilization by-products

    SciTech Connect

    Pekney, Natalie J.; Martello, Donald; Schroeder, Karl; Granite, Evan

    2009-05-01

    An environmental chamber was constructed to measure the mercury flux from coal utilization by-product (CUB) samples. Samples of fly ash, FGD gypsum, and wallboard made from FGD gypsum were tested under both dark and illuminated conditions with or without the addition of water to the sample. Mercury releases varied widely, with 7- day experiment averages ranging from -6.8 to 73 ng/m(2) h for the fly ash samples and -5.2 to 335 ng/m(2) h for the FGD/wallboard samples. Initial mercury content, fly ash type, and light exposure had no observable consistent effects on the mercury flux. For the fly ash samples, the effect of a mercury control technology was to decrease the emission. For three of the four pairs of FGD gypsum and wallboard samples, the wallboard sample released less (or absorbed more) mercury than the gypsum.

  1. Attofarad resolution capacitance-voltage measurement of nanometer scale field effect transistors utilizing ambient noise.

    PubMed

    Gokirmak, Ali; Inaltekin, Hazer; Tiwari, Sandip

    2009-08-19

    A high resolution capacitance-voltage (C-V) characterization technique, enabling direct measurement of electronic properties at the nanoscale in devices such as nanowire field effect transistors (FETs) through the use of random fluctuations, is described. The minimum noise level required for achieving sub-aF (10(-18) F) resolution, the leveraging of stochastic resonance, and the effect of higher levels of noise are illustrated through simulations. The non-linear DeltaC(gate-source/drain)-V(gate) response of FETs is utilized to determine the inversion layer capacitance (C(inv)) and carrier mobility. The technique is demonstrated by extracting the carrier concentration and effective electron mobility in a nanoscale Si FET with C(inv) = 60 aF. PMID:19636094

  2. Non-blinking (Zn)CuInS/ZnS Quantum Dots Prepared by In Situ Interfacial Alloying Approach

    PubMed Central

    Zhang, Aidi; Dong, Chaoqing; Li, Liang; Yin, Jinjin; Liu, Heng; Huang, Xiangyi; Ren, Jicun

    2015-01-01

    Semiconductor quantum dots (QDs) are very important optical nanomaterials with a wide range of potential applications. However, blinking behavior of single QD is an intrinsic drawback for some biological and photoelectric applications based on single-particle emission. Herein we present a rational strategy for fabrication of non-blinking (Zn)CuInS/ZnS QDs in organic phase through in situ interfacial alloying approach. This new strategy includes three steps: synthesis of CuInS QDs, eliminating the interior traps of QDs by forming graded (Zn)CuInS alloyed QDs, modifying the surface traps of QDs by introducing ZnS shells onto (Zn)CuInS QDs using alkylthiols as sulfur source and surface ligands. The suppressed blinking mechanism was mainly attributed to modifying QDs traps from interior to exterior via a step-by-step modification. Non-blinking QDs show high quantum yield, symmetric emission spectra and excellent crystallinity, and will enable applications from biology to optoelectronics that were previously hindered by blinking behavior of traditional QDs. PMID:26458511

  3. Non-blinking (Zn)CuInS/ZnS Quantum Dots Prepared by In Situ Interfacial Alloying Approach

    NASA Astrophysics Data System (ADS)

    Zhang, Aidi; Dong, Chaoqing; Li, Liang; Yin, Jinjin; Liu, Heng; Huang, Xiangyi; Ren, Jicun

    2015-10-01

    Semiconductor quantum dots (QDs) are very important optical nanomaterials with a wide range of potential applications. However, blinking behavior of single QD is an intrinsic drawback for some biological and photoelectric applications based on single-particle emission. Herein we present a rational strategy for fabrication of non-blinking (Zn)CuInS/ZnS QDs in organic phase through in situ interfacial alloying approach. This new strategy includes three steps: synthesis of CuInS QDs, eliminating the interior traps of QDs by forming graded (Zn)CuInS alloyed QDs, modifying the surface traps of QDs by introducing ZnS shells onto (Zn)CuInS QDs using alkylthiols as sulfur source and surface ligands. The suppressed blinking mechanism was mainly attributed to modifying QDs traps from interior to exterior via a step-by-step modification. Non-blinking QDs show high quantum yield, symmetric emission spectra and excellent crystallinity, and will enable applications from biology to optoelectronics that were previously hindered by blinking behavior of traditional QDs.

  4. The utility of automated measures of ocular metrics for detecting driver drowsiness during extended wakefulness.

    PubMed

    Jackson, Melinda L; Kennedy, Gerard A; Clarke, Catherine; Gullo, Melissa; Swann, Philip; Downey, Luke A; Hayley, Amie C; Pierce, Rob J; Howard, Mark E

    2016-02-01

    Slowed eyelid closure coupled with increased duration and frequency of closure is associated with drowsiness. This study assessed the utility of two devices for automated measurement of slow eyelid closure in a standard poor performance condition (alcohol) and following 12-h sleep deprivation. Twenty-two healthy participants (mean age=20.8 (SD 1.9) years) with no history of sleep disorders participated in the study. Participants underwent one baseline and one counterbalanced session each over two weeks; one 24-hour period of sleep deprivation, and one daytime session during which alcohol was consumed after a normal night of sleep. Participants completed a test battery consisting of a 30-min simulated driving task, a 10-min Psychomotor Vigilance Task (PVT) and the Karolinska Sleepiness Scale (KSS) each in two baseline sessions, and in two randomised, counterbalanced experimental sessions; following sleep deprivation and following alcohol consumption. Eyelid closure was measured during both tasks using two automated devices (Copilot and Optalert™). There was an increase in the proportion of time with eyelids closed and the Johns Drowsiness Score (incorporating relative velocity of eyelid movements) following sleep deprivation using Optalert (p<0.05 for both). These measures correlated significantly with crashes, PVT lapses and subjective sleepiness (r-values 0.46-0.69, p<0.05). No difference between the two sessions for PERCLOS recorded during the PVT or the driving task as measured by the Copilot. The duration of eyelid closure predicted frequent lapses following sleep deprivation (which were equivalent to the average lapses at a blood alcohol concentration of 0.05% - area under curve for ROC curve 0.87, p<0.01). The duration of time with slow eyelid closure, assessed by the automated devices, increased following sleep deprivation and was associated with deterioration in psychomotor performance and subjective sleepiness. Comprehensive algorithms inclusive of

  5. A systematic review of the psychometric properties of self-report research utilization measures used in healthcare

    PubMed Central

    2011-01-01

    Background In healthcare, a gap exists between what is known from research and what is practiced. Understanding this gap depends upon our ability to robustly measure research utilization. Objectives The objectives of this systematic review were: to identify self-report measures of research utilization used in healthcare, and to assess the psychometric properties (acceptability, reliability, and validity) of these measures. Methods We conducted a systematic review of literature reporting use or development of self-report research utilization measures. Our search included: multiple databases, ancestry searches, and a hand search. Acceptability was assessed by examining time to complete the measure and missing data rates. Our approach to reliability and validity assessment followed that outlined in the Standards for Educational and Psychological Testing. Results Of 42,770 titles screened, 97 original studies (108 articles) were included in this review. The 97 studies reported on the use or development of 60 unique self-report research utilization measures. Seven of the measures were assessed in more than one study. Study samples consisted of healthcare providers (92 studies) and healthcare decision makers (5 studies). No studies reported data on acceptability of the measures. Reliability was reported in 32 (33%) of the studies, representing 13 of the 60 measures. Internal consistency (Cronbach's Alpha) reliability was reported in 31 studies; values exceeded 0.70 in 29 studies. Test-retest reliability was reported in 3 studies with Pearson's r coefficients > 0.80. No validity information was reported for 12 of the 60 measures. The remaining 48 measures were classified into a three-level validity hierarchy according to the number of validity sources reported in 50% or more of the studies using the measure. Level one measures (n = 6) reported evidence from any three (out of four possible) Standards validity sources (which, in the case of single item measures, was all

  6. Assessment and Utility of Frailty Measures in Critical Illness, Cardiology, and Cardiac Surgery.

    PubMed

    Rajabali, Naheed; Rolfson, Darryl; Bagshaw, Sean M

    2016-09-01

    Frailty is a clearly emerging theme in acute care medicine, with obvious prognostic and health resource implications. "Frailty" is a term used to describe a multidimensional syndrome of loss of homeostatic reserves that gives rise to a vulnerability to adverse outcomes after relatively minor stressor events. This is conceptually simple, yet there has been little consensus on the operational definition. The gold standard method to diagnose frailty remains a comprehensive geriatric assessment; however, a variety of validated physical performance measures, judgement-based tools, and multidimensional scales are being applied in critical care, cardiology, and cardiac surgery settings, including open cardiac surgery and transcatheter aortic value replacement. Frailty is common among patients admitted to the intensive care unit and correlates with an increased risk for adverse events, increased resource use, and less favourable patient-centred outcomes. Analogous findings have been described across selected acute cardiology and cardiac surgical settings, in particular those that commonly intersect with critical care services. The optimal methods for screening and diagnosing frailty across these settings remains an active area of investigation. Routine assessment for frailty conceivably has numerous purported benefits for patients, families, health care providers, and health administrators through better informed decision-making regarding treatments or goals of care, prognosis for survival, expectations for recovery, risk of complications, and expected resource use. In this review, we discuss the measurement of frailty and its utility in patients with critical illness and in cardiology and cardiac surgery settings. PMID:27476983

  7. Quality of Life, Health Status, and Health Service Utilization Related to a New Measure of Health Literacy FLIGHT/VIDAS

    PubMed Central

    Ownby, Raymond L; Acevedo, Amarilis; Jacobs, Robin J.; Caballero, Joshua; Waldrop-Valverde, Drenna

    2014-01-01

    Objective Researchers have identified significant limitations in some currently-used measures of health literacy. The purpose of this paper is to present data on the relation of health-related quality of life, health status, and health service utilization to performance on a new measure of health literacy in a nonpatient population. Methods The new measure was administered to 475 English- and Spanish-speaking community-dwelling volunteers along with existing measures of health literacy and assessments of health-related quality of life, health status, and healthcare service utilization. Relations among measures were assessed via correlations and health status and utilization was tested across levels of health literacy using ANCOVA models. Results The new health literacy measure is significantly related to existing measures of health literacy as well as to participants’ health-related quality of life. Persons with lower levels of health literacy reported more health conditions, more frequent physical symptoms, and greater healthcare service utilization. Conclusion The new measure of health literacy is valid and shows relations to measures of conceptually-related constructs such as quality of life and health behaviors. Practice Implications: FLIGHT/VIDAS may be useful to researchers and clinicians interested in a computer administered and scored measure of health literacy. PMID:24856447

  8. A framework to utilize turbulent flux measurements for mesoscale models and remote sensing applications

    NASA Astrophysics Data System (ADS)

    Babel, W.; Huneke, S.; Foken, T.

    2011-05-01

    Meteorologically measured fluxes of energy and matter between the surface and the atmosphere originate from a source area of certain extent, located in the upwind sector of the device. The spatial representativeness of such measurements is strongly influenced by the heterogeneity of the landscape. The footprint concept is capable of linking observed data with spatial heterogeneity. This study aims at upscaling eddy covariance derived fluxes to a grid size of 1 km edge length, which is typical for mesoscale models or low resolution remote sensing data. Here an upscaling strategy is presented, utilizing footprint modelling and SVAT modelling as well as observations from a target land-use area. The general idea of this scheme is to model fluxes from adjacent land-use types and combine them with the measured flux data to yield a grid representative flux according to the land-use distribution within the grid cell. The performance of the upscaling routine is evaluated with real datasets, which are considered to be land-use specific fluxes in a grid cell. The measurements above rye and maize fields stem from the LITFASS experiment 2003 in Lindenberg, Germany and the respective modelled timeseries were derived by the SVAT model SEWAB. Contributions from each land-use type to the observations are estimated using a forward lagrangian stochastic model. A representation error is defined as the error in flux estimates made when accepting the measurements unchanged as grid representative flux and ignoring flux contributions from other land-use types within the respective grid cell. Results show that this representation error can be reduced up to 56 % when applying the spatial integration. This shows the potential for further application of this strategy, although the absolute differences between flux observations from rye and maize were so small, that the spatial integration would be rejected in a real situation. Corresponding thresholds for this decision have been estimated as

  9. Delay of the Blink Reflex in Patients Receiving Platinum-Analogue Chemotherapy

    PubMed Central

    Park, Kang Young; Park, Yun Hee; Chang, Hyun Jung; Cho, Eun Sol; Kim, Seok-Hyun; Kim, Woo Jin

    2016-01-01

    Objective To investigate the presence of cranial neuropathy in patients with platinum-analogue chemotherapy using electrodiagnostic evaluations. Methods Thirty-nine patients whose chemotherapy was completed within a month and 40 control subjects were enrolled in the study. Electrodiagnostic evaluation was performed using sensory and motor nerve conduction studies and blink reflex studies, in addition to the two-point discrimination test. Results The chemotherapy group had significantly longer latencies of bilateral R1 responses (left p<0.001; right p<0.001) and greater distance in two-point discrimination (p<0.001) compared to the control group. In the subgroup with peripheral polyneuropathy, the left R1 (p=0.01), both R2i (left p=0.02; right p=0.03) and the left R2c (p=0.02) were prolonged relative to those without the polyneuropathy, and both R1 (left p<0.001; right p<0.001), R2i (left p=0.01; right p=0.03), and the left R2c (p=0.01) were prolonged relative to the controls. On the other hand, the subgroup without the polyneuropathy showed only prolongation of both R1 (left p=0.006; right p<0.001) relative to the controls. Conclusion In the present study, comparison of blink reflex and two-point discrimination showed the likelihood of subclinical cranial neuropathy following platinum-analogue chemotherapy. Cranial neuropathy caused by platinum agents was more profound in patients with peripheral polyneuropathy and may be dependent on the cumulative dose of the drug. The blink reflex may be of value in detecting subclinical cranial neuropathy in patients undergoing platinum-analogue chemotherapy. PMID:26949671

  10. Nitrogen Species in the Post-Pinatubo Stratosphere: Model Analysis Utilizing UARS Measurements

    NASA Technical Reports Server (NTRS)

    Danilin, Michael Y.; Rodriguez, Jose M.; Hu, Wen-Jie; Ko, Malcolm K. W.; Weisenstein, Debra K.; Kumer, John B.; Mergenthaler, John L.; Russel, James M., III; Koike, Makoto; Yue, Glenn K.

    1999-01-01

    We present an analysis of the impact of heterogeneous chemistry on the partitioning of nitrogen species measured by the Upper Atmosphere Research Satellite (UARS) instruments. The UARS measurements utilized include N2O, HNO3, and ClONO2 from the cryogenic limb array etalon spectrometer (CLAES), version 7 (v.7), and temperature, methane, ozone, H2O, HCl, NO and NO2 from the halogen occultation experiment (HALOE), version 18. The analysis is carried out for the UARS data obtained between January 1992 and September 1994 in the 100-to 1-mbar (approx. 17-47 km) altitude range and over 10 degrees latitude bins from 70 S to 70 N. The spatiotemporal evolution of aerosol surface area density (SAD) is adopted from analysis of the Stratospheric Aerosol and Gas Experiment (SAGE) II data. A diurnal steady state photochemical box model, constrained by the temperature, ozone, H2O, CH4, aerosol SAD, and columns of O2 and O3 above the point of interest, has been used as the main tool to analyze these data. Total inorganic nitrogen (NOy) is obtained by three different methods: (1) as a sum of the UARS-measured NO, NO2, HNO3, and ClONO2; (2) from the N2O-NOy correlation, and (3) from the CH4-NOy correlation. To validate our current understanding of stratospheric heterogeneous chemistry for post-Pinatubo conditions, the model-calculated monthly averaged NOx/NOy ratios and the NO, NO2, and HNO3 profiles are compared with the UARS-derived data. In general, the UARS-constrained box model captures the main features of nitrogen species partitioning in the post-Pinatubo years, such as recovery of NOx after the eruption, their seasonal variability and vertical profiles. However, the model underestimates the NO2 content, particularly in the 30- to 7-mbar (approx.23-32 km) range. Comparisons of the calculated temporal behavior of the partial columns of NO2 and HNO3 and ground-based measurements at 45 S and 45 N are also presented. Our analysis indicates that ground-based and HALOE v.18

  11. Nitrogen Species in the Post-Pinatubo Stratosphere: Model Analysis Utilizing UARS Measurements. Appendix F

    NASA Technical Reports Server (NTRS)

    Danilin, Michael Y.; Rodriguez, Jose M.; Hu, Wenjie; Ko, Malcolm K. W.; Weisenstein, Debra K.; Kumer, John B.; Mergenthaler, John L.; Russell, James M., III; Koike, Makoto; Yue, Glenn K.

    1999-01-01

    We present an analysis of the impact of heterogeneous chemistry on the partitioning of nitrogen species measured by the Upper Atmosphere Research Satellite (UARS) instruments. The UARS measurements utilized include N2O, HNO3, and ClONO2 from the cryogenic limb array etalon spectrometer (CLAES), version 7 (v.7), and temperature, methane, ozone, H2O, HCl, NO and NO2 from the halogen occultation experiment (HALOE), version 18. The analysis is carried out for the UARS data obtained between January 1992 and September 1994 in the 100- to 1-mbar (approx. 17-47 km) altitude range and over 10 deg latitude bins from 70 deg S to 70 deg N. The spatiotemporal evolution of aerosol surface area density (SAD) is adopted from analysis of the Stratospheric Aerosol and Gas Experiment (SAGE) II data. A diurnal steady state photochemical box model, constrained by the temperature, ozone, H2O, CH4, aerosol SAD, and columns of O2 and O3 above the point of interest, has been used as the main tool to analyze these data. Total inorganic nitrogen (NOY) is obtained by three different methods: (1) as a sum of the UARS-measured NO, NO2, HNO3, and ClONO2; (2) from the N2O-NOY correlation; and (3) from the CH4-NOY correlation. To validate our current understanding of stratospheric heterogeneous chemistry for post-Pinatubo conditions, the model-calculated monthly averaged NO(x)/NO(y) ratios and the NO, NO2, and HNO3 profiles are compared with the UARS-derived data. In general, the UARS-constrained box model captures the main features of nitrogen species partitioning in the post-Pinatubo years, such as recovery of NO(x) after the eruption, their seasonal variability and vertical profiles. However, the model underestimates the NO2 content, particularly in the 30- to 7-mbar (approx. 23-32 km) range. Comparisons of the calculated temporal behavior of the partial columns of NO2 and HNO3 and ground-based measurements at 45 deg S and 45 deg N are also presented. Our analysis indicates that ground

  12. Nitrogen species in the post-Pinatubo stratosphere: Model analysis utilizing UARS measurements

    NASA Astrophysics Data System (ADS)

    Danilin, Michael Y.; Rodriguez, Jose M.; Hu, Wenjie; Ko, Malcolm K. W.; Weisenstein, Debra K.; Kumer, John B.; Mergenthaler, John L.; Russell, James M.; Koike, Makoto; Yue, Glenn K.; Jones, Nicholas B.; Johnston, Paul V.

    1999-04-01

    We present an analysis of the impact of heterogeneous chemistry on the partitioning of nitrogen species measured by the Upper Atmosphere Research Satellite (UARS) instruments. The UARS measurements utilized include N2O, HNO3, and ClONO2 from the cryogenic limb array etalon spectrometer (CLAES), version 7 (v.7), and temperature, methane, ozone, H2O, HCl, NO and NO2 from the halogen occultation experiment (HALOE), version 18. The analysis is carried out for the UARS data obtained between January 1992 and September 1994 in the 100- to 1-mbar (˜17-47 km) altitude range and over 10° latitude bins from 70°S to 70°N. The spatiotemporal evolution of aerosol surface area density (SAD) is adopted from analysis of the Stratospheric Aerosol and Gas Experiment (SAGE) II data. A diurnal steady state photochemical box model, constrained by the temperature, ozone, H2O, CH4, aerosol SAD, and columns of O2 and O3 above the point of interest, has been used as the main tool to analyze these data. Total inorganic nitrogen (NOy) is obtained by three different methods: (1) as a sum of the UARS-measured NO, NO2, HNO3, and ClONO2; (2) from the N2O-NOy correlation, and (3) from the CH4-NOy correlation. To validate our current understanding of stratospheric heterogeneous chemistry for post-Pinatubo conditions, the model-calculated monthly averaged NOx/NOy ratios and the NO, NO2, and HNO3 profiles are compared with the UARS-derived data. In general, the UARS-constrained box model captures the main features of nitrogen species partitioning in the post-Pinatubo years, such as recovery of NOx after the eruption, their seasonal variability and vertical profiles. However, the model underestimates the NO2 content, particularly in the 30- to 7-mbar (˜23-32 km) range. Comparisons of the calculated temporal behavior of the partial columns of NO2 and HNO3 and ground-based measurements at 45°S and 45°N are also presented. Our analysis indicates that ground-based and HALOE v. 18 measurements of

  13. Nitrogen Species in the Post-Pinatubo Stratosphere: Model Analysis Utilizing UARS Measurements

    NASA Technical Reports Server (NTRS)

    Danilin, M. Y.; Rodriquez, J. M.; Hu, W.; Ko, M. K. W.; Weisenstein, D. K.; Mergenthaler, J. L.; Russell, J. M., III; Koike, M.; Yue, G. K.

    1998-01-01

    We present an analysis of the impact of heterogeneous chemistry on the partitioning of nitrogen species measured by the Upper Atmosphere Research Satellite (UARS) instruments. The UARS measurements utilized include: N2O, HNO3 and ClONO2 (Cryogen Limb Array Etalon Spectrometer (CLAES), version 7), temperature, methane, ozone, H2O, HCl, NO and NO2 (HALogen Occultation Experiment (HALOE), version 18). The analysis is carried out for the data from January 1992 to September 1994 in the 100-1 mbar (approx.17-47 km) altitude range and over 10 degree latitude bins from 70degS to 70degN. Temporal-spatial evolution of aerosol surface area density (SAD) is adopted according to the Stratospheric Aerosol and Gas Experiment (SAGE) 11 data. A diurnal steady-state photochemical box model, constrained by the temperature, ozone, H2O, CH4, aerosol SAD and columns of O2 and O3 above the point of interest, has been used as the main tool to analyze these data. Total inorganic nitrogen (NO(y)) is obtained by three different methods: (1) as a sum of the UARS measured NO, NO2, HNO3, and ClONO2; (2) from the N2O-NO(y) correlation, and (3) from the CH4-NO(y) correlation. To validate our current understanding of stratospheric heterogeneous chemistry for post-Pinatubo conditions, the model-calculated NO(x)/NO(y) ratios and the NO, NO2, and HNO3 profiles are compared to the UARS-derived data. In general, the UARS-constrained box model captures the main features of nitrogen species partitioning in the post-Pinatubo years. However, the model underestimates the NO2 content, particularly, in the 30-7 mbar (approx. 23-32 km) range. Comparisons of the calculated temporal behavior of the partial columns of NO2 and HNO3 and ground based measurements at 45degS and 45degN are also presented. Our analysis indicates that ground-based and HALOE v. 18 measurements of the NO2 vertical columns are consistent within the range of their uncertainties and are systematically higher (up to 50%) than the model

  14. Nitrogen Species in the Post-Pinatubo Stratosphere: Model Analysis Utilizing UARS Measurements

    NASA Technical Reports Server (NTRS)

    Danilin, M. Y.; Rodriguez, J. M.; Hu, W.; Ko, M. K. W.; Weisenstein, D. K.; Kumer, J. B.; Mergenthaler, J. L.; Russell, J. M., III; Koike, M.; Yue, G. K.

    1998-01-01

    We present an analysis of the impact of heterogeneous chemistry on the partitioning of nitrogen species measured by the Upper Atmosphere Research Satellite (UARS) instruments. The UARS measurements utilized include: N2O, HNO3 and ClONO2 (Cryogen Limb Array Etalon Spectrometer (CLAES), version 7), temperature, methane, ozone, H2O, HCI, NO and NO2 (HALogen Occultation Experiment (HALOE), version 18). The analysis is carried out for the data from January 1992 to September 1994 in the 100-1 mbar (approximately 17-47 km) altitude range and over 10 degree latitude bins from 70 deg S to 70 deg N. Temporal-spatial evolution of aerosol surface area density (SAD) is adopted according to the Stratospheric Aerosol and Gas Experiment (SAGE) II data. A diurnal steady-state photochemical box model, constrained by the temperature, ozone, H2O, CH4, aerosol SAD and columns of O2 and O3 above the point of interest, has been used as the main tool to analyze these data. Total inorganic nitrogen (NOy) is obtained by three different methods: (1) as a sum of the UARS measured NO, NO2, HNO3, and CIONO2; (2) from the N2O-NOy correlation, (3) from the CH4-NOy correlation. To validate our current understanding of stratospheric heterogeneous chemistry for post-Pinatubo conditions, the model-calculated NOx/NOy ratios and the NO, NO2, and HNO3 profiles are compared to the UARS-derived data. In general, the UARS-constrained box model captures the main features of nitrogen species partitioning in the post-Pinatubo years. However, the model underestimates the NO2 content, particularly, in the 30-7 mbar (approximately 23-32 km) range. Comparisons of the calculated temporal behavior of the partial columns of NO2 and HNO3 and ground based measurements at 45 deg S and 45 deg N are also presented. Our analysis indicates that ground-based and HALOE v.18 measurements of the NO2 vertical columns are consistent within the range of their uncertainties and are systematically higher (up to 50%) than the model

  15. Light-assisted non-Poissonian fluorescence blinking from bosonic composite reservoirs

    SciTech Connect

    Budini, Adrian A.

    2007-08-15

    Single fluorophore systems attached to complex hosting molecules may exhibit a light-assisted fluorescence blinking phenomenon between two or more different intensity states whose sojourn statistic depends on the pumping laser intensity and also may depart from an exponential law. In contrast with standard phenomenological models, here we demonstrate that such kind of radiation patterns can be microscopically derived and characterized by describing the fluorophore decay through a composite reservoir where quantum degrees of freedom associated to the host molecule mediate the interaction between the fluorophore and a bosonic bath associated to its natural decay.

  16. Central cross-modal stochastic resonance in human tactile blink reflex

    NASA Astrophysics Data System (ADS)

    Yasuda, Hideaki; Miyaoka, Tsuyoshi; Horiguchi, Jun; Yamamoto, Yoshiharu

    2007-07-01

    We study cross-modal stochastic resonance in the human brain. The neural circuit in the brainstem for integration of both the auditory afferent pathway used to apply background noise and the tactile sensory pathway used to apply a signal is well known, so we expect a direct integration of signal and noise in this distinct circuit of the brain. Our results indeed confirm an optimization of response probabilities of tactile blink reflex by auditory noise, suggesting the direct involvement of background noise in the cross-modal sensory integration.

  17. Oral Administration of Royal Jelly Restores Tear Secretion Capacity in Rat Blink-Suppressed Dry Eye Model by Modulating Lacrimal Gland Function

    PubMed Central

    Imada, Toshihiro; Nakamura, Shigeru; Kitamura, Naoki; Shibuya, Izumi; Tsubota, Kazuo

    2014-01-01

    Tears are secreted from the lacrimal gland (LG), a dysfunction in which induces dry eye, resulting in ocular discomfort and visual impairment. Honey bee products are used as a nutritional source in daily life and medicine; however, little is known about their effects on dry eye. The aim of the present study was to investigate the effects of honey bee products on tear secretion capacity in dry eye. We selected raw honey, propolis, royal jelly (RJ), pollen, or larva from commercially available honey bee products. Tear secretion capacity was evaluated following the oral administration of each honey bee product in a rat blink-suppressed dry eye model. Changes in tear secretion, LG ATP content, and LG mitochondrial levels were measured. RJ restored the tear secretion capacity and decrease in LG ATP content and mitochondrial levels to the largest extent. Royal jelly can be used as a preventative intervention for dry eye by managing tear secretion capacity in the LG. PMID:25243778

  18. Methods for measuring utilization of mental health services in two epidemiologic studies

    PubMed Central

    NOVINS, DOUGLAS K.; BEALS, JANETTE; CROY, CALVIN; MANSON, SPERO M.

    2015-01-01

    Objectives of Study Psychiatric epidemiologic studies often include two or more sets of questions regarding service utilization, but the agreement across these different questions and the factors associated with their endorsement have not been examined. The objectives of this study were to describe the agreement of different sets of mental health service utilization questions that were included in the American Indian Service Utilization Psychiatric Epidemiology Risk and Protective Factors Project (AI-SUPERPFP), and compare the results to similar questions included in the baseline National Comorbidity Survey (NCS). Methods Responses to service utilization questions by 2878 AI-SUPERPFP and 5877 NCS participants were examined by calculating estimates of service use and agreement (κ) across the different sets of questions. Logistic regression models were developed to identify factors associated with endorsement of specific sets of questions. Results In both studies, estimates of mental health service utilization varied across the different sets of questions. Agreement across the different question sets was marginal to good (κ = 0.27–0.69). Characteristics of identified service users varied across the question sets. Limitations Neither survey included data to examine the validity of participant responses to service utilization questions. Recommendations for Further Research Question wording and placement appear to impact estimates of service utilization in psychiatric epidemiologic studies. Given the importance of these estimates for policy-making, further research into the validity of survey responses as well as impacts of question wording and context on rates of service utilization is warranted. PMID:18767205

  19. Comparison and Relative Utility of Inequality Measurements: As Applied to Scotland’s Child Dental Health

    PubMed Central

    Blair, Yvonne I.; McMahon, Alex D.; Macpherson, Lorna M. D.

    2013-01-01

    This study compared and assessed the utility of tests of inequality on a series of very large population caries datasets. National cross-sectional caries datasets for Scotland’s 5-year-olds in 1993/94 (n = 5,078); 1995/96 (n = 6,240); 1997/98 (n = 6,584); 1999/00 (n = 6,781); 2002/03 (n = 9,747); 2003/04 (n = 10,956); 2005/06 (n = 10,945) and 2007/08 (n = 12,067) were obtained. Outcomes were based on the d3mft metric (i.e. the number of decayed, missing and filled teeth). An area-based deprivation category (DepCat) measured the subjects’ socioeconomic status (SES). Simple absolute and relative inequality, Odds Ratios and the Significant Caries Index (SIC) as advocated by the World Health Organization were calculated. The measures of complex inequality applied to data were: the Slope Index of Inequality (absolute) and a variety of relative inequality tests i.e. Gini coefficient; Relative Index of Inequality; concentration curve; Koolman & Doorslaer’s transformed Concentration Index; Receiver Operator Curve and Population Attributable Risk (PAR). Additional tests used were plots of SIC deciles (SIC10) and a Scottish Caries Inequality Metric (SCIM10). Over the period, mean d3mft improved from 3.1(95%CI 3.0–3.2) to 1.9(95%CI 1.8–1.9) and d3mft = 0% from 41.1(95%CI 39.8–42.3) to 58.3(95%CI 57.8–59.7). Absolute simple and complex inequality decreased. Relative simple and complex inequality remained comparatively stable. Our results support the use of the SII and RII to measure complex absolute and relative SES inequalities alongside additional tests of complex relative inequality such as PAR and Koolman and Doorslaer’s transformed CI. The latter two have clear interpretations which may influence policy makers. Specialised dental metrics (i.e. SIC, SIC10 and SCIM10) permit the exploration of other important inequalities not determined by SES, and could be applied to many other types of disease where ranking of morbidity

  20. Viscoelastic models of tear film drainage after a blink

    NASA Astrophysics Data System (ADS)

    Braun, R. J.; Cook, L. P.

    2004-11-01

    Tiffany (Intl. Opthalmol. 15, (1991) 371-376) measured the viscosity of human tear fluid and found that the Cross equation can describe the shear thinning behavior of the tear film; the model predicts a -2/3 power for the decrease in viscosity with shear rate. We fit that data with FENE-P and Giesekus fluid models which incorporate shear thinning and elasticity. We apply lubrication theory to the drainage of the tear film for these fluids. The results show that localized thinning near the meniscus is exaggerated compared to a relative lack of motion in the interior of the film, when the Newtonian case is used as a reference. Extension to models including film formation and drainage will be discussed.

  1. Eye complaints in the office environment: precorneal tear film integrity influenced by eye blinking efficiency.

    PubMed

    Wolkoff, P; Nøjgaard, J K; Troiano, P; Piccoli, B

    2005-01-01

    To achieve a common base for understanding work related eye complaints in the office environment, it is necessary to merge approaches from indoor air science, occupational health, and ophthalmology. Based on database searches, it is concluded that precorneal tear film (PTF) alteration leads to eye complaints that may be caused by: (1) thermal factors (low relative humidity; high room temperature); (2) demanding task content (attention decreases blinking and widens the exposed ocular surface area); and (3) individual characteristics (for example, tear film alterations, blinking anomalies, gland dysfunctions, and use of contact lenses). These factors and conditions are able to progressively increase water evaporation and faster thinning of the PTF, which causes dryness and dry spot formation on the cornea, possibly followed by corneal and conjunctiva epithelial alterations and eye complaints. Another possible cause of eye complaints is certain irritating chemical compounds, in addition to oxidation mixtures that are formed in reactions between ozone and unsaturated organic compounds (alkenes). The effect may be exacerbated by low relative humidity. PMID:15613602

  2. Climbing Fiber Regulation of Spontaneous Purkinje Cell Activity and Cerebellum-Dependent Blink Responses123

    PubMed Central

    Bengtsson, Fredrik

    2016-01-01

    Abstract It has been known for a long time that GABAergic Purkinje cells in the cerebellar cortex, as well as their target neurons in the cerebellar nuclei, are spontaneously active. The cerebellar output will, therefore, depend on how input is integrated into this spontaneous activity. It has been shown that input from climbing fibers originating in the inferior olive controls the spontaneous activity in Purkinje cells. While blocking climbing fiber input to the Purkinje cells causes a dramatic increase in the firing rate, increased climbing fiber activity results in reduced Purkinje cell activity. However, the exact calibration of this regulation has not been examined systematically. Here we examine the relation between climbing fiber stimulation frequency and Purkinje cell activity in unanesthetized decerebrated ferrets. The results revealed a gradual suppression of Purkinje cell activity, starting at climbing fiber stimulation frequencies as low as 0.5 Hz. At 4 Hz, Purkinje cells were completely silenced. This effect lasted an average of 2 min after the stimulation rate was reduced to a lower level. We also examined the effect of sustained climbing fiber stimulation on overt behavior. Specifically, we analyzed conditioned blink responses, which are known to be dependent on the cerebellum, while stimulating the climbing fibers at different frequencies. In accordance with the neurophysiological data, the conditioned blink responses were suppressed at stimulation frequencies of ≥4 Hz. PMID:26839917

  3. Examination of in vivo tear film stability after eye blink and eye drying

    NASA Astrophysics Data System (ADS)

    Szczesna, Dorota H.; Kulas, Zbigniew; Kasprzak, Henryk T.; Stenevi, Ulf

    2007-07-01

    The purpose of this study is to investigate the kinetics of precorneal tear film stabilization process after eye blink and the process of creating the break-up of the tear film layer. The tear film of patients were examined in vivo by used the lateral shearing interferometer. The information about the distribution and stability of the tear film over the cornea is carried by the wave front reflected from the surface of tears and coded in interference fringes. Smooth and regular fringes indicate the smooth surface of tears over the cornea. Immediately after eye blink the interference fringes are observed on background of bright and dark areas. The contrast of this structure fades with time slowly and after 1-3 sec the background of interference fringes becomes uniform. The vertical orientation and instability of this structure suggests connection with eyelid movement and the spread of tears. If the eye is kept open for a long time, bright lines appear in the background of fringes after a dozen seconds. The slowly appearing structure might signify the tear film break-up. In case of eyes after a LASIK surgery the shape of the background structure has different nature and might be stable in time suggesting the stability of the corneal surface irregularities.

  4. Charge Blinking Statistics of Semiconductor Nanocrystals Revealed by Carbon Nanotube Single Charge Sensors.

    PubMed

    Zbydniewska, Ewa; Duzynska, Anna; Popoff, Michka; Hourlier, Djamila; Lenfant, Stéphane; Judek, Jaroslaw; Zdrojek, Mariusz; Mélin, Thierry

    2015-10-14

    We demonstrate the relation between the optical blinking of colloidal semiconductor nanocrystals (NCs) and their electrical charge blinking for which we provide the first experimental observation of power-law statistics. To show this, we harness the performance of CdSe/ZnS NCs coupled with carbon nanotube field-effect transistors (CNTFETs), which act as single charge-sensitive electrometers with submillisecond time resolution, at room temperature. A random telegraph signal (RTS) associated with the NC single-trap charging is observed and exhibits power-law temporal statistics (τ(-α), with α in the range of ∼1-3), and a Lorentzian current noise power spectrum with a well-defined 1/f(2) corner. The spectroscopic analysis of the NC-CNTFET devices is consistent with the charging of NC defect states with a charging energy of Ec ≥ 200 meV. These results pave the way for a deeper understanding of the physics and technology of nanocrystal-based optoelectronic devices. PMID:26418364

  5. Eye-Blink Conditioning Deficits Indicate Temporal Processing Abnormalities in Schizophrenia

    PubMed Central

    Bolbecker, Amanda R.; Mehta, Crystal; Edwards, Chad R.; Steinmetz, Joseph E.; O’Donnell, Brian F.; Hetrick, William P.

    2009-01-01

    Theoretical models suggest that symptoms of schizophrenia may be due to a dysfunctional modulatory system associated with the cerebellum. Although it has long been known that the cerebellum plays a critical role in associative learning and motor timing, recent evidence suggests that it also plays a role in nonmotor psychological processes. Indeed, cerebellar anomalies in schizophrenia have been linked to cognitive dysfunction and poor long-term outcome. To test the hypothesis that schizophrenia is associated with cerebellar dysfunction, cerebellar-dependent, delay eye-blink conditioning was examined in 62 individuals with schizophrenia and 62 age-matched non-psychiatric comparison subjects. The conditioned stimulus was a 400 ms tone, which co-terminated with a 50 ms unconditioned stimulus air puff. A subset of participants (25 with schizophrenia and 29 controls) also completed the Wechsler Abbreviated Scale of Intelligence. Participants with schizophrenia exhibited lower rates of eye-blink conditioning, including earlier (less adaptively timed) conditioned response latencies. Cognitive functioning was correlated with the rate of conditioned responsing in the non-psychiatric comparison subjects but not among those with schizophrenia, and the magnitude of these correlations significantly differed between groups. These findings are consistent with models of schizophrenia in which disruptions within the cortico-cerebellar-thalamic-cortical (CCTC) brain circuit are postulated to underlie the cognitive fragmentation that characterizes the disorder. PMID:19351577

  6. Brief Report: Attenuated Emotional Suppression of the Attentional Blink in Autism Spectrum Disorder--Another Non-Social Abnormality?

    ERIC Educational Resources Information Center

    Gaigg, Sebastian B.; Bowler, Dermot M.

    2009-01-01

    Twenty-five individuals with Autism Spectrum Disorder and 25 typically developed individuals participated in an Attentional Blink paradigm to determine whether emotional words would capture attention similarly in the two groups. Whilst the emotionality of words facilitated attention in typical comparison participants, this effect was attenuated in…

  7. Influence of the Inner-Shell Architecture on Quantum Yield and Blinking Dynamics in Core/Multishell Quantum Dots.

    PubMed

    Bajwa, Pooja; Gao, Feng; Nguyen, Anh; Omogo, Benard; Heyes, Colin D

    2016-03-01

    Choosing the composition of a shell for QDs is not trivial, as both the band-edge energy offset and interfacial lattice mismatch influence the final optical properties. One way to balance these competing effects is by forming multishells and/or gradient-alloy shells. However, this introduces multiple interfaces, and their relative effects on quantum yield and blinking are not yet fully understood. Here, we undertake a systematic, comparative study of the addition of inner shells of a single component versus gradient-alloy shells of cadmium/zinc chalogenides onto CdSe cores, and then capping with a thin ZnS outer shell to form various core/multishell configurations. We show that architecture of the inner shell between the CdSe core and the outer ZnS shell significantly influences both the quantum yield and blinking dynamics, but that these effects are not correlated-a high ensemble quantum yield doesn't necessarily equate to reduced blinking. Two mathematical models have been proposed to describe the blinking dynamics-the more common power-law model and a more recent multiexponential model. By binning the same data with 1 and 20 ms resolution, we show that the on times can be better described by the multiexponential model, whereas the off times can be better described by the power-law model. We discuss physical mechanisms that might explain this behavior and how it can be affected by the inner-shell architecture. PMID:26693950

  8. Super-Resolution Imaging of C-Type Lectin and Influenza Hemagglutinin Nanodomains on Plasma Membranes Using Blink Microscopy

    PubMed Central

    Itano, Michelle S.; Steinhauer, Christian; Schmied, Jürgen J.; Forthmann, Carsten; Liu, Ping; Neumann, Aaron K.; Thompson, Nancy L.; Tinnefeld, Philip; Jacobson, Ken

    2012-01-01

    Dendritic cells express DC-SIGN, a C-type lectin (CTL) that binds a variety of pathogens and facilitates their uptake for subsequent antigen presentation. DC-SIGN forms remarkably stable microdomains on the plasma membrane. However, inner leaflet lipid markers are able to diffuse through these microdomains suggesting that, rather than being densely packed with DC-SIGN proteins, an elemental substructure exists. Therefore, a super-resolution imaging technique, Blink Microscopy (Blink), was applied to further investigate the lateral distribution of DC-SIGN. Blink indicates that DC-SIGN, another CTL (CD206), and influenza hemagglutinin (HA) are all localized in small (∼80 nm in diameter) nanodomains. DC-SIGN and CD206 nanodomains are randomly distributed on the plasma membrane, whereas HA nanodomains cluster on length scales up to several microns. We estimate, as a lower limit, that DC-SIGN and HA nanodomains contain on average two tetramers or two trimers, respectively, whereas CD206 is often nonoligomerized. Two-color Blink determined that different CTLs rarely occupy the same nanodomain, although they appear colocalized using wide-field microscopy. What to our knowledge is a novel domain structure emerges in which elemental nanodomains, potentially capable of binding viruses, are organized in a random fashion; evidently, these nanodomains can be clustered into larger microdomains that act as receptor platforms for larger pathogens like yeasts. PMID:22500753

  9. On the Labile Memory Buffer in the Attentional Blink: Masking the T2 Representation by Onset Transients Mediates the AB

    ERIC Educational Resources Information Center

    Jannati, Ali; Spalek, Thomas M.; Di Lollo, Vincent

    2011-01-01

    Report of a second target (T2) is impaired when presented within 500 ms of the first (T1). This attentional blink (AB) is known to cause a delay in T2 processing during which T2 must be stored in a labile memory buffer. We explored the buffer's characteristics using different types of masks after T2. These characteristics were inferred by…

  10. USING RESPIROMETRY TO MEASURE HYDROGEN UTILIZATION IN SULFATE REDUCING BACTERIA IN THE PRESENCE OF COPPER AND ZINC

    EPA Science Inventory

    A respirometric method has been developed to measure hydrogen utilization by sulfate reducing bacteria (SRB). One application of this method has been to test inhibitory metals effects on the SRB culture used in a novel acid mine drainage treatment technology. As a control param...

  11. Utilization Measurement: Focusing on the "U" in "D & U." Special Report.

    ERIC Educational Resources Information Center

    Southwest Educational Development Lab., Austin, TX.

    One of a series of booklets on disability research, this paper is intended as an introduction to the role of evaluation in the utilization process. Its purpose is to help disability researchers grasp the importance of incorporating a focus on assessing use into plans for disseminating research outcomes. The paper begins by examining basic…

  12. The attentional blink is related to phonemic decoding, but not sight-word recognition, in typically reading adults.

    PubMed

    Tyson-Parry, Maree M; Sailah, Jessica; Boyes, Mark E; Badcock, Nicholas A

    2015-10-01

    This research investigated the relationship between the attentional blink (AB) and reading in typical adults. The AB is a deficit in the processing of the second of two rapidly presented targets when it occurs in close temporal proximity to the first target. Specifically, this experiment examined whether the AB was related to both phonological and sight-word reading abilities, and whether the relationship was mediated by accuracy on a single-target rapid serial visual processing task (single-target accuracy). Undergraduate university students completed a battery of tests measuring reading ability, non-verbal intelligence, and rapid automatised naming, in addition to rapid serial visual presentation tasks in which they were required to identify either two (AB task) or one (single target task) target/s (outlined shapes: circle, square, diamond, cross, and triangle) in a stream of random-dot distractors. The duration of the AB was related to phonological reading (n=41, β=-0.43): participants who exhibited longer ABs had poorer phonemic decoding skills. The AB was not related to sight-word reading. Single-target accuracy did not mediate the relationship between the AB and reading, but was significantly related to AB depth (non-linear fit, R(2)=.50): depth reflects the maximal cost in T2 reporting accuracy in the AB. The differential relationship between the AB and phonological versus sight-word reading implicates common resources used for phonemic decoding and target consolidation, which may be involved in cognitive control. The relationship between single-target accuracy and the AB is discussed in terms of cognitive preparation. PMID:26277018

  13. Charge-tunnelling and self-trapping: common origins for blinking, grey-state emission and photoluminescence enhancement in semiconductor quantum dots

    NASA Astrophysics Data System (ADS)

    Osborne, M. A.; Fisher, A. A. E.

    2016-04-01

    Understanding instabilities in the photoluminescence (PL) from light emitting materials is crucial to optimizing their performance for different applications. Semiconductor quantum dots (QDs) offer bright, size tunable emission, properties that are now being exploited in a broad range of developing technologies from displays and solar cells to biomaging and optical storage. However, instabilities such as photoluminescence intermittency, enhancement and bleaching of emission in these materials can be detrimental to their utility. Here, we report dielectric dependent blinking, intensity-``spikes'' and low-level, ``grey''-state emission, as well as PL enhancement in ZnS capped CdSe QDs; observations that we found consistent with a charge-tunnelling and self-trapping (CTST) description of exciton-dynamics on the QD-host system. In particular, modulation of PL in grey-states and PL enhancement are found to have a common origin in the equilibrium between exciton charge carrier core and surface-states within the CTST framework. Parameterized in terms of size and electrostatic properties of the QD and its nanoenvironment, the CTST offers predictive insight into exciton-dynamics in these nanomaterials.Understanding instabilities in the photoluminescence (PL) from light emitting materials is crucial to optimizing their performance for different applications. Semiconductor quantum dots (QDs) offer bright, size tunable emission, properties that are now being exploited in a broad range of developing technologies from displays and solar cells to biomaging and optical storage. However, instabilities such as photoluminescence intermittency, enhancement and bleaching of emission in these materials can be detrimental to their utility. Here, we report dielectric dependent blinking, intensity-``spikes'' and low-level, ``grey''-state emission, as well as PL enhancement in ZnS capped CdSe QDs; observations that we found consistent with a charge-tunnelling and self-trapping (CTST

  14. Odors enhance the salience of matching images during the attentional blink

    PubMed Central

    Robinson, Amanda K.; Mattingley, Jason B.; Reinhard, Judith

    2013-01-01

    As any food critic knows, the visual presentation of a dish can enhance its aroma. Is the reverse also true? Here we investigated whether odors can enhance the salience of familiar visual objects at the limits of perceptual discrimination, using rapid serial visual presentations (RSVP) to induce an attentional blink (AB). We had participants view RSVP streams containing photographs of odor-related objects (lemon, orange, rose, and mint) amongst non-odor related distractors. In each trial, participants inhaled a single odor, which either matched the odor-related target within the stream (congruent trials), did not match the odor-related target (incongruent trials), or was irrelevant with respect to the target. Congruent odors significantly attenuated the AB for odor-related visual targets, compared with incongruent and irrelevant odors. The findings suggest that familiar odors can render matching visual objects more salient, thereby enhancing their competitive strength at the limits of temporal attention. PMID:24223539

  15. Attentional blink magnitude is predicted by the ability to keep irrelevant material out of working memory.

    PubMed

    Arnell, Karen M; Stubitz, Shawn M

    2010-09-01

    Participants have difficulty in reporting the second of two masked targets if the second target is presented within 500 ms of the first target-an attentional blink (AB). Individual participants differ in the magnitude of their AB. The present study employed an individual differences design and two visual working memory tasks to examine whether visual working memory capacity and/or the ability to exclude irrelevant information from visual working memory (working memory filtering efficiency) could predict individual differences in the AB. Visual working memory capacity was positively related to filtering efficiency, but did not predict AB magnitude. However, the degree to which irrelevant stimuli were admitted into visual working memory (i.e., poor filtering efficiency) was positively correlated with AB magnitude over and above visual working memory capacity. Good filtering efficiency may benefit the AB by not allowing irrelevant RSVP distractors to gain access to working memory. PMID:19937451

  16. Attentional blink in young people with high-functioning autism and Asperger's disorder.

    PubMed

    Rinehart, Nicole; Tonge, Bruce; Brereton, Avril; Bradshaw, John

    2010-01-01

    The aim of the study was to examine the temporal characteristics of information processing in individuals with high-functioning autism and Asperger's disorder using a rapid serial visual presentation paradigm. The results clearly showed that such people demonstrate an attentional blink of similar magnitude to comparison groups. This supports the proposition that the social processing difficulties experienced by these individuals are not underpinned by a basic temporal-cognitive processing deficit, which is consistent with Minshew's complex information processing theory. This is the second study to show that automatic inhibitory processes are intact in both autism and Asperger's disorder, which appears to distinguish these disorders from some other frontostriatal disorders. The finding that individuals with autism were generally poorer than the comparison group at detecting black Xs, while being as good in responding to white letters, was accounted for in the context of a potential dual-task processing difficulty or visual search superiority. PMID:19770231

  17. The time course of semantic and associative priming effects is different in an attentional blink task.

    PubMed

    Murphy, Karen; Hunt, Hayley

    2013-08-01

    When two targets are presented using rapid serial visual presentation (RSVP) and the interval between the targets is 200-500 ms, report of the second target is impaired, a phenomena known as the attentional blink (AB). This study examined the time course of semantic-only and associate-semantic priming effects during an AB task. Three RSVP experiments were conducted using targets that shared either a semantic-only or an associative-semantic relationship. The results of the three experiments demonstrated semantic-only priming effects at the shortest stimulus onset asynchronies (SOAs). Associative-semantic priming was evident at shorter and longer SOAs. This suggests that priming in an AB task is driven by conceptual overlap facilitating lexical access at short SOAs and with longer SOAs lexical access benefits from word associations links between targets. PMID:23589233

  18. Modulation of Attentional Blink with Emotional Faces in Typical Development and in Autism Spectrum Disorders

    PubMed Central

    Yerys, Benjamin E.; Ruiz, Ericka; Strang, John; Sokoloff, Jennifer; Kenworthy, Lauren; Vaidya, Chandan J.

    2014-01-01

    Background The attentional blink (AB) phenomenon was used to assess the effect of emotional information on early visual attention in typically developing (TD) children and children with autism spectrum disorders (ASD). The AB effect is the momentary perceptual unawareness that follows target identification in a rapid serial visual processing stream. It is abolished or reduced for emotional stimuli, indicating that emotional information has privileged access to early visual attention processes. Method We examined the AB effect for faces with neutral and angry facial expressions in 8–14-year-old children with and without an ASD diagnosis. Results Children with ASD exhibited the same magnitude AB effect as typically developing children for both neutral and angry faces. Conclusions Early visual attention to emotional facial expressions was preserved in children with ASD. PMID:23176580

  19. Measurement of patient-derived utility values for periodontal health using a multi-attribute scale.

    PubMed

    Bellamy, C A; Brickley, M R; McAndrew, R

    1996-09-01

    Periodontal health states are difficult to quantify and no formal scale quantifying patients' utilities for periodontal health states exits. Multi-attribute utility (MAU) techniques were used to develop such a scale. The MAU scale may be used to quantify patients' assessment of their current periodontal health and that of possible treatment outcomes. Such data, combined with probability values in formal decision analysis techniques would result in improved rationality of treatment planning for periodontal disease. 20 patients attending for routine undergraduate care were interviewed. Data from these interviews were sorted into groups of common interest (domains). Intra-domain health statements were complied from the interview content. 21 patients ranked the intra-domain statements on a scale of 0-100. This same group of patients also performed an inter-domain weighting. Mean results showed that patients were 2X as concerned with how they felt and with the prognosis of possible outcomes, than with how they looked and what facts they knew about their oral health. However, the real value of utilities research lies in application of individual results to treatment planning as there is a wide range of opinion regarding outcome health states. PMID:8891929

  20. Correction: Charge-tunnelling and self-trapping: common origins for blinking, grey-state emission and photoluminescence enhancement in semiconductor quantum dots

    NASA Astrophysics Data System (ADS)

    Osborne, M. A.; Fisher, A. A. E.

    2016-07-01

    Correction for `Charge-tunnelling and self-trapping: common origins for blinking, grey-state emission and photoluminescence enhancement in semiconductor quantum dots' by M. A. Osborne, et al., Nanoscale, 2016, 8, 9272-9283.

  1. What Ambulatory Care Managers Need to Know About Examination Room Utilization Measurement and Analysis.

    PubMed

    Klarich, Mark J; Rea, Ronald W; Lal, Tarun Mohan; Garcia, Angel L; Steffens, Fay L

    2016-01-01

    Demand for ambulatory care visits is projected to increase 22% between 2008 and 2025. Given this growth, ambulatory care managers need to proactively plan for efficient use of scarce resources (ie, space, equipment, and staff). One important component of ambulatory care space (the number of examination rooms) is dependent on multiple factors, including variation in demand, hours of operation, scheduling, and staff. The authors (1) outline common data collection methods, (2) highlight analysis and reporting considerations for examination room utilization, and (3) provide a strategic framework for short- and long-term decision making for facility design or renovation. PMID:27232683

  2. Measurement of Peak Esophageal Luminal Cross Sectional Area Utilizing Nadir Intraluminal Impedance

    PubMed Central

    Zifan, Ali; Ledgerwood-Lee, Melissa; Mittal, Ravinder K

    2015-01-01

    BACKGROUND Multichannel intraluminal impedance (MII) is currently used to monitor gastroesophageal reflux and esophageal bolus clearance. We describe a novel methodology to measure maximal luminal CSA during bolus transport from MII measurements. METHODS Studies were conducted in-vitro (test tubes) and in-vivo (healthy subjects). Concurrent MII, HRM, and intraluminal ultrasound (US) were recorded 7 cm above the lower esophageal sphincter. Swallows with two concentrations of saline, 0.1N and 0.5N, of bolus volumes 5cc, 10cc and 15cc were performed. The CSA was estimated by solving two algebraic Ohm’s law equations, resulting from the two saline solutions. The CSA calculated from impedance method was compared with the CSA measured from the intraluminal US images. KEY RESULTS The CSA measured in duplicate from B-mode US images showed a mean difference between the two manual delineations to be near zero, and the repeatability coefficient was within 7.7% of the mean of the two CSA measurements. The calculated CSA from the impedance measurements strongly correlated with the US measured CSA (R2 ≅ 0.98). A detailed statistical analysis of the impedance and US measured CSA data indicated that the 95% limits of agreement between the two methods ranged from −9.1 to 13mm2. The root mean square error (RMS) of the two measurements was 4.8% of the mean US-measured CSA. CONCLUSIONS We describe a novel methodology to measure peak esophageal luminal CSA during peristalsis. Further studies are needed to determine if it is possible to measure patterns of luminal distension during peristalsis across the entire length of the esophagus. PMID:25930157

  3. The utility of surface magnetic field measurements in the MAGSAT program

    NASA Technical Reports Server (NTRS)

    Langel, R. A.; Fabiano, E. B.; Mead, G. D.

    1978-01-01

    To take full advantage of the global, vector, survey by the Magsat satellite, and international program of augmented surface measurements was proposed. For secular variation and upper mantle conductivity the proposed measurements are global. The repeat station measurements for secular variation should be occupied at 2-3 year intervals. A special observing period in November and December of 1979 is proposed during which simultaneous, continuous, global measurements for upper mantle conductivity studies are to be gathered. Finally, it is recommended that the networks in operation during the IMS extend their operation through the Fall of 1980 to provide correlative data useful for high latitude disturbance studies and for crustal conductivity studies.

  4. A Review of Acculturation Measures and Their Utility in Studies Promoting Latino Health

    ERIC Educational Resources Information Center

    Wallace, Phyllis M.; Pomery, Elizabeth A.; Latimer, Amy E.; Martinez, Josefa L.; Salovey, Peter

    2010-01-01

    The authors reviewed the acculturation literature with the goal of identifying measures used to assess acculturation in Hispanic populations in the context of studies of health knowledge, attitudes, and behavior change. Twenty-six acculturation measures were identified and summarized. As the Hispanic population continues to grow in the United…

  5. Measuring the Perceived Reality of Television: Perceived Plausibility, Perceived Superficiality and the Degree of Personal Utility.

    ERIC Educational Resources Information Center

    Elliott, William R.; And Others

    A tool was devised to measure the perceived reality of television, an important variable in understanding how television influences an individual's perception of social reality. This was accomplished by using a research plan that allowed university subjects to generate the measures used for tapping the "reality" of television content. University…

  6. Information Utility: Quantifying the Total Psychometric Information Provided by a Measure

    ERIC Educational Resources Information Center

    Markon, Kristian E.

    2013-01-01

    Although advances have improved our ability to describe the measurement precision of a test, it often remains challenging to summarize how well a test is performing overall. Reliability, for example, provides an overall summary of measurement precision, but it is sample-specific and might not reflect the potential usefulness of a test if the…

  7. Brain metabolism in autism. Resting cerebral glucose utilization rates as measured with positron emission tomography

    SciTech Connect

    Rumsey, J.M.; Duara, R.; Grady, C.; Rapoport, J.L.; Margolin, R.A.; Rapoport, S.I.; Cutler, N.R.

    1985-05-01

    The cerebral metabolic rate for glucose was studied in ten men (mean age = 26 years) with well-documented histories of infantile autism and in 15 age-matched normal male controls using positron emission tomography and (F-18) 2-fluoro-2-deoxy-D-glucose. Positron emission tomography was completed during rest, with reduced visual and auditory stimulation. While the autistic group as a whole showed significantly elevated glucose utilization in widespread regions of the brain, there was considerable overlap between the two groups. No brain region showed a reduced metabolic rate in the autistic group. Significantly more autistic, as compared with control, subjects showed extreme relative metabolic rates (ratios of regional metabolic rates to whole brain rates and asymmetries) in one or more brain regions.

  8. Improving Ion Mobility Measurement Sensitivity by Utilizing Helium in an Ion Funnel-Trap

    SciTech Connect

    Ibrahim, Yehia M.; Garimella, Venkata BS; Tolmachev, Aleksey V.; Baker, Erin Shammel; Smith, Richard D.

    2014-05-01

    Ion mobility instruments that utilize nitrogen as buffer gas are often preceded by an ion trap and accumulation region that also uses nitrogen, and for different inert gases no significant effects upon performance are expected for IMS of larger ions. However, we have observed significantly improved performance for an ion funnel trap upon adding helium; the signal intensities for higher m/z species were improved by more than an order of magnitude compared to using pure nitrogen. The effect of helium upon IMS resolving power was also studied by introducing a He/N2 gas mixture into the drift cell, and in some cases a slight improvement was observed compared to pure N2. The improvement in signal can be largely attributed to faster and more efficient ion ejection into the drift tube from the ion funnel trap.

  9. Blinking suppression of CdTe quantum dots on epitaxial graphene and the analysis with Marcus electron transfer

    SciTech Connect

    Hirose, Takuya; Tamai, Naoto; Kutsuma, Yasunori; Kurita, Atsusi; Kaneko, Tadaaki

    2014-08-25

    We have prepared epitaxial graphene by a Si sublimation method from 4H-SiC. Single-particle spectroscopy of CdTe quantum dots (QDs) on epitaxial graphene covered with polyvinylpyrrolidone (PVP) or polyethylene glycol (PEG) showed the suppression of luminescence blinking and ∼10 times decreased luminescence intensity as compared with those on a glass. The electronic coupling constant, H{sub 01}, between CdTe QDs and graphene was calculated to be (3.3 ± 0.4) × 10{sup 2 }cm{sup −1} in PVP and (3.7 ± 0.8) × 10{sup 2 }cm{sup −1} in PEG based on Marcus theory of electron transfer and Tang-Marcus model of blinking with statistical distribution.

  10. Human-Computer Interface Controlled by Horizontal Directional Eye Movements and Voluntary Blinks Using AC EOG Signals

    NASA Astrophysics Data System (ADS)

    Kajiwara, Yusuke; Murata, Hiroaki; Kimura, Haruhiko; Abe, Koji

    As a communication support tool for cases of amyotrophic lateral sclerosis (ALS), researches on eye gaze human-computer interfaces have been active. However, since voluntary and involuntary eye movements cannot be distinguished in the interfaces, their performance is still not sufficient for practical use. This paper presents a high performance human-computer interface system which unites high quality recognitions of horizontal directional eye movements and voluntary blinks. The experimental results have shown that the number of incorrect inputs is decreased by 35.1% in an existing system which equips recognitions of horizontal and vertical directional eye movements in addition to voluntary blinks and character inputs are speeded up by 17.4% from the existing system.

  11. Fundamental Kinetics Database Utilizing Shock Tube Measurements (Volumes 1, 2, 3, 4, and Volume 6)

    DOE Data Explorer

    Davidson, D. F.; Hanson, R. K

    The data from shock tube experiments generally takes three forms: ignition delay times, species concentration time-histories and reaction rate measurements. Volume 1 focuses on ignition delay time data measured and published by the Shock Tube Group in the Mechanical Engineering Department of Stanford University. The cut-off date for inclusion into this volume was January 2005. Volume 2 focuses on species concentration time-histories and was cut off December 2005. The two volumes are in PDF format and are accompanied by a zipped file of supporting data. Volume 3 was issued in 2009. Volume 4, Ignition delay times measurements came out in May, 2014, along with Reaction Rates Measurements, Vol 6. Volume 5 is not available at this time.

  12. Charge-tunnelling and self-trapping: common origins for blinking, grey-state emission and photoluminescence enhancement in semiconductor quantum dots.

    PubMed

    Osborne, M A; Fisher, A A E

    2016-04-28

    Understanding instabilities in the photoluminescence (PL) from light emitting materials is crucial to optimizing their performance for different applications. Semiconductor quantum dots (QDs) offer bright, size tunable emission, properties that are now being exploited in a broad range of developing technologies from displays and solar cells to biomaging and optical storage. However, instabilities such as photoluminescence intermittency, enhancement and bleaching of emission in these materials can be detrimental to their utility. Here, we report dielectric dependent blinking, intensity-"spikes" and low-level, "grey"-state emission, as well as PL enhancement in ZnS capped CdSe QDs; observations that we found consistent with a charge-tunnelling and self-trapping (CTST) description of exciton-dynamics on the QD-host system. In particular, modulation of PL in grey-states and PL enhancement are found to have a common origin in the equilibrium between exciton charge carrier core and surface-states within the CTST framework. Parameterized in terms of size and electrostatic properties of the QD and its nanoenvironment, the CTST offers predictive insight into exciton-dynamics in these nanomaterials. PMID:27088542

  13. Characterization of Solid Liquid Suspensions Utilizing Non-Invasive Ultrasonic Measurements

    SciTech Connect

    Panetta, P.D.; Tucker, B.; Ahmed, S.; Pappas, R.A.

    2004-03-31

    Rapid, on-line characterization of the particle size and concentration of moderate to highly concentrated slurries is required for efficient waste remediation at the DOE complexes. This paper discusses the advancements achieved under the Environmental Management Science Program to accurately characterize high-level waste at the high concentrations expected at the DOE complexes. In addition, the results are applicable to efficient process measurement and control in many chemical and pharmaceutical manufacturing processes. Existing methods for determining the particle size and concentration of non-dilute slurries based on ultrasonic attenuation can become inaccurate due to the complex interactions of ultrasonic waves with the constituents of the slurries and the necessity for very careful transducer alignment. Two measurements that help to overcome these difficulties are the ultrasonic backscattering and diffuse field. The backscattering measurement is attractive because viscous, thermal and inertial effects have small contributions to the backscattering. In addition, the backscattering theories are simpler than attenuation theories and lend themselves to more stable inversion processes. Furthermore, the measurements of backscattering measurement do not require long travel distances and can be made with a single transducer thus eliminating alignment problems. We will present ultrasonic measurements and theoretical comparisons on solid liquid suspensions designed to elucidate the particle size and concentration at high concentration relevant to the high level waste at the DOE complexes.

  14. Unintended Embodiment of Concepts into Percepts: Sensory Activation Boosts Attention for Same-Modality Concepts in the Attentional Blink Paradigm

    ERIC Educational Resources Information Center

    Vermeulen, Nicolas; Mermillod, Martial; Godefroid, Jimmy; Corneille, Olivier

    2009-01-01

    This study shows that sensory priming facilitates reports of same-modality concepts in an attentional blink paradigm. Participants had to detect and report two target words (T1 and T2) presented for 53 ms each among a series of nonwords distractors at a frequency of up to 19 items per second. SOA between target words was set to 53 ms or 213 ms,…

  15. DTI measures track and predict motor function outcomes in stroke rehabilitation utilizing BCI technology

    PubMed Central

    Song, Jie; Nair, Veena A.; Young, Brittany M.; Walton, Leo M.; Nigogosyan, Zack; Remsik, Alexander; Tyler, Mitchell E.; Farrar-Edwards, Dorothy; Caldera, Kristin E.; Sattin, Justin A.; Williams, Justin C.; Prabhakaran, Vivek

    2015-01-01

    Tracking and predicting motor outcomes is important in determining effective stroke rehabilitation strategies. Diffusion tensor imaging (DTI) allows for evaluation of the underlying structural integrity of brain white matter tracts and may serve as a potential biomarker for tracking and predicting motor recovery. In this study, we examined the longitudinal relationship between DTI measures of the posterior limb of the internal capsule (PLIC) and upper-limb motor outcomes in 13 stroke patients (median 20-month post-stroke) who completed up to 15 sessions of intervention using brain–computer interface (BCI) technology. Patients’ upper-limb motor outcomes and PLIC DTI measures including fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) were assessed longitudinally at four time points: pre-, mid-, immediately post- and 1-month-post intervention. DTI measures and ratios of each DTI measure comparing the ipsilesional and contralesional PLIC were correlated with patients’ motor outcomes to examine the relationship between structural integrity of the PLIC and patients’ motor recovery. We found that lower diffusivity and higher FA values of the ipsilesional PLIC were significantly correlated with better upper-limb motor function. Baseline DTI ratios were significantly correlated with motor outcomes measured immediately post and 1-month-post BCI interventions. A few patients achieved improvements in motor recovery meeting the minimum clinically important difference (MCID). These findings suggest that upper-limb motor recovery in stroke patients receiving BCI interventions relates to the microstructural status of the PLIC. Lower diffusivity and higher FA measures of the ipsilesional PLIC contribute toward better motor recovery in the stroke-affected upper-limb. DTI-derived measures may be a clinically useful biomarker in tracking and predicting motor recovery in stroke patients receiving BCI interventions. PMID

  16. DTI measures track and predict motor function outcomes in stroke rehabilitation utilizing BCI technology.

    PubMed

    Song, Jie; Nair, Veena A; Young, Brittany M; Walton, Leo M; Nigogosyan, Zack; Remsik, Alexander; Tyler, Mitchell E; Farrar-Edwards, Dorothy; Caldera, Kristin E; Sattin, Justin A; Williams, Justin C; Prabhakaran, Vivek

    2015-01-01

    Tracking and predicting motor outcomes is important in determining effective stroke rehabilitation strategies. Diffusion tensor imaging (DTI) allows for evaluation of the underlying structural integrity of brain white matter tracts and may serve as a potential biomarker for tracking and predicting motor recovery. In this study, we examined the longitudinal relationship between DTI measures of the posterior limb of the internal capsule (PLIC) and upper-limb motor outcomes in 13 stroke patients (median 20-month post-stroke) who completed up to 15 sessions of intervention using brain-computer interface (BCI) technology. Patients' upper-limb motor outcomes and PLIC DTI measures including fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) were assessed longitudinally at four time points: pre-, mid-, immediately post- and 1-month-post intervention. DTI measures and ratios of each DTI measure comparing the ipsilesional and contralesional PLIC were correlated with patients' motor outcomes to examine the relationship between structural integrity of the PLIC and patients' motor recovery. We found that lower diffusivity and higher FA values of the ipsilesional PLIC were significantly correlated with better upper-limb motor function. Baseline DTI ratios were significantly correlated with motor outcomes measured immediately post and 1-month-post BCI interventions. A few patients achieved improvements in motor recovery meeting the minimum clinically important difference (MCID). These findings suggest that upper-limb motor recovery in stroke patients receiving BCI interventions relates to the microstructural status of the PLIC. Lower diffusivity and higher FA measures of the ipsilesional PLIC contribute toward better motor recovery in the stroke-affected upper-limb. DTI-derived measures may be a clinically useful biomarker in tracking and predicting motor recovery in stroke patients receiving BCI interventions. PMID:25964753

  17. Coevaporation of Y, BaF sub 2 , and Cu utilizing a quadrupole mass spectrometer as a rate measuring probe

    SciTech Connect

    Hudner, J.; Oestling, M. ); Ohlsen, H.; Stolt, L. )

    1991-09-01

    An ultrahigh vacuum coevaporator equipped with three sources for preparation of Y--BaF{sub 2} --Cu--O thin films is described. Evaporation rates of Y, BaF{sub 2}, and Cu were controlled using a quadrupole mass spectrometer operating in a multiplexed mode. To evaluate the method depositions have been performed using different source configurations and evaporation rates. Utilizing Rutherford backscattering spectrometry absolute values of the actual evaporation rates were determined. It was observed that the mass-spectrometer sensitivity is highest for Y, followed by BaF{sub 2} (BaF{sup +} is the measured ion) and Cu. A partial pressure of oxygen during evaporation of Y, BaF{sub 2}, and Cu affected mainly the rate of Y. It is shown that the mass spectrometer can be utilized to precisely control the film composition.

  18. Sounding rocket measurement of the absolute solar EUV flux utilizing a silicon photodiode

    NASA Technical Reports Server (NTRS)

    Ogawa, H. S.; Mcmullin, D.; Judge, D. L.; Canfield, L. R.

    1990-01-01

    A newly developed stable and high quantum efficiency silicon photodiode was used to obtain an accurate measurement of the integrated absolute magnitude of the solar extreme UV photon flux in the spectral region between 50 and 800 A. The adjusted daily 10.7-cm solar radio flux and sunspot number were 168.4 and 121, respectively. The unattenuated absolute value of the solar EUV flux at 1 AU in the specified wavelength region was 6.81 x 10 to the 10th photons/sq cm per s. Based on a nominal probable error of 7 percent for National Institute of Standards and Technology detector efficiency measurements in the 50- to 500-A region (5 percent on longer wavelength measurements between 500 and 1216 A), and based on experimental errors associated with the present rocket instrumentation and analysis, a conservative total error estimate of about 14 percent is assigned to the absolute integral solar flux obtained.

  19. Continuous 30-day measurements utilizing the monkey metabolism pod. [study of weightlessness effects

    NASA Technical Reports Server (NTRS)

    Pace, N.; Kodama, A. M.; Mains, R. C.; Rahlmann, D. F.; Grunbaum, B. W.

    1977-01-01

    A fiberglass system was previously described, using which quantitative physiological measurements could be made to study the effects of weightlessness on 10 to 14 kg adult monkeys maintained in comfortable restraint under space flight conditions. Recent improvements in the system have made it possible to obtain continuous measurements of respiratory gas exchange, cardiovascular function, and mineral balance for periods of up to 30 days on pig-tailed monkeys. It has also been possible to operate two pods which share one set of instrumentation, thereby permitting simultaneous measurements to be made on two animals by commutating signal outputs from the pods. In principle, more than two pods could be operated in this fashion. The system is compatible with Spacelab design. Representative physiological data from ground tests of the system are presented.

  20. Compact high-quality CdSe-CdS core-shell nanocrystals with narrow emission linewidths and suppressed blinking.

    PubMed

    Chen, Ou; Zhao, Jing; Chauhan, Vikash P; Cui, Jian; Wong, Cliff; Harris, Daniel K; Wei, He; Han, Hee-Sun; Fukumura, Dai; Jain, Rakesh K; Bawendi, Moungi G

    2013-05-01

    High particle uniformity, high photoluminescence quantum yields, narrow and symmetric emission spectral lineshapes and minimal single-dot emission intermittency (known as blinking) have been recognized as universal requirements for the successful use of colloidal quantum dots in nearly all optical applications. However, synthesizing samples that simultaneously meet all these four criteria has proven challenging. Here, we report the synthesis of such high-quality CdSe-CdS core-shell quantum dots in an optimized process that maintains a slow growth rate of the shell through the use of octanethiol and cadmium oleate as precursors. In contrast with previous observations, single-dot blinking is significantly suppressed with only a relatively thin shell. Furthermore, we demonstrate the elimination of the ensemble luminescence photodarkening that is an intrinsic consequence of quantum dot blinking statistical ageing. Furthermore, the small size and high photoluminescence quantum yields of these novel quantum dots render them superior in vivo imaging agents compared with conventional quantum dots. We anticipate these quantum dots will also result in significant improvement in the performance of quantum dots in other applications such as solid-state lighting and illumination. PMID:23377294

  1. Utilization of AERONET polarimetric measurements for improving retrieval of aerosol microphysics: GSFC, Beijing and Dakar data analysis

    NASA Astrophysics Data System (ADS)

    Fedarenka, Anton; Dubovik, Oleg; Goloub, Philippe; Li, Zhengqiang; Lapyonok, Tatyana; Litvinov, Pavel; Barel, Luc; Gonzalez, Louis; Podvin, Thierry; Crozel, Didier

    2016-08-01

    The study presents the efforts on including the polarimetric data to the routine inversion of the radiometric ground-based measurements for characterization of the atmospheric aerosols and analysis of the obtained advantages in retrieval results. First, to operationally process the large amount of polarimetric data the data preparation tool was developed. The AERONET inversion code adapted for inversion of both intensity and polarization measurements was used for processing. Second, in order to estimate the effect from utilization of polarimetric information on aerosol retrieval results, both synthetic data and the real measurements were processed using developed routine and analyzed. The sensitivity study has been carried out using simulated data based on three main aerosol models: desert dust, urban industrial and urban clean aerosols. The test investigated the effects of utilization of polarization data in the presence of random noise, bias in measurements of optical thickness and angular pointing shift. The results demonstrate the advantage of polarization data utilization in the cases of aerosols with pronounced concentration of fine particles. Further, the extended set of AERONET observations was processed. The data for three sites have been used: GSFC, USA (clean urban aerosol dominated by fine particles), Beijing, China (polluted industrial aerosol characterized by pronounced mixture of both fine and coarse modes) and Dakar, Senegal (desert dust dominated by coarse particles). The results revealed considerable advantage of polarimetric data applying for characterizing fine mode dominated aerosols including industrial pollution (Beijing). The use of polarization corrects particle size distribution by decreasing overestimated fine mode and increasing the coarse mode. It also increases underestimated real part of the refractive index and improves the retrieval of the fraction of spherical particles due to high sensitivity of polarization to particle shape

  2. Cell compressibility studies utilizing noncontact hydrostatic pressure measurements on single living cells in a microchamber

    NASA Astrophysics Data System (ADS)

    Lin, L. A. G.; Liu, A. Q.; Yu, Y. F.; Zhang, C.; Lim, C. S.; Ng, S. H.; Yap, P. H.; Gao, H. J.

    2008-06-01

    A micro-optical-fluidic system (MOFS), which integrates a force generating device and an optical detector, is designed to measure the bulk modulus of a single living cell in real time under a controlled hydrostatic pressure. In this design, the accuracy of the bulk modulus measurement is improved because neither the force generating device nor the optical detector needs to be in contact with the cells. The MOFS device has been used to investigate the mechanotransduction of THP-1 human acute monocytic leukemia cells and the effects of the toxin lipopolysaccharide and colchicine on various properties of these cells.

  3. Preschool Executive Control on the Shape School Task: Measurement Considerations and Utility

    ERIC Educational Resources Information Center

    Pritchard, Verena E.; Woodward, Lianne J.

    2011-01-01

    Executive functions (EF) necessary for purposeful goal-directed activities undergo rapid change and development during the preschool years. However, of the few psychometrically valid measures of EF suitable for use with preschoolers, information on task sensitivity and predictive validity is scant. The neurodevelopmental correlates of early…

  4. Clinical Utility of the Modified Stroop Task as a Treatment Outcome Measure: Questions Raised

    ERIC Educational Resources Information Center

    Ball, Jillian R.; Mitchell, Philip B.; Touyz, Stephen W.; Griffiths, Rosalyn A.; Beumont, Pierre J. V.

    2004-01-01

    Data from an outpatient treatment trial for anorexia nervosa were examined to gain preliminary insights as to whether the modified Stroop colour-naming task might offer a useful measure of treatment outcome. It was hypothesised that interference for eating-, weight- and shape-related words on a modified version on the Stroop colour-naming task…

  5. Utilization of Leaf Reflectance Measurements in Louisiana Sugarcane Disease, Variety, and Harvest Management Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tests were initiated in 2005 to determine if visible and near-infrared leaf reflectance measurements could be used to predict sugarcane disease incidence, identify varieties, and estimate sucrose content. Leaf samples were collected from: sugarcane yellow leaf disease (SCYLD) and mosaic test plots; ...

  6. UTILIZING THE PAKS METHOD FOR MEASURING ACROLEIN AND OTHER ALDEHYDES IN DEARS

    EPA Science Inventory

    Acrolein is a hazardous air pollutant of high priority due to its high irritation potency and other potential adverse health effects. However, a reliable method is currently unavailable for measuring airborne acrolein at typical environmental levels. In the Detroit Exposure and A...

  7. Patient-Reported Shoulder Outcome Measures Utilized in Breast Cancer Survivors: A Systematic Review

    PubMed Central

    Harrington, Shana; Michener, Lori A; Kendig, Tiffany; Miale, Susan; George, Steven Z

    2014-01-01

    Objective 1) To identify English Language published patient-reported upper extremity outcome measures used in breast cancer research and 2) To examine construct validity and responsiveness in patient-reported upper extremity outcome measures used in breast cancer research. Data Sources PubMed, CINAHL and ProQuest MEDLINE® databases were searched up to February 5, 2013. Study Selection Studies were included if a patient-reported upper extremity outcome measure was administered, the participants were diagnosed with breast cancer, and published in English. Data Extraction Eight hundred and sixty-five articles were screened. Fifty-nine full text articles were assessed for eligibility. A total of 46 articles met the initial eligibility criteria for aim 1. Eleven of these articles reported mean and standard deviations for the outcome scores, and included a comparison group analysis for aim 2. Data Synthesis Construct validity was evaluated by calculating effect sizes for known group differences in 6 studies using the Disabilities of Arm, Shoulder and Hand (DASH), Penn Shoulder Score, Shoulder Disability Questionnaire-Dutch, and 10 Questions by Wingate (Wingate). Responsiveness was analyzed comparing a treatment and control group by calculating the coefficient of responsiveness in 5 studies for the DASH and Wingate. Conclusions Eight different patient-reported upper extremity outcome measures have been reported in the peer-review literature for women with breast cancer, some (n=3) were specifically developed for breast cancer survivors and others that were not (n=5). Based on the current evidence we recommend administering the DASH to assess patient-reported upper extremity function in breast cancer survivors because the DASH had most consistently large effects sizes for construct validity and responsiveness. Future large studies are needed for more definitive recommendations. PMID:23932969

  8. Eddy current nondestructive testing device for measuring variable characteristics of a sample utilizing Walsh functions

    DOEpatents

    Libby, Hugo L.; Hildebrand, Bernard P.

    1978-01-01

    An eddy current testing device for measuring variable characteristics of a sample generates a signal which varies with variations in such characteristics. A signal expander samples at least a portion of this generated signal and expands the sampled signal on a selected basis of square waves or Walsh functions to produce a plurality of signal components representative of the sampled signal. A network combines these components to provide a display of at least one of the characteristics of the sample.

  9. Utilizing Electroencephalography Measurements for Comparison of Task-Specific Neural Efficiencies: Spatial Intelligence Tasks.

    PubMed

    Call, Benjamin J; Goodridge, Wade; Villanueva, Idalis; Wan, Nicholas; Jordan, Kerry

    2016-01-01

    Spatial intelligence is often linked to success in engineering education and engineering professions. The use of electroencephalography enables comparative calculation of individuals' neural efficiency as they perform successive tasks requiring spatial ability to derive solutions. Neural efficiency here is defined as having less beta activation, and therefore expending fewer neural resources, to perform a task in comparison to other groups or other tasks. For inter-task comparisons of tasks with similar durations, these measurements may enable a comparison of task type difficulty. For intra-participant and inter-participant comparisons, these measurements provide potential insight into the participant's level of spatial ability and different engineering problem solving tasks. Performance on the selected tasks can be analyzed and correlated with beta activities. This work presents a detailed research protocol studying the neural efficiency of students engaged in the solving of typical spatial ability and Statics problems. Students completed problems specific to the Mental Cutting Test (MCT), Purdue Spatial Visualization test of Rotations (PSVT:R), and Statics. While engaged in solving these problems, participants' brain waves were measured with EEG allowing data to be collected regarding alpha and beta brain wave activation and use. The work looks to correlate functional performance on pure spatial tasks with spatially intensive engineering tasks to identify the pathways to successful performance in engineering and the resulting improvements in engineering education that may follow. PMID:27584838

  10. Temperature Measurements on Hot Spots of Power Substations Utilizing Surface Acoustic Wave Sensors

    NASA Astrophysics Data System (ADS)

    Cavaco, M. A. M.; Benedet, M. E.; Neto, L. R.

    2011-12-01

    In several applications in the field of metrology, the direct connection of the sensor element with the respective signal-processing unit of the measurement system is not trivial. It can be mentioned, as an example, the measurement of hot points in electric power substations because of the high electrical potential. To solve that problem, two alternatives were studied, one using active surface acoustic wave (SAW) sensors and other using passive SAW tags. For the passive sensor, a SAW radio-frequency identification (RFID) temperature detector was used. That technology is widely applied for typical transport identification (grain transportation, road traffic control), but its application in the field of metrology is innovative. The variation in temperature makes an alteration in the characteristics of the piezoelectric material of the SAW matrix, changing mostly the resonance frequency. Using SAW-RFID, the problem of measuring temperature basically is directed to the identification of the frequency of resonance of the SAW. The use of active SAW sensors has been demonstrated to be much more satisfactory for the solution of such a problem because of the limitation in the range of the passive sensors.

  11. Reducing Blinking in Small Core-Multishell Quantum Dots by Carefully Balancing Confinement Potential and Induced Lattice Strain: The "Goldilocks" Effect.

    PubMed

    Omogo, Benard; Gao, Feng; Bajwa, Pooja; Kaneko, Mizuho; Heyes, Colin D

    2016-04-26

    Currently, the most common way to reduce blinking in quantum dots (QDs) is accomplished by using very thick and/or perfectly crystalline CdS shells on CdSe cores. Ideally, a nontoxic material such as ZnS is preferred to be the outer material in order to reduce environmental and cytotoxic effects. Blinking suppression with multishell configurations of CdS and ZnS has been reported only for "giant" QDs of 15 nm or more. One of the main reasons for the limited progress is that the role that interfacial trap states play in blinking in these systems is not very well understood. Here, we show a "Goldilocks" effect to reduce blinking in small (∼7 nm) QDs by carefully controlling the thicknesses of the shells in multishell QDs. Furthermore, by correlating the fluorescence lifetime components with the fraction of time that a QD spends in the on-state, both with and without applying a threshold, we found evidence for two types of blinking that separately affect the average fluorescence lifetime of a single QD. A thorough characterization of the time-resolved fluorescence at the ensemble and single-particle level allowed us to propose a detailed physical model involving both short-lived interfacial trap states and long-lived surface trap states that are coupled. This model highlights a strategy of reducing QD blinking in small QDs by balancing the magnitude of the induced lattice strain, which results in the formation of interfacial trap states between the inner shell and the outer shell, and the confinement potential that determines how accessible the interfacial trap states are. The combination of reducing blinking while maintaining a small overall QD size and using a Cd-free outer shell of ZnS will be useful in a wide array of applications, particularly for advanced bioimaging. PMID:27058120

  12. Heart rate dynamics in patients with stable angina pectoris and utility of fractal and complexity measures

    NASA Technical Reports Server (NTRS)

    Makikallio, T. H.; Ristimae, T.; Airaksinen, K. E.; Peng, C. K.; Goldberger, A. L.; Huikuri, H. V.

    1998-01-01

    Dynamic analysis techniques may uncover abnormalities in heart rate (HR) behavior that are not easily detectable with conventional statistical measures. However, the applicability of these new methods for detecting possible abnormalities in HR behavior in various cardiovascular disorders is not well established. Conventional measures of HR variability were compared with short-term (< or = 11 beats, alpha1) and long-term (> 11 beats, alpha2) fractal correlation properties and with approximate entropy of RR interval data in 38 patients with stable angina pectoris without previous myocardial infarction or cardiac medication at the time of the study and 38 age-matched healthy controls. The short- and long-term fractal scaling exponents (alpha1, alpha2) were significantly higher in the coronary patients than in the healthy controls (1.34 +/- 0.15 vs 1.11 +/- 0.12 [p <0.001] and 1.10 +/- 0.08 vs 1.04 +/- 0.06 [p <0.01], respectively), and they also had lower approximate entropy (p <0.05), standard deviation of all RR intervals (p <0.01), and high-frequency spectral component of HR variability (p <0.05). The short-term fractal scaling exponent performed better than other heart rate variability parameters in differentiating patients with coronary artery disease from healthy subjects, but it was not related to the clinical or angiographic severity of coronary artery disease or any single nonspectral or spectral measure of HR variability in this retrospective study. Patients with stable angina pectoris have altered fractal properties and reduced complexity in their RR interval dynamics relative to age-matched healthy subjects. Dynamic analysis may complement traditional analyses in detecting altered HR behavior in patients with stable angina pectoris.

  13. Measuring midkine: the utility of midkine as a biomarker in cancer and other diseases

    PubMed Central

    Jones, D R

    2014-01-01

    Midkine (MK) is a pleiotropic growth factor prominently expressed during embryogenesis but down-regulated to neglible levels in healthy adults. Many published studies have demonstrated striking MK overexpression compared with healthy controls in various pathologies, including ischaemia, inflammation, autoimmunity and, most notably, in many cancers. MK expression is detectable in biopsies of diseased, but not healthy, tissues. Significantly, because it is a soluble cytokine, elevated MK is readily apparent in the blood and other body fluids such as urine and CSF, making MK a relatively convenient, accessible, non-invasive and inexpensive biomarker for population screening and early disease detection. The first diagnostic tests that quantify MK are just now receiving regulatory clearance and entering the clinic. This review examines the current state of knowledge pertaining to MK as a biomarker and highlights promising indications and clinical settings where measuring MK could make a difference to patient treatment. I also raise outstanding questions about reported variants of MK as well as MK's bio-distribution in vivo. Answering these questions in future studies will enhance our understanding of the significance of measured MK levels in both patients and healthy subjects, and may reveal further opportunities for measuring MK to diagnose disease. MK has already proven to be a biomarker that can significantly improve detection, management and treatment of cancer, and there is significant promise for developing further MK-based diagnostics in the future. Linked Article This article is part of a recent themed section on Midkine, published in volume 171 issue 4. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-4 PMID:24460734

  14. Utility of EEG measures of brain function in patients with acute stroke.

    PubMed

    Wu, Jennifer; Srinivasan, Ramesh; Burke Quinlan, Erin; Solodkin, Ana; Small, Steven L; Cramer, Steven C

    2016-06-01

    EEG has been used to study acute stroke for decades; however, because of several limitations EEG-based measures rarely inform clinical decision-making in this setting. Recent advances in EEG hardware, recording electrodes, and EEG software could overcome these limitations. The present study examined how well dense-array (256 electrodes) EEG, acquired with a saline-lead net and analyzed with whole brain partial least squares (PLS) modeling, captured extent of acute stroke behavioral deficits and varied in relation to acute brain injury. In 24 patients admitted for acute ischemic stroke, 3 min of resting-state EEG was acquired at bedside, including in the ER and ICU. Traditional quantitative EEG measures (power in a specific lead, in any frequency band) showed a modest association with behavioral deficits [NIH Stroke Scale (NIHSS) score] in bivariate models. However, PLS models of delta or beta power across whole brain correlated strongly with NIHSS score (R(2) = 0.85-0.90) and remained robust when further analyzed with cross-validation models (R(2) = 0.72-0.73). Larger infarct volume was associated with higher delta power, bilaterally; the contralesional findings were not attributable to mass effect, indicating that EEG captures significant information about acute stroke effects not available from MRI. We conclude that 1) dense-array EEG data are feasible as a bedside measure of brain function in patients with acute stroke; 2) high-dimension EEG data are strongly correlated with acute stroke behavioral deficits and are superior to traditional single-lead metrics in this regard; and 3) EEG captures significant information about acute stroke injury not available from structural brain imaging. PMID:26936984

  15. Progress in utilization of a mobile laboratory for making storm electricity measurements

    NASA Technical Reports Server (NTRS)

    Rust, W. David

    1988-01-01

    A mobile atmospheric science laboratory has been used to intercept and track storms on the Great Plains region of the U.S., with the intention of combining the data obtained with those from Doppler and conventional radars, NASA U-2 aircraft overflights, balloon soundings, and fixed-base storm electricity measurements. The mobile lab has proven to be valuable in the gathering of ground truth verifications for the two commercially operated lightning ground-strike locating systems. Data acquisition has recently been expanded by means of mobile ballooning before and during storms.

  16. Utilizing The Synergy of Airborne Backscatter Lidar and In-Situ Measurements for Evaluating CALIPSO

    NASA Astrophysics Data System (ADS)

    Tsekeri, Alexandra; Amiridis, Vassilis; Marenco, Franco; Marinou, Eleni; Rosenberg, Phil; Solomos, Stavros; Trembath, Jamie; Allan, James; Bacak, Asan; Nenes, Athanasios

    2016-06-01

    Airborne campaigns dedicated to satellite validation are crucial for the effective global aerosol monitoring. CALIPSO is currently the only active remote sensing satellite mission, acquiring the vertical profiles of the aerosol backscatter and extinction coefficients. Here we present a method for CALIPSO evaluation from combining lidar and in-situ airborne measurements. The limitations of the method have to do mainly with the in-situ instrumentation capabilities and the hydration modelling. We also discuss the future implementation of our method in the ICE-D campaign (Cape Verde, August 2015).

  17. The analytical approach to measuring horizontal market power in electric utility markets: A historical perspective

    SciTech Connect

    Surratt, W.

    1998-07-01

    Market power remains an important issue in electricity markets. FERC has taken important steps to clarify the process it uses in analyzing market power in merger, market-pricing, and ISO settings. Further change may be expected, although the policy goals remain the same: ensuring that consumer interests are protected and that competition may thrive. Section 1 of this article examines the history of market power measurement at FERC and details the changes in market power analysis, including the issuance of Order 592 and the methodology it prescribes. Section 2 contains some thoughts on future market power analyses and how those might be constructed. Section 3 presents conclusions.

  18. Wide measurement range scanning heterodyne interferometer utilizing astigmatic position sensing scheme

    NASA Astrophysics Data System (ADS)

    Park, Youngkyu; Kim, Kyoung-Eop; Kim, Seong-Jin; Park, June-Gyu; Joo, Young-Hun; Shin, Bu Hyun; Lee, Seung-Yop; Cho, Kyuman

    2011-08-01

    A scanning heterodyne I/Q-interferometer scheme is proposed to overcome phase ambiguity caused by the periodic nature of its phase-dependent signal. A position sensing scheme using an astigmatic method in the confocal arrangement has been interfaced to the interferometer to retrieve the real phase value during a scanning process. The experimental results show that the vertical measurement range can be expanded up to 16μm. The potential of this interferometer on the scanning microscopy of a rough surface is discussed.

  19. Orbit Determination Analysis Utilizing Radiometric and Laser Ranging Measurements for GPS Orbit

    NASA Technical Reports Server (NTRS)

    Welch, Bryan W.

    2007-01-01

    While navigation systems for the determination of the orbit of the Global Position System (GPS) have proven to be very effective, the current issues involve lowering the error in the GPS satellite ephemerides below their current level. In this document, the results of an orbit determination covariance assessment are provided. The analysis is intended to be the baseline orbit determination study comparing the benefits of adding laser ranging measurements from various numbers of ground stations. Results are shown for two starting longitude assumptions of the satellite location and for nine initial covariance cases for the GPS satellite state vector.

  20. Religious social capital: Its measurement and utility in the study of the social determinants of health

    PubMed Central

    Maselko, Joanna; Hughes, Cayce; Cheney, Rose

    2014-01-01

    As a social determinant of health, religiosity remains not well understood, despite the prevalence of religious activity and prominence of religious institutions in most societies. This paper introduces a working measure of Religious Social Capital and presents preliminary associations with neighborhood social capital and urban stressors. Religious social capital is defined as the social resources available to individuals and groups through their social connections with a religious community. Domains covered include group membership, social integration, values/norms, bonding/bridging trust as well as social support. Cross-sectional data come from a convenience sample of 104 community dwelling adults residing in a single urban neighborhood in a large US city, who also provided information on neighborhood social capital, and experiences of urban stressors. Results suggest that religious social capital is a valid construct that can be reliably measured. All indicators of religious social capital were higher among those who frequently attended religious services, with the exception of bridging trust (trust of people from different religious groups). A weak, inverse, association was also observed between religious and neighborhood social capital levels. Levels of religious social capital were correlated with higher levels of reported urban stressors, while neighborhood social capital was correlated with lower urban stressor levels. A significant percent of the sample was unaffiliated with a religious tradition and these individuals were more likely to be male, young and more highly educated. Social capital is a promising construct to help elucidate the influence of religion on population health. PMID:21802182

  1. Method for non-intrusively identifying a contained material utilizing uncollided nuclear transmission measurements

    DOEpatents

    Morrison, John L.; Stephens, Alan G.; Grover, S. Blaine

    2001-11-20

    An improved nuclear diagnostic method identifies a contained target material by measuring on-axis, mono-energetic uncollided particle radiation transmitted through a target material for two penetrating radiation beam energies, and applying specially developed algorithms to estimate a ratio of macroscopic neutron cross-sections for the uncollided particle radiation at the two energies, where the penetrating radiation is a neutron beam, or a ratio of linear attenuation coefficients for the uncollided particle radiation at the two energies, where the penetrating radiation is a gamma-ray beam. Alternatively, the measurements are used to derive a minimization formula based on the macroscopic neutron cross-sections for the uncollided particle radiation at the two neutron beam energies, or the linear attenuation coefficients for the uncollided particle radiation at the two gamma-ray beam energies. A candidate target material database, including known macroscopic neutron cross-sections or linear attenuation coefficients for target materials at the selected neutron or gamma-ray beam energies, is used to approximate the estimated ratio or to solve the minimization formula, such that the identity of the contained target material is discovered.

  2. On-line engine torque and torque fluctuation measurement for engine control utilizing crankshaft speed fluctuations

    SciTech Connect

    Citron, S.J.

    1987-10-06

    An adaptive idle control system is described for an internal combustion engine. It consists of an engine fuel distribution system, means for coupling the engine fuel distribution system to the engine's cylinders, means for sensing engine crankshaft position, and a clock for generating a time base. There is also a means for obtaining a measure of slowest crankshaft speed independent of the occurrence of a top dead center position of the engine crankshaft during the power stroke of each cylinder, means for coupling the clock and the crankshaft position sensor to the means for obtaining a measure of crankshaft speed, means for calculating an index of performance for each of the various cylinders, means for coupling the performance index calculating means to the clock and the crankshaft position sensor, and means for calculating engine roughness based upon the indices of performance. Plus there are means for coupling the roughness calculating means to the performance index calculating means, means for comparing the roughness to a roughness set point and adjusting the throttle in response to the comparison to control the idle speed of the engine, means for coupling the comparing and adjusting means to the throttle, means for determining the roughness set point in response to the indices of performance, and means for coupling the roughness set point determining means to the performance index calculating means.

  3. Utilizing photon number parity measurements to demonstrate quantum computation with cat-states in a cavity

    NASA Astrophysics Data System (ADS)

    Petrenko, A.; Ofek, N.; Vlastakis, B.; Sun, L.; Leghtas, Z.; Heeres, R.; Sliwa, K. M.; Mirrahimi, M.; Jiang, L.; Devoret, M. H.; Schoelkopf, R. J.

    2015-03-01

    Realizing a working quantum computer requires overcoming the many challenges that come with coupling large numbers of qubits to perform logical operations. These include improving coherence times, achieving high gate fidelities, and correcting for the inevitable errors that will occur throughout the duration of an algorithm. While impressive progress has been made in all of these areas, the difficulty of combining these ingredients to demonstrate an error-protected logical qubit, comprised of many physical qubits, still remains formidable. With its large Hilbert space, superior coherence properties, and single dominant error channel (single photon loss), a superconducting 3D resonator acting as a resource for a quantum memory offers a hardware-efficient alternative to multi-qubit codes [Leghtas et.al. PRL 2013]. Here we build upon recent work on cat-state encoding [Vlastakis et.al. Science 2013] and photon-parity jumps [Sun et.al. 2014] by exploring the effects of sequential measurements on a cavity state. Employing a transmon qubit dispersively coupled to two superconducting resonators in a cQED architecture, we explore further the application of parity measurements to characterizing such a hybrid qubit/cat state architecture. In so doing, we demonstrate the promise of integrating cat states as central constituents of future quantum codes.

  4. Method for Non-Intrusively Identifying a Contained Material Utilizing Uncollided Nuclear Transmission Measurements

    SciTech Connect

    Morrison, John L.; Stephens, Alan G.; Grover Blaine S.

    1999-02-26

    An improved nuclear diagnostic method identifies a contained target material by measuring on-axis, mono-energetic uncollided particle radiation transmitted through a target material for two penetrating radiation beam energies, and applying specially developed algorithms to estimate a ratio of macroscopic neutron cross-sections for the uncollided particle radiation at the two energies, where the penetrating radiation is a neutron beam, or a ratio of linear attenuation coefficients for the uncollided particle radiation at the two energies, where the penetrating radiation is a gamma-ray beam. Alternatively, the measurements are used to derive a minimization formula based on the macroscopic neutron cross-sections for the uncollided particle radiation at the two neutron beam energies, or the linear attenuation coefficients for the uncollided particle radiation at the two gamma-ray beam energies. A candidate target material database, including known macroscopic neutron cross-sections or linear attenuation coefficients for target materials at the selected neutron or gamma-ray beam energies, is used to approximate the estimated ratio or to solve the minimization formula, such that the identity of the contained target material is discovered.

  5. Costs and benefits from utility-funded commissioning of energy- efficiency measures in 16 buildings

    SciTech Connect

    Piette, M.A.; Nordman, B.

    1995-10-01

    This paper describes the costs and savings of commissioning of energy- efficiency measures in 16 buildings. A total of 46 EEMs were commissioned for all 16 buildings and 73 deficiencies were corrected. On average, commissioning was marginally cost effective on energy savings alone, although the results were mixed among all 16 buildings. When considered as a stand-alone measure, the median simple payback time of 6.5 years under the low energy prices in the Pacific Northwest. Under national average prices the median payback time is about three years. In estimating the present value of the energy savings from commissioning we considered low and high lifetimes for the persistence of savings from deficiency corrections. Under the low- lifetime case the average present value of the energy savings ($0. 21/ft{sup 2}) were about equal to the average commissioning costs ($0. 23/ft{sup 2}). Under the high-lifetime case the savings ($0.51/ft{sup 2}) were about twice the costs. Again, the savings would be about twice as large under national average prices. The results are subject to significant uncertainty because of the small sample size and lack of metered data in the evaluation. However, the findings suggest that investments in commissioning pay off. Building owners want buildings that work as intended, and are comfortable, healthy, and efficient. It is likely that the non-energy benefits, which are difficult to quantify, are larger than the energy-savings benefits.

  6. Can solid phase assays be better utilized to measure efficacy of antibody removal therapies?

    PubMed

    Tambur, Anat R; Glotz, Denis; Herrera, Nancy D; Chatroop, Erik N; Roitberg, Tal; Friedewald, John J; Gjertson, David

    2016-08-01

    Antibody removal therapies are used for patients with antibody-mediated-rejection or those requiring desensitization to become transplantable. Accurate measurement of antibody levels prior to, and during treatment, are required to choose the best therapeutic approach, and to provide measure of treatment efficacy. Currently, the FDA does not regard solid-phase assays for HLA-antibody identification as a reliable surrogate-marker for treatment efficacy. Serum samples from 40 patients (58 assays; >2200 positive data points) undergoing antibody-removal-therapies were tested as sample-pairs, pre- and post-treatment. MFI values of IgG and C1q single-antigen-bead assays were compared with antibody titer values (serial dilutions). Antibody reduction was tracked and the differences in pre-to-post-treatment values were calculated as delta-reduction of antibody levels. Dynamic patterns of titration studies reduced effects of serum-inherent inhibitory factors (prozone-like); eliminated over-saturation limitations, and provided better estimation of antibody-binding strength compared with the other methods. Moreover, delta-reduction of antibody values using titration studies was significantly more uniform compared with either IgG or C1q tests. Analyzing antibody results using only C1q positive or only higher MFI values did not change the overall magnitude of results. Overall, titration studies provided better estimate of responsiveness to treatment and thus can serve as companion to monitoring efficacy of antibody-removal therapies. PMID:27267046

  7. Development of a probing system for a micro-coordinate measuring machine by utilizing shear-force detection

    NASA Astrophysics Data System (ADS)

    Ito, So; Kodama, Issei; Gao, Wei

    2014-06-01

    This paper introduces a newly developed probing system for a micro-coordinate measurement machine (micro-CMM) based on an interaction force generated by the water layer on the surface of the measuring object. In order to measure the dimensions of the micrometric structures, a probing system using a nanopipette ball stylus has been developed. A glass microsphere with diameter of 9 µm is used as a stylus tip of the probing system. The glass nanopipette, which is fabricated from a capillary glass tube by a thermal pulling process, is employed as a stylus shaft to improve the fixation strength of the stylus tip. The approach between the stylus tip and the surface of the measuring object can be detected by utilizing the method of shear-force detection. The stylus is oscillated in the lateral direction at its resonant frequency to detect an interaction force owing to the viscoelasticity of the meniscus layer existing on the surface of the measuring object. The oscillation amplitude is decreased by the shear-force applied to the stylus tip. In this study, the basic characteristics of the probing system including sensitivity, resolution and reproducibility are investigated. The experimental result of dimensional measurement of micrometer-scale structure is presented.

  8. Mo' money, mo' problems: Monetary motivation can exacerbate the attentional blink.

    PubMed

    Biggs, Adam T; Adamo, Stephen H; Mitroff, Stephen R

    2015-01-01

    The attentional blink (AB) is a compelling psychological phenomenon wherein observers are less likely to identify a second target (T2) when it appears approximately 200 ms after a first target (T1) in a rapidly presented stream of items. The present investigation examined how monetary motivation could impact the AB when participants were differentially motivated to identify T1 versus T2. Participants completed one of three conditions where the only difference across conditions was a motivational manipulation: a standard AB task (control condition), a motivated condition with T1 worth double the points of T2, or a motivated condition with T1 worth half the points of T2 (points in the motivated conditions were linked to a possible monetary bonus). Motivation had an expected influence on overall performance as both motivated conditions had higher overall T1 accuracy relative to the control condition. More specific to the question at hand, the AB was exacerbated (ie T2 performance was worse shortly after T1) when T1 was worth more than T2. This finding suggests that participants overallocated attentional resources to T1 processing at the expense of T2 processing, and it supports current theories of the AB. PMID:26492726

  9. A new look at lubrication of the ocular surface: fluid mechanics behind the blinking eyelids.

    PubMed

    Cher, Ivan

    2008-04-01

    The concept of the dacruon was presented by the author in this journal in July 2007. Dacruon, defined as "the body of unshed fluid, constantly occupying the ocular surface sac [OSS], comprising the mucoaqueous pool [MAP] and its covering lipid sealant," prompts a fresh consideration of OSS lubrication. The author notes scientific agreement that in the preocular, interpalpebral OSS (the menisco-optical domain), the mucous gel of the MAP adheres to subjacent bulbar epithelium. In the retropalpebral recesses (the "lubrication domain"), lid and globe epithelia are juxtaposed. The author proposes that microvilli and glycocalyx "grasp" the bases of dacruon mucous gels, enabling lid and globe to "drive" fluid movement. The adherent gels and associated low viscosity mucous modules mitigate friction. There is no substantive lipid layer. The modules abut, "mirror-image" fashion, forming an interface concentric with the eyeball surface about midway between the palpebral and bulbar mucosae. Here, kinetic energy originating from both lid and globe has been progressively dissipated by fluid friction, residual movement reduced to creeping flow. Shear stress is displaced from the rapidly moving epithelia, to occur between the more remote, slow-moving midzone fluids, minimizing frictional blink-related microtrauma. The midway interface serves as a "slip interface," crucial to the mucoaqueous lubrication of the OSS. Concomitantly, the OSS also forms the anterior lubricating compartment of the "ball and socket" ocular joint. PMID:18418505

  10. An Individual Differences Approach to Temporal Integration and Order Reversals in the Attentional Blink Task

    PubMed Central

    Willems, Charlotte; Saija, Jefta D.; Akyürek, Elkan G.; Martens, Sander

    2016-01-01

    Background The reduced ability to identify a second target when it is presented in close temporal succession of a first target is called the attentional blink (AB). Studies have shown large individual differences in AB task performance, where lower task performance has been associated with more reversed order reports of both targets if these were presented in direct succession. In order to study the suggestion that reversed order reports reflect loss of temporal information, in the current study, we investigated whether individuals with a larger AB have a higher tendency to temporally integrate both targets into one visual event by using an AB paradigm containing symbol target stimuli. Methodology/Principal Findings Indeed, we found a positive relation between the tendency to temporally integrate information and individual AB magnitude. In contrast to earlier work, we found no relation between order reversals and individual AB magnitude. The occurrence of temporal integration was negatively related to the number of order reversals, indicating that individuals either integrated or separated and reversed information. Conclusion We conclude that individuals with better AB task performance use a shorter time window to integrate information, and therefore have higher preservation of temporal information. Furthermore, order reversals observed in paradigms with alphanumeric targets indeed seem to at least partially reflect temporal integration of both targets. Given the negative relation between temporal integration and ‘true’ order reversals observed with the current symbolic target set, these two behavioral outcomes seem to be two sides of the same coin. PMID:27228118

  11. Good vibrations, bad vibrations: Oscillatory brain activity in the attentional blink

    PubMed Central

    Janson, Jolanda; Kranczioch, Cornelia

    2011-01-01

    The attentional blink (AB) is a deficit in reporting the second (T2) of two targets (T1, T2) when presented in close temporal succession and within a stream of distractor stimuli. The AB has received a great deal of attention in the past two decades because it allows to study the mechanisms that influence the rate and depth of information processing in various setups and therefore provides an elegant way to study correlates of conscious perception in supra-threshold stimuli. Recently evidence has accumulated suggesting that oscillatory signals play a significant role in temporally coordinating information between brain areas. This review focuses on studies looking into oscillatory brain activity in the AB. The results of these studies indicate that the AB is related to modulations in oscillatory brain activity in the theta, alpha, beta, and gamma frequency bands. These modulations are sometimes restricted to a circumscribed brain area but more frequently include several brain regions. They occur before targets are presented as well as after the presentation of the targets. We will argue that the complexity of the findings supports the idea that the AB is not the result of a processing impairment in one particular process or brain area, but the consequence of a dynamic interplay between several processes and/or parts of a neural network. PMID:22253672

  12. The emotional blink: adult age differences in visual attention to emotional information.

    PubMed

    Langley, Linda K; Rokke, Paul D; Stark, Atiana C; Saville, Alyson L; Allen, Jaryn L; Bagne, Angela G

    2008-12-01

    To assess age differences in attention-emotion interactions, the authors asked young adults (ages 18-33 years) and older adults (ages 60-80 years) to identify target words in a rapid serial visual presentation (RSVP) task. The second of two target words was neutral or emotional in content (positive in Experiment 1, negative in Experiment 2). In general, the ability to identify targets from a word stream declined with age. Age differences specific to the attentional blink were greatly reduced when baseline detection accuracy was equated between groups. With regard to emotion effects, older adults showed enhanced identification of both positive and negative words relative to neutral words, whereas young adults showed enhanced identification of positive words and reduced identification of negative words. Together these findings suggest that the nature of attention-emotion interactions changes with age, but there was little support for a motivational shift consistent with emotional regulation goals at an early stage of cognitive processing. PMID:19140657

  13. Startle eye-blink modulation by facial self-resemblance and current mood.

    PubMed

    Finke, Johannes B; Larra, Mauro F; Schilling, Thomas M; Lass-Hennemann, Johanna; Blumenthal, Terry D; Schächinger, Hartmut

    2015-06-01

    Although salient stimuli are known to modulate startle eye-blink responses, and one's own face is considered of particular salience, effects of facial self-resemblance on startle responsiveness have not been systematically investigated. For the present study, pictures from the FACES database (rated as neutral) were digitally morphed to resemble the participants' (N=37) faces to varying degrees (25-50-75%). Perceptually matched geometrical shapes served as a control condition. At SOAs of either 300ms or 3000ms after picture onset, startle responses were elicited by white noise (50ms, 105dB), and recorded at the orbicularis oculi via EMG. Prior to the experiment, self-reported mood was assessed by means of the PANAS. Relative to non-face stimuli, the presentation of faces reduced startle magnitude at short, but not long, lead intervals. Furthermore, for probes presented at a SOA of 300ms, a linear decrease in startle magnitude with higher levels of self-resemblance was observed, presumably reflecting higher salience of the self-face. The startle modulating effect of self-resembling faces during longer lead intervals was moderated by the participants' current mood: negative affect predicted stronger patterns of attenuation, which might be interpreted as an increase in self-focus resulting from more negative mood. PMID:25913094

  14. Blink rate variability in patients with panic disorder: new trial using audiovisual stimulation.

    PubMed

    Kojima, Maki; Shioiri, Toshiki; Hosoki, Toshihiro; Sakai, Miwako; Bando, Takehiko; Someya, Toshiyuki

    2002-10-01

    Several lines of evidence have implicated central dopaminergic pathways in the modulation of spontaneous blink rate (BR). Furthermore, previous studies have indicated a relationship between spontaneous BR and anxiety and/or depression. However, to our knowledge, there is no report on the examination of BR in a group of patients with panic disorder (PD). During the conditions of rest and with audiovisual stimulation, exposed to a video of imaginary experiences, such as driving a motor vehicle or diving into the sea, BR was examined in 11 male patients with PD and compared with the BR of 16 age-matched normal controls. The BR was significantly higher in PD patients relative to normal controls under both conditions. In particular, the PD group had a higher BR score during the sea scene as relaxation compared with the normal controls. In conclusion, although the sample size was small the present preliminary study, these findings suggest that BR may have potential for application in the assessment of anxiety state, which is consistent with previous studies. PMID:12193245

  15. Fearful, but not Angry, Expressions Diffuse Attention to Peripheral Targets in an Attentional Blink Paradigm

    PubMed Central

    Taylor, James M.; Whalen, Paul J.

    2014-01-01

    We previously demonstrated that, within a passive viewing task, fearful facial expressions implicitly facilitate memory for contextual events, while angry facial expressions do not (Davis et al., 2011). The current study sought to more directly address the implicit effect of fearful expressions on attention for contextual events within a classic attentional paradigm (i.e., the attentional blink) where memory is tested on a trial-by-trial basis, thereby providing subjects with a clear explicit attentional strategy. Neutral faces of a single gender were presented via rapid serial visual presentation (RSVP) while bordered by four gray pound signs. Participants were told to watch for a gender change within the sequence (T1). Critically, the T1 face displayed either a neutral, fearful, or angry expression. Subjects were also told to detect a color change (i.e., gray to green; T2) at one of the four pound sign locations appearing after T1. This T2 color change could appear at one of six temporal positions. Participants were told to respond via button press immediately when a T2 target was presented. We found that fearful, compared to the neutral T1 faces, significantly increased target detection ability at four of the six temporal locations (all p’s < .05) while angry expressions showed no such effects. The results of this study suggest that fearful facial expressions can uniquely and implicitly enhance environmental monitoring above and beyond explicit attentional effects related to task instructions. PMID:24708498

  16. Inducing attention not to blink: auditory entrainment improves conscious visual processing.

    PubMed

    Ronconi, Luca; Pincham, Hannah L; Szűcs, Dénes; Facoetti, Andrea

    2016-09-01

    Our ability to allocate attention at different moments in time can sometimes fail to select stimuli occurring in close succession, preventing visual information from reaching awareness. This so-called attentional blink (AB) occurs when the second of two targets (T2) is presented closely after the first (T1) in a rapid serial visual presentation (RSVP). We hypothesized that entrainment to a rhythmic stream of stimuli-before visual targets appear-would reduce the AB. Experiment 1 tested the effect of auditory entrainment by presenting sounds with a regular or irregular interstimulus interval prior to a RSVP where T1 and T2 were separated by three possible lags (1, 3 and 8). Experiment 2 examined visual entrainment by presenting visual stimuli in place of auditory stimuli. Results revealed that irrespective of sensory modality, arrhythmic stimuli preceding the RSVP triggered an alerting effect that improved the T2 identification at lag 1, but impaired the recovery from the AB at lag 8. Importantly, only auditory rhythmic entrainment was effective in reducing the AB at lag 3. Our findings demonstrate that manipulating the pre-stimulus condition can reduce deficits in temporal attention characterizing the human cognitive architecture, suggesting innovative trainings for acquired and neurodevelopmental disorders. PMID:26215434

  17. Revisiting within-modality and cross-modality attentional blinks: effects of target-distractor similarity.

    PubMed

    Arnell, Karen M; Jenkins, Ryan

    2004-10-01

    When two masked targets (T1 and T2) require attention and are presented within half a second of each other, the report accuracy for T2 is reduced, relative to when the two targets are presented farther apart in time. This effect is known as the attentional blink (AB). Potter, Chun, Banks, and Muckenhoupt (1998) argued that all AB-like effects observed when at least one of the targets was presented outside of the visual modality did not represent true instances of the AB, but instead were artifacts of task-set switching. However, in the Potter et al. experiments the presence or absence of task-set switching opportunities was confounded with the T2 task, as well as the alphanumeric class of T2 with respect to the distractors. In the present experiment, we examine the influence of T1 alphanumeric class, T2 alphanumeric class, and switching operations in a fully crossed design that unconfounds these factors. In contrast to the conclusions of Potter et al., the present results suggest that the T2 alphanumeric class can account for the pattern of ABs observed across conditions, without necessarily implicating a separate switch cost. The implications for theoretical models of the AB and the debate over the validity of cross-modal ABs are discussed. PMID:15751472

  18. Characterization of Vertical Ozonesonde Measurements in Equatorial Regions Utilizing the Cooperative Enterprise SHADOZ

    NASA Technical Reports Server (NTRS)

    Schmidlin, F. J.; Thompson, A. M.; Holdren, D. H.; Northam, E. T.; Witte, J. C.; Oltmans, S. J.; Hoegger, B.; Levrat, G. M.; Kirchhoff, V.

    2000-01-01

    Vertical ozone profiles between the Equator and 10 S latitude available from the Southern Hemisphere Additional Ozone (SHADOZ) program provide consistent data Ozone sets from up to 10 sounding locations. SHADOZ designed to provide independent ozone profiles in the tropics for evaluation of satellite ozone data and models has made available over 600 soundings over the period 1998-1999. These observations provide an ideal data base for the detailed description of ozone and afford differential comparison between sites. TOMS total ozone when compared with correlative integrated total ozone overburden from the sondes is found to be negatively biased when using the classical constant mixing ratio procedure to determine residual ozone. On the other hand, the climatological method proposed by McPeters and Labow appears to give consistent results but is positively biased. The longer then two years series of measurements also was subjected to harmonic analysis to examine data cycles. These will be discussed as well.

  19. Utilizing Operational and Improved Remote Sensing Measurements to Assess Air Quality Monitoring Model Forecasts

    NASA Astrophysics Data System (ADS)

    Gan, Chuen-Meei

    Air quality model forecasts from Weather Research and Forecast (WRF) and Community Multiscale Air Quality (CMAQ) are often used to support air quality applications such as regulatory issues and scientific inquiries on atmospheric science processes. In urban environments, these models become more complex due to the inherent complexity of the land surface coupling and the enhanced pollutants emissions. This makes it very difficult to diagnose the model, if the surface parameter forecasts such as PM2.5 (particulate matter with aerodynamic diameter less than 2.5 microm) are not accurate. For this reason, getting accurate boundary layer dynamic forecasts is as essential as quantifying realistic pollutants emissions. In this thesis, we explore the usefulness of vertical sounding measurements on assessing meteorological and air quality forecast models. In particular, we focus on assessing the WRF model (12km x 12km) coupled with the CMAQ model for the urban New York City (NYC) area using multiple vertical profiling and column integrated remote sensing measurements. This assessment is helpful in probing the root causes for WRF-CMAQ overestimates of surface PM2.5 occurring both predawn and post-sunset in the NYC area during the summer. In particular, we find that the significant underestimates in the WRF PBL height forecast is a key factor in explaining this anomaly. On the other hand, the model predictions of the PBL height during daytime when convective heating dominates were found to be highly correlated to lidar derived PBL height with minimal bias. Additional topics covered in this thesis include mathematical method using direct Mie scattering approach to convert aerosol microphysical properties from CMAQ into optical parameters making direct comparisons with lidar and multispectral radiometers feasible. Finally, we explore some tentative ideas on combining visible (VIS) and mid-infrared (MIR) sensors to better separate aerosols into fine and coarse modes.

  20. Measuring an antibody affinity distribution molecule by molecule

    SciTech Connect

    Bradbury, Andrew M; Werner, James H; Temirov, Jamshid

    2008-01-01

    Single molecule fluorescence mIcroscopy was used to observe the binding and unbinding of hapten decorated quantum dots with individual surface immobilized antibodies. The fluorescence time history from an individual antibody site can be used to calculate its binding affinity. While quantum dot blinking occurs during these measurements, we describe a simple empirical method to correct the apparent/observed affinity to account for the blinking contribution. The combination of many single molecule affinity measurements from different antibodies yields not only the average affinity, it directly measures the full shape and character of the surface affinity distribution function.

  1. Utility of Ion Mobility Mass Spectrometry for Drug-to-Antibody Ratio Measurements in Antibody-Drug Conjugates

    NASA Astrophysics Data System (ADS)

    Huang, Richard Y.-C.; Deyanova, Ekaterina G.; Passmore, David; Rangan, Vangipuram; Deshpande, Shrikant; Tymiak, Adrienne A.; Chen, Guodong

    2015-06-01

    Antibody-drug conjugates (ADCs) are emerging modalities in the pharmaceutical industry. Characterization of ADC's drug-to-antibody ratio (DAR) becomes a key assessment because of its importance in ADC efficacy and safety. DAR characterization by conventional intact protein MS analysis, however, is challenging because of high heterogeneity of ADC samples. The analysis often requires protein deglycosylation, disulfide-bond reduction, or partial fragmentation. In this study, we illustrate the practical utility of ion mobility mass spectrometry (IM-MS) in a routine LC/MS workflow for DAR measurements. This strategy allows analyte "cleanup" in the gas phase, providing significant improvement of signal-to-noise ratios of ADC intact mass spectra for accurate DAR measurements. In addition, protein drift time analysis offers a new dimension in monitoring the changes of DAR in lot-to-lot analysis.

  2. Utilizing CAD/CAM to Measure Total Occlusal Convergence of Preclinical Dental Students' Crown Preparations.

    PubMed

    Mays, Keith A; Crisp, H Alex; Vos, Paul

    2016-01-01

    Traditionally, faculty assessment of preclinical crown preparations occurs by visualizing preparation features. However, contemporary CAD/CAM tools have the ability to more precisely evaluate preparation features, which is beneficial for psychomotor development. Taper is one of the most challenging features to objectively assess. The aim of this study was twofold: first, to validate the software's ability to distinguish differences in taper, and second, to compare traditional faculty assessment with digital assessment of taper. In the study, 30 all-metal crown preparations were created on typodont teeth with varying degrees of axial reduction and placed into three groups based on amount of taper (minimum, moderate, or excessive). Each tooth was scanned with the D4D scanner, and the taper was analyzed using E4D Compare. A second experiment used 50 crown preparations of tooth #19, which were done as a formative exercise. A comparison faculty assessment with CAD/CAM assessments of taper was performed. The results showed that when the taper was varied, E4D Compare was able to distinguish those differences; the Tukey post-hoc test revealed a significant difference (p=0.001). The qualitative analysis comparing faculty grading to CAD/CAM grading demonstrated a trend for CAD/CAM to be more precise. These results suggest that E4D Compare is an effective means of quantitatively measuring the amount of total occlusal convergence or taper on a crown preparation and that digital assessment may be more precise than faculty visual grading. PMID:26729690

  3. Characterization of compounds by time-of-flight measurement utilizing random fast ions

    DOEpatents

    Conzemius, Robert J.

    1989-01-01

    An apparatus for characterizing the mass of sample and daughter particles, comprising a source for providing sample ions; a fragmentation region wherein a fraction of the sample ions may fragment to produce daughter ion particles; an electrostatic field region held at a voltage level sufficient to effect ion-neutral separation and ion-ion separation of fragments from the same sample ion and to separate ions of different kinetic energy; a detector system for measuring the relative arrival times of particles; and processing means operatively connected to the detector system to receive and store the relative arrival times and operable to compare the arrival times with times detected at the detector when the electrostatic field region is held at a different voltage level and to thereafter characterize the particles. Sample and daughter particles are characterized with respect to mass and other characteristics by detecting at a particle detector the relative time of arrival for fragments of a sample ion at two different electrostatic voltage levels. The two sets of particle arrival times are used in conjunction with the known altered voltage levels to mathematically characterize the sample and daughter fragments. In an alternative embodiment the present invention may be used as a detector for a conventional mass spectrometer. In this embodiment, conventional mass spectrometry analysis is enhanced due to further mass resolving of the detected ions.

  4. Characterization of compounds by time-of-flight measurement utilizing random fast ions

    DOEpatents

    Conzemius, R.J.

    1989-04-04

    An apparatus is described for characterizing the mass of sample and daughter particles, comprising a source for providing sample ions; a fragmentation region wherein a fraction of the sample ions may fragment to produce daughter ion particles; an electrostatic field region held at a voltage level sufficient to effect ion-neutral separation and ion-ion separation of fragments from the same sample ion and to separate ions of different kinetic energy; a detector system for measuring the relative arrival times of particles; and processing means operatively connected to the detector system to receive and store the relative arrival times and operable to compare the arrival times with times detected at the detector when the electrostatic field region is held at a different voltage level and to thereafter characterize the particles. Sample and daughter particles are characterized with respect to mass and other characteristics by detecting at a particle detector the relative time of arrival for fragments of a sample ion at two different electrostatic voltage levels. The two sets of particle arrival times are used in conjunction with the known altered voltage levels to mathematically characterize the sample and daughter fragments. In an alternative embodiment the present invention may be used as a detector for a conventional mass spectrometer. In this embodiment, conventional mass spectrometry analysis is enhanced due to further mass resolving of the detected ions. 8 figs.

  5. Electrical Maxwell demon and Szilard engine utilizing Johnson noise, measurement, logic and control.

    PubMed

    Kish, Laszlo Bela; Granqvist, Claes-Göran

    2012-01-01

    We introduce a purely electrical version of Maxwell's demon which does not involve mechanically moving parts such as trapdoors, etc. It consists of a capacitor, resistors, amplifiers, logic circuitry and electronically controlled switches and uses thermal noise in resistors (Johnson noise) to pump heat. The only types of energy of importance in this demon are electrical energy and heat. We also demonstrate an entirely electrical version of Szilard's engine, i.e., an information-controlled device that can produce work by employing thermal fluctuations. The only moving part is a piston that executes work, and the engine has purely electronic controls and it is free of the major weakness of the original Szilard engine in not requiring removal and repositioning the piston at the end of the cycle. For both devices, the energy dissipation in the memory and other binary informatics components are insignificant compared to the exponentially large energy dissipation in the analog part responsible for creating new information by measurement and decision. This result contradicts the view that the energy dissipation in the memory during erasure is the most essential dissipation process in a demon. Nevertheless the dissipation in the memory and information processing parts is sufficient to secure the Second Law of Thermodynamics. PMID:23077525

  6. Utility of measuring FEV0.75/FVC ratio in preschoolers with uncontrolled wheezing disorder.

    PubMed

    Nève, Véronique; Hulo, Sébastien; Edmé, Jean-Louis; Boileau, Sophie; Baquet, Georges; Pouessel, Guillaume; Thumerelle, Caroline; Deschildre, Antoine; Matran, Régis

    2016-08-01

    Uncontrolled wheezing disorder is common in preschoolers and disease control assessment is challenging as parents frequently overestimate the extent to which their child's disease is controlled. This is the first study of forced expiratory volume in t s (FEVt)/forced vital capacity (FVC) ratio measurements (i.e. FEV1/FVC, FEV0.75/FVC and FEV0.5/FVC) in wheezy preschoolers in relation to disease control. Our objective was to evaluate whether FEVt/FVC ratios less than the lower limit of normal (LLN; z-score <-1.64) were associated with uncontrolled wheezing disorder in preschoolers.Valid FVC, FEV1, FEV0.75 and FEV0.5 values were obtained in 92 healthy and 125 wheezy (62% uncontrolled) children (3-5 years). Associations between spirometry value

  7. Measuring Family HRQoL Spillover Effects Using Direct Health Utility Assessment

    PubMed Central

    Lamarand, Kara; Gebremariam, Acham; Wittenberg, Eve

    2015-01-01

    Background. Applications of cost-effectiveness analysis do not typically incorporate effects on caregiver quality of life despite increasing evidence that these effects are measurable. Methods. Using a national sample of US adults, we conducted 2 cross-sectional surveys during December 2011 and January 2012. One version asked respondents to value their own experience as the family member of a person with a chronic illness (experienced sample), and the other version asked respondents to value hypothetical scenarios describing the experience of having a family member with a chronic illness (community sample). Conditions included Alzheimer’s disease/dementia, arthritis, cancer, and depression. Using standard gamble questions, respondents were asked to value the spillover effects of a family member’s illness. We used regression analysis to evaluate the disutility (loss in health-related quality of life) of having a family member with a chronic illness by condition and relationship type, controlling for the respondent’s own conditions and sociodemographic characteristics. Results. For the experienced sample (n = 1389), regression analyses suggested that greater spillover was associated with certain conditions (arthritis, depression) compared with other conditions (Alzheimer’s disease, cancer). For the community sample (n = 1205), regression analyses indicated that lower spillover was associated with condition (cancer) but not the type of relationship with the ill family member (parent, child, spouse). Conclusions. The effects of illness extend beyond the individual patient to include effects on caregivers of patients, parents of ill children, spouses, and other close family and household members. Cost-effectiveness analyses should consider the inclusion of health-related quality of life spillover effects in addition to caregiving time costs incurred by family members of ill individuals. PMID:25057048

  8. Measurements and properties of ice particles and carbon dioxide bubbles in aqueous mixture utilizing optical techniques

    NASA Astrophysics Data System (ADS)

    Diallo, Amadou O.

    Optical techniques are used to determine the size, shape and many other properties of particles ranging from the micro to a nano-level. These techniques have endless applications. This research is based on a project assigned by a "Vendor" that wants anonymity. The Leica optical microscope and the Dark Field Polarizing Metallurgical Microscope is used to determine the size and count of ice crystals (Vendors products) in multiple time frames. Since the ice temperature influences, its symmetry and the shape is subject to changes at room temperature (300 K) and the atmospheric pressure that is exerted on the ice crystals varies. The ice crystals are in a mixture of water, electrolytes and carbon dioxide with the optical spectroscopy (Qpod2) and Spectra suite, the optical density of the ice crystals is established from the absorbance and transmission measurements. The optical density in this case is also referred to as absorption; it is plotted with respect to a frequency (GHz), wavelength (nm) or Raman shift (1/cm) which shows the light colliding with the ice particles and CO2. Depending on the peaks positions, it is possible to profile the ice crystal sizes using a mean distribution plots. The region of absorbency wavelength expected for the ice is in the visible range; the water molecules in the (UV) Ultra-violet range and the CO2 in the (IR) infrared region. It is also possible to obtain the reflection and transmission output as a percentage change with the wavelengths ranging from 200 to 1100 nm. The refractive index of the ice can be correlated to the density based on the optical acoustic theorem, or Mie Scattering Theory. The viscosity of the ice crystals and the solutions from which the ice crystals are made of as well are recorded with the SV-10 viscometer. The baseline viscosity is used as reference and set lower than that of the ice crystals. The Zeta potential of the particles present in the mixture are approximated by first finding the viscosity of the

  9. Measures and procedures utilized to determine the added value of microprocessor-controlled prosthetic knee joints: a systematic review

    PubMed Central

    2013-01-01

    Background The effectiveness of microprocessor-controlled prosthetic knee joints (MPKs) has been assessed using a variety of outcome measures in a variety of health and health-related domains. However, if the patient is to receive a prosthetic knee joint that enables him to function optimally in daily life, it is vital that the clinician has adequate information about the effects of that particular component on all aspects of persons’ functioning. Especially information concerning activities and participation is of high importance, as this component of functioning closely describes the person’s ability to function with the prosthesis in daily life. The present study aimed to review the outcome measures that have been utilized to assess the effects of microprocessor-controlled prosthetic knee joints (MPK), in comparison with mechanically controlled prosthetic knee joints, and aimed to classify these measures according to the components and categories of functioning defined by the International Classification of Functioning, Disability and Health (ICF). Subsequently, the gaps in the scientific evidence regarding the effectiveness of MPKs were determined. Methods A systematic literature search in 6 databases (i.e. PubMed, CINAHL, Cochrane Library, Embase, Medline and PsychInfo) identified scientific studies that compared the effects of using MPKs with mechanically controlled prosthetic knee joints on persons’ functioning. The outcome measures that have been utilized in those studies were extracted and categorized according to the ICF framework. Also, a descriptive analysis regarding all studies has been performed. Results A total of 37 studies and 72 outcome measures have been identified. The majority (67%) of the outcome measures that described the effects of using an MPK on persons’ actual performance with the prosthesis covered the ICF body functions component. Only 31% of the measures on persons’ actual performance investigated how an MPK may affect

  10. Different behaviour of molecules in dark SERS state on colloidal Ag nanoparticles estimated by truncated power law analysis of blinking SERS.

    PubMed

    Kitahama, Yasutaka; Araki, Daichi; Yamamoto, Yuko S; Itoh, Tamitake; Ozaki, Yukihiro

    2015-09-01

    For single colloidal Ag nanoaggregates, covered with either large or small amounts of citrate anions, blinking surface-enhanced Raman scattering (SERS) of anionic thiacyanine was measured and analyzed by a truncated power law. The power law without and with an exponential function reproduces a probability distribution for bright and dark SERS events versus their duration times, respectively. On the Ag surface, except for junctions of the nanoaggregate with a large or small amount of the citrate anions, two-dimensional fast or one-dimensional slow random walk of the anionic thiacyanine, respectively, was estimated by the exponents and the truncation times in the power law for the dark SERS events. In addition, the power law exponents for the bright SERS events were derived to be of similar values, indicating a similar molecular random walk near the junction, which may be dominated evenly by a surface-plasmon-enhanced electromagnetic field on the same-sized Ag nanoaggregate. Thus, not only the bright SERS, but also the dark SERS molecular behaviour on the Ag surface was investigated by the truncated power law analysis. PMID:25571862

  11. The attentional blink is not affected by backward masking of T2, T2-mask SOA, or level of T2 impoverishment.

    PubMed

    Jannati, Ali; Spalek, Thomas M; Lagroix, Hayley E P; Di Lollo, Vincent

    2012-02-01

    Identification of the second of two targets (T2) is impaired when presented shortly after the first (T1). This attentional blink (AB) is thought to arise from a delay in T2 processing during which T2 is vulnerable to masking. Conventional studies have measured T2 accuracy which is constrained by the 100% ceiling. We avoided this problem by using a dynamic threshold-tracking procedure that is inherently free from ceiling constraints. In two experiments we examined how AB magnitude is affected by three masking-related factors: (a) presence/absence of T2 mask, (b) T2-mask stimulus onset asynchrony (SOA), and (c) level of T2 impoverishment (signal-to-noise ratio [SNR]). In Experiment 1, overall accuracy decreased with T2-mask SOA. The magnitude of the AB, however, was invariant with SOA and with mask presence/absence. Experiment 2 further showed that the AB was invariant with T2 SNR. The relationship among mask presence/absence, SOA, and T2 SNR and the AB is encompassed in a qualitative model. PMID:22060143

  12. The use of bilateral blink reflexes in intraoperative monitoring of facial-trigeminal nerves in cerebello-pontine angle operations

    PubMed Central

    Jamshidi Fard, Alireza; Dalvandi, Mohsen; Mohammadi, Alireza

    2012-01-01

    Abstract: Background: Intraoperative monitoring (IOM) of facial nerve is routinely recommended in Cerebello-Pontine Angle (CP Angle) operations. Middle cranial nerves: V, VII, VIII are mainly involved since these nerves are sometimes separated by the tumor mass causing an inadvertent section of the facial nerve. Blink reflex could be elicited by stimulation of supraorbital branch of Trigeminal nerve which elicits EMG responses in facial muscles. Threshold, amplitude, latencies, pre-post surgery are strong predictors of postoperative facial function. Methods: In 17 cases of CP angle tumors (24-43 mm, by MRI) approached suboccipitally, we performed bilateral blink reflexes pre/intra/post surgery. The setup consisted of a Nicolet Endeavor IOM system( VIASYS Healthcare, 2005, USA) with the ability to perform several voltage/current stimulations and recordingsup to 20 Evoked Potentials and Electromyography (EMG) simultaneously. Bilateral blink reflexes were evoked by stimulation of bilateral supraorbital nerves. Stimulating pulses of 0.1 ms duration and 5-20 mA intensity were applied percutaneously at the intervals of 10-20 s. The orbicularis oculi muscle responses were recorded using surface electrodes. Early EMG responses (R1) and later reflex activities (R2) were elicited ipsi/contra laterally (R1/2-i/c). Every five successive trials were superimposed and the lowest latencies were used for comparison. Blink reflexes of each subject considered pathologic if: 1- Loss of R1-i,c to the operation side, latencies are more than 15 ms or side differences are 3 ms or more; 2- Loss of R2-i, latencies are more than 50 ms or side differences are 10 ms or more. 3- Loss of R2-c, latencies are more than 55 ms or side differences are 10 ms or more. Recordings were performed 2-3 days before operaration, intraoperative and 21 days after operation. Results: Before surgery, in 15 subjects, the amplitudes of R1-i responses were significantly lower than the R1-c. However, in 2 cases with

  13. Tracking the attentional blink profile: a cross-sectional study from childhood to adolescence

    PubMed Central

    Heim, Sabine; Benasich, April A.; Wirth, Nadine; Keil, Andreas

    2014-01-01

    This cross-sectional study is the first to examine the developmental trajectory of temporal attention control from childhood to adolescence. We used a rapid serial visual presentation paradigm, calling for the identification of two targets (T1 and T2) embedded in a distractor stream. In adults, manipulating the lag time within the target doublet typically leads to pronounced impairment in report for T2, when it follows T1 after approximately 200 ms, with one intervening distractor (lag 2); this is referred to as the attentional blink (AB). Participants, however, tend to identify T2 more often when the targets have occurred in a row (“lag-1 sparing”), or are separated by larger lag times, resulting in a hook-shaped accuracy profile. Here, we investigated the extent to which this AB profile undergoes systematic developmental changes in 204 students aged between 6 and 16 years (grades 1–10). T1–T2 lags varied from zero up to seven intervening distractors. Behavioral accuracy in younger children (grades 1–2) was found to follow a linear path, having its minimum at the earliest lag. Lag-1 sparing, accompanied by a relative accuracy loss in the AB interval, first appeared in grade 3, and became more robust in grade 4. From grades 5 to 6, the hook-shaped profile remained stable, with steady increases in overall performance up through the highest grades. This suggests that younger children’s performance is limited by processing speed, while from preadolescence on, children are increasingly able to identify rapid target sequences at the cost of an interference sensitive, higher control system. PMID:24337973

  14. Dynamics of a pre-lens tear film after a blink: Model, evolution, and rupture

    NASA Astrophysics Data System (ADS)

    Usha, R.; Anjalaiah, Sanyasiraju, Y. V. S. S.

    2013-11-01

    A mathematical model is developed to investigate the dynamics and rupture of a pre-lens tear film on a contact lens. The contact lens is modeled as a saturated porous medium of constant, finite thickness and is described by the Darcy-Brinkman equations with stress-jump condition at the interface. The model incorporates the influence of capillarity, gravitational drainage, contact lens properties such as the permeability, the porosity, and the thickness of the contact lens on the evolution and rupture of a pre-lens tear film, when the eyelid has opened after a blink. Two models are derived for the evolution of a pre-lens tear film thickness using lubrication theory and are solved numerically; the first uses shear-free surface condition and the second, the tangentially immobile free surface condition. The results reveal that life span of a pre-lens tear film is longer on a thinner contact lens for all values of permeability and porosity parameter considered. An increase in permeability of contact lens, porosity or stress-jump parameter increases the rate of thinning of the film and advances the rupture time. The viscous-viscous interaction between the porous contact lens and the pre-lens tear film increases the resistance offered by the frictional forces to the rate of thinning of pre-lens tear film. This slows down the thinning process and hence delays the rupture of the film as compared to that predicted by the models of Nong and Anderson [SIAM. J. Appl. Math. 70, 2771-2795 (2010)] derived in the framework of Darcy model.

  15. Blink reflexes in patients with atypical odontalgia and matched healthy controls.

    PubMed

    Baad-Hansen, Lene; List, Thomas; Kaube, Holger; Jensen, Troels S; Svensson, Peter

    2006-07-01

    Atypical odontalgia (AO) is an orofacial pain condition which has been suggested to involve neuropathic pain mechanisms. The aim of this study was to use a brain stem reflex to investigate craniofacial nociceptive mechanisms in AO. In 38 AO patients and 27 matched healthy controls, the R2 component of the blink reflex (BR) was elicited using a "nociceptive-specific" electrode and recorded with surface electromyography electrodes on both orbicularis oculi muscles. The BR was tested by stimulation of both sides of the face of the participants before, during, and after an intraoral pain provocation test with capsaicin. The data were analyzed with three- and four-way mixed-model analyses of variance. The root mean square value of the ipsilateral R2 (R2i) was significantly reduced in patients compared with controls (P=0.046). No differences in R2 between stimulation sides were detected in either group (P>0.757). In all participants, R2 responses and the intensity of the pain evoked by the electrical stimulus were decreased during and after application of capsaicin compared with baseline (P<0.001). In patients, R2i onset latencies were significantly prolonged compared with controls (P=0.031). The present data show disturbances in the central processing of craniofacial information and that endogenous pain inhibitory systems in AO patients and healthy controls were activated to a similar degree by an acute intraoral nociceptive input. Additional clinical research with AO patients will be needed to determine to what extent neuropathic pain mechanisms are involved in this pain condition. PMID:16489436

  16. Distraction by emotion in early adolescence: affective facilitation and interference during the attentional blink

    PubMed Central

    Heim, Sabine; Benasich, April A.; Keil, Andreas

    2013-01-01

    This study examined the extent to which early adolescents (aged 10–13 years) differ from adults in their sensitivity to attention capture by affective stimuli during rapid processing. A rapid serial visual presentation paradigm (RSVP) was implemented as a dual task, requiring the report of two green target stimuli embedded in a stream of distractors. Known as the “attentional blink” (AB), task performance is typically impaired when the first and second targets (T1 and T2, respectively) are separated by at least one distractor and about 200 ms of time. Here we used written verbs of pleasant, neutral, and unpleasant content as T1 items, while affectively neutral exemplars served as T2 and distractor events. The temporal distance between T1 and T2 was manipulated to contain either one distractor (intertarget interval 232 ms) or five distractors (intertarget interval 696 ms). Students reported pleasant T1 words more accurately, compared to neutral and unpleasant words, indicating facilitation of appetitive content on performance during RSVP. Emotional relevance of T1 was at the expense of T2 accuracy: at an intertarget interval of 232 ms (i.e., during the AB period), identification of (neutral) T2 words was impaired when preceded by pleasant and unpleasant T1s. No interference across targets was observed, however, beyond the blink period, in which T1 and T2 were separated by 696 ms. Thus, emotionally relevant events capture and hold attentional resources, at the cost of attentive processing in subsequent episodes. Contrary to our findings in adults, these capture effects were most obvious when the available capacity was limited, i.e., during the critical interval of the AB. The findings are discussed in light of the use of alternative cognitive strategies as development proceeds beyond early adolescence into adulthood. PMID:24027547

  17. Abnormal blink reflex recovery cycle in manifesting and nonmanifesting carriers of the DYT1 gene mutation.

    PubMed

    Fong, Po-Yu; Edwards, Mark J; Lu, Chin-Song; Chen, Rou-Shayn; Rothwell, John C; Bhatia, Kailash P; Huang, Ying-Zu

    2016-09-28

    The aim of this study is to evaluate the brainstem function in DYT1 carriers manifesting clinical dystonia (MDYT1) and those without clinical symptoms (NMDYT1). Motor cortical inhibition and plasticity were found to be abnormal in MDYT1, whereas these were less abnormal in NMDYT1. However, the spinal reciprocal inhibition was abnormal in MDYT1, but normal in NMDYT1. Moreover, protein accumulation and perinuclear inclusion bodies were found in the brainstem, but not in other brain areas, in DYT1 patients. Therefore, we designed this study to investigate the brainstem physiology using the blink reflex (BR) recovery cycle test in MDYT1 and NMDYT1. We recruited eight MDYT1, five NMDYT1, and nine age-matched healthy controls. The BR recovery cycle was assessed with paired stimuli that induced the BR in a random order at interstimulus intervals of 250, 500, and 1000 ms. A two-way analysis of variance showed a significant difference between MDYT1, NMDYT1, and the healthy control (P=0.004). Post-hoc analysis showed that this was because of a significantly lower inhibition of R2 in MDYT1 and NMDYT1 compared with the controls (two-way analysis of variance: P=0.003 and 0.021, respectively). There was no difference between MDYT1 and NMDYT1 (P=0.224). The tested brainstem circuits were equally involved in MDYT1 and NMDYT1. The finding is in agreement with the pathological findings in DYT1 carriers. Together with previous findings in the motor cortex and the spinal cord, the brainstem may lie closer to the pathogenesis of dystonia than the motor cortex in DYT1 gene carriers. PMID:27508977

  18. Character Decomposition and Transposition Processes in Chinese Compound Words Modulates Attentional Blink

    PubMed Central

    Cao, Hongwen; Gao, Min; Yan, Hongmei

    2016-01-01

    The attentional blink (AB) is the phenomenon in which the identification of the second of two targets (T2) is attenuated if it is presented less than 500 ms after the first target (T1). Although the AB is eliminated in canonical word conditions, it remains unclear whether the character order in compound words affects the magnitude of the AB. Morpheme decomposition and transposition of Chinese two-character compound words can provide an effective means to examine AB priming and to assess combinations of the component representations inherent to visual word identification. In the present study, we examined the processing of consecutive targets in a rapid serial visual presentation (RSVP) paradigm using Chinese two-character compound words in which the two characters were transposed to form meaningful words or meaningless combinations (reversible, transposed, or canonical words). We found that when two Chinese characters that form a compound word, regardless of their order, are presented in an RSVP sequence, the likelihood of an AB for the second character is greatly reduced or eliminated compared to when the two characters constitute separate words rather than a compound word. Moreover, the order of the report for the two characters is more likely to be reversed when the normal order of the two characters in a compound word is reversed, especially when the interval between the presentation of the two characters is extremely short. These findings are more consistent with the cognitive strategy hypothesis than the resource-limited hypothesis during character decomposition and transposition of Chinese two-character compound words. These results suggest that compound characters are perceived as a unit, rather than two separate words. The data further suggest that readers could easily understand the text with character transpositions in compound words during Chinese reading. PMID:27379003

  19. Character Decomposition and Transposition Processes in Chinese Compound Words Modulates Attentional Blink.

    PubMed

    Cao, Hongwen; Gao, Min; Yan, Hongmei

    2016-01-01

    The attentional blink (AB) is the phenomenon in which the identification of the second of two targets (T2) is attenuated if it is presented less than 500 ms after the first target (T1). Although the AB is eliminated in canonical word conditions, it remains unclear whether the character order in compound words affects the magnitude of the AB. Morpheme decomposition and transposition of Chinese two-character compound words can provide an effective means to examine AB priming and to assess combinations of the component representations inherent to visual word identification. In the present study, we examined the processing of consecutive targets in a rapid serial visual presentation (RSVP) paradigm using Chinese two-character compound words in which the two characters were transposed to form meaningful words or meaningless combinations (reversible, transposed, or canonical words). We found that when two Chinese characters that form a compound word, regardless of their order, are presented in an RSVP sequence, the likelihood of an AB for the second character is greatly reduced or eliminated compared to when the two characters constitute separate words rather than a compound word. Moreover, the order of the report for the two characters is more likely to be reversed when the normal order of the two characters in a compound word is reversed, especially when the interval between the presentation of the two characters is extremely short. These findings are more consistent with the cognitive strategy hypothesis than the resource-limited hypothesis during character decomposition and transposition of Chinese two-character compound words. These results suggest that compound characters are perceived as a unit, rather than two separate words. The data further suggest that readers could easily understand the text with character transpositions in compound words during Chinese reading. PMID:27379003

  20. Tracking the attentional blink profile: a cross-sectional study from childhood to adolescence.

    PubMed

    Heim, Sabine; Benasich, April A; Wirth, Nadine; Keil, Andreas

    2015-01-01

    This cross-sectional study is the first to examine the developmental trajectory of temporal attention control from childhood to adolescence. We used a rapid serial visual presentation paradigm, calling for the identification of two targets (T1 and T2) embedded in a distractor stream. In adults, manipulating the lag time within the target doublet typically leads to pronounced impairment in report for T2, when it follows T1 after approximately 200 ms, with one intervening distractor (lag 2); this is referred to as the attentional blink (AB). Participants, however, tend to identify T2 more often when the targets have occurred in a row ("lag-1 sparing"), or are separated by larger lag times, resulting in a hook-shaped accuracy profile. Here, we investigated the extent to which this AB profile undergoes systematic developmental changes in 204 students aged between 6 and 16 years (grades 1-10). T1-T2 lags varied from zero up to seven intervening distractors. Behavioral accuracy in younger children (grades 1-2) was found to follow a linear path, having its minimum at the earliest lag. Lag-1 sparing, accompanied by a relative accuracy loss in the AB interval, first appeared in grade 3, and became more robust in grade 4. From grades 5-6, the hook-shaped profile remained stable, with steady increases in overall performance up through the highest grades. This suggests that younger children's performance is limited by processing speed, while from preadolescence onwards, children are increasingly able to identify rapid target sequences at the cost of an interference sensitive, higher control system. PMID:24337973

  1. The Observed Variance Between Predicted and Measured Radiation Dose in Breast and Prostate Patients Utilizing an In Vivo Dosimeter

    SciTech Connect

    Scarantino, Charles W. Prestidge, Bradley R.; Anscher, Mitchel S.; Ferree, Carolyn R.; Kearns, William T.; Black, Robert D.; Bolick, Natasha G.; Beyer, Gloria P.

    2008-10-01

    Purpose: Report the results of using a permanently implantable dosimeter in radiation therapy: determine specific adverse events, degree of migration, and acquire dose measurements during treatment to determine difference between expected and measured dose. Methods and Materials: The Dose Verification System is a wireless, permanently implantable metal-oxide semiconductor field-effect transistor dosimeter using a bidirectional antenna for power and data transfer. The study cohort includes 36 breast (33 patients received two devices) and 29 prostate (21 patients received two devices) cancer patients. A total of 1,783 and 1,749 daily dose measurements were obtained on breast and prostate patients, respectively. The measurements were compared with the planned expected dose. Biweekly computed tomography scans were obtained to evaluate migration and the National Cancer Institute's Common Toxicity Criteria, version 3, was used to evaluate adverse events. Results: Only Grade I/II adverse events of pain and bleeding were noted. There were only four instances of dosimeter migration of >5 mm from known factors. A deviation of {>=}7% in cumulative dose was noted in 7 of 36 (19%) for breast cancer patients. In prostate cancer patients, a {>=}7% deviation was noted in 6 of 29 (21%) and 8 of 19 (42%) during initial and boost irradiation, respectively. The two patterns of dose deviation were random and systematic. Some causes for these differences could involve organ movement, patient movement, or treatment plan considerations. Conclusions: The Dose Verification System was not associated with significant adverse events or migration. The dosimeter can measure dose in situ on a daily basis. The accuracy and utility of the dose verification system complements current image-guided radiation therapy and intensity-modulated radiation therapy techniques.

  2. Two blinking mechanisms in highly confined AgInS2 and AgInS2/ZnS quantum dots evaluated by single particle spectroscopy

    NASA Astrophysics Data System (ADS)

    Cichy, B.; Rich, R.; Olejniczak, A.; Gryczynski, Z.; Strek, W.

    2016-02-01

    Ternary AgInS2 quantum dots (QDs) have been found as promising cadmium-free, red-shifted, and tunable luminescent bio-probes with efficient Stokes and anti-Stokes excitations and luminescence lifetimes (ca. 100 ns) convenient for time resolved techniques like fluorescence life-time imaging. Although the spectral properties of the AgInS2 QDs are encouraging, the complex recombination kinetics in the QDs being still far from understood, limits their full utility. In this paper we report on a model describing the recombination pathways responsible for large deviations from the first-order decay law observed commonly in the ternary chalcogenides. The presented results were evaluated by means of individual AgInS2 QD spectroscopy aided by first principles calculations including the electronic structure and structural reconstruction of the QDs. Special attention was devoted to study the impact of the surface charge state on the excited state relaxation and effect of its passivation by Zn2+ ion alloying. Two different blinking mechanisms related to defect-assisted charge imbalance in the QD responsible for fast non-radiative relaxation of the excited states as well as surface recharging of the QD were found as the major causes of deviations from the first-order decay law. Careful optimization of the AgInS2 QDs would help to fabricate new red-shifted and tunable fluorescent bio-probes characterized by low-toxicity, high quantum yield, long luminescence lifetime, and time stability, leading to many novel in vitro and in vivo applications based on fluorescence lifetime imaging (FLIM) and time-gated detection.Ternary AgInS2 quantum dots (QDs) have been found as promising cadmium-free, red-shifted, and tunable luminescent bio-probes with efficient Stokes and anti-Stokes excitations and luminescence lifetimes (ca. 100 ns) convenient for time resolved techniques like fluorescence life-time imaging. Although the spectral properties of the AgInS2 QDs are encouraging, the complex

  3. Oxygen Reduction Reaction Measurements on Platinum Electrocatalysts Utilizing Rotating Disk Electrode Technique: I. Impact of Impurities, Measurement Protocols and Applied Corrections

    SciTech Connect

    Shinozaki, Kazuma; Zack, Jason W.; Richards, Ryan M.; Pivovar, Bryan S.; Kocha, Shyam S.

    2015-07-22

    The rotating disk electrode (RDE) technique is being extensively used as a screening tool to estimate the activity of novel PEMFC electrocatalysts synthesized in lab-scale (mg) quantities. Discrepancies in measured activity attributable to glassware and electrolyte impurity levels, as well as conditioning, protocols and corrections are prevalent in the literature. Moreover, the electrochemical response to a broad spectrum of commercially sourced perchloric acid and the effect of acid molarity on impurity levels and solution resistance were also assessed. Our findings reveal that an area specific activity (SA) exceeding 2.0 mA/cm2 (20 mV/s, 25°C, 100 kPa, 0.1 M HClO4) for polished poly-Pt is an indicator of impurity levels that do not impede the accurate measurement of the ORR activity of Pt based catalysts. After exploring various conditioning protocols to approach maximum utilization of the electrochemical area (ECA) and peak ORR activity without introducing catalyst degradation, an investigation of measurement protocols for ECA and ORR activity was conducted. Down-selected protocols were based on the criteria of reproducibility, duration of experiments, impurity effects and magnitude of pseudo-capacitive background correction. In sum, statistical reproducibility of ORR activity for poly-Pt and Pt supported on high surface area carbon was demonstrated.

  4. Oxygen Reduction Reaction Measurements on Platinum Electrocatalysts Utilizing Rotating Disk Electrode Technique: I. Impact of Impurities, Measurement Protocols and Applied Corrections

    DOE PAGESBeta

    Shinozaki, Kazuma; Zack, Jason W.; Richards, Ryan M.; Pivovar, Bryan S.; Kocha, Shyam S.

    2015-07-22

    The rotating disk electrode (RDE) technique is being extensively used as a screening tool to estimate the activity of novel PEMFC electrocatalysts synthesized in lab-scale (mg) quantities. Discrepancies in measured activity attributable to glassware and electrolyte impurity levels, as well as conditioning, protocols and corrections are prevalent in the literature. Moreover, the electrochemical response to a broad spectrum of commercially sourced perchloric acid and the effect of acid molarity on impurity levels and solution resistance were also assessed. Our findings reveal that an area specific activity (SA) exceeding 2.0 mA/cm2 (20 mV/s, 25°C, 100 kPa, 0.1 M HClO4) for polishedmore » poly-Pt is an indicator of impurity levels that do not impede the accurate measurement of the ORR activity of Pt based catalysts. After exploring various conditioning protocols to approach maximum utilization of the electrochemical area (ECA) and peak ORR activity without introducing catalyst degradation, an investigation of measurement protocols for ECA and ORR activity was conducted. Down-selected protocols were based on the criteria of reproducibility, duration of experiments, impurity effects and magnitude of pseudo-capacitive background correction. In sum, statistical reproducibility of ORR activity for poly-Pt and Pt supported on high surface area carbon was demonstrated.« less

  5. A Theoretical Framework for Utilizing Long-Term Measurements of Radiation and Clouds for Solar Energy Research

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Xie, Y.

    2015-12-01

    One of the greatest challenges facing solar energy research is accurately predicting global horizontal irradiance (GHI) for photovoltaic (PV) modules and direct normal irradiance (DNI) for concentrated solar power (CSP) plants at the surface with a high temporal resolution. Addressing this solar energy challenge is tied ultimately to the quantitative relationship between the direct, diffuse and total radiation reaching the surface and clouds in the atmosphere, which remains elusive. Here we will first introduce a theoretical framework that relates DNI and GHI to cloud fraction and cloud albedo through two dimensionless numbers: the relative cloud radiative forcing for the direct radiation (defined as the difference between the clear sky and all sky direct downwelling radiative fluxes normalized by the clear sky direct downwelling radiative fluxes) is primarily determined by cloud fraction; the ratio of the relative cloud radiative forcing for the total downwelling radiation to the relative cloud radiative forcing for the direct radiation is primarily determined by cloud albedo. We then use decade-long measurements of partitioned radiation and cloud properties at the ARM sites to validate the theoretical relationships between the two dimensionless radiation-based parameters and cloud properties. We will also explore the potentials and challenges of using the relationships between cloud properties and radiation partition at the surface for solar energy research, opening new avenues to utilizing ARM measurements.

  6. CO{sub 2}-mitigation measures through reduction of fossil fuel burning in power utilities. Which road to go?

    SciTech Connect

    Kaupp, A.

    1996-12-31

    Five conditions, at minimum, should be examined in the comparative analysis of CO{sub 2}-mitigation options for the power sector. Under the continuing constraint of scarce financial resources for any private or public investment in the power sector, the following combination of requirements characterise a successful CO{sub 2}-mitigation project: (1) Financial attractiveness for private or public investors. (2) Low, or even negative, long range marginal costs per ton of `CO{sub 2} saved`. (3) High impact on CO{sub 2}-mitigation, which indicates a large market potential for the measure. (4) The number of individual investments required to achieve the impact is relatively small. In other words, logistical difficulties in project implementation are minimised. (5) The projects are `socially fair` and have minimal negative impact on any segment of the society. This paper deals with options to reduce carbonaceous fuel burning in the power sector. Part I explains how projects should be selected and classified. Part II describes the technical options. Since reduction of carbonaceous fuel burning may be achieved through Demand Side Management (DSM) and Supply Side Management (SSM) both are treated. Within the context of this paper SSM does not mean to expand power supply as demand grows. It means to economically generate and distribute power as efficiently as possible. In too many instances DSM has degenerated into efficient lighting programs and utility managed incentives and rebate programs. To what extent this is a desirable situation for utilities in Developing Countries that face totally different problems as their counterparts in highly industrialised countries remains to be seen. Which road to go is the topic of this paper.

  7. The Utility of in situ X-ray Standing Wave Measurements to Help Constrain Surface Complexation Models

    NASA Astrophysics Data System (ADS)

    Machesky, M. L.; Ridley, M. K.; Wesolowski, D. J.; Palmer, D. A.; Zhang, Z.; Fenter, P. A.; Sturchio, N. C.

    2002-12-01

    Macroscopic ion adsorption data are typically rationalized with the aid of various Surface Complexation Models in which ion binding to surface functional groups is combined with various Electrical Double Layer (EDL) Models. However, model results are very loosely constrained with macroscopic data alone since many combinations of model parameters can adequately fit experimental data. X-ray standing wave (XSW) measurements help to greatly constrain possible model parameters since the location and bonding geometry of ions within the compact layer of the EDL can be precisely determined. The utility of XSW in constraining Surface Complexation Models will be illustrated for the adsorption of Sr2+ on rutile. Macroscopic ion adsorption data are available for rutile powders (with the (110) crystal face dominant) from 25 to 250oC, and in 0.03 and 0.30m NaCl and RbCl media. Corresponding XSW measurements are available for single crystals of rutile terminated by the (110) crystal plane at 25oC. These XSW measurements indicate that Sr2+ is bound to 2 singly coordinated and 2 bridged surface hydroxyl groups in a tetradentate configuration, with the average distance from these groups being about 1.4 angstroms. These XSW data can be accommodated by a MUSIC Model description of the rutile (110) surface combined with Stern based representation of EDL structure with the result that model fitting parameters for the rutile powder data are tightly constrained. Consequently, a major advantage of this combination of results is a more realistic description of EDL structure for the rutile (110) surface.

  8. Hybrid EEG—Eye Tracker: Automatic Identification and Removal of Eye Movement and Blink Artifacts from Electroencephalographic Signal

    PubMed Central

    Mannan, Malik M. Naeem; Kim, Shinjung; Jeong, Myung Yung; Kamran, M. Ahmad

    2016-01-01

    Contamination of eye movement and blink artifacts in Electroencephalogram (EEG) recording makes the analysis of EEG data more difficult and could result in mislead findings. Efficient removal of these artifacts from EEG data is an essential step in improving classification accuracy to develop the brain-computer interface (BCI). In this paper, we proposed an automatic framework based on independent component analysis (ICA) and system identification to identify and remove ocular artifacts from EEG data by using hybrid EEG and eye tracker system. The performance of the proposed algorithm is illustrated using experimental and standard EEG datasets. The proposed algorithm not only removes the ocular artifacts from artifactual zone but also preserves the neuronal activity related EEG signals in non-artifactual zone. The comparison with the two state-of-the-art techniques namely ADJUST based ICA and REGICA reveals the significant improved performance of the proposed algorithm for removing eye movement and blink artifacts from EEG data. Additionally, results demonstrate that the proposed algorithm can achieve lower relative error and higher mutual information values between corrected EEG and artifact-free EEG data. PMID:26907276

  9. Hybrid EEG--Eye Tracker: Automatic Identification and Removal of Eye Movement and Blink Artifacts from Electroencephalographic Signal.

    PubMed

    Mannan, Malik M Naeem; Kim, Shinjung; Jeong, Myung Yung; Kamran, M Ahmad

    2016-01-01

    Contamination of eye movement and blink artifacts in Electroencephalogram (EEG) recording makes the analysis of EEG data more difficult and could result in mislead findings. Efficient removal of these artifacts from EEG data is an essential step in improving classification accuracy to develop the brain-computer interface (BCI). In this paper, we proposed an automatic framework based on independent component analysis (ICA) and system identification to identify and remove ocular artifacts from EEG data by using hybrid EEG and eye tracker system. The performance of the proposed algorithm is illustrated using experimental and standard EEG datasets. The proposed algorithm not only removes the ocular artifacts from artifactual zone but also preserves the neuronal activity related EEG signals in non-artifactual zone. The comparison with the two state-of-the-art techniques namely ADJUST based ICA and REGICA reveals the significant improved performance of the proposed algorithm for removing eye movement and blink artifacts from EEG data. Additionally, results demonstrate that the proposed algorithm can achieve lower relative error and higher mutual information values between corrected EEG and artifact-free EEG data. PMID:26907276

  10. How humans search for targets through time: A review of data and theory from the attentional blink

    PubMed Central

    Dux, Paul E.; Marois, Réne

    2009-01-01

    Under conditions of rapid serial visual presentation (RSVP), subjects display a reduced ability to report the second of two targets (Target 2; T2) in a stream of distractors if it appears within 200–500 ms of Target 1 (T1). This effect, known as the attentional blink (AB), has been central in characterizing the limits of humans’ ability to consciously perceive stimuli distributed across time. Here we review theoretical accounts of the AB and examine how they explain key findings in the literature. We conclude that the AB arises from attentional demands of T1 for selection, working memory encoding, episodic registration and response selection, which prevents this high-level central resource from being applied to T2 at short T1–T2 lags. T1 processing also transiently impairs the re-deployment of these attentional resources to subsequent targets, and the inhibition of distractors that appear in close temporal proximity to T2. While these findings are consistent with a multi-factorial account of the AB, they can also be largely explained by assuming that the activation of these multiple processes depend on a common capacity-limited attentional process to select behaviorally relevant events presented amongst temporally distributed distractors. Thus, at its core, the attentional blink may ultimately reveal the temporal limits of the deployment of selective attention. PMID:19933555

  11. Unsupervised eye blink artifact denoising of EEG data with modified multiscale sample entropy, Kurtosis, and wavelet-ICA.

    PubMed

    Mahajan, Ruhi; Morshed, Bashir I

    2015-01-01

    Brain activities commonly recorded using the electroencephalogram (EEG) are contaminated with ocular artifacts. These activities can be suppressed using a robust independent component analysis (ICA) tool, but its efficiency relies on manual intervention to accurately identify the independent artifactual components. In this paper, we present a new unsupervised, robust, and computationally fast statistical algorithm that uses modified multiscale sample entropy (mMSE) and Kurtosis to automatically identify the independent eye blink artifactual components, and subsequently denoise these components using biorthogonal wavelet decomposition. A 95% two-sided confidence interval of the mean is used to determine the threshold for Kurtosis and mMSE to identify the blink related components in the ICA decomposed data. The algorithm preserves the persistent neural activity in the independent components and removes only the artifactual activity. Results have shown improved performance in the reconstructed EEG signals using the proposed unsupervised algorithm in terms of mutual information, correlation coefficient, and spectral coherence in comparison with conventional zeroing-ICA and wavelet enhanced ICA artifact removal techniques. The algorithm achieves an average sensitivity of 90% and an average specificity of 98%, with average execution time for the datasets ( N = 7) of 0.06 s ( SD = 0.021) compared to the conventional wICA requiring 0.1078 s ( SD = 0.004). The proposed algorithm neither requires manual identification for artifactual components nor additional electrooculographic channel. The algorithm was tested for 12 channels, but might be useful for dense EEG systems. PMID:24968340

  12. ViSA: a neurodynamic model for visuo-spatial working memory, attentional blink, and conscious access.

    PubMed

    Simione, Luca; Raffone, Antonino; Wolters, Gezinus; Salmas, Paola; Nakatani, Chie; Belardinelli, Marta Olivetti; van Leeuwen, Cees

    2012-10-01

    Two separate lines of study have clarified the role of selectivity in conscious access to visual information. Both involve presenting multiple targets and distracters: one simultaneously in a spatially distributed fashion, the other sequentially at a single location. To understand their findings in a unified framework, we propose a neurodynamic model for Visual Selection and Awareness (ViSA). ViSA supports the view that neural representations for conscious access and visuo-spatial working memory are globally distributed and are based on recurrent interactions between perceptual and access control processors. Its flexible global workspace mechanisms enable a unitary account of a broad range of effects: It accounts for the limited storage capacity of visuo-spatial working memory, attentional cueing, and efficient selection with multi-object displays, as well as for the attentional blink and associated sparing and masking effects. In particular, the speed of consolidation for storage in visuo-spatial working memory in ViSA is not fixed but depends adaptively on the input and recurrent signaling. Slowing down of consolidation due to weak bottom-up and recurrent input as a result of brief presentation and masking leads to the attentional blink. Thus, ViSA goes beyond earlier 2-stage and neuronal global workspace accounts of conscious processing limitations. PMID:22823385

  13. Influence of prepelleting inclusion of whole corn on performance, nutrient utilization, digestive tract measurements, and cecal microbiota of young broilers.

    PubMed

    Singh, Y; Ravindran, V; Wester, T J; Molan, A L; Ravindran, G

    2014-12-01

    The objective of the present study was to examine the effects of prepelleting inclusion of graded levels of whole corn on performance, digestive tract measurements, nutrient utilization, and cecal microbiota in broiler starters. Five diets, containing 600 g/kg of ground corn or 150, 300, 450, and 600 g/kg of whole corn replacing (wt/wt) ground corn, were formulated and cold-pelleted at 65°C. Each diet was offered ad libitum to 6 replicates (8 birds per replicate cage) from d 1 to 21 posthatch. The proportion of coarse particles (>1 mm) increased with increasing prepelleting inclusion of whole corn. Pellet quality, measured as pellet durability index, increased (quadratic effect, P < 0.001) with the inclusion of whole corn to 450 g/kg and then plateaued. Weight gain and feed intake decreased (linear effect, P < 0.001) with increasing prepelleting inclusion of whole corn. Feed per gain (quadratic effect, P < 0.05) increased as the inclusion level of whole corn increased to 300 g/kg and then plateaued with further inclusions. Relative gizzard weight (quadratic effect, P < 0.05) increased with increasing inclusion of whole corn up to 300 g/kg and then levelled off. The AME (quadratic effect, P < 0.05) increased up to 300 g/kg of whole corn inclusion and then decreased with further inclusion. Apparent ileal digestibility of DM (P < 0.001), N (linear effect, P = 0.07), and starch (linear effect, P < 0.001) increased with increasing inclusion levels of whole corn. Based on the fluorescence in situ hybridization method, a linear (P < 0.05) effect was determined for cecal microbiota numbers. Lactobacillus spp. counts increased and counts of Clostridium spp., Campylobacterium spp., and Bacteroides spp. decreased with increasing inclusion levels of whole corn. The present data showed that, despite increased gizzard weight and nutrient utilization, weight gain of broilers was poorer with prepelleting inclusion of whole corn due to reductions in the feed intake. PMID:25306459

  14. Dopamine, depressive symptoms, and decision-making: the relationship between spontaneous eye blink rate and depressive symptoms predicts Iowa Gambling Task performance.

    PubMed

    Byrne, Kaileigh A; Norris, Dominique D; Worthy, Darrell A

    2016-02-01

    Depressive symptomatology has been associated with alterations in decision-making, although conclusions have been mixed, with depressed individuals showing impairments in some contexts but advantages in others. The dopaminergic system may link depressive symptoms with decision-making performance. We assessed the role of striatal dopamine D2 receptor density, using spontaneous eye blink rates, in moderating the relationship between depressive symptoms and decision-making performance in a large undergraduate sample that had not been screened for mental illness (N = 104). The regression results revealed that eye blink rate moderated the relationship between depressive symptoms and advantageous decisions on the Iowa Gambling Task, in which individuals with more depressive symptomatology and high blink rates (higher striatal dopamine D2 receptor density) performed better on the task. Our computational modeling results demonstrated that depressive symptoms alone were associated with enhanced loss-aversive behavior, whereas individuals with high blink rates and elevated depressive symptoms tended to persevere in selecting options that led to net gains (avoiding options with net losses). These findings suggest that variation in striatal dopamine D2 receptor availability in individuals with depressive symptoms may contribute to differences in decision-making behavior. PMID:26383904

  15. Dopamine and the Management of Attentional Resources: Genetic Markers of Striatal D2 Dopamine Predict Individual Differences in the Attentional Blink

    ERIC Educational Resources Information Center

    Colzato, Lorenza S.; Slagter, Heleen A.; de Rover, Mischa; Hommel, Bernhard

    2011-01-01

    The attentional blink (AB)--a deficit in reporting the second of two target stimuli presented in close succession in a rapid sequence of distracters--has been related to processing limitations in working memory. Given that dopamine (DA) plays a crucial role working memory, the present study tested whether individual differences in the size of the…

  16. Tumor glucose utilization with FDG-PET and cell kinetic measurements with IUdR in primary rectal cancer

    SciTech Connect

    Schiepers, C.; Haustermans, K.; Penninckx, F.

    1996-05-01

    Rectal cancer is a common disease. Viable tumor cells show increased FDG uptake, which can be used to monitor radiotherapy (RT). Patients were studied in the fasting state (>6 hrs). 400-555 MBq F-18 FDG was administered i.v. and dynamic imaging started. Arterial blood was withdrawn to determine the plasma input function. A bladder catheter was flushed to clear tracer. Tumor glucose utilization (TuGluc) was calculated with a 3 compartment model, assuming a lumped constant of 1. Cell kinetics were measured with flow cytometry 6-8 hrs after in vivo labeling with iodo-deoxy-uridine (IUdR). Potential doubling time (Tpot) was determined. Two groups were investigated: (1) surgery only (n=9) and (2) before and 2-3 weeks after 30 Gy RT (n=9). For group 2 at baseline, a PET was done and tumor biopsies taken on the same day. The other PET studies were performed 1-2 days before surgery. Consecutive patients with a cT3 tumor without metastasis and over 50 yr were selected and randomized. The protocol was approved by the Human Studied Committee. At baseline TuGluc for group 1 was 222 {plus_minus} 104 nmol/min/ml (mean {plus_minus} 1 sd), and for group 2: 215 {plus_minus} 126 (p=Ns). After RT TuGluc decreased to 77 {plus_minus} 39 (p<.01). Tpot was 3.4 {plus_minus} 1.2 days for group 1 and 2.6 {plus_minus} 2.0 for group 2 at baseline (p=NS). After RT, Tpot slowed down to 5.5 {plus_minus} 3.5 days (p=0.06). A weak negative correlation of -0.2 was found between TuGluc and Tpot, a tendency for increased glucose utilization of faster dividing cells. Tpot is not clearly affected by RT suggesting undisturbed proliferation of viable cells 2-3 weeks after RT. However, TuGluc decreased indicating cell loss and histology revealed down staging in about half of patients. In conclusion: tumor FDG uptake and cell kinetics do not show a strong correlation in rectal cancer. RT results in overall loss of tumor cells and down staging, while proliferation of viable cells is maintained.

  17. Assessing the clinical utility of measuring Insulin-like Growth Factor Binding Proteins in tissues and sera of melanoma patients

    PubMed Central

    Yu, Jessie Z; Warycha, Melanie A; Christos, Paul J; Darvishian, Farbod; Yee, Herman; Kaminio, Hideko; Berman, Russell S; Shapiro, Richard L; Buckley, Michael T; Liebes, Leonard F; Pavlick, Anna C; Polsky, David; Brooks, Peter C; Osman, Iman

    2008-01-01

    Background Different Insulin-like Growth Factor Binding Proteins (IGFBPs) have been investigated as potential biomarkers in several types of tumors. In this study, we examined both IGFBP-3 and -4 levels in tissues and sera of melanoma patients representing different stages of melanoma progression. Methods The study cohort consisted of 132 melanoma patients (primary, n = 72; metastatic, n = 60; 64 Male, 68 Female; Median Age = 56) prospectively enrolled in the New York University School of Medicine Interdisciplinary Melanoma Cooperative Group (NYU IMCG) between August 2002 and December 2006. We assessed tumor-expression and circulating sera levels of IGFBP-3 and -4 using immunohistochemistry and ELISA assays. Correlations with clinicopathologic parameters were examined using Wilcoxon rank-sum tests and Spearman-rank correlation coefficients. Results Median IGFBP-4 tumor expression was significantly greater in primary versus metastatic patients (70% versus 10%, p = 0.01) A trend for greater median IGFBP-3 sera concentration was observed in metastatic versus primary patients (4.9 μg/ml vs. 3.4 μg/ml, respectively, p = 0.09). However, sera levels fell within a normal range for IGFBP-3. Neither IGFBP-3 nor -4 correlated with survival in this subset of patients. Conclusion Decreased IGFBP-4 tumor expression might be a step in the progression from primary to metastatic melanoma. Our data lend support to a recently-described novel tumor suppressor role of secreting IGFBPs in melanoma. However, data do not support the clinical utility of measuring levels of IGFBP-3 and -4 in sera of melanoma patients. PMID:19025658

  18. Sensing device and method for measuring emission time delay during irradiation of targeted samples utilizing variable phase tracking

    NASA Technical Reports Server (NTRS)

    Danielson, J. D. Sheldon (Inventor)

    2006-01-01

    An apparatus for measuring emission time delay during irradiation of targeted samples by utilizing digital signal processing to determine the emission phase shift caused by the sample is disclosed. The apparatus includes a source of electromagnetic radiation adapted to irradiate a target sample. A mechanism generates first and second digital input signals of known frequencies with a known phase relationship, and a device then converts the first and second digital input signals to analog sinusoidal signals. An element is provided to direct the first input signal to the electromagnetic radiation source to modulate the source by the frequency thereof to irradiate the target sample and generate a target sample emission. A device detects the target sample emission and produces a corresponding first output signal having a phase shift relative to the phase of the first input signal, the phase shift being caused by the irradiation time delay in the sample. A member produces a known phase shift in the second input signal to create a second output signal. A mechanism is then provided for converting each of the first and second analog output signals to digital signals. A mixer receives the first and second digital output signals and compares the signal phase relationship therebetween to produce a signal indicative of the change in phase relationship between the first and second output signals caused by the target sample emission. Finally, a feedback arrangement alters the phase of the second input signal based on the mixer signal to ultimately place the first and second output signals in quadrature. Mechanisms for enhancing this phase comparison and adjustment technique are also disclosed.

  19. Single Cesium Lead Halide Perovskite Nanocrystals at Low Temperature: Fast Single-Photon Emission, Reduced Blinking, and Exciton Fine Structure

    PubMed Central

    2016-01-01

    Metal-halide semiconductors with perovskite crystal structure are attractive due to their facile solution processability, and have recently been harnessed very successfully for high-efficiency photovoltaics and bright light sources. Here, we show that at low temperature single colloidal cesium lead halide (CsPbX3, where X = Cl/Br) nanocrystals exhibit stable, narrow-band emission with suppressed blinking and small spectral diffusion. Photon antibunching demonstrates unambiguously nonclassical single-photon emission with radiative decay on the order of 250 ps, representing a significant acceleration compared to other common quantum emitters. High-resolution spectroscopy provides insight into the complex nature of the emission process such as the fine structure and charged exciton dynamics. PMID:26771336

  20. Implementing Performance-Based Vocational Education Utilizing V-TECS Catalogs. Module 2. Understanding Performance Objectives, Criterion-Referenced Measures, and Performance Guides.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    This learning module on understanding performance objectives, criterion-referenced measures, and performance guides is one of nine developed for use in training administrators, teachers, and prospective teachers in the utilization of Vocational-Technical Education Consortium of States (V-TECS) catalogs. Readings are provided on the following…

  1. In the Blink of an Eye: Relating Positive-Feedback Sensitivity to Striatal Dopamine D2-Like Receptors through Blink Rate

    PubMed Central

    Groman, Stephanie M.; James, Alex S.; Seu, Emanuele; Tran, Steven; Clark, Taylor A.; Harpster, Sandra N.; Crawford, Maverick; Burtner, Joanna Lee; Feiler, Karen; Roth, Robert H.; Elsworth, John D.; London, Edythe D.

    2014-01-01

    For >30 years, positron emission tomography (PET) has proven to be a powerful approach for measuring aspects of dopaminergic transmission in the living human brain; this technique has revealed important relationships between dopamine D2-like receptors and dimensions of normal behavior, such as human impulsivity, and psychopathology, particularly behavioral addictions. Nevertheless, PET is an indirect estimate that lacks cellular and functional resolution and, in some cases, is not entirely pharmacologically specific. To identify the relationships between PET estimates of D2-like receptor availability and direct in vitro measures of receptor number, affinity, and function, we conducted neuroimaging and behavioral and molecular pharmacological assessments in a group of adult male vervet monkeys. Data gathered from these studies indicate that variation in D2-like receptor PET measurements is related to reversal-learning performance and sensitivity to positive feedback and is associated with in vitro estimates of the density of functional dopamine D2-like receptors. Furthermore, we report that a simple behavioral measure, eyeblink rate, reveals novel and crucial links between neuroimaging assessments and in vitro measures of dopamine D2 receptors. PMID:25339755

  2. Technology Transfer and Utilization: A Longitudinal Study Using Benefit Analysis to Measure the Results from an R&D Laboratory.

    ERIC Educational Resources Information Center

    Jolly, James A.; Creighton, J. W.

    This paper describes and evaluates the effectiveness of a program designed to improve technology transfer and utilization that was implemented in 1971 by the Naval Facilities Engineering Command. The authors first describe the organization of the technology transfer program and then attempt to evaluate its effectiveness over the three-year period…

  3. Measuring Growth in Bilingual and Monolingual Children's English Productive Vocabulary Development: The Utility of Combining Parent and Teacher Report

    ERIC Educational Resources Information Center

    Vagh, Shaher Banu; Pan, Barbara Alexander; Mancilla-Martinez, Jeannette

    2009-01-01

    This longitudinal study examined growth in the English productive vocabularies of bilingual and monolingual children between ages 24 and 36 months and explored the utility and validity of supplementing parent reports with teacher reports to improve the estimation of children's vocabulary. Low-income, English-speaking and English/Spanish-speaking…

  4. Quantitative measurements of regional glucose utilization and rate of valine incorporation into proteins by double-tracer autoradiography in the rat brain tumor model

    SciTech Connect

    Kirikae, M.; Diksic, M.; Yamamoto, Y.L.

    1989-02-01

    We examined the rate of glucose utilization and the rate of valine incorporation into proteins using 2-(/sup 18/F)fluoro-2-deoxyglucose and L-(1-14C)-valine in a rat brain tumor model by quantitative double-tracer autoradiography. We found that in the implanted tumor the rate of valine incorporation into proteins was about 22 times and the rate of glucose utilization was about 1.5 times that in the contralateral cortex. (In the ipsilateral cortex, the tumor had a profound effect on glucose utilization but no effect on the rate of valine incorporation into proteins.) Our findings suggest that it is more useful to measure protein synthesis than glucose utilization to assess the effectiveness of antitumor agents and their toxicity to normal brain tissue. We compared two methods to estimate the rate of valine incorporation: kinetic (quantitation done using an operational equation and the average brain rate coefficients) and washed slices (unbound labeled valine removed by washing brain slices in 10% trichloroacetic acid). The results were the same using either method. It would seem that the kinetic method can thus be used for quantitative measurement of protein synthesis in brain tumors and normal brain tissue using (/sup 11/C)-valine with positron emission tomography.

  5. Ecological Validity and Clinical Utility of Patient-Reported Outcomes Measurement Information System (PROMIS®) instruments for detecting premenstrual symptoms of depression, anger, and fatigue

    PubMed Central

    Junghaenel, Doerte U.; Schneider, Stefan; Stone, Arthur A.; Christodoulou, Christopher; Broderick, Joan E.

    2014-01-01

    Objective This study examined the ecological validity and clinical utility of NIH Patient Reported-Outcomes Measurement Information System (PROMIS®) instruments for anger, depression, and fatigue in women with premenstrual symptoms. Methods One-hundred women completed daily diaries and weekly PROMIS assessments over 4 weeks. Weekly assessments were administered through Computerized Adaptive Testing (CAT). Weekly CATs and corresponding daily scores were compared to evaluate ecological validity. To test clinical utility, we examined if CATs could detect changes in symptom levels, if these changes mirrored those obtained from daily scores, and if CATs could identify clinically meaningful premenstrual symptom change. Results PROMIS CAT scores were higher in the pre-menstrual than the baseline (ps < .0001) and post-menstrual (ps < .0001) weeks. The correlations between CATs and aggregated daily scores ranged from .73 to .88 supporting ecological validity. Mean CAT scores showed systematic changes in accordance with the menstrual cycle and the magnitudes of the changes were similar to those obtained from the daily scores. Finally, Receiver Operating Characteristic (ROC) analyses demonstrated the ability of the CATs to discriminate between women with and without clinically meaningful premenstrual symptom change. Conclusions PROMIS CAT instruments for anger, depression, and fatigue demonstrated validity and utility in premenstrual symptom assessment. The results provide encouraging initial evidence of the utility of PROMIS instruments for the measurement of affective premenstrual symptoms. PMID:24630180

  6. 'Giant' multishell CdSe nanocrystal quantum dots with supporessed blinking: novel fluorescent probes for real-time detection of single-molecule events

    SciTech Connect

    Hollingsworth, Jennifer A; Vela, Javier; Htoon, Han; Klimov, Victor I; Casson, Amy R; Chen, Yongfen

    2009-01-01

    We reported for the first time that key nanocrystal quantum dot (NQD) optical properties-quantum yield, photobleaching and blinking-can be rendered independent ofNQD surface chemistry and environment by growth of a very thick, defect-free inorganic shell. Here, we show the precise shell-thickness dependence of these effects. We demonstrate that 'giant-shell' NQDs can be largely non-blinking for observation times as long as 54 minutes and lhat on-time fractions are independent of experimental time-resolution from 1-200 ms. These effects are primarily demonstrated on (CdSe)CdS (core)shell NQDs, but we also show that alloyed shells comprising Cd.Znl.'S and terminated with a non-cytotoxic ZnS layer exhibit similar properties. The mechanism for suppressed blinking and dramatically enhanced stability is attributed to both effective isolation of the NQD core excitonic wavefunction from the NQD surface, as well as a quasi-Type II electronic structure. The unusual electronic structure provides for effective spatial separation of the electron and hole into the shell and core, respectively, and, thereby, for reduced efficiencies in non-radiative Auger recombination.

  7. Composition-dependent trap distributions in CdSe and InP quantum dots probed using photoluminescence blinking dynamics

    NASA Astrophysics Data System (ADS)

    Chung, Heejae; Cho, Kyung-Sang; Koh, Weon-Kyu; Kim, Dongho; Kim, Jiwon

    2016-07-01

    Although Group II-VI quantum dots (QDs) have attracted much attention due to their wide range of applications in QD-based devices, the presence of toxic ions in II-VI QDs raises environmental concerns. To fulfill the demands of nontoxic QDs, synthetic routes for III-V QDs have been developed. However, only a few comparative analyses on optical properties of III-V QDs have been performed. In this study, the composition-related energetic trap distributions have been explored by using three different types of core/multishell QDs: CdSe-CdS (CdSe/CdS/ZnS), InP-ZnSe (InP/ZnSe/ZnS), and InP-GaP (InP/GaP/ZnS). It was shown that CdSe-CdS QDs have much larger trap densities than InP-shell QDs at higher energy states (at least 1Eg (band gap energy) above the lowest conduction band edge) based on probability density plots and Auger ionization efficiencies which are determined by analyses of photoluminescence blinking dynamics. This result suggests that the composition of encapsulated QDs is closely associated with the charge trapping processes, and also provides an insight into the development of more environmentally friendly QD-based devices.Although Group II-VI quantum dots (QDs) have attracted much attention due to their wide range of applications in QD-based devices, the presence of toxic ions in II-VI QDs raises environmental concerns. To fulfill the demands of nontoxic QDs, synthetic routes for III-V QDs have been developed. However, only a few comparative analyses on optical properties of III-V QDs have been performed. In this study, the composition-related energetic trap distributions have been explored by using three different types of core/multishell QDs: CdSe-CdS (CdSe/CdS/ZnS), InP-ZnSe (InP/ZnSe/ZnS), and InP-GaP (InP/GaP/ZnS). It was shown that CdSe-CdS QDs have much larger trap densities than InP-shell QDs at higher energy states (at least 1Eg (band gap energy) above the lowest conduction band edge) based on probability density plots and Auger ionization

  8. Non-streaming high-efficiency perforated semiconductor neutron detectors, methods of making same and measuring wand and detector modules utilizing same

    DOEpatents

    McGregor, Douglas S.; Shultis, John K.; Rice, Blake B.; McNeil, Walter J.; Solomon, Clell J.; Patterson, Eric L.; Bellinger, Steven L.

    2010-12-21

    Non-streaming high-efficiency perforated semiconductor neutron detectors, method of making same and measuring wands and detector modules utilizing same are disclosed. The detectors have improved mechanical structure, flattened angular detector responses, and reduced leakage current. A plurality of such detectors can be assembled into imaging arrays, and can be used for neutron radiography, remote neutron sensing, cold neutron imaging, SNM monitoring, and various other applications.

  9. Linear Acceleration Measurement Utilizing Inter-Instrument Synchronization: A Comparison between Accelerometers and Motion-Based Tracking Approaches

    ERIC Educational Resources Information Center

    Callaway, Andrew J.; Cobb, Jon E.

    2012-01-01

    Where as video cameras are a reliable and established technology for the measurement of kinematic parameters, accelerometers are increasingly being employed for this type of measurement due to their ease of use, performance, and comparatively low cost. However, the majority of accelerometer-based studies involve a single channel due to the…

  10. Antenna heights for the optimum utilization of the oceanic evaporation duct. Part 3: Results from the Mediterranean measurements, volume 2

    NASA Astrophysics Data System (ADS)

    Richter, J. H.; Hitney, H. V.

    1988-01-01

    Extensive evaporation ducting measurements were conducted in the Eastern Mediterranean. The purpose of the measurements was to provide data for model validations and to determine if existing climatologies could be used for estimating the probability of occurrence for evaporation ducting conditions.

  11. Oxygen consumption rate v. rate of energy utilization of fishes: a comparison and brief history of the two measurements.

    PubMed

    Nelson, J A

    2016-01-01

    Accounting for energy use by fishes has been taking place for over 200 years. The original, and continuing gold standard for measuring energy use in terrestrial animals, is to account for the waste heat produced by all reactions of metabolism, a process referred to as direct calorimetry. Direct calorimetry is not easy or convenient in terrestrial animals and is extremely difficult in aquatic animals. Thus, the original and most subsequent measurements of metabolic activity in fishes have been measured via indirect calorimetry. Indirect calorimetry takes advantage of the fact that oxygen is consumed and carbon dioxide is produced during the catabolic conversion of foodstuffs or energy reserves to useful ATP energy. As measuring [CO2 ] in water is more challenging than measuring [O2 ], most indirect calorimetric studies on fishes have used the rate of O2 consumption. To relate measurements of O2 consumption back to actual energy usage requires knowledge of the substrate being oxidized. Many contemporary studies of O2 consumption by fishes do not attempt to relate this measurement back to actual energy usage. Thus, the rate of oxygen consumption (M˙O2 ) has become a measurement in its own right that is not necessarily synonymous with metabolic rate. Because all extant fishes are obligate aerobes (many fishes engage in substantial net anaerobiosis, but all require oxygen to complete their life cycle), this discrepancy does not appear to be of great concern to the fish biology community, and reports of fish oxygen consumption, without being related to energy, have proliferated. Unfortunately, under some circumstances, these measures can be quite different from one another. A review of the methodological history of the two measurements and a look towards the future are included. PMID:26768970

  12. Utilizing Longitudinal Measures of Fetal Growth to Create a Standard Method to Assess the Impacts of Maternal Disease and Environmental Exposure

    PubMed Central

    Cantonwine, David E.; Ferguson, Kelly K.; Mukherjee, Bhramar; Chen, Yin-Hsiu; Smith, Nicole A.; Robinson, Julian N.; Doubilet, Peter M.; Meeker, John D.; McElrath, Thomas F.

    2016-01-01

    Impaired or suboptimal fetal growth is associated with an increased risk of perinatal morbidity and mortality. By utilizing readily available clinical data on the relative size of the fetus at multiple points in pregnancy, including delivery, future epidemiological research can improve our understanding of the impacts of maternal, fetal, and environmental factors on fetal growth at different windows during pregnancy. This study presents mean and standard deviation ultrasound measurements from a clinically representative US population that can be utilized for creating Z-scores to this end. Between 2006 and 2012, 18, 904 non-anomalous pregnancies that received prenatal care, first and second trimester ultrasound evaluations, and ultimately delivered singleton newborns at Brigham and Women’s hospital in Boston were used to create the standard population. To illustrate the utility of this standard, we created Z-scores for ultrasound and delivery measurements for a cohort study population and examined associations with factors known to be associated with fetal growth. In addition to cross-sectional regression models, we created linear mixed models and generalized additive mixed models to illustrate how these scores can be utilized longitudinally and for the identification of windows of susceptibility. After adjustment for a priori confounders, maternal BMI was positively associated with increased fetal size beginning in the second trimester in cross-sectional models. Female infants and maternal smoking were associated with consistently reduced fetal size in the longitudinal models. Maternal age had a non-significant association with increased size in the first trimester that was attenuated as gestation progressed. As the growth measurements examined here are widely available in contemporary obstetrical practice, these data may be abstracted from medical records by investigators and standardized with the population means presented here. This will enable easy extension

  13. Measuring growth in bilingual and monolingual children's english productive vocabulary development: the utility of combining parent and teacher report.

    PubMed

    Vagh, Shaher Banu; Pan, Barbara Alexander; Mancilla-Martinez, Jeannette

    2009-01-01

    This longitudinal study examined growth in the English productive vocabularies of bilingual and monolingual children between ages 24 and 36 months and explored the utility and validity of supplementing parent reports with teacher reports to improve the estimation of children's vocabulary. Low-income, English-speaking and English/Spanish-speaking parents and Early Head Start and Head Start program teachers completed the MacArthur-Bates Communicative Development Inventory, Words and Sentences for 85 children. Results indicate faster growth rates for monolingual than for bilingual children and larger vocabularies for bilingual children who spoke mostly English than mostly Spanish at home. Parent-teacher composite reports, like parent reports, significantly related to children's directly assessed productive vocabulary at ages 30 and 36 months, but parent reports fit the model better. Implications for vocabulary assessment are discussed. PMID:19765017

  14. Daytime measurements of atmospheric temperature profiles (2-15 km) by lidar utilizing Rayleigh-Brillouin scattering.

    PubMed

    Witschas, Benjamin; Lemmerz, Christian; Reitebuch, Oliver

    2014-04-01

    In this Letter, we report on a novel method for measuring atmospheric temperature profiles by lidar during daytime for heights of 2-15.3 km, with a vertical resolution of 0.3-2.2 km, using Rayleigh-Brillouin scattering. The measurements are performed by scanning a laser (λ=355 nm) over a 12 GHz range and using a Fabry-Pérot interferometer as discriminator. The temperature is derived by using a new analytical line shape model assuming standard atmospheric pressure conditions. Two exemplary temperature profiles resulting from measurements over 14 and 27 min are shown. A comparison with radiosonde temperature measurements shows reasonable agreement. In cloud-free conditions, the temperature difference reaches up to 5 K within the boundary layer, and is smaller than 2.5 K above. The statistical error of the derived temperatures is between 0.15 and 1.5 K. PMID:24686652

  15. Measurement of the intensity of the beam in the abort gap at the Tevatron utilizing synchrotron light

    SciTech Connect

    Thurman-Keup, R.; Lorman, E.; Meyer, T.; Pordes, S.; De Santis, S.; /LBL, Berkeley

    2005-05-01

    This paper discusses the implementation of abort gap beam intensity monitoring at the Tevatron collider at Fermilab. There are two somewhat independent monitors which measure the intensity of the synchrotron light emitted by particles in the abort gaps. One system uses a gated Photomultiplier Tube (PMT) to measure the light intensity, and the other system uses a single lens telescope, gated image intensifier, and Charge Injection Device (CID) camera to image the beam.

  16. Composition-dependent trap distributions in CdSe and InP quantum dots probed using photoluminescence blinking dynamics.

    PubMed

    Chung, Heejae; Cho, Kyung-Sang; Koh, Weon-Kyu; Kim, Dongho; Kim, Jiwon

    2016-07-21

    Although Group II-VI quantum dots (QDs) have attracted much attention due to their wide range of applications in QD-based devices, the presence of toxic ions in II-VI QDs raises environmental concerns. To fulfill the demands of nontoxic QDs, synthetic routes for III-V QDs have been developed. However, only a few comparative analyses on optical properties of III-V QDs have been performed. In this study, the composition-related energetic trap distributions have been explored by using three different types of core/multishell QDs: CdSe-CdS (CdSe/CdS/ZnS), InP-ZnSe (InP/ZnSe/ZnS), and InP-GaP (InP/GaP/ZnS). It was shown that CdSe-CdS QDs have much larger trap densities than InP-shell QDs at higher energy states (at least 1Eg (band gap energy) above the lowest conduction band edge) based on probability density plots and Auger ionization efficiencies which are determined by analyses of photoluminescence blinking dynamics. This result suggests that the composition of encapsulated QDs is closely associated with the charge trapping processes, and also provides an insight into the development of more environmentally friendly QD-based devices. PMID:27272126

  17. Distributed Cortical Phase Synchronization in the EEG Reveals Parallel Attention and Working Memory Processes Involved in the Attentional Blink.

    PubMed

    Glennon, Mark; Keane, Michael A; Elliott, Mark A; Sauseng, Paul

    2016-05-01

    Attentional blink (AB) describes a visuo-perceptual phenomenon in which the second of 2 targets within a rapid serial visual presentation stream is not detected. There are several cognitive models attempting to explain the fundamentals of this information processing bottleneck. Here, we used electroencephalographic recordings and the analysis of interregional phase synchronization of rhythmical brain activity to investigate the neural bases of the AB. By investigating the time course of interregional phase synchronization separately for trials in which participants failed to report the second target correctly (AB trials) and trials in which no AB occurred, and by clustering interregional connections based on their functional similarity, it was possible to define several distinct cortical networks. Analyzing these networks comprising phase synchronization-over a large spectrum of brain frequencies from theta to gamma activity-it was possible to identify neural correlates for cognitive subfunctions involved in the AB, such as the encoding of targets into working memory, tuning of attentional filters, and the recruitment of general cognitive resources. This parallel activation of functionally distinct neural processes substantiates the eligibility of several cognitive models on the AB. PMID:25750255

  18. Two attentional deficits in serial target search: the visual attentional blink and an amodal task-switch deficit.

    PubMed

    Potter, M C; Chun, M M; Banks, B S; Muckenhoupt, M

    1998-07-01

    When monitoring a rapid serial visual presentation at 100 ms per item for 2 targets among distractors, viewers have difficulty reporting the 2nd target (T2) when it appears 200-500 ms after the onset of the 1st letter target (T1): an attentional blink (AB; M. M. Chun & M. C. Potter, 1995b; J. E. Raymond, K. L. Shapiro, & K. M. Arnell, 1992). Does the same deficit occur with auditory search? The authors compared search for auditory, visual, and cross-modal targets in 2 tasks: (a) identifying 2 target letters among digits (Experiments 1-3 and 5) or digits among letters (Experiment 6), and (b) identifying 1 digit among letters and deciding whether an X occurred among the subsequent letters (Experiment 4). In the experiments using the 1st task, the standard AB was found only when both targets were visual. In the 2nd task, with a change in selective set from T1 to T2, a task-switching deficit was obtained regardless of target modality. PMID:9699304

  19. Different relationships between central dopamine system and sub-processes of inhibition: Spontaneous eye blink rate relates with N2 but not P3 in a Go/Nogo task.

    PubMed

    Zhang, Ting; Wang, Cuicui; Tan, Fengping; Mou, Di; Zheng, Lijun; Chen, Antao

    2016-06-01

    Clinical studies show that dysfunction of the dopamine (DA) system could differently modulate N2 and P3 components in a Go/Nogo task, a classical inhibition task. However, results of previous clinical studies cannot be arbitrarily generalized to healthy adults. Thus, the present exploratory study aimed to investigate whether there are significant and variable relationships between individual differences of the DA system in normal healthy persons and N2- and P3-related sub-processes of inhibition in a Go/Nogo task. DA function was measured by spontaneous eye blink rate (EBR), which is an effective clinical and non-invasive measure and strongly related to the activity of the central dopaminergic system. A total of 28 young adults participated in this experiment. Results showed that Nogo-N2 and Nogo-P3 of all participants were larger than Go-N2 and Go-P3, while Nogo-N2 and Nogo-P3 were significantly related with Nogo-accuracy. Moreover, it was shown that higher EBRs were significantly correlated with larger and more negative N2 amplitudes under Go- and Nogo-conditions; however, there were no significant correlations between participants' EBRs and N2 latencies, and between EBRs and average amplitudes of P3 under the two conditions. Based on these results, we concluded that the central DA system was associated with the N2-related conflict monitoring rather than P3-related sub-process of inhibition. PMID:27115071

  20. Derivation of a new parametric impulse response matrix utilized for nodal wind load identification by response measurement

    NASA Astrophysics Data System (ADS)

    Kazemi Amiri, A.; Bucher, C.

    2015-05-01

    This paper provides new formulations to derive the impulse response matrix, which is then used in the problem of load identification with application to wind induced vibration. The applied loads are inversely identified based on the measured structural responses by solving the associated discrete ill-posed problem. To this end - based on an existing parametric structural model - the impulse response functions of acceleration, velocity and displacement have been computed. Time discretization of convolution integral has been implemented according to an existing and a newly proposed procedure, which differ in the numerical integration methods. The former was evaluated based on a constant rectangular approximation of the sampled data and impulse response function in a number of steps corresponding to the sampling rate, while the latter interpolates the sampled data in an arbitrary number of sub-steps and then integrates over the sub-steps and steps. The identification procedure was implemented for a simulation example as well as an experimental laboratory case. The ill-conditioning of the impulse response matrix made it necessary to use Tikhonov regularization to recover the applied force from noise polluted measured response. The optimal regularization parameter has been obtained by L-curve and GCV method. The results of simulation represent good agreement between identified and measured force. In the experiments the identification results based on the measured displacement as well as acceleration are provided. Further it is shown that the accuracy of experimentally identified load depends on the sensitivity of measurement instruments over the different frequency ranges.

  1. Antenna heights for the optimum utilization of the oceanic evaporation duct. Part 1: Results from the Pacific measurements. Part 2: Results from the Key West measurements, volume 1

    NASA Astrophysics Data System (ADS)

    Richter, J. H.; Hitney, H. V.

    1988-01-01

    Extensive evaporation ducting measurements were conducted over a period of 1 year in the Southern California offshore area and for 2 weeks between Key West and the Marquesas Keys. The purpose of the measurements was to provide data for model validations and to determine if existing climatologies could be used for estimating the probability of occurrence for evaporation ducting conditions.

  2. Method and Apparatus for Determining Changes in Intracranial Pressure Utilizing Measurement of the Circumferential Expansion or Contraction of a Patient's Skull

    NASA Technical Reports Server (NTRS)

    Yos, William T. (Inventor); Cantrell, John H., Jr. (Inventor)

    2004-01-01

    A method and apparatus for measuring changes in intracranial pressure (ICP) utilizing the variation of the surface wave propagation parameters of the patient's skull to determine the change in ICP. In one embodiment, the method comprises the steps of transmitting an ultrasonic bulk compressional wave onto the surface of the skull at a predetermined angle with respect to the skull so as to produce a surface wave, receiving the surface wave at an angle with respect tn the skull which is substantially the same as the predetermined angle and at a location that is a predetermined distance from where the ultrasonic bulk compressional wave was transmitted upon the skull, determining the retardation or advancement in phase of the received surface wave with respect to a reference phase, and processing the determined retardation or advancement in phase to determine circumferential expansion or contraction of the skull and utilizing the determined circumferential change to determine the change in intracranial pressure.

  3. A technique utilizing chemical reagents for direct measurement of temperature at a local area and its engineering applications

    NASA Astrophysics Data System (ADS)

    Saka, M.; Hasegawa, T.

    2009-04-01

    Temperature is one of the physical quantities through which quantitative evaluation of the safety and reliability of industrial products can be achieved, and this has been used widely in practice. Under any environmental condition, regardless of the size of the object to be inspected, accurate and reliable measurement of temperature is of great practical importance. This review article presents a simple and direct method of temperature measurement, that can be applied to the local areas with difficulty in measuring the temperature by using normal thermometers. In the present article, two different application examples are demonstrated. One addresses the study of the electromigration of solders which are used as bonding metals in electronic devices (micro-structures). The application of the method to the shaft of a motor used in heavy industrial fields is explained as the second.

  4. Non-Heme Iron Absorption and Utilization from Typical Whole Chinese Diets in Young Chinese Urban Men Measured by a Double-Labeled Stable Isotope Technique

    PubMed Central

    Yang, Lichen; Zhang, Yuhui; Wang, Jun; Huang, Zhengwu; Gou, Lingyan; Wang, Zhilin; Ren, Tongxiang; Piao, Jianhua; Yang, Xiaoguang

    2016-01-01

    Background This study was to observe the non-heme iron absorption and biological utilization from typical whole Chinese diets in young Chinese healthy urban men, and to observe if the iron absorption and utilization could be affected by the staple food patterns of Southern and Northern China. Materials and Methods Twenty-two young urban men aged 18–24 years were recruited and randomly assigned to two groups in which the staple food was rice and steamed buns, respectively. Each subject received 3 meals containing approximately 3.25 mg stable 57FeSO4 (the ratio of 57Fe content in breakfast, lunch and dinner was 1:2:2) daily for 2 consecutive days. In addition, approximately 2.4 mg 58FeSO4 was administered intravenously to each subject at 30–60 min after dinner each day. Blood samples were collected from each subject to measure the enrichment of the 57Fe and 58Fe. Fourteen days after the experimental diet, non-heme iron absorption was assessed by measuring 57Fe incorporation into red blood cells, and absorbed iron utilization was determined according to the red blood cell incorporation of intravenously infused 58Fe SO4. Results Non-heme iron intake values overall, and in the rice and steamed buns groups were 12.8 ±2.1, 11.3±1.3 and 14.3±1.5 mg, respectively; the mean 57Fe absorption rates were 11±7%, 13±7%, and 8±4%, respectively; and the mean infused 58Fe utilization rates were 85±8%, 84±6%, and 85±10%, respectively. There was no significantly difference in the iron intakes, and 57Fe absorption and infused 58Fe utilization rates between rice and steamed buns groups (all P>0.05). Conclusion We present the non-heme iron absorption and utilization rates from typical whole Chinese diets among young Chinese healthy urban men, which was not affected by the representative staple food patterns of Southern and Northern China. This study will provide a basis for the setting of Chinese iron DRIs. PMID:27099954

  5. A cluster randomized implementation trial to measure the effectiveness of an intervention package aiming to increase the utilization of skilled birth attendants by women for childbirth: study protocol

    PubMed Central

    2014-01-01

    Background Nepal is on track to achieve MDG 5 but there is a huge sub-national disparity with existing high maternal mortality in western and hilly regions. The national priority is to reduce this disparity to achieve the goal at sub-national level. Evidences from developing countries show that increasing utilization of skilled attendant at birth is an important indicator for reducing maternal death. Further, there is a very low utilization during childbirth in western and hilly regions of Nepal which clearly depicts the barriers in utilization of skilled birth attendants. So, there is a need to overcome the identified barriers to increase the utilization thereby decreasing the maternal mortality. The hypothesis of this study is that through a package of interventions the utilization of skilled birth attendants will be increased and hence improve maternal health in Nepal. Method/Design This study involves a cluster randomized controlled trial involving approximately 5000 pregnant women in 36 clusters. The 18 intervention clusters will receive the following interventions: i) mobilization of family support for pregnant women to reach the health facility, ii) availability of emergency funds for institutional childbirth, iii) availability of transport options to reach a health facility for childbirth, iv) training to health workers on communication skills, v) security provisions for SBAs to reach services 24/24 through community mobilization; 18 control clusters will not receive the intervention package. The final evaluation of the intervention is planned to be completed by October 2014. Primary study output of this study is utilization of SBA services. Secondary study outputs measure the uptake of antenatal care, post natal checkup for mother and baby, availability of transportation for childbirth, operation of emergency fund, improved reception of women at health services, and improved physical security of SBAs. Discussion The intervention package is designed to

  6. A procedural manual for measurement of uranium and thorium isotopes utilizing the USGS-Stanford Finnegan Mat 262

    USGS Publications Warehouse

    Shamp, Donald D.

    2001-01-01

    Over the past several decades investigators have extensively examined the 238U-234U- 230Th systematics of a variety of geologic materials using alpha spectroscopy. Analytical uncertainty for 230Th by alpha spectroscopy has been limited to about 2% (2σ). The advantage of thermal ionization mass spectroscopy (TIMS), introduced by Edwards and co-workers in the late 1980’s is the increased detectability of these isotopes by a factor of ~200, and decreases in the uncertainty for 230Th to about 5‰ (2σ) error. This report is a procedural manual for using the USGS-Stanford Finnegan-Mat 262 TIMS to collect and isolate Uranium and Thorium isotopic ratio data. Chemical separation of Uranium and Thorium from the sample media is accomplished using acid dissolution and then processed using anion exchange resins. The Finnegan-Mat262 Thermal Ionization Mass Spectrometer (TIMS) utilizes a surface ionization technique in which nitrates of Uranium and Thorium are placed on a source filament. Upon heating, positive ion emission occurs. The ions are then accelerated and focused into a beam which passes through a curved magnetic field dispersing the ions by mass. Faraday cups and/or an ion counter capture the ions and allow for quantitative analysis of the various isotopes.

  7. Adenosine triphosphate utilization rates and metabolic pool sizes in intact cells measured by transfer of 18O from water.

    PubMed Central

    Dawis, S M; Walseth, T F; Deeg, M A; Heyman, R A; Graeff, R M; Goldberg, N D

    1989-01-01

    The hydrolytic rates and metabolic pool sizes of ATP were determined in intact cells by monitoring the time courses of 18O incorporation from 18O-water into the gamma-phosphoryl of ATP and orthophosphate. To calculate the rate of ATP hydrolysis, a kinetic model is used to fit the time course of the 18O labeling. The size of the metabolic pool of ATP is calculated from the 18O distribution after isotopic equilibrium has been achieved. Metabolic pools have a binomial distribution of 18O whereas nonmetabolic pools exhibit negligible 18O labeling. The application and limitations of this approach are illustrated with data from isolated toad retinas and human platelets. At 22 degrees C, the time constant of ATP hydrolysis in the dark-adapted toad retina is about 30 s. Under these conditions, over 80% of the retinal ATP is involved in high-energy phosphate metabolism. It is calculated that when cGMP metabolic flux in the photoreceptors is maximally stimulated by light, it accounts for 10% of the ATP utilization by the entire retina. The time constant of ATP hydrolysis in human platelets at 37 degrees C is approximately 1 s, and 60% of the platelet ATP is involved in energy metabolism. PMID:2930826

  8. Locating interfaces in vertically-layered materials and determining concentrations in mixed materials utilizing acoustic impedance measurements

    DOEpatents

    Langlois, G.N.

    1983-09-13

    Measurement of the relative and actual value of acoustic characteristic impedances of an unknown substance, location of the interfaces of vertically-layered materials, and the determination of the concentration of a first material mixed in a second material are disclosed. A highly damped ultrasonic pulse is transmitted into one side of a reference plate, such as a tank wall, where the other side of the reference plate is in physical contact with the medium to be measured. The amplitude of a return signal, which is the reflection of the transmitted pulse from the interface between the other side of the reference plate and the medium, is measured. The amplitude value indicates the acoustic characteristic impedance of the substance relative to that of the reference plate or relative to that of other tested materials. Discontinuities in amplitude with repeated measurements for various heights indicate the location of interfaces in vertically-layered materials. Standardization techniques permit the relative acoustic characteristic impedance of a substance to be converted to an actual value. Calibration techniques for mixtures permit the amplitude to be converted to the concentration of a first material mixed in a second material. 6 figs.

  9. Locating interfaces in vertically-layered materials and determining concentrations in mixed materials utilizing acoustic impedance measurements

    DOEpatents

    Langlois, Gary N.

    1983-09-13

    Measurement of the relative and actual value of acoustic characteristic impedances of an unknown substance, location of the interfaces of vertically-layered materials, and the determination of the concentration of a first material mixed in a second material. A highly damped ultrasonic pulse is transmitted into one side of a reference plate, such as a tank wall, where the other side of the reference plate is in physical contact with the medium to be measured. The amplitude of a return signal, which is the reflection of the transmitted pulse from the interface between the other side of the reference plate and the medium, is measured. The amplitude value indicates the acoustic characteristic impedance of the substance relative to that of the reference plate or relative to that of other tested materials. Discontinuities in amplitude with repeated measurements for various heights indicate the location of interfaces in vertically-layered materials. Standardization techniques permit the relative acoustic characteristic impedance of a substance to be converted to an actual value. Calibration techniques for mixtures permit the amplitude to be converted to the concentration of a first material mixed in a second material.

  10. Measurement characteristics and clinical utility of the Patient Health Questionnaire-9 among individuals with spinal cord injury.

    PubMed

    Bombardier, Charles H; Smiley, Jill

    2015-05-01

    This Rehabilitation Measures Database summary provides a review of the psychometric properties of the PHQ-9 individuals with SCI. A full review of the PHQ-9 as well as reviews of over 300 other instruments can be found at www.rehabmeasures.org. PMID:26120747

  11. Measurement characteristics and clinical utility of the Brief Pain Inventory-Short Form for individuals with multiple sclerosis.

    PubMed

    Ehde, Dawn M; Nitsch, Kristian P; Smiley, Jill P

    2015-11-01

    This Rehabilitation Measures Database summary provides a review of the psychometric properties of the BPI in individuals with MS. A full review of the BPI as well as reviews of over 330 other instruments can be found at www.rehabmeasures.org. PMID:26618216

  12. CO{sub 2} laser-based dispersion interferometer utilizing orientation-patterned gallium arsenide for plasma density measurements

    SciTech Connect

    Bamford, D. J.; Cummings, E. A.; Panasenko, D.; Fenner, D. B.; Hensley, J. M.; Boivin, R. L.; Carlstrom, T. N.; Van Zeeland, M. A.

    2013-09-15

    A dispersion interferometer based on the second-harmonic generation of a carbon dioxide laser in orientation-patterned gallium arsenide has been developed for measuring electron density in plasmas. The interferometer includes two nonlinear optical crystals placed on opposite sides of the plasma. This instrument has been used to measure electron line densities in a pulsed radio-frequency generated argon plasma. A simple phase-extraction technique based on combining measurements from two successive pulses of the plasma has been used. The noise-equivalent line density was measured to be 1.7 × 10{sup 17} m{sup −2} in a detection bandwidth of 950 kHz. One of the orientation-patterned crystals produced 13 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 13 W of peak power. Two crystals arranged sequentially produced 58 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 37 W of peak power.

  13. Outcome Rating Scale and Session Rating Scale in Psychological Practice: Clinical Utility of Ultra-Brief Measures

    ERIC Educational Resources Information Center

    Campbell, Alistair; Hemsley, Samantha

    2009-01-01

    The validity and reliability of the Outcome Rating Scale (ORS) and the Session Rating Scale (SRS) were evaluated against existing longer measures, including the Outcome Questionnaire-45, Working Alliance Inventory, Depression Anxiety Stress Scale-21, Quality of Life Scale, Rosenberg Self-Esteem Scale and General Self-efficacy Scale. The measures…

  14. Utilization of point soil moisture measurements for field scale soil moisture averages and variances in agricultural landscapes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil moisture is a key variable in understanding the hydrologic processes and energy fluxes at the land surface. In spite of new technologies for in-situ soil moisture measurements and increased availability of remotely sensed soil moisture data, scaling issues between soil moisture observations and...

  15. CO2 laser-based dispersion interferometer utilizing orientation-patterned gallium arsenide for plasma density measurements.

    PubMed

    Bamford, D J; Cummings, E A; Panasenko, D; Fenner, D B; Hensley, J M; Boivin, R L; Carlstrom, T N; Van Zeeland, M A

    2013-09-01

    A dispersion interferometer based on the second-harmonic generation of a carbon dioxide laser in orientation-patterned gallium arsenide has been developed for measuring electron density in plasmas. The interferometer includes two nonlinear optical crystals placed on opposite sides of the plasma. This instrument has been used to measure electron line densities in a pulsed radio-frequency generated argon plasma. A simple phase-extraction technique based on combining measurements from two successive pulses of the plasma has been used. The noise-equivalent line density was measured to be 1.7 × 10(17) m(-2) in a detection bandwidth of 950 kHz. One of the orientation-patterned crystals produced 13 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 13 W of peak power. Two crystals arranged sequentially produced 58 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 37 W of peak power. PMID:24089824

  16. Locating interfaces in vertically-layered materials and determining concentrations in mixed materials utilizing acoustic-impedance measurements. [Patent application

    DOEpatents

    Not Available

    1981-06-10

    Measurement of the relative and actual value of acoustic characteristic impedances of an unknown substance, location of the interfaces of vertically-layered materials, and the determination of the concentration of a first material mixed in a second material are presented. A highly damped ultrasonic pulse is transmitted into one side of a reference plate, such as a tank wall, where the other side of the reference plate is in physical contact with the medium to be measured. The amplitude of a return signal, which is the reflection of the transmitted pulse from the interface between the other side of the reference plate and the medium, is measured. The amplitude value indicates the acoustic characteristic impedance of the substance relative to that of the reference plate or relative to that of other tested materials. Discontinuities in amplitude with repeated measurements for various heights indicate the location of interfaces in vertically-layered materials. Standardization techniques permit the relative acoustic characteristic impedance of a substance to be converted to an actual value. Calibration techniques for mixtures permit the amplitude to be converted to the concentration of a first material mixed in a second material.

  17. Labview utilities

    2011-09-30

    The software package provides several utilities written in LabView. These utilities don't form independent programs, but rather can be used as a library or controls in other labview programs. The utilities include several new controls (xcontrols), VIs for input and output routines, as well as other 'helper'-functions not provided in the standard LabView environment.

  18. Two-directional skin friction measurement utilizing a compact internally mounted thin-liquid-film skin friction meter

    NASA Technical Reports Server (NTRS)

    Seto, Jeffrey A.; Hornung, Hans G.

    1993-01-01

    A new, compact oil film skin friction meter capable of measuring skin friction in two directions has been designed and constructed. The instrument allows the thin liquid film technique to now be applied in flight and in a wider variety of laboratory conditions. The instrument was tested by comparing measurements with those given by a floating element gage in laminar, transitional, and turbulent boundary layers with zero pressure gradient. Both instruments agreed satisfactorily with each other and with the expected curves for the laminar and turbulent boundary layers. Significant differences were at first seen between the oil film meter and two floating element gages in the case of a favorable pressure gradient, but when a correction is applied to account for the normal force acting on the pendulum-type gage, the three instruents are much closer. The directional sensitivity of the oil film gage is also demonstrated.

  19. Utilization of profilometry, SEM, AFM and contact angle measurements in describing surfaces of plastic floor coverings and explaining their cleanability

    NASA Astrophysics Data System (ADS)

    Kuisma, R.; Pesonen-Leinonen, E.; Redsven, I.; Kymäläinen, H.-R.; Saarikoski, I.; Sjöberg, A.-M.; Hautala, M.

    2005-06-01

    The tendency to soil and cleanability of ten commercial plastic floor coverings: eight vinyl (PVC) floor coverings, one vinyl composite tile and one plastic composite tile, were examined. Floor coverings were soiled with inorganic, organic and biological soil. The cleanability was measured both by bioluminescence of ATP (adenosine triphosphate) and colorimetrically. The surface topography was studied by AFM, SEM and with a profilometer. From the 2D- and 3D-profilometric measurements several characteristic parameters of the surface profiles were extracted. The tendency to soil and cleanability were compared with the characteristics of the surface. A weak correlation was found between roughness and soilability but no correlation between roughness and cleanability. Roughness had no correlation with contact angle.

  20. Utilizing a scope and span of control tool to measure workload and determine supporting resources for nurse managers.

    PubMed

    Jones, Dawndra; McLaughlin, Maribeth; Gebbens, Christopher; Terhorst, Lauren

    2015-05-01

    The scope and span of control of the nurse manager directly impact turnover, succession planning, and satisfaction. Measuring and benchmarking scope and span of control remain a challenge. An interprofessional team across an integrated health delivery system developed and implemented such a tool, which was used to determine the amount of operational and clerical support for managers. Since implementation, there has been a decrease in turnover and time to fill nurse manager positions. PMID:25906131

  1. Zoometric measures and their utilization in prediction of live weight of local goats in southern México.

    PubMed

    Dorantes-Coronado, E J; Torres-Hernández, Glafiro; Hernández-Mendo, O; Rojo-Rubio, R

    2015-01-01

    Objectives of this study were: (a) to compare live weight (LW) and zoometric measures (ZM) of local goats in two locations, (b) to fit the best regression equation for goat LW prediction using ZM. LW, body length (BL), trunk length (TL), withers height (WH), hearth girth (HG), rump width (RW), rump length (RL), head length (HL), head width (HW), and ear length (EL) were measured in 318 Local does in Amatepec and Tejupilco, State of Mexico. Statistical methods included student's "t" tests for comparison of means, and correlation, principal components (PC), and multiple linear regression analyses. To evaluate the goodness of fit for LW prediction models the R(2) value was used as a criterion. Differences (P ≤ 0.05) were found between does of Amatepec and Tejupilco in LW, BL, TL, HG, RL, HL, HW, and EL. In Amatepec, LW was correlated with HG, BL, and HW (P ≤ 0.01), whereas in Tejupilco LW was correlated with HG, BL, TL, and HW (P ≤ 0.01). From the Amatepec measures 5 PC were extracted, and which in a multiple regression analysis explained 83.3 % of the total variance, whereas from Tejupilco 4 PC were extracted, and which in a multiple regression analysis explained 82.4 % of the total variance. The best regression model to predict doe LW in Amatepec included TL, HG, RW, and HW, whereas for Tejupilco the best model included BL, HG, HW, and EL. It is concluded that: (1) Amatepec does surpass those of Tejupilco in LW and most ZM, (2) there are reliable ZM for predicting LW of local does in both locations, HG, and HW being common measures for both populations. PMID:26587363

  2. Utility of the Measurement of Carboxyhemoglobin Level at the Site of Acute Carbon Monoxide Poisoning in Rural Areas

    PubMed Central

    Onodera, Makoto; Fujino, Yasuhisa; Kikuchi, Satoshi; Sato, Masayuki; Mori, Kiyofumi; Beppu, Takaaki; Inoue, Yoshihiro

    2016-01-01

    Objective. This study examined the hypothesis that correlations exist between the carbon monoxide exposure time and the carboxyhemoglobin concentration at the site of carbon monoxide poisoning, using a pulse carbon monoxide oximeter in rural areas or the carboxyhemoglobin concentration measured at a given medical institution. Background. In previous studies, no definitive relationships between the arterial blood carboxyhemoglobin level and the severity of carbon monoxide poisoning have been observed. Method. The subjects included patients treated for acute carbon monoxide poisoning in whom a medical emergency team was able to measure the carboxyhemoglobin level at the site of poisoning. We examined the relationship between the carboxyhemoglobin level at the site of poisoning and carbon monoxide exposure time and the relationships between the arterial blood carboxyhemoglobin level and carbon monoxide exposure time. Results. A total of 10 patients met the above criteria. The carboxyhemoglobin levels at the site of poisoning were significantly and positively correlated with the exposure time (rs = 0.710, p = 0.021), but the arterial blood carboxyhemoglobin levels were not correlated with the exposure time. Conclusion. In rural areas, the carboxyhemoglobin level measured at the site of carbon monoxide poisoning correlated with the exposure time. PMID:27239377

  3. Measurement of three-dimensional posture and trajectory of lower body during standing long jumping utilizing body-mounted sensors.

    PubMed

    Ibata, Yuki; Kitamura, Seiji; Motoi, Kosuke; Sagawa, Koichi

    2013-01-01

    The measurement method of three-dimensional posture and flying trajectory of lower body during jumping motion using body-mounted wireless inertial measurement units (WIMU) is introduced. The WIMU is composed of three-dimensional (3D) accelerometer and gyroscope of two kinds with different dynamic range and one 3D geomagnetic sensor to adapt to quick movement. Three WIMUs are mounted under the chest, right thigh and right shank. Thin film pressure sensors are connected to the shank WIMU and are installed under right heel and tiptoe to distinguish the state of the body motion between grounding and jumping. Initial and final postures of trunk, thigh and shank at standing-still are obtained using gravitational acceleration and geomagnetism. The posture of body is determined using the 3D direction of each segment updated by the numerical integration of angular velocity. Flying motion is detected from pressure sensors and 3D flying trajectory is derived by the double integration of trunk acceleration applying the 3D velocity of trunk at takeoff. Standing long jump experiments are performed and experimental results show that the joint angle and flying trajectory agree with the actual motion measured by the optical motion capture system. PMID:24110831

  4. Space environmental effects: Construction and utilization of a system to measure low thermal strain in one meter graphite epoxy tubes

    NASA Technical Reports Server (NTRS)

    Davis, J. H.; Rives, C.

    1982-01-01

    A system for measuring the expansion of low coefficient of thermal expansion (CTE) materials was constructed around a H.P. 5526-A laser measuring system. The vacuum CTE measurements in the -150 F to +120 F range were made over a 6 month period on a graphite epoxy tube yielding CTE values of 2.5 to one fifty-millionth/F above ambient and 2 + or - one ten-millionth F below ambient temperature. To assure that the below ambient, approximately 10 microns high open loop nature of the delta L/L vs. T curves was not apparatus related, similar size quartz tubes (A and B) were checked and found to have only a 2 micron (negligable for quartz) open loop component. These two quartz tubes, A and B, had ambient CTE values 20% and 45% respectively higher than the average handbook value. The overnight microcreep diminished an order of magnitude during the first several cycles after the system had been reopened.

  5. The Operational Utility of Space Environmental Measurements From Polar-Orbiting, Sun-Synchronous Satellites in AFWA Models and Applications

    NASA Astrophysics Data System (ADS)

    Citrone, P. J.; Bonadonna, M. F.; Cade, T.; Nobis, T. E.; Denig, W. F.

    2005-12-01

    Satellite-based measurements of the space environment provide vital data inputs to advanced space weather models and applications used by the Air Force Weather Agency (AFWA) to generate mission-tailored space weather intelligence in support of U.S. military operations. Since the 1970's, the Defense Meteorological Satellite Program (DMSP) has provided in-situ measurements of the topside ionosphere and of the differential energy flux of precipitating electrons and ions into the auroral and polar regions. Recently, DMSP has deployed a new class of ultraviolet remote sensors which offer opportunities for improved space environmental monitoring. The DMSP polar-orbiting, sun-synchronous satellite measurements provide critical data inputs for current and future AFWA space weather models that specify and forecast the global thermosphere, ionosphere, and magnetosphere. The AFWA Space Weather Technology Branch is pursuing an ongoing effort to transition to operations advanced research technologies associated with space environmental forecasting, to include related software applications used by AFWA to generate mission-tailored visualization products that depict space weather impacts on military systems. The Space Environmental Sensor Suite (SESS) on the National Polar-orbiting Operational Environmental Satellite System (NPOESS) will offer improved capabilities in terms of characterization and timeliness for space environmental data required by AFWA to meet new and emerging Department of Defense space weather operational requirements.

  6. Utility of the Measurement of Carboxyhemoglobin Level at the Site of Acute Carbon Monoxide Poisoning in Rural Areas.

    PubMed

    Onodera, Makoto; Fujino, Yasuhisa; Kikuchi, Satoshi; Sato, Masayuki; Mori, Kiyofumi; Beppu, Takaaki; Inoue, Yoshihiro

    2016-01-01

    Objective. This study examined the hypothesis that correlations exist between the carbon monoxide exposure time and the carboxyhemoglobin concentration at the site of carbon monoxide poisoning, using a pulse carbon monoxide oximeter in rural areas or the carboxyhemoglobin concentration measured at a given medical institution. Background. In previous studies, no definitive relationships between the arterial blood carboxyhemoglobin level and the severity of carbon monoxide poisoning have been observed. Method. The subjects included patients treated for acute carbon monoxide poisoning in whom a medical emergency team was able to measure the carboxyhemoglobin level at the site of poisoning. We examined the relationship between the carboxyhemoglobin level at the site of poisoning and carbon monoxide exposure time and the relationships between the arterial blood carboxyhemoglobin level and carbon monoxide exposure time. Results. A total of 10 patients met the above criteria. The carboxyhemoglobin levels at the site of poisoning were significantly and positively correlated with the exposure time (rs = 0.710, p = 0.021), but the arterial blood carboxyhemoglobin levels were not correlated with the exposure time. Conclusion. In rural areas, the carboxyhemoglobin level measured at the site of carbon monoxide poisoning correlated with the exposure time. PMID:27239377

  7. Psychometrics and utility of Psycho-Educational Profile-Revised as a developmental quotient measure among children with the dual disability of intellectual disability and autism.

    PubMed

    Alwinesh, Merlin Thanka Jemi; Joseph, Rachel Beulah Jansirani; Daniel, Anna; Abel, Julie Sandra; Shankar, Satya Raj; Mammen, Priya; Russell, Sushila; Russell, Paul Swamidhas Sudhakar

    2012-09-01

    There is no agreement about the measure to quantify the intellectual/developmental level in children with the dual disability of intellectual disability and autism. Therefore, we studied the psychometric properties and utility of Psycho-Educational Profile-Revised (PEP-R) as a developmental test in this population. We identified 116 children with dual disability from the day care and inpatient database of a specialised Autism Clinic. Scale and domain level scores of PEP-R were collected and analyzed. We examined the internal consistency, domain-total correlation of PEP-R and concurrent validity of PEP-R against Gesell's Developmental Schedule, inter-rater and test-retest reliability and utility of PEP-R among children with dual disability in different ages, functional level and severity of autism. Besides the adequate face and content validity, PEP-R demonstrates a good internal consistency (Cronbach's α ranging from 0.91 to 0.93) and domain-total correlation (ranging from 0.75 to 0.90). The inter-rater reliability (intraclass correlation coefficient, ICC = 0.96) and test-retest reliability (ICC = 0.87) for PEP-R is good. There is moderate-to-high concurrent validity with GDS (r ranging from 0.61 to 0.82; all Ps = 0.001). The utility of PEP-R as a developmental measure was good with infants, toddlers, pre-school and primary school children. The ability of PEP-R to measure the developmental age was good, irrespective of the severity of autism but was better with high-functioning children. The PEP-R as an intellectual/developmental test has strong psychometric properties in children with dual disability. It could be used in children with different age groups and severity of autism. PEP-R should be used with caution as a developmental test in children with dual disability who are low functioning. PMID:22833108

  8. Measuring Neutron Spectrum at MIT Research Reactor Utilizing He-3 Bonner Cylinder Approach with an Unfolding Analysis

    NASA Astrophysics Data System (ADS)

    Leder, Alexander; Ricochet Collaboration

    2016-03-01

    The Ricochet experiment seeks to measure Coherent (neutral-current) Elastic Neutrino-Nucleus Scattering (CENNS) using dark matter style detectors placed near a neutrino source, possibly the MIT research reactor (MITR), which offers a high continuous neutrino flux at high energies. Currently, Ricochet is characterizing the backgrounds at MITR. The main background is the neutrons emitted simultaneously from the core. To characterize this background, we wrapped a Bonner cylinder around a 3He thermal neutron detector, whose data was then unfolded to produce a neutron energy spectrum across several orders of magnitude. We discuss the resulting spectrum as well its implications for deploying Ricochet in the future.

  9. A pressurized ion chamber monitoring system for environmental radiation measurements utilizing a wide-range temperature-compensated electrometer

    SciTech Connect

    Stevenick, W. Van . Environmental Measurements Lab.)

    1994-08-01

    The performance of a complete pressurized ion chamber (PIC) radiation monitoring system is described. The design incorporates an improved temperature-compensated electrometer which is stable to [+-]3 [center dot] 10[sup [minus]16] A over the environmental range of temperature ([minus]40 to +40 C). Using a single 10[sup 11] [Omega] feed-back resistor, the electrometer accurately measures currents over a range from 3 [center dot] 10[sup [minus]15] A to 3 [center dot] 10[sup [minus]11] A. While retaining the sensitivity of the original PIC system (the instrument responds readily to small background fluctuations on the order of 0.1 [mu]R h[sup [minus]1]), the new system measures radiation levels up to the point where the collection efficiency of the ion chamber begins to drop off, typically [approximately]27 pA at 1 mR h[sup [minus]1]. A data recorder and system controller was designed using the Tattletale[trademark] Model 4A computer. Digital data is stored on removable solid-state, credit-card style memory cards.

  10. Social and Economic Costs of Food Allergies in Europe: Development of a Questionnaire to Measure Costs and Health Utility

    PubMed Central

    Fox, Margaret; Voordouw, Jantine; Mugford, Miranda; Cornelisse, Judith; Antonides, Gerrit; Frewer, Lynn

    2009-01-01

    Objectives To develop a questionnaire to measure the additional social costs of food allergies (FAs). Data Source and Study Setting People with FAs and sampled members of the general population (with and without FAs) in the Netherlands and the United Kingdom in 2006. Study Design (1) Literature review. (2) Focus group to identify key costs of FAs and seek views on the questionnaires. (3) Pilot survey to test the questionnaires in cases and controls. Data Collection Twenty-eight participants in the United Kingdom and the Netherlands with clinically or self-diagnosed FAs took part in one of five focus groups. A case–control postal survey was conducted in the United Kingdom and the Netherlands (with 125 FA cases and 62 controls). Principal Findings Methods exist to measure social costs in chronic illness, but not FAs. Focus groups found features of FAs likely to impact costs of living. Pilot results suggest higher costs of living and health care costs, and well-being in FAs. Conclusion The questionnaire is proposed for use in wider European and other comparative studies of FAs. PMID:19619251

  11. An Inverse Interpolation Method Utilizing In-Flight Strain Measurements for Determining Loads and Structural Response of Aerospace Vehicles

    NASA Technical Reports Server (NTRS)

    Shkarayev, S.; Krashantisa, R.; Tessler, A.

    2004-01-01

    An important and challenging technology aimed at the next generation of aerospace vehicles is that of structural health monitoring. The key problem is to determine accurately, reliably, and in real time the applied loads, stresses, and displacements experienced in flight, with such data establishing an information database for structural health monitoring. The present effort is aimed at developing a finite element-based methodology involving an inverse formulation that employs measured surface strains to recover the applied loads, stresses, and displacements in an aerospace vehicle in real time. The computational procedure uses a standard finite element model (i.e., "direct analysis") of a given airframe, with the subsequent application of the inverse interpolation approach. The inverse interpolation formulation is based on a parametric approximation of the loading and is further constructed through a least-squares minimization of calculated and measured strains. This procedure results in the governing system of linear algebraic equations, providing the unknown coefficients that accurately define the load approximation. Numerical simulations are carried out for problems involving various levels of structural approximation. These include plate-loading examples and an aircraft wing box. Accuracy and computational efficiency of the proposed method are discussed in detail. The experimental validation of the methodology by way of structural testing of an aircraft wing is also discussed.

  12. Development of an automated ballast water treatment verification system utilizing fluorescein diacetate hydrolysis as a measure of treatment efficacy.

    PubMed

    Akram, A C; Noman, S; Moniri-Javid, R; Gizicki, J P; Reed, E A; Singh, S B; Basu, A S; Banno, F; Fujimoto, M; Ram, J L

    2015-03-01

    Methods for verifying ballast water treatments in foreign vessels are needed to protect the Great Lakes from the discharge of live non-native organisms or pathogens. A prototype automated viability test system using fluorescein diacetate (FDA), a membrane permeable fluorogen, to differentiate live from dead bacteria and algae is described. The automated fluorescence intensity detection device (AFIDD) captures cultured algae or organisms in Detroit River water (simulated ballast water) on 0.2 μm filters, backwashes them from the filter into a cuvette with buffer and FDA for subsequent fluorescence intensity measurements, and washes the filters with sterile water for serial automated reuse. Preliminary manual versions of these procedures were also tested. Tests of various buffers determined N,N-Bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, N,N-Bis(2-hydroxyethyl)taurine (BES) and 3-(N-morpholino)propanesulfonic acid (MOPS) at pH 7.0 to be the best buffers, causing the least spontaneous FDA breakdown without inhibiting enzymatic activity. Fluorescence in the presence of live organisms increased linearly over time, and the rate of increase was dependent on the sample concentration. Following simulated ballast water treatments with heat or chlorine, the fluorescence produced by Detroit River samples decreased to near control (sterile water) levels. Automated measurements of FDA hydrolysis with a reusable filter backwash system should be applicable to near real-time remote-controlled monitoring of live organisms in ballast water. PMID:25555225

  13. The clinical utility of the continuous performance test and objective measures of activity for diagnosing and monitoring ADHD in children: a systematic review.

    PubMed

    Hall, Charlotte L; Valentine, Althea Z; Groom, Madeleine J; Walker, Gemma M; Sayal, Kapil; Daley, David; Hollis, Chris

    2016-07-01

    Attention-deficit hyperactivity disorder (ADHD) is typically diagnosed using clinical observation and subjective informant reports. Once children commence ADHD medication, robust monitoring is required to detect partial or non-responses. The extent to which neuropsychological continuous performance tests (CPTs) and objective measures of activity can clinically aid the assessment and titration process in ADHD is not fully understood. This review describes the current evidence base for the use of CPTs and objectively measured activity to support the diagnostic procedure and medication management for children with ADHD. Four databases (PsycINFO, Medline, Allied and Complementary Medicine (AMED), and PsycARTICLES) were systematically searched to understand the current evidence base for (1) the use of CPTs to aid clinical assessment of ADHD; (2) the use of CPTs to aid medication management; and (3) the clinical utility of objective measures of activity in ADHD. Sixty relevant articles were identified. The search revealed six commercially available CPTs that had been reported on for their clinical use. There were mixed findings with regard to the use of CPTs to assess and manage medication, with contrasting evidence on their ability to support clinical decision-making. There was a strong evidence base for the use of objective measures of activity to aid ADHD/non-ADHD group differentiation, which appears sensitive to medication effects and would also benefit from further research on their clinical utility. The findings suggest that combining CPTs and an objective measure of activity may be particularly useful as a clinical tool and worthy of further pursuit. PMID:26620873

  14. Utility of a single mid-trimester measurement of plasminogen activator Type 1 and fibronectin to predict preeclampsia in pregnancy

    PubMed Central

    Ajibola, S. O.; Adeyemo, T. A.; Afolabi, B. B.; Akanmu, A. S.

    2016-01-01

    Background: Preeclampsia (PE) is the second most common cause of maternal death after obstetric hemorrhage in Africa, a resource-limited region. This study was designed to examine the potential usefulness of a single screening plasma plasminogen activator inhibitor-1 (PAI-1) and fibronectin (FN) level for the prediction of PE in pregnant women. Materials and Methods: In a cohort of 180 pregnant women who were normotensive at baseline, venous blood samples were obtained before 20 weeks of gestation for the assay of plasma levels of PAI-1 and FN levels measured by enzyme-linked immunoassay technique. Twenty nonpregnant normotensive women were also evaluated as a control group. Outcomes of gestation were evaluated and correlated with the plasma levels of PAI and FN measured at mid-trimester. Mean plasma values of PAI-1 and FN were also compared between the different outcome groups. Results: Plasma PAI-1 level was significantly higher in the pregnant women (8.68 ± 0.56 ng/ml) than in nonpregnant controls (5.55 ± 0.32 ng/ml) (P = 0.01). However, plasma FN did not show any significant difference in pregnant women (2.60 ± 0.37 μg/ml) and nonpregnant controls (2.60 ± 0.23 μg/ml) (P = 0.9). Mid-trimester mean plasma PAI-1 level measured in women who developed PE (7.08 ± 5.49 ng/ml, n = 12) and gestational hypertension (GH) (9.78 ± 6.2 ng/ml, n = 13) was not significantly different in comparison to normotensive pregnant women (8.78 ± 5.63 ng/ml, n = 153) (P = 0.75). Likewise, the mean FN level in women who developed PE was also not significantly different from nonpreeclamptics; however, the FN level in the pregnant women who developed GH was significantly different from women who remained normotensive throughout pregnancy (P = 0.02). Conclusion: Single mid-trimester assessment of PAI-1 and FN levels in maternal plasma was not found to be useful in predicting PE as an outcome of pregnancy in the study population.

  15. The utility of using customized heterochromatic flicker photometry (cHFP) to measure macular pigment in patients with age-related macular degeneration.

    PubMed

    Stringham, J M; Hammond, B R; Nolan, J M; Wooten, B R; Mammen, A; Smollon, W; Snodderly, D M

    2008-11-01

    The purpose of this study was to assess the utility and validity of using customized heterochromatic flicker photometry (cHFP) to measure macular pigment optical density (MPOD) in patients with intermediate stages of age-related macular degeneration (AMD). The measurement procedure was optimized to accommodate individual differences in temporal vision related to age, disease, or other factors. The validity criteria were based on the similarity of the spectral absorption curves to ex vivo curves of lutein and zeaxanthin and the similarity of spatial density profiles to those measured in subjects without retinal disease. Macular pigment optical density (MPOD) spatial profiles were measured with an LED-based macular densitometer; spectral absorption curves were measured with a 3-channel Maxwellian view system including a monochromator. All patients were characterized via clinical exams and all but 2 subjects from whom data were obtained had masked grading of color fundus photographs using the Wisconsin Age-Related Maculopathy Grading System. Most of the patients were in AREDS category 2 (27%) or 3 (57%). Patients with visual acuity as poor as 20/80 were included, and could perform the task as long as they could see the stimulus. Eighty-one percent of the patients screened were able to perform the cHFP task, and data were obtained from 30 AMD patients. Spatial profiles of MPOD were measured in 19 subjects who could see the stimulus at all tested loci. These profiles were highly similar to those that have been measured with HFP in subjects without retinal disease. The average shape of the spectral absorption curves for the AMD subjects corresponded well to an ex vivo template. These data support both the utility and validity of the cHFP method for measuring MPOD in subjects with intermediate stages of AMD. The ability to measure the retinal response to nutritional intervention is of practical importance for monitoring patients being supplemented with lutein and

  16. Stereo-particle image velocimetry measurements of a patient-specific Fontan physiology utilizing novel pressure augmentation stents.

    PubMed

    Chopski, Steven G; Rangus, Owen M; Fox, Carson S; Moskowitz, William B; Throckmorton, Amy L

    2015-03-01

    Single ventricle anomalies are a challenging set of congenital heart defects that require lifelong clinical management due to progressive decline of cardiovascular function. Few therapeutic devices are available for these patients, and conventional blood pumps are not designed for the unique anatomy of the single ventricle physiology. To address this unmet need, we are developing an axial flow blood pump with a protective cage or stent for Fontan patients. This study investigates the 3-D particle image velocimetry measurements of two cage designs being deployed in a patient-specific Fontan anatomy. We considered a control case without a pump, impeller placed in the inferior vena cava, and two cases where the impeller has two protective stents with unique geometric characteristics. The experiments were evaluated at a cardiac output of 3 L/min, a fixed vena caval flow split of 40%/60%, a fixed pulmonary arterial flow split of 50%/50%, and for operating speeds of 1000-4000 rpm. The introduction of the cardiovascular stents had a substantial impact on the flow conditions leaving the pump and entering the cavopulmonary circulation. The findings indicated that rotational speeds above 4000 rpm for this pump could result in irregular flows in this specific circulatory condition. Although retrograde flow into the superior vena cava was not measured, the risk of this occurrence increases with higher pump speeds. The against-with stent geometry outperformed the other configurations by generating higher pressures and more energetic flows. These results provide further support for the viability of mechanical cavopulmonary assistance as a therapeutic treatment strategy for Fontan patients. PMID:25597518

  17. The blink reflex magnitude is continuously adjusted according to both current and predicted stimulus position with respect to the face.

    PubMed

    Wallwork, Sarah B; Talbot, Kerwin; Camfferman, Danny; Moseley, G L; Iannetti, G D

    2016-08-01

    The magnitude of the hand-blink reflex (HBR), a subcortical defensive reflex elicited by the electrical stimulation of the median nerve, is increased when the stimulated hand is close to the face ('far-near effect'). This enhancement occurs through a cortico-bulbar facilitation of the polysynaptic medullary pathways subserving the reflex. Here, in two experiments, we investigated the temporal characteristics of this facilitation, and its adjustment during voluntary movement of the stimulated hand. Given that individuals navigate in a fast changing environment, one would expect the cortico-bulbar modulation of this response to adjust rapidly, and as a function of the predicted spatial position of external threats. We observed two main results. First, the HBR modulation occurs without a temporal delay between when the hand has reached the stimulation position and when the stimulus happens (Experiments 1 and 2). Second, the voluntary movement of the hand interacts with the 'far-near effect': stimuli delivered when the hand is far from the face elicit an enhanced HBR if the hand is being moved towards the face, whereas stimuli delivered when the hand is near the face elicit an enhanced HBR regardless of the direction of the hand movement (Experiment 2). These results indicate that the top-down modulation of this subcortical defensive reflex occurs continuously, and takes into account both the current and the predicted position of potential threats with respect to the body. The continuous control of the excitability of subcortical reflex circuits ensures appropriate adjustment of defensive responses in a rapidly-changing sensory environment. PMID:27236372

  18. Penning trap mass measurements utilizing highly charged ions as a path to benchmark isospin-symmetry breaking corrections in 74Rb

    NASA Astrophysics Data System (ADS)

    Malbrunot-Ettenauer, S.; Brunner, T.; Chowdhury, U.; Gallant, A. T.; Simon, V. V.; Brodeur, M.; Chaudhuri, A.; Mané, E.; Simon, M. C.; Andreoiu, C.; Audi, G.; Crespo López-Urrutia, J. R.; Delheij, P.; Gwinner, G.; Lapierre, A.; Lunney, D.; Pearson, M. R.; Ringle, R.; Ullrich, J.; Dilling, J.

    2015-04-01

    Penning trap mass measurements of neutron-deficient Rb isotopes have been performed at TRIUMF's Ion Trap for Atomic and Nuclear Science (TITAN) facility by utilizing highly charged ions (HCIs). As imperative for a new approach with significant gain in measurement precision, experimental procedures, and systematic uncertainties are discussed in detail. Among the investigated nuclides, the superallowed nuclear β emitter 74Rb will especially benefit from the advantage offered by HCI because the limited attainable precision owing to its short half-life (T1 /2=65 ms) represents a challenge for conventional Penning trap mass spectrometry. Motivated by an updated QEC value for 74Rb of 10 416.8(3.9) keV and its large isospin-symmetry breaking corrections, we present a new test to benchmark the consistency between theoretical models of isospin-symmetry breaking corrections in superallowed decays, the conserved vector current hypothesis, and experimental data.

  19. Measuring the Safety of Excreta Disposal Behavior in India with the New Safe San Index: Reliability, Validity and Utility

    PubMed Central

    Jenkins, Marion W.; Freeman, Matthew C.; Routray, Parimita

    2014-01-01

    Methods to assess household excreta disposal practices are critical for informing public health outcomes of efforts to improve sanitation in developing countries. We present a new metric, the Safe San Index (SSI), to quantify the hygienic safety of a household’s defecation and human feces disposal practices in India, where behavioral outcomes from on-going public expenditures to construct household sanitation facilities and eliminate open defecation are poorly measured. We define hygienic safety of feces disposal as capture in a hygienic sanitation facility. The SSI consists of 15 self-report items and two sub-scales, Latrine Use Frequency and Seven-Day Open Defecation Rate. Households are scored on a standardized scale from 0 (no defecation safely captured) to 100 (all defecation safely captured). We present results of a pilot study in Odisha, India to apply the Index to assess excreta disposal behaviors among rural households and evaluate the reliability and validity of the Index for estimating the rate of correct and consistent sanitation facility usage of household with an improved latrine. PMID:25153464

  20. Methylene chloride intoxication in a furniture refinisher. A comparison of exposure estimates utilizing workplace air sampling and blood carboxyhemoglobin measurements

    SciTech Connect

    Shusterman, D.; Quinlan, P.; Lowengart, R.; Cone, J. )

    1990-05-01

    A 35-year-old furniture refinisher came to the occupational medicine clinic with complaints of upper respiratory irritation, fatigue, and lightheadedness occurring on a daily basis after using a methylene chloride-containing paint stripper. Determinations of blood carboxyhemoglobin (COHb) on three occasions showed an apparently linear elevation of COHb as a function of hours worked on the day of sampling. COHb levels predicted from spot industrial hygiene measurements were in close concordance with those observed in the patient, indicating the potential usefulness of COHb monitoring in estimating airborne exposure levels. Methylene chloride (or dichloromethane) is an organic solvent that has found wide use as a degreaser, paint remover, aerosol propellant, and a blowing agent for polyurethane foams, and as a solvent in food processing, photographic film production, and plastics manufacturing. Discovery of its unusual metabolic fate--conversion to carbon monoxide in vivo--has earned the compound a special place in the solvent toxicology literature. Demonstration of oncogenicity in experimental animals has occasioned a reconsideration of exposure limits, with emphasis upon stricter controls. In some workplaces, conditions prevail in which controls are inadequate to prevent even acute toxicity, much less long-term exposure risks.

  1. Clinical utility of urine neutrophil gelatinase-associated lipocalin measured at admission to predict outcomes in heterogeneous population of critically ill patients

    PubMed Central

    Nayak, N. M.; Madhumitha, S.; Annigeri, R. A.; Venkataraman, R.; Balasubramaian, S.; Seshadri, R.; Vadamalai, V.; Rao, B. S.; Kowdle, P. C.; Ramakrishnan, N.; Mani, M. K.

    2016-01-01

    Urine neutrophil gelatinase-associated lipocalin (uNGAL) is a reliable early biomarker of acute kidney injury (AKI) in a homogeneous patient population. However, its utility in a heterogeneous population of critically ill, in whom the time of onset of renal insult is often unclear, is not clearly established. We evaluated the ability of a single measurement of uNGAL in a heterogeneous adult population, on admission to intensive care unit (ICU), to predict the occurrence of AKI and hospital mortality. One hundred and two consecutive adult patients had uNGAL measured within 8 h of admission to ICU. The demographic and laboratory data were collected at admission. The diagnosis of AKI was based on AKI Network (AKIN) criteria. The primary outcome was the development of AKI, and the secondary outcome was hospital mortality. The mean age was 54 ± 16.4 years and 65% were males. Urine NGAL (ng/ml) was 69 ± 42 in patients with AKI (n = 42) and 30.4 ± 41.7 in those without AKI (P < 0.001). The area under the receiver operating characteristic (ROC) curve for prediction of AKI was 0.79 and for serum creatinine (SCr) was 0.88. The sensitivity and specificity for a cut-off value of uNGAL of 75 ng/ml to predict AKI were 0.5 and 0.85 respectively. uNGAL > 75 ng/ml was a strong (odd ratio = 5.17, 95% confidence interval: 1.39–19.3) and independent predictor of hospital mortality. A single measurement of uNGAL at admission to ICU exhibited good predictive ability for AKI though the sensitivity was low. The predictive ability of uNGAL was inferior to simultaneously measured SCr at admission, hence limited its clinical utility to predict AKI. However, admission uNGAL was a strong, independent predictor of hospital mortality. PMID:27051136

  2. Spectral Parameters Modulation and Source Localization of Blink-Related Alpha and Low-Beta Oscillations Differentiate Minimally Conscious State from Vegetative State/Unresponsive Wakefulness Syndrome

    PubMed Central

    Bonfiglio, Luca; Piarulli, Andrea; Olcese, Umberto; Andre, Paolo; Arrighi, Pieranna; Frisoli, Antonio; Rossi, Bruno; Bergamasco, Massimo; Carboncini, Maria Chiara

    2014-01-01

    Recently, the cortical source of blink-related delta oscillations (delta BROs) in resting healthy subjects has been localized in the posterior cingulate cortex/precuneus (PCC/PCu), one of the main core-hubs of the default-mode network. This has been interpreted as the electrophysiological signature of the automatic monitoring of the surrounding environment while subjects are immersed in self-reflecting mental activities. Although delta BROs were directly correlated to the degree of consciousness impairment in patients with disorders of consciousness, they failed to differentiate vegetative state/unresponsive wakefulness syndrome (VS/UWS) from minimally conscious state (MCS). In the present study, we have extended the analysis of BROs to frequency bands other than delta in the attempt to find a biological marker that could support the differential diagnosis between VS/UWS and MCS. Four patients with VS/UWS, 5 patients with MCS, and 12 healthy matched controls (CTRL) underwent standard 19-channels EEG recordings during resting conditions. Three-second-lasting EEG epochs centred on each blink instance were submitted to time-frequency analyses in order to extract the normalized Blink-Related Synchronization/Desynchronization (nBRS/BRD) of three bands of interest (low-alpha, high-alpha and low-beta) in the time-window of 50–550 ms after the blink-peak and to estimate the corresponding cortical sources of electrical activity. VS/UWS nBRS/BRD levels of all three bands were lower than those related to both CTRL and MCS, thus enabling the differential diagnosis between MCS and VS/UWS. Furthermore, MCS showed an intermediate signal intensity on PCC/PCu between CTRL and VS/UWS and a higher signal intensity on the left temporo-parieto-occipital junction and inferior occipito-temporal regions when compared to VS/UWS. This peculiar pattern of activation leads us to hypothesize that resting MCS patients have a bottom-up driven activation of the task positive network and thus

  3. Effects of Imagery Training on Cognitive Performance and Use of Physiological Measures as an Assessment Tool of Mental Effort

    ERIC Educational Resources Information Center

    Papadelis, Christos; Kourtidou-Papadeli, Chrysoula; Bamidis, Panagiotis; Albani, Maria

    2007-01-01

    The effectiveness of motor imagery training on cognitive performance was examined and the physiological mechanisms involved in the contribution of mental practice to motor learning were considered. The subject's mental effort during motor imagery was assessed by using psychophysiological measures and particularly eye blink activity as an…

  4. Instructional Facility Utilization.

    ERIC Educational Resources Information Center

    Kalamazoo Valley Community Coll., MI.

    Data describing campus facility use for instructional and related purposes for one week of activity in Fall 1978 were collected and evaluated at Kalamazoo Valley Community College. Four measures of space utilization were used: (1) percent of available time used; (2) percent of available space used; (3) percent of scheduled space utilized; and (4)…

  5. Utilizing In Situ Directional Hyperspectral Measurements to Validate Bio-Indicator Simulations for a Corn Crop Canopy

    NASA Technical Reports Server (NTRS)

    Cheng, Yen-Ben; Middleton, Elizabeth M.; Huemmrich, Karl F.; Zhang, Qingyuan; Campbell, Petya K. E.; Corp, Lawrence A.; Russ, Andrew L.; Kustas, William P.

    2010-01-01

    Two radiative transfer canopy models, SAIL and the two-layer Markov-Chain Canopy Reflectance Model (MCRM), were coupled with in situ leaf optical properties to simulate canopy-level spectral band ratio vegetation indices with the focus on the photochemical reflectance index in a cornfield. In situ hyperspectral measurements were made at both leaf and canopy levels. Leaf optical properties were obtained from both sunlit and shaded leaves. Canopy reflectance was acquired for eight different relative azimuth angles (psi) at three different view zenith angles (Theta (sub v)), and later used to validate model outputs. Field observations of photochemical reflectance index (PRI) for sunlit leaves exhibited lower values than shaded leaves, indicating higher light stress. Canopy PRI expressed obvious sensitivity to viewing geometry, as a function of both Theta (sub v) and psi . Overall, simulations from MCRM exhibited better agreements with in situ values than SAIL. When using only sunlit leaves as input, the MCRM-simulated PRI values showed satisfactory correlation and RMSE, as compared to in situ values. However, the performance of the MCRM model was significantly improved after defining a lower canopy layer comprised of shaded leaves beneath the upper sunlit leaf layer. Four other widely used band ratio vegetation indices were also studied and compared with the PRI results. MCRM simulations were able to generate satisfactory simulations for these other four indices when using only sunlit leaves as input; but unlike PRI, adding shaded leaves did not improve the performance of MCRM. These results support the hypothesis that the PRI is sensitive to physiological dynamics while the others detect static factors related to canopy structure. Sensitivity analysis was performed on MCRM in order to better understand the effects of structure related parameters on the PRI simulations. Leaf area index (LAI) showed the most significant impact on MCRM-simulated PRI among the parameters

  6. Individual differences in self-concept among smokers attempting to quit: Validation and predictive utility of measures of the smoker self-concept and abstainer self-concept.

    PubMed

    Shadel, W G; Mermelstein, R

    1996-09-01

    We tested a theoretical model of individual differences in smoking cessation using a social-cognitive conception of the self-concept. We developed and validated measures of the smoker self-concept and the abstainer self-concept. Each scale was shown to have good internal reliability and construct validity and was distinct from other important predictive measures used in smoking research (e.g. Fagerstrom Tolerance Questionnaire, smoking rate, motivation, self-efficacy). Importantly, we demonstrated the predictive validity of the self-concept scales. The interaction of baseline measures of the smoker self-concept and abstainer self-concept predicted smoking status three months after treatment; subjects were most likely to be abstinent if they began treatment with a strong abstainer selfconcept and a weak smoker self-concept. This interaction held over and above baseline smoking rate, Fagerstrom Tolerance scores, and measures of motivation and self-efficacy to quit. The utility of social-cognitive individual difference models and potential patient-treatment matching interventions are discussed. PMID:24203766

  7. Microvolt T-wave alternans physiological basis, methods of measurement, and clinical utility--consensus guideline by International Society for Holter and Noninvasive Electrocardiology.

    PubMed

    Verrier, Richard L; Klingenheben, Thomas; Malik, Marek; El-Sherif, Nabil; Exner, Derek V; Hohnloser, Stefan H; Ikeda, Takanori; Martínez, Juan Pablo; Narayan, Sanjiv M; Nieminen, Tuomo; Rosenbaum, David S

    2011-09-20

    This consensus guideline was prepared on behalf of the International Society for Holter and Noninvasive Electrocardiology and is cosponsored by the Japanese Circulation Society, the Computers in Cardiology Working Group on e-Cardiology of the European Society of Cardiology, and the European Cardiac Arrhythmia Society. It discusses the electrocardiographic phenomenon of T-wave alternans (TWA) (i.e., a beat-to-beat alternation in the morphology and amplitude of the ST-segment or T-wave). This statement focuses on its physiological basis and measurement technologies and its clinical utility in stratifying risk for life-threatening ventricular arrhythmias. Signal processing techniques including the frequency-domain Spectral Method and the time-domain Modified Moving Average method have demonstrated the utility of TWA in arrhythmia risk stratification in prospective studies in >12,000 patients. The majority of exercise-based studies using both methods have reported high relative risks for cardiovascular mortality and for sudden cardiac death in patients with preserved as well as depressed left ventricular ejection fraction. Studies with ambulatory electrocardiogram-based TWA analysis with Modified Moving Average method have yielded significant predictive capacity. However, negative studies with the Spectral Method have also appeared, including 2 interventional studies in patients with implantable defibrillators. Meta-analyses have been performed to gain insights into this issue. Frontiers of TWA research include use in arrhythmia risk stratification of individuals with preserved ejection fraction, improvements in predictivity with quantitative analysis, and utility in guiding medical as well as device-based therapy. Overall, although TWA appears to be a useful marker of risk for arrhythmic and cardiovascular death, there is as yet no definitive evidence that it can guide therapy. PMID:21920259

  8. Environmental impact assessment using a utility-based recursive evidential reasoning approach for structural flood mitigation measures in Metro Manila, Philippines.

    PubMed

    Gilbuena, Romeo; Kawamura, Akira; Medina, Reynaldo; Nakagawa, Naoko; Amaguchi, Hideo

    2013-12-15

    In recent years, the practice of environmental impact assessment (EIA) has created significant awareness on the role of environmentally sound projects in sustainable development. In view of the recent studies on the effects of climate change, the Philippine government has given high priority to the construction of flood control structures to alleviate the destructive effects of unmitigated floods, especially in highly urbanized areas like Metro Manila. EIA thus, should be carefully and effectively carried out to maximize or optimize the potential benefits that can be derived from structural flood mitigation measures (SFMMs). A utility-based environmental assessment approach may significantly aid flood managers and decision-makers in planning for effective and environmentally sound SFMM projects. This study proposes a utility-based assessment approach using the rapid impact assessment matrix (RIAM) technique, coupled with the evidential reasoning approach, to rationally and systematically evaluate the ecological and socio-economic impacts of 4 planned SFMM projects (i.e. 2 river channel improvements and 2 new open channels) in Metro Manila. Results show that the overall environmental effects of each of the planned SFMM projects are positive, which indicate that the utility of the positive impacts would generally outweigh the negative impacts. The results also imply that the planned river channel improvements will yield higher environmental benefits over the planned open channels. This study was able to present a clear and rational approach in the examination of overall environmental effects of SFMMs, which provides valuable insights that can be used by decision-makers and policy makers to improve the EIA practice and evaluation of projects in the Philippines. PMID:24157409

  9. Recent topics on single-molecule fluctuation analysis using blinking in surface-enhanced resonance Raman scattering: clarification by the electromagnetic mechanism.

    PubMed

    Itoh, Tamitake; Yamamoto, Yuko S

    2016-08-15

    Surface-enhanced Raman scattering (SERS) spectroscopy has become an ultrasensitive tool for clarifying molecular functions on plasmonic metal nanoparticles (NPs). SERS has been used for in situ probing of detailed behaviors of few or single molecules (SMs) at plasmonic NP junctions. SM SERS signals are commonly observed with temporal and spectral changes known as "blinking", which are related to various physical and chemical interactions between molecules and NP junctions. These temporal and spectral changes simultaneously take place, therefore resulting in serious complexities in interpretations of the SM SERS results. Dual contributions of Raman enhancement mechanisms in SERS (i.e., electromagnetic (EM) and chemical enhancements) also make interpretations more difficult. To resolve these issues and reduce the degree of complexities in SM SERS analyses, the present review is focused on the recent studies of probing SM behaviors using SERS exclusively within the framework of the EM mechanism. The EM mechanism is briefly introduced, and several recent topics on SM SERS blinking analysis are discussed in light of the EM mechanism. This review will provide a basis for clarification of complex SERS fluctuations of various molecules. PMID:27241875

  10. Objective measures on knee instability: dynamic tests: a review of devices for assessment of dynamic knee laxity through utilization of the pivot shift test.

    PubMed

    Sundemo, David; Alentorn-Geli, Eduard; Hoshino, Yuichi; Musahl, Volker; Karlsson, Jón; Samuelsson, Kristian

    2016-06-01

    Current reconstructive methods used after anterior cruciate ligament (ACL) injury do not entirely restore native knee kinematics. Evaluation of dynamic knee laxity is important to accurately diagnose ACL deficiency, to evaluate reconstructive techniques, and to construct treatment algorithms for patients with ACL injury. The purpose of this study is to present recent progress in evaluation of dynamic knee laxity through utilization of the pivot shift test. A thorough electronic search was performed and relevant studies were assessed. Certain dynamic knee laxity measurement methods have been present for over 10 years (Navigation system, Electromagnetic sensor system) while other methods (Inertial sensor, Image analysis system) have been introduced recently. Methods to evaluate dynamic knee laxity through the pivot shift test are already potent. However, further refinement is warranted. In addition, to correctly quantify the pivot shift test, the involved forces need to be controlled through either standardization or mechanization of the pivot shift test. PMID:26984465

  11. The utility of the Psychopathy Checklist: Youth Version (PCL: YV) and the Youth Psychopathic Trait Inventory (YPI)-Is it meaningful to measure psychopathy in young offenders?

    PubMed

    Shepherd, Stephane M; Strand, Susanne

    2016-04-01

    This study examined the convergent validity of 2 youth psychopathy instruments, the Psychopathy Checklist: Youth Version (PCL: YV) and the Youth Psychopathic Trait Inventory (YPI) and their relationship with problem behaviors and recidivism in an Australian sample of young offenders in custody. The PCL: YV demonstrated a capacity to identify severely antisocial youth; however, the tool was unable to differentiate between potentially psychopathic and nonpsychopathic antisocial youth. The YPI was receptive to a wide variety of problem behaviors which precluded the unique identification of core psychopathic traits in the sample. Both instruments were unable to meaningfully distinguish between recidivists and nonrecidivists. As such, the PCL: YV and the YPI demonstrate limited utility for antisocial young offenders in custody. Further research on the durability and developmental manifestation of psychopathy in adolescents is necessary before these instruments are employed in similar contexts. Implications for the clinical use of psychopathy measures are discussed. (PsycINFO Database Record PMID:26146951

  12. A longitudinal examination of the measurement properties and predictive utility of the Center for Epidemiologic Studies Depression Scale among North American Indigenous adolescents.

    PubMed

    Armenta, Brian E; Sittner Hartshorn, Kelley J; Whitbeck, Les B; Crawford, Devan M; Hoyt, Dan R

    2014-12-01

    We examined the longitudinal measurement properties and predictive utility of the Center for Epidemiologic Studies Depression Scale (CES-D) from early to late adolescence among a sample of North American Indigenous youths. Participants were 632 North American Indigenous adolescents (n = 632; 50.3% girls; M age at baseline = 11.11 years) participating in an 8-year, 8-wave longitudinal study. Via in-person interviews, participants completed the CES-D at Waves 1, 3, 5, and 7, and the major depressive disorder (MDD) module of the Diagnostic Interview Schedule for Children at Waves 1, 4, 6, and 8. Confirmatory factor analyses indicated that responses to the CES-D were similarly explained by 2-, 3-, and 4-factor models, as well as a 1-factor model with correlations between the error variances for the positively worded items. Longitudinal measurement equivalence analyses indicated full structural (i.e., factor structure), metric (i.e., factor loadings), and scalar (i.e., observed item intercepts) equivalence for each factor structure. Substantive analyses showed that the CES-D was significantly associated with MDD both concurrently and prospectively, although these effects were smaller than might be expected. Finally, the CES-D negative affect and somatic complaints subscales were the strongest and most consistent predictors of MDD. Among our sample of North American Indigenous youths, the measurement properties of the CES-D were stable from early to late adolescence. Moreover, somatic difficulties and depressed affect were the strongest predictors of MDD. PMID:25181394

  13. A Longitudinal Examination of the Measurement Properties and Predictive Utility of the Center for Epidemiologic Studies Depression Scale Among North American Indigenous Adolescents

    PubMed Central

    Armenta, Brian E.; Sittner Hartshorn, Kelley J.; Whitbeck, Les B.; Crawford, Devan M.; Hoyt, Dan R.

    2014-01-01

    We examined the longitudinal measurement properties and predictive utility of the Center for Epidemiologic Studies Depression Scale (CES-D) from early to late adolescence among a sample of North American Indigenous youths. Participants were 632 North American Indigenous adolescents (n = 632; 50.3% girls; M age at baseline = 11.11 years) participating in an 8-year, 8-wave longitudinal study. Via in-person interviews, participants completed the CES-D at Waves 1, 3, 5, and 7, and the major depressive disorder (MDD) module of the Diagnostic Interview Schedule for Children at Waves 1, 4, 6, and 8. Confirmatory factor analyses indicated that responses to the CES-D were similarly explained by 2-, 3-, and 4-factor models, as well as a 1-factor model with correlations between the error variances for the positively worded items. Longitudinal measurement equivalence analyses indicated full structural (i.e., factor structure), metric (i.e., factor loadings), and scalar (i.e., observed item intercepts) equivalence for each factor structure. Substantive analyses showed that the CES-D was significantly associated with MDD both concurrently and prospectively, although these effects were smaller than might be expected. Finally, the CES-D negative affect and somatic complaints subscales were the strongest and most consistent predictors of MDD. Among our sample of North American Indigenous youths, the measurement properties of the CES-D were stable from early to late adolescence. Moreover, somatic difficulties and depressed affect were the strongest predictors of MDD. PMID:25181394

  14. Utilizing chromophoric dissolved organic matter measurements to derive export and reactivity of dissolved organic carbon exported to the Arctic Ocean: A case study of the Yukon River, Alaska

    USGS Publications Warehouse

    Spencer, R.G.M.; Aiken, G.R.; Butler, K.D.; Dornblaser, M.M.; Striegl, R.G.; Hernes, P.J.

    2009-01-01

    The quality and quantity of dissolved organic matter (DOM) exported by Arctic rivers is known to vary with hydrology and this exported material plays a fundamental role in the biogeochemical cycling of carbon at high latitudes. We highlight the potential of optical measurements to examine DOM quality across the hydrograph in Arctic rivers. Furthermore, we establish chromophoric DOM (CDOM) relationships to dissolved organic carbon (DOC) and lignin phenols in the Yukon River and model DOC and lignin loads from CDOM measurements, the former in excellent agreement with long-term DOC monitoring data. Intensive sampling across the historically under-sampled spring flush period highlights the importance of this time for total export of DOC and particularly lignin. Calculated riverine DOC loads to the Arctic Ocean show an increase from previous estimates, especially when new higher discharge data are incorporated. Increased DOC loads indicate decreased residence times for terrigenous DOM in the Arctic Ocean with important implications for the reactivity and export of this material to the Atlantic Ocean. Citation: Spencer, R. G. M., G. R. Aiken, K. D. Butler, M. M. Dornblaser, R. G. Striegl, and P. J. Hernes (2009), Utilizing chromophoric dissolved organic matter measurements to derive export and reactivity of dissolved organic carbon exported to the Arctic Ocean: A case study of the Yukon River, Alaska, Geophys. Res. Lett., 36, L06401, doi:10.1029/ 2008GL036831. Copyright 2009 by the American Geophysical Union.

  15. BIOMASS UTILIZATION

    EPA Science Inventory

    The biomass utilization task consists of the evaluation of a biomass conversion technology including research and development initiatives. The project is expected to provide information on co-control of pollutants, as well as, to prove the feasibility of biomass conversion techn...

  16. Lighting Utilization.

    ERIC Educational Resources Information Center

    Crank, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with lighting utilization. Its objective is for the student to be able to outline the development of lighting use and conservation and identify major types and operating characteristics of lamps used in electric lighting. Some topics…

  17. Learning not to blink

    NASA Astrophysics Data System (ADS)

    McKnight, D. M.

    2012-12-01

    In all the fields of earth and environmental science, the pursuit of a research question on a topic that has captured one's interest represents both an exciting challenge and a serious responsibility. There is currently a great need to expand knowledge of many aspects of our changing world. Nonetheless, the scientific community, like other communities, has its own culture and values that can seem to be at odds with one's personal motivation and values. Further, it can seem that scientific institutions are organized in a manner to present a set of hurdles that must be cleared in the pursuit of research questions and dissemination of results. One strategy as a scientist is to deal with this community and its cultural constraints on one's own terms. For example, the scientific community has become necessarily focused on review and assessment in the distribution of limited research resources. Further, rankings to assess impact of journals and tracking of citations are being used commonly in assessing success in research. In mentoring interactions there is an opportunity to share experiences of persistence through the publication process, as new findings cannot make a difference unless they are published. One way to deal with the flaws in these metrics is to remain attuned to one's own sense of the intrinsic value and excitement of the research question being studied, and not lose track of the value of forward progress on tough questions, progress that may not be suitable for the high profile journals with a broad scope. In mentoring, it may be as important to convey that it is possible to have a rewarding scientific career by actively choosing when to compromise, to take risks or to go your own way, as to help students learn research techniques. Possible starting points for such discussions are the old spaghetti westerns starring Clint Eastwood.

  18. Excessive Blinking in Children

    MedlinePlus

    ... caused by blurry vision. What is a habitual tic? A habitual tic is a small, voluntary body movement. It may ... are not necessary. If the child displays multiple tics and/or auditory (vocal) tics, an appointment with ...

  19. Association of indoor nitrogen dioxide with respiratory symptoms in children: application of measurement error correction techniques to utilize data from multiple surrogates.

    PubMed

    Li, Ruifeng; Weller, Edie; Dockery, Douglas W; Neas, Lucas M; Spiegelman, Donna

    2006-07-01

    methodology illustrated in this paper, it became possible to utilize all data available and obtain a 34% more precise estimate of the NO(2) exposure effect on lower respiratory symptoms, which was adjusted for measurement error due to using NO(2) surrogates instead of directly measured NO(2). PMID:16519415

  20. Using Health Utility Index (HUI) for measuring the impact on health-related quality of Life (HRQL) among individuals with chronic diseases.

    PubMed

    Mo, Frank; Choi, Bernard C K; Li, Felix C K; Merrick, Joav

    2004-08-27

    Quality of life is an important indicator in assessing the burden of disease, especially for chronic conditions. The Health Utilities Index (HUI) is a recently developed system for measuring the overall health status and health-related quality of life (HRQL) of individuals, clinical groups, and general populations. Using the HUI (constructed based on eight attributes: vision, hearing, speech, mobility, dexterity, cognition, emotion, and pain/discomfort) to measure the HRQL for chronic disease patients and to detect possible associations between HUI system and various chronic conditions, this study provides information to improve the management of chronic diseases. This study is of interest to data analysts, policy makers, and public health practitioners involved in descriptive clinical studies, clinical trials, program evaluation, population health planning, and assessments. Based on the Canadian Community Health Survey (CCHS) for 2000-01, the HUI was used to measure the quality of life for individuals living with various chronic conditions (Alzheimer/other dementia, effects of stroke, urinary incontinence, arthritis/rheumatism, bowel disorder, cataracts, back problems, stomach/intestinal ulcers, emphysema/COPD, chronic bronchitis, epilepsy, heart disease, diabetes, migraine headaches, glaucoma, asthma, fibromyalgia, cancers, high blood pressure, multiple sclerosis, thyroid condition, and other remaining chronic diseases). Logistic Regression Model was employed to estimate the associations between the overall HUI scores and various chronic conditions. The HUI scores ranged from 0.00 (corresponding to a state close to death) to 1.00 (corresponding to perfect health); negative scores reflect health states considered worse than death. The mean HUI score by sex and age group indicated the typical quality of life for persons with various chronic conditions. Logistic Regression results showed a strong relationship between low HUI scores (< or = 0.5 and 0.06-1.0) and

  1. Astrocyte origin of activity-dependent release of ATP and glutamate in hippocampal slices: real-time measurement utilizing microelectrode biosensors

    PubMed Central

    Sershen, Henry

    2012-01-01

    It is well known that astrocytic and neuronal transmitter release processes are important for signalling, and that activity-dependent release of adenosine nucleotides and transmitters occurs after stimulation. Neurons and astrocytes can account for the source of ATP efflux. In this issue of the BJP, Heinrich et al. characterized K+ depolarization-evoked release of ATP, adenosine and glutamate in hippocampal slices, utilizing microelectrode biosensors for simultaneous real-time recordings of multiple transmitter effluxes. They demonstrated efflux of ATP, adenosine and glutamate from hippocampus slices, in response to K+-depolarization, with distinct kinetics and mechanisms, suggesting a coordinated pattern of transmitter release. Surprisingly, it turned out that a considerable amount of the transmitter efflux measured under these conditions had a glial origin. For a long time, it was believed that the glial cell did not play a major role in neurotransmission, but the latter results somewhat change this view. The release of ATP and glutamate from glial cells under these conditions involved P2X7 receptors, and a source of adenosine accumulation independent of the metabolism of extracellular ATP was identified. This study also highlighted a novel use of multi-enzymatic microelectrode biosensors, which enabled a better characterization of transmitter release processes with higher temporal and spatial resolution than obtained previously. This technique was originally developed and used for the detection of purine release. In the present study, it was modified to identify the interplay between different transmitters, measured simultaneously in hippocampal slices. LINKED ARTICLE This article is a commentary on Heinrich et al., pp. 1003–1020 of this issue. To view this paper visit http://dx.doi.org/10.1111/j.1476-5381.2012.01932.x PMID:22703189

  2. Utilization of computer processed high definition video imaging for measuring motility of microscopic nematode stages on a quantitative scale: “The Worminator”

    PubMed Central

    Storey, Bob; Marcellino, Chris; Miller, Melissa; Maclean, Mary; Mostafa, Eman; Howell, Sue; Sakanari, Judy; Wolstenholme, Adrian; Kaplan, Ray

    2014-01-01

    A major hindrance to evaluating nematode populations for anthelmintic resistance, as well as for screening existing drugs, new compounds, or bioactive plant extracts for anthelmintic properties, is the lack of an efficient, objective, and reproducible in vitro assay that is adaptable to multiple life stages and parasite genera. To address this need we have developed the “Worminator” system, which objectively and quantitatively measures the motility of microscopic stages of parasitic nematodes. The system is built around the computer application “WormAssay”, developed at the Center for Discovery and Innovation in Parasitic Diseases at the University of California, San Francisco. WormAssay was designed to assess motility of macroscopic parasites for the purpose of high throughput screening of potential anthelmintic compounds, utilizing high definition video as an input to assess motion of adult stage (macroscopic) parasites (e.g. Brugia malayi). We adapted this assay for use with microscopic parasites by modifying the software to support a full frame analysis mode that applies the motion algorithm to the entire video frame. Thus, the motility of all parasites in a given well are recorded and measured simultaneously. Assays performed on third-stage larvae (L3) of the bovine intestinal nematode Cooperia spp., as well as microfilariae (mf) of the filarioid nematodes B. malayi and Dirofilaria immitis, yielded reproducible dose responses using the macrocyclic lactones ivermectin, doramectin, and moxidectin, as well as the nicotinic agonists, pyrantel, oxantel, morantel, and tribendimidine. This new computer based-assay is simple to use, requires minimal new investment in equipment, is robust across nematode genera and developmental stage, and does not require subjective scoring of motility by an observer. Thus, the “Worminator” provides a relatively low-cost platform for developing genera- and stage-specific assays with high efficiency and reproducibility, low

  3. Individual differences in the attentional blink: Evidence from the amplitude of low-frequency fluctuations in non-blinkers and blinkers.

    PubMed

    Wang, Lijun; Chen, Jiangtao; Yang, Zhengyu; Liu, Congcong; Deng, Zhou; Chen, Antao

    2016-02-01

    The attentional blink (AB) is a deficit in reporting the second target (T2) when it is presented within 500ms of the first target (T1) as part of a rapid serial visual presentation (RSVP). Despite the considerable number of imaging studies having investigated the neural correlates of the AB, differences in the spontaneous neural activity of non-blinkers and blinkers remain unclear. In the present study, we investigated this issue using the RSVP task in 43 participants. The results revealed that the amplitude of low-frequency fluctuations (ALFF) in occipitotemporal regions and the cerebellum region was higher in blinkers than in non-blinkers. In contrast, the ALFF in frontoparietal regions was higher in non-blinkers than in blinkers. These findings suggest that the AB is due to an overinvestment of attentional resources in distractors as well as a weakness of attentional control in targets. PMID:26610651

  4. Heritability and molecular genetic basis of acoustic startle eye blink and affectively modulated startle response: A genome-wide association study

    PubMed Central

    VAIDYANATHAN, UMA; MALONE, STEPHEN M.; MILLER, MICHAEL B.; McGUE, MATT; IACONO, WILLIAM G.

    2014-01-01

    Acoustic startle responses have been studied extensively in relation to individual differences and psychopathology. We examined three indices of the blink response in a picture-viewing paradigm—overall startle magnitude across all picture types, and aversive and pleasant modulation scores—in 3,323 twins and parents. Biometric models and molecular genetic analyses showed that half the variance in overall startle was due to additive genetic effects. No single nucleotide polymorphism was genome-wide significant, but GRIK3 did produce a significant effect when examined as part of a candidate gene set. In contrast, emotion modulation scores showed little evidence of heritability in either biometric or molecular genetic analyses. However, in a genome-wide scan, PARP14 did produce a significant effect for aversive modulation. We conclude that, although overall startle retains potential as an endophenotype, emotion-modulated startle does not. PMID:25387708

  5. Did PEPFAR investments result in health system strengthening? A retrospective longitudinal study measuring non-HIV health service utilization at the district level

    PubMed Central

    Luboga, Samuel Abimerech; Stover, Bert; Lim, Travis W; Makumbi, Frederick; Kiwanuka, Noah; Lubega, Flavia; Ndizihiwe, Assay; Mukooyo, Eddie; Hurley, Erin K; Borse, Nagesh; Wood, Angela; Bernhardt, James; Lohman, Nathaniel; Sheppard, Lianne; Barnhart, Scott; Hagopian, Amy

    2016-01-01

    Objectives PEPFAR’s initial rapid scale-up approach was largely a vertical effort focused fairly exclusively on AIDS. The purpose of our research was to identify spill-over health system effects, if any, of investments intended to stem the HIV epidemic over a 6-year period with evidence from Uganda. The test of whether there were health system expansions (aside from direct HIV programming) was evidence of increases in utilization of non-HIV services—such as outpatient visits, in-facility births or immunizations—that could be associated with varying levels of PEPFAR investments at the district level. Methods Uganda’s Health Management Information System article-based records were available from mid-2005 onwards. We visited all 112 District Health offices to collect routine monthly reports (which contain data aggregated from monthly facility reports) and annual reports (which contain data aggregated from annual facility reports). Counts of individuals on anti-retroviral therapy (ART) at year-end served as our primary predictor variable. We grouped district-months into tertiles of high, medium or low PEPFAR investment based on their total reported number of patients on ART at the end of the year. We generated incidence-rate ratios, interpreted as the relative rate of the outcome measure in relation to the lowest investment PEPFAR tertile, holding constant control variables in the model. Results We found PEPFAR investment overall was associated with small declines in service volumes in several key areas of non-HIV care (outpatient care for young children, TB tests and in-facility deliveries), after adjusting for sanitation, elementary education and HIV prevalence. For example, districts with medium and high ART investment had 11% fewer outpatient visits for children aged 4 and younger compared with low investment districts, incidence rate ratio (IRR) of 0.89 for high investment compared with low (95% CI, 0.85–0.94) and IRR of 0.93 for medium compared

  6. Did PEPFAR investments result in health system strengthening? A retrospective longitudinal study measuring non-HIV health service utilization at the district level.

    PubMed

    Luboga, Samuel Abimerech; Stover, Bert; Lim, Travis W; Makumbi, Frederick; Kiwanuka, Noah; Lubega, Flavia; Ndizihiwe, Assay; Mukooyo, Eddie; Hurley, Erin K; Borse, Nagesh; Wood, Angela; Bernhardt, James; Lohman, Nathaniel; Sheppard, Lianne; Barnhart, Scott; Hagopian, Amy

    2016-09-01

    OBJECTIVES : PEPFAR's initial rapid scale-up approach was largely a vertical effort focused fairly exclusively on AIDS. The purpose of our research was to identify spill-over health system effects, if any, of investments intended to stem the HIV epidemic over a 6-year period with evidence from Uganda. The test of whether there were health system expansions (aside from direct HIV programming) was evidence of increases in utilization of non-HIV services-such as outpatient visits, in-facility births or immunizations-that could be associated with varying levels of PEPFAR investments at the district level. METHODS : Uganda's Health Management Information System article-based records were available from mid-2005 onwards. We visited all 112 District Health offices to collect routine monthly reports (which contain data aggregated from monthly facility reports) and annual reports (which contain data aggregated from annual facility reports). Counts of individuals on anti-retroviral therapy (ART) at year-end served as our primary predictor variable. We grouped district-months into tertiles of high, medium or low PEPFAR investment based on their total reported number of patients on ART at the end of the year. We generated incidence-rate ratios, interpreted as the relative rate of the outcome measure in relation to the lowest investment PEPFAR tertile, holding constant control variables in the model. RESULTS : We found PEPFAR investment overall was associated with small declines in service volumes in several key areas of non-HIV care (outpatient care for young children, TB tests and in-facility deliveries), after adjusting for sanitation, elementary education and HIV prevalence. For example, districts with medium and high ART investment had 11% fewer outpatient visits for children aged 4 and younger compared with low investment districts, incidence rate ratio (IRR) of 0.89 for high investment compared with low (95% CI, 0.85-0.94) and IRR of 0.93 for medium compared with

  7. Measuring the short-term substrate utilization response to high-carbohydrate and high-fat meals in the whole-body indirect calorimeter.

    PubMed

    Gribok, Andrei; Leger, Jayme L; Stevens, Michelle; Hoyt, Reed; Buller, Mark; Rumpler, William

    2016-06-01

    The paper demonstrates that minute-to-minute metabolic response to meals with different macronutrient content can be measured and discerned in the whole-body indirect calorimeter. The ability to discriminate between high-carbohydrate and high-fat meals is achieved by applying a modified regularization technique with additional constraints imposed on oxygen consumption rate. These additional constraints reduce the differences in accuracy between the oxygen and carbon dioxide analyzers. The modified technique was applied to 63 calorimeter sessions that were each 24 h long. The data were collected from 16 healthy volunteers (eight males, eight females, aged 22-35 years). Each volunteer performed four 24-h long calorimeter sessions. At each session, they received one of four treatment combinations involving exercise (high or low intensity) and diet (a high-fat or high-carbohydrate shake for lunch). One volunteer did not complete all four assignments, which brought the total number of sessions to 63 instead of 64. During the 24-h stay in the calorimeter, subjects wore a continuous glucose monitoring system, which was used as a benchmark for subject's postprandial glycemic response. The minute-by-minute respiratory exchange ratio (RER) data showed excellent agreement with concurrent subcutaneous glucose concentrations in postprandial state. The averaged minute-to-minute RER response to the high-carbohydrate shake was significantly different from the response to high-fat shake. Also, postprandial RER slopes were significantly different for two dietary treatments. The results show that whole-body respiration calorimeters can be utilized as tools to study short-term kinetics of substrate oxidation in humans. PMID:27354539

  8. Utilizing Multifaceted Rasch Measurement through Facets to Evaluate Science Education Data Sets Composed of Judges, Respondents, and Rating Scale Items: An Exemplar Utilizing the Elementary Science Teaching Analysis Matrix Instrument

    ERIC Educational Resources Information Center

    Boone, William J.; Townsend, J. Scott; Staver, John R.

    2016-01-01

    When collecting data, science education researchers frequently have multiple respondents evaluate multiple artifacts using multiple criteria. Herein, the authors introduce Multifaceted Rasch Measurement (MFRM) analysis and explain why MFRM must be used when "judges'" data are collected. The authors use data from elementary science…

  9. Patient preferences and cost-utility analysis.

    PubMed

    Elnitsky, Christine A; Stone, Patricia

    2005-05-01

    This column discusses patient preference measures and their application in cost utility analysis. A variety of methods of eliciting patient preferences by use of generic utility measures are described. Practical issues in the use of utility measures are discussed. PMID:15991103

  10. Simulation of the water regime for a vast agricultural region territory utilizing measurements from polar-orbital and geostationary meteorological satellites

    NASA Astrophysics Data System (ADS)

    Muzylev, Eugene; Uspensky, Alexander; Startseva, Zoya; Volkova, Elena; Kukharsky, Alexander; Uspensky, Sergey

    2013-04-01

    The model of land surface-atmosphere interaction has been developed to calculate the water and heat balance components for vast vegetation covered areas during the growing season. The model is adjusted to utilize estimates of the land surface and meteorological characteristics derived from satellite-based measurements of radiometers AVHRR/NOAA, MODIS/EOS Terra, Aqua, and SEVIRI/Meteosat-9. The studies have been conducted for the territory of the European Russia Central Black Earth Region (CCR) with area of 227,300 km2 comprising seven regions of the Russian Federation for years 2009-2012 vegetation seasons. The technologies of AVHRR and MODIS data thematic processing have been refined and adapted to the study region providing the retrieval of land surface temperature Tls and emissivity E, land-air temperature (temperature at vegetation cover level) Ta, normalized difference vegetation index NDVI, vegetation cover fraction B, as well as the leaf area index LAI. The updated linear regression estimators for Tls, Ta and LAI have been built using more representative training samples compiled for the above vegetation seasons. The updated software package has been applied for AVHRR data processing to generate named remote sensing products for various dates of the mentioned vegetation periods. On the base of special technology and Internet resources the remote sounding products (Tls, E, NDVI, LAI), derived from MODIS data and covering the CCR, have been downloaded from LP DAAC web-site for the same vegetation seasons. The new method and technology have been developed and adopted for the retrieval of Tls and E from SEVIRI data. The retrievals cover the region of interest and are produced at daylight and nighttime. Method provides the derivation of Tls and E from SEVIRI measurements carried out at three successive times (for example, at 11.00, 12.00, 13.00 UTC), classified as 100% cloud-free for the study region without accurate a priori knowledge of E. The validation of

  11. SECOND SYMPOSIUM ON THE TRANSFER AND UTILIZATION OF PARTICULATE CONTROL TECHNOLOGY: VOLUME IV. SPECIAL APPLICATIONS FOR AIR POLLUTION MEASUREMENT AND CONTROL

    EPA Science Inventory

    The proceedings document the approximately 120 presentations at the EPA/IERL-RTP-sponsored symposium, attended by nearly 800 representatives of a wide variety of companies (including 17 utilities). The keynote speech for the 4-day meeting was by EPA's Frank Princiotta. This volum...

  12. Single-particle spectroscopy of I-III-VI semiconductor nanocrystals: spectral diffusion and suppression of blinking by two-color excitation

    NASA Astrophysics Data System (ADS)

    Sharma, Dharmendar Kumar; Hirata, Shuzo; Bujak, Lukasz; Biju, Vasudevanpillai; Kameyama, Tatsuya; Kishi, Marino; Torimoto, Tsukasa; Vacha, Martin

    2016-07-01

    Ternary I-III-VI semiconductor nanocrystals have been explored as non-toxic alternatives to II-VI semiconductors for optoelectronic and sensing applications, but large photoluminescence spectral width and moderate brightness restrict their practical use. Here, using single-particle photoluminescence spectroscopy on nanocrystals of (AgIn)xZn2(1-x)S2 we show that the photoluminescence band is inhomogeneously broadened and that size distribution is the dominant factor in the broadening. The residual homogeneous linewidth of individual nanocrystals reaches up to 75% of the ensemble spectral width. Single nanocrystals undergo spectral diffusion which also contributes to the inhomogeneous band. Excitation with two lasers with energies above and below the bandgap reveals coexistence of two emitting donor states within one particle. Spectral diffusion in such particles is due to temporal activation and deactivation of one such state. Filling of a trap state with a lower-energy laser enables optical modulation of photoluminescence intermittency (blinking) and leads to an almost two-fold increase in brightness.Ternary I-III-VI semiconductor nanocrystals have been explored as non-toxic alternatives to II-VI semiconductors for optoelectronic and sensing applications, but large photoluminescence spectral width and moderate brightness restrict their practical use. Here, using single-particle photoluminescence spectroscopy on nanocrystals of (AgIn)xZn2(1-x)S2 we show that the photoluminescence band is inhomogeneously broadened and that size distribution is the dominant factor in the broadening. The residual homogeneous linewidth of individual nanocrystals reaches up to 75% of the ensemble spectral width. Single nanocrystals undergo spectral diffusion which also contributes to the inhomogeneous band. Excitation with two lasers with energies above and below the bandgap reveals coexistence of two emitting donor states within one particle. Spectral diffusion in such particles is due

  13. In situ measurement of ammonium utilization by phytoplankton in the Sacramento River to determine the impacts of high nutrient loading on the base of the food web

    NASA Astrophysics Data System (ADS)

    Schmidt, C.; Kendall, C.; Silva, S. R.; Young, M. B.

    2012-12-01

    High concentrations of ammonium in the Sacramento River and San Francisco Bay-Delta Estuary (SFE) have been hypothesized to inhibit the growth of larger phytoplankton such as diatoms, which are an important food source to zooplankton at the base of the pelagic food web. The goal of this research is to use stable isotope approaches to distinguish ammonium and nitrate utilization at the base of the food web in a range of habitats extending from freshwater portions of Sacramento River through San Pablo Bay. Preliminary results from transects sampled over a range of hydrologic conditions between 2007 and 2010 indicate shifts in the δ15N composition of the bulk particulate organic matter (POM) where ammonium concentrations increase downstream of the Sacramento Regional Wastewater Treatment Plant and again where ammonium concentrations decrease near the confluence of the Sacramento and San Joaquin Rivers. However, interpretation of δ15N of bulk POM as a proxy for δ15N of phytoplankton is complicated by the fact that the C:N ratios of bulk POM often increase to values greater than 8 downstream of the confluence of the Sacramento and San Joaquin Rivers, suggesting that in this region of the estuary bulk POM includes a significant proportion of terrestrial detrital material. Given the interest in understanding nitrogen source utilization in this portion of the estuary, work is currently underway to isolate algae from bulk POM using flow cytometry prior to isotopic analysis. δ15N vales from isolated algal samples will allow downstream changes in nutrient source utilization to be distinguished from mixing of different POM sources. Because considerable bulk POM isotopic data have been collected over the last ten years, greater understanding of the relationship between δ15N-POM and δ15N of isolated algal and terrestrial fractions will allow for improved use of the bulk POM isotope record to understand the potential link between historical changes in phytoplankton nutrient

  14. Two-state theory of binned photon statistics for a large class of waiting time distributions and its application to quantum dot blinking

    SciTech Connect

    Volkán-Kacsó, Sándor

    2014-06-14

    A theoretical method is proposed for the calculation of the photon counting probability distribution during a bin time. Two-state fluorescence and steady excitation are assumed. A key feature is a kinetic scheme that allows for an extensive class of stochastic waiting time distribution functions, including power laws, expanded as a sum of weighted decaying exponentials. The solution is analytic in certain conditions, and an exact and simple expression is found for the integral contribution of “bright” and “dark” states. As an application for power law kinetics, theoretical results are compared with experimental intensity histograms from a number of blinking CdSe/ZnS quantum dots. The histograms are consistent with distributions of intensity states around a “bright” and a “dark” maximum. A gap of states is also revealed in the more-or-less flat inter-peak region. The slope and to some extent the flatness of the inter-peak feature are found to be sensitive to the power-law exponents. Possible models consistent with these findings are discussed, such as the combination of multiple charging and fluctuating non-radiative channels or the multiple recombination center model. A fitting of the latter to experiment provides constraints on the interaction parameter between the recombination centers. Further extensions and applications of the photon counting theory are also discussed.

  15. Single-particle spectroscopy of I-III-VI semiconductor nanocrystals: spectral diffusion and suppression of blinking by two-color excitation.

    PubMed

    Sharma, Dharmendar Kumar; Hirata, Shuzo; Bujak, Lukasz; Biju, Vasudevanpillai; Kameyama, Tatsuya; Kishi, Marino; Torimoto, Tsukasa; Vacha, Martin

    2016-07-14

    Ternary I-III-VI semiconductor nanocrystals have been explored as non-toxic alternatives to II-VI semiconductors for optoelectronic and sensing applications, but large photoluminescence spectral width and moderate brightness restrict their practical use. Here, using single-particle photoluminescence spectroscopy on nanocrystals of (AgIn)xZn2(1-x)S2 we show that the photoluminescence band is inhomogeneously broadened and that size distribution is the dominant factor in the broadening. The residual homogeneous linewidth of individual nanocrystals reaches up to 75% of the ensemble spectral width. Single nanocrystals undergo spectral diffusion which also contributes to the inhomogeneous band. Excitation with two lasers with energies above and below the bandgap reveals coexistence of two emitting donor states within one particle. Spectral diffusion in such particles is due to temporal activation and deactivation of one such state. Filling of a trap state with a lower-energy laser enables optical modulation of photoluminescence intermittency (blinking) and leads to an almost two-fold increase in brightness. PMID:27376712

  16. Rhythm and Attention: Does the Beat Position of a Visual or Auditory Regular Pulse Modulate T2 Detection in the Attentional Blink?

    PubMed Central

    Bermeitinger, Christina; Frings, Christian

    2015-01-01

    The attentional blink (AB) is one impressive demonstration of limited attentional capacities in time: a second target (T2) is often missed when it should be detected within 200–600 ms after a first target. According to the dynamic attending theory, attention cycles oscillatory. Regular rhythms (i.e., pulses) should evoke expectations regarding the point of the next occurrence of a tone/element in the rhythm. At this point, more attentional resources should be provided. Thus, if rhythmic information can be used to optimize attentional release, we assume a modulation of the AB when an additional rhythm is given. We tested this idea in two experiments with a visual (Experiment 1) or an auditory (Experiment 2) rhythm. We found large AB effects. However, the rhythm did not modulate the AB. If the rhythm had an influence at all, then Experiment 2 showed that an auditory rhythm (or stimulus) falling on T2 might generally boost visual processing, irrespective of attentional resources as indexed by the AB paradigm. Our experiments suggest that oscillatory cycling attention does not affect temporal selection as tapped in the AB paradigm. PMID:26648899

  17. Energy utilization in phonation

    NASA Astrophysics Data System (ADS)

    Krane, Michael

    2015-11-01

    A control volume analysis of energy utilization in phonation is presented. Conversion of subglottal airstream potential energy into work done vibrating the vocal folds, air flowing through the glottis, and radiating sound are described. An approximate numerical model is used to compute the contributions of each of these mechanisms, as a function of subglottal pressure, for normal phonation. An efficiency measure for each energy conversion mechanism is proposed. Acknowledge NIH grant 2R01 2R01DC005642.

  18. Utility Bill Analysis Saves Money.

    ERIC Educational Resources Information Center

    Lucht, Ray; Dembowski, Frederick L.

    1987-01-01

    Analysis of school utility bills is a good business practice for administrators. Efficient energy management of equipment is measured by the "load factor"--the ratio of average demand to maximum demand. An audit enables control of this factor. (CJH)

  19. Utility solar water heating workshops

    SciTech Connect

    Barrett, L.B.

    1992-01-01

    The objective of this project was to explore the problems and opportunities for utility participation with solar water heating as a DSM measure. Expected benefits from the workshops included an increased awareness and interest by utilities in solar water heating as well as greater understanding by federal research and policy officials of utility perspectives for purposes of planning and programming. Ultimately, the project could result in better information transfer, increased implementation of solar water heating programs, greater penetration of solar systems, and more effective research projects. The objective of the workshops was satisfied. Each workshop succeeded in exploring the problems and opportunities for utility participation with solar water heating as a DSM option. The participants provided a range of ideas and suggestions regarding useful next steps for utilities and NREL. According to evaluations, the participants believed the workshops were very valuable, and they returned to their utilities with new information, ideas, and commitment.

  20. Predictive Utility and Classification Accuracy of Oral Reading Fluency and the Measures of Academic Progress for the Wisconsin Knowledge and Concepts Exam

    ERIC Educational Resources Information Center

    Ball, Carrie R.; O'Connor, Edward

    2016-01-01

    This study examined the predictive validity and classification accuracy of two commonly used universal screening measures relative to a statewide achievement test. Results indicated that second-grade performance on oral reading fluency and the Measures of Academic Progress (MAP), together with special education status, explained 68% of the…