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Sample records for spontaneous blink rate

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

    Science.gov (United States)

    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…

  2. Decreased spontaneous eye blink rates in chronic cannabis users: evidence for striatal cannabinoid-dopamine interactions.

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    Mikael A Kowal

    Full Text Available 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.

  3. Blink rate and blink timing in children with ADHD and the influence of stimulant medication

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    Groen, Y.; Borger, N.A.; Koerts, J.; Thome, J.; Tucha, O.

    Spontaneous eye blink rate is modulated by task demands and internal state, and is demonstrated to reflect central dopamine activity. Also, spontaneous eye blinks are strategically timed around salient stimuli. This study investigates whether children with attention deficit hyperactivity disorder

  4. Quantitative study of spontaneous eye blinks and eye tics in Gilles de la Tourette's syndrome

    NARCIS (Netherlands)

    J.H.M. Tulen (Joke); M. Azzolini; J.A. de Vries; W.H. Groeneveld; J. Passchier (Jan); B.J.M. van de Wetering (Ben)

    1999-01-01

    textabstractSpontaneous eye blink rate and frequency of eye tics were studied in nine Tourette patients during periods of rest, conversation, and video watching. In comparison with controls, the Tourette patients showed a significantly higher blink rate during rest

  5. Blink rate, incomplete blinks and computer vision syndrome.

    Science.gov (United States)

    Portello, Joan K; Rosenfield, Mark; Chu, Christina A

    2013-05-01

    Computer vision syndrome (CVS), a highly prevalent condition, is frequently associated with dry eye disorders. Furthermore, a reduced blink rate has been observed during computer use. The present study examined whether post task ocular and visual symptoms are associated with either a decreased blink rate or a higher prevalence of incomplete blinks. An additional trial tested whether increasing the blink rate would reduce CVS symptoms. Subjects (N = 21) were required to perform a continuous 15-minute reading task on a desktop computer at a viewing distance of 50 cm. Subjects were videotaped during the task to determine their blink rate and amplitude. Immediately after the task, subjects completed a questionnaire regarding ocular symptoms experienced during the trial. In a second session, the blink rate was increased by means of an audible tone that sounded every 4 seconds, with subjects being instructed to blink on hearing the tone. The mean blink rate during the task without the audible tone was 11.6 blinks per minute (SD, 7.84). The percentage of blinks deemed incomplete for each subject ranged from 0.9 to 56.5%, with a mean of 16.1% (SD, 15.7). A significant positive correlation was observed between the total symptom score and the percentage of incomplete blinks during the task (p = 0.002). Furthermore, a significant negative correlation was noted between the blink score and symptoms (p = 0.035). Increasing the mean blink rate to 23.5 blinks per minute by means of the audible tone did not produce a significant change in the symptom score. Whereas CVS symptoms are associated with a reduced blink rate, the completeness of the blink may be equally significant. Because instructing a patient to increase his or her blink rate may be ineffective or impractical, actions to achieve complete corneal coverage during blinking may be more helpful in alleviating symptoms during computer operation.

  6. Spontaneous Blinking from a Tribological Viewpoint.

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    Pult, Heiko; Tosatti, Samuele G P; Spencer, Nicholas D; Asfour, Jean-Michel; Ebenhoch, Michael; Murphy, Paul J

    2015-07-01

    The mechanical forces between the lid wiper and the ocular surface, and between a contact lens and the lid wiper, are reported to be related to dry eye symptoms. Furthermore, the mechanical forces between these sliding partners are assumed to be related to the ocular signs of lid-wiper epitheliopathy (LWE) and lid-parallel conjunctival folds (LIPCOF). Recent literature provides some evidence that a contact lens with a low coefficient of friction (CoF) improves wearing comfort by reducing the mechanical forces between the contact lens surface and the lid wiper. This review discusses the mechanical forces during spontaneous blinks from a tribological perspective, at both low and high sliding velocities, in a healthy subject. It concludes that the coefficient of friction of the ocular surfaces appears to be strongly comparable to that of hydrophilic polymer brushes at low sliding velocity, and that, with increased sliding velocity, there is no wear at the sliding partners' surfaces thanks to the presence of a fluid film between the two sliding partners. In contrast, in the case of dry eye, the failure to maintain a full fluid film lubrication regime at high blinking speeds may lead to increased shear rates, resulting in deformation and wear of the sliding pairs. These shear rates are most likely related to tear film viscosity. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Spontaneous Blinking Kinematics in Patients Who Have Undergone Autogeneous Fascia Frontalis Suspension.

    Science.gov (United States)

    Baccega, Adriano; Garcia, Denny Marcos; Cruz, Antonio Augusto V

    2017-09-01

    To measure spontaneous blink metrics and brow motion in patients with congenital ptosis operated with frontalis slings with autogenous fascia lata. An infrared three-dimensional video motion analyzer was employed to simultaneously measure brow motion and spontaneous blinks of 17 patients with congenital ptosis who underwent frontalis sling with autogenous fascia lata and a control group of equal number of healthy subjects. A customized software identified and quantified the amplitude and maximum velocity spontaneous blinks eyelid and brown motion during a 5-minute observation of a commercial movie. The corneal status of the patients with and without lagophthamos was evaluated with slit-lamp biomicroscopy with fluorescein staining. Lagophthalmos was detected on 13 (76.5%) patients. Out of these 3 (23%) showed signs of inferior superficial keratopathy despite the presence of normal (upwards) Bell's phenomenon in all of them. Blink rate was significantly diminished in the patients. The distribution of interblink time was similar in both groups. The mean amplitude of the down-phase of the patients' blinks was only 38% of the controls. The main sequence slope of the patients' blinks was abnormally low. In controls brow motion was a minute and random event no related to blinks. In the patients, the mean brow amplitude was five times higher than in controls reaching 45% of the blink amplitude. Spontaneous blink amplitude and velocity are severely impaired in patients with fascia lata autogenous slings. After surgery blinking amplitude is linearly related to the amplitude of brow motion.

  8. Blink Rate and Incomplete Blinks in Six Different Controlled Hard-Copy and Electronic Reading Conditions.

    Science.gov (United States)

    Argilés, Marc; Cardona, Genís; Pérez-Cabré, Elisabet; Rodríguez, Margarita

    2015-10-01

    To evaluate spontaneous eye blink rate (SEBR) and percentage of incomplete blinks in different hard-copy and visual display terminal (VDT) reading conditions, compared with baseline conditions. A sample of 50 participants (29 females, age range, 18-74 years) were recruited for this study. All participants had good ocular health and reported no symptoms of dry eye (OSDI score landscape picture at 2 m (baseline) and during six different, 6-minute controlled reading experimental conditions. Texts were presented in electronic (tablet and computer display at 100% and 330% zoom levels) and hard-copy (text in book position in silence and aloud and text pasted on the computer display) formats. Video analysis was subsequently conducted to assess blink parameters. All reading conditions resulted in a decrease in SEBR when compared with baseline conditions (all P Spanish Abstract.

  9. Neurobiological correlates of impulsivity in healthy adults: Lower prefrontal gray matter volume and spontaneous eye-blink rate but greater resting-state functional connectivity in basal ganglia-thalamo-cortical circuitry.

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    Korponay, Cole; Dentico, Daniela; Kral, Tammi; Ly, Martina; Kruis, Ayla; Goldman, Robin; Lutz, Antoine; Davidson, Richard J

    2017-08-15

    Studies consistently implicate aberrance of the brain's reward-processing and decision-making networks in disorders featuring high levels of impulsivity, such as attention-deficit hyperactivity disorder, substance use disorder, and psychopathy. However, less is known about the neurobiological determinants of individual differences in impulsivity in the general population. In this study of 105 healthy adults, we examined relationships between impulsivity and three neurobiological metrics - gray matter volume, resting-state functional connectivity, and spontaneous eye-blink rate, a physiological indicator of central dopaminergic activity. Impulsivity was measured both by performance on a task of behavioral inhibition (go/no-go task) and by self-ratings of attentional, motor, and non-planning impulsivity using the Barratt Impulsiveness Scale (BIS-11). Overall, we found that less gray matter in medial orbitofrontal cortex and paracingulate gyrus, greater resting-state functional connectivity between nodes of the basal ganglia-thalamo-cortical network, and lower spontaneous eye-blink rate were associated with greater impulsivity. Specifically, less prefrontal gray matter was associated with higher BIS-11 motor and non-planning impulsivity scores, but was not related to task performance; greater correlated resting-state functional connectivity between the basal ganglia and thalamus, motor cortices, and prefrontal cortex was associated with worse no-go trial accuracy on the task and with higher BIS-11 motor impulsivity scores; lower spontaneous eye-blink rate was associated with worse no-go trial accuracy and with higher BIS-11 motor impulsivity scores. These data provide evidence that individual differences in impulsivity in the general population are related to variability in multiple neurobiological metrics in the brain's reward-processing and decision-making networks. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  12. Effect of distance vision and refractive error on the spontaneous eye blink activity in human subjects in primary eye gaze.

    Science.gov (United States)

    Doughty, Michael J

    2018-04-04

    To evaluate whether visual target character and visibility affects spontaneous eye blink rate (SEBR) in primary eye gaze and silence. Video recordings were made of young healthy adults who were either emmetropic (n=32) or who wore spectacles for refractive error (range -4.75D and +4.50D (n=31). Emmetropes had 5min recordings made whilst seated and looking towards a distant whiteboard. For spectacle wearers, recordings were made whilst looking towards the whiteboard with a 35mm sized cross, and repeated after spectacle removal. The average number of eye blinks over 5min was assessed, and its intra-subject variability as the coefficient of variation (COV). Over 5min without a distance target, an average SEBR of 10.4blinks/min was observed in emmetropes with a of COV=38.1%, and a significant increase in SEBR over the 5th minute to 13.6blinks/min. Hyperopes being asked to look towards a distant target showed the essentially same blinking rate of 11.1/min with or without spectacle wear with the intra-subject variability (COV) being 21.3%. Myopic subjects showed a slightly higher SEBR if looking towards a target without their spectacles (12.4 vs. 11.0blinks/min), with the COV being 18.8%. The studies indicate that some form of visual target could be useful to promote constancy of spontaneous eye blink activity over time, but that a distance visual target (when provided) does not need to be seen clearly. Crown Copyright © 2018. Published by Elsevier España, S.L.U. All rights reserved.

  13. A green-light-emitting, spontaneously blinking fluorophore based on intramolecular spirocyclization for dual-colour super-resolution imaging.

    Science.gov (United States)

    Uno, Shin-Nosuke; Kamiya, Mako; Morozumi, Akihiko; Urano, Yasuteru

    2017-12-19

    We have developed the first green-light-emitting, spontaneously blinking fluorophore (SBF), HEtetTFER. In combination with our near-infrared-light-emitting SBF (HMSiR), HEtetTFER allows dual-colour single-molecule localization microscopy (SMLM) in buffer solution without any additive and without photoactivation.

  14. Changes in blink rate and ocular symptoms during different reading tasks

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    Abusharha AA

    2017-11-01

    Full Text Available Ali A Abusharha Department of Optometry and Vision Sciences, King Saud University, Riyadh, Saudi Arabia Background: Reading from tablets is fundamental to modern culture. This study measured differences in the blink rate and symptoms of ocular discomfort in healthy participants during reading from a tablet and a paper book.Methods: Forty healthy, normal males subjects were recruited for this study. Subjects were video recorded during reading a text presented on an electronic device (9.7 inch tablet and a hard copy format, for 15 min. Ocular discomfort experienced during reading was scored using a visual analog scale. Each participant was examined performing one of the two tasks (randomized on one visit and the other on a separate visit (crossover design. All subjects were evaluated before the reading tasks and every 5 min during 15 min of reading.Results: The mean ± standard deviation blink rate was 19.74 ± 9.12/min at baseline. The blink rate decreased significantly under both reading conditions (to 11.35 ± 10.20 and 14.93 ± 10.90/min when reading from a book and a tablet, respectively. There was no significant difference in the blink rate over 15 min during either type of reading. The mean discomfort symptom scores were 148 for the book and 134 for the tablet; both were significantly higher than baseline. A gradual increase in symptoms was found every 5 min during both types of reading.Conclusion: The study confirmed that both the blink rate and ocular discomfort symptoms were strongly affected during performance of close visual tasks. Both reading conditions affected blinking; this may interfere with tear film dynamics. Such effects were reflected in the immediate development of ocular symptoms, which increased significantly during both types of reading. Keywords: blink rate, tear film, reading tasks

  15. What Does Eye-Blink Rate Variability Dynamics Tell Us About Cognitive Performance?

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    Rafal Paprocki

    2017-12-01

    Full Text Available Cognitive performance is defined as the ability to utilize knowledge, attention, memory, and working memory. In this study, we briefly discuss various markers that have been proposed to predict cognitive performance. Next, we develop a novel approach to characterize cognitive performance by analyzing eye-blink rate variability dynamics. Our findings are based on a sample of 24 subjects. The subjects were given a 5-min resting period prior to a 10-min IQ test. During both stages, eye blinks were recorded from Fp1 and Fp2 electrodes. We found that scale exponents estimated for blink rate variability during rest were correlated with subjects' performance on the subsequent IQ test. This surprising phenomenon could be explained by the person to person variation in concentrations of dopamine in PFC and accumulation of GABA in the visual cortex, as both neurotransmitters play a key role in cognitive processes and affect blinking. This study demonstrates the possibility that blink rate variability dynamics at rest carry information about cognitive performance and can be employed in the assessment of cognitive abilities without taking a test.

  16. Blinking and driving: the influence of saccades and cognitive workload.

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    Cardona, Genís; Quevedo, Noa

    2014-03-01

    The aim of this study was to investigate the joint influence of cognitive demands and large amplitude saccades on spontaneous blink rate. Twenty healthy volunteers were enrolled in the study and instructed to follow a 60-minute real-life driving circuit while a video camera recorded ocular movements and blinking. Five different complexity levels were predefined in terms of driving difficulty and traffic intensity, that is, cognitive workload. Five one-minute segments were selected for each complexity level in each driving trial, whereupon spontaneous blink rate and horizontal saccades were monitored. Saccades were classified according to their amplitude and blink-saccade pairs were recorded. Albeit showing a high inter-subject variability, spontaneous blink rate and saccades were consistent within the same complexity level. At different complexity levels, no statistically significant difference in spontaneous blink rate was encountered, with an average of 20.3 ± 1.6 blinks/minute (mean ± SD). The number of large amplitude gaze shifts increased with the level of complexity (F = 15.403; p < 0.001). An average of 87.5% of large amplitude saccades were accompanied by a blink, and this percentage was similar for all complexity levels, that is, the number of blink-saccade pairs increased at higher complexity levels (F = 20.597; p < 0.001). In a complex, dynamic visual setting, spontaneous blinking accompanying large amplitude saccades may help in counteracting the reduction in blink rate associated with high cognitive demands.

  17. Changes in blink rate and ocular symptoms during different reading tasks

    OpenAIRE

    Abusharha,Ali

    2017-01-01

    Ali A Abusharha Department of Optometry and Vision Sciences, King Saud University, Riyadh, Saudi Arabia Background: Reading from tablets is fundamental to modern culture. This study measured differences in the blink rate and symptoms of ocular discomfort in healthy participants during reading from a tablet and a paper book.Methods: Forty healthy, normal males subjects were recruited for this study. Subjects were video recorded during reading a text presented on an electronic device (9.7 inch ...

  18. Tracking Real-Time Changes in Working Memory Updating and Gating with the Event-Based Eye-Blink Rate

    NARCIS (Netherlands)

    Rac-Lubashevsky, R.; Slagter, H.A.; Kessler, Y.

    2017-01-01

    Effective working memory (WM) functioning depends on the gating process that regulates the balance between maintenance and updating of WM. The present study used the event-based eye-blink rate (ebEBR), which presumably reflects phasic striatal dopamine activity, to examine how the cognitive

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

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

    2014-07-01

    We investigated the relationship between dopamine activity (DA), as measured by Eye Blink Rate (EBR), and cognitive function in old adults with Mild Cognitive Impairment (MCI) and healthy controls. Research has been inconclusive so far about the factors responsible for the transition from MCI to dementia. However, some studies suggest that cortical hyperexcitability in very early stages of pathological aging may progressively lead to cell death, and thus to Alzheimer's disease. Hence, we speculated that a dysfunction of DA activity, as measured by EBR, may characterize people with MCI, and account for their poor cognitive function. Thirty three (33) healthy and thirty six (36) old adults with MCI (Mean age = 67.52 y.o.) participated in this study. The EBR was recorded under resting conditions, using two gold skin electrodes above and below the left eye. Cognitive function was assessed with a battery of neuropsychological tests. Participants with MCI showed significantly higher EBR than the healthy controls. Also, EBR was negatively related to scores on the Montreal Cognitive Assessment test (MoCA) test. We propose that abnormally increased dopamine activity, as indexed by relatively high EBR, may be partially responsible for the neurotransmitter imbalance in the central nervous system of people with MCI, and the overall impaired cognitive performance. In addition, this finding suggests that an abnormally high EBR may be a potential biomarker of the transition from healthy aging to dementia. © 2013. Published by Elsevier B.V. All rights reserved.

  20. Spontaneous mutation rates and the rate-doubling dose

    International Nuclear Information System (INIS)

    Von Borstel, R.C.; Moustaccki, E.; Latarjet, R.

    1978-01-01

    The amount of radiation required to double the frequency of mutations or tumours over the rate of those that occur spontaneously is called the rate-doubling dose. An equivalent concept has been proposed for exposure to other environmental mutagens. The doubling dose concept is predicated on the assumption that all human populations have the same spontaneous mutation rate, and that this spontaneous mutation rate is known. It is now established for prokaryotes and lower eukaryotes that numerous genes control the spontaneous mutation rate, and it is likely that the same is true for human cells as well. Given that the accepted mode of evolution of human populatons is from small, isolated groups of individuals, it seems likely that each population would have a different spontaneous mutation rate. Given that a minimum of twenty genes control or affect the spontaneous mutation rate, and that each of these in turn is susceptible to spontaneously arising or environmentally induced mutations, it seems likely that every individual within a population (except for siblings from identical multiple births) will have a unique spontaneous mutation rate. If each individual in a population does have a different spontaneous mutation rate, the doubling dose concept, in rigorous terms, is fallacious. Therefore, as with other concepts of risk evaluation, the doubling dose concept is subject to criticism. Nevertheless, until we know individual spontaneous mutation rates with precision, and can evaluate risks based on this information, the doubling dose concept has a heuristic value and is needed for practical assessment of risks for defined populations. (author)

  1. Effects of meditation practice on spontaneous eyeblink rate.

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    Kruis, Ayla; Slagter, Heleen A; Bachhuber, David R W; Davidson, Richard J; Lutz, Antoine

    2016-05-01

    A rapidly growing body of research suggests that meditation can change brain and cognitive functioning. Yet little is known about the neurochemical mechanisms underlying meditation-related changes in cognition. Here, we investigated the effects of meditation on spontaneous eyeblink rates (sEBR), a noninvasive peripheral correlate of striatal dopamine activity. Previous studies have shown a relationship between sEBR and cognitive functions such as mind wandering, cognitive flexibility, and attention-functions that are also affected by meditation. We therefore expected that long-term meditation practice would alter eyeblink activity. To test this, we recorded baseline sEBR and intereyeblink intervals (IEBI) in long-term meditators (LTM) and meditation-naive participants (MNP). We found that LTM not only blinked less frequently, but also showed a different eyeblink pattern than MNP. This pattern had good to high degree of consistency over three time points. Moreover, we examined the effects of an 8-week course of mindfulness-based stress reduction on sEBR and IEBI, compared to an active control group and a waitlist control group. No effect of short-term meditation practice was found. Finally, we investigated whether different types of meditation differentially alter eyeblink activity by measuring sEBR and IEBI after a full day of two kinds of meditation practices in the LTM. No effect of meditation type was found. Taken together, these findings may suggest either that individual difference in dopaminergic neurotransmission is a self-selection factor for meditation practice, or that long-term, but not short-term meditation practice induces stable changes in baseline striatal dopaminergic functioning. © 2016 Society for Psychophysiological Research.

  2. Eliminating the attentional blink through binaural beats: A case for tailored cognitive enhancement

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    Susan A. Reedijk

    2015-06-01

    Full Text Available 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 task. As predicted from a neurocognitive approach to cognitive control, high-frequency binaural beats eliminated the attentional blink, 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.

  3. Eye Movements Blink the Attentional Blink

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    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…

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

    Science.gov (United States)

    Yorzinski, Jessica L

    2016-08-30

    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.

  5. Capsaicin effects on blinking Efectos de la capsaicina en el parpadeo

    OpenAIRE

    Fidias E. Leon-Sarmiento; Jaime Bayona-Prieto; Marta E. Leon-S

    2005-01-01

    Blinking is a normal human phenomenom involving trigeminal and facial patways. To gain understanding on the neurobiology of blinking, five normal subjects were investigated before and after application of transdermal capsaicin at the forehead for two weeks. No effects of topical capsaicin were detected in eye blink rates. However, when capsaicin was applied to a female subject with blepharospasm, she showed a dramatic restoration of her vision subsequent to blinking modification. Deactivation...

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

    Science.gov (United States)

    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.

  7. Did Lavoisier Blink?

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    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…

  8. Blink frequency and duration during perimetry and their relationship to test-retest threshold variability.

    Science.gov (United States)

    Wang, Yanfang; Toor, Sonia S; Gautam, Ramesh; Henson, David B

    2011-06-28

    To describe different patterns of blinking in patients undergoing a visual field test and to establish whether the blink parameters are related to threshold variability. Thirty-nine patients with diagnosed or suspected glaucoma were recruited to undertake a perimetric task twice. Blinks were detected with a video eye-tracker system that records at a sampling rate of 60 Hz. Blink frequency, duration, and episodes of microsleep (eye closures >500 ms) were analyzed, and correlated with test-retest threshold variability. The timing of blinks with respect to stimulus presentation was analyzed and the percentage of seen stimuli for all presentations (POS(overall)) and those overlapped with blinks (POS(overlapped)) were compared. Blink frequency ranged from 0 to 58 per minute. A significant increase in blink frequency was observed in the second test (P POS(overall) and POS(overlapped) was significant (P POS(overlapped) was observed with the increase of overlap duration. A wide range of blink frequencies was observed during perimetric testing. Although no blink parameters showed significant influence on threshold variability, when the blinks overlapped with a stimulus presentation, the probability of seeing was reduced. For suprathreshold stimuli, blinks often occurred after the presentation, whereas for subthreshold presentations, there was no relationship to presentation time.

  9. Estimating spontaneous mutation rates at enzyme loci in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Mukai, Terumi; Yamazaki, Tsuneyuki; Harada, Ko; Kusakabe, Shin-ichi

    1990-04-01

    Spontaneous mutations were accumulated for 1,620,826 allele-generations on chromosomes that originated from six stem second chromosomes of Drosophila melanogaster. Only null-electromorph mutations were detected. Band-electromorph mutations were not found. The average rate of null-electromorph mutations was 2.71 x 10 -5 per locus per generation. The 95% confidence interval (μ n ) was 1.97 x 10 -5 n -5 per locus per generation. The upper 95% confidence limit of the band-electromorph mutation rate (μ B ) was 2.28 x 10 -6 per locus per generation. It appeared that null mutations were induced by movable genetic elements and that the mutation rates were different from chromosome to chromosome. (author)

  10. How much do we know about spontaneous human mutation rates

    Energy Technology Data Exchange (ETDEWEB)

    Crow, J.F. (Univ. of Wisconsin, Madison, WI (United States))

    1993-01-01

    The much larger number of cell divisions between zygote and sperm than between zygote and egg, the increased age of fathers of children with new dominant mutations, and the greater evolution rate of pseudogenes on the Y chromosome than of those on autosomes all point to a much higher mutation rate in human males than in females, as first pointed out by Haldane in his classical study of X-linked hemophilia. The age of the father is the main factor determining the human spontaneous mutation rate, and probably the total mutation rate. The total mutation rate in Drosophila males of genes causing minor reduction in viability is at least 0.4 per sperm and may be considerably higher. The great mutation load implied by a rate of [approx] 1 per zygote can be greatly ameliorated by quasi-transition selection. Corresponding data are not available for the human population. The evolution rate of pseudogenes in primates suggests some 10[sup 2] new mutations per zygote. Presumably the overwhelming majority of these are neutral, but even the approximate fraction is not known. Statistical evidence in Drosophilia shows that mutations with minor effects cause about the same heterozygous impairment of fitness as those that are lethal when homozygous. The magnitude of heterozygous effect is such that almost all mutant genes are eliminated as heterozygotes before ever becoming homozygous. Although quantitative data in the human species are lacking, anecdotal information supports the conclusion that partial dominance is the rule here as well. This suggests that if the human mutation rate were increased or decreased, the effects would be spread over a period of 50-100 generations. 31 refs., 3 figs., 2 tabs.

  11. The rate of spontaneous mutations in human myeloid cells

    International Nuclear Information System (INIS)

    Araten, David J.; Krejci, Ondrej; DiTata, Kimberly; Wunderlich, Mark; Sanders, Katie J.; Zamechek, Leah; Mulloy, James C.

    2013-01-01

    Highlights: • We provide the first measurement of the mutation rate (μ) in human myeloid cells. • μ is measured to be 3.6–23 × 10 −7 per cell division. • The AML-ETO and MLL-AF9 fusions do not seem to increase μ. • Cooperating mutations in NRAS, FLT3 and p53 not seem to increase μ. • Hypermutability may be required to explain leukemogenesis. - Abstract: The mutation rate (μ) is likely to be a key parameter in leukemogenesis, but historically, it has been difficult to measure in humans. The PIG-A gene has some advantages for the detection of spontaneous mutations because it is X-linked, and therefore only one mutation is required to disrupt its function. Furthermore, the PIG-A-null phenotype is readily detected by flow cytometry. Using PIG-A, we have now provided the first in vitro measurement of μ in myeloid cells, using cultures of CD34+ cells that are transduced with either the AML-ETO or the MLL-AF9 fusion genes and expanded with cytokines. For the AML-ETO cultures, the median μ value was ∼9.4 × 10 −7 (range ∼3.6–23 × 10 −7 ) per cell division. In contrast, few spontaneous mutations were observed in the MLL-AF9 cultures. Knockdown of p53 or introduction of mutant NRAS or FLT3 alleles did not have much of an effect on μ. Based on these data, we provide a model to predict whether hypermutability must occur in the process of leukemogenesis

  12. Spontaneous sigh rates during sedentary activity: watching television vs reading.

    Science.gov (United States)

    Hark, William T; Thompson, William M; McLaughlin, Timothy E; Wheatley, Lisa M; Platts-Mills, Thomas A E

    2005-02-01

    Spontaneous sighs are thought to play an important role in preventing atelectasis and in regulating airway tone. Recent studies have provided a mechanism by which expansion of the lungs could cause relaxation of smooth muscle. To investigate breathing patterns during 2 forms of sedentary behavior: reading and watching television. Breathing patterns were monitored for 1 to 2 hours to document respiratory rates and sigh rates. Each participant was monitored while reading and while watching a movie on videotape. During the first experiment (17 controls), metabolic rates were also measured. In the second experiment (18 controls and 9 patients with mild-to-moderate asthma), only breathing patterns were monitored. There were no significant differences in respiratory or metabolic rates between the 2 activities. In contrast, in the first experiment, 13 of 17 controls had lower sigh rates while watching a videotape than while reading (P < .01). In the second experiment, the sigh rate was significantly lower overall while watching a videotape (mean, 13.7 sighs per hour; range, 1.8-26.0 sighs per hour) than while reading (mean, 19.3 sighs per hour; range, 7.7-30.0 sighs per hour) (P < .001). A similar decrease was observed in patients with asthma (P < .01). Given that many children and adults watch television for 5 or more hours per day, breathing patterns during this time may be relevant to lung function. Our results demonstrate that prolonged periods of watching a videotape are associated with lower sigh rates than while reading. Further research is needed to determine whether these changes are relevant to increased bronchial reactivity.

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

    Science.gov (United States)

    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

  14. Automated Detection and Quantification of Circadian Eye Blinks Using a Contact Lens Sensor.

    Science.gov (United States)

    Gisler, Christophe; Ridi, Antonio; Hennebert, Jean; Weinreb, Robert N; Mansouri, Kaweh

    2015-01-01

    To detect and quantify eye blinks during 24-hour intraocular pressure (IOP) monitoring with a contact lens sensor (CLS). A total of 249 recordings of 24-hour IOP patterns from 202 participants using a CLS were included. Software was developed to automatically detect eye blinks, and wake and sleep periods. The blink detection method was based on detection of CLS signal peaks greater than a threshold proportional to the signal amplitude. Three methods for automated detection of the sleep and wake periods were evaluated. These relied on blink detection and subsequent comparison of the local signal amplitude with a threshold proportional to the mean signal amplitude. These methods were compared to manual sleep/wake verification. In a pilot, simultaneous video recording of 10 subjects was performed to compare the software to observer-measured blink rates. Mean (SD) age of participants was 57.4 ± 16.5 years (males, 49.5%). There was excellent agreement between software-detected number of blinks and visually measured blinks for both observers (intraclass correlation coefficient [ICC], 0.97 for observer 1; ICC, 0.98 for observer 2). The CLS measured a mean blink frequency of 29.8 ± 15.4 blinks/min, a blink duration of 0.26 ± 0.21 seconds and an interblink interval of 1.91 ± 2.03 seconds. The best method for identifying sleep periods had an accuracy of 95.2 ± 0.5%. Automated analysis of CLS 24-hour IOP recordings can accurately quantify eye blinks, and identify sleep and wake periods. This study sheds new light on the potential importance of eye blinks in glaucoma and may contribute to improved understanding of circadian IOP characteristics.

  15. Effects of transient blur and VDT screen luminance changes on eyeblink rate.

    Science.gov (United States)

    Cardona, Genís; Gómez, Marcelo; Quevedo, Lluïsa; Gispets, Joan

    2014-10-01

    A study was designed to evaluate the efficacy of three different strategies aiming at increasing spontaneous eyeblink rate (SEBR) during computer use. A total of 12 subjects (5 female) with a mean age of 28.7 years were instructed to read a text presented on a computer display terminal during 15min. Four reading sessions (reference and three "blinking events" [BE]) were programmed in which SEBR was digitally recorded. "Blinking events" were based on either a slight distortion of the text characters or on the presentation of a white screen instead of the text, with or without accompanying blinking instructions. All BE had a duration of 20ms and occurred every 15s. Participants graded the intrusiveness of each BE configuration, and the number of lines participants read in each session was recorded. Data from 11 subjects was analysed. A statistically significant difference in SEBR was encountered between the experimental configuration consisting on a white screen plus blinking instructions (7.8 blinks/min) and both reference (5.2 blinks/min; p=0.049) and white screen without blinking instructions (4.8 blinks/min; p=0.038). All three BE had superior levels of intrusiveness than reference conditions, although the performance of participants (line count) was not compromised. The joint contribution of white screen and blinking instructions has been shown to result in a short term improvement in blinking rate in the present sample of non-dry eye computer users. Further work is necessary to improve the acceptance of any BE aiming at influencing SEBR. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  16. Spontaneous mutation rate in Chinese hamster cell clones differing in UV-sensitivity

    International Nuclear Information System (INIS)

    Manuilova, E.S.; Bagrova, A.M.; Moskovskij Gosudarstvennyj Univ.

    1983-01-01

    The spontaneous rate of appearance of mutations to 6-mercaptopurine (6 MP) resistence in the cells of CHR2 and CHs2 clones dofferent in sensitivity to lethal and matagenous effect of UV-rays, is investigated. Increased UV-sensitivity of CHs2 clone is caused by the violation of postreplicative DNA reparation. It is established that the purity of spontaneously occuring mutations in both clones turns out to be similar, i.e. (1.5-1.8)x10 -5 for the cell pergeneration. It is shown that the effect of postreplicative DNA reparation in the cells of chinese hamster is not connected with the increase of spontaneous mutation ability. The problem on the possible role of reparation in the mechanism of appearance of spontaneous and induced mutations in the cells of Chinese hamster with increased UV-sensitivity is discussed

  17. Modeling aftershock rates using simulations of spontaneous earthquake nucleation on rate and state faults

    Science.gov (United States)

    Kaneko, Y.; Lapusta, N.

    2005-12-01

    Large earthquakes are followed by increased seismic activity, usually referred to as aftershock sequences, that decays to the background rate over time. The decay of aftershocks is well-described empirically by Omori's law. Dieterich (1994) proposed that Omori's law could result from perturbing, by static stress steps, a population of nucleation sites governed by laboratory-derived rate and state friction. He used one-degree-of-freedom spring-slider system to represent elastic interactions and made a simplified assumption about frictional behavior during nucleation. The model was further explored in a number of studies (i.e., Gomberg et al., 2000) and used to interpret observations (i.e., Toda et al., 1998). In this study, we explore the consequences of Dieterich's approach using models of faults embedded in elastic continuum, where the nucleation process can be more complicated than assumed in Dieterich's model. Our approach is different from previous studies of aftershock rates with rate and state friction in that here, nucleation processes are simulated as a part of spontaneously occurring earthquake sequences in continuum fault models. We use two 2D models of a vertical strike-slip fault, the depth-variable model (Rice, 1993; Lapusta at el., 2000) and the crustal-plane model (Myers et al., 1996). We find that nucleation processes in continuum models and the resulting aftershock rates are well-described by the model of Dieterich (1994) when Dieterich's assumption that the state variable of the rate and state friction law is significantly behind its steady-state value holds during the entire nucleation process. On the contrary, aftershock rates in models where the state variable assumption is violated for a significant portion of the nucleation process exhibit behavior different from Dieterich's model. The state variable assumption is significantly violated, and hence the aftershock rates are affected, when stress heterogeneities are present within the nucleation

  18. Resource sharing in the attentional blink

    NARCIS (Netherlands)

    Shapiro, K; Schmitz, Frank; Martens, S; Hommel, B; Schnitzler, A

    2006-01-01

    Humans have difficulty processing more than one event at a time, as is evidenced by the attentional blink ('blink') phenomenon: the second of two targets in a visual stream of events cannot be reported accurately if it appears between 100 and 500 ms after the first. By using whole-head

  19. Blinking and the Brain: Pathways and Pathology

    NARCIS (Netherlands)

    A.E. Smit (Albertine Eline)

    2009-01-01

    textabstractA blink is a rapid bilateral eyelid closure and co-occurring eye movement. The eyes rotate down towards the tip of the nose and back up again. Seemingly, this generally unnoticed often repeated action is not very spectacular. However, if not for the occasional blink we would all be

  20. Assessment of baroreflex sensitivity from spontaneous oscillations of blood pressure and heart rate: proven clinical value?

    International Nuclear Information System (INIS)

    Pinna, Gian Domenico; Maestri, Roberto; La Rovere, Maria Teresa

    2015-01-01

    The baroreceptor-heart rate reflex (baroreflex sensitivity, BRS) is a key mechanism contributing to the neural regulation of the cardiovascular system. Several methods have been proposed so far to assess BRS by analyzing the spontaneous beat-to-beat fluctuations of arterial blood pressure and heart rate. These methods are inherently simple, non-invasive and low-cost. This study is an attempt to address the question of whether spontaneous baroreflex methods have proven to be of value in the clinical setting. In the first part of this article, we critically review most representative clinical studies using spontaneous BRS techniques either for risk stratification or treatment evaluation, these being major issues in the clinical management of the patients. In the second part, we address two important aspects of spontaneous BRS measurements: measurability and reliability. Estimation of BRS in the studies selected for the review was performed according to the sequence, transfer function, alpha-index and phase-rectified signal averaging method. Arterial blood pressure was recorded non-invasively during supine, short-term (<30 min) laboratory recordings. The conclusion from this review is that spontaneous BRS techniques have been shown to be of great value in clinical practice but further work is needed to confirm the validity of previous findings and to widen the field of clinical applications. Measurability and reliability can be a major issue in the measurement of spontaneous BRS, particularly in some patient populations like post-myocardial infarction and heart failure patents. Main causes of poor measurability are: non-sinus rhythm, a high rate of ectopic beats and the need for recorded time series of RR interval and arterial blood pressure to satisfy the constraints of the different BRS estimation algorithms. As for reliability, within-subject variability is rather high in the measurements of spontaneous BRS and, therefore, should be carefully taken into account

  1. Nonstressed antepartum heart-rate monitoring - implications of decelerations after spontaneous contractions

    NARCIS (Netherlands)

    Visser, G. H. A.; REDMAN, CWG; HUISJES, HJ; TURNBULL, AC

    1980-01-01

    Fetal outcome in 98 patients with spontaneous antepartum late decelerations was studied by combining the data of two obstetric departments. Heart rate variability was used to classify the different patterns into two categories: terminal and decelerative. In 14 of the 47 pregnancies in which a

  2. Short-term memory across eye blinks.

    Science.gov (United States)

    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.

  3. Transfer of spontaneously hatching or hatched blastocyst yields better pregnancy rates than expanded blastocyst transfer

    Directory of Open Access Journals (Sweden)

    Natachandra M Chimote

    2013-01-01

    Full Text Available Context: Blastocyst stage embryo transfer (ET has become routine practice in recent years. However, probably due to limitations of assisted hatching techniques, expanded blastocyst transfer (EBT is still the preferred mode. Inexplicably, not much consideration has been given to spontaneously hatching/hatched blastocyst transfer (SHBT. Aim: This study aimed to investigate developmental potential of spontaneously hatching/hatched blastocyst against EBT in in vitro fertilization (IVF cycles. Settings and Design: Prospective study of 146 women undergoing their first IVF- ET cycle. SUBJECTS AND Methods: On the basis of blastocyst status, women were classified into SHBT and EBT groups. Intracytoplasmic sperm injection cycles were excluded to remove male factor bias. Implantation rate (IR, clinical pregnancy rate, and live birth rate were the main outcome measures. Statistical Analysis: Graph-pad Prism 5 statistical package. Results: SHBT group showed significantly higher blastocyst formation rate (53.3 ± 17.5 vs. 43.1 ± 14.5%, P = 0.0098, top-quality blastocysts (71.8 vs. 53.7%, P = 0.0436, IR (43.6 vs. 27.9%, P = 0.0408, pregnancy rate (59.4 vs. 45.1%, P = 0.0173, and live birth rate (36.8 vs. 22.8%, P = 0.003 compared to EBT group. Multiple pregnancy rates remained comparable between the two groups. Implantation correlated strongly with top-quality blastocysts (Pearson, r = 0.4441 in SHBT group, while the correlation was nonsignificant in EBT group. Conclusion: Extending culture of expanded blastocysts by a few hours to allow transfer of spontaneously hatching/hatched blastocysts gives higher implantation and pregnancy rates with no added risk of multiple gestations. Spontaneously hatching/hatched blastocysts have a better potential to implant and develop into a positive pregnancy.

  4. Startle and blink reflex in high functioning autism.

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  5. Endo- and exocytic rate constants for spontaneous and protein kinase C-activated T cell receptor cycling

    DEFF Research Database (Denmark)

    Menné, Charlotte; Møller Sørensen, Tine; Siersma, Volkert

    2002-01-01

    To determine the rate constants of spontaneous and activated TCR cycling, we examined TCR endo- and exocytosis in the human T cell line Jurkat by three different methods. Using a simple kinetic model for TCR cycling and non-linear regression analyses, we found that the spontaneous endocytic rate...

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

    Directory of Open Access Journals (Sweden)

    Mohan M. Trivedi

    2008-04-01

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

  7. Distractor inhibition predicts individual differences in recovery from the attentional blink.

    Directory of Open Access Journals (Sweden)

    Heleen A Slagter

    Full Text Available BACKGROUND: The attentional blink (AB refers to an impairment in detecting the second of two target stimuli presented in close succession in a rapid stream of distractors. Recent studies indicate that the AB results, in part, from distractor suppression mechanisms, that may be mediated by striatal dopamine. Yet, it is currently unclear how distractor suppression ability may contribute to the AB. Here, we examined whether distractor suppression ability is predictive of an individual's AB depth and/or recovery. In addition, we investigated the relationship between individual spontaneous eye blink rate (sEBR, a marker of striatal dopaminergic functioning, and AB performance. METHODOLOGY/PRINCIPAL FINDINGS: Subjects were presented with rapid streams of letters containing white distractors, a red T1 and a green T2. T2 was presented either at Lag2, Lag4 or Lag10, and preceded by a distractor that shared the same identity as T2 (T2 primed or not (T2 not primed. Replicating previous work [1], we found that slow AB recovery (poor T2 performance in Lag4 vs. Lag10 was associated with a failure to inhibit distractors, as indexed by greater positive priming. However, no relationship was observed between a subject's ability to suppress distractors and AB depth (Lag10 vs. Lag2. Moreover, no relationship between sEBR and AB performance was observed. RESULTS/SIGNIFICANCE: These results indicate that a failure to inhibit distracting information impairs AB recovery, possibly by interfering with target encoding in working memory - but does not affect AB magnitude. The absence of a relationship between individual sEBR and AB performance may be explained by task specifics.

  8. How variable is a spontaneous mutation rate in cultured mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Boesen, Jan J.B.; Niericker, Matthieu J.; Dieteren, Nicole; Simons, Jo W.I.M. (MGC-Dept. of Radiation Genetics and Chemical Mutagenesis, State Univ. of Leiden (Netherlands))

    1994-05-01

    The Luria-Delbrueck fluctuation analysis provides a method to estimate mutation rates and is commonly applied in somatic cell genetics and in cancer biology. We developed an assay for a Luria-Delbrueck fluctuation analysis using the mouse lymphoma cell line, GRSL13. As these cells grow in suspension, one can handle hundreds of parallel cultures using multiwell dishes and dispensers. This assay thereby allows not only an accurate determination of the mutation rate per cell generation but also makes it possible to determine at which time after seeding mutations take place. Using approx. 8000 parallel cultures it has been possible to test whether the mutation rate is constant during the assay. It has been found that the spontaneous mutation rate of GRSL13 cells decreases in the course of a fluctuation test from 2x10[sup -6] to about 2x10[sup -7]/cell/generation. It was shown that this increased replication fidelity may partly be caused by cell density: maintenance of cells at high cell density resulted in a spontaneous mutation rate of 0.7[+-]4.0x10[sup -7] compared to 4.0[+-]3.1x10[sup -7] for the standard protocol. In contrast, growing the cells at extremely low cell density resulted in an enhanced mutation rate of 7.7[+-]1.3x10[sup -7]. Thus altogether the mutation rate can vary from 2x10[sup -6] to 0.7x10[sup -7] (approx. 30-fold). These results show that the spontaneous mutation rate is not constant, but highly dependent on experimental conditions. As incomplete expression and metabolic cooperation cannot explain the findings, the data suggest that the fidelity of DNA replication is not fixed but open to variation. Hence, determination of replication infidelity in cultured cells needs rigorous standardization or/and application of controlled variation in culture conditions.

  9. Large social disparities in spontaneous preterm birth rates in transitional Russia.

    Science.gov (United States)

    Grjibovski, A M; Bygren, L O; Yngve, A; Sjöström, M

    2005-02-01

    This study estimated the effect of maternal sociodemographic, obstetric and lifestyle factors on the risk of spontaneous preterm birth in a Russian town. All women with singleton pregnancies registered at prenatal care centres in Severodvinsk in 1999 comprised the cohort for this study (n=1559). Analysis was based on spontaneous live singleton births at the maternity home (n=1103). Multivariable logistic regression was applied to quantify the effect of the studied factors on the risk of preterm birth. Differences in gestation duration were studied using multiple linear regression. In total, 5.6% of all spontaneous births were preterm. Increased risks of preterm delivery were found in women with lower levels of education and in students. Placental complications, stress and a history of fetal death in previous pregnancies were also associated with elevated risks for preterm delivery. Smoking, hypertension and multigravidity were associated with reduced length of pregnancy in metric form. In addition to medical risk factors, social factors are important determinants of preterm birth in transitional Russia. Large disparities in preterm birth rates may reflect the level of inequalities in transitional Russia. Social variations in pregnancy outcomes should be monitored.

  10. Accuracy of rate coding: When shorter time window and higher spontaneous activity help

    Czech Academy of Sciences Publication Activity Database

    Leváková, Marie; Tamborrino, M.; Košťál, Lubomír; Lánský, Petr

    2017-01-01

    Roč. 95, č. 2 (2017), č. článku 022310. ISSN 2470-0045 R&D Projects: GA ČR(CZ) GA15-08066S; GA MŠk(CZ) 7AMB17AT048 Institutional support: RVO:67985823 Keywords : rate coding * observation window * spontaneous activity * Fisher information * perfect integrate- and -fire model * Wiener process Subject RIV: BB - Applied Statistics, Operational Research OBOR OECD: Biology (theoretical, mathematical, thermal, cryobiology, biological rhythm), Evolutionary biology Impact factor: 2.366, year: 2016

  11. Temporal constraints on visual perception: A psychophysical investigation of the relation between attention capture and the attentional blink

    DEFF Research Database (Denmark)

    Nielsen, Simon

    While the richness of our visual perceptions is nearly boundless, the rate with which we can perceive information is limited. For instance when we are required to perceive two consecutive target objects following briefly after each other, the accuracy with which we can report the second target...... is often reduced in the first half second. This phenomenon is known as the attentional blink (Raymond, Shapiro & Arnell, 1992) and as suggests by the name is assumed to pertain to how fast attention can be reallocated. Bottleneck models suggest that the attentional blink is caused by limited capacity...... in processing targets, which effectively causes a perceptual bottleneck (Chun & Potter, 1995). According to bottleneck models, making the first target easier to perceive should improve processing in the bottleneck and reduce the attentional blink. However, recent studies suggest that an attentional blink may...

  12. Is there a proportionality between the spontaneous and the X-ray-induction rates of mutations

    International Nuclear Information System (INIS)

    Shukla, P.T.; Sankaranarayanan, K.; Sobels, F.H.

    1979-01-01

    The X-ray induction of recessive visible specific locus mutations at 14 X-chromosome loci was studied in Drosophila melanogaster using the 'Maxy' technique. The X-ray exposure was 3000 R to 5 day-old males and the sampling of germ cells was restricted to mature spermatozoa. Presumptive mutant females recovered in the F 1 generation were tested for transmission, allelism, fertility and viability in males. A total of 128 mutations (115 completes and 13 mosaics including those that were male-viable as well as male-lethal) recovered among 38 898 female progeny were found to be transmitted. On the basis of the above frequency, the average mutation rate can be estimated as 7.8 X 10 -8 /locus/R; for mutations that were viable and fertile in males, the rate is 3.0 X 10 -8 /locus/R(49 mutations among 38 898 progeny). The frequency of mutations at the different loci encompassed a wide range: while no mutations were recovered at the raspberry and carnation loci, at others, the numbers ranged from 1 at echinus to 31 at garnet; in addition, the proportion of mutations that was male-viable was also different, depending on the locus. Schalet's extensive data on spontaneous mutations at 13 (of the 14 loci employed in the present study) loci permit an estimate of the spontaneous rate which is 6.1 X 10 -6 /locus (a total of 39 mutations among 490 000 progeny); for mutations that were viable and fertile in males, the rate is 3.0 X 10 -6 /locus (19 mutations among 490 000 progeny). The mutability of the different loci varied over a 9-fold range. (Auth.)

  13. Irrelevant Words Trigger an Attentional Blink

    NARCIS (Netherlands)

    Stein, T.; Zwickel, J.; Kitzmantel, M.; Ritter, J.; Schneider, W.X.

    2010-01-01

    It has been argued that salient distractor items displayed during rapid serial visual presentation (RSVP) trigger an attentional blink (AB) when they share features with the target item. Here we demonstrate that salient distractor words induce an AB independently of feature overlap with the target.

  14. Blink reflex in type 2 diabetes mellitus.

    Science.gov (United States)

    Elkholy, Saly H; Hosny, Hanan M; Shalaby, Nevein M; El-Hadidy, Reem A; Abd El-Rahim, Noha T; Mohamed, Manal M

    2014-12-01

    An evaluation of the extent of damage of the central nervous system in diabetes mellitus is of high value in current research. Electrophysiological abnormalities are frequently present in asymptomatic patients with diabetes mellitus. Diabetic cranial neuropathy is one of the complications of the disease. Blink reflex is used to diagnose subclinical cranial neuropathy. The objective is to test the utility of blink reflex in detecting subclinical cranial nerve involvement in patients with type 2 diabetes mellitus. Forty patients with type 2 diabetes mellitus, aged from 30 to 60 years examined clinically and neurologically. Blink reflex and nerve conduction studies for the upper and lower limbs were performed and compared with 20 matched normal controls. Diabetic patients with peripheral neuropathy showed significant prolonged distal latency and reduced amplitudes of the R2C response compared with the control, patients without peripheral neuropathy showed insignificant changes. Alteration of R2 correlated with the type of treatment and the duration of the disease. In patients without peripheral neuropathy, ulnar sensory distal latencies showed significant positive correlation with R2I latency, whereas its Conduction Velocity (CV) showed significant positive correlation with R2C amplitudes and negative correlation with R2C latency. R2C is the most sensitive parameter in the blink reflex, which can help in the diagnosis of subclinical diabetic cranial neuropathy.

  15. Blink the power of thinking without thinking

    CERN Document Server

    Gladwell, Malcolm

    2005-01-01

    In his landmark bestseller The Tipping Point, Malcolm Gladwell redefined how we understand the world around us. Now, in Blink, he revolutionizes the way we understand the world within. Blink is a book about how we think without thinking, about choices that seem to be made in an instant-in the blink of an eye-that actually aren't as simple as they seem. Why are some people brilliant decision makers, while others are consistently inept? Why do some people follow their instincts and win, while others end up stumbling into error? How do our brains really work-in the office, in the classroom, in the kitchen, and in the bedroom? And why are the best decisions often those that are impossible to explain to others?In Blink we meet the psychologist who has learned to predict whether a marriage will last, based on a few minutes of observing a couple; the tennis coach who knows when a player will double-fault before the racket even makes contact with the ball; the antiquities experts who recognize a fake at a glance. Her...

  16. Spontaneous mutation rate is a plastic trait associated with population density across domains of life.

    Science.gov (United States)

    Krašovec, Rok; Richards, Huw; Gifford, Danna R; Hatcher, Charlie; Faulkner, Katy J; Belavkin, Roman V; Channon, Alastair; Aston, Elizabeth; McBain, Andrew J; Knight, Christopher G

    2017-08-01

    Rates of random, spontaneous mutation can vary plastically, dependent upon the environment. Such plasticity affects evolutionary trajectories and may be adaptive. We recently identified an inverse plastic association between mutation rate and population density at 1 locus in 1 species of bacterium. It is unknown how widespread this association is, whether it varies among organisms, and what molecular mechanisms of mutagenesis or repair are required for this mutation-rate plasticity. Here, we address all 3 questions. We identify a strong negative association between mutation rate and population density across 70 years of published literature, comprising hundreds of mutation rates estimated using phenotypic markers of mutation (fluctuation tests) from all domains of life and viruses. We test this relationship experimentally, determining that there is indeed density-associated mutation-rate plasticity (DAMP) at multiple loci in both eukaryotes and bacteria, with up to 23-fold lower mutation rates at higher population densities. We find that the degree of plasticity varies, even among closely related organisms. Nonetheless, in each domain tested, DAMP requires proteins scavenging the mutagenic oxidised nucleotide 8-oxo-dGTP. This implies that phenotypic markers give a more precise view of mutation rate than previously believed: having accounted for other known factors affecting mutation rate, controlling for population density can reduce variation in mutation-rate estimates by 93%. Widespread DAMP, which we manipulate genetically in disparate organisms, also provides a novel trait to use in the fight against the evolution of antimicrobial resistance. Such a prevalent environmental association and conserved mechanism suggest that mutation has varied plastically with population density since the early origins of life.

  17. Spontaneous mutation rate is a plastic trait associated with population density across domains of life.

    Directory of Open Access Journals (Sweden)

    Rok Krašovec

    2017-08-01

    Full Text Available Rates of random, spontaneous mutation can vary plastically, dependent upon the environment. Such plasticity affects evolutionary trajectories and may be adaptive. We recently identified an inverse plastic association between mutation rate and population density at 1 locus in 1 species of bacterium. It is unknown how widespread this association is, whether it varies among organisms, and what molecular mechanisms of mutagenesis or repair are required for this mutation-rate plasticity. Here, we address all 3 questions. We identify a strong negative association between mutation rate and population density across 70 years of published literature, comprising hundreds of mutation rates estimated using phenotypic markers of mutation (fluctuation tests from all domains of life and viruses. We test this relationship experimentally, determining that there is indeed density-associated mutation-rate plasticity (DAMP at multiple loci in both eukaryotes and bacteria, with up to 23-fold lower mutation rates at higher population densities. We find that the degree of plasticity varies, even among closely related organisms. Nonetheless, in each domain tested, DAMP requires proteins scavenging the mutagenic oxidised nucleotide 8-oxo-dGTP. This implies that phenotypic markers give a more precise view of mutation rate than previously believed: having accounted for other known factors affecting mutation rate, controlling for population density can reduce variation in mutation-rate estimates by 93%. Widespread DAMP, which we manipulate genetically in disparate organisms, also provides a novel trait to use in the fight against the evolution of antimicrobial resistance. Such a prevalent environmental association and conserved mechanism suggest that mutation has varied plastically with population density since the early origins of life.

  18. Mutation rate and spectrum of spontaneous mutations of deinococcus radiodurans under rifampin stress

    International Nuclear Information System (INIS)

    Hua Xiaoting; Wang Chao; Huang Lifen

    2010-01-01

    An rpoB/Rif r mutation analysis system has been developed from D. radiodurans based on the conservation of rpoB gene. To investigate the concentration effect of rifampin on the spontaneous mutation rate and spectrum of D. radiodurans, the mutation frequencies and rates of D. radiodurans were measured under a wide concentration range of 5∼50 μg /ml of rifampin. It was found that the mutation rate of the bacterium in 5μg /ml of rifampin was significantly higher than those in 25 and 50μg /ml rifampin. Rifampin had concentration-dependent effect not only on the mutation rate but also on the mutation spectrum. The different mutation spectrum under different concentration of rifampin suggested that D. radiodurans might change its anti-mutant strategy under reactive oxygen species (ROS) stress caused by low concentration of rifampin. It is speculated that D. radiodurans focuses on preventing base substitution mutation under low concentration of rifampin as ROS induces mainly oxidative base damage. (authors)

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

    Directory of Open Access Journals (Sweden)

    Travis eSeymour

    2013-02-01

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

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

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

    2011-01-01

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

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

    Science.gov (United States)

    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…

  3. Attentional blink in children with attention deficit hyperactivity disorder

    Directory of Open Access Journals (Sweden)

    Juan A. Amador-Campos

    2015-06-01

    Full Text Available Objective:To explore the temporal mechanism of attention in children with attention deficit hyperactivity disorder (ADHD and controls using a rapid serial visual presentation (RSVP task in which two letters (T1 and T2 were presented in close temporal proximity among distractors (attentional blink [AB].Method:Thirty children aged between 9 and 13 years (12 with ADHD combined type and 18 controls took part in the study. Both groups performed two kinds of RSVP task. In the single task, participants simply had to identify a target letter (T1, whereas in the dual task, they had to identify a target letter (T1 and a probe letter (T2.Results:The ADHD and control groups were equivalent in their single-task performance. However, in the dual-task condition, there were significant between-group differences in the rate of detection of the probe letter (T2 at lag + 1 and lag + 4. The ADHD group exhibited a larger overall AB compared with controls.Conclusion:Our findings provide support for a link between ADHD and attentional blink.

  4. Attentional blink in children with attention deficit hyperactivity disorder.

    Science.gov (United States)

    Amador-Campos, Juan A; Aznar-Casanova, J Antonio; Bezerra, Izabela; Torro-Alves, Nelson; Sánchez, Manuel M

    2015-01-01

    To explore the temporal mechanism of attention in children with attention deficit hyperactivity disorder (ADHD) and controls using a rapid serial visual presentation (RSVP) task in which two letters (T1 and T2) were presented in close temporal proximity among distractors (attentional blink [AB]). Thirty children aged between 9 and 13 years (12 with ADHD combined type and 18 controls) took part in the study. Both groups performed two kinds of RSVP task. In the single task, participants simply had to identify a target letter (T1), whereas in the dual task, they had to identify a target letter (T1) and a probe letter (T2). The ADHD and control groups were equivalent in their single-task performance. However, in the dual-task condition, there were significant between-group differences in the rate of detection of the probe letter (T2) at lag + 1 and lag + 4. The ADHD group exhibited a larger overall AB compared with controls. Our findings provide support for a link between ADHD and attentional blink.

  5. The three faces of riboviral spontaneous mutation: spectrum, mode of genome replication, and mutation rate.

    Directory of Open Access Journals (Sweden)

    Libertad García-Villada

    Full Text Available Riboviruses (RNA viruses without DNA replication intermediates are the most abundant pathogens infecting animals and plants. Only a few riboviral infections can be controlled with antiviral drugs, mainly because of the rapid appearance of resistance mutations. Little reliable information is available concerning i kinds and relative frequencies of mutations (the mutational spectrum, ii mode of genome replication and mutation accumulation, and iii rates of spontaneous mutation. To illuminate these issues, we developed a model in vivo system based on phage Qß infecting its natural host, Escherichia coli. The Qß RT gene encoding the Read-Through protein was used as a mutation reporter. To reduce uncertainties in mutation frequencies due to selection, the experimental Qß populations were established after a single cycle of infection and selection against RT(- mutants during phage growth was ameliorated by plasmid-based RT complementation in trans. The dynamics of Qß genome replication were confirmed to reflect the linear process of iterative copying (the stamping-machine mode. A total of 32 RT mutants were detected among 7,517 Qß isolates. Sequencing analysis of 45 RT mutations revealed a spectrum dominated by 39 transitions, plus 4 transversions and 2 indels. A clear template•primer mismatch bias was observed: A•C>C•A>U•G>G•U> transversion mismatches. The average mutation rate per base replication was ≈9.1×10(-6 for base substitutions and ≈2.3×10(-7 for indels. The estimated mutation rate per genome replication, μ(g, was ≈0.04 (or, per phage generation, ≈0.08, although secondary RT mutations arose during the growth of some RT mutants at a rate about 7-fold higher, signaling the possible impact of transitory bouts of hypermutation. These results are contrasted with those previously reported for other riboviruses to depict the current state of the art in riboviral mutagenesis.

  6. High rate of hepatitis C virus (HCV) recurrence in HIV-infected individuals with spontaneous HCV RNA clearance

    NARCIS (Netherlands)

    Peters, L.; Mocroft, A.; Soriano, V.; Rockstroh, J. K.; Kirkby, N.; Reiss, P.; Katlama, C.; Zakharova, N.; Flisiak, R.; Lundgren, J. D.

    2014-01-01

    Following resolution of hepatitis C virus (HCV) infection, recurrence has been shown to occur in some persons with repeated exposure to HCV. We aimed to investigate the rate and factors associated with HCV RNA recurrence among HIV-1-infected patients with prior spontaneous HCV RNA clearance in the

  7. The Electrooculogram and a New Blink Detection Algorithm

    Science.gov (United States)

    2015-10-30

    signed// //signed// APRIL M. COURTICE SCOTT M. GALSTER Work Unit Manager Chief, Applied Neuroscience Branch Applied Neuroscience ...laboratory and real-world settings. Wilson and Russell (2007) demonstrated that physiologically-determined adaptive automation could be used to...2013). Blinks are classified in three ways. Voluntary blinks are those that occur with a conscious decision to shortly close the eye. Involuntary

  8. A Hybrid System for On-line Blink Detection

    NARCIS (Netherlands)

    Sun, Yijia; Zafeiriou, Stefanos; Pantic, Maja; Jensen, Matthew; Meservy, Thomas; Burgoon, Judee; Nunamaker, Jay

    2013-01-01

    Eye blinking behaviour has been shown to be one of the most informative non-verbal behavioural cues for indicating deceptive behaviour. Traditional blink detection methods tend to use a tracker to extract static eye region images and classify those images as open and closed eyes in order to detect

  9. Irrelevant Auditory and Visual Events Induce a Visual Attentional Blink

    NARCIS (Netherlands)

    Van der Burg, Erik; Nieuwenstein, Mark R.; Theeuwes, Jan; Olivers, Christian N. L.

    2013-01-01

    In the present study we investigated whether a task-irrelevant distractor can induce a visual attentional blink pattern. Participants were asked to detect only a visual target letter (A, B, or C) and to ignore the preceding auditory, visual, or audiovisual distractor. An attentional blink was

  10. Spontaneous first trimester miscarriage rates per woman among parous women with 1 or more pregnancies of 24 weeks or more.

    Science.gov (United States)

    Cohain, Judy Slome; Buxbaum, Rina E; Mankuta, David

    2017-12-22

    The purpose of this study was to quantify spontaneous first trimester miscarriage rates per woman among parous women. A vast amount of data has accumulated regarding miscarriage rates per recognized pregnancy as well as about recurrent miscarriage. This is the second study of miscarriage rates per woman in a parous population and the first study of recurrent and non-recurrent, spontaneous first trimester miscarriage rates per woman in a large parous population. Extraction of the following variables from all delivery room admissions from both Hadassah Medical Centers in Jerusalem Israel, 2004-2014: # of first trimester spontaneous miscarriages, # live births; # living children; age on admission, pre-pregnancy height and weight, any smoking this pregnancy, any alcohol or drug abuse this pregnancy, blood type, history of ectopic pregnancy, history of cesarean surgery (CS) and use of any fertility treatment(s). Among 53,479 different women admitted to labor and delivery ward, 43% of women reported having had 1 or more first trimester spontaneous miscarriages; 27% reported having had one, 10% two, 4% three, 1.3% four, 0.6% five and 0.05% reported having 6-16 spontaneous first trimester miscarriages. 18.5% had one or more first trimester miscarriages before their first live birth. Eighty-one percent of women with 11 or more living children experienced one or more first trimester miscarriages. First trimester miscarriage rates rose with increasing age, increasing parity, after previous ectopic pregnancy, after previous cesarean surgery, with any smoking during pregnancy and pre-pregnancy BMI ≥30. Miscarriages are common among parous women; 43% of parous women report having experienced one or more first trimester spontaneous miscarriages, rising to 81% among women with 11 or more living children. One in every 17 parous women have three or more miscarriages. Depending on her health, nutrition and lifestyle choices, even a 39 year old parous woman with a history of 3 or

  11. Using neutron angular anisotropy information to dynamically determine the ratio of the (α,n) rate to spontaneous fission rate for coincidence counting applications

    Science.gov (United States)

    Holewa, L.; Charlton, W.; Miller, E.; Pozzi, S.

    2013-02-01

    Typically, when neutron coincidence or multiplicity counting is performed, there are three unknowns: the sample mass, the leakage self-multiplication, and the ratio of the (α,n) rate of the source to the spontaneous fission rate. For a given counting time, the strength of the source or the detector efficiency must be sufficiently high for the singles, doubles, and triples count rates to represent statistically meaningful quantities. Often, the strength of the source and the allotted counting time are such that only the singles and doubles count rates are statistically meaningful. In this latter case, the ratio of (α,n) to the spontaneous fission must be estimated through some other means. With a simulated (α,n) rate, the two equations related to the singles and doubles count rates can be used to determine the sample mass. In order to determine the ratio of (α,n) to spontaneous fission rate of the source, the isotopic composition of the sample as well as the light element impurities inside the source must be known. Ideally, there would be a way to dynamically determine the (α,n) rate of the source from count rate information. In this paper, it is shown that the (α,n) rate of the source can be determined by using information about the ratio of the number of coincident neutrons at 180° to the number at 90°. By using this information, the three aforementioned unknowns can be dynamically determined through the sole use of singles and doubles count rates.

  12. Effect of longwall face advance rate on spontaneous heating process in the gob area - CFD modelling

    Czech Academy of Sciences Publication Activity Database

    Taraba, B.; Michalec, Zdeněk

    2011-01-01

    Roč. 90, č. 8 (2011), s. 2790-2797 ISSN 0016-2361 R&D Projects: GA ČR GA105/06/0630 Grant - others:GA ČR(CZ) GA105/08/1414 Institutional research plan: CEZ:AV0Z30860518 Keywords : coal oxidation * spontaneous heating * CFD modelling * Fluent Subject RIV: DH - Mining, incl. Coal Mining Impact factor: 3.248, year: 2011 http://www.sciencedirect.com/science/article/pii/S0016236111001724

  13. Eyeblink rate watching classical Hollywood and post-classical MTV editing styles, in media and non-media professionals.

    Science.gov (United States)

    Andreu-Sánchez, Celia; Martín-Pascual, Miguel Ángel; Gruart, Agnès; Delgado-García, José María

    2017-02-21

    While movie edition creates a discontinuity in audio-visual works for narrative and economy-of-storytelling reasons, eyeblink creates a discontinuity in visual perception for protective and cognitive reasons. We were interested in analyzing eyeblink rate linked to cinematographic edition styles. We created three video stimuli with different editing styles and analyzed spontaneous blink rate in participants (N = 40). We were also interested in looking for different perceptive patterns in blink rate related to media professionalization. For that, of our participants, half (n = 20) were media professionals, and the other half were not. According to our results, MTV editing style inhibits eyeblinks more than Hollywood style and one-shot style. More interestingly, we obtained differences in visual perception related to media professionalization: we found that media professionals inhibit eyeblink rate substantially compared with non-media professionals, in any style of audio-visual edition.

  14. Eye blink frequency during different computer tasks quantified by electrooculography

    DEFF Research Database (Denmark)

    Skotte, J H; Nøjgaard, J K; Jørgensen, L V

    2007-01-01

    The purpose of the study was to evaluate electrooculography (EOG) as an automatic method to measure the human eye blink frequency (BF) during passive and interactive computer tasks performed at two screen heights. Ten healthy subjects (5 males and 5 females) participated in the study in a 23...... degrees C temperature and 30-35% relative humidity controlled simulated office environment. Each test subject completed a 2 x 10 min active task of computer work and a 3 x 10 min passive task of watching a film on a video display unit (VDU). Both tasks included two viewing angles: standard (the monitors...... counted manually from the video recordings and compared to the EOG measurements. The method showed a high validity to detect blinks during computer work: 95.4% of the blinks were retrieved by the EOG method and very few artefacts from eye movements were erroneously classified as eye blinks (2.4%). By use...

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

    Directory of Open Access Journals (Sweden)

    Philipp eKanske

    2013-10-01

    Full Text Available 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.

  16. Mitochondrial Mutation Rate, Spectrum and Heteroplasmy in Caenorhabditis elegans Spontaneous Mutation Accumulation Lines of Differing Population Size.

    Science.gov (United States)

    Konrad, Anke; Thompson, Owen; Waterston, Robert H; Moerman, Donald G; Keightley, Peter D; Bergthorsson, Ulfar; Katju, Vaishali

    2017-06-01

    Mitochondrial genomes of metazoans, given their elevated rates of evolution, have served as pivotal markers for phylogeographic studies and recent phylogenetic events. In order to determine the dynamics of spontaneous mitochondrial mutations in small populations in the absence and presence of selection, we evolved mutation accumulation (MA) lines of Caenorhabditis elegans in parallel over 409 consecutive generations at three varying population sizes of N = 1, 10, and 100 hermaphrodites. The N =1 populations should have a minimal influence of natural selection to provide the spontaneous mutation rate and the expected rate of neutral evolution, whereas larger population sizes should experience increasing intensity of selection. New mutations were identified by Illumina paired-end sequencing of 86 mtDNA genomes across 35 experimental lines and compared with published genomes of natural isolates. The spontaneous mitochondrial mutation rate was estimated at 1.05 × 10-7/site/generation. A strong G/C→A/T mutational bias was observed in both the MA lines and the natural isolates. This suggests that the low G + C content at synonymous sites is the product of mutation bias rather than selection as previously proposed. The mitochondrial effective population size per worm generation was estimated to be 62. Although it was previously concluded that heteroplasmy was rare in C. elegans, the vast majority of mutations in this study were heteroplasmic despite an experimental regime exceeding 400 generations. The frequencies of frameshift and nonsynonymous mutations were negatively correlated with population size, which suggests their deleterious effects on fitness and a potent role for selection in their eradication. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. High rate of hepatitis C virus (HCV) recurrence in HIV-infected individuals with spontaneous HCV RNA clearance

    DEFF Research Database (Denmark)

    Peters, L; Mocroft, A; Soriano, V

    2014-01-01

    OBJECTIVES: Following resolution of hepatitis C virus (HCV) infection, recurrence has been shown to occur in some persons with repeated exposure to HCV. We aimed to investigate the rate and factors associated with HCV RNA recurrence among HIV-1-infected patients with prior spontaneous HCV RNA...... clearance in the EuroSIDA cohort. METHODS: All HIV-infected patients with documented prior spontaneous HCV clearance, and at least one subsequently collected plasma sample, were examined. The last sample was tested for HCV RNA and those with HCV RNA ≥ 615 IU/mL were defined as having HCV recurrence...... less likely to have HCV RNA recurrence, whereas IDUs were over 6 times more likely to have HCV RNA recurrence compared with non-IDUs (OR 6.58; 95% CI 1.48-29.28; P = 0.013). CONCLUSIONS: Around 1 in 5 HIV-infected patients with prior spontaneous HCV RNA clearance had detectable HCV RNA during follow...

  18. A novel blink detection method based on pupillometry noise.

    Science.gov (United States)

    Hershman, Ronen; Henik, Avishai; Cohen, Noga

    2018-02-01

    Pupillometry (or the measurement of pupil size) is commonly used as an index of cognitive load and arousal. Pupil size data are recorded using eyetracking devices that provide an output containing pupil size at various points in time. During blinks the eyetracking device loses track of the pupil, resulting in missing values in the output file. The missing-sample time window is preceded and followed by a sharp change in the recorded pupil size, due to the opening and closing of the eyelids. This eyelid signal can create artificial effects if it is not removed from the data. Thus, accurate detection of the onset and the offset of blinks is necessary for pupil size analysis. Although there are several approaches to detecting and removing blinks from the data, most of these approaches do not remove the eyelid signal or can result in a relatively large amount of data loss. The present work suggests a novel blink detection algorithm based on the fluctuations that characterize pupil data. These fluctuations ("noise") result from measurement error produced by the eyetracker device. Our algorithm finds the onset and offset of the blinks on the basis of this fluctuation pattern and its distinctiveness from the eyelid signal. By comparing our algorithm to three other common blink detection methods and to results from two independent human raters, we demonstrate the effectiveness of our algorithm in detecting blink onset and offset. The algorithm's code and example files for processing multiple eye blinks are freely available for download ( https://osf.io/jyz43 ).

  19. Capsaicin effects on blinking Efectos de la capsaicina en el parpadeo

    Directory of Open Access Journals (Sweden)

    Fidias E. Leon-Sarmiento

    2005-09-01

    Full Text Available Blinking is a normal human phenomenom involving trigeminal and facial patways. To gain understanding on the neurobiology of blinking, five normal subjects were investigated before and after application of transdermal capsaicin at the forehead for two weeks. No effects of topical capsaicin were detected in eye blink rates. However, when capsaicin was applied to a female subject with blepharospasm, she showed a dramatic restoration of her vision subsequent to blinking modification. Deactivation of abnormal A-to-C fibers cross talks at the trigeminal-facial pathways seems to be the most likely mechanism of such improvement.El parpadeo es un fenómeno normal en los humanos que involucra las vías trigéminas faciales. Con el fin de conocer un poco más la neurobiología de este fenómeno estudiamos cinco individuos normales antes y después de aplicar capsaicina trasdérmica en la frente de cada uno de ellos, por dos semanas. La frecuencia de parpadeo no se alteró con la aplicación de capsaicina tópica. Sin embargo, cuando la misma sustancia se aplicó a una paciente con blefaroespasmo hubo dramática restauración de su visión, la cual fue secundaria a la modificación de la actividad muscular palpebral. La desactivación del cruce patológico de información que pasa de las fibras A a las fibras C, pertenecientes a las vías trigémino-faciales, parece ser el mecanismo de acción relacionado con la aplicación de capsaicina, el que estaría directamente relacionado con la recuperación clínica observada en la paciente con blefaroespasmo.

  20. Comment on anomalous dispersion and scattering rates for multiphonon spontaneous decay in He II

    Science.gov (United States)

    Haavasoja, T.; Narayanamurti, V.; Chin, M. A.

    1984-10-01

    We report on new measurements of the spontaneous decay threshold energy E c for high-frequency phonon propagation in He II at saturated vapor pressure at T=0.1 K. Superconducting tin tunnel generators and aluminum tunnel detectors were used in this study. The measurements show that the mean free path becomes much larger than the propagation length of 1.1 mm for a value of E c =9.8±0.15 K. This agrees with the value originally reported ( E c =9.5±0.4 K) by Dynes and Narayanamurti using aluminum tunnel generators, but is shown to correspond to the point where the phase velocity equals the sound velocity, when the phonons become stable, as first proposed by Pitayevski and Levinson. Evidence for n-phonon decay at energies lower than E c is presented for n≳2 with a short mean free path (neutron data due to Donnelly, Donnelly, and Hills.

  1. Success and spontaneous pregnancy rates following systemic methotrexate versus laparoscopic surgery for tubal pregnancies: A randomized trial

    DEFF Research Database (Denmark)

    Krag Moeller, Lars Bo; Moeller, Charlotte; Thomsen, Sten Grove

    2009-01-01

    . A total of 106 women diagnosed with ectopic pregnancy (EP). Methods. Between March 1997 and September 2000, 1,265 women were diagnosed with EP, 395 (31%) were eligible, 109 (9%) were randomized of whom 106 had an EP. The study was originally powered to a sample size of 422 patients. The women were......, subsequent intrauterine, and recurrent ectopic pregnancies. Results. The success rates were 74% following MTX treatment and 87% after surgery (n.s.); the subsequent spontaneous intrauterine pregnancy rate was 73% after MTX and 62% after surgery; and the EP rate was 9.6% after MTX and 17.3% following surgery......Objective. To determine which treatment should be offered to women with a non-ruptured tubal pregnancy: a single dose of methotrexate (MTX) or laparoscopic surgery. Design. Prospective, randomized, open multicenter study. Setting. Seven Danish departments of obstetrics and gynecology. Sample...

  2. The effects of MSH2 deficiency on spontaneous and radiation-induced mutation rates in the mouse germline

    International Nuclear Information System (INIS)

    Burr, Karen L-A.; Duyn-Goedhart, Annemarie van; Hickenbotham, Peter; Monger, Karen; Buul, Paul P.W. van; Dubrova, Yuri E.

    2007-01-01

    Mutation rates at two expanded simple tandem repeat (ESTR) loci were studied in the germline of mismatch repair deficient Msh2 knock-out mice. Spontaneous mutation rates in homozygous Msh2 -/- males were significantly higher than those in isogenic wild-type (Msh2 +/+ ) and heterozygous (Msh2 +/- ) mice. In contrast, the irradiated Msh2 -/- mice did not show any detectable increases in their mutation rate, whereas significant ESTR mutation induction was observed in the irradiated Msh2 +/+ and Msh2 +/- animals. Considering these data and the results of other publications, we propose that the Msh2-deficient mice possess a mutator phenotype in their germline and somatic tissues while the loss of a single Msh2 allele does not affect the stability of heterozygotes

  3. A moving overlay shrinks the attentional blink.

    Science.gov (United States)

    Chua, Fook K

    2015-01-01

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

  4. Blink reflexes in patients with atypical odontalgia.

    Science.gov (United States)

    Baad-Hansen, Lene; List, Thomas; Jensen, Troels Staehelin; Leijon, Göran; Svensson, Peter

    2005-01-01

    To use the human blink reflex (BR) to explore possible neuropathic pain mechanisms in patients with atypical odontalgia (AO). In 13 AO patients, the BR was elicited using a concentric electrode and recorded bilaterally with surface electromyographic (EMG) electrodes on both orbicularis oculi muscles. Electrical stimuli were applied to the skin above branches of the V1, V2, and V3 nerves and to the V branch contralateral to the painful branch. Sensory and pain thresholds were determined. The BR examination of the painful V branch was repeated during a capsaicin pain-provocation test. The data were analyzed with nonparametric statistics. The BR responses (R2 and R3) evoked by stimulation of V3 were significantly smaller than the BR responses evoked by stimulation of V1 and V2 (P .569), and the BR (R2 and R3) was not significantly modulated by experimental pain (P > .080). The sensory thresholds were significantly lower on the painful side compared to the nonpainful side (P = .014). The pain thresholds were not different between sides (P > .910). No major differences between the V nociceptive pathways on the right and left sides were found in a relatively small group of AO patients. Future studies that compare BRs in AO patients and healthy volunteers are needed to provide further knowledge on the pain mechanisms in AO.

  5. Ultrafast modification of the spontaneous decay rate by plasmonic nanostructures: a step toward manipulation of a single atom

    International Nuclear Information System (INIS)

    Zavareian, N

    2014-01-01

    A controllable method for modifying spontaneous emission of an electric dipole located in close proximity to a plasmonic nanostructure is proposed. The nanostructure constructed of two triangular nanowires, in the form of a dimer, on a substrate in which the gallium film on the micrometer scale is the main layer. The results illustrate that phase transition of the gallium film from the α-crystalline to liquid phase leads to variation of the spectrum of radiative and nonradiative decay rates of the dipole where such a transition depends on parameters of the dipole, e.g. position, orientation and emission wavelength as well as on the nanostructure, e.g. shape and size of the dimer and also properties of the substrate. On the other hand, it is found that during phase transition modification of nanostructure resonances is negligible while the radiative decay rate changes. (letter)

  6. Spontaneous abortion rate and advanced maternal age: Consequences for prenatal diagnosis

    NARCIS (Netherlands)

    T.E. Cohen-Overbeek (Titia); W.C.J. Hop (Wim); M.E.M. Den Ouden; L. Pijpers (Leendert); M.G. Jahoda (M.); J.W. Wladimiroff (Juriy)

    1990-01-01

    markdownabstractAbstract Maternal age related and procedure-related fetal abortion rates were studied in 384 women aged 36 and over scheduled for transabdominal chorionic villus sampling (TA-CVS) at 12-14 weeks of gestation. The pre-TA-CVS abortion rate within 30 days of intake (at 6-10 weeks of

  7. Probing and controlling fluorescence blinking of single semiconductor nanoparticles

    Directory of Open Access Journals (Sweden)

    Hsien-Chen Ko

    2011-02-01

    Full Text Available In this review we present an overview of the experimental and theoretical development on fluorescence intermittency (blinking and the roles of electron transfer in semiconductor crystalline nanoparticles. Blinking is a very interesting phenomenon commonly observed in single molecule/particle experiments. Under continuous laser illumination, the fluorescence time trace of these single nanoparticles exhibit random light and dark periods. Since its first observation in the mid-1990s, this intriguing phenomenon has attracted wide attention among researchers from many disciplines. We will first present the historical background of the discovery and the observation of unusual inverse power-law dependence for the waiting time distributions of light and dark periods. Then, we will describe our theoretical modeling efforts to elucidate the causes for the power-law behavior, to probe the roles of electron transfer in blinking, and eventually to control blinking and to achieve complete suppression of the blinking, which is an annoying feature in many applications of quantum dots as light sources and fluorescence labels for biomedical imaging.

  8. VANADIUM EXPOSURE ALTERS SPONTANEOUS BEAT RATE AND GENE EXPRESSION OF CULTURED CARDIAC MYOCYTES

    Science.gov (United States)

    Ambient air pollution particulate matter (PM) exposure is associated with increased morbidity and mortality. Recent toxicological studies report PM-induced changes in a number of cardiac parameters, including heart rate variability, arrhythmias, repolarization, and internal defib...

  9. The attentional blink as an indicator of sexual interest

    Directory of Open Access Journals (Sweden)

    Susan Mac Conaill

    2012-05-01

    Full Text Available Using implicit measures in psychological assessment is new in research. The Attentional Blink is a widely supported phenomenon in the cognitive literature. It has been reported that emotionally salient stimuli, particularly those of a sexual nature, can produce it, leading to lower recall of a neutral target presented after the stimulus item. This study looked at the Attentional Blink as a measure of sexual interest. It also looked at the use of computer-generated (CG images as an alternative to real images. Findings showed that nude images produced the largest Attentional Blink, real images are most effective, and CG images produced some effect. These finding are promising for the development of CG images of children for use in paedophile assessment.

  10. Effects of Nanoparticle Morphology and Acyl Chain Length on Spontaneous Lipid Transfer Rates.

    Science.gov (United States)

    Xia, Yan; Li, Ming; Charubin, Kamil; Liu, Ying; Heberle, Frederick A; Katsaras, John; Jing, Benxin; Zhu, Yingxi; Nieh, Mu-Ping

    2015-12-01

    We report on studies of lipid transfer rates between different morphology nanoparticles and lipids with different length acyl chains. The lipid transfer rate of dimyristoylphosphatidylcholine (di-C14, DMPC) in discoidal "bicelles" (0.156 h(-1)) is 2 orders of magnitude greater than that of DMPC vesicles (ULVs) (1.1 × 10(-3) h(-1)). For both bicellar and ULV morphologies, increasing the acyl chain length by two carbons [going from di-C14 DMPC to di-C16, dipalmitoylphosphatidylcholine (DPPC)] causes lipid transfer rates to decrease by more than 2 orders of magnitude. Results from small angle neutron scattering (SANS), differential scanning calorimetry (DSC), and fluorescence correlation spectroscopy (FCS) are in good agreement. The present studies highlight the importance of lipid dynamic processes taking place in different morphology biomimetic membranes.

  11. Fundamental limitations in spontaneous emission rate of single-photon sources

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.; Khurgin, Jacob B.

    2016-01-01

    The rate of single-photon generation by quantum emitters (QEs) can be enhanced by placing a QE inside a resonant structure. This structure can represent an all-dielectric micro-resonator or waveguide and thus be characterized by ultra-low loss and dimensions on the order of wavelength. Or it can ...

  12. Chronic baroreflex activation restores spontaneous baroreflex control and variability of heart rate in obesity-induced hypertension.

    Science.gov (United States)

    Iliescu, Radu; Tudorancea, Ionut; Irwin, Eric D; Lohmeier, Thomas E

    2013-10-01

    The sensitivity of baroreflex control of heart rate is depressed in subjects with obesity hypertension, which increases the risk for cardiac arrhythmias. The mechanisms are not fully known, and there are no therapies to improve this dysfunction. To determine the cardiovascular dynamic effects of progressive increases in body weight leading to obesity and hypertension in dogs fed a high-fat diet, 24-h continuous recordings of spontaneous fluctuations in blood pressure and heart rate were analyzed in the time and frequency domains. Furthermore, we investigated whether autonomic mechanisms stimulated by chronic baroreflex activation and renal denervation-current therapies in patients with resistant hypertension, who are commonly obese-restore cardiovascular dynamic control. Increases in body weight to ∼150% of control led to a gradual increase in mean arterial pressure to 17 ± 3 mmHg above control (100 ± 2 mmHg) after 4 wk on the high-fat diet. In contrast to the gradual increase in arterial pressure, tachycardia, attenuated chronotropic baroreflex responses, and reduced heart rate variability were manifest within 1-4 days on high-fat intake, reaching 130 ± 4 beats per minute (bpm) (control = 86 ± 3 bpm) and ∼45% and baroreflex activation and renal denervation abolished the hypertension. However, only baroreflex activation effectively attenuated the tachycardia and restored cardiac baroreflex sensitivity and heart rate variability. These findings suggest that baroreflex activation therapy may reduce the risk factors for cardiac arrhythmias as well as lower arterial pressure.

  13. Cross Time-Frequency Analysis for Combining Information of Several Sources: Application to Estimation of Spontaneous Respiratory Rate from Photoplethysmography

    Science.gov (United States)

    Peláez-Coca, M. D.; Orini, M.; Lázaro, J.; Bailón, R.; Gil, E.

    2013-01-01

    A methodology that combines information from several nonstationary biological signals is presented. This methodology is based on time-frequency coherence, that quantifies the similarity of two signals in the time-frequency domain. A cross time-frequency analysis method, based on quadratic time-frequency distribution, has been used for combining information of several nonstationary biomedical signals. In order to evaluate this methodology, the respiratory rate from the photoplethysmographic (PPG) signal is estimated. The respiration provokes simultaneous changes in the pulse interval, amplitude, and width of the PPG signal. This suggests that the combination of information from these sources will improve the accuracy of the estimation of the respiratory rate. Another target of this paper is to implement an algorithm which provides a robust estimation. Therefore, respiratory rate was estimated only in those intervals where the features extracted from the PPG signals are linearly coupled. In 38 spontaneous breathing subjects, among which 7 were characterized by a respiratory rate lower than 0.15 Hz, this methodology provided accurate estimates, with the median error {0.00; 0.98} mHz ({0.00; 0.31}%) and the interquartile range error {4.88; 6.59} mHz ({1.60; 1.92}%). The estimation error of the presented methodology was largely lower than the estimation error obtained without combining different PPG features related to respiration. PMID:24363777

  14. Cross Time-Frequency Analysis for Combining Information of Several Sources: Application to Estimation of Spontaneous Respiratory Rate from Photoplethysmography

    Directory of Open Access Journals (Sweden)

    M. D. Peláez-Coca

    2013-01-01

    Full Text Available A methodology that combines information from several nonstationary biological signals is presented. This methodology is based on time-frequency coherence, that quantifies the similarity of two signals in the time-frequency domain. A cross time-frequency analysis method, based on quadratic time-frequency distribution, has been used for combining information of several nonstationary biomedical signals. In order to evaluate this methodology, the respiratory rate from the photoplethysmographic (PPG signal is estimated. The respiration provokes simultaneous changes in the pulse interval, amplitude, and width of the PPG signal. This suggests that the combination of information from these sources will improve the accuracy of the estimation of the respiratory rate. Another target of this paper is to implement an algorithm which provides a robust estimation. Therefore, respiratory rate was estimated only in those intervals where the features extracted from the PPG signals are linearly coupled. In 38 spontaneous breathing subjects, among which 7 were characterized by a respiratory rate lower than 0.15 Hz, this methodology provided accurate estimates, with the median error {0.00; 0.98} mHz ({0.00; 0.31}% and the interquartile range error {4.88; 6.59} mHz ({1.60; 1.92}%. The estimation error of the presented methodology was largely lower than the estimation error obtained without combining different PPG features related to respiration.

  15. Mutation Rates, Spectra, and Genome-Wide Distribution of Spontaneous Mutations in Mismatch Repair Deficient Yeast

    Science.gov (United States)

    Lang, Gregory I.; Parsons, Lance; Gammie, Alison E.

    2013-01-01

    DNA mismatch repair is a highly conserved DNA repair pathway. In humans, germline mutations in hMSH2 or hMLH1, key components of mismatch repair, have been associated with Lynch syndrome, a leading cause of inherited cancer mortality. Current estimates of the mutation rate and the mutational spectra in mismatch repair defective cells are primarily limited to a small number of individual reporter loci. Here we use the yeast Saccharomyces cerevisiae to generate a genome-wide view of the rates, spectra, and distribution of mutation in the absence of mismatch repair. We performed mutation accumulation assays and next generation sequencing on 19 strains, including 16 msh2 missense variants implicated in Lynch cancer syndrome. The mutation rate for DNA mismatch repair null strains was approximately 1 mutation per genome per generation, 225-fold greater than the wild-type rate. The mutations were distributed randomly throughout the genome, independent of replication timing. The mutation spectra included insertions/deletions at homopolymeric runs (87.7%) and at larger microsatellites (5.9%), as well as transitions (4.5%) and transversions (1.9%). Additionally, repeat regions with proximal repeats are more likely to be mutated. A bias toward deletions at homopolymers and insertions at (AT)n microsatellites suggests a different mechanism for mismatch generation at these sites. Interestingly, 5% of the single base pair substitutions might represent double-slippage events that occurred at the junction of immediately adjacent repeats, resulting in a shift in the repeat boundary. These data suggest a closer scrutiny of tumor suppressors with homopolymeric runs with proximal repeats as the potential drivers of oncogenesis in mismatch repair defective cells. PMID:23821616

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

    Science.gov (United States)

    Ryan, Michael; Kaminer, Jaime; Enmore, Patricia; Evinger, Craig

    2014-02-01

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

  17. Enhancement of spontaneous emission rate and reduction in amplified spontaneous emission threshold in electrodeposited three-dimensional ZnO photonic crystal

    Science.gov (United States)

    Zhong, Yongchun; Yue, Zhounan; Wong, George K. L.; Xi, Yan Yan; Hsu, Yuk Fan; Djurišić, Aleksandra B.; Dong, Jian-Wen; Chen, Wen-Jie; Wong, Kam Sing

    2010-11-01

    ZnO photonic crystal (PC) with face-center-cube type structure is fabricated by electrodeposition using holographic lithographically made organic (SU-8) template. Photonic band gap effect (reflection peak and transmission dip in infrared spectral region) is clearly seen. Observation of strong enhancement and blueshift of the emission peak (from 383.8 to 378.8 nm), shortening of the exciton photoluminescence lifetime (from 88 to 34 ps), and reduction in amplified spontaneous emission threshold of ZnO PC compared to that of the reference nonstructured electrodeposited ZnO showed clear evidence of PC structure affecting the ZnO exciton emission.

  18. Experimental characterization of true spontaneous emission rate of optically-pumped InGaAs/GaAs quantum-well laser structure

    Directory of Open Access Journals (Sweden)

    Q.-N. Yu

    2017-08-01

    Full Text Available In this paper, an experimental approach to acquiring true spontaneous emission rate of optically-pumped InGaAs/GaAs quantum-well laser structure is described. This method is based on a single edge-emitting laser chip with simple sample processing. The photoluminescence spectra are measured at both facets of the edge-emitting device and transformed to the spontaneous emission rate following the theory described here. The unusual double peaks appearing in the spontaneous emission rate spectra are observed for the InGaAs/GaAs quantum-well structure. The result is analyzed in terms of Indium-rich island and Model-Solid theories. The proposed method is suitable for electrically-pumped quantum-well laser structures, as well.

  19. An EEG-Based Person Authentication System with Open-Set Capability Combining Eye Blinking Signals

    Directory of Open Access Journals (Sweden)

    Qunjian Wu

    2018-01-01

    Full Text Available The electroencephalogram (EEG signal represents a subject’s specific brain activity patterns and is considered as an ideal biometric given its superior forgery prevention. However, the accuracy and stability of the current EEG-based person authentication systems are still unsatisfactory in practical application. In this paper, a multi-task EEG-based person authentication system combining eye blinking is proposed, which can achieve high precision and robustness. Firstly, we design a novel EEG-based biometric evoked paradigm using self- or non-self-face rapid serial visual presentation (RSVP. The designed paradigm could obtain a distinct and stable biometric trait from EEG with a lower time cost. Secondly, the event-related potential (ERP features and morphological features are extracted from EEG signals and eye blinking signals, respectively. Thirdly, convolutional neural network and back propagation neural network are severally designed to gain the score estimation of EEG features and eye blinking features. Finally, a score fusion technology based on least square method is proposed to get the final estimation score. The performance of multi-task authentication system is improved significantly compared to the system using EEG only, with an increasing average accuracy from 92.4% to 97.6%. Moreover, open-set authentication tests for additional imposters and permanence tests for users are conducted to simulate the practical scenarios, which have never been employed in previous EEG-based person authentication systems. A mean false accepted rate (FAR of 3.90% and a mean false rejected rate (FRR of 3.87% are accomplished in open-set authentication tests and permanence tests, respectively, which illustrate the open-set authentication and permanence capability of our systems.

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

    Science.gov (United States)

    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

    2016-09-29

    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.

  1. Is attentional blink a byproduct of neocortical attractors?

    Directory of Open Access Journals (Sweden)

    David N Silverstein

    2011-05-01

    Full Text Available This study proposes a computational model for attentional blink or blink of the mind, a phenomenon where a human subject misses perception of a later expected visual pattern as two expected visual patterns are presented less than 500 ms apart. A neocortical patch modeled as an attractor network is stimulated with a sequence of 14 patterns 100 ms apart, two of which are expected targets. Patterns that become active attractors are considered recognized. A neocortical patch is represented as a square matrix of hypercolumns, each containing a set of minicolumns with synaptic connections within and across both minicolumns and hypercolumns. Each minicolumn consists of locally connected layer 2/3 pyramidal cells with interacting basket cells and layer 4 pyramidal cells for input stimulation. All neurons are implemented using the Hodgkin-Huxley multi-compartmental cell formalism and include calcium dynamics, and they interact via saturating and depressing AMPA / NMDA and GABAA synapses. Stored patterns are encoded with global connectivity of minicolumns across hypercolumns and active patterns compete as the result of lateral inhibition in the network. Stored patterns were stimulated over time intervals to create attractor interference measurable with synthetic spike traces. This setup corresponds with item presentations in human visual attentional blink studies. Stored target patterns were depolarized while distractor patterns where hyperpolarized to represent expectation of items in working memory. Additionally, studies on the inhibitory effect of benzodiazopines on attentional blink in human subjects were compared with neocortical simulations where the GABAA receptor conductance and decay time were increased. Simulations showed increases in the attentional blink duration, agreeing with observations in human studies.

  2. Heart rate variability and stroke volume variability to detect central hypovolemia during spontaneous breathing and supported ventilation in young, healthy volunteers

    International Nuclear Information System (INIS)

    Elstad, Maja; Walløe, Lars

    2015-01-01

    Cardiovascular oscillations exist in many different variables and may give important diagnostic and prognostic information in patients. Variability in cardiac stroke volume (SVV) is used in clinical practice for diagnosis of hypovolemia, but currently is limited to patients on mechanical ventilation. We investigated if SVV and heart rate variability (HRV) could detect central hypovolemia in spontaneously breathing humans: We also compared cardiovascular variability during spontaneous breathing with supported mechanical ventilation.Ten subjects underwent simulated central hypovolemia by lower body negative pressure (LBNP) with >10% reduction of cardiac stroke volume. The subjects breathed spontaneously and with supported mechanical ventilation. Heart rate, respiratory frequency and mean arterial blood pressure were measured. Stroke volume (SV) was estimated by ModelFlow (Finometer). Respiratory SVV was calculated by: 1) SVV% = (SVmax − SVmin)/SVmean during one respiratory cycle, 2) SVIntegral from the power spectra (Fourier transform) at 0.15–0.4 Hz and 3) SVV-norm = (√SVIntegral)/SVmean. HRV was calculated by the same methods.During spontaneous breathing two measures of SVV and all three measures of HRV were reduced during hypovolemia compared to baseline. During spontaneous breathing SVIntegral and HRV% were best to detect hypovolemia (area under receiver operating curve 0.81). HRV% ≤ 11% and SVIntegral ≤ 12 ml 2 differentiated between hypovolemia and baseline during spontaneous breathing.During supported mechanical ventilation, none of the three measures of SVV changed and two of the HRV measures were reduced during hypovolemia. Neither measures of SVV nor HRV were classified as a good detector of hypovolemia.We conclude that HRV% and SVIntegral detect hypovolemia during spontaneous breathing and both are candidates for further clinical testing. (paper)

  3. Disruption of the p53-mediated G{sub 1}/S cell cycle checkpoint results in elevated rates of spontaneous genetic recombination in human fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Strasfeld, L.; Brainerd, E.; Meyn, M.S. [Yale Univ. School of Medicine, New Haven, CT (United States)

    1994-09-01

    A key feature of the cancer-prone inherited disease ataxia-telangiectasia (A-T) is genetic instability. We recently demonstrated that one aspect of genetic instability in A-T is a marked elevation in the spontaneous rates of intrachromosomal mitotic recombination. We have proposed a model for A-T that attributes these high recombination rates to a lack of DNA damage-sensitive cell cycle checkpoints. One prediction of this model is that disrupting p53 function in normal cells should increase their spontaneous rates of recombination by interfering with their p53-dependent G{sub 1}/S cell cycle checkpoint. To test this prediction, we transfected control and A-T fibroblast lines that each harbor a single integrated copy of lacZ-based recombination vector (pLrec) with derivatives of a eukaryotic expression vector (pRep5) that contain either a dominant-negative p53 mutant (143{sup val{yields}ala}) or a human papilloma virus E6 gene (HPV18 E6). Expression of either of these genes results in loss of p53 function and abolition of the G{sub 1}/S cell cycle checkpoint. Four independent p53{sup 143ala} transformants of the control line showed 25-80 fold elevations in spontaneous recombination rates when compared to their parent cell line. Elevations in spontaneous recombination rates were also detected following transfection with the HPV18 E6 gene. In contrast, four independent p53{sup 143ala} transformants of the A-T cell line showed no significant changes in their already high spontaneous recombination rates. We are now extending these observations to additional normal human fibroblast lines and carrying out molecular analyses of the products of these recombinational events. Our results support our hypothesis that the lack of a p53-dependent G{sub 1}/S cell cycle checkpoint contributes to the hyperrecombination seen in A-T.

  4. Altered heart rate variability in spontaneously hypertensive rats is associated with specific particulate matter components in Detroit, Michigan.

    Science.gov (United States)

    Rohr, Annette C; Kamal, Ali; Morishita, Masako; Mukherjee, Bhramar; Keeler, Gerald J; Harkema, Jack R; Wagner, James G

    2011-04-01

    Exposure to fine particulate matter [aerodynamic diameter ≤ 2.5 μm (PM2.5)] is linked to adverse cardiopulmonary health effects; however, the responsible constituents are not well defined. We used a rat model to investigate linkages between cardiac effects of concentrated ambient particle (CAP) constituents and source factors using a unique, highly time-resolved data set. Spontaneously hypertensive rats inhaled Detroit Michigan, CAPs during summer or winter (2005-2006) for 13 consecutive days. Electrocardiogram data were recorded continuously, and heart rate (HR) and heart rate variability (HRV) metrics were derived. Extensive CAP characterization, including use of a Semicontinuous Elements in Aerosol Sampler (SEAS), was performed, and positive matrix factorization was applied to investigate source factors. Mean CAP exposure concentrations were 518 μg/m(3) and 357 μg/m(3) in the summer and winter, respectively. Significant reductions in the standard deviation of the normal-to-normal intervals (SDNN) in the summer were strongly associated with cement/lime, iron/steel, and gasoline/diesel factors, whereas associations with the sludge factor and components were less consistent. In winter, increases in HR were associated with a refinery factor and its components. CAP-associated HR decreases in winter were linked to sludge incineration, cement/lime, and coal/secondary sulfate factors and most of their associated components. Specific relationships for increased root mean square of the standard deviation of successive normal-to-normal intervals (RMSSD) in winter were difficult to determine because of lack of consistency between factors and associated constituents. Our results indicate that specific modulation of cardiac function in Detroit was most strongly linked to local industrial sources. Findings also highlight the need to consider both factor analytical results and component-specific results when interpreting findings.

  5. 3D super-resolution imaging with blinking quantum dots

    Science.gov (United States)

    Wang, Yong; Fruhwirth, Gilbert; Cai, En; Ng, Tony; Selvin, Paul R.

    2013-01-01

    Quantum dots are promising candidates for single molecule imaging due to their exceptional photophysical properties, including their intense brightness and resistance to photobleaching. They are also notorious for their blinking. Here we report a novel way to take advantage of quantum dot blinking to develop an imaging technique in three-dimensions with nanometric resolution. We first applied this method to simulated images of quantum dots, and then to quantum dots immobilized on microspheres. We achieved imaging resolutions (FWHM) of 8–17 nm in the x-y plane and 58 nm (on coverslip) or 81 nm (deep in solution) in the z-direction, approximately 3–7 times better than what has been achieved previously with quantum dots. This approach was applied to resolve the 3D distribution of epidermal growth factor receptor (EGFR) molecules at, and inside of, the plasma membrane of resting basal breast cancer cells. PMID:24093439

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

    Science.gov (United States)

    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. Copyright © 2013 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    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

  8. Effect of calorie restriction on spontaneous physical activity and body mass in mice divergently selected for basal metabolic rate (BMR).

    Science.gov (United States)

    Brzęk, Paweł; Gębczyński, Andrzej K; Książek, Aneta; Konarzewski, Marek

    2016-07-01

    Spontaneous physical activity (SPA) represents an important component of daily energy expenditures in animals and humans. Intra-specific variation in SPA may be related to the susceptibility to metabolic disease or obesity. In particular, reduced SPA under conditions of limited food availability may conserve energy and prevent loss of body and fat mass ('thrifty genotype hypothesis'). However, both SPA and its changes during food restriction show wide inter-individual variations. We studied the effect of 30% caloric restriction (CR) on SPA in laboratory mice divergently selected for high (H-BMR) and low (L-BMR) basal metabolic rate. Selection increased SPA in the H-BMR line but did not change it in the L-BMR mice. This effect reflected changes in SPA intensity but not SPA duration. CR increased SPA intensity more strongly in the L-BMR line than in the H-BMR line and significantly modified the temporal variation of SPA. However, the initial between-line differences in SPA were not affected by CR. Loss of body mass during CR did not differ between both lines. Our results show that the H-BMR mice can maintain their genetically determined high SPA under conditions of reduced food intake without sacrificing their body mass. We hypothesize that this pattern may reflect the higher flexibility in the energy budget in the H-BMR line, as we showed previously that mice from this line reduced their BMR during CR. These energy savings may allow for the maintenance of elevated SPA in spite of reduced food intake. We conclude that the effect of CR on SPA is in large part determined by the initial level of BMR, whose variation may account for the lack of universal pattern of behavioural responses to CR. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Quantum dot blueing and blinking enables fluorescence nanoscopy.

    Science.gov (United States)

    Hoyer, Patrick; Staudt, Thorsten; Engelhardt, Johann; Hell, Stefan W

    2011-01-12

    We demonstrate superresolution fluorescence imaging of cells using bioconjugated CdSe/ZnS quantum dot markers. Fluorescence blueing of quantum dot cores facilitates separation of blinking markers residing closer than the diffraction barrier. The high number of successively emitted photons enables ground state depletion microscopy followed by individual marker return with a resolving power of the size of a single dot (∼12 nm). Nanoscale imaging is feasible with a simple webcam.

  10. Attentional blink in children with attention deficit hyperactivity disorder

    OpenAIRE

    Amador, Juan Antonio; Aznar Casanova, José Antonio; Bezerra, Izabela; Torro Alves, Nelson; Moreno Sánchez, Manuel

    2015-01-01

    Objective: To explore the temporal mechanism of attention in children with attention deficit hyperactivity disorder (ADHD) and controls using a rapid serial visual presentation (RSVP) task in which two letters (T1 and T2) were presented in close temporal proximity among distractors (attentional blink [AB]). Method: Thirty children aged between 9 and 13 years (12 with ADHD combined type and 18 controls) took part in the study. Both groups performed two kinds of RSVP task. In the single task, p...

  11. Etiologies and treatments of abnormal blinking in children

    Directory of Open Access Journals (Sweden)

    Fen Du

    2015-12-01

    Full Text Available AIM:To analyze the etiology and effective therapies of abnormal blinking in children. METHODS:Children with abnormal blinking in our hospital were collected into the study from July 2012 to July 2015. The etiologies and corresponding treatments, according to the result of interrogation and examination of eyes were analyzed and the therapeutic effect was observed. RESULTS:Totally, 5 561 cases were collected into the study including 4 025 cases of male, 1536 cases of female, and the ratio was 2.6:1; age range was 2~14 years old with average age was(6.9±0.6years old. Etiologies were as follows:refractive(hyperopia, myopia and astigmatism2054 cases(36.9%; allergic conjunctivitis 1670 cases(30.0%; children dry eyes 982 cases(17.7%; partial eclipse children with 605 cases(10.9%; lead pollution 590 care(10.6%; strabismus 156 cases(2.8%; trichiasis with 129 cases(2.3%; trace element deficiency(calcium, iron, zinc, magnesium and copperfor a total of 102 cases(1.8%; chalazion 37 cases(0.7%; keratitis and corneal injury 24 cases(0.4%, palpebral dermatitis, allergic rhinitis, dermatitis, 37 cases(0.7%; conjunctival stone 8 cases(0.1%; tic disorders of 30 patients(0.5%, asthenopia of 6 cases(0.1%; lacrimal duct obstruction, dacryocystitis 9 cases(0.1%. The etiologies of children with abnormal blinking were not caused by single factors. After examination, its etiology in children was resulted by one kind or more of a combination of factors. All of them were carried out ear acupoint application therapy and psychological intervention therapy, and symptomatic treatment was given after finding the cause. Following all the cases 1~3mo, blinking can obviously relieve,in which 4 560 cases(81.9%were cured, 5286 cares were improved, the recovery(including curedwas 95.1%; slightly improved(including relapse cases102 cases(1.8%; No significant changes in 173 cases(3.1%. CONCLUSION:A variety of causes that can lead to children's abnormal blinking, refractive error

  12. The determination of 210Pb, 210Bi, 210Po by counting gross α and gross β rate of spontaneous deposited samples on Ni foil

    International Nuclear Information System (INIS)

    Wang Yuxue; Guo Dongfa; Huang Qiuhong

    2012-01-01

    The optimum spontaneous deposition conditions of 210 Bi and 210 Po on Ni foil is studied in this paper, and a simultaneous or continuous testing method of 210 Pb, 210 Bi, 210 Po in samples by counting gross α and gross β rate of spontaneous deposited samples on Ni foil is set up. The research results show that under the conditions of the Ni foil area being 3.14 cm 2 , the concentration of HCl being 1.0 mol/L, the volume of HCl being 25 mL, the constant experiment temperature being 90℃, the vibration frequency being 180/min, the vibration amplitude being 20 mm and the spontaneous deposition time being 60 min, 210 Bi and 210 Po on Ni foil can be simultaneously and quantitatively deposited. The linear correlation coefficient between 210 Po activity and its α-counting rate is 0.9998, 210 Bi activity and its β-counting rate is 0.9997. The effects of 210 Bi and 210 Po short half-time radioisotopes on testing will decrease while standing the Ni foil for a certain length of time before measuring, in case of hydrazine hydrochloride and tartaric acid presence, lots of coexisting elements do not produce interference to testing. Degree of precision of this testing technology si higher than 5%, total recovery rate reaches 99.5%∼100.5%. (authors)

  13. Effect of low-intensity low-dose rate irradiation on the incidence and the development of spontaneous leukosis in AKR mice

    International Nuclear Information System (INIS)

    Burlakova, E.B.; Erokhin, V.N.

    2001-01-01

    Development of spontaneous leukosis in AKR mice is accelerated by irradiation with low doses of 1.2-2.4 cGy and low dose rate 0.06 cGy/day. The leukoses incidence rate increases. Deaths of the animals from leukosis occurs earlier, shortening the average and maximum life-spans of the animals. The dynamics of changes in the mass of organs of the immune systems (thymus and spleen) shows extrema. The moment of reaching the extremum correlates with the maximum rate of animals' deaths [ru

  14. Quasi-static method and finite element method for obtaining the modifications of the spontaneous emission rate and energy level shift near a plasmonic nanostructure.

    Science.gov (United States)

    Zhao, Yun-Jin; Tian, Meng; Wang, Xiao-Yun; Yang, Hong; Zhao, Heping; Huang, Yong-Gang

    2018-01-22

    We provide numerical demonstrations of the applicability and accuracy of the quasi-static method and the finite-element method in the investigation of the modifications of the spontaneous emission rate and the energy level shift of an emitter placed near a silver-air interface or a silver nano-sphere. The analytical results are presented as a reference. Our calculations show that the finite element method is an accurate and general method. For frequency away from the radiative mode, the quasi-static method can be applied more effectively for calculating the energy level shift than the spontaneous emission rate. But for frequency around, there is a blue shift for both and this shift increases with the increasing of emitter-silver distance. Applying the theory to the nanosphere dimmer, we see similar phenomenon and find extremely large modifications of the spontaneous emission rate and energy level shift. These findings are instructive in the fields of quantum light-matter interactions.

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

    Science.gov (United States)

    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. © 2014 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  16. Differential effect of central command on aortic and carotid sinus baroreceptor-heart rate reflexes at the onset of spontaneous, fictive motor activity.

    Science.gov (United States)

    Matsukawa, Kanji; Ishii, Kei; Kadowaki, Akito; Liang, Nan; Ishida, Tomoko

    2012-08-15

    Our laboratory has reported that central command blunts the sensitivity of the aortic baroreceptor-heart rate (HR) reflex at the onset of voluntary static exercise in conscious cats and spontaneous contraction in decerebrate cats. The purpose of this study was to examine whether central command attenuates the sensitivity of the carotid sinus baroreceptor-HR reflex at the onset of spontaneous, fictive motor activity in paralyzed, decerebrate cats. We confirmed that aortic nerve (AN)-stimulation-induced bradycardia was markedly blunted to 26 ± 4.4% of the control (21 ± 1.3 beats/min) at the onset of spontaneous motor activity. Although the baroreflex bradycardia by electrical stimulation of the carotid sinus nerve (CSN) was suppressed (P activity was much weaker (P abdominal aorta was blunted to 36% of the control (36 ± 1.6 beats/min) during spontaneous motor activity, suggesting that central command is able to inhibit the cardiomotor sensitivity of arterial baroreflexes as the net effect. Mechanical stretch of the triceps surae muscle never affected the baroreflex bradycardia elicited by AN or CSN stimulation and by aortic occlusion, suggesting that muscle mechanoreflex did not modify the cardiomotor sensitivity of aortic and carotid sinus baroreflex. Since the inhibitory effect of central command on the carotid baroreflex pathway, associated with spontaneous motor activity, was much weaker compared with the aortic baroreflex pathway, it is concluded that central command does not force a generalized modulation on the whole pathways of arterial baroreflexes but provides selective inhibition for the cardiomotor component of the aortic baroreflex.

  17. The absence of an auditory-visual attentional blink is not due to echoic memory

    NARCIS (Netherlands)

    Burg, E. van der; Olivers, C.N.L.; Bronkhorst, A.W.; Koelewijn, T.; Theeuwes, J.

    2007-01-01

    Als binnen een halve seconde twee visuele items in een serieel aangeboden stroom moeten worden geselecteerd, is de prestatie voor het tweede item vaak relatief slecht (er treedt een “attentional blink” op); wanneer het eerste echter item auditief wordt aangeboden, verdwijnt de blink meestal. We

  18. Effects of a hot-water extract of porcini (Boletus aestivalis) mushrooms on the blood pressure and heart rate of spontaneously hypertensive rats.

    Science.gov (United States)

    Midoh, Naoki; Miyazawa, Noriko; Eguchi, Fumio

    2013-01-01

    The repeated once-daily oral administration of a hot-water extract of porcini, Boletus aestivalis, mushrooms (WEP) to spontaneously hypertensive rats (SHR) for 18 weeks decreased the systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate. The WEP administration also decreased blood urea nitrogen (BUN), creatinine (Cre), and triglyceride (TG), and increased high-density lipoprotein-cholesterol (HDL-C) in the blood, suggesting that WEP improved the status of hypertension, as well as the high heart rate and metabolic abnormalities involved in hypertension.

  19. Capture of exogenous attention modulates the attentional blink

    DEFF Research Database (Denmark)

    Nielsen, Simon; Andersen, Tobias

    2011-01-01

    When two targets (T1 & T2) are presented in rapid succession, observers often fail to report T2 if they attend to T1. Bottleneck theories propose that this attentional blink (AB) is due to T1 occupying a slow processing stage when T2 is presented. Accordingly, if increasing T1 difficulty increases...... the AB have reported inconsistent results. For example, some found a negative correlation between T1 contrast and T2 performance (Chua, 2005) where others find a positive correlation (Christmann & Leuthold, 2004). Here, we use additive Gaussian noise to tease apart the exogenous capture effect from...

  20. Further studies of contact lens motion during blinking.

    Science.gov (United States)

    Conway, H D; Knoll, H A

    1986-10-01

    Contact lens motion is felt to be of increasing importance in connection with debris elimination, particularly in extended wear lenses. Thus an improved analysis is made of a simple model for investigating the initial motion of a hard contact lens over the eye during blinking. It is shown that the assumption of constant tear film thickness is a reasonable one. This greatly simplifies the analysis. Various vertical force vs. time variations are considered and lens velocity/time graphs and maximum lens displacement calculated. These are in good agreement with the results of experiment.

  1. Timing of the brain events underlying access to consciousness during the attentional blink.

    Science.gov (United States)

    Sergent, Claire; Baillet, Sylvain; Dehaene, Stanislas

    2005-10-01

    In the phenomenon of attentional blink, identical visual stimuli are sometimes fully perceived and sometimes not detected at all. This phenomenon thus provides an optimal situation to study the fate of stimuli not consciously perceived and the differences between conscious and nonconscious processing. We correlated behavioral visibility ratings and recordings of event-related potentials to study the temporal dynamics of access to consciousness. Intact early potentials (P1 and N1) were evoked by unseen words, suggesting that these brain events are not the primary correlates of conscious perception. However, we observed a rapid divergence around 270 ms, after which several brain events were evoked solely by seen words. Thus, we suggest that the transition toward access to consciousness relates to the optional triggering of a late wave of activation that spreads through a distributed network of cortical association areas.

  2. Preconception Optimization of Glucose and Insulin Metabolism in Women Wanting to Conceive - High Rate of Spontaneous Conception Prior to Planned Assisted Reproduction.

    Science.gov (United States)

    Fill Malfertheiner, Sara; Gutknecht, Dagmar; Bals-Pratsch, Monika

    2017-12-01

    A hyperglycemic metabolic status with insulin resistance can have a negative effect on fertility and pregnancy outcomes. The aim of this retrospective study was to investigate disorders of glucose and insulin metabolism in women wanting to conceive who conceived spontaneously prior to planned assisted reproduction (ART). Associated risk factors of patients in terms of live births and miscarriages were also analyzed. Out of total study population of 589 pregnancies, the pregnancies of 129 women wishing to have children who conceived spontaneously prior to planned ART were analyzed in more detail. A 75 g OGTT (OGTT: oral glucose tolerance test) was carried out prior to conception and after determination of pregnancy, including glucose measurement and testing of insulin resistance. If anomalies or risk factors for gestational diabetes (GDM) were detected, patients received metformin therapy prior to conception (off-label use). The course and outcome of pregnancies in the defined cohort were recorded. The rate of spontaneous conception before planned ART after treatment for disorders of glucose/insulin metabolism was 21.9% (n = 129/589). 66.7% of the 129 pregnancies resulted in a live birth, 32 patients had a miscarriage. 76.0% of patients were treated with metformin (off-label use) for polycystic ovary syndrome (PCOS), positive risk profile for GDM, or abnormal glucose/insulin metabolism prior to conception. 55.8% of the cohort developed GDM. The insulin requirements of patients with GDM differed significantly depending on their metformin intake. 24.6% of GDM patients receiving metformin treatment developed GDM requiring insulin treatment compared to 53.8% who did not receive metformin medication. The PCOS rate in the study population who had live births was significantly higher (57.0%) than in the group who had miscarriages (31.3%). There were no significant differences with regard to rate of live births and rate of miscarriages with/without metformin treatment

  3. Blink and masseter inhibitory reflexes in Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Stamenović Jelena

    2010-01-01

    Full Text Available Background/Aim. Idiopathic Parkinson's disease (PD is a chronic, progressive, neurodegenerative disorder with prevalence from 60 to 187 per 100 000 persons in general population. The aim of the study was to determine the abnormalities of the blink reflex (BR and the masseter inhibitory reflex (MIR in parkinsonian patients, as indices of the functional status of brainstem neuronal network, and abnormality level dependence on disease progression. Methods. The investigation was conducted at the Clinic of Neurology, Clinical Center Niš, comprising a group of 60 subjects of both sexes, suffering from idiopathic Parkinson's disease in I-IV stages, according to the Hoehn and Yahr scale. The control group included 30 healthy subjects of both sexes and corresponding age. Testing of the patients was performed during the 'on' phase by registering MIR and BR. Results. Latency of polysynaptic R2 and R2' blink reflex responses and latency of polysynaptic S2 response, as well as a silent period of MIR, are linearly shortened in the subjects with PD, and more expressed in the subsequent stages of the disease compared to the control group. Conclusion. There is a positive correlation between the applied neurophysiological tests results and clinical stage of PD.

  4. Bereitschaftspotential preceding eyelid blinks in Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Isabella Araújo Mota

    Full Text Available ABSTRACT The Bereitschaftspotential (BP is a negative wave observed in EEG retrograde averaging, preceding a motor act. The objective was to study the BP preceding voluntary eyelid blinks in Parkinson’s disease (PD patients during off and on phases of levodopa. Methods Ten PD patients in stages 1 and 2 of the Hoehn & Yahr classification were compared to 18 healthy controls. Artifact-free EEG segments of two seconds preceding the onset of the blink potential were averaged and analyzed, and the statistical significance of the measured amplitudes were evaluated by analysis of variance models. Results The presence of a BP in the PD patients was demonstrated. The mean amplitudes at 0 ms were respectively 0.6 µV and 3.3 µV for the BP patients and the normal controls, respectively. Conclusions The BP amplitudes were significantly smaller in PD patients than normal participants. The amplitudes of the BP were not modified by levodopa.

  5. Fluoroquinolone-associated anaphylaxis in spontaneous adverse drug reaction reports in Germany: differences in reporting rates between individual fluoroquinolones and occurrence after first-ever use.

    Science.gov (United States)

    Sachs, Bernhardt; Riegel, Stefan; Seebeck, Jörg; Beier, Rainer; Schichler, Dagmar; Barger, Antina; Merk, Hans F; Erdmann, Stephan

    2006-01-01

    The frequency of fluoroquinolone-associated anaphylaxis has been estimated to be 1.8-23 per 10 million days of treatment based on spontaneous reports. It is unknown whether there are differences between the reporting rates of anaphylaxis with individual fluoroquinolones. According to pathophysiology, anaphylaxis may be immune mediated (anaphylactic) or not (anaphylactoid). The latter may occur after first-ever intake since no sensitisation phase is necessary. To analyse spontaneous reports of fluoroquinolone-associated anaphylaxis contained in the spontaneous adverse drug reaction database of the Federal Institute for Drugs and Medical Devices in Germany with regard to differences in reporting rates between various fluoroquinolones, the previous intake and the time to onset of the reaction. All fluoroquinolone-associated cases of anaphylaxis, anaphylactic shock, and anaphylactic/anaphylactoid reaction spontaneously reported to the Federal Institute for Drugs and Medical Devices between 1 January 1993 and 31 December 2004 were identified and assessed with regard to the correctness of the diagnosis of anaphylaxis, the causal relationship with the drug, the previous intake of fluoroquinolones and the time to onset of the reaction. In 166 of 204 cases identified, the diagnosis of anaphylaxis and a causal relationship with the drug were considered at least possible. Moxifloxacin, levofloxacin, ciprofloxacin and ofloxacin accounted for 90 (54%), 25 (15%), 21 (13%) and 16 (10%) of the 166 cases, respectively. The corresponding reporting rates per 1 million defined daily doses based on crude estimates of exposure were 3.3, 0.6, 0.2 and 0.2 for moxifloxacin, levofloxacin, ciprofloxacin and ofloxacin, respectively. The occurrence of anaphylaxis after the first dose or within the first three days was reported in 71 of 166 (43%) cases, but no information on prior exposure with this or any other fluoroquinolone was provided with these reports. In 21 of 166 (13%) cases, the

  6. [Blink restoration by the functional electrical stimulation in unilateral facial nerve palsy rabbits].

    Science.gov (United States)

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

    2014-07-01

    Tocompare the effects of different waveforms and parameters of electrical stimulation to elicit a blink, and construct a functional electrical stimulation (FES) system to restore synchronous blink in unilateral facial nerve palsy (FNP). Firstly, twenty-four rabbits were surgically induced unilateral FNP and were divided into three groups, who received square, sine and triangle pulse wareforms, respectirely. Both the healthy and the paralysis eyelids of the rabbits received pulse train stimulation to produce a blink in both eyes. For each rabbit, twenty-seven combinations of frequencies (25 Hz, 50 Hz and 100 Hz) and nine pulse widths (1-9 ms) were stimulated. The threshold amplitude and electric charge to elicit a blink was compared between different waveforms and different parameters. Secondly, a FES system was constructed to treat six surgically induced unilateral FNP rabbit chosen in the twenty-four rabbits, it consisted by an electromyogram (EMG) amplifier module which record the EMG of the healthy muscle, and a stimulator which received the EMG input and output a pulse train stimulation when triggered by the EMG. When the carrier frequency of the pulse train was 25 Hz, it was not able to induce a smooth blink. However, when the carrier frequencies were 50 Hz and 100 Hz, a smooth blink could be induced. The voltage required by 100 Hz was lower than 50 Hz, but it cost more electric charge. The amplitude that square waveforms required was far lower than sine and triangle, but the electric charge between the three waveforms was similar. Synchronous blink could be restored in the six unilateral FNP rabbits with the FES system. To elicit a blink, square pulse train delivered in 50 Hz is a preferable option. The motion of the healthy eyelids as a source of information for stimulation of the paralyzed sides can restore the synchronous blink in unilateral FNP rabbits.

  7. Spontaneous pneumothorax

    Directory of Open Access Journals (Sweden)

    Davari R

    1996-07-01

    Full Text Available A case with bilateral spontaneous pneumothorax was presented. Etiology, mechanism, and treatment were discussed on the review of literature. Spontaneous Pneumothorax is a clinical entity resulting from a sudden non traumatic rupture of the lung. Biach reported in 1880 that 78% of 916 patients with spontaneous pneumothorax had tuberculosis. Kjergaard emphasized 1932 the primary importance of subpleural bleb disease. Currently the clinical spectrum of spontaneous pneumothorax seems to have entered a third era with the recognition of the interstitial lung disease and AIDS as a significant etiology. Standard treatment is including: observation, thoracocentesis, tube thoracostomy. Chemical pleurodesis, bullectomy or wedge resection of lung with pleural abrasion and occasionally pleurectomy. Little information has been reported regarding the efficacy of such treatment in spontaneous pneumothorax secondary to non bleb disease

  8. Spontaneous Unfolding-Refolding of Fibronectin Type III Domains Assayed by Thiol Exchange: THERMODYNAMIC STABILITY CORRELATES WITH RATES OF UNFOLDING RATHER THAN FOLDING.

    Science.gov (United States)

    Shah, Riddhi; Ohashi, Tomoo; Erickson, Harold P; Oas, Terrence G

    2017-01-20

    Globular proteins are not permanently folded but spontaneously unfold and refold on time scales that can span orders of magnitude for different proteins. A longstanding debate in the protein-folding field is whether unfolding rates or folding rates correlate to the stability of a protein. In the present study, we have determined the unfolding and folding kinetics of 10 FNIII domains. FNIII domains are one of the most common protein folds and are present in 2% of animal proteins. FNIII domains are ideal for this study because they have an identical seven-strand β-sandwich structure, but they vary widely in sequence and thermodynamic stability. We assayed thermodynamic stability of each domain by equilibrium denaturation in urea. We then assayed the kinetics of domain opening and closing by a technique known as thiol exchange. For this we introduced a buried Cys at the identical location in each FNIII domain and measured the kinetics of labeling with DTNB over a range of urea concentrations. A global fit of the kinetics data gave the kinetics of spontaneous unfolding and refolding in zero urea. We found that the folding rates were relatively similar, ∼0.1-1 s -1 , for the different domains. The unfolding rates varied widely and correlated with thermodynamic stability. Our study is the first to address this question using a set of domains that are structurally homologous but evolved with widely varying sequence identity and thermodynamic stability. These data add new evidence that thermodynamic stability correlates primarily with unfolding rate rather than folding rate. The study also has implications for the question of whether opening of FNIII domains contributes to the stretching of fibronectin matrix fibrils. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

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

    Science.gov (United States)

    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.

  10. Return of spontaneous Circulation Is Not Affected by Different Chest Compression Rates Superimposed with Sustained Inflations during Cardiopulmonary Resuscitation in Newborn Piglets

    Science.gov (United States)

    Li, Elliott S.; Cheung, Po-Yin; Lee, Tze-Fun; Lu, Min; O'Reilly, Megan

    2016-01-01

    Objective Recently, sustained inflations (SI) during chest compression (CC) have been suggested as an alternative to the current approach during neonatal resuscitation. However, the optimal rate of CC during SI has not yet been established. Our aim was to determine whether different CC rates during SI reduce time to return of spontaneous circulation (ROSC) and improve hemodynamic recovery in newborn piglets with asphyxia-induced bradycardia. Intervention and measurements Term newborn piglets were anesthetized, intubated, instrumented and exposed to 45-min normocapnic hypoxia followed by asphyxia. Resuscitation was initiated when heart rate decreased to 25% of baseline. Piglets were randomized into three groups: CC superimposed by SI at a rate of 90 CC per minute (SI+CC 90, n = 8), CC superimposed by SI at a rate of 120 CC per minute (SI+CC 120, n = 8), or a sham group (n = 6). Cardiac function, carotid blood flow, cerebral oxygenation and respiratory parameters were continuously recorded throughout the experiment. Main results Both treatment groups had similar time of ROSC, survival rates, hemodynamic and respiratory parameters during cardiopulmonary resuscitation. The hemodynamic recovery in the subsequent 4h was similar in both groups and was only slightly lower than sham-operated piglets at the end of experiment. Conclusion Newborn piglets resuscitated by SI+CC 120 did not show a significant advantage in ROSC, survival, and hemodynamic recovery as compared to those piglets resuscitated by SI+CC 90. PMID:27304210

  11. An evaluation of fresh gas flow rates for spontaneously breathing cats and small dogs on the Humphrey ADE semi-closed breathing system.

    Science.gov (United States)

    Gale, Elizabeth; Ticehurst, Kim E; Zaki, Sanaa

    2015-05-01

    To evaluate the fresh gas flow (FGF) rate requirements for the Humphrey ADE semi-closed breathing system in the Mapleson A mode; to determine the FGF at which rebreathing occurs, and compare the efficiency of this system to the Bain (Mapleson D) system in spontaneously breathing cats and small dogs. Prospective clinical study. Twenty-five healthy (ASA score I or II) client-owned cats and dogs (mean ± SD age 4.7 ± 5.0 years, and body weight 5.64 ± 3.26 kg) undergoing elective surgery or minor procedures. Anaesthesia was maintained with isoflurane delivered via the Humphrey ADE system in the A mode using an oxygen FGF of 100 mL kg(-1) minute(-1). The FGF was then reduced incrementally by 5-10 mL kg(-1) minute(-1) at approximately five-minute intervals, until rebreathing (inspired CO(2) >5 mmHg (0.7 kPa)) was observed, after which flow rates were increased. In six animals, once the minimum FGF at which rebreathing occurred was found, the breathing system was changed to the Bain, and the effects of this FGF delivery examined, before FGF was increased. Rebreathing did not occur at the FGF recommended by the manufacturer for the ADE. The mean ± SD FGF that resulted in rebreathing was 60 ± 20 mL kg(-1) minute(-1). The mean minimum FGF at which rebreathing did not occur with the ADE was 87 ± 39 mL kg(-1) minute(-1). This FGF resulted in significant rebreathing (inspired CO(2) 8.8 ± 2.6 mmHg (1.2 ± 0.3 kPa)) on the Bain system. The FGF rates recommended for the Humphrey ADE are adequate to prevent rebreathing in spontaneously breathing cats and dogs cats and small dogs. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

  12. Automated eye blink detection and correction method for clinical MR eye imaging.

    Science.gov (United States)

    Wezel, Joep; Garpebring, Anders; Webb, Andrew G; van Osch, Matthias J P; Beenakker, Jan-Willem M

    2017-07-01

    To implement an on-line monitoring system to detect eye blinks during ocular MRI using field probes, and to reacquire corrupted k-space lines by means of an automatic feedback system integrated with the MR scanner. Six healthy subjects were scanned on a 7 Tesla MRI whole-body system using a custom-built receive coil. Subjects were asked to blink multiple times during the MR-scan. The local magnetic field changes were detected with an external fluorine-based field probe which was positioned close to the eye. The eye blink produces a field shift greater than a threshold level, this was communicated in real-time to the MR system which immediately reacquired the motion-corrupted k-space lines. The uncorrected images, using the original motion-corrupted data, showed severe artifacts, whereas the corrected images, using the reacquired data, provided an image quality similar to images acquired without blinks. Field probes can successfully detect eye blinks during MRI scans. By automatically reacquiring the eye blink-corrupted data, high quality MR-images of the eye can be acquired. Magn Reson Med 78:165-171, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  13. The Rate and Spectrum of Spontaneous Mutations in Mycobacterium smegmatis, a Bacterium Naturally Devoid of the Postreplicative Mismatch Repair Pathway

    Directory of Open Access Journals (Sweden)

    Sibel Kucukyildirim

    2016-07-01

    Full Text Available Mycobacterium smegmatis is a bacterium that is naturally devoid of known postreplicative DNA mismatch repair (MMR homologs, mutS and mutL, providing an opportunity to investigate how the mutation rate and spectrum has evolved in the absence of a highly conserved primary repair pathway. Mutation accumulation experiments of M. smegmatis yielded a base-substitution mutation rate of 5.27 × 10−10 per site per generation, or 0.0036 per genome per generation, which is surprisingly similar to the mutation rate in MMR-functional unicellular organisms. Transitions were found more frequently than transversions, with the A:T→G:C transition rate significantly higher than the G:C→A:T transition rate, opposite to what is observed in most studied bacteria. We also found that the transition-mutation rate of M. smegmatis is significantly lower than that of other naturally MMR-devoid or MMR-knockout organisms. Two possible candidates that could be responsible for maintaining high DNA fidelity in this MMR-deficient organism are the ancestral-like DNA polymerase DnaE1, which contains a highly efficient DNA proofreading histidinol phosphatase (PHP domain, and/or the existence of a uracil-DNA glycosylase B (UdgB homolog that might protect the GC-rich M. smegmatis genome against DNA damage arising from oxidation or deamination. Our results suggest that M. smegmatis has a noncanonical Dam (DNA adenine methylase methylation system, with target motifs differing from those previously reported. The mutation features of M. smegmatis provide further evidence that genomes harbor alternative routes for improving replication fidelity, even in the absence of major repair pathways.

  14. The Rate and Spectrum of Spontaneous Mutations in Mycobacterium smegmatis, a Bacterium Naturally Devoid of the Postreplicative Mismatch Repair Pathway.

    Science.gov (United States)

    Kucukyildirim, Sibel; Long, Hongan; Sung, Way; Miller, Samuel F; Doak, Thomas G; Lynch, Michael

    2016-07-07

    Mycobacterium smegmatis is a bacterium that is naturally devoid of known postreplicative DNA mismatch repair (MMR) homologs, mutS and mutL, providing an opportunity to investigate how the mutation rate and spectrum has evolved in the absence of a highly conserved primary repair pathway. Mutation accumulation experiments of M. smegmatis yielded a base-substitution mutation rate of 5.27 × 10(-10) per site per generation, or 0.0036 per genome per generation, which is surprisingly similar to the mutation rate in MMR-functional unicellular organisms. Transitions were found more frequently than transversions, with the A:T→G:C transition rate significantly higher than the G:C→A:T transition rate, opposite to what is observed in most studied bacteria. We also found that the transition-mutation rate of M. smegmatis is significantly lower than that of other naturally MMR-devoid or MMR-knockout organisms. Two possible candidates that could be responsible for maintaining high DNA fidelity in this MMR-deficient organism are the ancestral-like DNA polymerase DnaE1, which contains a highly efficient DNA proofreading histidinol phosphatase (PHP) domain, and/or the existence of a uracil-DNA glycosylase B (UdgB) homolog that might protect the GC-rich M. smegmatis genome against DNA damage arising from oxidation or deamination. Our results suggest that M. smegmatis has a noncanonical Dam (DNA adenine methylase) methylation system, with target motifs differing from those previously reported. The mutation features of M. smegmatis provide further evidence that genomes harbor alternative routes for improving replication fidelity, even in the absence of major repair pathways. Copyright © 2016 Kucukyildirim et al.

  15. Glucagon-like peptide-1 acutely affects renal blood flow and urinary flow rate in spontaneously hypertensive rats despite significantly reduced renal expression of GLP-1 receptors

    DEFF Research Database (Denmark)

    Ronn, Jonas; Jensen, Elisa P; Wewer Albrechtsen, Nicolai J

    2017-01-01

    in the kidney from SHR. However, acute intrarenal infusion of GLP-1 increased MAP, RBF, dieresis, and natriuresis without affecting heart rate in both rat strains. These results suggest that the acute renal effects of GLP-1 in SHR are caused either by extrarenal GLP-1 receptors activating other mechanisms (e...... to increased mean arterial pressure (MAP) and increased renal blood flow (RBF). In hypertensive animal models, GLP-1 has been reported both to increase and decrease MAP. The aim of this study was to examine expression of renal GLP-1 receptors in spontaneously hypertensive rats (SHR) and to assess the effect...... of acute intrarenal infusion of GLP-1. We hypothesized that GLP-1 would increase diuresis and natriuresis and reduce MAP in SHR. Immunohistochemical staining and in situ hybridization for the GLP-1 receptor were used to localize GLP-1 receptors in the kidney. Sevoflurane-anesthetized normotensive Sprague...

  16. Evidence of circadian rhythm, oxygen regulation capacity, metabolic repeatability and positive correlations between forced and spontaneous maximal metabolic rates in lake sturgeon Acipenser fulvescens.

    Science.gov (United States)

    Svendsen, Jon C; Genz, Janet; Anderson, W Gary; Stol, Jennifer A; Watkinson, Douglas A; Enders, Eva C

    2014-01-01

    Animal metabolic rate is variable and may be affected by endogenous and exogenous factors, but such relationships remain poorly understood in many primitive fishes, including members of the family Acipenseridae (sturgeons). Using juvenile lake sturgeon (Acipenser fulvescens), the objective of this study was to test four hypotheses: 1) A. fulvescens exhibits a circadian rhythm influencing metabolic rate and behaviour; 2) A. fulvescens has the capacity to regulate metabolic rate when exposed to environmental hypoxia; 3) measurements of forced maximum metabolic rate (MMR(F)) are repeatable in individual fish; and 4) MMR(F) correlates positively with spontaneous maximum metabolic rate (MMR(S)). Metabolic rates were measured using intermittent flow respirometry, and a standard chase protocol was employed to elicit MMR(F). Trials lasting 24 h were used to measure standard metabolic rate (SMR) and MMR(S). Repeatability and correlations between MMR(F) and MMR(S) were analyzed using residual body mass corrected values. Results revealed that A. fulvescens exhibit a circadian rhythm in metabolic rate, with metabolism peaking at dawn. SMR was unaffected by hypoxia (30% air saturation (O(2sat))), demonstrating oxygen regulation. In contrast, MMR(F) was affected by hypoxia and decreased across the range from 100% O(2sat) to 70% O(2sat). MMR(F) was repeatable in individual fish, and MMR(F) correlated positively with MMR(S), but the relationships between MMR(F) and MMR(S) were only revealed in fish exposed to hypoxia or 24 h constant light (i.e. environmental stressor). Our study provides evidence that the physiology of A. fulvescens is influenced by a circadian rhythm and suggests that A. fulvescens is an oxygen regulator, like most teleost fish. Finally, metabolic repeatability and positive correlations between MMR(F) and MMR(S) support the conjecture that MMR(F) represents a measure of organism performance that could be a target of natural selection.

  17. Evidence of circadian rhythm, oxygen regulation capacity, metabolic repeatability and positive correlations between forced and spontaneous maximal metabolic rates in lake sturgeon Acipenser fulvescens.

    Directory of Open Access Journals (Sweden)

    Jon C Svendsen

    Full Text Available Animal metabolic rate is variable and may be affected by endogenous and exogenous factors, but such relationships remain poorly understood in many primitive fishes, including members of the family Acipenseridae (sturgeons. Using juvenile lake sturgeon (Acipenser fulvescens, the objective of this study was to test four hypotheses: 1 A. fulvescens exhibits a circadian rhythm influencing metabolic rate and behaviour; 2 A. fulvescens has the capacity to regulate metabolic rate when exposed to environmental hypoxia; 3 measurements of forced maximum metabolic rate (MMR(F are repeatable in individual fish; and 4 MMR(F correlates positively with spontaneous maximum metabolic rate (MMR(S. Metabolic rates were measured using intermittent flow respirometry, and a standard chase protocol was employed to elicit MMR(F. Trials lasting 24 h were used to measure standard metabolic rate (SMR and MMR(S. Repeatability and correlations between MMR(F and MMR(S were analyzed using residual body mass corrected values. Results revealed that A. fulvescens exhibit a circadian rhythm in metabolic rate, with metabolism peaking at dawn. SMR was unaffected by hypoxia (30% air saturation (O(2sat, demonstrating oxygen regulation. In contrast, MMR(F was affected by hypoxia and decreased across the range from 100% O(2sat to 70% O(2sat. MMR(F was repeatable in individual fish, and MMR(F correlated positively with MMR(S, but the relationships between MMR(F and MMR(S were only revealed in fish exposed to hypoxia or 24 h constant light (i.e. environmental stressor. Our study provides evidence that the physiology of A. fulvescens is influenced by a circadian rhythm and suggests that A. fulvescens is an oxygen regulator, like most teleost fish. Finally, metabolic repeatability and positive correlations between MMR(F and MMR(S support the conjecture that MMR(F represents a measure of organism performance that could be a target of natural selection.

  18. Spontaneous breathing trial in T-tube negatively impact on autonomic modulation of heart rate compared with pressure support in critically ill patients.

    Science.gov (United States)

    Güntzel Chiappa, Adriana M; Chiappa, Gaspar R; Cipriano, Gerson; Moraes, Ruy S; Ferlin, Elton L; Borghi-Silva, Audrey; Vieira, Silvia R

    2017-07-01

    Spontaneous breathing with a conventional T-piece (TT) connected to the tracheal tube orotraqueal has been frequently used in clinical setting to weaning of mechanical ventilation (MV), when compared with pressure support ventilation (PSV). However, the acute effects of spontaneous breathing with TT versus PSV on autonomic function assessed through heart rate variability (HRV) have not been fully elucidated. The purpose of this study was to examine the acute effects of spontaneous breathing in TT vs PSV in critically ill patients. Twenty-one patients who had received MV for ≥ 48 h and who met the study inclusion criteria for weaning were assessed. Eligible patients were randomized to TT and PSV. Cardiorespiratory responses (respiratory rate -ƒ, tidal volume-V T , mean blood pressure (MBP) and diastolic blood pressure (DBP), end tidal dioxide carbone (P ET CO 2 ), peripheral oxygen saturation (SpO 2 ) and HRV indices in frequency domain (low-LF, high frequency (HF) and LF/HF ratio were evaluated. TT increased ƒ (20 ± 5 vs 25 ± 4 breaths/min, P<0.05), MBP (90 ± 14 vs 94 ± 18 mmHg, P<0.05), HR (90 ± 17 vs 96 ± 12 beats/min, P<0.05), P ET CO 2 (33 ± 8 vs 48 ± 10 mmHg, P<0.05) and reduced SpO 2 (98 ± 1.6 vs 96 ± 1.6%, P<0.05). In addition, LF increased (47 ± 18 vs 38 ± 12 nu, P<0.05) and HF reduced (29 ± 13 vs 32 ± 16 nu, P<0.05), resulting in higher LF/HF ratio (1.62 ± 2 vs 1.18 ± 1, P<0.05) during TT. Conversely, V T increased with PSV (0.58 ± 0.16 vs 0.50 ± 0.15 L, P<0.05) compared with TT. Acute effects of TT mode may be closely linked to cardiorespiratory mismatches and cardiac autonomic imbalance in critically ill patients. © 2015 John Wiley & Sons Ltd.

  19. Relative prediction error and protection from attentional blink in human associative learning.

    Science.gov (United States)

    Glautier, Steven; Shih, Shui-L

    2015-01-01

    The relationship between predictive learning and attentional processing was investigated in two experiments. During a learning procedure participants viewed rapid serial visual presentation (RSVP) of stimuli in the context of a choice-reaction-time (CRT) task. Salient stimuli in the RSVP streams were either predictive or non-predictive for the outcome of the CRT task. Following this procedure we measured attentional blink (AB) to the predictive and non-predictive stimuli. In Experiment 1, despite the use of a large sample and checks demonstrating the validity of the learning procedure and the AB measure, we did not observe reduced AB for predictive stimuli. In contrast, in Experiment 2, where the predictive stimuli occurred alongside salient non-predictive comparison stimuli, we did find less AB for predictive than for non-predictive stimuli. Our results support an attentional model of learning in which relative prediction error is used to increase learning rates for good predictors and reduce learning rates for poor predictors and provide confirmation of the AB learning effect.

  20. The success rate of bupivacaine and lidocaine as anesthetic agents in inferior alveolar nerve block in teeth with irreversible pulpitis without spontaneous pain

    Science.gov (United States)

    Yosefi, Mohammad Hosein; Nakhaee, Nouzar

    2015-01-01

    Objectives Achieving adequate anesthesia with inferior alveolar nerve blocks (IANB) is of great importance during dental procedures. The aim of the present study was to assess the success rate of two anesthetic agents (bupivacaine and lidocaine) for IANB when treating teeth with irreversible pulpitis. Materials and Methods Sixty volunteer male and female patients who required root canal treatment of a mandibular molar due to caries participated in the present study. The inclusion criteria included prolonged pain to thermal stimulus but no spontaneous pain. The patients were randomly allocated to receive either 2% lidocaine with 1:80,000 epinephrine or 0.5% bupivacaine with 1:200,000 epinephrine as an IANB injection. The sensitivity of the teeth to a cold test as well as the amount of pain during access cavity preparation and root canal instrumentation were recorded. Results were statistically analyzed with the Chi-Square and Fischer's exact tests. Results At the final step, fifty-nine patients were included in the study. The success rate for bupivacaine and lidocaine groups were 20.0% and 24.1%, respectively. There was no significant difference between the two groups at any stage of the treatment procedure. Conclusions There was no difference in success rates of anesthesia when bupivacaine and lidocaine were used for IANB injections to treat mandibular molar teeth with irreversible pulpitis. Neither agent was able to completely anesthetize the teeth effectively. Therefore, practitioners should be prepared to administer supplemental anesthesia to overcome pain during root canal treatment. PMID:25984478

  1. The success rate of bupivacaine and lidocaine as anesthetic agents in inferior alveolar nerve block in teeth with irreversible pulpitis without spontaneous pain

    Directory of Open Access Journals (Sweden)

    Masoud Parirokh

    2015-05-01

    Full Text Available Objectives Achieving adequate anesthesia with inferior alveolar nerve blocks (IANB is of great importance during dental procedures. The aim of the present study was to assess the success rate of two anesthetic agents (bupivacaine and lidocaine for IANB when treating teeth with irreversible pulpitis. Materials and Methods Sixty volunteer male and female patients who required root canal treatment of a mandibular molar due to caries participated in the present study. The inclusion criteria included prolonged pain to thermal stimulus but no spontaneous pain. The patients were randomly allocated to receive either 2% lidocaine with 1:80,000 epinephrine or 0.5% bupivacaine with 1:200,000 epinephrine as an IANB injection. The sensitivity of the teeth to a cold test as well as the amount of pain during access cavity preparation and root canal instrumentation were recorded. Results were statistically analyzed with the Chi-Square and Fischer's exact tests. Results At the final step, fifty-nine patients were included in the study. The success rate for bupivacaine and lidocaine groups were 20.0% and 24.1%, respectively. There was no significant difference between the two groups at any stage of the treatment procedure. Conclusions There was no difference in success rates of anesthesia when bupivacaine and lidocaine were used for IANB injections to treat mandibular molar teeth with irreversible pulpitis. Neither agent was able to completely anesthetize the teeth effectively. Therefore, practitioners should be prepared to administer supplemental anesthesia to overcome pain during root canal treatment.

  2. Temporal dynamics of access to consciousness in the attentional blink.

    Science.gov (United States)

    Kranczioch, Cornelia; Debener, Stefan; Maye, Alexander; Engel, Andreas K

    2007-09-01

    Presentation of two targets in close temporal succession often results in an impairment of conscious perception for the second stimulus. Previous studies have identified several electrophysiological correlates for this so-called 'attentional blink'. Components of the event-related potential (ERP) such as the N2 and the P3, but also oscillatory brain signals have been shown to distinguish between detected and missed stimuli, and thus, conscious perception. Here we investigate oscillatory responses that specifically relate to conscious stimulus processing together with potential ERP predictors. Our results show that successful target detection is associated with enhanced coherence in the low beta frequency range, but a decrease in alpha coherence before and during target presentation. In addition, we find an inverse relation between the P3 amplitudes associated with the first and second target. We conclude that the resources allocated to first and second target processing are directly mirrored by the P3 component and, moreover, that brain states before and during stimulus presentation, as reflected by oscillatory brain activity, strongly determine the access to consciousness. Thus, becoming aware of a stimulus seems to depend on the dynamic interaction between a number of widely distributed neural processes, rather than on the modulation of one single process or component.

  3. Cerebral correlates of heart rate variations during a spontaneous panic attack in the fMRI scanner.

    Science.gov (United States)

    Spiegelhalder, Kai; Hornyak, Magdolna; Kyle, Simon David; Paul, Dominik; Blechert, Jens; Seifritz, Erich; Hennig, Jürgen; Tebartz van Elst, Ludger; Riemann, Dieter; Feige, Bernd

    2009-12-01

    We report the first published case study of a suddenly occurring panic attack in a patient with no prior history of panic disorder during combined functional magnetic resonance imaging (fMRI, 1.5 Tesla) and electrocardiogram (ECG) recording. The single case was a 46-year-old woman who developed a panic attack near the planned end of the fMRI acquisition session, which therefore had to be aborted. Correlational analysis of heart rate fluctuations and fMRI data revealed a significant negative association in the left middle temporal gyrus. Additionally, regions-of-interest (ROI) analyses indicated significant positive associations in the left amygdala, and trends towards significance in the right amygdala and left insula.

  4. Spontaneous deregulation

    NARCIS (Netherlands)

    Edelman, Benjamin; Geradin, Damien

    Platform businesses such as Airbnb and Uber have risen to success partly by sidestepping laws and regulations that encumber their traditional competitors. Such rule flouting is what the authors call “spontaneous private deregulation,” and it’s happening in a growing number of industries. The authors

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

    Science.gov (United States)

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

    2017-10-01

    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, 105B: 1799-1807, 2017. © 2016 Wiley Periodicals, Inc.

  6. Startle eye-blink modulation by facial self-resemblance and current mood.

    Science.gov (United States)

    Finke, Johannes B; Larra, Mauro F; Schilling, Thomas M; Lass-Hennemann, Johanna; Blumenthal, Terry D; Schächinger, Hartmut

    2015-06-01

    Although salient stimuli are known to modulate startle eye-blink responses, and one's own face is considered of particular salience, effects of facial self-resemblance on startle responsiveness have not been systematically investigated. For the present study, pictures from the FACES database (rated as neutral) were digitally morphed to resemble the participants' (N=37) faces to varying degrees (25-50-75%). Perceptually matched geometrical shapes served as a control condition. At SOAs of either 300ms or 3000ms after picture onset, startle responses were elicited by white noise (50ms, 105dB), and recorded at the orbicularis oculi via EMG. Prior to the experiment, self-reported mood was assessed by means of the PANAS. Relative to non-face stimuli, the presentation of faces reduced startle magnitude at short, but not long, lead intervals. Furthermore, for probes presented at a SOA of 300ms, a linear decrease in startle magnitude with higher levels of self-resemblance was observed, presumably reflecting higher salience of the self-face. The startle modulating effect of self-resembling faces during longer lead intervals was moderated by the participants' current mood: negative affect predicted stronger patterns of attenuation, which might be interpreted as an increase in self-focus resulting from more negative mood. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Rombach-Riegraf, Verena; Oswald, Peter; Bienert, Roland; Petersen, Jan [Albert-Ludwigs-Universitaet Freiburg, Institut fuer Physikalische Chemie, Albertstrasse 23a, 79104 Freiburg (Germany); Domingo, M.P. [Instituto de Carboquimica (CSIC), Miguel Luesma 4, 50018 Zaragoza (Spain); Pardo, Julian [Grupo Apoptosis, Inmunidad y Cancer, Departamento Bioquimica y Biologia Molecular y Celular, Fac. Ciencias, Universidad de Zaragoza, Zaragoza (Spain); Fundacion Aragon I-D (ARAID), Gobierno de Aragon, Zaragoza (Spain); Immune Effector Cells Group, Aragon Health Research Institute (IIS Aragon), Biomedical Research Centre of Aragon (CIBA) Fundacion Aragon I-D - ARAID, Gobierno de Aragon, Zaragoza (Spain); Graeber, P. [Albert-Ludwigs-Universitaet Freiburg, Institut fuer Physikalische Chemie, Albertstrasse 23a, 79104 Freiburg (Germany); Galvez, E.M., E-mail: eva@icb.csic.es [Instituto de Carboquimica (CSIC), Miguel Luesma 4, 50018 Zaragoza (Spain); Immune Effector Cells Group, Aragon Health Research Institute (IIS Aragon), Biomedical Research Centre of Aragon (CIBA) Fundacion Aragon I-D - ARAID, Gobierno de Aragon, Zaragoza (Spain)

    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.

  9. Musical minds: attentional blink reveals modality-specific restrictions.

    Directory of Open Access Journals (Sweden)

    Sander Martens

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

  10. Musical minds: attentional blink reveals modality-specific restrictions.

    Science.gov (United States)

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

    2015-01-01

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

  11. Priming the semantic neighbourhood during the attentional blink.

    Directory of Open Access Journals (Sweden)

    Irina M Harris

    2010-09-01

    Full Text Available When two targets are presented in close temporal proximity amongst a rapid serial visual stream of distractors, a period of disrupted attention and attenuated awareness lasting 200-500 ms follows identification of the first target (T1. This phenomenon is known as the "attentional blink" (AB and is generally attributed to a failure to consolidate information in visual short-term memory due to depleted or disrupted attentional resources. Previous research has shown that items presented during the AB that fail to reach conscious awareness are still processed to relatively high levels, including the level of meaning. For example, missed word stimuli have been shown to prime later targets that are closely associated words. Although these findings have been interpreted as evidence for semantic processing during the AB, closely associated words (e.g., day-night may also rely on specific, well-worn, lexical associative links which enhance attention to the relevant target.We used a measure of semantic distance to create prime-target pairs that are conceptually close, but have low word associations (e.g., wagon and van and investigated priming from a distractor stimulus presented during the AB to a subsequent target (T2. The stimuli were words (concrete nouns in Experiment 1 and the corresponding pictures of objects in Experiment 2. In both experiments, report of T2 was facilitated when this item was preceded by a semantically-related distractor.This study is the first to show conclusively that conceptual information is extracted from distractor stimuli presented during a period of attenuated awareness and that this information spreads to neighbouring concepts within a semantic network.

  12. Assessing the blinking state of fluorescent quantum dots in free solution by combining fluorescence correlation spectroscopy with ensemble spectroscopic methods.

    Science.gov (United States)

    Dong, Chaoqing; Liu, Heng; Ren, Jicun

    2014-11-04

    The current method for investigating the blinking behavior is to immobilize quantum dots (QDs) in the matrix and then apply a fluorescent technique to monitor the fluorescent trajectories of individual QDs. So far, no method can be used to directly assess the blinking state of ensemble QDs in free solution. In this study, a new method was described to characterize the blinking state of the QDs in free solution by combining single molecule fluorescence correlation spectroscopy (FCS) with ensemble spectroscopic methods. Its principle is based on the observation that the apparent concentration of bright QDs obtained by FCS is less than its actual concentration measured by ensemble spectroscopic method due to the QDs blinking. We proposed a blinking index (Kblink) for characterizing the blinking state of QDs, and Kblink is defined as the ratio of the actual concentration (Cb,actual) measured by the ensemble spectroscopic method to the apparent concentration (Cb,app) of QDs obtained by FCS. The effects of certain factors such as laser intensity, growth process, and ligands on blinking of QDs were investigated. The Kblink data of QDs obtained were successfully used to characterize the blinking state of QDs and explain certain experimental results.

  13. Eigen-analysis reveals components supporting super-resolution imaging of blinking fluorophores.

    Science.gov (United States)

    Agarwal, Krishna; Prasad, Dilip K

    2017-06-30

    This paper presents eigen-analysis of image stack of blinking fluorophores to identify the components that enable super-resolved imaging of blinking fluorophores. Eigen-analysis reveals that the contributions of spatial distribution of fluorophores and their temporal photon emission characteristics can be completely separated. While cross-emitter cross-pixel information of spatial distribution that permits super-resolution is encoded in two matrices, temporal statistics weigh the contribution of these matrices to the measured data. The properties and conditions of exploitation of these matrices are investigated. Con-temporary super-resolution imaging methods that use blinking for super-resolution are studied in the context of the presented analysis. Besides providing insight into the capabilities and limitations of existing super-resolution methods, the analysis shall help in designing better super-resolution techniques that directly exploit these matrices.

  14. Under which conditions does T1 difficulty affect T2 performance in the attentional blink?

    DEFF Research Database (Denmark)

    Nielsen, Simon; Petersen, Anders; Andersen, Tobias Søren

    2009-01-01

    When two visual targets (T1 & T2) are presented in rapid succession, performance of T2 suffers up to 900 ms. One theory of this attentional blink (Raymond, Shapiro, & Arnell, 1992) propose that T1 and T2 compete for limited processing resources (Chun & Potter, 1995), and predict that prolonging...... exposure duration was the same as in the hard condition while T1 contrast was adjusted individually to reach the same performance on the T1 identification task as obtained in the long duration condition. Six observers completed 260 trials in each of the three conditions. We found a strong effect of T1–T2...... latency on performance in the T2 identification task in all conditions, replicating the finding of an attentional blink. However, we found no difference in the attentional blink between conditions. We conclude that increasing the perceptual difficulty of T1 either by decreasing T1 contrast or T1 exposure...

  15. [Spontaneous bacterial peritonitis].

    Science.gov (United States)

    Strauss, Edna; Caly, Wanda Regina

    2003-01-01

    Spontaneous bacterial peritonitis occurs in 30% of patients with ascites due to cirrhosis leading to high morbidity and mortality rates. The pathogenesis of spontaneous bacterial peritonitis is related to altered host defenses observed in end-stage liver disease, overgrowth of microorganisms, and bacterial translocation from the intestinal lumen to mesenteric lymph nodes. Clinical manifestations vary from severe to slight or absent, demanding analysis of the ascitic fluid. The diagnosis is confirmed by a number of neutrophils over 250/mm3 associated or not to bacterial growth in culture of an ascites sample. Enterobacteriae prevail and Escherichia coli has been the most frequent bacterium reported. Mortality rates decreased markedly in the last two decades due to early diagnosis and prompt antibiotic treatment. Third generation intravenous cephalosporins are effective in 70% to 95% of the cases. Recurrence of spontaneous bacterial peritonitis is common and can be prevented by the continuous use of oral norfloxacin. The development of bacterial resistance demands the search for new options in the prophylaxis of spontaneous bacterial peritonitis; probiotics are a promising new approach, but deserve further evaluation. Short-term antibiotic prophylaxis is recommended for patients with cirrhosis and ascites shortly after an acute episode of gastrointestinal bleeding.

  16. Glucagon-like peptide-1 acutely affects renal blood flow and urinary flow rate in spontaneously hypertensive rats despite significantly reduced renal expression of GLP-1 receptors.

    Science.gov (United States)

    Ronn, Jonas; Jensen, Elisa P; Wewer Albrechtsen, Nicolai J; Holst, Jens Juul; Sorensen, Charlotte M

    2017-12-01

    Glucagon-like peptide-1 (GLP-1) is an incretin hormone increasing postprandial insulin release. GLP-1 also induces diuresis and natriuresis in humans and rodents. The GLP-1 receptor is extensively expressed in the renal vascular tree in normotensive rats where acute GLP-1 treatment leads to increased mean arterial pressure (MAP) and increased renal blood flow (RBF). In hypertensive animal models, GLP-1 has been reported both to increase and decrease MAP. The aim of this study was to examine expression of renal GLP-1 receptors in spontaneously hypertensive rats (SHR) and to assess the effect of acute intrarenal infusion of GLP-1. We hypothesized that GLP-1 would increase diuresis and natriuresis and reduce MAP in SHR. Immunohistochemical staining and in situ hybridization for the GLP-1 receptor were used to localize GLP-1 receptors in the kidney. Sevoflurane-anesthetized normotensive Sprague-Dawley rats and SHR received a 20 min intrarenal infusion of GLP-1 and changes in MAP, RBF, heart rate, dieresis, and natriuresis were measured. The vasodilatory effect of GLP-1 was assessed in isolated interlobar arteries from normo- and hypertensive rats. We found no expression of GLP-1 receptors in the kidney from SHR. However, acute intrarenal infusion of GLP-1 increased MAP, RBF, dieresis, and natriuresis without affecting heart rate in both rat strains. These results suggest that the acute renal effects of GLP-1 in SHR are caused either by extrarenal GLP-1 receptors activating other mechanisms (e.g., insulin) to induce the renal changes observed or possibly by an alternative renal GLP-1 receptor. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  17. Working memory capacity, intelligence, and the magnitude of the attentional blink revisited

    NARCIS (Netherlands)

    Martens, Sander; Johnson, Addie

    The attentional blink (AB) is a well-established phenomenon in the study of attention. This deficit in reporting the second of two targets presented in rapid serial visual presentation when it occurs 200-500 ms after the first is considered to reflect a fundamental limitation in attentional

  18. Short-term memory and the attentional blink : Capacity versus content

    NARCIS (Netherlands)

    Akyürek, Elkan G; Hommel, Bernhard

    When people monitor the rapid serial visual presentation (RSVP) of stimuli for two targets (T1 and T2), they often miss T2 if it falls into a time window of about half a second after T1 onset, a phenomenon known as the attentional blink (AB). We found that overall performance in an RSVP task was

  19. Priming T2 in a Visual and Auditory Attentional Blink Task

    NARCIS (Netherlands)

    Burg, E. van der; Olivers, C.N.L.; Bronkhorst, A.W.; Theeuwes, J.

    2008-01-01

    Participants performed an attentional blink (AB) task including digits as targets and letters as distractors within the visual and auditory domains. Prior to the rapid serial visual presentation, a visual or auditory prime was presented in the form of a digit that was identical to the second target

  20. Temporal constraints on conscious vision : On the ubiquitous nature of the attentional blink

    NARCIS (Netherlands)

    Nieuwenstein, Mark; Van der Burg, Erik; Theeuwes, Jan; Wyble, Brad; Potter, Mary

    2009-01-01

    The attentional blink ( AB) refers to the. finding that observers often miss the second of two masked visual targets (T1 and T2, e. g., letters) appearing within 200-500 ms. Although the presence of a T1 mask is thought to be required for this effect, we recently found that an AB deficit can be

  1. BLINK REFLEX IN MULTIPLE SCLEROSIS: AN ANCILLARY TEST FOR DETECTING BRAIN STEM LESIONS

    Directory of Open Access Journals (Sweden)

    M ETEMEDYFAR

    2001-09-01

    Full Text Available Introduction. Electrodiagnostic tests are one of the ancillary procedures that are used for diagnosis of multiple sclerosis (MS. This study investigates the frequency of abnormal blink reflex in patients with MS. Methods. In this cross sectional diagnostic study, 100 patients (26 male and 74 female with definite MS were selected based on clinical and MRI findings. they were referred to Al- zahra hospital (affiliated to iUMSHS during year 2000. Blink reflex (BR waves including R1, R2, R2 were recorded inpatients through the stimulation of supraorbital nerve. Results. The frequency of abnormal BR in MS patients with brain stem involvement was 77.9 percent and in those without brain stem involvement was 36.6 percent (P < 0.001. There was a significant relationship between the duration of MS and the abnormality in BR. Discussion. The frequency of abnormal blink reflex in MS is significantly associated with site of involvement in the brain. The majority of MS patients with brain stem involvement have abnormal BR. It is proposed that in patients with symptoms and signs of MS if there was no accessibility for MRI or if the results of MRI were equivocal, blink reflex test should be performed in addition to other ancillary tests.

  2. Blink reflexes and lateral spreading in patients with synkinesia after Bell's palsy and in hemifacial spasm

    NARCIS (Netherlands)

    Eekhof, J. L.; Aramideh, M.; Speelman, J. D.; Devriese, P. P.; Ongerboer de Visser, B. W.

    2000-01-01

    We compared various electrodiagnostical tests in patients with hemifacial spasm and in patients who developed synkinesia after Bell's palsy. We examined the evoked blink reflexes in the orbicularis oculi (o. oculi) and orbicularis oris (o. oris) muscles in 23 patients with hemifacial spasm (HFS), in

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

    Science.gov (United States)

    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 (pmovie. PMID:26529091

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

    Science.gov (United States)

    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. T1 difficulty modulates the attentional blink only when T1 is unmasked

    DEFF Research Database (Denmark)

    Nielsen, Simon; Andersen, Tobias S

    The attentional blink (AB) is consistently observed when people are required to identify or detect two consecutive targets (T1 and T2). T2 suffers in performance when it is presented less than 500 ms after T1. The two stage theory (Chun & Potter, 1995) proposes that the AB is caused by limited pr...

  6. Too much control can hurt : A threaded cognition model of the attentional blink

    NARCIS (Netherlands)

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

    Explanations for the attentional blink (AB; a deficit in identifying the second of two targets when presented 200-500 ms 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

  7. Differences in Adverse Event Reporting Rates of Therapeutic Failure Between Two Once-daily Extended-release Methylphenidate Medications in Canada: Analysis of Spontaneous Adverse Event Reporting Databases.

    Science.gov (United States)

    Park-Wyllie, Laura; van Stralen, Judy; Castillon, Genaro; Sherman, Stephen E; Almagor, Doron

    2017-10-01

    premature loss of efficacy (shorter duration of action) was described in 98 cases (42.6%) and occurred primarily in the afternoon. Impacts on social functioning, such as disruption in work or school performance or adverse social behaviors, were found in 51 cases (22.2%). The ~10-fold higher reporting rate of therapeutic failure with the generic product relative to its reference product in the present Canadian study resembles findings with US-marketed generic products. While these results should be interpreted with caution due to the limitations of spontaneous adverse event reporting, which may confound comparisons across products, similar findings nonetheless led the US Food and Drug Administration to declare in 2014 that 2 methylphenidate ER generic products in the United States were neither bioequivalent nor interchangeable with OROS methylphenidate-their reference product. Our results indicate a potential safety issue with the Canadian-marketed generic and suggest a need for further investigation by Health Canada. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  8. Cytologic anaplasia is a prognostic factor in osteosarcoma biopsies, but mitotic rate or extent of spontaneous tumor necrosis are not: a critique of the College of American Pathologists Bone Biopsy template.

    Science.gov (United States)

    Cates, Justin Mm; Dupont, William D

    2017-01-01

    The current College of American Pathologists cancer template for reporting biopsies of bone tumors recommends including information that is of unproven prognostic significance for osteosarcoma, such as the presence of spontaneous tumor necrosis and mitotic rate. Conversely, the degree of cytologic anaplasia (degree of differentiation) is not reported in this template. This retrospective cohort study of 125 patients with high-grade osteosarcoma was performed to evaluate the prognostic impact of these factors in diagnostic biopsy specimens in predicting the clinical outcome and response to neoadjuvant chemotherapy. Multivariate Cox regression was performed to adjust survival analyses for well-established prognostic factors. Multivariate logistic regression was used to determine odds ratios for good chemotherapy response (≥90% tumor necrosis). Osteosarcomas with severe anaplasia were independently associated with increased overall and disease-free survival, but mitotic rate and spontaneous necrosis had no prognostic impact after controlling for other confounding factors. Mitotic rate showed a trend towards increased odds of a good histologic response, but this effect was diminished after controlling for other predictive factors. Neither spontaneous necrosis nor the degree of cytologic anaplasia observed in biopsy specimens was predictive of a good response to chemotherapy. Mitotic rate and spontaneous tumor necrosis observed in pretreatment biopsy specimens of high-grade osteosarcoma are not strong independent prognostic factors for clinical outcome or predictors of response to neoadjuvant chemotherapy. Therefore, reporting these parameters for osteosarcoma, as recommended in the College of American Pathologists Bone Biopsy template, does not appear to have clinical utility. In contrast, histologic grading schemes for osteosarcoma based on the degree of cytologic anaplasia may have independent prognostic value and should continue to be evaluated.

  9. Blink Reflex as a Complementary Test to MRI in Early Detection of Brainstem Infarctions: Comparison of Blink Reflex Abnormalities in Anterior Versus Posterior Circulation Strokes

    Directory of Open Access Journals (Sweden)

    K Basiri

    2004-08-01

    Full Text Available Background: Early detection of vertebro-basilar insufficiency is of paramount importance. Brain MRI was the only method of diagnosis for many years, but in addition to high cost and delay in report, it may not detect all brain stem lesions. In this study Blink reflex (BR was evaluated as a complementary test to MRI. Methods: Fifty-four patients were studied [27 anterior circulation stroke patients (ACSP and 27 posterior circulation stroke patients (PCSP]. MRI was performed within the first week after the onset of stroke. Nineteen age and sex matched healthy people enrolled as controls. BR was performed within the first 24 hours of the onset. Frequency of abnormal blink reflex in ACSP and PCSP was compared with MRI findings. Then abnormal responses in two groups were compared by chi-square test. Results: In both ACSP and PCSP, two patients had normal BR responses, and in 25 patients R1 or R2 components of blink responses were absent or prolonged (92.5%. R1was absent or delayed in 16 PCSP, but it was abnormal in only two ACSP (P < 0.001. Abnormal R2 responses were detected in 22 PCSP and 24 ACSP. Conclusion: BR abnormalities had high correlation with MRI findings in PCSP (92.5% BR can be performed within the first 24 hours of onset of stroke, and its results is available immediately. This test is easy to perform and comfortable for the patient, has low cost, and is available every where. Therefore we introduced BR as a complementary (but not replacing test to MRI in early detection of brainstem infarctions. Comparison of BR responses in ACSP and PCSP showed that abnormalities of R1 responses had high accuracy in differentiation between anterior and posterior circulation strokes. We concluded that BR responses not only can detect brainstem infarctions rapidly and readily in its early stages, but also can differentiate ACSP from PCSP with high accuracy. Keywords: Blink Reflex, Anterior Circulation Stroke, Posterior Circulation Stroke Patients

  10. Active Bio-sensor System, Compatible with Arm Muscle Movement or Blinking Signals in BCI Application

    Directory of Open Access Journals (Sweden)

    Saeid Mehrkanoon

    2008-05-01

    Full Text Available This paper addresses a bionic active sensor system for the BCI application. Proposed system involves analog and digital parts. Two types of accurate sensors are used to pickup the blinking and muscle movement signals. A precision micro-power instrumentation amplifier with the adjustable gain, a sixth order low pass active filter with cutoff frequency 0.1 Hz, and a sixth order band pas filter with the bandwidth of 2-6 Hz are constructed to provide the clean blinking and arm muscle movement signals. TMS320C25 DSP processor is used for independent and unique command signals which are prepared for BCI application by a power amplifier and driver.

  11. Right visual-field advantage in the attentional blink: Asymmetry in attentional gating across time and space.

    Science.gov (United States)

    Bergerbest, Dafna; Shilkrot, Orit; Joseph, Michal; Salti, Moti

    2017-10-01

    When two targets are presented in a rapid serial visual presentation (RSVP), recognition of the second target (T2) is usually reduced when presented 150-500 ms after the first target, demonstrating an attentional blink (AB). Previous studies have shown a left visual-field (LVF) advantage in T2 recognition, when T2 was embedded in one of two streams, demanding top-down attention for its recognition. Here, we explored the impact of bottom-up saliency on spatial asymmetry in the AB. When T2 was spatially shifted outside from the RSVP, creating an abrupt onset of T2, right T2s showed a right visual-field (RVF) advantage. In lag-1 trials, right T2s were not only better recognized, but also showed a low T1-T2 order error rate. In contrast, recognized left T2s exhibited high order error rate. Without abrupt onset, symmetrical AB was found and order error rate was similarly low in both sides. Follow-up experiments showed that, while RVF advantage was related to bottom-up saliency, order errors were affected by T1 mask. The discrepancy between LVF and RVF advantage in the AB could be resolved in terms of two mechanisms of attentional gating: top-down attentional gating, which is biased towards LVF, and bottom-up attentional gating, which is biased towards RVF.

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

    OpenAIRE

    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 detecti...

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

    OpenAIRE

    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 co...

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

    Directory of Open Access Journals (Sweden)

    Daniel J. V. Beetsma

    2013-01-01

    Full Text Available 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.

  15. Single molecule localization imaging of exosomes using blinking silicon quantum dots

    Science.gov (United States)

    Zong, Shenfei; Zong, Junzhu; Chen, Chen; Jiang, Xiaoyue; Zhang, Yizhi; Wang, Zhuyuan; Cui, Yiping

    2018-02-01

    Discovering new fluorophores, which are suitable for single molecule localization microscopy (SMLM) is important for promoting the applications of SMLM in biological or material sciences. Here, we found that silicon quantum dots (Si QDs) possess a fluorescence blinking behavior, making them an excellent candidate for SMLM. The Si QDs are fabricated using a facile microwave-assisted method. Blinking of Si QDs is confirmed by single particle fluorescence measurement and the spatial resolution achieved is about 30 nm. To explore the potential application of Si QDs as the nanoprobes for SMLM imaging, cell derived exosomes are chosen as the object owing to their small size (50-100 nm in diameter). Since CD63 is commonly presented on the membrane of exosomes, CD63 aptamers are attached to the surface of Si QDs to form nanoprobes which can specifically recognize exosomes. SMLM imaging shows that Si QDs based nanoprobes can indeed realize super resolved optical imaging of exosomes. More importantly, blinking of Si QDs is observed in water or PBS buffer with no need for special imaging buffers. Besides, considering that silicon is highly biocompatible, Si QDs should have minimal cytotoxicity. These features make Si QDs quite suitable for SMLM applications especially for live cell imaging.

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

    Science.gov (United States)

    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

  17. Is performance on probed serial recall tasks in schizophrenia related to duration of Attentional Blink?

    Directory of Open Access Journals (Sweden)

    David P. McAllindon

    2017-03-01

    Full Text Available Schizophrenia is associated with a deficit in working memory, with the degree of working memory impairment related to the level of social and occupational functioning. This study tests the hypothesis that the working memory deficits in individuals with schizophrenia can be explained by slow processing of visual stimuli, as measured by the attentional blink (AB task. Individuals with schizophrenia (SC and controls (HC were recruited from an early intervention service for psychosis and the local community. Data from 16 SC (11M/5F, mean = 26.4 yo and 20 age-matched HC (11M/9F, mean = 25.8 yo were analyzed. Each subject performed an AB task to determine their AB duration, defined as the lag to reach their plateau performance (ltpp. As expected, mean AB duration in the SC group (575 ms was significantly slower than HC (460 ms; p = 0.007. Recall accuracy of the SC group on a working memory task, a 6-item probed serial recall task (PSR, was reduced compared to the HC group at a standard interstimulus interval (ISI (p = 0.002. When the individual's AB duration was then used to adjust the ISI on the PSR task to three relative ISI rates (Slow (2 × ltpp, Medium (ltpp and Fast (1/2 × ltpp, performance on the PSR task was affected by group, position and ISI and qualified by an ISI ∗ position (p = 0.001 and a trend to a triple interaction (p = 0.054. There was main effect of group at all ISIs, but group ∗ position interaction only at Slow ISI (p = 0.01. Our interpretation of the results is that absolute ISI, rather than ISI relative to AB duration, affected performance.

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

    Science.gov (United States)

    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

  19. Optical antenna enhanced spontaneous emission.

    Science.gov (United States)

    Eggleston, Michael S; Messer, Kevin; Zhang, Liming; Yablonovitch, Eli; Wu, Ming C

    2015-02-10

    Atoms and molecules are too small to act as efficient antennas for their own emission wavelengths. By providing an external optical antenna, the balance can be shifted; spontaneous emission could become faster than stimulated emission, which is handicapped by practically achievable pump intensities. In our experiments, InGaAsP nanorods emitting at ∼ 200 THz optical frequency show a spontaneous emission intensity enhancement of 35 × corresponding to a spontaneous emission rate speedup ∼ 115 ×, for antenna gap spacing, d = 40 nm. Classical antenna theory predicts ∼ 2,500 × spontaneous emission speedup at d ∼ 10 nm, proportional to 1/d(2). Unfortunately, at d antenna efficiency drops below 50%, owing to optical spreading resistance, exacerbated by the anomalous skin effect (electron surface collisions). Quantum dipole oscillations in the emitter excited state produce an optical ac equivalent circuit current, I(o) = qω|x(o)|/d, feeding the antenna-enhanced spontaneous emission, where q|x(o)| is the dipole matrix element. Despite the quantum-mechanical origin of the drive current, antenna theory makes no reference to the Purcell effect nor to local density of states models. Moreover, plasmonic effects are minor at 200 THz, producing only a small shift of antenna resonance frequency.

  20. Blinking model and synchronization in small-world networks with a time-varying coupling

    Science.gov (United States)

    Belykh, Igor V.; Belykh, Vladimir N.; Hasler, Martin

    2004-08-01

    The paper proposes a new type of small-world networks of cells with chaotic behavior. This network consists of a regular lattice of cells with constant 2 K-nearest neighbor couplings and time-dependent on-off couplings between any other pair of cells. In each time interval of duration τ such a coupling is switched on with probability p and the corresponding switching random variables are independent for different links and for different times. At each moment, the coupling structure corresponds to a small-world graph, but the shortcuts change from time interval to time interval, which is a good model for many real-world dynamical networks. It is to be distinguished from networks that have randomly chosen shortcuts, fixed in time. Here, we apply the Connection Graph Stability method, developed in the companion paper (“Connection graph stability method for synchronized coupled chaotic systems”, see this issue), to the study of global synchronization in this network with the time-varying coupling structure, in the case where the on-off switching is fast with respect to the characteristic synchronization time of the network. The synchronization thresholds are explicitly linked with the average path length of the coupling graph and with the probability p of shortcut switchings in this blinking model. We prove that for the blinking model, a few random shortcut additions significantly lower the synchronization threshold together with the effective characteristic path length. Short interactions between cells, as in the blinking model, are important in practice. To cite prominent examples, computers networked over the Internet interact by sending packets of information, and neurons in our brain interact by sending short pulses, called spikes. The rare interaction between arbitrary nodes in the network greatly facilitates synchronization without loading the network much. In this respect, we believe that it is more efficient than a structure of fixed random connections.

  1. Pre-pulse inhibition of the acoustic startle eye-blink in the Göttingen minipig

    DEFF Research Database (Denmark)

    Arnfred, S. M.; Lind, N. M.; Hansen, A. K.

    2004-01-01

    by a weak white noise pre-pulse (PP), the interval between the PP and the startle noise stimulus (SNS) determining the degree of inhibition. Aiming at developing a new animal model of schizophrenia, we have investigated the acoustic startle eye-blink and PPI in 10 Göttingen minipigs. The stimuli...... in the pigs are in accordance with findings in studies of the human startle eye-blink EMG and this initial study promotes further studies and the use of the PPI measure in the validation of minipig models of psychiatric disorders.......Pre-pulse inhibition (PPI) of the startle response is a measure of sensorimotor gating which has been frequently shown to be deficient in schizophrenic patients. In humans it is typically measured as the attenuation of the startle eye-blink reflex EMG when a startle eliciting noise is preceded...

  2. Under which conditions does T1 difficulty affect T2 performance in the attentional blink?

    DEFF Research Database (Denmark)

    Nielsen, Simon; Petersen, Anders; Andersen, Tobias

    When two visual targets (T1 & T2) are presented in rapid succession, performance of T2 suffers up to 900 ms. One theory of this attentional blink (Raymond, Shapiro, & Arnell, 1992) propose that T1 and T2 compete for limited processing resources (Chun & Potter, 1995), and predict that prolonging...... exposure duration was the same as in the hard condition while T1 contrast was adjusted individually to reach the same performance on the T1 identification task as obtained in the long duration condition. Six observers completed 260 trials in each of the three conditions. We found a strong effect of T1-T2...... latency on performance in the T2 identification task in all conditions, replicating the finding of an attentional blink. However, we found no difference in the attentional blink between conditions. We conclude that increasing the perceptual difficulty of T1 either by decreasing T1 contrast or T1 exposure...

  3. Rates of spontaneous reports of adverse drug reactions for drugs reported in children: a cross-sectional study with data from the Swedish adverse drug reaction database and the Swedish Prescribed Drug Register.

    Science.gov (United States)

    Wallerstedt, Susanna M; Brunlöf, Gertrud; Sundström, Anders

    2011-08-01

    Knowledge of drug safety is limited in the paediatric population, especially for drugs not used as labelled. Spontaneous reporting of adverse drug reactions (ADRs) may be an important source for increased knowledge, but the extent of the overall rate of reporting in children is not known. The main objective of the study was to determine the extent of the spontaneous reporting of ADRs in children with a focus on drugs not used as labelled; this involved investigations of reporting rates of individual case safety reports (ICSRs) per 1000 treated individuals for drugs reported in children, to compare these between drugs labelled and not labelled for use in children, and to compare the rates for children with those of adults. ICSRs (extracted from the Swedish ADR database) and number of treated individuals (extracted from the Swedish Prescribed Drug Register) were analysed for a 2-year period (2006-7). For drugs with one or more ICSR regarding children, rates of ICSRs per 1000 treated individuals were determined and compared between children (10% of the volume was sold over-the-counter or for in-hospital use were excluded. The overall reporting ratio of aggregated ICSRs per 1000 treated individuals was calculated between drugs not labelled and drugs labelled for use in children, separately for children and adults. The overall reporting ratio was also calculated between children and adults, separately for drugs labelled and drugs not labelled for use in children. A total of 255 (children) and 1402 (adults) ICSRs concerning 94 drugs were included in the analysis. Seventy-four (29%) and 711 (51%) ICSRs in children and adults, respectively, were registered as serious (p rates of ICSRs per 1000 treated individuals varied between (range) 0.01-6.45 (children) and 0.01-6.39 (adults). For 17 of the drugs (18%) the rates of ICSRs per treated individual were significantly higher for children than for adults, and for 2 of the drugs (2%) the result was the opposite. The overall

  4. Spontaneous pneumothorax in weightlifters.

    Science.gov (United States)

    Marnejon, T; Sarac, S; Cropp, A J

    1995-06-01

    Spontaneous pneumothorax is infrequently caused by strenuous exertion. To our knowledge there has only been one case of spontaneous pneumothorax associated with weightlifting reported in the medical literature. We describe three consecutive cases of spontaneous pneumothorax associated with weightlifting. We postulate that spontaneous pneumothorax in these patients may be secondary to improper breathing techniques. It is important that physicians and weight trainers be aware of the association between weight lifting and spontaneous pneumothorax and assure that proper instruction is given to athletes who work with weights.

  5. Spontaneous transition rates for electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2) and magnetic quadrupole (M2) transitions for He-like calcium and sulfur ions

    International Nuclear Information System (INIS)

    Kingston, A.E.; Norrington, P.H.; Boone, A.W.

    2002-01-01

    The spontaneous decay rates for the electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1) and magnetic quadrupole (M2) transitions between all of the 1s 2 , 1s2 l and 1s3 l states have been obtained for helium-like calcium and sulfur ions. To assess the accuracy of the calculations, the transition probabilities were calculated using two sets of configuration interaction wavefunctions. One set of wavefunctions was generated using the fully relativistic GRASP code and the other was obtained using CIV3, in which relativistic effects are introduced using the Breit-Pauli approximation. The transition rates, A values, oscillator strengths and line strengths from our two calculations are found to be similar and to compare very well with other recent results for Δn=1 or 2 transitions. For Δn=0 transitions the agreement is much less good; this is mainly due to differences in the calculated excitation energies. (author)

  6. The role of (micro)saccades and blinks in perceptual bi-stability from slant rivalry.

    Science.gov (United States)

    van Dam, Loes C J; van Ee, Raymond

    2005-08-01

    We exposed the visual system to an ambiguous 3D slant rivalry stimulus consisting of a grid for which monocular (perspective) and binocular (disparity) cues independently specified a slant about a horizontal axis. When those cues specified similar slants, observers perceived a single slant. When the difference between the specified slants was large, observers alternatively perceived a perspective- or a disparity-dominated slant. Eye movement measurements revealed that there was no positive correlation between a perceptual flip and both saccades (microsaccades as well as larger saccades) and blinks that occurred prior to a perceptual flip. We also found that changes in horizontal vergence were not responsible for perceptual flips. Thus, eye movements were not essential to flip from one percept to the other. After the moment of a perceptual flip the occurrence probabilities of both saccades and blinks were reduced. The reduced probability of saccades mainly occurred for larger voluntary saccades, rather than for involuntary microsaccades. We suggest that the reduced probability of voluntary saccades reflects a reset of saccade planning.

  7. The effects of motivational reward on the pathological attentional blink following right hemisphere stroke.

    Science.gov (United States)

    Li, Korina; Russell, Charlotte; Balaji, Nikita; Saleh, Youssuf; Soto, David; Malhotra, Paresh A

    2016-11-01

    Recent work has shown that attentional deficits following stroke can be modulated by motivational stimulation, particularly anticipated monetary reward. Here we examined the effects of anticipated reward on the pathological attentional blink (AB), an index of temporal selective attention, which is prolonged in patients with right hemisphere damage and a history of left neglect. We specifically compared the effects of reward versus feedback-without-reward on the AB in 17 patients. We found that the patients all manifested impaired performance compared to healthy controls and that reward modulated the pathological blink in the patient group, but only in the second experimental session. When the performance of patients whose neglect had recovered was compared with that of patients who had ongoing or persistent neglect, reward appeared to only influence the AB in the former. These results have implications for our understanding of motivation-attention interactions following right hemisphere stroke, and how they may impact upon recovery from spatial neglect. Copyright © 2016. Published by Elsevier Ltd.

  8. Rating

    OpenAIRE

    Karas, Vladimír

    2006-01-01

    Charakteristika ratingu. Dělení a druhy ratingu (rating emise × rating emitenta; dlouhodobý rating × krátkodobý rating; mezinárodní rating × lokální rating). Obecné požadavky kladené na rating. Proces tvorby ratingu. Vyžádaný rating. Nevyžádaný rating. Ratingový proces na bázi volně přístupných informací. Uplatňované ratingové systémy. Ratingová kriteria. Využití a interpretace ratingové známky. Funkce ratingu. Rating v souvislosti s BASEL II. Rating v souvislosti s hospodářskými krizemi....

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

    Science.gov (United States)

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

    2011-01-01

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

  10. Spontaneous emission by moving atoms

    International Nuclear Information System (INIS)

    Meystre, P.; Wilkens, M.

    1994-01-01

    It is well known that spontaneous emission is not an intrinsic atomic property, but rather results from the coupling of the atom to the vacuum modes of the electromagnetic field. As such, it can be modified by tailoring the electromagnetic environment into which the atom can radiate. This was already realized by Purcell, who noted that the spontaneous emission rate can be enhanced if the atom placed inside a cavity is resonant with one of the cavity is resonant with one of the cavity modes, and by Kleppner, who discussed the opposite case of inhibited spontaneous emission. It has also been recognized that spontaneous emission need not be an irreversible process. Indeed, a system consisting of a single atom coupled to a single mode of the electromagnetic field undergoes a periodic exchange of excitation between the atom and the field. This periodic exchange remains dominant as long as the strength of the coupling between the atom and a cavity mode is itself dominant. 23 refs., 6 figs

  11. An automatic algorithm for blink-artifact suppression based on iterative template matching: application to single channel recording of cortical auditory evoked potentials

    Science.gov (United States)

    Valderrama, Joaquin T.; de la Torre, Angel; Van Dun, Bram

    2018-02-01

    Objective. Artifact reduction in electroencephalogram (EEG) signals is usually necessary to carry out data analysis appropriately. Despite the large amount of denoising techniques available with a multichannel setup, there is a lack of efficient algorithms that remove (not only detect) blink-artifacts from a single channel EEG, which is of interest in many clinical and research applications. This paper describes and evaluates the iterative template matching and suppression (ITMS), a new method proposed for detecting and suppressing the artifact associated with the blink activity from a single channel EEG. Approach. The approach of ITMS consists of (a) an iterative process in which blink-events are detected and the blink-artifact waveform of the analyzed subject is estimated, (b) generation of a signal modeling the blink-artifact, and (c) suppression of this signal from the raw EEG. The performance of ITMS is compared with the multi-window summation of derivatives within a window (MSDW) technique using both synthesized and real EEG data. Main results. Results suggest that ITMS presents an adequate performance in detecting and suppressing blink-artifacts from a single channel EEG. When applied to the analysis of cortical auditory evoked potentials (CAEPs), ITMS provides a significant quality improvement in the resulting responses, i.e. in a cohort of 30 adults, the mean correlation coefficient improved from 0.37 to 0.65 when the blink-artifacts were detected and suppressed by ITMS. Significance. ITMS is an efficient solution to the problem of denoising blink-artifacts in single-channel EEG applications, both in clinical and research fields. The proposed ITMS algorithm is stable; automatic, since it does not require human intervention; low-invasive, because the EEG segments not contaminated by blink-artifacts remain unaltered; and easy to implement, as can be observed in the Matlab script implemeting the algorithm provided as supporting material.

  12. Spontaneous uterine rupture

    African Journals Online (AJOL)

    ABSTRACT. Rupture of a gravid uterus is a surgical emergency. Predisposing factors include a scarred uterus. Spontaneous rupture of an unscarred uterus during pregnancy is a rare occurrence. We hereby present the case of a spontaneous complete uterine rupture at a gestational age of 34 weeks in a 35 year old patient ...

  13. Spontaneous intracranial hypotension.

    LENUS (Irish Health Repository)

    Fullam, L

    2012-01-31

    INTRODUCTION: Spontaneous\\/primary intracranial hypotension is characterised by orthostatic headache and is associated with characteristic magnetic resonance imaging findings. CASE REPORT: We present a case report of a patient with typical symptoms and classical radiological images. DISCUSSION: Spontaneous intracranial hypotension is an under-recognised cause of headache and can be diagnosed by history of typical orthostatic headache and findings on MRI brain.

  14. Clock frequency estimation under spontaneous emission

    Science.gov (United States)

    Qin, Xi-Zhou; Huang, Jia-Hao; Zhong, Hong-Hua; Lee, Chaohong

    2018-02-01

    We investigate the quantum dynamics of a driven two-level system under spontaneous emission and its application in clock frequency estimation. By using the Lindblad equation to describe the system, we analytically obtain its exact solutions, which show three different regimes: Rabi oscillation, damped oscillation, and overdamped decay. From the analytical solutions, we explore how the spontaneous emission affects the clock frequency estimation. We find that under a moderate spontaneous emission rate, the transition frequency can still be inferred from the Rabi oscillation. Our results enable potential practical applications in frequency measurement and quantum control under decoherence.

  15. The Attentional Blink Paradigm in Individuals with High and Low Levels of Depression and Anxiety

    Directory of Open Access Journals (Sweden)

    Hannah Kathleen Skinner

    2014-12-01

    Full Text Available The attentional biases of individuals with high and low levels of depression and anxiety were tested using the Attentional Blink paradigm. A rapid serial visual presentation (RSVP task was used to detect biases in identification of emotionally valenced target images. The independent variables were depression, anxiety, lag of target stimulus, and emotional valence of target images. The dependent variables were accuracy, reaction times, and pupil dilation. As predicted, attentional biases were found for symptoms of both depression and anxiety, independently and co-morbidly, for dependent variables. The data suggest that there are both differences and similarities in the effects of symptoms of anxiety and depression on attentional biases around emotional stimuli.

  16. Relationship between blood lead level and abnormal eye blinking in children

    Directory of Open Access Journals (Sweden)

    Fen Du

    2015-05-01

    Full Text Available AIM: To study the relationship between blood lead level and abnormal eye blinking in children. METHODS: The patients with chief complaint of frequent eye blinking, whose diagnosis of abnormal eye blinking, were randomized to experimental group. The patients in this group carried out vision and the slit-lamp examination, detected corneal fluorescein staining and tear break-up time, and improved the level of blood lead and trace elements examination. The patients in control group with chief complaint of health physical examination in our hospital, excepted of blood lead level, the other body check results were normal and were divided into boys group and girls group according to the gender. The changes of the experimental group and control group in blood lead level were compared. RESULTS: Totally 371 cases(male: 295 cases; female: 76 caseswith mean age was 6.56±2.41 years and 6.08±2.82 years respectively were in experimental groupe. In control group, there were 300 cases(male: 186 cases; female: 114 caseswith mean age was 6.99±3.01 years and 6.56±2.80 years respectively. The average of blood lead level of boys in experimental group was 63.82±24.56μg/L and 53.98±15.42μg/L in control group. The average of blood lead level in experimental group was higher than that in control group. The difference between of the two group was statistically significant(χ2=16.96, Pχ2=5.77, P=0.56. In control group, the average of blood lead level with 6 years children were 48.73±11.67μg/L, 51.39±14.87μg/L,52.98±14.45μg/L respectively. In expirement group, the results were 56.57±17.89μg/L, 59.92±18.46μg/L and 67.00±32.55μg/L in 6 children, respectively. There was no significant difference with χ2=3.54, P=0.17. The difference with 3~6 years and >6 years children were statistically significant(χ2=9.62, P=0.008and(χ2=19.22, P=0.000respectively. The blood lead level were divided into three grades: 100μg/L, and relative risk(RRwere 0.65, 1.22, and

  17. Sparing from the attentional blink is not spared from structural limitations.

    Science.gov (United States)

    Dell'Acqua, R; Dux, P E; Wyble, B; Jolicœur, P

    2012-04-01

    When a series of three successive to-be-reported items (targets) is displayed in a rapid serial visual presentation (RSVP) stream of distractors, it has been shown that no attentional blink--a marked impairment in the report of the second of two targets, typically observed when the targets appear within 200-600 ms of one another--occurs in target accuracy. The present study examines three recently introduced computational models that provide different explanations of this protracted sparing effect. Using a standard RSVP design and these models, we provide empirical data and simulations that illustrate that structural limitations affect the processing of successive targets. In addition, we compare the candidate mechanisms that might underlie these limitations.

  18. Chronological changes of blink reflex and MRI in a patient with lateral medullary infarction

    International Nuclear Information System (INIS)

    Kawamura, Hirotsune; Amano, Keiichi; Tanikawa, Tatsuya; Kawabatake, Hiroko; Kubo, Osami; Kitamura, Koichi; Ono, Yuko

    1986-01-01

    Recently, the brainstem pathways of bilateral late reflexes (R2) of electrically elicited blink reflex have been well established. An afferent delay or block of the late reflexes is closely related to a lesion of the lateral medullary portion. The chronological alteration of blink reflex (BR) was studied to compare with radiological abnormalities on MRI in a patient with lateral medullary infarction on the right side. A diagnosis of Wallenberg syndrome was made clinically and location of the lesion was identified in detail by MRI. The infarcted region which was well demonstrated as an increased intensity area on SE images obtained 52 days after the onset of symptoms was much smaller than that on SE as well as on IR image 21 days after the onset of symptoms. Therefore, it was concluded that more than half of the increased intensity area on the SE images obtained 21 days after the onset of symptoms recovered from the condition of being extremely damaged by ischemia on the right lateral medullary portion in this patient. On the other hand, in the initial BR 26 days after the onset of symptoms, the late reflexes (R2) were consistently absent bilaterally when the affected side (right) was stimulated and normal when the normal side (left) was stimulated. This type of BR abnormality is compatible with an afferent block of late reflexes (R2). The early reflex (R1) was normal on either side. Whereas in the second BR at 55 days after the onset of symptoms, the late reflexes turned to be normal in latency when the right side was stimulated. This recovery of late reflexes after the stimulation of the supraorbital nerve on the affected side was thought to be relevant to the part of disappearance of increased intensity area on the SE images obtained 52 days after the onset of symptoms. (J.P.N.)

  19. Spontaneous regression of metastatic Merkel cell carcinoma.

    LENUS (Irish Health Repository)

    Hassan, S J

    2010-01-01

    Merkel cell carcinoma is a rare aggressive neuroendocrine carcinoma of the skin predominantly affecting elderly Caucasians. It has a high rate of local recurrence and regional lymph node metastases. It is associated with a poor prognosis. Complete spontaneous regression of Merkel cell carcinoma has been reported but is a poorly understood phenomenon. Here we present a case of complete spontaneous regression of metastatic Merkel cell carcinoma demonstrating a markedly different pattern of events from those previously published.

  20. Management of intractable spontaneous epistaxis

    Science.gov (United States)

    Rudmik, Luke

    2012-01-01

    Background: Epistaxis is a common otolaryngology emergency and is often controlled with first-line interventions such as cautery, hemostatic agents, or anterior nasal packing. A subset of patients will continue to bleed and require more aggressive therapy. Methods: Intractable spontaneous epistaxis was traditionally managed with posterior nasal packing and prolonged hospital admission. In an effort to reduce patient morbidity and shorten hospital stay, surgical and endovascular techniques have gained popularity. A literature review was conducted. Results: Transnasal endoscopic sphenopalatine artery ligation and arterial embolization provide excellent control rates but the decision to choose one over the other can be challenging. The role of transnasal endoscopic anterior ethmoid artery ligation is unclear but may be considered in certain cases when bleeding localizes to the ethmoid region. Conclusion: This article will focus on the management of intractable spontaneous epistaxis and discuss the role of endoscopic arterial ligation and embolization as it pertains to this challenging clinical scenario. PMID:22391084

  1. Associative stimulation of the supraorbital nerve fails to induce timing-specific plasticity in the human blink reflex

    DEFF Research Database (Denmark)

    Zeuner, Kirsten E; Knutzen, Arne; Al-Ali, Asmaa

    2010-01-01

    Associative high-frequency electrical stimulation (HFS) of the supraorbital nerve in five healthy individuals induced long-term potentiation (LTP)-like or depression (LTD)-like changes in the human blink reflex circuit according to the rules of spike timing-dependent plasticity (Mao and Evinger, ...... the orbicularis oculi muscles, HFS(LTP) induced excessive LTP-like associative plasticity relative to healthy controls, which was normalized after botulinum toxin (BTX) injections (Quartarone et al, 2006).......Associative high-frequency electrical stimulation (HFS) of the supraorbital nerve in five healthy individuals induced long-term potentiation (LTP)-like or depression (LTD)-like changes in the human blink reflex circuit according to the rules of spike timing-dependent plasticity (Mao and Evinger...

  2. The blink reflex test does not show abnormalities in a large group of patients with chronic migraine

    Directory of Open Access Journals (Sweden)

    Joseph Bruno Bidin Brooks

    2013-11-01

    Full Text Available The blink reflex – a simple, non-invasive and inexpensive test – may be indicative of lesions or dysfunctions of the brainstem, and particularly assesses the trigeminal-facial arch. Results from alterations of the blink reflex in patients with headaches have provided controversial data. Method Registration of the waves R1 and R2 (ipsilateral to the stimulus and R2c (contralateral to the stimulus by electroneuromyography. Results A large number of controls (n=160 and patients with chronic migraine (n=160 were studied. No significant differences were observed between the two groups. Conclusion It is possible that this relatively simple and primitive reflex is not affected unless there is significant damage to the brainstem.

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

    Science.gov (United States)

    Somers, Ben; Bertrand, Alexander

    2016-12-01

    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. 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. 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. 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.

  4. Spontaneous oscillations in microfluidic networks

    Science.gov (United States)

    Case, Daniel; Angilella, Jean-Regis; Motter, Adilson

    2017-11-01

    Precisely controlling flows within microfluidic systems is often difficult which typically results in systems being heavily reliant on numerous external pumps and computers. Here, I present a simple microfluidic network that exhibits flow rate switching, bistablity, and spontaneous oscillations controlled by a single pressure. That is, by solely changing the driving pressure, it is possible to switch between an oscillating and steady flow state. Such functionality does not rely on external hardware and may even serve as an on-chip memory or timing mechanism. I use an analytic model and rigorous fluid dynamics simulations to show these results.

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

    Science.gov (United States)

    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. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Conscious access is linked to ongoing brain state: electrophysiological evidence from the attentional blink.

    Science.gov (United States)

    Pincham, Hannah L; Szucs, Dénes

    2012-10-01

    Neuroscience explanations of conscious access focus on neural events elicited by stimuli. In contrast, here, we used the attentional blink paradigm in combination with event-related brain potentials to examine whether the ongoing state of the brain before a stimulus can determine both conscious access and the poststimulus neural events associated with consciousness. Participants were required to detect 2 target letters from digit distractors while their brain activity was being recorded. Trials were classified based on whether the secondcritical target (T2) was detected. We found that T2-detection was predetermined by brain activity prior to the onset of the stimulation stream. Specifically, T2-detected trials were predicated by a frontocentral positive going deflection that started more than 200 ms before the stream began. Accurate T2 detection was also accompanied by enhanced poststimulus neural activity, as reflected by a larger P3b component. Furthermore, prestimulus and poststimulus markers of T2-detection were highly correlated with one another. We therefore argue that conscious experiences are shaped by potentially random fluctuations in neural activity. Overall, the results reveal that conscious access is underpinned by an important relationship involving predictive prestimulus neural activity and responsive poststimulus brain activity.

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

    Science.gov (United States)

    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.

  8. An Individual Differences Approach to Temporal Integration and Order Reversals in the Attentional Blink Task.

    Science.gov (United States)

    Willems, Charlotte; Saija, Jefta D; Akyürek, Elkan G; Martens, Sander

    2016-01-01

    The reduced ability to identify a second target when it is presented in close temporal succession of a first target is called the attentional blink (AB). Studies have shown large individual differences in AB task performance, where lower task performance has been associated with more reversed order reports of both targets if these were presented in direct succession. In order to study the suggestion that reversed order reports reflect loss of temporal information, in the current study, we investigated whether individuals with a larger AB have a higher tendency to temporally integrate both targets into one visual event by using an AB paradigm containing symbol target stimuli. Indeed, we found a positive relation between the tendency to temporally integrate information and individual AB magnitude. In contrast to earlier work, we found no relation between order reversals and individual AB magnitude. The occurrence of temporal integration was negatively related to the number of order reversals, indicating that individuals either integrated or separated and reversed information. We conclude that individuals with better AB task performance use a shorter time window to integrate information, and therefore have higher preservation of temporal information. Furthermore, order reversals observed in paradigms with alphanumeric targets indeed seem to at least partially reflect temporal integration of both targets. Given the negative relation between temporal integration and 'true' order reversals observed with the current symbolic target set, these two behavioral outcomes seem to be two sides of the same coin.

  9. Amplification of attentional blink by distress-related facial expressions: relationships with alexithymia and affectivity.

    Science.gov (United States)

    Grynberg, Delphine; Vermeulen, Nicolas; Luminet, Olivier

    2014-10-01

    The present studies aimed to analyse the modulatory effect of distressing facial expressions on attention processing. The attentional blink (AB) paradigm is one of the most widely used paradigms for studying temporal attention, and is increasingly applied to study the temporal dynamics of emotion processing. The aims of this study were to investigate how identifying fear and pain facial expressions (Study 1) and fear and anger facial expressions (Study 2) would influence the detection of subsequent stimuli presented within short time intervals, and to assess the moderating influence of alexithymia and affectivity on this effect. It has been suggested that high alexithymia scorers need more attentional resources to process distressing facial expressions and that negative affectivity increases the AB. We showed that fear, anger and pain produced an AB and that alexithymia moderated it such that difficulty in describing feelings (Study 1) and externally oriented thinking (Study 2) were associated with higher interference after the processing of fear and anger at short time presentations. These studies provide evidence that distressing facial expressions modulate the attentional processing at short time intervals and that alexithymia influences the early attentional processing of fear and anger expressions. Controlling for state affect did not change these conclusions. © 2013 International Union of Psychological Science.

  10. The emotional blink: adult age differences in visual attention to emotional information.

    Science.gov (United States)

    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. Copyright (c) 2009 APA, all rights reserved.

  11. The absence of an auditory-visual attentional blink is not due to echoic memory.

    Science.gov (United States)

    Van der Burg, Erik; Olivers, Christian N; Bronkhorst, Adelbei W; Koelewijn, Thomas; Theeuwes, Jan

    2007-10-01

    The second of two targets is often missed when presented shortly after the first target--a phenomenon referred to as the attentional blink (AB). Whereas the AB is a robust phenomenon within sensory modalities, the evidence for cross-modal ABs is rather mixed. Here, we test the possibility that the absence of an auditory-visual AB for visual letter recognition when streams of tones are used is due to the efficient use of echoic memory, allowing for the postponement of auditory processing. However, forcing participants to immediately process the auditory target, either by presenting interfering sounds during retrieval or by making the first target directly relevant for a speeded response to the second target, did not result in a return of a cross-modal AB. Thefindings argue against echoic memory as an explanation for efficient cross-modal processing. Instead, we hypothesized that a cross-modal AB may be observed when the different modalities use common representations, such as semantic representations. In support of this, a deficit for visual letter recognition returned when the auditory task required a distinction between spoken digits and letters.

  12. The attentional blink is modulated by first target contrast: Implications of an attention capture hypothesis

    DEFF Research Database (Denmark)

    Nielsen, Simon; Andersen, Tobias S

    2011-01-01

    When two targets (T1 & T2) are presented in rapid succession, observers often fail to report T2 if they attend to T1. The bottleneck theory proposes that this attentional blink (AB) is due to T1 occupying a slow processing stage when T2 is presented. Accordingly, if increasing T1 difficulty...... increases T1 processing time, this should cause a greater AB. The attention capture hypothesis suggests that T1 captures attention, which cannot be reallocated to T2 in time. Accordingly, if increasing T1 difficulty decreases T1 saliency, this should cause a smaller AB. In two experiments we find support...... for an attention capture hypothesis. In Experiment 1 we find that AB magnitude increases with T1 contrast – but only when T1 is unmasked. In Experiment 2 we add Gaussian noise to targets and vary T1 contrast but keep T1 ‘s SNR constant. Again we find that AB magnitude increases with T1 contrast....

  13. The Attentional Blink is Modulated by First Target Contrast: Implications of an Attention Capture Hypothesis

    DEFF Research Database (Denmark)

    Nielsen, Simon; Andersen, Tobias

    2011-01-01

    When two targets (T1 & T2) are presented in rapid succession, observers often fail to report T2 if they attend to T1. The bottleneck theory proposes that this attentional blink (AB) is due to T1 occupying a slow processing stage when T2 is presented. Accordingly, if increasing T1 difficulty...... increases T1 processing time, this should cause a greater AB. The attention capture hypothesis suggests that T1 captures attention, which cannot be reallocated to T2 in time. Accordingly, if increasing T1 difficulty decreases T1 saliency, this should cause a smaller AB. In two experiments we find support...... for an attention capture hypothesis. In Experiment 1 we find that AB magnitude increases with T1 contrast – but only when T1 is unmasked. In Experiment 2 we add Gaussian noise to targets and vary T1 contrast but keep T1 ‘s SNR constant. Again we find that AB magnitude increases with T1 contrast....

  14. Spiking Neural Network With Distributed Plasticity Reproduces Cerebellar Learning in Eye Blink Conditioning Paradigms.

    Science.gov (United States)

    Antonietti, Alberto; Casellato, Claudia; Garrido, Jesús A; Luque, Niceto R; Naveros, Francisco; Ros, Eduardo; D' Angelo, Egidio; Pedrocchi, Alessandra

    2016-01-01

    In this study, we defined a realistic cerebellar model through the use of artificial spiking neural networks, testing it in computational simulations that reproduce associative motor tasks in multiple sessions of acquisition and extinction. By evolutionary algorithms, we tuned the cerebellar microcircuit to find out the near-optimal plasticity mechanism parameters that better reproduced human-like behavior in eye blink classical conditioning, one of the most extensively studied paradigms related to the cerebellum. We used two models: one with only the cortical plasticity and another including two additional plasticity sites at nuclear level. First, both spiking cerebellar models were able to well reproduce the real human behaviors, in terms of both "timing" and "amplitude", expressing rapid acquisition, stable late acquisition, rapid extinction, and faster reacquisition of an associative motor task. Even though the model with only the cortical plasticity site showed good learning capabilities, the model with distributed plasticity produced faster and more stable acquisition of conditioned responses in the reacquisition phase. This behavior is explained by the effect of the nuclear plasticities, which have slow dynamics and can express memory consolidation and saving. We showed how the spiking dynamics of multiple interactive neural mechanisms implicitly drive multiple essential components of complex learning processes.  This study presents a very advanced computational model, developed together by biomedical engineers, computer scientists, and neuroscientists. Since its realistic features, the proposed model can provide confirmations and suggestions about neurophysiological and pathological hypotheses and can be used in challenging clinical applications.

  15. An Individual Differences Approach to Temporal Integration and Order Reversals in the Attentional Blink Task.

    Directory of Open Access Journals (Sweden)

    Charlotte Willems

    Full Text Available The reduced ability to identify a second target when it is presented in close temporal succession of a first target is called the attentional blink (AB. Studies have shown large individual differences in AB task performance, where lower task performance has been associated with more reversed order reports of both targets if these were presented in direct succession. In order to study the suggestion that reversed order reports reflect loss of temporal information, in the current study, we investigated whether individuals with a larger AB have a higher tendency to temporally integrate both targets into one visual event by using an AB paradigm containing symbol target stimuli.Indeed, we found a positive relation between the tendency to temporally integrate information and individual AB magnitude. In contrast to earlier work, we found no relation between order reversals and individual AB magnitude. The occurrence of temporal integration was negatively related to the number of order reversals, indicating that individuals either integrated or separated and reversed information.We conclude that individuals with better AB task performance use a shorter time window to integrate information, and therefore have higher preservation of temporal information. Furthermore, order reversals observed in paradigms with alphanumeric targets indeed seem to at least partially reflect temporal integration of both targets. Given the negative relation between temporal integration and 'true' order reversals observed with the current symbolic target set, these two behavioral outcomes seem to be two sides of the same coin.

  16. The Effects of Emotional Target and Mood State of Participants on Attentional Blink

    Directory of Open Access Journals (Sweden)

    Wai-Shan Chan

    2011-05-01

    Full Text Available Previous studies have found that attentional blink (AB, a failure to report targets temporally close to each other, can be attenuated separately by (1 emotionally significant test stimuli (T2 and (2 the emotional state of the observer. In the present study, we asked whether and how the (1 and (2 interact. Participants were induced with either positive or negative music and asked to complete an AB task which consisted of low-arousal positive, neutral and negative words as T2. We found low arousal negative words significantly reduced AB more than did other words, while no main nor interaction effect for mood was observed. However, on repeating the experiment and replacing low arousal words with high-arousal ones we not only were able to replicate the finding of an advantage of negative words over others, but detected an effect for the mood of the observer: participants who were induced to become happier using music performed better in detecting T2 across lags and word categories than did participants who became sadder. Our findings suggest an interaction of arousal level of emotional target with the induced mood of participants although the underlying mechanisms responsible for this effect need further investigation.

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

    Science.gov (United States)

    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.

  18. Spontaneous Atraumatic Mediastinal Hemorrhage

    Directory of Open Access Journals (Sweden)

    Morkos Iskander BSc, BMBS, MRCS, PGCertMedEd

    2013-04-01

    Full Text Available Spontaneous atraumatic mediastinal hematomas are rare. We present a case of a previously fit and well middle-aged lady who presented with acute breathlessness and an increasing neck swelling and spontaneous neck bruising. On plain chest radiograph, widening of the mediastinum was noted. The bruising was later confirmed to be secondary to mediastinal hematoma. This life-threatening diagnostic conundrum was managed conservatively with a multidisciplinary team approach involving upper gastrointestinal and thoracic surgeons, gastroenterologists, radiologists, intensivists, and hematologists along with a variety of diagnostic modalities. A review of literature is also presented to help surgeons manage such challenging and complicated cases.

  19. Spontaneous Appendicocutaneous Fistula I

    African Journals Online (AJOL)

    M T0k0de* MB, BS and. Dr 0. A. AWOj0bi+ FMCS (Nig). ABSTRACT. Ruptured appendicitis is not a common cause of spontaneous enterocutaneous fistula. A case of ruptured retrocaecal appendicitis presenting as an enterocutaneous fistula in a Nigerian woman is presented. The literature on this disorder is also reviewed.

  20. Spontaneous Grammar Explanations.

    Science.gov (United States)

    Tjoo, Hong Sing; Lewis, Marilyn

    1998-01-01

    Describes one New Zealand university language teacher's reflection on her own grammar explanations to university-level students of Bahasa Indonesian. Examines form-focused instruction through the teacher's spontaneous answers to students' questions about the form of the language they are studying. The teacher's experiences show that it takes time…

  1. EDITORIAL SPONTANEOUS BACTERIAL PERITONITIS ...

    African Journals Online (AJOL)

    hi-tech

    Spontaneous bacterial peritonitis (SBP) frequent]y occurs in patients with liver cirrhosis and ascites. It is defined as an infection of previously sterile ascitic fluid without any demonstrable intrabdominal source of infection. It is now internationally agreed that a polymorphonuclear (PMN) cell count in the ascitic fluid of over 250 ...

  2. Spontaneous dimensional reduction?

    Science.gov (United States)

    Carlip, Steven

    2012-10-01

    Over the past few years, evidence has begun to accumulate suggesting that spacetime may undergo a "spontaneous dimensional reduction" to two dimensions near the Planck scale. I review some of this evidence, and discuss the (still very speculative) proposal that the underlying mechanism may be related to short-distance focusing of light rays by quantum fluctuations.

  3. Results of Investigations on the Blink Reflex as a Protective Means against Laser and LED Radiation: A Description Based on Fundamental Psychophysical Laws

    International Nuclear Information System (INIS)

    Hans-Dieter Reidenbach

    2006-01-01

    2,650 volunteers have been investigated in blink-reflex studies with various test equipment, where a laser beam or a single element L.E.D. or an array have been used to irradiate the human eye in order to initiate a physiological reaction. In addition 1,196 volunteers took part in aversion response studies. 491 persons out of 2,650, i.e., 18.53 %, showed a blink reflex or lid closure, upon exposure to irradiation from a laser or an L.E.D.. Only 6.19 %, i. e., 74 out of 1,196 volunteers, showed other aversion responses, like gross eye or head movements. The different parameters which are mainly responsible for the respective results concerning the blink reflex will be dealt with and explained, as they have been achieved up to now. In addition some experimentally verified dependencies on fundamental psychophysical laws will be described. Besides the statement that the blink reflex should not be used as a sufficient physiological protective means it can be generally stated that in order to ensure their safety, in spite of the missing blink-reflex and other aversion responses, users of low-power lasers should be instructed to perform active protective reactions, e.g., to close the eyes voluntarily and simultaneously move the head away from the beam in the case of an unintentional exposure or intrabeam viewing. (author)

  4. Recurrent spontaneous intracerebral hemorrhage associated with ...

    African Journals Online (AJOL)

    Spontaneous intracerebral hemorrhage (ICH) accounts for 15% of stroke cases in the US and Europe and up to 30% in Asian populations. Intracerebral hemorrhage is a relatively uncommon form of stroke-it causes only 10 to 15 percent of all strokes. It is more disabling and has a higher mortality rate than ischemic stroke, ...

  5. Spontaneous splenic rupture in pregnancy: a case report | Makwe ...

    African Journals Online (AJOL)

    Spontaneous splenic rupture in pregnancy is a rare condition, associated with very high maternal mortality rate and fetal wastage. It is frequently misdiagnosed at presentation. We report a case of a 33-year-old, gravida 2, para 1 lady at 29 weeks' gestation with spontaneous splenic rupture, which was initially diagnosed as ...

  6. Emotional modulation of attention: fear increases but disgust reduces the attentional blink.

    Directory of Open Access Journals (Sweden)

    Nicolas Vermeulen

    Full Text Available BACKGROUND: It is well known that facial expressions represent important social cues. In humans expressing facial emotion, fear may be configured to maximize sensory exposure (e.g., increases visual input whereas disgust can reduce sensory exposure (e.g., decreases visual input. To investigate whether such effects also extend to the attentional system, we used the "attentional blink" (AB paradigm. Many studies have documented that the second target (T2 of a pair is typically missed when presented within a time window of about 200-500 ms from the first to-be-detected target (T1; i.e., the AB effect. It has recently been proposed that the AB effect depends on the efficiency of a gating system which facilitates the entrance of relevant input into working memory, while inhibiting irrelevant input. Following the inhibitory response on post T1 distractors, prolonged inhibition of the subsequent T2 is observed. In the present study, we hypothesized that processing facial expressions of emotion would influence this attentional gating. Fearful faces would increase but disgust faces would decrease inhibition of the second target. METHODOLOGY/PRINCIPAL FINDINGS: We showed that processing fearful versus disgust faces has different effects on these attentional processes. We found that processing fear faces impaired the detection of T2 to a greater extent than did the processing disgust faces. This finding implies emotion-specific modulation of attention. CONCLUSIONS/SIGNIFICANCE: Based on the recent literature on attention, our finding suggests that processing fear-related stimuli exerts greater inhibitory responses on distractors relative to processing disgust-related stimuli. This finding is of particular interest for researchers examining the influence of emotional processing on attention and memory in both clinical and normal populations. For example, future research could extend upon the current study to examine whether inhibitory processes invoked by

  7. Perception of temporal order during the attentional blink: Using stimulus salience to modulate prior entry.

    Science.gov (United States)

    Lagroix, Hayley E P; Patten, James W; Di Lollo, Vincent; Spalek, Thomas M

    2016-05-01

    When multiple targets are presented in rapid sequence, observers frequently confuse the order in which they were presented. The probability of order reversals is known to vary throughout the period of the attentional blink (AB), which refers to impairment in the perception of the second of two targets when it is presented within approximately 500 ms from the first. Our objective was to examine the principle of prior entry (in which perception of temporal order is said to be affected by the relative latency at which each target is processed) as a determinant of the perception of temporal order throughout the AB. In two experiments, three letter targets (T1, T2, T3) were inserted in a stream of digit distractors, with T3 always presented directly after T2. The T1-T2 lag was varied to assess the perception of T2-T3 temporal order throughout the period of the AB. Processing latency was manipulated by means of salience. In Experiment 1, salience of T2 and T3 was manipulated exogenously by coloring the salient target red with all other stimuli being green. In Experiment 2, salience was modulated endogenously by manipulating which of the two targets matched the contents of working memory. Consistent with the principle of prior entry, perception of temporal order in both experiments was enhanced throughout the period of the AB when T2 was salient, and impaired when T3 was salient. Simulations based on the Episodic Simultaneous Type, Serial Token (eSTST) model that incorporates prior-entry, matched the empirical results.

  8. Blink reflexes in patients with atypical odontalgia and matched healthy controls.

    Science.gov (United States)

    Baad-Hansen, Lene; List, Thomas; Kaube, Holger; Jensen, Troels S; Svensson, Peter

    2006-07-01

    Atypical odontalgia (AO) is an orofacial pain condition which has been suggested to involve neuropathic pain mechanisms. The aim of this study was to use a brain stem reflex to investigate craniofacial nociceptive mechanisms in AO. In 38 AO patients and 27 matched healthy controls, the R2 component of the blink reflex (BR) was elicited using a "nociceptive-specific" electrode and recorded with surface electromyography electrodes on both orbicularis oculi muscles. The BR was tested by stimulation of both sides of the face of the participants before, during, and after an intraoral pain provocation test with capsaicin. The data were analyzed with three- and four-way mixed-model analyses of variance. The root mean square value of the ipsilateral R2 (R2i) was significantly reduced in patients compared with controls (P=0.046). No differences in R2 between stimulation sides were detected in either group (P>0.757). In all participants, R2 responses and the intensity of the pain evoked by the electrical stimulus were decreased during and after application of capsaicin compared with baseline (P<0.001). In patients, R2i onset latencies were significantly prolonged compared with controls (P=0.031). The present data show disturbances in the central processing of craniofacial information and that endogenous pain inhibitory systems in AO patients and healthy controls were activated to a similar degree by an acute intraoral nociceptive input. Additional clinical research with AO patients will be needed to determine to what extent neuropathic pain mechanisms are involved in this pain condition.

  9. Spontaneous healing of spontaneous coronary artery dissection.

    Science.gov (United States)

    Almafragi, Amar; Convens, Carl; Heuvel, Paul Van Den

    2010-01-01

    Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome and sudden cardiac death. It should be suspected in every healthy young woman without cardiac risk factors, especially during the peripartum or postpartum periods. It is important to check for a history of drug abuse, collagen vascular disease or blunt trauma of the chest. Coronary angiography is essential for diagnosis and early management. We wonder whether thrombolysis might aggravate coronary dissection. All types of treatment (medical therapy, percutaneous intervention or surgery) improve the prognosis without affecting survival times if used appropriately according to the clinical stability and the angiographic features of the involved coronary arteries. Prompt recognition and targeted treatment improve outcomes. We report a case of SCAD in a young female free of traditional cardiovascular risk factors, who presented six hours after thrombolysis for ST elevation myocardial infarction. Coronary angiography showed a dissection of the left anterior descending and immediate branch. She had successful coronary artery bypass grafting, with complete healing of left anterior descending dissection.

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

    Science.gov (United States)

    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.

  11. Computed tomographic findings of spontaneous intracranial hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Seung Sook; Kim, Young Sook; Kim, Young Chul [College of Medicine, Chosun University, Kwangju (Korea, Republic of)

    1987-10-15

    Computed tomography (CT) was a reliable technique to evaluate the exact size and location of spontaneous intracranial hemorrhage and to predict it's prognosis. Fifty-nine cases of spontaneous intracranial hemorrhage were evaluated and reviewed by CT scan. The following results were obtained. 1. The sex ratio of male to female was 1 to 1.4, The highest incidence was in 6th and 7th decades. 2. The most common cause of spontaneous intracranial hemorrhage was hypertension (74.6%), followed by the aneurysm (13.5%), arteriovenous malformation (5.1%), occlusive vascular disease (3.4%), and blood dyscrasia (3.4%). 3. The most common location was basal ganglia and thalamic hemorrhage (37.3%), followed by lobar hemorrhage (27.1%), cerebellar hemorrhage (13.5%), and subarachnoid hemorrhage (11.9%). 4. Primary intraventricular hemorrhage carried the highest mortality. 5. The larger volume of hematoma, the higher the mortality rate.

  12. Spontaneous spinal epidural abscess.

    LENUS (Irish Health Repository)

    Ellanti, P

    2011-10-01

    Spinal epidural abscess is an uncommon entity, the frequency of which is increasing. They occur spontaneously or as a complication of intervention. The classical triad of fever, back pain and neurological symptoms are not always present. High index of suspicion is key to diagnosis. Any delay in diagnosis and treatment can have significant neurological consequences. We present the case of a previously well man with a one month history of back pain resulting from an epidural abscess.

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

    Science.gov (United States)

    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.

  14. ViSA: a neurodynamic model for visuo-spatial working memory, attentional blink, and conscious access.

    Science.gov (United States)

    Simione, Luca; Raffone, Antonino; Wolters, Gezinus; Salmas, Paola; Nakatani, Chie; Belardinelli, Marta Olivetti; van Leeuwen, Cees

    2012-10-01

    Two separate lines of study have clarified the role of selectivity in conscious access to visual information. Both involve presenting multiple targets and distracters: one simultaneously in a spatially distributed fashion, the other sequentially at a single location. To understand their findings in a unified framework, we propose a neurodynamic model for Visual Selection and Awareness (ViSA). ViSA supports the view that neural representations for conscious access and visuo-spatial working memory are globally distributed and are based on recurrent interactions between perceptual and access control processors. Its flexible global workspace mechanisms enable a unitary account of a broad range of effects: It accounts for the limited storage capacity of visuo-spatial working memory, attentional cueing, and efficient selection with multi-object displays, as well as for the attentional blink and associated sparing and masking effects. In particular, the speed of consolidation for storage in visuo-spatial working memory in ViSA is not fixed but depends adaptively on the input and recurrent signaling. Slowing down of consolidation due to weak bottom-up and recurrent input as a result of brief presentation and masking leads to the attentional blink. Thus, ViSA goes beyond earlier 2-stage and neuronal global workspace accounts of conscious processing limitations. PsycINFO Database Record (c) 2012 APA, all rights reserved.

  15. Excessive blinking and ataxia in a child with occult neuroblastoma and voltage-gated potassium channel antibodies.

    LENUS (Irish Health Repository)

    Allen, Nicholas M

    2012-05-01

    A previously healthy 9-year-old girl presented with a 10-day history of slowly progressive unsteadiness, slurred speech, and behavior change. On examination there was cerebellar ataxia and dysarthria, excessive blinking, subtle perioral myoclonus, and labile mood. The finding of oligoclonal bands in the cerebrospinal fluid prompted paraneoplastic serological evaluation and search for an occult neural crest tumor. Antineuronal nuclear autoantibody type 1 (anti-Hu) and voltage-gated potassium channel complex antibodies were detected in serum. Metaiodobenzylguanidine scan and computed tomography scan of the abdomen showed a localized abdominal mass in the region of the porta hepatis. A diagnosis of occult neuroblastoma was made. Resection of the stage 1 neuroblastoma and treatment with pulsed corticosteroids resulted in resolution of all symptoms and signs. Excessive blinking has rarely been described with neuroblastoma, and, when it is not an isolated finding, it may be a useful clue to this paraneoplastic syndrome. Although voltage-gated potassium channel complex autoimmunity has not been described previously in the setting of neuroblastoma, it is associated with a spectrum of paraneoplastic neurologic manifestations in adults, including peripheral nerve hyperexcitability disorders.

  16. Hybrid EEG—Eye Tracker: Automatic Identification and Removal of Eye Movement and Blink Artifacts from Electroencephalographic Signal

    Directory of Open Access Journals (Sweden)

    Malik M. Naeem Mannan

    2016-02-01

    Full Text Available 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.

  17. Word frequency and the attentional blink: the effects of target difficulty on retrieval and consolidation processes.

    Directory of Open Access Journals (Sweden)

    Stefan M Wierda

    Full Text Available BACKGROUND: When a second target (T2 is presented in close succession of a first target (T1 within a stream of non-targets, people often fail to detect T2-a deficit known as the attentional blink (AB. Two types of theories can be distinguished that have tried to account for this phenomenon. Whereas attentional-control theories suggest that protection of consolidation processes induces the AB, limited-resource theories claim that the AB is caused by a lack of resources. According to the latter type of theories, increasing difficulty of one or both targets should increase the magnitude of the AB. Similarly, attentional-control theories predict that a difficult T1 increases the AB due to prolonged processing. However, the prediction for T2 is not as straightforward. Prolonged processing of T2 could cause conflicts and increase the AB. However, if consolidation of T2 is postponed without loss of identity, the AB might be attenuated. METHODOLOGY/PRINCIPAL FINDINGS: Participants performed an AB task that consisted of a stream of distractor non-words and two target words. Difficulty of T1 and T2 was manipulated by varying word-frequency. Overall performance for high-frequency words was better than for low-frequency words. When T1 was highly frequent, the AB was reduced. The opposite effect was found for T2. When T2 was highly frequent, performance during the AB period was relatively worse than for a low-frequency T2. A threaded-cognition model of the AB was presented that simulated the observed pattern of behavior by taking changes in the time-course of retrieval and consolidation processes into account. Our results were replicated in a subsequent ERP study. CONCLUSIONS/SIGNIFICANCE: The finding that a difficult low-frequency T2 reduces the magnitude of the AB is at odds with limited-resource accounts of the AB. However, it was successfully accounted for by the threaded-cognition model, thus providing an explanation in terms of attentional control.

  18. Spontaneous Thigh Compartment Syndrome

    Directory of Open Access Journals (Sweden)

    Khan, Sameer K

    2011-02-01

    Full Text Available A young man presented with a painful and swollen thigh, without any history of trauma, illness, coagulopathic medication or recent exertional exercise. Preliminary imaging delineated a haematoma in the anterior thigh, without any fractures or muscle trauma. Emergent fasciotomies were performed. No pathology could be identified intra-operatively, or on follow-up imaging. A review of thigh compartment syndromes described in literature is presented in a table. Emergency physicians and traumatologists should be cognisant of spontaneous atraumatic presentations of thigh compartment syndrome, to ensure prompt referral and definitive management of this limb-threatening condition. [West J Emerg Med. 2011;12(1:134-138].

  19. Spontaneous sensorimotor coupling with multipart music.

    Science.gov (United States)

    Hurley, Brian K; Martens, Peter A; Janata, Petr

    2014-08-01

    Music often evokes spontaneous movements in listeners that are synchronized with the music, a phenomenon that has been characterized as being in "the groove." However, the musical factors that contribute to listeners' initiation of stimulus-coupled action remain unclear. Evidence suggests that newly appearing objects in auditory scenes orient listeners' attention, and that in multipart music, newly appearing instrument or voice parts can engage listeners' attention and elicit arousal. We posit that attentional engagement with music can influence listeners' spontaneous stimulus-coupled movement. Here, 2 experiments-involving participants with and without musical training-tested the effect of staggering instrument entrances across time and varying the number of concurrent instrument parts within novel multipart music on listeners' engagement with the music, as assessed by spontaneous sensorimotor behavior and self-reports. Experiment 1 assessed listeners' moment-to-moment ratings of perceived groove, and Experiment 2 examined their spontaneous tapping and head movements. We found that, for both musically trained and untrained participants, music with more instruments led to higher ratings of perceived groove, and that music with staggered instrument entrances elicited both increased sensorimotor coupling and increased reports of perceived groove. Although untrained participants were more likely to rate music as higher in groove, trained participants showed greater propensity for tapping along, and they did so more accurately. The quality of synchronization of head movements with the music, however, did not differ as a function of training. Our results shed new light on the relationship between complex musical scenes, attention, and spontaneous sensorimotor behavior.

  20. Acquisition of Sign Language by Autistic Children II: Spontaneity and Generalization Effects.

    Science.gov (United States)

    Carr, Edward G.; Kologinsky, Eileen

    1983-01-01

    Six autistic children were trained to use their sign repertoire to make spontaneous requests of adults. Training consisted of imitative prompting, fading, and differential reinforcement, with aspects of incidental teaching. Ss displayed increased rate and variety of spontaneous sign requests and generalization of spontaneity across different…

  1. Spontaneous Tumor Lysis Syndrome

    Directory of Open Access Journals (Sweden)

    Alicia C. Weeks MD

    2015-08-01

    Full Text Available Tumor lysis syndrome (TLS is a known complication of malignancy and its treatment. The incidence varies on malignancy type, but is most common with hematologic neoplasms during cytotoxic treatment. Spontaneous TLS is thought to be rare. This case study is of a 62-year-old female admitted with multisystem organ failure, with subsequent diagnosis of aggressive B cell lymphoma. On admission, laboratory abnormalities included renal failure, elevated uric acid (20.7 mg/dL, and 3+ amorphous urates on urinalysis. Oliguric renal failure persisted despite aggressive hydration and diuretic use, requiring initiation of hemodialysis prior to chemotherapy. Antihyperuricemic therapy and hemodialysis were used to resolve hyperuricemia. However, due to multisystem organ dysfunction syndrome with extremely poor prognosis, the patient ultimately expired in the setting of a terminal ventilator wean. Although our patient did not meet current TLS criteria, she required hemodialysis due to uric acid nephropathy, a complication of TLS. This poses the clinical question of whether adequate diagnostic criteria exist for spontaneous TLS and if the lack of currently accepted guidelines has resulted in the underestimation of its incidence. Allopurinol and rasburicase are commonly used for prevention and treatment of TLS. Although both drugs decrease uric acid levels, allopurinol mechanistically prevents formation of the substrate rasburicase acts to solubilize. These drugs were administered together in our patient, although no established guidelines recommend combined use. This raises the clinical question of whether combined therapy is truly beneficial or, conversely, detrimental to patient outcomes.

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

    Science.gov (United States)

    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…

  3. Dopamine and the management of attentional resources: genetic markers of striatal D2 dopamine predict individual differences in the attentional blink

    NARCIS (Netherlands)

    Colzato, L.S.; Slagter, H.A.; de Rover, M.; Hommel, B.

    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

  4. Individual differences in spontaneous analogical transfer.

    Science.gov (United States)

    Kubricht, James R; Lu, Hongjing; Holyoak, Keith J

    2017-05-01

    Research on analogical problem solving has shown that people often fail to spontaneously notice the relevance of a semantically remote source analog when solving a target problem, although they are able to form mappings and derive inferences when given a hint to recall the source. Relatively little work has investigated possible individual differences that predict spontaneous transfer, or how such differences may interact with interventions that facilitate transfer. In this study, fluid intelligence was measured for participants in an analogical problem-solving task, using an abridged version of the Raven's Progressive Matrices (RPM) test. In two experiments, we systematically compared the effect of augmenting verbal descriptions of the source with animations or static diagrams. Solution rates to Duncker's radiation problem were measured across varying source presentation conditions, and participants' understanding of the relevant source material was assessed. The pattern of transfer was best fit by a moderated mediation model: the positive impact of fluid intelligence on spontaneous transfer was mediated by its influence on source comprehension; however, this path was in turn modulated by provision of a supplemental animation via its influence on comprehension of the source. Animated source depictions were most beneficial in facilitating spontaneous transfer for those participants with low scores on the fluid intelligence measure.

  5. Spontaneous Intracranial Hypotension

    International Nuclear Information System (INIS)

    Joash, Dr.

    2015-01-01

    Epidemiology is not only rare but an important cause of new daily persistent headaches among young & middle age individuals. The Etiology & Pathogenesis is generally caused by spinal CSF leak. Precise cause remains largely unknown, underlying structural weakness of spinal meninges is suspected. There are several MR Signs of Intracranial Hypotension that include:- diffuse pachymeningeal (dural) enhancement; bilateral subdural, effusion/hematomas; Downward displacement of brain; enlargement of pituitary gland; Engorgement of dural venous sinuses; prominence of spinal epidural venous plexus and Venous sinus thrombosis & isolated cortical vein thrombosis. The sum of volumes of intracranial blood, CSF & cerebral tissue must remain constant in an intact cranium. Treatment in Many cases can be resolved spontaneously or by use Conservative approach that include bed rest, oral hydration, caffeine intake and use of abdominal binder. Imaging Modalities for Detection of CSF leakage include CT myelography, Radioisotope cisternography, MR myelography, MR imaging and Intrathecal Gd-enhanced MR

  6. Spontaneous wave packet reduction

    International Nuclear Information System (INIS)

    Ghirardi, G.C.

    1994-06-01

    There are taken into account the main conceptual difficulties met by standard quantum mechanics in dealing with physical processes involving macroscopic system. It is stressed how J.A.Wheeler's remarks and lucid analysis have been relevant to pinpoint and to bring to its extreme consequences the puzzling aspects of quantum phenomena. It is shown how the recently proposed models of spontaneous dynamical reduction represent a consistent way to overcome the conceptual difficulties of the standard theory. Obviously, many nontrivial problems remain open, the first and more relevant one being that of generalizing the model theories considered to the relativistic case. This is the challenge of the dynamical reduction program. 43 refs, 2 figs

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

    Science.gov (United States)

    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. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  8. Self energy QED: Multipole spontaneous emission

    International Nuclear Information System (INIS)

    Salamin, Y.I.

    1990-08-01

    Within the context of Barut's self-field approach, we write the exact expression of the spontaneous atomic decay rate (Phys. Rev. A37, 2284 (1988)), in the long wavelength approximation, in terms of electric- and magnetic-like multipole contributions which are related to the matrix elements of the transition charge and current distributions of the relativistic electron. A number of features of these expressions are discussed and their generalization to interacting composite systems is also pointed out. (author). 8 refs

  9. Simultaneous bilateral primary spontaneous pneumothorax

    Directory of Open Access Journals (Sweden)

    Arife Zeybek

    2014-04-01

    Full Text Available Simultaneous bilateral primary pneumothorax is a very rare (1.6 / 100,000 and life-threatening condition. Clinical presentation may vary from mild dyspnea to tension pneumothorax. It may be milder particularly in younger patients, but more severe in patients with advanced age, and tube thoracostomy is a life preserver in the latter group. Since mortality and recurrence rates following tube thoracostomy are high, endoscopic approaches to bilateral hemithorax have been reported in literature. Apical wedge resection and pleural procedures are recommended in video thoracoscopy or mini thoracotomy even if no bulla and/or bleb are detected. Bilateral surgical interventions and additional pleural procedures are associated with increased rate of post-operative complications and longer postoperative hospital-stays. As a first-line approach, the surgical method toward any side of lung with air leakage following a previous tube thoracostomy is considered less invasive, especially in younger patients. Here, we present a case of simultaneous bilateral primary spontaneous pneumothorax (SBPSP in a 21-year old male with no history of smoking and chronic pulmonary disease. A unilateral surgical intervention was performed, and no recurrence was observed during 5-year follow up.

  10. Spontaneous compactification to homogeneous spaces

    International Nuclear Information System (INIS)

    Mourao, J.M.

    1988-01-01

    The spontaneous compactification of extra dimensions to compact homogeneous spaces is studied. The methods developed within the framework of coset space dimensional reduction scheme and the most general form of invariant metrics are used to find solutions of spontaneous compactification equations

  11. Screening for spontaneous preterm birth

    NARCIS (Netherlands)

    van Os, M.A.; van Dam, A.J.E.M.

    2015-01-01

    Preterm birth is the most important cause of perinatal morbidity and mortality worldwide. In this thesis studies on spontaneous preterm birth are presented. The main objective was to investigate the predictive capacity of mid-trimester cervical length measurement for spontaneous preterm birth in a

  12. Spontaneous Pneumomediastinum: Hamman Syndrome

    Directory of Open Access Journals (Sweden)

    Tushank Chadha, BS

    2018-04-01

    significant fat stranding. The image also showed an intraluminal stent traversing the gastric antrum and gastric pylorus with no indication of obstruction. Circumferential mural thickening of the gastric antrum and body were consistent with the patient’s history of gastric adenocarcinoma. The shotty perigastric lymph nodes with associated fat stranding, along the greater curvature of the distal gastric body suggested local regional nodal metastases and possible peritoneal carcinomatosis. The thoracic CT scans showed extensive pneumomediastinum that tracked into the soft tissues of the neck, which given the history of vomiting also raised concern for esophageal perforation. There was still no evidence of mediastinal abscess or fat stranding. Additionally, a left subclavian vein port catheter, which terminates with tip at the cavoatrial junction of the superior vena cava can also be seen on the image. Discussion: Spontaneous Pneumomediastinum, also known as Hamman syndrome, is defined by the uncommon incidence of free air in the mediastinum due to the bursting of alveoli, as a result of extended spells of shouting, coughing, or vomiting.1,2 The condition is diagnosed when a clear cause (aerodigestive rupture, barotrauma, infection secondary to gas-forming organisms3 for pneumomediastinum cannot be clearly identified on diagnostic studies. Macklin and Macklin were the first to note the pathogenesis of the syndrome and explained that the common denominator to spontaneous pneumomediastinum was that increased alveolar pressure leads to alveolar rupture.3 Common clinical findings for spontaneous pneumomediastinum include: chest pain, dyspnea, cough, and emesis.4 The condition is not always readily recognized on initial presentation in part for its rare incidence, estimated to be approximately 1 in every 44,500 ED patients3and also because of the non-specific presenting symptoms. For this patient, there was no clear singular cause, and therefore she received care for spontaneous

  13. Clinical and laboratory features of spontaneous bacterial peritonitis ...

    African Journals Online (AJOL)

    Background: Spontaneous Bacterial Peritonitis (SBP) is a complication of cirrhosis. The mortality rate is approximately 30-50%. SBP is defined as an ascitic fluid infection in the absence of any obvious intraabdominal infectious foci. While earlier reports of SBP emphasized high mortality rates, recently lower mortality rates ...

  14. Teaching Spontaneous Responses to Young Children With Autism

    OpenAIRE

    Jones, Emily A; Feeley, Kathleen M; Takacs, Jennifer

    2007-01-01

    Using a multiple probe design across responses, we demonstrated the effectiveness of intensive intervention in establishing spontaneous verbal responses to 2 3-year-old children with autism with generalization to novel settings involving novel persons. Intervention involved discrete-trial instruction (i.e., repeated instructional opportunities presented in close proximity to high rates of reinforcement), specific prompts, and error correction. Spontaneous responses were defined as specific ve...

  15. Spontaneous breaking of supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Zumino, B.

    1981-12-01

    There has been recently a revival of interest in supersymmetric gauge theories, stimulated by the hope that supersymmetry might help in clarifying some of the questions which remain unanswered in the so called Grand Unified Theories and in particular the gauge hierarchy problem. In a Grand Unified Theory one has two widely different mass scales: the unification mass M approx. = 10/sup 15/GeV at which the unification group (e.g. SU(5)) breaks down to SU(3) x SU(2) x U(1) and the mass ..mu.. approx. = 100 GeV at which SU(2) x U(1) is broken down to the U(1) of electromagnetism. There is at present no theoretical understanding of the extreme smallness of the ratio ..mu../M of these two numbers. This is the gauge hierarchy problem. This lecture attempts to review the various mechanisms for spontaneous supersymmetry breaking in gauge theories. Most of the discussions are concerned with the tree approximation, but what is presently known about radiative correction is also reviewed.

  16. Spontaneous intracranial hypotension

    International Nuclear Information System (INIS)

    Haritanti, A.; Karacostas, D.; Drevelengas, A.; Kanellopoulos, V.; Paraskevopoulou, E.; Lefkopoulos, A.; Economou, I.; Dimitriadis, A.S.

    2009-01-01

    Spontaneous intracranial hypotension (SIH) is an uncommon but increasingly recognized syndrome. Orthostatic headache with typical findings on magnetic resonance imaging (MRI) are the key to diagnosis. Delayed diagnosis of this condition may subject patients to unnecessary procedures and prolong morbidity. We describe six patients with SIH and outline the important clinical and neuroimaging findings. They were all relatively young, 20-54 years old, with clearly orthostatic headache, minimal neurological signs (only abducent nerve paresis in two) and diffuse pachymeningeal gadolinium enhancement on brain MRI, while two of them presented subdural hygromas. Spinal MRI was helpful in detecting a cervical cerebrospinal fluid leak in three patients and dilatation of the vertebral venous plexus with extradural fluid collection in another. Conservative management resulted in rapid resolution of symptoms in five patients (10 days-3 weeks) and in one who developed cerebral venous sinus thrombosis, the condition resolved in 2 months. However, this rapid clinical improvement was not accompanied by an analogous regression of the brain MR findings that persisted on a longer follow-up. Along with recent literature data, our patients further point out that SIH, to be correctly diagnosed, necessitates increased alertness by the attending physician, in the evaluation of headaches

  17. Spontaneous lateral temporal encephalocele.

    Science.gov (United States)

    Tuncbilek, Gokhan; Calis, Mert; Akalan, Nejat

    2013-01-01

    A spontaneous encephalocele is one that develops either because of embryological maldevelopment or from a poorly understood postnatal process that permits brain herniation to occur. We here report a rare case of lateral temporal encephalocele extending to the infratemporal fossa under the zygomatic arch. At birth, the infant was noted to have a large cystic mass in the right side of the face. After being operated on initially in another center in the newborn period, the patient was referred to our clinic with a diagnosis of temporal encephalocele. He was 6 months old at the time of admission. Computerized tomography scan and magnetic resonance imaging studies revealed a 8 × 9 cm fluid-filled, multiloculated cystic mass at the right infratemporal fossa. No intracranial pathology or connection is seen. The patient was operated on to reduce the distortion effect of the growing mass. The histopathological examination of the sac revealed well-differentiated mature glial tissue stained with glial fibrillary acid protein. This rare clinical presentation of encephaloceles should be taken into consideration during the evaluation of the lateral facial masses in the infancy period, and possible intracranial connection should be ruled out before surgery to avoid complications.

  18. On the interplay between working memory consolidation and attentional selection in controlling conscious access : Parallel processing at a cost-a comment on 'The interplay of attention and consciousness in visual search, attentional blink and working memory consolidation'

    NARCIS (Netherlands)

    Wyble, Brad; Bowman, Howard; Nieuwenstein, Mark

    On the interplay between working memory consolidation and attentional selection in controlling conscious access: parallel processing at a cost-a comment on 'The interplay of attention and consciousness in visual search, attentional blink and working memory consolidation'

  19. Spontaneous light emission from fibers in MINOS

    International Nuclear Information System (INIS)

    Avvakumov, S.; Barrett, W.L.; Belias, T.; Bower, C.; Erwin, A.; Kordosky, M.; Lang, K.; Lee, R.; Liu, J.; Miller, W.; Mualem, L.; Nichol, R.; Nelson, J.; Pearce, G.; Proga, M.; Rebel, B.; Ruddick, K.; Smith, C.; Thomas, J.; Vahle, P.; Webb, R.

    2005-01-01

    We report on the observation and measurements of unexpected background rates in the MINOS Far Detector. The noise level at the Far Detector is significantly greater than that expected from natural radioactivity and intrinsic photomultiplier dark current. We have conducted a series of additional tests which demonstrate that the excess rate is caused by spontaneous light emission in the wavelength-shifting fibers, which are used to read out signals from scintillator strips. This noise due to fibers exhibits an exponential fall off with time with a decay time constant of the order of 100 days

  20. Bilateral spontaneous carotid artery dissection.

    Science.gov (United States)

    Townend, Bradley Scott; Traves, Laura; Crimmins, Denis

    2005-06-01

    Bilateral internal carotid artery dissections have been reported, but spontaneous bilateral dissections are rare. Internal carotid artery dissection can present with a spectrum of symptoms ranging from headache to completed stroke. Two cases of spontaneous bilateral carotid artery dissection are presented, one with headache and minimal symptoms and the other with a stroke syndrome. No cause could be found in either case, making the dissections completely spontaneous. Bilateral internal carotid artery dissection (ICAD) should be considered in young patients with unexplained head and neck pain with or without focal neurological symptoms and signs. The increasing availability of imaging would sustain the higher index of suspicion.

  1. Corticomuscular Coherence Is Tuned to the Spontaneous Rhythmicity of Speech at 2-3 Hz

    OpenAIRE

    Ruspantini, I.; Saarinen, T.; Belardinelli, P.; Jalava, A.; Parviainen, T.; Kujala, J.; Salmelin, Riitta

    2012-01-01

    Human speech features rhythmicity that frames distinctive, fine-grained speech patterns. Speech can thus be counted among rhythmic motor behaviors that generally manifest characteristic spontaneous rates. However, the critical neural evidence for tuning of articulatory control to a spontaneous rate of speech has not been uncovered. The present study examined the spontaneous rhythmicity in speech production and its relationship to cortex–muscle neurocommunication, which is essential for speech...

  2. Spontaneous intraorbital hematoma: case report

    Directory of Open Access Journals (Sweden)

    Vinodan Paramanathan

    2010-12-01

    Full Text Available Vinodan Paramanathan, Ardalan ZolnourianQueen's Hospital NHS Foundation Trust, Burton on Trent, Staffordshire DE13 0RB, UKAbstract: Spontaneous intraorbital hematoma is an uncommon clinical entity seen in ophthalmology practice. It is poorly represented in the literature. Current evidence attributes it to orbital trauma, neoplasm, vascular malformations, acute sinusitis, and systemic abnormalities. A 65-year-old female presented with spontaneous intraorbital hematoma manifesting as severe ocular pains, eyelid edema, proptosis, and diplopia, without a history of trauma. Computer tomography demonstrated a fairly well defined extraconal lesion with opacification of the paranasal sinuses. The principal differential based on all findings was that of a spreading sinus infection and an extraconal tumor. An unprecedented finding of a spontaneous orbital hematoma was discovered when the patient was taken to theater. We discuss the rarity of this condition and its management.Keywords: hemorrhage, ophthalmology, spontaneous, intra-orbital, hematoma

  3. Spontaneous ischaemic stroke in dogs

    DEFF Research Database (Denmark)

    Gredal, Hanne Birgit; Skerritt, G. C.; Gideon, P.

    2013-01-01

    Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms.......Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms....

  4. Spontaneity and international marketing performance

    OpenAIRE

    Souchon, Anne L.; Hughes, Paul; Farrell, Andrew M.; Nemkova, Ekaterina; Oliveira, Joao S.

    2016-01-01

    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Purpose – The purpose of this paper is to ascertain how today’s international marketers can perform better on the global scene by harnessing spontaneity. Design/methodology/approach – The authors draw on contingency theory to develop a model of the spontaneity – international marketing performance relationship, and identify three potential m...

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

    Science.gov (United States)

    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

  6. Observation time and spontaneous resolution of primary phimosis in children

    Directory of Open Access Journals (Sweden)

    Pedro Luiz Toledo de Arruda Lourenção

    Full Text Available ABSTRACT Objective: to investigate spontaneous resolution rate of a series of patients with physiologic phimosis in relation to observation time and presence of symptoms. Methods: retrospective and longitudinal follow-up study of patients with physiologic phimosis, that did not apply topic treatment. These patients were invited for a new visit for reevaluation, or recent data were obtained by chart analysis. Spontaneous resolution rate was determined and statistically compared to age, presence of symptoms at first medical visit and time until reevaluation. Results: seventy one patients were included. Medium time of observation from first visit to reevaluation was 37.4 months. There was spontaneous resolution of phimosis in 32 (45% patients. Children with spontaneous resolution were younger at initial diagnosis and were observed during a longer period of time. Most asymptomatic patients at first visit presented spontaneous resolution. However, it was not possible to stablish a significant relationship between presence of symptoms and evolution of physiologic phimosis. Conclusions: time of observation was the main determinant of spontaneous resolution of patients with physiologic phimosis, reinforcing the current more conservative approach regarding circumcision of those patients.

  7. Verbascoside is not genotoxic in the ST and HB crosses of the Drosophila wing spot test, and its constituent, caffeic acid, decreases the spontaneous mutation rate in the ST cross.

    Science.gov (United States)

    Santos-Cruz, Luis Felipe; Ávila-Acevedo, José Guillermo; Ortega-Capitaine, Diego; Ojeda-Duplancher, Jesús Clemente; Perdigón-Moya, Juana Laura; Hernández-Portilla, Luis Barbo; López-Dionicio, Héctor; Durán-Díaz, Angel; Dueñas-García, Irma Elena; Castañeda-Partida, Laura; García-Bores, Ana María; Heres-Pulido, María Eugenia

    2012-03-01

    Verbascoside (VB) is a phenylpropanoid isolated from Buddleja species, some of which originate in Mexico, and was first described in the sixteenth century in the codices of Mexican traditional medicine. VB is present in alcohol extracts and is widely used in the north of Mexico as a sunscreen. VB absorbs UV-A and UV-B radiation and has high antioxidant and anti-inflammatory capacities. VB and its constituent caffeic acid (CA) were screened to determine their genotoxic activity using the Drosophila wing spot test. Third instar larvae (72±4 h) of the standard (ST) and high bioactivation (HB) crosses, with regulated and high levels of cytochrome P450s (Cyp450s), respectively, were exposed to VB or CA (0, 27, 57, 81, 135, and 173 mM). VB was not genotoxic at any of the concentrations tested in both crosses. The amount of VB residue as determined by HPLC in the adult flies that were fed with VB indicated a low metabolism of this compound, which explains the absence of genotoxicity. CA decreased the spontaneous frequencies of small and total spots and showed putative toxicity in the ST cross. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Spontaneous unscheduled DNA synthesis in human lymphocytes

    International Nuclear Information System (INIS)

    Forell, B.; Myers, L.S. Jr.; Norman, A.

    1979-01-01

    The rate of spontaneous unscheduled DNA synthesis in human lymphocytes was estimated from measurements of tritiated thymidine incorporation into double-stranded DNA (ds-DNA) during incubation of cells in vitro. The contribution of scheduled DNA synthesis to the observed incorporation was reduced by inhibiting replication with hydroxyurea and by separating freshly replicated single-stranded DNA (ss-DNA) from repaired ds-DNA by column chromatography. The residual contribution of scheduled DNA synthesis was estimated by observing effects on thymidine incorporation of: (a) increasing the rate of production of apurinic sites, and alternatively, (b) increasing the number of cells in S-phase. Corrections based on estimates of endogenous pool size were also made. The rate of spontaneous unscheduled DNA synthesis is estimated to be 490 +- 120 thymidine molecules incorporated per cell per hour. These results compare favorably with estimates made from rates of depurination and depyrimidination of DNA, measured in molecular systems if we assume thymidine is incorporated by a short patch mechanism which incorporates an average of four bases per lesion

  9. A case of spontaneous ventriculocisternostomy

    International Nuclear Information System (INIS)

    Yamane, Kanji; Yoshimoto, Hisanori; Harada, Kiyoshi; Uozumi, Tohru; Kuwabara, Satoshi.

    1983-01-01

    The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300mmH 2 O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy. (J.P.N.)

  10. Progesterone to prevent spontaneous preterm birth

    Science.gov (United States)

    Romero, Roberto; Yeo, Lami; Chaemsaithong, Piya; Chaiworapongsa, Tinnakorn; Hassan, Sonia

    2014-01-01

    Summary Preterm birth is the leading cause of perinatal morbidity and mortality worldwide, and its prevention is an important healthcare priority. Preterm parturition is one of the ‘great obstetrical syndromes’ and is caused by multiple etiologies. One of the mechanisms of disease is the untimely decline in progesterone action, which can be manifested by a sonographic short cervix in the midtrimester. The detection of a short cervix in the midtrimester is a powerful risk factor for preterm delivery. Vaginal progesterone can reduce the rate of preterm delivery by 45%, and the rate of neonatal morbidity (admission to neonatal intensive care unit, respiratory distress syndrome, need for mechanical ventilation, etc.). To prevent one case of spontaneous preterm birth birth in women with a short cervix both with and without a prior history of preterm birth. In patients with a prior history of preterm birth, vaginal progesterone is as effective as cervical cerclage to prevent preterm delivery. 17α-Hydroxyprogesterone caproate has not been shown to be effective in reducing the rate of spontaneous preterm birth in women with a short cervix. PMID:24315687

  11. Body Mass Index and spontaneous miscarriage.

    LENUS (Irish Health Repository)

    Turner, Michael J

    2012-02-01

    OBJECTIVE: We compared the incidence of spontaneous miscarriage in women categorised as obese, based on a Body Mass Index (BMI) >29.9 kg\\/m(2), with women in other BMI categories. STUDY DESIGN: In a prospective observational study conducted in a university teaching hospital, women were enrolled at their convenience in the first trimester after a sonogram confirmed an ongoing singleton pregnancy with fetal heart activity present. Maternal height and weight were measured digitally and BMI calculated. Maternal body composition was measured by advanced bioelectrical impedance analysis. RESULTS: In 1200 women, the overall miscarriage rate was 2.8% (n=33). The mean gestational age at enrolment was 9.9 weeks. In the obese category (n=217), the miscarriage rate was 2.3% compared with 3.3% in the overweight category (n=329), and 2.3% in the normal BMI group (n=621). There was no difference in the mean body composition parameters, particularly fat mass parameters, between those women who miscarried and those who did not. CONCLUSIONS: In women with sonographic evidence of fetal heart activity in the first trimester, the rate of spontaneous miscarriage is low and is not increased in women with BMI>29.9 kg\\/m(2) compared to women in the normal BMI category.

  12. Spontaneous Pregnancy Loss in Denmark Following Economic Downturns

    DEFF Research Database (Denmark)

    Bruckner, Tim A.; Mortensen, Laust H.; Catalano, Ralph A.

    2016-01-01

    ,449) and the unemployment rate in Denmark beginning in January 1995 and ending in December 2009. Our statistical methods controlled for temporal patterns in spontaneous abortion (e.g., seasonality, trend) and changes in the population of pregnancies at risk of loss. Unexpected increases in the unemployment rate preceded...... in elective abortions and in the cohort composition of high-risk pregnancies did not account for results. It appears that in Denmark, ambient stressors as common as increasing unemployment may precede a population-level increase in spontaneous abortion....

  13. Spontaneous emission near non-trivial conducting surfaces

    International Nuclear Information System (INIS)

    Melo e Souza, Reinaldo de; Kort-Kamp, W.J.M.; Taddei, M.M.; Farina, C.

    2013-01-01

    Full text: One of the remarkable phenomena associated with the zero-point fluctuations of the electromagnetic field is the spontaneous emission, which accounts for the emission of photons by an excited atom placed in vacuum. As discovered by Purcell in the 1940's, the spontaneous emission rate depends not only on the atomic properties but also on the nearby bodies. This should be expected once the electromagnetic field modes are affected by the boundary conditions imposed by these bodies. We begin our presentation reviewing a method which establishes a striking connection between the spontaneous emission of an excited atom and the classical radiation emitted by an oscillating real dipole. In fact, it can be shown, the influence of the neighbouring bodies is the same in both cases. We use this approach to evaluate the influence of an infinite conducting plane with a circular aperture on the spontaneous emission rate of the atom. This geometry will be particularly interesting if the atom is placed on the axis of symmetry of the hole and if it is predominantly polarizable in this axis, once this configuration is one of the those rare configurations that give rise to repulsive dispersive interactions. It would be very interesting to establish some connection between how the spontaneous emission rate of an excited atom is influenced by the presence of material bodies and the attractive or repulsive character of the dispersive force between that atom (in its ground state) and those material bodies. (author)

  14. Spontaneous subcapsular and perirrenal hemorrhage

    International Nuclear Information System (INIS)

    Fuster, M.J.; Saez, J.; Perez-Paya, F.J.; Fernandez, F.

    1997-01-01

    To assess the role of CT in the etiologic diagnosis of spontaneous subcapsular and perirrenal hemorrhage. The CT findings are described in 13 patients presenting subcapsular and perirrenal hemorrhage. Those patients in whom the bleeding was not spontaneous were excluded. Surgical confirmation was obtained in nine cases. In 11 of the 13 cases (84.6%), involving five adenocarcinomas, five angiomyolipoma, two complicated cysts and one case of panarterities nodosa, CT disclosed the underlying pathology. In two cases (15.4%), it only revealed the extension of the hematoma, but gave no clue to its origin. CT is the technique of choice when spontaneous subcapsular and perirrenal hemorrhage is suspected since, in most cases, it reveals the underlying pathology. (Author)

  15. Spontaneous Coronary Artery Dissection Associated With Pregnancy.

    Science.gov (United States)

    Tweet, Marysia S; Hayes, Sharonne N; Codsi, Elisabeth; Gulati, Rajiv; Rose, Carl H; Best, Patricia J M

    2017-07-25

    Spontaneous coronary artery dissection (SCAD) is the most common cause of pregnancy-associated myocardial infarction and remains poorly characterized. This study sought to assess presentation, clinical factors, and outcomes of pregnancy-associated spontaneous coronary artery dissection (P-SCAD) compared with spontaneous coronary artery dissection not associated with pregnancy (NP-SCAD). A Mayo Clinic registry was established in 2010 to include comprehensive retrospective and prospective SCAD data. Records were reviewed to identify women who were pregnant or ≤12 weeks postpartum at time of SCAD. Complete records were available for 323 women; 54 women met criteria for P-SCAD (4 during pregnancy) and they were compared with 269 women with NP-SCAD. Most events occurred within the first month postpartum (35 of 50). Compared with NP-SCAD, P-SCAD patients more frequently presented with ST-segment elevation myocardial infarction (57% vs. 36%; p = 0.009), left main or multivessel SCAD (24% vs. 5%; p vs. 14%; p = 0.0027, respectively), and left ventricular function ≤35% (26% vs. 10%; p = 0.0071). Among women with imaging of other vascular territories, P-SCAD was less likely with a diagnosis of fibromuscular dysplasia and extracoronary vascular abnormalities (42% vs. 64%; p = 0.047; and 46% vs. 77%; p = 0.0032, respectively). Compared with U.S. birth data, women with P-SCAD were more often multiparous (p = 0.0167), had a history of infertility therapies (p = 0.0004), and had pre-eclampsia (p = 0.001). On long-term follow-up (median 2.3 years) recurrent SCAD occurred in 51 patients, with no difference in the Kaplan Meier 5-year recurrence rates (10% vs. 23%; p = 0.18). P-SCAD patients had more acute presentations and high-risk features than women with NP-SCAD did. The highest frequency of P-SCAD occurred during the first postpartum month and P-SCAD patients less often had extracoronary vascular abnormalities. Hormonal, hemodynamic variations, and yet

  16. Spontaneous isolated celiac artery dissection

    Directory of Open Access Journals (Sweden)

    Tuba Cimilli Ozturk

    2011-01-01

    Full Text Available Dyspepsia with mild, stabbing epigastric discomfort without history of trauma is a very common symptom that emergency physicians see in their daily practice. Vascular emergencies, mostly the aortic dissection and aneurysm, are always described in the differential diagnosis with persistent symptoms. Isolated celiac artery dissection occurring spontaneously is a very rare diagnosis. The involvement of branch vessels is generally observed and patients show various clinical signs and symptoms according to the involved branch vessel. Here we are presenting a case with spontaneous isolated celiac artery dissection, without any branch vessel involvement or visceral damage, detected by computed tomography scans taken on admission.

  17. Spontaneous waves in muscle fibres

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Stefan; Kruse, Karsten [Department of Theoretical Physics, Saarland University, 66041 Saarbruecken (Germany); Max Planck Institute for the Physics of Complex Systems, Noethnitzer Street 38, 01187 Dresden (Germany)

    2007-11-15

    Mechanical oscillations are important for many cellular processes, e.g. the beating of cilia and flagella or the sensation of sound by hair cells. These dynamic states originate from spontaneous oscillations of molecular motors. A particularly clear example of such oscillations has been observed in muscle fibers under non-physiological conditions. In that case, motor oscillations lead to contraction waves along the fiber. By a macroscopic analysis of muscle fiber dynamics we find that the spontaneous waves involve non-hydrodynamic modes. A simple microscopic model of sarcomere dynamics highlights mechanical aspects of the motor dynamics and fits with the experimental observations.

  18. Spontaneous abortion: a prospective cohort study of younger women from the general population in Denmark. Validation, occurrence and risk determinants.

    Science.gov (United States)

    Buss, L; Tolstrup, J; Munk, C; Bergholt, T; Ottesen, B; Grønbaek, M; Kjaer, S K

    2006-01-01

    To assess the occurrence of spontaneous abortion, comparing two different data sources. To estimate the rate of spontaneous abortion over a 2-year period, and examine potential predictors of the risk for incident spontaneous abortion. We used interview data from a population-based prospective cohort study comprising 11,088 women and data from a linkage of the cohort with the Hospital Discharge Register to compare spontaneous abortions as reported in the interview with those identified in the register. Based on interview data, we estimated the rate of spontaneous abortion during the two-year follow-up. Finally, risk determinants for incident spontaneous abortion were analyzed by means of logistic regression. A total of 654 spontaneous abortions before enrolment in the study were reported by the women compared to 531 abortions found in the register. More than 80% of the spontaneous abortions identified from both sources were recorded in the same year. During follow-up a total of 20.9% of pregnancies intended to be carried to term ended as a spontaneous abortion. In the risk factor analysis, we found that previous spontaneous abortion, being single, never having used oral contraceptives, and use of intrauterine device were associated with increased risk of subsequent spontaneous abortion. In addition, it was indicated that a short interpregnancy interval following a spontaneous abortion may confer an increased risk of abortion in the subsequent pregnancy. We found a high rate of spontaneous abortion in the present study and an acceptable agreement between information obtained by interview and register information. More than 25% of the spontaneous abortions were only reported by the women, and this could not be explained by erroneously reported induced abortions, and may be early, nonhospitalized abortions. We confirm that number of previous spontaneous abortions is a strong determinant, and our data may also indicate a role of previous contraceptive habits. A role of

  19. Human Papillomavirus Infection as a Possible Cause of Spontaneous Abortion and Spontaneous Preterm Delivery

    DEFF Research Database (Denmark)

    Ambühl, Lea Maria Margareta; Baandrup, Ulrik; Dybkær, Karen

    2016-01-01

    , and 10.9% (95% CI; 10.1–11.7) for umbilical cord blood. Summary estimates for HPV prevalence of spontaneous abortions and spontaneous preterm deliveries, in cervix (spontaneous abortions: 24.5%, and pretermdeliveries: 47%, resp.) and placenta (spontaneous abortions: 24.9%, and preterm deliveries: 50......%, resp.), were identified to be higher compared to normal full-term pregnancies (푃 spontaneous abortion, spontaneous preterm...

  20. Spontaneous Development of Moral Concepts

    Science.gov (United States)

    Siegal, M.

    1975-01-01

    Moral competence is more difficult to attain than scientific competence. Since language comprehension plays a central role in conceptual development, and moral language is difficult to learn, there is a common deficiency in moral conceptual development. This suggests a theory of non-spontaneous solutions to moral problems. (Author/MS)

  1. Shell theorem for spontaneous emission

    DEFF Research Database (Denmark)

    Kristensen, Philip Trøst; Mortensen, Jakob Egeberg; Lodahl, Peter

    2013-01-01

    and therefore is given exactly by the dipole approximation theory. This surprising result is a spontaneous emission counterpart to the shell theorems of classical mechanics and electrostatics and provides insights into the physics of mesoscopic emitters as well as great simplifications in practical calculations....

  2. Prediction of Spontaneous Preterm Birth

    NARCIS (Netherlands)

    Dijkstra, Karolien

    2002-01-01

    Preterm birth is a leading cause of neonatal morbidity and mortality. It is a major goal in obstetrics to lower the incidence of spontaneous preterm birth (SPB) and related neonatal morbidity and mortality. One of the principal objectives is to discover early markers that would allow us to identify

  3. EAMJ Dec. Spontaneous.indd

    African Journals Online (AJOL)

    2008-12-12

    Dec 12, 2008 ... surgical abortion at one month gestation without any complication. The second pregnancy which was a year prior resulted in a spontaneous miscarriage at two months followed by evacuation of retained products of conception with no post abortion complications. Antibiotics were taken following both.

  4. Spontaneous fission of superheavy nuclei

    Indian Academy of Sciences (India)

    the Yukawa-plus-exponential potential. The microscopic shell and pairing corrections are obtained using the Strutinsky and BCS approaches and the cranking formulae yield the inertia tensor. Finally, the WKB method is used to calculate penetrabilities and spontaneous fission half-lives. Calculations are performed for the ...

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

    NARCIS (Netherlands)

    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

  6. A propulsion injury following a spontaneous electronic cigarette explosion

    Directory of Open Access Journals (Sweden)

    Cherrie Chan Yiru

    2017-05-01

    Full Text Available Electronic cigarettes (e-cigarettes have become increasingly popular at an alarming rate. This coincides with the public perception that they are a safer mean of nicotine consumption. Unregulated devices carry unrecognized safety risks that have led to numerous cases of burns, associating with spontaneous combustions of e-cigarettes.

  7. Spontaneous emission of quantum dots in disordered photonic crystal waveguides

    DEFF Research Database (Denmark)

    Sapienza, Luca; Nielsen, Henri Thyrrestrup; Stobbe, Søren

    2010-01-01

    We report on the enhancement of the spontaneous emission rate of single semiconductor quantum dots embedded in a photonic crystal waveguide with engineered disorder. Random high-Q cavities, that are signature of Anderson localization, are measured in photoluminescence experiments and appear in th...

  8. Spontaneous Emission Enhancement at Finite-length Metal

    DEFF Research Database (Denmark)

    Filonenko, K.; Willatzen, Morten; Bordo, V.

    2013-01-01

    We study spontaneous emission enhancement of a two-level atomic emitter placed in a dielectric medium near a finite-length cylindrical metal nanowire. We calculate the dependence of the Purcell factor and the normalized decay rate to a continuous spectrum on the nanowire radius for several emitter...

  9. Spontaneous Retropharyngeal Emphysema: A Case Report | Chi ...

    African Journals Online (AJOL)

    ... is a rare clinical condition in pediatric otolaryngology. The predominant symptoms are sore throat, odynophagia, dysphagia, and neck pain. Here, we report a case of spontaneous retropharyngeal emphysema. Keywords: Iatrogenic injury, retropharyngeal emphysema, spontaneous retropharyngeal emphysem, trauma ...

  10. La maladie de Grisel : Spontaneous atlantoaxial subluxation

    NARCIS (Netherlands)

    Meek, MF; Robinson, PH; Hermens, RAEC

    Objective: "La maladie de Grisel" (Grisel's syndrome) is a spontaneously occurring atlantoaxial subluxation with torticollis. We present a case of atlantoaxial subluxation occurring in a 20-year period of pharyngoplasty surgery. The occurrence of a "spontaneous" atlantoaxial subluxation after oral

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

    Science.gov (United States)

    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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. The lid wiper contains goblet cells and goblet cell crypts for ocular surface lubrication during the blink.

    Science.gov (United States)

    Knop, Nadja; Korb, Donald R; Blackie, Caroline A; Knop, Erich

    2012-06-01

    The conjunctival side of the upper and lower inner eyelid borders, termed the lid wiper, has a thickened epithelial lip for apposition to the globe, assumed to distribute the preocular tear film. The human lid wiper structure and its goblet cells are investigated. Conjunctival whole mounts, including lid margins from 17 eyes of human body donors, were investigated by routine histology and semithin plastic sections, using histology, histochemistry, and immunohistochemistry. In routine histology, the conjunctival lid wiper epithelium regularly showed goblet cells, single and in clusters, at the luminal surface and also deep within the epithelium without apparent surface contact. Semithin sections revealed that the deep goblet cells were often connected to cryptal epithelial infoldings that opened to the surface, hence making their mucins available at the surface. The goblet cells produced mucins of neutral (periodic acid-Schiff) and acidic (Alcian blue) type and stained positive for the gel-forming mucin MUC5AC. Surprisingly, MUC5AC-negative goblet cells were also observed in the lid wiper. Contrary to conventional assumptions, the lid wiper is part of the conjunctiva. It contains previously undescribed goblet cell crypts deep in the epithelium, suitable as an internal lubrication system for reduction of friction between the lid margin and the globe. This provides the first evidence of the morphological basis for the hydrodynamic type of lubrication and a more conclusive understanding of lid-margin lubrication and tear film distribution. It is another strong indication that the lid wiper is that area in apposition with the globe for distributing the thin preocular tear film during the blink.

  13. Controlling the spontaneous emission of a superconducting transmon qubit.

    Science.gov (United States)

    Houck, A A; Schreier, J A; Johnson, B R; Chow, J M; Koch, Jens; Gambetta, J M; Schuster, D I; Frunzio, L; Devoret, M H; Girvin, S M; Schoelkopf, R J

    2008-08-22

    We present a detailed characterization of coherence in seven transmon qubits in a circuit QED architecture. We find that spontaneous emission rates are strongly influenced by far off-resonant modes of the cavity and can be understood within a semiclassical circuit model. A careful analysis of the spontaneous qubit decay into a microwave transmission-line cavity can accurately predict the qubit lifetimes over 2 orders of magnitude in time and more than an octave in frequency. Coherence times T1 and T_{2};{*} of more than a microsecond are reproducibly demonstrated.

  14. Systematics of spontaneous positron lines

    International Nuclear Information System (INIS)

    Mueller, U.; Reus, T. de; Reinhardt, J.; Mueller, B.; Greiner, W.

    1985-08-01

    Dynamical and spontaneous positron emission are investigated for heavy-ion collisions with long time delay using a semiclassical description. Numerical results and analytical expressions for the characteristic quantities of the resulting spontaneous positron line, i.e., its position, width, and cross section, are compared. The expected behaviour of the line position and cross section and its visibility against the spectrum of dynamically created positrons is discussed in dependence of the united charge Zsub(u) of projectile and target nucleus in a range of systems from Zsub(u)=180 up to Zsub(u)=188. The results are confronted with presently available experimental data, and possible implications on further experiments are worked out. (orig.)

  15. Spontaneous Rotational Inversion in Phycomyces

    KAUST Repository

    Goriely, Alain

    2011-03-01

    The filamentary fungus Phycomyces blakesleeanus undergoes a series of remarkable transitions during aerial growth. During what is known as the stagea IV growth phase, the fungus extends while rotating in a counterclockwise manner when viewed from above (stagea IVa) and then, while continuing to grow, spontaneously reverses to a clockwise rotation (stagea IVb). This phase lasts for 24-48Ah and is sometimes followed by yet another reversal (stageAIVc) before the overall growth ends. Here, we propose a continuum mechanical model of this entire process using nonlinear, anisotropic, elasticity and show how helical anisotropy associated with the cell wall structure can induce spontaneous rotation and, under appropriate circumstances, the observed reversal of rotational handedness. © 2011 American Physical Society.

  16. Spontaneous regression of colon cancer.

    Science.gov (United States)

    Kihara, Kyoichi; Fujita, Shin; Ohshiro, Taihei; Yamamoto, Seiichiro; Sekine, Shigeki

    2015-01-01

    A case of spontaneous regression of transverse colon cancer is reported. A 64-year-old man was diagnosed as having cancer of the transverse colon at a local hospital. Initial and second colonoscopy examinations revealed a typical cancer of the transverse colon, which was diagnosed as moderately differentiated adenocarcinoma. The patient underwent right hemicolectomy 6 weeks after the initial colonoscopy. The resected specimen showed only a scar at the tumor site, and no cancerous tissue was proven histologically. The patient is alive with no evidence of recurrence 1 year after surgery. Although an antitumor immune response is the most likely explanation, the exact nature of the phenomenon was unclear. We describe this rare case and review the literature pertaining to spontaneous regression of colorectal cancer. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Spontaneous baryogenesis in warm inflation

    OpenAIRE

    Brandenberger, Robert H.; Yamaguchi, Masahide

    2003-01-01

    We discuss spontaneous baryogenesis in the warm inflation scenario. In contrast with standard inflation models, radiation always exists in the warm inflation scenario, and the inflaton must be directly coupled to it. Also, the transition to the post-inflationary radiation dominated phase is smooth and the entropy is not significantly increased at the end of the period of inflation. In addition, after the period of warm inflation ends, the inflaton does not oscillate coherently but slowly roll...

  18. Spontaneous Splenic Rupture in Melanoma

    Directory of Open Access Journals (Sweden)

    Hadi Mirfazaelian

    2014-01-01

    Full Text Available Spontaneous rupture of spleen due to malignant melanoma is a rare situation, with only a few case reports in the literature. This study reports a previously healthy, 30-year-old man who came with chief complaint of acute abdominal pain to emergency room. On physical examination, abdominal tenderness and guarding were detected to be coincident with hypotension. Ultrasonography revealed mild splenomegaly with moderate free fluid in abdominopelvic cavity. Considering acute abdominal pain and hemodynamic instability, he underwent splenectomy with splenic rupture as the source of bleeding. Histologic examination showed diffuse infiltration by tumor. Immunohistochemical study (positive for S100, HMB45, and vimentin and negative for CK, CD10, CK20, CK7, CD30, LCA, EMA, and chromogranin confirmed metastatic malignant melanoma. On further questioning, there was a past history of a nasal dark skin lesion which was removed two years ago with no pathologic examination. Spontaneous (nontraumatic rupture of spleen is an uncommon situation and it happens very rarely due to neoplastic metastasis. Metastasis of malignant melanoma is one of the rare causes of the spontaneous rupture of spleen.

  19. Ulcerogenicity of piroxicam: an analysis of spontaneously reported data.

    Science.gov (United States)

    Rossi, A C; Hsu, J P; Faich, G A

    1987-01-01

    Previous reports have suggested that piroxicam may be more ulcerogenic than other non-steroidal anti-inflammatory drugs (NSAIDs) in use. Critics have attributed this putative relation to flawed comparisons of spontaneously reported data. In this study cases of upper gastrointestinal bleeding, perforation, and ulcer reported to the Food and Drug Administration's spontaneous reporting system over 12 years were examined. Reporting rates for eight NSAIDs were compared over identical periods of their marketing life cycles. After adjustments were made for the heterogeneity in the underlying reporting rates the difference in rates between piroxicam and the other drugs was considerably reduced but piroxicam retained its top ranking among the drugs; however, large and clinically important differences in the frequency of cases of upper gastrointestinal bleeding, perforation, and ulcer between piroxicam and the rest of the NSAIDs compared probably do not exist. PMID:3109543

  20. General features of spontaneous baryogenesis

    Science.gov (United States)

    Arbuzova, Elena

    2017-04-01

    The classical version of spontaneous baryogenesis is studied in details. It is shown that the relation between the time derivative of the (pseudo)goldstone field and the baryonic chemical potential essentially depends upon the representation chosen for the fermionic fields with non-zero baryonic number (quarks). The kinetic equation, used for the calculations of the cosmological baryon asymmetry, is generalized to the case of non-stationary background. The effects of the finite interval of the integration over time are also included into consideration.

  1. Spontaneous osteonecrosis of the knee

    Energy Technology Data Exchange (ETDEWEB)

    Kattapuram, Taj M. [Department of Radiology, Massachusetts General Hospital (United States); Kattapuram, Susan V. [Department of Radiology, Massachusetts General Hospital (United States)], E-mail: skattapuram@partners.org

    2008-07-15

    Spontaneous osteonecrosis of the knee presents with acute onset of severe, pain in elderly patients, usually female and usually without a history of trauma. Originally described as idiopathic osteonecrosis, the exact etiology is still debated. Evidence suggests that an acute fracture occurs as a result of chronic stress or minor trauma to a weakened subchondral bone plate. The imaging characteristics on MR reflect the age of the lesion and the symptoms. More appropriate terminology may be ' subchondral insufficiency fracture of the knee' or 'focal subchondral osteonecrosis'.

  2. Spontaneous usage of different shortcuts based on the commutativity principle.

    Directory of Open Access Journals (Sweden)

    Robert Gaschler

    Full Text Available Based on research on expertise a person can be said to possess integrated conceptual knowledge when she/he is able to spontaneously identify task relevant information in order to solve a problem efficiently. Despite the lack of instruction or explicit cueing, the person should be able to recognize which shortcut strategy can be applied--even when the task context differs from the one in which procedural knowledge about the shortcut was originally acquired. For mental arithmetic, first signs of such adaptive flexibility should develop already in primary school. The current study introduces a paper-and-pencil-based as well as an eyetracking-based approach to unobtrusively measure how students spot and apply (known shortcut options in mental arithmetic. We investigated the development and the relation of the spontaneous use of two strategies derived from the mathematical concept of commutativity. Children from grade 2 to grade 7 and university students solved three-addends addition problems, which are rarely used in class. Some problems allowed the use of either of two commutativity-based shortcut strategies. Results suggest that from grade three onwards both of the shortcuts were used spontaneously and application of one shortcut correlated positively with application of the other. Rate of spontaneous usage was substantial but smaller than in an instructed variant. Eyetracking data suggested similar fixation patterns for spontaneous an instructed shortcut application. The data are consistent with the development of an integrated concept of the mathematical principle so that it can be spontaneously applied in different contexts and strategies.

  3. Dynamics of Spontaneous Emission Controlled by Local Density of States in Photonic Crystals

    DEFF Research Database (Denmark)

    Lodahl, Peter; Nikolaev, Ivan S.; van Driel, A. Floris

    2006-01-01

    We have measured time-resolved spontaneous emission from quantum dots in 3D photonic crystals. Due to the spatially dependent local density of states, the distribution of decay rates varies strongly with the photonic crystal lattice parameter.......We have measured time-resolved spontaneous emission from quantum dots in 3D photonic crystals. Due to the spatially dependent local density of states, the distribution of decay rates varies strongly with the photonic crystal lattice parameter....

  4. Radiological evaluation of spontaneous pneumoperitoneum

    International Nuclear Information System (INIS)

    Kim, H. S.; Kim, J. D.; Rhee, H. S.

    1982-01-01

    112 cases of spontaneous penumoperitoneum, the causes of which were confirmed by clinical and surgical procedure at Presbyterian Medical Center from January, 1977 to July, 1981 were reviewed radiologically. The results were as follows: 1. Perforation of duodenal ulcer (46/112: 41.1%), stomach ulcer (22/112: 19.6%), and stomach cancer (11/112: 9.8%) were the three most common causes of spontaneous penumoperitoneum. These were 70.5% of all causes. 2. The most common site of free gas was both subdiaphragmatic areas (46: 41.1%). Others were Rt. subdiaphragmatic only (31: 27.7%), both subdiaphragmatic with subhepatic (16: 14.3%), Rt. subdiaphragmatic with subhepatic (7: 6.2%), Rt. subdiaphragmatic only (5: 4.4%), diffuse in abdomen (4: 3.6%), and subhepatic only (3: 2.7%). So 92.0% (103/112) were located in RUQ. 3. The radiological shape of free gas was classified: crescent (52: 46.4%) of small amount; half-moon (21: 18.8%) of moderate amount; large or diffuse (39: 34.8%) of large amount.4. The age between 31 and 60 occupied 69.1% (77/112), and male was predominant (5.2 times). 5. The patient's position showing free air most frequently was erect

  5. Control of spontaneous emission rate in luminescent resonant diamond particles

    Science.gov (United States)

    Savelev, R.; Zalogina, A.; Kudryashov, S.; Ivanova, A.; Levchenko, A.; Makarov, S.; Zuev, D.; Shadrivov, I.

    2018-01-01

    We study the properties of luminescent diamond particles of different sizes (up to ~1.5 μm) containing multiple NV-centers. We theoretically predict that the average liftetime in such particles is decreased by several times as compared to optically small subwavelength nanodiamonds. In our experiments, samples were obtained by milling the plasma-enhanced chemical vapor deposited diamond film, and characterized by Raman spectroscopy and dark- field spectroscopy methods. Time-resolved luminescence measurements of the excited state of NV-centers showed that their average lifetime varies from 10 to 17 ns in different samples. By comparing this data to the values of the lifetime of the NV-centers in optically small nanodiamonds, known from literature, we confirm a severalfold decrease of the lifetime in resonant particles.

  6. A Case of Multiple Spontaneous Keloid Scars

    Directory of Open Access Journals (Sweden)

    Abdulhadi Jfri

    2015-07-01

    Full Text Available Keloid scars result from an abnormal healing response to cutaneous injury or inflammation that extends beyond the borders of the original wound. Spontaneous keloid scars forming in the absence of any previous trauma or surgical procedure are rare. Certain syndromes have been associated with this phenomenon, and few reports have discussed the evidence of single spontaneous keloid scar, which raises the question whether they are really spontaneous. Here, we present a 27-year-old mentally retarded single female with orbital hypertelorism, broad nasal bridge, repaired cleft lip and high-arched palate who presented with progressive multiple spontaneous keloid scars in different parts of her body which were confirmed histologically by the presence of typical keloidal collagen. This report supports the fact that keloid scars can appear spontaneously and are possibly linked to a genetic factor. Furthermore, it describes a new presentation of spontaneous keloid scars in the form of multiple large lesions in different sites of the body.

  7. Spontaneity of communication in individuals with autism.

    Science.gov (United States)

    Chiang, Hsu-Min; Carter, Mark

    2008-04-01

    This article provides an examination of issues related to spontaneity of communication in children with autism. Deficits relating to spontaneity or initiation are frequently reported in individuals with autism, particularly in relation to communication and social behavior. Nevertheless, spontaneity is not necessarily clearly conceptualized or measured. Several approaches to conceptualization of communicative spontaneity are examined with a particular focus on the continuum model and how it might be practically applied. A range of possible explanations for deficits in spontaneity of communication in children with autism is subsequently explored, including external factors (highly structured teaching programs, failure to systematically instruct for spontaneity) and intrinsic characteristics (intellectual disability, stimulus overselectivity, weak central coherence). Possible implications for future research are presented.

  8. Spontaneous cryptococcal peritonitis in cirrhotic patients.

    Directory of Open Access Journals (Sweden)

    Sungkanuparph S

    2002-07-01

    Full Text Available Spontaneous bacterial peritonitis is a common complication in patients with cirrhosis and ascites. However, spontaneous peritonitis caused by Cryptococcus neoformans is uncommon. Delayed diagnosis of cryptococcal peritonitis often results in death. We describe three cases of spontaneous cryptococcal peritonitis in patients with decompensated cirrhosis. One case had associated symptomatic human immunodeficiency virus infection. Clinical awareness of this entity may lead to the early diagnosis and proper treatment.

  9. Spontaneous Intracranial Hypotension without Orthostatic Headache

    Directory of Open Access Journals (Sweden)

    Tülay Kansu

    2009-03-01

    Full Text Available We report 2 cases of spontaneous intracranial hypotension that presented with unilateral abducens nerve palsy, without orthostatic headache. While sixth nerve palsies improved without any intervention, subdural hematoma was detected with magnetic resonance imaging. We conclude that headache may be absent in spontaneous intracranial hypotension and spontaneous improvement of sixth nerve palsy can occur, even after the development of a subdural hematoma

  10. Spontaneous renal hematoma - a case report

    International Nuclear Information System (INIS)

    Obrzut, M.; Obrzut, M.; Homa, J.; Obrzut, B.

    2006-01-01

    Spontaneous pararenal hematoma is a rare pathology most frequently coexisting with renal tumours, vascular anomalies and inflammatory processes. In some cases one cannot establish its etiology. The paper describes a case of a 58-year-old man with a spontaneous pararenal hematoma and presents a diagnostic algorithm. Ultrasonography and CT play an important role in diagnostics of spontaneous pararenal haemorrhages. These methods enable a precise evaluation of size and location of hematoma and its evolution. (author)

  11. Learning not to blink

    Science.gov (United States)

    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.

  12. Spontaneous Clearance of Hepatitis C after Liver and Renal Transplantation

    Directory of Open Access Journals (Sweden)

    CH Dale

    2009-01-01

    Full Text Available Spontaneous clearance of hepatitis C virus (HCV is rare in immunocompromised patients, such as those who have undergone organ transplantation. It has been recognized that patients receiving liver transplantation for HCV-related disease have decreased graft and patient survival compared with those transplanted for other etiologies. There is a growing trend toward treating HCV recurrence aggressively after liver transplantation. For other organ transplant recipients with concurrent HCV, treatment is not often an option, given the high rates of graft rejection and loss secondary to interferon and its immunomodulatory effects. Although spontaneous clearance of HCV has been reported in recipients of solitary liver and renal transplants, a common factor arising in these cases has been previous exposure to interferon. To date, no reports of spontaneous clearance of HCV RNA have been reported in a multiorgan transplant recipient. A case of spontaneous clearance of HCV RNA in an immunocompromised patient, within five months of simultaneous liver and kidney retransplantation is described. Importantly, this patient had no previous exposure to interferon.

  13. Biomarkers of spontaneous preterm birth

    DEFF Research Database (Denmark)

    Polettini, Jossimara; Cobo, Teresa; Kacerovsky, Marian

    2017-01-01

    predictors of pregnancy outcome. This systematic review was conducted to synthesize the knowledge on PTB biomarkers identified using multiplex analysis. Three electronic databases (PubMed, EMBASE and Web of Science) were searched for studies in any language reporting the use of multiplex assays for maternal......Despite decades of research on risk indicators of spontaneous preterm birth (PTB), reliable biomarkers are still not available to screen or diagnose high-risk pregnancies. Several biomarkers in maternal and fetal compartments have been mechanistically linked to PTB, but none of them are reliable......) followed by MIP-1β, GM-CSF, Eotaxin, and TNF-RI (two studies) were reported more than once in maternal serum. However, results could not be combined due to heterogeneity in type of sample, study population, assay, and analysis methods. By this systematic review, we conclude that multiplex assays...

  14. Spontaneous Strategies in Innovation Networks

    DEFF Research Database (Denmark)

    Plesner, Ursula; Husted, Emil Krastrup

    and a site ontology, we show how physical sites and objects become constitutive of the inside of virtual worlds through innovation processes. This argument is in line with ANT’s perspective on strategy, where sites and objects are considered a strategically relevant resource in the innovation process...... of materiality in relation to the organization and structuring of virtual worlds. We examine various innovation processes in five Danish entrepreneurial companies where actors continuously struggle to stabilize virtual worlds as platforms for professional communication. With inspiration from actor-network theory....... Empirically, the analysis is founded on descriptive accounts from the five entrepreneurs. By highlighting the spontaneous strategies described by actors, we show how sites and objects are actively used as an element in their strategy, and also how the sites and objects end up facilitating new ways of thinking...

  15. Recurrent spontaneous attacks of dizziness.

    Science.gov (United States)

    Lempert, Thomas

    2012-10-01

    This article describes the common causes of recurrent vertigo and dizziness that can be diagnosed largely on the basis of history. Ninety percent of spontaneous recurrent vertigo and dizziness can be explained by six disorders: (1) Ménière disease is characterized by vertigo attacks, lasting 20 minutes to several hours, with concomitant hearing loss, tinnitus, and aural fullness. Aural symptoms become permanent during the course of the disease. (2) Attacks of vestibular migraine may last anywhere from minutes to days. Most patients have a previous history of migraine headaches, and many experience migraine symptoms during the attack. (3) Vertebrobasilar TIAs affect older adults with vascular risk factors. Most attacks last less than 1 hour and are accompanied by other symptoms from the posterior circulation territory. (4) Vestibular paroxysmia is caused by vascular compression of the eighth cranial nerve. It manifests itself with brief attacks of vertigo that recur many times per day, sometimes with concomitant cochlear symptoms. (5) Orthostatic hypotension causes brief episodes of dizziness lasting seconds to a few minutes after standing up and is relieved by sitting or lying down. In older adults, it may be accompanied by supine hypertension. (6) Panic attacks usually last minutes, occur in specific situations, and are accompanied by choking, palpitations, tremor, heat, and anxiety. Less common causes of spontaneous recurrent vertigo and dizziness include perilymph fistula, superior canal dehiscence, autoimmune inner ear disease, otosclerosis, cardiac arrhythmia, and medication side effects. Neurologists need to venture into otolaryngology, internal medicine, and psychiatry to master the differential diagnosis of recurrent dizziness.

  16. Crows spontaneously exhibit analogical reasoning.

    Science.gov (United States)

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Vacuum stability with spontaneous violation of lepton number

    Directory of Open Access Journals (Sweden)

    Cesar Bonilla

    2016-05-01

    Full Text Available The vacuum of the Standard Model is known to be unstable for the measured values of the top and Higgs masses. Here we show how vacuum stability can be achieved naturally if lepton number is violated spontaneously at the TeV scale. More precise Higgs measurements in the next LHC run should provide a crucial test of our symmetry breaking scenario. In addition, these schemes typically lead to enhanced rates for processes involving lepton flavor violation.

  18. Enhancement of Pleasure during Spontaneous Dance

    Directory of Open Access Journals (Sweden)

    Nicolò F. Bernardi

    2017-11-01

    Full Text Available Dancing emphasizes the motor expression of emotional experiences. The bodily expression of emotions can modulate the subjective experience of emotions, as when adopting emotion-specific postures and faces. Thus, dancing potentially offers a ground for emotional coping through emotional enhancement and regulation. Here we investigated the emotional responses to music in individuals without any prior dance training while they either freely danced or refrained from movement. Participants were also tested while imitating their own dance movements but in the absence of music as a control condition. Emotional ratings and cardio-respiratory measures were collected following each condition. Dance movements were recorded using motion capture. We found that emotional valence was increased specifically during spontaneous dance of groovy excerpts, compared to both still listening and motor imitation. Furthermore, parasympathetic-related heart rate variability (HRV increased during dance compared to motor imitation. Nevertheless, subjective and physiological arousal increased during movement production, regardless of whether participants were dancing or imitating. Significant correlations were found between inter-individual differences in the emotions experienced during dance and whole-body acceleration profiles. The combination of movement and music during dance results in a distinct state characterized by acutely heightened pleasure, which is of potential interest for the use of dance in therapeutic settings.

  19. Spontaneous canine hydrocephalus: cerebrospinal fluid dynamics1

    Science.gov (United States)

    Sahar, A.; Hochwald, G. M.; Kay, W. J.; Ransohoff, J.

    1971-01-01

    Cerebrospinal fluid dynamics were studied in 14 dogs with spontaneous hydrocephalus. In nine of the dogs aqueductal obstruction was observed and the remainder had a `communicating type' hydrocephalus. The major histological findings consisted of severe ependymal destruction, spongy changes in the periventricular white matter, increased density of capillaries in this area, and varying degrees of thickening, fibrosis, and fusion of the choroid villi. The formation and absorption of CSF were studied by perfusion of the cerebral ventricles. The rate of formation of CSF was found to decrease with perfusion pressure by Vf = 0·02595−0·00022 P ml./min (P = pressure in cm H2O). The absorption of spinal fluid was found to increase linearly with pressure by Va = 0·0165 + 0·00050 P. The various factors influencing the formation and absorption of the spinal fluid are discussed. The meaning and attainment of `arrest' of the hydrocephalic process in terms of the measured rates of CSF formation and absorption in these animals are considered. Images PMID:5571319

  20. Enhancement of Pleasure during Spontaneous Dance

    Science.gov (United States)

    Bernardi, Nicolò F.; Bellemare-Pepin, Antoine; Peretz, Isabelle

    2017-01-01

    Dancing emphasizes the motor expression of emotional experiences. The bodily expression of emotions can modulate the subjective experience of emotions, as when adopting emotion-specific postures and faces. Thus, dancing potentially offers a ground for emotional coping through emotional enhancement and regulation. Here we investigated the emotional responses to music in individuals without any prior dance training while they either freely danced or refrained from movement. Participants were also tested while imitating their own dance movements but in the absence of music as a control condition. Emotional ratings and cardio-respiratory measures were collected following each condition. Dance movements were recorded using motion capture. We found that emotional valence was increased specifically during spontaneous dance of groovy excerpts, compared to both still listening and motor imitation. Furthermore, parasympathetic-related heart rate variability (HRV) increased during dance compared to motor imitation. Nevertheless, subjective and physiological arousal increased during movement production, regardless of whether participants were dancing or imitating. Significant correlations were found between inter-individual differences in the emotions experienced during dance and whole-body acceleration profiles. The combination of movement and music during dance results in a distinct state characterized by acutely heightened pleasure, which is of potential interest for the use of dance in therapeutic settings. PMID:29238298

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

    Directory of Open Access Journals (Sweden)

    Toshihiro Imada

    Full Text Available 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.

  2. Stabiliteit spontane taal bij chronische milde afasie

    NARCIS (Netherlands)

    Wolthuis, Nienke; Mendez Orellana, Carolina; Nouwens, Femke; Jonkers, Roel; Visch-Brink, Evy; Bastiaanse, Roelien

    2014-01-01

    In aphasia, an analysis of spontaneous speech provides opportunities to establish the linguistic and communicative abilities, to create suitable therapy plans and to measure language progress. The current study investigated the stability of spontaneous speech within an interview of ten mild aphasic

  3. Spontaneously broken abelian gauge invariant supersymmetric model

    International Nuclear Information System (INIS)

    Mainland, G.B.; Tanaka, K.

    A model is presented that is invariant under an Abelian gauge transformation and a modified supersymmetry transformation. This model is broken spontaneously, and the interplay between symmetry breaking, Goldstone particles, and mass breaking is studied. In the present model, spontaneously breaking the Abelian symmetry of the vacuum restores the invariance of the vacuum under a modified supersymmetry transformation. (U.S.)

  4. Spontaneous Achilles tendon rupture in alkaptonuria | Mohammed ...

    African Journals Online (AJOL)

    Spontaneous Achilles tendon ruptures are uncommon. We present a 46-year-old man with spontaneous Achilles tendon rupture due to ochronosis. To our knowledge, this has not been previously reported in Sudan literature. The tendon of the reported patient healed well after debridement and primary repairs.

  5. Spontaneous rupture of choledochal cyst: case report

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ho Seob; Nam, Kyung Jin; Lee, Jin Hwa; Kim, Chan Sung; Choi, Jong Cheol; Oh, Jong Young [Dong-a University College of Medicine, Pusan (Korea, Republic of)

    2002-11-01

    Spontaneous rupture of a choledochal cyst leading to biliary peritonitis is a rare complication which can be fatal if not promptly diagnosed. The authors report the ultrasound and CT findings of two cases of spontaneous choledochal cystic rupture and the biliary peritonitis which ensued.

  6. Spontaneity and Equilibrium II: Multireaction Systems

    Science.gov (United States)

    Raff, Lionel M.

    2014-01-01

    The thermodynamic criteria for spontaneity and equilibrium in multireaction systems are developed and discussed. When N reactions are occurring simultaneously, it is shown that G and A will depend upon N independent reaction coordinates, ?a (a = 1,2, ..., N), in addition to T and p for G or T and V for A. The general criteria for spontaneity and…

  7. Early pregnancy angiogenic markers and spontaneous abortion

    DEFF Research Database (Denmark)

    Andersen, Louise B; Dechend, Ralf; Karumanchi, S Ananth

    2016-01-01

    BACKGROUND: Spontaneous abortion is the most commonly observed adverse pregnancy outcome. The angiogenic factors soluble Fms-like kinase 1 and placental growth factor are critical for normal pregnancy and may be associated to spontaneous abortion. OBJECTIVE: We investigated the association between...... maternal serum concentrations of soluble Fms-like kinase 1 and placental growth factor, and subsequent spontaneous abortion. STUDY DESIGN: In the prospective observational Odense Child Cohort, 1676 pregnant women donated serum in early pregnancy, gestational week ..., interquartile range 71-103). Concentrations of soluble Fms-like kinase 1 and placental growth factor were determined with novel automated assays. Spontaneous abortion was defined as complete or incomplete spontaneous abortion, missed abortion, or blighted ovum

  8. Respiratory modulation of startle eye blink: a new approach to assess afferent signals from the respiratory system.

    Science.gov (United States)

    Schulz, André; Schilling, Thomas M; Vögele, Claus; Larra, Mauro F; Schächinger, Hartmut

    2016-11-19

    Current approaches to assess interoception of respiratory functions cannot differentiate between the physiological basis of interoception, i.e. visceral-afferent signal processing, and the psychological process of attention focusing. Furthermore, they typically involve invasive procedures, e.g. induction of respiratory occlusions or the inhalation of CO 2 -enriched air. The aim of this study was to test the capacity of startle methodology to reflect respiratory-related afferent signal processing, independent of invasive procedures. Forty-two healthy participants were tested in a spontaneous breathing and in a 0.25 Hz paced breathing condition. Acoustic startle noises of 105 dB(A) intensity (50 ms white noise) were presented with identical trial frequency at peak and on-going inspiration and expiration, based on a new pattern detection method, involving the online processing of the respiratory belt signal. The results show the highest startle magnitudes during on-going expiration compared with any other measurement points during the respiratory cycle, independent of whether breathing was spontaneous or paced. Afferent signals from slow adapting phasic pulmonary stretch receptors may be responsible for this effect. This study is the first to demonstrate startle modulation by respiration. These results offer the potential to apply startle methodology in the non-invasive testing of interoception-related aspects in respiratory psychophysiology.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'. © 2016 The Author(s).

  9. Spontaneous emission of a cesium atom near a nanofiber: Efficient coupling of light to guided modes

    International Nuclear Information System (INIS)

    Le Kien, Fam; Hakuta, K.; Dutta Gupta, S.; Balykin, V.I.

    2005-01-01

    We study the spontaneous emission of a cesium atom in the vicinity of a subwavelength-diameter fiber. We show that the confinement of the guided modes and the degeneracy of the excited and ground states substantially affect the spontaneous emission process. We demonstrate that different magnetic sublevels have different decay rates. When the fiber radius is about 200 nm, a significant fraction (up to 28%) of spontaneous emission by the atom can be channeled into guided modes. Our results may find applications for developing nanoprobes for atoms and efficient couplers for subwavelength-diameter fibers

  10. The (perceived) meaning of spontaneous thoughts.

    Science.gov (United States)

    Morewedge, Carey K; Giblin, Colleen E; Norton, Michael I

    2014-08-01

    Spontaneous thoughts, the output of a broad category of uncontrolled and inaccessible higher order mental processes, arise frequently in everyday life. The seeming randomness by which spontaneous thoughts arise might give people good reason to dismiss them as meaningless. We suggest that it is precisely the lack of control over and access to the processes by which they arise that leads people to perceive spontaneous thoughts as revealing meaningful self-insight. Consequently, spontaneous thoughts potently influence judgment. A series of experiments provides evidence supporting two hypotheses. First, we hypothesize that the more a thought is perceived to be spontaneous, the more it is perceived to provide meaningful self-insight. Participants perceived more spontaneous kinds of thought (e.g., intuition) to reveal greater self-insight than did more controlled kinds of thought in Study 1 (e.g., deliberation). In Studies 2 and 3, participants perceived thoughts with the same content and target to reveal greater self-insight when spontaneously rather than deliberately generated (i.e., childhood memories and impressions formed). Second, we hypothesize that the greater self-insight attributed to thoughts that are (perceived to be) spontaneous leads those thoughts to more potently influence judgment. Participants felt more sexually attracted to an attractive person whom they thought of spontaneously than deliberately in Study 4, and reported their commitment to a current romantic relationship would be more affected by the spontaneous rather than deliberate recollection of a good or bad experience with their romantic partner in Study 5. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  11. Successful protocol of anaesthesia for measuring transepithelial nasal potential difference in spontaneously breathing mice.

    Science.gov (United States)

    Leal, T; Lebacq, J; Vanbinst, R; Lederman, Ch; De Kock, M; Wallemacq, P

    2006-01-01

    Numerous difficulties arise during in vivo measurements of transepithelial nasal potential difference (PD) in mice, such as inadequate duration and depth of anaesthesia, bronchoaspiration of solutions perfused in the nose, and respiratory and/or cardiovascular depression. Anaesthesia was induced in adult C57 mice with intraperitoneal injection of a combination of fentanyl, droperidol and medetomidine, each of these at either a small dose (0.20, 10 and 0.33 mg/kg, respectively) or at a large dose (0.40, 20 and 0.40 mg/kg, respectively), combined with a fixed dose of 0.375 microg clonidine. In order to establish a pharmacokinetic-pharmacodynamic relationship, blood concentrations of the first three drugs were measured in 24 animals by liquid-chromatography tandem mass spectrometry. At the end of the experiment, naloxone, a competitive morphinic antagonist, and atipamezole, an alpha-2 adrenergic antagonist, were administered. Bronchoaspiration was prevented by tilting the animal head downwards and by absorbing the excess fluid from the opposite nostril and from the oral cavity. Optimal assessment of anaesthesia associated with regular respiration, loss of blink, pupillary and pedal withdrawal reflexes was obtained with doses of fentanyl, droperidol and medetomidine corresponding to 0.20, 20 and 0.40 mg/kg, respectively. Blood concentrations of fentanyl around 17 ng/mL induced loss of respiratory efforts and were followed by death during the experiment. Integrity of ion transport was demonstrated under continuous perfusion by successive depolarization after amiloride and repolarization after chloride-free solution. The combination investigated in this study lead to adequate surgical anaesthesia (stage III, plane 2) for prolonged nasal PD measurements in spontaneously breathing mice.

  12. How to identify twins at low risk of spontaneous preterm delivery

    DEFF Research Database (Denmark)

    Sperling, Lene; Kiil, C; Larsen, L U

    2005-01-01

    OBJECTIVE: The aim of this study was to evaluate transvaginal sonographic assessment of cervical length at 23 weeks as a screening test for spontaneous preterm delivery in order to define a cut-off value that could be used to select twin pregnancies at low risk of spontaneous preterm delivery....... METHODS: In a prospective multicenter study of 383 twin pregnancies included before 14 + 6 weeks a cervical scan with measurement of the cervical length was performed at 23 weeks' gestation. The results were blinded for the clinicians if the cervical length was > or = 15 mm. The rates of spontaneous...... delivery at different cut-off levels of cervical length were determined. RESULTS: Eighty-nine percent of the twins had dichorionic placentation and 58% were conceived after assisted reproduction. The rate of spontaneous preterm delivery was 2.3% (1.5% for dichorionic (DC) and 9.1% for (MC) monochorionic...

  13. Effects of socioeconomic position and clinical risk factors on spontaneous and iatrogenic preterm birth.

    Science.gov (United States)

    Joseph, K S; Fahey, John; Shankardass, Ketan; Allen, Victoria M; O'Campo, Patricia; Dodds, Linda; Liston, Robert M; Allen, Alexander C

    2014-03-27

    The literature shows a variable and inconsistent relationship between socioeconomic position and preterm birth. We examined risk factors for spontaneous and iatrogenic preterm birth, with a focus on socioeconomic position and clinical risk factors, in order to explain the observed inconsistency. We carried out a retrospective population-based cohort study of all singleton deliveries in Nova Scotia from 1988 to 2003. Data were obtained from the Nova Scotia Atlee Perinatal Database and the federal income tax T1 Family Files. Separate logistic models were used to quantify the association between socioeconomic position, clinical risk factors and spontaneous preterm birth and iatrogenic preterm birth. The study population included 132,714 singleton deliveries and the rate of preterm birth was 5.5%. Preterm birth rates were significantly higher among the women in the lowest (versus the highest) family income group for spontaneous (rate ratio 1.14, 95% confidence interval (CI) 1.03, 1.25) but not iatrogenic preterm birth (rate ratio 0.95, 95% CI 0.75, 1.19). Adjustment for maternal characteristics attenuated the family income-spontaneous preterm birth relationship but strengthened the relationship with iatrogenic preterm birth. Clinical risk factors such as hypertension were differentially associated with spontaneous (rate ratio 3.92, 95% CI 3.47, 4.44) and iatrogenic preterm (rate ratio 14.1, 95% CI 11.4, 17.4) but factors such as diabetes mellitus were not (rate ratio 4.38, 95% CI 3.21, 5.99 for spontaneous and 4.02, 95% CI 2.07, 7.80 for iatrogenic preterm birth). Socioeconomic position and clinical risk factors have different effects on spontaneous and iatrogenic preterm. Recent temporal increases in iatrogenic preterm birth appear to be responsible for the inconsistent relationship between socioeconomic position and preterm birth.

  14. Modulation response of quantum dot nanolight-emitting-diodes exploiting purcell-enhanced spontaneous emission

    DEFF Research Database (Denmark)

    Skovgård, Troels Suhr; Gregersen, Niels; Lorke, Michael

    2011-01-01

    The modulation bandwidth for a quantum dot light-emitting device is calculated using a detailed model for the spontaneous emission including the optical and electronic density-of-states. We show that the Purcell enhancement of the spontaneous emission rate depends critically on the degree...... of inhomogeneous broadening relative to the cavity linewidth and can improve the modulation speed only within certain parameter regimes....

  15. Spontaneous Metacognition in Rhesus Monkeys.

    Science.gov (United States)

    Rosati, Alexandra G; Santos, Laurie R

    2016-09-01

    Metacognition is the ability to think about thinking. Although monitoring and controlling one's knowledge is a key feature of human cognition, its evolutionary origins are debated. In the current study, we examined whether rhesus monkeys (Macaca mulatta; N = 120) could make metacognitive inferences in a one-shot decision. Each monkey experienced one of four conditions, observing a human appearing to hide a food reward in an apparatus consisting of either one or two tubes. The monkeys tended to search the correct location when they observed this baiting event, but engaged in information seeking-by peering into a center location where they could check both potential hiding spots-if their view had been occluded and information seeking was possible. The monkeys only occasionally approached the center when information seeking was not possible. These results show that monkeys spontaneously use information about their own knowledge states to solve naturalistic foraging problems, and thus provide the first evidence that nonhumans exhibit information-seeking responses in situations with which they have no prior experience. © The Author(s) 2016.

  16. Spontaneous flocking in human groups.

    Science.gov (United States)

    Belz, Michael; Pyritz, Lennart W; Boos, Margarete

    2013-01-01

    Flocking behaviour, as a type of self-organised collective behaviour, is described as the spatial formation of groups without global control and explicit inter-individual recruitment signals. It can be observed in many animals, such as bird flocks, shoals or herds of ungulates. Spatial attraction between humans as the central component of flocking behaviour has been simulated in a number of seminal models but it has not been detected experimentally in human groups so far. The two other sub-processes of this self-organised collective movement - collision avoidance and alignment - are excluded or held constant respectively in this study. We created a computer-based, multi-agent game where human players, represented as black dots, moved on a virtual playground. The participants were deprived of social cues about each other and could neither communicate verbally nor nonverbally. They played two games: (1) Single Game, where other players were invisible, and (2) Joint Game, where each player could see players' positions in a local radius around himself/herself. We found that individuals approached their neighbours spontaneously if their positions were visible, leading to less spatial dispersion of the whole group compared to moving alone. We conclude that human groups show the basic component of flocking behaviour without being explicitly instructed or rewarded to do so. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Bilateral spontaneous hemotympanum: Case report

    Directory of Open Access Journals (Sweden)

    Economou Nicolas C

    2006-10-01

    Full Text Available Abstract Background The most common causes of hemotympanum are therapeutic nasal packing, epistaxis, blood disorders and blunt trauma to the head. Hemotympanum is characterized as idiopathic, when it is detected in the presence of chronic otitis media. A rare case of spontaneous bilateral hemotympanum in a patient treated with anticoagulants is presented herein. Case presentation A 72-year-old male presented with acute deterioration of hearing. In the patient's medical history aortic valve replacement 1 year before presentation was reported. Since then he had been administered regularly coumarinic anticoagulants, with INR levels maintained between 3.4 and 4.0. Otoscopy revealed the presence of bilateral hemotympanum. The audiogram showed symmetrical moderately severe mixed hearing loss bilaterally, with the conductive component predominating. Tympanograms were flat bilaterally with absent acoustic reflexes. A computerized tomography scan showed the presence of fluid in the mastoid and middle ear bilaterally. Treatment was conservative and consisted of a 10-day course of antibiotics, anticongestants and temporary interruption of the anticoagulant therapy. After 3 weeks, normal tympanic membranes were found and hearing had returned to previous levels. Conclusion Anticoagulant intake should be included in the differential diagnosis of hemotympanum, because its detection and appropriate treatment may lead to resolution of the disorder.

  18. Stock market speculation: Spontaneous symmetry breaking of economic valuation

    Science.gov (United States)

    Sornette, Didier

    2000-09-01

    Firm foundation theory estimates a security's firm fundamental value based on four determinants: expected growth rate, expected dividend payout, the market interest rate and the degree of risk. In contrast, other views of decision-making in the stock market, using alternatives such as human psychology and behavior, bounded rationality, agent-based modeling and evolutionary game theory, expound that speculative and crowd behavior of investors may play a major role in shaping market prices. Here, we propose that the two views refer to two classes of companies connected through a "phase transition". Our theory is based on (1) the identification of the fundamental parity symmetry of prices (p→-p), which results from the relative direction of payment flux compared to commodity flux and (2) the observation that a company's risk-adjusted growth rate discounted by the market interest rate behaves as a control parameter for the observable price. We find a critical value of this control parameter at which a spontaneous symmetry-breaking of prices occurs, leading to a spontaneous valuation in absence of earnings, similarly to the emergence of a spontaneous magnetization in Ising models in absence of a magnetic field. The low growth rate phase is described by the firm foundation theory while the large growth rate phase is the regime of speculation and crowd behavior. In practice, while large "finite-time horizon" effects round off the predicted singularities, our symmetry-breaking speculation theory accounts for the apparent over-pricing and the high volatility of fast growing companies on the stock markets.

  19. Shaping the Spontaneous Emission Pulse from a Superconducting Qubit

    Science.gov (United States)

    Srinivasan, Srikanth; Liu, Yanbing; Zhang, Gengyan; Yu, Terri; Gambetta, Jay; Girvin, Steven; Houck, Andrew

    2013-03-01

    We report on measurements of spontaneous emission in a circuit quantum electrodynamics system. A superconducting qubit with tunable coupling to a coplanar waveguide cavity is operated in a regime where the qubit relaxation time, and consequently the spontaneous emission rate, is dominated by the interaction strength. This fast control knob on the coupling strength is used to shape the emitted single photon's wavepacket. The independent control over the coupling allows the dressed qubit frequency to remain truly constant during the emission. The wavepacket shape becomes important in experiments where quantum information needs to be transported between various nodes in a quantum network. The transfer can happen with a very high fidelity if the wavepacket is time-symmetric, since emission by the source and absorption by the destination become time reversed processes. Authors would like to thank IARPA for their generous support.

  20. Assessing subjective memory complaints: a comparison of spontaneous reports and structured questionnaire methods.

    Science.gov (United States)

    Burmester, Bridget; Leathem, Janet; Merrick, Paul

    2015-01-01

    Subjective memory complaints (SMCs) are a common occurrence for adults, which increase with age, and cause considerable distress. Traditionally SMCs have been assessed by either questionnaires, which ask whether a person has experienced given examples of SMCs, or open-ended questions which elicit spontaneous reports of SMCs. However, little is known about how these methods of assessment might influence reporting of SMCs. Four hundred and twenty one adults aged 40 years and above were surveyed about SMCs using spontaneous report and questionnaire methods. As expected, spontaneously reported SMCs were fewer in number and rated more distressing overall than SMCs endorsed on a questionnaire. However, comparison of individual SMCs revealed that distress ratings tended to be higher when assessed in a questionnaire than spontaneously reported, which may be due to the context of a questionnaire causing inflated ratings. Participants also reported SMCs which were not well assessed by the questionnaire, including some which were among the most distressing SMCs overall. Conversely, other SMCs were over-sampled by the questionnaire and did not feature in spontaneous reports. Implications for clinical assessment of SMCs are that open-ended questioning might be preferable to initial use of prescriptive questionnaires, in order to elicit SMCs that are most distressing. While use of questionnaires may reveal endorsement of a wider range of SMCs than are spontaneously reported, they can take focus away from, or even fail to assess, those SMCs which cause most subjective distress (and therefore should be the target of interventions).

  1. Spontaneously settled refugees in Northwestern Province, Zambia.

    Science.gov (United States)

    Freund, P J; Kalumba, K

    1986-01-01

    The UN High Commissioner for Refugees (UNHCR) commissioned researchers from the University of Zambia to conduct a socioeconomic survey and census of "spontaneously settled" Zairean and Angolan refugees in the Northwestern Province of Zambia in 1982. The sample consisted of 188 Angolans, 201 Zaireans, and 2 South Africans. The difficulties experienced by refugees in Northwestern Province in achieving integration were related to a combination of factors including the lack of a clear national policy on refugees and refugee status, a national concern for maintaining security, the popular belief that aliens are responsible for an increasing crime rate, the desire by immigration officials for stricter laws to control alien infiltration, conflict between traditional and modern leaders, and Zambia's deteriorating economic situation. In spite of the problems described, the integration of refugees into existing communities is a desirable goal and should be encouraged. One should not assume that self-settling refugees are able to live with ethnic kin, receive assistance and hospitality, and thus are better off than those in camps. The Zambian case provides ample evidence that integration is not easy even with kin support, shared ethnicity, language, and historical connections. Moreover, given the fact that Zambia will continue to receive refugees it is vital that there is a well defined refugee policy and an administrative mechanism for implementing that policy at all levels. This will be particularly important in Zambia as it will undoubtedly continue to receive large influxes of refugees, from countries such as Namibia, Uganda, Angola, Mozambique, and South Africa.

  2. Clinical features of multiple spontaneous intracerebral hemorrhages

    Directory of Open Access Journals (Sweden)

    Tao CHANG

    2016-01-01

    Full Text Available Objective To analyze the clinical features of multiple spontaneous intracerebral hemorrhages (MICH. Methods Conservative therapy, puncture and drainage, hematoma removal and/or decompressive craniectomy were used in the treatment of 630 intracerebral hemorrhage (ICH patients, who were divided into 2 groups: 30 cases with MICH and another 600 cases with solitary intracerebral hemorrhage (SICH. Three months after onset, modified Rankin Scale (mRS was used to evaluate the prognosis of all cases. Results Compared with patients in SICH group, the occurrence rate of hypertension > 5 years (P = 0.008, diabetes mellitus (P = 0.024, hypercholesterolemia (P = 0.050 and previous ischemic stroke (P = 0.026 were all significantly higher in MICH group. The mean arterial pressure (MAP level (P = 0.002 and the incidence of limb movement disorder (P = 0.000 were significantly higher in patients with MICH than those with SICH. Basal ganglia and thalamus were the predilection sites of hematoma (P = 0.001. Patients with MICH had worse prognosis compared to those with SICH 3 months after onset (P = 0.006. Conclusions Hypertension > 5 years, diabetes mellitus, hypercholesterolemia and ischemic stroke were identified to be the pathophysiological basis of MICH in this study. All patients with MICH had more serious clinical manifestations after onset and worse prognosis. DOI: 10.3969/j.issn.1672-6731.2016.01.008

  3. Spontaneous Bacterial Peritonitis in Subclinical Hypothyroidism

    Directory of Open Access Journals (Sweden)

    Dalip Gupta

    2013-11-01

    Full Text Available Hypothyroidism is an uncommon cause of ascites. Here we describe a case of a 75 year-old female patient with spontaneous bacterial peritonitis and subclinical hypothyroidism that resolved with thyroid replacement and antibiotic therapy respectively. Ascitic fluid analysis revealed a gram-positive bacterium on gram staining. A review of the literature revealed just one other reported case of myxoedema ascites with concomitant spontaneous bacterial peritonitis and no case has till been reported of spontaneous bacterial peritonitis in subclinical hypothyroidism.

  4. Spontaneous regression of an invasive thymoma.

    Science.gov (United States)

    Yutaka, Yojiro; Omasa, Mitsugu; Shikuma, Kei; Okuda, Masato; Taki, Toshihiko

    2009-05-01

    Although there are many reports of spontaneous regression of noninvasive thymoma, there are no reports of spontaneous regression of an invasive thymoma. Moreover, the mechanism of the spontaneous regression is still unknown. The present case concerns a 47-year-old man who presented with chest pain. Computed tomography (CT) showed a large anterior mediastinal mass with left pleural effusion that occluded the innominate vein. The tissue obtained by video-assisted thoracic surgery suggested a diagnosis of invasive thymic carcinoma. One month later CT showed prominent regression of the tumor, and the tumor was completely resected. On pathology, the diagnosis was thymoma type B3.

  5. Spontaneous Dissection of the Superior Mesenteric Artery

    International Nuclear Information System (INIS)

    Sheldon, Patrick J.; Esther, James B.; Sheldon, Elana L.; Sparks, Steven R.; Brophy, David P.; Oglevie, Steven B.

    2001-01-01

    Spontaneous dissection of the superior mesenteric artery (SMA) is a rare occurrence, especially when not associated with aortic dissection. Currently, only 28 cases appear to have been reported. Due to the scarcity of cases in the literature, the natural history of isolated, spontaneous SMA dissection is unclear. CT has been reported to be useful for the initial diagnosis of SMA dissection [2-5]. We present two recent cases of spontaneous SMA dissection in which enhanced spiral CT was instrumental in following the disease process and guiding clinical decision making

  6. Does Spontaneous Favorability to Power (vs. Universalism) Values Predict Spontaneous Prejudice and Discrimination?

    Science.gov (United States)

    Souchon, Nicolas; Maio, Gregory R; Hanel, Paul H P; Bardin, Brigitte

    2017-10-01

    We conducted five studies testing whether an implicit measure of favorability toward power over universalism values predicts spontaneous prejudice and discrimination. Studies 1 (N = 192) and 2 (N = 86) examined correlations between spontaneous favorability toward power (vs. universalism) values, achievement (vs. benevolence) values, and a spontaneous measure of prejudice toward ethnic minorities. Study 3 (N = 159) tested whether conditioning participants to associate power values with positive adjectives and universalism values with negative adjectives (or inversely) affects spontaneous prejudice. Study 4 (N = 95) tested whether decision bias toward female handball players could be predicted by spontaneous attitude toward power (vs. universalism) values. Study 5 (N = 123) examined correlations between spontaneous attitude toward power (vs. universalism) values, spontaneous importance toward power (vs. universalism) values, and spontaneous prejudice toward Black African people. Spontaneous positivity toward power (vs. universalism) values was associated with spontaneous negativity toward minorities and predicted gender bias in a decision task, whereas the explicit measures did not. These results indicate that the implicit assessment of evaluative responses attached to human values helps to model value-attitude-behavior relations. © 2016 The Authors. Journal of Personality Published by Wiley Periodicals, Inc.

  7. SWAP-70 contributes to spontaneous transformation of mouse embryo fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yu-Tzu; Shu, Chung-Li; Lai, Jing-Yang; Lin, Ching-Yu; Chuu, Chih-Pin [Institute of Cellular and System Medicine National Health Research Institute, Zhunan Town 35053, Miaoli County, Taiwan, ROC (China); Morishita, Kazuhiro; Ichikawa, Tomonaga [Division of Tumor and Cellular Biochemistry Department of Medical Sciences Faculty of Medicine University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-shi, Miyazaki 889-1692 Japan (Japan); Jessberger, Rolf [Faculty of Medicine Carl Gustav Carus, Institute of Physiological Chemistry, Dresden University of Technology, Dresden (Germany); Fukui, Yasuhisa, E-mail: 990412@nhri.org.tw [Institute of Cellular and System Medicine National Health Research Institute, Zhunan Town 35053, Miaoli County, Taiwan, ROC (China)

    2016-07-15

    Mouse embryo fibroblasts (MEFs) grow slowly after cultivation from animals, however, after an extended period of cultivation, their growth accelerates. We found that SWAP-70 deficient MEFs failed to increase growth rates. They maintain normal growth rates and proliferation cycles for at least 5 years. Complementing SWAP-70 deficiency in one of these MEF clones, MEF1F2, by expressing human SWAP-70 resulted in fast growth of the cells after further cultivation for a long period. The resulting cells show a transformation phenotype, since they grow on top of each other and do not show contact inhibition. This phenotype was reverted when sanguinarine, a putative SWAP-70 inhibitor, was added. Two SWAP-70 expressing clones were examined in detail. Even after cell density became very high their cdc2 and NFκB were still activated suggesting that they do not stop growing. One of the clones formed colonies in soft agar and formed tumors in nude mice. Lately, one more clone became transformed being able to make colonies in soft agar. We maintain 4 human SWAP-70 expressing MEF1F2 cell lines. Three out of 4 clones exhibited transforming phenotypes. The mouse SWAP-70 gene also promoted transformation of MEFs. Taken together our data suggest that SWAP-70 is not a typical oncogene, but is required for spontaneous transformation of MEFs. - Highlights: • Mouse embryo fibroblasts (MEFs) lacking SWAP-70 do not cause spontaneous transform. • Adding back of SWAP-70 to SWAP-70-deficient MEFs induces spontaneous transformation. • SWAP-70 is required for spontaneous transformation of MEFs.

  8. Right Diaphragm Spontaneous Rupture: A Surgical Approach

    Directory of Open Access Journals (Sweden)

    Duilio Divisi

    2011-01-01

    Full Text Available We present a case of spontaneous rupture of the diaphragm, characterized by nonspecific symptoms. The rapid diagnosis and appropriate surgical approach led to a positive resolution of the pathology.

  9. Spontaneous cecal perforation secondary to acute fulminant ...

    African Journals Online (AJOL)

    Spontaneous cecal perforation secondary to acute fulminant gastroenteritis: report of a rare case. Duvuru Ram, Vilvapathy S. Karthikeyan, Sarath C. Sistla, Sheik M. Ali, Parnandi Sridhar, Nagarajan Rajkumar ...

  10. Spontaneous Trait Inferences on Social Media.

    Science.gov (United States)

    Levordashka, Ana; Utz, Sonja

    2017-01-01

    The present research investigates whether spontaneous trait inferences occur under conditions characteristic of social media and networking sites: nonextreme, ostensibly self-generated content, simultaneous presentation of multiple cues, and self-paced browsing. We used an established measure of trait inferences (false recognition paradigm) and a direct assessment of impressions. Without being asked to do so, participants spontaneously formed impressions of people whose status updates they saw. Our results suggest that trait inferences occurred from nonextreme self-generated content, which is commonly found in social media updates (Experiment 1) and when nine status updates from different people were presented in parallel (Experiment 2). Although inferences did occur during free browsing, the results suggest that participants did not necessarily associate the traits with the corresponding status update authors (Experiment 3). Overall, the findings suggest that spontaneous trait inferences occur on social media. We discuss implications for online communication and research on spontaneous trait inferences.

  11. Spontane abdominale arteriovenøse fistler

    DEFF Research Database (Denmark)

    Flarup, S; Lindholt, Jes Sanddal

    1997-01-01

    Spontaneous arteriovenous fistulas between major abdominal vessels (AAVF) complicates about 1% of abdominal aortic aneurysms. AAVF produces severe circulatory disturbances with high operative mortality. Preoperative diagnosis is important but difficult due to the varied nature of presentation. Fo...

  12. Depressive disorder and grief following spontaneous abortion.

    Science.gov (United States)

    Kulathilaka, Susil; Hanwella, Raveen; de Silva, Varuni A

    2016-04-12

    Abortion is associated with moderate to high risk of psychological problems such as depression, use of alcohol or marijuana, anxiety, depression and suicidal behaviours. The increased risk of depression after spontaneous abortion in Asian populations has not been clearly established. Only a few studies have explored the relationship between grief and depression after abortion. A study was conducted to assess the prevalence and risk factors of depressive disorder and complicated grief among women 6-10 weeks after spontaneous abortion and compare the risk of depression with pregnant women attending an antenatal clinic. Spontaneous abortion group consisted of women diagnosed with spontaneous abortion by a Consultant Obstetrician. Women with confirmed or suspected induced abortion were excluded. The comparison group consisted of randomly selected pregnant, females attending the antenatal clinics of the two hospitals. Diagnosis of depressive disorder was made according to ICD-10 clinical criteria based on a structured clinical interview. This assessment was conducted in both groups. The severity of depressive symptoms were assessed using the Patients Health Questionnaire (PHQ-9). Grief was assessed using the Perinatal Grief Scale which was administered to the women who had experienced spontaneous abortion. The sample consisted of 137 women in each group. The spontaneous abortion group (mean age 30.39 years (SD = 6.38) were significantly older than the comparison group (mean age 28.79 years (SD = 6.26)). There were more females with ≥10 years of education in the spontaneous abortion group (n = 54; SD = 39.4) compared to the comparison group (n = 37; SD = 27.0). The prevalence of depression in the spontaneous abortion group was 18.6 % (95 CI, 11.51-25.77). The prevalence of depression in the comparison group was 9.5 % (95 CI, 4.52-14.46). Of the 64 women fulfilling criteria for grief, 17 (26.6 %) also fulfilled criteria for a depressive episode. The relative risk of

  13. Observation of magnetic flux generated spontaneously during a rapid quench of superconducting films

    International Nuclear Information System (INIS)

    Maniv, A.; Polturak, E.; Koren, G.

    2003-01-01

    We report observations of spontaneous formation of magnetic flux lines during a rapid quench of YBa 2 Cu 3 O 7-δ films through T c . This effect is predicted according to the Kibble-Zurek mechanism of creation of topological defects of the order parameter during a symmetry-breaking phase transition. Our previous experiment, at a quench rate of 20 K/s, gave null results. In the present experiment, the quench rate was increased to >10 8 K/s. The amount of spontaneous flux increases weakly with the cooling rate

  14. Postmenopausal spontaneous uterine perforation: Case report

    Science.gov (United States)

    İşlek Seçen, Elçin; Ağış, Hilal; Altunkaya, Canan; Avşar, Ayşe Filiz

    2015-01-01

    Spontaneous uterine rupture and generalized peritonitis caused by pyometra occurs rarely with high morbidity and mortality. A correct and definite diagnosis can be made with laparotomy or laparoscopy. The clinical findings of perforated pyometra are similar to perforation of the gastrointestinal tract and gynecologic symptoms are less frequent, which makes preoperative diagnosis difficult. We report a case of a patient aged 82 years who underwent surgery for spontaneous uterine rupture and generalized peritonitis as a result of pyometra. PMID:28913055

  15. Endometriosis-related spontaneous diaphragmatic rupture.

    Science.gov (United States)

    Triponez, Frédéric; Alifano, Marco; Bobbio, Antonio; Regnard, Jean-François

    2010-10-01

    Non-traumatic, spontaneous diaphragmatic rupture is a rare event whose pathophysiology is not known. We report the case of endometriosis-related spontaneous rupture of the right diaphragm with intrathoracic herniation of the liver, gallbladder and colon. We hypothesize that the invasiveness of endometriotic tissue caused diaphragm fragility, which finally lead to its complete rupture without traumatic event. The treatment consisted of a classical management of diaphragmatic rupture, with excision of the endometriotic nodule followed by medical ovarian suppression for six months.

  16. Spontaneous intracranial epidural hematoma during rivaroxaban treatment

    Energy Technology Data Exchange (ETDEWEB)

    Ruschel, Leonardo Gilmone; Rego, Felipe Marques Monteiro do; Milano, Jeronimo Buzetti; Jung, Gustavo Simiano; Silva Junior, Luis Fernando; Ramina, Ricardo, E-mail: leonardoruschel@yahoo.com.br [Instituto de Neurologia de Curitiba (INC), Curitiba, PR (Brazil)

    2016-11-15

    According to our research, this is the first case described in the literature of spontaneous intracranial epidural hematoma secondary to the use of Xarelto®. Spontaneous intracranial epidural hematomas are rarely described in the literature. They are associated with infectious diseases of the skull, coagulation disorders, vascular malformations of the dura mater and metastasis to the skull. Long-term post-marketing monitoring and independent reports will probably detect the full spectrum of hemorrhagic complications of the use of rivaroxaban. (author)

  17. Spontaneous intracranial epidural hematoma during rivaroxaban treatment.

    Science.gov (United States)

    Ruschel, Leonardo Gilmone; Rego, Felipe Marques Monteiro do; Milano, Jerônimo Buzetti; Jung, Gustavo Simiano; Silva, Luis Fernando; Ramina, Ricardo

    2016-11-01

    According to our research, this is the first case described in the literature of spontaneous intracranial epidural hematoma secondary to the use of Xareltor. Spontaneous intracranial epidural hematomas are rarely described in the literature. They are associated with infectious diseases of the skull, coagulation disorders, vascular malformations of the dura mater and metastasis to the skull. Long-term post-marketing monitoring and independent reports will probably detect the full spectrum of hemorrhagic complications of the use of rivaroxaban.

  18. Spontaneous resolution of asymptomatic Chlamydia trachomatis in pregnancy.

    Science.gov (United States)

    Sheffield, Jeanne S; Andrews, Williams W; Klebanoff, Mark A; Macpherson, Cora; Carey, J Christopher; Ernest, J M; Wapner, Ronald J; Trout, Wayne; Moawad, Atef; Miodovnik, Menachem; Sibai, Baha; Varner, Michael W; Caritis, Steve N; Dombrowski, Mitchell; Langer, Oded; O'Sullivan, Mary J

    2005-03-01

    We sought to estimate the rate of spontaneous resolution of asymptomatic Chlamydia trachomatis in pregnancy and to evaluate factors associated with its resolution. A cohort of women enrolled in a large multicenter randomized bacterial vaginosis antibiotic trial (metronidazole versus placebo) that, when randomly allocated, had asymptomatic C trachomatis diagnosed by urine ligase chain reaction (from frozen archival specimens) between 16(0/7) and 23(6/7) weeks were included. The urine ligase chain reaction is a highly accurate predictor of genital tract chlamydial infection. A follow-up ligase chain reaction was performed between 24(0/7) and 29(6/7) weeks. A total of 1,953 women were enrolled in the original antibiotic trial; 1,547 (79%) had ligase chain reaction performed both at randomization and follow-up. Women receiving antibiotics effective against Chlamydia between randomization and follow-up or having symptomatic Chlamydia infection were excluded (26 women). Of the 140 women (9%) who were diagnosed as positive via the initial ligase chain reaction assay, 61 (44%) had spontaneous resolution of Chlamydia by the follow-up ligase chain reaction assay. Factors associated with spontaneous resolution included older age (P = .02), more than 5 weeks from randomization to follow-up (P = .02), and a greater number of lifetime sexual partners (P = .02). Using a logistic regression model, maternal age and a greater-than-5-week follow-up interval remained significant; for every 5-year increase in maternal age, the odds of a positive result on the ligase chain reaction test at follow-up decreased by 40% (odds ratio 0.6; 95% confidence interval 0.4-0.9). Race, substance abuse, parity, and treatment with metronidazole were not associated with spontaneous resolution. Gram stain score and vaginal pH at randomization and follow-up also were not associated. The prevalence of asymptomatic C trachomatis in pregnancy was 9%; infection resolved spontaneously in almost half of these

  19. FEL gain optimisation and spontaneous radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bali, L.M.; Srivastava, A.; Pandya, T.P. [Lucknow Univ. (India)] [and others

    1995-12-31

    Colson have evaluated FEL gains for small deviations from perfect electron beam injection, with radiation of the same polarisation as that of the wiggler fields. We find that for optimum gain the polarisation of the optical field should be the same as that of the spontaneous emission under these conditions. With a helical wiggler the axial oscillations resulting from small departures from perfect electron beam injection lead to injection dependent unequal amplitudes and phases of the spontaneous radiation in the two transverse directions. Viewed along the axis therefore the spontaneous emission is elliptically polarised. The azimuth of the ellipse varies with the difference of phase of the two transverse components of spontaneous emission but the eccentricity remains the same. With planar wigglers the spontaneous emission viewed in the axial direction is linearly polarised, again with an injection dependent azimuth. For optimum coherent gain of a radiation field its polarisation characteristics must be the same as those of the spontaneous radiation with both types of wiggler. Thus, with a helical wiggler and the data reported earlier, an increase of 10% in the FEL gain at the fundamental frequency and of 11% at the fifth harmonic has been calculated in the small gain per pass limit. Larger enhancements in gain may result from more favourable values of input parameters.

  20. Is there a predilection for breech infants to demonstrate spontaneous stabilization of DDH instability?

    Science.gov (United States)

    Sarkissian, Eric J; Sankar, Wudbhav N; Baldwin, Keith; Flynn, John M

    2014-01-01

    Breech position subjects the fetal hip to abnormal mechanical forces. However, unlike genetic or tissue factors linked to developmental dysplasia of the hip (DDH), the causative effect of the breech position ends when the infant is born. The purpose of this study was to evaluate the rate of spontaneous stabilization in mildly unstable hips of breech-presenting infants compared with similarly lax hips in infants with a genetic or tissue-related cause of DDH. We studied a consecutive series of infants presenting to our institution at 8 weeks of age or younger with DDH from January 2008 to January 2012. Infants with increased hip laxity on dynamic ultrasound examination but without frank instability on clinical provocation maneuvers and no history of prior treatment were evaluated. The endpoint was spontaneous stabilization of ultrasound-detected instability, or intervention due to persistent instability on follow-up dynamic ultrasound. A logistic regression model using backward likelihood ratio method was used to analyze predictors of spontaneous stabilization. We identified 122 hips in 79 infants with instability on dynamic ultrasound evaluation but with stable clinical examinations. Spontaneous stabilization of sonographic instability occurred in 90 hips (74%) at a mean age of 9 weeks (range, 4 to 18 wk). Breech hips more frequently spontaneously stabilized compared with nonbreech hips (80% vs. 66%). Regression analysis determined that breech presentation was a strong independent predictor for spontaneous hip stabilization (odds ratio, 3.72; 95% confidence interval, 1.45-9.60; P=0.006). Sex, family history, intrauterine positioning syndromes, side involved, bilateralism, and grade of sonographic hip instability were not independently predictive of spontaneous hip stabilization. DDH infants with a history of breech presentation are 3.72 times more likely to experience spontaneous resolution of mild hip instability compared with nonbreech infants. Awareness that

  1. Spontaneous abortions in sibship of children with congenital malformation or malignant disease.

    Science.gov (United States)

    Spira, A; Lazar, P

    1979-04-01

    Parents of 751 children affected by cancer/leukemia, congenital heart disease, strawberry nevus or mental retardation have been investigated with respect to their reproductive history and their exposure to risk factors for spontaneous abortion. Differences between the four groups were established for the number of children in the sibship, the proportion of multigravidae and the spontaneous abortion rate among these women. The greatest differences were observed in the two groups of malformed children compared with the other two groups, being as marked in those with a severe malformation (heart defect) as in those with a benign one (strawberry nevus). Taking known risk factors for spontaneous abortion into account did not explain the observed differences. An etiological hypothesis is put forward which takes account of the high proportion of quantitative abnormalities of the karyotype associated with congenital heart disease and spontaneous abortion.

  2. Spontaneous emission of an atom in the presence of nanobodies

    International Nuclear Information System (INIS)

    Klimov, Vasilii V; Ducloy, M; Letokhov, V S

    2001-01-01

    The effect of nanobodies, i.e., the bodies whose size is small compared to the emission wavelength, on spontaneous emission of an atom located near them is considered. The results of calculations performed within the framework of quantum and classical electrodynamics are presented both in analytic and graphical forms and can be readily used for planning experiments and analysis of experimental data. It is shown that nanobodies can be used to control efficiently the rate of spontaneous transitions. Thus, an excited atom located near a nanocylinder or a nanospheroid pole, whose transition dipole moment is directed normally to the nanobody surface, can decay with the rate that is tens and hundreds times higher than the decay rate in a free space. In the case of some (negative) dielectric constants, the decay rate can increase by a factor of 10 5 -10 6 and more. On the other hand, the decay of an excited atom whose transition dipole moment is directed tangentially to the nanobody surface substantially slows down. The probability of nonradiative decay of the excited state is shown to increase substantially in the presence of na-nobodies possessing losses. (review)

  3. Spontaneous activity in the statoacoustic ganglion of the chicken embryo.

    Science.gov (United States)

    Jones, T A; Jones, S M

    2000-03-01

    Statoacoustic ganglion cells in the mature bird include neurons that are responsive to sound (auditory) and those that are not (nonauditory). Those that are nonauditory have been shown to innervate an otolith organ, the macula lagena, whereas auditory neurons innervate the basilar papilla. In the present study, single-unit recordings of statoacoustic ganglion cells were made in embryonic (E19, mean = 19.2 days of incubation) and hatchling (P6-P14, mean = 8.6 days posthatch) chickens. Spontaneous activity from the two age groups was compared with developmental changes. Activity was evaluated for 47 auditory, 11 nonauditory, and 6 undefined eighth nerve neurons in embryos and 29 auditory, 26 nonauditory, and 1 undefined neurons in hatchlings. For auditory neurons, spontaneous activity displayed an irregular pattern [discharge interval coefficient of variation (CV) was >0.5, mean CV for embryos was 1.46 +/- 0.58 and for hatchlings was 1.02 +/- 0.25; means +/- SD]. Embryonic discharge rates ranged from 0.05 to 97.6 spikes per second (sp/s) for all neurons (mean 18.6 +/- 16.9 sp/s). Hatchling spontaneous rates ranged from 1.2 to 185.2 sp/s (mean 66.5 +/- 39.6 sp/s). Discharge rates were significantly higher for hatchlings (P embryonic auditory neurons displayed long silent periods between irregular bursts of neural activity, a feature not seen posthatch. All regular bursting discharge patterns were correlated with heart rate in both embryos and hatchlings. Preferred intervals were visible in the time interval histograms (TIHs) of only one embryonic neuron in contrast to 55% of the neurons in posthatch animals. Generally, the embryonic auditory TIH displayed a modified quasi-Poisson distribution. Nonauditory units generally displayed regular (CV 0.5) activity and Gaussian and modified-Gaussian TIHs. Long silent periods or bursting patterns were not a characteristic of embryonic nonauditory neurons. CV varied systematically as a function of discharge rate in nonauditory

  4. Spontaneous body movements in spatial cognition

    Directory of Open Access Journals (Sweden)

    Sergiu eTcaci Popescu

    2012-05-01

    Full Text Available People often perform spontaneous body movements during spatial tasks such as giving complex directions or orienting themselves on maps. How are these spontaneous gestures related to spatial problem-solving? We measured spontaneous movements during a perspective-taking task inspired by map reading. Analyzing the motion data to isolate rotation and translation components of motion in specific geometric relation to the task, we found out that most participants executed spontaneous miniature rotations of the head that were significantly related to the main task parameter. These head rotations were as if participants were trying to align themselves with the orientation on the map either in the image plane or on the ground plane, but with tiny amplitudes, typically below 1% of the actual movements. Our results are consistent with a model of sensorimotor prediction driving spatial reasoning. The efference copy of planned movements triggers this prediction mechanism. The movements themselves may then be mostly inhibited; the small spontaneous gestures that we measure are the visible traces of these planned but inhibited actions.

  5. Bilateral spontaneous rupture of 'hale' kidneys

    International Nuclear Information System (INIS)

    Naumov, N.; Zozikov, B.; Otzetov, A.; Kamenova, M.; Martinova, F.; Kalyonski, R.

    2002-01-01

    A rare case of spontaneous bilateral rupture of the kidneys, occurring consecutively over a one-year period in a young male patient with 'hale' kidneys until then, is described. The patient's past history and thorough examination performed do not justify to assign the case under the heading of some of the etiological factors as the underlying cause of spontaneous kidney rupture. The literature survey on spontaneous bilateral non-tumor ruptures of kidneys shows that over a 20-year period, only 3 cases of bilateral spontaneous ruptures have been reported. It is pointed out that panarteritis nodosa followed by hemorrhagic fever with renal syndrome is the commonest underlying cause of such ruptures. Clinically spontaneous ruptures become manifest with emergency condition presenting severe renal colic, impaired to serious general condition, often with acute abdomen and hemodynamic breakdown, and no past history evidence of renal disease or injury. In the initial phase diagnosing is not always easy; it is usually made on the ground of physical examination and the full range of imaging studies used in urological practice and during operative treatment. Emphasis is laid on the fact that the imaging methods are not invariably sufficient to identify the exact etiological factor giving rise to such a severe condition, but nevertheless these methods have an essential practical bearing on diagnosing a rupture. (authors)

  6. Surgical management of spontaneous hypertensive brainstem hemorrhage

    Directory of Open Access Journals (Sweden)

    Bal Krishna Shrestha

    2015-09-01

    Full Text Available Spontaneous hypertensive brainstem hemorrhage is the spontaneous brainstem hemorrhage associated with long term hypertension but not having definite focal or objective lesion. It is a catastrophic event which has a poor prognosis and usually managed conservatively. It is not uncommon, especially in eastern Asian populations, accounting approximately for 10% of the intracerebral hemorrhage. Before the advent of computed tomography, the diagnosis of brainstem hemorrhage was usually based on the clinical picture or by autopsy and believed to be untreatable via surgery. The introduction of computed tomography permitted to categorize the subtypes of brainstem hemorrhage with more predicted outcome. Continuous ongoing developments in the stereotactic surgery and microsurgery have added more specific surgical management in these patients. However, whether to manage conservatively or promptly with surgical evacuation of hematoma is still a controversy. Studies have shown that an accurate prognostic assessment based on clinical and radiological features on admission is critical for establishing a reasonable therapeutic approach. Some authors have advocate conservative management, whereas others have suggested the efficacy of surgical treatment in brainstem hemorrhage. With the widening knowledge in microsurgical techniques as well as neuroimaging technology, there seems to have more optimistic hope of surgical management of spontaneous hypertensive brainstem hemorrhage for better prognosis. Here we present five cases of severe spontaneous hypertensive brainstem hemorrhage patients who had undergone surgery; and explore the possibilities of surgical management in patients with the spontaneous hypertensive brainstem hemorrhage.

  7. Cursed lamp: the problem of spontaneous abortion.

    Science.gov (United States)

    Simkulet, William

    2017-08-09

    Many people believe human fetuses have the same moral status as adult human persons, that it is wrong to allow harm to befall things with this moral status, and thus voluntary, induced abortion is seriously morally wrong. Recently, many prochoice theorists have argued that this antiabortion stance is inconsistent; approximately 60% of human fetuses die from spontaneous abortion, far more than die from induced abortion, so if antiabortion theorists really believe that human fetuses have significant moral status, they have strong moral obligations to oppose spontaneous abortion. Yet, few antiabortion theorists devote any effort to doing so. Many prochoice theorists argue that to resolve this inconsistency, antiabortion theorists should abandon their opposition to induced abortion. Here, I argue that those who do not abandon their opposition to induced abortion but continue to neglect spontaneous abortion act immorally. Aristotle argues that moral responsibility requires both control and awareness; I argue that once an antiabortion theorist becomes aware of the frequency of spontaneous abortion, they have a strong moral obligation to redirect their efforts towards combating spontaneous abortion; failure to do so is morally monstrous. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. Evidence that Illness-Compatible Cues Are Rewarding in Women Recovered from Anorexia Nervosa: A Study of the Effects of Dopamine Depletion on Eye-Blink Startle Responses.

    Directory of Open Access Journals (Sweden)

    Caitlin B O'Hara

    Full Text Available In anorexia nervosa (AN, motivational salience is attributed to illness-compatible cues (e.g., underweight and active female bodies and this is hypothesised to involve dopaminergic reward circuitry. We investigated the effects of reducing dopamine (DA transmission on the motivational processing of AN-compatible cues in women recovered from AN (AN REC, n = 17 and healthy controls (HC, n = 15. This involved the acute phenylalanine and tyrosine depletion (APTD procedure and a startle eye-blink modulation (SEM task. In a balanced amino acid state, AN REC showed an increased appetitive response (decreased startle potentiation to illness-compatible cues (underweight and active female body pictures (relative to neutral and non-active cues, respectively. The HC had an aversive response (increased startle potentiation to the same illness-compatible stimuli (relative to neutral cues. Importantly, these effects, which may be taken to resemble symptoms observed in the acute stage of illness and healthy behaviour respectively, were not present when DA was depleted. Thus, AN REC implicitly appraised underweight and exercise cues as more rewarding than did HC and the process may, in part, be DA-dependent. It is proposed that the positive motivational salience attributed to cues of emaciation and physical activity is, in part, mediated by dopaminergic reward processes and this contributes to illness pathology. These observations are consistent with the proposal that, in AN, aberrant reward-based learning contributes to the development of habituation of AN-compatible behaviours.

  9. Dopamine and the management of attentional resources: genetic markers of striatal D2 dopamine predict individual differences in the attentional blink.

    Science.gov (United States)

    Colzato, Lorenza S; Slagter, Heleen A; de Rover, Mischa; Hommel, Bernhard

    2011-11-01

    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 AB can be predicted by differences in genetic predisposition related to the efficiency of dopaminergic pathways. Polymorphisms related to mesocortical and nigrostriatal dopaminergic pathways were considered, as well as polymorphisms related to norepinephrine (NE), a transmitter system that has also been suspected to play a role in the AB. In a sample of 157 healthy adults, we studied the dependency of the individual magnitude of the AB and the C957T polymorphism at the DRD2 gene (associated with striatal DA/D2 receptors), the DARPP32 polymorphism (associated with striatal DA/D1), the COMT Val(158)Met polymorphism (associated with frontal DA), DBH444 g/a and DBH5'-ins/del polymorphisms (polymorphisms strongly correlated with DA beta hydroxylase, the enzyme catalyzing the DA-NE conversion) and NET T-182C (a polymorphism related to the NE transporter). DRD2 C957T T/T homozygotes showed a significantly smaller AB, whereas polymorphisms associated with frontal DA and NE were unrelated to performance. This outcome pattern suggests a crucial role of the nigrostriatal dopaminergic pathway and of nigrostriatal D2 receptors, in particular, in the management of attentional resources.

  10. Two-state theory of binned photon statistics for a large class of waiting time distributions and its application to quantum dot blinking

    Energy Technology Data Exchange (ETDEWEB)

    Volkán-Kacsó, Sándor [Noyes Laboratory of Chemical Physics, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125 (United States)

    2014-06-14

    A theoretical method is proposed for the calculation of the photon counting probability distribution during a bin time. Two-state fluorescence and steady excitation are assumed. A key feature is a kinetic scheme that allows for an extensive class of stochastic waiting time distribution functions, including power laws, expanded as a sum of weighted decaying exponentials. The solution is analytic in certain conditions, and an exact and simple expression is found for the integral contribution of “bright” and “dark” states. As an application for power law kinetics, theoretical results are compared with experimental intensity histograms from a number of blinking CdSe/ZnS quantum dots. The histograms are consistent with distributions of intensity states around a “bright” and a “dark” maximum. A gap of states is also revealed in the more-or-less flat inter-peak region. The slope and to some extent the flatness of the inter-peak feature are found to be sensitive to the power-law exponents. Possible models consistent with these findings are discussed, such as the combination of multiple charging and fluctuating non-radiative channels or the multiple recombination center model. A fitting of the latter to experiment provides constraints on the interaction parameter between the recombination centers. Further extensions and applications of the photon counting theory are also discussed.

  11. Two-state theory of binned photon statistics for a large class of waiting time distributions and its application to quantum dot blinking.

    Science.gov (United States)

    Volkán-Kacsó, Sándor

    2014-06-14

    A theoretical method is proposed for the calculation of the photon counting probability distribution during a bin time. Two-state fluorescence and steady excitation are assumed. A key feature is a kinetic scheme that allows for an extensive class of stochastic waiting time distribution functions, including power laws, expanded as a sum of weighted decaying exponentials. The solution is analytic in certain conditions, and an exact and simple expression is found for the integral contribution of "bright" and "dark" states. As an application for power law kinetics, theoretical results are compared with experimental intensity histograms from a number of blinking CdSe/ZnS quantum dots. The histograms are consistent with distributions of intensity states around a "bright" and a "dark" maximum. A gap of states is also revealed in the more-or-less flat inter-peak region. The slope and to some extent the flatness of the inter-peak feature are found to be sensitive to the power-law exponents. Possible models consistent with these findings are discussed, such as the combination of multiple charging and fluctuating non-radiative channels or the multiple recombination center model. A fitting of the latter to experiment provides constraints on the interaction parameter between the recombination centers. Further extensions and applications of the photon counting theory are also discussed.

  12. Spontaneous excitation of a static multilevel atom coupled with electromagnetic vacuum fluctuations in Schwarzschild spacetime

    International Nuclear Information System (INIS)

    Zhou Wenting; Yu Hongwei

    2012-01-01

    We study the spontaneous excitation of a radially polarized static multilevel atom outside a spherically symmetric black hole in multipolar interaction with quantum electromagnetic fluctuations in the Boulware, Unruh and Hartle-Hawking vacuum states. We find that spontaneous excitation does not occur in the Boulware vacuum, and, in contrast to the scalar field case, the spontaneous emission rate is not well behaved at the event horizon as a result of the blow-up of the proper acceleration of the static atom. However, spontaneous excitation can take place both in the Unruh and the Hartle-Hawking vacua as if there were thermal radiation from the black hole. Distinctive features in contrast to the scalar field case are the existence of a term proportional to the proper acceleration squared in the rate of change of the mean atomic energy in the Unruh and the Hartle-Hawking vacua and the structural similarity in the spontaneous excitation rate between the static atoms outside a black hole and uniformly accelerated ones in a flat space with a reflecting boundary, which is particularly dramatic at the event horizon where a complete equivalence exists. (paper)

  13. [Difference between perinatal mortality in multiple pregnancies obtained spontaneously versus assisted reproduction].

    Science.gov (United States)

    del Rayo Rivas-Ortiz, Yazmín; Hernández-Herrera, Ricardo Jorge

    2010-06-01

    Recently assisted reproduction techniques are more common, which increases multiple pregnancies and adverse perinatal outcomes. Some authors report increased mortality in multiple pregnancies products obtained by techniques of assisted reproduction vs. conceived spontaneously, although other authors found no significant difference. To evaluate mortality rate of multiple pregnancies comparing those obtained by assisted reproduction vs. spontaneous conception. Retrospective, observational and comparative study. We included pregnant women with 3 or more products that went to the Unidad Médica de Alta Especialidad No. 23, IMSS, in Monterrey, NL (Mexico), between 2002-2008. We compared the number of complicated pregnancies and dead products obtained by a technique of assisted reproduction vs. spontaneous. 68 multiple pregnancies were included. On average, spontaneously conceived fetuses had more weeks of gestation and more birth weight than those achieved by assisted reproduction techniques (p = ns). 20.5% (14/68) of multiple pregnancies had one or more fatal events: 10/40 (25%) by assisted reproduction techniques vs. 4/28 (14%) of spontaneous multiple pregnancies (p = 0.22). 21/134 (16%) of the products conceived by assisted reproduction techniques and 6/88 (7%) of spontaneous (p assisted reproduction and 21% of the cases had one or more fatal events (11% more in pregnancies achieved by assisted reproduction techniques). 12% of the products of multiple pregnancies died (9% more in those obtained by a technique of assisted reproduction).

  14. Spontaneous swallow frequency compared with clinical screening in the identification of dysphagia in acute stroke.

    Science.gov (United States)

    Crary, Michael A; Carnaby, Giselle D; Sia, Isaac

    2014-09-01

    The aim of this study was to compare spontaneous swallow frequency analysis (SFA) with clinical screening protocols for identification of dysphagia in acute stroke. In all, 62 patients with acute stroke were evaluated for spontaneous swallow frequency rates using a validated acoustic analysis technique. Independent of SFA, these same patients received a routine nurse-administered clinical dysphagia screening as part of standard stroke care. Both screening tools were compared against a validated clinical assessment of dysphagia for acute stroke. In addition, psychometric properties of SFA were compared against published, validated clinical screening protocols. Spontaneous SFA differentiates patients with versus without dysphagia after acute stroke. Using a previously identified cut point based on swallows per minute, spontaneous SFA demonstrated superior ability to identify dysphagia cases compared with a nurse-administered clinical screening tool. In addition, spontaneous SFA demonstrated equal or superior psychometric properties to 4 validated, published clinical dysphagia screening tools. Spontaneous SFA has high potential to identify dysphagia in acute stroke with psychometric properties equal or superior to clinical screening protocols. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  15. Sympathovagal effects of spinal anesthesia assessed by the spontaneous cardiac baroreflex.

    Science.gov (United States)

    Gratadour, P; Viale, J P; Parlow, J; Sagnard, P; Counioux, H; Bagou, G; Annat, G; Hughson, R; Quintin, L

    1997-12-01

    The changes in sympathovagal balance induced by spinal anesthesia remain controversial. The spontaneous baroreflex method allows the continuous assessment of the spontaneous engagement of the cardiac baroreflex, giving an index of sympathovagal balance. The purpose of this study was to follow the effects of spinal anesthesia on spontaneous baroreflex sensitivity. Continuous electrocardiogram and noninvasive blood pressure were recorded in 24 patients scheduled for elective inguinal hernia repair and randomly assigned to three groups: (1) no volume loading, (2) volume loading of 15 ml/kg lactated Ringer's solution, and (3) continuous infusion of etilefrine (an ephedrine-like drug). Each patient was studied before, during, and after bupivacaine-induced spinal anesthesia (mean sensory block: T4). Spontaneous baroreflex sensitivity and parameters of time-domain analysis of heart rate variability were calculated from 30 min of recording of each period. No significant change in spontaneous baroreflex slope or parameters of time-domain analysis were observed after regional anesthesia in any group. However, three patients experienced episodes of bradycardia and hypotension in the absence of a high block; these three patients showed an increase in spontaneous baroreflex sensitivity and time-domain parameters. Using a noninvasive, continuous technique to estimate cardiac sympathovagal balance, no significant variation in autonomic balance induced by spinal anesthesia was observed. However, untoward episodes of bradycardia and hypotension occurred in three patients, who could not be prospectively identified by the parameters studied.

  16. Spontaneous Regression of Lumbar Herniated Disc

    Directory of Open Access Journals (Sweden)

    Chun-Wei Chang

    2009-12-01

    Full Text Available Intervertebral disc herniation of the lumbar spine is a common disease presenting with low back pain and involving nerve root radiculopathy. Some neurological symptoms in the majority of patients frequently improve after a period of conservative treatment. This has been regarded as the result of a decrease of pressure exerted from the herniated disc on neighboring neurostructures and a gradual regression of inflammation. Recently, with advances in magnetic resonance imaging, many reports have demonstrated that the herniated disc has the potential for spontaneous regression. Regression coincided with the improvement of associated symptoms. However, the exact regression mechanism remains unclear. Here, we present 2 cases of lumbar intervertebral disc herniation with spontaneous regression. We review the literature and discuss the possible mechanisms, the precipitating factors of spontaneous disc regression and the proper timing of surgical intervention.

  17. Spontaneous hemothorax: primary pleural epithelioid angiosarcoma

    Directory of Open Access Journals (Sweden)

    Amit Panjwani

    2016-01-01

    Full Text Available Spontaneous hemothorax is a rare condition seen in coagulation and vascular disorders. Uncommonly, malignant neoplasms may cause spontaneous hemothorax. Primary pleural epithelioid angiosarcomas (excluding the cases with pleuropulmonary or chest wall involvement are extremely rare pleural tumors, which may be mistaken for mesothelioma or adenocarcinoma, and only 19 cases (one of them from India have been reported in the English literature, to date. It commonly occurs in older men, has a nonspecific clinicoradiological presentation, and carries a poor prognosis with no survivors beyond a year of establishing the diagnosis. We report a case of primary pleural epithelioid angiosarcoma presenting as a life-threatening spontaneous hemothorax. We also present a brief literature review on pleural angiosarcoma.

  18. Spontaneous Perforation of Pyometra: A Case Report

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Pyometra is the accumulation of purulent material in the uterine cavity. Its reported incidence is 0.01–0.5% in gynecologic patients; however, as far as elderly patients are concerned, its incidence is 13.6% [3]. The most common cause of pyometra is malignant diseases of genital tract and the consequences of their treatment (radiotherapy. Other causes are benign tumors like leiomyoma, endometrial polyps, senile cervicitis, cervical occlusion after surgery, puerperal infections, and congenital cervical anomalies. Spontaneous rupture of the uterus is an extremely rare complication of pyometra. To our knowledge, only 21 cases of spontaneous perforation of pyometra have been reported in English literature since 1980. This paper reports an additional case of spontaneous uterine rupture.

  19. Spontaneous dyskinesia in first-episode psychosis in a Southeast Asian population.

    Science.gov (United States)

    Lee, Jimmy; Poon, Lye-Yin; Chong, Siow-Ann

    2008-10-01

    Spontaneous dyskinesia in first-episode psychosis was described previously with varying incidence rates ranging from zero to 53%. Dyskinesia was also found to be more common in siblings of patients with both schizophrenia and dyskinesia. This condition was linked with structural brain abnormalities and posited to be another subtype of schizophrenia with striatal pathology. Whether there are ethnic variations in the rates of spontaneous dyskinesia is unknown because of the paucity of studies in this area. This study aims to establish the rates of spontaneous dyskinesia in a Southeast Asian population of drug-naive patients experiencing their first psychotic episode and to examine the clinical correlates. A total of 908 patients were examined, of which, 76.1% were Chinese; 15.4%, Malays; 6.2%, Indians; and 2.3%, from other minor ethnic groups. Schizophrenia was diagnosed in 48.9% of the population. There were 3 patients of Chinese descent who had "minimal" or "mild" dyskinetic movements when rated with the Abnormal Involuntary Movement Scale, but none fulfilled the Schooler and Kane criteria for spontaneous dyskinesia. Their dyskinetic movements resolved when reassessed 3 and 6 months after treatment with antipsychotic medications. Of the 3 patients, 2 were treatment resistant and subsequently treated with clozapine. This is the largest study to date examining the prevalence of spontaneous dyskinesia. We hypothesize that there is an ethnically based difference in the rates of spontaneous dyskinesia that could reflect underlying genetic variations. Patients with dyskinetic movements at baseline could have a more treatment refractory course of illness.

  20. On spontaneous breakdown in Σ-models

    International Nuclear Information System (INIS)

    Ivanov, E.A.

    1975-01-01

    The group theory aspects of spontaneous breakdown in linear Σ-models are discussed. General conditions are formulated under which multiplet of group G (compact or noncompact) is suitable for constructing the Σ-model with a given subgroup of stability of vacuum. It is shown that the Σ-models of spontaneously broken space-time symmetries can be constructed in general only if some extra coordinates are introduced in addition to an ordinary 4-coordinate xsub(μ). The connection between Σ-models of internal symmetries and appropriate nonlinear realizations has also been investigated

  1. Two cases of spontaneous temporal encephalocele.

    Science.gov (United States)

    Kamiya, Kouhei; Mori, Harushi; Kunimatsu, Akira; Kawai, Kensuke; Usami, Kenichi; Ohtomo, Kuni

    2012-12-01

    This is a report of two cases of spontaneous temporal encephalocele: one was anteroinferior and presented with epilepsy; the other was posteroinferior and presented with facial neuritis and labyrinthitis. Spontaneous temporal encephalocele is relatively rare and apparently not familiar to a majority of primary physicians. It may present with a variety of symptoms according to its anatomical location, including cerebrospinal fluid fistulas, recurrent meningitis, chronic otitis media, hearing loss, facial nerve palsy and medically intractable epilepsy. Attention should be paid to this disease entity, as it is easily overlooked in imaging studies and can leave serious neurological deficits. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  2. Spontaneous abortion and physical strain around implantation

    DEFF Research Database (Denmark)

    Hjollund, N H; Jensen, Tina Kold; Bonde, Jens Peter

    2000-01-01

    Existing studies of physical strain and spontaneous abortion are mainly retrospective or based only on pregnancies that have survived the first trimester. Furthermore, almost all studies have relied on averaged measures of physical strain, which tend to blur an effect if peak values during short...... pregnancy the women recorded physical strain prospectively in a structured diary. Physical strain around the time of implantation was associated with later spontaneous abortion. The adjusted risk ratio for women who reported physical strain higher than average at day 6 to 9 after the estimated date...

  3. Need for spontaneous breakdown of chiral symmetry

    International Nuclear Information System (INIS)

    Salomone, A.; Schechter, J.; Tudron, T.

    1981-01-01

    The question of whether the chiral symmetry of the theory of strong interactions (with massless quarks) is required to be spontaneously broken is examined in the framework of a previously discussed effective Lagrangian for quantum chromodynamics. The assumption that physical masses of the theory be finite leads in a very direct way to the necessity of spontaneous breakdown. This result holds for all N/sub F/> or =2, where N/sub F/ is the number of different flavors of light quarks. The atypical cases N/sub F/ = 1,2 are discussed separately

  4. Spontaneous subdural hematoma associated to Duret hemorrhage

    Directory of Open Access Journals (Sweden)

    William Alves Martins, MD

    2015-03-01

    Full Text Available Subdural hematoma (SH is a neurosurgical emergency, usually caused by head trauma. Non-traumatic causes include aneurysm or arterial–venous malformation rupture, coagulopathy and others. We report the case of a 66 year-old man who developed apparently unprovoked signs of increased intracranial pressure. Brain computed tomography scan showed an acute spontaneous SH, surgically treated. Throughout surgery, a ruptured cortical artery with intensive bleeding appeared and was cauterized. After surgery, patient remained comatose and a new CT demonstrated Duret hemorrhage at the brainstem. Acute spontaneous SH of arterial origin is rare and highly lethal, in which a good prognosis relies on early diagnosis and treatment.

  5. Primer on spontaneous heating and pyrophoricity

    Energy Technology Data Exchange (ETDEWEB)

    1994-12-01

    This primer was prepared as an information resource for personnel responsible for operation of DOE nuclear facilities. It has sections on combustion principles, spontaneous heating/ignition of hydrocarbons and organics, pyrophoric gases and liquids, pyrophoric nonmetallic solids, pyrophoric metals (including Pu and U), and accident case studies. Although the information in this primer is not all-encompassing, it should provide the reader with a fundamental knowledge level sufficient to recognize most spontaneous combustion hazards and how to prevent ignition and widespread fires. This primer is provided as an information resource only, and is not intended to replace any fire protection or hazardous material training.

  6. Cavity enhanced rephased amplified spontaneous emission

    International Nuclear Information System (INIS)

    A Williamson, Lewis; J Longdell, Jevon

    2014-01-01

    Amplified spontaneous emission is usually treated as an incoherent noise process. Recent theoretical and experimental work using rephasing optical pulses has shown that rephased amplified spontaneous emission (RASE) is a potential source of wide bandwidth time-delayed entanglement. Due to poor echo efficiency the plain RASE protocol does not in theory achieve perfect entanglement. Experiments done to date show a very small amount of entanglement at best. Here we show that RASE can, in principle, produce perfect multimode time-delayed two mode squeezing when the active medium is placed inside a Q-switched cavity. (paper)

  7. Spontaneous supersymmetry breaking on the lattice

    Energy Technology Data Exchange (ETDEWEB)

    Wenger, Urs [Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland)

    2013-07-01

    We discuss various strategies for regularising supersymmetric quantum field theories on a space-time lattice. In general, simulations of lattice models with spontaneously broken supersymmetry suffer from a fermion sign problem related to the vanishing of the Witten index. We discuss a novel approach which evades this problem in low dimensions by formulating the path integral on the lattice in terms of fermion loops. Then we present exact results on the spectrum and the Witten index for N=2 supersymmetric quantum mechanics and results from simulations of the spontaneously broken N=1 Wess-Zumino model.

  8. INVESTIGATION OF SPONTANEOUS COMBUSTION TENDENCY

    Directory of Open Access Journals (Sweden)

    Ivan HRUŠOVSKÝ

    2015-12-01

    Full Text Available The potential of vegetable oils to undergo violent thermal oxidation is long-known problem. The process of this oxidation is investigated by the means of differential thermal analysis. Polyurethane foam was saturated with Tung oil rich in unsaturated fatty acids at three different mass rations, and airfl ow at three different rates is introduces to the sample to ensure suffi cient volume of air for oxidation. The samples were thermally stressed both dynamically and isothermally. The results were compared to results of standard differential Mackey test.

  9. Multivariate prediction of spontaneous repetitive responses in ventricular myocardium exposed in vitro to simulated ischemic conditions.

    Science.gov (United States)

    Schiariti, M; Puddu, P E; Rouet, R

    1994-06-01

    Guinea-pig ventricular myocardium was partly exposed to normal Tyrode's superfusion and partly to altered conditions (using modified Tyrode's solution) set to simulate acute myocardial ischemia (PO2 80 +/- 10 mmHg; no glucose; pH 7.00 +/- 0.05; K+ 12 mM). Using a double-chamber tissue bath and standard microelectrode technique, the occurrence of spontaneous repetitive responses was investigated during simulated ischemia (occlusion) and after reperfusing the previously ischemic superfused tissue with normal Tyrode's solution (reperfusion). In 62 experiments (42 animals) the effects of: (1) duration of simulated ischemia (1321 +/- 435 s), (2) stimulation rate (1002 +/- 549 ms) and (3) number of successive simulated ischemic periods (occlusions) (1.58 +/- 0.92) on: (1) resting membrane potential, (2) action potential amplitude, (3) duration of 50 and 90% action potentials and (4) maximal upstroke velocity of action potential were studied. All variables were considered as gradients (delta) between normal and ischemic tissue. Both during occlusion and upon reperfusion, spontaneous repetitive responses were coded as single, couplets, salvos (three to nine and > 10) or total spontaneous repetitive responses (coded present when at least one of the above-mentioned types was seen). The incidence of total spontaneous repetitive responses was 31% (19/62) on occlusion and 85% (53/62) upon reperfusion. Cox's models (forced and stepwise) were used to predict multivariately the occurrence of arrhythmic events considered as both total spontaneous repetitive responses and as separate entities. These models were applicable since continuous monitoring of the experiments enabled exact timing of spontaneous repetitive response onset during both occlusion and reperfusion. In predicting reperfusion spontaneous repetitive responses, total spontaneous repetitive responses and blocks observed during the occlusion period were also considered. Total occlusion spontaneous repetitive responses

  10. [Perinatal outcomes of twin pregnancies conceived through in vitro fertilization versus spontaneous].

    Science.gov (United States)

    Rubio-Cid, Paula; Alvarez-Silvares, E; Aves-Pérez, María Teresa; García-Lavandeira, Sandra; Pérez-Adán, Marta

    2015-10-01

    Determine maternal and fetal characteristics of in vitro fertilization twin pregnancies in comparison with spontaneous twin pregnancies. Retrospective historical cohort study between 2011 and 2013. Statistical analysis was performed with SPSS 15.0 program and Epidat 3.0. A value of p<0.05 was considered statistically significant. 96 twin pregnancies met inclusive criteria with an incidence of 2.01%, of which 54.16% were spontaneous twin pregnancies and 45.83% in vitro fertilization twin pregnancies. Mean maternal age at delivery was higher in vitro fertilization twin pregnancies (p=0.004). The primigravidae were more frequent in vitro fertilization twin pregnancies group (p<0.001). Monochorionic pregnancies percentage was superior in spontaneous pregnancies (p=0.009). Amenorrhea at delivery was not a significant difference between cohorts (p=.9). Preterm rate was superior in spontaneous twin pregnancies group (p=0.003). However, "great preterm deliveries" were higher in in vitro fertilization twin pregnancies (p<0.001). Significant differences were not observed in fetal presentation at delivery, first-born child birth-weight or intrauterine growth retardation between the two groups. Nevertheless, the mean birth-weight of second-born spontaneously conceived twins was higher than second-born twins of the in vitro fertilization conceived group (p=0.027). Gestational pathology presented the same distribution in both cohorts. There was no significant difference in the mode of delivery between the two groups. Total perinatal mortality rate was 20,83%o and comprised 2 first born twins and 2 second born twins. Three of the stillbirths came from the spontaneous pregnancies group and one from the in vitro fertilization group. Perinatal death was secondary to stillbirths, which we found higher in spontaneously conceived twin pregnancies due to higher number of monochorionic pregnancies.

  11. Measuring emotional and cognitive empathy using dynamic, naturalistic, and spontaneous emotion displays.

    Science.gov (United States)

    Buck, Ross; Powers, Stacie R; Hull, Kyle S

    2017-10-01

    Most measures of nonverbal receiving ability use posed expressions as stimuli. As empathy measures, such stimuli lack ecological validity, as the participant is not actually experiencing emotion. An alternative approach uses natural and dynamic displays of spontaneous expressions. The Communication of Affect Receiving Ability Test (CARAT) uses as stimuli spontaneous facial expressions and gestures filmed by an unobtrusive camera of solitary participants responding to emotional images. This article reports the development and initial validation of the CARAT-Spontaneous, Posed, Regulated (CARAT-SPR), which measures both abilities to detect emotion from spontaneous displays (emotion communication accuracy) and to differentiate spontaneous, posed, and regulated displays (expression categorization ability). Although spontaneous displays are natural responses to emotional images, posed displays involve asking the sender to display "as if" responding to a particular sort of image when no image is in fact present (simulation), while Regulated displays involve asking the sender to display "as if" responding to a particular sort of image when an image of opposite valence is in fact present (masking). Expression categorization ability involves judging deception-simulation and masking-and conceptually involves a kind of perspective-taking or cognitive empathy. Emotion communication using spontaneous clips achieved a high level of accuracy and was strongly correlated with ratings of sender expressivity. Expression categorization ability was not significantly correlated with expressivity ratings and was modestly negatively correlated with emotion communication accuracy. In a brief version of the CARAT-SPR, women showed evidence of greater emotion signal detection, whereas men reported greater confidence in expression categorization. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  12. Neural substrates of spontaneous narrative production in focal neurodegenerative disease.

    Science.gov (United States)

    Gola, Kelly A; Thorne, Avril; Veldhuisen, Lisa D; Felix, Cordula M; Hankinson, Sarah; Pham, Julie; Shany-Ur, Tal; Schauer, Guido P; Stanley, Christine M; Glenn, Shenly; Miller, Bruce L; Rankin, Katherine P

    2015-12-01

    Conversational storytelling integrates diverse cognitive and socio-emotional abilities that critically differ across neurodegenerative disease groups. Storytelling patterns may have diagnostic relevance and predict anatomic changes. The present study employed mixed methods discourse and quantitative analyses to delineate patterns of storytelling across focal neurodegenerative disease groups, and to clarify the neuroanatomical contributions to common storytelling characteristics. Transcripts of spontaneous social interactions of 46 participants (15 behavioral variant frontotemporal dementia (bvFTD), 7 semantic variant primary progressive aphasia (svPPA), 12 Alzheimer's disease (AD), and 12 healthy older normal controls (NC)) were analyzed for storytelling frequency and characteristics, and videos of the interactions were rated for patients' level of social attentiveness. Compared to controls, svPPAs told more stories and autobiographical stories, and perseverated on aspects of self during the interaction, whereas ADs told fewer autobiographical stories than NCs. svPPAs and bvFTDs were rated as less attentive to social cues. Aspects of storytelling were related to diverse cognitive and socio-emotional functions, and voxel-based anatomic analysis of structural magnetic resonance imaging revealed that temporal organization, narrative evaluations patterns, and social attentiveness correlated with atrophy corresponding to known intrinsic connectivity networks, including the default mode, limbic, salience, and stable task control networks. Differences in spontaneous storytelling among neurodegenerative groups elucidated diverse cognitive, socio-emotional, and neural contributions to narrative production, with implications for diagnostic screening and therapeutic intervention. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Wheaten ferments spontaneous fermantation in biotechnological methods

    OpenAIRE

    KAKHRAMON SANOQULOVICH RAKHMONOV; ISABAEV ISMAIL BABADJANOVICH

    2016-01-01

    In article are shown results of research of biotechnological properties of wheaten leavens of spontaneous fermentation (in the example of pea-anisetree leaven) and their analysis. Also is established influence of the given type of leavens on the basic biopolymers of the flour, on the property of the pastry and quality of bread from wheaten flour.

  14. Original article Spontaneous Pregnancy Outcome after Surgical ...

    African Journals Online (AJOL)

    2011-09-28

    Sep 28, 2011 ... Table 2: Spontaneous pregnancy in relation to postoperative semen parameters. (no statistically significant difference), comparable to the mean ages of 22, 28.4 and. 34.9 years, respectively, reported by Bach et al9, Abdel- Meguid et al10 and Baazeem et al11. The mean age of the wives who did or did.

  15. Spontaneous symmetry breakdown in gauge theories

    International Nuclear Information System (INIS)

    Scadron, M.D.

    1982-01-01

    The dynamical theory of spontaneous breakdown correctly predicts the bound states and relates the order parameters of electron-photon superconductivity and quark-gluon chiral symmetry. A similar statement cannot be made for the standard electro-weak gauge symmetry. (author)

  16. Identical Twin Primigravid Sisters -Spontaneous Labour and ...

    African Journals Online (AJOL)

    We report 2 cases of identical twin sisters, the older sibling getting married 14 months earlier but both got pregnant for their first child at about the same time and were managed by the same Obstetrician and fell into spontaneous labour within a few hours of each other. Both were delivered by emergency caesarean section ...

  17. SPONTANEOUS CP VIOLATION AND QUARK MASS AMBIGUITIES.

    Energy Technology Data Exchange (ETDEWEB)

    CREUTZ,M.

    2004-09-21

    I explore the regions of quark masses where CP will be spontaneously broken in the strong interactions. The boundaries of these regions are controlled by the chiral anomaly, which manifests itself in ambiguities in the definition of non-degenerate quark masses. In particular, the concept of a single massless quark is ill defined.

  18. 1 INFLUENCE OF SPONTANEOUS FERMENTATION ON SOME ...

    African Journals Online (AJOL)

    RopSvr

    Spontaneous fermentation has been identified to improve the quality characteristics of foods derived from them. When combined with cowpea fortification and nixtamalization, it is expected to improve the nutritional, functional, physico-chemical and sensory qualities of maize based foods thereby improving the qualities as ...

  19. Association between Nutritional Status with Spontaneous Abortion

    Directory of Open Access Journals (Sweden)

    Rahimeh Ahmadi

    2016-11-01

    Full Text Available Background: Spontaneous abortion is the most common adverse pregnancy outcome. We aimed to investigate a possible link between nutrient deficiencies and the risk of spontaneous abortion. Materials and Methods: This case-control study included the case group (n=331 experiencing a spontaneous abortion before 14 weeks of pregnancy and the control group (n=331 who were healthy pregnant women over 14 weeks of pregnancy. The participants filled out Food Frequency Questionnaire (FFQ, in which they reported their frequency of consumption for a given serving of each food item during the past three months, on a daily, weekly or monthly basis. The reported frequency for each food item was converted to a daily intake. Then, consumption of nutrients was compared between the two groups. Results: There are significant differences between the two groups regarding consumed servings/day of vegetables, bread and cereal, meat, poultry, fish, eggs, beans, fats, oils and dairy products (P=0.012, P<0.001, P=0.004, P<0.001, P=0.019, respectively. There are significant differences between the two groups in all micronutrient including folic acid, iron, vitamin C, vitamin B6, vitamin B12 and zinc (P<0.001. Conclusion: Poor nutrientions may be correlated with increased risk of spontaneous abortion

  20. Spontaneous regression of an intraspinal disc cyst

    Energy Technology Data Exchange (ETDEWEB)

    Demaerel, P.; Eerens, I.; Wilms, G. [University Hospital, Leuven (Belgium). Dept. of Radiology; Goffin, J. [Dept. of Neurosurgery, University Hospitals, Leuven (Belgium)

    2001-11-01

    We present a patient with a so-called disc cyst. Its location in the ventrolateral epidural space and its communication with the herniated disc are clearly shown. The disc cyst developed rapidly and regressed spontaneously. This observation, which has not been reported until now, appears to support focal degeneration with cyst formation as the pathogenesis. (orig.)

  1. Spontaneous rupture of an infected renal cyst

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, W.; Toelly, E.; Ebner, F.; Kullnig, P.

    1986-07-01

    Spontaneous or traumatic rupture of renal cysts is a rare occurrence. The contents of the cyst can perforate into the renal calyx system or into the perirenal space. Perforation into the peritoneal cavity has also been described (1, 2, 4, 5).

  2. Proteomic Biomarkers for Spontaneous Preterm Birth

    DEFF Research Database (Denmark)

    Kacerovsky, Marian; Lenco, Juraj; Musilova, Ivana

    2014-01-01

    This review aimed to identify, synthesize, and analyze the findings of studies on proteomic biomarkers for spontaneous preterm birth (PTB). Three electronic databases (Medline, Embase, and Scopus) were searched for studies in any language reporting the use of proteomic biomarkers for PTB published...

  3. Spontaneous emission from saturated parametric amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Ott, Johan Raunkjær; Steffensen, Henrik

    2009-01-01

    Noise performance of parametric amplifiers is typically calculated assuming un-depleted operation. However, in many applications especially when applied as regenerative amplifiers in systems based on phase shift keyed modulation schemes, this assumption is not valid. Here we show the impact...... on accumulated spontaneous emission for a parametric amplifier operated in saturation....

  4. Spontaneous Non-verbal Counting in Toddlers

    Science.gov (United States)

    Sella, Francesco; Berteletti, Ilaria; Lucangeli, Daniela; Zorzi, Marco

    2016-01-01

    A wealth of studies have investigated numerical abilities in infants and in children aged 3 or above, but research on pre-counting toddlers is sparse. Here we devised a novel version of an imitation task that was previously used to assess spontaneous focusing on numerosity (i.e. the predisposition to grasp numerical properties of the environment)…

  5. Editorial: Spontaneous bacterial peritonitis | Lule | East African ...

    African Journals Online (AJOL)

    Journal Home > Vol 81, No 3 (2004) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Editorial: Spontaneous bacterial peritonitis. GN Lule. Abstract. No Abstract Available. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT ...

  6. Spontaneous conversion of first onset atrial fibrillation

    DEFF Research Database (Denmark)

    Lindberg, Søren Østergaard; Hansen, Sidsel; Nielsen, Tonny

    2011-01-01

    Background  We studied all patients admitted to hospital with first onset atrial fibrillation (AF) to determine the probability of spontaneous conversion to sinus rhythm and to identify factors predictive of such a conversion. Methods and Results  We retrospectively reviewed charts of 438...

  7. Spontaneous dimensional reduction in quantum gravity

    Science.gov (United States)

    Carlip, S.

    2016-07-01

    Hints from a number of different approaches to quantum gravity point to a phenomenon of “spontaneous dimensional reduction” to two spacetime dimensions near the Planck scale. I examine the physical meaning of the term “dimension” in this context, summarize the evidence for dimensional reduction, and discuss possible physical explanations.

  8. Surgical management of spontaneous ruptured hepatocellular adenoma

    Directory of Open Access Journals (Sweden)

    Marcelo Augusto Fontenelle Ribeiro Junior

    2009-01-01

    Full Text Available AIMS: Spontaneous ruptured hepatocellular adenoma (SRHA is a rare life-threatening condition that may require surgical treatment to control hemorrhaging and also stabilize the patient. We report a series of emergency surgeries performed at our institution for this condition. METHODS: We reviewed medical records and radiology files of 28 patients (from 1989 to 2006 with a proven diagnosis of hepatocellular adenoma (HA. Three (10.7% of 28 patients had spontaneous ruptured hepatocellular adenoma, two of which were associated with intrahepatic hemorrhage while one had intraperitoneal bleeding. Two patients were female and one was male. Both female patients had a background history of oral contraceptive use. Sudden abdominal pain associated with hemodynamic instability occurred in all patients who suffered from spontaneous ruptured hepatocellular adenoma. The mean age was 41.6 years old. The preoperative assessment included liver function tests, ultrasonography and computed tomography. RESULTS: The surgical approaches were as follows: right hemihepatectomy for controlling intraperitoneal bleeding, and right extended hepatectomy and non-anatomic resection of the liver for intrahepatic hemorrhage. There were no deaths, and the postoperative complications were bile leakage and wound infection (re-operation, as well as intraperitoneal abscess (re-operation and pleural effusion. CONCLUSION: Spontaneous ruptured hepatocellular adenoma may be treated by surgery for controlling hemorrhages and stabilizing the patient, and the decision to operate depends upon both the patient's condition and the expertise of the surgical team.

  9. Chronic Allium sativum administration alters spontaneous ...

    African Journals Online (AJOL)

    This study was conducted to investigate the effects of Allium sativum extract on the medial prefrontal cortex and neurobehaviour of adult Wistar rats. ... altered spontaneous alternation, while cellular pathologic changes were observed in the medial prefrontal cortex of these test groups in a dose dependent sequence.

  10. Spontaneous hedonic reactions to social media cues

    NARCIS (Netherlands)

    Koningsbruggen, G.M. van; Hartmann, T.; Eden, A.; Veling, H.P.

    2017-01-01

    Why is it so difficult to resist the desire to use social media? One possibility is that frequent social media users possess strong and spontaneous hedonic reactions to social media cues, which, in turn, makes it difficult to resist social media temptations. In two studies (total N = 200), we

  11. Ovarian hyperstimulation syndrome in a spontaneous pregnancy ...

    African Journals Online (AJOL)

    It is known that most cases of Ovarian Hyperstimulation Syndrome (OHSS) are associated with the therapies for ovulation induction. However, OHSS may rarely be associated with a spontaneous ovulatory cycle, usually in the case of multiple gestations, hypothyroidism or polycystic ovary syndrome. We report a case of ...

  12. Spontaneous left main coronary artery dissection

    Directory of Open Access Journals (Sweden)

    Alptug Tokatli

    2016-03-01

    Full Text Available Spontaneous coronary artery dissection (SCAD is a very rare clinical condition. Physiopathology of SCAD is still mostly unclear. Clinical presentation of SCAD ranges from atypical symptoms to sudden cardiac death. The diagnosis of dissection is generally made by using conventional coronary angiography. Invasive or conservative treatment is reasonable.

  13. Spontaneous extracranial decompression of epidural hematoma

    International Nuclear Information System (INIS)

    Neely, John C.; Jones, Blaise V.; Crone, Kerry R.

    2008-01-01

    Epidural hematoma (EDH) is a common sequela of head trauma in children. An increasing number are managed nonsurgically, with close clinical and imaging observation. We report the case of a traumatic EDH that spontaneously decompressed into the subgaleal space, demonstrated on serial CT scans that showed resolution of the EDH and concurrent enlargement of the subgaleal hematoma. (orig.)

  14. Spontaneous extracranial decompression of epidural hematoma

    Energy Technology Data Exchange (ETDEWEB)

    Neely, John C. [Marshall University School of Medicine, Huntington, WV (United States); Jones, Blaise V. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Crone, Kerry R. [Cincinnati Children' s Hospital Medical Center, Division of Neurosurgery, Cincinnati, OH (United States)

    2008-03-15

    Epidural hematoma (EDH) is a common sequela of head trauma in children. An increasing number are managed nonsurgically, with close clinical and imaging observation. We report the case of a traumatic EDH that spontaneously decompressed into the subgaleal space, demonstrated on serial CT scans that showed resolution of the EDH and concurrent enlargement of the subgaleal hematoma. (orig.)

  15. Spontaneous Sourcing among Students Reading Multiple Documents

    Science.gov (United States)

    Stromso, Helge I.; Braten, Ivar; Britt, M. Anne; Ferguson, Leila E.

    2013-01-01

    This study used think-aloud methodology to explore undergraduates' spontaneous attention to and use of source information while reading six documents that presented conflicting views on a controversial social scientific issue in a Google-like environment. Results showed that students explicitly and implicitly paid attention to sources of documents…

  16. Massive Spontaneous Hemothorax, Giant Intrathoracic Meningocele ...

    African Journals Online (AJOL)

    haemothorax associated with von Recklinghausen's disease: Review of occurrence in Japan. Thorax 1997;52:575‑8. 3. Fedoruk LM, English J, Fradet GJ. Spontaneous hemothorax and neurofibromatosis: A review of a lethal combination. Asian Cardiovasc. Thorac Ann 2007;15:342‑4. 4. Conlon NP, Redmond KC, Celi LA.

  17. A Fatal Complication of Dermatomyositis: Spontaneous Pneumomediastinum

    Directory of Open Access Journals (Sweden)

    Ezgi Demirdöğen Çetinoğlu

    2016-04-01

    Full Text Available Interstitial lung disease (ILD is a negative prognostic factor associated with increased morbidity and mortality in patients with dermatomyositis (DM. Spontaneous pneumomediastinum is a rare complication of DM and it can be fatal. We present a 48-year-old woman with DM and ILD complicated by pneumomediastinum without pneumothorax and subcutaneous emphysema.

  18. Grooming behavior of spontaneously hypertensive rats

    NARCIS (Netherlands)

    Buuse, M. van den; Jong, Wybren de

    1987-01-01

    In an open field spontaneously hypertensive rats (SHR) exhibited lower scores for grooming when compared to their normotensive controls, the Wistar Kyoto rats (WKY). After i.c.v. injection of 1 μg ACTH1–24 cumulative 50-min grooming scores were lower in SHR. Analysis of subscores indicated that the

  19. Spontaneous abortion and physical strain around implantation

    DEFF Research Database (Denmark)

    Hjollund, N H; Jensen, Tina Kold; Bonde, Jens Peter

    2000-01-01

    Existing studies of physical strain and spontaneous abortion are mainly retrospective or based only on pregnancies that have survived the first trimester. Furthermore, almost all studies have relied on averaged measures of physical strain, which tend to blur an effect if peak values during short ...

  20. Spontaneous Hedonic Reactions to Social Media Cues.

    Science.gov (United States)

    van Koningsbruggen, Guido M; Hartmann, Tilo; Eden, Allison; Veling, Harm

    2017-05-01

    Why is it so difficult to resist the desire to use social media? One possibility is that frequent social media users possess strong and spontaneous hedonic reactions to social media cues, which, in turn, makes it difficult to resist social media temptations. In two studies (total N = 200), we investigated less-frequent and frequent social media users' spontaneous hedonic reactions to social media cues using the Affect Misattribution Procedure-an implicit measure of affective reactions. Results demonstrated that frequent social media users showed more favorable affective reactions in response to social media (vs. control) cues, whereas less-frequent social media users' affective reactions did not differ between social media and control cues (Studies 1 and 2). Moreover, the spontaneous hedonic reactions to social media (vs. control) cues were related to self-reported cravings to use social media and partially accounted for the link between social media use and social media cravings (Study 2). These findings suggest that frequent social media users' spontaneous hedonic reactions in response to social media cues might contribute to their difficulties in resisting desires to use social media.

  1. Spontaneous electric fields in solid films: spontelectrics

    DEFF Research Database (Denmark)

    Field, David; Plekan, Oksana; Cassidy, Andrew

    2013-01-01

    When dipolar gases are condensed at sufficiently low temperature onto a solid surface, they form films that may spontaneously exhibit electric fields in excess of 108V/m. This effect, called the ‘spontelectric effect’, was recently revealed using an instrument designed to measure scattering...

  2. Spontaneous Retroperitoneal Hemorrhage from Adrenal Artery Aneurysm

    International Nuclear Information System (INIS)

    Gonzalez Valverde, F.M.; Balsalobre, M.; Torregrosa, N.; Molto, M.; Gomez Ramos, M.J.; Vazquez Rojas, J.L.

    2007-01-01

    Spontaneous adrenal hemorrhage is a very rare but serious disorder of the adrenal gland that can require emergent treatment. We report on a 42-year-old man who underwent selective angiography for diagnosis and treatment of retroperitoneal hemorrhage from small adrenal artery aneurysm. This case gives further details about the value of transluminal artery embolization in the management of visceral aneurysm rupture

  3. Spontaneous regression of a mandibular arteriovenous malformation

    Directory of Open Access Journals (Sweden)

    Scott B. Raymond, MD, PhD

    2015-06-01

    Full Text Available Mandibular arteriovenous malformations (AVMs are rare lesions that may initially present as catastrophic bleeding during dental surgical procedures. Owing to the significant risk of bleeding, most mandibular AVMs are treated definitively by resection or embolization. In this report, we describe a mandibular AVM that spontaneously regressed after biopsy.

  4. Unified gauge theories with spontaneous symmetry breaking

    International Nuclear Information System (INIS)

    MacDowell, S.W.

    1975-01-01

    Unified gauge theories with spontaneous symmetry breaking are studied with a view to renormalize quantum field theory. Georgi-Glashow and Weinberg-Salam models to unify weak and electromagnetic interactions are discussed in detail. Gauge theories of strong interactions are also considered [pt

  5. Influence of spontaneous fermentation on some quality ...

    African Journals Online (AJOL)

    Spontaneous fermentation has been identified to improve the quality characteristics of foods derived from them. When combined with cowpea fortification and nixtamalization, it is expected to improve the nutritional, functional, physico- chemical and sensory qualities of maize based foods thereby improving the qualities as ...

  6. Maternal Factors Associated With Early Spontaneous Singleton ...

    African Journals Online (AJOL)

    Background: Knowledge of the maternal factors predisposing to preterm deliveries should affect the anticipatory care of mothers at risk of delivering preterm babies and improve perinatal outcome. Objective: To determine the maternal socio-biological characteristics associated with the delivery of early spontaneous ...

  7. PERIODIC-SOLUTIONS IN SPONTANEOUSLY BROKEN THEORIES

    NARCIS (Netherlands)

    BRIHAYE, Y; KUNZ, J

    A class of spontaneously broken field theories is proposed, and the occurrence of their periodic, classical solutions is investigated in detail. The emergence of multiple solutions is observed, their normal modes of oscillation are studied, and the bifurcations of the classical energy functional are

  8. Comparison of application value of DSA and MRA in diagnosis of subacute spontaneous intracerebral hemorrhage

    International Nuclear Information System (INIS)

    Zhou Mingli; Qu Tianrong; Feng Jun

    2012-01-01

    Objective: To explore the clinical value of digital subtraction angiography (DSA) and magnetic resonance angiography (MRA) in diagnosis of cerebral vascular structural abnormalities in the patients with spontaneous cerebral hemorrhage in subacute phase, and to provide clinical basis for detection of cerebral vascular structural abnormalities. Methods: 183 patients with subacute spontaneous intracerebral hemorrhage within 1 week were selected, the vascular structures of the patients were detected by DSA and MRA, and the influence factors were analyzed. Results: The DSA and MRA results showed that the parietal lobe, frontal lobe, and lenticular nucleus had the largest incidence rates of spontaneous intracerebral hemorrhage, and accounted for 17.5% , 16.9% , and 14.2% , respectively. The age and the incidence of the hypertension of the patients with cerebral vascular structural abnormalities were significantly lower than those of the patients without cerebral vascular structural abnormalities (P<0.05). There were positive correlations between subacute spontaneous cerebral hemorrhage and the age and the incidence of hypertension (r=0.43, r=0.46, P<0.05). The rates of cerebrovascular malformation detected with MRA and DSA had no statistically significant difference. The DSA was regarded as detection gold standard, the sensitivities and specificities of MRA in detection of cerebrovascular malformation were 98.8% and 96.9% . Conclusion: The abnormal vascular structures of patients with subacute spontaneous intracerebral hemorrhage can be detected mostly by MRA and DSA. MRA has the advantages of non-invasion, which is worthy to be applied in clinic. (authors)

  9. Variation among internet based calculators in predicting spontaneous resolution of vesicoureteral reflux.

    Science.gov (United States)

    Routh, Jonathan C; Gong, Edward M; Cannon, Glenn M; Yu, Richard N; Gargollo, Patricio C; Nelson, Caleb P

    2010-04-01

    An increasing number of parents and practitioners use the Internet for health related purposes, and an increasing number of models are available on the Internet for predicting spontaneous resolution rates for children with vesicoureteral reflux. We sought to determine whether currently available Internet based calculators for vesicoureteral reflux resolution produce systematically different results. Following a systematic Internet search we identified 3 Internet based calculators of spontaneous resolution rates for children with vesicoureteral reflux, of which 2 were academic affiliated and 1 was industry affiliated. We generated a random cohort of 100 hypothetical patients with a wide range of clinical characteristics and entered the data on each patient into each calculator. We then compared the results from the calculators in terms of mean predicted resolution probability and number of cases deemed likely to resolve at various cutoff probabilities. Mean predicted resolution probabilities were 41% and 36% (range 31% to 41%) for the 2 academic affiliated calculators and 33% for the industry affiliated calculator (p = 0.02). For some patients the calculators produced markedly different probabilities of spontaneous resolution, in some instances ranging from 24% to 89% for the same patient. At thresholds greater than 5%, 10% and 25% probability of spontaneous resolution the calculators differed significantly regarding whether cases would resolve (all p calculators. For certain patients, particularly those with a lower probability of spontaneous resolution, these differences can significantly influence clinical decision making. Copyright (c) 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  10. Spontaneous swallowing frequency has potential to identify dysphagia in acute stroke.

    Science.gov (United States)

    Crary, Michael A; Carnaby, Giselle D; Sia, Isaac; Khanna, Anna; Waters, Michael F

    2013-12-01

    Spontaneous swallowing frequency has been described as an index of dysphagia in various health conditions. This study evaluated the potential of spontaneous swallow frequency analysis as a screening protocol for dysphagia in acute stroke. In a cohort of 63 acute stroke cases, swallow frequency rates (swallows per minute [SPM]) were compared with stroke and swallow severity indices, age, time from stroke to assessment, and consciousness level. Mean differences in SPM were compared between patients with versus without clinically significant dysphagia. Receiver operating characteristic curve analysis was used to identify the optimal threshold in SPM, which was compared with a validated clinical dysphagia examination for identification of dysphagia cases. Time series analysis was used to identify the minimally adequate time period to complete spontaneous swallow frequency analysis. SPM correlated significantly with stroke and swallow severity indices but not with age, time from stroke onset, or consciousness level. Patients with dysphagia demonstrated significantly lower SPM rates. SPM differed by dysphagia severity. Receiver operating characteristic curve analysis yielded a threshold of SPM≤0.40 that identified dysphagia (per the criterion referent) with 0.96 sensitivity, 0.68 specificity, and 0.96 negative predictive value. Time series analysis indicated that a 5- to 10-minute sampling window was sufficient to calculate spontaneous swallow frequency to identify dysphagia cases in acute stroke. Spontaneous swallowing frequency presents high potential to screen for dysphagia in acute stroke without the need for trained, available personnel.

  11. Spontaneous Swallowing Frequency [Has Potential to] Identify Dysphagia in Acute Stroke

    Science.gov (United States)

    Carnaby, Giselle D; Sia, Isaac; Khanna, Anna; Waters, Michael

    2014-01-01

    Background and Purpose Spontaneous swallowing frequency has been described as an index of dysphagia in various health conditions. This study evaluated the potential of spontaneous swallow frequency analysis as a screening protocol for dysphagia in acute stroke. Methods In a cohort of 63 acute stroke cases swallow frequency rates (swallows per minute: SPM) were compared to stroke and swallow severity indices, age, time from stroke to assessment, and consciousness level. Mean differences in SPM were compared between patients with vs. without clinically significant dysphagia. ROC analysis was used to identify the optimal threshold in SPM which was compared to a validated clinical dysphagia examination for identification of dysphagia cases. Time series analysis was employed to identify the minimally adequate time period to complete spontaneous swallow frequency analysis. Results SPM correlated significantly with stroke and swallow severity indices but not with age, time from stroke onset, or consciousness level. Patients with dysphagia demonstrated significantly lower SPM rates. SPM differed by dysphagia severity. ROC analysis yielded a threshold of SPM ≤ 0.40 which identified dysphagia (per the criterion referent) with 0.96 sensitivity, 0.68 specificity, and 0.96 negative predictive value. Time series analysis indicated that a 5 to 10 minute sampling window was sufficient to calculate spontaneous swallow frequency to identify dysphagia cases in acute stroke. Conclusions Spontaneous swallowing frequency presents high potential to screen for dysphagia in acute stroke without the need for trained, available personnel. PMID:24149008

  12. Pathogenesis of hypercalciuria in spontaneously hypertensive rats.

    Science.gov (United States)

    Hsu, C H; Chen, P S; Smith, D E; Yang, C S

    1986-01-01

    The etiology of hypercalciuria remains unknown in spontaneously hypertensive rats (SHR). In order to differentiate absorptive versus renal hypercalciuria, serial measurements of urinary calcium (UCaV) excretion were made weekly under fasting (3-hour urine collection) and after oral administration of CaCl2 (50 mg/100 g; 4-hour urine collection) from age 8 to 14 weeks in SHR (n = 14) and normotensive Wistar Kyoto rats (WKY; n = 14). Fasting UCaV was significantly greater in WKY than in SHR throughout the periods of observation. In contrast, after oral Ca loading UCaV was greater in SHR after 13 weeks of age (13 weeks: SHR UCaV = 954 micrograms/mg creatinine, WKY UCaV = 541 p less than 0.01; 14 weeks: SHR UCaV = 988 micrograms/mg creatinine, WKY UCaV = 534, p less than 0.01). Fasting urinary cyclic adenosine monophosphate (AMP) excretion was not different between WKY and SHR. However, cyclic AMP excretion of SHR, but not WKY, was decreased after calcium loading when compared to the fasting values. The cyclic AMP was also significantly lower in SHR than in WKY rats after calcium loading. Calcium handling by the kidney was not different between SHR and WKY with or without parathyroidectomy. Calcium disposition kinetic studies were performed on these animals at age 15 and 16 weeks. No significant difference of intravenous 45Ca was observed between WKY (n = 6) and SHR (n = 6) in total plasma clearance, nonrenal clearance, biologic half-life, and elimination rate constant from the central compartment. However, the WKY had a significantly greater renal clearance of 45Ca than the SHR (0.48 +/- 0.04 vs. 0.24 +/- 0.02 ml/n, p less than 0.001). Since tissue disposition of intravenous 45Ca was not different between WKY and SHR, the increased renal excretion of calcium after oral administration in SHR, therefore, reflects increased intestinal absorption of calcium. Correction of established hypertension did not abolish the hypercalciuria. We believe that increased

  13. Controlling spontaneous emission dynamics in semiconductor micro cavities

    Science.gov (United States)

    Gayral, B.

    Spontaneous emission of light can be controlled, cavity quantum electrodynamics tells us, and many experiments in atomic physics demonstrated this fact. In particular, coupling an emitter to a resonant photon mode of a cavity can enhance its spontaneous emission rate: this is the so-called Purcell effect. Though appealing it might seem to implement these concepts for the benefit of light-emitting semiconductor devices, great care has to be taken as to which emitter/cavity system should be used. Semiconductor quantum boxes prove to be good candidates for witnessing the Purcell effect. Also, low volume cavities having a high optical quality in other words a long photon storage time are required. State-of-the-art fabrication techniques of such cavities are presented and discussed.We demonstrate spontaneous emission rate enhancement for InAs/GaAs quantum boxes in time-resolved and continuous-wave photoluminescence experiments. This is done for two kinds of cavities, namely GaAs/AlAs micropillars (global enhancement by a factor of 5), and GaAs microdisks (global enhancement by a factor of 20). Prospects for lasers, light-emitting diodes and single photon sources based on the Purcell effect are discussed. L'émission spontanée de lumière peut être contrôlée, ainsi que nous l'enseigne l'électrodynamique quantique en cavité, ce fait a été démontré expérimentalement en physique atomique. En particulier, coupler un émetteur à un mode photonique résonnant d'une cavité peut exalter son taux d'émission spontanée : c'est l'effet Purcell. Bien qu'il semble très prometteur de mettre en pratique ces concepts pour améliorer les dispositifs semi-conducteurs émetteurs de lumière, le choix du système émetteur/cavité est crucial. Nous montrons que les boîtes quantiques semi-conductrices sont des bons candidats pour observer l'effet Purcell. Il faut par ailleurs des cavités de faible volume ayant une grande qualité optique en d'autres mots un long temps de

  14. Differences between sexes in dissociation and spontaneity of smile in facial paralysis reanimation with the masseteric nerve.

    Science.gov (United States)

    Hontanilla, Bernardo; Marre, Diego

    2014-08-01

    A patient's sex is likely to play an important role in facial paralysis reanimation, with women being superior in terms of development of brain plasticity after reanimation. The purpose of this study was to compare the rate of movement dissociation and spontaneity of men versus women reanimated with gracilis transfer neurotized to the masseteric nerve. We conducted a retrospective chart review of 27 patients who underwent facial paralysis reanimation with microvascular gracilis transplants neurotized to the ipsilateral masseteric nerve. Patients were classified by sex, comparing age at surgery, denervation time, and follow-up, as well as the rates of movement dissociation and smile spontaneity. After reanimation with gracilis to masseteric nerve, movement dissociation and spontaneity were higher in women during the first year after onset of facial movement (p=.02 and p=.01, respectively). After reanimation with masseteric nerve, women seem to be able to smile spontaneously and independently from teeth clenching earlier than men. Copyright © 2013 Wiley Periodicals, Inc.

  15. Spontaneous unilateral Twin Ectopic Pregnancy: A case report

    Directory of Open Access Journals (Sweden)

    هادی اریا منش

    2017-03-01

    Full Text Available Abstract Aim & Objective: Twin pregnancy in the tube is a few and due to more frequent use of ovulatory medicine and increased maternal mortality rate. In this article, we report a case of  untitled twin ectopic pregnancy. Case study: The pregnant women was a 28 year-old  to had  a  history infertility, PCOD, Abortion and cortege,   too have one 5 years girl by CS and  Mild cramp pain in both abdominal lower quadrants and metroreghia . That have not treatment by projection. The ultra-sonography showed a twin pregnancy uterus with a moderate amount of fluid in pelvic cavity was seen. And do salpanjectimy surgery. Conclusion:  We report one Untitled Spontaneous Twin Ectopic Pregnancy,  is necessary any pregnant woman with  positive BhCG and metrorhoghia must be considered for Ectopic pregnancy. To decrease maternal mortality rate. Key words:

  16. The production of spontaneous false memories across childhood.

    Science.gov (United States)

    Otgaar, Henry; Howe, Mark L; Peters, Maarten; Smeets, Tom; Moritz, Steffen

    2014-05-01

    We found evidence that the usual developmental trends in children's spontaneous false memories were eliminated using novel stimuli containing obvious themes. That is, children created more false memories than adults when scenes needed to be remembered. In Experiment 1, 7- and 8-year-olds had higher false memory rates than adults when using visual scenes. Experiment 2 showed that gist cuing could not account for this effect. In Experiment 3, children and adults received visual scenes and story contexts in which these scenes were embedded. For both types of stimuli, we found that children had the highest false memory rates. Our results indicate that the underlying theme of these scenes is easily identified, resulting in our developmental false memory trend. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. A deletion mutation in GDF9 in sisters with spontaneous DZ twins.

    NARCIS (Netherlands)

    Montgomery, GW; Zhao, Z.Z.; Marsh, A.J.; Mayne, R.; Treloar, S.A.; James, M.; Martin, N.G.; Boomsma, D.I.; Duffy, DL

    2004-01-01

    A loss of function mutation in growth differentiation factor 9 (GDF9) in sheep causes increased ovulation rate and infertility in a dosage-sensitive manner. Spontaneous dizygotic (DZ) twinning in the human is under genetic control and women with a history of DZ twinning have an increased incidence

  18. Metformin exposure in early pregnancy and spontaneous abortions in women with polycystic ovary syndrome

    DEFF Research Database (Denmark)

    Lauszus, Finn; Viftrup-Lund, Mette; Gade, Melina

    2014-01-01

    Objective: We sought to determine whether metformin affects the rate of first trimester spontaneous abortions and congenital malformations in women with PCOS. Design. Consecutive series of metformin treated women with a questionnaire followup. Setting. Department of Gynecology and Obstetrics at H...

  19. Are the Concepts of Dynamic Equilibrium and the Thermodynamic Criteria for Spontaneity, Nonspontaneity, and Equilibrium Compatible?

    Science.gov (United States)

    Silverberg, Lee J.; Raff, Lionel M.

    2015-01-01

    Thermodynamic spontaneity-equilibrium criteria require that in a single-reaction system, reactions in either the forward or reverse direction at equilibrium be nonspontaneous. Conversely, the concept of dynamic equilibrium holds that forward and reverse reactions both occur at equal rates at equilibrium to the extent allowed by kinetic…

  20. Spontaneous vesicoureteral refl ux resolution in children: A ten-year ...

    African Journals Online (AJOL)

    Background/Aim: To evaluate the spontaneous resolution rate in infants and young children with vesicoureteral reflux (VUR). Patients and Methods: Paediatric patients with VUR treated in our hospital from January 2000 to December 2010 were retrospectively analyzed. Only patients with pretreatment and followup voiding ...

  1. Socioeconomic position and the risk of spontaneous abortion

    DEFF Research Database (Denmark)

    Norsker, Filippa Nyboe; Espenhain, Laura; rogvi, Sofie

    2012-01-01

    To investigate the relationship between different indicators of socioeconomic position and the risk of spontaneous abortion.......To investigate the relationship between different indicators of socioeconomic position and the risk of spontaneous abortion....

  2. Alterations in Spontaneous Transmitter Release by Divalent Cations after Treatment of the Neuromuscular Junction with Alpha-Bungarotoxin

    Science.gov (United States)

    1982-01-01

    to change the spontaneous release rate of quantal acetylcholine . The simplest interpretation of these results is that toxin treatment increases the...Gage. 1973; Kita et al.. 1981), Mn increases spontaneous relese . The potentiations of transmitte- release by cobalt and nickel after toxin treatment...and Van der Kkw.. W. (1976). Effects of the ionophore X-537A on acetylcholine release at the frog neuromuscular junction. J. PuIwOl. Loand. 29 177-4

  3. [Bacterial vaginosis and spontaneous preterm birth].

    Science.gov (United States)

    Brabant, G

    2016-12-01

    To determine if bacterial vaginosis is a marker for risk of spontaneous preterm delivery and if its detection and treatment can reduce this risk. Consultation of the database Pubmed/Medline, Science Direct, and international guidelines of medical societies. Bacterial vaginosis (BV) is a dysbiosis resulting in an imbalance in the vaginal flora through the multiplication of anaerobic bacteria and jointly of a disappearance of well-known protective Lactobacilli. His diagnosis is based on clinical Amsel criteria and/or a Gram stain with establishment of the Nugent score. The prevalence of the BV extraordinarily varies according to ethnic and/or geographical origin (4-58 %), in France, it is close to 7 % in the first trimester of pregnancy (EL2). The link between BV and spontaneous premature delivery is low with an odds ratio between 1.5 and 2 in the most recent studies (EL3). Metronidazole or clindamycin is effective to treat BV (EL3). It is recommended to prescribe one of these antibiotics in the case of symptomatic BV (Professional Consensus). The testing associated with the treatment of BV in the global population showed no benefit in the prevention of the risk of spontaneous preterm delivery (EL2). Concerning low-risk asymptomatic population (defined by the absence of antecedent of premature delivery), it has been failed profit to track and treat the BV in the prevention of the risk of spontaneous preterm delivery (EL1). Concerning the high-risk population (defined by a history of preterm delivery), it has been failed profit to track and treat the VB in the prevention of the risk of spontaneous preterm delivery (EL3). However, in the sub population of patients with a history of preterm delivery occurred in a context of materno-fetal bacterial infection, there may be a benefit to detect and treat early and systematically genital infection, and in particular the BV (Professional Consensus). The screening and treatment of BV during pregnancy in asymptomatic low

  4. Adaptability of drowsiness level detection that measures blinks utilizing image processing to changes in the ambient light; Hikari kankyo no henka ni tekiosuru kao gazo shori ni yoru inemuri unten kenchi

    Energy Technology Data Exchange (ETDEWEB)

    Kaneda, M.; Obara, H.; Nasu, T. [Nissan Motor Co. Ltd, Tokyo (Japan)

    1997-10-01

    A drowsiness warning system that measures blinks utilizing image processing technology has a number of issues that need to be resolved. One issue is the adaptability of the system to changes in the ambient light environment in the actual vehicle interior. We have devised image processing software which is robust to changes in the ambient light. The drowsiness detection performance of the system was evaluated in laboratory tests and actual driving tests. It was found that the system can has a positive effect on detecting drowsiness level. 3 refs., 10 figs.

  5. Spontaneous Extensor Tendon Rupture in the Rheumatoid Wrist: Risk Factors and Preventive Role of Extended Tenosynovectomy.

    Science.gov (United States)

    Hsueh, Jung-Hua; Liu, Wen-Chung; Yang, Kuo-Chung; Hsu, Kuei-Chang; Lin, Cheng-Ta; Chen, Lee-Wei

    2016-03-01

    Spontaneous extensor tendon rupture is often seen in rheumatoid arthritis (RA) patients, but the risk factors are not clearly defined. We therefore collected the data of RA patients with previous extensor tendon rupture and those with tenosynovitis and analyzed the relationship between extended tenosynovectomy and spontaneous extensor tendon rupture. We retrospectively reviewed 17 spontaneous extensor tendon rupture episodes in 15 RA patients and 14 tenosynovitis episodes that required tenosynovectomy in 12 RA patients from 1997 to 2013. Correlations between the incidence of tendon rupture, X-ray findings, and clinical findings in the affected wrists before tendon rupture were analyzed statistically using the test for proportion. The following parameters were significantly correlated with spontaneous extensor tendon rupture: disease duration longer than 8 years, persistent tenosynovitis longer than 1 year duration, and Larsen grade greater than 4 (P = 0.02, 0.03, and 0.01, respectively). Dislocation of the distal end of the ulna, carpal collapse, and the scallop sign on X-ray contributed to a higher spontaneous extensor tendon rupture rate among RA patients (P = 0.01, 0.05, and 0.03, respectively). Extended tenosynovectomy was performed on 14 wrists in 12 RA patients with persistent tenosynovitis longer than 6 months, and Larsen grade did not deteriorate in this group compared with those who did not undergo the surgery. No spontaneous extensor tendon rupture occurred following the surgery. Risk factors of spontaneous extensor tendon rupture included disease duration longer than 8 years, persistent tenosynovitis longer than 1 year, and wrist Larsen grade greater than 4. Dislocation of the distal end of the ulna, carpal collapse, and the scallop sign on X-ray indicated a higher probability of extensor tendon rupture. Rheumatologists should consult with hand surgeons promptly to preserve hand function before tendon rupture. Prophylactic extended tenosynovectomy

  6. Spontaneous fluxon production in annular Josephson tunnel junctions in the presence of a magnetic field

    DEFF Research Database (Denmark)

    Monaco, Roberto; Aarøe, Morten; Mygind, Jesper

    2008-01-01

    We report on the spontaneous production of fluxons in annular Josephson tunnel junctions during a thermal quench in the presence of a symmetry-breaking magnetic field. The dependence on field intensity B of the probability (f) over bar (1) to trap a single defect during the N-S phase transition...... depends drastically on the sample circumferences. We show that this can be understood in the framework of the same picture of spontaneous defect formation that leads to the experimentally well attested scaling behavior of (f) over bar (1) with quench rate in the absence of an external field....

  7. F. VON HAYEK’S THEORY OF SPONTANEOUS ORDER

    Directory of Open Access Journals (Sweden)

    О. Nesterenko

    2013-04-01

    Full Text Available The essence and the genesis of spontaneous order are disclosed in the context of critical analysis of constructivism. The author’s approach to the definition of the characteristic features of the spontaneous order is proposed. The dichotomy of the order is revealed towards the economic sphere in form of spontaneous order and organization.

  8. DUAL THEORY OF ACTION IONIZING RADIATION AND SPONTANEOUS CANCER

    Directory of Open Access Journals (Sweden)

    A. T. Gubin

    2015-01-01

    Full Text Available A mathematical model for radiogenic increasing of mortality was proposed, taking into account spontaneous background damages of the genetic material, that always occur in cells due to the influence of non-radiation internal and environmental factors. The model is based on the representation of indistinguishability between radiogenic andspontaneous cancers and on the postulates of the Kellerer-Rossi dual action theory. It was proposed that duringformation of premalignant damages dual interactions occur both between primary radiation damages, and betweenradiation and spontaneous primary damages (hybrid interactions. The role of the latter is particularly important at low levels exposure that corresponds to a linear dependence of cancer incidence on dose. Their significance is indicated by the following factor: at the adopted value of the nominal (radiation risk factor (0,05 Sv-1 and cancer mortality share among the population (0,15–0,2, the contribution of non-radiative carcinogenic factors for the total life is equivalent to radiation dose of 3–4 Sv or radiation at a constant dose rate of 40–50 mSv / year.The model assumes formation in DNA of both spaced apart (single damages with high probability of recovery, and nearby (double damages, which are more likely to interact, entering into the permanent state. Permanent damages being formed in certain portions of DNA can be inherited to daughter cells as premalignant defects. The relative role of spontaneous primary damages is greater the more single damages are formed as compared to double ones within the area of potential interaction.It was shown within this model that the presence of background cancer mortality for initial and finite population in the used by ICRP expression for interpopulation risk transfer has logical and biophysical justifications. Accounting of spontaneous primary damages and hybrid interactions enhances the capabilities for development of radiation risk models.

  9. Spontaneous ovulation or male effect in alpacas and llamas

    Directory of Open Access Journals (Sweden)

    Sumar JB

    2016-08-01

    Full Text Available New discoveries in ovulation induced mammals, researchers considered the question of whether spontaneous and induced ovulations are distinct entities or individual parts of a single continuum of a “malefacilitated oestrus and ovulation”. This rigid classification should be taken with precaution, because is possible that the various mechanisms involved in the spontaneous ovulation can, under specific conditions coexist in some determined species. It is possible that male hormones can provoke the ovulation by masculine pheromones. The “Ram Effect” can be used to synchronize ewes naturally, for artificial insemination. Pheromones are specialized hormones released by the ram and smelled by the ewes; they are found in the wool and wax, in such a way that synchronized the heat and the advancement of the breeding season Also, using artificial vaginal-cervical stimulation (AVS with a glass rod, ovulation has been induced in the mink, shrews and felids. This form of tactile stimulation (AVS has found no ability for induction of ovulation in SAC. Additional stimuli/cues are often necessary to facilitate the ovulatory response. They include olfactory, visual, auditory or posture, more of them very common in SAC. Few research studies in alpacas and llamas showed a variable number of females ovulating by the sole proximity of the male to the female, by adopting the copulatory position (posture (sitting or prone position, female to female mounting (tactile, males mounting females covered with aprons to avoid penis intromission (tactile and auditory, interrupted matings, sitting close to a male copulating to a female (visual, olfactory?, the guttural sound (orgling made by the copulating male (auditory, and probably other non-identified cues. The rate of spontaneous ovulation in alpacas and llamas, increase up to 50% during the breeding season. These spontaneous ovulation has been diagnosed by sexual behavior (female rejection to the male, by

  10. [Spontaneous renal artery dissection: a case report].

    Science.gov (United States)

    Maehana, Takeshi; Nishida, Sachiyo; Shindo, Tetsuya; Miyamoto, Shintaro; Muranaka, Takashi; Suzuki, Kazuhiro; Yanase, Masahiro

    2008-01-01

    A 65-year-old female was admitted to our hospital complaining of left upper abdominal pain. Although the symptom improved with observation, serum creatinine rose to 2.0 mg/dl. Slight atrophy of the left kidney was seen on abdominal plain computed tomography. In order to examine the possibility of renal infarction from thrombosis with angiography, we consulted the department of cardiovascular medicine. Even though we did not detect thrombosis with left renal angiography or intravascular ultrasound, there was a dissection finding localized at the left renal artery. Based on this finding, we made a diagnosis of spontaneous renal artery dissection and performed stent placement. Spontaneous renal artery dissection is extremely rare and the frequency of occurrence is reported to be less than 0.05%. Recently, however the frequency of detection has risen with the development of clinical imaging. We must keep in mind that the condition has the possibility of leading to renal blood circulation disorders.

  11. Thermal influences on spontaneous rock dome exfoliation

    Science.gov (United States)

    Collins, Brian D.; Stock, Greg M.; Eppes, Martha C.; Lewis, Scott W.; Corbett, Skye C.; Smith, Joel B.

    2018-01-01

    Rock domes, with their onion-skin layers of exfoliation sheets, are among the most captivating landforms on Earth. Long recognized as integral in shaping domes, the exact mechanism(s) by which exfoliation occurs remains enigmatic, mainly due to the lack of direct observations of natural events. In August 2014, during the hottest days of summer, a granitic dome in California, USA, spontaneously exfoliated; witnesses observed extensive cracking, including a ~8000 kg sheet popping into the air. Subsequent exfoliation episodes during the following two summers were recorded by instrumentation that captured—for the first time—exfoliation deformation and stress conditions. Here we show that thermal cycling and cumulative dome surface heating can induce subcritical cracking that culminates in seemingly spontaneous exfoliation. Our results indicate that thermal stresses—largely discounted in dome formation literature—can play a key role in triggering exfoliation and therefore may be an important control for shaping domes worldwide.

  12. Spontaneous abortion and physical strain around implantation

    DEFF Research Database (Denmark)

    Hjøllund, Niels Henrik Ingvar; Jensen, T.K.; Bonde, J.P.

    2000-01-01

    Existing studies of physical strain and spontaneous abortion are mainly retrospective or based only on pregnancies that have survived the first trimester. Furthermore, almost all studies have relied on averaged measures of physical strain, which tend to blur an effect if peak values during short...... time periods are the relevant measure. We followed a cohort of first pregnancy planners from termination of birth control until pregnancy for a maximum of six menstrual cycles. The analyses include 181 pregnancies, of which 32 were subclinical pregnancies detected by hCG analysis only. During early...... pregnancy the women recorded physical strain prospectively in a structured diary. Physical strain around the time of implantation was associated with later spontaneous abortion. The adjusted risk ratio for women who reported physical strain higher than average at day 6 to 9 after the estimated date...

  13. Spontaneous Enterocutaneous Fistula Resulting from Richter's Hernia.

    Science.gov (United States)

    Hajong, Ranendra; Khongwar, Donkupar; Komut, Ojing; Naku, Narang; Baru, Kappa

    2017-08-01

    Richter's hernia is due to the entrapment of a part of circumference of the bowel wall. As the bowel continuity is maintained, the patients usually do not have intestinal obstruction. Some patients with Richter's hernia may present with enterocutaneous fistula either spontaneous or due to surgical intervention mistaking the obstructed hernia to be inguinal abscess. This is more so in developing countries due to lack of awareness among the masses or due to the delay in seeking medical attention. Presenting here is a case of a 53-year-old male patient with enterocutaneous fistula which occurred spontaneously and sought medical attention only after about three years of repeated discharge of yellowish fluid from the left inguinal region. Magnetic resonance fistulogram confirmed the diagnosis of enterocutaneous fistula. Laparotomy with resection and primary anastomosis of the fistulous bowel was done. Patient recovered uneventfully without any complications or recurrence.

  14. Spontaneous Coronary Artery Dissection and Pregnancy.

    Science.gov (United States)

    Naderi, Sahar

    2017-09-01

    Spontaneous coronary artery dissection (SCAD) is a non-atherosclerotic, non-traumatic cause of coronary artery dissection. SCAD is the most common cause of myocardial infarction in pregnancy or the postpartum period and results in significant cardiovascular morbidity and mortality in the pregnant population. It is important to consider pregnancy-associated spontaneous coronary artery dissection (PASCAD) high on the differential for a pregnant woman who presents with symptoms consistent with acute coronary syndrome. Management of these patients requires a thoughtful, multidisciplinary approach, with consideration of conservative management if possible. Counseling regarding future pregnancies is also critical and requires compassionate care. Given our limited understanding of SCAD, including PASCAD, more data and research are needed to help guide diagnosis, management, and determination of prognosis.

  15. Spontaneous stress fractures of the femoral neck

    International Nuclear Information System (INIS)

    Dorne, H.L.; Lander, P.H.

    1985-01-01

    The diagnosis of spontaneous stress fractures of the femoral neck, a form of insufficiency stress fracture, can be missed easily. Patients present with unremitting hip pain without a history of significant trauma or unusual increase in daily activity. The initial radiographic features include osteoporosis, minor alterations of trabecular alignment, minimal extracortical or endosteal reaction, and lucent fracture lines. Initial scintigraphic examinations performed in three of four patients showed focal increased radionuclide uptake in two and no focal abnormality in one. Emphasis is placed on the paucity of early findings. Evaluation of patients with persistent hip pain requires a high degree of clinical suspicion and close follow-up; the sequelae of undetected spontaneous fractures are subcapital fracture with displacement, angular deformity, and a vascular necrosis of the femoral head

  16. Motivational Projections of Russian Spontaneous Speech

    Directory of Open Access Journals (Sweden)

    Galina M. Shipitsina

    2017-06-01

    Full Text Available The article deals with the semantic, pragmatic and structural features of words, phrases, dialogues motivation, in the contemporary Russian popular speech. These structural features are characterized by originality and unconventional use. Language material is the result of authors` direct observation of spontaneous verbal communication between people of different social and age groups. The words and remarks were analyzed in compliance with the communication system of national Russian language and cultural background of popular speech. Studies have discovered that in spoken discourse there are some other ways to increase the expression statement. It is important to note that spontaneous speech identifies lacunae in the nominative language and its vocabulary system. It is proved, prefixation is also effective and regular way of the same action presenting. The most typical forms, ways and means to update language resources as a result of the linguistic creativity of native speakers were identified.

  17. Phenomenology of muon number violation in spontaneously broken gauge theories

    International Nuclear Information System (INIS)

    Shanker, O.U.

    1980-01-01

    The phenomenology of muon number violation in gauge theories of weak and electromagnetic interactions is studied. In the first chapter a brief introduction to the concept of muon number and to spontaneously broken gauge theories is given. A review of the phenomenology and experimental situation regarding different muon number violating processes is made in the second chapter. A detailed phenomenological study of the μe conversion process μ - + (A,Z) → e - + (A,Z) is given in the third chapter. In the fourth chapter some specific gauge theories incorporating spontaneously broken horizontal gauge symmetries between different fermion generations are discussed with special reference to muon number violation in the theories. The μe conversion process seems to be a good process to search for muon number violation if it occurs. The K/sub L/-K/sub S/ mass difference is likely to constrain muon number violating rates to lie far below present experimental limits unless strangeness changing neutral currents changing strangeness by two units are suppressed

  18. Quantum theory of spontaneous and stimulated emission of surface plasmons

    International Nuclear Information System (INIS)

    Archambault, Alexandre; Marquier, Francois; Greffet, Jean-Jacques; Arnold, Christophe

    2010-01-01

    We introduce a quantization scheme that can be applied to surface waves propagating along a plane interface. An important result is the derivation of the energy of the surface wave for dispersive nonlossy media without invoking any specific model for the dielectric constant. Working in Coulomb's gauge, we use a modal representation of the fields. Each mode can be associated with a quantum harmonic oscillator. We have applied the formalism to derive quantum mechanically the spontaneous emission rate of surface plasmon by a two-level system. The result is in very good agreement with Green's tensor approach in the nonlossy case. Green's approach allows also to account for losses, so that the limitations of a quantum approach of surface plasmons are clearly defined. Finally, the issue of stimulated versus spontaneous emission has been addressed. Because of the increasing density of states near the asymptote of the dispersion relation, it is quantitatively shown that the stimulated emission probability is too small to obtain gain in this frequency region.

  19. Coherent control of spontaneous emission near a photonic band edge

    International Nuclear Information System (INIS)

    Woldeyohannes, Mesfin; John, Sajeev

    2003-01-01

    We demonstrate the coherent control of spontaneous emission for a three-level atom located within a photonic band gap (PBG) material, with one resonant frequency near the edge of the PBG. Spontaneous emission from the three-level atom can be totally suppressed or strongly enhanced depending on the relative phase between the steady-state control laser coupling the two upper levels and the pump laser pulse used to create an excited state of the atom in the form of a coherent superposition of the two upper levels. Unlike the free-space case, the steady-state inversion of the atomic system is strongly dependent on the externally prescribed initial conditions. This non-zero steady-state population is achieved by virtue of the localization of light in the vicinity of the emitting atom. It is robust to decoherence effects provided that the Rabi frequency of the control laser field exceeds the rate of dephasing interactions. As a result, such a system may be relevant for a single-atom, phase-sensitive optical memory device on the atomic scale. The protected electric dipole within the PBG provides a basis for a qubit to encode information for quantum computations. A detailed literature survey on the nature, fabrication and applications of PBG materials is presented to provide context for this research. (phd tutorial)

  20. Spontaneous gas gangrene in a patient with Crohn's disease.

    Science.gov (United States)

    Vaidya, Yash P; Vaidya, Tanvi P

    2012-01-01

    Spontaneous gas gangrene is necrosis of muscles in the absence of trauma, causing an acutely painful and potentially fatal condition. However, the occurrence of this condition in Crohn's disease has been very rarely documented. In this extremely rare case we describe an occurrence of spontaneous gas gangrene, in a known case of Crohn's disease. The patient presented with fever and pain in the left arm and abdomen. After admission and initial management with antibiotics, the patient developed crepitus in the arm and myonecrosis necessitating a fasciotomy and later an emergency amputation of his left upper limb. The pathogenesis of gas gangrene in inflammatory bowel disease is not fully understood. Management includes aggressive antibiotic administration followed by amputation of the non-salvageable limb. A high index of suspicion of such rare complications is a must and surgical intervention is life saving; however, the efficacy of anti-gas gangrene serum is controversial. We recommend use of a multipronged approach in such cases with high mortality rates.

  1. Blinking fluorescence of single donor-acceptor pairs: important role of "dark'' states in resonance energy transfer via singlet levels.

    Science.gov (United States)

    Osad'ko, I S; Shchukina, A L

    2012-06-01

    The influence of triplet levels on Förster resonance energy transfer via singlet levels in donor-acceptor (D-A) pairs is studied. Four types of D-A pair are considered: (i) two-level donor and two-level acceptor, (ii) three-level donor and two-level acceptor, (iii) two-level donor and three-level acceptor, and (iv) three-level donor and three-level acceptor. If singlet-triplet transitions in a three-level acceptor molecule are ineffective, the energy transfer efficiency E=I_{A}/(I_{A}+I_{D}), where I_{D} and I_{A} are the average intensities of donor and acceptor fluorescence, can be described by the simple theoretical equation E(F)=FT_{D}/(1+FT_{D}). Here F is the rate of energy transfer, and T_{D} is the donor fluorescence lifetime. In accordance with the last equation, 100% of the donor electronic energy can be transferred to an acceptor molecule at FT_{D}≫1. However, if singlet-triplet transitions in a three-level acceptor molecule are effective, the energy transfer efficiency is described by another theoretical equation, E(F)=F[over ¯](F)T_{D}/[1+F[over ¯](F)T_{D}]. Here F[over ¯](F) is a function of F depending on singlet-triplet transitions in both donor and acceptor molecules. Expressions for the functions F[over ¯](F) are derived. In this case the energy transfer efficiency will be far from 100% even at FT_{D}≫1. The character of the intensity fluctuations of donor and acceptor fluorescence indicates which of the two equations for E(F) should be used to find the value of the rate F. Therefore, random time instants of photon emission in both donor and acceptor fluorescence are calculated by the Monte Carlo method for all four types of D-A pair. Theoretical expressions for start-stop correlators (waiting time distributions) in donor and acceptor fluorescence are derived. The probabilities w_{N}^{D}(t) and w_{N}^{A}(t) of finding N photons of donor and acceptor fluorescence in the time interval t are calculated for various values of the energy

  2. Spontaneous radiative recombination and nonradiative Auger recombination in quantum-confined heterostructures

    International Nuclear Information System (INIS)

    Asryan, L V

    2005-01-01

    General approach is described to the rates, fluxes and current densities associated with spontaneous radiative and nonradiative Auger recombinations in heterostructure lasers with different types of a quantum-confined active region (quantum wells, quantum wires, and quantum dots). The proper way of defining the spontaneous radiative and Auger recombination coefficients and their dimensionality are discussed. It is shown that only in a quantum dot, true time constants can be introduced for spontaneous radiative and nonradiative Auger recombinations, which are independent of the injection level. Closed-form elegant expressions are presented for the radiative recombination coefficient as an explicit function of temperature and parameters in bulk and quantum-confined structures. These expressions clearly demonstrate inappropriateness of the common practice of deriving the recombination coefficients in low-dimensional heterostructures from the bulk values. (lasers)

  3. Spontaneous initiation of communication in infants at low and heightened risk for autism spectrum disorders.

    Science.gov (United States)

    Winder, Breanna M; Wozniak, Robert H; Parladé, Meaghan V; Iverson, Jana M

    2013-10-01

    Communication spontaneously initiated by infants at heightened risk (HR; n = 15) for autism spectrum disorders (ASD) is compared with that in low-risk (LR; n = 15) infants at 13 and 18 months of age. Infants were observed longitudinally during naturalistic in-home interaction and semistructured play with caregivers. At both ages, HR infants spontaneously produced Words, Communicative Non-Word Vocalizations, show and point Gestures, and Gesture + Non-Word Vocalization combinations at lower rates than LR peers. This difference also held for Gesture + Word combinations at 18 but not 13 months. At 36 months, all HR children were evaluated for ASD, and 3 received a diagnosis of autistic disorder. At both 13 and 18 months, these 3 children had been at or near the bottom of the distribution on all spontaneous communication variables.

  4. Spontaneous pneumomediastinum due to paralytic rabies

    Directory of Open Access Journals (Sweden)

    Wuping Wang

    2013-02-01

    Full Text Available Rabies is a fatal disease resulting from rabies virus infection, causing severe neurological symptoms and ultimately death by destroying the nervous system. In general, a patient tends to see a neurologist or an infectious diseases physician, with very common and typical discipline-related signs and symptoms, such as hydrophobia, aerophobia, and mental disorders. However, we reported a rabies patient who was first admitted to see a thoracic surgeon with spontaneous pneumomediastinum.

  5. Spontaneous pneumomediastinum due to paralytic rabies

    Directory of Open Access Journals (Sweden)

    Wuping Wang

    Full Text Available Rabies is a fatal disease resulting from rabies virus infection, causing severe neurological symptoms and ultimately death by destroying the nervous system. In general, a patient tends to see a neurologist or an infectious diseases physician, with very common and typical discipline-related signs and symptoms, such as hydrophobia, aerophobia, and mental disorders. However, we reported a rabies patient who was first admitted to see a thoracic surgeon with spontaneous pneumomediastinum.

  6. Quantum mechanics with spontaneous localization and experiments

    International Nuclear Information System (INIS)

    Benatti, F.; Grassi, R.

    1994-05-01

    We examine from an experimental point of view the recently proposed models of spontaneous reduction. We compare their implications about decoherence with those of environmental effects. We discuss the treatment, within the considered models, of the so called quantum telegraph phenomenon and we show that, contrary to what has been recently stated, no problems are met. Finally, we review recent interesting work investigating the implications of dynamical reduction for the proton decay. (author). 16 refs, 4 figs, 3 tabs

  7. Spontaneous atlantoaxial subluxation associated with tonsillitis

    OpenAIRE

    Shunmugam, Meenalochani; Poonnoose, Santosh

    2015-01-01

    Atlantoaxial subluxation is a rare condition and requires a high index of suspicion to diagnose and treat in order to avoid long-term sequelae. Here, we present a case of late presentation of a nontraumatic rotatory subluxation of the atlantoaxial joint or atlantoaxial rotatory subluxation. A 17-year-old girl presented 3 months after the onset of nonspecific upper limb sensory symptoms which eventually settled spontaneously. Initial conservative management by the general practitioner had no e...

  8. Effects of Amoxicillin and Clavulanic Acid on the Spontaneous Mechanical Activity of Juvenile Rat Duodenum.

    Science.gov (United States)

    Ciciora, Steven L; Williams, Kent C; Gariepy, Cheryl E

    2015-09-01

    There are a limited number of medications for the treatment of foregut dysmotility. Enteral amoxicillin/clavulanic acid induces phase III duodenal contractions in a fasting pediatric patient. The mechanism by which this occurs is unknown. We examined the individual contributions of amoxicillin and clavulanic acid on the spontaneous mechanical activity of juvenile rat duodenum to better understand this phenomenon. Duodenal segments from juvenile rats were longitudinally attached to force transducers in organ baths. Samples were cumulatively exposed to amoxicillin or clavulanic acid. Separate samples were exposed to carbachol alone to assess response in both the presence and absence of amoxicillin or clavulanic acid. Basal tone, frequency, and amplitude of contractions were digitized and recorded. The amplitude of the spontaneous contractions increased with amoxicillin. Inhibition of neuronal activity prevented this effect. Clavulanic acid did not affect the spontaneous contractions. Basal tone and the rate of contractions did not differ with either drug. Stimulation with carbachol in the presence of amoxicillin caused a statistically significant increase in the contractility compared with carbachol alone. Amoxicillin alters the spontaneous longitudinal mechanical activity of juvenile rat duodenum. Our results suggest that amoxicillin modulates the spontaneous pattern of cyclic mechanical activity of duodenal smooth muscle through noncholinergic, neurally mediated mechanisms. Our work provides an initial physiologic basis for the therapeutic use of amoxicillin in patients with gastrointestinal dysmotility.

  9. The Mirror to Our Soul? Comparisons of Spontaneous and Posed Vocal Expression of Emotion.

    Science.gov (United States)

    Juslin, Patrik N; Laukka, Petri; Bänziger, Tanja

    2018-01-01

    It has been the subject of much debate in the study of vocal expression of emotions whether posed expressions (e.g., actor portrayals) are different from spontaneous expressions. In the present investigation, we assembled a new database consisting of 1877 voice clips from 23 datasets, and used it to systematically compare spontaneous and posed expressions across 3 experiments. Results showed that (a) spontaneous expressions were generally rated as more genuinely emotional than were posed expressions, even when controlling for differences in emotion intensity, (b) there were differences between the two stimulus types with regard to their acoustic characteristics, and (c) spontaneous expressions with a high emotion intensity conveyed discrete emotions to listeners to a similar degree as has previously been found for posed expressions, supporting a dose-response relationship between intensity of expression and discreteness in perceived emotions. Our conclusion is that there are reliable differences between spontaneous and posed expressions, though not necessarily in the ways commonly assumed. Implications for emotion theories and the use of emotion portrayals in studies of vocal expression are discussed.

  10. Spontaneous Regression of a Cervical Disk Herniation

    Directory of Open Access Journals (Sweden)

    Emre Delen

    2014-03-01

    Full Text Available A 54 years old female patient was admitted to our outpatient clinic with a two months history of muscle spasms of her neck and pain radiating to the left upper extremity. Magnetic resonance imaging had shown a large left-sided paracentral disk herniation at the C6-C7 disk space (Figure 1. Neurological examination showed no obvious neurological deficit. She received conservative treatment including bed rest, rehabilitation, and analgesic drugs. After 13 months, requested by the patient, a second magnetic resonance imaging study showed resolution of the disc herniation.(Figure 2 Although the literature contains several reports about spontaneous regression of herniated lumbar disc without surgical intervention, that of phenomenon reported for herniated cervical level is rare, and such reports are few[1]. In conclusion, herniated intervertebral disc have the potential to spontaneously regress independently from the spine level. With further studies, determining the predictive signs for prognostic evaluation for spontaneous regression which would yield to conservative treatment would be beneficial.

  11. Spontaneously emerging cortical representations of visual attributes

    Science.gov (United States)

    Kenet, Tal; Bibitchkov, Dmitri; Tsodyks, Misha; Grinvald, Amiram; Arieli, Amos

    2003-10-01

    Spontaneous cortical activity-ongoing activity in the absence of intentional sensory input-has been studied extensively, using methods ranging from EEG (electroencephalography), through voltage sensitive dye imaging, down to recordings from single neurons. Ongoing cortical activity has been shown to play a critical role in development, and must also be essential for processing sensory perception, because it modulates stimulus-evoked activity, and is correlated with behaviour. Yet its role in the processing of external information and its relationship to internal representations of sensory attributes remains unknown. Using voltage sensitive dye imaging, we previously established a close link between ongoing activity in the visual cortex of anaesthetized cats and the spontaneous firing of a single neuron. Here we report that such activity encompasses a set of dynamically switching cortical states, many of which correspond closely to orientation maps. When such an orientation state emerged spontaneously, it spanned several hypercolumns and was often followed by a state corresponding to a proximal orientation. We suggest that dynamically switching cortical states could represent the brain's internal context, and therefore reflect or influence memory, perception and behaviour.

  12. Spontaneous prediction error generation in schizophrenia.

    Directory of Open Access Journals (Sweden)

    Yuichi Yamashita

    Full Text Available Goal-directed human behavior is enabled by hierarchically-organized neural systems that process executive commands associated with higher brain areas in response to sensory and motor signals from lower brain areas. Psychiatric diseases and psychotic conditions are postulated to involve disturbances in these hierarchical network interactions, but the mechanism for how aberrant disease signals are generated in networks, and a systems-level framework linking disease signals to specific psychiatric symptoms remains undetermined. In this study, we show that neural networks containing schizophrenia-like deficits can spontaneously generate uncompensated error signals with properties that explain psychiatric disease symptoms, including fictive perception, altered sense of self, and unpredictable behavior. To distinguish dysfunction at the behavioral versus network level, we monitored the interactive behavior of a humanoid robot driven by the network. Mild perturbations in network connectivity resulted in the spontaneous appearance of uncompensated prediction errors and altered interactions within the network without external changes in behavior, correlating to the fictive sensations and agency experienced by episodic disease patients. In contrast, more severe deficits resulted in unstable network dynamics resulting in overt changes in behavior similar to those observed in chronic disease patients. These findings demonstrate that prediction error disequilibrium may represent an intrinsic property of schizophrenic brain networks reporting the severity and variability of disease symptoms. Moreover, these results support a systems-level model for psychiatric disease that features the spontaneous generation of maladaptive signals in hierarchical neural networks.

  13. Spontaneous Large Serous Retinal Pigment Epithelial Tear

    Directory of Open Access Journals (Sweden)

    Voraporn Chaikitmongkol

    2012-10-01

    Full Text Available Purpose: To report cases of spontaneous retinal pigment epithelial (RPE tear complicating serous pigment epithelial detachment (PED. Methods: The records of 3 Asian patients with spontaneous giant RPE tear were reviewed retrospectively by including clinical presentation, angiography, optical coherence tomography, fundus autofluorescence imaging, and visual outcome. Results: Three patients (4 eyes were included in this study, with a mean age of 48.3 (42–56 years, and a mean follow-up period of 7.75 (4–18 months. Fundus examination in all patients showed giant RPE tear associated with bullous PED. Two cases had a history of prior corticosteroid use, and 1 had no history of medication use. All 3 patients developed spontaneous resolution of subretinal fluid with no treatment. However, in patients who used corticosteroids, initial progression of the tear and subretinal fluid were observed despite ceasing medication. On subsequent follow-up, an incomplete RPE regeneration was demonstrated by fundus autofluorescence imaging, and choroidal neovascularization developed in 1 patient. Conclusion: Large PED with RPE tear is a rare manifestation. When the fovea is spared, visual prognosis is favorable. No specific treatment is required, but careful choroidal neovascularization monitoring should be performed.

  14. Spontaneous fission of the heaviest elements

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, D.C.

    1989-04-01

    Although spontaneous fission was discovered in /sup 238/U in 1940, detailed studies of the process were first made possible in the 1960's with the availability of milligram quantities of /sup 252/Cf. The advent of solid-state detectors made it possible to perform measurements of coincident fission fragments from even very short-lived spontaneous fission activities or those available in only very small quantities. Until 1971 it was believed that the main features of the mass and kinetic-energy distributions were essentially the same as those for thermal neutron-induced fission and that all low-energy fission proceeded via asymmetric mass division with total kinetic energies which could be derived by linear extrapolation from those of lighter elements. In 1971, measurements of /sup 257/Fm showed an increase in symmetric mass division with anomalously high TKE's. Subsequent experiments showed that in /sup 258/Fm and /sup 259/Fm, the most probable mass split was symmetric with very high total kinetic energy. Measurements for the heavier elements have shown symmetric mass distributions with both high and low total kinetic energies. Recent results for spontaneous fission properties of the heaviest elements are reviewed and compared with theory. 31 refs., 8 figs., 1 tab.

  15. The Effect of Live Spontaneous Harp Music on Patients in the Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    Ann Marie Chiasson

    2013-01-01

    Full Text Available This study was performed to investigate the effect of live, spontaneous harp music on individual patients in an intensive care unit (ICU, either pre- or postoperatively. The purpose was to determine whether this intervention would serve as a relaxation or healing modality, as evidenced by the effect on patient’s pain, heart rate, respiratory rate, blood pressure, oxygen saturation, and heart rate variability. Each consenting patient was randomly assigned to receive either a live 10-minute concert of spontaneous music played by an expert harpist or a 10-minute rest period. Spontaneous harp music significantly decreased patient perception of pain by 27% but did not significantly affect heart rate, respiratory rate, oxygen saturation, blood pressure, or heart rate variability. Trends emerged, although being not statistically significant, that systolic blood pressure increased while heart rate variability decreased. These findings may invoke patient engagement, as opposed to relaxation, as the underlying mechanism of the decrease in the patients’ pain and of the healing benefit that arises from the relationship between healer, healing modality, and patient.

  16. Extralobar pulmonary sequestration in neonates: The natural course and predictive factors associated with spontaneous regression

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hee Mang; Jung, Ah Young; Cho, Young Ah; Yoon, Chong Hyun; Lee, Jin Seong [Asan Medical Center Children' s Hospital, University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Songpa-gu, Seoul (Korea, Republic of); Kim, Ellen Ai-Rhan [University of Ulsan College of Medicine, Division of Neonatology, Asan Medical Center Children' s Hospital, Seoul (Korea, Republic of); Chung, Sung-Hoon [Kyung Hee University School of Medicine, Department of Pediatrics, Seoul (Korea, Republic of); Kim, Seon-Ok [Asan Medical Center, Department of Clinical Epidemiology and Biostatistics, Seoul (Korea, Republic of)

    2017-06-15

    To describe the natural course of extralobar pulmonary sequestration (EPS) and identify factors associated with spontaneous regression of EPS. We retrospectively searched for patients diagnosed with EPS on initial contrast CT scan within 1 month after birth and had a follow-up CT scan without treatment. Spontaneous regression of EPS was assessed by percentage decrease in volume (PDV) and percentage decrease in sum of the diameter of systemic feeding arteries (PDD) by comparing initial and follow-up CT scans. Clinical and CT features were analysed to determine factors associated with PDV and PDD rates. Fifty-one neonates were included. The cumulative proportions of patients reaching PDV > 50 % and PDD > 50 % were 93.0 % and 73.3 % at 4 years, respectively. Tissue attenuation was significantly associated with PDV rate (B = -21.78, P <.001). The tissue attenuation (B = -22.62, P =.001) and diameter of the largest systemic feeding arteries (B = -48.31, P =.011) were significant factors associated with PDD rate. The volume and diameter of systemic feeding arteries of EPS spontaneously decreased within 4 years without treatment. EPSs showing a low tissue attenuation and small diameter of the largest systemic feeding arteries on initial contrast-enhanced CT scans were likely to regress spontaneously. (orig.)

  17. The probability of spontaneous regression of lumbar herniated disc: a systematic review.

    Science.gov (United States)

    Chiu, Chun-Chieh; Chuang, Tai-Yuan; Chang, Kwang-Hwa; Wu, Chien-Hua; Lin, Po-Wei; Hsu, Wen-Yen

    2015-02-01

    To determine the probability of spontaneous disc regression among each type of lumbar herniated disc, using a systematic review. Medline, Cochrane Library, CINAHL, and Web of Science were searched using key words for relevant original articles published before March 2014. Articles were limited to those published in English and human studies. Articles had to: (1) include patients with lumbar disc herniation treated conservatively; (2) have at least two imaging evaluations of the lumbar spine; and (3) exclude patients with prior lumbar surgery, spinal infections, tumors, spondylolisthesis, or spinal stenosis. Two reviewers independently extracted study details and findings. Thirty-one studies met the inclusion criteria. Furthermore, if the classification of herniation matched the recommended classification of the combined Task Forces, the data were used for combined analysis of the probability of disc regression of each type. Nine studies were applicable for probability calculation. The rate of spontaneous regression was found to be 96% for disc sequestration, 70% for disc extrusion, 41% for disc protrusion, and 13% for disc bulging. The rate of complete resolution of disc herniation was 43% for sequestrated discs and 15% for extruded discs. Spontaneous regression of herniated disc tissue can occur, and can completely resolve after conservative treatment. Patients with disc extrusion and sequestration had a significantly higher possibility of having spontaneous regression than did those with bulging or protruding discs. Disc sequestration had a significantly higher rate of complete regression than did disc extrusion. © The Author(s) 2014.

  18. Effects of dopamine D4 receptor antagonist on spontaneous alternation in rats

    Directory of Open Access Journals (Sweden)

    Lind Nanna M

    2008-10-01

    Full Text Available Abstract Background The present study was a component of a series of studies scrutinising the neuroreceptor substrate of behavioural flexibility in a rat model. Spontaneous alternation paradigms model the natural tendency of rodents to spontaneously and flexibly shift between alternative spatial responses. In the study it was tested for the first time if the neurochemical substrate mediating spontaneous alternation behaviour includes the dopamine D4 receptor. Methods The acute effects of the highly selective dopamine D4 receptor antagonist L-745,870 on rats' performance in a spontaneous alternation paradigm in a T-maze were examined. The paradigm was a food-rewarded continuous trial procedure performed for 20 trials. Results The spontaneous alternation rate was not affected by the doses of the drug administered (0.02 mg/kg; 0.2 mg/kg; 2 mg/kg, but the position bias of the group receiving the highest L-745,870 dose (2 mg/kg was significantly increased compared to the group that received the lowest dose (0.02 mg/kg. No significant effects on position bias were found compared to saline. The drug did not increase response perseveration. Conclusion The results show that the neural substrate mediating the spatial distribution of responses in the spontaneous alternation paradigm includes the D4 receptor. However, the statistically significant effect of L-745,870 on position bias was found comparing a high drug dose with a low drug dose, and not comparing the drug doses with saline. For the tested doses of L-745,870 the effect on position bias was not large enough to affect the alternation rate.

  19. Brazilian multicentre study on preterm birth (EMIP: prevalence and factors associated with spontaneous preterm birth.

    Directory of Open Access Journals (Sweden)

    Renato Passini

    Full Text Available BACKGROUND: Preterm birth rate is increasing and is currently a worldwide concern. The purpose of this study was to estimate the prevalence of preterm birth in a sample of health facilities in Brazil and to identify the main risk factors associated with spontaneous preterm births. METHODS AND FINDINGS: This was a multicentre cross sectional study on preterm births in 20 referral obstetric hospitals with a case-control component to identify factors associated with spontaneous preterm birth. Surveillance was implemented at all centres to identify preterm births. For eligible consenting women, data were collected through a post-delivery questionnaire completed with information from all mother-newborn medical records until death or discharge or at a maximum of 60 days post-delivery, whichever came first. The risk of spontaneous preterm birth was estimated with OR and 95%CI for several predictors. A non-conditional logistic regression analysis was then performed to identify independently associated factors. The overall prevalence of preterm birth was 12.3%. Among them, 64.6% were spontaneous and 35.4% therapeutic. In the case-control component, 2,682 spontaneous preterm births were compared to a sample of 1,146 term births. Multivariate analyses identified the following as risk factors for spontaneous preterm birth among women with at least one previous birth: a previous preterm birth (ORadj = 3.19, 2.30-4.43, multiple pregnancy (ORadj = 29.06, 8.43-100.2, cervical insufficiency (ORadj = 2.93, 1.07-8.05, foetal malformation (ORadj = 2.63, 1.43-4.85, polyhydramnios (ORadj = 2.30, 1.17-4.54, vaginal bleeding (ORadj = 2.16, 1.50-3.11, and previous abortion (ORadj = 1.39, 1.08-1.78. High BMI (ORadj = 0.94, 0.91-0.97 and weight gain during gestation (ORadj = 0.92, 0.89-0.95 were found to be protective factors. CONCLUSIONS: The preterm birth rate in these health facilities in Brazil is high and spontaneous preterm births

  20. Spontaneous emission of an atom in the presence of a plasmonic cloaking sphere

    International Nuclear Information System (INIS)

    Kort-Kamp, W.J.M.; Rosa, F.S.S.; Pinheiro, F.A.; Farina, Carlos

    2012-01-01

    Full text: Cavity Quantum Electrodynamics (CQED) consists, essentially, in the study of the influence of the neighborhood of an atomic system in its radiative properties. The purpose of this kind of study is not only to obtain more precise results for atomic quantities like the anomalous magnetic moment of the electron, but also to control the radiative properties of the system as, for example, the atomic transition frequencies or the natural line widths. Particularly, spontaneous emission rates, which are directly related to the natural line widths, may be enhanced, weakened or even suppressed due to the presence of appropriately arranged perfectly conducting walls in the vicinity of the atomic system. The work considered as a landmark of CQED, presented in a conference of the American Physical Society by Purcell in 1946, was precisely about this kind of influence. Purcell showed that the spontaneous emission associated to nuclear magnetic dipole transitions could be enhanced if the system were appropriately coupled to a resonant external electric circuit. Nowadays, there are several studies about the influence in the spontaneous emission rate of an atom due to the presence of new materials in its neighborhood. Particularly, the so-called metamaterials, the name given to material structures artificially constructed with desired electromagnetic properties, give rise to a new way of controlling the radiative properties of an atomic system.In the present work, after making a brief introduction on spontaneous emission, which includes the calculation of Einstein's coefficient in some simple cases as, for example, an atom embedded in a negative refractive index metamaterial, we discuss how the spontaneous emission rate of a two level atom is altered due to the presence of a plasmonic cloaking sphere. Among other things, our result shows that the emission rate exhibits an oscillatory behavior with the mutual distance between the atom and sphere. Also, we show that for a

  1. Resting heart rate variability predicts safety learning and fear extinction in an interoceptive fear conditioning paradigm.

    Directory of Open Access Journals (Sweden)

    Meike Pappens

    Full Text Available This study aimed to investigate whether interindividual differences in autonomic inhibitory control predict safety learning and fear extinction in an interoceptive fear conditioning paradigm. Data from a previously reported study (N = 40 were extended (N = 17 and re-analyzed to test whether healthy participants' resting heart rate variability (HRV - a proxy of cardiac vagal tone - predicts learning performance. The conditioned stimulus (CS was a slight sensation of breathlessness induced by a flow resistor, the unconditioned stimulus (US was an aversive short-lasting suffocation experience induced by a complete occlusion of the breathing circuitry. During acquisition, the paired group received 6 paired CS-US presentations; the control group received 6 explicitly unpaired CS-US presentations. In the extinction phase, both groups were exposed to 6 CS-only presentations. Measures included startle blink EMG, skin conductance responses (SCR and US-expectancy ratings. Resting HRV significantly predicted the startle blink EMG learning curves both during acquisition and extinction. In the unpaired group, higher levels of HRV at rest predicted safety learning to the CS during acquisition. In the paired group, higher levels of HRV were associated with better extinction. Our findings suggest that the strength or integrity of prefrontal inhibitory mechanisms involved in safety- and extinction learning can be indexed by HRV at rest.

  2. Successful Treatment of Septic Shock due to Spontaneous Esophageal Perforation 96 Hours after Onset by Drainage and Enteral Nutrition

    Directory of Open Access Journals (Sweden)

    Risako Yamashita

    2014-12-01

    Full Text Available Spontaneous esophageal perforation is relatively uncommon, but carries a high mortality rate if diagnosis or treatment is delayed. We report the case of a 68-year-old man with spontaneous esophageal perforation who was successfully treated over 96 h after onset by thoracic drainage and jejunostomy for enteral nutrition. He vomited after drinking alcohol, soon followed by epigastralgia. Heart failure was suspected on admission to another hospital. Spontaneous esophageal perforation was diagnosed 48 h after admission. Chest tube drainage was performed, but his general condition deteriorated and he was transferred to our hospital. Emergent surgery was performed and esophageal perforation combined with pyothorax and mediastinitis was identified on the left side of the lower esophagus. The left thoracic cavity was rinsed and thoracic drainage was performed. Feeding jejunostomy was performed for postoperative enteral nutrition. Effective drainage and sufficient nutrition management appear extremely valuable in treating spontaneous esophageal perforation.

  3. Instabilities, rheology and spontaneous flows in magnetotactic bacterial suspensions

    Science.gov (United States)

    Alonso-Matilla, Roberto; Saintillan, David

    2017-11-01

    Magnetotactic bacteria are motile prokaryotes, mostly present in marine habitats, that synthesize intracellular magnetic membrane-bounded crystals known as magnetosomes. They behave as self-propelled permanent magnetic dipoles that orient and migrate along the geomagnetic field lines of the Earth. In this work, we analyze the macroscopic transport properties of suspensions of such bacteria in microfluidic devices. When placed in an external magnetic field, these microorganisms feel a net magnetic torque which is transmitted to the surrounding fluid, and can give rise to a net unidirectional fluid flow in a planar channel, with a flow rate and direction that can be controlled by adjusting both the magnitude and orientation of the external field. Using a continuum kinetic model, we provide a physical explanation for the onset of these spontaneous flows. We also study the rheological properties and stability of these suspensions in both an applied shear flow and a pressure-driven flow.

  4. Spontaneous successful pregnancy in posthypophysectomy hypopituitarism: A rare case report

    Directory of Open Access Journals (Sweden)

    Indu Lata

    2014-01-01

    Full Text Available Pregnancy in patients with pan-hypopituitarism following surgery of pituitary adenoma is rare and considered high risk. Hormonal dysfunction in these patients involves more than one axis (gonadotrophic, thyroidal, and adrenal. However, advance in infertility treatment have led to the increased pregnancy rate in hypopituitarism women. We present a case of nonfunctioning pituitary macroadenoma, who after pituitary surgery (hypophysectomy developed hypopituitarism followed by multiple tuberculoma brain with hydrocephalus with arachnoiditis. She conceived spontaneously after 9 years of pituitary surgery and carried her pregnancy to the term. Elective caesarean section was done at 38 weeks and both infant and mother are well. The case highlights the rarity of the phenomenon and the safe outcome of the pregnancy with proper replacement.

  5. Prophylaxis of venous thrombosis in patients with spontaneous intracerebral bleeding

    Directory of Open Access Journals (Sweden)

    Emanuele Rezoagli

    2011-08-01

    Full Text Available Spontaneous intracerebral haemorrhage (SIH represents a severe clinical event that is associated with high rates of mortality and morbidity. Only a minority of SIH patients receive surgical treatment, whereas the majority are treated conservatively. Venous thromboembolism (VTE is one of the most common complications in SIH patients and a potential cause of death. Because of the lack of adequate evidences from the literature, the risk to benefit ratio of pharmacologic prophylaxis of VTE, represented on the one hand by hematoma enlargement and/or rebleeding and on the other hand by an expected reduction of the risk of VTE, remains controversial. Mechanical prophylaxis is a potentially safer alternative, but the efficacy of this approach is uncertain. In the absence of specific clinical guidelines containing clear-cut recommendations, physicians have insufficient tools to assist their therapeutic decisions.

  6. Different spontaneous breathing trials in patients with atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Y.-H. Tseng

    2015-09-01

    Full Text Available Introduction: Weaning from mechanical ventilation is one of the most important and challenging problems for most intensive care unit (ICU patients. Spontaneous breathing trial (SBT is the most common method used to evaluate patients’ ability to breathe by themselves and plays an important role in decision making for weaning. The aim of our study was to investigate the effect of different methods of SBT in respiratory care unit (RCU patients with atrial fibrillation (AF on weaning outcome. Methods: We retrospectively analyzed different methods of SBT in patients with and without AF. We enrolled RCU patients who required mechanical ventilation and had undergone transthoracic echocardiography from January 2011 to January 2012. Results: There was a higher SBT passing rate among AF patients who received pressure support ventilation (PSV trial than in those who received T-piece trail (92.5% vs. 73.1%, p = 0.041. The weaning rates between these two groups were not significantly different (83.8% vs. 94.7%, p = 0.403. Total ventilator days were longer in T-piece group than in PSV group (median 40.0, IQR: 18.2–125.1 days vs. 33.0, IQR: 29.6–51.0 days respectively, p = 0.580, but this difference was not statistically significant. These results were not found in patients without AF. Conclusions: The use of PSV trial might be considered first instead of T-piece trial for SBT when AF patients were ready to wean. Keywords: Atrial fibrillation (AF, Intensive care unit (ICU, Mechanical ventilation, Spontaneous breathing trial (SBT, Ventilator weaning

  7. Spontaneous Pneumothoraces in Patients with Birt-Hogg-Dubé Syndrome.

    Science.gov (United States)

    Gupta, Nishant; Kopras, Elizabeth J; Henske, Elizabeth P; James, Laura E; El-Chemaly, Souheil; Veeraraghavan, Srihari; Drake, Matthew G; McCormack, Francis X

    2017-05-01

    Spontaneous pneumothorax is a common complication of Birt-Hogg-Dubé syndrome (BHD). The optimal approach to treatment and prevention of BHD-associated spontaneous pneumothorax, and to advising patients with BHD regarding risk of pneumothorax associated with air travel, is not well established. Patients with BHD were recruited from the Rare Lung Diseases Clinic Network and the BHD Foundation and surveyed about disease manifestations and air travel experiences. A total of 104 patients completed the survey. The average age at diagnosis was 47 years, with an average delay from first symptoms of 13 years. Pulmonary cysts were the most frequent phenotypic manifestation of BHD, present in 85% of patients. Spontaneous pneumothorax was the presenting manifestation that led to the diagnosis of BHD in 65% of patients, typically after the second episode (mean, 2.4 episodes). Seventy-nine (76%) of 104 patients had at least one spontaneous pneumothorax during their lifetime, and 82% had multiple pneumothoraces. Among patients with multiple pneumothoraces, 73% had an ipsilateral recurrence, and 48% had a subsequent contralateral spontaneous pneumothorax following a sentinel event. The mean ages at first and second pneumothoraces were 36.5 years (range, 14-63 yr) and 37 years (range, 20-55 yr), respectively. The average number of spontaneous pneumothoraces experienced by patients with a sentinel pneumothorax was 3.6. Pleurodesis was generally performed after the second (mean, 2.4) ipsilateral pneumothorax and reduced the ipsilateral recurrence rate by half. A total of 11 episodes of spontaneous pneumothorax occurred among eight patients either during or within the 24-hour period following air travel, consistent with an air travel-related pneumothorax rate of 8% per patient and 0.12% per flight. Prior pleurodesis reduced the occurrence of a subsequent flight-related pneumothorax. Spontaneous pneumothorax is an important, recurrent manifestation of pulmonary involvement in patients

  8. Analysis of three surgical treatments for spontaneous supratentorial intracerebral hemorrhage

    Science.gov (United States)

    Cai, Qiang; Zhang, Huaping; Zhao, Dong; Yang, Zhaohui; Hu, Keqi; Wang, Long; Zhang, Wenfei; Chen, Zhibiao; Chen, Qianxue

    2017-01-01

    Abstract This retrospective study aimed to evaluate the effectiveness and safety of 3 surgical procedures for Spontaneous Supratentorial Intracerebral Hemorrhage (SICH). A total of 63 patients with SICH were randomized into 3 groups. Group A (n = 21) underwent craniotomy surgery, group B (n = 22) underwent burr hole, urokinase infusion and catheter drainage, and group C (n = 20) underwent neuroendoscopic surgery. The hematoma evacuation rate of the operation was analyzed by 3D Slice software and the average surgery time, visualization during operation, decompressive effect, mortality, Glasgow Coma Scale (GCS) improvement, complications include rebleeding, pneumonia, intracranial infection were also compared among 3 groups. All procedures were successfully completed and the hematoma evacuation rate was significant differences among 3 groups which were 79.8%, 43.1%, 89.3% respectively (P intracranial infection, GCS improvement and mortality rate. All these 3 methods had its own advantages and shortcomings, and every approach had its indications for SICH. Although for neuroendoscopic technical's minimal invasive, direct vision, effectively hematoma evacuation rate, and the relatively optimistic result, it might be a more promising approach for SICH. PMID:29069046

  9. Changes of spontaneous parthenogenetic activation and development potential of golden hamster oocytes during the aging process.

    Science.gov (United States)

    Jiang, Han; Wang, Ce; Guan, Jiyu; Wang, Lingyan; Li, Ziyi

    2015-01-01

    The golden hamster is an excellent animal experimental model for oocyte research. The hamster oocytes are very useful in clinical examination of human spermatozoan activity. Non-fertile oocytes can lead to time-dependent processes of aging, which will affect the results of human spermatozoa examination. As a consequence there is a need to investigate the aging and anti-aging processes of golden hamster oocytes. In order to study the aging processes and parthenogenetic activation of golden hamster oocytes, in vivo oocytes, oocytes cultured with or without cumulus cells, and oocytes treated with Trichostatin A (TSA) or caffeine were collected and investigated. We found that: (1) spontaneous parthenogenetic activation, developmental potential (cleavage rate), and zona pellucida (ZP) hardening undergo age-dependent changes in in vivo, in vitro, and after TSA or caffeine treatment; (2) in vivo, oocytes became spontaneously parthenogenetic 25 h post-hCG treatment; (3) in vitro, cumulus cells did not significantly increase the parthenogenetic activation rate of cultured hamster oocytes; and (4) TSA or caffeine could delay spontaneous oocyte parthenogenetic activation and the aging processes by at least 5h, but also accelerated the hardening of the ZP. These results define the conditions for the aging and anti-aging processes in golden hamster oocytes. TSA and caffeine play roles in controlling spontaneous activation, which could facilitate the storage and use of golden hamster oocytes for studying processes relevant to human reproduction. Copyright © 2014 Elsevier GmbH. All rights reserved.

  10. Multiple genetic switches spontaneously modulating bacterial mutability

    Directory of Open Access Journals (Sweden)

    Johnston Randal N

    2010-09-01

    Full Text Available Abstract Background All life forms need both high genetic stability to survive as species and a degree of mutability to evolve for adaptation, but little is known about how the organisms balance the two seemingly conflicting aspects of life: genetic stability and mutability. The DNA mismatch repair (MMR system is essential for maintaining genetic stability and defects in MMR lead to high mutability. Evolution is driven by genetic novelty, such as point mutation and lateral gene transfer, both of which require genetic mutability. However, normally a functional MMR system would strongly inhibit such genomic changes. Our previous work indicated that MMR gene allele conversion between functional and non-functional states through copy number changes of small tandem repeats could occur spontaneously via slipped-strand mis-pairing during DNA replication and therefore may play a role of genetic switches to modulate the bacterial mutability at the population level. The open question was: when the conversion from functional to defective MMR is prohibited, will bacteria still be able to evolve by accepting laterally transferred DNA or accumulating mutations? Results To prohibit allele conversion, we "locked" the MMR genes through nucleotide replacements. We then scored changes in bacterial mutability and found that Salmonella strains with MMR locked at the functional state had significantly decreased mutability. To determine the generalizability of this kind of mutability 'switching' among a wider range of bacteria, we examined the distribution of tandem repeats within MMR genes in over 100 bacterial species and found that multiple genetic switches might exist in these bacteria and may spontaneously modulate bacterial mutability during evolution. Conclusions MMR allele conversion through repeats-mediated slipped-strand mis-pairing may function as a spontaneous mechanism to switch between high genetic stability and mutability during bacterial evolution.

  11. Being Spontaneous: The Future of Telehealth Implementation?

    Science.gov (United States)

    Mars, Maurice; Scott, Richard E

    2017-09-01

    The smartphone simplifies interprofessional communication, and smartphone applications can facilitate telemedicine activity. Much has been written about the steps that need to be followed to implement and establish a successful telemedicine service that is integrated into everyday clinical practice. A traditional and systematic approach has evolved incorporating activities such as strategy development, needs assessment, business cases and plans, readiness assessment, implementation plans, change management interventions, and ongoing monitoring and evaluation. This "best practice" has been promoted in the telehealth literature for many years. In contrast, several recent initiatives have arisen without any such formal undertakings. This article describes the strengths and weaknesses of two "spontaneous" telemedicine services in dermatology and burn management that have evolved in South Africa. Two spontaneous services were identified and reviewed. In one unsolicited service, doctors at rural referring hospitals have been taking photographs of skin lesions and sending them with a brief text message history to dermatologists using the instant messaging smartphone app, WhatsApp. In the other, burns service, admissions to the burns unit or the clinic were triaged by telephonic description of the case and completion of a preadmission questionnaire. More recently, management and referral decisions are made only after completion of the questionnaire and subsequent submission of photographs of the burn sent by WhatsApp, with the decision transmitted by text message. Although efficient and effective, potential legal and ethical shortcomings have been identified. These "spontaneous" telehealth services challenge traditional best practice, yet appear to lead to truly integrated practice and, therefore, are successful and warrant further study.

  12. Angyomatous vocal polypus: a complete spontaneous regression

    Directory of Open Access Journals (Sweden)

    Edmir Américo Lourenço

    Full Text Available The authors describe a male patient who had malignant lymphoma seven years ago which remitted with chemotherapy.Two years ago he developed dysphonia. An unilateral, pediculate smooth red lesion on the right vocal fold was later discovered. Even without benefit of medicamentosus treatment, the patient refused surgery. In a reevaluation using rigid telescopy of the larynx two years later, the lesion had disappeared, completely and spontaneously. As there are no existing publications on this topic, this case report is an alert that surgery should be recommended with extreme caution in this type of vocal disease.

  13. Cerebrovascular gene expression in spontaneously hypertensive rats

    DEFF Research Database (Denmark)

    Grell, Anne-Sofie; Frederiksen, Simona Denise; Edvinsson, Lars

    2017-01-01

    in the middle cerebral arteries from hypertensive compared to normotensive rats. The gene expression of 72 genes was decreased and the gene expression of 97 genes was increased. The following genes with a fold difference ≥1.40 were verified by quantitative PCR; Postn, Olr1, Fas, Vldlr, Mmp2, Timp1, Serpine1......, Mmp11, Cd34, Ptgs1 and Ptgs2. The gene expression of Postn, Olr1, Fas, Vldlr, Mmp2, Timp1 and Serpine1 and the protein expression of LOX1 (also known as OLR1) were significantly increased in the middle cerebral arteries from spontaneously hypertensive rats compared to Wistar-Kyoto rats. In conclusion...

  14. Fracture of maternal sternum during spontaneous delivery.

    Science.gov (United States)

    Stubert, J; Gerber, B

    2009-12-01

    We report of a maternal sternal fracture during a spontaneous delivery in a 31-year-old primipara without a suitable trauma. The putative mechanism of fracture was strong hyperflexion of the thoracic spine and additional cervical flexion with pushing the chin to the thorax due to active management of labour. The history of the healthy woman was free of related risk factors. A possible promoting factor might be pregnancy-induced bone loss. Although there were clear symptoms, the diagnosis of the fracture was delayed by a week because nobody took account of such a possibility.

  15. Neural correlates of the affective properties of spontaneous and volitional laughter types.

    Science.gov (United States)

    Lavan, Nadine; Rankin, Georgia; Lorking, Nicole; Scott, Sophie; McGettigan, Carolyn

    2017-01-27

    Previous investigations of vocal expressions of emotion have identified acoustic and perceptual distinctions between expressions of different emotion categories, and between spontaneous and volitional (or acted) variants of a given category. Recent work on laughter has identified relationships between acoustic properties of laughs and their perceived affective properties (arousal and valence) that are similar across spontaneous and volitional types (Bryant & Aktipis, 2014; Lavan et al., 2016). In the current study, we explored the neural correlates of such relationships by measuring modulations of the BOLD response in the presence of itemwise variability in the subjective affective properties of spontaneous and volitional laughter. Across all laughs, and within spontaneous and volitional sets, we consistently observed linear increases in the response of bilateral auditory cortices (including Heschl's gyrus and superior temporal gyrus [STG]) associated with higher ratings of perceived arousal, valence and authenticity. Areas in the anterior medial prefrontal cortex (amPFC) showed negative linear correlations with valence and authenticity ratings across the full set of spontaneous and volitional laughs; in line with previous research (McGettigan et al., 2015; Szameitat et al., 2010), we suggest that this reflects increased engagement of these regions in response to laughter of greater social ambiguity. Strikingly, an investigation of higher-order relationships between the entire laughter set and the neural response revealed a positive quadratic profile of the BOLD response in right-dominant STG (extending onto the dorsal bank of the STS), where this region responded most strongly to laughs rated at the extremes of the authenticity scale. While previous studies claimed a role for right STG in bipolar representation of emotional valence, we instead argue that this may in fact exhibit a relatively categorical response to emotional signals, whether positive or negative

  16. Functional neurological evaluation of the brainstem. Part I: the blink reflex Evaluación neurofuncional del tallo cerebral. Parte I: Reflejo del parpadeo

    Directory of Open Access Journals (Sweden)

    Jaime Bedoya

    2009-11-01

    Full Text Available

    The blink reflex is the neural response elicited in the orbicular oculi muscle after single or paired supraorbital nerve stimulation, by either electrical, mechanical, acoustic, thermal, chemical or magnetic stimulation. It is made up of three responses called R1, R2 and R3. R1 is an early response that follows A beta fibers, and does not habituate. R2 is a middle-latency response that follows A beta and A delta fibers, tends to habituate and is modulated by sensorimotor suprasegmental structures.

    R3 is a long-latency response, generated by stimulation of a multisynaptic chain of neurons that involve type C fibers belonging to a complex pontothalamic-amigdalo-cerebellar pathway. It is also possible to record three silent periods if the blink reflex is obtained while the subject makes a voluntary facial muscle effort.

    The functional study of this reflex allows to define with certainty whether the lesion is in afferent or efferent pathways or if it involves an abnormal sensorimotor integration due to disorders of the central, autonomic or peripheral nervous systems. A correct execution of these studies, and their appropriate interpretation, based on the underlying mechanisms of neural plasticity, will guide toward better neurorehabilitation protocols.

    Comparison of evoked vs. spontaneous tics in a patient with trigeminal neuralgia (tic doloureux

    Directory of Open Access Journals (Sweden)

    Aiello-Lammens Matthew

    2007-11-01

    Full Text Available Abstract A 53-year old woman with tic doloureaux, affecting her right maxillary division of the trigeminal nerve (V2, could elicit shooting pains by slightly tapping her teeth when off medication. The pains, which she normally rated as > 6/10 on a visual analog scale (VAS, were electric shock-like in nature. She had no other spontaneous or ongoing background pain affecting the region. Based on her ability to elicit these tics, functional magnetic resonance imaging (fMRI was performed while she produced brief shocks every 2 minutes on cue (evoked pain over a 20 min period. In addition, she had 1–2 spontaneous shocks manifested between these evoked pains over the course of functional image acquisition. Increased fMRI activation for both evoked and spontaneous tics was observed throughout cortical and subcortical structures commonly observed in experimental pain studies with healthy subjects; including the primary somatosensory cortex, insula, anterior cingulate, and thalamus. Spontaneous tics produced more decrease in signals in a number of regions including the posterior cingulate cortex and amygdala, suggesting that regions known to be involved in expectation/anticipation may have been activated for the evoked, but not spontaneous, tics. In this patient there were large increases in activation observed in the frontal regions, including the anterior cingulate cortex and the basal ganglia. Spontaneous tics showed increased activation in classic aversion circuitry that may contribute to increased levels of anxiety. We believe that this is the first report of functional imaging of brain changes in tic-doloureaux.

  17. Spontaneously Reported Symptoms by Informants Are Associated with Clinical Severity in Dementia Help-Seekers.

    Science.gov (United States)

    Xu, Jia-Qi; Choy, Jacky C P; Tang, Jennifer Y M; Liu, Tian-Yin; Luo, Hao; Lou, Vivian W Q; Lum, Terry Y S; Wong, Gloria H Y

    2017-09-01

    To investigate the predictive value of symptoms of dementia that the person or an informant noticed spontaneously in determining the clinical severity of dementia. Cross-sectional. Community-based open-referral dementia assessment service in Hong Kong between 2005 and 2013. Help-seekers for dementia assessment service and their informants (N = 965 dyads). Participants underwent a clinical dementia interview based on the Clinical Dementia Rating. Spontaneous complaints that the person and the informant made that had prompted their help-seeking of groups with interview results suggestive of no impairment, mild cognitive impairment, and dementia were compared. Logistic regression was used to evaluate the predictive value of spontaneous complaints for clinical severity. Independent raters blinded to clinical results coded spontaneously reported symptoms into theoretical themes: memory, executive function, language, time and place orientation, neuropsychiatric, mood, and avolition. Memory problems were the most frequently reported complaints for participants (87.7%) and their informants (95.5%), followed by self-reported language (33.0%) and informant-reported orientation (33.0%) difficulties. Informant-reported but not self-reported symptoms predicted clinical severity. Compared with the persons themselves, informants reported more pervasive symptoms corresponding to clinical severity. Persons with dementia self-reported fewer types of symptoms than their healthy or mildly impaired counterparts. Spontaneously reported language and orientation symptoms by the informant distinguished persons with mild or worse dementia (P < .001, Nagelkerke coefficient of determination = 29.7%, percentage correct 85.6%). The type and pervasiveness of symptoms spontaneously that informants reported predicted clinical severity. This may provide a quick reference for triage. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

  18. Spontaneous cooperation for prosocials, but not for proselfs: Social value orientation moderates spontaneous cooperation behavior

    Science.gov (United States)

    Mischkowski, Dorothee; Glöckner, Andreas

    2016-01-01

    Cooperation is essential for the success of societies and there is an ongoing debate whether individuals have therefore developed a general spontaneous tendency to cooperate or not. Findings that cooperative behavior is related to shorter decision times provide support for the spontaneous cooperation effect, although contrary results have also been reported. We show that cooperative behavior is better described as person × situation interaction, in that there is a spontaneous cooperation effect for prosocial but not for proself persons. In three studies, one involving population representative samples from the US and Germany, we found that cooperation in a public good game is dependent on an interaction between individuals’ social value orientation and decision time. Increasing deliberation about the dilemma situation does not affect persons that are selfish to begin with, but it is related to decreasing cooperation for prosocial persons that gain positive utility from outcomes of others and score high on the related general personality trait honesty/humility. Our results demonstrate that the spontaneous cooperation hypothesis has to be qualified in that it is limited to persons with a specific personality and social values. Furthermore, they allow reconciling conflicting previous findings by identifying an important moderator for the effect. PMID:26876773

  19. Spontaneous regression of intracranial malignant lymphoma

    International Nuclear Information System (INIS)

    Kojo, Nobuto; Tokutomi, Takashi; Eguchi, Gihachirou; Takagi, Shigeyuki; Matsumoto, Tomie; Sasaguri, Yasuyuki; Shigemori, Minoru.

    1988-01-01

    In a 46-year-old female with a 1-month history of gait and speech disturbances, computed tomography (CT) demonstrated mass lesions of slightly high density in the left basal ganglia and left frontal lobe. The lesions were markedly enhanced by contrast medium. The patient received no specific treatment, but her clinical manifestations gradually abated and the lesions decreased in size. Five months after her initial examination, the lesions were absent on CT scans; only a small area of low density remained. Residual clinical symptoms included mild right hemiparesis and aphasia. After 14 months the patient again deteriorated, and a CT scan revealed mass lesions in the right frontal lobe and the pons. However, no enhancement was observed in the previously affected regions. A biopsy revealed malignant lymphoma. Despite treatment with steroids and radiation, the patient's clinical status progressively worsened and she died 27 months after initial presentation. Seven other cases of spontaneous regression of primary malignant lymphoma have been reported. In this case, the mechanism of the spontaneous regression was not clear, but changes in immunologic status may have been involved. (author)