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Sample records for measures blinks utilizing

  1. Camera vibration measurement using blinking light-emitting diode array.

    PubMed

    Nishi, Kazuki; Matsuda, Yuichi

    2017-01-23

    We present a new method for measuring camera vibrations such as camera shake and shutter shock. This method successfully detects the vibration trajectory and transient waveforms from the camera image itself. We employ a time-varying pattern as the camera test chart over the conventional static pattern. This pattern is implemented using a specially developed blinking light-emitting-diode array. We describe the theoretical framework and pattern analysis of the camera image for measuring camera vibrations. Our verification experiments show that our method has a detection accuracy and sensitivity of 0.1 pixels, and is robust against image distortion. Measurement results of camera vibrations in commercial cameras are also demonstrated.

  2. Kalman filter detection of blinks in video-oculography: applications for VVOR measurement during locomotion.

    PubMed

    McGibbon, C A; Palmer, T; Goldvasser, D; Krebs, D E

    2001-04-30

    A Kalman filter algorithm was implemented for automatic detection of blink artifacts in video-oculography (VOG) data, and a cubic spline used to patch the eliminated data. The algorithm was tested by randomly introducing artificial blinks into eye movement data and computing the errors introduced by the patches. We also computed visual vestibulo-ocular reflex (VVOR) gain and phase in healthy and vestibulopathic subjects during a locomotor task, before and after blink removal, to demonstrate the interpretive importance of eliminating blink artifacts. The error introduced by the patched data was small (0.50+/-0.32 degrees ) and within the resolution of head angle measurements. Comparison of gain and phase shift before and after removing blinks revealed that even when calculated values are within expected limits, coherence of the VVOR signal was significantly (p=0.003) lower prior to blink removal (0.51+/-0.37) compared to that after blink removal (0.92+/-0.08). Comparison of VVOR calculations between healthy and vestibulopathic subjects (after removal of blinks) revealed that vestibulopathic subjects had significantly decreased gains (p=0.018) and increased phase shifts (p=0.009): these results agree with data reported in literature. We conclude that the Kalman filter detection and cubic spline patching algorithms are useful tools for VOG and should enable reliable VVOR measurements during unconstrained, ecologically meaningful locomotor activities.

  3. Asymmetry of Blinking

    PubMed Central

    Kassem, Iris S.; Evinger, Craig

    2012-01-01

    Purpose Too investigate asymmetry in eyelid movements with blinking, the stability of the asymmetry, and its modifiability in normal humans. Methods Differences in the start time and amplitude between the two eyelids were assessed for voluntary blinks and reflex blinks evoked by supraorbital trigeminal nerve stimulation. These variables were also measured before and up to 18 months after 2 hours of unilateral upper lid restraint. Results With voluntary blinks, one eyelid consistently began to close earlier and made a larger eyelid movement than the other eyelid. Stimulation of the supraorbital branch of the trigeminal nerve evoked relatively larger amplitude blinks in one eyelid that correlated with the asymmetries of voluntary blinks. There was a continuum of eyelid asymmetry across all subjects that was stable and independent of other biological asymmetries, such as handedness. Briefly reducing eyelid mobility created a long-lasting change in eyelid asymmetry with blinking. Conclusions Eyelid asymmetry results from differences in the excitability of motoneurons in the left and right facial motor nuclei and does not appear to involve asymmetries in cortical inputs to the brain stem. Because adaptive processes modify the motoneuron excitability that creates eyelid asymmetry, these processes may underlie changes in blinking associated with facial palsy and may play a role in the development of disorders that affect one side of the face, such as hemifacial spasm. PMID:16384962

  4. Measurement of the hydrodynamic radius of quantum dots by fluorescence correlation spectroscopy excluding blinking.

    PubMed

    de Thomaz, A A; Almeida, D B; Pelegati, V B; Carvalho, H F; Cesar, C L

    2015-03-19

    One of the most important properties of quantum dots (QDs) is their size. Their size will determine optical properties and in a colloidal medium their range of interaction. The most common techniques used to measure QD size are transmission electron microscopy (TEM) and X-ray diffraction. However, these techniques demand the sample to be dried and under a vacuum. This way any hydrodynamic information is excluded and the preparation process may alter even the size of the QDs. Fluorescence correlation spectroscopy (FCS) is an optical technique with single molecule sensitivity capable of extracting the hydrodynamic radius (HR) of the QDs. The main drawback of FCS is the blinking phenomenon that alters the correlation function implicating in a QD apparent size smaller than it really is. In this work, we developed a method to exclude blinking of the FCS and measured the HR of colloidal QDs. We compared our results with TEM images, and the HR obtained by FCS is higher than the radius measured by TEM. We attribute this difference to the cap layer of the QD that cannot be seen in the TEM images.

  5. Evoked potential, cardiac, blink, and respiration measures of pilot workload in air-to-ground missions.

    PubMed

    Wilson, G F; Fullenkamp, P; Davis, I

    1994-02-01

    Brain evoked potentials were successfully recorded from F-4 pilots during air-to-ground training missions. They were recorded during two flight segments. During one the pilot was flying, and during the other, the weapon systems officer was flying the aircraft. The P2 component of the brain-evoked potential evidenced reduced amplitude during the pilot-flying segment, while the N1 component was reduced during both flight tasks compared to ground-based tasks. These data indicate that the P2 amplitude is sensitive to the level of pilot workload. These results were further substantiated using simultaneously recorded physiological data and subjective workload measures. For example, cardiac inter-beat intervals decreased during flight segments relative to those recorded when performing a tracking task, and further reduced for the pilot-flying vs. the weapon systems officer-flying segment. Eye blink measures were sensitive to the visual demands of the various tasks. These data show that evoked potentials can be recorded during flight, and that, together with cardiac and eye blink data, they provide a composite picture of operator state.

  6. 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.

  7. Eyelid contour detection and tracking for startle research related eye-blink measurements from high-speed video records.

    PubMed

    Bernard, Florian; Deuter, Christian Eric; Gemmar, Peter; Schachinger, Hartmut

    2013-10-01

    Using the positions of the eyelids is an effective and contact-free way for the measurement of startle induced eye-blinks, which plays an important role in human psychophysiological research. To the best of our knowledge, no methods for an efficient detection and tracking of the exact eyelid contours in image sequences captured at high-speed exist that are conveniently usable by psychophysiological researchers. In this publication a semi-automatic model-based eyelid contour detection and tracking algorithm for the analysis of high-speed video recordings from an eye tracker is presented. As a large number of images have been acquired prior to method development it was important that our technique is able to deal with images that are recorded without any special parametrisation of the eye tracker. The method entails pupil detection, specular reflection removal and makes use of dynamic model adaption. In a proof-of-concept study we could achieve a correct detection rate of 90.6%. With this approach, we provide a feasible method to accurately assess eye-blinks from high-speed video recordings.

  8. Measuring Resource Utilization

    PubMed Central

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

    2016-01-01

    Abstract 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

  9. 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

  10. Short-term memory across eye blinks.

    PubMed

    Irwin, David E

    2014-01-01

    The effect of eye blinks on short-term memory was examined in two experiments. On each trial, participants viewed an initial display of coloured, oriented lines, then after a retention interval they viewed a test display that was either identical or different by one feature. Participants kept their eyes open throughout the retention interval on some blocks of trials, whereas on others they made a single eye blink. Accuracy was measured as a function of the number of items in the display to determine the capacity of short-term memory on blink and no-blink trials. In separate blocks of trials participants were instructed to remember colour only, orientation only, or both colour and orientation. Eye blinks reduced short-term memory capacity by approximately 0.6-0.8 items for both feature and conjunction stimuli. A third, control, experiment showed that a button press during the retention interval had no effect on short-term memory capacity, indicating that the effect of an eye blink was not due to general motoric dual-task interference. Eye blinks might instead reduce short-term memory capacity by interfering with attention-based rehearsal processes.

  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. Unmasking the Attentional Blink

    ERIC Educational Resources Information Center

    Nieuwenstein, Mark R.; Potter, Mary C.; Theeuwes, Jan

    2009-01-01

    When asked to identify 2 visual targets (T1 and T2 for the 1st and 2nd targets, respectively) embedded in a sequence of distractors, observers will often fail to identify T2 when it appears within 200-500 ms of T1--an effect called the "attentional blink". Recent work shows that attention does not blink when the task is to encode a…

  14. Withdrawal of voluntary inhibition unravels the off state of the spontaneous blink generator.

    PubMed

    Moraitis, Timoleon; Ghosh, Arko

    2014-12-01

    Involuntary movements such as spontaneous eye blinks can be successfully inhibited at will. Little do we know how the voluntary motor circuits countermand spontaneous blinks. Do the voluntary inhibitory commands act to pause or to turn off the endogenous blink generator, or does inhibition intersect and counter the generator׳s excitatory outputs? In theory, the time taken for the system to generate an after-inhibition blink will reflect onto the form of inhibition. For instance, if voluntary commands were to turn the blink generator off then the after-blink latency would be fixed to the inhibition offset and reflect the time it takes for the generator to rebound and turn on. In this study we measured the after-blink latency from the offset of voluntary inhibition. Volunteers inhibited their blinks in response to sound tones of randomly varying durations. At the offset volunteers withdrew the inhibition and relaxed. Interestingly, the spontaneous after-blinks were fixed to the offset of the inhibition as if the generator rebounded from an off state. The after-blink latency was not related to the duration of the inhibition, and inhibiting even for a small fraction of the mean inter-blink interval generated an after-blink time-locked to the inhibition offset. Interestingly, the insertion of voluntary blinks after inhibition further altered the blink generator by delaying the spontaneous after-blinks. We propose that the inhibition of spontaneous blinks at the level of the generator allows for highly effective voluntary countermanding. Nevertheless, the withdrawal of such inhibition was strongly associated with motor excitation.

  15. 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.

  16. 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…

  17. 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

  18. 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

  19. 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…

  20. 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…

  1. The Attentional Blink in Developing Readers

    ERIC Educational Resources Information Center

    McLean, Gregor M. T.; Stuart, Geoffrey W.; Visser, Troy A. W.; Castles, Anne

    2009-01-01

    The attentional blink refers to a reduction in accuracy that occurs when identifying the second of two targets presented within approximately 500 msec of each other. This research explored individual differences in the attentional blink in a sample of 86 children (aged 8-10) with normally developing reading skills. The attentional blink was…

  2. Objective Tinnitus Concomitant with Eye Blinking: A Case Report

    PubMed Central

    Kim, Tae Hwan; Jang, Ho Joon; Park, Soon Hyung

    2015-01-01

    Tinnitus is a common auditory phenomenon associated with many otological diseases, and is usually subjective. Objective tinnitus can be generated by para-auditory structures, usually derived from vascular or myogenic sources, or the eustachian tube. We present a rare case of intermittent unilateral tinnitus associated with eye blinking. Otoendoscopic examination showed that the external auditory canals and tympanic membranes were normal; however, rhythmic movements of both tympanic membranes, concomitant with the tinnitus, were evident whenever the patient blinked. The tympanometry and stapedial reflexes measured via impedance audiometry exhibited saw-tooth patterns; movement of the tympanic membrane was associated with eyelid blinking. The patient was managed conservatively, with reassurance and medication, and the condition became well-controlled. Here, we present this educational case and review the literature. PMID:26413577

  3. 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

  4. Human intracranial recordings link suppressed transients rather than 'filling-in' to perceptual continuity across blinks

    PubMed Central

    Golan, Tal; Davidesco, Ido; Meshulam, Meir; Groppe, David M; Mégevand, Pierre; Yeagle, Erin M; Goldfinger, Matthew S; Harel, Michal; Melloni, Lucia; Schroeder, Charles E; Deouell, Leon Y; Mehta, Ashesh D; Malach, Rafael

    2016-01-01

    We hardly notice our eye blinks, yet an externally generated retinal interruption of a similar duration is perceptually salient. We examined the neural correlates of this perceptual distinction using intracranially measured ECoG signals from the human visual cortex in 14 patients. In early visual areas (V1 and V2), the disappearance of the stimulus due to either invisible blinks or salient blank video frames ('gaps') led to a similar drop in activity level, followed by a positive overshoot beyond baseline, triggered by stimulus reappearance. Ascending the visual hierarchy, the reappearance-related overshoot gradually subsided for blinks but not for gaps. By contrast, the disappearance-related drop did not follow the perceptual distinction – it was actually slightly more pronounced for blinks than for gaps. These findings suggest that blinks' limited visibility compared with gaps is correlated with suppression of blink-related visual activity transients, rather than with "filling-in" of the occluded content during blinks. DOI: http://dx.doi.org/10.7554/eLife.17243.001 PMID:27685352

  5. Real-time nanoscopy by using blinking enhanced quantum dots.

    PubMed

    Watanabe, Tomonobu M; Fukui, Shingo; Jin, Takashi; Fujii, Fumihiko; Yanagida, Toshio

    2010-10-06

    Superresolution optical microscopy (nanoscopy) is of current interest in many biological fields. Superresolution optical fluctuation imaging, which utilizes higher-order cumulant of fluorescence temporal fluctuations, is an excellent method for nanoscopy, as it requires neither complicated optics nor illuminations. However, it does need an impractical number of images for real-time observation. Here, we achieved real-time nanoscopy by modifying superresolution optical fluctuation imaging and enhancing the fluctuation of quantum dots. Our developed quantum dots have higher blinking than commercially available ones. The fluctuation of the blinking improved the resolution when using a variance calculation for each pixel instead of a cumulant calculation. This enabled us to obtain microscopic images with 90-nm and 80-ms spatial-temporal resolution by using a conventional fluorescence microscope without any optics or devices.

  6. Real-Time Nanoscopy by Using Blinking Enhanced Quantum Dots

    PubMed Central

    Watanabe, Tomonobu M.; Fukui, Shingo; Jin, Takashi; Fujii, Fumihiko; Yanagida, Toshio

    2010-01-01

    Superresolution optical microscopy (nanoscopy) is of current interest in many biological fields. Superresolution optical fluctuation imaging, which utilizes higher-order cumulant of fluorescence temporal fluctuations, is an excellent method for nanoscopy, as it requires neither complicated optics nor illuminations. However, it does need an impractical number of images for real-time observation. Here, we achieved real-time nanoscopy by modifying superresolution optical fluctuation imaging and enhancing the fluctuation of quantum dots. Our developed quantum dots have higher blinking than commercially available ones. The fluctuation of the blinking improved the resolution when using a variance calculation for each pixel instead of a cumulant calculation. This enabled us to obtain microscopic images with 90-nm and 80-ms spatial-temporal resolution by using a conventional fluorescence microscope without any optics or devices. PMID:20923631

  7. Blinks slow memory-guided saccades.

    PubMed

    Powers, Alice S; Basso, Michele A; Evinger, Craig

    2013-02-01

    Memory-guided saccades are slower than visually guided saccades. The usual explanation for this slowing is that the absence of a visual drive reduces the discharge of neurons in the superior colliculus. We tested a related hypothesis: that the slowing of memory-guided saccades was due also to the more frequent occurrence of gaze-evoked blinks with memory-guided saccades compared with visually guided saccades. We recorded gaze-evoked blinks in three monkeys while they performed visually guided and memory-guided saccades and compared the kinematics of the different saccade types with and without blinks. Gaze-evoked blinks were more common during memory-guided saccades than during visually guided saccades, and the well-established relationship between peak and average velocity for saccades was disrupted by blinking. The occurrence of gaze-evoked blinks was associated with a greater slowing of memory-guided saccades compared with visually guided saccades. Likewise, when blinks were absent, the peak velocity of visually guided saccades was only slightly higher than that of memory-guided saccades. Our results reveal interactions between circuits generating saccades and blink-evoked eye movements. The interaction leads to increased curvature of saccade trajectories and a corresponding decrease in saccade velocity. Consistent with this interpretation, the amount of saccade curvature and slowing increased with gaze-evoked blink amplitude. Thus, although the absence of vision decreases the velocity of memory-guided saccades relative to visually guided saccades somewhat, the cooccurrence of gaze-evoked blinks produces the majority of slowing for memory-guided saccades.

  8. 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

  9. 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

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

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

    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.

  11. A MODEL FOR THE TEAR FILM AND OCULAR SURFACE TEMPERATURE FOR PARTIAL BLINKS

    PubMed Central

    Deng, Quan; Braun, R. J.; Driscoll, T. A.; King-Smith, P. E.

    2015-01-01

    In this paper, we investigate the dynamics of tear film and the associated temperature variation for partial blinks. We investigate the mechanism of fluid supply during partial blink cycles, and compare the film thickness with observation in vivo. We find that varying the thickness of the fluid layer beneath the moving upper lid improves the agreement for the in vivo measurement of tear film thickness after a half blink. By examining the flux of the fluid, we provide an explanation of this assumption. We also investigate the temperature dynamics both at the ocular surface and inside the simulated anterior chamber. Our simulation results suggest that the ocular surface temperature readjusts rapidly to normal temperature distribution after partial blinks. PMID:25635242

  12. The attentional blink in amblyopia.

    PubMed

    Popple, Ariella V; Levi, Dennis M

    2008-10-31

    Amblyopia is a disorder of visual acuity in one eye, thought to arise from suppression by the other eye during development of the visual cortex. In the attentional blink, the second of two targets (T2) in a Rapid Serial Visual Presentation (RSVP) stream is difficult to detect and identify when it appears shortly but not immediately after the first target (T1). We investigated the attentional blink seen through amblyopic eyes and found that it was less finely tuned in time than when the 12 amblyopic observers viewed the stimuli with their preferred eyes. T2 performance was slightly better through amblyopic eyes two frames after T1 but worse one frame after T1. Previously (A. V. Popple & D. M. Levi, 2007), we showed that when the targets were red letters in a stream of gray letters (or vice versa), normal observers frequently confused T2 with the letters before and after it (neighbor errors). Observers viewing through their amblyopic eyes made significantly fewer neighbor errors and more T2 responses consisting of letters that were never presented. In normal observers, T1 (on the rare occasions when it was reported incorrectly) was often confused with the letter immediately after it. Viewing through their amblyopic eyes, observers with amblyopia made more responses to the letter immediately before T1. These results suggest that childhood suppression of the input from amblyopic eyes disrupts attentive processing. We hypothesize reduced connectivity between monocularly tuned lower visual areas, subcortical structures that drive foveal attention, and more frontal regions of the brain responsible for letter recognition and working memory. Perhaps when viewing through their amblyopic eyes, the observers were still processing the letter identity of a prior distractor when the color flash associated with the target was detected. After T1, unfocused temporal attention may have bound together erroneously the features of succeeding letters, resulting in the appearance of

  13. 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 ...

  14. 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.

  15. Eye blink rate predicts individual differences in pseudoneglect

    PubMed Central

    Slagter, Heleen A.; Davidson, Richard J.; Tomer, Rachel

    2010-01-01

    Most healthy individuals display a subtle spatial attentional bias, exhibiting relative inattention for stimuli on one side of the visual field, a phenomenon known as pseudoneglect. Prior work in animals and patients has implicated dopamine in spatial attention asymmetries. The current study therefore examined - in healthy individuals - the relationship between the attentional bias and spontaneous eye-blink rate (EBR), a putative measure of central dopaminergic function. We found that those individuals, who blinked more often under resting conditions, displayed greater preference for the right side of the visual display in a subsequent attention task. This finding may support the idea that the observed attentional bias in healthy individuals reflects asymmetries in dopaminergic circuits, and corroborates previous findings implicating dopamine in spatial attention. PMID:20036680

  16. Characterizing The Spontaneous Blink Generator: An Animal Model

    PubMed Central

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

    2011-01-01

    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 in order 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

  17. 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.

  18. Corneal Sensitivity in Tear Dysfunction and its Correlation with Clinical Parameters and Blink Rate

    PubMed Central

    Rahman, Effie Z.; Lam, Peter K.; Chu, Chia-Kai; Moore, Quianta; Pflugfelder, Stephen C.

    2015-01-01

    Purpose To compare corneal sensitivity in tear dysfunction due to a variety of causes using contact and non-contact esthesiometers and to evaluate correlations between corneal sensitivity, blink rate and clinical parameters. Design Comparative observational case series. Methods Ten normal and 33 subjects with tear dysfunction [meibomian gland disease (n = 11), aqueous tear deficiency (n = 10) - without (n = 7) and with (n = 3) Sjögren syndrome (SS) and conjunctivochalasis (n = 12)] were evaluated. Corneal sensitivity was measured with Cochet-Bonnet and air jet esthesiometers and blink rate by electromyelography. Eye irritation symptoms, tear meniscus height, tear break-up time (TBUT), and corneal and conjunctival dye staining were measured. Between group means were compared and correlations calculated. Results Compared with control (Cochet-Bonnet 5.45 mm, air esthesiometer 3.62 mg), mean sensory thresholds were significantly higher in aqueous tear deficiency using either Cochet-Bonnet (3.6 mm; P = 0.003) or air (11.7 mg; P = 0.046) esthesiometers, but were not significantly different in the other groups. Reduced corneal sensitivity significantly correlated with more rapid TBUT and blink rate, and greater irritation and ocular surface dye staining with one or both esthesiometers. Mean blink rates were significantly higher in both aqueous tear deficiency and conjunctivochalasis compared with control. Among all subjects, blink rate positively correlated with ocular surface staining and irritation and inversely correlated with TBUT. Conclusion Amongst conditions causing tear dysfunction, reduced corneal sensitivity is associated with greater irritation, tear instability, ocular surface disease and blink rate. Rapid blinking is associated with worse ocular surface disease and tear stability. PMID:26255576

  19. 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.

  20. Blinking supervision in a working environment.

    PubMed

    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.

  1. 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,...

  2. Effect of blinking on the level of oxygen beneath hard and soft gas-permeable contact lenses.

    PubMed

    Efron, N; Carney, L G

    1983-03-01

    The oxygen tension, which can also be stated as the equivalent oxygen percentage (EOP), was measured beneath a variety of hard and soft gas-permeable contact lenses following static and dynamic wearing conditions. The significant increases in EOP beneath rigid lenses upon blinking were to be expected in view of the tear pumping mechanisms known to exist with such lenses. However, blinking was found to have a minimal effect on the EOP beneath hydrogen lenses, confirming earlier predictions.

  3. Optimization-based technique for separation and detection of saccadic movements and eye-blinking in electrooculography biosignals.

    PubMed

    Krupiński, Robert; Mazurek, Przemysław

    2011-01-01

    Electrooculography (EOG) gives the possibility of eye tracking using biosignal measurements. Typical EOG signal consists of rapid value changes (saccades) separated by almost constant values. Additionally, the pulse shape from eyelid blinking is observed. The separation of them is possible using numerous methods, like median filtering. The proposed optimization method based on a model fitting using the variable number of parameters gives the possibility of features localization even for nearby saccades and blinking pulses.

  4. 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.

  5. Power Measurement Errors on a Utility Aircraft

    NASA Technical Reports Server (NTRS)

    Bousman, William G.

    2002-01-01

    Extensive flight test data obtained from two recent performance tests of a UH 60A aircraft are reviewed. A power difference is calculated from the power balance equation and is used to examine power measurement errors. It is shown that the baseline measurement errors are highly non-Gaussian in their frequency distribution and are therefore influenced by additional, unquantified variables. Linear regression is used to examine the influence of other variables and it is shown that a substantial portion of the variance depends upon measurements of atmospheric parameters. Correcting for temperature dependence, although reducing the variance in the measurement errors, still leaves unquantified effects. Examination of the power difference over individual test runs indicates significant errors from drift, although it is unclear how these may be corrected. In an idealized case, where the drift is correctable, it is shown that the power measurement errors are significantly reduced and the error distribution is Gaussian. A new flight test program is recommended that will quantify the thermal environment for all torque measurements on the UH 60. Subsequently, the torque measurement systems will be recalibrated based on the measured thermal environment and a new power measurement assessment performed.

  6. 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.…

  7. 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…

  8. 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,…

  9. An Eye-Blinking-Based Beamforming Control Protocol for Hearing Aid Users With Neurological Motor Disease or Limb Amputation.

    PubMed

    Yoon, Jungmin; Nam, Kyoung Won; Lee, Jun Chang; Jang, Dong Pyo; Kim, In Young

    2017-02-01

    For hearing-impaired individuals with neurological motor deficits or finger/arm amputation due to accident or disease, hearing aid adjustment using a conventional finger manipulation-based remote controller is unavailable, and a more dedicated, hands-free alternative is required. In this study, we propose an eye-blinking-based beamforming control scheme for hearing aid users. Three electroencephalogram signals measured around the ears were utilized to detect eye-blinking patterns based on a three-layer artificial neural network. The performance of the proposed control scheme was evaluated by both subjective experiments and objective index comparison tests in simulated situations. Experimental results from the subjective test demonstrated that without the pretraining phase, the accuracy and latency time were 68.57 ± 18.50% and 10.06 ± 0.94 s, respectively; in contrast, after the pretraining phase, both the accuracy and latency time were improved to 91.00 ± 4.69% and 8.60 ± 1.05 s, respectively. In index comparison tests, the proposed control scheme exhibited improvements in the signal-to-noise ratio (SNR) as well as the segmental SNR in all tested situations, as compared to a conventional forward-focusing beamforming algorithm. We believe that the proposed control scheme provides a novel, hands-free way in which to control the operation of hearing aids for hearing-impaired patients with additional motor deficits or amputation.

  10. Objectivism in Information Utilization: Theory and Measurement.

    ERIC Educational Resources Information Center

    Leary, Mark R.; And Others

    A self-report scale was constructed and validated that measures individual differences in objectivism--the tendency to base one's judgments and beliefs upon empirical information and rational considerations. Validity data showed that, compared to people who score low on the Objectivism Scale, highly objective individuals enjoy thinking more, rely…

  11. Tear-film lipid layer morphology and corneal sensation in the development of blinking in neonates and infants

    PubMed Central

    Lawrenson, John G; Birhah, Rosalind; Murphy, Paul J

    2005-01-01

    The aim of the study was to evaluate the role of lipid layer thickness and corneal sensation in the development of blinking in neonates. The study group comprised sixty-four neonates and infants (mean age 27.5 ± 15 (sd) weeks, range 3.4–52) whose mothers were attending a general practice healthy baby clinic. Spontaneous eye-blink activity was determined from digital videographic recordings; tear film lipid layer morphology wasexamined using interference patterns produced by the Keeler Tearscope™ Plus over a five-point grading scale (higher grades are associated with thick and stable lipid films); corneal sensation threshold was assessed with the Non-Contact Corneal Aesthesiometer (NCCA), using the eye-blink response as an objective indication that the cooling stimulus had been felt; palpebral aperture dimensions were measured using calibrated digital still images of the eye in the primary position. The overall mean spontaneous blink-rate was found to be 3.6 (± 0.3) blinks min−1, and the mean interblink time was 21.6 (± 2.8) s. The lowest blink-rates were observed in the 0–17-week age group (average 2 blinks min−1). The blink-rate showed a highly significant correlation with age (r = 0.46, P < 0.01). The overall mean lipid layer grading was 3.6 (± 0.2 SE) arbitrary units. Higher grades were found in the newborn and the mean grading score reduced with age (P < 0.01). The mean sensation threshold to blink (TTB) was 0.69 (0.04 SE) mbar, which did not differ from a control group of older subjects (P > 0.05). There was a rapid increase in palpebral aperture length and width from birth to 1 year old, with surface area increasing by 50% over the same period. We concluded that the low rate of spontaneous eye blink activity in neonates is associated with a thick stable lipid layer that may be a function of a small palpebral aperture. Furthermore, neonates appear to have the capacity to detect ocular surface cooling, which is a major trigger for spontaneous

  12. Objectivism in information utilization: theory and measurement.

    PubMed

    Leary, M R; Shepperd, J A; McNeil, M S; Jenkins, T B; Barnes, B D

    1986-01-01

    A self-report scale was constructed and validated that measures individual differences in objectivism--the tendency to base one's judgments and beliefs on empirical information and rational considerations. Validity data showed that, compared to people who score low on the Objectivism Scale, highly objective individuals enjoy thinking more, rely more on observable facts when making decisions, and place less emphasis on subjective and intuitive styles of decision making. Among graduate students in psychology, objectivism correlated positively with ratings of research-oriented careers, but negatively with ratings of mental health careers; also, highly objective students were more critical of nonobjective psychological assessment techniques and placed greater importance on research. Objectivism also predicted preferences for newspaper articles, college course selections, and the criteria respondents use when making decisions.

  13. In the Blink of an Eye: Investigating the Role of Awareness in Fear Responding by Measuring the Latency of Startle Potentiation

    PubMed Central

    Åsli, Ole; Flaten, Magne A.

    2012-01-01

    The latency of startle reflex potentiation may shed light on the aware and unaware processes underlying associative learning, especially associative fear learning. We review research suggesting that single-cue delay classical conditioning is independent of awareness of the contingency between the conditioned stimulus (CS) and the unconditioned stimulus (US). Moreover, we discuss research that argues that conditioning independent of awareness has not been proven. Subsequently, three studies from our lab are presented that have investigated the role of awareness in classical conditioning, by measuring the minimum latency from CS onset to observed changes in reflexive behavior. In sum, research using this method shows that startle is potentiated 30 to 100 ms after CS onset following delay conditioning. Following trace fear conditioning, startle is potentiated 1500 ms after CS presentation. These results indicate that the process underlying delay conditioned responding is independent of awareness, and that trace fear conditioned responding is dependent on awareness. Finally, this method of investigating the role of awareness is discussed and future research possibilities are proposed. PMID:24962686

  14. 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…

  15. Heat transfer and tear film dynamics over multiple blink cycles

    NASA Astrophysics Data System (ADS)

    Deng, Quan; Braun, R. J.; Driscoll, Tobin A.

    2014-07-01

    We consider model problems for the tear film over multiple blink cycles with heat transfer from the posterior side of the tear film. A nonlinear partial differential equation governs the film thickness on a moving domain in one space dimension and time. One end of the tear film moves in order to mimic blinking in the eye. The film thickness is coupled with the diffusion of heat from the posterior of the film, where the underlying cornea and aqueous humor are modeled as a rectangular domain. The domain of the tear film is located on one edge of the rectangle. The resulting problem is solved using the method of lines with a Chebyshev spectral method in space. Evaporation is included in the model, with end fluxes specified to compensate for the evaporation from the film. The numerical results reveal a similarity to quantitative in vivo observations of the film dynamics and measured ocular surface temperature. Periodicity in the film and temperature dynamics is explored with different flux conditions and end motions, and a transition between periodic and non-periodic solutions is analyzed.

  16. Spontaneous blinks of Parkinson's disease patients evaluated by EMG and EOG.

    PubMed

    Kaneko, K; Sakamoto, K

    2001-03-01

    In a study of spontaneous blinks, both electromyographic (EMG) activities from m. orbicularis oculi which is responsible for initiating closure of the eyelid and electro-oculogram (EOG) of vertical direction to the movement of the eyelid were measured in ten patients with Parkinson's disease and in thirty normal subjects. The aim of this study was to evaluate the generative mechanism of the spontaneous blinks by comparison of both the EMG and the EOG waveforms in the patients with Parkinson's disease and those in the normal subjects. The mean duration and the amplitude of both the EMG and the EOG were evaluated by the averaging of ten waveforms for the spontaneous blinks. The time lag between the onset of the generation of the EMG and the onset of the EOG signal was analyzed. The mean duration of the EMG and the mean amplitude of both the EMG and the EOG in the patients with Parkinson's disease were shorter and smaller than those in the normal subjects by the significant level of 1%, respectively. There was no difference of the time lag between the subject groups. These results suggest that the function of m. orbicularis oculi for the spontaneous blinks is reduced in patients with Parkinson's disease, because the motoneurones of the facial nucleus innervating the m. orbicularis oculi becomes hypoactive due to abnormal output of basal ganglia.

  17. 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.

  18. [Value of blink reflex studies in neurosurgical problems].

    PubMed

    Jamjoom, Z; Nahser, H C; Nau, H E

    1983-09-01

    Blinking reflex studies were done in neurosurgical patients with processes in the posterior fossa and idiopathic trigeminal neuralgia. Alterations were found in space occupying, ischemic, and traumatic lesions of the trigemino-facial system. The analysis of the components of the blinking reflex can give hints to the site of the lesion and also to the prognosis of the underlying process.

  19. The Attentional Blink Provides Episodic Distinctiveness: Sparing at a Cost

    ERIC Educational Resources Information Center

    Wyble, Brad; Bowman, Howard; Nieuwenstein, Mark

    2009-01-01

    The attentional blink (J. E. Raymond, K. L. Shapiro, & K. M. Arnell, 1992) refers to an apparent gap in perception observed when a second target follows a first within several hundred milliseconds. Theoretical and computational work have provided explanations for early sets of blink data, but more recent data have challenged these accounts by…

  20. The attentional blink reveals serial working memory encoding: evidence from virtual and human event-related potentials.

    PubMed

    Craston, Patrick; Wyble, Brad; Chennu, Srivas; Bowman, Howard

    2009-03-01

    Observers often miss a second target (T2) if it follows an identified first target item (T1) within half a second in rapid serial visual presentation (RSVP), a finding termed the attentional blink. If two targets are presented in immediate succession, however, accuracy is excellent (Lag 1 sparing). The resource sharing hypothesis proposes a dynamic distribution of resources over a time span of up to 600 msec during the attentional blink. In contrast, the ST(2) model argues that working memory encoding is serial during the attentional blink and that, due to joint consolidation, Lag 1 is the only case where resources are shared. Experiment 1 investigates the P3 ERP component evoked by targets in RSVP. The results suggest that, in this context, P3 amplitude is an indication of bottom-up strength rather than a measure of cognitive resource allocation. Experiment 2, employing a two-target paradigm, suggests that T1 consolidation is not affected by the presentation of T2 during the attentional blink. However, if targets are presented in immediate succession (Lag 1 sparing), they are jointly encoded into working memory. We use the ST(2) model's neural network implementation, which replicates a range of behavioral results related to the attentional blink, to generate "virtual ERPs" by summing across activation traces. We compare virtual to human ERPs and show how the results suggest a serial nature of working memory encoding as implied by the ST(2) model.

  1. The Health Utilities Index (HUI): concepts, measurement properties and applications.

    PubMed

    Horsman, John; Furlong, William; Feeny, David; Torrance, George

    2003-10-16

    This is a review of the Health Utilities Index (HUI) multi-attribute health-status classification systems, and single- and multi-attribute utility scoring systems. HUI refers to both HUI Mark 2 (HUI2) and HUI Mark 3 (HUI3) instruments. The classification systems provide compact but comprehensive frameworks within which to describe health status. The multi-attribute utility functions provide all the information required to calculate single-summary scores of health-related quality of life (HRQL) for each health state defined by the classification systems. The use of HUI in clinical studies for a wide variety of conditions in a large number of countries is illustrated. HUI provides comprehensive, reliable, responsive and valid measures of health status and HRQL for subjects in clinical studies. Utility scores of overall HRQL for patients are also used in cost-utility and cost-effectiveness analyses. Population norm data are available from numerous large general population surveys. The widespread use of HUI facilitates the interpretation of results and permits comparisons of disease and treatment outcomes, and comparisons of long-term sequelae at the local, national and international levels.

  2. 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.

  3. 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.

  4. 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.

  5. Coverage-mediated suppression of blinking in solid state quantum dot conjugated organic composite nanostructures.

    PubMed

    Hammer, Nathan I; Early, Kevin T; Sill, Kevin; Odoi, Michael Y; Emrick, Todd; Barnes, Michael D

    2006-07-27

    Size-correlated single-molecule fluorescence measurements on CdSe quantum dots functionalized with oligo(phenylene vinylene) (OPV) ligands exhibit modified fluorescence intermittency (blinking) statistics that are highly sensitive to the degree of ligand coverage on the quantum dot surface. As evidenced by a distinct surface height signature, fully covered CdSe-OPV nanostructures (approximately 25 ligands) show complete suppression of blinking in the solid state on an integration time scale of 1 s. Some access to dark states is observed on finer time scales (100 ms) with average persistence times significantly shorter than those from ZnS-capped CdSe quantum dots. This effect is interpreted as resulting from charge transport from photoexcited OPV into vacant trap sites on the quantum dot surface. These results suggest exciting new applications of composite quantum dot/organic systems in optoelectronic systems.

  6. 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.

  7. Utility measurement in healthcare: the things I never got to.

    PubMed

    Torrance, George W

    2006-01-01

    The present article provides a brief historical background on the development of utility measurement and cost-utility analysis in healthcare. It then outlines a number of research ideas in this field that the author never got to. The first idea is extremely fundamental. Why is health economics the only application of economics that does not use the discipline of economics? And, more importantly, what discipline should it use? Research ideas are discussed to investigate precisely the underlying theory and axiom systems of both Paretian welfare economics and the decision-theoretical utility approach. Can the two approaches be integrated or modified in some appropriate way so that they better reflect the needs of the health field? The investigation is described both for the individual and societal levels. Constructing a 'Robinson Crusoe' society of only a few individuals with different health needs, preferences and willingness to pay is suggested as a method for gaining insight into the problem. The second idea concerns the interval property of utilities and, therefore, QALYs. It specifically concerns the important requirement that changes of equal magnitude anywhere on the utility scale, or alternatively on the QALY scale, should be equally desirable. Unfortunately, one of the original restrictions on utility theory states that such comparisons are not permitted by the theory. It is shown, in an important new finding, that while this restriction applies in a world of certainty, it does not in a world of uncertainty, such as healthcare. Further research is suggested to investigate this property under both certainty and uncertainty. Other research ideas that are described include: the development of a precise axiomatic basis for the time trade-off method; the investigation of chaining as a method of preference measurement with the standard gamble or time trade-off; the development and training of a representative panel of the general public to improve the completeness

  8. Blink reflex in Parkinson's disease with levodopa-induced dyskinesia.

    PubMed

    Iriarte, L M; Chacon, J; Madrazo, J; Chaparro, P

    1989-01-01

    We have studied the electrically evoked blink reflex (R1 and R2 components) in 40 parkinsonian patients with levodopa-induced dyskinesia (15 with facial dyskinesia, 13 with limb-truncal dyskinesia and 12 with mixed dyskinesia). R2 latencies (both ipsilateral and contralateral) were significantly prolonged in dyskinetic patients. These findings are indicative of decreased excitability of brainstem interneurones in the dyskinetic parkinsonians. We found no correlation between the neurophysiological pattern of blink reflex and the localization of dyskinesia.

  9. 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

  10. 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

  11. 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.

  12. 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

  13. Measuring Nursing Practice Models using Multi-Attribute Utility theory.

    PubMed

    Brennan, P F; Anthony, M K

    2000-10-01

    Nursing Practice Models (NPMs) represent the structural and contextual features that exist within any group practice of nursing. Currently, measurement of NPMs relies on costly and nonreproducible global judgments by experts. Quantitative measurement techniques are needed to provide a useful evaluation of nursing practice. Guided by Multi-Attribute Utility theory (MAU theory), an expert panel identified 24 factors representative of N PMs. The factors became elements in a computational index that, when summed, assigns a score to a given nursing unit reflecting the extent to which that unit's nursing practice model achieves the nursing professional ideal. Initial validation of the index and its elements consisted of comparing assessments of 40 nursing units generated by the index with a global evaluation provided by each of the expert panelists who proposed the model factors. Pearson correlations between the index-generated scores and the global assigned scores provided evidence supporting the preliminary validation of the index.

  14. Utilization, measurement, and funding of recovery supports and services.

    PubMed

    Cousins, Sarah J; Antonini, Valerie P; Rawson, Richard A

    2012-01-01

    An environmental survey was conducted regarding substance abuse recovery supports and services (RSS) delivered across California, where these services are offered, and by whom. Inquiries were made regarding RSS measurement efforts, funding mechanisms, and technical assistance needs. A survey was disseminated to all 57 administrators of county alcohol and other drug or behavioral departments. Results indicate that 62% (23 of 37) of responding counties offer RSS. Overall, certified addiction counselors (CACs) were the staff most utilized to provide RSS, followed by peers, clinicians, and volunteers. Among recovery-community organizations (RCOs), peers, volunteers, and CACs were the most utilized staff. Sober living homes were the most prevalent type of RCO, followed by recovery centers, faith-based/recovery ministries, and recovery schools. Forty-five percent of counties reported funding RSS; 37.8% collect data. RSS may provide valuable support services for individuals recovering from alcohol/drug use; however, the field must further define RSS and develop measurement strategies to justify RSS funding.

  15. 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.

  16. 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

  17. 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.

  18. Shipboard Geomagnetic Vector Measurement Utilizing GPS Attitude Sensor

    NASA Astrophysics Data System (ADS)

    Yamazaki, Toshitsugu

    Performance of a new shipboard three-component magnetometer system utilizing a GPS (Global Positioning System) attitude sensor was compared with that of a conventional system using a gyrocompass for ship's heading and a pitch/roll sensor constituted by accelerometer and fibre-optics gyro. Response of the GPS attitude sensor is quick enough for shipboard magnetic measurement. During "figure-8 turns" for measuring ship's magnetization, difference in heading between the two systems varied about 1° systematically with heading. Differences in pitch and roll changed at about 1° depending on the turning directions. This is most likely caused by error in the gyros due to acceleration during the turns. Previously it was known that significant bias often occurred in each component of magnetic vector anomalies after the correction of ship's magnetization. The significant error in attitude determination during "figure-8 turns" as well as viscous remnant magnetization are responsible for the bias. Significant error of about 0.5° at maximum remains in gyrocompass for 30 to 60 minutes after a turn, and this causes strange fluctuation in Y (east) component of magnetic vector anomalies at the beginning of each survey line. GPS attitude sensor can overcome these problems, and increase the accuracy of shipboard magnetic vector measurement.

  19. Triple helix conformation-specific blinking of Cy3 in DNA.

    PubMed

    Kawai, Kiyohiko; Maruyama, Atsushi

    2015-03-21

    We report that Cy3 undergoes triple helix conformation-specific blinking in DNA. Blinking patterns were affected by the stabilization of the Hoogsteen base-pair, suggesting that not only the presence but also the fluctuating behaviour of the triple helix can be monitored by the changes in the Cy3 blinking patterns.

  20. 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…

  1. Somatosensory-evoked blink response: investigation of the physiological mechanisms.

    PubMed

    Miwa, H; Nohara, C; Hotta, M; Shimo, Y; Amemiya, K

    1998-02-01

    The somatosensory-evoked blink response (SBR) is a newly identified blink reflex elicited by electrical stimulation of peripheral nerves. The present study was performed to investigate the physiological mechanism underlying the SBR elicited by median nerve stimulation in normal subjects. The peripheral afferents responsible for the SBR included low-threshold cutaneous fibres. In the SBR-positive subjects, the late (R2) component of the blink reflex elicited by supraorbital nerve stimulation and the SBR facilitated each other when both responses were induced at the same time, but they each caused long-lasting inhibition in the other when one stimulus was given as a conditioning stimulus. The extent of inhibition was correlated with the size of the preceding SBR. In the SBR-negative subjects, simultaneous inhibition of R2 was observed when median nerve stimulation was applied as a conditioning stimulus. Brainstem excitability, as evaluated by blink-reflex recovery studies, did not differ between SBR-positive and SBR-negative subjects. Therefore, based on anatomical and physiological findings, it appears that the reflex pathways of the SBR and R2 converge within the brainstem and compete with each other, presumably by presynaptic inhibition at the premotor level, before entering the common blink-reflex pathway. The influence of median nerve stimulation upon tonic contraction of the orbicularis oculi muscle was studied to detect the latent SBR. There was not only a facilitatory period corresponding to the SBR but also an active inhibitory period (exteroceptive suppression), suggesting that the mechanism generating the SBR is not only influenced by blink-reflex volleys but also by active exteroceptive suppression. Thus, the SBR may appear as a result of integration of facilitatory and inhibitory mechanisms within the brainstem.

  2. 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.

  3. Neuromagnetic brain responses to other person's eye blinks seen on video.

    PubMed

    Mandel, Anne; Helokunnas, Siiri; Pihko, Elina; Hari, Riitta

    2014-08-01

    Eye blinks, typically occurring 15-20 times per minute, rarely capture attention during face-to-face interaction. To determine the extent to which eye blinks affect the viewer's brain activity, we recorded magnetoencephalographic brain responses to natural blinks, and to the same blinks slowed down to 38% of the original speed. The stimuli were presented on video once every 2.3-6.2 s. As a control, we presented two horizontal black bars moving with the same time courses and the same extent as the eyelids in the blink video. Both types of blinks and bars elicited clear responses peaking at about 200 ms in the occipital areas, with no systematic differences between hemispheres. For the bars, these main responses were (as expected) weaker (by 24%) and later (by 33 ms) to slow-motion than normal-speed stimuli. For blinks, however, the responses to both normal-speed and slow-motion stimuli were of the same amplitude and latency. Our results demonstrate that the brain not only responds to other persons' eye blinks, but that the responses are as fast and of equal size even when the blinks are considerably slowed down. We interpret this finding to reflect the increased social salience of the slowed-down blinks that counteracted the general tendency of the brain to react more weakly and more slowly to slowly- vs. quickly-changing stimuli. This finding may relate to the social importance of facial gestures, including eye blinks.

  4. 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…

  5. 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…

  6. Excessive blinking as an initial manifestation of juvenile Huntington's disease.

    PubMed

    Xing, Shihui; Chen, Ling; Chen, Xi; Pei, Zhong; Zeng, Jinsheng; Li, Jinru

    2008-09-01

    Juvenile Huntington's disease (JHD) is mostly characterized by rigidity, myoclonus, bradykinesia, dystonia and seizure. We report a 9-year-old male JHD patient presenting excessive blinking as the initial symptom two years prior to typical JHD symptoms. Genetic analysis revealed expansion of 108 CAG repeats and magnetic resonance imaging showed caudate atrophy with lateral ventricular enlargement.

  7. Somatosensory eye blink reflex in peripheral facial palsy.

    PubMed

    Erkol, Gökhan; Kiziltan, Meral E; Uluduz, Derya; Uzun, Nurten

    2009-09-04

    To investigate the association between somatosensory blink reflex (SBR) and peripheral facial palsy (PFP) severity and trigeminal blink reflex (BR) changes in cases with PFP and subsequent postparalytic facial syndrome development (PFS). One hundred and twenty subjects with peripheral facial palsy and post-facial syndrome and 44 age and gender matched healthy volunteers were enrolled to this study. Blink reflexes and somatosensory blink reflex were studied in all. The association between R1 and R2 responses of the BR and SBR positivity was investigated. SBR was elicited in 36.3% of normal subjects, in 18.3% of PFP and in 65.3% of PFS patients. In the paralytic side, the frequency of SBR positivity was significantly lower in PFP group compared to controls and SBR was most frequently observed in patients with PFS. Compared to PFP and control groups, SBR positivity on the non-paralytic side significantly revealed a higher rate in PFS patients. SBR positivity of patients in whom R1 or R2 were absent, was significantly lower than those subjects with prolonged or normal R1 or R2 responses. PFP and successive PFS are good models for the sensory motor gate mechanisms and/or excitability enhancement of brainstem neurons responsible for SBR.

  8. Viewpoint Costs Occur during Consolidation: Evidence from the Attentional Blink

    ERIC Educational Resources Information Center

    Dux, Paul E.; Harris, Irina M.

    2007-01-01

    Do the viewpoint costs incurred when naming rotated familiar objects arise during initial identification or during consolidation? To answer this question we employed an attentional blink (AB) task where two target objects appeared amongst a rapid stream of distractor objects. Our assumption was that while both targets and distractors undergo…

  9. 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.

  10. The clinical utility of bone marker measurements in osteoporosis.

    PubMed

    Wheater, Gillian; Elshahaly, Mohsen; Tuck, Stephen P; Datta, Harish K; van Laar, Jacob M

    2013-08-29

    Osteoporosis is characterised by low bone mass and structural deterioration of bone tissue, resulting in increased fragility and susceptibility to fracture. Osteoporotic fractures are a significant cause of morbidity and mortality. Direct medical costs from such fractures in the UK are currently estimated at over two billion pounds per year, resulting in a substantial healthcare burden that is expected to rise exponentially due to increasing life expectancy. Currently bone mineral density is the WHO standard for diagnosis of osteoporosis, but poor sensitivity means that potential fractures will be missed if it is used alone. During the past decade considerable progress has been made in the identification and characterisation of specific biomarkers to aid the management of metabolic bone disease. Technological developments have greatly enhanced assay performance producing reliable, rapid, non-invasive cost effective assays with improved sensitivity and specificity. We now have a greater understanding of the need to regulate pre-analytical sample collection to minimise the effects of biological variation. However, bone turnover markers (BTMs) still have limited clinical utility. It is not routinely recommended to use BTMs to select those at risk of fractures, but baseline measurements of resorption markers are useful before commencement of anti-resorptive treatment and can be checked 3-6 months later to monitor response and adherence to treatment. Similarly, formation markers can be used to monitor bone forming agents. BTMs may also be useful when monitoring patients during treatment holidays and aid in the decision as to when therapy should be recommenced. Recent recommendations by the Bone Marker Standards Working Group propose to standardise research and include a specific marker of bone resorption (CTX) and bone formation (P1NP) in all future studies. It is hoped that improved research in turn will lead to optimised markers for the clinical management of

  11. SPAD imagers for super resolution localization microscopy enable analysis of fast fluorophore blinking

    PubMed Central

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

    2017-01-01

    sCMOS imagers are currently utilized (replacing EMCCD imagers) to increase the acquisition speed in super resolution localization microscopy. Single-photon avalanche diode (SPAD) imagers feature frame rates per bit depth comparable to or higher than sCMOS imagers, while generating microsecond 1-bit-frames without readout noise, thus paving the way to in-depth time-resolved image analysis. High timing resolution can also be exploited to explore fluorescent dye blinking and other photophysical properties, which can be used for dye optimization. We present the methodology for the blinking analysis of fluorescent dyes on experimental data. Furthermore, the recent use of microlenses has enabled a substantial increase of SPAD imager overall sensitivity (12-fold in our case), reaching satisfactory values for sensitivity-critical applications. This has allowed us to record the first super resolution localization microscopy results obtained with a SPAD imager, with a localization uncertainty of 20 nm and a resolution of 80 nm. PMID:28287122

  12. SPAD imagers for super resolution localization microscopy enable analysis of fast fluorophore blinking.

    PubMed

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

    2017-03-13

    sCMOS imagers are currently utilized (replacing EMCCD imagers) to increase the acquisition speed in super resolution localization microscopy. Single-photon avalanche diode (SPAD) imagers feature frame rates per bit depth comparable to or higher than sCMOS imagers, while generating microsecond 1-bit-frames without readout noise, thus paving the way to in-depth time-resolved image analysis. High timing resolution can also be exploited to explore fluorescent dye blinking and other photophysical properties, which can be used for dye optimization. We present the methodology for the blinking analysis of fluorescent dyes on experimental data. Furthermore, the recent use of microlenses has enabled a substantial increase of SPAD imager overall sensitivity (12-fold in our case), reaching satisfactory values for sensitivity-critical applications. This has allowed us to record the first super resolution localization microscopy results obtained with a SPAD imager, with a localization uncertainty of 20 nm and a resolution of 80 nm.

  13. SPAD imagers for super resolution localization microscopy enable analysis of fast fluorophore blinking

    NASA Astrophysics Data System (ADS)

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

    2017-03-01

    sCMOS imagers are currently utilized (replacing EMCCD imagers) to increase the acquisition speed in super resolution localization microscopy. Single-photon avalanche diode (SPAD) imagers feature frame rates per bit depth comparable to or higher than sCMOS imagers, while generating microsecond 1-bit-frames without readout noise, thus paving the way to in-depth time-resolved image analysis. High timing resolution can also be exploited to explore fluorescent dye blinking and other photophysical properties, which can be used for dye optimization. We present the methodology for the blinking analysis of fluorescent dyes on experimental data. Furthermore, the recent use of microlenses has enabled a substantial increase of SPAD imager overall sensitivity (12-fold in our case), reaching satisfactory values for sensitivity-critical applications. This has allowed us to record the first super resolution localization microscopy results obtained with a SPAD imager, with a localization uncertainty of 20 nm and a resolution of 80 nm.

  14. 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…

  15. 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…

  16. 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

  17. 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.

  18. Correlated blinking of fluorescent emitters mediated by single plasmons

    NASA Astrophysics Data System (ADS)

    Bouchet, D.; Lhuillier, E.; Ithurria, S.; Gulinatti, A.; Rech, I.; Carminati, R.; De Wilde, Y.; Krachmalnicoff, V.

    2017-03-01

    We observe time-correlated emission between a single CdSe/CdS/ZnS quantum dot exhibiting single-photon statistics and a fluorescent nanobead located micrometers apart. This is accomplished by coupling both emitters to a silver nanowire. Single plasmons are created on the latter from the quantum dot, and transfer energy to excite in turn the fluorescent nanobead. We demonstrate that the molecules inside the bead show the same blinking behavior as the quantum dot.

  19. 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…

  20. Understanding unconscious intelligence and intuition: "blink" and beyond.

    PubMed

    Isenman, Lois

    2013-01-01

    The importance of unconscious intelligence and intuition is increasingly acknowledged by the scientific community. This essay examines and assesses the varied views on the topic presented in three books that bridge the scientific world and reading public: Blink by Malcolm Gladwell (2005), Gut Feelings by Gerd Gigerenzer (2008), and How Doctors Think by Jerome Groopman (2007). The analysis differentiates among kinds of unconscious intelligence and points towards a more complete understanding of the higher cognitive potential of the unconscious mind.

  1. 43 CFR 3275.15 - How accurately must I measure my production and utilization?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... production and utilization? 3275.15 Section 3275.15 Public Lands: Interior Regulations Relating to Public...) GEOTHERMAL RESOURCE LEASING Conducting Utilization Operations § 3275.15 How accurately must I measure my production and utilization? It depends on whether you use a meter to calculate Federal production or...

  2. 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? 3275.15 Section 3275.15 Public Lands: Interior Regulations Relating to Public...) GEOTHERMAL RESOURCE LEASING Conducting Utilization Operations § 3275.15 How accurately must I measure my production and utilization? It depends on whether you use a meter to calculate Federal production or...

  3. 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? 3275.15 Section 3275.15 Public Lands: Interior Regulations Relating to Public...) GEOTHERMAL RESOURCE LEASING Conducting Utilization Operations § 3275.15 How accurately must I measure my production and utilization? It depends on whether you use a meter to calculate Federal production or...

  4. 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.

  5. 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

  6. 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

  7. Removal of eye blink artifacts in wireless EEG sensor networks using reduced-bandwidth canonical correlation analysis

    NASA Astrophysics Data System (ADS)

    Somers, Ben; Bertrand, Alexander

    2016-12-01

    Objective. Chronic, 24/7 EEG monitoring requires the use of highly miniaturized EEG modules, which only measure a few EEG channels over a small area. For improved spatial coverage, a wireless EEG sensor network (WESN) can be deployed, consisting of multiple EEG modules, which interact through short-distance wireless communication. In this paper, we aim to remove eye blink artifacts in each EEG channel of a WESN by optimally exploiting the correlation between EEG signals from different modules, under stringent communication bandwidth constraints. Approach. We apply a distributed canonical correlation analysis (CCA-)based algorithm, in which each module only transmits an optimal linear combination of its local EEG channels to the other modules. The method is validated on both synthetic and real EEG data sets, with emulated wireless transmissions. Main results. While strongly reducing the amount of data that is shared between nodes, we demonstrate that the algorithm achieves the same eye blink artifact removal performance as the equivalent centralized CCA algorithm, which is at least as good as other state-of-the-art multi-channel algorithms that require a transmission of all channels. Significance. Due to their potential for extreme miniaturization, WESNs are viewed as an enabling technology for chronic EEG monitoring. However, multi-channel analysis is hampered in WESNs due to the high energy cost for wireless communication. This paper shows that multi-channel eye blink artifact removal is possible with a significantly reduced wireless communication between EEG modules.

  8. Origin and control of blinking in quantum dots.

    PubMed

    Efros, Alexander L; Nesbitt, David J

    2016-08-03

    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.

  9. Correlated fluorescence blinking in two-dimensional semiconductor heterostructures

    NASA Astrophysics Data System (ADS)

    Xu, Weigao; Liu, Weiwei; Schmidt, Jan F.; Zhao, Weijie; Lu, Xin; Raab, Timo; Diederichs, Carole; Gao, Weibo; Seletskiy, Denis V.; Xiong, Qihua

    2016-12-01

    ‘Blinking’, or ‘fluorescence intermittency’, refers to a random switching between ‘ON’ (bright) and ‘OFF’ (dark) states of an emitter; it has been studied widely in zero-dimensional quantum dots and molecules, and scarcely in one-dimensional systems. A generally accepted mechanism for blinking in quantum dots involves random switching between neutral and charged states (or is accompanied by fluctuations in charge-carrier traps), which substantially alters the dynamics of radiative and non-radiative decay. Here, we uncover a new type of blinking effect in vertically stacked, two-dimensional semiconductor heterostructures, which consist of two distinct monolayers of transition metal dichalcogenides (TMDs) that are weakly coupled by van der Waals forces. Unlike zero-dimensional or one-dimensional systems, two-dimensional TMD heterostructures show a correlated blinking effect, comprising randomly switching bright, neutral and dark states. Fluorescence cross-correlation spectroscopy analyses show that a bright state occurring in one monolayer will simultaneously lead to a dark state in the other monolayer, owing to an intermittent interlayer carrier-transfer process. Our findings suggest that bilayer van der Waals heterostructures provide unique platforms for the study of charge-transfer dynamics and non-equilibrium-state physics, and could see application as correlated light emitters in quantum technology.

  10. Efficient topological chaos embedded in the blinking vortex system.

    PubMed

    Kin, Eiko; Sakajo, Takashi

    2005-06-01

    We consider the particle mixing in the plane by two vortex points appearing one after the other, called the blinking vortex system. Mathematical and numerical studies of the system reveal that the chaotic particle mixing, i.e., the chaotic advection, is observed due to the homoclinic chaos, but the mixing region is restricted locally in the neighborhood of the vortex points. The present article shows that it is possible to realize a global and efficient chaotic advection in the blinking vortex system with the help of the Thurston-Nielsen theory, which classifies periodic orbits for homeomorphisms in the plane into three types: periodic, reducible, and pseudo-Anosov (pA). It is mathematically shown that periodic orbits of pA type generate a complicated dynamics, which is called topological chaos. We show that the combination of the local chaotic mixing due to the topological chaos and the dipole-like return orbits realize an efficient and global particle mixing in the blinking vortex system.

  11. Improved solution of the lidar equation utilizing particle counter measurements

    NASA Technical Reports Server (NTRS)

    Jaeger, H.; Hofmann, D. J.; Jaeger, H.; Hofmann, D. J.

    1986-01-01

    The extraction of particle backscattering from incoherent lidar measurements poses some problems. In the case of measurements of the stratospheric aerosol layer the solution of the lidar equation is based on two assumptions which are necessary to normalize the measured signal and to correct it with the two-way transmission of the laser pulse. Normalization and transmission are tackled by adding the information contained in aerosol particle counter measurements of the University of Wyoming to the ruby lidar measurements at Garmisch-Partenkirchen. Calculated backscattering from height levels above 25 km for the El Chichon period will be compared with lidar measurements and necessary corrections. The calculated backscatter-to-extinction ratios are compared to those, which were derived from a comparison of published extinction values to measured lidar backscattering at Garmisch. These ratios were used to calculate the Garmisch lidar returns. For the period 4 to 12 months after the El Chichon eruption a backscater-to-extinction ratio of 0.026 1/sr was applied with smaller values before and after that time.

  12. Ipsilateral blinking seizures during left fronto-temporal ictal pattern on scalp EEG.

    PubMed

    Pestana, Elia M; Gupta, Ajay

    2007-12-01

    We report an infant with left eye blinking seizures accompanying a left (ipsilateral) fronto-temporal scalp EEG ictal pattern. The epileptogenic lesion was a left frontal encephalomalacia along the ventriculo-peritoneal shunt tract. The shunt was inserted for treatment of communicating hydrocephalus. This case illustrates the lateralizing value of the ictal blinking. Review of the literature suggests that seizures with unilateral blinking are likely to be produced by activation of ipsilateral trigeminal fibers innervating subdural intracranial structures and pial vessels in temporal and frontal lobes. Ipsilateral blinking could also be produced by activation of the ipsilateral cerebellar hemisphere.

  13. 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.

  14. 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.

  15. 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 esophageal

  16. Prediction of parturition in bitches utilizing continuous vaginal temperature measurement.

    PubMed

    Geiser, B; Burfeind, O; Heuwieser, W; Arlt, S

    2014-02-01

    The objective of this study was to determine sensitivity and specificity of a body temperature decline in bitches to predict parturition. Temperature loggers were placed into the vaginal cavity of 16 pregnant bitches on day 56-61 after estimated ovulation or first mating. This measurement technique has been validated previously and enabled continuous sampling of body temperature. The temperature loggers were expelled from the vagina before delivery of the first pup. The computed values for specificity (77-92%) were higher than sensitivity (53-69%), indicating a more precise prognosis of parturition not occurring. In conclusion, our findings may assist interpreting vaginal temperature measurements in order to predict parturition in bitches.

  17. Characterization of Solid Liquid Suspensions Utilizing Ultrasonic Measurements

    NASA Astrophysics Data System (ADS)

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

    2003-03-01

    Rapid, on-line determination of particle size and concentration is required for the efficient process measurement and control of many processes in government and industrial applications such as waste remediation for the Department of Energy sites and process control for chemical and pharmaceutical manufacturing. However, existing methods based on ultrasonic attenuation can become inaccurate for highly concentrated suspensions due to careful transducer alignment and the complicated mathematics required to describe multiple scattering, which controls the attenuation. Two measurements that help to overcome these difficulties are the ultrasonic backscattering and diffuse field. Backscattering is attractive because the single scattering theories typically used to describe backscattering are mathematically simpler than attenuation theories and lend themselves to more stable inversion processes. Also, the measurements of backscattering and diffuse fields do not require long travel distances and can be made with a single transducer thus eliminating alignment problems. We will present ultrasonic measurements on solid liquid suspensions designed to elucidate the particle size and concentration at high concentrations.

  18. 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...

  19. 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...

  20. Measuring Constraint-Set Utility for Partitional Clustering Algorithms

    NASA Technical Reports Server (NTRS)

    Davidson, Ian; Wagstaff, Kiri L.; Basu, Sugato

    2006-01-01

    Clustering with constraints is an active area of machine learning and data mining research. Previous empirical work has convincingly shown that adding constraints to clustering improves the performance of a variety of algorithms. However, in most of these experiments, results are averaged over different randomly chosen constraint sets from a given set of labels, thereby masking interesting properties of individual sets. We demonstrate that constraint sets vary significantly in how useful they are for constrained clustering; some constraint sets can actually decrease algorithm performance. We create two quantitative measures, informativeness and coherence, that can be used to identify useful constraint sets. We show that these measures can also help explain differences in performance for four particular constrained clustering algorithms.

  1. 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.

  2. Quantitation of and measurements utilizing the sphenoid ridge.

    PubMed

    Tubbs, R Shane; Salter, E George; Oakes, W Jerry

    2007-03-01

    The sphenoid ridge (posterior aspect of the lesser wings) is encountered in many intracranial procedures. Increased knowledge of its morphology and relationships is, therefore, of importance to the neurosurgeon and clinician who appreciate imaging of this anatomical region. We have quantitated this part of the sphenoid bone in dry human skulls (35) and made cadaveric (15) measurements between its parts and surrounding neuroanatomical structures in all three cranial fossae. The length of the left and right lesser wings was on average 4.2 and 4 cm, respectively. The mean widths of this bony part at its midline, midpoint, and lateral point (crista alaris) were 1.5 cm, 2.0 cm, and 2 mm, respectively. From the crista alaris the mean distances to the crista galli, V3 at its exit through the foramen ovale, entrance of the occulomotor nerve into the cavernous sinus, middle meningeal artery at its emergence from the foramen spinosum, and the facial and vestibulocochlear nerves at the internal auditory meatus were 4.9, 4.5, 5, 4.7, and 6.1 cm, respectively. From the midpoint of the lesser wing, the mean distances to the crista galli, V3 at its exit through the foramen ovale, entrance of the occulomotor nerve into the cavernous sinus, middle meningeal artery at its emergence from the foramen spinosum, and the facial and vestibulocochlear nerves at the internal auditory meatus were 4.2, 2.9, 3, 3.4, and 4.7 cm, respectively. From the anterior clinoid process of the lesser wing, the mean distances to the crista galli, V3 at its exit through the foramen ovale, entrance of the oculomotor nerve into the cavernous sinus, middle meningeal artery at its emergence from the foramen spinosum, and the facial and vestibulocochlear nerves at the internal auditory meatus were 4.3, 2.8, 1, 3.3, and 4.1 cm, respectively. Additional measurements between the parts of the sphenoid ridge and surrounding anatomical structures may assist the surgeon who operates in this region or the clinician who

  3. 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.

  4. Macaque Pontine Omnipause Neurons Play No Direct Role in the Generation of Eye Blinks

    PubMed Central

    Schultz, K. P.; Williams, C. R.

    2010-01-01

    We recorded the activity of pontine omnipause neurons (OPNs) in two macaques during saccadic eye movements and blinks. As previously reported, we found that OPNs fire tonically during fixation and pause about 15 ms before a saccadic eye movement. In contrast, for blinks elicited by air puffs, the OPNs paused <2 ms before the onset of the blink. Thus the burst in the agonist orbicularis oculi motoneurons (OOMNs) and the pause in the antagonist levator palpabrae superioris motoneurons (LPSMNs) necessarily precede the OPN pause. For spontaneous blinks there was no correlation between blink and pause onsets. In addition, the OPN pause continued for 40–60 ms after the time of the maximum downward closing of the eyelids, which occurs around the end of the OOMN burst of firing. LPSMN activity is not responsible for terminating the OPN pause because OPN resumption was very rapid, whereas the resumption of LPSMN firing during the reopening phase is gradual. OPN pause onset does not directly control blink onset, nor does pause offset control or encode the transition between the end of the OOMN firing and the resumption of the LPSMNs. The onset of the blink-related eye transients preceded both blink and OPN pause onsets. Therefore they initiated while the saccadic short-lead burst neurons were still fully inhibited by the OPNs and cannot be saccadic in origin. The abrupt dynamic change of the vertical eye transients from an oscillatory behavior to a single time constant exponential drift predicted the resumption of the OPNs. PMID:20164389

  5. 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.

  6. A kinetic study of blinking responses in cats

    PubMed Central

    Trigo, José Alberto; Roa, Laura; Gruart, Agnès; Delgado-García, José María

    2003-01-01

    Reflexively evoked and eye-related eyelid responses were recorded using the search coil in a magnetic field technique in alert cats. The downward phase of a blink was a large (up to 21 deg), fast (up to 2000 deg s−1) eyelid displacement in the closing direction, with an almost fixed rise time duration (15-20 ms); its maximum velocity was achieved in ≈10 ms. Upward eyelid motion was separated into two phases. The first phase consisted of a fast eyelid displacement, with a short duration (≈30 ms) and a maximum velocity up to 900 deg s−1. The second phase had an exponential-like form, lasting for 200–400 ms, and a maximum velocity ranging between 30 and 250 deg s−1. Maximum blink velocity in the downward direction was linearly related to maximum velocity of the first upward phase. The first phase in the upward direction was never observed if the eyelid stayed closed for a long period (> 50 ms) or moved slowly in the closing direction before it started to open. In these two cases, the upswing motion of the blink reflex contained only the exponential-like movement characteristic of the second upward phase, and maximum velocity in the downward direction was not related to that of the eyelid upward displacement. Mean duration of eyelid downward saccades was ≈130 ms, and their peak velocities ranged between 50 and 440 ms. A physiological model is presented explaining the active and passive forces involved in both reflex and saccadic eyelid responses. A second-order system seems to be appropriate to describe the postulated biomechanical model. PMID:12665614

  7. Non-blinking semiconductor colloidal quantum dots for biology, optoelectronics and quantum optics.

    PubMed

    Spinicelli, Piernicola; Mahler, Benoit; Buil, Stéphanie; Quélin, Xavier; Dubertret, Benoit; Hermier, Jean-Pierre

    2009-04-14

    Twinkle, twinkle: The blinking of semiconductor colloidal nanocrystals is the main inconvenience of these bright nanoemitters. There are various approaches for obtaining non-blinking nanocrystals, one of which is to grow a thick coat of CdS on the CdSe core (see picture). Applications of this method in the fields of optoelectronic devices, biologic labelling and quantum information processing are discussed.The blinking of semiconductor colloidal nanocrystals is the main inconvenience of these bright nanoemitters. For some years, research on this phenomenon has demonstrated the possibility to progress beyond this problem by suppressing this fluorescence intermittency in various ways. After a brief overview on the microscopic mechanism of blinking, we review the various approaches used to obtain non-blinking nanocrystals and discuss the commitment of this crucial improvement to applications in the fields of optoelectronic devices, biologic labelling and quantum information processing.

  8. Blink reflex in dyskinetic and nondyskinetic patients with Parkinson's disease.

    PubMed

    Iriarte, L M; Chacon, J; Madrazo, J; Chaparro, P; Vadillo, J

    1989-01-01

    An electrophysiological study of the blink Reflex was undertaken in 40 dyskinetic and 20 nondyskinetic patients with Parkinson's disease, who were matched for age, stage of disease, duration of illness and amount and nature of antiparkinsonian medication. We found that latencies of R2 responses (both ipsilateral and contralateral) were prolonged in the dyskinetic group compared to the nondyskinetic group. Moreover, the late response was more easily inhibited by conditioning stimulation in dyskinetic patients. This behavior of late response in dyskinetic parkinsonians may be attributed to the reinstatement of dopaminergic suppressive control over the segmental multisynaptic systems belonging to the reflex.

  9. Interactions between gaze-evoked blinks and gaze shifts in monkeys.

    PubMed

    Gandhi, Neeraj J

    2012-02-01

    Rapid eyelid closure, or a blink, often accompanies head-restrained and head-unrestrained gaze shifts. This study examines the interactions between such gaze-evoked blinks and gaze shifts in monkeys. Blink probability increases with gaze amplitude and at a faster rate for head-unrestrained movements. Across animals, blink likelihood is inversely correlated with the average gaze velocity of large-amplitude control movements. Gaze-evoked blinks induce robust perturbations in eye velocity. Peak and average velocities are reduced, duration is increased, but accuracy is preserved. The temporal features of the perturbation depend on factors such as the time of blink relative to gaze onset, inherent velocity kinematics of control movements, and perhaps initial eye-in-head position. Although variable across animals, the initial effect is a reduction in eye velocity, followed by a reacceleration that yields two or more peaks in its waveform. Interestingly, head velocity is not attenuated; instead, it peaks slightly later and with a larger magnitude. Gaze latency is slightly reduced on trials with gaze-evoked blinks, although the effect was more variable during head-unrestrained movements; no reduction in head latency is observed. Preliminary data also demonstrate a similar perturbation of gaze-evoked blinks during vertical saccades. The results are compared with previously reported effects of reflexive blinks (evoked by air-puff delivered to one eye or supraorbital nerve stimulation) and discussed in terms of effects of blinks on saccadic suppression, neural correlates of the altered eye velocity signals, and implications on the hypothesis that the attenuation in eye velocity is produced by a head movement command.

  10. Fear conditioned potentiation of the acoustic blink reflex in patients with cerebellar lesions

    PubMed Central

    Maschke, M.; Drepper, J.; Kindsvater, K.; Kolb, F.; Diener, H.; Timmann, D.

    2000-01-01

    OBJECTIVE—To investigate whether the human cerebellum takes part in fear conditioned potentiation of the acoustic blink reflex.
METHODS—A group of 10 cerebellar patients (eight patients with lesions involving the medial cerebellum, two patients with circumscribed lesions of the cerebellar hemispheres) was compared with a group of 16 age and sex matched healthy control subjects. The fear conditioned potentiation paradigm consisted of three phases. During the first, habituation phase subjects received 20 successive acoustic blink stimuli. In the subsequent fear conditioning phase, subjects passed through 20 paired presentations of the unconditioned fear stimulus (US; an electric shock) and the conditioned stimulus (CS; a light). Thereafter, subjects underwent the potentiation phase, which consisted of a pseudorandom order of 12 trials of the acoustic blink stimulus alone, 12 acoustic blink stimuli paired with the conditioned stimulus, and six conditioned stimuli paired with the unconditioned stimulus. The EMG of the acoustic blink reflex was recorded at the orbicularis oculi muscles. The potentiation effect was determined as the difference in normalised peak amplitude of the blink reflex evoked by pairs of CS and acoustic blink stimuli and evoked by the acoustic stimulus alone.
RESULTS—In the habituation phase, short term habituation of the acoustic blink reflex was preserved in all cerebellar patients. However, in the potentiation phase, the potentiation effect of the blink reflex was significantly reduced in patients with medial cerebellar lesions compared with the controls (mean (SD) potentiation effect (%), patients: −6.4 (15.3), controls: 21.6 (35.6)), but was within normal limits in the two patients with lateral lesions.
CONCLUSIONS—The present findings suggest that the human medial cerebellum is involved in associative learning of non-specific aversive reactions—that is, the fear conditioned potentiation of the acoustic blink reflex

  11. Integration of Advance Information about a Forthcoming Task Switch – Evidence from Eye Blink Rates

    PubMed Central

    Kleinsorge, Thomas; Scheil, Juliane

    2017-01-01

    We investigated task switching among four tasks by means of a modified cuing procedure with two types of cues. One type of cue consisted of a standard task cue indicating the next task. In half of the trials, this task cue was preceded by another type of cue that reduced the set of candidate tasks from four to two tasks. In addition, we measured participants’ spontaneous eye blink rates (EBRs) at the beginning, in the middle, and at the end of the experiment. Whereas interindividual differences in mean EBR had no pronounced effect on task switching performance, changes in EBRs during the first half of the experiment significantly modulated the interaction of the effects of the two types of cues. We suggest that changes in EBRs in the early phase of the experiment reflect adaptations of dopaminergic projections serving to integrate advance information about a forthcoming task switch. PMID:28293210

  12. Noisy cooperative intermittent processes: From blinking quantum dots to human consciousness

    NASA Astrophysics Data System (ADS)

    Allegrini, Paolo; Paradisi, Paolo; Menicucci, Danilo; Bedini, Remo; Gemignani, Angelo; Fronzoni, Leone

    2011-07-01

    We study the superposition of a non-Poisson renewal process with the presence of a superimposed Poisson noise. The non-Poisson renewals mark the passage between meta-stable states in system with self-organization. We propose methods to measure the amount of information due to the two independent processes independently, and we see that a superficial study based on the survival probabilities yield stretched-exponential relaxations. Our method is in fact able to unravel the inverse-power law relaxation of the isolated non-Poisson processes, even when noise is present. We provide examples of this behavior in system of diverse nature, from blinking nano-crystals to weak turbulence. Finally we focus our discussion on events extracted from human electroencephalograms, and we discuss their connection with emerging properties of integrated neural dynamics, i.e. consciousness.

  13. Inhibitory Control under Threat: The Role of Spontaneous Eye Blinks in Post-Traumatic Stress Disorder.

    PubMed

    Rubin, Mikael; Hien, Denise A; Das, Dipanjana; Melara, Robert D

    2017-02-04

    This study is the first to explore spontaneous eye blink rate (sEBR) in individuals with post-traumatic stress disorder (PTSD). We investigated the connection between the magnitude of flanker interference in PTSD participants and sEBR during performance on a modified version of the Eriksen flanker task. As a peripheral measure of cognitive control and dopaminergic function, sEBR may illuminate the relationship between PTSD and executive function. Findings revealed a positive relationship between sEBR and flanker interference in participants diagnosed with PTSD, to both threat-related and neutral stimuli, whereas this relationship was negative in participants exposed to trauma but without PTSD and in healthy controls. Although our results are suggestive of sEBR as a potential physiological index of emotional management in PTSD, most of the correlations were not significant, indicating that further research with a larger sample is needed.

  14. Inhibitory Control under Threat: The Role of Spontaneous Eye Blinks in Post-Traumatic Stress Disorder

    PubMed Central

    Rubin, Mikael; Hien, Denise A.; Das, Dipanjana; Melara, Robert D.

    2017-01-01

    This study is the first to explore spontaneous eye blink rate (sEBR) in individuals with post-traumatic stress disorder (PTSD). We investigated the connection between the magnitude of flanker interference in PTSD participants and sEBR during performance on a modified version of the Eriksen flanker task. As a peripheral measure of cognitive control and dopaminergic function, sEBR may illuminate the relationship between PTSD and executive function. Findings revealed a positive relationship between sEBR and flanker interference in participants diagnosed with PTSD, to both threat-related and neutral stimuli, whereas this relationship was negative in participants exposed to trauma but without PTSD and in healthy controls. Although our results are suggestive of sEBR as a potential physiological index of emotional management in PTSD, most of the correlations were not significant, indicating that further research with a larger sample is needed. PMID:28165364

  15. FL-41 Tint Improves Blink Frequency, Light Sensitivity, and Functional Limitations in Patients with Benign Essential Blepharospasm

    PubMed Central

    Blackburn, Marcus K.; Lamb, Randy D.; Digre, Kathleen B.; Gordon Smith, A.; Warner, Judith E.A.; McClane, Robert W; Nandedkar, Sanjeev D.; Langeberg, Wendy J.; Holubkov, Richard; Katz, Bradley J.

    2009-01-01

    Objective The objective of these two studies was to assess the efficacy of FL-41 tinted lenses in the treatment of benign essential blepharospasm (BEB). Design A randomized crossover study and a randomized crossover case-control study. Participants The first study included 30 subjects with BEB. The second study included 26 subjects with BEB and 26 controls. Methods For the first study, subjects were randomized to wear either FL-41 or gray tinted lenses for 2 weeks. After a two-week washout period, the other lens was worn for 2 weeks. Questionnaires were completed at baseline, after the first lens, and after the second lens. In the second study, surface electromyography (EMG) was used to measure blink frequency, duration, and force while subjects read and wore FL-41, rose, or gray tinted lenses. Main Outcome Measures Questionnaires were used to assess perceptions of light sensitivity and the effect of light sensitivity on activities of daily living. EMG was used to measure blink frequency, duration, and force. Results Most participants observed improvement while wearing both FL-41 and gray tinted lenses. FL-41 tinted lenses provided superior improvement in the areas of reading, fluorescent light sensitivity, overall light sensitivity, blepharospasm frequency, and blepharospasm severity. FL-41 lenses reduced mean blink rate compared to both rose and gray tinted lenses, and reduced eyelid contraction force compared to rose tinted lenses. Conclusions FL-41 lenses provided both subjective and objective benefit to subjects with BEB. Physicians should consider recommending this noninvasive and inexpensive lens tint to patients with BEB. PMID:19410958

  16. Patient preferences and the measurement of utilities in the evaluation of dental technologies.

    PubMed

    Birch, S; Ismail, A I

    2002-07-01

    Advances in life sciences that are predicted in the 21st century will present many challenges for health professionals and policy-makers. The major questions will be how to allocate resources to pay for costs of new technologies and who will best benefit from advances in new diagnostic and treatment methods. We review in this paper the concept of utility and how it can be applied and expanded to provide data to help health professionals make decisions that are preferred by patients and the public at large. Utility is a measure of people's well-being or preferences for outcomes. The measurement of utilities of a new diagnostic technology, for example, can be carried out with the use of simple methods that do not incorporate all of the uncertainties and potential outcomes associated with providing the test, or with more complex methods that can incorporate most uncertainties. This review describes and critiques the different measurement methods of utilities.

  17. 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.

  18. Blinking in quantum dots: The origin of the grey state and power law statistics

    NASA Astrophysics Data System (ADS)

    Ye, Mao; Searson, Peter C.

    2011-09-01

    Quantum dot (QD) blinking is characterized by switching between an “on” state and an “off” state, and a power-law distribution of on and off times with exponents from 1.0 to 2.0. The origin of blinking behavior in QDs, however, has remained a mystery. Here we describe an energy-band model for QDs that captures the full range of blinking behavior reported in the literature and provides new insight into features such as the gray state, the power-law distribution of on and off times, and the power-law exponents.

  19. 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.

  20. A tribute to Lawrence Rogers Blinks (1900-1989): light and algae.

    PubMed

    Thorhaug, Anitra; Berlyn, Graeme

    2009-06-01

    We honor Lawrence Rogers Blinks (1900-1989) in this tribute. We introduce his scientific life that started at the Harvard University, and ended at the Hopkins Marine Station of Stanford University. We discuss his pioneering contributions in the areas of ion transport in membranes and of photosynthesis, particularly of the phenomenon that became known as the Blinks Effect, later linked to the two-light and two-pigment system scheme of photosynthesis. We have drawn information from the 2006 symposium held in his honor in California, and from the extensive 2006 and 2008 recollections of Francis Haxo, one of the major coworkers of Blinks.

  1. 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…

  2. Contact lens and tear film dynamics during blinking

    NASA Astrophysics Data System (ADS)

    Reid, Timothy; Anderson, Daniel

    2016-11-01

    We develop a mathematical model that couples the dynamics of the tear film and contact lens during blinking. We derive an ordinary differential equation for the motion of the contact lens (parallel to the cornea) driven and retarded by viscous forces in the thin fluid films separating the contact lens from the eyelids and the corneal surface. Using the contact lens motion and tear film dynamics models we calculate a numerical solution of tear film thickness, showing that the lens and lid motion influence the tear film dynamics. The numerical solution uses a mapped Chebyshev spectral method for the spatial derivatives to reduce the model to a system of differential algebraic equations. National Science Foundation Grants (DMS-1407087) and (DMS-1107848).

  3. 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.

  4. Non-blinking single-photon emitters in silica

    SciTech Connect

    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, 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.

  5. Non-blinking single-photon emitters in silica

    DOE PAGES

    Rabouw, Freddy T.; Cogan, Nicole M. B.; Berends, Anne C.; ...

    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

  6. 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

  7. Delayed blink reflex in dementia with Lewy bodies

    PubMed Central

    Bonanni, Laura; Anzellotti, Francesca; Varanese, Sara; Thomas, Astrid; Manzoli, Lamberto; Onofrj, Marco

    2007-01-01

    Blink reflexes (BR) to electric stimuli of the supraorbital nerve were recorded in 26 patients with dementia with Lewy bodies (DLB), 26 patients with multiple system atrophy, 26 patients with Parkinson's disease, with or without REM sleep behaviour disorder (RBD), and in 20 patients with Alzheimer's disease and 20 with progressive supranuclear palsy without RBD, and compared with recordings in 30 healthy controls. BR were significantly delayed (p<0.001) only in DLB patients in comparison with controls and with the other groups of patients; 14 (53.8%) patients had BR latency above 2 SD of the control mean, ranging from 36.1 to 46.3 ms. BR latency was not related to the presence of RBD, while a Spearman correlation rho of 0.68 was found for scores assessing the presence of cognitive fluctuations. R2 delay was prominently (71.5%) bilateral. PMID:17878193

  8. 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.

  9. Filter Feeding, Chaotic Filtration, and a Blinking Stokeslet

    NASA Astrophysics Data System (ADS)

    Blake, J. R.; Otto, S. R.; Blake, D. A.

    The filtering mechanisms in bivalve molluscs, such as the mussel Mytilus edulis, and in sessile organisms, such as Vorticella or Stentor, involve complex fluid mechanical phenomena. In the former example, three different sets of cilia serving different functions are involved in the process whereas in the sessile organisms the flexibility and contractile nature of the stalk may play an important role in increasing the filtering efficiency of the organisms. In both cases, beating microscopic cilia are the ``engines'' driving the fluid motion, so the fluid mechanics will be dominated entirely by viscous forces. A fluid mechanical model is developed for the filtering mechanism in mussels that enables estimates to be made of the pressure drop through the gill filaments due to (i) latero-frontal filtering cilia, (ii) the lateral (pumping) cilia, and (iii) through the non-ciliated zone of the ventral end of the filament. The velocity profile across the filaments indicates that a backflow can occur in the centre of the channel leading to the formation of two ``standing'' eddies which may drive particles towards the mucus-laden short cilia, the third set of cilia. Filter feeding in the sessile organisms is modelled by a point force above a rigid boundary. The point force periodically changes its point of application according to a given protocol (a blinking stokeslet). The resulting fluid field is illustrated via Poincaré sections and particle dispersion-showing the potential for a much improved filtering efficiency. Returning to filter feeding in bivalve molluscs, this concept is extended to a pair of blinking stokeslets above a rigid boundary to give insight into possible mechanisms for movement of food particles onto the short mucus-bearing cilia. The appendix contains a Latin and English version of an ``Ode of Achievement'' in celebration of Sir James Lighthill's contributions to mathematics and fluid mechanics.

  10. 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

  11. 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

  12. 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.

  13. Blinks, Saccades, and Fixation Pauses During Vigilance Task Performance: 1. Time on Task.

    DTIC Science & Technology

    1994-12-01

    aircraft (Stoliarov sion checks. Though these authors minimize the im- personal communication, 1991). portance of the obtained TOT effects, to those...E. ing. Journal of Experimental Psychology, 18, 708- (1988). Spontaneous blink rate, schizophrenia, 724. and schizotypal ...terminals. eyelid movements. Journal ofNervous and Mental Human Factors, 23, 529-540. Disorders , 132, 31-48. Orchard, L. & Stern, J.A. (1991). Blinks

  14. Blink reflex in 57 parkinsonian patients with correlation between the clinical and electrophysiological parameters.

    PubMed

    Iriarte, L M; Chacón, J; Madrazo, J; Chaparro, P; Vadillo, J

    1988-01-01

    An electrophysiological study of the blink reflex was undertaken in 25 control subjects and in 57 patients with Parkinson's disease. An increase in the ipsilateral and contralateral late response was the most evident finding. The excitability cycle of recovery of the R2 component of the blink reflex after a prior conditioning shock was enhanced in the patients. A statistically significant correlation was established between the increase in the late response and the severity of akinesia and rigidity.

  15. 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.

  16. 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

  17. Assessing the Utility of a Daily Log for Measuring Principal Leadership Practice

    ERIC Educational Resources Information Center

    Camburn, Eric M.; Spillane, James P.; Sebastian, James

    2010-01-01

    Purpose: This study examines the feasibility and utility of a daily log for measuring principal leadership practice. Setting and Sample: The study was conducted in an urban district with approximately 50 principals. Approach: The log was assessed against two criteria: (a) Is it feasible to induce strong cooperation and high response rates among…

  18. A balloon ozone measurement utilizing an optical absorption cell and an ejector air sampler

    NASA Technical Reports Server (NTRS)

    Hilsenrath, E.; Ashenfelter, T. E.

    1976-01-01

    Stratospheric ozone was measured from a balloon utilizing an ultraviolet absorption cell. The ambient air was sampled by means of an aspirator attached to the output end of the optical cell. A nominal ozone distribution was obtained from 16 km to the float altitude of 38 km.

  19. 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

  20. Fabry-Pérot interferometer utilized for displacement measurement in a large measuring range.

    PubMed

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

    2010-09-01

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

  1. 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.

  2. Differential effects of blinks on horizontal saccade and smooth pursuit initiation in humans.

    PubMed

    Rambold, Holger; El Baz, Ieman; Helmchen, Christoph

    2004-06-01

    Blinks executed during eye movements affect kinetic eye movement parameters, e.g., peak velocity of saccades is decreased, their duration is increased, but their amplitude is not altered. This effect is mainly explained by the decreased activity of premotor neurons in the brainstem: omni-pause neurons (OPN) in the nucleus raphe interpositus. Previous studies examined the immediate effect of blinks directly on eye movements but not their effect when they are elicited several hundred milliseconds before the eye movements. In order to address this question we tested blinks elicited before the target onset of saccades and pursuit and compared the results to the gap effect: if a fixation light is extinguished for several hundred milliseconds, the reaction time (latency) for subsequent saccades or smooth pursuit eye movements is decreased. Monocular eye and lid movements were recorded in nine healthy subjects using the scleral search-coil system. Laser stimuli were front-projected onto a tangent screen in front of the subjects. Horizontal step-ramp smooth pursuit of 20 deg/s was elicited in one session, or 5 deg horizontal visually guided saccades in another experimental session. In one-third of the trials (smooth pursuit or saccades) the fixation light was extinguished for 200 ms before stimulus onset (gap condition), and in another third of the trials reflexive blinks were elicited by a short airpuff before the stimulus onset (blink condition). The last third of the trials served as controls (control condition). Stimulus direction and the three conditions were randomized for saccades and smooth pursuit separately. The latency of the step-ramp smooth pursuit in the blink condition was found to be decreased by 10 ms, which was less than in the gap condition (38 ms). However, the initial acceleration and steady-state velocity of smooth pursuit did not differ in the three conditions. In contrast, the latency of the saccades in the gap condition was decreased by 39 ms, but

  3. 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.

  4. The attentional blink in typically developing and reading-disabled children.

    PubMed

    de Groot, Barry J A; van den Bos, Kees P; van der Meulen, Bieuwe F; Minnaert, Alexander E M G

    2015-11-01

    This study's research question was whether selective visual attention, and specifically the attentional blink (AB) as operationalized by a dual target rapid serial visual presentation (RSVP) task, can explain individual differences in word reading (WR) and reading-related phonological performances in typically developing children and reading-disabled subgroups. A total of 407 Dutch school children (Grades 3-6) were classified either as typically developing (n = 302) or as belonging to one of three reading-disabled subgroups: reading disabilities only (RD-only, n = 69), both RD and attention problems (RD+ADHD, n = 16), or both RD and a specific language impairment (RD+SLI, n = 20). The RSVP task employed alphanumeric stimuli that were presented in two blocks. Standardized Dutch tests were used to measure WR, phonemic awareness (PA), and alphanumeric rapid naming (RAN). Results indicate that, controlling for PA and RAN performance, general RSVP task performance contributes significant unique variance to the prediction of WR. Specifically, consistent group main effects for the parameter of AB(minimum) were found, whereas there were no AB-specific effects (i.e., AB(width) and AB(amplitude)) except for the RD+SLI group. Finally, there was a group by measurement interaction, indicating that the RD-only and comorbid groups are differentially sensitive for prolonged testing sessions. These results suggest that more general factors involved in RSVP processing may explain the group differences found.

  5. Changes in the activity of units of the cat motor cortex with rapid conditioning and extinction of a compound eye blink movement.

    PubMed

    Aou, S; Woody, C D; Birt, D

    1992-02-01

    Patterns of spike activity were measured in the pericruciate cortex of conscious cats before and after development of a Pavlovian conditioned eye blink response. Unit activity was tested with presentations of a click conditioned stimulus (CS) and a hiss discriminative stimulus (DS) of similar intensity to the click. Unit discharge in response to the CS increased after conditioning, but not after backward conditioning when conditioned reflexes (CRs) were not performed. Rates of spontaneous, baseline discharge were not increased after conditioning with respect to rates of discharge measured in the naive state. It appeared that an increase in the ratio of CS-elicited discharge to background activity, together with an increase in the number of units responding to the CS after conditioning, supported discrimination of the CS from the DS and performance of the conditioned blink response. This is the first detailed characterization of patterns of a rapidly conditioned Pavlovian response. Activation of units by the CS preceded the onset of the CR, supporting the hypothesis that the activity played a role in initiating the conditioned eye blink movement. Extinction with retention of performance of the CR was associated with perseverance of the increased unit discharge in response to the CS. Extinction with substantially reduced performance of the CR was associated with diminution of the unit response to the CS below levels found with conditioning. Averages of patterns of spike activity elicited by the CS after conditioning showed components of discharge with onsets of 8-40 msec (alpha 1), 40-72 msec (alpha 2), 72-112 msec (beta), and greater than 112 msec (gamma), corresponding to each of four separate excitatory EMG components of the compound blink CR. Each component increased in magnitude after conditioning, relative to levels found in the naive state. The finding that long- as well as short-latency components of unit activation increased after conditioning supported the

  6. Facial expression influences face identity recognition during the attentional blink.

    PubMed

    Bach, Dominik R; Schmidt-Daffy, Martin; Dolan, Raymond J

    2014-12-01

    Emotional stimuli (e.g., negative facial expressions) enjoy prioritized memory access when task relevant, consistent with their ability to capture attention. Whether emotional expression also impacts on memory access when task-irrelevant is important for arbitrating between feature-based and object-based attentional capture. Here, the authors address this question in 3 experiments using an attentional blink task with face photographs as first and second target (T1, T2). They demonstrate reduced neutral T2 identity recognition after angry or happy T1 expression, compared to neutral T1, and this supports attentional capture by a task-irrelevant feature. Crucially, after neutral T1, T2 identity recognition was enhanced and not suppressed when T2 was angry-suggesting that attentional capture by this task-irrelevant feature may be object-based and not feature-based. As an unexpected finding, both angry and happy facial expressions suppress memory access for competing objects, but only angry facial expression enjoyed privileged memory access. This could imply that these 2 processes are relatively independent from one another.

  7. 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.

  8. Global measures: utility in defining and measuring treatment response in dementia.

    PubMed

    Reisberg, Barry

    2007-06-01

    Global measures used in treatment trials in dementia encompass two distinct categories: (1) clinician's interview-based global severity scales, and (2) clinician's interview-based global change scales. The global severity scales that have been used include: the Clinical Dementia Rating (CDR) and the related CDR-sum of boxes (CDR-SB), the Global Deterioration Scale (GDS), and the Functional Assessment Staging (FAST) procedure. The global severity scales are clearly useful in subject categorization in treatment trials, in part because they are relatively free of many of the sociocultural biases inherent in mental status and psychometric descriptors. Global severity scales can also be used to demonstrate therapeutic efficacy in terms of the general progression of the dementia process. These measures have also proven to be useful in sensitively assessing pharmacotherapeutic effects in Alzheimer's disease (AD) treatment trials. For example, in pivotal trials: (1) in Mild to Moderate AD, the GDS has shown significant change in response to medication, whereas the results on the Mini-mental State Examination (MMSE) were not significant, and (2) in Moderate to Severe AD, the FAST has shown significant pharmacotherapeutic efficacy, whereas the results using the MMSE were not significant. The global change scales employed in dementia trials differ widely in assessment methodology. Clinical Global Impressions of Change (CGIC) scales do not have defined methodologies, whereas Clinician's Interview-Based Impression of Change Plus Caregiver Input (CIBIC-Plus) scales are much more elaborate. The CIBIC-Plus procedures require an independent clinician assessment and can provide independent, comprehensive evidence of therapeutic efficacy. The CIBIC-Plus procedure may also be useful in sensitively assessing efficacy in future prevention trials, for example in subjects with Subjective Cognitive Impairment. For Mild Cognitive Impairment (MCI), global severity scales already appear to be

  9. 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.

  10. Blink-related delta oscillations in the resting-state EEG: a wavelet analysis.

    PubMed

    Bonfiglio, Luca; Sello, Stefano; Andre, Paolo; Carboncini, Maria Chiara; Arrighi, Pieranna; Rossi, Bruno

    2009-01-02

    Over the past decades, many studies have linked the variations in frequency of spontaneous blinking with certain aspects of information processing and in particular with attention and working memory functions. On the other hand, according to the theory postulated by Crick and Koch, the actual function of primary consciousness is based on the reciprocal interaction between attention and working memory in the automatic and serial mode. The purpose of this study was to investigate for electrophysiological correlates compatible with the cognitive nature of spontaneous blinking, by using the EEG recordings obtained in a group of seven healthy volunteers while they rested quietly though awake, with their eyes open, but not actively engaged in attention-demanding goal-directed behaviours. The global wavelet analysis - at total of 189 three-second EEG epochs time-locked to the blink - revealed an increase in the delta band signal corresponding to the blink. In particular, a reconstruction of the EEG signal by means of inverse-wavelet transform (IWT) showed a blink-related P300-like wave at mid-parietal site. We assumed this phenomenon to represent an electrophysiological sign of the automatic processing of contextual environmental information. This might play a role in maintaining perceptive awareness of the environment at a low level of processing, while the subject is not engaged in attention-demanding tasks but rather introspectively oriented mental activities or free association(s).

  11. 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.

  12. Simultaneous measurements of umbilical uptake, fetal utilization rate, and fetal turnover rate of glucose.

    PubMed

    Hay, W W; Sparks, J W; Quissell, B J; Battaglia, F C; Meschia, G

    1981-06-01

    Fetal umbilical glucose uptake was compared with simultaneous measurements of glucose turnover and utilization rates in 12 pregnant sheep, at a mean of 137 days gestational age (range, 118-146 days). Umbilical glucose uptake was calculated by application of the Fick principle. Fetal glucose turnover rate was measured by a primed-constant infusion of [14C]- and [3H]glucose (glucose turnover rate = tracer infusion rate divided by fetal glucose sp act). The calculation of fetal glucose utilization rate required substraction of the loss of tracer to the placenta from the tracer infusion rate, thus defining the net tracer entry into the fetus for direct comparison with the net umbilical glucose uptake. In fed, normoglycemic sheep, these measurements demonstrated statistical equivalence of umbilical glucose uptake rate (4.77 mg.min-1.kg-1 +/- 0.34 SE) and glucose utilization rate ([14C]glucose, 5.58 mg.min-1.kg-1 +/- 0.54 SE; and [3H]glucose, 7.19 mg.min-1.kg-1 +/- 1.24 SE) when tested by two-way analysis of variance (P greater than 0.1). In three fasted, hypoglycemic sheep, the umbilical glucose uptake rate fell to 1.43 mg.min-1.kg-1 +/- 0.56 SE, which was considerably lower than the simultaneous glucose utilization rate ([14C]glucose, 4.78 mg.min-1.kg-1 +/- 0.48 SE; and [3H]glucose, 6.81 mg.min-1.kg-1 +/- 2.19 SE). Thus, in the normoglycemic, late-gestation fetal lamb, there appears to be little glucogenesis, whereas glucogenesis may become significant during fasting-induced fetal hypoglycemia.

  13. Statistical properties of a utility measure of observer performance compared to area under the ROC curve

    NASA Astrophysics Data System (ADS)

    Abbey, Craig K.; Samuelson, Frank W.; Gallas, Brandon D.; Boone, John M.; Niklason, Loren T.

    2013-03-01

    The receiver operating characteristic (ROC) curve has become a common tool for evaluating diagnostic imaging technologies, and the primary endpoint of such evaluations is the area under the curve (AUC), which integrates sensitivity over the entire false positive range. An alternative figure of merit for ROC studies is expected utility (EU), which focuses on the relevant region of the ROC curve as defined by disease prevalence and the relative utility of the task. However if this measure is to be used, it must also have desirable statistical properties keep the burden of observer performance studies as low as possible. Here, we evaluate effect size and variability for EU and AUC. We use two observer performance studies recently submitted to the FDA to compare the EU and AUC endpoints. The studies were conducted using the multi-reader multi-case methodology in which all readers score all cases in all modalities. ROC curves from the study were used to generate both the AUC and EU values for each reader and modality. The EU measure was computed assuming an iso-utility slope of 1.03. We find mean effect sizes, the reader averaged difference between modalities, to be roughly 2.0 times as big for EU as AUC. The standard deviation across readers is roughly 1.4 times as large, suggesting better statistical properties for the EU endpoint. In a simple power analysis of paired comparison across readers, the utility measure required 36% fewer readers on average to achieve 80% statistical power compared to AUC.

  14. Size Dependence of Fluorescence Blinking Statistics from CdSe Nanorods

    NASA Astrophysics Data System (ADS)

    Wang, Siying; Querner, Claudia; Emmons, Thomas; Drndic, Marija; Crouch, Catherine

    2007-03-01

    We report fluorescence blinking statistics measured from single CdSe nanorods (NRs) of seven different sizes with aspect ratios ranging from 3 to 11. The off-times follow a power-law probability distribution; on-times follow a truncated power law distribution, P(τon)˜τon^-αe^-τon/τc. At fixed excitation intensity, the truncation rate 1/τc increases with increasing aspect ratio. For a particular sample, 1/τc increases gradually with increasing excitation intensity. Examining 1/τc vs. single-particle photon absorption rate for all samples indicates that the shape dependence of the absorption cross-section does not fully account for the observed variation in crossover time τc. Surprisingly, we observe no significant difference between core and core/shell nanorods or core rods with different surface ligands. Our results suggest that NR internal structural defects or degree of quantum confinement may contribute to the shape dependence of the crossover time.

  15. 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.

  16. 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.

  17. 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

  18. 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…

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. 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

  4. Revisiting the spread of sparing in the attentional blink.

    PubMed

    Chen, Xi; Zhou, Xiaolin

    2015-07-01

    The attentional blink (AB) refers to a deficit in reporting the second of two targets (T2) in a rapid serial visual presentation (RSVP) stream when this target is presented less than 500 ms after the onset of the first target (T1). It is under debate whether the AB originates from a limitation of cognitive resources or from an attentional suppression process triggered by a distractor or by target discontinuity. In this study, we placed a distractor (D(inter)) or an extra target (T(inter)) between T1 and T2 while at the same time manipulating the time interval between D(inter) (or T(inter)) and T2 (0, 200, or 500 ms). The level of attentional enhancement induced by the detection of T1 was also manipulated by adding external noise to T1. The results showed that, as compared to the dual-target condition, T2 performance was better in the consecutive-target condition, when T2 was close in time to T(inter) (i.e., the spread of sparing), but was worse with a longer interval between T2 and the preceding item. Adding external noise to T1 improved T2 performance when T2 was close in time to the preceding item, irrespective of whether this item was D(inter) or T(inter). These findings present difficulties for the existing models of the AB, although the overall pattern observed is generally more consistent with the episodic simultaneous-type, serial-token (eSTST) model than with conventional resource accounts or distractor-based attentional selection accounts of the AB.

  5. Abnormalities of the blink reflex in burning mouth syndrome.

    PubMed

    Jääskeläinen, S K; Forssell, H; Tenovuo, O

    1997-12-01

    To our knowledge, this is the first report on pain-related abnormalities of the eye blink reflex (BR) in a clinical pain patient population. The objective of this study was to evaluate the possible neuropathic mechanisms underlying the burning mouth syndrome (BMS), by means of objective electrophysiological examination of the trigemino-facial system. We studied the BR with stimulation of the supraorbital nerve (SON) with particular emphasis on the occurrence of the pain-related ultralate R3 components, and the habituation response of the R2 components. The subjects consisted of eleven BMS patients and 10 healthy control subjects. All patients underwent thorough clinical oral and neurological examinations. The motor function of the trigeminal nerve was assessed with a jaw reflex recording, and a needle-EMG examination of the facial and masticatory muscles was performed in the patients with abnormalities in the BR recordings. The jaw reflexes, the latencies of the BR components, and the needle-EMG examinations were normal in all patients. As a group, the BMS patients had statistically significantly higher stimulus thresholds for the tactile R 1 components of the BR compared with the control subjects. With non-noxious stimulation, the BMS patients showed more frequently pain-related R3 components (11/22 SONs) compared with the controls (3/20 SONs). In addition, four BMS patients had abnormal habituation of the R2 components. In two of these patients, the findings were segmental (i.e., unilateral), coinciding with the side of the subjective BM symptoms. The abnormalities of the BR tests appeared to be related to longer disease duration. Our results suggest a possible pathologic involvement of the nervous system in chronic BMS.

  6. Circadian Change in Blink Reflex Recovery in Restless Legs Syndrome

    PubMed Central

    UZUN, Nurten; GÜNDÜZ, Ayşegül; KARADENİZ, Derya; KIZILTAN, Meral E.

    2016-01-01

    Introduction Restless legs syndrome (RLS) is associated with dysfunction of the dopaminergic systems in the pathways that specifically link the sensory input and motor output. Keeping in mind that clinical symptomatology in RLS and cerebrospinal fluid dopamine concentrations in healthy individuals show changes throughout the day, we hypothesized that excitability of the related pathways increases during the night in RLS, and in the present study, we aimed to analyze our hypothesis by the assessment of blink reflex (BR) recovery. Methods Eleven patients with primary RLS and eight age- and gender-matched healthy subjects were included in the study. All participants underwent detailed interviews and neurological examinations. BR responses were recorded after single and paired supraorbital stimulation during the early afternoon and late at night. For double stimulation, interstimulus intervals (ISI) of 100, 300, and 500 ms were used. Daytime and nighttime investigations were separately compared between the patient and control groups (between-group analyses). In-group analyses were conducted between daytime and nighttime investigations of the patient and control groups. Results BR responses to single stimuli were normal in all participants at all sessions. R2 recovery was the highest in the patient group during nighttime investigations. In-group analysis showed a reduction of R2 recovery during the night in healthy subjects. R2 recoveries at ISIs of 300 and 500 ms at nighttime were higher in RLS patients but did not reach statistical significance. Conclusion The BR circuit is less excitable during the night in healthy individuals, whereas the reduction of excitability is lost in RLS. Despite the limited number of included subjects, we suggest that the normal circadian modulation of the BR circuit is lost in RLS. PMID:28373805

  7. Measuring preferences for cost-utility analysis: how choice of method may influence decision-making.

    PubMed

    McDonough, Christine M; Tosteson, Anna N A

    2007-01-01

    Preferences for health are required when the economic value of healthcare interventions are assessed within the framework of cost-utility analysis. The objective of this paper was to review alternative methods for preference measurement and to evaluate the extent to which the method may affect healthcare decision-making. Two broad approaches to preference measurement that provide societal health state values were considered: (i) direct measurement; and (ii) preference-based health state classification systems. Among studies that compared alternative preference-based systems, the EQ-5D tended to provide larger change scores and more favourable cost-effectiveness ratios than the Health Utilities Index (HUI)-2 and -3, while the SF-6D provided smaller change scores and less favourable ratios than the other systems. However, these patterns may not hold for all applications. Empirical evidence comparing systems and decision-making impact suggests that preferences will have the greatest impact on economic analyses when chronic conditions or long-term sequelae are involved. At present, there is no clearly superior method, and further study of cost-effectiveness ratios from alternative systems is needed to evaluate system performance. Although there is some evidence that incremental cost-effectiveness ratio (ICER) thresholds (e.g. $US50,000 per QALY gained) are used in decision-making, they are not strictly applied. Nonetheless, as ICERs rise, the probability of acceptance of a new therapy is likely to decrease, making the differences in QALYs obtained using alternative methods potentially meaningful. It is imperative that those conducting cost-utility analyses characterise the impact that uncertainty in health state values has on the economic value of the interventions studied. Consistent reporting of such analyses would provide further insight into the policy implications of preference measurement.

  8. Clinical utility of corpus callosum measurements in head sonograms of preterm infants: a cohort study

    PubMed Central

    Perenyi, Agnes; Amodio, John; Katz, Joanne S; Stefanov, Dimitre G

    2013-01-01

    Objective To assess the clinical usefulness of measurement of corpus callosum (CC) size in head ultrasound (HUS) to predict short-term neurodevelopmental (ND) outcomes in preterm infants. We hypothesised that including CC measurements in routine HUS will be an additional tool for early identification of infants at risk of adverse short-term ND outcome, over and above the predictive power of perinatal morbidities. Design Retrospective cohort study. Setting Level III neonatal intensive care unit (NICU) and outpatient NICU follow-up clinic of an academic medical centre in New York City. Participants 929 HUS of 502 infants with gestational age of 23–36 weeks in African-American infants were initially studied. Exclusion criteria included those who died, had gross abnormalities in HUS, infants with race other than African-American, infants with suboptimal quality of HUS, late preterm infants and infants who did not participate in ND follow-up. A total of 173 infants completed the study. Interventions CC size (length and thickness) was measured in a subset of 87 infants who had routine HUS between 23 and 29 weeks (0–6 postnatal weeks). Relevant clinical variables were collected from chart reviews. ND assessments were completed in outpatient follow-up clinics. A statistical model was developed to assess the clinical utility and possible predictive value of CC measurements for adverse short-term ND outcome, while adjusting for perinatal morbidities. Primary and secondary outcome measures CC size and ND status. Results Measurements of CC size did not add substantial predictive power to predict short-term ND outcome beyond the information provided by the presence of morbidities related to prematurity. Conclusions No association was found between morbidities related to prematurity and short-term ND outcome and CC size in preterm infants. CC measurements in HUS early in life did not have an additional value in predicting short-term ND outcome, therefore did not seem to

  9. Augmentative and Alternative Communication Training Using Eye Blink Switch for Locked-in Syndrome Patient

    PubMed Central

    Park, Si-Woon; Yi, Sook-hee; Kim, Hyun-young; Jung, Seung-min

    2012-01-01

    Locked-in Syndrome is a severe pontine stroke causing quadriplegia, lower cranial nerve paralysis, and mutism with preservation of only vertical gaze and upper eyelid movement in a conscious patient. We present a case of a Locked-in Syndrome patient who received communication training with augmentative and alternative communication equipment by using eye blinks. After 3 weeks of training, the patient was able to make an attempt to interact with other people, and associate a new word by Korean alphabet selection. Augmentative and alternative communication equipment which uses eye blinks might be considered to be beneficial in improving the communication skills of locked-in syndrome patients. PMID:22639753

  10. Augmentative and Alternative Communication Training Using Eye Blink Switch for Locked-in Syndrome Patient.

    PubMed

    Park, Si-Woon; Yim, You-Lim; Yi, Sook-Hee; Kim, Hyun-Young; Jung, Seung-Min

    2012-04-01

    Locked-in Syndrome is a severe pontine stroke causing quadriplegia, lower cranial nerve paralysis, and mutism with preservation of only vertical gaze and upper eyelid movement in a conscious patient. We present a case of a Locked-in Syndrome patient who received communication training with augmentative and alternative communication equipment by using eye blinks. After 3 weeks of training, the patient was able to make an attempt to interact with other people, and associate a new word by Korean alphabet selection. Augmentative and alternative communication equipment which uses eye blinks might be considered to be beneficial in improving the communication skills of locked-in syndrome patients.

  11. Observation and control of blinking nitrogen-vacancy centres in discrete nanodiamonds.

    PubMed

    Bradac, C; Gaebel, T; Naidoo, N; Sellars, M J; Twamley, J; Brown, L J; Barnard, A S; Plakhotnik, T; Zvyagin, A V; Rabeau, J R

    2010-05-01

    Nitrogen-vacancy colour centres in diamond can undergo strong, spin-sensitive optical transitions under ambient conditions, which makes them attractive for applications in quantum optics, nanoscale magnetometry and biolabelling. Although nitrogen-vacancy centres have been observed in aggregated detonation nanodiamonds and milled nanodiamonds, they have not been observed in very small isolated nanodiamonds. Here, we report the first direct observation of nitrogen-vacancy centres in discrete 5-nm nanodiamonds at room temperature, including evidence for intermittency in the luminescence (blinking) from the nanodiamonds. We also show that it is possible to control this blinking by modifying the surface of the nanodiamonds.

  12. 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.

  13. 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.

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

    PubMed

    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

  15. 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

  16. Intraindividual and Interindividual Differences in Spontaneous Eye Blinking: Relationships to Working Memory Performance and Frontal EEG Asymmetry.

    PubMed

    Bacher, Leigh F; Retz, Shirley; Lindon, Courtney; Bell, Martha Ann

    2017-01-01

    The rate and timing of spontaneous eye blinking (SB) may be used to explore mechanisms of cognitive activity in infancy. In particular, SB rate is believed to reflect some dimensions of dopamine function; therefore, we hypothesized that SB rate would relate to working memory performance and to frontal electroencephalogram (EEG) asymmetry. Forty, 10-mo-old infants completed an A-not-B task while SB and EEG were measured throughout. We found that SB rate varied across phases of the task, variability in SB rate was positively related to working memory performance, and frontal EEG asymmetry was related to individual differences in the rate of SB. Results provide indirect, but convergent support for the hypothesis that SB rate reflects dopamine function early in human development. As such, these results have implications for understanding the tonic and phasic effects of dopamine on cognitive activity early in human development.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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…

  2. 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…

  3. Seeing the Light: Adapting Luminance Reveals Low-Level Visual Processes in the Attentional Blink

    ERIC Educational Resources Information Center

    Giesbrecht, Barry; Bischof, Walter F.; Kingstone, Alan

    2004-01-01

    It is widely assumed that high-level visual processes subserve the attentional blink (AB). Recent evidence from studies of visual masking during the AB that were designed to directly test the contributions of high-level masking effects, however, have failed to provide empirical support for this position.The implication is that low-level visual…

  4. 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…

  5. 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…

  6. 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…

  7. 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…

  8. Reevaluating Encoding-Capacity Limitations as a Cause of the Attentional Blink

    ERIC Educational Resources Information Center

    Dell'Acqua, Roberto; Jolicoeur, Pierre; Luria, Roy; Pluchino, Patrik

    2009-01-01

    A number of researchers have emphasized the role of distractors intervening between successive targets as the primary determinant of the attentional blink (AB) phenomenon. They argued that the AB is abolished when 3 or more targets are displayed as temporally contiguous items in rapidly presented serial sequences. In 3 experiments, the authors…

  9. 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…

  10. 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…

  11. Heterostructuring Nanocrystal Quantum Dots Toward Intentional Suppression of Blinking and Auger Recombination

    PubMed Central

    Hollingsworth, Jennifer A.

    2013-01-01

    At the level of a single particle, nanocrystal quantum dots (NQDs) are observed to fluoresce intermittently or “blink.” They are also characterized by an efficient non-radiative recombination process known as Auger Recombination (AR). Recently, new approaches to NQD heterostructuring have been developed that directly impact both blinking and AR, resulting in dramatic suppression of these unwanted processes. The three successful hetero-NQD motifs are reviewed here: (1) interfacial alloying, (2) thick or “giant” shells, and (3) specific type-II electronic structures. These approaches, which rely on modifying or tuning internal NQD core/shell structures, are compared with alternative strategies for blinking suppression that rely, instead, on surface modifications or surface-mediated interactions. Finally, in each case, the unique synthetic approaches or challenges addressed that have driven the realization of novel and important functionality are discussed, along with the implications for development of a comprehensive ‘materials design’ strategy for blinking and AR-suppressed heterostructured NQDs. PMID:24062602

  12. Spontaneous eye blink rate predicts learning from negative, but not positive, outcomes.

    PubMed

    Slagter, Heleen A; Georgopoulou, Katerina; Frank, Michael J

    2015-05-01

    A large body of research shows that striatal dopamine critically affects the extent to which we learn from the positive and negative outcomes of our decisions. In this study, we examined the relationship between reinforcement learning and spontaneous eye blink rate (sEBR), a cheap, non-invasive, and easy to obtain marker of striatal dopaminergic activity. Based on previous findings from pharmacological and patient studies, our main prediction was that in healthy individuals, low blink rates (and concomitant lower striatal dopamine levels) would be associated with better learning from negative choices, while high blink rates (and concomitant higher striatal dopamine levels) would be associated with learning from positive choices. Behavioral analyses showed that in healthy individuals, lower blink rates were indeed associated with greater learning from negative outcomes, indicating that lower dopamine levels per se may enhance avoidance learning. Yet, higher EBR was not associated with better learning from positive outcomes. These observations support the notion that sEBR reflects tonic dopamine levels, and suggest that sEBR may specifically relate to dopamine D2 receptor function, given the importance of the dopaminergic D2 pathway in avoidance learning. More generally, these findings highlight the usefulness of sEBR as a non-invasive and cheap method for assessing the relationship between striatal dopaminergic function and behavior.

  13. 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…

  14. 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…

  15. 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.

  16. Suppressed blinking in single quantum dots (QDs) immobilized near silver island films (SIFs)

    NASA Astrophysics Data System (ADS)

    Fu, Yi; Zhang, Jian; Lakowicz, Joseph R.

    2007-10-01

    In this report, we use single-molecule spectroscopic method to study emission behaviors of streptavidin-conjugated quantum dots immobilized on a biotinylated BSA (bovine serum albumin) monolayer near non-continuous rough silver nanostructures. We observed greatly reduced blinking and enhanced emission fluorescence of quantum dots next to silver island films.

  17. The Beneficial Effects of Additional Task Load, Positive Affect, and Instruction on the Attentional Blink

    ERIC Educational Resources Information Center

    Olivers, Christian N. L.; Nieuwenhuis, Sander

    2006-01-01

    The attentional blink reflects the impaired ability to identify the 2nd of 2 targets presented in close succession--a phenomenon that is generally thought to reflect a fundamental cognitive limitation. However, the fundamental nature of this impairment has recently been called into question by the counterintuitive finding that task-irrelevant…

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

    PubMed

    Pincham, Hannah L; Szücs, Dénes

    2014-10-03

    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.

  20. Cortical source of blink-related delta oscillations and their correlation with levels of consciousness.

    PubMed

    Bonfiglio, Luca; Olcese, Umberto; Rossi, Bruno; Frisoli, Antonio; Arrighi, Pieranna; Greco, Giovanni; Carozzo, Simone; Andre, Paolo; Bergamasco, Massimo; Carboncini, Maria Chiara

    2013-09-01

    Recently, blink-related delta oscillations (delta BROs) have been observed in healthy subjects during spontaneous blinking at rest. Delta BROs have been linked with continuous gathering of information from the surrounding environment, which is classically attributed to the precuneus. Furthermore, fMRI studies have shown that precuneal activity is reduced or missing when consciousness is low or absent. We therefore hypothesized that the source of delta BROs in healthy subjects could be located in the precuneus and that delta BROs could be absent or reduced in patients with disorders of consciousness (DOC). To test these hypotheses, electroencephalographic (EEG) activity at rest was recorded in 12 healthy controls and nine patients with DOC (four vegetative states, and five minimally conscious states). Three-second-lasting EEG epochs centred on each blink instance were analyzed in both time- (BROs) and frequency domains (event-related spectral perturbation or ERSP and intertrial coherence or ITC). Cortical sources of the maximum blink-related delta power, corresponding to the positive peak of the delta BROs, were estimated by standardized Low Resolution Electromagnetic Tomography. In control subjects, as expected, the source of delta BROs was located in the precuneus, whereas in DOC patients, delta BROs were not recognizable and no precuneal localization was possible. Furthermore, we observed a direct relationship between spectral indexes and levels of cognitive functioning in all subjects participating in the study. This reinforces the hypothesis that delta BROs reflect neural processes linked with awareness of the self and of the environment.

  1. 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…

  2. Distractor Devaluation Effect in the Attentional Blink: Direct Evidence for Distractor Inhibition

    ERIC Educational Resources Information Center

    Kihara, Ken; Yagi, Yoshihiko; Takeda, Yuji; Kawahara, Jun I.

    2011-01-01

    When two targets (T1 and T2) are embedded in rapid serial visual presentation (RSVP), T2 is often missed (attentional blink, AB) if T2 follows T1 by less than 500 ms. Some have proposed that inhibition of a distractor following T1 contributes to the AB, but no direct evidence supports this proposal. This study examined distractor inhibition by…

  3. 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…

  4. 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.

  5. 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.

  6. Measuring the Capacity Utilization of Public District Hospitals in Tunisia: Using Dual Data Envelopment Analysis Approach

    PubMed Central

    Arfa, Chokri; Leleu, Hervé; Goaïed, Mohamed; van Mosseveld, Cornelis

    2017-01-01

    Background: Public district hospitals (PDHs) in Tunisia are not operating at full plant capacity and underutilize their operating budget. Methods: Individual PDHs capacity utilization (CU) is measured for 2000 and 2010 using dual data envelopment analysis (DEA) approach with shadow prices input and output restrictions. The CU is estimated for 101 of 105 PDH in 2000 and 94 of 105 PDH in 2010. Results: In average, unused capacity is estimated at 18% in 2010 vs. 13% in 2000. Of PDHs 26% underutilize their operating budget in 2010 vs. 21% in 2000. Conclusion: Inadequate supply, health quality and the lack of operating budget should be tackled to reduce unmet user’s needs and the bypassing of the PDHs and, thus to increase their CU. Social health insurance should be turned into a direct purchaser of curative and preventive care for the PDHs. PMID:28005538

  7. Novel design and sensitivity analysis of displacement measurement system utilizing knife edge diffraction for nanopositioning stages.

    PubMed

    Lee, ChaBum; Lee, Sun-Kyu; Tarbutton, Joshua A

    2014-09-01

    This paper presents a novel design and sensitivity analysis of a knife edge-based optical displacement sensor that can be embedded with nanopositioning stages. The measurement system consists of a laser, two knife edge locations, two photodetectors, and axillary optics components in a simple configuration. The knife edge is installed on the stage parallel to its moving direction and two separated laser beams are incident on knife edges. While the stage is in motion, the direct transverse and diffracted light at each knife edge is superposed producing interference at the detector. The interference is measured with two photodetectors in a differential amplification configuration. The performance of the proposed sensor was mathematically modeled, and the effect of the optical and mechanical parameters, wavelength, beam diameter, distances from laser to knife edge to photodetector, and knife edge topography, on sensor outputs was investigated to obtain a novel analytical method to predict linearity and sensitivity. From the model, all parameters except for the beam diameter have a significant influence on measurement range and sensitivity of the proposed sensing system. To validate the model, two types of knife edges with different edge topography were used for the experiment. By utilizing a shorter wavelength, smaller sensor distance and higher edge quality increased measurement sensitivity can be obtained. The model was experimentally validated and the results showed a good agreement with the theoretically estimated results. This sensor is expected to be easily implemented into nanopositioning stage applications at a low cost and mathematical model introduced here can be used for design and performance estimation of the knife edge-based sensor as a tool.

  8. Utilizing Multidimensional Measures of Race in Education Research: The Case of Teacher Perceptions

    PubMed Central

    Irizarry, Yasmiyn

    2015-01-01

    Education scholarship on race using quantitative data analysis consists largely of studies on the black-white dichotomy, and more recently, on the experiences of student within conventional racial/ethnic categories (white, Hispanic/Latina/o, Asian, black). Despite substantial shifts in the racial and ethnic composition of American children, studies continue to overlook the diverse racialized experiences for students of Asian and Latina/o descent, the racialization of immigration status, and the educational experiences of Native American students. This study provides one possible strategy for developing multidimensional measures of race using large-scale datasets and demonstrates the utility of multidimensional measures for examining educational inequality, using teacher perceptions of student behavior as a case in point. With data from the first grade wave of the Early Childhood Longitudinal Study, Kindergarten Cohort of 1998–1999, I examine differences in teacher ratings of Externalizing Problem Behaviors and Approaches to Learning across fourteen racialized subgroups at the intersections of race, ethnicity, and immigrant status. Results show substantial subgroup variation in teacher perceptions of problem and learning behaviors, while also highlighting key points of divergence and convergence within conventional racial/ethnic categories. PMID:26413559

  9. Utilizing Multidimensional Measures of Race in Education Research: The Case of Teacher Perceptions.

    PubMed

    Irizarry, Yasmiyn

    2015-10-01

    Education scholarship on race using quantitative data analysis consists largely of studies on the black-white dichotomy, and more recently, on the experiences of student within conventional racial/ethnic categories (white, Hispanic/Latina/o, Asian, black). Despite substantial shifts in the racial and ethnic composition of American children, studies continue to overlook the diverse racialized experiences for students of Asian and Latina/o descent, the racialization of immigration status, and the educational experiences of Native American students. This study provides one possible strategy for developing multidimensional measures of race using large-scale datasets and demonstrates the utility of multidimensional measures for examining educational inequality, using teacher perceptions of student behavior as a case in point. With data from the first grade wave of the Early Childhood Longitudinal Study, Kindergarten Cohort of 1998-1999, I examine differences in teacher ratings of Externalizing Problem Behaviors and Approaches to Learning across fourteen racialized subgroups at the intersections of race, ethnicity, and immigrant status. Results show substantial subgroup variation in teacher perceptions of problem and learning behaviors, while also highlighting key points of divergence and convergence within conventional racial/ethnic categories.

  10. Pilot measurements of ELF contact currents in some electric utility occupations.

    PubMed

    Bowman, Joseph; Niple, John; Kavet, Rob

    2006-06-01

    Contact currents from touching objects with different voltages can produce electric fields within the body that produce neurological and other biological effects. To begin measuring these exposures among electric utility workers, a new contact current meter (CCM) was tested in a pilot study at Southern California Edison. The CCM was worn for 82 full-shift measurements by 76 volunteers from eight occupations who did not work directly with energized electrical equipment. The volunteers were exposed to an average of 285.8 contact current events above the meter's 1-microA threshold, but most of these were electrostatic spark discharges. Fourteen employees experienced an average of 135.1 contact currents events whose primary frequency was 60 Hz. Using a circuit model of the human body, the average contact currents going from arm to arm was 9.8 microA (maximum = 178.0 microA), and the average going down the torso was 25.5 microA (maximum = 662.0). The maximum exposures were experienced by a technical support employee working in a substation. All measurements in this pilot study were below the 3000 microA maximum permissible exposure for contact currents set by the Institute of Electrical and Electronic Engineers (IEEE). Combining these current measurements with the results of high-resolution dosimetry, the internal electric fields averaged an estimated 1.7 mV/m in the heart (maximum = 21.0 mV/m), and 1.9 mV/m in the hematopoietic bone marrow in the torso (maximum = 56.5 mV/m). These internal electric fields from contact currents are below the basic restriction of 943 mV/m in the IEEE exposure standards but are above 1 mV/m, a level where biological effects have been often reported in laboratory studies. Safety concerns limited the measurements to de-energized equipment, so we did not obtain data on work in energized high-voltage environments, the most likely sources of high contact currents. This pilot study identified other improvements to the contact current meter that

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. Low dimensional temporal organization of spontaneous eye blinks in adults with developmental disabilities and stereotyped movement disorder.

    PubMed

    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 group and both of these groups had a lower blink rate than a contrast group of healthy adults. In the IDD group the n to n+1 sequential organization over time of the eye-blink durations showed a stronger compensatory organization than the contrast group suggesting decreased complexity/dimensionality of eye-blink behavior. Very low blink rate (and thus insufficient time series data) precluded analysis of time-dependent sequential properties in the IDD+SMD group. These findings support the hypothesis that both IDD and SMD are associated with a reduction in the dimension and adaptability of movement behavior and that this may serve as a risk factor for the expression of abnormal movements.

  18. The Predictive Utility of a Brief Kindergarten Screening Measure of Child Behavior Problems

    PubMed Central

    Racz, Sarah Jensen; King, Kevin M.; Wu, Johnny; Witkiewitz, Katie; McMahon, Robert J.

    2013-01-01

    Objective Kindergarten teacher ratings, such as those from the Teacher Observation of Classroom Adaptation–Revised (TOCA-R), are a promising cost- and time-effective screening method to identify children at risk for later problems. Previous research with the TOCA-R has been mainly limited to outcomes in a single domain measured during elementary school. The goal of the current study was to examine the ability of TOCA-R sum scores to predict outcomes in multiple domains across distinct developmental periods (i.e., late childhood, middle adolescence, late adolescence). Method We used data from the Fast Track Project, a large multisite study with children at risk for conduct problems (n = 752; M age at start of study = 6.55 years; 57.7% male; 49.9% Caucasian, 46.3% African American). Kindergarten TOCA-R sum scores were used as the predictor in regression analyses; outcomes included school difficulties, externalizing diagnoses and symptom counts, and substance use. Results TOCA-R sum scores predicted school outcomes at all time points, diagnosis of ADHD in 9th grade, several externalizing disorder symptom counts, and cigarette use in 12th grade. Conclusions The findings demonstrate the predictive utility of the TOCA-R when examining outcomes within the school setting. Therefore, these results suggest the 10-item TOCA-R may provide a quick and accurate screening of children at risk for later problems. Implications for prevention and intervention programs are discussed. PMID:23544679

  19. Modeling strategy to identify patients with primary immunodeficiency utilizing risk management and outcome measurement.

    PubMed

    Modell, Vicki; Quinn, Jessica; Ginsberg, Grant; Gladue, Ron; Orange, Jordan; Modell, Fred

    2017-02-21

    This study seeks to generate analytic insights into risk management and probability of an identifiable primary immunodeficiency defect. The Jeffrey Modell Centers Network database, Jeffrey Modell Foundation's 10 Warning Signs, the 4 Stages of Testing Algorithm, physician-reported clinical outcomes, programs of physician education and public awareness, the SPIRIT® Analyzer, and newborn screening, taken together, generates P values of less than 0.05%. This indicates that the data results do not occur by chance, and that there is a better than 95% probability that the data are valid. The objectives are to improve patients' quality of life, while generating significant reduction of costs. The advances of the world's experts aligned with these JMF programs can generate analytic insights as to risk management and probability of an identifiable primary immunodeficiency defect. This strategy reduces the uncertainties related to primary immunodeficiency risks, as we can screen, test, identify, and treat undiagnosed patients. We can also address regional differences and prevalence, age, gender, treatment modalities, and sites of care, as well as economic benefits. These tools support high net benefits, substantial financial savings, and significant reduction of costs. All stakeholders, including patients, clinicians, pharmaceutical companies, third party payers, and government healthcare agencies, must address the earliest possible precise diagnosis, appropriate intervention and treatment, as well as stringent control of healthcare costs through risk assessment and outcome measurement. An affected patient is entitled to nothing less, and stakeholders are responsible to utilize tools currently available. Implementation offers a significant challenge to the entire primary immunodeficiency community.

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

    PubMed

    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.

  1. 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.

  2. The influence of stimulus sex and emotional expression on the attentional blink.

    PubMed

    Stebbins, Hilary E; Vanous, Jesse B

    2015-08-01

    Past studies have demonstrated that angry faces used as the first target (T1) in an attentional blink paradigm interfere with processing of a second, neutral target (T2). However, despite research that suggests that the sex and emotional expression of a face are confounded, no study has investigated whether the sex of a stimulus might interact with emotional expression to influence the attentional blink. In the current study, both the sex and emotional expression of a T1 stimulus were manipulated to assess participants' ability to report the presences of a subsequent neutral target. Although the findings revealed limited evidence to support an interaction between sex and emotion, both the sex and emotional expression of the T1 stimulus were found to independently affect reporting of T2. These findings suggest that both emotional expression and stimulus sex are important in the temporal allocation of attentional resources to faces.

  3. 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

  4. Tritium-helium dating in the sargasso sea: a measurement of oxygen utilization rates.

    PubMed

    Jenkins, W J

    1977-04-15

    The newly developed technique of "tritium-helium dating" has been used to investigate in situ rates of oceanic oxygen utilization. As an example, an apparent oxygen utilization rate of 0.20 +/- 0.02 milliliter per liter of water per year has been obtained for the Subtropical Mode water (18 degrees C water) in the Sargasso Sea.

  5. 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

  6. 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.

  7. 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,…

  8. Eye-blink conditioning is associated with changes in synaptic ultrastructure in the rabbit interpositus nuclei

    PubMed Central

    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 mechanism that may underlie learning and memory, but localizing these changes has been difficult. Thus, the current experiment took advantage of the large amount of research conducted on the neural circuitry that supports eye-blink conditioning by examining synaptic changes in the rabbit interpositus nucleus. Synaptic quantifications included total number of synapses per neuron, numbers of excitatory versus inhibitory synapses, synaptic curvature, synaptic perforations, and the maximum length of the synapses. No overall changes in synaptic number, shape, or perforations were observed. There was, however, a significant increase in the length of excitatory synapses in the conditioned animals. This increase in synaptic length was particularly evident in the concave-shaped synapses. These results, together with previous findings, begin to describe a sequence of synaptic change in the interpositus nuclei following eye-blink conditioning that would appear to begin with structural change and end with an increase in synaptic number. PMID:17551096

  9. 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

  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. 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.

    2013-01-01

    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 2X2 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:23187147

  12. Effects of Visual Cortex Activation on the Nociceptive Blink Reflex in Healthy Subjects

    PubMed Central

    Sava, Simona L.; de Pasqua, Victor; Magis, Delphine; 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

  13. 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...

  14. The total cost and measured performance of utility-sponsored energy efficiency programs

    SciTech Connect

    Eto, J.; Vine, E.; Shown, L.

    1996-06-01

    By examining the actual performance of conservation or demand-side management (DSM) programs for ten utilities, Joskow and Marron (1992) have made an important contribution to policy discussions about the wisdom of relying on utilities to improve customer energy efficiency. We use Joskow and Marron`s method to analyze twenty utility commercial lighting programs and, like Joskow and Marron, find wide variations in industry reporting practices and savings evaluation methods. We extend the method by systematically accounting for several of the most important sources of variation and comment on how they influence total program costs. Our accounting also allows us to relate remaining program cost variations to the program sizes and the electric supply costs avoided by the programs. We draw qualified, yet affirmative, conclusions regarding the cost effectiveness of the programs.

  15. 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.

  16. 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

  17. Biexciton quantum yield heterogeneities in single CdSe(CdS) core(shell) nanocrystals and its correlation to exciton blinking

    PubMed Central

    Zhao, Jing; Chen, Ou; Strasfeld, David B.

    2012-01-01

    We explore biexciton (BX) non-radiative recombination processes in single semiconductor nanocrystals (NCs) using confocal fluorescence microscopy and second-order photon intensity correlation. More specifically, we measure the photoluminescence blinking and BX quantum yields (QYs), and study the correlation between these two measurements for single core(shell) CdSe(CdS) nanocrystals (NCs). We find that NCs with a high “on” time fraction are significantly more likely to have a high BX QY than NCs with a low “on” fraction, even though the BX QYs of NCs with a high “on” fraction vary dramatically. The BX QYs of single NCs are also weakly dependent upon excitation wavelength. The weak correlation between exciton “on” fractions and BX QYs suggests that multiple recombination processes are involved in the BX recombination. To explain our results, we propose a model that combines both trapping and an Auger mechanism for BX recombination. PMID:22871126

  18. Eye blink correction: a test on the preservation of common ERP components using a regression based technique.

    PubMed

    Woltering, Steven; Bazargani, Narges; Liu, Zhong-Xu

    2013-01-01

    Eye blinks are a pervasive problem in electroencephalography research as they contaminate the brain signal. This paper tests the merits of a software tool employing the regression-based Gratton method that claims to remove the detrimental effects of the eye blink and leaves the activity of the brain. The efficacy of the correction tool was tested on five common stimulus-locked Event Related Potential (ERP) components used in a standard Go/Nogo task. Results suggested that the 'corrected' data could be predicted from data containing no eye blinks, suggesting the tool does not distort the data to great extent. This effect was found significant for all components, except for the P3. The conclusion is that this tool distorts the data at acceptable levels, yet caution should be taken when interpreting later components, like the P3.

  19. Eye blink correction: a test on the preservation of common ERP components using a regression based technique

    PubMed Central

    Bazargani, Narges; Liu, Zhong-Xu

    2013-01-01

    Eye blinks are a pervasive problem in electroencephalography research as they contaminate the brain signal. This paper tests the merits of a software tool employing the regression-based Gratton method that claims to remove the detrimental effects of the eye blink and leaves the activity of the brain. The efficacy of the correction tool was tested on five common stimulus-locked Event Related Potential (ERP) components used in a standard Go/Nogo task. Results suggested that the ‘corrected’ data could be predicted from data containing no eye blinks, suggesting the tool does not distort the data to great extent. This effect was found significant for all components, except for the P3. The conclusion is that this tool distorts the data at acceptable levels, yet caution should be taken when interpreting later components, like the P3. PMID:23682349

  20. Video-based data acquisition system for use in eye blink classical conditioning procedures in sheep.

    PubMed

    Nation, Kelsey; Birge, Adam; Lunde, Emily; Cudd, Timothy; Goodlett, Charles; Washburn, Shannon

    2016-11-04

    Pavlovian eye blink conditioning (EBC) has been extensively studied in humans and laboratory animals, providing one of the best-understood models of learning in neuroscience. EBC has been especially useful in translational studies of cerebellar and hippocampal function. We recently reported a novel extension of EBC procedures for use in sheep, and now describe new advances in a digital video-based system. The system delivers paired presentations of conditioned stimuli (CSs; a tone) and unconditioned stimuli (USs; an air puff to the eye), or CS-alone "unpaired" trials. This system tracks the linear distance between the eyelids to identify blinks occurring as either unconditioned (URs) or conditioned (CRs) responses, to a resolution of 5 ms. A separate software application (Eye Blink Reviewer) is used to review and autoscore the trial CRs and URs, on the basis of a set of predetermined rules, permitting an operator to confirm (or rescore, if needed) the autoscore results, thereby providing quality control for accuracy of scoring. Learning curves may then be quantified in terms of the frequencies of CRs over sessions, both on trials with paired CS-US presentations and on CS-alone trials. The latency to CR onset, latency to CR peak, and occurrence of URs are also obtained. As we demonstrated in two example cases, this video-based system provides efficient automated means to conduct EBC in sheep and can facilitate fully powered studies with multigroup designs that involve paired and unpaired training. This can help extend new studies in sheep, a species well suited for translational studies of neurodevelopmental disorders resulting from gestational exposure to drugs, toxins, or intrauterine distress.

  1. Self-Induced Attentional Blink: A Cause of Errors in Multiple-Target Visual Search

    DTIC Science & Technology

    2012-08-15

    found that an attentional blink can underlie SOS errors. Summary Visual search, looking for a target amongst distractors , is key to everyday...Participants completed a visual search task for target “T” shapes amongst distractor “L” shapes on a white background. Targets were either of high salience (57...65% black) or low salience (22–45%) while the majority of distractors were low salience (Figure 1A). There were 25 items (1.3° × 1.3°) in each

  2. Fluorescence enhancement, blinking suppression, and gray states of individual semiconductor nanocrystals close to gold nanoparticles.

    PubMed

    Ma, Xuedan; Tan, Hua; Kipp, Tobias; Mews, Alf

    2010-10-13

    The optical properties of nanocrystals are drastically changed by the interaction with adjacent metal nanoparticles. By time-resolved photoluminescence spectroscopy, we investigate CdSe multishell nanocrystals coupled to self-assembled films of Au nanoparticles. The distance between emitter and metal is adjusted by coating the nanocrystals with silica shells. These NCs showed increased fluorescence intensity, a decreased fluorescence lifetime, strong blinking suppression, and fluorescence from gray states. These observations can be explained by the metal particle induced change of excitation and recombination rates.

  3. The anti-fatigue driving system design based on the eye blink detect

    NASA Astrophysics Data System (ADS)

    Yang, Shuyu; Song, Xin; Zhang, Li; Yu, Jie

    2017-01-01

    Traffic accident is one of the severe social problems in the world, but the appraisal and prevention of the fatigue driving is still a difficult problem that can not be solved. This paper is to study the results of fatigue driving and the existing antifatigue driving products, collecting brain wave with the TGAM (ThinkGear AM) Brain Wave Sensor Chip. We analyze the collected waveform based on eye blink detect algorithm to work out current situation of the driver. According to the analysis results, Sound Module and controllable speed car will make a series of feedback. Finally, an effective Anti- Fatigue Driving System is designed based on all above.

  4. Giant photoluminescence blinking of perovskite nanocrystals reveals single-trap control of luminescence.

    PubMed

    Tian, Yuxi; Merdasa, Aboma; Peter, Maximilian; Abdellah, Mohamed; Zheng, Kaibo; Ponseca, Carlito S; Pullerits, Tõnu; Yartsev, Arkady; Sundström, Villy; Scheblykin, Ivan G

    2015-03-11

    Fluorescence super-resolution microscopy showed correlated fluctuations of photoluminescence intensity and spatial localization of individual perovskite (CH3NH3PbI3) nanocrystals of size ∼200 × 30 × 30 nm(3). The photoluminescence blinking amplitude caused by a single quencher was a hundred thousand times larger than that of a typical dye molecule at the same excitation power density. The quencher is proposed to be a chemical or structural defect that traps free charges leading to nonradiative recombination. These trapping sites can be activated and deactivated by light.

  5. The R3 component of the electrically elicited blink reflex is present in patients with congenital insensitivity to pain.

    PubMed

    Téllez, Maria J; Axelrod, Felicia; Kaufmann, Horacio

    2009-01-01

    To clarify whether the R3 component of the electrically elicited blink reflex is a nociceptive response we studied two patients with congenital insensitivity to pain due to the impaired development of Adelta and C nerve fibers (hereditary sensory and autonomic neuropathy types III and IV). We postulated that if the R3 component is a nociceptive reflex, it should be absent in these patients. The R3 responses were elicited in both sides in both the patients at all intensities, strongly suggesting that the R3 component of the blink reflex is not a nociceptive response.

  6. Oral administration of royal jelly restores tear secretion capacity in rat blink-suppressed dry eye model by modulating lacrimal gland function.

    PubMed

    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.

  7. 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

  8. 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

  9. 43 CFR 3275.15 - How accurately must I measure my production and utilization?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... royalty: (1) If the meter measures electricity, it must have an accuracy of ±0.25% or better of reading... meter measures water flowing at more than 500,000 lbs/hr on a monthly basis, it must have an accuracy reading of ±2 percent or better; (5) If the meter measures water flowing at 500,000 lbs/hr or less on...

  10. 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.

  11. Measurement of high-energy neutron flux above ground utilizing a spallation based multiplicity technique

    DOE PAGES

    Roecker, Caleb; Bernstein, Adam; Marleau, Peter; ...

    2016-11-14

    Cosmogenic high-energy neutrons are a ubiquitous, difficult to shield, poorly measured background. Above ground the high-energy neutron energy-dependent flux has been measured, with significantly varying results. Below ground, high-energy neutron fluxes are largely unmeasured. Here we present a reconstruction algorithm to unfold the incident neutron energy-dependent flux measured using the Multiplicity and Recoil Spectrometer (MARS), simulated test cases to verify the algorithm, and provide a new measurement of the above ground high-energy neutron energy-dependent flux with a detailed systematic uncertainty analysis. Uncertainty estimates are provided based upon the measurement statistics, the incident angular distribution, the surrounding environment of the Montemore » Carlo model, and the MARS triggering efficiency. Quantified systematic uncertainty is dominated by the assumed incident neutron angular distribution and surrounding environment of the Monte Carlo model. The energy-dependent neutron flux between 90 MeV and 400 MeV is reported. Between 90 MeV and 250 MeV the MARS results are comparable to previous Bonner sphere measurements. Over the total energy regime measured, the MARS result are located within the span of previous measurements. Lastly, these results demonstrate the feasibility of future below ground measurements with MARS.« less

  12. Measurement of high-energy neutron flux above ground utilizing a spallation based multiplicity technique

    SciTech Connect

    Roecker, Caleb; Bernstein, Adam; Marleau, Peter; Vetter, Kai

    2016-11-14

    Cosmogenic high-energy neutrons are a ubiquitous, difficult to shield, poorly measured background. Above ground the high-energy neutron energy-dependent flux has been measured, with significantly varying results. Below ground, high-energy neutron fluxes are largely unmeasured. Here we present a reconstruction algorithm to unfold the incident neutron energy-dependent flux measured using the Multiplicity and Recoil Spectrometer (MARS), simulated test cases to verify the algorithm, and provide a new measurement of the above ground high-energy neutron energy-dependent flux with a detailed systematic uncertainty analysis. Uncertainty estimates are provided based upon the measurement statistics, the incident angular distribution, the surrounding environment of the Monte Carlo model, and the MARS triggering efficiency. Quantified systematic uncertainty is dominated by the assumed incident neutron angular distribution and surrounding environment of the Monte Carlo model. The energy-dependent neutron flux between 90 MeV and 400 MeV is reported. Between 90 MeV and 250 MeV the MARS results are comparable to previous Bonner sphere measurements. Over the total energy regime measured, the MARS result are located within the span of previous measurements. Lastly, these results demonstrate the feasibility of future below ground measurements with MARS.

  13. 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…

  14. 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…

  15. Tripartite dimensions of emotion in a child clinical sample: measurement strategies and implications for clinical utility.

    PubMed

    Chorpita, Bruce F; Daleiden, Eric L

    2002-10-01

    Several measurement strategies to assess the tripartite model of emotion in child and adolescent samples have been developed. However, no studies have comparatively examined the most suitable strategies in clinical samples of children and adolescents. This study involved the evaluation of 2 distinct measures of tripartite constructs relative to anxiety and depression criterion variables in a clinical sample of 226 children in Grades 1 through 12. Results indicated that the measures performed similarly overall, but some differences were pronounced enough to suggest that the measures indexed slightly different aspects of the same constructs. These differences appear consistent with the scale design of each instrument. Implications for measurement of these constructs in future research are highlighted.

  16. Assessment of wood utility pole climbability using psychophysical and mechanical measurements.

    PubMed

    Beauchamps, Y; Thomas, M; Arteau, J; Marchand, D

    1999-01-01

    The issue of climbability has been raised on several occasions for more than a decade in North America. Presently, climbability is estimated from the pole hardness measured by the Pilodyn measurements (6 J). However, the use of Pilodyn measurements to discriminate the pole hardness value is criticized by climbers, who claim that the Pilodyn hardness measurement is affected by species-treatment combinations and that it does not reflect gaff penetration or climbability. Furthermore, climbability evaluations have been conducted in which test poles were climbed by linemen, and corresponding subjective ratings were recorded. However, the ability of psychophysical measurements to accurately discriminate close hardness pole values and to differentiate species-treatment combinations at specific hardness levels have not yet been fully documented. The aim of this study is to evaluate the psychophysical perception of linemen and the mechanical measurements of gaff penetration and gaff impact during the climbing of different wood species and treatment combinations in order to compare these results with Pilodyn measurements within a precise range of pole hardnesses, to study the relationships between these variables, and, finally, to propose various design guidelines for the development of a better tool for the evaluation of climbability.

  17. Improving ion mobility measurement sensitivity by utilizing helium in an ion funnel trap.

    PubMed

    Ibrahim, Yehia M; Garimella, Sandilya V B; Tolmachev, Aleksey V; Baker, Erin S; Smith, Richard D

    2014-06-03

    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 ion mobility spectrometry (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.

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

    PubMed Central

    2015-01-01

    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 ion mobility spectrometry (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. PMID:24786390

  19. Application of multi-attribute utility theory to measure social preferences for health states.

    PubMed

    Torrance, G W; Boyle, M H; Horwood, S P

    1982-01-01

    A four-attribute health state classification system designed to uniquely categorize the health status of all individuals two years of age and over is presented. A social preference function defined over the health state classification system is required. Standard multi-attribute utility theory is investigated for the task, problems are identified and modifications to the standard method are proposed. The modified methods is field tested in a survey research project involving 112 home interviews. Results are presented and discussed in detail for both the social preference function and the performance of the modified method. A recommended social preference function is presented, complete with a range of uncertainty. The modified method is found to be applicable to the task--no insurmountable difficulties are encountered. Recommendations are presented, based on our experience, for other investigators who may be interested in reapplying the method in other studies.

  20. 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.

  1. 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

  2. Colloidal Spherical Quantum Wells with Near-Unity Photoluminescence Quantum Yield and Suppressed Blinking.

    PubMed

    Jeong, Byeong Guk; Park, Young-Shin; Chang, Jun Hyuk; Cho, Ikjun; Kim, Jai Kyeong; Kim, Heesuk; Char, Kookheon; Cho, Jinhan; Klimov, Victor I; Park, Philip; Lee, Doh C; Bae, Wan Ki

    2016-10-02

    Thick inorganic shell endows colloidal nanocrystals (NCs) with enhanced photochemical stability and suppression of photoluminescence intermittency (also known as blinking). However, the progress of using thick-shell heterostructure NCs in applications has been limited, due to low photoluminescence quantum yield (PL QY  60%) at room temperature. Here, we demonstrate thick-shell NCs with CdS/CdSe/CdS seed/spherical quantum well/shell (SQW) geometry that exhibit near-unity PL QY at room temperature and suppression of blinking. In SQW NCs, the lattice mismatch is diminished between the emissive CdSe layer and the surrounding CdS layers as a result of coherent strain, which suppresses the formation of misfit defects and consequently permits ~ 100% PL QY for SQW NCs with thick CdS shell (≥ 5 nm). High PL QY of thick-shell SQW NCs are preserved even in concentrated dispersion and in film under thermal stress, which makes them promising candidates for applications in solid-state lightings and luminescent solar concentrators.

  3. Reaching back: the relative strength of the retroactive emotional attentional blink

    PubMed Central

    Ní Choisdealbha, Áine; Piech, Richard M.; Fuller, John K.; Zald, David H.

    2017-01-01

    Visual stimuli with emotional content appearing in close temporal proximity either before or after a target stimulus can hinder conscious perceptual processing of the target via an emotional attentional blink (EAB). This occurs for targets that appear after the emotional stimulus (forward EAB) and for those appearing before the emotional stimulus (retroactive EAB). Additionally, the traditional attentional blink (AB) occurs because detection of any target hinders detection of a subsequent target. The present study investigated the relations between these different attentional processes. Rapid sequences of landscape images were presented to thirty-one male participants with occasional landscape targets (rotated images). For the forward EAB, emotional or neutral distractor images of people were presented before the target; for the retroactive EAB, such images were also targets and presented after the landscape target. In the latter case, this design allowed investigation of the AB as well. Erotic and gory images caused more EABs than neutral images, but there were no differential effects on the AB. This pattern is striking because while using different target categories (rotated landscapes, people) appears to have eliminated the AB, the retroactive EAB still occurred, offering additional evidence for the power of emotional stimuli over conscious attention. PMID:28255172

  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.

  5. Accurate and unbiased estimation of power-law exponents from single-emitter blinking data.

    PubMed

    Hoogenboom, Jacob P; den Otter, Wouter K; Offerhaus, Herman L

    2006-11-28

    Single emitter blinking with a power-law distribution for the on and off times has been observed on a variety of systems including semiconductor nanocrystals, conjugated polymers, fluorescent proteins, and organic fluorophores. The origin of this behavior is still under debate. Reliable estimation of power exponents from experimental data is crucial in validating the various models under consideration. We derive a maximum likelihood estimator for power-law distributed data and analyze its accuracy as a function of data set size and power exponent both analytically and numerically. Results are compared to least-squares fitting of the double logarithmically transformed probability density. We demonstrate that least-squares fitting introduces a severe bias in the estimation result and that the maximum likelihood procedure is superior in retrieving the correct exponent and reducing the statistical error. For a data set as small as 50 data points, the error margins of the maximum likelihood estimator are already below 7%, giving the possibility to quantify blinking behavior when data set size is limited, e.g., due to photobleaching.

  6. The effects of threat and nonthreat word lead stimuli on blink modification.

    PubMed

    Aitken, C J; Siddle, D A; Lipp, O V

    1999-11-01

    Two experiments examined the effects of visually presented threat and nonthreat word lead stimuli on blink modification among unselected young adults (Experiment 1, N = 35) and participants selected for low and high trait anxiety (Experiment 2, N = 60). The blink reflex was elicited by a white noise probe of 105 dB. Lead stimulus intervals of 60, 120, 240, and 2000 ms were used in both experiments. Prepulse inhibition was observed at the 240-ms interval and prepulse facilitation was observed at the 60-ms interval in both experiments. Also, greater facilitation was found in both experiments during threat words at the 60-ms interval and greater inhibition during threat words at the 240-ms interval. Experiment 2 provided some evidence that the greater facilitation during threat words than during nonthreat words at the 60-ms probe interval may be found in high trait anxious participants, but not in low trait anxious participants. The results are discussed in relation to contemporary information processing theories of anxiety.

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

    PubMed Central

    Wolkoff, P; Nojgaard, J; 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

  8. 43 CFR 3272.12 - What environmental protection measures must I include in my utilization plan?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... minimum, your proposed measures to: (1) Prevent or control fires; (2) Prevent soil erosion; (3) Protect... resources; (6) Minimize air and noise pollution; and (7) Minimize hazards to public health and safety...

  9. 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.

  10. Surface Roughness Measurements Utilizing Long-Range Surface-Plasma Waves

    DTIC Science & Technology

    1984-11-01

    Surface Roughness Measurements ... ______ 12. PERSONAL AuJTMORJSI Dror Sarid 13&~ TvrP OP REPORT 13b TIME COVERED 114 OATE OF REPORT Y,. Mo.. Day, 15...Investigator: Dror Sarid During the contract period we (1) performed an experiment to measure the dispersion of the long-range surf ace-plasmon... Dror Sarid , Robert. T. Deck. Alan. Z. Craig. Robert. K. Itickersell, Ralph S. Jameson. and Joseph J. Fasano. -Optical Field Enhancement by Long-Range

  11. Ultrasonic transmission measurements in the characterization of viscoelasticity utilizing polymeric waveguides

    NASA Astrophysics Data System (ADS)

    Bause, Fabian; Rautenberg, Jens; Feldmann, Nadine; Webersen, Manuel; Claes, Leander; Gravenkamp, Hauke; Henning, Bernd

    2016-10-01

    For the numerical simulation of acoustic wave propagation in (measurement) systems and their design, the use of reliable material models and material parameters is a central issue. Especially in polymers, acoustic material parameters cannot be evaluated based on quasistatically measured parameters, as are specified in data sheets by the manufacturers. In this work, a measurement method is presented which quantifies, for a given polymeric material sample, a complex-valued and frequency-dependent material model. A novel three-dimensional approach for modeling viscoelasticity is introduced. The material samples are designed as hollow cylindrical waveguides to account for the high damping characteristics of the polymers under test and to provide an axisymmetric structure for good performance of waveguide modeling and reproducible coupling conditions arising from the smaller coupling area in the experiment. Ultrasonic transmission measurements are carried out between the parallel faces of the sample. To account for the frequency dependency of the material properties, five different transducer pairs with ascending central frequency from 750~\\text{kHz} to 2.5~\\text{MHz} are used. After passing through the sample, each of the five received signals contains information on the material parameters which are determined in an inverse procedure. The solution of the inverse problem is carried out by iterative comparison of an innovative forward SBFEM-based simulations of the entire measurement system with the experimentally determined measurement data. For a given solution of the inverse problem, an estimate of the measurement uncertainty of each identified material parameter is calculated. Moreover, a second measurement setup, based on laser-acoustic excitation of Lamb modes in plate-shaped specimens, is presented. Using this setup, the identified material properties can be verified on samples with a varied geometry, but made from the same material.

  12. 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.

  13. Exposure to electromagnetic fields from smart utility meters in GB; part I) laboratory measurements.

    PubMed

    Peyman, Azadeh; Addison, Darren; Mee, Terry; Goiceanu, Cristian; Maslanyj, Myron; Mann, Simon

    2017-05-01

    Laboratory measurements of electric fields have been carried out around examples of smart meter devices used in Great Britain. The aim was to quantify exposure of people to radiofrequency signals emitted from smart meter devices operating at 2.4 GHz, and then to compare this with international (ICNIRP) health-related guidelines and with exposures from other telecommunication sources such as mobile phones and Wi-Fi devices. The angular distribution of the electric fields from a sample of 39 smart meter devices was measured in a controlled laboratory environment. The angular direction where the power density was greatest was identified and the equivalent isotropically radiated power was determined in the same direction. Finally, measurements were carried out as a function of distance at the angles where maximum field strengths were recorded around each device. The maximum equivalent power density measured during transmission around smart meter devices at 0.5 m and beyond was 15 mWm(-2) , with an estimation of maximum duty factor of only 1%. One outlier device had a maximum power density of 91 mWm(-2) . All power density measurements reported in this study were well below the 10 W m(-2) ICNIRP reference level for the general public. Bioelectromagnetics. 2017;38:280-294. © 2017 Crown copyright. BIOELECTROMAGNETICS © 2017 Wiley Periodicals, Inc.

  14. 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.

  15. Utility of an open field Shack-Hartmann aberrometer for measurement of refractive error in infants and young children

    PubMed Central

    Harvey, Erin M.; Miller, Joseph M.; Schwiegerling, Jim

    2013-01-01

    PURPOSE To assess the utility of an open-field Shack-Hartmann aberrometer for measurement of refractive error without cycloplegia in infants and young children. METHOD Data included 2698 subject encounters with Native American infants and children aged 6 months to <8 years. We attempted right eye measurements without cycloplegia using the pediatric wavefront evaluator (PeWE) on all participants while they viewed near (50 cm) and distant (2 m) fixation targets. Cycloplegic autorefraction (Rmax [Nikon Retinomax K-plus2]) measurements were obtained for children aged ≥3 years. RESULTS The success rates of noncycloplegic PeWE measurement for near (70%) and distant targets (56%) significantly improved with age. Significant differences in mean spherical equivalent (M) across near versus distant fixation target conditions were consistent with the difference in accommodative demand. Differences in astigmatism measurements for near versus distant target conditions were not clinically significant. Noncycloplegic PeWE and cycloplegic Rmax measurements of M and astigmatism were strongly correlated. Mean noncycloplegic PeWE M was significantly more myopic or less hyperopic and astigmatism measurements tended to be greater in magnitude compared with cycloplegic Rmax. CONCLUSIONS The PeWE tended to overestimate myopia and underestimate hyperopia when cycloplegia was not used. The PeWE is useful for measuring accommodation and astigmatism. PMID:24160970

  16. 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

  17. 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...

  18. 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…

  19. Further Evidence of the Utility and Validity of a Measure of Outcome for Children and Adolescents

    ERIC Educational Resources Information Center

    Turchik, Jessica A.; Karpenko, Veronika; Ogles, Benjamin M.

    2007-01-01

    The "Ohio Youth Problems, Functioning, and Satisfaction Scales" (Ohio Scales) are a recently developed set of measures designed to be a brief, practical assessment of changes in behavior over time in children and adolescents. The authors explored the convergent validity of the Ohio Scales by examining the relationship between the scales and…

  20. Measuring emotional processes in animals: the utility of a cognitive approach.

    PubMed

    Paul, Elizabeth S; Harding, Emma J; Mendl, Michael

    2005-05-01

    Contemporary researchers regard emotional states as multifaceted, comprising physiological, behavioural, cognitive and subjective components. Subjective, conscious experience of emotion can be inferred from linguistic report in humans, but is inaccessible to direct measurement in non-human animals. However, measurement of other components of emotion is possible, and a variety of methods exist for monitoring emotional processes in animals by measuring behavioural and physiological changes. These are important tools, but they have limitations including difficulties of interpretation and the likelihood that many may be sensitive indicators of emotional arousal but not valence-pleasantness/unpleasantness. Cognitive components of emotion are a largely unexplored source of information about animal emotions, despite the fact that cognition-emotion links have been extensively researched in human cognitive science indicating that cognitive processes-appraisals of stimuli, events and situations-play an important role in the generation of emotional states, and that emotional states influence cognitive functioning by inducing attentional, memory and judgement biases. Building on this research, it is possible to design non-linguistic cognitive measures of animal emotion that may be especially informative in offering new methods for assessing emotional valence (positive as well as negative), discriminating same-valenced emotion of different types, identifying phenotypes with a cognitive predisposition to develop affective disorders, and perhaps shedding light on the issue of conscious emotional experiences in animals.

  1. 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…

  2. 43 CFR 3272.12 - What environmental protection measures must I include in my utilization plan?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... minimum, your proposed measures to: (1) Prevent or control fires; (2) Prevent soil erosion; (3) Protect surface or ground water; (4) Protect fish and wildlife; (5) Protect cultural, visual, and other natural... operations to ensure that they comply with the requirements of § 3200.4, and applicable noise, air, and...

  3. The Frequency and Quality of Measures Utilized in Federally-Sponsored Research on Children and Adolescents.

    ERIC Educational Resources Information Center

    Heyneman, Stephen P.; Mintz, Pamela Cope

    Every test intended for use in federally-funded research on children or youth during fiscal year 1975 was placed on a list. The list enentually comprised the titles of 1,570 instruments. The question pursued was whether there would be any realtionship between an instrument's quality and the frequenc with which it was used. For measures of quality…

  4. Evidence for Mental Ability Related Individual Differences in the Attentional Blink Obtained by an Analysis of the P300 Component

    ERIC Educational Resources Information Center

    Troche, Stefan J.; Indermuhle, Rebekka; Rammsayer, Thomas H.

    2012-01-01

    Attentional blink (AB) refers to impaired identification of a target (T2) when this target follows a preceding target (T1) after about 150-450 ms within a stream of rapidly presented stimuli. Previous research on a possible relation between AB and mental ability (MA) turned out to be highly ambiguous. The present study investigated MA-related…

  5. 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…

  6. Potential clinical utility of a fibre optic-coupled dosemeter for dose measurements in diagnostic radiology.

    PubMed

    Jones, A Kyle; Hintenlang, David

    2008-01-01

    Many types of dosemeters have been investigated for absorbed dose measurements in diagnostic radiology, including ionisation chambers, metal-oxide semiconductor field-effect transistor dosemeters, thermoluminescent dosemeters, optically stimulated luminescence detectors, film and diodes. Each of the aforementioned dosemeters suffers from a critical limitation, either the need to interrogate, or read, the dosemeter to retrieve dose information or large size to achieve adequate sensitivity. This work presents an evaluation of a fibre optic-coupled dosemeter (FOCD) for use in diagnostic radiology dose measurement. This dosemeter is small, tissue-equivalent and capable of providing true real-time dose information. The FOCD has been evaluated for dose linearity, angular dependence, sensitivity and energy dependence at energies, beam qualities and beam quantities relevant to diagnostic radiology. The FOCD displayed excellent dose linearity and high sensitivity, while exhibiting minimal angular dependence of response. However, the dosemeter does exhibit positive energy dependence, and is subject to attenuation of response when bent.

  7. Weighted minimum-norm source estimation of magnetoencephalography utilizing the temporal information of the measured data

    NASA Astrophysics Data System (ADS)

    Iwaki, Sunao; Ueno, Shoogo

    1998-06-01

    The weighted minimum-norm estimation (wMNE) is a popular method to obtain the source distribution in the human brain from magneto- and electro- encephalograpic measurements when detailed information about the generator profile is not available. We propose a method to reconstruct current distributions in the human brain based on the wMNE technique with the weighting factors defined by a simplified multiple signal classification (MUSIC) prescanning. In this method, in addition to the conventional depth normalization technique, weighting factors of the wMNE were determined by the cost values previously calculated by a simplified MUSIC scanning which contains the temporal information of the measured data. We performed computer simulations of this method and compared it with the conventional wMNE method. The results show that the proposed method is effective for the reconstruction of the current distributions from noisy data.

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

    SciTech Connect

    Ogawa, H.S.; McMullin, D.; Judge, D.L. ); Canfield, L.R. )

    1990-04-01

    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 ultraviolet photon flux in the spectral region between 50 and 800 {angstrom}. The detector was flown aboard a solar point sounding rocket launched from White Sands Missile Range in New Mexico on October 24, 1988. 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 {times} 10{sup 10} photons cm{sup {minus}2} s{sup {minus}1}. Based on a nominal probable error of 7% for National Institute of Standards and Technology detector efficiency measurements in the 50- to 500-{angstrom} region (5% on longer wavelength measurements between 500 and 1216 {angstrom}), and based on experimental errors associated with their rocket instrumentation and analysis, a conservative total error estimate of {approximately}14% is assigned to the absolute integral solar flux obtained.

  10. Diffusion and sedimentation interaction parameters for measuring the second virial coefficient and their utility as predictors of protein aggregation.

    PubMed

    Saluja, Atul; Fesinmeyer, R Matthew; Hogan, Sabine; Brems, David N; Gokarn, Yatin R

    2010-10-20

    The concentration-dependence of the diffusion and sedimentation coefficients (k(D) and k(s), respectively) of a protein can be used to determine the second virial coefficient (B₂), a parameter valuable in predicting protein-protein interactions. Accurate measurement of B₂ under physiologically and pharmaceutically relevant conditions, however, requires independent measurement of k(D) and k(s) via orthogonal techniques. We demonstrate this by utilizing sedimentation velocity (SV) and dynamic light scattering (DLS) to analyze solutions of hen-egg white lysozyme (HEWL) and a monoclonal antibody (mAb1) in different salt solutions. The accuracy of the SV-DLS method was established by comparing measured and literature B₂ values for HEWL. In contrast to the assumptions necessary for determining k(D) and k(s) via SV alone, k(D) and ks were of comparable magnitudes, and solution conditions were noted for both HEWL and mAb1 under which 1), k(D) and k(s) assumed opposite signs; and 2), k(D) ≥k(s). Further, we demonstrate the utility of k(D) and k(s) as qualitative predictors of protein aggregation through agitation and accelerated stability studies. Aggregation of mAb1 correlated well with B₂, k(D), and k(s), thus establishing the potential for k(D) to serve as a high-throughput predictor of protein aggregation.

  11. 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.

  12. Utilizing Turbidity and Measurements of Suspended Sediment Concentrations to Better Understand Sediment Transport within Urban Streams

    NASA Astrophysics Data System (ADS)

    Elkins, T. M.; Napieralski, J. A.

    2009-12-01

    The Rouge River watershed in Southeast Michigan is an urban watershed, which has been exposed to more than 100 years of anthropogenic activities related to industrialization and urbanization. This urbanization has degraded water quality by increasing erosion and altering the transport mechanism and chemistry of bed and suspended sediments. This study aims to explore the relationship between development within the Lower Rouge watershed and watershed hydrology through an examination of USGS discharge data, stream water quality and suspended sediment loads during storm and base flow. Two YSI dataloggers are used to continuously measure water quality parameters during baseflow and storm events (varying hydrologic conditions), including: turbidity, dissolved oxygen, conductivity, salinity, total dissolved solids, and temperature. Depth-integrated sediment samples are collected and analyzed for sediment concentration using Imhoff cones and filtration methods. Correlations between discharge weighted continuous turbidity measurements and discharge weighted suspended sediment samples are used to estimate sediment loads; essentially, turbidity readings and measured sediment concentrations form a near-linear relationship. In addition, sediment samples are analyzed for inorganic heavy metal contaminants common to Southeast Michigan to characterize both suspended sediments and sediments frequently deposited on adjacent floodplains. These metals (i.e. Lead, Copper, Chromium, Nickle) are commonly known as the “Michigan Metals” and represent indicator species of mobilized and deposited contaminants associated with urbanization and industrialization. The results will provide a baseline for better understanding the transport and fate of contaminated sediments within the Rouge watershed, as well as guide ongoing development and management practices along the Rouge River.

  13. Utilizing the N beam position monitor method for turn-by-turn optics measurements

    NASA Astrophysics Data System (ADS)

    Langner, A.; Benedetti, G.; Carlà, M.; Iriso, U.; Martí, Z.; de Portugal, J. Coello; Tomás, R.

    2016-09-01

    The N beam position monitor method (N -BPM) which was recently developed for the LHC has significantly improved the precision of optics measurements that are based on BPM turn-by-turn data. The main improvement is due to the consideration of correlations for statistical and systematic error sources, as well as increasing the amount of BPM combinations which are used to derive the β -function at one location. We present how this technique can be applied at light sources like ALBA, and compare the results with other methods.

  14. Noiseless Quantum Measurement and Squeezing of Microwave Fields Utilizing Mechanical Vibrations

    NASA Astrophysics Data System (ADS)

    Ockeloen-Korppi, C. F.; Damskägg, E.; Pirkkalainen, J.-M.; Heikkilä, T. T.; Massel, F.; Sillanpää, M. A.

    2017-03-01

    A process which strongly amplifies both quadrature amplitudes of an oscillatory signal necessarily adds noise. Alternatively, if the information in one quadrature is lost in phase-sensitive amplification, it is possible to completely reconstruct the other quadrature. Here we demonstrate such a nearly perfect phase-sensitive measurement using a cavity optomechanical scheme, characterized by an extremely small noise less than 0.2 quanta. The device also strongly squeezes microwave radiation by 8 dB below vacuum. A source of bright squeezed microwaves opens up applications in manipulations of quantum systems, and noiseless amplification can be used even at modest cryogenic temperatures.

  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. 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.

  17. Noiseless Quantum Measurement and Squeezing of Microwave Fields Utilizing Mechanical Vibrations.

    PubMed

    Ockeloen-Korppi, C F; Damskägg, E; Pirkkalainen, J-M; Heikkilä, T T; Massel, F; Sillanpää, M A

    2017-03-10

    A process which strongly amplifies both quadrature amplitudes of an oscillatory signal necessarily adds noise. Alternatively, if the information in one quadrature is lost in phase-sensitive amplification, it is possible to completely reconstruct the other quadrature. Here we demonstrate such a nearly perfect phase-sensitive measurement using a cavity optomechanical scheme, characterized by an extremely small noise less than 0.2 quanta. The device also strongly squeezes microwave radiation by 8 dB below vacuum. A source of bright squeezed microwaves opens up applications in manipulations of quantum systems, and noiseless amplification can be used even at modest cryogenic temperatures.

  18. 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).

  19. Utility of a baffle probe for measurements in a magnetized plasma^*

    NASA Astrophysics Data System (ADS)

    Demidov, Vladimir; Finnegan, Sean; Koepke, Mark; Reynolds, Eric

    2003-10-01

    A probe for measurements of space potential and its oscillations in magnetized plasmas is tested. The probe consists of a tungsten wire tip, situated perpendicular to the magnetic field, and is partially shielded by ceramic baffles. The probe works under the condition that electron Larmor radius is much smaller than the probe radius, and the ion Larmor radius is comparable to or larger than the probe radius. By rotating the baffle configuration around the probe tip, the ratio between electron and ion probe current can be adjusted. The probe uses the same principle as Katsumata probe, but has the advantage of convenient controllability of the ratio between electron and ion current. Experiments have been conducted in a fully ionized, barium plasma in the WVUniversity Q-machine. By rotating of the probe it is possible to make electron and ion contributions to the floating probe's collected current comparable within a fraction of T_e/e of the dc space potential. Measurements of ac probe potentials allow us to distinguish income of oscillations from space potentials and electron temperature fluctuations. ^*This research supported by NSF

  20. 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.

  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. 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.

  3. UTILITY OF SHORT-TERM BASEMENT SCREENING RADON MEASUREMENTS TO PREDICT YEAR-LONG RESIDENTIAL RADON CONCENTRATIONS ON UPPER FLOORS.

    PubMed

    Barros, Nirmalla; Steck, Daniel J; William Field, R

    2016-11-01

    This study investigated temporal and spatial variability between basement radon concentrations (measured for ∼7 d using electret ion chambers) and basement and upper floor radon concentrations (measured for 1 y using alpha track detectors) in 158 residences in Iowa, USA. Utility of short-term measurements to approximate a person's residential radon exposure and effect of housing/occupant factors on predictive ability were evaluated. About 60 % of basement short-term, 60 % of basement year-long and 30 % of upper floor year-long radon measurements were equal to or above the United States Environmental Protection Agency's radon action level of 148 Bq m(-3) Predictive value of a positive short-term test was 44 % given the year-long living space concentration was equal to or above this action level. Findings from this study indicate that cumulative radon-related exposure was more closely approximated by upper floor year-long measurements than short-term or year-long measurements in the basement.

  4. 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.

  5. Differential Absorption Lidar (DIAL) Measurements of Atmospheric Water Vapor Utilizing Robotic Aircraft

    NASA Technical Reports Server (NTRS)

    Hoang, Ngoc; DeYoung, Russell J.; Prasad, Coorg R.; Laufer, Gabriel

    1998-01-01

    A new unpiloted air vehicle (UAV) based water vapor DIAL system will be described. This system is expected to offer lower operating costs, longer test duration and severe weather capabilities. A new high-efficiency, compact, light weight, diode-pumped, tunable Cr:LiSAF laser will be developed to meet the UAV payload weight and size limitations and its constraints in cooling capacity, physical size and payload. Similarly, a new receiver system using a single mirror telescope and an avalanche photo diode (APD) will be developed. Projected UAV parameters are expected to allow operation at altitudes up to 20 km, endurance of 24 hrs and speed of 400 km/hr. At these conditions measurements of water vapor at an uncertainty of 2-10% with a vertical resolution of 200 m and horizontal resolution of 10 km will be possible.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Utilizing a Wristband Sensor to Measure the Stress Level for People with Dementia

    PubMed Central

    Kikhia, Basel; Stavropoulos, Thanos G.; Andreadis, Stelios; Karvonen, Niklas; Kompatsiaris, Ioannis; Sävenstedt, Stefan; Pijl, Marten; Melander, Catharina

    2016-01-01

    Stress is a common problem that affects most people with dementia and their caregivers. Stress symptoms for people with dementia are often measured by answering a checklist of questions by the clinical staff who work closely with the person with the dementia. This process requires a lot of effort with continuous observation of the person with dementia over the long term. This article investigates the effectiveness of using a straightforward method, based on a single wristband sensor to classify events of “Stressed” and “Not stressed” for people with dementia. The presented system calculates the stress level as an integer value from zero to five, providing clinical information of behavioral patterns to the clinical staff. Thirty staff members participated in this experiment, together with six residents suffering from dementia, from two nursing homes. The residents were equipped with the wristband sensor during the day, and the staff were writing observation notes during the experiment to serve as ground truth. Experimental evaluation showed relationships between staff observations and sensor analysis, while stress level thresholds adjusted to each individual can serve different scenarios. PMID:27886155

  11. The utility of endometrial thickness measurement in asymptomatic postmenopausal women with endometrial fluid.

    PubMed

    Seckin, B; Ozgu-Erdinc, A S; Dogan, M; Turker, M; Cicek, M N

    2016-01-01

    The aim of this study was to assess the clinical usefulness of sonographic endometrium thickness measurement in asymptomatic postmenopausal women with endometrial fluid collection. Fifty-two asymptomatic postmenopausal women with endometrial fluid, who underwent endometrial sampling were evaluated. Histopathological findings revealed that 25 (48.1%) women had insufficient tissue, 20 (38.4%) had atrophic endometrium and 7 (13.5%) had endometrial polyps. No case of malignancy was found. There was no statistically significant difference between the various histopathological categories (insufficient tissue, atrophic endometrium and polyp) with regard to the mean single-layer endometrial thickness (1.54 ± 0.87, 2.04 ± 1.76 and 1.79 ± 0.69 mm, respectively, p = 0.436). Out of 44 patients with endometrial thickness of less than 3 mm, 38 (86.4%) had atrophic changes or insufficient tissue and 6 (13.6%) had endometrial polyps. In conclusion, if the endometrial thickness is 3 mm or less, endometrial sampling is not necessary in asymptomatic postmenopausal women with endometrial fluid.

  12. Laser heating of a cavity versus a plane surface for metal targets utilizing photothermal deflection measurements

    NASA Astrophysics Data System (ADS)

    Jeong, S. H.; Greif, R.; Russo, R. E.

    1996-08-01

    The effects of a cylindrical cavity in a metal surface on the energy coupling of a laser beam with the solid were investigated by using a photothermal deflection technique. The photothermal deflection of a probe beam over the cavity was measured while the bottom of the cavity was heated with a Nd-YAG laser with a wavelength of 1064 nm. Cavities in three different materials and with two different aspect ratios were used for the experiment. Temperature distributions in the solid and the surrounding air were computed numerically and used to calculate photothermal deflections for cavity heating and for plane surface heating. Reflection of the heating laser beam inside the cavity increased the photothermal deflection amplitude significantly with larger increases for materials with larger thermal diffusivity. The computed photothermal deflections agreed more closely with the experimental results when reflection of the heating laser beam inside the cavity was included in the numerical model. The overall energy coupling between a heating laser and a solid is enhanced by a cavity.

  13. 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.

  14. Electrical Maxwell Demon and Szilard Engine Utilizing Johnson Noise, Measurement, Logic and Control

    PubMed Central

    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

  15. [Isolation of a methane-utilizing bacterium and its application in measuring methane gas].

    PubMed

    Zhao, Gengui; Zheng, Jun; Wen, Guangming; Yang, Suping; Dong, Chuan

    2008-03-01

    A bacterial strain ME16 was isolated from Jinyang Lake in Taiyuan of Shanxi Province, China. Gas chromatography analysis showed that the strain could use methane as the sole carbon and energy source. Based on 16S rDNA sequence analysis, the strain was identified as Pseudomonas aeruginosa. Effects of inoculum size, temperature, methane content and initial pH of media on cell growth were studied. In addition, we examined the response time of methane gas to dissolved oxygen and the relationship between consumption of dissolved oxygen and different methane gas content with PVA-H3BO3 immobilized cell of ME16 using electrochemical method. The optimal conditions for cell growth were 2% inoculum size, 25% methane content, 30 degrees C and pH 6.0. Response time was within 100 s after adding of immobilized cells to reaction system. The linear range of measured methane content was from 0 to 16%, with the correlation coefficient 0.9954. Hence, this strain has potential application in developing of methane biosensor.

  16. Suppression of quantum dot blinking in DTT-doped polymer films

    PubMed Central

    Antelman, Josh; Ebenstein, Yuval; Dertinger, Thomas; Michalet, Xavier; Weiss, Shimon

    2009-01-01

    In this report we evaluate the emission properties of single quantum dots embedded in a thin, thiol containing polymer film. We report the suppression of quantum dot blinking leading to a continuous photon flux from both organic and water soluble quantum dots and demonstrate their application as robust fluorescent point sources for ultrahigh resolution localization. In addition, we apply the polymer coating to cell samples immunostained with antibody conjugated QDs and show that fluorescence intensity from the polymer embedded cells shows no sign of degradation after 67 hours of continuous excitation. The reported thin polymer film coating may prove advantageous for immuno-cyto/histo-chemistry as well as for the fabrication of quantum dot containing devices requiring a reliable and stable photon source (including a single photon source) or stable charge characteristics while maintaining intimate contact between the quantum dot and the surrounding matrix. PMID:20161096

  17. Resetting capacity limitations revealed by long-lasting elimination of attentional blink through training

    PubMed Central

    Choi, Hoon; Chang, Li-Hung; Shibata, Kazuhisa; Sasaki, Yuka; Watanabe, Takeo

    2012-01-01

    As with other cognitive phenomena that are based upon the capacity limitations of visual processing, it is thought that attentional blink (AB) cannot be eliminated, even after extensive training. We report in this paper that just 1 h of specific attentional training can completely eliminate AB, and that this effect is robust enough to persist for a few months after training. Results of subsequent behavioral and functional magnetic resonance imaging (fMRI) experiments indicate that this learning effect is associated with improvements in temporal resolution, which are mainly due to processing in the prefrontal areas. Contrary to prior wisdom, we conclude that capacity limitations can be overcome by short-term training. PMID:22778408

  18. Zolmitriptan reverses blink reflex changes induced during the migraine attack in humans.

    PubMed

    de Tommaso, M; Guido, M; Libro, G; Sciruicchio, V; Puca, F

    2000-07-28

    The question about the 5-hydroxytryptamine (5-HT)(1B-1D) receptors agonists, if the clinical efficacy in migraine attacks is linked with the action at the central level or at the peripheral one, is still unresolved. We evaluated the effects of zolmitriptan and sumatriptan on blink reflex in thirty migraine without aura patients during the attacks in order to assess the central action on the trigeminal system. Both drugs were effective in reducing headache severity compared to placebo. In the migraine attack an increased area of the R3 component on the pain side was observed; it was suppressed by zolmitriptan, which confirmed its action on the central trigeminal circuits, though the clinical relevance of this effect could be questioned.

  19. Consciousness isn't all-or-none: Evidence for partial awareness during the attentional blink.

    PubMed

    Elliott, James C; Baird, Benjamin; Giesbrecht, Barry

    2016-02-01

    Alternative views of the nature of consciousness posit that awareness of an object is either an all-or-none phenomenon or that awareness can be partial, occurring independently for different levels of representation. The all-or-none hypothesis predicts that when one feature of an object is identified, all other features should be consciously accessible. The partial awareness hypothesis predicts that one feature may reach consciousness while others do not. These competing predictions were tested in two experiments that presented two targets within a central stream of letters. We used the attentional blink evoked by the first target to assess consciousness for two different features of the second target. The results provide evidence that there can be a severe impairment in conscious access to one feature even when another feature is accurately reported. This behavioral evidence supports the partial awareness hypothesis, showing that consciousness of different features of the same object can be dissociated.

  20. 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.

  1. The attentional blink reveals the probabilistic nature of discrete conscious perception.

    PubMed

    Asplund, Christopher L; Fougnie, Daryl; Zughni, Samir; Martin, Justin W; Marois, René

    2014-03-01

    Attention and awareness are two tightly coupled processes that have been the subject of the same enduring debate: Are they allocated in a discrete or in a graded fashion? Using the attentional blink paradigm and mixture-modeling analysis, we show that awareness arises at central stages of information processing in an all-or-none manner. Manipulating the temporal delay between two targets affected subjects' likelihood of consciously perceiving the second target, but did not affect the precision of its representation. Furthermore, these results held across stimulus categories and paradigms, and they were dependent on attention having been allocated to the first target. The findings distinguish the fundamental contributions of attention and awareness at central stages of visual cognition: Conscious perception emerges in a quantal manner, with attention serving to modulate the probability that representations reach awareness.

  2. The Emotional Blink: Adult Age Differences in Visual Attention to Emotional Information

    PubMed Central

    Langley, Linda K.; Rokke, Paul D.; Stark, Atiana C.; Saville, Alyson L.; Allen, Jaryn L.; Bagne, Angela G.

    2008-01-01

    To assess age differences in attention-emotion interactions, younger adults (ages 18–33 yrs) and older adults (ages 60–80 yrs) identified 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 younger 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

  3. Blink-related momentary activation of the default mode network while viewing videos.

    PubMed

    Nakano, Tamami; Kato, Makoto; Morito, Yusuke; Itoi, Seishi; Kitazawa, Shigeru

    2013-01-08

    It remains unknown why we generate spontaneous eyeblinks every few seconds, more often than necessary for ocular lubrication. Because eyeblinks tend to occur at implicit breakpoints while viewing videos, we hypothesized that eyeblinks are actively involved in the release of attention. We show that while viewing videos, cortical activity momentarily decreases in the dorsal attention network after blink onset but increases in the default-mode network implicated in internal processing. In contrast, physical blackouts of the video do not elicit such reciprocal changes in brain networks. The results suggest that eyeblinks are actively involved in the process of attentional disengagement during a cognitive behavior by momentarily activating the default-mode network while deactivating the dorsal attention network.

  4. Decreased Spontaneous Eye Blink Rates in Chronic Cannabis Users: Evidence for Striatal Cannabinoid-Dopamine Interactions

    PubMed Central

    Kowal, Mikael A.; Colzato, Lorenza S.; Hommel, Bernhard

    2011-01-01

    Chronic cannabis use has been shown to block long-term depression of GABA-glutamate synapses in the striatum, which is likely to reduce the extent to which endogenous cannabinoids modulate GABA- and glutamate-related neuronal activity. The current study aimed at investigating the effect of this process on striatal dopamine levels by studying the spontaneous eye blink rate (EBR), a clinical marker of dopamine level in the striatum. 25 adult regular cannabis users and 25 non-user controls matched for age, gender, race, and IQ were compared. Results show a significant reduction in EBR in chronic users as compared to non-users, suggesting an indirect detrimental effect of chronic cannabis use on striatal dopaminergic functioning. Additionally, EBR correlated negatively with years of cannabis exposure, monthly peak cannabis consumption, and lifetime cannabis consumption, pointing to a relationship between the degree of impairment of striatal dopaminergic transmission and cannabis consumption history. PMID:22125599

  5. 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.

  6. The comparison of environmental effects on michelson and fabry-perot interferometers utilized for the displacement measurement.

    PubMed

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

    2010-01-01

    The optical structure of general commercial interferometers, e.g., the Michelson interferometers, is based on a non-common optical path. Such interferometers suffer from environmental effects because of the different phase changes induced in different optical paths and consequently the measurement precision will be significantly influenced by tiny variations of the environmental conditions. Fabry-Perot interferometers, which feature common optical paths, are insensitive to environmental disturbances. That would be advantageous for precision displacement measurements under ordinary environmental conditions. To verify and analyze this influence, displacement measurements with the two types of interferometers, i.e., a self-fabricated Fabry-Perot interferometer and a commercial Michelson interferometer, have been performed and compared under various environmental disturbance scenarios. Under several test conditions, the self-fabricated Fabry-Perot interferometer was obviously less sensitive to environmental disturbances than a commercial Michelson interferometer. Experimental results have shown that induced errors from environmental disturbances in a Fabry-Perot interferometer are one fifth of those in a Michelson interferometer. This has proved that an interferometer with the common optical path structure will be much more independent of environmental disturbances than those with a non-common optical path structure. It would be beneficial for the solution of interferometers utilized for precision displacement measurements in ordinary measurement environments.

  7. Modulation of trigeminal reflex excitability in migraine: effects of attention and habituation on the blink reflex.

    PubMed

    de Tommaso, Marina; Murasecco, Donatella; Libro, Giuseppe; Guido, Marco; Sciruicchio, Vittorio; Specchio, Luigi Maria; Gallai, Virgilio; Puca, Francomichele

    2002-06-01

    The modulation of trigeminal reflex excitability in migraine patients was evaluated during the asymptomatic phase by studying the effects of attention, habituation and preconditioning stimulus on the R2 and R3 components of the blink reflex (BR). Fifty patients suffering from migraine without aura, 20 affected by migraine with aura and 35 sex- and age-matched controls were selected. In subgroups of migraine with-aura and without-aura patients, and normal controls, the blink reflex was elicited during different cognitive situations: (a) spontaneous mental activity; (b) stimulus anticipation; (c) recognition of target numbers. In the remaining subjects, R2 and R3 habituation was evaluated by repetitive stimulation at 1, 5, 10, 15, 20, 25 and 30 s intervals. The R2 and R3 recovery curves were also computed. A reduced R3 threshold with a normal pain threshold was found in migraine with-aura and without-aura patients; the R3 component was not significantly correlated with the pain thresholds in patients and controls. The R2 and R3 components were less influenced by the warning of the stimulus in migraine without-aura and migraine with-aura patients, in comparison with the control group. A slight increase of both R2 and R3 recovery after preconditioning stimulus was also observed in migraine patients, probably caused by a phenomenon of trigeminal hyperexcitability persisting after the last attack. The abnormal BR modulation by alerting expresses in migraine a dysfunction of adaptation capacity to environmental conditions, probably predisposing to migraine.

  8. Distractor Detection and Suppression Have a Beneficial Effect on Attentional Blink

    PubMed Central

    Zhao, Jing; Li, Hong; Ding, Cody; Chen, Antao

    2012-01-01

    Background Attentional blink (AB) is a phenomenon that describes the difficulty individuals have in reporting the second of two masked targets if the second target (T2) arrives 200–500 ms after the first target (T1). Recent studies explain the AB from cognitive resources limitation to distractors interference. For example, the temporary loss of control (TLC) hypothesis suggests that the AB is conduced by distractors disrupting the input filter for target processing. The inhibition models suggest that the T1+1 distractor triggers a suppression mechanism which could be beneficial for T1 processing but would suppress T2 at short T1–T2 lags. These models consider that the AB is caused by the appearance of distractors. However, in the present study, two methods were taken to help individuals to detect the distractors more effectively. An attenuated AB deficit was found when the distractors could be excluded or suppressed in time. We consider that under an appropriate condition the distractors detection and suppression have a beneficial effect on attentional blink. Methodology/Principal Findings Two methods were employed to help individuals to detect the distractors more effectively: enlarging the low-level-physical characteristic difference between targets and distractors (Experiment 1) and restricting the sets of distractors (Experiment 2). Attenuated AB deficits were found as using the above manipulations. Conclusions/Significance The present study found when the distractors are detected or identified quickly, they could be effectively suppressed, in order to reduce the interference from the targets and result in a smaller AB deficit. We suggest that the suppression mechanism for distractors have a beneficial effect on AB. PMID:22984558

  9. 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

  10. 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

  11. Using the near-field coupling of a sharp tip to tune fluorescence-emission fluctuations during quantum-dot blinking.

    PubMed

    Shafran, Eyal; Mangum, Benjamin D; Gerton, Jordan M

    2011-07-15

    We demonstrate that the cycling between internal states of quantum dots during fluorescence blinking can be used to tune the near-field coupling with a sharp tip. In particular, the fluorescence emission from states with high quantum yield is quenched due to energy transfer, while that from low-yield states is elevated due to field enhancement. Thus, as a quantum dot blinks, its emission fluctuations are progressively suppressed upon approach of a tip.

  12. Measuring cost savings in the operating room: a matter of FOCUS (follow-through, obsolescence, control, utilization, standardization).

    PubMed

    Blake, W; Duerkop, L; McNally, P

    1990-11-01

    In summary, changes came slowly at first in the OR. The biggest inventory reduction came about a year after the effort had begun. It would seem that tackling obsolescence, standardizing products, etc. would give an initial "big chunk" savings, with small amounts coming later as inventories are lowered. What we expected did not occur, due to the inherent nature of practices and what was customarily being used. For example, previously, some equipment purchases were paid for by purchasing product, which resulted in long-term commitments and high supply costs. The OR at times seemed more like a process of managing change, not just supplies. FOCUS is a daily process. How many times can you afford to overlook this process? How often are the mistakes of the past repeated? In review, we suggest this simple outline: Follow-through (review each case from start to finish), Obsolescence (schedule inventories every six months), Control (achieve inventory management by adjusting PAR levels to needs), Utilization (utilize product/equipment with your control), and Standardization (standardize products and measure results).

  13. Deriving welfare measures from discrete choice experiments: inconsistency between current methods and random utility and welfare theory.

    PubMed

    Lancsar, Emily; Savage, Elizabeth

    2004-09-01

    Discrete choice experiments (DCEs) are being used increasingly in health economics to elicit preferences for products and programs. The results of such experiments have been used to calculate measures of welfare or more specifically, respondents' 'willingness to pay' (WTP) for products and programs and their 'marginal willingness to pay' (MWTP) for the attributes that make up such products and programs. In this note we show that the methods currently used to derive measures of welfare from DCEs in the health economics literature are not consistent with random utility theory (RUT), or with microeconomic welfare theory more generally. The inconsistency with welfare theory is an important limitation on the use of such WTP estimates in cost-benefit analyses. We describe an alternative method of deriving measures of welfare (compensating variation) from DCEs that is consistent with RUT and is derived using welfare theory. We demonstrate its use in an empirical application to derive the WTP for asthma medication and compare it to the results elicited from the method currently used in the health economics literature.

  14. Measuring infant memory: Utility of the visual paired-comparison test paradigm for studies in developmental neurotoxicology.

    PubMed

    Burbacher, Thomas M; Grant, Kimberly S

    2012-01-01

    The assessment of brain function and behavior in young infants is central to understanding the effects of chemical exposure on central nervous system development. One approach to infant cognitive assessment, based on the direct observation of infant eye movements, is known as the Visual Paired-Comparison task. The Visual Paired-Comparison test methodology uses selective visual attention as a vehicle to study emerging recognition memory skills. The utility of this procedure to study visual recognition memory has been well established in both human and nonhuman primate infants. The primary outcome measure produced by this assessment technique is known as the Novelty Preference Score, reflecting the amount of time the infant spends actively looking at novel rather than familiar test stimuli. Visual recognition memory testing has demonstrated a strong sensitivity to conditions that may place infants at risk for poor developmental outcome (e.g. preterm birth, Down syndrome) and in humans; performance is significantly related to later measures of I.Q. and language competency. This assessment methodology has been successfully applied to the study of neurobehavioral effects after fetal neurotoxicant exposure. Field and laboratory studies have used tests of visual recognition memory to better understand the effects of compounds such as lead, methylmercury and polychlorinated biphenyls on emergent cognitive processing. The Visual Paired-Comparison paradigm and its capacity to measure recognition memory in preverbal infants provides a valid and theoretically meaningful approach to neurobehavioral assessment for studies in developmental toxicology and teratology.

  15. What Does the WRAML2 Core Battery Measure? Utilizing Exploratory and Confirmatory Techniques to Disclose Higher Order Structure.

    PubMed

    McGill, Ryan J; Dombrowski, Stefan C

    2016-11-19

    The present study examined the factor structure of the Wide Range Assessment of Memory and Learning-Second Edition (WRAML2) core battery with participants from the normative sample aged 9 to 90 years (n = 880) using higher order exploratory and confirmatory factor analytic techniques that were not reported in the in the WRAML2 Administration and Technical Manual Exploratory factor analysis results suggested only one factor, whereas confirmatory factor analysis results favored the three factors posited by the test authors. Although model fit statistics were equivalent for the oblique, indirect hierarchical, and direct hierarchical measurement models, it was determined that the bifactor model best disclosed the influence of latent dimensions on WRAML2 manifest variables. In the three-factor bifactor model, the general factor accounted for 31% of the total variance and 69% of the common variance, whereas the three first-order factors combined accounted for 41% of the total variance and 31% of the common variance. Latent factor reliability coefficients (as estimated by ωh) indicated that only the general factor was measured with enough precision to warrant confident clinical interpretation. Implications for clinical interpretation of WRAML2 scores and the procedures utilized in the development of related measures are discussed.

  16. Measurements of the Backstreaming Proton IONS in the Self-Magnetic Pinch (SMP) Diode Utilizing Copper Activation Technique

    NASA Astrophysics Data System (ADS)

    Mazarakis, Michael; Cuneo, Michael; Fournier, Sean; Johnston, Mark; Kiefer, Mark; Leckbee, Joshua; Simpson, Sean; Renk, Timothy; Webb, Timothy; Bennett, Nichelle

    2016-10-01

    The results presented here were obtained with an SMP diode mounted at the front high voltage end of the 8-10-MV RITS Self-Magnetically Insulated Transmission Line (MITL) voltage adder. Our experiments had two objectives: first, to measure the contribution of the back-streaming proton currents emitted from the anode target, and second, to evaluate the energy of those ions and hence the actual Anode-Cathode (A-K) gap voltage. The accelerating voltage quoted in the literature is estimated utilizing para-potential flow theories. Thus, it is interesting to have another independent measurement of the A-K voltage. We have measured the back-streaming protons emitted from the anode and propagating through a hollow cathode tip for various diode configurations and different techniques of target cleaning treatment, namely, heating at very high temperatures with DC and pulsed current, with RF plasma cleaning, and with both plasma cleaning and heating. We have also evaluated the A-K gap voltage by energy filtering techniques. Sandia is operated by Sandia Corporation, a subsidiary of Lockheed Martin Company, for the US DOE NNSA under Contract No. DE-AC04-94AL85000.

  17. The Observed Variance Between Predicted and Measured Radiation Dose in Breast and Prostate Patients Utilizing an in-vivo Dosimeter

    PubMed Central

    Scarantino, Charles W.; Prestidge, Bradley R.; Anscher, Mitchel S.; Ferree, Carolyn R.; Kearns, William T.; Black, Robert D.; Bolick, Natasha G.; Beyer, Gloria P.

    2008-01-01

    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 DVS (Dose Verification System) is a wireless, permanently implantable MOSFET dosimeter using a bidirectional antenna for power and data transfer. The study cohort includes 36 breast (33 received 2 devices) and 29 prostate (21 received 2 devices) cancer patients. A total of 1783 and 1749 daily dose measurements were obtained on breast and prostate patients, respectively. The measurements were compared to the planned expected dose. Bi-weekly CT scans were obtained to evaluate migration and NCI CTCv3 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 >5mm due to 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 and/or treatment plan considerations. Conclusions The DVS 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 DVS complements current IGRT and IMRT techniques. PMID:18793963

  18. Oxy-Mat™ Mattress System Development Utilizing Simultaneous Measurement of Interface Pressure and Deep Tissue Oxygen Saturation.

    PubMed

    Butler, Glenn J; Kenyon, David J; Gorenstein, Scott; Davenport, Thomas; Golembe, Edward; Lee, Bok; Vieweg, Jacques

    2015-05-01

    The development and management of pressure ulcers (PUs) among hospital and nursing home patients is one of the greatest preventable challenges to healthcare worldwide. For over 50 years, pressure mapping and subjective comfort has been the primary indicators for mattress selection. Our research demonstrates that mattress/patient interface pressure and relative blood/oxygen perfusion do not inversely correlate and pressure is not a meaningful, real-time indicator of tissue ischemia and risk of pressure ulcer development. Developed in our research is a real-time sensor system to simultaneously measure and record these parameters over the anatomical sites at risk for PUs. Measurements focused on the heel, sacrum, trochanter, ischium, scapula and occipital. A modified pressure mapping system is used for interface pressure measurements and integrated with multiple near-infrared sensors to measure specific deep tissue hemoglobin saturated oxygen or rSO2. Testing and mattress design development was done during the period of 2008 to present. Over 200 human tests of commercially available mattresses were conducted in supine, 30 degree, and 70 degree positions, ranging in times of up to four hours. During this time period, we utilized 20 test subjects-eight female and 12 male-with ages ranging from 18 to 65 years. The result of this proprietary off-loading device evaluation and design system shows that the new Oxy-Mat™ (Off-Loading Technologies, Tarrytown, NY) Non-Powered Mattress System consistently provides optimized tissue perfusion as measured by natural deep tissue oxygen saturation levels. In extensive laboratory and clinical evaluations, the Oxy-Mat™ was shown to be functionally superior to CMS Group 2 powered mattresses. Another outcome of our research was that a powered mattress system may not be appropriate for most sensate and semi-ambulatory patients. Further research is underway.

  19. 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.

  20. 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.

  1. Challenge to the Charging Model of Semiconductor-Nanocrystal Fluorescence Intermittency from Off-State Quantum Yields and Multiexciton Blinking

    NASA Astrophysics Data System (ADS)

    Zhao, Jing; Nair, Gautham; Fisher, Brent R.; Bawendi, Moungi G.

    2010-04-01

    Semiconductor nanocrystals emit light intermittently; i.e., they “blink,” under steady illumination. The dark periods have been widely assumed to be due to photoluminescence (PL) quenching by an Auger-like process involving a single additional charge present in the nanocrystal. Our results challenge this long-standing assumption. Close examination of exciton PL intensity time traces of single CdSe(CdZnS) core(shell) nanocrystals reveals that the dark state PL quantum yield can be 10 times less than the biexciton PL quantum yield. In addition, we observe spectrally resolved multiexciton emission and find that it also blinks with an on/off ratio greater than 10∶1. These results directly contradict the predictions of the charging model.

  2. Challenge to the Charging Model of Semiconductor-Nanocrystal Fluorescence Intermittency from Off-State Quantum Yields and Multiexciton Blinking

    PubMed Central

    Zhao, Jing; Nair, Gautham; Fisher, Brent R.; Bawendi, Moungi G.

    2012-01-01

    Semiconductor nanocrystals emit light intermittently; i.e., they “blink,” under steady illumination. The dark periods have been widely assumed to be due to photoluminescence (PL) quenching by an Auger-like process involving a single additional charge present in the nanocrystal. Our results challenge this long-standing assumption. Close examination of exciton PL intensity time traces of single CdSe(CdZnS) core (shell) nanocrystals reveals that the dark state PL quantum yield can be 10 times less than the biexciton PL quantum yield. In addition, we observe spectrally resolved multiexciton emission and find that it also blinks with an on/off ratio greater than 10:1. These results directly contradict the predictions of the charging model. PMID:20482016

  3. Challenge to the charging model of semiconductor-nanocrystal fluorescence intermittency from off-state quantum yields and multiexciton blinking.

    PubMed

    Zhao, Jing; Nair, Gautham; Fisher, Brent R; Bawendi, Moungi G

    2010-04-16

    Semiconductor nanocrystals emit light intermittently; i.e., they "blink," under steady illumination. The dark periods have been widely assumed to be due to photoluminescence (PL) quenching by an Auger-like process involving a single additional charge present in the nanocrystal. Our results challenge this long-standing assumption. Close examination of exciton PL intensity time traces of single CdSe(CdZnS) core(shell) nanocrystals reveals that the dark state PL quantum yield can be 10 times less than the biexciton PL quantum yield. In addition, we observe spectrally resolved multiexciton emission and find that it also blinks with an on/off ratio greater than 10:1. These results directly contradict the predictions of the charging model.

  4. 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,…

  5. The effect of repeated lateral compression and expansions mimicking blinking on selected tear film polar lipid monofilms.

    PubMed

    Patterson, Matthew; Vogel, Hans J; Prenner, Elmar J

    2017-03-01

    The tear film lipid layer is formed on the anterior surface of the eye, functioning as a barrier to excess evaporation and foreign particles, while also providing stability to the tear film. The lipid layer is organized into a polar lipid layer consisting of phospholipids, ceramides, and free fatty acids that act as a surfactant to a non-polar multilayer of wax and cholesterol esters. Due to shear forces from eye movement and the compression and expansion of blinking, the tear lipids are under constant stress. However, tear film is able to resist immediate rupture and remains intact over multiple blinks. This work aimed to better understand the lateral organization of selected tear film polar lipids. The polar lipid biomimetic studied here consisted of dipalmitoyl phosphatidylcholine (DPPC), dipalmitoyl phosphatidylethanolamine (DPPE), palmitoyl glucosylceramide (PGC), and palmitoyl sphingomyelin (PSM). Surface pressure-area isocycles mimicked blinking and films were visualized by Brewster angle microscopy (BAM). All lipid systems formed relatively reversible films as indicated by limited hysteresis. However, pure DPPC and PSM films experienced greater changes in lipid packing upon compression and expansion compared to pure PGC and DPPE. This suggests that the driving force behind maintaining the lateral organization of the polar lipids from tear film may be the hydrogen bonding propensities of the head groups. Additionally, isocycles of films containing DPPC, DPPE, and PGC mixtures exhibited evidence for reversible multilayer formation or folding. This was supported by 3D analysis of structures that formed during compression but reintegrated back into the bulk lipid film during expansion near the in vitro tear film surface pressure of the open eye. Therefore, the polar lipids of tear film may be directly involved in preventing film rupture during a blink.

  6. Neural Control of Voluntary Eye Closure: A Case Study and an fMRI Investigation of Blinking and Winking

    PubMed Central

    van Koningsbruggen, Martijn G.; Peelen, Marius V.; Davies, Eilir; Rafal, Robert D.

    2012-01-01

    The current paper describes a rare case of a patient who suffered from unilateral apraxia of eye closure as a result of a bilateral stroke. Interestingly, the patient’s ability to voluntarily close both eyelids (i.e. blinking) was not affected, indicating that different neural mechanisms control each type of eye closure. The stroke caused damage to a large part of the right frontal cortex, including the motor cortex, pre-motor cortex and the frontal eye field (FEF). The lesion in the left hemisphere was restricted to the FEF. In order to further study the neural mechanisms of eye closure, we conducted an fMRI study in a group of neurological healthy subjects. We found that all areas of the oculomotor cortex were activated by both left and right winking, including the FEF, supplementary eye field (SEF), and posterior parietal cortex (PPC). Blinking activated FEF and SEF, but not PPC. Both FEF and PPC were significantly more active during winking than blinking. Together, these results provide evidence for a critical role of the FEF in voluntary unilateral eye closure. PMID:22530264

  7. Methane emissions measurements of natural gas components using a utility terrain vehicle and portable methane quantification system

    NASA Astrophysics Data System (ADS)

    Johnson, Derek; Heltzel, Robert

    2016-11-01

    Greenhouse Gas (GHG) emissions are a growing problem in the United States (US). Methane (CH4) is a potent GHG produced by several stages of the natural gas sector. Current scrutiny focuses on the natural gas boom associated with unconventional shale gas; however, focus should still be given to conventional wells and outdated equipment. In an attempt to quantify these emissions, researchers modified an off-road utility terrain vehicle (UTV) to include a Full Flow Sampling system (FFS) for methane quantification. GHG emissions were measured from non-producing and remote low throughput natural gas components in the Marcellus region. Site audits were conducted at eleven locations and leaks were identified and quantified at seven locations including at a low throughput conventional gas and oil well, two out-of-service gathering compressors, a conventional natural gas well, a coalbed methane well, and two conventional and operating gathering compressors. No leaks were detected at the four remaining sites, all of which were coal bed methane wells. The total methane emissions rate from all sources measured was 5.3 ± 0.23 kg/hr, at a minimum.

  8. Optical 3D Deformation Measurement Utilizing Non-planar Surface for the Development of an “Intelligent Tire”

    NASA Astrophysics Data System (ADS)

    Matsuzaki, Ryosuke; Hiraoka, Naoki; Todoroki, Akira; Mizutani, Yoshihiro

    Intelligent tires, also known as smart tires, are equipped with sensors to monitor the strain of the interior surface and the rolling radius of tire, and are expected to improve the reliability of tires and tire control systems such as anti-lock braking systems (ABS). However, the high stiffness of an attached sensor like a strain gauge causes sensors to debond from the tire rubber. In the present study, a novel optical method is used for the concurrent monitoring of in-plane strain and out-of-plane displacement (rolling radius) utilizing the non-planar surface of the monitoring object. The optical method enables noncontact measurement of strain distribution. The in-plane strain and out-of-plane displacement are calculated by using image processing with an image of the interior surface of a tire that is taken with a single CCD camera fixed on the wheel rim. This new monitoring system is applied to an aluminum beam and a commercially available radial tire. As a result, the monitoring system provides concurrent measurement of in-plane strain, out-of-plane displacement and tire pressure, and is shown to be an effective monitoring system for intelligent tires.

  9. 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.

  10. Oxygen Reduction Reaction Measurements on Platinum Electrocatalysts Utilizing Rotating Disk Electrode Technique: I. Impact of Impurities, Measurement Protocols and Applied Corrections

    DOE PAGES

    Shinozaki, Kazuma; Zack, Jason W.; Richards, Ryan M.; ...

    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

  11. Year rather than farming system influences protein utilization and energy value of vegetables when measured in a rat model.

    PubMed

    Jørgensen, Henry; Brandt, Kirsten; Lauridsen, Charlotte

    2008-12-01

    The aim of the study was to measure protein utilization and energy value of dried apple, carrot, kale, pea, and potato prepared for human consumption and grown in 2 consecutive years with 3 different farming systems: (1) low input of fertilizer without pesticides (LIminusP), (2) low input of fertilizers and high input of pesticides (LIplusP), (3) and high input of fertilizers and high input of pesticides (HIplusP). In addition, the study goal was to verify the nutritional values, taking into consideration the physiologic state. In experiment 1, the nutritive values, including protein digestibility-corrected amino acid score, were determined in single ingredients in trials with young rats (3-4 weeks) as recommended by the Food and Agriculture Organization of the United Nations/World Health Organization for all age groups. A second experiment was carried out with adult rats to assess the usefulness of digestibility values to predict the digestibility and nutritive value of mixed diets and study the age aspect. Each plant material was included in the diet with protein-free basal mixtures or casein to contain 10% dietary protein. The results showed that variations in protein utilization and energy value determined on single ingredients between cultivation strategies were inconsistent and smaller than between harvest years. Overall, dietary crude fiber was negatively correlated with energy digestibility. The energy value of apple, kale, and pea was lower than expected from literature values. A mixture of plant ingredients fed to adult rats showed lower protein digestibility and higher energy digestibility than predicted. The protein digestibility data obtained using young rats in the calculation of protein digestibility-corrected amino acid score overestimates protein digestibility and quality and underestimates energy value for mature rats. The present study provides new data on protein utilization and energy digestibility of some typical plant foods that may

  12. 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.

  13. The three responses of the blink reflex in adult and juvenile migraine.

    PubMed

    de Tommaso, M; Guido, M; Libro, G; Sciruicchio, V; Puca, F

    2000-06-01

    Recent theories about migraine pathogenesis have emphasized the role of the trigeminal system in the pathogenesis of migraine attacks (Moskowitz, 1997). The blink reflex (BR) could be a suitable method to evaluate the trigeminal system in migraine, as it is generally elicited by stimulation of the trigeminal ophthalmic division (Kimura et al., 1967), involved in migraine attacks. Sixty one adult and 15 juvenile migraine without aura subjects were selected, in order to evaluate the BR features, including the subjective perceptive and pain thresholds and the R1, R2 and R3 components intensity thresholds and amplitudes. The electrophysiological procedure was carried out during the pain free phase. The findings were compared with those of 28 healthy controls, 18 adults and 10 children. In both adult and juvenile migraine sufferers an early appearance of the R3 response at almost the R2 threshold was observed in comparison with age-matched controls. Unfortunately, the anatomic and physiologic organization of the R3 component is uncertain: its early onset could suggest a dysfunction of the inhibitory control system on the trigeminal networks, which may predispose to migraine attacks.

  14. Distractor devaluation effect in the attentional blink: direct evidence for distractor inhibition.

    PubMed

    Kihara, Ken; Yagi, Yoshihiko; Takeda, Yuji; Kawahara, Jun I

    2011-02-01

    When two targets (T1 and T2) are embedded in rapid serial visual presentation (RSVP), T2 is often missed (attentional blink, AB) if T2 follows T1 by less than 500 ms. Some have proposed that inhibition of a distractor following T1 contributes to the AB, but no direct evidence supports this proposal. This study examined distractor inhibition by assessing a distractor devaluation effect where inhibited items were evaluated less positively than controls. Experiments 1 and 2 showed that a distractor presented just after T1 was evaluated less favorably when T2 was misidentified, independently of stimulus characteristics. Experiment 3 produced distractor devaluation in T2 incorrect trials when the evaluated distractor was the second item after T1. In contrast, a distractor presented before T1 was not devaluated (Experiment 4). Experiment 5 demonstrated that participants could not recognize presented distractors after an RSVP task, rejecting the possibility that memorized distractors were devalued. Results show a relationship between the devaluation of distractors following T1 and the AB, providing the first direct evidence of the distractor inhibition during the AB.

  15. The interplay of attention and consciousness in visual search, attentional blink and working memory consolidation.

    PubMed

    Raffone, Antonino; Srinivasan, Narayanan; van Leeuwen, Cees

    2014-05-05

    Despite the acknowledged relationship between consciousness and attention, theories of the two have mostly been developed separately. Moreover, these theories have independently attempted to explain phenomena in which both are likely to interact, such as the attentional blink (AB) and working memory (WM) consolidation. Here, we make an effort to bridge the gap between, on the one hand, a theory of consciousness based on the notion of global workspace (GW) and, on the other, a synthesis of theories of visual attention. We offer a theory of attention and consciousness (TAC) that provides a unified neurocognitive account of several phenomena associated with visual search, AB and WM consolidation. TAC assumes multiple processing stages between early visual representation and conscious access, and extends the dynamics of the global neuronal workspace model to a visual attentional workspace (VAW). The VAW is controlled by executive routers, higher-order representations of executive operations in the GW, without the need for explicit saliency or priority maps. TAC leads to newly proposed mechanisms for illusory conjunctions, AB, inattentional blindness and WM capacity, and suggests neural correlates of phenomenal consciousness. Finally, the theory reconciles the all-or-none and graded perspectives on conscious representation.

  16. Drug release from liposome coated hydrogels for soft contact lenses: the blinking and temperature effect.

    PubMed

    Paradiso, P; Colaço, R; Mata, J L G; Krastev, R; Saramago, B; Serro, A P

    2016-05-18

    In this article, liposome-based coatings aiming to control drug release from therapeutic soft contact lenses (SCLs) materials are analyzed. A PHEMA based hydrogel material loaded with levofloxacin is used as model system for this research. The coatings are formed by polyelectrolyte layers containing liposomes of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and DMPC + cholesterol (DMPC + CHOL). The effect of friction and temperature on the drug release is investigated. The aim of the friction tests is to simulate the blinking of the eyelid in order to verify if the SCLs materials coated with liposomes are able to keep their properties, in particular the drug release ability. It was observed that under the study conditions, friction did not affect significantly the drug release from the liposome coated PHEMA material. In contrast, increasing the temperature of release leads to an increase of the drug diffusion rate through the hydrogel. This phenomenon is recorded both in the control and in the coated samples. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016.

  17. Usefulness of blink reflex in hypothyroid patients with or without polyneuropathy: a case control study.

    PubMed

    Pawar, Sachin; Udan, Vikas; Jain, Jyoti; Shende, Vinod; Singh, Ramji

    2014-01-01

    Central nervous system (CNS) dysfunction is an important consequence of thyroid deficiency. Cranial nerves are frequently affected in hypothyroid process. On routine nerve conduction studies, symptomatic peripheral and cranial neuropathy can be detected, however, diagnosing subclinical cranial neuropathy pose the major problem. Blink reflex (BR), has been shown to be an effective method for revealing subclinical involvement of cranial nerves in generalized neuropathies. The present study was undertaken to evaluate the efficacy of BR as a method for early diagnosis of subclinical cranial neuropathy in hypothyroid patients with or without overt peripheral polyneuropathy. A case control study was conducted on 150 subjects aged 18 years and above (100 controls, 50 cases). A routine nerve conduction study and BR evaluation was done in all the subjects. We found abnormal BR response in 50% of hypothyroid patients studied. In hypothyroid patient without polyneuropathy R1 latency was significantly prolonged (P < 0.05 Vs control). Ipsilateral and contralateral R2 latencies were significantly prolonged in hypothyroid cases with or without polyneuropathy on bilateral stimulation. Magnitude of prolongation was greater in with polyneuropathy group. In conclusion, study suggests that BR is a useful non-invasive method for the detection of clinically silent cranial nerve compromise in hypothyroid patients.

  18. 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

  19. Can attenuation of attentional blink also evoke removal of repetition blindness?

    PubMed

    Choi, Hoon; Watanabe, Takeo

    2014-06-01

    A recent study showed that attentional blink (AB), which has been considered to reflect the capacity limitation of visual temporal attention, can be attenuated after a short period of the color-salient training, in which the second target (T2) within the AB period is given a salient color (Choi et al., 2012). The current study explored whether the effect of the color-salient training could be transferred to another phenomenon. In addition to AB, repetition blindness (RB) was employed, which is phenomenologically similar to, but fundamentally different from AB. After completion of the color-salient training with a nonrepeated T2 (corresponding to AB), RB was still observed, whereas AB was completely removed. However, the color-salient training with a repeated T2 (similar to RB) induced not only a significant reduction of RB but also an attenuation of AB. This result provides further evidence for dissociation between AB and RB. In addition, it implies that the color-salient training improves the attentional control mechanism related to target-distractor discrimination rather than to the perceptual system.

  20. 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.

  1. On/off blinking and switching behaviour of single molecules of green fluorescent protein

    NASA Astrophysics Data System (ADS)

    Dickson, Robert M.; Cubitt, Andrew B.; Tsien, Roger Y.; Moerner, W. E.

    1997-07-01

    Optical studies of individual molecules at low and room temperature can provide information about the dynamics of local environments in solids, liquids and biological systems unobscured by ensemble averaging. Here we present a study of the photophysical behaviour of single molecules of the green fluorescent protein (GFP) derived from the jellyfish Aequorea victoria. Wild-type GFP and its mutant have attracted interest as fluorescent biological labels because the fluorophore may be formed in vivo. GFP mutants immobilized in aereated aqueous polymer gels and excited by 488-nm light undergo repeated cycles of fluorescent emission (`blinking') on a timescale of several seconds-behaviour that would be unobservable in bulk studies. Eventually the individual GFP molecules reach a long-lasting dark state, from which they can be switched back to the original emissive state by irradiation at 405 nm. This suggests the possibility of using these GFPs as fluorescent markers for time-dependent cell processes, and as molecular photonic switches or optical storage elements, addressable on the single-molecule level.

  2. Assessment of Blink Reflex in Genetic Generalized Epilepsy Patients With Eyelid Myoclonia.

    PubMed

    Altıokka-Uzun, Güneş; Ekizoğlu, Esme; Kocasoy-Orhan, Elif; Bebek, Nerses; Gürses, Candan; Gökyiğit, Ayşen; Öge, Ali Emre; Baykan, Betül

    2017-03-01

    Eyelid myoclonia (EM) with or without absences are a rare type of generalized seizures associated with a variety of epilepsy syndromes with an unknown pathophysiology. The aim of this study was to investigate the possible contribution of the brainstem structures in this underrecognized special type of seizures. Sixteen consecutive patients with EM, diagnosed with genetic generalized epilepsy (GGE) according to International League Against Epilepsy 2010 criteria were included. Brainstem excitabilities were examined by blink reflex (BR) studies. The results of BR studies in GGE patients with EM were statistically compared with 2 control groups; namely age- and gender-matched healthy volunteers and juvenile myoclonic epilepsy (JME) patients without any absences and using similar antiepileptic drugs. There were no statistical differences between the thresholds of the BR studies and the BR recovery curves in terms of amplitudes and areas of healthy subjects, JME patients and GGE patients with EM. Our findings do not support a profound interictal hyperexcitability in the BR-related brainstem structures of the GGE patients with EM. It can be considered that EM may be associated with excitability changes of the occipital cortex and other cortical areas.

  3. Emotional modulation of the attentional blink: is there an effect of stress?

    PubMed

    Schwabe, Lars; Wolf, Oliver T

    2010-04-01

    Individuals are often unable to identify the second target (T2) of two when it is presented within 500 ms after the first target (T1). This "attentional blink" (AB) is attenuated by an emotionally arousing T2. Stress is known to affect cognitive performance, in particular for emotional material. In the present study, we asked whether (a) an emotional T2 reduces the AB when preceded by an emotional T1 and (b) the emotional modulation of the AB is affected by stress. Participants were presented neutral and aversive words as T1 and T2 in rapid serial visual presentation after they were exposed to stress (socially evaluated cold pressor test) or a control condition in a crossover manner. Our results indicate that an aversive T1 extends the AB. Aversive T2 attenuated the AB in the presence of a neutral, but not an aversive, T1. Stress-enhanced T2 detection and high cortisol responses to stress reduced the AB. However, neither stress nor cortisol interacted with the emotionality of the target words. In summary, these findings point to a strong impact of emotional factors on early perceptual experiences.

  4. [Utilization of healthcare services by groups in the Israeli population as a measurement reflecting equity in the healthcare system].

    PubMed

    Afek, Arnon

    2008-04-01

    The Israeli health care system bases itself on the principles of justice, equality, and social solidarity. In 1994 a Health Insurance Act was passed, based upon these principles, which helped to reduce the differences between Israeli population groups. People from lower socio-economic status suffer from more illnesses and have shorter life spans than their more fortunate countrymen. These differences in well-being, as well as being unnecessary and avoidable, are also unfair and unjust - and define the inequities in our health care system. Therefore, the goal of the health care system should be to reduce or eliminate these disparities, especially when they are avoidable and unjust. A study by Orna Apel Brown describes the results of a health care survey among new immigrants to Israel from the former U.S.S.R. She shows that there has been an increase in their utilization of healthcare services, excluding preventive measures such as mammography, along with a reduction in the differences in their self perception of health care status and well-being - now placing them on the same par as their fellow Israeli-born citizens. The results, although encouraging, stress the importance of the health care system's need to direct its efforts to decreasing the disparity and making the system more equitable to the underprivileged populations in Israel.

  5. Responses of Nitrogen Utilization and Apparent Nitrogen Loss to Different Control Measures in the Wheat and Maize Rotation System

    PubMed Central

    Peng, Zhengping; Liu, Yanan; Li, Yingchun; Abawi, Yahya; Wang, Yanqun; Men, Mingxin; An-Vo, Duc-Anh

    2017-01-01

    Nitrogen (N) is an essential macronutrient for plant growth and excessive application rates can decrease crop yield and increase N loss into the environment. Field experiments were carried out to understand the effects of N fertilizers on N utilization, crop yield and net income in wheat and maize rotation system of the North China Plain (NCP). Compared to farmers’ N rate (FN), the yield of wheat and maize in reduction N rate by 21–24% based on FN (RN) was improved by 451 kg ha-1, N uptakes improved by 17 kg ha-1 and net income increased by 1671 CNY ha-1, while apparent N loss was reduced by 156 kg ha-1. The controlled-release fertilizer with a 20% reduction of RN (CRF80%), a 20% reduction of RN together with dicyandiamide (RN80%+DCD) and a 20% reduction of RN added with nano-carbon (RN80%+NC) all resulted in an improvement in crop yield and decreased the apparent N losses compared to RN. Contrasted with RN80%+NC, the total crop yield in RN80%+DCD improved by 1185 kg ha-1, N uptake enhanced by 9 kg ha-1 and net income increased by 3929 CNY ha-1, while apparent N loss was similar. Therefore, a 37–39% overall decrease in N rate compared to farmers plus the nitrification inhibitor, DCD, was effective N control measure that increased crop yields, enhanced N efficiencies, and improved economic benefits, while mitigating apparent N loss. There is considerable scope for improved N use effieincy in the intensive wheat -maize rotation of the NCP. PMID:28228772

  6. 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.

  7. Responses of Nitrogen Utilization and Apparent Nitrogen Loss to Different Control Measures in the Wheat and Maize Rotation System.

    PubMed

    Peng, Zhengping; Liu, Yanan; Li, Yingchun; Abawi, Yahya; Wang, Yanqun; Men, Mingxin; An-Vo, Duc-Anh

    2017-01-01

    Nitrogen (N) is an essential macronutrient for plant growth and excessive application rates can decrease crop yield and increase N loss into the environment. Field experiments were carried out to understand the effects of N fertilizers on N utilization, crop yield and net income in wheat and maize rotation system of the North China Plain (NCP). Compared to farmers' N rate (FN), the yield of wheat and maize in reduction N rate by 21-24% based on FN (RN) was improved by 451 kg ha(-1), N uptakes improved by 17 kg ha(-1) and net income increased by 1671 CNY ha(-1), while apparent N loss was reduced by 156 kg ha(-1). The controlled-release fertilizer with a 20% reduction of RN (CRF80%), a 20% reduction of RN together with dicyandiamide (RN80%+DCD) and a 20% reduction of RN added with nano-carbon (RN80%+NC) all resulted in an improvement in crop yield and decreased the apparent N losses compared to RN. Contrasted with RN80%+NC, the total crop yield in RN80%+DCD improved by 1185 kg ha(-1), N uptake enhanced by 9 kg ha(-1) and net income increased by 3929 CNY ha(-1), while apparent N loss was similar. Therefore, a 37-39% overall decrease in N rate compared to farmers plus the nitrification inhibitor, DCD, was effective N control measure that increased crop yields, enhanced N efficiencies, and improved economic benefits, while mitigating apparent N loss. There is considerable scope for improved N use effieincy in the intensive wheat -maize rotation of the NCP.

  8. 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.

  9. A Method for Utilizing Bivariate Efficacy Outcome Measures to Screen Regimens for Activity in 2-Stage Phase II Clinical Trials

    PubMed Central

    Rubinstein, Larry; Litwin, Samuel; Yothers, Greg

    2012-01-01

    Background Most phase II clinical trials utilize a single primary endpoint to determine the promise of a regimen for future study. However, many disorders manifest themselves in complex ways. For example, migraine headaches can cause pain, auras, photophobia, and emesis. Investigators may believe a drug is effective at reducing migraine pain and the severity of emesis during an attack. Nevertheless, they could still be interested in proceeding with development of the drug if it is effective against only one of these symptoms. Such a study would be a candidate for a clinical trial with co-primary endpoints. Purpose The purpose of the article is to provide a method for designing a 2-stage clinical trial with dichotomous co-primary endpoints of efficacy that has the ability to detect activity on either response measure with high probability when the drug is active on one or both measures, while at the same time rejecting the drug with high probability when there is little activity on both dimensions. The design enables early closure for futility and is flexible with regard to attained accrual. Methods The design is proposed in the context of cancer clinical trials where tumor response is used to assess a drug's ability to kill tumor cells and progression-free survival (PFS) status after a certain period is used to evaluate the drug's ability to stabilize tumor growth. Both endpoints are assumed to be distributed as binomial random variables, and uninteresting probabilities of success are determined from historical controls. Given the necessity of accrual flexibility, exhaustive searching algorithms to find optimum designs do not seem feasible at this time. Instead, critical values are determined for realized sample sizes using specific procedures. Then accrual windows are found to achieve a design's desired level of significance, probability of early termination (PET), and power. Results The design is illustrated with a clinical trial that examined bevacizumab in

  10. 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

  11. 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.

  12. 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.

  13. About the effect of eye blinking on drug release from pHEMA-based hydrogels: an in vitro study.

    PubMed

    Galante, R; Paradiso, P; Moutinho, M G; Fernandes, A I; Mata, J L G; Matos, A P A; Colaço, R; Saramago, B; Serro, A P

    2015-01-01

    The development of new ophthalmic drug delivery systems capable of increasing the residence time of drugs in the eye and improve its bioavailability relatively to eyedrops has been object of intense research in recent years. Several studies have shown that drug-loaded therapeutic soft contact lenses (SCLs) constitute a promising approach, with several potential advantages as compared with collyria. The main objective of this work is to study the effect of repetitive load and friction cycles caused by the eye blinking, on the drug release from hydrogels used in SCLs which, as far as we know, was never investigated before. Two poly-2-hydroxyethylmethacrylate-based hydrogels, pHEMA-T and pHEMA-UV, were used as model materials. Levofloxaxin was chosen as model drug. The hydrogels were fully characterized in what concerns structural and physicochemical properties. pHEMA-UV revealed some superficial porosity and a lower short-range order than pHEMA-T. We observe that the load and friction cycles enhanced the drug release from pHEMA-UV hydrogels. The application of a simple mathematical model, which takes into account the drug dilution caused by the tear flow, showed that the enhancement of the drug release caused by blinking on this hydrogel may be relevant in in vivo conditions. Conversely, the more sustained drug release from pHEMA-T is not affected by load and friction cycles. The conclusion is that, depending on the physicochemical and microstructural characteristics of the hydrogels, blinking is a factor that may affect the amount of drug delivered to the eye by SCLs and should thus be considered.

  14. Reciprocal dynamics of EEG alpha and delta oscillations during spontaneous blinking at rest: a survey on a default mode-based visuo-spatial awareness.

    PubMed

    Bonfiglio, Luca; Sello, Stefano; Carboncini, Maria Chiara; Arrighi, Pieranna; Andre, Paolo; Rossi, Bruno

    2011-04-01

    By means of a narrowband wavelet analysis (0.5-6Hz), EEG delta event-related oscillations (EROs), both time- and phase-locked to spontaneous blinking (delta blink-related oscillations or delta BROs), have recently been demonstrated. On the basis of their spatiotemporal characteristics, delta BROs have been proposed as being involved in an automatic mechanism of maintaining awareness in a visuo-spatial context. The aim of the present study was: a) to investigate whether spontaneous blinking was also able to modulate alpha oscillations and, if so, b) whether this modulation was consistent with delta BROs, in order c) to acquire additional information for a better understanding of the cognitive phenomena underlying blinking. Using a broadband (0.5-100 Hz) continuous wavelet transform (CWT), we analysed a total of 189 three-second EEG epochs time-locked to the blinks of seven healthy volunteers. The EEG signals were submitted both to band-pass filtered cross-trial averaging (to obtain frequency-specific BROs) and to alpha event-related synchronization/desynchronization (i.e., blink-related synchronization/desynchronization, BRS/BRD). The alpha oscillations showed: a) an early BRS; b) a BRD in the same temporal window of the delta BROs and, c) a late BRS. We postulate that: a) the early BRS represents the short-term memory maintenance of the last visually perceived trace of the surroundings; b) the alpha BRD is associated with the comparison between the newly perceived image of the environment and its mnestic representation, and, lastly, c) the late BRS is connected with neuronal recovery phenomena.

  15. An automatic electroencephalography blinking artefact detection and removal method based on template matching and ensemble empirical mode decomposition.

    PubMed

    Bizopoulos, Paschalis A; Al-Ani, Tarik; Tsalikakis, Dimitrios G; Tzallas, Alexandros T; Koutsouris, Dimitrios D; Fotiadis, Dimitrios I

    2013-01-01

    Electrooculographic (EOG) artefacts are one of the most common causes of Electroencephalogram (EEG) distortion. In this paper, we propose a method for EOG Blinking Artefacts (BAs) detection and removal from EEG. Normalized Correlation Coefficient (NCC), based on a predetermined BA template library was used for detecting the BA. Ensemble Empirical Mode Decomposition (EEMD) was applied to the contaminated region and a statistical algorithm determined which Intrinsic Mode Functions (IMFs) correspond to the BA. The proposed method was applied in simulated EEG signals, which were contaminated with artificially created EOG BAs, increasing the Signal-to-Error Ratio (SER) of the EEG Contaminated Region (CR) by 35 dB on average.

  16. Personal names do not always survive the attentional blink: Behavioral evidence for a flexible locus of selection

    PubMed Central

    Giesbrecht, Barry; Sy, Jocelyn L.; Lewis, Megan K.

    2009-01-01

    Models of the attentional blink phenomenon (AB) typically assume that unattended information is processed to the post-perceptual level prior to selection for access to consciousness. The present experiments test this assumption by manipulating the perceptual load of the first target task (T1) and whether the second target (T2) was the participant’s own name or someone else’s name. In three experiments, increasing T1-load increased the severity of the AB for personal names. The results suggest that selection during the AB is not fixed at the post-perceptual stage, but rather the stage at which selection occurs during the AB is flexible. PMID:18396308

  17. Fluorescence Blinking and Photoactivation of All-Inorganic Perovskite Nanocrystals CsPbBr3 and CsPbBr2I.

    PubMed

    Seth, Sudipta; Mondal, Navendu; Patra, Satyajit; Samanta, Anunay

    2016-01-21

    Study of the emission behavior of all-inorganic perovskite nanocrystals CsPbBr3 and CsPbBr2I as a function of the excitation power employing fluorescence correlation spectroscopy and conventional techniques reveals fluorescence blinking in the microsecond time scale and photoinduced emission enhancement. The observation provides insight into the radiative and nonradiative deactivation pathways of these promising substances. Because both blinking and photoactivation processes are intimately linked to the charge separation efficiency and dynamics of the nanocrystals, these key findings are likely to be helpful in realizing the true potential of these substances in photovoltaic and optoelectronic applications.

  18. Estimation of a valuation function for a diabetes mellitus-specific preference-based measure of health: the Diabetes Utility Index.

    PubMed

    Sundaram, Murali; Smith, Michael J; Revicki, Dennis A; Miller, Lesley-Ann; Madhavan, Suresh; Hobbs, Gerry

    2010-01-01

    Preference-based measures of health (PBMH) provide 'preference' or 'utility' weights that enable the calculation of QALYs for the economic evaluations of interventions. The Diabetes Utility Index (DUI) was developed as a brief, self-administered, diabetes mellitus-specific PBMH that can efficiently estimate patient-derived health state utilities. To describe the development of the valuation function for the DUI, and to report the validation results of the valuation function. Multi-Attribute Utility Theory (MAUT) was used as the framework to develop a valuation function for the DUI. Twenty of 768 possible health states of the DUI classified as anchor states, single-attribute level states including corner states, and marker states were selected and described for preference elicitation interviews. Visual analogue scale and standard gamble (SG) exercises were used to measure preferences from individuals with diabetes recruited from primary care and community settings in and around Morgantown, WV, USA for the 20 health states defined by combinations of DUI attributes and severity levels. Data collected in the interviews were used to develop a valuation function that calculates utilities for the DUI health states and calculates attribute-level utilities. A validation survey of the valuation function was conducted in collaboration with the West Virginia University (WVU) Diabetes Institute. A total of 100 individuals with diabetes were interviewed and their preferences for various DUI health states measured. From data generated in the interviews, a DUI valuation function was developed on a scale where 1.00 = perfect health (PH) and 0.00 = the all worse 'pits' state, and adjusted to yield utilities on the conventional scale 1.00 = PH and 0.00 = dead. A total of 396 patients with diabetes who received care at WVU clinics completed a DUI mail validation survey (response rate = 33%). Clinical data consisting of International Classification of Diseases, 9th edition, diagnosis

  19. 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…

  20. Program Measurement and Evaluation; The Utilization of Data and Its Relationship to Program Planning and Implementation Within Library Operations.

    ERIC Educational Resources Information Center

    Phelps, Thomas C.

    The data gathering forms and activities developed during the planning and implementation of an adult independent study and guidance program at the Salt Lake City Public Library are described. The need for a utilization of this data is outlined, and the study's goals and objectives are stated. Appendixes contain flow charts of the Salt Lake City…

  1. Autocorrelation analysis for the unbiased determination of power-law exponents in single-quantum-dot blinking.

    PubMed

    Houel, Julien; Doan, Quang T; Cajgfinger, Thomas; Ledoux, Gilles; Amans, David; Aubret, Antoine; Dominjon, Agnès; Ferriol, Sylvain; Barbier, Rémi; Nasilowski, Michel; Lhuillier, Emmanuel; Dubertret, Benoît; Dujardin, Christophe; Kulzer, Florian

    2015-01-27

    We present an unbiased and robust analysis method for power-law blinking statistics in the photoluminescence of single nanoemitters, allowing us to extract both the bright- and dark-state power-law exponents from the emitters' intensity autocorrelation functions. As opposed to the widely used threshold method, our technique therefore does not require discriminating the emission levels of bright and dark states in the experimental intensity timetraces. We rely on the simultaneous recording of 450 emission timetraces of single CdSe/CdS core/shell quantum dots at a frame rate of 250 Hz with single photon sensitivity. Under these conditions, our approach can determine ON and OFF power-law exponents with a precision of 3% from a comparison to numerical simulations, even for shot-noise-dominated emission signals with an average intensity below 1 photon per frame and per quantum dot. These capabilities pave the way for the unbiased, threshold-free determination of blinking power-law exponents at the microsecond time scale.

  2. 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

    2016-02-19

    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.

  3. 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

  4. 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…

  5. Utility of ADC measurement on diffusion-weighted MRI in differentiation of prostate cancer, normal prostate and prostatitis.

    PubMed

    Esen, Meltem; Onur, Mehmet Ruhi; Akpolat, Nusret; Orhan, Irfan; Kocakoc, Ercan

    2013-08-01

    To determine the utility of apparent diffusion coefficient (ADC) values in differentiation of prostate cancer from normal prostate parenchyma and prostatitis we obtained ADC values of 50 patients at b 100, 600 and 1,000 s/mm(2) diffusion gradients. The ADC values of prostate cancer group were significantly lower than normal prostate and prostatitis group at b 600 and 1,000 s/mm(2) gradients. The ADC values at high diffusion gradients may be used in differentiation prostate cancer from normal prostate and prostatitis.

  6. 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.

  7. Brain responds to another person's eye blinks in a natural setting-the more empathetic the viewer the stronger the responses.

    PubMed

    Mandel, Anne; Helokunnas, Siiri; Pihko, Elina; Hari, Riitta

    2015-10-01

    An observer's brain is known to respond to another person's small nonverbal signals, such as gaze shifts and eye blinks. Here we aimed to find out how an observer's brain reacts to a speaker's eye blinks in the presence of other audiovisual information. Magnetoencephalographic brain responses along with eye gaze were recorded from 13 adults who watched a video of a person telling a story. The video was presented first without sound (visual), then with sound (audiovisual), and finally the audio story was presented with a still-frame picture on the screen (audio control). The viewers mainly gazed at the eye region of the speaker. Their saccades were suppressed at about 180 ms after the start of the speaker's blinks, a subsequent increase of saccade occurence to the base level, or higher, at around 340 ms. The suppression occurred in visual and audiovisual conditions but not during the control audio presentation. Prominent brain responses to blinks peaked in the viewer's occipital cortex at about 250 ms, with no differences in mean peak amplitudes or latencies between visual and audiovisual conditions. During the audiovisual, but not visual-only, presentation, the responses were the stronger the more empathetic the subject was according to the Empathic Concern score of the Interpersonal Reactivity Index questionnaire (Spearman's rank correlation, 0.73). The other person's eye blinks, nonverbal signs that often go unnoticed, thus elicited clear brain responses even in the presence of attention-attracting audiovisual information from the narrative, with stronger responses in people with higher empathy scores.

  8. Internal efficiency of nutrient utilization: what is it and how to measure it during vegetative plant growth?

    PubMed

    Santa-María, Guillermo E; Moriconi, Jorge I; Oliferuk, Sonia

    2015-06-01

    Efficient use of the resources required by plants to sustain crop production is considered an important objective in agriculture. In this context, the idea of developing crops with an enhanced ability to utilize mineral nutrients already taken up by roots has been proposed. In recent years powerful tools that allow the association of phenotypic variation with high-resolution genetic maps of crop plants have also emerged. To take advantage of these tools, accurate methods are needed to estimate the internal efficiency of nutrient utilization (ENU) at the whole-plant level, which requires using suitable conceptual and experimental approaches. Here we highlight some inconsistencies in the definitions of ENU commonly used for ENU 'phenotyping' at the vegetative stage and suggest that it would be convenient to adopt a dynamic definition. The idea that ENU should provide information about the relationship between carbon and mineral nutrient economies mainly during the period under which growth is actually affected by low internal nutrient concentration is here advocated as a guide for the selection of adequate operational ENU formulae for the vegetative stage. The desirability of using experimental approaches that allow removal of the influence of nutrient acquisition efficiency on ENU estimations is highlighted. It is proposed that the use of simulation models could help refine the conclusions obtained through these experimental procedures. Some potential limitations in breeding for high ENU are also considered.

  9. 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

    DTIC Science & Technology

    1988-01-01

    evaporation ducting measurements wore conducted over a period of 1 year in the Southern California off- shore area and for 2 weeks between Key Wast and the...WORD In the early 1970s, a series of extensive evaporation ducting measurements was conducted in different ocean areas . The purpose of the measurements...period of one year in the Southern California off-shore area . The purpose of the measurements was to determine antenna heights for optimum

  10. 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…

  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.

  12. 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.

  13. 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.

  14. The utility of intra-operative three-dimensional transoesophageal echocardiography for dynamic measurement of stroke volume.

    PubMed

    Suehiro, K; Tanaka, K; Yamada, T; Matsuura, T; Funao, T; Mori, T; Nishikawa, K

    2015-02-01

    Measurement of left ventricular stroke volume and cardiac output is very important for managing haemodynamically unstable or critically ill patients. The aims of this study were to compare stroke volume measured by three-dimensional transoesophageal echocardiography with stroke volume measured using a pulmonary artery catheter, and to examine the ability of three-dimensional transoesophageal echocardiography to track stroke volume changes induced by haemodynamic interventions. This study included 40 cardiac surgery patients. Haemodynamic variables were measured before and 2 min after haemodynamic interventions, which consisted of phenylephrine 100 μg or ephedrine 5 mg. We used Bland-Altman analysis to assess the agreement between the stroke volume measured by three-dimensional transoesophageal echocardiography and by the pulmonary artery catheter. Polar-plot and 4-quadrant plot analyses were used to assess the trending ability of three-dimensional transoesophageal echocardiography compared with the pulmonary artery catheter. Bias and percentage error were -1.2 ml and 20%, respectively. The concordance rate in the 4-quadrant analysis after phenylephrine and ephedrine administration was 75% and 84%, respectively. In the polar-plot analysis, the angular concordance rate was 66% and 73% after phenylephrine and ephedrine administration, respectively. Three-dimensional transoesophageal echocardiography was clinically acceptable for measuring stroke volume; however, it was not sufficiently reliable for tracking stroke volume changes after haemodynamic interventions.

  15. 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

  16. Differential effects of exogenous and endogenous cueing in multi-stream RSVP: implications for theories of attentional blink

    PubMed Central

    Zhang, Dexuan; Shao, Liping; Martens, Sander

    2010-01-01

    The attentional blink (AB) refers to the finding that performance on the second of two targets (T1 and T2) in a rapid serial visual presentation (RSVP) stream is impaired when the targets are presented within 200–500 ms. To explore the possible interaction between spatial attentional orienting and temporary attentional deficits, this study used central (endogenous) and peripheral (exogenous) cues in a multi-stream RSVP task and compared the endogenous and exogenous cueing effects inside and outside of the AB period. While the endogenous cueing effect was constant in magnitude over time, the exogenous cueing effect was significantly larger inside than outside of the AB period. Theoretical implications of these findings for the interaction between attention mechanisms in spatial and temporal domains are discussed. PMID:20686889

  17. Derivation of a new parametric impulse response matrix utilized for nodal wind load identification by response measurement.

    PubMed

    Kazemi Amiri, A; Bucher, C

    2015-05-26

    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.

  18. Curriculum-Based Measures for Secondary Students: Utility and Task Specificity of Text-Based Reading and Vocabulary Measures for Predicting Performance on Content-Area Tasks.

    ERIC Educational Resources Information Center

    Espin, Christine A.; Deno, Stanley L.

    1995-01-01

    This study of 121 10th-grade students investigated the criterion-related validity of 2 potential curriculum-based measurements, reading from text and identifying vocabulary meaning, for predicting student performance on content-area study tasks. Correlational and multiple regression techniques found the vocabulary measure to be the stronger…

  19. 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.

  20. [Measures to prevent patient identification errors in blood collection/physiological function testing utilizing a laboratory information system].

    PubMed

    Shimazu, Chisato; Hoshino, Satoshi; Furukawa, Taiji

    2013-08-01

    We constructed an integrated personal identification workflow chart using both bar code reading and an all in-one laboratory information system. The information system not only handles test data but also the information needed for patient guidance in the laboratory department. The reception terminals at the entrance, displays for patient guidance and patient identification tools at blood-sampling booths are all controlled by the information system. The number of patient identification errors was greatly reduced by the system. However, identification errors have not been abolished in the ultrasound department. After re-evaluation of the patient identification process in this department, we recognized that the major reason for the errors came from excessive identification workflow. Ordinarily, an ultrasound test requires patient identification 3 times, because 3 different systems are required during the entire test process, i.e. ultrasound modality system, laboratory information system and a system for producing reports. We are trying to connect the 3 different systems to develop a one-time identification workflow, but it is not a simple task and has not been completed yet. Utilization of the laboratory information system is effective, but is not yet perfect for patient identification. The most fundamental procedure for patient identification is to ask a person's name even today. Everyday checks in the ordinary workflow and everyone's participation in safety-management activity are important for the prevention of patient identification errors.

  1. 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.

  2. 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

  3. 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…

  4. RDT&E Laboratory Capacity Utilization and Productivity Measurement Methods for Financial Decision-Making within DON.

    DTIC Science & Technology

    1998-06-01

    would have to include both tangible and intangible factors. There can be little doubt that, in today’s knowledge-based economy, intangible assets (like...Stewart, 1994). Measuring intangible assets , such as intellectual assets of research scientists, programmers, and technicians, that comprise the

  5. Career Instruments and High School Students with Learning Disabilities: Support for the Utility of Three Vocational Measures

    ERIC Educational Resources Information Center

    Dipeolu, Abiola O.

    2007-01-01

    Conventional wisdom in the area of assessment strongly supports the notion that instruments used for vocational or career decision-making purposes should possess sound psychometric properties. This study is a preliminary attempt to examine the reliability and validity of three important career decision-making measures administered to high school…

  6. 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.

  7. 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.

  8. 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.

  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. 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.

  11. 41 CFR 102-74.310 - What measures must Federal agencies take to improve the utilization of parking facilities?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 74-FACILITY MANAGEMENT Facility Management Parking Facilities... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false What measures...

  12. 41 CFR 102-74.310 - What measures must Federal agencies take to improve the utilization of parking facilities?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 74-FACILITY MANAGEMENT Facility Management Parking Facilities... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false What measures...

  13. 41 CFR 102-74.310 - What measures must Federal agencies take to improve the utilization of parking facilities?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 74-FACILITY MANAGEMENT Facility Management Parking Facilities... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false What measures...

  14. Assessment of near-source air pollution at a fine spatial scale utilizing a mobile measurement platform approach

    EPA Science Inventory

    Mobile monitoring is an emerging strategy to characterize spatially and temporally variable air pollution in areas near sources. EPA’s Geospatial Monitoring of Air Pollution (GMAP) vehicle, an all-electric vehicle measuring real-time concentrations of particulate and gaseous poll...

  15. A surface work function measurement technique utilizing constant deflected grazing electron trajectories: oxygen uptake on Cu(001).

    PubMed

    Ermakov, A V; Ciftlikli, E Z; Syssoev, S E; Shuttleworth, I G; Hinch, B J

    2010-10-01

    We report on the application of a novel nondestructive in-vacuum technique for relative work function measurements, employing a grazing incidence electron deflection above a sample with a planar surface. Two deflected electron beam detectors are used as a position sensitive detector to control feedback to the sample potential as the sample work function changes. With feedback the sample potential exactly follows the surface sample-size averaged work function variation, so that the deflected beam trajectory remains stable. We also discuss methods to optimize the initial electron trajectories for this method, so as to minimize unwanted effects such as from uncontrolled external magnetic fields. As the electron beam does not impinge on the surface in this new technique electron induced desorption, ionization, dissociation, and/or decomposition is not induced at the interface. Importantly also the technique allows for free access to the surfaces enabling simultaneous deposition/evaporation and/or application of other surface characterization methods. We demonstrate its application in concurrent measurements of helium atom reflectivity and work function changes taking place during molecular oxygen exposure of a Cu(001) surface. A work function measurement sensitivity and stability is demonstrated at ∼10 mV at a sampling rate of 1 Hz and after application of an ∼7 s smoothing routine. In comparison to the helium atom reflectivity measurements, the work function measurements are more sensitive to the initial O uptake, and less so to the final coverage variations and possible surface reordering at higher O coverages.

  16. Labview utilities

    SciTech Connect

    Persaud, Arun

    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.

  17. Utilizing artificial neural networks in MATLAB to achieve parts-per-billion mass measurement accuracy with a fourier transform ion cyclotron resonance mass spectrometer.

    PubMed

    Williams, D Keith; Kovach, Alexander L; Muddiman, David C; Hanck, Kenneth W

    2009-07-01

    Fourier transform ion cyclotron resonance mass spectrometry has the ability to realize exceptional mass measurement accuracy (MMA); MMA is one of the most significant attributes of mass spectrometric measurements as it affords extraordinary molecular specificity. However, due to space-charge effects, the achievable MMA significantly depends on the total number of ions trapped in the ICR cell for a particular measurement, as well as relative ion abundance of a given species. Artificial neural network calibration in conjunction with automatic gain control (AGC) is utilized in these experiments to formally account for the differences in total ion population in the ICR cell between the external calibration spectra and experimental spectra. In addition, artificial neural network calibration is used to account for both differences in total ion population in the ICR cell as well as relative ion abundance of a given species, which also affords mean MMA values at the parts-per-billion level.

  18. 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.

  19. 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.

  20. Achieving High Pressure Shock Hugoniot Measurements in Cylindrical Geometry Utilizing a High-Explosive Pulsed Power Drive

    DTIC Science & Technology

    2011-06-01

    to conduct high velocity material experiments and measure shock velocities at pressures near 1 TPa. The DEMG (Disk Explosive Magnetic Generator ... Explosive Magnetic Generator ) will be able to achieve extremely high currents with as much as 70 MA usable for driving a z-pinch experiment. In this...shock velocities at pressures near 1 TPa. The DEMG (Disk Explosive Magnetic Generator ) is used to drive a >60MA current that accelerates an aluminum

  1. Depression in multiple sclerosis: The utility of common self-report instruments and development of a disease-specific measure.

    PubMed

    Strober, Lauren B; Arnett, Peter A

    2015-01-01

    The ultimate objective of the present investigation was to improve the detection of depression in multiple sclerosis (MS) by comparing common self-report depression measures to a new, modified measure, which takes into account the contribution that symptoms of MS may have on individuals' reports. There has been a longstanding concern regarding the accurate assessment of depression in MS, particularly with regard to the overlap of MS symptomatology and neurovegetative depression symptoms on self-report questionnaires, which may lead to an overdiagnosis of depression in MS. To address these difficulties, we previously proposed a "trunk and branch" of depression in MS. This model allows for the delineation of what symptoms are most reflective of depression in MS. By identifying these symptoms, it was possible to develop a modified Beck Depression Inventory (BDI) in which only the items found to be most related to depression in MS are included in the new measure, the MS Specific BDI (MS-BDI). We compared this measure to common self-report instruments (Beck Depression Inventory-Second Edition, BDI-II; Beck Depression Inventory-Fast Screen, BDI-FS; Chicago Multiscale Depression Inventory, CMDI). Results suggest that cutoffs of 4 on the BDI-FS and 23 on the CMDI Mood subscale are most useful when screening for depression in MS, with a sensitivity for both of 100%, while a cutoff of 19 on the BDI-II, a cutoff of 22 on the CMDI Evaluative scale, and a cutoff of 8 on the MS-BDI had high specificities, suggesting they can be used as to assist in diagnosing depression in MS.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. The Utility and Dynamics of Salivary Sex Hormone Measurements in the National Social Life, Health, and Aging Project, Wave 2

    PubMed Central

    Schumm, L. Philip; McClintock, Martha K.

    2014-01-01

    Objectives. Sex hormones affect physical, mental, and social health, yet their role in mediating social effects on aging is understudied. To facilitate such analyses with the National Social Life, Health & Aging Project Wave 2, we summarize the conceptual background, collection protocols, laboratory assays, and data analysis strategies for biologically active (free) levels of testosterone, estradiol, progesterone, and dehydroepiandrosterone (DHEA). Method. Saliva from passive drool was collected from returning Wave 1 respondents and non-respondents as well as their partners during an in-home interview. Specimens were frozen and sent to Dresden LabService GmbH for duplicate assays of biologically active steroids using identical assay kits from National Social Life, Health, and Aging Project (NSHAP) Wave 1 (SaliCap, Catalog No. RE69995). Overall, 2,772 testosterone, 2,504 estradiol, 2,714 progesterone, and 2,800 DHEA measurements are publically available for Wave 2 analyses. Through a series of weighted linear regressions, all 4 steroids are compared by gender and age and to Wave 1 measurements. Results. Men had higher levels of both free testosterone and progesterone than women; women and men had the same levels of estradiol and DHEA. Both free testosterone and DHEA decreased with age. We also found significant wave effects for all 4 sex hormones. Conclusion. NSHAP Waves 1 and 2 are the first U.S. probability sample studies to measure these 4 salivary sex hormones simultaneously, providing individual profiles 5 years apart. Wave 2 data demonstrate differences by gender and trends by age that are similar to those found in other saliva-based and serum-based studies of free steroid levels. The differences between waves arising from the change in assay laboratory need to be adjusted in future longitudinal analyses using NSHAP Wave 1 and Wave 2 steroid data. PMID:25360023

  8. Examining the utility of a bite-count-based measure of eating activity in free-living human beings.

    PubMed

    Scisco, Jenna L; Muth, Eric R; Hoover, Adam W

    2014-03-01

    The obesity epidemic has triggered a need for novel methods for measuring eating activity in free-living settings. Here, we introduce a bite-count method that has the potential to be used in long-term investigations of eating activity. The purpose of our observational study was to describe the relationship between bite count and energy intake and determine whether there are sex and body mass index group differences in kilocalories per bite in free-living human beings. From October 2011 to February 2012, 77 participants used a wrist-worn device for 2 weeks to measure bite count during 2,975 eating activities. An automated self-administered 24-hour recall was completed daily to provide kilocalorie estimates for each eating activity. Pearson's correlation indicated a moderate, positive correlation between bite count and kilocalories (r=0.44; P<0.001) across all 2,975 eating activities. The average per-individual correlation was 0.53. A 2 (sex)×3 (body mass index group: normal, overweight, obese) analysis of variance indicated that men consumed 6 kcal more per bite than women on average. However, there were no body mass index group differences in kilocalories per bite. This was the longest study of a body-worn sensor for monitoring eating activity of free-living human beings to date, which highlights the strong potential for this method to be used in future, long-term investigations.

  9. 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.

  10. Utility of measuring serum concentrations of anti-TNF agents and anti-drug antibodies in inflammatory bowel disease.

    PubMed

    Guerra, Iván; Chaparro, María; Bermejo, Fernando; Gisbert, Javier P

    2011-07-01

    Tumor necrosis factor alpha (TNFα) is a cytokine with a critical role in the pathogenesis of some chronic inflammatory diseases, such as inflammatory bowel diseases. Anti-TNF agents, which neutralize the biological activity of TNFα, are widely used among the different therapeutic options for the treatment of patients with inflammatory bowel diseases. These drugs are very useful in clinical practice, but some patients experience lack and loss of response during the treatment. Drug serum concentration, antibodies against anti-TNF agents, clearance of the drug, formation of immune complexes, a more severe disease and probably other unknown factors can influence the treatment's efficacy. Nowadays, the management of patients with lack or loss of response is empirical. The measurement of drug concentrations and antibodies against anti-TNF agents might be useful for improving the selection of patients that will benefit from the maintenance treatment. In clinical practice, these methods may help us decide which strategy will be used in cases of loss of response: treatment intensification, shortening the infusion interval, increasing the dose, switching to another anti-TNF agent or to a drug with another mechanism of action. The optimal strategy in the future may be comprised of an early detection of loss of response to the treatment by assessing clinical symptoms and finding evidence of activity of the disease on endoscopic or radiological examinations when necessary, as well as a better management of anti-TNF treatment aided by measuring the serum concentration of the drug and antibodies against the drug.

  11. 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.

  12. Examining the utility of the PCL:SV as a screening measure using competing factor models of psychopathy.

    PubMed

    Guy, Laura S; Douglas, Kevin S

    2006-06-01

    The correspondence between the Hare Psychopathy Checklist: Screening Version (PCL:SV; S. D. Hart, D. N. Cox, & R. D. Hare, 1995) and the Hare Psychopathy Checklist-Revised (PCL-R; R. D. Hare, 1991, 2003) was examined in forensic (N = 175) and correctional (N = 188) samples. Intermeasure correlations for Total scores (.95 forensic, .94 correctional) and the original 2-factor, D. J. Cooke and C. Michie's (2001) 3-factor, and R. D. Hare's (2003) 4-facet models (range = .87-.95) were high. Area under the curve values for the PCL:SV were .98 in both samples (cutoff = PCL-R Total score of 25). The PCL:SV performed well as a screen, maximizing false positive relative to false negative errors. Close correlations for prediction of violent recidivism in the correctional sample were obtained for the PCL-R (.42) and PCL:SV (.37). Results indicate the robust relation between the measures is maintained whether they are completed on the basis of file review only or file plus interview and whether the same or different raters score the measures.

  13. The Utility of Clinical Measures for the Diagnosis of Achilles Tendon Injuries: A Systematic Review With Meta-Analysis

    PubMed Central

    Reiman, Michael; Burgi, Ciara; Strube, Eileen; Prue, Kevin; Ray, Keaton; Elliott, Amanda; Goode, Adam

    2014-01-01

    Objective: To summarize and evaluate the current diagnostic accuracy of clinical measures used to diagnose Achilles tendon injuries. Data Sources: A literature search of MEDLINE, CINAHL, and EMBASE databases was conducted with key words related to diagnostic accuracy and Achilles tendon injuries. Study Selection: Original research articles investigating Achilles tendon injuries against an acceptable reference standard were included. Data Extraction: Three studies met the inclusion criteria. Quality assessment was conducted using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. DerSimonian-Laird random-effects models were used to pool sensitivity (SN), specificity (SP), and diagnostic odds ratios with their 95% confidence intervals (CIs). Data Synthesis: The SN and negative likelihood ratio (−LR) values for Achilles tendon rupture measures ranged from 0.73 (95% CI = 0.65, 0.81) and 0.30 (95% CI = 0.23, 0.40) to 0.96 (95% CI = 0.93, 0.99) and 0.04 (95% CI = 0.02, 0.10), respectively, whereas SP and positive likelihood ratio (+LR) values ranged from 0.85 (95% CI = 0.72, 0.98) and 6.29 (95% CI = 2.33, 19.96) to 0.93 (95% CI = 0.84, 1.00) and 13.71 (95% CI = 3.54, 51.24), respectively, with the highest SN and SP both reported in the calf-squeeze test. The SN and −LR values for Achilles tendinopathy measures ranged from 0.03 (95% CI = 0.00, 0.08) and 0.97 (95% CI = not reported) to 0.89 (95% CI = 0.75, 0.98) and 0.19 (95% CI = not reported), whereas SP and +LR values ranged from 0.58 (95% CI = 0.38, 0.77) and 2.12 (95% CI = not reported) to 1.00 (95% CI = 1.00, 1.00) and infinity, respectively, with the highest SN and SP reported for morning stiffness and palpation for crepitus. Pooled analyses demonstrated similar diagnostic properties in all 3 clinical measures (arc sign, palpation, and Royal London Hospital test), with SN and −LR ranging from 0.42 (95% CI = 0.23, 0.62) and 0.68 (95% CI = 0.50, 0.93), respectively, for the arc sign, to 0.64 (95% CI

  14. 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.

  15. Measurement and modeling of optical performance of wire grids and liquid-crystal displays utilizing grid polarizers.

    PubMed

    Sergan, Tatiana; Lavrentovich, Marina; Kelly, Jack; Gardner, Eric; Hansen, Douglas

    2002-09-01

    We studied the optical performance of a reflective wire-grid polarizer designed for visible light. The polarizer reflects E polarization and transmits H polarization with low losses. The studies of transmission and reflectivity of nonpolarized and polarized light from single grids and stacked grids show that the optical performance of wire-grid polarizers can be adequately described by representing the polarizer as an effective uniaxial medium with anisotropic absorption. The description facilitates the incorporation of the polarizers in modeling procedures widely used in the design of liquid-crystal devices. We present the modeling and measurement results of twisted-nematic devices with wire-grid polarizers serving simultaneously as reflective polarizers, alignment layers, and back electrodes. The application of wire-grid polarizers for reflective liquid-crystal devices provides brightness enhancement, high contrast ratio at wide viewing angles, and elimination of viewing parallax.

  16. POLICY EVALUATION FOR THE EFFECTIVE UTILIZATION MEASURES OF EXTENSIVE USED SPACES IN THE CENTRAL AREA OF KUMAMOTO CITY

    NASA Astrophysics Data System (ADS)

    Mizokami, Shoshi; Egawa, Taichi

    Recently, The Open-air Parkin g increases in city center. Therefore, the decline of th e central area is caused as a results and the number of those who visit th e town has decreased. Purposes of research are as follows. It clarifies that landowners and leaseholders that have the Open-air Parking in the central area think land use. It examines that support plan that the administration should do to straighten out that problem. Various support plans are examined from the cost benefit analysis, revenue, and value of support plan. The composition is as follows. In Chapte r 2, it clarifies that landowners and leaseholders that have the Open-air Parking in the central area think land use from "Land use intention investigation". In Chapter 3, the effective profit use usage selection model is presumed. In Chapter 4, the simulation analysis that measures the effect and the value of the support plan is done.

  17. Utility of the Tono-Pen in Measuring Intraocular Pressure in Trinidad: A Cross-sectional Study

    PubMed Central

    Billy, A; David, PE; Mahabir, AK; Seerattan, CP; Street, JM; Walcott, VD; Yarna, RJ; Murray, DC; Maharaj, RG

    2015-01-01

    ABSTRACT Aim: To determine the sensitivity and specificity of the Reichert™ Tono-Pen AVIA® when used by novice medical students in an ethnically diverse population in Trinidad. Subject and Methods: Participants were residents of Trinidad between the ages of 20 and 90 years attending the Ophthalmology Clinic at the Eric Williams Medical Sciences Complex (EWMSC). Intraocular pressure (IOP) was measured using the Goldmann applanation tonometer (the gold standard) for ophthalmology clinic patients as part of their routine care. Intraocular pressure measurements were then taken using the Tono-Pen. Results: One hundred persons participated, consisting of Indo-Trinidadians (55%), Afro-Trinidadians (36%), Mixed (8%) and 1% of Caucasian descent. Fourteen per cent reported a diagnosis of glaucoma with 70.6% of these being of African descent. One hundred and ninety-eight readings of IOP were taken. At a cut-off point of 21 mmHg, there were nine true positives, four false positives, seven false negatives and 178 true negatives. The sensitivity and specificity were found to be 56.3% (95% CI 33.2, 76.9) and 97.8% (95% CI 94.5, 99.1), respectively. The positive predictive value was calculated as 69.2% (95% CI 42.4, 87.3) while the negative predictive value was 96.2% (95% CI 92.4, 98.2). The prevalence of elevated IOP in this population was 8.1% (95% CI 4.8, 13.0). The likelihood ratio of a positive result was calculated to be 25.6 (95% CI 8.6, 73.9). Conclusion: The high specificity and negative predictive value suggests that the Tono-Pen can be used with minimal training, and can prove beneficial at the primary care level in the exclusion of increased IOP in an ethnically diverse high-risk Caribbean population. PMID:26624589

  18. 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

  19. The blink reflex and the corneal reflex are followed by cortical activity resembling the nociceptive potentials induced by trigeminal laser stimulation in man.

    PubMed

    de Tommaso, M; Libro, G; Guido, M; Sciruicchio, V; Puca, F

    2001-09-07

    Laser stimulation of the supraorbital regions evokes brain potentials (LEPs) related to trigeminal nociception. The aim of this study was to record the R2 component of the blink reflex and the corneal reflex in 20 normal subjects, comparing the scalp activity following these reflexes with the nociceptive potentials evoked by CO2 laser stimulation of supraorbital regions. Cortical and muscular reflexes evoked by stimulation of the first trigeminal branch were recorded simultaneously. The R2 component of the blink reflex and the corneal reflex were followed by two cortical peaks, which resembled morphologically N-P waves of LEPs. The two peaks demonstrated a difference in latency of approximately 40 ms, which is consistent with activation time of nociception. This finding suggests that these reflexes are induced by activation of small pain-related fibers.

  20. 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

  1. Measuring the safety of excreta disposal behavior in India with the new Safe San Index: reliability, validity and utility.

    PubMed

    Jenkins, Marion W; Freeman, Matthew C; Routray, Parimita

    2014-08-15

    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.

  2. Utility of behavioral versus cognitive measures in differentiating between subtypes of frontotemporal lobar degeneration and Alzheimer's disease.

    PubMed

    Heidler-Gary, Jennifer; Gottesman, Rebecca; Newhart, Melissa; Chang, Shannon; Ken, Lynda; Hillis, Argye E

    2007-01-01

    We hypothesized that a modified version of the Frontal Behavioral Inventory (FBI-mod), along with a few cognitive tests, would be clinically useful in distinguishing between clinically defined Alzheimer's disease (AD) and subtypes of frontotemporal lobar degeneration (FTLD): frontotemporal dementia (dysexecutive type), progressive nonfluent aphasia, and semantic dementia. We studied 80 patients who were diagnosed with AD (n = 30) or FTLD (n = 50), on the basis of a comprehensive neuropsychological battery, imaging, neurological examination, and history. We found significant between-group differences on the FBI-mod, two subtests of the Rey Auditory Verbal Learning Test (verbal learning and delayed recall), and the Trail Making Test Part B (one measure of 'executive functioning'). AD was characterized by relatively severe impairment in verbal learning, delayed recall, and executive functioning, with relatively normal scores on the FBI-mod. Frontotemporal dementia was characterized by relatively severe impairment on the FBI-mod and executive functioning in the absence of severe impairment in verbal learning and recall. Progressive nonfluent aphasia was characterized by severe impairment in executive functioning with relatively normal scores on verbal learning and recall and FBI-mod. Finally, semantic dementia was characterized by relatively severe deficits in delayed recall, but relatively normal performance on new learning, executive functioning, and on FBI-mod. Discriminant function analysis confirmed that the FBI-mod, in conjunction with the Rey Auditory Verbal Learning Test, and the Trail Making Test Part B categorized the majority of patients as subtypes of FTLD or AD in the same way as a full neuropsychological battery, neurological examination, complete history, and imaging. These tests may be useful for efficient clinical diagnosis, although progressive nonfluent aphasia and semantic dementia are likely to be best distinguished by language tests not included

  3. 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

  4. 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

  5. Discharge profiles of abducens, accessory abducens, and orbicularis oculi motoneurons during reflex and conditioned blinks in alert cats.

    PubMed

    Trigo, J A; Gruart, A; Delgado-García, J M

    1999-04-01

    The discharge profiles of identified abducens, accessory abducens, and orbicularis oculi motoneurons have been recorded extra- and intracellularly in alert behaving cats during spontaneous, reflexively evoked, and classically conditioned eyelid responses. The movement of the upper lid and the electromyographic activity of the orbicularis oculi muscle also were recorded. Animals were conditioned by short, weak air puffs or 350-ms tones as conditioned stimuli (CS) and long, strong air puffs as unconditioned stimulus (US) using both trace and delayed conditioning paradigms. Motoneurons were identified by antidromic activation from their respective cranial nerves. Orbicularis oculi and accessory abducens motoneurons fired an early, double burst of action potentials (at 4-6 and 10-16 ms) in response to air puffs or to the electrical stimulation of the supraorbital nerve. Orbicularis oculi, but not accessory abducens, motoneurons fired in response to flash and tone presentations. Only 10-15% of recorded abducens motoneurons fired a late, weak burst after air puff, supraorbital nerve, and flash stimulations. Spontaneous fasciculations of the orbicularis oculi muscle and the activity of single orbicularis oculi motoneurons that generated them also were recorded. The activation of orbicularis oculi motoneurons during the acquisition of classically conditioned eyelid responses happened in a gradual, sequential manner. Initially, some putative excitatory synaptic potentials were observed in the time window corresponding to the CS-US interval; by the second to the fourth conditioning session, some isolated action potentials appeared that increased in number until some small movements were noticed in eyelid position traces. No accessory abducens motoneuron fired and no abducens motoneuron modified their discharge rate for conditioned eyelid responses. The firing of orbicularis oculi motoneurons was related linearly to lid velocity during reflex blinks but to lid position during

  6. The Limited Clinical Utility of Testosterone, Estradiol, and Sex Hormone Binding Globulin Measurements in the Prediction of Fracture Risk and Bone Loss in Older Men.

    PubMed

    Orwoll, Eric S; Lapidus, Jodi; Wang, Patty Y; Vandenput, Liesbeth; Hoffman, Andrew; Fink, Howard A; Laughlin, Gail A; Nethander, Maria; Ljunggren, Östen; Kindmark, Andreas; Lorentzon, Mattias; Karlsson, Magnus K; Mellström, Dan; Kwok, Anthony; Khosla, Sundeep; Kwok, Timothy; Ohlsson, Claes

    2017-03-01

    Measurement of serum testosterone (T) levels is recommended in the evaluation of osteoporosis in older men and estradiol (E2) and sex hormone binding globulin (SHBG) levels are associated with the rate of bone loss and fractures, but the clinical utility of sex steroid and SHBG measurements for the evaluation of osteoporosis in men has not been examined. To evaluate whether measurements of T, E2, and/or SHBG are useful for the prediction of fracture risk or the rate of bone loss in older men, we analyzed longitudinal data from 5487 community-based men participating in the Osteoporotic Fractures in Men (MrOS) study in the United States, Sweden, and Hong Kong. Serum T, E2, and SHBG levels were assessed at baseline; incident fractures were self-reported at 4-month intervals with radiographic verification (US), or ascertained via national health records (Sweden, Hong Kong). Rate of bone loss was assessed by serial measures of hip bone mineral density (BMD). We used receiver operating characteristic (ROC) curves, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) to assess improvement in prediction. Mean age at baseline was 72 to 75 years and the prevalence of low T levels (<300 ng/dL) was 7.6% to 21.3% in the three cohorts. There were 619 incident major osteoporotic and 266 hip fractures during follow-up of approximately 10 years. Based on ROC curves, there were no improvements in fracture risk discrimination for any biochemical measure when added to models, including the Fracture Risk Assessment Tool (FRAX) with BMD. Although minor improvements in NRI were observed for the dichotomous parameters low bioavailable E2 (BioE2) (<11.4 pg/mL) and high SHBG (>59.1 nM), neither sex steroids nor SHBG provided clinically useful improvement in fracture risk discrimination. Similarly, they did not contribute to the prediction of BMD change. In conclusion, there is limited clinical utility of serum E2, T, and SHBG measures for the

  7. 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.

  8. Utilization and utility of immunohistochemistry in dermatopathology.

    PubMed

    Naert, Karen A; Trotter, Martin J

    2013-02-01

    Immunohistochemistry (IHC) is considered a valuable ancillary tool for dermatopathology diagnosis, but few studies have measured IHC utilization by dermatopathologists or assessed its diagnostic utility. In a regionalized, community-based dermatopathology practice, we measured IHC utilization (total requests, specific antibodies requested, and final diagnosis) over a 12-month period. Next, we assessed diagnostic utility by comparing a preliminary "pre-IHC" diagnosis based on routine histochemical staining with the final diagnosis rendered after consideration of IHC results. The dermatopathology IHC utilization rate was 1.2%, averaging 3.6 stains requested per case. Melanocytic, hematolymphoid, and fibrohistiocytic lesions made up 23%, 18%, and 16%, respectively, of the total cases requiring IHC. S100 and Melan A were the most frequently requested stains, ordered on 50% and 34% of IHC cases, respectively. The utility study revealed that IHC changed the diagnosis in 11%, confirmed a diagnosis, or excluded a differential diagnosis in 77%, and was noncontributory in 4% of cases. Where IHC results prompted a change in diagnosis, 14% were a change from a benign to malignant lesion, whereas 32% changed from one malignant entity to another. IHC is most commonly used in cutaneous melanocytic and hematolymphoid lesions. In 11% of dermatopathology cases in which IHC is used, information is provided that changes the H&E diagnosis. Such changes may have significant treatment implications. IHC is noncontributory in only a small percentage of cases.

  9. The utility of a non-verbal prospective memory measure as a sensitive marker for early-stage Alzheimer's disease in Hong Kong.

    PubMed

    Tse, C S; Chang, J F; Fung, Ada W T; Lam, Linda C W; Hau, K T; Leung, Grace T Y; Balota, D A

    2014-09-23

    ABSTRACT Background: With the proportion of older adults in Hong Kong projected to double in size in the next 30 years, it is important to develop measures for detecting individuals in the earliest stage of Alzheimer's disease (AD, 0.5 in Clinical Dementia Rating, CDR). We tested the utility of a non-verbal prospective memory task (PM, ability to remember what one has to do when a specific event occurs in the future) as an early marker for AD in Hong Kong Chinese. Methods: A large community dwelling sample of older adults who are healthy controls (CDR 0, N = 125), in the earliest stage of AD (CDR 0.5, N = 125), or with mild AD (CDR 1, N = 30) participated in this study. Their reaction time/accuracy data were analyzed by mixed-factor analyses of variance to compare the performance of the three CDR groups. Logistic regression analyses were performed to test the discriminative power of these measures for CDR 0 versus 0.5 participants. Results: Prospective memory performance declined as a function of AD severity: CDR 0 > CDR 0.5 > CDR 1, suggesting the effects of early-stage AD and AD progression on PM. After partialling out the variance explained by psychometric measures (e.g., ADAS-Cog), reaction time/accuracy measures that reflected the PM still significantly discriminated between CDR 0 versus 0.5 participants in most of the cases. Conclusion: The effectiveness of PM measures in discriminating individuals in the earliest stage of AD from healthy older adults suggests that these measures should be further developed as tools for early-stage AD discrimination.

  10. Measuring the utility of the Science, Technology, Engineering, Mathematics (STEM) Academy Measurement Tool in assessing the development of K-8 STEM academies as professional learning communities

    NASA Astrophysics Data System (ADS)

    Irish, Teresa J.

    The aim of this study was to provide insights addressing national concerns in Science, Technology, Engineering, and Mathematics (STEM) education by examining how a set of six perimeter urban K-12 schools were transformed into STEM-focused professional learning communities (PLC). The concept of a STEM Academy as a STEM-focused PLC emphasizes the development of a STEM culture where professional discourse and teaching are focused on STEM learning. The STEM Academies examined used the STEM Academy Measurement Tool and Rubric (Tool) as a catalyst for discussion and change. This Tool was developed with input from stakeholders and used for school-wide initiatives, teacher professional development and K-12 student engagement to improve STEM teaching and learning. Two primary goals of this study were to assess the levels of awareness and use of the tool by all stakeholders involved in the project and to determine how the Tool assisted in the development and advancement of these schools as STEM PLCs. Data from the STEM Academy Participant Survey was analyzed to determine stakeholders' perceptions of the Tool in terms of (i) how aware stakeholders were of the Tool, (ii) whether they participated in the use of the Tool, (iii) how the characteristics of PLCs were perceived in their schools, and finally (iv) how the awareness of the Tool influenced teachers' perceptions of the presence of PLC characteristics. Findings indicate that school faculty were aware of the Tool on a number of different levels and evidence exists that the use of the Tool assisted in the development of STEM Academies, however impact varied from school to school. Implications of this study suggest that the survey should be used for a longer period of time to gain more in-depth knowledge on teachers' perceptions of the Tool as a catalyst across time. Additional findings indicate that the process for using the Tool should be ongoing and involve the stakeholders to have the greatest impact on school culture

  11. The effective stimulating pulse for restoration of blink function in unilateral facial nerve paralysis rabbits, verified by a simple FES system.

    PubMed

    Jie, Tan; Zhiqiang, Gao; Guodong, Feng; Yubin, Xue; Xiuyong, Ding; Tingting, Cui; Yang, Zhao

    2016-10-01

    The trains of 200 ms biphasic square pulses with the width of 9 ms delivered at 50 Hz were found to be the most suitable and effective mean as stimulation in FES system of restoring the blink function in unilateral facial nerve paralysis rabbit model. FES system is a reliable tool for these patients. Facial paralysis affects thousands of people every year. Many will have long term facial difficulties and the loss of the ability to blink the eye, which can lead to potential loss of the eye. Although many treatments exist, no one approach corrects all the deficits associated with the loss of orbicularis oculi function. FES is a means of providing movement in paralysed muscles to assist with practical activities and one possible way of restoring blink and other functions in these patients. Although some previous researches had investigated the effect of simple FES system on restoration of paralyzed facial muscles, there is still controversy about the appropriate details of the most effective stimulating pulses, such as the frequency, wave pattern and pulse width. Our aim is to find out the parameters of the most appropriate and effective stimulatin verify it by a simple FES system. 24 healthy adult male New Zealand white rabbits were accepted the surgery of right side facial nerve main trunk transaction under general anesthesia as the unilateral facial nerve paralysis models. The platinum tungsten alloy electrodes were implanted in orbicularis oculi muscle. The parameters of stimulus pulses were set to a 200 ms biphasic pulse with different waveforms (square, sine and triangle), different frequencies (25, 50, 100 Hz) and different widths from 1 to 9 ms. Next, we set up a simple FES system to verify the previous results as the stimulus signal. We observed the movement of the both sides of eyelid when eye blink induced by different kinds of pulses. In all animals, the three kinds of waveforms pulse with frequency of 25 Hz could not evoke the smooth blink movement

  12. 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.

  13. 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.

  14. 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.

  15. Simultaneous, real-time measurement of nitric oxide and oxygen dynamics during cardiac ischemia-reperfusion of the rat utilizing sol-gel-derived electrochemical microsensors.

    PubMed

    Kang, Sung Wook; Kim, Ok Kyun; Seo, Bochan; Lee, Sung Ho; Quan, Fu Shi; Shin, Jae Ho; Lee, Gi-Ja; Park, Hun-Kuk

    2013-11-13

    In this study, we simultaneously measured nitric oxide (NO) and oxygen (O2) dynamics in the myocardium during myocardial ischemia-reperfusion (IR) utilizing sol-gel modified electrochemical NO and O2 microsensors. In addition, we attempted to clarify the correlation between NO release in the ischemic period and O2 restoration in the myocardium after reperfusion, comparing a control heart with a remote ischemic preconditioning (RIPC)-treated heart as an attractive strategy for myocardial protection. Rat hearts were randomly divided into two groups: a control group (n=5) and an RIPC group (n=5, with RIPC treatment). Myocardia that underwent RIPC treatment (182±70 nM, p<0.05) released more NO during the ischemic period than those of the control group (63±41 nM). The restoration value of oxygen tension (pO2) in the RIPC group significantly increased and was restored to pre-ischemic levels (92.6±36.8%); however, the pO2 of the control group did not increase throughout the reperfusion period (5.7±7.5%, p=0.001). Myocardial infarct size measurements revealed a significant decrease in cell death in the myocardium region of the RIPC group (41.44±6.42%, p=0.001) compared with the control group (60.05±10.91%). As a result, we showed that the cardioprotective effect of RIPC could be attributed to endogenous NO production during the ischemic period, which subsequently promoted reoxygenation in post-ischemic myocardia during early reperfusion. Our results suggest that the promotion of endogenous formation during an ischemic episode might be helpful as a therapeutic strategy for protecting the myocardium from IR injury. Additionally, our NO and O2 perm-selective microsensors could be utilized to evaluate the effect of drug or treatment.

  16. 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.

  17. The Relative Utility of Three English Language Dominance Measures in Predicting the Neuropsychological Performance of HIV+ Bilingual Latino/a Adults

    PubMed Central

    Miranda, Caitlin; Rentería, Miguel Arce; Fuentes, Armando; Coulehan, Kelly; Arentoft, Alyssa; Byrd, Desiree; Rosario, Ana; Monzones, Jennifer; Morgello, Susan; Mindt, Monica Rivera

    2016-01-01

    Objective Given the disproportionate impact of neurologic disorders such as HIV on racial/ethnic minorities, neuropsychologists are increasingly evaluating individuals of diverse linguistic backgrounds. This study compares the utility of two brief and one comprehensive language measure to account for variation in English neuropsychological performance within a bilingual population. Method Sixty-two HIV+ English/Spanish bilingual Latino adults completed three language measures in English and Spanish: Self-Reported Language Ability; Verbal Fluency (FAS/PMR); and the Woodcock Munoz Language Survey-Revised (WMLS-R). All participants also completed an English language neuropsychological (NP) battery. Results It was hypothesized that the comprehensive English/Spanish WMLS-R language dominance index (LDI) would be significantly correlated with NP performance, as well as the best predictor of NP performance over and above the two brief language measures. Contrary to our hypothesis, the WMLS-R LDI was not significantly correlated to NP performance, whereas the easily administered Verbal Fluency and Self-Report LDIs were each correlated with global NP performance and multiple NP domains. After accounting for Verbal Fluency and Self-Report LDI in a multivariate regression predicting NP performance, the WMLS-R LDI did not provide a unique contribution to the model. Conclusions These findings suggest that the more comprehensive WMLS-R does not improve understanding of the effects of language on NP performance in an HIV+ bilingual Latino population. PMID:26934820

  18. B-LINK: A hemicentin, plakin and integrin-dependent adhesion system that links tissues by connecting adjacent basement membranes

    PubMed Central

    Morrissey, Meghan A.; Keeley, Daniel P.; Hagedorn, Elliott J.; McClatchey, Shelly T. H.; Chi, Qiuyi; Hall, David H.; Sherwood, David R.

    2014-01-01

    Summary Basement membrane (BM), a sheet-like form of extracellular matrix, surrounds most tissues. During organogenesis specific adhesions between adjoining tissues frequently occur, however their molecular basis is unclear. Using live-cell imaging and electron microscopy we identify an adhesion system that connects the uterine and gonadal tissues through their juxtaposed BMs at the site of anchor cell (AC) invasion in C. elegans. We find that the extracellular matrix component hemicentin (HIM-4), found between BMs, forms punctate accumulations under the AC and controls BM linkage to promote rapid invasion. Through targeted screening we identify the integrin-binding cytolinker plakin (VAB-10A) and integrin (INA-1/PAT-3) as key BM-BM linkage regulators: VAB-10A localizes to the AC-BM interface and tethers hemicentin to the AC while integrin promotes hemicentin punctae formation. Together, plakin, integrin and hemicentin are founding components of a cell-directed adhesion system, which we name a B-LINK (Basement membrane-LINKage), that connects adjacent tissues through adjoining BMs. PMID:25443298

  19. 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.

  20. 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…

  1. Effects of Achieving Target Measures in Rheumatoid Arthritis on Functional Status, Quality of Life, and Resource Utilization: Analysis of Clinical Practice Data

    PubMed Central

    Joo, Seongjung; Kawabata, Hugh; Al, Maiwenn J.; Allison, Paul D.; Rutten‐van Mölken, Maureen P. M. H.; Frits, Michelle L.; Iannaccone, Christine K.; Shadick, Nancy A.; Weinblatt, Michael E.

    2016-01-01

    Objective To evaluate associations between achieving guideline‐recommended targets of disease activity, defined by the Disease Activity Score in 28 joints using C‐reactive protein level (DAS28‐CRP) <2.6, the Simplified Disease Activity Index (SDAI) ≤3.3, or the Clinical Disease Activity Index (CDAI) ≤2.8, and other health outcomes in a longitudinal observational study. Methods Other defined thresholds included low disease activity (LDA), moderate (MDA), or severe disease activity (SDA). To control for intraclass correlation and estimate effects of independent variables on outcomes of the modified Health Assessment Questionnaire (M‐HAQ), the EuroQol 5‐domain (EQ‐5D; a quality‐of‐life measure), hospitalization, and durable medical equipment (DME) use, we employed mixed models for continuous outcomes and generalized estimating equations for binary outcomes. Results Among 1,297 subjects, achievement (versus nonachievement) of recommended disease targets was associated with enhanced physical functioning and lower health resource utilization. After controlling for baseline covariates, achievement of disease targets (versus LDA) was associated with significantly enhanced physical functioning based on SDAI ≤3.3 (ΔM‐HAQ −0.047; P = 0.0100) and CDAI ≤2.8 (−0.073; P = 0.0003) but not DAS28‐CRP <2.6 (−0.022; P = 0.1735). Target attainment was associated with significantly improved EQ‐5D (0.022–0.096; P < 0.0030 versus LDA, MDA, or SDA). Patients achieving guideline‐recommended disease targets were 36–45% less likely to be hospitalized (P < 0.0500) and 23–45% less likely to utilize DME (P < 0.0100). Conclusion Attaining recommended target disease‐activity measures was associated with enhanced physical functioning and health‐related quality of life. Some health outcomes were similar in subjects attaining guideline targets versus LDA. Achieving LDA is a worthy clinical objective in some patients. PMID:26238974

  2. Heterosynaptic long-term depression of craniofacial nociception: divergent effects on pain perception and blink reflex in man.

    PubMed

    Yekta, Sareh Said; Lamp, Susanne; Ellrich, Jens

    2006-04-01

    Noxious low-frequency stimulation (LFS) of presynaptic nerve fibers induces long-term depression (LTD) of synaptic transmission. In vitro studies suggest a sole homosynaptic effect. Consequently, the present study addressed the hypothesis that LTD of craniofacial nociception in man is mediated by a homosynaptic mechanism. Nociceptive supraorbital afferents were excited by electric pulses via a concentric electrode in ten healthy volunteers. The electrically evoked bilateral blink reflex (BR) was recorded from both orbicularis oculi muscles by surface electrodes. The BR was evoked in blocks of ten electric stimuli each (0.1 Hz) with an interblock interval of 8 min. Conditioning noxious LFS (1 Hz, 20 min) was applied via concentric electrode either to the same site as BR test stimuli (ipsilateral) or to the corresponding contralateral forehead area (contralateral). LFS and test stimulus intensities corresponded to about threefold the pain threshold. After three baseline stimulus blocks, either conditioning ipsilateral or contralateral LFS were applied or stimulation was interrupted for 20 min as a control task. Afterwards, test stimulation blocks were continued for 40 min. Each volunteer participated in all three sessions on different days. Noxious LFS induced LTD of the BR independently from the side of conditioning stimulation. Pain perception decreased after ipsilateral LFS but not after contralateral LFS. The bilateral effect of noxious LFS on the BR provides evidence for heterosynaptic LTD based on bilateral projections of supraorbital nerve afferents onto spinal trigeminal nuclei. The divergent effect on pain perception may be due to a preferential contralateral projection of nociceptive afferents onto reflex interneurons but not onto trigeminothalamic projection neurons.

  3. Transcutaneous trigeminal nerve stimulation induces a long-term depression-like plasticity of the human blink reflex.

    PubMed

    Pilurzi, Giovanna; Mercante, Beniamina; Ginatempo, Francesca; Follesa, Paolo; Tolu, Eusebio; Deriu, Franca

    2016-02-01

    The beneficial effects of trigeminal nerve stimulation (TNS) on several neurological disorders are increasingly acknowledged. Hypothesized mechanisms include the modulation of excitability in networks involved by the disease, and its main site of action has been recently reported at brain stem level. Aim of this work was to test whether acute TNS modulates brain stem plasticity using the blink reflex (BR) as a model. The BR was recorded from 20 healthy volunteers before and after 20 min of cyclic transcutaneous TNS delivered bilaterally to the infraorbital nerve. Eleven subjects underwent sham-TNS administration and were compared to the real-TNS group. In 12 subjects, effects of unilateral TNS were tested. The areas of the R1 and R2 components of the BR were recorded before and after 0 (T0), 15 (T15), 30 (T30), and 45 (T45) min from TNS. In three subjects, T60 and T90 time points were also evaluated. Ipsi- and contralateral R2 areas were significantly suppressed after bilateral real-TNS at T15 (p = 0.013), T30 (p = 0.002), and T45 (p = 0.001), while R1 response appeared unaffected. The TNS-induced inhibitory effect on R2 responses lasted up to 60 min. Real- and sham-TNS protocols produced significantly different effects (p = 0.005), with sham-TNS being ineffective at any time point tested. Bilateral TNS was more effective (p = 0.009) than unilateral TNS. Acute TNS induced a bilateral long-lasting inhibition of the R2 component of the BR, which resembles a long-term depression-like effect, providing evidence of brain stem plasticity produced by transcutaneous TNS. These findings add new insight into mechanisms of TNS neuromodulation and into physiopathology of those neurological disorders where clinical benefits of TNS are recognized.

  4. Clustering of CdSe/CdS Quantum Dot/Quantum Rods into Micelles Can Form Bright, Non-blinking, Stable, and Biocompatible Probes.

    PubMed

    Rafipoor, Mona; Schmidtke, Christian; Wolter, Christopher; Strelow, Christian; Weller, Horst; Lange, Holger

    2015-09-01

    We investigate clustered CdSe/CdS quantum dots/quantum rods, ranging from single to multiple encapsulated rods within amphiphilic diblock copolymer micelles, by time-resolved optical spectroscopy. The effect of the clustering and the cluster size on the optical properties is addressed. The clusters are bright and stable and show no blinking while retaining the fundamental optical properties of the individual quantum dots/quantum rods. Cell studies show neither unspecific uptake nor morphological changes of the cells, despite the increased sizes of the clusters.

  5. Effect of a retention interval between pre-exposure and conditioning on latent inhibition in humans using a blink conditioning procedure.

    PubMed

    De la Casa Rivas, Luis Gonzalo; Traverso Arcos, Luis Miguel; Márquez Zamora, Raúl

    2010-11-01

    Latent inhibition, retarded learning after pre-exposure to the to-be-conditioned stimulus, was examined using a blink conditioned procedure in humans. Experiment 1 showed that the procedure is suited to inducing the latent inhibition effect. In Experiment 2, the introduction of a 3-minute interval between pre-exposure and conditioning phases attenuated latent inhibition. These results contribute to identify the mechanisms involved in pre-exposure and subsequent conditioning of a stimulus, which is particularly important if we bear in mind that latent inhibition has been used repeatedly as an instrument to analyze the course of attentional processes in normal and pathological populations.

  6. 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

    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 are

  7. 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

  8. 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

  9. 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

  10. Utilization of computer processed high definition video imaging for measuring motility of microscopic nematode stages on a quantitative scale: "The Worminator".

    PubMed

    Storey, Bob; Marcellino, Chris; Miller, Melissa; Maclean, Mary; Mostafa, Eman; Howell, Sue; Sakanari, Judy; Wolstenholme, Adrian; Kaplan, Ray

    2014-12-01

    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 labor input

  11. Factor Structure, Reliability and Measurement Invariance of the Alberta Context Tool and the Conceptual Research Utilization Scale, for German Residential Long Term Care

    PubMed Central

    Hoben, Matthias; Estabrooks, Carole A.; Squires, Janet E.; Behrens, Johann

    2016-01-01

    We translated the Canadian residential long term care versions of the Alberta Context Tool (ACT) and the Conceptual Research Utilization (CRU) Scale into German, to study the association between organizational context factors and research utilization in German nursing homes. The rigorous translation process was based on best practice guidelines for tool translation, and we previously published methods and results of this process in two papers. Both instruments are self-report questionnaires used with care providers working in nursing homes. The aim of this study was to assess the factor structure, reliability, and measurement invariance (MI) between care provider groups responding to these instruments. In a stratified random sample of 38 nursing homes in one German region (Metropolregion Rhein-Neckar), we collected questionnaires from 273 care aides, 196 regulated nurses, 152 allied health providers, 6 quality improvement specialists, 129 clinical leaders, and 65 nursing students. The factor structure was assessed using confirmatory factor models. The first model included all 10 ACT concepts. We also decided a priori to run two separate models for the scale-based and the count-based ACT concepts as suggested by the instrument developers. The fourth model included the five CRU Scale items. Reliability scores were calculated based on the parameters of the best-fitting factor models. Multiple-group confirmatory factor models were used to assess MI between provider groups. Rather than the hypothesized ten-factor structure of the ACT, confirmatory factor models suggested 13 factors. The one-factor solution of the CRU Scale was confirmed. The reliability was acceptable (>0.7 in the entire sample and in all provider groups) for 10 of 13 ACT concepts, and high (0.90–0.96) for the CRU Scale. We could demonstrate partial strong MI for both ACT models and partial strict MI for the CRU Scale. Our results suggest that the scores of the German ACT and the CRU Scale for nursing

  12. 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

  13. 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

  14. 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.

  15. 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

  16. 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…

  17. Community-Based Health Education Programs Designed to Improve Clinical Measures Are Unlikely to Reduce Short-Term Costs or Utilization Without Additional Features Targeting These Outcomes.

    PubMed

    Burton, Joe; Eggleston, Barry; Brenner, Jeffrey; Truchil, Aaron; Zulkiewicz, Brittany A; Lewis, Megan A

    2016-06-07

    Stakeholders often expect programs for persons with chronic conditions to "bend the cost curve." This study assessed whether a diabetes self-management education (DSME) program offered as part of a multicomponent initiative could affect emergency department (ED) visits, hospital stays, and the associated costs for an underserved population in addition to the clinical indicators that DSME programs attempt to improve. The program was implemented in Camden, New Jersey, by the Camden Coalition of Healthcare Providers to address disparities in diabetes care. Data used are from medical records and from patient-level information about hospital services from Camden's hospitals. Using multivariate regression models to control for individual characteristics, changes in utilization over time and changes relative to 2 comparison groups were assessed. No reductions in ED visits, inpatient stays, or costs for participants were found over time or relative to the comparison groups. High utilization rates and costs for diabetes are associated with longer term disease progression and its sequelae; thus, DSME or peer support may not affect these in the near term. Some clinical indicators improved among participants, and these might lead to fewer costly adverse health events in the future. DSME deployed at the community level, without explicit segmentation and targeting of high health care utilizers or without components designed to affect costs and utilization, should not be expected to reduce short-term medical needs for participating individuals or care-seeking behaviors such that utilization is reduced. Stakeholders must include financial outcomes in a program's design if those outcomes are to improve. (Population Health Management 20XX;XX:XXX-XXX).

  18. 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.

  19. 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

  20. 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