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Sample records for perturbations dictate sudden

  1. Control of trunk motion following sudden stop perturbations during cart pushing.

    Science.gov (United States)

    Lee, Yun-Ju; Hoozemans, Marco J M; van Dieën, Jaap H

    2011-01-04

    External perturbations during pushing tasks have been suggested to be a risk factor for low-back symptoms. An experiment was designed to investigate whether self-induced and externally induced sudden stops while pushing a high inertia cart influence trunk motions, and how flexor and extensor muscles counteract these perturbations. Twelve healthy male participants pushed a 200 kg cart at shoulder height and hip height. Pushing while walking was compared to situations in which participants had to stop the cart suddenly (self-induced stop) or in which the wheels of the cart were unexpectedly blocked (externally induced stop). For the perturbed conditions, the peak values and the maximum changes from the reference condition (pushing while walking) of the external moment at L5/S1, trunk inclination and electromyographic amplitudes of trunk muscles were determined. In the self-induced stop, a voluntary trunk extension occurred. Initial responses in both stops consisted of flexor and extensor muscle cocontraction. In self-induced stops this was followed by sustained extensor activity. In the externally induced stops, an external extension moment caused a decrease in trunk inclination. The opposite directions of the internal moment and trunk motion in the externally induced stop while pushing at shoulder height may indicate insufficient active control of trunk posture. Consequently, sudden blocking of the wheels in pushing at shoulder height may put the low back at risk of mechanical injury. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. Influence of Lumbar Muscle Fatigue on Trunk Adaptations during Sudden External Perturbations

    Science.gov (United States)

    Abboud, Jacques; Nougarou, François; Lardon, Arnaud; Dugas, Claude; Descarreaux, Martin

    2016-01-01

    Introduction: When the spine is subjected to perturbations, neuromuscular responses such as reflex muscle contractions contribute to the overall balance control and spinal stabilization mechanisms. These responses are influenced by muscle fatigue, which has been shown to trigger changes in muscle recruitment patterns. Neuromuscular adaptations, e.g., attenuation of reflex activation and/or postural oscillations following repeated unexpected external perturbations, have also been described. However, the characterization of these adaptations still remains unclear. Using high-density electromyography (EMG) may help understand how the nervous system chooses to deal with an unknown perturbation in different physiological and/or mechanical perturbation environments. Aim: To characterize trunk neuromuscular adaptations following repeated sudden external perturbations after a back muscle fatigue task using high-density EMG. Methods: Twenty-five healthy participants experienced a series of 15 sudden external perturbations before and after back muscle fatigue. Erector spinae muscle activity was recorded using high-density EMG. Trunk kinematics during perturbation trials were collected using a 3-D motion analysis system. A two-way repeated measure ANOVA was conducted to assess: (1) the adaptation effect across trials; (2) the fatigue effect; and (3) the interaction effect (fatigue × adaptation) for the baseline activity, the reflex latency, the reflex peak and trunk kinematic variables (flexion angle, velocity and time to peak velocity). Muscle activity spatial distribution before and following the fatigue task was also compared using t-tests for dependent samples. Results: An attenuation of muscle reflex peak was observed across perturbation trials before the fatigue task, but not after. The spatial distribution of muscle activity was significantly higher before the fatigue task compared to post-fatigue trials. Baseline activity showed a trend to higher values after muscle

  3. Influence of lumbar muscle fatigue on trunk adaptations during sudden external perturbations

    Directory of Open Access Journals (Sweden)

    Jacques Abboud

    2016-11-01

    Full Text Available IntroductionWhen the spine is subjected to perturbations, neuromuscular responses such as reflex muscle contractions contribute to the overall balance control and spinal stabilization mechanisms. These responses are influenced by muscle fatigue, which has been shown to trigger changes in muscle recruitment patterns. Neuromuscular adaptations, e.g. attenuation of reflex activation and/or postural oscillations following repeated unexpected external perturbations, have also been described. However, the characterization of these adaptations still remains unclear. Using high-density electromyography (EMG may help understand how the nervous system chooses to deal with an unknown perturbation in different physiological and/or mechanical perturbation environments. AimTo characterize trunk neuromuscular adaptations following repeated sudden external perturbations after a back muscle fatigue task using high-density EMG.MethodsTwenty-five healthy participants experienced a series of 15 sudden external perturbations before and after back muscle fatigue. Erector spinae muscle activity was recorded using high-density EMG. Trunk kinematics during perturbation trials were collected using a 3-D motion analysis system. A two-way repeated measure ANOVA was conducted to assess 1 the adaptation effect across trials, 2 the fatigue effect, and 3 the interaction effect (fatigue x adaptation for the baseline activity, the reflex latency, the reflex peak and trunk kinematic variables (flexion angle, velocity and time to peak velocity. Muscle activity spatial distribution before and following the fatigue task was also compared using t-tests for dependent samples. ResultsAn attenuation of muscle reflex peak was observed across perturbation trials before the fatigue task, but not after. The spatial distribution of muscle activity was significantly higher before the fatigue task compared to post-fatigue trials. Baseline activity showed a trend to higher values after muscle

  4. Monosynaptic Stretch Reflex Fails to Explain the Initial Postural Response to Sudden Lateral Perturbations

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    Andreas Mühlbeier

    2017-06-01

    Full Text Available Postural reflexes are essential for locomotion and postural stability, and may play an important role in the etiology of chronic back pain. It has recently been theoretically predicted, and with the help of unilateral perturbations of the trunk experimentally confirmed that the sensorimotor control must lower the reflex amplitude for increasing reflex delays to maintain spinal stability. The underlying neuromuscular mechanism for the compensation of postural perturbations, however, is not yet fully understood. In this study, we applied unilateral and bilateral sudden external perturbations to the trunk of healthy subjects and measured the muscular activity and the movement onset of the trunk. We found that the onset of the trunk muscle activity is prior to, or coincident with, the onset of the trunk movement. Additionally, the results of our experiments imply that the muscular response mechanism integrates distant sensory information from both sides of the body. These findings rule out a simple monosynaptic stretch reflex in favor of a more complex polysynaptic postural reflex mechanism to compensate postural perturbations. Moreover, the previously predicted negative correlation between reflex delay and reflex gain was also confirmed for bilateral perturbations.

  5. Primordial spectra from sudden turning trajectory

    Science.gov (United States)

    Noumi, Toshifumi; Yamaguchi, Masahide

    2013-12-01

    Effects of heavy fields on primordial spectra of curvature perturbations are discussed in inflationary models with a sudden turning trajectory. When heavy fields are excited after the sudden turn and oscillate around the bottom of the potential, the following two effects are generically induced: deformation of the inflationary background spacetime and conversion interactions between adiabatic and isocurvature perturbations, both of which can affect the primordial density perturbations. In this paper, we calculate primordial spectra in inflationary models with sudden turning potentials taking into account both of the two effects appropriately. We find that there are some non-trivial correlations between the two effects in the power spectrum and, as a consequence, the primordial scalar power spectrum has a peak around the scale exiting the horizon at the turn. Though both effects can induce parametric resonance amplifications, they are shown to be canceled out for the case with the canonical kinetic terms. The peak feature and the scale dependence of bispectra are also discussed.

  6. Effect of Workplace- versus Home-Based Physical Exercise on Muscle Response to Sudden Trunk Perturbation among Healthcare Workers

    DEFF Research Database (Denmark)

    Jakobsen, Markus D; Sundstrup, Emil; Brandt, Mikkel

    2015-01-01

    Objectives. The present study investigates the effect of workplace- versus home-based physical exercise on muscle reflex response to sudden trunk perturbation among healthcare workers. Methods. Two hundred female healthcare workers (age: 42 [SD 11], BMI: 24 [SD 4], and pain intensity: 3.1 [SD 2.......2] on a scale of 0-10) from 18 departments at three hospitals were randomized at the cluster level to 10 weeks of (1) workplace physical exercise (WORK) performed in groups during working hours for 5 × 10 minutes per week and up to 5 group-based coaching sessions on motivation for regular physical exercise...... perturbation. Furthermore, EMG preactivation of the erector spinae and fear avoidance were reduced more following WORK than HOME (95% CI -2.7--0.7 (P training sessions per week, respectively...

  7. Effect of workplace- versus home-based physical exercise on muscle response to sudden trunk perturbation among healthcare workers

    DEFF Research Database (Denmark)

    Jakobsen, Markus D.; Sundstrup, Emil; Brandt, Mikkel

    2015-01-01

    .2] on a scale of 0-10) from 18 departments at three hospitals were randomized at the cluster level to 10 weeks of (1) workplace physical exercise (WORK) performed in groups during working hours for 5 × 10 minutes per week and up to 5 group-based coaching sessions on motivation for regular physical exercise...... perturbation. Furthermore, EMG preactivation of the erector spinae and fear avoidance were reduced more following WORK than HOME (95% CI -2.7--0.7 (P WORK and HOME performed 2.2 (SD: 1.1) and 1.0 (SD: 1.2) training sessions per week, respectively......Objectives. The present study investigates the effect of workplace- versus home-based physical exercise on muscle reflex response to sudden trunk perturbation among healthcare workers. Methods. Two hundred female healthcare workers (age: 42 [SD 11], BMI: 24 [SD 4], and pain intensity: 3.1 [SD 2...

  8. Effect of Workplace- versus Home-Based Physical Exercise on Muscle Response to Sudden Trunk Perturbation among Healthcare Workers: A Cluster Randomized Controlled Trial

    Science.gov (United States)

    Jakobsen, Markus D.; Jay, Kenneth

    2015-01-01

    Objectives. The present study investigates the effect of workplace- versus home-based physical exercise on muscle reflex response to sudden trunk perturbation among healthcare workers. Methods. Two hundred female healthcare workers (age: 42 [SD 11], BMI: 24 [SD 4], and pain intensity: 3.1 [SD 2.2] on a scale of 0–10) from 18 departments at three hospitals were randomized at the cluster level to 10 weeks of (1) workplace physical exercise (WORK) performed in groups during working hours for 5 × 10 minutes per week and up to 5 group-based coaching sessions on motivation for regular physical exercise, or (2) home-based physical exercise (HOME) performed during leisure time for 5 × 10 minutes per week. Mechanical and neuromuscular (EMG) response to randomly assigned unloading and loading trunk perturbations and questions of fear avoidance were assessed at baseline and 10-week follow-up. Results. No group by time interaction for the mechanical trunk response and EMG latency time was seen following the ten weeks (P = 0.17–0.75). However, both groups demonstrated within-group changes (P < 0.05) in stopping time during the loading and unloading perturbation and in stopping distance during the loading perturbation. Furthermore, EMG preactivation of the erector spinae and fear avoidance were reduced more following WORK than HOME (95% CI −2.7–−0.7 (P < 0.05) and −0.14 (−0.30 to 0.02) (P = 0.09)), respectively. WORK and HOME performed 2.2 (SD: 1.1) and 1.0 (SD: 1.2) training sessions per week, respectively. Conclusions. Although training adherence was higher following WORK compared to HOME this additional training volume did not lead to significant between-group differences in the responses to sudden trunk perturbations. However, WORK led to reduced fear avoidance and reduced muscle preactivity prior to the perturbation onset, compared with HOME. This trial is registered with Clinicaltrials.gov (NCT01921764). PMID:26583145

  9. Effect of Workplace- versus Home-Based Physical Exercise on Muscle Response to Sudden Trunk Perturbation among Healthcare Workers: A Cluster Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Markus D. Jakobsen

    2015-01-01

    Full Text Available Objectives. The present study investigates the effect of workplace- versus home-based physical exercise on muscle reflex response to sudden trunk perturbation among healthcare workers. Methods. Two hundred female healthcare workers (age: 42 [SD 11], BMI: 24 [SD 4], and pain intensity: 3.1 [SD 2.2] on a scale of 0–10 from 18 departments at three hospitals were randomized at the cluster level to 10 weeks of (1 workplace physical exercise (WORK performed in groups during working hours for 5 × 10 minutes per week and up to 5 group-based coaching sessions on motivation for regular physical exercise, or (2 home-based physical exercise (HOME performed during leisure time for 5 × 10 minutes per week. Mechanical and neuromuscular (EMG response to randomly assigned unloading and loading trunk perturbations and questions of fear avoidance were assessed at baseline and 10-week follow-up. Results. No group by time interaction for the mechanical trunk response and EMG latency time was seen following the ten weeks (P = 0.17–0.75. However, both groups demonstrated within-group changes (P<0.05 in stopping time during the loading and unloading perturbation and in stopping distance during the loading perturbation. Furthermore, EMG preactivation of the erector spinae and fear avoidance were reduced more following WORK than HOME (95% CI −2.7–−0.7 (P<0.05 and −0.14 (−0.30 to 0.02 (P=0.09, respectively. WORK and HOME performed 2.2 (SD: 1.1 and 1.0 (SD: 1.2 training sessions per week, respectively. Conclusions. Although training adherence was higher following WORK compared to HOME this additional training volume did not lead to significant between-group differences in the responses to sudden trunk perturbations. However, WORK led to reduced fear avoidance and reduced muscle preactivity prior to the perturbation onset, compared with HOME. This trial is registered with Clinicaltrials.gov (NCT01921764.

  10. A Survey of Great Dictators.

    Science.gov (United States)

    Zoerner, C. E., Jr.

    1981-01-01

    A survey of 14 business managers possessing outstanding dictating skills reveals that preparation is the key to efficient dictation, dictation is not confined to brief letters or memos, the ability to dictate over the phone and to machines is important, and you cannot dictate if you cannot write. (FL)

  11. Pervasive orbital eccentricities dictate the habitability of extrasolar earths.

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    Kita, Ryosuke; Rasio, Frederic; Takeda, Genya

    2010-09-01

    The long-term habitability of Earth-like planets requires low orbital eccentricities. A secular perturbation from a distant stellar companion is a very important mechanism in exciting planetary eccentricities, as many of the extrasolar planetary systems are associated with stellar companions. Although the orbital evolution of an Earth-like planet in a stellar binary system is well understood, the effect of a binary perturbation on a more realistic system containing additional gas-giant planets has been very little studied. Here, we provide analytic criteria confirmed by a large ensemble of numerical integrations that identify the initial orbital parameters leading to eccentric orbits. We show that an extrasolar earth is likely to experience a broad range of orbital evolution dictated by the location of a gas-giant planet, which necessitates more focused studies on the effect of eccentricity on the potential for life.

  12. Effects of pushing height on trunk posture and trunk muscle activity when a cart suddenly starts or stops moving.

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    Lee, Yun-Ju; Hoozemans, Marco J M; van Dieën, Jaap H

    2012-01-01

    Unexpected sudden (un)loading of the trunk may induce inadequate responses of trunk muscles and uncontrolled trunk motion. These unexpected perturbations may occur in pushing tasks, when the cart suddenly starts moving (unloading) or is blocked by an obstacle (loading). In pushing, handle height affects the user's working posture, which may influence trunk muscle activity and trunk movement in response to the perturbation. Eleven healthy male subjects pushed a 200 kg cart with handles at shoulder and hip height in a start condition (sudden release of brakes) and a stop condition (bumping into an obstacle). Before the perturbation, the baseline of the trunk inclination, internal moment and trunk extensor muscle activity were significantly higher when pushing at hip height than at shoulder height. After the perturbation, the changes in trunk inclination and internal moment were significantly larger when pushing at shoulder height than at hip height in both conditions. The opposite directions of changes in trunk inclination and internal moment suggest that the unexpected perturbations caused uncontrolled trunk motion. Pushing at shoulder height may impose a high risk of low-back injury due to the low trunk stiffness and large involuntary trunk motion occurring after carts suddenly move or stop.

  13. Prevention of sudden cardiac death in young athletes: controversies and conundrums.

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    Rowland, Thomas

    2011-01-01

    Strategies for preventing sudden cardiac death in young athletes are predicated on the assumption that: (1) these events reflect pre-existing, clinically silent heart disease, and (2) means for detecting these abnormalities on the pre-participation evaluation are both feasible and accurate. Recent controversy has surrounded both of these presumptions. Some evidence suggests that the myocardial hypertrophy accompanying sports training itself might serve as a substrate for fatal arrhythmias. As well, vigorous debate has arisen over the optimal content of the pre-participation evaluation, particularly regarding the inclusion of routine screening electrocardiograms. As the rarity of these fatal events does not lend itself to an experimental approach, such disagreements are not easily resolved. Consequently, it is expected that decisions regarding approaches to prevention of sudden death in athletes will be dictated largely by region-specific financial, political, and cultural factors. This chapter examines the aetiologies of sudden cardiac death in young athletes as well as the controversies surrounding the prevention of these tragedies. Copyright © 2011 S. Karger AG, Basel.

  14. Machine Dictation and Transcription.

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    Harvey, Evelyn; And Others

    This instructional package contains both an instructor's manual and a student's manual for a course in machine dictation and transcription. The instructor's manual contains an overview with tips on teaching the course, letters for dictation, and a key to the letters. The student's manual contains an overview of the course and of the skills needed…

  15. The sudden death and sudden birth of quantum discord.

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    Xia, Wei; Hou, Jin-Xing; Wang, Xiao-Hui; Liu, Si-Yuan

    2018-03-28

    The interaction of quantum system and its environment brings out abundant quantum phenomenons. The sudden death of quantum resources, including entanglement, quantum discord and coherence, have been studied from the perspective of quantum breaking channels (QBC). QBC of quantum resources reveal the common features of quantum resources. The definition of QBC implies the relationship between quantum resources. However, sudden death of quantum resources can also appear under some other quantum channels. We consider the dynamics of Bell-diagonal states under a stochastic dephasing noise along the z-direction, and the sudden death and sudden birth of quantum discord are investigated. Next we explain this phenomenon from the geometric structure of quantum discord. According to the above results, the states with sudden death and sudden birth can be filtered in three-parameter space. Then we provide two necessary conditions to judge which kind of noise channels can make Bell-diagonal states sudden death and sudden birth. Moreover, the relation between quantum discord and coherence indicates that the sudden death and sudden birth of quantum discord implies the sudden death and sudden birth of coherence in an optimal basis.

  16. A wearable vibrotactile biofeedback system improves balance control of healthy young adults following perturbations from quiet stance.

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    Ma, Christina Zong-Hao; Lee, Winson Chiu-Chun

    2017-10-01

    Maintaining postural equilibrium requires fast reactions and constant adjustments of the center of mass (CoM) position to prevent falls, especially when there is a sudden perturbation of the support surface. During this study, a newly developed wearable feedback system provided immediate vibrotactile clues to users based on plantar force measurement, in an attempt to reduce reaction time and CoM displacement in response to a perturbation of the floor. Ten healthy young adults participated in this study. They stood on a support surface, which suddenly moved in one of four horizontal directions (forward, backward, left and right), with the biofeedback system turned on or off. The testing sequence of the four perturbation directions and the two system conditions (turned on or off) was randomized. The resulting reaction time and CoM displacement were analysed. Results showed that the vibrotactile feedback system significantly improved balance control during translational perturbations. The positive results of this preliminary study highlight the potential of a plantar force measurement based biofeedback system in improving balance under perturbations of the support surface. Future system optimizations could facilitate its application in fall prevention in real life conditions, such as standing in buses or trains that suddenly decelerate or accelerate. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Anticipation of direction and time of perturbation modulates the onset latency of trunk muscle responses during sitting perturbations.

    Science.gov (United States)

    Milosevic, Matija; Shinya, Masahiro; Masani, Kei; Patel, Kramay; McConville, Kristiina M V; Nakazawa, Kimitaka; Popovic, Milos R

    2016-02-01

    Trunk muscles are responsible for maintaining trunk stability during sitting. However, the effects of anticipation of perturbation on trunk muscle responses are not well understood. The objectives of this study were to identify the responses of trunk muscles to sudden support surface translations and quantify the effects of anticipation of direction and time of perturbation on the trunk neuromuscular responses. Twelve able-bodied individuals participated in the study. Participants were seated on a kneeling chair and support surface translations were applied in the forward and backward directions with and without direction and time of perturbation cues. The trunk started moving on average approximately 40ms after the perturbation. During unanticipated perturbations, average latencies of the trunk muscle contractions were in the range between 103.4 and 117.4ms. When participants anticipated the perturbations, trunk muscle latencies were reduced by 16.8±10.0ms and the time it took the trunk to reach maximum velocity was also reduced, suggesting a biomechanical advantage caused by faster muscle responses. These results suggested that trunk muscles have medium latency responses and use reflexive mechanisms. Moreover, anticipation of perturbation decreased trunk muscles latencies, suggesting that the central nervous system modulated readiness of the trunk based on anticipatory information. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Cryotherapy does not affect peroneal reaction following sudden inversion.

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    Berg, Christine L; Hart, Joseph M; Palmieri-Smith, Riann; Cross, Kevin M; Ingersoll, Christopher D

    2007-11-01

    If ankle joint cryotherapy impairs the ability of the ankle musculature to counteract potentially injurious forces, the ankle is left vulnerable to injury. To compare peroneal reaction to sudden inversion following ankle joint cryotherapy. Repeated measures design with independent variables, treatment (cryotherapy and control), and time (baseline, immediately post treatment, 15 minutes post treatment, and 30 minutes post treatment). University research laboratory. Twenty-seven healthy volunteers. An ice bag was secured to the lateral ankle joint for 20 minutes. The onset and average root mean square amplitude of EMG activity in the peroneal muscles was calculated following the release of a trap door mechanism causing inversion. There was no statistically significant change from baseline for peroneal reaction time or average peroneal muscle activity at any post treatment time. Cryotherapy does not affect peroneal muscle reaction following sudden inversion perturbation.

  19. Large leptonic Dirac CP phase from broken democracy with random perturbations

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    Ge, Shao-Feng; Kusenko, Alexander; Yanagida, Tsutomu T.

    2018-06-01

    A large value of the leptonic Dirac CP phase can arise from broken democracy, where the mass matrices are democratic up to small random perturbations. Such perturbations are a natural consequence of broken residual S3 symmetries that dictate the democratic mass matrices at leading order. With random perturbations, the leptonic Dirac CP phase has a higher probability to attain a value around ± π / 2. Comparing with the anarchy model, broken democracy can benefit from residual S3 symmetries, and it can produce much better, realistic predictions for the mass hierarchy, mixing angles, and Dirac CP phase in both quark and lepton sectors. Our approach provides a general framework for a class of models in which a residual symmetry determines the general features at leading order, and where, in the absence of other fundamental principles, the symmetry breaking appears in the form of random perturbations.

  20. Sudden transition and sudden change from open spin environments

    International Nuclear Information System (INIS)

    Hu, Zheng-Da; Xu, Jing-Bo; Yao, Dao-Xin

    2014-01-01

    We investigate the necessary conditions for the existence of sudden transition or sudden change phenomenon for appropriate initial states under dephasing. As illustrative examples, we study the behaviors of quantum correlation dynamics of two noninteracting qubits in independent and common open spin environments, respectively. For the independent environments case, we find that the quantum correlation dynamics is closely related to the Loschmidt echo and the dynamics exhibits a sudden transition from classical to quantum correlation decay. It is also shown that the sudden change phenomenon may occur for the common environment case and stationary quantum discord is found at the high temperature region of the environment. Finally, we investigate the quantum criticality of the open spin environment by exploring the probability distribution of the Loschmidt echo and the scaling transformation behavior of quantum discord, respectively. - Highlights: • Sudden transition or sudden change from open spin baths are studied. • Quantum discord is related to the Loschmidt echo in independent open spin baths. • Steady quantum discord is found in a common open spin bath. • The probability distribution of the Loschmidt echo is analyzed. • The scaling transformation behavior of quantum discord is displayed

  1. Stepping stability: effects of sensory perturbation

    Directory of Open Access Journals (Sweden)

    Krebs David E

    2005-05-01

    Full Text Available Abstract Background Few tools exist for quantifying locomotor stability in balance impaired populations. The objective of this study was to develop and evaluate a technique for quantifying stability of stepping in healthy people and people with peripheral (vestibular hypofunction, VH and central (cerebellar pathology, CB balance dysfunction by means a sensory (auditory perturbation test. Methods Balance impaired and healthy subjects performed a repeated bench stepping task. The perturbation was applied by suddenly changing the cadence of the metronome (100 beat/min to 80 beat/min at a predetermined time (but unpredictable by the subject during the trial. Perturbation response was quantified by computing the Euclidian distance, expressed as a fractional error, between the anterior-posterior center of gravity attractor trajectory before and after the perturbation was applied. The error immediately after the perturbation (Emax, error after recovery (Emin and the recovery response (Edif were documented for each participant, and groups were compared with ANOVA. Results Both balance impaired groups exhibited significantly higher Emax (p = .019 and Emin (p = .028 fractional errors compared to the healthy (HE subjects, but there were no significant differences between CB and VH groups. Although response recovery was slower for CB and VH groups compared to the HE group, the difference was not significant (p = .051. Conclusion The findings suggest that individuals with balance impairment have reduced ability to stabilize locomotor patterns following perturbation, revealing the fragility of their impairment adaptations and compensations. These data suggest that auditory perturbations applied during a challenging stepping task may be useful for measuring rehabilitation outcomes.

  2. All-or-Nothing Dictator Games : A Field Experiment

    NARCIS (Netherlands)

    Bekkers, R.

    2006-01-01

    The dictator game has become well known for its results violating predictions based on ‘rational choice’ models of human behavior with orthodox assumptions on self-interest (Colin F. Camerer, 2003). Prosocial allocations in dictator games seem to suggest that there is some altruism in ‘human

  3. Goal-based dictator game

    Science.gov (United States)

    Zaibidi, Nerda Zura; Ibrahim, Adyda; Abidin, Norhaslinda Zainal

    2014-12-01

    A considerable number of studies have been conducted to study fairness issues using two-player game. Dictator Game is one of the two-player games that receive much attention. In this paper, we develop an evolutionary approach to the Dictator Game by using Goal programming to build a model of human decision-making for cooperation. The model is formulated based on the theories of cognitive neuroscience that is capable in capturing a more realistic fairness concerns between players in the games. We show that fairness will evolve by taking into account players' aspirations and preferences explicitly in terms of profit and fairness concerns. The model is then simulated to investigate any possible effective strategy for people in economics to deal with fairness coalition. Parallels are drawn between the approach and concepts of human decision making from the field of cognitive neuroscience and psychology. The proposed model is also able to help decision makers to plan or enhance the effective strategies for business purposes.

  4. Effects of Two Listening Strategies for Melodic Dictation

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    Buonviri, Nathan O.

    2017-01-01

    The purpose of this research was to examine effects of two listening strategies on melodic dictation scores. Fifty-four undergraduate music majors completed short tonal melodic dictations in a within-subjects design with three conditions: (a) no specified strategy in the instructions, (b) required listening before writing, and (c) required writing…

  5. The values of ex-ante and ex-post communication in dictator games

    OpenAIRE

    Pascal Langenbach

    2014-01-01

    In the dictator game, the recipient's opportunity to send a message to the dictator increases giving. This paperreports two experimentswhich study how the timing of messages affects dictators' decisions (experiment 1) and which value recipients attach to communication opportunities (experiment 2). The first experiment shows that the effect of communication on dictator giving is equally strong when the recipient can send a message before or after the dictator has decided. However, recipients i...

  6. Adapting a Computerized Medical Dictation System to Prepare Academic Papers in Radiology.

    Science.gov (United States)

    Sánchez, Yadiel; Prabhakar, Anand M; Uppot, Raul N

    2017-09-14

    Everyday radiologists use dictation software to compose clinical reports of imaging findings. The dictation software is tailored for medical use and to the speech pattern of each radiologist. Over the past 10 years we have used dictation software to compose academic manuscripts, correspondence letters, and texts of educational exhibits. The advantages of using voice dictation is faster composition of manuscripts. However, use of such software requires preparation. The purpose of this article is to review the steps of adapting a clinical dictation software for dictating academic manuscripts and detail the advantages and limitations of this technique. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Sudden cardiac death

    Directory of Open Access Journals (Sweden)

    Neeraj Parakh

    2015-01-01

    Full Text Available Sudden cardiac death is one of the most common cause of mortality worldwide. Despite significant advances in the medical science, there is little improvement in the sudden cardiac death related mortality. Coronary artery disease is the most common etiology behind sudden cardiac death, in the above 40 years population. Even in the apparently healthy population, there is a small percentage of patients dying from sudden cardiac death. Given the large denominator, this small percentage contributes to the largest burden of sudden cardiac death. Identification of this at risk group among the apparently healthy individual is a great challenge for the medical fraternity. This article looks into the causes and methods of preventing SCD and at some of the Indian data. Details of Brugada syndrome, Long QT syndrome, Genetics of SCD are discussed. Recent guidelines on many of these causes are summarised.

  8. Moral distance in dictator games

    Directory of Open Access Journals (Sweden)

    Fernando Aguiar

    2008-04-01

    Full Text Available We perform an experimental investigation using a dictator game in which individuals must make a moral decision --- to give or not to give an amount of money to poor people in the Third World. A questionnaire in which the subjects are asked about the reasons for their decision shows that, at least in this case, moral motivations carry a heavy weight in the decision: the majority of dictators give the money for reasons of a consequentialist nature. Based on the results presented here and of other analogous experiments, we conclude that dicator behavior can be understood in terms of moral distance rather than social distance and that it systematically deviates from the egoism assumption in economic models and game theory. %extit{JEL}: A13, C72, C91

  9. Muscle contributions to elbow joint rotational stiffness in preparation for sudden external arm perturbations.

    Science.gov (United States)

    Holmes, Michael W R; Keir, Peter J

    2014-04-01

    Understanding joint stiffness and stability is beneficial for assessing injury risk. The purpose of this study was to examine joint rotational stiffness for individual muscles contributing to elbow joint stability. Fifteen male participants maintained combinations of three body orientations (standing, supine, sitting) and three hand preloads (no load, solid tube, fluid filled tube) while a device imposed a sudden elbow extension. Elbow angle and activity from nine muscles were inputs to a biomechanical model to determine relative contributions to elbow joint rotational stiffness, reported as percent of total stiffness. A body orientation by preload interaction was evident for most muscles (Psafety.

  10. Social Preferences and Cognitive Reflection: Evidence from Dictator Game Experiment

    Directory of Open Access Journals (Sweden)

    Giovanni Benedetto Ponti

    2015-06-01

    Full Text Available This paper provides experimental evidence on the relationship between social preferences and cognitive abilities, which we measure using the Cognitive Reflection Test (CRT. We elicit social preferences by way of 24 dictatorial situations, in which the Dictator’s choice sets include i standard Dictator games, where increasing the Dictator’s payoff yields a loss for the Recipient, ii efficient Dicator games, where increasing the Dictator’s payoff also increases that the Recipient’s; as well as other situations in which iii either the Dictator’s or iv the Recipient’s monetary payoff is held constant. We partition our subject pool in three groups: reflective (scoring 2 or more in the CRT, impulsive (opting twice or more for the intuitive but wrong answers in the CRT and the remainder. We find that impulsive Dictators show a marked inequity aversion attitude, especially in standard Dictator Games. By contrast, reflective Dictators show lower distributional concerns, except for the situations in which the Dictators’ payoff is held constant. In this case, reflective Dictators give significantly more.

  11. Vision Loss, Sudden

    Science.gov (United States)

    ... cornea (the clear layer in front of the iris and pupil), then the lens, and then the ... sudden start of symptoms may instead be sudden recognition. For example, a person with long-standing reduced ...

  12. Exponential time-dependent perturbation theory in rotationally inelastic scattering

    International Nuclear Information System (INIS)

    Cross, R.J.

    1983-01-01

    An exponential form of time-dependent perturbation theory (the Magnus approximation) is developed for rotationally inelastic scattering. A phase-shift matrix is calculated as an integral in time over the anisotropic part of the potential. The trajectory used for this integral is specified by the diagonal part of the potential matrix and the arithmetic average of the initial and final velocities and the average orbital angular momentum. The exponential of the phase-shift matrix gives the scattering matrix and the various cross sections. A special representation is used where the orbital angular momentum is either treated classically or may be frozen out to yield the orbital sudden approximation. Calculations on Ar+N 2 and Ar+TIF show that the theory generally gives very good agreement with accurate calculations, even where the orbital sudden approximation (coupled-states) results are seriously in error

  13. Electron correlation effects in the presence of non-symmetry dictated ...

    Indian Academy of Sciences (India)

    We numerically study the effect of non-symmetry dictated nodes (NSDN) on electron ... the absence of NSDN, attractive interaction between electrons give such an ... and the violation of parity effect, we first explain what are symmetry dictated.

  14. Dictator Perpetuus: Julius Caesar--did he have seizures? If so, what was the etiology?

    Science.gov (United States)

    Hughes, John R

    2004-10-01

    The "Dictator Perpetuus" of the Roman Empire, the great Julius Caesar, was not the one for whom the well-known cesarean operation was named; instead, this term is derived from a Latin word meaning "to cut." Caesar likely had epilepsy on the basis of four attacks that were probably complex partial seizures: (1) while listening to an oration by Cicero, (2) in the Senate while being offered the Emperor's Crown, and in military campaigns, (3) near Thapsus (North Africa) and (4) Corduba (Spain). Also, it is possible that he had absence attacks as a child and as a teenager. His son, Caesarion, by Queen Cleopatra, likely had seizures as a child, but the evidence is only suggestive. His great-great-great grandnephews Caligula and Britannicus also had seizures. The etiology of these seizures in this Julio-Claudian family was most likely through inheritance, with the possibility of sudden unexpected death in epilepsy (SUDEP) in his great grandfather and also his father. Our best evidence comes from the ancient sources of Suetonius, Plutarch, Pliny, and Appianus.

  15. Sudden Event Recognition: A Survey

    Directory of Open Access Journals (Sweden)

    Mohd Asyraf Zulkifley

    2013-08-01

    Full Text Available Event recognition is one of the most active research areas in video surveillance fields. Advancement in event recognition systems mainly aims to provide convenience, safety and an efficient lifestyle for humanity. A precise, accurate and robust approach is necessary to enable event recognition systems to respond to sudden changes in various uncontrolled environments, such as the case of an emergency, physical threat and a fire or bomb alert. The performance of sudden event recognition systems depends heavily on the accuracy of low level processing, like detection, recognition, tracking and machine learning algorithms. This survey aims to detect and characterize a sudden event, which is a subset of an abnormal event in several video surveillance applications. This paper discusses the following in detail: (1 the importance of a sudden event over a general anomalous event; (2 frameworks used in sudden event recognition; (3 the requirements and comparative studies of a sudden event recognition system and (4 various decision-making approaches for sudden event recognition. The advantages and drawbacks of using 3D images from multiple cameras for real-time application are also discussed. The paper concludes with suggestions for future research directions in sudden event recognition.

  16. Sudden death victims

    NARCIS (Netherlands)

    Ceelen, Manon; van der Werf, Christian; Hendrix, Anneke; Naujocks, Tatjana; Woonink, Frits; de Vries, Philip; van der Wal, Allard; Das, Kees

    2015-01-01

    The goal of this study was to ascertain accordance between cause of death established by the forensic physician and autopsy results in young sudden death victims in the Netherlands. Sudden death victims aged 1-45 years examined by forensic physicians operating in the participating regions which also

  17. Sudden cardiac death in children and adolescents (excluding Sudden Infant Death Syndrome

    Directory of Open Access Journals (Sweden)

    Gajewski Kelly

    2010-01-01

    Full Text Available Sudden death in the young is rare. About 25% of cases occur during sports. Most young people with sudden cardiac death (SCD have underlying heart disease, with hypertrophic cardiomyopathy and coronary artery anomalies being commonest in most series. Arrhythmogenic right ventricular dysplasia and long QT syndrome are the most common primary arrhythmic causes of SCD. It is estimated that early cardiopulmonary resuscitation and widespread availability of automatic external defibrillators could prevent about a quarter of pediatric sudden deaths.

  18. Sudden Stratospheric Warming Compendium

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sudden Stratospheric Warming Compendium (SSWC) data set documents the stratospheric, tropospheric, and surface climate impacts of sudden stratospheric warmings. This...

  19. Flow in a circular expansion pipe flow: effect of a vortex perturbation on localised turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Selvam, Kamal; Peixinho, Jorge [Laboratoire Ondes Milieux Complexes, CNRS and Université du Havre, F-76600 Le Havre (France); Willis, Ashley P, E-mail: jorge.peixinho@univ-lehavre.fr [School of Mathematics and Statistics, University of Sheffield, Sheffield S3 7RH (United Kingdom)

    2016-12-15

    We report the results of three-dimensional direct numerical simulations for incompressible viscous fluid in a circular pipe flow with a sudden expansion. At the inlet, a parabolic velocity profile is applied together with a finite amplitude perturbation in the form of a vortex with its axis parallel to the axis of the pipe. At sufficiently high Reynolds numbers the recirculation region breaks into a turbulent patch that changes position axially, depending on the strength of the perturbation. This vortex perturbation is believed to produce a less abrupt transition than in previous studies, which applied a tilt perturbation, as the localised turbulence is observed via the formation of a wavy structure at a low order azimuthal mode, which resembles an optimally amplified perturbation. For large vortex amplitude, the localised turbulence remains at a constant axial position. It is further investigated using proper orthogonal decomposition, which indicates that the centre region close to the expansion is highly energetic. (paper)

  20. Effects of a Preparatory Singing Pattern on Melodic Dictation Success

    Science.gov (United States)

    Buonviri, Nathan O.

    2015-01-01

    The purpose of this study was to investigate effects of a preparatory contextual singing pattern on melodic dictation test scores. Forty-nine undergraduate music education majors took melodic dictations under three conditions. After hearing an orienting chord sequence, they (1) sang a preparatory solfége pattern in the key, meter, and tempo of the…

  1. Sudden birth versus sudden death of entanglement for the extended Werner-like state in a dissipative environment

    International Nuclear Information System (INIS)

    Chuan-Jia, Shan; Tao, Chen; Ji-Bing, Liu; Wei-Wen, Cheng; Tang-Kun, Liu; Yan-Xia, Huang; Hong, Li

    2010-01-01

    In this paper, we investigate the dynamical behaviour of entanglement in terms of concurrence in a bipartite system subjected to an external magnetic field under the action of dissipative environments in the extended Werner-like initial state. The interesting phenomenon of entanglement sudden death as well as sudden birth appears during the evolution process. We analyse in detail the effect of the purity of the initial entangled state of two qubits via Heisenberg XY interaction on the apparition time of entanglement sudden death and entanglement sudden birth. Furthermore, the conditions on the conversion of entanglement sudden death and entanglement sudden birth can be generalized when the initial entangled state is not pure. In particular, a critical purity of the initial mixed entangled state exists, above which entanglement sudden birth vanishes while entanglement sudden death appears. It is also noticed that stable entanglement, which is independent of different initial states of the qubits (pure or mixed state), occurs even in the presence of decoherence. These results arising from the combination of the extended Werner-like initial state and dissipative environments suggest an approach to control and enhance the entanglement even after purity induced sudden birth, death and revival. (general)

  2. Systemic Steroid Application Caused Sudden Death of a Patient with Sudden Deafness

    Directory of Open Access Journals (Sweden)

    Eriko Ogino-Nishimura

    2013-01-01

    Full Text Available A 63-year-old man, who was diagnosed with sudden sensorineural hearing loss (SSHL, showed severe hypertension 10 hours after prednisolone administration. Subsequently, the patient suddenly died due to pulmonary edema. The autopsy indicated a pheochromocytoma in the right adrenal gland, and the cause of death was determined to be a pheochromocytoma crisis induced by systemic administration of prednisolone. Pheochromocytoma crisis is a life-threatening condition and can result from the use of corticosteroids. Physicians should consider the risk of a pheochromocytoma crisis due to systemic corticosteroids in the treatment of patients with sudden sensorineural hearing loss.

  3. Examining the accuracy of the infinite order sudden approximation using sensitivity analysis

    Science.gov (United States)

    Eno, Larry; Rabitz, Herschel

    1981-08-01

    A method is developed for assessing the accuracy of scattering observables calculated within the framework of the infinite order sudden (IOS) approximation. In particular, we focus on the energy sudden assumption of the IOS method and our approach involves the determination of the sensitivity of the IOS scattering matrix SIOS with respect to a parameter which reintroduces the internal energy operator ?0 into the IOS Hamiltonian. This procedure is an example of sensitivity analysis of missing model components (?0 in this case) in the reference Hamiltonian. In contrast to simple first-order perturbation theory a finite result is obtained for the effect of ?0 on SIOS. As an illustration, our method of analysis is applied to integral state-to-state cross sections for the scattering of an atom and rigid rotor. Results are generated within the He+H2 system and a comparison is made between IOS and coupled states cross sections and the corresponding IOS sensitivities. It is found that the sensitivity coefficients are very useful indicators of the accuracy of the IOS results. Finally, further developments and applications are discussed.

  4. Effects of core perturbations on the structure of the sun

    International Nuclear Information System (INIS)

    Sweigart, A.V.

    1983-01-01

    A number of numerical experiments have been carried out in order to investigate the sensivity of the solar luminosity and radius to perturbations within the radiative core. In these experiments the core was perturbed by suddenly mixing various parts of the composition profile during evolutionary sequences for the present Sun. The hydrostatic readjustment caused by these ''mixing events'' induced an immediate change in the surface luminosity and radius on both the hydrodynamic time scale (approx.15 minutes) and the thermal time scale of the superadiabatic layers (approx.1 day). The subsequent evolution of the luminosity and radius perturbations was followed for 5 x 10 5 yr after each mixing event. The time-dependent behavior of these perturbations was found to depend on where the mixing event occurred. In all cases, however, the ratio W(t) = Δ log R/Δ log L had an initial value of 0.71 and showed only a mild time dependence during the first several thousand years. Two other relationships between the luminosity and radius perturbations are also discussed. One of these, V(t) = (d log R/dd)/(d log L/dt), has a fairly constant value of 0.3 +- 0.1. Both perturbations in the mixing-length ratio α and perturbations in the magnetic pressure within the solar convective envelope yield the same value for V/(t). During the normal unperturbed evolution of the present Sun, V(t) = 0.4. Our results show that core perturbations such as the present mixing events cannot explain the decrease in the solar radius indicated by the solar eclipse data between 1925 and 1980

  5. Modeling Inequity Aversion in a Dictator Game with Production

    Directory of Open Access Journals (Sweden)

    Ismael Rodriguez-Lara

    2012-10-01

    Full Text Available We expand upon the previous models of inequity aversion of Fehr and Schmidt [1], and Frohlich et al. [2], which assume that dictators get disutility if the final allocation of surplus deviates from the equal split (egalitarian principle or from the subjects' production (libertarian principle. In our model, dictators may also account for the way in which the surplus was generated. More precisely, our model incorporates the idea of liberal egalitarian ethics into the analysis, making it possible for dictators to divide the surplus according to the accountability principle, which states that subjects should only be rewarded for factors under their control. This fairness ideal does not hold subjects responsible for factors beyond their control in the production of the surplus, an idea that is absent in the models of inequity aversion cited above (JEL Codes: D3, D6, D63.

  6. Nonlinear dynamics analysis of the human balance control subjected to physical and sensory perturbations.

    Science.gov (United States)

    Ashtiani, Mohammed N; Mahmood-Reza, Azghani

    2017-01-01

    Postural control after applying perturbation involves neural and muscular efforts to limit the center of mass (CoM) motion. Linear dynamical approaches may not unveil all complexities of body efforts. This study was aimed at determining two nonlinear dynamics parameters (fractal dimension (FD) and largest Lyapunov exponent (LLE)) in addition to the linear standing metrics of balance in perturbed stance. Sixteen healthy young males were subjected to sudden rotations of the standing platform. The vision and cognition during the standing were also interfered. Motion capturing was used to measure the lower limb joints and the CoM displacements. The CoM path length as a linear parameter was increased by elimination of vision (pnonlinear metric FD was decreased due to the cognitive loads (pnonlinear metrics of the perturbed stance showed that a combination of them may properly represent the body behavior.

  7. Sudden losses and sudden gains during a DBT-PTSD treatment for posttraumatic stress disorder following childhood sexual abuse

    Directory of Open Access Journals (Sweden)

    Antje Krüger

    2014-09-01

    Full Text Available Background: Exposure-based treatment approaches are first-line interventions for patients suffering from posttraumatic stress disorder (PTSD. However, the dissemination of exposure-based treatments for PTSD is challenging, as a large proportion of clinicians report being concerned about symptoms worsening as a result of this type of intervention and are therefore reluctant to offer it to patients with PTSD. However, there is only little empirical evidence to date on the pattern of symptom worsening during exposure-based treatment for PTSD. Objective: The goal of the present study was to explore the frequency of sudden losses and sudden gains in the course of an exposure-based treatment programme for female patients suffering from PTSD related to childhood sexual abuse who also show severe comorbidity. In addition, the relationship between sudden changes and treatment outcome was examined. Methods: Female participants (N=74 were randomised to either a 12-week residential DBT-PTSD programme or a treatment-as-usual wait list. The pattern of symptom change was assessed via weekly assessments using the Posttraumatic Diagnostic Scale (PDS. Sudden changes were computed as suggested by the literature on sudden gains. Results: During treatment, only one participant (3% experienced a sudden loss, whereas 25% of participants experienced sudden gains. In the waiting condition, 8% of the participants experienced sudden losses and 5% experienced sudden gains during the same time period. No symptom worsening was observed in response to exposure sessions. However, sudden gains occurred during exposure and non-exposure treatment weeks. Patients with sudden gains showed better treatment outcome in the post-treatment and follow-up assessments. Conclusions: Exposure-based treatment did not lead to PTSD symptom worsening in the study sample. Results show that sudden gains occur frequently during PTSD treatment and have a prognostic value for treatment outcome.

  8. Exact scattering solutions in an energy sudden (ES) representation

    International Nuclear Information System (INIS)

    Chang, B.; Eno, L.; Rabitz, H.

    1983-01-01

    In this paper, we lay down the theoretical foundations for computing exact scattering wave functions in a reference frame which moves in unison with the system internal coordinates. In this frame the (internal) coordinates appear to be fixed and its adoption leads very naturally (in zeroth order) to the energy sudden (ES) approximation [and the related infinite order sudden (IOS) method]. For this reason we call the new representation for describing the exact dynamics of a many channel scattering problem, the ES representation. Exact scattering solutions are derived in both time dependent and time independent frameworks for the representation and many interesting results in these frames are established. It is shown, e.g., that in a time dependent frame the usual Schroedinger propagator factorizes into internal Hamiltonian, ES, and energy correcting propagators. We also show that in a time independent frame the full Green's functions can be similarly factorized. Another important feature of the new representation is that it forms a firm foundation for seeking corrections to the ES approximation. Thus, for example, the singularity which arises in conventional perturbative expansions of the full Green's functions (with the ES Green's function as the zeroth order solution) is avoided in the ES representation. Finally, a number of both time independent and time dependent ES correction schemes are suggested

  9. Fingering patterns in magnetic fluids: Perturbative solutions and the stability of exact stationary shapes

    Science.gov (United States)

    Anjos, Pedro H. A.; Lira, Sérgio A.; Miranda, José A.

    2018-04-01

    We examine the formation of interfacial patterns when a magnetic liquid droplet (ferrofluid, or a magnetorheological fluid), surrounded by a nonmagnetic fluid, is subjected to a radial magnetic field in a Hele-Shaw cell. By using a vortex-sheet formalism, we find exact stationary solutions for the fluid-fluid interface in the form of n -fold polygonal shapes. A weakly nonlinear, mode-coupling method is then utilized to find time-evolving perturbative solutions for the interfacial patterns. The stability of such nonzero surface tension exact solutions is checked and discussed, by trying to systematically approach the exact stationary shapes through perturbative solutions containing an increasingly larger number of participating Fourier modes. Our results indicate that the exact stationary solutions of the problem are stable, and that a good matching between exact and perturbative shape solutions is achieved just by using a few Fourier modes. The stability of such solutions is substantiated by a linearization process close to the stationary shape, where a system of mode-coupling equations is diagonalized, determining the eigenvalues which dictate the stability of a fixed point.

  10. Sudden death in eating disorders

    Directory of Open Access Journals (Sweden)

    Jáuregui-Garrido B

    2012-02-01

    Full Text Available Beatriz Jáuregui-Garrido1, Ignacio Jáuregui-Lobera2,31Department of Cardiology, University Hospital Virgen del Rocío, 2Behavioral Sciences Institute, 3Pablo de Olavide University, Seville, SpainAbstract: Eating disorders are usually associated with an increased risk of premature death with a wide range of rates and causes of mortality. “Sudden death” has been defined as the abrupt and unexpected occurrence of fatality for which no satisfactory explanation of the cause can be ascertained. In many cases of sudden death, autopsies do not clarify the main cause. Cardiovascular complications are usually involved in these deaths. The purpose of this review was to report an update of the existing literature data on the main findings with respect to sudden death in eating disorders by means of a search conducted in PubMed. The most relevant conclusion of this review seems to be that the main causes of sudden death in eating disorders are those related to cardiovascular complications. The predictive value of the increased QT interval dispersion as a marker of sudden acute ventricular arrhythmia and death has been demonstrated. Eating disorder patients with severe cardiovascular symptoms should be hospitalized. In general, with respect to sudden death in eating disorders, some findings (eg, long-term eating disorders, chronic hypokalemia, chronically low plasma albumin, and QT intervals >600 milliseconds must be taken into account, and it must be highlighted that during refeeding, the adverse effects of hypophosphatemia include cardiac failure. Monitoring vital signs and performing electrocardiograms and serial measurements of plasma potassium are relevant during the treatment of eating disorder patients.Keywords: sudden death, cardiovascular complications, refeeding syndrome, QT interval, hypokalemia

  11. Examining the accuracy of the infinite order sudden approximation using sensitivity analysis

    International Nuclear Information System (INIS)

    Eno, L.; Rabitz, H.

    1981-01-01

    A method is developed for assessing the accuracy of scattering observables calculated within the framework of the infinite order sudden (IOS) approximation. In particular, we focus on the energy sudden assumption of the IOS method and our approach involves the determination of the sensitivity of the IOS scattering matrix S/sup IOS/ with respect to a parameter which reintroduces the internal energy operator h 0 into the IOS Hamiltonian. This procedure is an example of sensitivity analysis of missing model components (h 0 in this case) in the reference Hamiltonian. In contrast to simple first-order perturbation theory a finite result is obtained for the effect of h 0 on S/sup IOS/. As an illustration, our method of analysis is applied to integral state-to-state cross sections for the scattering of an atom and rigid rotor. Results are generated within the He+H 2 system and a comparison is made between IOS and coupled states cross sections and the corresponding IOS sensitivities. It is found that the sensitivity coefficients are very useful indicators of the accuracy of the IOS results. Finally, further developments and applications are discussed

  12. A feeling of flow: exploring junior scientists' experiences with dictation of scientific articles.

    Science.gov (United States)

    Spanager, Lene; Danielsen, Anne Kjaergaard; Pommergaard, Hans-Christian; Burcharth, Jakob; Rosenberg, Jacob

    2013-08-10

    Science involves publishing results, but many scientists do not master this. We introduced dictation as a method of producing a manuscript draft, participating in writing teams and attending a writing retreat to junior scientists in our department. This study aimed to explore the scientists' experiences with this process. Four focus group interviews were conducted and comprised all participating scientists (n = 14). Each transcript was transcribed verbatim and coded independently by two interviewers. The coding structure was discussed until consensus and from this the emergent themes were identified. Participants were 7 PhD students, 5 scholarship students and 2 clinical research nurses. Three main themes were identified: 'Preparing and then letting go' indicated that dictating worked best when properly prepared. 'The big dictation machine' described benefits of writing teams when junior scientists got feedback on both content and structure of their papers. 'Barriers to and drivers for participation' described flow-like states that participants experienced during the dictation. Motivation and a high level of preparation were pivotal to be able to dictate a full article in one day. The descriptions of flow-like states seemed analogous to the theoretical model of flow which is interesting, as flow is usually deemed a state reserved to skilled experts. Our findings suggest that other academic groups might benefit from using the concept including dictation of manuscripts to encourage participants' confidence in their writing skills.

  13. Reactive Balance in Individuals With Chronic Stroke: Biomechanical Factors Related to Perturbation-Induced Backward Falling.

    Science.gov (United States)

    Salot, Pooja; Patel, Prakruti; Bhatt, Tanvi

    2016-03-01

    An effective compensatory stepping response is the first line of defense for preventing a fall during sudden large external perturbations. The biomechanical factors that contribute to heightened fall risk in survivors of stroke, however, are not clearly understood. It is known that impending sensorimotor and balance deficits poststroke predispose these individuals to a risk of fall during sudden external perturbations. The purpose of this study was to examine the mechanism of fall risk in survivors of chronic stroke when exposed to sudden, slip-like forward perturbations in stance. This was a cross-sectional study. Fourteen individuals with stroke, 14 age-matched controls (AC group), and 14 young controls (YC group) were exposed to large-magnitude forward stance perturbations. Postural stability was computed as center of mass (COM) position (XCOM/BOS) and velocity (ẊCOM/BOS) relative to the base of support (BOS) at first step lift-off (LO) and touch-down (TD) and at second step TD. Limb support was quantified as vertical hip descent (Zhip) from baseline after perturbation onset. All participants showed a backward balance loss, with 71% of the stroke group experiencing a fall compared with no falls in the control groups (AC and YC groups). At first step LO, no between-group differences in XCOM/BOS and ẊCOM/BOS were noted. At first step TD, however, the stroke group had a significantly posterior XCOM/BOS and backward ẊCOM/BOS compared with the control groups. At second step TD, individuals with stroke were still more unstable (more posterior XCOM/BOS and backward ẊCOM/BOS) compared with the AC group. Individuals with stroke also showed greater peak Zhip compared with the control groups. Furthermore, the stroke group took a larger number of steps with shorter step length and delayed step initiation compared with the control groups. Although the study highlights the reactive balance deficits increasing fall risk in survivors of stroke compared with healthy

  14. Dictator games: A meta study

    OpenAIRE

    Engel, Christoph

    2010-01-01

    Over the last 25 years, more than a hundred dictator game experiments have been published. This meta study summarizes the evidence. Exploiting the fact that most experiments had to fix parameters they did not intend to test, in multiple regression the meta study is able to assess the effect of single manipulations, controlling for a host of alternative explanatory factors. The resulting rich dataset also provides a testbed for comparing alternative specifications of the statistical model for ...

  15. Sudden cardiac death in athletes

    Directory of Open Access Journals (Sweden)

    Fábio Camilo Pellegrino dos Santos

    2012-11-01

    Full Text Available ABSTRACT The most accepted definition of sudden cardiac death nowadays is an unexplained death occurred suddenly within one hour of symptom onset. If it was not witnessed, individuals need to had been observed for at least 24 hours before the event and should be discarded the possibility of non cardiac causes of sudden death, pulmonary embolism or extensive malignancy. The term athlete refers to individuals of any age who participate in collective or individual regular physical activity, as well as physical training program for regular competitions. The sudden death of a young athlete, whether amateur or professional, especially during competitions, is always dramatic, with strong negative social impact and in the media. The fact that sports are recommended as a formula for longevity and quality of life makes these events a cause for concern in sports and society in general.

  16. Sudden Infant Death Syndrome (SIDS)

    Science.gov (United States)

    Sudden infant death syndrome (SIDS) Overview Sudden infant death syndrome (SIDS) is the unexplained death, usually during sleep, of a seemingly healthy baby ... year old. SIDS is sometimes known as crib death because the infants often die in their cribs. ...

  17. Improving the Dictation in Attention Deficit Hyperactivity Disorder by Using Computer Based Interventions: A Clinical Trial

    Directory of Open Access Journals (Sweden)

    Mahdi Tehranidoost

    2006-07-01

    Full Text Available Objective: The aim of the current study was to assess the impact of computer games and computer-assisted type instruction on dictation scores of elementary school children with attention deficit – hyperactivity disorder (ADHD. Method: In this single-blind clinical trial, 37 elementary school children with ADHD, selected by convenience sampling and divided into group I (n=17 and group II (n=20, underwent eight one-hour sessions (3 sessions per week of intervention by computer games versus computer-assisted type instruction, respectively. 12 school dictation scores were considered: 4 scores preintervention, 4 scores during interventions, and 4 scores post-intervention. Dictation test was taken during each session. Data was analyzed using repeated measure ANOVA. Results: Two groups were matched for age, gender, school grade, medication, IQ, parent’s and teacher’s Conners’ scale scores, having computer at home, history of working with computer, and mean dictation scores. There was no significant difference in dictation scores before and after interventions and also between the study groups. The improvement in school dictation scores had no significant correlation with age, gender, Ritalin use, owning a computer at home and past history of computer work, baseline dictation scores, Ritalin dose, educational status, IQ, and the total score of parent’s and teacher’s Conners’ rating scale. Conclusion: Absence of significant improvement in dictation scores in study groups may be due to the confounding effect of other variables with known impact on dictation scores. Further studies in this field should also assess the change of attention and memory.

  18. Consistency and Stability of Italian Children's Spelling in Dictation versus Composition Assessments

    Science.gov (United States)

    Bigozzi, Lucia; Tarchi, Christian; Pinto, Giuliana

    2017-01-01

    The purpose of this study was to investigate consistency in spelling skills across 2 different tasks of written production (dictation vs. composition) and stability of performance across 4 different grades. We assessed 2nd, 3rd, 4th, and 5th graders' spelling performance through 4 tasks: 2 dictation tasks (passage and sentences) and 2 composition…

  19. Sport and sudden death in children

    Directory of Open Access Journals (Sweden)

    L. M. Makarov

    2017-01-01

    Full Text Available The article presents data on contemporary views of the prevalence, causes, circumstances of sudden cardiac death, and its prevention measures in children and adolescents during sports activity. It notes a difficulty in defining the epidemiology of the above condition because the data are primarily based upon mass media news coverage. The incidence of sudden cardiac death is approximately 1 per 100,000 young athletes; more than 90% boys die. The sports, during which sudden cardiac death often occurs, include (both American and European football, basketball, and hockey. Sudden cardiac death due to cоmmоtio cordis (life-threatening cardiac arrhythmias resulting from a blow with a blunt instrument to the area of the heart during the vulnerable phase of the cardiac cycle is considered separately. Children who die suddenly during sports are frequently detected to have hypertrophic cardiomyopathy or myocarditis; but no changes are found in more than 50% of cases at autopsy, which is suggestive of primary arrhythmogenic death. The basis for prevention is the early detection of diseases that can cause sudden death during sports, regular examination, knowledge of ECG characteristics in athletes, and first aid techniques, including the use of automated external defibrillators.

  20. Sudden bilateral hearing loss after organophosphate inhalation

    Directory of Open Access Journals (Sweden)

    Mehmet Akif Dundar

    2016-12-01

    Full Text Available Sudden bilateral hearing loss are seen rarely and the toxic substance exposure constitutes a small part of etiology. A Fifty-eight-year-old woman admitted to our clinic with sudden bilateral hearing loss shortly after chlorpyrifos-ethyl exposure. Otolaryngologic examination findings were normal. The patient had 40 dB sensorineural hearing loss (SNHL on the right ear and 48 dB SNHL on the left ear. Additional diagnostic tests were normal. The conventional treatment for sudden hearing loss was performed. On the second week following organophosphate (OP exposure the patient's hearing loss almost completely resolved. OP's are heavily used in agriculture and should be taken into consideration as an etiologic factor in sudden hearing loss. Keywords: Organophosphates, Hearing loss, Sudden

  1. Written object naming, spelling to dictation, and immediate copying: Different tasks, different pathways?

    Science.gov (United States)

    Bonin, Patrick; Méot, Alain; Lagarrigue, Aurélie; Roux, Sébastien

    2015-01-01

    We report an investigation of cross-task comparisons of handwritten latencies in written object naming, spelling to dictation, and immediate copying. In three separate sessions, adults had to write down a list of concrete nouns from their corresponding pictures (written naming), from their spoken (spelling to dictation) and from their visual presentation (immediate copying). Linear mixed models without random slopes were performed on the latencies in order to study and compare within-task fixed effects. By-participants random slopes were then included to investigate individual differences within and across tasks. Overall, the findings suggest that written naming, spelling to dictation, and copying all involve a lexical pathway, but that written naming relies on this pathway more than the other two tasks do. Only spelling to dictation strongly involves a nonlexical pathway. Finally, the analyses performed at the level of participants indicate that, depending on the type of task, the slower participants are more or less influenced by certain psycholinguistic variables.

  2. The effect of $1, $5 and $10 stakes in an online dictator game.

    Science.gov (United States)

    Raihani, Nichola J; Mace, Ruth; Lamba, Shakti

    2013-01-01

    The decision rules underpinning human cooperative behaviour are often investigated under laboratory conditions using monetary incentives. A major concern with this approach is that stake size may bias subjects' decisions. This concern is particularly acute in online studies, where stakes are often far lower than those used in laboratory or field settings. We address this concern by conducting a Dictator Game using Amazon Mechanical Turk. In this two-player game, one player (the dictator) determines the division of an endowment between himself and the other player. We recruited subjects from India and the USA to play an online Dictator Game. Dictators received endowments of $1, $5 or $10. We collected two batches of data over two consecutive years. We found that players from India were less generous when playing with a $10 stake. By contrast, the effect of stake size among players from the USA was very small. This study indicates that the effects of stake size on decision making in economic games may vary across populations.

  3. Residual entanglement and sudden death: A direct connection

    International Nuclear Information System (INIS)

    Oliveira, J.G.G. de; Peixoto de Faria, J.G.; Nemes, M.C.

    2011-01-01

    We explore the results of [V. Coffman, et al., Phys. Rev. A 61 (2000) 052306] derived for general tripartite states in a dynamical context. We study a class of physically motivated tripartite systems. We show that whenever entanglement sudden death occurs in one of the partitions residual entanglement will appear. For fourpartite systems however, the appearance of residual entanglement is not conditioned by sudden death of entanglement. We can only say that if sudden death of entanglement occurs in some partition there will certainly be residual entanglement. -- Highlights: ► For tripartite systems we show there exists residual entanglement if sudden death occurs. ► For fourpartite systems, the residual entanglement is not conditioned by sudden death. ► If sudden death of entanglement occurs there will certainly be residual entanglement.

  4. Sudden Cardiac Arrest (SCA) Risk Assessment

    Science.gov (United States)

    ... HRS Find a Specialist Share Twitter Facebook SCA Risk Assessment Sudden Cardiac Arrest (SCA) occurs abruptly and without ... people of all ages and health conditions. Start Risk Assessment The Sudden Cardiac Arrest (SCA) Risk Assessment Tool ...

  5. Teaching Melodic Dictation in Advanced Placement Music Theory

    Science.gov (United States)

    Paney, Andrew S.; Buonviri, Nathan O.

    2014-01-01

    In this study approaches to teaching melodic dictation skills used by Advanced Placement (AP) Music Theory teachers were examined. Twelve high school teachers from four states were interviewed. Four themes emerged from the interview transcripts: cognitive frameworks, processing strategies, rhythm, and course design. Participants generally…

  6. The effect of $1, $5 and $10 stakes in an online dictator game.

    Directory of Open Access Journals (Sweden)

    Nichola J Raihani

    Full Text Available The decision rules underpinning human cooperative behaviour are often investigated under laboratory conditions using monetary incentives. A major concern with this approach is that stake size may bias subjects' decisions. This concern is particularly acute in online studies, where stakes are often far lower than those used in laboratory or field settings. We address this concern by conducting a Dictator Game using Amazon Mechanical Turk. In this two-player game, one player (the dictator determines the division of an endowment between himself and the other player. We recruited subjects from India and the USA to play an online Dictator Game. Dictators received endowments of $1, $5 or $10. We collected two batches of data over two consecutive years. We found that players from India were less generous when playing with a $10 stake. By contrast, the effect of stake size among players from the USA was very small. This study indicates that the effects of stake size on decision making in economic games may vary across populations.

  7. Hypokalemia and sudden cardiac death

    DEFF Research Database (Denmark)

    Kjeldsen, Keld

    2010-01-01

    Worldwide, approximately three million people suffer sudden cardiac death annually. These deaths often emerge from a complex interplay of substrates and triggers. Disturbed potassium homeostasis among heart cells is an example of such a trigger. Thus, hypokalemia and, also, more transient...... of fatal arrhythmia and sudden cardiac death a patient is, the more attention should be given to the potassium homeostasis....

  8. Sudden Death Following Exercise; a Case Series Study

    Directory of Open Access Journals (Sweden)

    Fares Najari

    2016-04-01

    Full Text Available Introduction: Natural and unexpected death that happens within less than one hour of first symptom occurrence is called sudden death. Cardiovascular diseases are the main known reason of sudden death and more than 75% of sudden deaths in athletes are assigned to it. Here we reported the autopsy results of all cases with sudden death following exercise that were referred to forensic center of Tehran, Iran, from 2009 to 2014. Methods: In this cross sectional study all subjects who were registered to forensic medicine center of Tehran, Iran, from 2009 to 2014, as a case of sudden death following exercise were evaluated. Demographic data and medical history as well as autopsy and toxicology findings were retrospectively gathered using profiles of the deceased. Results were reported using descriptive analysis. Results: 14 cases were registered as sudden death following exercise in forensic medicine profiles during the study period. Exploring the files of the mentioned deceased, revealed five non-compatible cases in this regard. Finally, 9 eligible cases were enrolled (88.9% male. The mean age of the deceased was 28.66 ± 10.86 years (range: 7 – 40. Toxicological tests were available for 7 cases, one of which was positive for tramadol. Sudden death following football was reported most frequently (44.4%. Only 3 (33.3% cases had herald signs such as chest pain, syncope, or loss of consciousness. 1 case (11.11% had a positive history of sudden death in relatives. Conclusion: Although most sudden death victims are asymptomatic until the event, all those who suffer from symptoms such as chest pain, shortness of breath, dizziness, fatigue and irregular heart rate during physical activities, should be screened regarding common probable causes of sudden death.

  9. Bilateral electromyogram response latency following platform perturbation in unilateral transtibial prosthesis users: influence of weight distribution and limb position.

    Science.gov (United States)

    Rusaw, David; Hagberg, Kerstin; Nolan, Lee; Ramstrand, Nerrolyn

    2013-01-01

    Appropriate muscular response following an external perturbation is essential in preventing falls. Transtibial prosthesis users lack a foot-ankle complex and associated sensorimotor structures on the side with the prosthesis. The effect of this lack on rapid responses of the lower limb to external surface perturbations is unknown. The aim of the present study was to compare electromyogram (EMG) response latencies of otherwise healthy, unilateral, transtibial prosthesis users (n = 23, mean +/- standard deviation [SD] age = 48 +/- 14 yr) and a matched control group (n = 23, mean +/- SD age = 48 +/- 13 yr) following sudden support-surface rotations in the pitch plane (toes-up and toes-down). Perturbations were elicited in various weight-bearing and limb-perturbed conditions. The results indicated that transtibial prosthesis users have delayed responses of multiple muscles of the lower limb following perturbation, both in the intact and residual limbs. Weight-bearing had no influence on the response latency in the residual limb, but did on the intact limb. Which limb received the perturbation was found to influence the muscular response, with the intact limb showing a significantly delayed response when the perturbation was received only on the side with a prosthesis. These delayed responses may represent an increased risk of falling for individuals who use transtibial prostheses.

  10. Observation and Modeling of the Generation Mechanism of Ion Upflow during Sudden Commencement

    Science.gov (United States)

    Zou, S.; Ozturk, D. S.; Li, C.; Varney, R. H.; Reimer, A.

    2017-12-01

    Sudden commencement (SC) induced by solar wind pressure enhancement can produce significant global impact on the coupled magnetosphere-ionosphere (MI) system, and its effects have been studied extensively using ground magnetometers and coherent scatter radars. However, very limited observations have been reported about the effects of SC on the ionospheric plasma. We study the ionosphere response to the SC using the Poker Flat incoherent scatter radar (PFISR) and numerical simulations. A detailed case study of SC during the 17 March 2015 storm was conducted. PFISR observed lifting of the F region ionosphere, transient field-aligned ion upflow, prompt but short-lived ion temperature increase, subsequent F region density decrease, and persistent electron temperature increase. A global magnetohydrodynamic (MHD) simulation has been carried out to characterize the SC-induced current, convection, and magnetic perturbations. Simulated magnetic perturbations at Poker Flat show a satisfactory agreement with observations. The simulation provides a global context for linking localized PFISR observations to large-scale dynamic processes in the MI system. Following the case study, we also perform a statistical study of the effects of SC on the ionosphere focusing on the magnetic local time and latitudinal asymmetries using PFISR and GPS TEC.

  11. Sudden unexpected death caused by stroke

    DEFF Research Database (Denmark)

    Ågesen, Frederik Nybye; Risgaard, Bjarke; Zachariasardóttir, Sára

    2017-01-01

    Background Stroke is the fifth leading cause of death in young individuals globally. Data on the burden of sudden death by stroke are sparse in the young. Aims The aim of this study was to report mortality rates, cause of death, stroke subtype, and symptoms in children and young adults who suffered....... There was a male predominance (56%) and the median age was 33 years. The incidence of sudden death by stroke in individuals aged 1-49 years was 0.19 deaths per 100,000 person-years. Stroke was hemorrhagic in 94% of cases, whereof subarachnoid hemorrhage was the cause of death in 63% of cases. Seventeen (33%) cases...... contacted the healthcare system because of neurological symptoms, whereof one was suspected of having a stroke (6%). Conclusions Sudden death by stroke in children and young adults occurs primarily due to hemorrhagic stroke. We report a high frequency of neurological symptoms prior to sudden death by stroke...

  12. Cognition and balance control: does processing of explicit contextual cues of impending perturbations modulate automatic postural responses?

    Science.gov (United States)

    Coelho, Daniel Boari; Teixeira, Luis Augusto

    2017-08-01

    Processing of predictive contextual cues of an impending perturbation is thought to induce adaptive postural responses. Cueing in previous research has been provided through repeated perturbations with a constant foreperiod. This experimental strategy confounds explicit predictive cueing with adaptation and non-specific properties of temporal cueing. Two experiments were performed to assess those factors separately. To perturb upright balance, the base of support was suddenly displaced backwards in three amplitudes: 5, 10 and 15 cm. In Experiment 1, we tested the effect of cueing the amplitude of the impending postural perturbation by means of visual signals, and the effect of adaptation to repeated exposures by comparing block versus random sequences of perturbation. In Experiment 2, we evaluated separately the effects of cueing the characteristics of an impending balance perturbation and cueing the timing of perturbation onset. Results from Experiment 1 showed that the block sequence of perturbations led to increased stability of automatic postural responses, and modulation of magnitude and onset latency of muscular responses. Results from Experiment 2 showed that only the condition cueing timing of platform translation onset led to increased balance stability and modulation of onset latency of muscular responses. Conversely, cueing platform displacement amplitude failed to induce any effects on automatic postural responses in both experiments. Our findings support the interpretation of improved postural responses via optimized sensorimotor processes, at the same time that cast doubt on the notion that cognitive processing of explicit contextual cues advancing the magnitude of an impending perturbation can preset adaptive postural responses.

  13. H{sup +}{sub 2} ionization by ultra-short electromagnetic pulses investigated through a non-perturbative Coulomb-Volkov approach

    Energy Technology Data Exchange (ETDEWEB)

    RodrIguez, V D [Departamento de Fisica, FCEyN, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Macri, P [Departamento de Fisica, FCEyN, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Instituto de Astronomia y Fisica del Espacio, Consejo Nacional de Investigaciones CientIficas y Tecnicas, 1428 Buenos Aires (Argentina); Gayet, R [CELIA, Centre Lasers Intenses et Applications, UMR 5107, Unite Mixte de Recherche CNRS-CEA-Universite Bordeaux 1, Universite Bordeaux 1, 351 Cours de la Liberation, 33405 Talence Cedex (France)

    2005-08-14

    The sudden Coulomb-Volkov theoretical approximation has been shown to well describe atomic ionization by intense and ultra-short electromagnetic pulses, such as pulses generated by very fast highly-charged ions. This approach is extended here to investigate single ionization of homonuclear diatomic molecules by such pulses in the framework of one-active electron. Under particular conditions, a Young-like interference formula can approximately be factored out. Present calculations show interference effects originating from the molecular two-centre structure. Fivefold differential angular distributions of the ejected electron are studied as a function of the molecular orientation and internuclear distance. Both non-perturbative and perturbative regimes are examined. In the non-perturbative case, an interference pattern is visible but a main lobe, opposite to the electric field polarization direction, dominates the angular distribution. In contrast, in perturbation conditions the structure of interferences shows analogies to the Young-like interference pattern obtained in ionization of molecules by fast electron impacts. Finally, the strong dependence of these Young-like angular distributions on the internuclear distance is addressed.

  14. Controllable entanglement sudden birth of Heisenberg spins

    International Nuclear Information System (INIS)

    Zheng Qiang; Zhi Qijun; Zhang Xiaoping; Ren Zhongzhou

    2011-01-01

    We investigate the Entanglement Sudden Birth (ESB) of two Heisenberg spins A and B. The third controller, qutrit C is introduced, which only has the Dzyaloshinskii-Moriya (DM) spin-orbit interaction with qubit B. We find that the DM interaction is necessary to induce the Entanglement Sudden Birth of the system qubits A and B, and the initial states of the system qubits and the qutrit C are also important to control its Entanglement Sudden Birth. (authors)

  15. Declining risk of sudden death in heart failure

    DEFF Research Database (Denmark)

    Shen, Li; Jhund, Pardeep S.; Petrie, Mark C.

    2017-01-01

    BACKGROUND The risk of sudden death has changed over time among patients with symptomatic heart failure and reduced ejection fraction with the sequential introduction of medications including angiotensin-converting-enzyme inhibitors, angiotensin-receptor blockers, beta-blockers, and mineralocorti......BACKGROUND The risk of sudden death has changed over time among patients with symptomatic heart failure and reduced ejection fraction with the sequential introduction of medications including angiotensin-converting-enzyme inhibitors, angiotensin-receptor blockers, beta...... cardioverter-defibrillator at the time of trial enrollment were excluded. Weighted multivariable regression was used to examine trends in rates of sudden death over time. Adjusted hazard ratios for sudden death in each trial group were calculated with the use of Cox regression models. The cumulative incidence...... rates of sudden death were assessed at different time points after randomization and according to the length of time between the diagnosis of heart failure and randomization. RESULTS Sudden death was reported in 3583 patients. Such patients were older and were more often male, with an ischemic cause...

  16. Cardiovascular causes of maternal sudden death. Sudden arrhythmic death syndrome is leading cause in UK.

    Science.gov (United States)

    Krexi, Dimitra; Sheppard, Mary N

    2017-05-01

    This study aims to determine the causes of sudden cardiac death during pregnancy and in the postpartum period and patients' characteristics. There are few studies in the literature. Eighty cases of sudden unexpected death due to cardiac causes in relation to pregnancy and postpartum period in a database of 4678 patients were found and examined macroscopically and microscopically. The mean age was 30±7 years with a range from 16 to 43 years. About 30% were 35 years old or older; 50% of deaths occurred during pregnancy and 50% during the postpartum period. About 59.18% were obese or overweight where body mass index data were available. The leading causes of death were sudden arrhythmic death syndrome (SADS) (53.75%) and cardiomyopathies (13.80%). Other causes include dissection of aorta or its branches (8.75%), congenital heart disease (2.50%) and valvular disease (3.75%). This study highlights sudden cardiac death in pregnancy or in the postpartum period, which is mainly due to SADS with underlying channelopathies and cardiomyopathy. We wish to raise awareness of these frequently under-recognised entities in maternal deaths and the need of cardiological screening of the family as a result of the diagnosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Social evaluation-induced amylase elevation and economic decision-making in the dictator game in humans.

    Science.gov (United States)

    Takahashi, Taiki; Ikeda, Koki; Hasegawa, Toshikazu

    2007-10-01

    Little is known regarding the relationship between social evaluation-induced neuroendocrine responses and generosity in game-theoretic situations. Previous studies demonstrated that reputation formation plays a pivotal role in prosocial behavior. This study aimed to examine the relationships between a social evaluation-induced salivary alpha-amylase (sAA) response and generosity in the dictator game. The relationship is potentially important in neuroeconomics of altruism and game theory. We assessed sAA and allocated money in the dictator game in male students with and without social evaluation. RESULTS Social evaluation-responders allocated significantly more money than controls; while there was no significant correlation between social evaluation-induced sAA elevation and the allocated money. Social evaluation significantly increases generosity in the dictator game, and individual differences in trait characteristics such as altruism and reward sensitivity may be important determinants of generosity in the dictator game task.

  18. Sudden Death in Young People--Heart Problems Often Blamed

    Science.gov (United States)

    Sudden death in young people: Heart problems often blamed Sudden death in young people is rare, but those at ... causes and treatments. By Mayo Clinic Staff Sudden death in people younger than 35, often due to ...

  19. Supravalvular aortic stenosis with sudden cardiac death

    Directory of Open Access Journals (Sweden)

    Pradeep Vaideeswar

    2015-01-01

    Full Text Available Sudden cardiac death (SCD most commonly results from previously undiagnosed congenital, acquired, or hereditary cardiac diseases. Congenital aortic valvular, subvalvular, and supravalvular disease with left ventricular outflow tract obstruction is an important preventable cause of sudden death. This report documents sudden death presumably due to acute myocardial ischemia in a young male with an undiagnosed supravalvular aortic stenosis (SVAS due to a rare association of isolation of coronary sinuses of Valsalva. Congenital supravalvular pulmonary stenosis and mitral valvular dysplasia were also present.

  20. The locus of word frequency effects in skilled spelling-to-dictation.

    Science.gov (United States)

    Chua, Shi Min; Liow, Susan J Rickard

    2014-01-01

    In spelling-to-dictation tasks, skilled spellers consistently initiate spelling of high-frequency words faster than that of low-frequency words. Tainturier and Rapp's model of spelling shows three possible loci for this frequency effect: spoken word recognition, orthographic retrieval, and response execution of the first letter. Thus far, researchers have attributed the effect solely to orthographic retrieval without considering spoken word recognition or response execution. To investigate word frequency effects at each of these three loci, Experiment 1 involved a delayed spelling-to-dictation task and Experiment 2 involved a delayed/uncertain task. In Experiment 1, no frequency effect was found in the 1200-ms delayed condition, suggesting that response execution is not affected by word frequency. In Experiment 2, no frequency effect was found in the delayed/uncertain task that reflects the orthographic retrieval, whereas a frequency effect was found in the comparison immediate/uncertain task that reflects both spoken word recognition and orthographic retrieval. The results of this two-part study suggest that frequency effects in spoken word recognition play a substantial role in skilled spelling-to-dictation. Discrepancies between these findings and previous research, and the limitations of the present study, are discussed.

  1. 4. Assessment Typologies Used Within the Discipline Theory, Solfeggio, Musical Dictation

    Directory of Open Access Journals (Sweden)

    Duţică Luminiţa

    2018-03-01

    Full Text Available Assessment is a distinct stage within the teaching process, aiming to measure the level of the knowledge, skills and competences acquired within a given time frame. The discipline Theory, Solfeggio, Musical Dictation involves a synthesis between the theoretical and the practical side of the matter, and, as a result, it uses specific assessment tools for each side. Modern assessment methods involve personalized systems based on the diversification of types of docimological tests, quizzes, practical tests, etc. In this study we will present a series of personal contributions referring to the contents specific to the discipline Theory, Solfeggio, Musical Dictation taught at university.

  2. Gastrointestinal causes of sudden unexpected death: A review.

    Science.gov (United States)

    Menezes, Ritesh G; Ahmed, Saba; Pasha, Syed Bilal; Hussain, Syed Ather; Fatima, Huda; Kharoshah, Magdy A; Madadin, Mohammed

    2018-01-01

    Gastrointestinal conditions are a less common cause of sudden unexpected death when compared to other conditions such as cardiovascular conditions, but they are equally important. Various congenital and acquired gastrointestinal conditions that have resulted in sudden unexpected death are discussed. The possible lethal mechanisms behind each condition, along with any associated risk factors or secondary diseases, have been described. Through this article, we aim to highlight the need for physicians to prevent death in such conditions by ensuring that subclinical cases are diagnosed correctly before it is too late and by providing timely and efficacious treatment to the patient concerned. In addition, this review would certainly benefit the forensic pathologist while dealing with cases of sudden unexpected death due to gastrointestinal causes. This article is a review of the major gastrointestinal causes of sudden unexpected death. In addition, related fatal cases encountered occasionally in forensic autopsy practice are also included. There are several unusual and rare causes of life-threatening gastrointestinal bleeding that may lead to sudden unexpected death to cover all the entities in detail. Nevertheless, this article is a general guide to the topic of gastrointestinal causes of sudden unexpected death.

  3. Sudden Cardiac Arrest during Participation in Competitive Sports.

    Science.gov (United States)

    Landry, Cameron H; Allan, Katherine S; Connelly, Kim A; Cunningham, Kris; Morrison, Laurie J; Dorian, Paul

    2017-11-16

    The incidence of sudden cardiac arrest during participation in sports activities remains unknown. Preparticipation screening programs aimed at preventing sudden cardiac arrest during sports activities are thought to be able to identify at-risk athletes; however, the efficacy of these programs remains controversial. We sought to identify all sudden cardiac arrests that occurred during participation in sports activities within a specific region of Canada and to determine their causes. In this retrospective study, we used the Rescu Epistry cardiac arrest database (which contains records of every cardiac arrest attended by paramedics in the network region) to identify all out-of-hospital cardiac arrests that occurred from 2009 through 2014 in persons 12 to 45 years of age during participation in a sport. Cases were adjudicated as sudden cardiac arrest (i.e., having a cardiac cause) or as an event resulting from a noncardiac cause, on the basis of records from multiple sources, including ambulance call reports, autopsy reports, in-hospital data, and records of direct interviews with patients or family members. Over the course of 18.5 million person-years of observation, 74 sudden cardiac arrests occurred during participation in a sport; of these, 16 occurred during competitive sports and 58 occurred during noncompetitive sports. The incidence of sudden cardiac arrest during competitive sports was 0.76 cases per 100,000 athlete-years, with 43.8% of the athletes surviving until they were discharged from the hospital. Among the competitive athletes, two deaths were attributed to hypertrophic cardiomyopathy and none to arrhythmogenic right ventricular cardiomyopathy. Three cases of sudden cardiac arrest that occurred during participation in competitive sports were determined to have been potentially identifiable if the athletes had undergone preparticipation screening. In our study involving persons who had out-of-hospital cardiac arrest, the incidence of sudden cardiac

  4. Outlining and dictating scientific manuscripts is a useful method for health researchers: A focus group interview.

    Science.gov (United States)

    Andresen, Kristoffer; Laursen, Jannie; Rosenberg, Jacob

    2018-01-01

    Young researchers may experience difficulties when writing scientific articles for publication in biomedical journals. Various methods may facilitate the writing process including outlining the paper before the actual writing and using dictation instead of writing the first draft. The aim of this study was to investigate the experiences and difficulties for young, experienced researchers when writing articles using a detailed outline and dictation of the first draft. We used qualitative focus group interviews and the study was reported according to the COnsolidated criteria for REporting Qualitative research guideline. Participants were sampled from a group of researchers participating in a writing retreat/course. The interviews were recorded on a digital recorder and transcribed. The text was analyzed according to content analysis and coded and condensed into themes and subthemes. Groups of participants were added until data saturation was reached. A total of 14 researchers participated (9 women and 5 men). Their clinical experience was median (range) of 6 (1-11) years since graduation from medical school. Two themes arose during the analyses of the data: "Process guidance with the outline as the map" and "arrival at dictation." The outline was used in the preparation phase leading up to the day of dictation and was used in collaboration with co-authors and supervisors. The participants found it to be a useful tool for preparing the manuscript and dictating their initial first full draft. Experienced young researchers found beneficial effects of using a structured outline to prepare for dictation of scientific articles. The outline was a tool that would develop in close collaboration with co-authors and mentors. With dictation, a full first draft of a manuscript can be produced in a few hours. Participants positively evaluated this structured and reproducible way of producing scientific articles.

  5. English-to-Japanese Translation vs. Dictation vs. Post-editing

    DEFF Research Database (Denmark)

    Carl, Michael; Aizawa, Akiko; Yamada, Masaru

    2016-01-01

    of text production. This paper introduces and evaluates a corpus of more than 55 hours of English-to-Japanese user activity data that were collected within the ENJA15 project, in which translators were observed while writing and speaking translations (translation dictation) and during machine translation...

  6. Risk factors and causes of sudden noncardiac death

    DEFF Research Database (Denmark)

    Risgaard, Bjarke; Lynge, Thomas Hadberg; Wissenberg, Mads

    2015-01-01

    was to report the risk factors and causes of SNCD. METHODS: We conducted a retrospective, nationwide study including all deaths between 2000 and 2006 of individuals aged 1-35 years and all deaths between 2007 and 2009 of individuals aged 1-49 years. Two physicians identified all sudden death cases through.......3-2.3; OR 3.0, 95% CI 2.0-4.4; and OR 4.3, 95% CI 2.5-7.4, respectively). The most common cause of SNCD was pulmonary disease (n = 115 [40%]). CONCLUSION: Sudden death among individuals aged caused by noncardiac diseases in 28% of cases. Risk factors were female sex, age, and the absence......BACKGROUND: On the performance of an autopsy, sudden deaths may be divided into 2 classifications: (1) sudden cardiac deaths and (2) sudden noncardiac deaths (SNCDs). Families of SNCD victims should not be followed up as a means of searching for cardiac disease. OBJECTIVE: The purpose of this study...

  7. How to measure responses of the knee to lateral perturbations during gait? A proof-of-principle for quantification of knee instability.

    Science.gov (United States)

    van den Noort, Josien C; Sloot, Lizeth H; Bruijn, Sjoerd M; Harlaar, Jaap

    2017-08-16

    Knee instability is a major problem in patients with anterior cruciate ligament injury or knee osteoarthritis. A valid and clinically meaningful measure for functional knee instability is lacking. The concept of the gait sensitivity norm, the normalized perturbation response of a walking system to external perturbations, could be a sensible way to quantify knee instability. The aim of this study is to explore the feasibility of this concept for measurement of knee responses, using controlled external perturbations during walking in healthy subjects. Nine young healthy participants walked on a treadmill, while three dimensional kinematics were measured. Sudden lateral translations of the treadmill were applied at five different intensities during stance. Right knee kinematic responses and spatio-temporal parameters were tracked for the perturbed stride and following four cycles, to calculate perturbation response and gait sensitivity norm values (i.e. response/perturbation) in various ways. The perturbation response values in terms of knee flexion and abduction increased with perturbation intensity and decreased with an increased number of steps after perturbation. For flexion and ab/adduction during midswing, the gait sensitivity norm values were shown to be constant over perturbation intensities, demonstrating the potential of the gait sensitivity norm as a robust measure of knee responses to perturbations. These results show the feasibility of using the gait sensitivity norm concept for certain gait indicators based on kinematics of the knee, as a measure of responses during perturbed gait. The current findings in healthy subjects could serve as reference-data to quantify pathological knee instability. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Sudden gains in group cognitive-behavioral therapy for panic disorder.

    Science.gov (United States)

    Clerkin, Elise M; Teachman, Bethany A; Smith-Janik, Shannan B

    2008-11-01

    The current study investigates sudden gains (rapid symptom reduction) in group cognitive-behavioral therapy for panic disorder. Sudden gains occurring after session 2 of treatment predicted overall symptom reduction at treatment termination and some changes in cognitive biases. Meanwhile, sudden gains occurring immediately following session 1 were not associated with symptom reduction or cognitive change. Together, this research points to the importance of examining sudden gains across the entire span of treatment, as well as the potential role of sudden gains in recovery from panic disorder.

  9. Locus of word frequency effects in spelling to dictation: Still at the orthographic level!

    Science.gov (United States)

    Bonin, Patrick; Laroche, Betty; Perret, Cyril

    2016-11-01

    The present study was aimed at testing the locus of word frequency effects in spelling to dictation: Are they located at the level of spoken word recognition (Chua & Rickard Liow, 2014) or at the level of the orthographic output lexicon (Delattre, Bonin, & Barry, 2006)? Words that varied on objective word frequency and on phonological neighborhood density were orally presented to adults who had to write them down. Following the additive factors logic (Sternberg, 1969, 2001), if word frequency in spelling to dictation influences a processing level, that is, the orthographic output level, different from that influenced by phonological neighborhood density, that is, spoken word recognition, the impact of the 2 factors should be additive. In contrast, their influence should be overadditive if they act at the same processing level in spelling to dictation, namely the spoken word recognition level. We found that both factors had a reliable influence on the spelling latencies but did not interact. This finding is in line with an orthographic output locus hypothesis of word frequency effects in spelling to dictation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  10. Specific acoustic models for spontaneous and dictated style in indonesian speech recognition

    Science.gov (United States)

    Vista, C. B.; Satriawan, C. H.; Lestari, D. P.; Widyantoro, D. H.

    2018-03-01

    The performance of an automatic speech recognition system is affected by differences in speech style between the data the model is originally trained upon and incoming speech to be recognized. In this paper, the usage of GMM-HMM acoustic models for specific speech styles is investigated. We develop two systems for the experiments; the first employs a speech style classifier to predict the speech style of incoming speech, either spontaneous or dictated, then decodes this speech using an acoustic model specifically trained for that speech style. The second system uses both acoustic models to recognise incoming speech and decides upon a final result by calculating a confidence score of decoding. Results show that training specific acoustic models for spontaneous and dictated speech styles confers a slight recognition advantage as compared to a baseline model trained on a mixture of spontaneous and dictated training data. In addition, the speech style classifier approach of the first system produced slightly more accurate results than the confidence scoring employed in the second system.

  11. Sudden Cardiac Death

    DEFF Research Database (Denmark)

    Risgaard, Bjarke; Winkel, Bo Gregers; Jabbari, Reza

    2017-01-01

    Objectives This study sought to describe the use of pharmacotherapy in a nationwide cohort of young patients with sudden cardiac death (SCD). Background Several drugs have been associated with an increased risk of SCD and sudden arrhythmic death syndrome (SADS). It remains unclear how...... pharmacotherapy may contribute to the overall burden of SCD in the general population. Methods This was a nationwide study that included all deaths that occurred between 2000 and 2009 and between 2007 and 2009 in people age 1 to 35 years and 36 to 49 years, respectively. Two physicians identified all SCDs through...... review of death certificates. Autopsy reports were collected. Pharmacotherapy prescribed within 90 days before SCD was identified in the Danish Registry of Medicinal Product Statistics. Results We identified 1,363 SCDs; median age was 38 years (interquartile range: 29 to 45 years), and 72% (n = 975) were men...

  12. Sudden Cardiac Death in Children. Part 1

    Directory of Open Access Journals (Sweden)

    Ye.V. Pshenichnaya

    2013-02-01

    Full Text Available This article presents the prevalence, terminology, classification of sudden cardiac death. A description of congenital structural heart diseases associated with a risk of sudden cardiac death is given. The issues of etiology and pathogenesis of life-threatening conditions are described in detail.

  13. Give and Take in Dictator Games

    DEFF Research Database (Denmark)

    Cappelen, Alexander W.; Nielsen, Ulrik Haagen; Sørensen, Erik Ø.

    2014-01-01

    It has been shown that participants in the dictator game are less willing to give money to the other participant when their choice set also includes the option to take money. We examine whether this effect is due to the choice set providing a signal about entitlements in a setting where...... entitlements initially may be considered unclear. We find that the share of positive transfers depends on the choice set even when there is no uncertainty about entitlements, and that this choice-set effect is robust across a heterogenous group of participants recruited from the general adult population...

  14. The bystander effect in an N-person dictator game

    NARCIS (Netherlands)

    Panchanathan, K.; Frankenhuis, W.E.; Silk, J.B.

    2013-01-01

    Dozens of studies show that bystanders are less likely to help victims as bystander number increases. However, these studies model one particular situation, in which victims need only one helper. Using a multi-player dictator game, we study a different but common situation, in which a recipient’s

  15. Sudden cardiac death in adults: causes, incidence and interventions.

    Science.gov (United States)

    Walker, Wendy Marina

    Many nurses will be familiar with the unexpected death of an adult patient following a sudden, life-threatening cardiac event. It is a situation that demands sensitive nursing care and skilled interventions to provide a foundation for recovery and promote healthy bereavement. This article examines the causes and incidence of sudden cardiac death in adults. Possible reactions of those who are suddenly bereaved are described and immediate care interventions aimed at dealing with the grief process are discussed. The article concludes by identifying ways in which the incidence of sudden cardiac death may be reduced.

  16. [Psychological stress and sudden death].

    Science.gov (United States)

    Pignalberi, Carlo; Ricci, Renato; Santini, Massimo

    2002-10-01

    Recent studies provide relevant evidence that psychological stress significantly influences the pathogenesis of sudden cardiac death. Psychological stress expresses a situation of imbalance, derived from a real or perceived disparity between environmental demands and the individual's ability to cope with these demands. A situation of psychological stress may include different components: personality factors and character traits, anxiety and depression, social isolation and acute or chronic adverse life events. In particular, it has been documented that a sudden extremely hard event, such as an earthquake or a war strike, can significantly increase the incidence of sudden death. Nevertheless, each one of these factors, if not present, can balance a partially unfavorable situation; this overview suggests a multifactorial situation where almost all elements are present and in which the relative influence of each one varies according to the individual examined. Sudden death occurs when a transient disruption (such as acute myocardial ischemia, platelet activation or neuroendocrine variations), occurring in a patient with a diseased myocardium (such as one with a post-necrotic scar or hypertrophy), triggers a malignant arrhythmia. Psychological stress acts at both levels: by means of a "chronic" action it contributes to create the myocardial background, while by means of an acute action it can create the transient trigger precipitating sudden death. In the chronic action two possible mechanisms can be detected: the first is a direct interaction, which contributes to cause a hypertension status or to exacerbate coronary atherosclerosis consequent to endothelial dysfunction; the second one acts through adverse health behaviors, such as a poor diet, alcohol consumption or smoking. In case of acute psychological stress, the mechanisms involved are mainly the ability to trigger myocardial ischemia, to promote arrhythmogenesis, to stimulate platelet function, and to increase

  17. Structural imaging biomarkers of sudden unexpected death in epilepsy.

    Science.gov (United States)

    Wandschneider, Britta; Koepp, Matthias; Scott, Catherine; Micallef, Caroline; Balestrini, Simona; Sisodiya, Sanjay M; Thom, Maria; Harper, Ronald M; Sander, Josemir W; Vos, Sjoerd B; Duncan, John S; Lhatoo, Samden; Diehl, Beate

    2015-10-01

    Sudden unexpected death in epilepsy is a major cause of premature death in people with epilepsy. We aimed to assess whether structural changes potentially attributable to sudden death pathogenesis were present on magnetic resonance imaging in people who subsequently died of sudden unexpected death in epilepsy. In a retrospective, voxel-based analysis of T1 volume scans, we compared grey matter volumes in 12 cases of sudden unexpected death in epilepsy (two definite, 10 probable; eight males), acquired 2 years [median, interquartile range (IQR) 2.8] before death [median (IQR) age at scanning 33.5 (22) years], with 34 people at high risk [age 30.5 (12); 19 males], 19 at low risk [age 30 (7.5); 12 males] of sudden death, and 15 healthy controls [age 37 (16); seven males]. At-risk subjects were defined based on risk factors of sudden unexpected death in epilepsy identified in a recent combined risk factor analysis. We identified increased grey matter volume in the right anterior hippocampus/amygdala and parahippocampus in sudden death cases and people at high risk, when compared to those at low risk and controls. Compared to controls, posterior thalamic grey matter volume, an area mediating oxygen regulation, was reduced in cases of sudden unexpected death in epilepsy and subjects at high risk. The extent of reduction correlated with disease duration in all subjects with epilepsy. Increased amygdalo-hippocampal grey matter volume with right-sided changes is consistent with histo-pathological findings reported in sudden infant death syndrome. We speculate that the right-sided predominance reflects asymmetric central influences on autonomic outflow, contributing to cardiac arrhythmia. Pulvinar damage may impair hypoxia regulation. The imaging findings in sudden unexpected death in epilepsy and people at high risk may be useful as a biomarker for risk-stratification in future studies. The Author (2015). Published by Oxford University Press on behalf of the Guarantors of

  18. Partner Selection and the Division of Surplus: Evidence from Ultimatum and Dictator Experiments

    Directory of Open Access Journals (Sweden)

    Priyodorshi Banerjee

    2016-01-01

    Full Text Available We study ultimatum and dictator environments with one-way, unenforceable pre-play communication from the proposer to the recipient, semantically framed as a promise. After observing this promise regarding how much the proposer will offer if selected, in our treatment conditions, recipients choose whether or not to select a particular proposer. We find that offers can increase in the ultimatum game both with non-competitive selection with a single potential proposer, and more so with competition, where the recipient chooses one of two potential proposers, as compared to the no selection baseline. Furthermore, the offer is rejected with higher probability if the promisemade by the selected proposer is higher than the eventual offer. Our dictator environment does not give the power to reject offers, thus selection power carries no benefits in the dictator game. Finally, independent of the game institution or proposer selection mechanism, promises provide credible signals for offers.

  19. Athletes at Risk for Sudden Cardiac Death

    Science.gov (United States)

    Subasic, Kim

    2010-01-01

    High school athletes represent the largest group of individuals affected by sudden cardiac death, with an estimated incidence of once or twice per week. Structural cardiovascular abnormalities are the most frequent cause of sudden cardiac death. Athletes participating in basketball, football, track, soccer, baseball, and swimming were found to…

  20. Sudden Hearing Loss after Rabies Vaccination

    OpenAIRE

    Güçlü, Oğuz; Dereköy, Fevzi Sefa

    2014-01-01

    Background: Sudden hearing loss developing after immunisation is a very rare situation. Rabies is a viral disease characterised by encephalitis and death. Treatment involves active and passive immunisation. Neurologic complications including Guillain-Barre syndrome or facial paralysis are reported in the literature as a side effect after rabies immunisation. Case Report: Sudden hearing loss was detected in an 11 year-old male patient who had taken the medication for rabies immunisatio...

  1. Sudden Hearing Loss after Rabies Vaccination

    OpenAIRE

    Güçlü, Oğuz; Dereköy, Fevzi Sefa

    2013-01-01

    Background: Sudden hearing loss developing after immunisation is a very rare situation. Rabies is a viral disease characterised by encephalitis and death. Treatment involves active and passive immunisation. Neurologic complications including Guillain-Barre syndrome or facial paralysis are reported in the literature as a side effect after rabies immunisation. Case Report: Sudden hearing loss was detected in an 11 year-old male patient who had taken the medication for rabies immunisat...

  2. Sudden Cardiac Death in Children. Part 2

    Directory of Open Access Journals (Sweden)

    Ye.V. Pshenichnaya

    2013-03-01

    Full Text Available This article deals with the dysplastic changes in musculo-valve structures of the heart, arrhythmias and conduction disorders, associated with a risk of sudden cardiac death. The diagnostic criteria for sudden cardiac death, the events of cardio-pulmonary resuscitation, prevention of life-threatening conditions in children are provided.

  3. Distillability Sudden Birth of Entanglement for Qutrit-Qutrit Systems

    International Nuclear Information System (INIS)

    Huang Jiang; Ali Mazhar

    2014-01-01

    We report the sudden appearance of distillability between two statistically independent reservoirs modelled as qutrit-qutrit systems. This feature of bipartite quantum systems is different from the previously observed phenomenon of entanglement sudden birth. It is found that the states of reservoirs first become bound entangled, thus exhibiting entanglement sudden birth, consequently followed by the sudden birth of distillability, and it is shown that whenever distillability is lost abruptly from principal system, it also necessarily appears abruptly among reservoirs' degrees of freedom. This surprising observation reflects yet another peculiarity of dynamical aspects of quantum entanglement

  4. Sudden Sensorineural Hearing Loss; Prognostic Factors

    OpenAIRE

    Arjun, Dass; Neha, Goel; Surinder K, Singhal; Ravi, Kapoor

    2015-01-01

    Introduction: Sudden sensorineural hearing loss (SSNHL) is a frightening and frustrating symptom for the patient as well as the physician. Prognosis is affected by multiple factors including duration of hearing loss, presence of associated vertigo and tinnitus, and co-morbidities such as hypertension and diabetes.   Materials and Methods: Forty subjects presenting to our department with features of sudden hearing loss were included in the study. Detailed otological history and examination, se...

  5. Profile of sudden death in an adult population (1999-2008).

    LENUS (Irish Health Repository)

    Downes, M R

    2010-06-01

    Sudden death is the sudden and unexpected death of an individual within 24 hours of symptom onset. The vast majority of these cases are found, at autopsy, to be due to underlying ischaemic cardiac disease. We retrospectively reviewed all adult post mortems performed at Beaumont Hospital over a decade (1999-2008). Our aim was to identify all sudden death cases (natural and accidental) and subclassify them according to age profile and organ system involved. We identified 1230 sudden death cases in the review period with 775 (63%) deaths attributable to ischaemic heart disease. The rate of sudden death remained constant over the decade with 663 (54%) deaths occurring in the first five years. Our negative autopsy rate was 2.8% corresponding to 35 cases. This is the first Irish study to retrospectively review all adult sudden deaths within a defined catchment area and analyse them as outlined above.

  6. Geomagnetic Storm Sudden Commencements

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Storm Sudden Commencements (ssc) 1868 to present: STORM1 and STORM2 Lists: (Some text here is taken from the International Association of Geomagnetism and Aeronomy...

  7. Limitations of the Dual-Process-Theory regarding the Writing of Words and Non-Words to Dictation

    Science.gov (United States)

    Tucha, Oliver; Trumpp, Christian; Lange, Klaus W.

    2004-01-01

    It is generally assumed that the lexical and phonological systems are involved in writing to dictation. In an experiment concerned with the writing of words and non-words to dictation, the handwriting of female students was registered using a digitising tablet. The data contradict the assumption that the phonological system represents an alexical…

  8. Antipsychotics and the risk of sudden cardiac death

    NARCIS (Netherlands)

    Straus, S.M.J.M.; Bleumink, G.S.; Dieleman, J.P.; van der Lei, J.; 't Jong, G.W.; Kingma, J. Herre; Sturkenboom, M.C J M; Stricker, B.H C

    2004-01-01

    Background Antipsychotics have been associated with prolongation of the corrected QT interval and sudden cardiac death. Only a few epidemiological studies have investigated this association. We performed a case-control study to investigate the association between use of antipsychotics and sudden

  9. Sudden Ionospheric Disturbances (SID)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sudden ionospheric disturbances (SID) are caused by solar flare enhanced X-rays in the 1 to 10 angstrom range. Solar flares can produce large increases of ionization...

  10. Magnetic resonance imaging in sudden deafness

    International Nuclear Information System (INIS)

    Ramos, Hugo Valter Lisboa; Barros, Flavia Alencar; Penido, Norma de Oliveira; Souza, Ana Claudia Valerio de; Yamaoka, Wellington Yugo; Yamashita, Helio

    2005-01-01

    The etiology of sudden deafness can remain undetermined despite extensive investigation. This study addresses the value of magnetic resonance imaging in the analysis of sudden deafness patients.Study Design: transversal cohort.Material And Method: In a prospective study, 49 patients attended at otolaryngology emergency room of Federal University of Sao Paulo - Escola Paulista de Medicina, from April 2001 to May 2003, were submitted to magnetic resonance imaging.Results: Magnetic Resonance abnormalities were seen in 23 (46.9%) patients and revealed two tumors suggestive of meningioma, three vestibular schwannomas, thirteen microangiopathic changes of the brain and five (21.7%) pathological conditions of the labyrinth.Conclusion: Sudden deafness should be approached as a symptom common to different diseases. The presence of cerebellopontine angle tumors in 10.2% of our cases, among other treatable causes, justifies the recommendation of gadolinium-enhanced magnetic resonance use, not only to study the auditory peripheral pathway, but to study the whole auditory pathway including the brain. (author)

  11. Supersingular quantum perturbations

    International Nuclear Information System (INIS)

    Detwiler, L.C.; Klauder, J.R.

    1975-01-01

    A perturbation potential is called supersingular whenever generally every matrix element of the perturbation in the unperturbed eigenstates is infinite. It follows that supersingular perturbations do not have conventional perturbation expansions, say for energy eigenvalues. By invoking variational arguments, we determine the asymptotic behavior of the energy eigenvalues for asymptotically small values of the coupling constant of the supersingular perturbation

  12. CARDIOVASCULAR CAUSES OF SUDDEN DEATH- AN AUTOPSY STUDY

    Directory of Open Access Journals (Sweden)

    Deepu Thankappan

    2016-10-01

    Full Text Available BACKGROUND Present study “Cardiovascular Causes of Sudden Death- An Autopsy Study” was a cross-sectional study conducted in Department of Forensic Medicine, Government Medical College, Kottayam, during the time period from June 1 st 2013 to June 1 st 2014. The objective of the study was to find out the cardiovascular causes of sudden deaths and to correlate the postmortem findings with the histopathological examination. 57 cases brought for postmortem examination with history suggestive of sudden natural death were taken into the study and those cases observed to have a cardiovascular cause of sudden death during autopsy were further examined and their heart specimens were subjected to histopathological examination. Then, the sociodemographic factors, postmortem findings and histopathological findings were correlated and analysed. MATERIALS AND METHODS 57 cases brought for autopsy at Department of Forensic Medicine, Government Medical College, Kottayam from 01.06.2013 to 31.05.2014 were autopsied and subjected to histopathological examination of the heart. The socio-demographic data were collected; they were analyzed and correlated with the postmortem and histopathological findings. RESULTS Out of the 57 subjects who were taken into the study, maximum number of Sudden natural deaths were in the 36-50 year age group (42.2%, 33.3% in the 51-65 year age group and 14% of cases were in the 66-80 year age group. CONCLUSION Histopathological examination of the samples showed myocardial infarction in 33.3% of cases; chronic ischaemic heart disease in 56.1% of cases and myocarditis in 19.3% of cases. The major cardiovascular cause of sudden death was ascertained as Coronary artery disease.

  13. Changes in cortical activity associated with adaptive behavior during repeated balance perturbation of unpredictable timing

    Directory of Open Access Journals (Sweden)

    Andreas eMierau

    2015-10-01

    Full Text Available The compensation for a sudden balance perturbation, unpracticed and unpredictable in timing and magnitude is accompanied by pronounced postural instability that is suggested to be causal to falls. However, subsequent presentations of an identical perturbation are characterized by a marked decrease of the amplitude of postural reactions; a phenomenon called adaptation or habituation. This study aimed to identify cortical characteristics associated with adaptive behavior during repetitive balance perturbations based on single-trial analyses of the P1 and N1 perturbation-evoked potentials. Thirty-seven young men were exposed to ten transient balance perturbations while balancing on the dominant leg. 32-channel EEG, surface EMG of the ankle plantar flexor muscles and postural sway (i.e. Euclidean distance of the supporting platform were recorded simultaneously. The P1 and N1 potentials were localized and the amplitude/latency was analyzed trial by trial. The best match sources for P1 and N1 potentials were located in the parietal (Brodmann area 5 and midline fronto-central cortex (Brodmann area 6, respectively. The amplitude and latency of the P1 potential remained unchanged over trials. In contrast, a significant adaptation of the N1 amplitude was observed. Similar adaptation effects were found with regard to postural sway and m. peroneus longus EMG activity of the non-dominant (free leg; an indicator reduced muscular co-contraction and/or less temporary bipedal stance to regain stability. Significant but weak correlations were found between N1 amplitude and postural sway as well as EMG activity. These results highlight the important role of the midline fronto-central cortex for adaptive behavior associated with balance control.

  14. Cardiac Channelopathies and Sudden Death: Recent Clinical and Genetic Advances

    OpenAIRE

    Fernández Falgueras, Anna; Sarquella Brugada, Georgia; Brugada Terradellas, Josep; Brugada, Ramon; Campuzano Larrea, Oscar

    2017-01-01

    Sudden cardiac death poses a unique challenge to clinicians because it may be the only symptom of an inherited heart condition. Indeed, inherited heart diseases can cause sudden cardiac death in older and younger individuals. Two groups of familial diseases are responsible for sudden cardiac death: cardiomyopathies (mainly hypertrophic cardiomyopathy, dilated cardiomyopathy, and arrhythmogenic cardiomyopathy) and channelopathies (mainly long QT syndrome, Brugada syndrome, short QT syndrome, a...

  15. Experimental similitude determination of the influence of perturbations in the thickness of a heating channel on the isolated wall temperatures (1960); Determination experimentale en similitude de l'influence de perturbations dans l'epaisseur d'un canal chauffant sur les temperatures de la paroi isolee (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Vernier, Ph [Commissariat a l' Energie Atomique, Grenoble (France).Centre d' Etudes Nucleaires; Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    A study is made of the local heating phenomena produced on the isolated wall of a channel heated by the Joule effect by a sudden fluctuation in the conducting thickness. By the use of an experimental scale model it has been possible to measure the differences in the isolated wall temperature along the abscissa of the perturbation. The tests carried out show that the temperature differences are contained within a range of {+-} 4 per cent with respect to the temperature differences between the isolated and the isolated walls. (author) [French] On analyse le phenomene thermique local cree sur la paroi isolee d'un canal chauffe par effet Joule, par une perturbation brusque de l'epaisseur conductrice. Un modele experimental a l'echelle a permis de mesurer les ecarts de temperature de la paroi isolee a l'abscisse de la perturbation. Les essais realises ont montre que les ecarts de temperature se situaient dans une bande de {+-} 4 pour cent par rapport a l'ecart de temperature moyen entre paroi isolee et paroi refroidie. (auteur)

  16. PHOX2B polyalanine repeat length is associated with sudden infant death syndrome and unclassified sudden infant death in the Dutch population

    NARCIS (Netherlands)

    G. Liebrechts-Akkerman (Germaine); F. Liu (Fan); O. Lao Grueso (Oscar); A.H.A.G. Ooms (Ariadne ); K. van Duijn (Kate); M. Vermeulen (Mark); V.W.V. Jaddoe (Vincent); A. Hofman (Albert); A.C. Engelberts (Adele); M.H. Kayser (Manfred)

    2014-01-01

    textabstractUnclassified sudden infant death (USID) is the sudden and unexpected death of an infant that remains unexplained after thorough case investigation including performance of a complete autopsy and review of the circumstances of death and the clinical history. When the infant is below 1

  17. Graphene Edges Dictate the Morphology of Nanoparticles during Catalytic Channeling

    DEFF Research Database (Denmark)

    Pizzocchero, Filippo; Vanin, Marco; Kling, Jens

    2014-01-01

    We perform in-situ transmission electron microscopy (TEM) experiments of silver nanoparticles channeling on mono-, bi-, and few-layer graphene and discover that the interactions in the one-dimensional particle–graphene contact line are sufficiently strong so as to dictate the three-dimensional sh......We perform in-situ transmission electron microscopy (TEM) experiments of silver nanoparticles channeling on mono-, bi-, and few-layer graphene and discover that the interactions in the one-dimensional particle–graphene contact line are sufficiently strong so as to dictate the three......-dimensional shape of the nanoparticles. We find a characteristic faceted shape in particles channeling along graphene ⟨100⟩ directions that is lost during turning and thus represents a dynamic equilibrium state of the graphene–particle system. We propose a model for the mechanism of zigzag edge formation...... and an explanation of the rate-limiting step for this process, supported by density functional theory (DFT) calculations, and obtain a good agreement between the DFT-predicted and experimentally obtained activation energies of 0.39 and 0.56 eV, respectively. Understanding the origin of the channels' orientation...

  18. Major life events as potential triggers of sudden cardiac arrest.

    Science.gov (United States)

    Wicks, April F; Lumley, Thomas; Lemaitre, Rozenn N; Sotoodehnia, Nona; Rea, Thomas D; McKnight, Barbara; Strogatz, David S; Bovbjerg, Viktor E; Siscovick, David S

    2012-05-01

    We investigated the risk of sudden cardiac arrest in association with the recent loss of, or separation from, a family member or friend. Our case-crossover study included 490 apparently healthy married residents of King County, Washington, who suffered sudden cardiac arrest between 1988 and 2005. We compared exposure to spouse-reported family/friend events occurring ≤ 1 month before sudden cardiac arrest with events occurring in the previous 5 months. We evaluated potential effect modification by habitual vigorous physical activity. Recent family/friend events were associated with a higher risk of sudden cardiac arrest (odds ratio [OR] = 1.6; 95% confidence interval [CI] = 1.1-2.4). ORs for cases with and without habitual vigorous physical activity were 1.1 (0.6-2.2) and 2.0 (1.2-3.1), respectively (interaction P = 0.02). These results suggest family/friend events may trigger sudden cardiac arrest and raise the hypothesis that habitual vigorous physical activity may lower susceptibility to these potential triggers.

  19. Mobile phone usage does not affect sudden sensorineural hearing loss.

    Science.gov (United States)

    Sagiv, D; Migirov, L; Madgar, O; Nakache, G; Wolf, M; Shapira, Y

    2018-01-01

    Recent studies found that mobile phone users had a significantly greater risk of having elevated thresholds in speech frequencies. This study investigated the correlation between the laterality of sudden sensorineural hearing loss, handedness and the preferred ear for mobile phone use. The study included all patients who presented with sudden sensorineural hearing loss to the Department of Otolaryngology - Head and Neck Surgery in our tertiary referral medical centre between 2014 and 2016. Patients were asked to indicate their dominant hand and preferred ear for mobile phone use. The study comprised 160 patients. No correlation was found between the dominant hand or preferred ear for mobile phone use and the side of sudden sensorineural hearing loss. There was no correlation between the side of the sudden sensorineural hearing loss (preferable or non-preferable for mobile phone use) and audiometric characteristics. No correlation was found between the laterality of ears used for mobile phone and sudden sensorineural hearing loss.

  20. Non-perturbative versus perturbative renormalization of lattice operators

    International Nuclear Information System (INIS)

    Goeckeler, M.; Technische Hochschule Aachen; Horsley, R.; Ilgenfritz, E.M.; Oelrich, H.; Forschungszentrum Juelich GmbH; Schierholz, G.; Forschungszentrum Juelich GmbH; Perlt, H.; Schiller, A.; Rakow, P.

    1995-09-01

    Our objective is to compute the moments of the deep-inelastic structure functions of the nucleon on the lattice. A major source of uncertainty is the renormalization of the lattice operators that enter the calculation. In this talk we compare the renormalization constants of the most relevant twist-two bilinear quark operators which we have computed non-perturbatively and perturbatively to one loop order. Furthermore, we discuss the use of tadpole improved perturbation theory. (orig.)

  1. Sudden unexpected death in infancy in Denmark

    DEFF Research Database (Denmark)

    Winkel, Bo Gregers; Holst, Anders Gaarsdal; Theilade, Juliane

    2011-01-01

    Abstract Background. Incidence of sudden unexpected death in infancy (SUDI) and sudden infant death syndrome (SIDS) differs among studies and non-autopsied cases are difficult to assess. Objectives. To investigate causes of sudden death in infancy in a nationwide setting. Validate the use...... of the ICD-10 code for SIDS (R95) in the Danish Cause of Death registry. Design. A retrospective analysis of all infant deaths (death certificates and autopsy reports were read. Results. We identified 192 SUDI cases (10% of total deaths, 0.42 per 1000 births......) with autopsy performed in 87% of cases. In total, 49% of autopsied SUDI cases were defined as SIDS (5% of all deaths, 0.22 per 1000 births); Cardiac cause of death was denoted in 24% of cases. The Danish Cause of Death Registry misclassified 30% of SIDS cases. Conclusions. A large proportion of infant deaths...

  2. 18 Dictation as a Veritable Tool for Language Proficiency on Project ...

    African Journals Online (AJOL)

    User

    Dictation is a valuable language teaching and learning device that has been used for centuries ... English language among the second learners of English language in a ... through effective study English by developing the language curriculum and ... language teachers need to be abreast with different methods of language.

  3. Chiral perturbation theory approach to hadronic weak amplitudes

    International Nuclear Information System (INIS)

    Rafael, E. de

    1989-01-01

    We are concerned with applications to the non-leptonic weak interactions in the sector of light quark flavors: u, d and s. Both strangeness changing ΔS=1 and ΔS=2 non-leptonic transitions can be described as weak perturbations to the strong effective chiral Lagrangian; the chiral structure of the weak effective Lagrangian being dictated by the transformation properties of the weak non-leptonic Hamiltonian of the Standard Model under global SU(3) Left xSU(3) Right rotations of the quark-fields. These lectures are organized as follows. Section 2 gives a review of the basic properties of chiral symmetry. Section 3 explains the effective chiral realization of the non-leptonic weak Hamiltonian of the Standard Model to lowest order in derivatives and masses. Section 4 deals with non-leptonic weak transitions in the presence of electromagnetism. Some recent applications to radiative kaon decays are reviewed and the effect of the so called electromagnetic penguin like diagrams is also discussed. Section 5 explains the basic ideas of the QCD-hadronic duality approach to the evaluation of coupling constants of the non-leptonic chiral weak Lagrangian. (orig./HSI)

  4. CAUSES OF SUDDEN NATURAL DEATH: A MEDICO-LEGAL ...

    African Journals Online (AJOL)

    89 No. 10 October 2012 ... The age range of the cases was 19-105 years with a mean age ... majority of cases (39.3%), the cause of death was related to the cardio-vascular ... Six hundred and twenty six cases of sudden natural .... (39/60) and a mean age of 54.2±15years. ..... D. A population-based autopsy study of sudden,.

  5. Social phobia with sudden onset--post-panic social phobia?

    DEFF Research Database (Denmark)

    Kristensen, Ann Suhl; Mortensen, Erik Lykke; Mors, Ole

    2008-01-01

    Overlap between social phobia (SP) and panic disorder (PD) has been observed in epidemiological, family, and challenge studies. One possible explanation is that some cases of SP develop as a consequence of a panic attack in a social situation. By definition, these cases of SP have sudden onset...... recruited as part of an etiological study. Patients with SP with sudden onset did, as hypothesized, differ from patients with SP without sudden onset with regard to age of onset and extraversion, but not with regard to symptoms. They did not differ markedly from patients with comorbid SP and PD. The concept...

  6. The dictator effect: how long years in office affect economic development

    NARCIS (Netherlands)

    Papaioannou, Kostadis; van Zanden, Jan Luiten

    This paper contributes to the growing literature on the links between political regimes and economic development by studying the effects of years in office on economic development. The hypothesis is that dictators who stay in office for a long time period will find it increasingly difficult to carry

  7. The dictator effect: how long years in office affect economic development

    NARCIS (Netherlands)

    Papaioannou, K.I.; Zanden, van J.L.

    2015-01-01

    This paper contributes to the growing literature on the links between political regimes and economic development by studying the effects of years in office on economic development. The hypothesis is that dictators who stay in office for a long time period will find it increasingly difficult to carry

  8. Melodic Dictation Instruction: A Survey of Advanced Placement Music Theory Teachers

    Science.gov (United States)

    Buonviri, Nathan O.; Paney, Andrew S.

    2015-01-01

    Based on relevant literature and recent qualitative findings, the purpose of this survey research was to identify pedagogical approaches to melodic dictation employed by Advanced Placement (AP) Music Theory teachers across the United States. The researcher-designed survey questions focused on pitch and rhythm skills, instructional resources,…

  9. Good news is bad news: Leverage cycles and sudden stops

    OpenAIRE

    Akinci, Ozge; Chahrour, Ryan

    2015-01-01

    We show that a model with imperfectly forecastable changes in future productivity and an occasionally binding collateral constraint can match a set of stylized facts about “sudden stop” events. “Good” news about future productivity raises leverage during times of expansion, increasing the probability that the constraint binds, and a sudden stop occurs, in future periods. The economy exhibits a boom period in the run-up to the sudden stop, with output, consumption, and investment all above tre...

  10. A computer case definition for sudden cardiac death.

    Science.gov (United States)

    Chung, Cecilia P; Murray, Katherine T; Stein, C Michael; Hall, Kathi; Ray, Wayne A

    2010-06-01

    To facilitate studies of medications and sudden cardiac death, we developed and validated a computer case definition for these deaths. The study of community dwelling Tennessee Medicaid enrollees 30-74 years of age utilized a linked database with Medicaid inpatient/outpatient files, state death certificate files, and a state 'all-payers' hospital discharge file. The computerized case definition was developed from a retrospective cohort study of sudden cardiac deaths occurring between 1990 and 1993. Medical records for 926 potential cases had been adjudicated for this study to determine if they met the clinical definition for sudden cardiac death occurring in the community and were likely to be due to ventricular tachyarrhythmias. The computerized case definition included deaths with (1) no evidence of a terminal hospital admission/nursing home stay in any of the data sources; (2) an underlying cause of death code consistent with sudden cardiac death; and (3) no terminal procedures inconsistent with unresuscitated cardiac arrest. This definition was validated in an independent sample of 174 adjudicated deaths occurring between 1994 and 2005. The positive predictive value of the computer case definition was 86.0% in the development sample and 86.8% in the validation sample. The positive predictive value did not vary materially for deaths coded according to the ICO-9 (1994-1998, positive predictive value = 85.1%) or ICD-10 (1999-2005, 87.4%) systems. A computerized Medicaid database, linked with death certificate files and a state hospital discharge database, can be used for a computer case definition of sudden cardiac death. Copyright (c) 2009 John Wiley & Sons, Ltd.

  11. Sudden gains in Cognitive Therapy and Interpersonal Psychotherapy for adult depression.

    Science.gov (United States)

    Lemmens, Lotte H J M; DeRubeis, Robert J; Arntz, Arnoud; Peeters, Frenk P M L; Huibers, Marcus J H

    2016-02-01

    We examined the rates, baseline predictors and clinical impact of sudden gains in a randomized comparison of individual Cognitive Therapy (CT) and Interpersonal Psychotherapy (IPT) for adult depression. 117 depressed outpatients received 16-20 sessions of either CT or IPT. Session-by-session symptom severity was assessed using the BDI-II. Sudden gains were examined using the original criteria as defined by Tang and DeRubeis (1999b). Furthermore, we examined whether the duration of the between-session interval at which sudden gains were recorded affected the results. There were significantly more patients with sudden gains in CT (42.2%) as compared to IPT (24.5%). The difference appeared to be driven by the criterion representing the stability of the gain. No between-group differences were found with regard to the magnitude, timing and predictors of the gains. Those with sudden gains were less depressed at post-treatment and follow-up. After controlling for the duration of the between-session interval, the difference in rates between the two conditions became a non-significant trend. Other sudden gains characteristics were similar to those observed when allowing for longer intervals as well. The current study indicates differences in occurrence of sudden gains in two treatment modalities that overall showed similar results, which might reflect different mechanisms of change. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Haloperidol and sudden cardiac death in dementia: autopsy findings in psychiatric inpatients.

    Science.gov (United States)

    Ifteni, Petru; Grudnikoff, Eugene; Koppel, Jeremy; Kremen, Neil; Correll, Christoph U; Kane, John M; Manu, Peter

    2015-12-01

    Treatment with haloperidol has been shown, in studies using death certificates and prescription files, to be associated with an excess of sudden cardiac deaths, and regulatory warnings highlight this risk in patients with dementia. We used autopsy findings to determine whether the rate of sudden cardiac death is greater in cases of unexpected deaths of patients with dementia treated with haloperidol. From 1989 through 2013, 1219 patients with a primary diagnosis of dementia with behavioral disturbance were admitted to a psychiatric hospital, and 65 (5.3%) died suddenly. Sixty-five patients (5.3%) died unexpectedly. Complete post-mortem examinations after the sudden death were performed in 55 (84.6%) patients. Twenty-seven of the autopsied cases (49.1%) had been treated with haloperidol orally (2.2 mg ± 2.1 mg/day), the only antipsychotic used in this cohort. Univariable comparisons and multivariable regression analyses compared the groups of patients with or without sudden cardiac death. The leading causes of death were sudden cardiac death (32.7%), myocardial infarction (25.5% of patients), pneumonia (23.6%), and stroke (10.9%). Patients with sudden cardiac death and those with anatomically established cause of death were similar regarding the use of haloperidol (p = 0.5). Sudden cardiac death patients were more likely to suffer from Alzheimer's dementia (p = 0.027) and to have a past history of heart disease (p = 0.0094), and less likely to have been treated with a mood stabilizer (p = 0.024), but none of these variables were independent predictors of sudden cardiac death. Autopsy data suggest that oral haloperidol is not associated with increased risk of sudden cardiac death in psychiatric inpatients with dementia. Copyright © 2015 John Wiley & Sons, Ltd.

  13. The Impact of Morphological Awareness on Word Reading and Dictation in Chinese Early Adolescent Readers With and Without Dyslexia.

    Science.gov (United States)

    Kalindi, Sylvia Chanda; Chung, Kevin Kien Hoa

    2018-01-01

    This study investigated the role of morphological awareness in understanding Chinese word reading and dictation among Chinese-speaking adolescent readers in Hong Kong as well as the cognitive-linguistic profile of early adolescent readers with dyslexia. Fifty-four readers with dyslexia in Grades 5 and 6 were compared with 54 chronological age-matched (CA) typical readers on the following measures of cognitive-linguistic and literacy skills: morphological awareness, phonological awareness, visual-orthographic knowledge, rapid naming, vocabulary knowledge, verbal short-term memory (STM), Chinese word reading, and dictation (or spelling). The results indicated that early adolescent readers with dyslexia performed less well than the typical readers on all cognitive-linguistic and literacy measures except the phonological measures. Both groups' scores showed substantial correlations between morphological awareness and Chinese word reading and dictation. Visual-orthographic knowledge and rapid naming were also associated with dictation in early adolescent readers with and without dyslexia, respectively. Moderated multiple regression analyses further revealed that morphological awareness and rapid naming explained unique variance in word reading and dictation for the readers with dyslexia and typical readers separately after controlling readers' age and group effect. These results highlight the potential importance of morphological awareness and rapid naming in Chinese word reading and writing in Chinese early adolescents' literacy development and impairment.

  14. Child-centered reading intervention: See, talk, dictate, read, write!

    Directory of Open Access Journals (Sweden)

    Muhammet BAŞTUĞ

    2016-06-01

    Full Text Available Poor reading achievement of children in elementary schools has been one of the major concerns in education. The aim of this study is to examine the effectiveness of a child-centered reading intervention in eliminating the reading problems of a student with poor reading achievement. The research was conducted with a student having difficulty in reading. A reading intervention was designed that targeted multiple areas of reading and aimed to improve reading skills through the use of multiple strategies. This intervention is child-centered and includes visual aids, talking, dictating, reading and writing stages. The study was performed in 35 sessions consisting of stages of a single sentence (5 sessions, two sentences (5 sessions, three sentences (20 sessions and the text stage (5 sessions. The intervention sessions were audio-taped. These recordings and the written responses to the reading comprehension questions provided the data for analysis. The findings on the reading intervention revealed positive outcomes. The student exhibited certain improvements at the levels of reading, reading rate and reading comprehension. These results were discussed in the literature and the findings suggest that child-centered reading strategies such as talking, dictating and writing should be the main focus of instruction for students with low reading literacy achievement to enable these students to meet the demands of the curriculum.

  15. The neural basis for writing from dictation in the temporoparietal cortex.

    Science.gov (United States)

    Roux, Franck-Emmanuel; Durand, Jean-Baptiste; Réhault, Emilie; Planton, Samuel; Draper, Louisa; Démonet, Jean-François

    2014-01-01

    Cortical electrical stimulation mapping was used to study neural substrates of the function of writing in the temporoparietal cortex. We identified the sites involved in oral language (sentence reading and naming) and writing from dictation, in order to spare these areas during removal of brain tumours in 30 patients (23 in the left, and 7 in the right hemisphere). Electrostimulation of the cortex impaired writing ability in 62 restricted cortical areas (.25 cm2). These were found in left temporoparietal lobes and were mostly located along the superior temporal gyrus (Brodmann's areas 22 and 42). Stimulation of right temporoparietal lobes in right-handed patients produced no writing impairments. However there was a high variability of location between individuals. Stimulation resulted in combined symptoms (affecting oral language and writing) in fourteen patients, whereas in eight other patients, stimulation-induced pure agraphia symptoms with no oral language disturbance in twelve of the identified areas. Each detected area affected writing in a different way. We detected the various different stages of the auditory-to-motor pathway of writing from dictation: either through comprehension of the dictated sentences (word deafness areas), lexico-semantic retrieval, or phonologic processing. In group analysis, barycentres of all different types of writing interferences reveal a hierarchical functional organization along the superior temporal gyrus from initial word recognition to lexico-semantic and phonologic processes along the ventral and the dorsal comprehension pathways, supporting the previously described auditory-to-motor process. The left posterior Sylvian region supports different aspects of writing function that are extremely specialized and localized, sometimes being segregated in a way that could account for the occurrence of pure agraphia that has long-been described in cases of damage to this region. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. A positive effect of flowers rather than eye images in a large-scale, cross-cultural dictator game.

    Science.gov (United States)

    Raihani, Nichola J; Bshary, Redouan

    2012-09-07

    People often consider how their behaviour will be viewed by others, and may cooperate to avoid gaining a bad reputation. Sensitivity to reputation may be elicited by subtle social cues of being watched: previous studies have shown that people behave more cooperatively when they see images of eyes rather than control images. Here, we tested whether eye images enhance cooperation in a dictator game, using the online labour market Amazon Mechanical Turk (AMT). In contrast to our predictions and the results of most previous studies, dictators gave away more money when they saw images of flowers rather than eye images. Donations in response to eye images were not significantly different to donations under control treatments. Dictator donations varied significantly across cultures but there was no systematic variation in responses to different image types across cultures. Unlike most previous studies, players interacting via AMT may feel truly anonymous when making decisions and, as such, may not respond to subtle social cues of being watched. Nevertheless, dictators gave away similar amounts as in previous studies, so anonymity did not erase helpfulness. We suggest that eye images might only promote cooperative behaviour in relatively public settings and that people may ignore these cues when they know their behaviour is truly anonymous.

  17. The Impact of Sudden Gains in Cognitive Behavioral Therapy for Posttraumatic Stress Disorder

    Science.gov (United States)

    Kelly, Kacie A.; Rizvi, Shireen L.; Monson, Candice M.; Resick, Patricia A.

    2009-01-01

    This study investigated sudden gains, i.e., rapid and stable improvements, in posttraumatic stress disorder (PTSD) symptoms that may occur in cognitive–behavioral therapy. Twenty-nine of 72 participants (39.2%) experienced a sudden gain during treatment. Mixed model ANOVAs analyzed sudden gains impact on clinician-rated PTSD symptom severity, patient-rated PTSD symptom severity, and patient-rated depressive symptom severity. Sudden gains in PTSD symptomology were associated with greater reductions in PTSD symptom severity for the avoidance/numbing and hyperarousal symptom clusters at posttreatment. By 6-month follow-up, the sudden gains group had maintained those reductions in symptoms, but the nonsudden gains group had achieved equal reductions in symptom severity. Participants experiencing sudden gains on PTSD measures had lower depression severity at posttreatment and follow-up. PMID:19637322

  18. Measuring Altruistic Behavior in Surveys: The All-or-Nothing Dictator Game

    Directory of Open Access Journals (Sweden)

    Rene Bekkers

    2007-12-01

    Full Text Available A field study of altruistic behaviour is presented using a modification of the dictator game in a large random sample survey in the netherlands (n=1,964. In line with laboratory experiments, only 5.7% donated money. In line with other survey research on giving, generosity increased with age, education, income, trust, and prosocial value orientation.

  19. Equatorial storm sudden commencements and interplanetary magnetic field

    International Nuclear Information System (INIS)

    Rastogi, R.G.

    1980-01-01

    A comparison is made of the signatures of interplanetary (IP) shocks in the B and theta plots of interplanetary magnetic field (IMF) data of satellites Explorer 33, 34 and 35 and in the H magnetograms at ground observatories within the equatorial electrojet belt, Huancayo, Addis Ababa and Trivandrum associated with major storm sudden commencements during 1967-70. The IP shocks showing sudden increase of the scalar value of IMF, i.e. B without any change of the latitude theta or with the southward turning of theta, were followed by a purely positive sudden increase of H, at any of the magnetic observatories, either on the dayside or the nightside of the earth. The IP shocks identified by a sudden increase of B and with the northward turning of the latitude theta (positive ΔBsub(z)) were associated with purely positive sudden commencement (SC) at the observatories in the nightside, but at the equatorial observatories in the dayside of the earth the signature of the shock was a SC in H with a preliminary negative impulse followed by the main positive excursion (SC-+). It is suggested that the SCs in H at low latitudes are composed of two effects, viz. (i) one due to hydromagnetic pressure on the magnetosphere by the solar plasma and (ii) the other due to the induced electric field associated with the solar wind velocity, V and the Z-component of the IP magnetic field (E = - V x Bsub(z)). The effect of magnetosphere electric field is faster than the effect due to the compression of the magnetosphere by the impinging solar plasma. The negative impulse of SC-+ at low latitude is seen at stations close to the dip equator and only during daytime due to the existence of high ionospheric conductivities in the equatorial electrojet region. (author)

  20. Effect of a perturbation-based balance training program on compensatory stepping and grasping reactions in older adults: a randomized controlled trial.

    Science.gov (United States)

    Mansfield, Avril; Peters, Amy L; Liu, Barbara A; Maki, Brian E

    2010-04-01

    Compensatory stepping and grasping reactions are prevalent responses to sudden loss of balance and play a critical role in preventing falls. The ability to execute these reactions effectively is impaired in older adults. The purpose of this study was to evaluate a perturbation-based balance training program designed to target specific age-related impairments in compensatory stepping and grasping balance recovery reactions. This was a double-blind randomized controlled trial. The study was conducted at research laboratories in a large urban hospital. Thirty community-dwelling older adults (aged 64-80 years) with a recent history of falls or self-reported instability participated in the study. Participants were randomly assigned to receive either a 6-week perturbation-based (motion platform) balance training program or a 6-week control program involving flexibility and relaxation training. Features of balance reactions targeted by the perturbation-based program were: (1) multi-step reactions, (2) extra lateral steps following anteroposterior perturbations, (3) foot collisions following lateral perturbations, and (4) time to complete grasping reactions. The reactions were evoked during testing by highly unpredictable surface translation and cable pull perturbations, both of which differed from the perturbations used during training. /b> Compared with the control program, the perturbation-based training led to greater reductions in frequency of multi-step reactions and foot collisions that were statistically significant for surface translations but not cable pulls. The perturbation group also showed significantly greater reduction in handrail contact time compared with the control group for cable pulls and a possible trend in this direction for surface translations. Further work is needed to determine whether a maintenance program is needed to retain the training benefits and to assess whether these benefits reduce fall risk in daily life. Perturbation-based training

  1. Sudden cardiac death in athletes and its preventive strategies: review article

    Directory of Open Access Journals (Sweden)

    Farzin Halabchi

    2017-12-01

    Full Text Available Sudden cardiac death in sport, although rare, but is a tragic event, attracting the media and public attention. Sport and exercise may act as a trigger for sudden cardiac death. Risk of sudden death in young athletes with cardiovascular disease is 2.5 times more frequent than non-athlete individuals. More than 90% of cases of sudden death occur during or immediately after training or competition. Incidence of sudden cardiac death in any population, including athletes, is related to multiple factors such as gender, age, race, nationality, diagnostic screening methods and preventive measures for sudden cardiac death. Otherwise, incidence rate of sudden cardiac death is linked to the used definition and method of diagnosis. Different cardiovascular disorders may result in death of young athletes and hypertrophic cardiomyopathy, congenital coronary anomalies, arrhythmogenic right ventricular dysplasia and aortic rupture are among the most common causes. Marfan syndrome, dilated cardiomyopathy, viral myocarditis, Wolff-Parkinson-White (WPW syndrome, congenital long QT syndrome, Brugada syndrome and commotio cordis are reported as other etiologies. In older athletes (more than 35 years, ischemic coronary heart disease is responsible for majority of the cases similar to the general population. Because the outcome of sudden cardiac arrest in sports is very poor except in few cases, proper national strategies are needed to diminish the burden of sudden death in young athletes. It seems that there are two main strategies to achieve this goal: A Primary prevention with use of purposeful pre-participation evaluation programs. This evaluation should focuss on the proper history and physical examination. Nevertheless, there is significant debate between American and European countries regarding the use of paraclinical investigations (especially ECG. American heart association does not recommend ECG as an essential part of evaluation. In contrast, European

  2. Investigating Insight as Sudden Learning

    Science.gov (United States)

    Ash, Ivan K.; Jee, Benjamin D.; Wiley, Jennifer

    2012-01-01

    Gestalt psychologists proposed two distinct learning mechanisms. Associative learning occurs gradually through the repeated co-occurrence of external stimuli or memories. Insight learning occurs suddenly when people discover new relationships within their prior knowledge as a result of reasoning or problem solving processes that re-organize or…

  3. Boundary perturbations coupled to core 3/2 tearing modes on the DIII-D tokamak

    International Nuclear Information System (INIS)

    Tobias, B; Yu, L; Domier, C W; Luhmann, N C Jr; Austin, M E; Paz-Soldan, C; Turnbull, A D; Classen, I G J

    2013-01-01

    High confinement (H-mode) discharges on the DIII-D tokamak are routinely subject to the formation of long-lived, non-disruptive magnetic islands that degrade confinement and limit fusion performance. Simultaneous, 2D measurement of electron temperature fluctuations in the core and edge regions allows for reconstruction of the radially resolved poloidal mode number spectrum and phase of the global plasma response associated with these modes. Coherent, n = 2 excursions of the plasma boundary are found to be the result of coupling to an n = 2, kink-like mode which arises locked in phase to the 3/2 island chain. This coupling dictates the relative phase of the displacement at the boundary with respect to the tearing mode. This unambiguous phase relationship, for which no counter-examples are observed, is presented as a test for modeling of the perturbed fields to be expected outside the confined plasma. (paper)

  4. Population-based studies of antithyroid drugs and sudden cardiac death

    NARCIS (Netherlands)

    C. van Noord (Charlotte); M.C.J.M. Sturkenboom (Miriam); S.M.J.M. Straus (Sabine); A. Hofman (Albert); J.C.M. Witteman (Jacqueline); B.H.Ch. Stricker (Bruno)

    2009-01-01

    textabstractWHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Thyroid hormone free T4 is associated with QTc-interval prolongation, which is a risk factor for sudden cardiac death. • The association between hyperthyroidism and ventricular arrhythmias or sudden cardiac death has been reported in several

  5. Sudden cardiac death in children (1-18 years)

    DEFF Research Database (Denmark)

    Winkel, Bo Gregers; Risgaard, Bjarke; Sadjadieh, Golnaz

    2014-01-01

    AIMS: Hitherto, sudden cardiac death in children (SCDc)-defined as sudden cardiac death (SCD) in the 1-18 years old-has been incompletely described in the general population. Knowledge on incidence rates, causes of death and symptoms prior to death is sparse and has been affected by reporting...... and referral bias. METHODS AND RESULTS: In a nationwide setting all deaths in children aged 1-18 years in Denmark in 2000-06 were included. To chart causes of death and incidence rates, death certificates and autopsy reports were collected and read. By additional use of the extensive healthcare registries...... in Denmark, we were also able to investigate prior disease and symptoms. During the 7-year study period there was an average of 1.11 million persons aged 1-18 years. There were a total of 1504 deaths (214 deaths per year) from 7.78 million person-years. A total of 114 (7.5%) were sudden and unexpected...

  6. Imaging spectrum of sudden athlete cardiac death

    Energy Technology Data Exchange (ETDEWEB)

    Arrigan, M.T., E-mail: martinarrigan@gmail.co [Department of Radiology, Adelaide and Meath Hospital incorporating the National Children' s Hospital, Dublin (Ireland); Killeen, R.P. [Department of Radiology, Adelaide and Meath Hospital incorporating the National Children' s Hospital, Dublin (Ireland); Dodd, J.D. [Department of Radiology, St Vincent' s University Hospital, Dublin (Ireland); Torreggiani, W.C. [Department of Radiology, Adelaide and Meath Hospital incorporating the National Children' s Hospital, Dublin (Ireland)

    2011-03-15

    Sudden athlete death (SAD) is a widely publicized and increasingly reported phenomenon. For many, the athlete population epitomize human physical endeavour and achievement and their unexpected death comes with a significant emotional impact on the public. Sudden deaths within this group are often without prior warning. Preceding symptoms of exertional syncope and chest pain do, however, occur and warrant investigation. Similarly, a positive family history of sudden death in a young person or a known family history of a condition associated with SAD necessitates further tests. Screening programmes aimed at detecting those at risk individuals also exist with the aim of reducing fatalities. In this paper we review the topic of SAD and discuss the epidemiology, aetiology, and clinical presentations. We then proceed to discuss each underlying cause, in turn discussing the pathophysiology of each condition. This is followed by a discussion of useful imaging methods with an emphasis on cardiac magnetic resonance and cardiac computed tomography and how these address the various issues raised by the pathophysiology of each entity. We conclude by proposing imaging algorithms for the investigation of patients considered at risk for these conditions and discuss the various issues raised in screening.

  7. Imaging spectrum of sudden athlete cardiac death

    International Nuclear Information System (INIS)

    Arrigan, M.T.; Killeen, R.P.; Dodd, J.D.; Torreggiani, W.C.

    2011-01-01

    Sudden athlete death (SAD) is a widely publicized and increasingly reported phenomenon. For many, the athlete population epitomize human physical endeavour and achievement and their unexpected death comes with a significant emotional impact on the public. Sudden deaths within this group are often without prior warning. Preceding symptoms of exertional syncope and chest pain do, however, occur and warrant investigation. Similarly, a positive family history of sudden death in a young person or a known family history of a condition associated with SAD necessitates further tests. Screening programmes aimed at detecting those at risk individuals also exist with the aim of reducing fatalities. In this paper we review the topic of SAD and discuss the epidemiology, aetiology, and clinical presentations. We then proceed to discuss each underlying cause, in turn discussing the pathophysiology of each condition. This is followed by a discussion of useful imaging methods with an emphasis on cardiac magnetic resonance and cardiac computed tomography and how these address the various issues raised by the pathophysiology of each entity. We conclude by proposing imaging algorithms for the investigation of patients considered at risk for these conditions and discuss the various issues raised in screening.

  8. Imaging spectrum of sudden athlete cardiac death.

    LENUS (Irish Health Repository)

    Arrigan, M T

    2012-02-01

    Sudden athlete death (SAD) is a widely publicized and increasingly reported phenomenon. For many, the athlete population epitomize human physical endeavour and achievement and their unexpected death comes with a significant emotional impact on the public. Sudden deaths within this group are often without prior warning. Preceding symptoms of exertional syncope and chest pain do, however, occur and warrant investigation. Similarly, a positive family history of sudden death in a young person or a known family history of a condition associated with SAD necessitates further tests. Screening programmes aimed at detecting those at risk individuals also exist with the aim of reducing fatalities. In this paper we review the topic of SAD and discuss the epidemiology, aetiology, and clinical presentations. We then proceed to discuss each underlying cause, in turn discussing the pathophysiology of each condition. This is followed by a discussion of useful imaging methods with an emphasis on cardiac magnetic resonance and cardiac computed tomography and how these address the various issues raised by the pathophysiology of each entity. We conclude by proposing imaging algorithms for the investigation of patients considered at risk for these conditions and discuss the various issues raised in screening.

  9. Sudden Sensorineural Hearing Loss; Prognostic Factors

    Directory of Open Access Journals (Sweden)

    Arjun Dass

    2015-09-01

    Full Text Available Introduction: Sudden sensorineural hearing loss (SSNHL is a frightening and frustrating symptom for the patient as well as the physician. Prognosis is affected by multiple factors including duration of hearing loss, presence of associated vertigo and tinnitus, and co-morbidities such as hypertension and diabetes.   Materials and Methods: Forty subjects presenting to our department with features of sudden hearing loss were included in the study. Detailed otological history and examination, serial audiometric findings and course of disease were studied.   Results: Subjects presenting late (in older age, having associated vertigo, hypertension and diabetes had a significantly lower rate of recovery.   Conclusion:  Only 60–65% of patients experiencing SSNHL recover within a period of 1 month; this rate is further affected by presence of multiple prognostic indicators.

  10. Lattice topology dictates photon statistics.

    Science.gov (United States)

    Kondakci, H Esat; Abouraddy, Ayman F; Saleh, Bahaa E A

    2017-08-21

    Propagation of coherent light through a disordered network is accompanied by randomization and possible conversion into thermal light. Here, we show that network topology plays a decisive role in determining the statistics of the emerging field if the underlying lattice is endowed with chiral symmetry. In such lattices, eigenmode pairs come in skew-symmetric pairs with oppositely signed eigenvalues. By examining one-dimensional arrays of randomly coupled waveguides arranged on linear and ring topologies, we are led to a remarkable prediction: the field circularity and the photon statistics in ring lattices are dictated by its parity while the same quantities are insensitive to the parity of a linear lattice. For a ring lattice, adding or subtracting a single lattice site can switch the photon statistics from super-thermal to sub-thermal, or vice versa. This behavior is understood by examining the real and imaginary fields on a lattice exhibiting chiral symmetry, which form two strands that interleave along the lattice sites. These strands can be fully braided around an even-sited ring lattice thereby producing super-thermal photon statistics, while an odd-sited lattice is incommensurate with such an arrangement and the statistics become sub-thermal.

  11. Perturbed effects at radiation physics

    International Nuclear Information System (INIS)

    Külahcı, Fatih; Şen, Zekâi

    2013-01-01

    Perturbation methodology is applied in order to assess the linear attenuation coefficient, mass attenuation coefficient and cross-section behavior with random components in the basic variables such as the radiation amounts frequently used in the radiation physics and chemistry. Additionally, layer attenuation coefficient (LAC) and perturbed LAC (PLAC) are proposed for different contact materials. Perturbation methodology provides opportunity to obtain results with random deviations from the average behavior of each variable that enters the whole mathematical expression. The basic photon intensity variation expression as the inverse exponential power law (as Beer–Lambert's law) is adopted for perturbation method exposition. Perturbed results are presented not only in terms of the mean but additionally the standard deviation and the correlation coefficients. Such perturbation expressions provide one to assess small random variability in basic variables. - Highlights: • Perturbation methodology is applied to Radiation Physics. • Layer attenuation coefficient (LAC) and perturbed LAC are proposed for contact materials. • Perturbed linear attenuation coefficient is proposed. • Perturbed mass attenuation coefficient (PMAC) is proposed. • Perturbed cross-section is proposed

  12. Genetic testing to predict sudden cardiac death: current perspectives and future goals

    Directory of Open Access Journals (Sweden)

    Silvia G. Priori

    2014-01-01

    Full Text Available It is known that monogenic traits may predispose young and otherwise healthy individuals to die suddenly. Diseases such as Long QT Syndrome, Brugada Syndrome and Arrhythmogenic Right Ventricular Cardiomyopathy are well known causes of arrhythmic death in young individuals. For several years the concept of “genetic predisposition” to sudden cardiac death has been limited to these uncommon diseases. In the last few years clinical data have supported the view that risk of dying suddenly may cluster in families, supporting the hypothesis of a genetic component for sudden cardiac death. In this review I will try to provide an overview of current knowledge about genetics of sudden death. I will approach this topic by discussing first where we stand in the use of genetics for risk stratification and therapy selection in monogenic diseases and I will then move to discuss the contribution of genetics to patient profiling in acquired cardiovascular diseases.

  13. Perturbative anyon gas

    International Nuclear Information System (INIS)

    Dasnieres de Veigy, A.; Ouvry, S.; Paris-6 Univ., 75

    1992-06-01

    The problem of the statistical mechanics of an anyon gas is addressed. A perturbative analysis in the anyonic coupling constant α is reviewed, and the thermodynamical potential is computed at first and second order. An adequate second quantized formalism (field theory at finite temperature) is proposed. At first order in perturbation theory, the results are strikingly simple: only the second virial coefficient close to bosonic statistics is corrected. At second order, however, the complexity of the anyon model appears. One can compute exactly the perturbative correction to each cluster coefficient. However, and contrary to first order, a closed expression for the equation of state seems out of reach. As an illustration, the perturbative expressions of a 3 , a 4 , a 5 and a 6 are given at second order. Finally, using the same formalism, the equation of state of an anyon gas in a constant magnetic field is analyzed at first order in perturbation theory. (K.A.) 16 refs.; 3 figs.; 7 tabs

  14. Perturbation theory

    International Nuclear Information System (INIS)

    Bartlett, R.; Kirtman, B.; Davidson, E.R.

    1978-01-01

    After noting some advantages of using perturbation theory some of the various types are related on a chart and described, including many-body nonlinear summations, quartic force-field fit for geometry, fourth-order correlation approximations, and a survey of some recent work. Alternative initial approximations in perturbation theory are also discussed. 25 references

  15. Post-mortem toxicology in young sudden cardiac death victims

    DEFF Research Database (Denmark)

    Bjune, Thea; Risgaard, Bjarke; Kruckow, Line

    2017-01-01

    Aims: Several drugs increase the risk of ventricular fibrillation and sudden cardiac death (SCD). We aimed to investigate in detail the toxicological findings of all young SCD throughout Denmark. Methods and results: Deaths in persons aged 1-49 years were included over a 10-year period. Death...... certificates and autopsy reports were retrieved and read to identify cases of sudden death and establish cause of death. All medico-legal autopsied SCD were included and toxicological reports collected. Positive toxicology was defined as the presence of any substance (licit and/or illicit). All toxicological...... findings had previously been evaluated not to have caused the death (i.e. lethal concentrations were excluded). We identified 620 medico-legal autopsied cases of SCD, of which 77% (n = 477) were toxicologically investigated post-mortem, and 57% (n = 270) had a positive toxicology profile. Sudden cardiac...

  16. Sudden unexpected death from natural diseases: Fifteen years' experience with 484 cases in Seychelles.

    Science.gov (United States)

    Zhao, Peng; Wang, Ji-Gang; Gao, Peng; Li, Xia; Brewer, Rubell

    2016-01-01

    The aim of this study is to identify and subclassify sudden natural death (sudden death from natural diseases) cases in Seychelles. A total of 484 sudden natural death cases with autopsy at the Clinical Pathology Laboratory, Victoria Hospital, Seychelles between 1997 through 2012 were retrospectively reviewed. Among them, 363 cases (75%) were male and 121 (25%) were female. The most frequent sudden deaths were attributed to cardiovascular diseases (78.5%), and then followed by infectious diseases (9.9%), and gastrointestinal diseases (9.1%). This is the largest population-based study on sudden natural deaths in Seychelles. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  17. Sudden Death: An Uncommon Occurrence in Dementia with Lewy Bodies.

    Science.gov (United States)

    Molenaar, Joery P; Wilbers, Joyce; Aerts, Marjolein B; Leijten, Quinten H; van Dijk, Jan G; Esselink, Rianne A; Bloem, Bastiaan R

    2016-01-01

    We present a 75-year-old woman with dementia and parkinsonism who developed severe orthostatic hypotension and eventually died. Autopsy revealed extensive Lewy body formation in the midbrain, limbic system, intermediate spinal cord, and medulla oblongata. Furthermore, a vast amount of Lewy bodies was seen in the paravertebral sympathetic ganglia which likely explained the severe autonomic failure. We speculate that this autonomic failure caused sudden death through dysregulation of respiration or heart rhythm, reminiscent of sudden death in multiple system atrophy (MSA). Clinicians should be aware of this complication in patients presenting with parkinsonism and autonomic dysfunction, and that sudden death may occur in dementia with Lewy bodies (DLB) as it does in MSA.

  18. Writing to dictation and handwriting performance among Chinese children with dyslexia: relationships with orthographic knowledge and perceptual-motor skills.

    Science.gov (United States)

    Cheng-Lai, Alice; Li-Tsang, Cecilia W P; Chan, Alan H L; Lo, Amy G W

    2013-10-01

    The purpose of this study was to investigate the relationships between writing to dictation, handwriting, orthographic, and perceptual-motor skills among Chinese children with dyslexia. A cross-sectional design was used. A total of 45 third graders with dyslexia were assessed. Results of stepwise multiple regression models showed that Chinese character naming was the only predictor associated with word dictation (β=.32); handwriting speed was related to deficits in rapid automatic naming (β=-.36) and saccadic efficiency (β=-.29), and visual-motor integration predicted both of the number of characters exceeded grid (β=-.41) and variability of character size (β=-.38). The findings provided support to a multi-stage working memory model of writing for explaining the possible underlying mechanism of writing to dictation and handwriting difficulties. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Observation of thermal quench induced by runaway electrons in magnetic perturbation

    Science.gov (United States)

    Cheon, MunSeong; Seo, Dongcheol; Kim, Junghee

    2018-04-01

    Experimental observations in Korea Superconducting Tokamak Advanced Research (KSTAR) plasmas show that a loss of pre-disruptive runaway electrons can induce a rapid radiative cooling of the plasma, by generating impurity clouds from the first wall. The synchrotron radiation image shows that the loss of runaway electrons occurs from the edge region when the resonant magnetic perturbation is applied on the plasma. When the impact of the runaway electrons on the wall is strong enough, a sudden drop of the electron cyclotron emission (ECE) signal occurs with the characteristic plasma behaviors such as the positive spike and following decay of the plasma current, Dα spike, big magnetic fluctuation, etc. The visible images at this runaway loss show an evidence of the generation of impurity cloud and the following radiative cooling. When the runaway beam is located on the plasma edge, thermal quenches are expected to occur without global destruction of the magnetic structure up to the core.

  20. What Behaviors are Disapproved? Experimental Evidence from Five Dictator Games

    Directory of Open Access Journals (Sweden)

    Marc Vorsatz

    2012-04-01

    Full Text Available The literature on social norms has often stressed that social disapproval is crucial to foster compliance with norms and promote fair and cooperative behavior. With this in mind, we explore the disapproval of allocation decisions using experimental data from five dictator games with a feedback stage. Our data suggests that subjects are heterogeneous in their disapproval patterns, distinguishing two main groups: (1 Subjects who only disapprove choices that harm them, and (2 subjects who disapprove socially inefficient choices.

  1. Developments in perturbation theory

    International Nuclear Information System (INIS)

    Greenspan, E.

    1976-01-01

    Included are sections dealing with perturbation expressions for reactivity, methods for the calculation of perturbed fluxes, integral transport theory formulations for reactivity, generalized perturbation theory, sensitivity and optimization studies, multigroup calculations of bilinear functionals, and solution of inhomogeneous Boltzmann equations with singular operators

  2. Allowing for Reflection Time does not Change Behavior in Dictator and Cheating Games

    DEFF Research Database (Denmark)

    Andersen, Steffen; Gneezy, Uri; Kajackaite, Agne

    2018-01-01

    Reaction time, usually measured in seconds, has been shown to be correlated with decisions in experimental games. In this paper, we study how allowing for a full day of “reflection time” alters behavior. We compare behavior in dictator and cheating games when participants make immediate choices...

  3. PerturbationAnalyzer: a tool for investigating the effects of concentration perturbation on protein interaction networks.

    Science.gov (United States)

    Li, Fei; Li, Peng; Xu, Wenjian; Peng, Yuxing; Bo, Xiaochen; Wang, Shengqi

    2010-01-15

    The propagation of perturbations in protein concentration through a protein interaction network (PIN) can shed light on network dynamics and function. In order to facilitate this type of study, PerturbationAnalyzer, which is an open source plugin for Cytoscape, has been developed. PerturbationAnalyzer can be used in manual mode for simulating user-defined perturbations, as well as in batch mode for evaluating network robustness and identifying significant proteins that cause large propagation effects in the PINs when their concentrations are perturbed. Results from PerturbationAnalyzer can be represented in an intuitive and customizable way and can also be exported for further exploration. PerturbationAnalyzer has great potential in mining the design principles of protein networks, and may be a useful tool for identifying drug targets. PerturbationAnalyzer can be accessed from the Cytoscape web site http://www.cytoscape.org/plugins/index.php or http://biotech.bmi.ac.cn/PerturbationAnalyzer. Supplementary data are available at Bioinformatics online.

  4. Mutations in calmodulin cause ventricular tachycardia and sudden cardiac death

    DEFF Research Database (Denmark)

    Nyegaard, Mette; Overgaard, Michael Toft; Sondergaard, M.T.

    2012-01-01

    a substantial part of sudden cardiac deaths in young individuals. Mutations in RYR2, encoding the cardiac sarcoplasmic calcium channel, have been identified as causative in approximately half of all dominantly inherited CPVT cases. Applying a genome-wide linkage analysis in a large Swedish family with a severe......Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a devastating inherited disorder characterized by episodic syncope and/or sudden cardiac arrest during exercise or acute emotion in individuals without structural cardiac abnormalities. Although rare, CPVT is suspected to cause...... calmodulin-binding-domain peptide at low calcium concentrations. We conclude that calmodulin mutations can cause severe cardiac arrhythmia and that the calmodulin genes are candidates for genetic screening of individual cases and families with idiopathic ventricular tachycardia and unexplained sudden cardiac...

  5. Sudden entanglement death, and ways to avoid it

    International Nuclear Information System (INIS)

    Eberly, J.H.; Ting Yu

    2005-01-01

    We report that non-communicating but entangled qubit pairs are almost universally liable to sudden entanglement death. In the presence of minor and purely local environmental noises their mixed-state entanglement may abruptly become zero long before the noises are able to destroy the local qubit coherence. Despite the inability of unitary transformations to alter entanglement, for example of Werner states, unitary transformations have been found to delay or defeat the sudden death event. These results upset the conventional understanding that entanglement lifetime can be estimated from qubit lifetime. This is not even approximately or qualitatively true. (author)

  6. Classification of sudden and arrhythmic death

    DEFF Research Database (Denmark)

    Torp-Pedersen, C; Køber, L; Elming, H

    1997-01-01

    was nearly abolished by the implantable defibrillator, indicating that arrhythmic death by this classification is meaningful, at least in the population studied. For future investigations, a call is made for committees to present data in a way that allows the reader to examine the quality of the data used......Since all death is (eventually) sudden and associated with cardiac arrhythmias, the concept of sudden death is only meaningful if it is unexpected, while arrhythmic death is only meaningful if life could have continued had the arrhythmia been prevented or treated. Current classifications of death...... or autopsy) are available in only a few percent of cases. A main problem in using classifications is the lack of validation data. This situation has, with the MADIT trial, changed in the case of the Thaler and Hinkle classification of arrhythmic death. The MADIT trial demonstrated that arrhythmic death...

  7. Sudden unexpected death in children with a previously diagnosed cardiovascular disorder

    NARCIS (Netherlands)

    Polderman, Florens N.; Cohen, Joeri; Blom, Nico A.; Delhaas, Tammo; Helbing, Wim A.; Lam, Jan; Sobotka-Plojhar, Marta A.; Temmerman, Arno M.; Sreeram, Narayanswani

    2004-01-01

    BACKGROUND: It is known that children with previously diagnosed heart defects die suddenly. The causes of death are often unknown. OBJECTIVE: The aim of the study was to identify all infants and children within the Netherlands with previously diagnosed heart disease who had a sudden unexpected death

  8. Sudden unexpected death in children with a previously diagnosed cardiovascular disorder

    NARCIS (Netherlands)

    Polderman, F.N.; Cohen, Joeri; Blom, N.A.; Delhaas, T.; Helbing, W.A.; Lam, J.; Sobotka-Plojhar, M.A.; Temmerman, Arno M.; Sreeram, N.

    2004-01-01

    Background: It is known that children with previously diagnosed heart defects die suddenly. The causes of death are often unknown. Objective: The aim of the study was to identify all infants and children within the Netherlands with previously diagnosed heart disease who had a sudden unexpected death

  9. Sudden oak death and Phytophthora ramorum: a summary of the literature

    Science.gov (United States)

    John T. Kliejunas

    2010-01-01

    Sudden oak death and Phytophthora ramorum, both first recognized about a decade ago, have been the subject of hundreds of scientific and popular press articles. This document presents a comprehensive, concise summary of sudden oak death and P. ramorum research findings and management activities. Topics covered include...

  10. The molecular autopsy: an indispensable step following sudden cardiac death in the young?

    Science.gov (United States)

    Boczek, Nicole J.; Tester, David J.; Ackerman, Michael J.

    2013-01-01

    Annually thousands of sudden deaths involving young individuals (autopsy. In fact, epidemiological studies have estimated that over half of sudden deaths involving previously healthy young individuals have no morphological abnormalities identifiable at autopsy. Cardiac channelopathies associated with structurally normal hearts such as long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), and Brugada syndrome (BrS), leave no evidence to be found at autopsy, leaving investigators to only speculate that a lethal arrhythmia might lie at the heart of a sudden unexplained death (SUD). In cases of autopsy-negative SUD, continued investigation, through the use of a cardiological and genetic evaluation of first- or second-degree relatives and/or a molecular autopsy, may pinpoint the underlying mechanism attributing to the sudden death and allow for the identification of living family members with the pathogenic substrate that renders them vulnerable to an increased risk for cardiac events, including sudden death. PMID:22993115

  11. Difference scheme for a singularly perturbed parabolic convection-diffusion equation in the presence of perturbations

    Science.gov (United States)

    Shishkin, G. I.

    2015-11-01

    An initial-boundary value problem is considered for a singularly perturbed parabolic convection-diffusion equation with a perturbation parameter ɛ (ɛ ∈ (0, 1]) multiplying the highest order derivative. The stability of a standard difference scheme based on monotone approximations of the problem on a uniform mesh is analyzed, and the behavior of discrete solutions in the presence of perturbations is examined. The scheme does not converge ɛ-uniformly in the maximum norm as the number of its grid nodes is increased. When the solution of the difference scheme converges, which occurs if N -1 ≪ ɛ and N -1 0 ≪ 1, where N and N 0 are the numbers of grid intervals in x and t, respectively, the scheme is not ɛ-uniformly well conditioned or stable to data perturbations in the grid problem and to computer perturbations. For the standard difference scheme in the presence of data perturbations in the grid problem and/or computer perturbations, conditions on the "parameters" of the difference scheme and of the computer (namely, on ɛ, N, N 0, admissible data perturbations in the grid problem, and admissible computer perturbations) are obtained that ensure the convergence of the perturbed solutions. Additionally, the conditions are obtained under which the perturbed numerical solution has the same order of convergence as the solution of the unperturbed standard difference scheme.

  12. Non-Perturbative Asymptotic Improvement of Perturbation Theory and Mellin-Barnes Representation

    Directory of Open Access Journals (Sweden)

    Samuel Friot

    2010-10-01

    Full Text Available Using a method mixing Mellin-Barnes representation and Borel resummation we show how to obtain hyperasymptotic expansions from the (divergent formal power series which follow from the perturbative evaluation of arbitrary ''N-point'' functions for the simple case of zero-dimensional φ4 field theory. This hyperasymptotic improvement appears from an iterative procedure, based on inverse factorial expansions, and gives birth to interwoven non-perturbative partial sums whose coefficients are related to the perturbative ones by an interesting resurgence phenomenon. It is a non-perturbative improvement in the sense that, for some optimal truncations of the partial sums, the remainder at a given hyperasymptotic level is exponentially suppressed compared to the remainder at the preceding hyperasymptotic level. The Mellin-Barnes representation allows our results to be automatically valid for a wide range of the phase of the complex coupling constant, including Stokes lines. A numerical analysis is performed to emphasize the improved accuracy that this method allows to reach compared to the usual perturbative approach, and the importance of hyperasymptotic optimal truncation schemes.

  13. Does aging with a cortical lesion increase fall-risk: Examining effect of age versus stroke on intensity modulation of reactive balance responses from slip-like perturbations.

    Science.gov (United States)

    Patel, Prakruti J; Bhatt, Tanvi

    2016-10-01

    We examined whether aging with and without a cerebral lesion such as stroke affects modulation of reactive balance response for recovery from increasing intensity of sudden slip-like stance perturbations. Ten young adults, older age-match adults and older chronic stroke survivors were exposed to three different levels of slip-like perturbations, level 1 (7.75m/s(2)), Level II (12.00m/s(2)) and level III (16.75m/s(2)) in stance. The center of mass (COM) state stability was computed as the shortest distance of the instantaneous COM position and velocity relative to base of support (BOS) from a theoretical threshold for backward loss of balance (BLOB). The COM position (XCOM/BOS) and velocity (ẊCOM/BOS) relative to BOS at compensatory step touchdown, compensatory step length and trunk angle at touchdown were also recorded. At liftoff, stability reduced with increasing perturbation intensity across all groups (main effect of intensity pbalance control, potentially contributing toward a higher fall risk in older stroke survivors. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  14. Developing Students' Listening Metacognitive Strategies Using Online Videotext Self-Dictation-Generation Learning Activity

    Science.gov (United States)

    Chang, Ching; Chang, Chih-Kai

    2014-01-01

    The study is based on the use of a flexible learning framework to help students improve information processes underlying strategy instruction in EFL listening. By exploiting the online videotext self-dictation-generation (video-SDG) learning activity implemented on the YouTube caption manager platform, the learning cycle was emphasized to promote…

  15. Sudden infant death syndrome, childhood thrombosis, and presence of genetic risk factors for thrombosis

    DEFF Research Database (Denmark)

    Larsen, TB; Nørgaard-Pedersen, B; Lundemose, JB

    2000-01-01

    in the child. This prompted us to investigate these genetic markers of thromboembolic disease in 121 cases of sudden infant death syndrome and in relevant controls, in the expectation of a more frequent occurrence of these markers if thrombosis is an etiological factor in sudden infant death syndrome...... or unknown risk factors for thrombosis as possible etiological factors for sudden infant death syndrome. It is likely that we must continuously employ the exclusion principle on possible etiological causes in genetic material from a large group of victims of sudden infant death syndrome if the phenomenon...

  16. Sudden death due to inhalant abuse in youth: Case report

    Directory of Open Access Journals (Sweden)

    Ramazan Akcan

    2010-06-01

    Full Text Available Intentional inhalation or abuse of volatile substances is a common public health problem all over the world. As these substances generate euphoria frequency of use among adolescents and young adults is increasing steadily. In cases using inhalants to achieve a euphoric state -without knowing possible consequences- sudden death may occurdue to acute cardio-pulmonary dysfunction.Here we present a case of sudden death of a nineteen-year-old female due to inhalation of volatile from butane containing lighter gas tube, with the findings of autopsy and death scene investigation.In the context of this case; it was aimed to draw attention to the risk of sudden death and steady increase of frequencyof volatile substance abuse among adolescents and young adults due to various psycho-social factors.

  17. Initial conditions and entanglement sudden death

    International Nuclear Information System (INIS)

    Qian, Xiao-Feng; Eberly, J.H.

    2012-01-01

    We report results bearing on the behavior of non-local decoherence and its potential for being managed or even controlled. The decoherence process known as entanglement sudden death (ESD) can drive prepared entanglement to zero at the same time that local coherences and fidelity remain non-zero. For a generic ESD-susceptible Bell superposition state, we provide rules restricting the occurrence and timing of ESD, amounting to management tools over a continuous variation of initial conditions. These depend on only three parameters: initial purity, entanglement and excitation. Knowledge or control of initial phases is not needed. -- Highlights: ► We study the possibility of managing disentanglement through initial conditions. ► The initial parameters are the amount of entanglement, excitation, and purity. ► Entanglement sudden death (ESD) free and ESD susceptible phases are identified. ► ESD onset time is also presented in the ESD susceptible phase. ► Our results may guide experiments to prepare ESD free or delayed ESD states.

  18. How sudden is a compelling desire to void? An observational cystometric study on the suddenness of this sensation.

    Science.gov (United States)

    De Wachter, Stefan; Wyndaele, Jean-Jacques

    2008-04-01

    To evaluate whether a compelling desire to void (CDV) is always perceived suddenly, or whether it can result from the gradual build-up of bladder-filling sensations. The pattern of filling sensations was evaluated during standard cystometric bladder filling in 75 patients who complained of urgency and showed detrusor overactivity during cystometry. Cystometric filling ended when a CDV was reported. The 'warning volume' is defined as the difference in volume between the first perception of filling and the volume at CDV. Different patterns of bladder-filling sensations were reported. A CDV occurred suddenly, without a preceding sensation in 13% of the patients, whereas 66% reported at least two normal preceding filling sensations before a CDV. The bladder volume at the CDV was significantly smaller in patients that reported no or just one preceding sensation compared with those that reported the normal pattern of two or three sensations (P perception was reported was not different regardless of whether it was described as a first sensation of filling, a first desire or a CDV (P = 0.42). The warning volumes were not different between patients with one or no standardized filling sensations (P = 0.7), but they were significantly smaller than in patients with two or three filling sensations (P = 0.85). A CDV can occur suddenly if normal filling sensation is disturbed, but also gradually if normal filling sensation is preserved. In cases of disturbed filling sensation, the volume at CDV and the warning volume are significantly lower.

  19. Anonymity versus privacy in the dictator game: revealing donor decisions to recipients does not substantially impact donor behavior.

    Directory of Open Access Journals (Sweden)

    Jeffrey Winking

    Full Text Available Anonymity is often offered in economic experiments in order to eliminate observer effects and induce behavior that would be exhibited under private circumstances. However, anonymity differs from privacy in that interactants are only unaware of each others' identities, while having full knowledge of each others' actions. Such situations are rare outside the laboratory and anonymity might not meet the requirements of some participants to psychologically engage as if their actions were private. In order to explore the impact of a lack of privacy on prosocial behaviors, I expand on a study reported in Dana et al. (2006 in which recipients were left unaware of the Dictator Game and given donations as "bonuses" to their show-up fees for other tasks. In the current study, I explore whether differences between a private Dictator Game (sensu Dana et al. (2006 and a standard anonymous one are due to a desire by dictators to avoid shame or to pursue prestige. Participants of a Dictator Game were randomly assigned to one of four categories-one in which the recipient knew of (1 any donation by an anonymous donor (including zero donations, (2 nothing at all, (3 only zero donations, and (4 and only non-zero donations. The results suggest that a lack of privacy increases the shame that selfish-acting participants experience, but that removing such a cost has only minimal effects on actual behavior.

  20. Relationship between sudden natural death and abdominal fat evaluated on postmortem CT scans.

    Science.gov (United States)

    Kaichi, Y; Sakane, H; Higashibori, H; Honda, Y; Tatsugami, F; Baba, Y; Iida, M; Awai, K

    2017-06-01

    This study examined the association between sudden natural death and abdominal fat using postmortem computed tomography (CT) scans. Postmortem CT images at the umbilical level of 241 subjects were used to measure abdominal areas of subcutaneous- and visceral fat, the rate of visceral fat and the waist circumference. Of the study subjects, 174 died of sudden natural death (130 men and 44 women), and 67 died of different causes (46 men and 21 women). All were between 40 and 75 years of age. Logistic regression analysis was performed to identify independent abdominal parameters associated with sudden natural death. By univariate analysis, the areas of subcutaneous and visceral fat were significantly larger in sudden natural death than who died of different causes (subcutaneous fat, odds ratio [OR] = 1.004, 95% confidence interval [CI] = 1.000-1.007, p  = 0.03; visceral fat, OR = 1.008, 95% CI = 1.003-1.013, p  fat was an independent factor associated with the risk of sudden natural death (OR = 1.008, 95% CI = 1.002-1.015, p  = 0.02). Postmortem CT revealed that sudden natural death was related to abdominal fat deposits.

  1. The Effect of the Tuning System and Instrument Variables on Modal Dictation Performance

    Science.gov (United States)

    Demirbatir, Rasim Erol; Çeliktas, Hatice; Engür, Doruk

    2018-01-01

    Ear training and musical literacy (ETML) education is one of the main dimensions of the bachelor degree program of music teacher education departments, which provides professional music education. In ETML education, hearing, sight-reading and dictation studies for Turkish music makams have an important place. In this study, it was aimed to…

  2. An Experimental Study on Flow Boiling Critical Heat Flux Characteristics of Suddenly Expanded Region

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Jin; Song, Sub Lee; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Moon, Sang Ki [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this experiment, test section has been designed to simulate sudden flow path change due to deformation of cladding. It was tended to simulate cladding deformation that has discontinuous diameter change so coolant flow path changes suddenly. Experiments are in progress. Experiments on test section that simulate deformed flow path which contains sudden contraction and sudden expansion part have been done. Location of CHF has been varied by different condition of experiment. CHF at the outlet of test section fits well into the Macbeth's correlation and data of reference experiment, which was held on plain test section that had same diameter with inlet diameter of deformed test section. CHF at sudden expansion part was in churn flow regime and CHF was very low compared to expectation. It is discussed that liquid film separation from wall or bubble accumulation by backflow might be the reason of this result. For future work, experiments for two additional blockage ratio conditions will be carried out. Also, discussion and model development for deformed channel with sudden expand flow path will be held on.

  3. Stationary axially symmetric perturbations of a rotating black hole. [Space-time perturbation, Newman-Penrose formalism

    Energy Technology Data Exchange (ETDEWEB)

    Demianski, M [California Inst. of Tech., Pasadena (USA)

    1976-07-01

    A stationary axially symmetric perturbation of a rotating black hole due to a distribution of test matter is investigated. The Newman-Penrose spin coefficient formalism is used to derive a general set of equations describing the perturbed space-time. In a linear approximation it is shown that the mass and angular momentum of a rotating black hole is not affected by the perturbation. The metric perturbations near the horizon are given. It is concluded that given a perturbing test fluid distribution, one can always find a corresponding metric perturbation such that the mass and angular momentum of the black hole are not changed. It was also noticed that when a tends to M, those perturbed spin coefficients and components of the Weyl tensor which determine the intrinsic properties of the incoming null cone near the horizon grow indefinitely.

  4. Definition of Sudden Infant Death and Sudden Intrauterine Unexpected Death Syndromes (SIDS and SIUDS with Regard to the Anatomo-Pathological Examination

    Directory of Open Access Journals (Sweden)

    Giulia Ottaviani

    2016-09-01

    Full Text Available Crib death, or sudden infant death syndrome (SIDS, is the most frequent form of death in the first year of life, striking one baby in every 1,700–2,000. Yet despite advances in maternal-infant care, sudden intrauterine unexplained/unexpected death syndrome (SIUDS, has a six-eightfold greater incidence than that of SIDS. Frequent congenital abnormalities, likely morphological substrates for SIDS-SIUDS, were detected, mainly represented by alterations of the cardiac conduction system, such as accessory pathways and abnormal resorptive degeneration, and hypoplasia/agenesis of the vital brainstem structures. On the basis of these considerations, the new common definition of the SIDS-SIUDS complex is The sudden death of a fetus after the 25th gestational week or infant under one year of age which is unexpected by history and remains unexplained after a thorough case investigation, including examination of the death scene, performance of a general autopsy and examination of the fetal adnexa. Therefore, given that the general autopsy does not disclose any cause of death, a more in-depth histopathological analysis of the cardiac conduction system and autonomic nervous system by specialized pathologists will become necessary.

  5. Sudden death amongst people practicing competitive sports (Review Article

    Directory of Open Access Journals (Sweden)

    Bartłomiej Wrzesiński

    2018-02-01

    Full Text Available Sudden cardiac death is and unexpected cardiac arrest that may occur both during exercise and also an hour after its completion. It most often occurs in young sportsmen under 35 years of age and is usually associated with improperly performed physical activity proceeded by lack of specialized medical examination and research. Natural and cardiac causes are two basic phenomena that lead to cardiac death. As confirmed by Framingham Heart Study, conducted in the eighties of the twentieth century on the population of Americans, natural causes accounted for 13% while cardiac causes accounted for 88% off all. The statistics of the largest centers of sport medicine are presented as follows: Germany – 1 death per 200,000 people practicing sports (total while United States of America – 1 death per 80,000 people per year. The problem of of sudden deaths is and important topic worthy of a broader and more specific analysis. It should be noted that physical exertion is not is not a direct cause of sudden deaths. Currently the most research concerns professional athletes who have extensive support and knowledge about the exercise they perform. The main problem concerning subject of sudden deaths are not diagnosed hearth defects. Additional topic of interest is rarity of medical tests performed by amateur athletes and athletes at the lower levels of competition. Such athletes do not  have as extensive knowledge as their experienced idols, which may bring tragic consequences.

  6. Steroid Treatments Equally Effective Against Sudden Deafness

    Science.gov (United States)

    ... NIGMS NIMH NIMHD NINDS NINR NLM CC CIT CSR FIC NCATS NCCIH OD About NIH Who We ... with sudden deafness should discuss the risks and benefits of both treatments with their doctor.” Related Links ...

  7. Laryngeal dystonia gravidarum: sudden onset of adductor spasmodic dysphonia in pregnancy.

    Science.gov (United States)

    Ankola, Ashish; Sulica, Lucian; Murry, Thomas

    2013-12-01

    The purpose of this study was to identify the presence or absence of known factors related to onset of adductor spasmodic dysphonia (ADSD) in a population with sudden onset during or after pregnancy. Retrospective review. A review of 350 patient records identified five patients with sudden onset of ADSD related to pregnancy. An age-matched group with sudden onset of ADSD not related to pregnancy served as controls. All subjects completed a 20-question survey of risk factors relevant to ADSD. The average age of onset in both groups was 31 years. Three had onset of ADSD in the postpartum period, the other two during pregnancy. Significantly increased avocational voice use was found in the pregnant group compared to the control group. There was a significant difference in the two groups regarding cumulative risk factors traditionally associated with ADSD. Sudden onset of ADSD can occur in pregnancy in women with clinical profiles that differ from traditional ADSD patients. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

  8. Bilateral sudden sensorineural hearing loss as a first symptom of infective endocarditis: two case reports.

    Science.gov (United States)

    Chroni, M; Prappa, E; Kokkevi, I

    2018-04-01

    Septic emboli are an unusual cause of sudden sensorineural hearing loss, for which few reports exist in the literature. This paper presents two cases of sudden sensorineural hearing loss, initially considered as idiopathic, but which were caused by septic emboli. Hearing loss in these cases was bilateral, sequential and total. The first patient had mild fever one week prior to their presentation with sudden sensorineural hearing loss; the other patient had no additional symptoms at presentation. These patients were later diagnosed with infective endocarditis, at two and seven months following the sudden sensorineural hearing loss respectively, showing that septic emboli had been the cause of sudden sensorineural hearing loss. Septic emboli should be considered as a possible cause of sudden sensorineural hearing loss in cases of total hearing loss. This form of hearing loss should prompt the otolaryngologist to further investigate for infective endocarditis.

  9. Impact of Sudden Stratospheric Warming of 2009 on the Equatorial and Low-Latitude Ionosphere of the Indian Longitudes: A Case Study

    Science.gov (United States)

    Yadav, Sneha; Pant, Tarun K.; Choudhary, R. K.; Vineeth, C.; Sunda, Surendra; Kumar, K. K.; Shreedevi, P. R.; Mukherjee, S.

    2017-10-01

    Using the equatorial electrojet (EEJ)-induced surface magnetic field and total electron content (TEC) measurements, we investigated the impact of the sudden stratospheric warming (SSW) of January 2009 on the equatorial electrodynamics and low-latitude ionosphere over the Indian longitudes. Results indicate that the intensity of EEJ and the TEC over low latitudes (extending up to 30°N) exhibit significant perturbations during and after the SSW peak. One of the interesting features is the deviation of EEJ and TEC from the normal quiet time behavior well before the onset of the SSW. This is found to coincide with the beginning of enhanced planetary wave (PW) activity over high latitudes. The substantial amplification of the semidiurnal perturbation after the SSW peak is seen to be coinciding with the onset of new and full moons. The response of TEC to SSW is found to be latitude dependent as the near-equatorial (NE) stations show the semidiurnal perturbation only after the SSW peak. Another notable feature is the presence of reduced ionization in the night sector over the NE and low-latitude regions, appearing as an "ionization hole," well after the SSW peak. The investigation revealed the existence of a quasi 16 day wave in the TEC over low latitudes similar to the one present in the EEJ strength. These results have been discussed in the light of changes in the dynamical background because of enhanced PW activity during SSW, which creates favorable conditions for the amplification of lunar tides, and their subsequent interaction with the lower thermospheric tidal fields.

  10. Sudden death in young persons with uncontrolled asthma--a nationwide cohort study in Denmark

    DEFF Research Database (Denmark)

    Gullach, Anders Juul; Risgaard, Bjarke; Lynge, Thomas Hadberg

    2015-01-01

    BACKGROUND: Asthma is a common chronic disease among young adults, and several studies have reported increased mortality rates in patients with asthma. However, no study has described sudden unexpected death in a nationwide setting in patients with uncontrolled asthma. We defined uncontrolled...... in preventing sudden unexpected deaths. We therefore aimed to describe clinical characteristics, symptoms, causes of death, and contact with the healthcare system prior to sudden unexpected death in young persons with uncontrolled asthma. METHODS: Through the review of death certificates, we found 625 sudden...... individuals who suffered from uncontrolled asthma. This corresponds to an incidence rate of 0.32 per 100,000 person-years. The cause of death in 31 cases (63%) was sudden cardiac death, and in 13 cases (27%), it was a fatal asthma attack. Symptoms (chest pain, dyspnea, seizures, general malaise, syncope...

  11. The Metabolic Syndrome and Risk of Sudden Cardiac Death: The Atherosclerosis Risk in Communities Study.

    Science.gov (United States)

    Hess, Paul L; Al-Khalidi, Hussein R; Friedman, Daniel J; Mulder, Hillary; Kucharska-Newton, Anna; Rosamond, Wayne R; Lopes, Renato D; Gersh, Bernard J; Mark, Daniel B; Curtis, Lesley H; Post, Wendy S; Prineas, Ronald J; Sotoodehnia, Nona; Al-Khatib, Sana M

    2017-08-23

    Prior studies have demonstrated a link between the metabolic syndrome and increased risk of cardiovascular mortality. Whether the metabolic syndrome is associated with sudden cardiac death is uncertain. We characterized the relationship between sudden cardiac death and metabolic syndrome status among participants of the ARIC (Atherosclerosis Risk in Communities) Study (1987-2012) free of prevalent coronary heart disease or heart failure. Among 13 168 participants, 357 (2.7%) sudden cardiac deaths occurred during a median follow-up of 23.6 years. Participants with the metabolic syndrome (n=4444) had a higher cumulative incidence of sudden cardiac death than those without it (n=8724) (4.1% versus 2.3%, P metabolic syndrome, the metabolic syndrome was independently associated with sudden cardiac death (hazard ratio, 1.70, 95% confidence interval, 1.37-2.12, P metabolic syndrome criteria components. The risk of sudden cardiac death varied according to the number of metabolic syndrome components (hazard ratio 1.31 per additional component of the metabolic syndrome, 95% confidence interval, 1.19-1.44, P metabolic syndrome was associated with a significantly increased risk of sudden cardiac death irrespective of sex or race. The risk of sudden cardiac death was proportional to the number of metabolic syndrome components. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  12. Investigation of neutrophil-to-lymphocyte ratio and mean platelet volume in sudden hearing loss,

    Directory of Open Access Journals (Sweden)

    Rauf Oguzhan Kum

    2015-12-01

    Full Text Available ABSTRACT INTRODUCTION: Several theories attempt to explain the pathophysiology of sudden hearing loss. OBJECTIVE: The objective of this study was to investigate the possible role of inflammation and atherothrombosis in sudden hearing loss patients through the neutrophil-to-lymphocyte ratio and mean platelet volume. METHODS: Study design - retrospective cross-sectional historical cohort. This study was conducted on two groups: one with 59 individuals diagnosed with sudden hearing loss, and other with 59 healthy individuals with the same characteristics of gender and age distribution, neutrophil-to-lymphocyte ratio and mean platelet volume levels were measured in patients diagnosed with sudden hearing loss as well as in the control group, and it was verified whether these results interfered for a better or worse prognosis with treatment of sudden deafness. RESULTS: Neutrophil-to-lymphocyte ratio levels are much higher in patients diagnosed with sudden hearing loss compared to the control group. Similarly, mean levels of neutrophil-to-lymphocyte ratio are higher in non-recovered versus recovered patients (p = 0.001. However, we could not find a correlation with mean platelet volume levels (p > 0.05. CONCLUSION: Neutrophil-to-lymphocyte ratio is a quick and reliable indicator regarding diagnosis and prognosis of sudden hearing loss; on the other hand, mean platelet volume may be considered a less important indicator in this aspect.

  13. Cardiac symptoms before sudden cardiac death caused by coronary artery disease

    DEFF Research Database (Denmark)

    Jabbari, Reza; Risgaard, Bjarke; Holst, Anders G

    2013-01-01

    The aim of this nationwide case-control study was to identify and characterise symptoms before sudden death of young persons who had died due to coronary artery disease (CAD).......The aim of this nationwide case-control study was to identify and characterise symptoms before sudden death of young persons who had died due to coronary artery disease (CAD)....

  14. A peptide extension dictates IgM assembly.

    Science.gov (United States)

    Pasalic, Dzana; Weber, Benedikt; Giannone, Chiara; Anelli, Tiziana; Müller, Roger; Fagioli, Claudio; Felkl, Manuel; John, Christine; Mossuto, Maria Francesca; Becker, Christian F W; Sitia, Roberto; Buchner, Johannes

    2017-10-10

    Professional secretory cells can produce large amounts of high-quality complex molecules, including IgM antibodies. Owing to their multivalency, polymeric IgM antibodies provide an efficient first-line of defense against pathogens. To decipher the mechanisms of IgM assembly, we investigated its biosynthesis in living cells and faithfully reconstituted the underlying processes in vitro. We find that a conserved peptide extension at the C-terminal end of the IgM heavy (Ig-μ) chains, termed the tailpiece, is necessary and sufficient to establish the correct geometry. Alanine scanning revealed that hydrophobic amino acids in the first half of the tailpiece contain essential information for generating the correct topology. Assembly is triggered by the formation of a disulfide bond linking two tailpieces. This induces conformational changes in the tailpiece and the adjacent domain, which drive further polymerization. Thus, the biogenesis of large and topologically challenging IgM complexes is dictated by a local conformational switch in a peptide extension.

  15. Numerical Investigation of Pressure Losses in Axisymmetric Sudden Expansion with a Chamfer

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Youngmin; Kim, Youngin; Kim, Keung Koo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this paper, the pressure losses through axisymmetric sudden expansions with a chamfer are analyzed by means of numerical simulation, with an emphasis on the effect of the Reynolds number. In this study, we investigate numerically the turbulent flow in axisymmetric sudden expansions having a slight chamfer on the edge. With the aim of investigating the impact of Reynolds number on the expansion losses in a time-averaged sense, an extensive set of simulations is carried out. On the basis of numerical results, we also propose a general correlation to estimate the local loss coefficient in sudden expansions with a chamfer.

  16. Numerical Investigation of Pressure Losses in Axisymmetric Sudden Expansion with a Chamfer

    International Nuclear Information System (INIS)

    Bae, Youngmin; Kim, Youngin; Kim, Keung Koo

    2014-01-01

    In this paper, the pressure losses through axisymmetric sudden expansions with a chamfer are analyzed by means of numerical simulation, with an emphasis on the effect of the Reynolds number. In this study, we investigate numerically the turbulent flow in axisymmetric sudden expansions having a slight chamfer on the edge. With the aim of investigating the impact of Reynolds number on the expansion losses in a time-averaged sense, an extensive set of simulations is carried out. On the basis of numerical results, we also propose a general correlation to estimate the local loss coefficient in sudden expansions with a chamfer

  17. F-MARC: promoting the prevention and management of sudden cardiac arrest in football.

    Science.gov (United States)

    Kramer, Efraim Benjamin; Dvorak, J; Schmied, C; Meyer, T

    2015-05-01

    Sudden cardiac death is the most common cause of unnatural death in football. To prevent and urgently manage sudden cardiac arrest on the football field-of-play, F-MARC (FIFA Medical and Research Centre) has been fully committed to a programme of research, education, standardisation and practical implementation. This strategy has detected football players at medical risk during mandatory precompetition medical assessments. Additionally, FIFA has (1) sponsored internationally accepted guidelines for the interpretation of an athlete's ECG, (2) developed field-of-play-specific protocols for the recognition, response, resuscitation and removal of a football player having sudden cardiac arrest and (3) introduced and distributed the FIFA medical emergency bag which has already resulted in the successful resuscitation of a football player who had a sudden cardiac arrest on the field-of-play. Recently FIFA, in association with the Institute of Sports and Preventive Medicine in Saarbrücken, Germany, established a worldwide Sudden Death Registry with a view to documenting fatal events on the football field-of-play. These activities by F-MARC are testimony to FIFA's continued commitment to minimising sudden cardiac arrest while playing football. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  18. Sudden infant death syndrome, childhood thrombosis, and presence of genetic risk factors for thrombosis

    DEFF Research Database (Denmark)

    Larsen, T B; Nørgaard-Pedersen, B; Banner, Jytte

    2000-01-01

    in the child. This prompted us to investigate these genetic markers of thromboembolic disease in 121 cases of sudden infant death syndrome and in relevant controls, in the expectation of a more frequent occurrence of these markers if thrombosis is an etiological factor in sudden infant death syndrome......Sudden infant death syndrome or "cot death" has until the late eighties been a significant cause of death in children between the ages of 1 month and 1 year. Approximately two per 1000 children born alive dies of sudden infant death syndrome each year in Western Europe, North America, and Australia....... The vulnerability of the infant brain stem to ischemia has been suggested to be a conceivable cause of sudden infant death syndrome. This is compatible with a hypothesis that genetic risk factors for cerebral thrombosis could cause microinfarction in the brain stem during the first month of life, affecting vital...

  19. Perturbative and constructive renormalization

    International Nuclear Information System (INIS)

    Veiga, P.A. Faria da

    2000-01-01

    These notes are a survey of the material treated in a series of lectures delivered at the X Summer School Jorge Andre Swieca. They are concerned with renormalization in Quantum Field Theories. At the level of perturbation series, we review classical results as Feynman graphs, ultraviolet and infrared divergences of Feynman integrals. Weinberg's theorem and Hepp's theorem, the renormalization group and the Callan-Symanzik equation, the large order behavior and the divergence of most perturbation series. Out of the perturbative regime, as an example of a constructive method, we review Borel summability and point out how it is possible to circumvent the perturbation diseases. These lectures are a preparation for the joint course given by professor V. Rivasseau at the same school, where more sophisticated non-perturbative analytical methods based on rigorous renormalization group techniques are presented, aiming at furthering our understanding about the subject and bringing field theoretical models to a satisfactory mathematical level. (author)

  20. When Ignorance is Bliss - Information Asymmetries Enhance Prosocial Behavior in Dictator Games

    OpenAIRE

    Evguenia Winschel; Philipp Zahn

    2014-01-01

    In most laboratory experiments concerning prosocial behavior subjects are fully informed how their decision influences the payoff of other players. Outside the laboratory, however, individuals typically have to decide without such detailed knowledge. To assess the effect of information asymmetries on prosocial behavior, we conduct a laboratory experiment with a simple non-strategic interaction. A dictator has only limited knowledge about the benefits his prosocial action generates for a recip...

  1. Sudden unexplained death in childhood. An audit of the quality of Autopsy reporting

    LENUS (Irish Health Repository)

    Treacy, A

    2013-03-01

    Cases of sudden unexplained death in childhood (SUDC) in Ireland in children aged >1year and <5 years were examined in order to assess the quality of autopsy reporting. All SUDC cases are notified to and documented by the National Sudden Infant Death Register (NSIDR) in Ireland along with all cases of sudden infant death syndrome (SIDS) referring to sudden infant deaths less than one year of age. The database of the NSIDR in Ireland was interrogated and cases of SIDS and SUDC were compared over a fifteen-year period (1995-2009). SIDS cases whose autopsies were conducted in the same hospital in the same year as the index SUDC case were used for comparison. The autopsy report for each case was examined and modified Rushton(MR) scores 1\\r\

  2. The most common cause of sudden cardiac death in athletes

    Directory of Open Access Journals (Sweden)

    Topalović Nikola

    2016-01-01

    Full Text Available The positive impact of exercise on cardiovascular health is well known. Athletes, who are constantly physically active, are considered to be the healthiest members of our society. That is why their sudden death, during the training or competition, attracts the attention of the general public. Rarely, tragic events of sudden cardiac death (SCD are the reason for questioning if by many positive there are also negative impact of physical exercise. The first case of SCD is recorded as far back as the year 490 BC, when the Greek soldier Pheidippides died after he conveyed news of the great victory of the Greeks over the Persians. Risk of SCD is recognized in the middle of the twentieth century. In our region, discussion about this issue began after the World Basketball Championship, which was held in Ljubljana in 1970, because of the sudden death of the national team member Trajko Rajkovic. One of the important goals of modern sports medicine is to reduce the risk of SCD in athletes to 'inevitable rarity'. Definition of SCD is considered to be any unexpected death due to sudden cardiac arrest. Pedo (Pedoe has divided all causes of SCD in the sport into three categories: Commotio cordis (agitation of the heart, which results from blunt impact to the athletes chest with consequent fatal disorder of heart rhythm; SCD of athletes under the age of 35 because of structural, congenital and inflammatory heart disease, which includes hypertrophic cardiomyopathy as the most important cause of sudden cardiac death, congenital anomalies of the coronary arteries, arrhythmogenic right ventricular cardiomyopathy, myocarditis and other; SCD of athletes older than 35 years which is most common due coronary artery disease - atherosclerosis (the dominant risk in the marathon and half-marathon. .

  3. A 23-year review of sudden natural death autopsies in the Niger ...

    African Journals Online (AJOL)

    Background: Death occurring suddenly especially when the victim was active and recently fit, call for attention and thorough investigation to rule out secret homicide. Aim: To study the pattern of sudden natural death in the Niger Delta region of Nigeria. Methodology: The coroner's autopsy reports and hospital autopsy ...

  4. Sudden death in the first 2 years of life following immunization in the Republic of Korea.

    Science.gov (United States)

    Choe, Young June; Kim, Jong-Hee; Son, Hyun Jin; Bae, Geun-Ryang; Lee, Duk-hyoung

    2012-12-01

    Because the peak age for incidence of sudden deaths in infancy temporally coincides with the age of infant primary immunization, some have raised the question as to whether immunization is a risk factor for sudden death in infancy. Recent occurrence of two sudden deaths in infants in Korea has renewed concerns about the causal association between immunization and sudden deaths in infants. We carried out a retrospective review of data from the Korea Centers for Disease Control and Prevention Adverse Events Following Immunization Surveillance System and Vaccine Compensation programs. From 1994 to 2011, a total of 45 cases of sudden deaths in the first 2 years of life following immunization were reported in Korea. The causes of death were classified as follows: infectious diseases (n= 13); accidental injuries (n= 7); congenital abnormalities (n= 2); and malignancy (n= 1). Of 20 sudden deaths in infancy, nine deaths met Brighton Collaboration case definition level I and II, and therefore were classified as possible sudden infant death syndrome cases. Hepatitis B vaccine (n= 13) was the most frequent vaccine with temporal association with sudden deaths in the first 2 years of life. Few sudden deaths in the first 2 years of life following immunization have been reported, despite the use of universal immunization in Korea. The majority of deaths in infancy did not meet case definition for sudden infant death syndrome. Encouraging investigators to perform thorough investigation, including postmortem autopsy and death scene examination, may promote data comparability and provide guidance on decision-making in the vaccine-safety monitoring and response system in Korea. © 2012 The Authors. Pediatrics International © 2012 Japan Pediatric Society.

  5. New Methods in Non-Perturbative QCD

    Energy Technology Data Exchange (ETDEWEB)

    Unsal, Mithat [North Carolina State Univ., Raleigh, NC (United States)

    2017-01-31

    In this work, we investigate the properties of quantum chromodynamics (QCD), by using newly developing mathematics and physics formalisms. Almost all of the mass in the visible universe emerges from a quantum chromodynamics (QCD), which has a completely negligible microscopic mass content. An intimately related issue in QCD is the quark confinement problem. Answers to non-perturbative questions in QCD remained largely elusive despite much effort over the years. It is also believed that the usual perturbation theory is inadequate to address these kinds of problems. Perturbation theory gives a divergent asymptotic series (even when the theory is properly renormalized), and there are non-perturbative phenomena which never appear at any order in perturbation theory. Recently, a fascinating bridge between perturbation theory and non-perturbative effects has been found: a formalism called resurgence theory in mathematics tells us that perturbative data and non-perturbative data are intimately related. Translating this to the language of quantum field theory, it turns out that non-perturbative information is present in a coded form in perturbation theory and it can be decoded. We take advantage of this feature, which is particularly useful to understand some unresolved mysteries of QCD from first principles. In particular, we use: a) Circle compactifications which provide a semi-classical window to study confinement and mass gap problems, and calculable prototypes of the deconfinement phase transition; b) Resurgence theory and transseries which provide a unified framework for perturbative and non-perturbative expansion; c) Analytic continuation of path integrals and Lefschetz thimbles which may be useful to address sign problem in QCD at finite density.

  6. Genetic mutation in Korean patients of sudden cardiac arrest as a surrogating marker of idiopathic ventricular arrhythmia.

    Science.gov (United States)

    Son, Myoung Kyun; Ki, Chang-Seok; Park, Seung-Jung; Huh, June; Kim, June Soo; On, Young Keun

    2013-07-01

    Mutation or common intronic variants in cardiac ion channel genes have been suggested to be associated with sudden cardiac death caused by idiopathic ventricular tachyarrhythmia. This study aimed to find mutations in cardiac ion channel genes of Korean sudden cardiac arrest patients with structurally normal heart and to verify association between common genetic variation in cardiac ion channel and sudden cardiac arrest by idiopathic ventricular tachyarrhythmia in Koreans. Study participants were Korean survivors of sudden cardiac arrest caused by idiopathic ventricular tachycardia or fibrillation. All coding exons of the SCN5A, KCNQ1, and KCNH2 genes were analyzed by Sanger sequencing. Fifteen survivors of sudden cardiac arrest were included. Three male patients had mutations in SCN5A gene and none in KCNQ1 and KCNH2 genes. Intronic variant (rs2283222) in KCNQ1 gene showed significant association with sudden cardiac arrest (OR 4.05). Four male sudden cardiac arrest survivors had intronic variant (rs11720524) in SCN5A gene. None of female survivors of sudden cardiac arrest had SCN5A gene mutations despite similar frequencies of intronic variants between males and females in 55 normal controls. Common intronic variant in KCNQ1 gene is associated with sudden cardiac arrest caused by idiopathic ventricular tachyarrhythmia in Koreans.

  7. Spatial distribution of volcanic ash deposits of 2011 Puyehue-Cordón Caulle eruption in Patagonia as measured by a perturbation in NDVI temporal dynamics

    Science.gov (United States)

    Easdale, M. H.; Bruzzone, O.

    2018-03-01

    Volcanic ash fallout is a recurrent environmental disturbance in forests, arid and semi-arid rangelands of Patagonia, South America. The ash deposits over large areas are responsible for several impacts on ecological processes, agricultural production and health of local communities. Public policy decision making needs monitoring information of the affected areas by ash fallout, in order to better orient social, economic and productive aids. The aim of this study was to analyze the spatial distribution of volcanic ash deposits from the eruption of Puyehue-Cordón Caulle in 2011, by identifying a sudden change in the Normalized Difference Vegetation Index (NDVI) temporal dynamics, defined as a perturbation located in the time series. We applied a sparse-wavelet transform using the Basis Pursuit algorithm to NDVI time series obtained from the Moderate Resolution Image Spectroradiometer (MODIS) sensor, to identify perturbations at a pixel level. The spatial distribution of the perturbation promoted by ash deposits in Patagonia was successfully identified and characterized by means of a perturbation in NDVI temporal dynamics. Results are encouraging for the future development of a new platform, in combination with data from forecasting models and tracking of ash cloud trajectories and dispersion, to inform stakeholders to mitigate impact of volcanic ash on agricultural production and to orient public intervention strategies after a volcanic eruption followed by ash fallout over a wide region.

  8. Tympanotomy and sealing of the round window for treatment of sudden deafness

    DEFF Research Database (Denmark)

    Ul-Mulk, Jamshaid; Friis, Søren; Hahn, Christoffer Holst

    2011-01-01

    The objective of this study was to evaluate the effectiveness of explorative tympanotomy and sealing of the round window in patients diagnosed with sudden deafness.......The objective of this study was to evaluate the effectiveness of explorative tympanotomy and sealing of the round window in patients diagnosed with sudden deafness....

  9. Cosmological perturbation theory and quantum gravity

    Energy Technology Data Exchange (ETDEWEB)

    Brunetti, Romeo [Dipartimento di Matematica, Università di Trento,Via Sommarive 14, 38123 Povo TN (Italy); Fredenhagen, Klaus [II Institute für Theoretische Physik, Universität Hamburg,Luruper Chaussee 149, 22761 Hamburg (Germany); Hack, Thomas-Paul [Institute für Theoretische Physik, Universität Leipzig,Brüderstr. 16, 04103 Leipzig (Germany); Pinamonti, Nicola [Dipartimento di Matematica, Università di Genova,Via Dodecaneso 35, 16146 Genova (Italy); INFN, Sezione di Genova,Via Dodecaneso 33, 16146 Genova (Italy); Rejzner, Katarzyna [Department of Mathematics, University of York,Heslington, York YO10 5DD (United Kingdom)

    2016-08-04

    It is shown how cosmological perturbation theory arises from a fully quantized perturbative theory of quantum gravity. Central for the derivation is a non-perturbative concept of gauge-invariant local observables by means of which perturbative invariant expressions of arbitrary order are generated. In particular, in the linearised theory, first order gauge-invariant observables familiar from cosmological perturbation theory are recovered. Explicit expressions of second order quantities are presented as well.

  10. Systematic review of the incidence of sudden cardiac death in the United States.

    Science.gov (United States)

    Kong, Melissa H; Fonarow, Gregg C; Peterson, Eric D; Curtis, Anne B; Hernandez, Adrian F; Sanders, Gillian D; Thomas, Kevin L; Hayes, David L; Al-Khatib, Sana M

    2011-02-15

    The need for consistent and current data describing the true incidence of sudden cardiac arrest (SCA) and/or sudden cardiac death (SCD) was highlighted during the most recent Sudden Cardiac Arrest Thought Leadership Alliance's (SCATLA) Think Tank meeting of national experts with broad representation of key stakeholders, including thought leaders and representatives from the American College of Cardiology, American Heart Association, and the Heart Rhythm Society. As such, to evaluate the true magnitude of this public health problem, we performed a systematic literature search in MEDLINE using the MeSH headings, "death, sudden" OR the terms "sudden cardiac death" OR "sudden cardiac arrest" OR "cardiac arrest" OR "cardiac death" OR "sudden death" OR "arrhythmic death." Study selection criteria included peer-reviewed publications of primary data used to estimate SCD incidence in the U.S. We used Web of Science's Cited Reference Search to evaluate the impact of each primary estimate on the medical literature by determining the number of times each "primary source" has been cited. The estimated U.S. annual incidence of SCD varied widely from 180,000 to >450,000 among 6 included studies. These different estimates were in part due to different data sources (with data age ranging from 1980 to 2007), definitions of SCD, case ascertainment criteria, methods of estimation/extrapolation, and sources of case ascertainment. The true incidence of SCA and/or SCD in the U.S. remains unclear, with a wide range in the available estimates that are badly dated. As reliable estimates of SCD incidence are important for improving risk stratification and prevention, future efforts are clearly needed to establish uniform definitions of SCA and SCD and then to prospectively and precisely capture cases of SCA and SCD in the overall U.S. population. Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  11. Sudden Oak Death - Eastern (Pest Alert)

    Science.gov (United States)

    Joseph O' Brien; Manfred Mielke; Steve Oak; Bruce Moltzan

    2002-01-01

    A phenomenon known as Sudden Oak Death was first reported in 1995 in central coastal California. Since then, tens of thousands of tanoaks (Lithocarpus densiflorus), coast live oaks (Quercus agrifolia), and California black oaks (Quercus kelloggii) have been killed by a newly identified fungus, Phytophthora ramorum. On these hosts, the fungus causes a bleeding canker on...

  12. Nationwide survey of rotavirus-associated encephalopathy and sudden unexpected death in Japan.

    Science.gov (United States)

    Kawamura, Yoshiki; Ohashi, Masahiro; Ihira, Masaru; Hashimoto, Shuji; Taniguchi, Koki; Yoshikawa, Tetsushi

    2014-08-01

    Rotavirus can cause severe complications such as encephalopathy/encephalitis and sudden unexpected death. The incidence of rotavirus-associated encephalopathy/encephalitis or sudden unexpected death remains unknown. To clarify the clinical features of rotavirus-associated encephalitis/encephalopathy and sudden unexpected death, we conducted a nationwide survey in Japan. A two-part questionnaire was designed to determine the number of the cases and the clinical features of severe cases of rotavirus infection, including encephalitis/encephalopathy and sudden unexpected death, between 2009 and 2011. Of the 1365 questionnaires sent to hospitals, 963 (70.5%) were returned and eligible for analysis. We determined 58 cases of rotavirus-associated encephalitis/encephalopathy and 7 cases of sudden unexpected death. These patients were diagnosed with rotavirus infection by immunochromatography. Although 36/58 (62.1%) encephalitis/encephalopathy patients had no sequelae, 15/58 (25.9%) patients had neurological sequelae, and 7/58 (12.1%) patients had fatal outcomes. Pleocytosis was observed in 9/40 (22.5%) patients and cerebrospinal fluid protein levels were elevated in only 4/40 (10%) patients. Elevated lactate dehydrogenase (LDH) (>500 IU/L) or acidemia (pHdeath were 44.0 and 4.9 cases in Japan, respectively. Elevated LDH (>500 IU/L) or acidemia (pH<7.15) were related to a poor prognosis of the encephalitis/encephalopathy. Copyright © 2013 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  13. Is there an association between depression and cardiovascular mortality or sudden death?

    Science.gov (United States)

    Alboni, Paolo; Favaron, Elisa; Paparella, Nelly; Sciammarella, Massimo; Pedaci, Mario

    2008-04-01

    The results of many studies and recent meta-analyses strongly suggest that depression is a risk factor for total and cardiovascular mortality, both in the general population and in patients with known heart disease. By contrast, the association between depression and sudden death or cardiac arrest has received little attention. This issue has been investigated in three recent studies; two were carried out in the general population and showed depression to be a independent risk factor for sudden death. The other study was carried out in patients with acute myocardial infarction (AMI); the adjusted relative risk (RR) of sudden death was significantly increased in depressed patients but, after adjustment for dyspnea/fatigue (a common symptom for heart disease and depression), the RR was no longer statistically significant. However, when the cognitive-affective depressive symptoms were examined separately from the somatic ones (dyspnea/fatigue, etc.), there was a clear trend for an association between cognitive-affective symptoms and sudden death. Because a risk factor can be defined as 'independent' only in a multivariate analysis in which variables are dichotomized, the presence of common symptoms between heart disease and depression represents a very difficult problem. However, taken together, the results of studies carried out in the general population and in patients with AMI strongly suggest that depression is a significant risk factor for sudden death.

  14. Timing of muscle response to a sudden leg perturbation: comparison between adolescents and adults with Down syndrome.

    Directory of Open Access Journals (Sweden)

    Maria Stella Valle

    Full Text Available Movement disturbances associated with Down syndrome reduce mechanical stability, worsening the execution of important tasks such as walking and upright standing. To compensate these deficits, persons with Down syndrome increase joint stability modulating the level of activation of single muscles or producing an agonist-antagonist co-activation. Such activations are also observed when a relaxed, extended leg is suddenly released and left to oscillate passively under the influence of gravity (Wartenberg test. In this case, the Rectus femoris of adults with Down syndrome displayed peaks of activation after the onset of the first leg flexion. With the aim to verify if these muscular reactions were acquired during the development time and to find evidences useful to give them a functional explanation, we used the Wartenberg test to compare the knee joint kinematics and the surface electromyography of the Rectus femoris and Biceps femoris caput longus between adolescents and adults with Down syndrome. During the first leg flexion, adolescents and adults showed single Rectus femoris activations while, a restricted number of participants exhibited agonist-antagonist co-activations. However, regardless the pattern of activation, adults initiated the muscle activity significantly later than adolescents. Although most of the mechanical parameters and the total movement variability were similar in the two groups, the onset of the Rectus femoris activation was well correlated with the time of the minimum acceleration variability. Thus, in adolescents the maximum mechanical stability occurred short after the onset of the leg fall, while adults reached their best joint stability late during the first flexion. These results suggest that between the adolescence and adulthood, persons with Down syndrome explore a temporal window to select an appropriate timing of muscle activation to overcome their inherent mechanical instability.

  15. Sudden viscous dissipation in compressing plasma turbulence

    Science.gov (United States)

    Davidovits, Seth; Fisch, Nathaniel

    2015-11-01

    Compression of a turbulent plasma or fluid can cause amplification of the turbulent kinetic energy, if the compression is fast compared to the turnover and viscous dissipation times of the turbulent eddies. The consideration of compressing turbulent flows in inviscid fluids has been motivated by the suggestion that amplification of turbulent kinetic energy occurred on experiments at the Weizmann Institute of Science Z-Pinch. We demonstrate a sudden viscous dissipation mechanism whereby this amplified turbulent kinetic energy is rapidly converted into thermal energy, which further increases the temperature, feeding back to further enhance the dissipation. Application of this mechanism in compression experiments may be advantageous, if the plasma can be kept comparatively cold during much of the compression, reducing radiation and conduction losses, until the plasma suddenly becomes hot. This work was supported by DOE through contract 67350-9960 (Prime # DOE DE-NA0001836) and by the DTRA.

  16. Perturbations i have Known and Loved

    Science.gov (United States)

    Field, Robert W.

    2011-06-01

    A spectroscopic perturbation is a disruption of a ^1Σ-^1Σ-like regular pattern that can embody level-shifts, extra lines, and intensity anomalies. Once upon a time, when a band was labeled ``perturbed,'' it was considered worthless because it could at best yield molecular constants unsuited for archival tables. Nevertheless, a few brave spectroscopists, notably Albin Lagerqvist and Richard Barrow, collected perturbations because they knew that the pattern of multiple perturbations formed an intricate puzzle that would eventually reveal the presence and electronic symmetry of otherwise unobservable electronic states. There are many kinds of patterns of broken patterns. In my PhD thesis I showed how to determine absolute vibrational assignments for the perturber from patterns among the observed values of perturbation matrix elements. When a ^3Π state is perturbed, its six (Ω, parity) components capture a pattern of level shifts and intensity anomalies that reveals more about the nature of the perturber than a simple perturbation of the single component of a ^1Σ state. In perturbation-facilitated OODR, a perturbed singlet level acts as a spectroscopic doorway through which the entire triplet manifold may be systematically explored. For polyatomic molecule vibrations, a vibrational polyad (a group of mutually perturbing vibrational levels, among which the perturbation matrix elements are expected to follow harmonic oscillator scaling rules) can contain more components than a ^3Π state and intrapolyad patterns can be exquisitely sensitive not merely to the nature of an interloper within the polyad but also to the eigenvector character of the vibronic state from which the polyad is viewed. Variation of scaled polyad interaction parameters from one polyad to the next, a pattern of patterns, can signal proximity to an isomerization barrier. Everything in Rydberg-land seems to scale as N⋆-3, yet a trespassing valence state causes all scaling and propensity rules go

  17. How far is it to a sudden future singularity of pressure?

    International Nuclear Information System (INIS)

    DaPbrowski, Mariusz P.; Denkiewicz, Tomasz; Hendry, Martin A.

    2007-01-01

    We discuss the constraints coming from current observations of type Ia supernovae on cosmological models which allow sudden future singularities of pressure (with the scale factor and the energy density regular). We show that such a sudden singularity may happen in the very near future (e.g. within 10x10 6 years) and its prediction at the present moment of cosmic evolution cannot be distinguished, with current observational data, from the prediction given by the standard quintessence scenario of future evolution. Fortunately, sudden future singularities are characterized by a momentary peak of infinite tidal forces only; there is no geodesic incompleteness, which means that the evolution of the universe may eventually be continued throughout until another 'more serious' singularity such as a big crunch or big rip

  18. Sudden unexpected death due to Graves' disease during physical altercation.

    Science.gov (United States)

    Wei, Dengming; Yuan, Xiaogang; Yang, Tiantong; Chang, Lin; Zhang, Xiang; Burke, Allen; Fowler, David; Li, Ling

    2013-09-01

    We report a case of a 30-year-old woman who suddenly collapsed after having a physical altercation with her husband. Despite immediate resuscitation, she died on arrival at the hospital. The victim's parents requested an autopsy because they believed that their daughter was killed by her husband. Postmortem examination revealed that the victim had a diffusely enlarged thyroid gland and cardiomegaly with left ventricular hypertrophy. There was no evidence of significant trauma on the body. Further postmortem thyroid function tests and review of her medical history indicated that her death was due to Graves' disease. To the best of our knowledge, this is the first case reported of sudden death due to cardiac arrhythmia from Graves' disease induced by physical and emotional stress associated with the criminal activity of another person. The autopsy findings are described. In addition, the literature is reviewed and the significance of postmortem evaluation of thyroid hormones in the cases of sudden death is discussed. © 2013 American Academy of Forensic Sciences.

  19. Cardiac Channelopathies and Sudden Death: Recent Clinical and Genetic Advances.

    Science.gov (United States)

    Fernández-Falgueras, Anna; Sarquella-Brugada, Georgia; Brugada, Josep; Brugada, Ramon; Campuzano, Oscar

    2017-01-29

    Sudden cardiac death poses a unique challenge to clinicians because it may be the only symptom of an inherited heart condition. Indeed, inherited heart diseases can cause sudden cardiac death in older and younger individuals. Two groups of familial diseases are responsible for sudden cardiac death: cardiomyopathies (mainly hypertrophic cardiomyopathy, dilated cardiomyopathy, and arrhythmogenic cardiomyopathy) and channelopathies (mainly long QT syndrome, Brugada syndrome, short QT syndrome, and catecholaminergic polymorphic ventricular tachycardia). This review focuses on cardiac channelopathies, which are characterized by lethal arrhythmias in the structurally normal heart, incomplete penetrance, and variable expressivity. Arrhythmias in these diseases result from pathogenic variants in genes encoding cardiac ion channels or associated proteins. Due to a lack of gross structural changes in the heart, channelopathies are often considered as potential causes of death in otherwise unexplained forensic autopsies. The asymptomatic nature of channelopathies is cause for concern in family members who may be carrying genetic risk factors, making the identification of these genetic factors of significant clinical importance.

  20. [Sudden death from hypoglycemia].

    Science.gov (United States)

    Asmundo, A; Aragona, M; Gualniera, P; Aragona, F

    1995-12-01

    The sudden death by hypoglycemia is an aspect of the forensic pathology frequently neglected. Authors initially described the pathogenesis of different hypoglycemia forms, distinguishing the primary ones due to hyperinsulinism and the secondary ones due to functional insufficiency of other organs (hypophysis, thyroid, adrenal gland, liver); after that Authors described three cases of sudden death induced hypoglycemia by hyperinsulinism: two were unweaned with nesidioblastosis and one adolescent. In any form of hypoglycemia the central nervous system damage is present with evident neuronal degenerative-necrotic phenomena, widespread edema with microhemorrhage, swollen and dissociation of myelin sheath, glial cells hyperplasia. Death caused by primary hypoglycemia is histopathologically different from the secondary one because of the maintenance of hepatic glycogen content in the former, that increase in striated muscles, including the heart, in spite of the constant secretion of catecholamine from the adrenal medulla. Glycogen is depleted in secondary hypoglycemia. In the primary form, behind the adrenal medulla hyperfunction, the increased functional activity of the adrenal cortex is moderate, contrasting with the seriousness of the syndrome, due prevalently to inhibit the gluconeogenesis response conditioned by the persistence of stored glycogen in the liver, heart and striated muscles. The rare anoxic processes coming with resynthesis of hepatic glycogen have to be considered in the differential diagnosis. The primary hypoglycemic death, especially in unweaned, is frequently promoted by other processes inducing hypoxia (fetal asphyxia outcome, pneumonia, etc.) or worsening the hypoglycemia (hypothyroidism, etc.). The secondary hypoglycemias are characterized by the normality of exocrine pancreas and by organic alterations that cause glycogen depletion from the liver.

  1. Towards Better Understanding of the Pathogenesis of Neuronal Respiratory Network in Sudden Perinatal Death

    Directory of Open Access Journals (Sweden)

    Riffat Mehboob

    2017-07-01

    Full Text Available Sudden perinatal death that includes the victims of sudden infant death syndrome, sudden intrauterine death syndrome, and stillbirth are heartbreaking events in the life of parents. Most of the studies about sudden perinatal death were reported from Italy, highlighting two main etiological factors: prone sleeping position and smoking. Other probable contributory factors are prematurity, male gender, lack of breastfeeding, respiratory tract infections, use of pacifiers, infant botulism, extensive use of pesticides and insecticides, etc. However, extensive studies across the world are required to establish the role of these factors in a different subset of populations. Previous studies confirmed the widely accepted hypothesis that neuropathology of the brainstem is one of the main cause of sudden perinatal death. This study is an effort to summarize the neuropathological evaluation of the brainstems and their association to sudden perinatal death. Brainstem nuclei in vulnerable infants undergo certain changes that may alter the sleep arousal cycle, cardiorespiratory control, and ultimately culminate in death. This review focuses on the roles of different brainstem nuclei, their pathologies, and the established facts in this regard in terms of it’s link to such deaths. This study will also help to understand the role of brainstem nuclei in controlling the cardiorespiratory cycles in sudden perinatal death and may provide a better understanding to resolve the mystery of these deaths in future. It is also found that a global initiative to deal with perinatal death is required to facilitate the diagnosis and prevention in developed and as well as developing countries.

  2. Utility of Post-Mortem Genetic Testing in Cases of Sudden Arrhythmic Death Syndrome

    DEFF Research Database (Denmark)

    Lahrouchi, Najim; Raju, Hariharan; Lodder, Elisabeth M

    2017-01-01

    BACKGROUND: Sudden arrhythmic death syndrome (SADS) describes a sudden death with negative autopsy and toxicological analysis. Cardiac genetic disease is a likely etiology. OBJECTIVES: This study investigated the clinical utility and combined yield of post-mortem genetic testing (molecular autopsy...

  3. Prolonged QTc interval and risk of sudden cardiac death in a population of older adults

    DEFF Research Database (Denmark)

    Straus, Sabine M J M; Kors, Jan A; De Bruin, Marie L

    2006-01-01

    OBJECTIVES: This study sought to investigate whether prolongation of the heart rate-corrected QT (QTc) interval is a risk factor for sudden cardiac death in the general population. BACKGROUND: In developed countries, sudden cardiac death is a major cause of cardiovascular mortality. Prolongation...... of the QTc interval has been associated with ventricular arrhythmias, but in most population-based studies no consistent association was found between QTc prolongation and total or cardiovascular mortality. Only very few of these studies specifically addressed sudden cardiac death. METHODS: This study......). The association between a prolonged QTc interval and sudden cardiac death was estimated using Cox proportional hazards analysis. RESULTS: During an average follow-up period of 6.7 years (standard deviation, 2.3 years) 125 patients died of sudden cardiac death. An abnormally prolonged QTc interval (>450 ms in men...

  4. Current state of the problem sudden infant death at home

    OpenAIRE

    Berlay Margarita Vasilievna; Kopylov Anatoliy Vasilievich; Karpov Sergey Mikhailovich

    2017-01-01

    The “Sudden Infant Death Syndrome” stands for unexpected nonviolent death of apparently healthy chest age child when there is no history or pathomorphological features which can be adequate explanations for death reasons. In Russian Federation, the death rate from this syndrome in the range of 0,06 to 2,8 per 1000 live births. In Stavropol region, average figures are equal to 0,36 per 1000 live births in the period of 2005–2014. Rates of incidence sudden infant death syndrome are similar to t...

  5. [Idiopathic sudden deafness: a report of 96 patients].

    Science.gov (United States)

    Gabanou, F; Bera, G; Vincent, C

    2012-01-01

    Evaluation of the management of idiopathic sudden deafness indicating the usefulness of biological assessments and the pronostic factors of hearing recovery. This is a retrospective study of 96 patients with idiopathic sudden deafness referred to a tertiary centre between 2005 and 2009 treated with corticosteroids intravenously at a daily dose of 1 mg/kg. Mean tonal thresholds were assessed (PTA = [500 Hz + 1000 Hz + 2000 Hz + 4000 Hz]/4). Each audiogram was classified as five classes according to its frequency profile. The hearing recovery is significant between D0-D5 and D5-M1 for the frequencies 0.5, 1 and 2 kHz. For 4 kHz, the recovery is significant between 0 and J5. There is no statistically significant correlation between the presence of associated signs (tinnitus, vertigo) and hearing recovery. Hearing recovery according to the five types of audiograms has the same evolution in the follow-up time but with audiograms type E (cophosis or subcophosis) often associated with an hyporeactivity at the videonystagmography. The presence of cardiovascular disease is a predictor of poor hearing recovery. The usefullness of systematic extensive blood tests is low. In sudden deafness, the maximum hearing recovery takes place in the month following the onset of symptoms. The predictors of poor hearing recovery are an initial mean threshold > 70 dB, the existence of an associated cardiovascular disease.

  6. Utility of Post-Mortem Genetic Testing in Cases of Sudden Arrhythmic Death Syndrome

    NARCIS (Netherlands)

    Lahrouchi, Najim; Raju, Hariharan; Lodder, Elisabeth M.; Papatheodorou, Efstathios; Ware, James S.; Papadakis, Michael; Tadros, Rafik; Cole, Della; Skinner, Jonathan R.; Crawford, Jackie; Love, Donald R.; Pua, Chee J.; Soh, Bee Y.; Bhalshankar, Jaydutt D.; Govind, Risha; Tfelt-Hansen, Jacob; Winkel, Bo G.; van der Werf, Christian; Wijeyeratne, Yanushi D.; Mellor, Greg; Till, Jan; Cohen, Marta C.; Tome-Esteban, Maria; Sharma, Sanjay; Wilde, Arthur A. M.; Cook, Stuart A.; Bezzina, Connie R.; Sheppard, Mary N.; Behr, Elijah R.

    2017-01-01

    Sudden arrhythmic death syndrome (SADS) describes a sudden death with negative autopsy and toxicological analysis. Cardiac genetic disease is a likely etiology. This study investigated the clinical utility and combined yield of post-mortem genetic testing (molecular autopsy) in cases of SADS and

  7. Acute otitis media associated bilateral sudden hearing loss: case report and literature review.

    Science.gov (United States)

    Smith, A; Gutteridge, I; Elliott, D; Cronin, M

    2017-07-01

    Sudden sensorineural hearing loss is a rare otological condition with potential for dire outcomes including permanent hearing loss. Although the majority of cases are deemed idiopathic, bilateral sudden sensorineural hearing loss represents a rare subset typically related to systemic conditions, with higher morbidity and mortality. A controversial association with acute otitis media has been reported, with few bilateral cases published in the literature. A very rare case of bilateral sudden sensorineural hearing loss associated with acute otitis media is described, with a review of the literature. The limited evidence available suggests that acute otitis media with tinnitus and/or bacterial pathology may have an increased risk of sudden sensorineural hearing loss, which is consistent with the case described. Although there is no sufficiently powered published evidence to provide definitive treatment guidelines, the literature reviewed suggests that early myringotomy and antibiotics may greatly improve treatment outcomes.

  8. Optimal random perturbations for stochastic approximation using a simultaneous perturbation gradient approximation

    DEFF Research Database (Denmark)

    Sadegh, Payman; Spall, J. C.

    1998-01-01

    simultaneous perturbation approximation to the gradient based on loss function measurements. SPSA is based on picking a simultaneous perturbation (random) vector in a Monte Carlo fashion as part of generating the approximation to the gradient. This paper derives the optimal distribution for the Monte Carlo...

  9. Disformal transformation of cosmological perturbations

    Directory of Open Access Journals (Sweden)

    Masato Minamitsuji

    2014-10-01

    Full Text Available We investigate the gauge-invariant cosmological perturbations in the gravity and matter frames in the general scalar–tensor theory where two frames are related by the disformal transformation. The gravity and matter frames are the extensions of the Einstein and Jordan frames in the scalar–tensor theory where two frames are related by the conformal transformation, respectively. First, it is shown that the curvature perturbation in the comoving gauge to the scalar field is disformally invariant as well as conformally invariant, which gives the predictions from the cosmological model where the scalar field is responsible both for inflation and cosmological perturbations. Second, in case that the disformally coupled matter sector also contributes to curvature perturbations, we derive the evolution equations of the curvature perturbation in the uniform matter energy density gauge from the energy (nonconservation in the matter sector, which are independent of the choice of the gravity sector. While in the matter frame the curvature perturbation in the uniform matter energy density gauge is conserved on superhorizon scales for the vanishing nonadiabatic pressure, in the gravity frame it is not conserved even if the nonadiabatic pressure vanishes. The formula relating two frames gives the amplitude of the curvature perturbation in the matter frame, once it is evaluated in the gravity frame.

  10. Disformal transformation of cosmological perturbations

    International Nuclear Information System (INIS)

    Minamitsuji, Masato

    2014-01-01

    We investigate the gauge-invariant cosmological perturbations in the gravity and matter frames in the general scalar–tensor theory where two frames are related by the disformal transformation. The gravity and matter frames are the extensions of the Einstein and Jordan frames in the scalar–tensor theory where two frames are related by the conformal transformation, respectively. First, it is shown that the curvature perturbation in the comoving gauge to the scalar field is disformally invariant as well as conformally invariant, which gives the predictions from the cosmological model where the scalar field is responsible both for inflation and cosmological perturbations. Second, in case that the disformally coupled matter sector also contributes to curvature perturbations, we derive the evolution equations of the curvature perturbation in the uniform matter energy density gauge from the energy (non)conservation in the matter sector, which are independent of the choice of the gravity sector. While in the matter frame the curvature perturbation in the uniform matter energy density gauge is conserved on superhorizon scales for the vanishing nonadiabatic pressure, in the gravity frame it is not conserved even if the nonadiabatic pressure vanishes. The formula relating two frames gives the amplitude of the curvature perturbation in the matter frame, once it is evaluated in the gravity frame

  11. Survival and sudden cardiac death after septal ablation for hypertrophic obstructive cardiomyopathy

    DEFF Research Database (Denmark)

    Jensen, Morten Kvistholm; Havndrup, Ole; Hassager, Christian

    2011-01-01

    Reports of long-term survival and the risk of sudden cardiac death (SCD) after percutaneous transluminal septal myocardial ablation (PTSMA) in patients with hypertrophic obstructive cardiomyopathy (HOCM) are sparse.......Reports of long-term survival and the risk of sudden cardiac death (SCD) after percutaneous transluminal septal myocardial ablation (PTSMA) in patients with hypertrophic obstructive cardiomyopathy (HOCM) are sparse....

  12. Damage Detection on Sudden Stiffness Reduction Based on Discrete Wavelet Transform

    Directory of Open Access Journals (Sweden)

    Bo Chen

    2014-01-01

    Full Text Available The sudden stiffness reduction in a structure may cause the signal discontinuity in the acceleration responses close to the damage location at the damage time instant. To this end, the damage detection on sudden stiffness reduction of building structures has been actively investigated in this study. The signal discontinuity of the structural acceleration responses of an example building is extracted based on the discrete wavelet transform. It is proved that the variation of the first level detail coefficients of the wavelet transform at damage instant is linearly proportional to the magnitude of the stiffness reduction. A new damage index is proposed and implemented to detect the damage time instant, location, and severity of a structure due to a sudden change of structural stiffness. Numerical simulation using a five-story shear building under different types of excitation is carried out to assess the effectiveness and reliability of the proposed damage index for the building at different damage levels. The sensitivity of the damage index to the intensity and frequency range of measurement noise is also investigated. The made observations demonstrate that the proposed damage index can accurately identify the sudden damage events if the noise intensity is limited.

  13. Written Spelling to Dictation: Sound-To-Spelling Regularity Affects Both Writing Latencies and Durations

    Science.gov (United States)

    Delattre, Marie; Bonin, Patrick; Barry, Christopher

    2006-01-01

    The authors examined the effect of sound-to-spelling regularity on written spelling latencies and writing durations in a dictation task in which participants had to write each target word 3 times in succession. The authors found that irregular words (i.e., those containing low-probability phoneme-to-grapheme mappings) were slower both to…

  14. Locus of Word Frequency Effects in Spelling to Dictation: Still at the Orthographic Level!

    Science.gov (United States)

    Bonin, Patrick; Laroche, Betty; Perret, Cyril

    2016-01-01

    The present study was aimed at testing the locus of word frequency effects in spelling to dictation: Are they located at the level of spoken word recognition (Chua & Rickard Liow, 2014) or at the level of the orthographic output lexicon (Delattre, Bonin, & Barry, 2006)? Words that varied on objective word frequency and on phonological…

  15. Back muscle response to sudden trunk loading can be modified by training among healthcare workers

    DEFF Research Database (Denmark)

    Pedersen, Mogens Theisen; Essendrop, Morten; Skotte, Jørgen H.

    2007-01-01

    Study Design. Experimental study of the effect of physical training on the reaction to sudden back loading. Objective. To investigate the effect and sustainability of "on the job training" on the reaction to sudden back loading among employees at a geriatric ward. Summary of Background Data...... of the trunk (stopping time). Data on the possibilities of a training-induced improvement in the reflex response among workers exposed to sudden trunk loading on the job are, however, nonexistent, and there is no evidence of long-term benefits, i.e., the sustainability of a positive training effect. Methods....... Available data suggest that a delayed muscle reflex response to sudden trunk loading may increase the risk of low back injuries. We have previously shown that training may alter the response to sudden trunk loading in healthy subjects and decrease the time elapsed until stopping of the forward movement...

  16. Febrile seizures prior to sudden cardiac death

    DEFF Research Database (Denmark)

    Stampe, Niels Kjær; Glinge, Charlotte; Jabbari, Reza

    2018-01-01

    Aims: Febrile seizure (FS) is a common disorder affecting 2-5% of children up to 5 years of age. The aim of this study was to determine whether FS in early childhood are over-represented in young adults dying from sudden cardiac death (SCD). Methods and results: We included all deaths (n = 4595...... with FS was sudden arrhythmic death syndrome (5/8; 62.5%). Conclusion: In conclusion, this study demonstrates a significantly two-fold increase in the frequency of FS prior to death in young SCD cases compared with the two control groups, suggesting that FS could potentially contribute in a risk......) nationwide and through review of all death certificates, we identified 245 SCD in Danes aged 1-30 years in 2000-09. Through the usage of nationwide registries, we identified all persons admitted with first FS among SCD cases (14/245; 5.7%) and in the corresponding living Danish population (71 027/2 369 785...

  17. Preheating curvaton perturbations

    International Nuclear Information System (INIS)

    Bastero-Gil, M.; Di Clemente, V.; King, S.F.

    2005-01-01

    We discuss the potentially important role played by preheating in certain variants of the curvaton mechanism in which isocurvature perturbations of a D-flat (and F-flat) direction become converted to curvature perturbations during reheating. We discover that parametric resonance of the isocurvature components amplifies the superhorizon fluctuations by a significant amount. As an example of these effects we develop a particle physics motivated model which involves hybrid inflation with the waterfall field N being responsible for generating the μ term, the right-handed neutrino mass scale, and the Peccei-Quinn symmetry breaking scale. The role of the curvaton field can be played either by usual Higgs field, or the lightest right-handed sneutrino. Our new results show that it is possible to achieve the correct curvature perturbations for initial values of the curvaton fields of order the weak scale. In this model we show that the prediction for the spectral index of the final curvature perturbation only depends on the mass of the curvaton during inflation, where consistency with current observational data requires the ratio of this mass to the Hubble constant to be 0.3

  18. Cardiovascular Risk Factors in Primary Relatives of Sudden Cardiac Death Victims

    Science.gov (United States)

    1991-01-01

    hypertriglyceridemia and hypertension as risk factors in relatives of sudden death victims. The sample for both studies will be the same. 5 Chapter II The...provided most of the research information on SCD. Pathology of Sudden Cardiac Death There appear to be several different pathologic scenarios which render a...had severe two or three vessel disease. By comparison, 100 age matched controls who died of other causes, had a combined 27% incidence of two and

  19. Sudden Gains during Therapy of Social Phobia

    Science.gov (United States)

    Hofmann, Stefan G.; Schultz, Stefan M.; Meuret, Alicia E.; Moscovitch, David A.; Suvak, Michael

    2006-01-01

    The present study investigated the phenomenon of sudden gains in 107 participants with social phobia (social anxiety disorder) who received either cognitive-behavioral group therapy or exposure group therapy without explicit cognitive interventions, which primarily used public speaking situations as exposure tasks. Twenty-two out of 967…

  20. Febrile convulsions and sudden infant death syndrome

    DEFF Research Database (Denmark)

    Vestergaard, Mogens; Basso, Olga; Henriksen, Tine Brink

    2002-01-01

    It has been suggested that sudden infant death syndrome (SIDS) and febrile convulsions are related aetiologically. We compared the risk of SIDS in 9877 siblings of children who had had febrile convulsions with that of 20.177 siblings of children who had never had febrile convulsions. We found...

  1. Sudden (reversible) sensorineural hearing loss in pregnancy.

    LENUS (Irish Health Repository)

    Kenny, R

    2011-03-01

    Sudden hearing loss directly associated with pregnancy or birth is a little known and rare occurrence. The temporary, unilateral, low-frequency sensorineural hearing loss in this case was reported after the birth of the patient\\'s first child, and again during the third trimester of her second pregnancy.

  2. Wave vector modification of the infinite order sudden approximation

    International Nuclear Information System (INIS)

    Sachs, J.G.; Bowman, J.M.

    1980-01-01

    A simple method is proposed to modify the infinite order sudden approximation (IOS) in order to extend its region of quantitative validity. The method involves modifying the phase of the IOS scattering matrix to include a part calculated at the outgoing relative kinetic energy as well as a part calculated at the incoming kinetic energy. An immediate advantage of this modification is that the resulting S matrix is symmetric. We also present a closely related method in which the relative kinetic energies used in the calculation of the phase are determined from quasiclassical trajectory calculations. A set of trajectories is run with the initial state being the incoming state, and another set is run with the initial state being the outgoing state, and the average final relative kinetic energy of each set is obtained. One part of the S-operator phase is then calculated at each of these kinetic energies. We apply these methods to vibrationally inelastic collinear collisions of an atom and a harmonic oscillator, and calculate transition probabilities P/sub n/1→nf for three model systems. For systems which are sudden, or nearly so, the agreement with exact quantum close-coupling calculations is substantially improved over standard IOS ones when Δn=such thatub f/-n/sub i/ is large, and the corresponding transition probability is small, i.e., less than 0.1. However, the modifications we propose will not improve the accuracy of the IOS transition probabilities for any collisional system unless the standard form of IOS already gives at least qualitative agreement with exact quantal calculations. We also suggest comparisons between some classical quantities and sudden predictions which should help in determining the validity of the sudden approximation. This is useful when exact quantal data is not available for comparison

  3. Wave vector modification of the infinite order sudden approximation

    Science.gov (United States)

    Sachs, Judith Grobe; Bowman, Joel M.

    1980-10-01

    A simple method is proposed to modify the infinite order sudden approximation (IOS) in order to extend its region of quantitative validity. The method involves modifying the phase of the IOS scattering matrix to include a part calculated at the outgoing relative kinetic energy as well as a part calculated at the incoming kinetic energy. An immediate advantage of this modification is that the resulting S matrix is symmetric. We also present a closely related method in which the relative kinetic energies used in the calculation of the phase are determined from quasiclassical trajectory calculations. A set of trajectories is run with the initial state being the incoming state, and another set is run with the initial state being the outgoing state, and the average final relative kinetic energy of each set is obtained. One part of the S-operator phase is then calculated at each of these kinetic energies. We apply these methods to vibrationally inelastic collinear collisions of an atom and a harmonic oscillator, and calculate transition probabilities Pn1→nf for three model systems. For systems which are sudden, or nearly so, the agreement with exact quantum close-coupling calculations is substantially improved over standard IOS ones when Δn=‖nf-ni‖ is large, and the corresponding transition probability is small, i.e., less than 0.1. However, the modifications we propose will not improve the accuracy of the IOS transition probabilities for any collisional system unless the standard form of IOS already gives at least qualitative agreement with exact quantal calculations. We also suggest comparisons between some classical quantities and sudden predictions which should help in determining the validity of the sudden approximation. This is useful when exact quantal data is not available for comparison.

  4. Severe ionosphere disturbances caused by the sudden response of evening subequatorial ionospheres to geomagnetic storms

    International Nuclear Information System (INIS)

    Tanaka, T.

    1981-01-01

    By monitoring C band beacon signals from geostationary satellites in Japan, we have observed anomalously strong ionospheric scintillations several times during three years from 1978 to 1980. These severe scinitillations occur associated with geomagnetic storms and accompany sudden and intense ionospheric perturbations in the low-latiude region. Through the analysis of these phenomena we have identified a new type of ionospheric disturbances characterized by intensifications of equatorial anomalies and successive severe ionospheric scintillations that extend to the C band range. The events occur only during a limited local time interval after the sunset, when storm time decreases of midlatitude geomagnetic fields in the same meridan take place during the same time interval. From the viewpoint of ionospheric storms, these disturbances precede the occurrence of midlatitude negative phases and storm time depressions of equatorial anomalies to indicate that the cause of the events is different from distrubed thermospheric circulations. The timing and magnitude of substorms at high-latitudes not always correlate with the events. We have concluded that the phenomena are closely related with penetrations toward low-latitudes of electric fields owing to the partial closure of asymmetrical ring currents

  5. Sudden cardiac death in young athletes

    Directory of Open Access Journals (Sweden)

    Östman-Smith I

    2011-07-01

    Full Text Available Ingegerd Östman-SmithDivision of Paediatric Cardiology, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg University, SwedenAbstract: Athletic activity is associated with an increased risk of sudden death for individuals with some congenital or acquired heart disorders. This review considers in particular the causes of death affecting athletes below 35 years of age. In this age group the largest proportion of deaths are caused by diseases with autosomal dominant inheritance such as hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, long QT-syndrome, and Marfan’s syndrome. A policy of early cascade-screening of all first-degree relatives of patients with these disorders will therefore detect a substantial number of individuals at risk. A strictly regulated system with preparticipation screening of all athletes following a protocol pioneered in Italy, including school-age children, can also detect cases caused by sporadic new mutations and has been shown to reduce excess mortality among athletes substantially. Recommendations for screening procedure are reviewed. It is concluded that ECG screening ought to be part of preparticipation screening, but using criteria that do not cause too many false positives among athletes. One such suggested protocol will show positive in approximately 5% of screened individuals, among whom many will be screened for these diseases. On this point further research is needed to define what kind of false-positive and false-negative rate these new criteria result in. A less formal system based on cascade-screening of relatives, education of coaches about suspicious symptoms, and preparticipation questionnaires used by athletic clubs, has been associated over time with a sizeable reduction in sudden cardiac deaths among Swedish athletes, and thus appears to be worth implementing even for junior athletes not recommended for formal preparticipation screening. It is strongly argued

  6. Sickle cell trait and sudden death--bringing it home.

    Science.gov (United States)

    Mitchell, Bruce L.

    2007-01-01

    Sickle cell trait continues to be the leading cause of sudden death for young African Americans in military basic training and civilian organized sports. The syndrome may have caused the death of up to 10 college football players since 1974 and, as recently as 2000, was suspected as the cause of death of three U.S. Army recruits. The penal military-style boot camps in the United States and the recent death of two teenagers with sickle cell trait merits renewed vigor in the education of athletic instructors, the military and the public about conditions associated with sudden death in individuals with sickle cell trait. Images Figure 1 Figure 2 PMID:17393956

  7. Cardiac channelopathies and sudden infant death syndrome

    DEFF Research Database (Denmark)

    Tfelt-Hansen, Jacob; Winkel, Bo Gregers; Grunnet, Morten

    2011-01-01

    Sudden infant death syndrome (SIDS) is always a devastating and unexpected occurrence. SIDS is the leading cause of death in the first 6 months after birth in the industrialized world. Since the discovery in 1998 of long QT syndrome as an underlying substrate for SIDS, around 10-20% of SIDS cases...

  8. Sudden death syndrome of soybean in Argentina

    Science.gov (United States)

    Sudden death syndrome (SDS) is one of the most common and widely spread root disease affecting soybean [Glycine max (L.) Merr.] in Argentina where it is an economically important crop. This disease was first discovered in this country in 1992 in the Pampas Region, and the following year in Northwest...

  9. Risk factors and causes of sudden noncardiac death: A nationwide cohort study in Denmark.

    Science.gov (United States)

    Risgaard, Bjarke; Lynge, Thomas Hadberg; Wissenberg, Mads; Jabbari, Reza; Glinge, Charlotte; Gislason, Gunnar Hilmar; Haunsø, Stig; Winkel, Bo Gregers; Tfelt-Hansen, Jacob

    2015-05-01

    On the performance of an autopsy, sudden deaths may be divided into 2 classifications: (1) sudden cardiac deaths and (2) sudden noncardiac deaths (SNCDs). Families of SNCD victims should not be followed up as a means of searching for cardiac disease. The purpose of this study was to report the risk factors and causes of SNCD. We conducted a retrospective, nationwide study including all deaths between 2000 and 2006 of individuals aged 1-35 years and all deaths between 2007 and 2009 of individuals aged 1-49 years. Two physicians identified all sudden death cases through review of death certificates. Autopsy reports were collected. A multivariable logistic regression model was used to identify both clinical characteristics and risk factors associated with SNCD. We identified 1039 autopsied cases of sudden death, of which 286 (28%) were classified as SNCD. The median age in the SNCD death population was 32 years. Increasing age was inversely associated with SNCD (odds ratio [OR] 0.93, 95% confidence interval [CI] 0.87-0.98). Female sex, in-hospital location, and the absence of cardiac comorbidities were positively associated with SNCD (OR 1.7, 95% CI 1.3-2.3; OR 3.0, 95% CI 2.0-4.4; and OR 4.3, 95% CI 2.5-7.4, respectively). The most common cause of SNCD was pulmonary disease (n = 115 [40%]). Sudden death among individuals aged caused by noncardiac diseases in 28% of cases. Risk factors were female sex, age, and the absence of cardiac comorbidities. These data may guide future strategies for the follow-up of family members of nonautopsied sudden death victims, improve risk stratification, and influence public health strategies. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  10. Singular perturbation of simple eigenvalues

    International Nuclear Information System (INIS)

    Greenlee, W.M.

    1976-01-01

    Two operator theoretic theorems which generalize those of asymptotic regular perturbation theory and which apply to singular perturbation problems are proved. Application of these theorems to concrete problems is involved, but the perturbation expansions for eigenvalues and eigenvectors are developed in terms of solutions of linear operator equations. The method of correctors, as well as traditional boundary layer techniques, can be used to apply these theorems. The current formulation should be applicable to highly singular ''hard core'' potential perturbations of the radial equation of quantum mechanics. The theorems are applied to a comparatively simple model problem whose analysis is basic to that of the quantum mechanical problem

  11. Base case and perturbation scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Edmunds, T

    1998-10-01

    This report describes fourteen energy factors that could affect electricity markets in the future (demand, process, source mix, etc.). These fourteen factors are believed to have the most influence on the State's energy environment. A base case, or most probable, characterization is given for each of these fourteen factors over a twenty year time horizon. The base case characterization is derived from quantitative and qualitative information provided by State of California government agencies, where possible. Federal government databases are nsed where needed to supplement the California data. It is envisioned that a initial selection of issue areas will be based upon an evaluation of them under base case conditions. For most of the fourteen factors, the report identities possible perturbations from base case values or assumptions that may be used to construct additional scenarios. Only those perturbations that are plausible and would have a significant effect on energy markets are included in the table. The fourteen factors and potential perturbations of the factors are listed in Table 1.1. These perturbations can be combined to generate internally consist.ent. combinations of perturbations relative to the base case. For example, a low natural gas price perturbation should be combined with a high natural gas demand perturbation. The factor perturbations are based upon alternative quantitative forecasts provided by other institutions (the Department of Energy - Energy Information Administration in some cases), changes in assumptions that drive the quantitative forecasts, or changes in assumptions about the structure of the California energy markets. The perturbations are intended to be used for a qualitative reexamination of issue areas after an initial evaluation under the base case. The perturbation information would be used as a "tiebreaker;" to make decisions regarding those issue areas that were marginally accepted or rejected under the base case. Hf a

  12. Scalar cosmological perturbations

    International Nuclear Information System (INIS)

    Uggla, Claes; Wainwright, John

    2012-01-01

    Scalar perturbations of Friedmann-Lemaitre cosmologies can be analyzed in a variety of ways using Einstein's field equations, the Ricci and Bianchi identities, or the conservation equations for the stress-energy tensor, and possibly introducing a timelike reference congruence. The common ground is the use of gauge invariants derived from the metric tensor, the stress-energy tensor, or from vectors associated with a reference congruence, as basic variables. Although there is a complication in that there is no unique choice of gauge invariants, we will show that this can be used to advantage. With this in mind our first goal is to present an efficient way of constructing dimensionless gauge invariants associated with the tensors that are involved, and of determining their inter-relationships. Our second goal is to give a unified treatment of the various ways of writing the governing equations in dimensionless form using gauge-invariant variables, showing how simplicity can be achieved by a suitable choice of variables and normalization factors. Our third goal is to elucidate the connection between the metric-based approach and the so-called 1 + 3 gauge-invariant approach to cosmological perturbations. We restrict our considerations to linear perturbations, but our intent is to set the stage for the extension to second-order perturbations. (paper)

  13. Divergent Perturbation Series

    International Nuclear Information System (INIS)

    Suslov, I.M.

    2005-01-01

    Various perturbation series are factorially divergent. The behavior of their high-order terms can be determined by Lipatov's method, which involves the use of instanton configurations of appropriate functional integrals. When the Lipatov asymptotic form is known and several lowest order terms of the perturbation series are found by direct calculation of diagrams, one can gain insight into the behavior of the remaining terms of the series, which can be resummed to solve various strong-coupling problems in a certain approximation. This approach is demonstrated by determining the Gell-Mann-Low functions in φ 4 theory, QED, and QCD with arbitrary coupling constants. An overview of the mathematical theory of divergent series is presented, and interpretation of perturbation series is discussed. Explicit derivations of the Lipatov asymptotic form are presented for some basic problems in theoretical physics. A solution is proposed to the problem of renormalon contributions, which hampered progress in this field in the late 1970s. Practical perturbation-series summation schemes are described both for a coupling constant of order unity and in the strong-coupling limit. An interpretation of the Borel integral is given for 'non-Borel-summable' series. Higher order corrections to the Lipatov asymptotic form are discussed

  14. Metabolic Syndrome Increases the Risk of Sudden Sensorineural Hearing Loss in Taiwan: A Case-Control Study.

    Science.gov (United States)

    Chien, Chen-Yu; Tai, Shu-Yu; Wang, Ling-Feng; Hsi, Edward; Chang, Ning-Chia; Wu, Ming-Tsang; Ho, Kuen-Yao

    2015-07-01

    Sudden sensorineural hearing loss has been reported to be associated with diabetes mellitus, hypertension, and hyperlipidemia in previous studies. The aim of this study was to examine whether metabolic syndrome increases the risk of sudden sensorineural hearing loss in Taiwan. A case-control study. Tertiary university hospital. We retrospectively investigated 181 cases of sudden sensorineural hearing loss and 181 controls from the Department of Otorhinolaryngology, Kaohsiung Medical University Hospital, in southern Taiwan from 2010 to 2012, comparing their clinical variables. We analyzed the relationship between metabolic syndrome and sudden sensorineural hearing loss. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III with Asian modifications. The demographic and clinical characteristics, audiometry results, and outcome were reviewed. Subjects with metabolic syndrome had a 3.54-fold increased risk (95% confidence interval [CI] = 2.00-6.43, P diabetes mellitus, hypertension, and hyperlipidemia. With increases in the number of metabolic syndrome components, the risk of sudden sensorineural hearing loss increased (P for trend Vertigo was associated with a poor outcome (P = .02; 95% CI = 1.13~5.13, adjusted odds ratio = 2.39). The hearing loss pattern may influence the outcome of sudden sensorineural hearing loss (P Vertigo and total hearing loss were indicators of a poor outcome in sudden sensorineural hearing loss. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  15. Ependymal alterations in sudden intrauterine unexplained death and sudden infant death syndrome: possible primary consequence of prenatal exposure to cigarette smoking

    Directory of Open Access Journals (Sweden)

    Matturri Luigi

    2010-07-01

    Full Text Available Abstract Background The ependyma, the lining providing a protective barrier and filtration system separating brain parenchyma from cerebrospinal fluid, is still inadequately understood in humans. In this study we aimed to define, by morphological and immunohistochemical methods, the sequence of developmental steps of the human ependyma in the brainstem (ventricular ependyma and thoracic spinal cord (central canal ependyma of a large sample of fetal and infant death victims, aged from 17 gestational weeks to 8 postnatal months. Additionally, we investigated a possible link between alterations of this structure, sudden unexplained fetal and infant death and maternal smoking. Results Our results demonstrate that in early fetal life the human ependyma shows a pseudostratified cytoarchitecture including many tanycytes and ciliated cells together with numerous apoptotic and reactive astrocytes in the subependymal layer. The ependyma is fully differentiated, with a monolayer of uniform cells, after 32 to 34 gestational weeks. We observed a wide spectrum of ependymal pathological changes in sudden death victims, such as desquamation, clusters of ependymal cells in the subventricular zone, radial glial cells, and the unusual presence of neurons within and over the ependymal lining. These alterations were significantly related to maternal smoking in pregnancy. Conclusions We conclude that in smoking mothers, nicotine and its derivatives easily reach the cerebrospinal fluid in the fetus, immediately causing ependymal damage. Consequently, we suggest that the ependyma should be examined in-depth first in victims of sudden fetal or infant death with mothers who smoke.

  16. Large-order perturbation theory

    International Nuclear Information System (INIS)

    Wu, T.T.

    1982-01-01

    The original motivation for studying the asymptotic behavior of the coefficients of perturbation series came from quantum field theory. An overview is given of some of the attempts to understand quantum field theory beyond finite-order perturbation series. At least is the case of the Thirring model and probably in general, the full content of a relativistic quantum field theory cannot be recovered from its perturbation series. This difficulty, however, does not occur in quantum mechanics, and the anharmonic oscillator is used to illustrate the methods used in large-order perturbation theory. Two completely different methods are discussed, the first one using the WKB approximation, and a second one involving the statistical analysis of Feynman diagrams. The first one is well developed and gives detailed information about the desired asymptotic behavior, while the second one is still in its infancy and gives instead information about the distribution of vertices of the Feynman diagrams

  17. Perturbation theory in light-cone gauge

    International Nuclear Information System (INIS)

    Vianello, Eliana

    2000-01-01

    Perturbation calculations are presented for the light-cone gauge Schwinger model. Eigenstates can be calculated perturbatively but the perturbation theory is nonstandard. We hope to extend the work to QCD 2 to resolve some outstanding issues in those theories

  18. On dark energy isocurvature perturbation

    International Nuclear Information System (INIS)

    Liu, Jie; Zhang, Xinmin; Li, Mingzhe

    2011-01-01

    Determining the equation of state of dark energy with astronomical observations is crucially important to understand the nature of dark energy. In performing a likelihood analysis of the data, especially of the cosmic microwave background and large scale structure data the dark energy perturbations have to be taken into account both for theoretical consistency and for numerical accuracy. Usually, one assumes in the global fitting analysis that the dark energy perturbations are adiabatic. In this paper, we study the dark energy isocurvature perturbation analytically and discuss its implications for the cosmic microwave background radiation and large scale structure. Furthermore, with the current astronomical observational data and by employing Markov Chain Monte Carlo method, we perform a global analysis of cosmological parameters assuming general initial conditions for the dark energy perturbations. The results show that the dark energy isocurvature perturbations are very weakly constrained and that purely adiabatic initial conditions are consistent with the data

  19. The epidemiology of sudden oak death in Oregon forests

    Science.gov (United States)

    Ebba K. Peterson

    2011-01-01

    The phytopathogen Phytophthora ramorum (Werres, DeCock & Man in't Veld), causal agent of Sudden Oak Death (SOD) of oaks (Quercus spp.) and tanoaks (Notholithocarpus densiflorus syn. Lithocarpus densiflorus...

  20. A Comparison of the Incremental Difference between the Beginning and Ending Heart Rate When Shorthand Writers Are Informed and Not Informed of Speeds of Dictation.

    Science.gov (United States)

    Dickey, Patsy A.

    1980-01-01

    Forty female students were used to compare the incremental difference in heart rate of shorthand writers when they were informed and not informed of shorthand speeds prior to dictation. It was concluded that students' performances were enhanced by receiving instructions as to speed of dictation prior to the take. (Author/CT)

  1. Heat transfer in oscillating flows with sudden change in cross section

    Science.gov (United States)

    Ibrahim, Mounir; Hashim, Waqar; Tew, Roy C.; Dudenhoefer, James E.

    1992-01-01

    Oscillating fluid flow (zero mean) with heat transfer, between two parallel plates with a sudden change in cross section, was examined computationally. Over 30 different cases were examined; these cases cover wide ranges of Re sub max (187.5 to 30,000), Va (1 to 350), expansion ratio (1:2, 1:4, 1:8, and 1:12) and A sub r (0.68 to 4). Three different geometric cases were considered (asymmetric expansion and/or contraction, symmetric expansion/contraction, and symmetric blunt body). The heat transfer cases were based on constant wall temperature at higher (heating) or lower (cooling) value than the inflow fluid temperature. As a result of the oscillating flow, the fluid undergoes sudden expansion in one half of the cycle and sudden contraction in the other half. Instantaneous friction factors and heat transfer coefficients, for some ranges of Re sub max and Va, deviated substantially from those predicted with steady state correlations.

  2. Stratification of the Risk of Sudden Death in Nonischemic Heart Failure

    Directory of Open Access Journals (Sweden)

    Maurício Pimentel

    2014-10-01

    Full Text Available Despite significant therapeutic advancements, heart failure remains a highly prevalent clinical condition associated with significant morbidity and mortality. In 30%-40% patients, the etiology of heart failure is nonischemic. The implantable cardioverter-defibrillator (ICD is capable of preventing sudden death and decreasing total mortality in patients with nonischemic heart failure. However, a significant number of patients receiving ICD do not receive any kind of therapy during follow-up. Moreover, considering the situation in Brazil and several other countries, ICD cannot be implanted in all patients with nonischemic heart failure. Therefore, there is an urgent need to identify patients at an increased risk of sudden death because these would benefit more than patients at a lower risk, despite the presence of heart failure in both risk groups. In this study, the authors review the primary available methods for the stratification of the risk of sudden death in patients with nonischemic heart failure.

  3. Magnetic resonance imaging in sudden deafness; Ressonancia magnetica em surdez subita

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Hugo Valter Lisboa; Barros, Flavia Alencar; Penido, Norma de Oliveira; Souza, Ana Claudia Valerio de; Yamaoka, Wellington Yugo [Sao Paulo Univ., SP (Brazil). Dept. de Otorinolaringologia e Cirurgia da Cabeca e Pescoco; Yamashita, Helio [Sao Paulo Univ., SP (Brazil). Dept. de Imagem e Diagnostico]. E-mail: hvlramos@gmail.com

    2005-07-15

    The etiology of sudden deafness can remain undetermined despite extensive investigation. This study addresses the value of magnetic resonance imaging in the analysis of sudden deafness patients.Study Design: transversal cohort.Material And Method: In a prospective study, 49 patients attended at otolaryngology emergency room of Federal University of Sao Paulo - Escola Paulista de Medicina, from April 2001 to May 2003, were submitted to magnetic resonance imaging.Results: Magnetic Resonance abnormalities were seen in 23 (46.9%) patients and revealed two tumors suggestive of meningioma, three vestibular schwannomas, thirteen microangiopathic changes of the brain and five (21.7%) pathological conditions of the labyrinth.Conclusion: Sudden deafness should be approached as a symptom common to different diseases. The presence of cerebellopontine angle tumors in 10.2% of our cases, among other treatable causes, justifies the recommendation of gadolinium-enhanced magnetic resonance use, not only to study the auditory peripheral pathway, but to study the whole auditory pathway including the brain. (author)

  4. Perturbation Theory of Embedded Eigenvalues

    DEFF Research Database (Denmark)

    Engelmann, Matthias

    project gives a general and systematic approach to analytic perturbation theory of embedded eigenvalues. The spectral deformation technique originally developed in the theory of dilation analytic potentials in the context of Schrödinger operators is systematized by the use of Mourre theory. The group...... of dilations is thereby replaced by the unitary group generated y the conjugate operator. This then allows to treat the perturbation problem with the usual Kato theory.......We study problems connected to perturbation theory of embedded eigenvalues in two different setups. The first part deals with second order perturbation theory of mass shells in massive translation invariant Nelson type models. To this end an expansion of the eigenvalues w.r.t. fiber parameter up...

  5. Chiral perturbation theory

    International Nuclear Information System (INIS)

    Ecker, G.

    1996-06-01

    After a general introduction to the structure of effective field theories, the main ingredients of chiral perturbation theory are reviewed. Applications include the light quark mass ratios and pion-pion scattering to two-loop accuracy. In the pion-nucleon system, the linear σ model is contrasted with chiral perturbation theory. The heavy-nucleon expansion is used to construct the effective pion-nucleon Lagrangian to third order in the low-energy expansion, with applications to nucleon Compton scattering. (author)

  6. Otolaryngological aspects of sudden infant death syndrome.

    Science.gov (United States)

    Marom, Tal; Cinamon, Udi; Castellanos, Paul F; Cohen, Marta C

    2012-03-01

    Sudden infant death syndrome (SIDS) is characterized by the sudden death of an apparently otherwise healthy infant, typically during sleep, and with no obvious case after a thorough post-mortem and scene death examination. To address the problem from the otolaryngologist's perspective, describe relevant pathologies, discuss controversies and suggest preventive measures in high-risk populations. A MEDLINE search and hand search were conducted to identify reports published between 1969 and 2011 in the English language on the pathophysiology of SIDS related to the head and neck organs. Search terms included SIDS (MeSH term), SIDS and pathophysiology (text words), and SIDS and autopsy (text words). A growing number of reports suggested head and neck organs involvement in SIDS autopsies. Laryngeal, oropharyngeal, maxillofacial, otologic, cervical vascular abnormalities and infectious etiologies, were recognized and discussed. Otolaryngologists should be aware of relevant pathologies, as some are treatable, if identified early enough in infancy. A proactive risk-management approach is warranted in infants presenting with certain abnormalities reviewed here. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. Proportion offered in the Dictator and Ultimatum Games decreases with amount and social distance.

    Science.gov (United States)

    Bechler, Christopher; Green, Leonard; Myerson, Joel

    2015-06-01

    Behavior in both the Dictator Game and the Ultimatum Game is of special interest because proposers often violate the predictions of normative economic theory: On average, offers in both games are higher than what would be considered income-maximizing. In the present study, the initial amount provided to the proposer and the social distance between the proposer and the respondent were both varied across a wide range, and the effects of these manipulations on offers in the Dictator Game and the Ultimatum Game were examined in a broad sample of participants recruited via MTurk. Although the amount offered was consistently higher in the Ultimatum Game, the proportion of the amount offered decreased as the size of the initial amount increased in both games. Moreover, the proportion offered also decreased as a function of the social distance between the proposer and the responder. The present results extend our knowledge of the determinants of proposers' behavior in two-person economic games and emphasize the importance of social distance and the amount of money at stake as factors that affect people's economic decisions. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Sudden Cardiac Death of a Body Packer Due to Cocaine Cardiotoxicity

    Directory of Open Access Journals (Sweden)

    Parthasarathi Pramanik

    2016-01-01

    Full Text Available This article presents a case of sudden cardiac death due to the effects of cocaine concealed in the body of a male drug smuggler in his 40s, a so-called body packer. A total of 57 body packets filled with cocaine powder were discovered in his body cavities. The detailed autopsy examination, including histopathology and toxicology findings, is discussed with the aim of describing the mechanism of cocaine intoxication in the body packer and an analysis of cocaine-induced cardiotoxicity and sudden death.

  9. Dynamics of a single ion in a perturbed Penning trap: Octupolar perturbation

    International Nuclear Information System (INIS)

    Lara, Martin; Salas, J. Pablo

    2004-01-01

    Imperfections in the design or implementation of Penning traps may give rise to electrostatic perturbations that introduce nonlinearities in the dynamics. In this paper we investigate, from the point of view of classical mechanics, the dynamics of a single ion trapped in a Penning trap perturbed by an octupolar perturbation. Because of the axial symmetry of the problem, the system has two degrees of freedom. Hence, this model is ideal to be managed by numerical techniques like continuation of families of periodic orbits and Poincare surfaces of section. We find that, through the variation of the two parameters controlling the dynamics, several periodic orbits emanate from two fundamental periodic orbits. This process produces important changes (bifurcations) in the phase space structure leading to chaotic behavior

  10. Brugada Syndrome in a Patient with Vascular Ehlers-Danlos Syndrome: Sudden Death Risk Amplified.

    Science.gov (United States)

    D'Souza, Jason; Malhotra, Divyanshu; Goud, Aditya; Dahagam, Chanukya; Everett, George

    2017-04-19

    The vast majority of sudden cardiac arrests occur in patients with structural heart disease and in approximately 10% of the cases, it can occur in those with structurally normal hearts. Brugada syndrome is an autosomal dominant sodium channelopathy that has been implicated in sudden deaths. Given their low prevalence, our knowledge about Brugada syndrome is still evolving. Apart from schizophrenia, there have been no reports of associated medical conditions. We recently encountered a patient with vascular Ehlers-Danlos syndrome who was also found to have Brugada syndrome. Both these conditions share some common clinical presentations including a propensity for sudden death.

  11. Familial Atrial Septal Defect and Sudden Cardiac Death

    DEFF Research Database (Denmark)

    Ellesøe, Sabrina Gade; Johansen, Morten Munk; Bjerre, Jesper Vandborg

    2016-01-01

    OBJECTIVE: Atrial septal defect (ASD) is the second most common congenital heart defect (CHD) and is observed in families as an autosomal dominant trait as well as in nonfamilial CHD. Mutations in the NKX2-5 gene, located on chromosome 5, are associated with ASD, often combined with conduction...... disturbances, cardiomyopathies, complex CHD, and sudden cardiac death as well. Here, we show that NKX2-5 mutations primarily occur in ASD patients with conduction disturbances and heritable ASD. Furthermore, these families are at increased risk of sudden cardiac death. RESULTS: We screened 39 probands...... with familial CHD for mutations in NKX2-5 and discovered a novel mutation in one family (2.5%) with ASD and atrioventricular block. A review of the literature revealed 59 different NKX2-5 mutations in 202 patients. Mutations were significantly more common in familial cases compared to nonfamilial cases (P = 7...

  12. Regulatory T cell suppressive potency dictates the balance between bacterial proliferation and clearance during persistent Salmonella infection.

    Directory of Open Access Journals (Sweden)

    Tanner M Johanns

    2010-08-01

    Full Text Available The pathogenesis of persistent infection is dictated by the balance between opposing immune activation and suppression signals. Herein, virulent Salmonella was used to explore the role and potential importance of Foxp3-expressing regulatory T cells in dictating the natural progression of persistent bacterial infection. Two distinct phases of persistent Salmonella infection are identified. In the first 3-4 weeks after infection, progressively increasing bacterial burden was associated with delayed effector T cell activation. Reciprocally, at later time points after infection, reductions in bacterial burden were associated with robust effector T cell activation. Using Foxp3(GFP reporter mice for ex vivo isolation of regulatory T cells, we demonstrate that the dichotomy in infection tempo between early and late time points is directly paralleled by drastic changes in Foxp3(+ Treg suppressive potency. In complementary experiments using Foxp3(DTR mice, the significance of these shifts in Treg suppressive potency on infection outcome was verified by enumerating the relative impacts of regulatory T cell ablation on bacterial burden and effector T cell activation at early and late time points during persistent Salmonella infection. Moreover, Treg expression of CTLA-4 directly paralleled changes in suppressive potency, and the relative effects of Treg ablation could be largely recapitulated by CTLA-4 in vivo blockade. Together, these results demonstrate that dynamic regulation of Treg suppressive potency dictates the course of persistent bacterial infection.

  13. Status of perturbative QCD

    International Nuclear Information System (INIS)

    Collins, J.C.

    1985-01-01

    Progress in quantum chromodynamics in the past year is reviewed in these specific areas: proof of factorization for hadron-hadron collisions, fast calculation of higher order graphs, perturbative Monte Carlo calculations for hadron-hadron scattering, applicability of perturbative methods to heavy quark production, and understanding of the small-x problem. 22 refs

  14. FRW Cosmological Perturbations in Massive Bigravity

    CERN Document Server

    Comelli, D; Pilo, L

    2014-01-01

    Cosmological perturbations of FRW solutions in ghost free massive bigravity, including also a second matter sector, are studied in detail. At early time, we find that sub horizon exponential instabilities are unavoidable and they lead to a premature departure from the perturbative regime of cosmological perturbations.

  15. Chaotic inflation with metric and matter perturbations

    International Nuclear Information System (INIS)

    Feldman, H.A.; Brandenberger, R.H.

    1989-01-01

    A perturbative scheme to analyze the evolution of both metric and scalar field perturbations in an expanding universe is developed. The scheme is applied to study chaotic inflation with initial metric and scalar field perturbations present. It is shown that initial gravitational perturbations with wavelength smaller than the Hubble radius rapidly decay. The metric simultaneously picks up small perturbations determined by the matter inhomogeneities. Both are frozen in once the wavelength exceeds the Hubble radius. (orig.)

  16. Approximations of time-dependent phenomena in quantum mechanics: adiabatic versus sudden processes

    International Nuclear Information System (INIS)

    Melnichuk, S V; Dijk, W van; Nogami, Y

    2005-01-01

    By means of a one-dimensional model of a particle in an infinite square-well potential with one wall moving at a constant speed, we examine aspects of time-dependent phenomena in quantum mechanics such as adiabatic and sudden processes. The particle is assumed to be initially in the ground state of the potential with its initial width. The time dependence of the wavefunction of the particle in the well is generally more complicated when the potential well is compressed than when it is expanded. We are particularly interested in the case in which the potential well is suddenly compressed. The so-called sudden approximation is not applicable in this case. We also study the energy of the particle in the changing well as a function of time for expansion and contraction as well as for expansion followed by contraction and vice versa

  17. Left Ventricular Aneurysm: Sudden Unexpected Deaths in a 29-Year-Old Man.

    Science.gov (United States)

    Srettabunjong, Supawon

    2018-05-01

    Left ventricular aneurysm (LVA) is an abnormal dilated heart structure, either congenital or acquired. LVA is a rare cardiac condition with no symptoms in most cases, thus occasionally diagnosed during investigations of other diseases. Its association with certain cardiac complications and sudden cardiac deaths has been reported. However, its role as a cause of sudden unexpected death is rare. The author reported a sudden cardiac death in a 29-year-old man with LVA. Without a significant coronary artery disease and known etiologies of LVA, such an abnormal heart structure in the present case was considered congenital LVA. As no other possible mechanisms of death could be identified other than LVA with its associated pathologic lesions, mural thrombi, and dilated cardiomegaly, his death was attributable to fatal cardiac arrhythmia (most commonly ventricular tachycardia) secondary to LVA. © 2017 American Academy of Forensic Sciences.

  18. Sudden hearing loss after an explosion

    Directory of Open Access Journals (Sweden)

    Irfan Mohamad

    2013-12-01

    Full Text Available An 18-year-old man presented with a sudden onset of bilateral hearing loss after a home-made firework exploded near the right side of his scalp. The hearing loss was associated with tinnitus. Examination revealed an area of skin loss on the right pinna. There was mild bleeding from the right pinna and scalp at the mastoid region, which spontaneously resolved. An otoscopic examination is shown in Figure 1.

  19. Epilepsy and risk of death and sudden unexpected death in the young

    DEFF Research Database (Denmark)

    Holst, Anders Gaarsdal; Winkel, Bo Gregers; Risgaard, Bjarke

    2013-01-01

    Patients with epilepsy are at increased risk of premature death from all causes and likely also from sudden unexplained death (SUD). Many patients with epilepsy have significant comorbidity, and it is unclear how much of the increased risk can be explained by epilepsy itself. We aimed to chart...... the incidence of sudden unexpected death in epilepsy (SUDEP) and estimate the risk of death from all causes and SUD conferred by epilepsy independently....

  20. Guidelines for autopsy investigation of sudden cardiac death

    NARCIS (Netherlands)

    Basso, Cristina; Burke, Margaret; Fornes, Paul; Gallagher, Patrick J.; de Gouveia, Rosa Henriques; Sheppard, Mary; Thiene, Gaetano; van der Wal, Allard

    2010-01-01

    Although sudden cardiac death is one of the most important mode of death in Western Countries, pathologists and public health physicians have not given this problem the attention it deserves. New methods of preventing potentially fatal arrhythmias have been developed, and the accurate diagnosis of

  1. Guidelines for autopsy investigation of sudden cardiac death

    NARCIS (Netherlands)

    Basso, C.; Burke, M.; Fornes, P.; Gallagher, P. J.; de Gouveia, R. H.; Sheppard, M.; Thiene, G.; van der Wal, A.

    2010-01-01

    Although sudden cardiac death is one of the most important mode of death in Western Countries, pathologists and public health physicians have not given this problem the attention it deserves. New methods of preventing potentially fatal arrhythmias have been developed and the accurate diagnosis of

  2. Guidelines for autopsy investigation of sudden cardiac death

    NARCIS (Netherlands)

    Basso, Cristina; Burke, Margaret; Fornes, Paul; Gallagher, Patrick J.; de Gouveia, Rosa Henriques; Sheppard, Mary; Thiene, Gaetano; van der Wal, Allard

    2008-01-01

    Although sudden cardiac death is one of the most important mode of death in Western Countries, pathologists and public health physicians have not given this problem the attention it deserves. New methods of preventing potentially fatal arrhythmias have been developed, and the accurate diagnosis of

  3. Cosmological perturbations in antigravity

    Science.gov (United States)

    Oltean, Marius; Brandenberger, Robert

    2014-10-01

    We compute the evolution of cosmological perturbations in a recently proposed Weyl-symmetric theory of two scalar fields with oppositely signed conformal couplings to Einstein gravity. It is motivated from the minimal conformal extension of the standard model, such that one of these scalar fields is the Higgs while the other is a new particle, the dilaton, introduced to make the Higgs mass conformally symmetric. At the background level, the theory admits novel geodesically complete cyclic cosmological solutions characterized by a brief period of repulsive gravity, or "antigravity," during each successive transition from a big crunch to a big bang. For simplicity, we consider scalar perturbations in the absence of anisotropies, with potential set to zero and without any radiation. We show that despite the necessarily wrong-signed kinetic term of the dilaton in the full action, these perturbations are neither ghostlike nor tachyonic in the limit of strongly repulsive gravity. On this basis, we argue—pending a future analysis of vector and tensor perturbations—that, with respect to perturbative stability, the cosmological solutions of this theory are viable.

  4. Gauge-invariant cosmological density perturbations

    International Nuclear Information System (INIS)

    Sasaki, Misao.

    1986-06-01

    Gauge-invariant formulation of cosmological density perturbation theory is reviewed with special emphasis on its geometrical aspects. Then the gauge-invariant measure of the magnitude of a given perturbation is presented. (author)

  5. Twisting perturbed parafermions

    Directory of Open Access Journals (Sweden)

    A.V. Belitsky

    2017-07-01

    Full Text Available The near-collinear expansion of scattering amplitudes in maximally supersymmetric Yang–Mills theory at strong coupling is governed by the dynamics of stings propagating on the five sphere. The pentagon transitions in the operator product expansion which systematize the series get reformulated in terms of matrix elements of branch-point twist operators in the two-dimensional O(6 nonlinear sigma model. The facts that the latter is an asymptotically free field theory and that there exists no local realization of twist fields prevents one from explicit calculation of their scaling dimensions and operator product expansion coefficients. This complication is bypassed making use of the equivalence of the sigma model to the infinite-level limit of WZNW models perturbed by current–current interactions, such that one can use conformal symmetry and conformal perturbation theory for systematic calculations. Presently, to set up the formalism, we consider the O(3 sigma model which is reformulated as perturbed parafermions.

  6. Effect of Hydrotherapy on Static and Dynamic Balance in Older Adults: Comparison of Perturbed and Non-Perturbed Programs

    Directory of Open Access Journals (Sweden)

    Elham Azimzadeh

    2013-01-01

    Full Text Available Objectives: Falling is a main cause of mortality in elderly. Balance training exercises can help to prevent falls in older adults. According to the principle of specificity of training, the perturbation-based trainings are more similar to the real world. So these training programs can improve balance in elderly. Furthermore, exercising in an aquatic environment can reduce the limitations for balance training rather than a non-aquatic on. The aim of this study is comparing the effectiveness of perturbed and non-perturbed balance training programs in water on static and dynamic balance in aforementioned population group. Methods & Materials: 37 old women (age 80-65, were randomized to the following groups: perturbation-based training (n=12, non-perturbation-based training (n=12 and control (n=13 groups. Static and dynamic balance had been tested before and after the eight weeks of training by the postural stability test of the Biodex balance system using dynamic (level 4 and static platform. The data were analyzed by one sample paired t-test, Independent t-test and ANOVA. Results: There was a significant improvement for all indexes of static and dynamic balance in perturbation-based training (P<0.05. However, in non-perturbed group, all indexes were improved except ML (P<0.05. ANOVA showed that perturbed training was more effective than non-perturbed training on both static and dynamic balances. Conclusion: The findings confirmed the specificity principle of training. Although balance training can improve balance abilities, these kinds of trainings are not such specific for improving balance neuromuscular activities.The perturbation-based trainings can activate postural compensatory responses and reduce falling risk. According to results, we can conclude that hydrotherapy especially with perturbation-based programs will be useful for rehabilitation interventions in elderly .

  7. Multiplicative perturbations of local C-semigroups

    Indian Academy of Sciences (India)

    In this paper, we establish some left and right multiplicative perturbation theorems concerning local -semigroups when the generator of a perturbed local -semigroup S ( ⋅ ) may not be densely defined and the perturbation operator is a bounded linear operator from D ( A ) ¯ into () such that = on D ( A ) ¯ ...

  8. Multiplicative perturbations of local C-semigroups

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... In this paper, we establish some left and right multiplicative perturbation theorems concerning local -semigroups when the generator of a perturbed local -semigroup S(⋅) may not be densely defined and the perturbation operator is a bounded linear operator from ¯D(A) into () such that = ...

  9. Perturbative QCD (1/3)

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    Perturbative QCD is the general theoretical framework for describing hard scattering processes yielding multiparticle production at hadron colliders. In these lectures, we shall introduce fundamental features of perturbative QCD and describe its application to several high energy collider processes, including jet production in electron-positron annihilation, deep inelastic scattering, Higgs boson and gauge boson production at the LHC.

  10. Numerical simulation of the transport phenomena due to sudden heating in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Lei, S.Y.; Zheng, G.Y.; Wang, B.X.; Yang, R.G.; Xia, C.M.

    1997-07-01

    Such process as wet porous media suddenly heated by hot fluids frequently occurs in nature and in industrial applications. The three-variable simulation model was developed to predict violent transport phenomena due to sudden heating in porous media. Two sets of independent variables were applied to different regions in porous media in the simulation. For the wet zone, temperature, wet saturation and air pressure were used as the independent variables. For the dry zone, the independent variables were temperature, vapor pressure and air pressure. The model simulated two complicated transport processes in wet unsaturated porous media which is suddenly heated by melting metal or boiling water. The effect of the gas pressure is also investigated on the overall transport phenomena.

  11. Contrast-enhanced MR imaging of the endolymphatic sac in patients with sudden hearing loss

    International Nuclear Information System (INIS)

    Naganawa, Shinji; Koshikawa, Tokiko; Fukatsu, Hiroshi; Ishigaki, Takeo; Nakashima, Tsutomu; Ichinose, Nobuyasu

    2002-01-01

    Our objective was to evaluate the frequency of contrast enhancement of the endolymphatic sac in patients with sudden hearing loss. Forty consecutive patients with sudden sensorineural hearing loss (20 males and 20 females; age range 11-82 years), 40 age-matched control subjects, and 5 patients with Meniere's disease were examined using the same imaging protocol on a 1.5-T MR system. Pre- and post-contrast-enhanced T1-weighted 3D spoiled gradient-echo sequence (3D SPGR; TR/TE=23/10 ms, no. of excitations=1, flip angle=30 ) images were obtained using a voxel size of 0.6 x 0.7 x 0.8 mm 3 . Contrast enhancement in the area of the endolymphatic sac was assessed by two radiologists, and the frequency of contrast enhancement was compared between the three study groups. Enhancement of the ipsilateral endolymphatic sac was observed in 30 of the 40 patients with sudden hearing loss (75%). Twenty of these 30 patients also showed enhancement on the contralateral side, and 1 patient showed enhancement only on the contralateral side. Only 1 of the 5 patients with Meniere's disease showed enhancement. Nine of the 40 control subjects (22.5%) showed enhancement (bilateral enhancement in 5 subjects, unilateral in 4). The frequency of enhancement in patients with sudden hearing loss was significantly higher than that in control subjects (P<0.0001) or patients with Meniere's disease (P<0.05). The frequency of contrast enhancement of the endolymphatic sac is significantly increased in patients with sudden hearing loss, but further study is necessary to clarify the relationship between this finding and the pathophysiology of sudden hearing loss. (orig.)

  12. Geometric Hamiltonian structures and perturbation theory

    International Nuclear Information System (INIS)

    Omohundro, S.

    1984-08-01

    We have been engaged in a program of investigating the Hamiltonian structure of the various perturbation theories used in practice. We describe the geometry of a Hamiltonian structure for non-singular perturbation theory applied to Hamiltonian systems on symplectic manifolds and the connection with singular perturbation techniques based on the method of averaging

  13. Guidelines for autopsy investigation of sudden cardiac death

    DEFF Research Database (Denmark)

    Basso, Cristina; Aguilera, Beatriz; Banner, Jytte

    2017-01-01

    diagnosis of the causes of SCD is now of particular importance. Pathologists are responsible for determining the precise cause and mechanism of sudden death but there is still considerable variation in the way in which they approach this increasingly complex task. The Association for European Cardiovascular...

  14. Recent advances in understanding and prevention of sudden cardiac death [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Jamie I. Vandenberg

    2017-08-01

    Full Text Available There have been tremendous advances in the diagnosis and treatment of heart disease over the last 50 years. Nevertheless, it remains the number one cause of death. About half of heart-related deaths occur suddenly, and in about half of these cases the person was unaware that they had underlying heart disease. Genetic heart disease accounts for only approximately 2% of sudden cardiac deaths, but as it typically occurs in younger people it has been a particular focus of activity in our quest to not only understand the underlying mechanisms of cardiac arrhythmogenesis but also develop better strategies for earlier detection and prevention. In this brief review, we will highlight trends in the recent literature focused on sudden cardiac death in genetic heart diseases and how these studies are contributing to a broader understanding of sudden death in the community.

  15. About a cocaine-associated sudden death casework.

    Science.gov (United States)

    Pileggi, P; Teatino, A; La Marca, A; Barbaro, A

    2004-12-02

    A man 24-year-old died suddenly while he was doing shopping. It was supposed that the death was caused by ictus or by cardiac pathology. During the autopsy, some biological samples were taken (hair, urine, blood and lachrymal liquid) for the toxicological analysis and also the heart, some fragments from the liver, lungs, spleen, and kidneys for the histo-pathological analysis.

  16. Clinical Simulation and Workflow by use of two Clinical Information Systems, the Electronic Health Record and Digital Dictation

    DEFF Research Database (Denmark)

    Schou Jensen, Iben; Koldby, Sven

    2013-01-01

    digital dictation and the EHR (electronic health record) were simulated in realistic and controlled clinical environments. Useful information dealing with workflow and patient safety were obtained. The clinical simulation demonstrated that the EHR locks during use of the integration of digital dictation......Clinical information systems do not always support clinician workflows. An increasing number of unintended clinical inci-dents might be related to implementation of clinical infor-mation systems and to a new registration praxis of unin-tended clinical incidents. Evidence of performing clinical...... simulations before implementation of new clinical information systems provides the basis for use of this method. The intention has been to evaluate patient safety issues, functionality, workflow, and usefulness of a new solution before implementation in the hospitals. Use of a solution which integrates...

  17. Cerebral Paragonimiasis Presenting with Sudden Death.

    Science.gov (United States)

    Amaro, Deirdre E; Cowell, Annie; Tuohy, Marion J; Procop, Gary W; Morhaime, Jacquelyn; Reed, Sharon L

    2016-12-07

    A 58-year-old Korean-born woman with a history of seizures and psychiatric issues was found dead at home. Autopsy was notable for large, calcified nodules that had nearly replaced her right temporal lobe. Histologic examination revealed the presence of Paragonimus eggs. This case demonstrates a rare manifestation of an aberrantly migrated lung fluke that resulted in epilepsy and sudden death years after the initial infection. © The American Society of Tropical Medicine and Hygiene.

  18. Sudden behavior change in a cat.

    Science.gov (United States)

    Gelberg, H B

    2013-11-01

    A 5-year-old, spayed female, domestic short-haired cat had a 10-day history of sudden behavioral changes followed by seizures. Blood parameters were in the reference ranges, and radiographs failed to detect a mass lesion in the brain. Euthanasia was followed by rabies testing, which was negative. Gross lesions were absent. Histologic changes were present only in the brain and consisted of foci of hippocampal pyramidal cell loss, mild gliosis, pallor of the associated neuropil, and neovascularization.

  19. Sudden death in paediatrics as a traumatic experience for critical care nurses.

    Science.gov (United States)

    Lima, Lígia; Gonçalves, Sandra; Pinto, Cândida

    2018-01-01

    Research shows that nurses working in critical care units and in particular, paediatric units, are at risk of developing symptoms of secondary traumatic stress (STS). However, little attention has been given to this phenomenon when associated with situations of sudden death in paediatrics. This study aimed to examine the impact of sudden death in paediatrics on nurses working in paediatrics critical care units and to explore nurses' experiences of this event. This study used a mixed-methods design. The Impact of Event Scale - Revised was used for investigating the presence of STS symptoms. In addition, an interview was conducted with six nurses. Fifty-seven percent of nurses responded to the surveys and six nurses were interviewed. The results showed that the sudden death of children and adolescents is an event that elicits symptoms of STS in nurses. The quantitative assessment, revealed that 19·4% presented total scores indicating high impact. The participants interviewed described experiences of subjective distress, such as intrusive thoughts, avoidance and hyperarousal. Other factors were also reported as influencing the experience of the sudden death of a child/adolescent, namely, the child's age, the cause of death and the family's reaction to the loss. According to the participants, the emotional impact was also determined by parenthood, previous training and professional experience. Sudden death in paediatric critical care units is one of the most difficult situations in nursing practice and elicits STS symptoms, which may severely impact the physical and psychological health of nurses and ultimately affect the quality of the provided care. This study emphasizes the need for promoting better conditions for professional practice, namely, with regard to emotional support, as well as training programmes for skills development in the area of management of traumatic situations and of communication with clients. © 2017 British Association of Critical Care

  20. Non-perturbative effects in supersymmetry

    International Nuclear Information System (INIS)

    Veneziano, G.

    1987-01-01

    Some non perturbative aspects of globally supersymmetric (SUSY) gauge theories are discussed. These share with their non-supersymmetric analogues interesting non perturbative features, such as the spontaneous breaking of chiral symmetries via condensates. What is peculiar about supersymmetric theories, however, is that one is able to say a lot about non-perturbative effects even without resorting to elaborate numerical calculations: general arguments, supersymmetric and chiral Ward identities and analytic, dynamical calculations will turn out to effectively determine most of the supersymmetric vacuum properties. 28 references, 5 figures

  1. The theory of singular perturbations

    CERN Document Server

    De Jager, E M

    1996-01-01

    The subject of this textbook is the mathematical theory of singular perturbations, which despite its respectable history is still in a state of vigorous development. Singular perturbations of cumulative and of boundary layer type are presented. Attention has been given to composite expansions of solutions of initial and boundary value problems for ordinary and partial differential equations, linear as well as quasilinear; also turning points are discussed. The main emphasis lies on several methods of approximation for solutions of singularly perturbed differential equations and on the mathemat

  2. Adaptation to sudden unexpected loading of the low back - the effects of repeated trials

    DEFF Research Database (Denmark)

    Skotte, J.H.; Fallentin, N.; Pedersen, Mogens Theisen

    2004-01-01

    The purpose of this study was to investigate short-term changes in reactions to sudden unexpected loading of the low back. The study utilized a set-up where a horizontal force of 58 N pointing forward suddenly was applied to the upper part of the subject's trunk. EMG activity from the erector...

  3. Local perturbations perturb—exponentially–locally

    International Nuclear Information System (INIS)

    De Roeck, W.; Schütz, M.

    2015-01-01

    We elaborate on the principle that for gapped quantum spin systems with local interaction, “local perturbations [in the Hamiltonian] perturb locally [the groundstate].” This principle was established by Bachmann et al. [Commun. Math. Phys. 309, 835–871 (2012)], relying on the “spectral flow technique” or “quasi-adiabatic continuation” [M. B. Hastings, Phys. Rev. B 69, 104431 (2004)] to obtain locality estimates with sub-exponential decay in the distance to the spatial support of the perturbation. We use ideas of Hamza et al. [J. Math. Phys. 50, 095213 (2009)] to obtain similarly a transformation between gapped eigenvectors and their perturbations that is local with exponential decay. This allows to improve locality bounds on the effect of perturbations on the low lying states in certain gapped models with a unique “bulk ground state” or “topological quantum order.” We also give some estimate on the exponential decay of correlations in models with impurities where some relevant correlations decay faster than one would naively infer from the global gap of the system, as one also expects in disordered systems with a localized groundstate

  4. Perturbation theory in large order

    International Nuclear Information System (INIS)

    Bender, C.M.

    1978-01-01

    For many quantum mechanical models, the behavior of perturbation theory in large order is strikingly simple. For example, in the quantum anharmonic oscillator, which is defined by -y'' + (x 2 /4 + ex 4 /4 - E) y = 0, y ( +- infinity) = 0, the perturbation coefficients, A/sub n/, in the expansion for the ground-state energy, E(ground state) approx. EPSILON/sub n = 0//sup infinity/ A/sub n/epsilon/sup n/, simplify dramatically as n → infinity: A/sub n/ approx. (6/π 3 )/sup 1/2/(-3)/sup n/GAMMA(n + 1/2). Methods of applied mathematics are used to investigate the nature of perturbation theory in quantum mechanics and show that its large-order behavior is determined by the semiclassical content of the theory. In quantum field theory the perturbation coefficients are computed by summing Feynman graphs. A statistical procedure in a simple lambda phi 4 model for summing the set of all graphs as the number of vertices → infinity is presented. Finally, the connection between the large-order behavior of perturbation theory in quantum electrodynamics and the value of α, the charge on the electron, is discussed. 7 figures

  5. Some remarks on perturbation in flame photometry; Quelques remarques sur les perturbations dans la photometrie de flamme

    Energy Technology Data Exchange (ETDEWEB)

    Malinowski, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    After classifying the various types of perturbations, the author attempts to explain their causes. He then gives examples of possibilities of suppressing them. (author) [French] Ayant classe les divers types de perturbations en categories, l'auteur essaie d'expliquer les causes de ces perturbations. Il donne ensuite des exemples de possibilites de les supprimer. (auteur)

  6. Perturbation theory of effective Hamiltonians

    International Nuclear Information System (INIS)

    Brandow, B.H.

    1975-01-01

    This paper constitutes a review of the many papers which have used perturbation theory to derive ''effective'' or ''model'' Hamiltonians. It begins with a brief review of nondegenerate and non-many-body perturbation theory, and then considers the degenerate but non-many-body problem in some detail. It turns out that the degenerate perturbation problem is not uniquely defined, but there are some practical criteria for choosing among the various possibilities. Finally, the literature dealing with the linked-cluster aspects of open-shell many-body systems is reviewed. (U.S.)

  7. [Analyses of clinical features and efficacy of sudden deafness with vertigo and dizziness].

    Science.gov (United States)

    Liu, Bo; Han, Demin; Zhang, Yi; Li, Yongxin; Gong, Shusheng; Chen, Xiuwu; Meng, Xixi; Tang, Junxiang; Xiang, Jie; Jiang, Xuejun; Yang, Ning; Tian, Ying; Hui, Lian; Feng, Shuai

    2015-06-01

    To investigate the clinical characteristics and the effect of drug treatment for sudden hearing loss with vertigo or dizziness. In a prospective, randomized, single blinded randomized multicenter clinical study, patients with sudden deafness, ranging in age from 18 to 65 years old, with a duration less than 2 weeks, and with no any medical treatments were collected. In accordance with the hearing curve, those patients were divided into four types, i.e., low and intermediate frequency descent type; high frequency descent type; fall flat type; and total deafness type. Each type was treated by four different treatment options, according to the unified design of the random table, and randomly selected one of the options for treatment. The efficacy of the patients with sudden deafness with vertigo and dizziness was analyzed statistically after the follow-up for 4 weeks. SPSS 13.0 software was used to analyze the data. In August 2007 to October 2011, 33 hospitals in the country included 1 024 patients with sudden deafness in line with the inclusion criteria, of whom 296 (28.91%) were accompanied by vertigo/dizziness symptoms, 126 were males and 170 were females, with an average age of (41.2 ± 13.5) years old. types of the different audiometric curves of sudden deafness, the occurrence of complete deafness with vertigo/dizziness was the highest (44.93%), followed by flat down type (25.87%), high frequency descent type (21.28%) and low intermediate frequency descent type (18.54%). After the standard treatment, the vertigo and dizziness symptoms of the sudden deafness patients could disappear, and the hearing in each group was obviously improved. The hearing curative effect on patients accompanied by vertigo/dizziness of low frequency and intermediate frequency descent type was the best, and the total efficiency can reach up to 94.74%, with the cure rate of 68.42%; followed by flat type, in which the total effective rate was 80.76%, with the recovery rate of 22.12%; and

  8. Sudden death in patients with myocardial infarction and left ventricular dysfunction, heart failure, or both

    DEFF Research Database (Denmark)

    Solomon, Scott D; Zelenkofske, Steve; McMurray, John J V

    2005-01-01

    BACKGROUND: The risk of sudden death from cardiac causes is increased among survivors of acute myocardial infarction with reduced left ventricular systolic function. We assessed the risk and time course of sudden death in high-risk patients after myocardial infarction. METHODS: We studied 14......,609 patients with left ventricular dysfunction, heart failure, or both after myocardial infarction to assess the incidence and timing of sudden unexpected death or cardiac arrest with resuscitation in relation to the left ventricular ejection fraction. RESULTS: Of 14,609 patients, 1067 (7 percent) had an event...... percent confidence interval, 0.11 to 0.18 percent) after 2 years. Patients with a left ventricular ejection fraction of 30 percent or less were at highest risk in this early period (rate, 2.3 percent per month; 95 percent confidence interval, 1.8 to 2.8 percent). Nineteen percent of all sudden deaths...

  9. On the non-perturbative effects

    International Nuclear Information System (INIS)

    Manjavidze, J.; Voronyuk, V.

    2004-01-01

    The quantum correspondence principle based on the time reversibility is adopted to take into account the non-Abelian symmetry constrains. The main properties of the new strong-coupling perturbation theory which take into account non-perturbative effects are described. (author)

  10. The effect of amount and tangibility of endowment and certainty of recipients on selfishness in a modified dictator game.

    Science.gov (United States)

    Chang, Shao-Chuan; Lin, Li-Yun; Horng, Ruey-Yun; Wang, Yau-De

    2014-06-01

    Taiwanese college students (N = 101) participated in the study to examine the effects of the amount of an endowment, the tangibility of an endowment, and the certainty of the recipient on selfishness in a modified dictator game. Results showed that dictators were more selfish when allocating tangible (money) than less tangible (honor credits) endowments. Selfishness was higher when large amounts of money were involved. The certainty of the recipient was manipulated by whether the recipient was chosen and announced before or after the decision. Unexpectedly, participants were more self-interested in the certain-recipient condition than in the uncertain-recipient condition. In the honor condition, the amount of an endowment and the certainty of the recipient did not affect participants' allocations.

  11. Research on a Sudden Explosion and its Environmental Impact

    Science.gov (United States)

    Ye, Maosheng; Ma, Hui; Ni, Qingwei

    2017-12-01

    A sudden blast was chosen as the studied topic. Also, one computer based virtual experimentation was used to estimate the dimensional impact of initial pollutant plume from blasts. Self-made method using Mathcad code was used to generate the output for the period of the first tenth of a second (1deci-second) to 1minute (60s) of the blast at the point source. It also depicted long-range air pollution travel within the first 1 to 10 minutes. In the case study, it assumed an average directional diffusivity of 1720 m2s-1 which is about 25 per cent of the average generated speed of common explosives. The newly developed model revealed a plume cloud impact of 6.8×107µgm-3 in the first 1millisecond (0.01s) which decayed suddenly to a value of 1.7×107µgm-3 in the first 1decisecond (0.1s). The impact concentration at the point source by the end of the first second (1.0s) was 3.2×105µgm-3 which implied a 99.5% sudden decay when compared to 0.01s concentration value at the emission point source. Computerized experiments observed that air pollutants release from explosives/blasts were dispersed into the atmosphere in the first few seconds by forceful injection instead of by gradual dispersion as is the case with normal air pollutants plume releases.

  12. Thyroid gland and cerebella lesions: New risk factors for sudden cardiac death in schizophrenia?

    Science.gov (United States)

    Scorza, Fulvio A; Cavalheiro, Esper A; de Albuquerque, Marly; de Albuquerque, Juliana; Cysneiros, Roberta M; Terra, Vera C; Arida, Ricardo M

    2011-02-01

    People with schizophrenia show a two to threefold increased risk to die prematurely than those without schizophrenia. Patients' life style, suicide, premature development of cardiovascular disease, high prevalence of metabolic syndrome and sudden cardiac death are well-known causes of the excess mortality. The exact pathophysiological cause of sudden death in schizophrenia is unknown, but it is likely that cardiac arrhythmia and respiratory abnormalities play potential role. Some antipsychotics may be associated with cardiovascular adverse events (e.g., QT interval prolongation) and lesions in specific brain regions, such as cerebella may be associated with respiratory abnormalities, suggesting that metabolic and brain dysfunction could lead to sudden cardiac death in patients with schizophrenia. However, exact knowledge regarding the association of these findings and schizophrenia is lacking. As subclinical hyperthyroidism has been linked with increased risk of cardiovascular disease and cerebella progressive atrophy has been observed in patients with schizophrenia, we propose in this paper that subclinical thyroid dysfunction and cerebella volume loss could be considered as new risk factor for sudden cardiac death in schizophrenia. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Reactive Balance Control in Response to Perturbation in Unilateral Stance: Interaction Effects of Direction, Displacement and Velocity on Compensatory Neuromuscular and Kinematic Responses

    Science.gov (United States)

    Freyler, Kathrin; Gollhofer, Albert; Colin, Ralf; Brüderlin, Uli; Ritzmann, Ramona

    2015-01-01

    Unexpected sudden perturbations challenge postural equilibrium and require reactive compensation. This study aimed to assess interaction effects of the direction, displacement and velocity of perturbations on electromyographic (EMG) activity, centre of pressure (COP) displacement and joint kinematics to detect neuromuscular characteristics (phasic and segmental) and kinematic strategies of compensatory reactions in an unilateral balance paradigm. In 20 subjects, COP displacement and velocity, ankle, knee and hip joint excursions and EMG during short (SLR), medium (MLR) and long latency response (LLR) of four shank and five thigh muscles were analysed during random surface translations varying in direction (anterior-posterior (sagittal plane), medial-lateral (frontal plane)), displacement (2 vs. 3cm) and velocity (0.11 vs. 0.18m/s) of perturbation when balancing on one leg on a movable platform. Phases: SLR and MLR were scaled to increased velocity (Pjoints compensated for both increasing displacement and velocity in all directions (Pjoint deflections were particularly sensitive to increasing displacement in the sagittal (Pjoint deflections to increasing velocity in the frontal plane (P<0.05). COP measures increased with increasing perturbation velocity and displacement (P<0.05). Interaction effects indicate that compensatory responses are based on complex processes, including different postural strategies characterised by phasic and segmental specifications, precisely adjusted to the type of balance disturbance. To regain balance after surface translation, muscles of the distal segment govern the quick regain of equilibrium; the muscles of the proximal limb serve as delayed stabilisers after a balance disturbance. Further, a kinematic distinction regarding the compensation for balance disturbance indicated different plane- and segment-specific sensitivities with respect to the determinants displacement and velocity. PMID:26678061

  14. Next of kin’s experiences of sudden and unexpected death from stroke - a study of narratives

    Science.gov (United States)

    2013-01-01

    Background Death always evokes feelings in those close to the afflicted person. When death comes suddenly the time for preparation is minimal and the next of kin have to cope with the situation despite their own sorrow. The suddenness is found to be stressful for the next of kin and communication both with healthcare professionals and information about what has happened has been found helpful. The aim of this study was to illuminate the experiences of next of kin from the sudden and unexpected death of a relative from acute stroke. Methods Data was collected over a 12-month period in 2009–2010. Twelve next of kin of patients cared for in stroke units who died suddenly and unexpectedly from stroke were interviewed using a narrative method. The narratives were analyzed using narrative thematic analysis. Results Three themes emerged showing facets of next of kin’s experiences of a relative’s sudden and unexpected death from stroke: Divided feelings about the sudden and unexpected death; Perception of time and directed attention when keeping vigil; Contradictions and arbitrary memories when searching for understanding. Conclusions To have to live in the aftermath of severe stroke is absolute horror in people’s imagination and death is seen as the lesser of two evils. The sudden and unexpected death totally pervades the next of kin’s life, directs their attention to the dying person and even causes them to forget themselves and their own needs, and leads to difficulties in information intake. It is a challenge for the healthcare professionals to be able to identify the individual needs of the next of kin in this situation. PMID:23590246

  15. Nationwide study of sudden cardiac death in persons aged 1-35 years

    DEFF Research Database (Denmark)

    Winkel, Bo Gregers; Holst, Anders Gaarsdal; Theilade, Juliane

    2011-01-01

    Aims The aim of this investigation was to study the incidence of sudden cardiac death (SCD) in persons aged 1-35 years in a nationwide setting (5.38 million people) by systematic evaluation of all deaths. Methods and results All deaths in persons aged 1-35 years in Denmark in 2000-06 were included....... Death certificates were read independently by two physicians. The National Patient Registry was used to retrieve information on prior medical history. All autopsy reports were read and the cause of death was revised based on autopsy findings. We identified 625 cases of sudden unexpected death (10......% of all deaths), of which 156 (25%) were not autopsied. Of the 469 autopsied cases, 314 (67%) were SCD. The most common cardiac cause of death was ischaemic heart disease (13%); 29% of autopsied sudden unexpected death cases were unexplained. In 45% of SCD cases, the death was witnessed; 34% died during...

  16. Congenital and hereditary causes of sudden cardiac death in young adults: diagnosis, differential diagnosis, and risk stratification.

    Science.gov (United States)

    Stojanovska, Jadranka; Garg, Anubhav; Patel, Smita; Melville, David M; Kazerooni, Ella A; Mueller, Gisela C

    2013-01-01

    Sudden cardiac death is defined as death from unexpected circulatory arrest-usually a result of cardiac arrhythmia-that occurs within 1 hour of the onset of symptoms. Proper and timely identification of individuals at risk for sudden cardiac death and the diagnosis of its predisposing conditions are vital. A careful history and physical examination, in addition to electrocardiography and cardiac imaging, are essential to identify conditions associated with sudden cardiac death. Among young adults (18-35 years), sudden cardiac death most commonly results from a previously undiagnosed congenital or hereditary condition, such as coronary artery anomalies and inherited cardiomyopathies (eg, hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy [ARVC], dilated cardiomyopathy, and noncompaction cardiomyopathy). Overall, the most common causes of sudden cardiac death in young adults are, in descending order of frequency, hypertrophic cardiomyopathy, coronary artery anomalies with an interarterial or intramural course, and ARVC. Often, sudden cardiac death is precipitated by ventricular tachycardia or fibrillation and may be prevented with an implantable cardioverter defibrillator (ICD). Risk stratification to determine the need for an ICD is challenging and involves imaging, particularly echocardiography and cardiac magnetic resonance (MR) imaging. Coronary artery anomalies, a diverse group of congenital disorders with a variable manifestation, may be depicted at coronary computed tomographic angiography or MR angiography. A thorough understanding of clinical risk stratification, imaging features, and complementary diagnostic tools for the evaluation of cardiac disorders that may lead to sudden cardiac death is essential to effectively use imaging to guide diagnosis and therapy.

  17. Evolution of the curvature perturbations during warm inflation

    International Nuclear Information System (INIS)

    Matsuda, Tomohiro

    2009-01-01

    This paper considers warm inflation as an interesting application of multi-field inflation. Delta-N formalism is used for the calculation of the evolution of the curvature perturbations during warm inflation. Although the perturbations considered in this paper are decaying after the horizon exit, the corrections to the curvature perturbations sourced by these perturbations can remain and dominate the curvature perturbations at large scales. In addition to the typical evolution of the curvature perturbations, inhomogeneous diffusion rate is considered for warm inflation, which may lead to significant non-Gaussianity of the spectrum

  18. F-MARC: promoting the prevention and management of sudden cardiac arrest in football

    OpenAIRE

    Kramer, Efraim Benjamin; Dvorak, J; Schmied, C; Meyer, T

    2015-01-01

    Sudden cardiac death is the most common cause of unnatural death in football. To prevent and urgently manage sudden cardiac arrest on the football field-of-play, F-MARC (FIFA Medical and Research Centre) has been fully committed to a programme of research, education, standardisation and practical implementation. This strategy has detected football players at medical risk during mandatory precompetition medical assessments. Additionally, FIFA has (1) sponsored internationally accepted guidelin...

  19. Perturbative spacetimes from Yang-Mills theory

    Energy Technology Data Exchange (ETDEWEB)

    Luna, Andrés [School of Physics and Astronomy, University of Glasgow,Glasgow G12 8QQ, Scotland (United Kingdom); Monteiro, Ricardo [Theoretical Physics Department, CERN,Geneva (Switzerland); Nicholson, Isobel; Ochirov, Alexander; O’Connell, Donal [Higgs Centre for Theoretical Physics,School of Physics and Astronomy, The University of Edinburgh,Edinburgh EH9 3JZ, Scotland (United Kingdom); Westerberg, Niclas [Institute of Photonics and Quantum Sciences,School of Engineering and Physical Sciences, Heriot-Watt University,Edinburgh (United Kingdom); Higgs Centre for Theoretical Physics,School of Physics and Astronomy, The University of Edinburgh,Edinburgh EH9 3JZ, Scotland (United Kingdom); White, Chris D. [Centre for Research in String Theory,School of Physics and Astronomy, Queen Mary University of London,327 Mile End Road, London E1 4NS (United Kingdom)

    2017-04-12

    The double copy relates scattering amplitudes in gauge and gravity theories. In this paper, we expand the scope of the double copy to construct spacetime metrics through a systematic perturbative expansion. The perturbative procedure is based on direct calculation in Yang-Mills theory, followed by squaring the numerator of certain perturbative diagrams as specified by the double-copy algorithm. The simplest spherically symmetric, stationary spacetime from the point of view of this procedure is a particular member of the Janis-Newman-Winicour family of naked singularities. Our work paves the way for applications of the double copy to physically interesting problems such as perturbative black-hole scattering.

  20. Nonperturbative perturbation theory

    International Nuclear Information System (INIS)

    Bender, C.M.

    1989-01-01

    In this talk we describe a recently proposed graphical perturbative calculational scheme for quantum field theory. The basic idea is to expand in the power of the interaction term. For example, to solve a λφ 4 theory in d-dimensional space-time, we introduce a small parameter δ and consider a λ(φ 2 ) 1+δ field theory. We show how to expand such a theory as a series in powers of δ. The resulting perturbation series appears to have a finite radius of convergence and numerical results for low-dimensional models are good. We have computed the two-point and four-point Green's functions to second order in powers of δ and the 2n-point Green's functions (n>2) to order δ. We explain how to renormalize the theory and show that, to first order in powers of δ, when δ>0 and d≥4 the theory is free. This conclusion remains valid to second order in powers of δ, and we believe that it remains valid to all orders in powers of δ. The new perturbative scheme is consistent with global supersymmetry invariance. We examine a two-dimensional supersymmetric quantum field theory in which we do not know of any other means for doing analytical calculations. We illustrate the power of this new technique by computing the ground-state energy density E to second order in this new perturbation theory. We show that there is a beautiful and delicate cancellation between infinite classes of graphs which leads to the result that E=0. (orig.)

  1. THE PSYCHOBIOLOGY OF MEALS

    NARCIS (Netherlands)

    WOODS, SC; STRUBBE, JH; Woods, Stephen C.

    Meals are considered as bouts of behavior that, although necessary for supplying nutrients to the body, result in undesirable perturbations of homeostatically controlled parameters. If the environment dictates that an animal mainly eat very large meals, these meal-associated perturbations become

  2. Sudden unilateral deafness with endolymphatic sac adenocarcinoma: MRI

    International Nuclear Information System (INIS)

    Gaeta, M.; Blandino, A.; Minutoli, F.; Pandolfo, I.

    1999-01-01

    A 30-year-old man presented with sudden left deafness and vertigo. CT showed an osteolytic retrolabyrinthine tumour of the left temporal bone. High signal from the tumour and labyrinth was seen on fat-suppressed T 1-weighted images. At surgery, a haemorrhagic papillary-cystic adenocarcinoma of the endolymphatic sac was found. (orig.)

  3. Sudden unilateral deafness with endolymphatic sac adenocarcinoma: MRI

    Energy Technology Data Exchange (ETDEWEB)

    Gaeta, M.; Blandino, A.; Minutoli, F.; Pandolfo, I. [Inst. of Radiological Sciences, Univ. of Messina (Italy)

    1999-10-01

    A 30-year-old man presented with sudden left deafness and vertigo. CT showed an osteolytic retrolabyrinthine tumour of the left temporal bone. High signal from the tumour and labyrinth was seen on fat-suppressed T 1-weighted images. At surgery, a haemorrhagic papillary-cystic adenocarcinoma of the endolymphatic sac was found. (orig.)

  4. Temporal epidemiology of sudden oak death in Oregon

    Science.gov (United States)

    Ebba K. Peterson; Everett M. Hansen; Alan Kanaskie

    2015-01-01

    An effort to eradicate Phytophthora ramorum, causal agent of sudden oak death, has been underway since its discovery in Oregon forests. Using an information-theoretical approach, we sought to model yearly variation in the size of newly infested areas and dispersal distance. Maximum dispersal distances were best modeled by spring and winter...

  5. Relationship between coronary atherosclerosis and 'sudden cardiac death'

    International Nuclear Information System (INIS)

    Lundholm, C.E.; Sundbom, L.; Lundholm, L.

    1989-01-01

    Coronary arteriosclerosis in mini-pigs was produced by combination of hypercholesterolemia and twofold X irradiation of the cardiac region. 15-21 weeks following irradiation 40% of the adult animals and 58% of the juvenils died of 'sudden cardiac death'. The mortality rate decreased significantly after application of the calcium-channel blocking agent nifedipine

  6. Kerr-CFT and gravitational perturbations

    International Nuclear Information System (INIS)

    Dias, Oscar J.C.; Reall, Harvey S.; Santos, Jorge E.

    2009-01-01

    Motivated by the Kerr-CFT conjecture, we investigate perturbations of the near-horizon extreme Kerr spacetime. The Teukolsky equation for a massless field of arbitrary spin is solved. Solutions fall into two classes: normal modes and traveling waves. Imposing suitable (outgoing) boundary conditions, we find that there are no unstable modes. The explicit form of metric perturbations is obtained using the Hertz potential formalism, and compared with the Kerr-CFT boundary conditions. The energy and angular momentum associated with scalar field and gravitational normal modes are calculated. The energy is positive in all cases. The behaviour of second order perturbations is discussed.

  7. The power of perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    Serone, Marco [SISSA International School for Advanced Studies and INFN Trieste, Via Bonomea 265, 34136, Trieste (Italy); Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151, Trieste (Italy); Spada, Gabriele [SISSA International School for Advanced Studies and INFN Trieste, Via Bonomea 265, 34136, Trieste (Italy); Villadoro, Giovanni [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151, Trieste (Italy)

    2017-05-10

    We study quantum mechanical systems with a discrete spectrum. We show that the asymptotic series associated to certain paths of steepest-descent (Lefschetz thimbles) are Borel resummable to the full result. Using a geometrical approach based on the Picard-Lefschetz theory we characterize the conditions under which perturbative expansions lead to exact results. Even when such conditions are not met, we explain how to define a different perturbative expansion that reproduces the full answer without the need of transseries, i.e. non-perturbative effects, such as real (or complex) instantons. Applications to several quantum mechanical systems are presented.

  8. Sudden Cardiac Arrest due to Brugada Syndrome: a Case Report and Literature Review

    Directory of Open Access Journals (Sweden)

    R Soleimanirad

    2013-04-01

    Full Text Available Brugada Syndrome is a rare cause of sudden cardiac arrest and has a unique ECG pattern. In fact, with ST-segment elevation down sloping in the right precordial leads (v1-v3, RBBB pattern in lateral leads and J-point elevation is revealed. We must notice and avoid trigger factors of this syndrome during general anesthesia. Patient is a 39 old man who attended to emergency department with sudden cardiac arrest and resuscitate. He was transferred to ICU for management of hypoxic ischemic encephalopathy. Complementary studies concluded the diagnosis of Brugada syndrome. We must consider Brugada syndrome within patients with family history of sudden cardiac arrest. Moreover, we must avoid trigger factors of this syndrome such as fever, bradicardia and electrolyte abnormality (specialy Na, Ca abnormalities during general anesthesia and if they appear, we should treat them.

  9. Anti-HERG activity and the risk of drug-induced arrhythmias and sudden death

    DEFF Research Database (Denmark)

    De Bruin, M L; Pettersson, M; Meyboom, R H B

    2005-01-01

    AIMS: Drug-induced QTc-prolongation, resulting from inhibition of HERG potassium channels may lead to serious ventricular arrhythmias and sudden death. We studied the quantitative anti-HERG activity of pro-arrhythmic drugs as a risk factor for this outcome in day-to-day practice. METHODS...... defined as reports of cardiac arrest, sudden death, torsade de pointes, ventricular fibrillation, and ventricular tachycardia (n = 5591), and compared with non-cases regarding the anti-HERG activity, defined as the effective therapeutic plasma concentration (ETCPunbound) divided by the HERG IC50 value......, of suspected drugs. We identified a significant association of 1.93 (95% CI: 1.89-1.98) between the anti-HERG activity of drugs, measured as log10 (ETCPunbound/IC50), and reporting of serious ventricular arrhythmias and sudden death to the WHO-UMC database. CONCLUSION: Anti-HERG activity is associated...

  10. Non-adiabatic perturbations in multi-component perfect fluids

    Energy Technology Data Exchange (ETDEWEB)

    Koshelev, N.A., E-mail: koshna71@inbox.ru [Ulyanovsk State University, Leo Tolstoy str 42, 432970 (Russian Federation)

    2011-04-01

    The evolution of non-adiabatic perturbations in models with multiple coupled perfect fluids with non-adiabatic sound speed is considered. Instead of splitting the entropy perturbation into relative and intrinsic parts, we introduce a set of symmetric quantities, which also govern the non-adiabatic pressure perturbation in models with energy transfer. We write the gauge invariant equations for the variables that determine on a large scale the non-adiabatic pressure perturbation and the rate of changes of the comoving curvature perturbation. The analysis of evolution of the non-adiabatic pressure perturbation has been made for several particular models.

  11. Non-adiabatic perturbations in multi-component perfect fluids

    International Nuclear Information System (INIS)

    Koshelev, N.A.

    2011-01-01

    The evolution of non-adiabatic perturbations in models with multiple coupled perfect fluids with non-adiabatic sound speed is considered. Instead of splitting the entropy perturbation into relative and intrinsic parts, we introduce a set of symmetric quantities, which also govern the non-adiabatic pressure perturbation in models with energy transfer. We write the gauge invariant equations for the variables that determine on a large scale the non-adiabatic pressure perturbation and the rate of changes of the comoving curvature perturbation. The analysis of evolution of the non-adiabatic pressure perturbation has been made for several particular models

  12. Assessing the initial adaptability and impact of a mobile dictation and reporting system in the radiology department of an academic hospital

    Science.gov (United States)

    Gali, Raja L.; Dave, Jaydev K.

    2017-03-01

    Mobile Radiologist 360, rolled out as part of the voice dictation system upgrade from Nuance Powerscribe 5.0 to PS360 allows an attending radiologist to edit and sign-off a report assigned by a trainee or that has been started by the radiologist on a workstation. The purpose of this study was to evaluate the adoptability and impact of this application. Report turnaround time data was extracted from the RIS (GE-Centricity RIS-IC) for 60 days before- (period-1) and 60 days after- (period-2) the application implementation and then, for 60 days after end of period-2 (period-3). Adoptability of the application was evaluated using two metrics; first, the number of attending radiologists who signed-off reports using the application in periods 2 and 3, and second, the proportion of reports signed-off by the top five users of the mobile application using the application. Impact of the application was evaluated by comparing the time from initial dictation to final sign-off (time_PF) for the top five users of the mobile application to the time_PF by other five radiologists who did not use the application. 41% radiologists used the mobile application at least once during the study period; the proportion of cases signed-off using the mobile application ranged from 1% to 20%. ANOVA revealed no statistically significant effect of the mobile application system on time_PF (p=0.842). In conclusion, there was low initial adoptability and no impact of the mobile dictation and reporting system in reducing the time from initial dictation to final sign-off on a radiology report.

  13. Closed form bound-state perturbation theory

    Directory of Open Access Journals (Sweden)

    Ollie J. Rose

    1980-01-01

    Full Text Available The perturbed Schrödinger eigenvalue problem for bound states is cast into integral form using Green's Functions. A systematic algorithm is developed and applied to the resulting equation giving rise to approximate solutions expressed as functions of the given perturbation parameter. As a by-product, convergence radii for the traditional Rayleigh-Schrödinger and Brillouin-Wigner perturbation theories emerge in a natural way.

  14. Incidence and causes of sudden death in U.S. college athletes.

    Science.gov (United States)

    Maron, Barry J; Haas, Tammy S; Murphy, Caleb J; Ahluwalia, Aneesha; Rutten-Ramos, Stephanie

    2014-04-29

    The goal of this study was to reliably define the incidence and causes of sudden death in college student-athletes. The frequency with which cardiovascular-related sudden death occurs in competitive athletes importantly influences considerations for pre-participation screening strategies. We assessed databases (including autopsy reports) from both the U.S. National Registry of Sudden Death in Athletes and the National Collegiate Athletic Association (2002 to 2011). Over the 10-year study period, 182 sudden deaths occurred (age 20 ± 1.7 years; 85% male; 64% white), 52 resulting from suicide (n = 31) or drug abuse (n = 21) and 64 probably or likely attributable to cardiovascular causes (6/year). Of these 64 athletes, 47 had a confirmed post-mortem diagnosis; the most common were hypertrophic cardiomyopathy in 21 and congenital coronary anomalies in 8. The 4,052,369 athlete participations (in 30 sports over 10 years) incurred mortality risks as follows: suicide and drugs combined, 1.3/100,000 athlete participation-years (5 deaths/year); and documented cardiovascular disease, 1.2/100,000 athlete participation-years (4 deaths/year). Notably, cardiovascular deaths were 5-fold more common in African-American athletes than in white athletes (3.8 vs. 0.7/100,000 athlete participation-years; p death due to cardiovascular disease is relatively low, with mortality rates similar to suicide and drug abuse, but less than expected in the general population, although highest in African-American athletes. A substantial minority of confirmed cardiovascular deaths would not likely have been reliably detected by pre-participation screening with 12-lead electrocardiograms. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  15. Pulmonary thromboembolism and sudden death in psychiatric patients: Two cases reports

    Directory of Open Access Journals (Sweden)

    Marinković Nadica

    2017-01-01

    Full Text Available Introduction. Pulmonary thromboembolism occurs usually by running a thrombus from the deep veins of the legs rarely periprostatic or periuteric veins. Virchow's triad of necessary conditions for the occurrence of thrombosis involves disruption of blood flow, disruption of blood chemistry and damage to the vessel wall. Venous thrombosis is often associated with the implementation of antipsychotic therapy. Case report. We reported two cases of sudden death of psychiatric patients who were in both cases fixed during hospitalization. The first case was a 26-year-old woman treated a year with the diagnose of postpartum reactive psychosis. She was hospitalized because of mental state worsening with a dominant depressed mood, visual and auditory hallucinations. Her therapy was determined by diazepam, clozapine, haloperidol and lamotrigine. Suddenly, the patient died on the fifth day of hospitalization. The autopsy showed massive thromboembolism of the pulmonary artery branches. Toxicological analysis revealed the presence of therapeutic doses of antipsychotics. The second case was a-45-yearold men, a long-time alcoholic. On admission, the diagnosis of delirium tremens was established, and diazepam and haloperidol were administered. On the fifth day of hospitalization, he suddenly died. The autopsy showed thromboembolism of the branch of the pulmonary artery. Toxicological analysis established the presence of nordiazepam in urine (0.06 mg/L. Both patients were fixed during hospitalization. Conclusion. Both presented psychiatric patients were younger than 50 years, were not overweight, did not have changes of the venous blood vessels. Nowadays, when the issue of medical responsibility often arises in these and similar cases of sudden death in patients treated in psychiatric clinics, the questions on medical malpractice could be expected.

  16. On summation of perturbation expansions

    International Nuclear Information System (INIS)

    Horzela, A.

    1985-04-01

    The problem of the restoration of physical quantities defined by divergent perturbation expansions is analysed. The Pad'e and Borel summability is proved for alternating perturbation expansions with factorially growing coefficients. The proof is based on the methods of the classical moments theory. 17 refs. (author)

  17. Perturbation theory and collision probability formalism. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Nasr, M [National Center for Nuclear Safety and Radiation Control, Atomic Energy Authority, Cairo (Egypt)

    1996-03-01

    Perturbation theory is commonly used in evaluating the activity effects, particularly those resulting from small and localized perturbation in multiplying media., e.g. in small sample reactivity measurements. The Boltzmann integral transport equation is generally used for evaluating the direct and adjoint fluxes in the heterogenous lattice cells to be used in the perturbation equations. When applying perturbation theory in this formalism, a term involving the perturbation effects on the special transfer kernel arises. This term is difficult to evaluate correctly, since it involves an integration all over the entire system. The main advantage of the perturbation theory which is the limitation of the integration procedure on the perturbation region is found to be of no practical use in such cases. In the present work, the perturbation equation in the collision probability formalism is analyzed. A mathematical treatment of the term in question is performed. A new mathematical expression for this term is derived. The new expression which can be estimated easily is derived.

  18. Dynamic stability under sudden loads

    International Nuclear Information System (INIS)

    Simitses, G.J.

    1998-01-01

    The concept of dynamic stability of elastic structures subjected to sudden (step) loads is discussed. The various criteria and related methodologies for estimating critical conditions are presented with the emphasis on their similarities and differences. These are demonstrated by employing a simple mechanical model. Several structural configurations are analyzed, for demonstration purposes, with the intention of comparing critical dynamic loads to critical static loads. These configurations include shallow arches and shallow spherical caps, two bar frames, and imperfect cylindrical shells of metallic as well as laminated composite construction. In the demonstration examples, the effect of static pre loading on the dynamic critical load is presented

  19. Law enforcement duties and sudden cardiac death among police officers in United States: case distribution study.

    Science.gov (United States)

    Varvarigou, Vasileia; Farioli, Andrea; Korre, Maria; Sato, Sho; Dahabreh, Issa J; Kales, Stefanos N

    2014-11-18

    To assess the association between risk of sudden cardiac death and stressful law enforcement duties compared with routine/non-emergency duties. Case distribution study (case series with survey information on referent exposures). United States law enforcement. Summaries of deaths of over 4500 US police officers provided by the National Law Enforcement Officers Memorial Fund and the Officer Down Memorial Page from 1984 to 2010. Observed and expected sudden cardiac death counts and relative risks for sudden cardiac death events during specific strenuous duties versus routine/non-emergency activities. Independent estimates of the proportion of time that police officers spend across various law enforcement duties obtained from surveys of police chiefs and front line officers. Impact of varying exposure assessments, covariates, and missing cases in sensitivity and stability analyses. 441 sudden cardiac deaths were observed during the study period. Sudden cardiac death was associated with restraints/altercations (25%, n=108), physical training (20%, n=88), pursuits of suspects (12%, n=53), medical/rescue operations (8%, n=34), routine duties (23%, n=101), and other activities (11%, n=57). Compared with routine/non-emergency activities, the risk of sudden cardiac death was 34-69 times higher during restraints/altercations, 32-51 times higher during pursuits, 20-23 times higher during physical training, and 6-9 times higher during medical/rescue operations. Results were robust to all sensitivity and stability analyses. Stressful law enforcement duties are associated with a risk of sudden cardiac death that is markedly higher than the risk during routine/non-emergency duties. Restraints/altercations and pursuits are associated with the greatest risk. Our findings have public health implications and suggest that primary and secondary cardiovascular prevention efforts are needed among law enforcement officers. © Varvarigou et al 2014.

  20. The analysis of Sudden Infant Death Syndrome in Poland

    Directory of Open Access Journals (Sweden)

    Anna Lewandowska

    2017-05-01

    Full Text Available Introduction: Sudden Infant Death Syndrome is defined in literature similarly as a sudden and unexpected death of an infant occurring during sleep and, at the same time, causes of which cannot be explained based on anamnesis, circumstances of death or comprehensive post-mortem examinations. Sudden Infant Death Syndrome is considered to be the most frequent cause of death among infants in the developed countries. Incidence of SIDS in the whole world ranges from about 0.1 to 6.0/1,000 live births. As much as 90% concerns deaths in the first year of life of a child, whereas 70% stands for deaths for which the cause remains unknown. In SIDS, about 90% of cases concern children under 1 year old and, in particular, at the age of between 2 and 4 months. The aim: The aim of the study was to present the most significant aspects of SIDS as well as description and analysis of risk factors for occurrence of sudden infant death syndrome based on statistical data. Materials and methods: For the purpose of the study, the secondary data analysis and desk research technique have been applied. The analysis is based on statistical data from the time period 2009-2014 released by the Central Statistical Office of Poland. Results: In 2009-2014, the highest number of deaths of infants and new-borns was reported in 2009 with the number being as high as 2,327. In the following years, the number of deaths of new-borns and infants systematically decreased. In 2010 it was 2,057 and in 2011 – 1,836, in 2012 – 1,791, in 2013 – 1,684, and in 2014 – 1,583. The highest number of deaths of boys was reported in 2009 – 1,298, while the number of deaths of girls in that year, although it was the highest in the analysed period, was lower – 1,029. Conclusions: cases of death were more frequent among boys rather than girls. The highest number of deaths was reported among infants under the age of one month and the number decreased with an increasing infants’ age. More

  1. Kosovo, the beginning and end of the adventure of a dictator in Europe

    Directory of Open Access Journals (Sweden)

    Xhavit Sadrijaj

    2016-07-01

    Full Text Available When desires are not based in reality, the result is the only one that can be expected from such desires. In such games winning is actually called losing. That also happened with the consuming desires of the late dictator in Europe, Milošević. The permanent Yugoslav president Tito, was known for his philosophy: “We decline what is not ours; ours we will relinquish not”. Although it was not like that, this philosophy had its success. It kept the morale of strength and the existence of a state of over 30 nations who lived in it and who remained steadfast and unbeaten throughout the Cold War. With Tito's death his country died too, altogether with the philosophy. The fact that it really was just philosophy was shown several years later, when in the absence of a successor to Tito, but also through new anticommunist movements in the world, the state collapsed becoming involved in war and chaos that was manifested by bloody tragedies of very large dimensions. Of course all this tragedy was preceded by Serbian chauvinist passions and desires which were planned for a century in all forms, and which were implemented by a dictator who also will remain in history as such, Slobodan Milošević and his clique. This executioner chose Kosovo as the most appropriate level for its establishment in the peaks of power and certainly had not imagined then that was also his end.

  2. Sudden Oak Death, Phytophthora ramorum: A Persistent Threat to Oaks and Other Tree Species

    Science.gov (United States)

    S.J. Frankel; K.M. Palmieri

    2014-01-01

    This paper reviews the status and management of sudden oak death and “sudden larch death” in the urban and wildland forests of California, Oregon, and the UK. The causal pathogen, Phytophthora ramorum, was discovered in all three locations over a decade ago; however, efforts to contain and eliminate infestations have been unsuccessful. These less...

  3. Picture quiz: a case of sudden severe chest pain.

    Science.gov (United States)

    Rabia, Mustafa Abu; Sullivan, P; Stivaros, Stavros M

    2007-01-01

    An 18-year-old male with no previous medical history presented to hospital with sudden onset of acute epigastric pain radiating to the anterior chest wall and both shoulders. There was no history of recent trauma and he had not been vomiting.

  4. Secondary isocurvature perturbations from acoustic reheating

    Science.gov (United States)

    Ota, Atsuhisa; Yamaguchi, Masahide

    2018-06-01

    The superhorizon (iso)curvature perturbations are conserved if the following conditions are satisfied: (i) (each) non adiabatic pressure perturbation is zero, (ii) the gradient terms are ignored, that is, at the leading order of the gradient expansion (iii) (each) total energy momentum tensor is conserved. We consider the case with the violation of the last two requirements and discuss the generation of secondary isocurvature perturbations during the late time universe. Second order gradient terms are not necessarily ignored even if we are interested in the long wavelength modes because of the convolutions which may pick products of short wavelength perturbations up. We then introduce second order conserved quantities on superhorizon scales under the conditions (i) and (iii) even in the presence of the gradient terms by employing the full second order cosmological perturbation theory. We also discuss the violation of the condition (iii), that is, the energy momentum tensor is conserved for the total system but not for each component fluid. As an example, we explicitly evaluate second order heat conduction between baryons and photons due to the weak Compton scattering, which dominates during the period just before recombination. We show that such secondary effects can be recast into the isocurvature perturbations on superhorizon scales if the local type primordial non Gaussianity exists a priori.

  5. Generalized chiral perturbation theory

    International Nuclear Information System (INIS)

    Knecht, M.; Stern, J.

    1994-01-01

    The Generalized Chiral Perturbation Theory enlarges the framework of the standard χPT (Chiral Perturbation Theory), relaxing certain assumptions which do not necessarily follow from QCD or from experiment, and which are crucial for the usual formulation of the low energy expansion. In this way, experimental tests of the foundations of the standard χPT become possible. Emphasis is put on physical aspects rather than on formal developments of GχPT. (author). 31 refs

  6. [Three good reasons to perform a postmortem examination in all cases of juvenile sudden death].

    Science.gov (United States)

    d'Amati, Giulia; di Gioia, Cira R T; Silenzi, Paola F; Gallo, Pietro

    2009-04-01

    The aim of this review is to underline the reasons why a post-mortem examination has to be performed in all cases of juvenile sudden death. Sudden death in children and young adults can be caused by potentially heritable cardiovascular disorders and fatal outcome is often the first symptom in apparently healthy subjects. In these cases, a careful autopsy, performed according to a standardized protocol, becomes the sole diagnostic tool to guide clinical and molecular genetic family screening and to adopt the proper therapeutic and preventive strategies. Thus, a post-mortem examination is a fundamental part of a multidisciplinary approach to the issue of juvenile sudden death.

  7. Infinite-order-sudden method for light--heavy--light reactions: Application to D+HCl→DCl+H

    International Nuclear Information System (INIS)

    Clary, D.C.; Drolshagen, G.

    1982-01-01

    An infinite-order-sudden (IOS) theory for light-heavy-light reactions is applied to the D+HCl(v = 0, j)→DCl(v'< or =1, j')+H reaction. The results are compared with those obtained using a more accurate quantum-dynamical technique, the ESA--CSA method, in which the energy sudden approximation is used for the entrance channel, while the centrifugal sudden approximation is employed for the exit channel. The computations have been performed using LEPS and DIM potential energy surfaces. We obtain good agreement between the IOS and ESA--CSA results, not only for averaged quantities such as rate coefficients, but also for detailed vibrational-rotational reactive cross sections

  8. Postural Responses to a Suddenly Released Pulling Force in Older Adults with Chronic Low Back Pain: An Experimental Study.

    Directory of Open Access Journals (Sweden)

    Pei-Yun Lee

    Full Text Available Chronic low back pain (CLBP, one of the most common musculoskeletal conditions in older adults, might affect balance and functional independence. The purpose of this study was to investigate the postural responses to a suddenly released pulling force in older adults with and without CLBP. Thirty community-dwelling older adults with CLBP and 26 voluntary controls without CLBP were enrolled. Participants were required to stand on a force platform while, with one hand, they pulled a string that was fastened at the other end to a 2-kg or to a 4-kg force in the opposite direction at a random order. The number of times the participants lost their balance and motions of center of pressure (COP when the string was suddenly released were recorded. The results demonstrated that although the loss of balance rates for each pulling force condition did not differ between groups, older adults with CLBP had poorer postural responses: delayed reaction, larger displacement, higher velocity, longer path length, and greater COP sway area compared to the older controls. Furthermore, both groups showed larger postural responses in the 4-kg pulling force condition. Although aging is generally believed to be associated with declining balance and postural control, these findings highlight the effect of CLBP on reactive balance when responding to an externally generated force in an older population. This study also suggests that, for older adults with CLBP, in addition to treating them for pain and disability, reactive balance evaluation and training, such as reaction and movement strategy training should be included in their interventions. Clinicians and older patients with CLBP need to be made aware of the significance of impaired reactive balance and the increased risk of falls when encountering unexpected perturbations.

  9. Discordance in investigator-reported and adjudicated sudden death in TIOSPIR

    Directory of Open Access Journals (Sweden)

    Robert A. Wise

    2017-03-01

    Full Text Available Accurate and consistent determination of cause of death is challenging in chronic obstructive pulmonary disease (COPD patients. TIOSPIR (N=17 135 compared the safety and efficacy of tiotropium Respimat 5/2.5 µg with HandiHaler 18 µg in COPD patients. All-cause mortality was a primary end-point. A mortality adjudication committee (MAC assessed all deaths. We aimed to investigate causes of discordance in investigator-reported and MAC-adjudicated causes of death and their impact on results, especially cardiac and sudden death. The MAC provided independent, blinded assessment of investigator-reported deaths (n=1302 and assigned underlying cause of death. Discordance between causes of death was assessed descriptively (shift tables. There was agreement between investigator-reported and MAC-adjudicated deaths in 69.4% of cases at the system organ class level. Differences were mainly observed for cardiac deaths (16.4% investigator, 5.1% MAC and deaths assigned to general disorders including sudden death (17.4% investigator, 24.6% MAC. Reasons for discrepancies included investigator attribution to the immediate (e.g. myocardial infarction (MI over the underlying cause of death (e.g. COPD and insufficient information for a definitive cause. Cause-specific mortality varies in COPD, depending on the method of assignment. Sudden death, witnessed and unwitnessed, is common in COPD and often attributed to MI without supporting evidence.

  10. Cosmological perturbations beyond linear order

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    Cosmological perturbation theory is the standard tool to understand the formation of the large scale structure in the Universe. However, its degree of applicability is limited by the growth of the amplitude of the matter perturbations with time. This problem can be tackled with by using N-body simulations or analytical techniques that go beyond the linear calculation. In my talk, I'll summarise some recent efforts in the latter that ameliorate the bad convergence of the standard perturbative expansion. The new techniques allow better analytical control on observables (as the matter power spectrum) over scales very relevant to understand the expansion history and formation of structure in the Universe.

  11. Instabilities in mimetic matter perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Firouzjahi, Hassan; Gorji, Mohammad Ali [School of Astronomy, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Mansoori, Seyed Ali Hosseini, E-mail: firouz@ipm.ir, E-mail: gorji@ipm.ir, E-mail: shosseini@shahroodut.ac.ir, E-mail: shossein@ipm.ir [Physics Department, Shahrood University of Technology, P.O. Box 3619995161 Shahrood (Iran, Islamic Republic of)

    2017-07-01

    We study cosmological perturbations in mimetic matter scenario with a general higher derivative function. We calculate the quadratic action and show that both the kinetic term and the gradient term have the wrong sings. We perform the analysis in both comoving and Newtonian gauges and confirm that the Hamiltonians and the associated instabilities are consistent with each other in both gauges. The existence of instabilities is independent of the specific form of higher derivative function which generates gradients for mimetic field perturbations. It is verified that the ghost instability in mimetic perturbations is not associated with the higher derivative instabilities such as the Ostrogradsky ghost.

  12. Gauge-invariant perturbations in a spatially flat anisotropic universe

    International Nuclear Information System (INIS)

    Den, Mitsue.

    1986-12-01

    The gauge-invariant perturbations in a spatially flat anisotropic universe with an arbitrary dimension (= N) are studied. In a previous paper the equations for the perturbations with a wave vector k a in one of the axial directions were derived and their solutions were shown. In this paper the perturbations with k a in arbitrary directions are treated. The remarkable properties are that all three types (scalar, vector, and tensor) of perturbations are generally coupled, so that a density perturbation can be produced also by vector or tensor perturbations. The formulation is quite general, but the behavior of the perturbations is discussed in a simple case such that N = 4 and k a is orthogonal to one of the axial directions. In this case, the perturbations are divided into two groups which are dynamically decoupled from each other. The asymptotic behavior of the perturbations in the group containing the density perturbation is discussed. (author)

  13. [Expression of proBNP and NT-proBNP in Sudden Death of Coronary Heart Disease].

    Science.gov (United States)

    Zeng, Q; Sun, R F; Li, Z; Zhai, L Q; Liu, M Z; Guo, X J; Gao, C R

    2017-10-01

    To study the expression change of pro-brain natriuretic peptide (proBNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in sudden death of coronary atherosclerotic heart disease, and to explore its application in forensic diagnosis. Myocardial and blood samples were collected from normal control group, sudden death of coronary atherosclerotic heart disease group and single coronary stenosis group (20 cases in each group). The expression of proBNP in myocardial samples were detected by immunohistochemical staining and Western blotting, and that of BNP mRNA were detected by reverse transcription PCR (RT-PCR). The content of NT-proBNP in plasma were detected by ELISA. Immunohistochemical staining showed positive expression of proBNP in both sudden death of coronary atherosclerotic heart disease group and single coronary stenosis group. There was no positive expression in normal control group. For sudden death of coronary atherosclerotic heart disease group and single coronary stenosis group, the relative expression of proBNP protein and BNP mRNA in myocardial tissue and the NT-proBNP content in plasma were higher than that of normal control group ( P heart disease group was higher than that of single coronary stenosis group ( P heart disease and determine whether the sudden death due to coronary atherosclerotic heart disease. Copyright© by the Editorial Department of Journal of Forensic Medicine

  14. Lattice regularized chiral perturbation theory

    International Nuclear Information System (INIS)

    Borasoy, Bugra; Lewis, Randy; Ouimet, Pierre-Philippe A.

    2004-01-01

    Chiral perturbation theory can be defined and regularized on a spacetime lattice. A few motivations are discussed here, and an explicit lattice Lagrangian is reviewed. A particular aspect of the connection between lattice chiral perturbation theory and lattice QCD is explored through a study of the Wess-Zumino-Witten term

  15. Output synchronization of chaotic systems under nonvanishing perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Mancilla, Didier [Departamento de Ciencias Exactas y Tecnologicas, Centro Universitario de los Lagos, Universidad de Guadalajara (CULagos-UdeG), Enrique Diaz de Leon s/n, 47460 Lagos de Moreno, Jal. (Mexico)], E-mail: didier@uabc.mx; Cruz-Hernandez, Cesar [Electronics and Telecommunications Department, Scientific Research and Advanced Studies of Ensenada (CICESE), Km. 107, Carretera Tijuana-Ensenada, 22860 Ensenada, B.C. (Mexico)], E-mail: ccruz@cicese.mx

    2008-08-15

    In this paper, an analysis for chaos synchronization under nonvanishing perturbations is presented. In particular, we use model-matching approach from nonlinear control theory for output synchronization of identical and nonidentical chaotic systems under nonvanishing perturbations in a master-slave configuration. We show that the proposed approach is indeed suitable to synchronize a class of perturbed slaves with a chaotic master system; that is the synchronization error trajectories remain bounded if the perturbations satisfy some conditions. In order to illustrate this robustness synchronization property, we present two cases of study: (i) for identical systems, a pair of coupled Roessler systems, the first like a master and the other like a perturbed slave, and (ii) for nonidentical systems, a Chua's circuit driving a Roessler/slave system with a perturbed control law, in both cases a quantitative analysis on the perturbation is included.

  16. Output synchronization of chaotic systems under nonvanishing perturbations

    International Nuclear Information System (INIS)

    Lopez-Mancilla, Didier; Cruz-Hernandez, Cesar

    2008-01-01

    In this paper, an analysis for chaos synchronization under nonvanishing perturbations is presented. In particular, we use model-matching approach from nonlinear control theory for output synchronization of identical and nonidentical chaotic systems under nonvanishing perturbations in a master-slave configuration. We show that the proposed approach is indeed suitable to synchronize a class of perturbed slaves with a chaotic master system; that is the synchronization error trajectories remain bounded if the perturbations satisfy some conditions. In order to illustrate this robustness synchronization property, we present two cases of study: (i) for identical systems, a pair of coupled Roessler systems, the first like a master and the other like a perturbed slave, and (ii) for nonidentical systems, a Chua's circuit driving a Roessler/slave system with a perturbed control law, in both cases a quantitative analysis on the perturbation is included

  17. Two-body perturbation theory versus first order perturbation theory: A comparison based on the square-well fluid.

    Science.gov (United States)

    Mercier Franco, Luís Fernando; Castier, Marcelo; Economou, Ioannis G

    2017-12-07

    We show that the Zwanzig first-order perturbation theory can be obtained directly from a truncated Taylor series expansion of a two-body perturbation theory and that such truncation provides a more accurate prediction of thermodynamic properties than the full two-body perturbation theory. This unexpected result is explained by the quality of the resulting approximation for the fluid radial distribution function. We prove that the first-order and the two-body perturbation theories are based on different approximations for the fluid radial distribution function. To illustrate the calculations, the square-well fluid is adopted. We develop an analytical expression for the two-body perturbed Helmholtz free energy for the square-well fluid. The equation of state obtained using such an expression is compared to the equation of state obtained from the first-order approximation. The vapor-liquid coexistence curve and the supercritical compressibility factor of a square-well fluid are calculated using both equations of state and compared to Monte Carlo simulation data. Finally, we show that the approximation for the fluid radial distribution function given by the first-order perturbation theory provides closer values to the ones calculated via Monte Carlo simulations. This explains why such theory gives a better description of the fluid thermodynamic behavior.

  18. Sudden infant death syndrome (SIDS)--standardised investigations and classification

    DEFF Research Database (Denmark)

    Bajanowski, Thomas; Vege, Ashild; Byard, Roger W

    2007-01-01

    Sudden infant death syndrome (SIDS) still accounts for considerable numbers of unexpected infant deaths in many countries. While numerous theories have been advanced to explain these events, it is increasingly clear that this group of infant deaths results from the complex interaction of a variet...

  19. Isocurvature perturbations in the Ekpyrotic Universe

    International Nuclear Information System (INIS)

    Notari, A.; Riotto, A.

    2002-01-01

    The Ekpyrotic scenario assumes that our visible Universe is a boundary brane in a five-dimensional bulk and that the hot Big Bang occurs when a nearly supersymmetric five-brane travelling along the fifth dimension collides with our visible brane. We show that the generation of isocurvature perturbations is a generic prediction of the Ekpyrotic Universe. This is due to the interactions in the kinetic terms between the brane modulus parameterizing the position of the five-brane in the bulk and the dilaton and volume moduli. We show how to separate explicitly the adiabatic and isocurvature modes by performing a rotation in field space. Our results indicate that adiabatic and isocurvature perturbations might be cross-correlated and that curvature perturbations might be entirely seeded by isocurvature perturbations

  20. Symptoms Before Sudden Arrhythmic Death Syndrome

    DEFF Research Database (Denmark)

    Glinge, Charlotte; Jabbari, Reza; Risgaard, Bjarke

    2015-01-01

    INTRODUCTION: No studies in an unselected and nationwide setting have characterized the symptoms and medical history of patients with sudden arrhythmic death syndrome (SADS). The aim of this study was to identify and describe the symptoms and medical history of patients before the presentation......%), palpitations (n = 2, 1%), presyncope/syncope (n = 23, 17%), and aborted SCD (n = 2, 1%). In addition, seizures (n = 25, 18%) were prevalent. In 61 (45%) SADS cases, no previous medical history were recorded. CONCLUSION: In this unselected, nationwide study of 136 young SADS patients, 35% had experienced...

  1. Continual integral in perturbation theory

    International Nuclear Information System (INIS)

    Slavnov, A.A.

    1975-01-01

    It is shown that all results obtained by means of continual integration within the framework of perturbation theory are completely equivalent to those obtained by the usual diagram technique and are therfore just as rigorous. A rigorous justification is given for the rules for operating with continual integrals in perturbation theory. (author)

  2. Hypothesis: solid tumours behave as systemic metabolic dictators.

    Science.gov (United States)

    Lee, Yang-Ming; Chang, Wei-Chun; Ma, Wen-Lung

    2016-06-01

    Current knowledge regarding mechanisms of carcinogenesis in human beings centres around the accumulation of genetic instability, amplified cellular signalling, disturbed cellular energy metabolism and microenvironmental regulation governed by complicated cell-cell interactions. In this article, we provide an alternative view of cancer biology. We propose that cancer behaves as a systemic dictator that interacts with tissues throughout the body to control their metabolism and eventually homeostasis. The mechanism of development of this endocrine organ-like tumour (EOLT) tissue might be the driving force for cancer progression. Here, we review the literature that led to the development of this hypothesis. The EOLT phenotype can be defined as a tumour that alters systemic homeostasis. The literature indicates that the EOLT phenotype is present throughout cancer progression. The feedback mechanism that governs the interaction between tumours and various organs is unknown. We believe that investigating the mechanism of EOLT development may advance the current knowledge of regulation within the tumour macroenvironment and consequently lead to new diagnostic methods and therapy. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  3. Symmetry-dictated trucation: Solutions of the spherical shell model for heavy nuclei

    International Nuclear Information System (INIS)

    Guidry, M.W.

    1992-01-01

    Principles of dynamical symmetry are used to simplify the spherical shell model. The resulting symmetry-dictated truncation leads to dynamical symmetry solutions that are often in quantitative agreement with a variety of observables. Numerical calculations, including terms that break the dynamical symmetries, are shown that correspond to shell model calculations for heavy deformed nuclei. The effective residual interaction is simple, well-behaved, and can be determined from basic observables. With this approach, we intend to apply the shell model in systematic fashion to all nuclei. The implications for nuclear structure far from stability and for nuclear masses and other quantities of interest in astrophysics are discussed

  4. Medico legal investigations into sudden sniffing deaths linked with trichloroethylene.

    Science.gov (United States)

    Da Broi, Ugo; Colatutto, Antonio; Sala, Pierguido; Desinan, Lorenzo

    2015-08-01

    Sudden deaths attributed to sniffing trichloroethylene are caused by the abuse of this solvent which produces pleasant inebriating effects with rapid dissipation. In the event of repeated cycles of inhalation, a dangerous and uncontrolled systemic accumulation of trichloroethylene may occur, followed by central nervous system depression, coma and lethal cardiorespiratory arrest. Sometimes death occurs outside the hospital environment, without medical intervention or witnesses and without specific necroscopic signs. Medico legal investigations into sudden sniffing deaths associated with trichloroethylene demand careful analysis of the death scene and related circumstances, a detailed understanding of the deceased's medical history and background of substance abuse and an accurate evaluation of all autopsy and laboratory data, with close cooperation between the judiciary, coroners and toxicologists. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  5. Kato expansion in quantum canonical perturbation theory

    International Nuclear Information System (INIS)

    Nikolaev, Andrey

    2016-01-01

    This work establishes a connection between canonical perturbation series in quantum mechanics and a Kato expansion for the resolvent of the Liouville superoperator. Our approach leads to an explicit expression for a generator of a block-diagonalizing Dyson’s ordered exponential in arbitrary perturbation order. Unitary intertwining of perturbed and unperturbed averaging superprojectors allows for a description of ambiguities in the generator and block-diagonalized Hamiltonian. We compare the efficiency of the corresponding computational algorithm with the efficiencies of the Van Vleck and Magnus methods for high perturbative orders.

  6. Kato expansion in quantum canonical perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaev, Andrey, E-mail: Andrey.Nikolaev@rdtex.ru [Institute of Computing for Physics and Technology, Protvino, Moscow Region, Russia and RDTeX LTD, Moscow (Russian Federation)

    2016-06-15

    This work establishes a connection between canonical perturbation series in quantum mechanics and a Kato expansion for the resolvent of the Liouville superoperator. Our approach leads to an explicit expression for a generator of a block-diagonalizing Dyson’s ordered exponential in arbitrary perturbation order. Unitary intertwining of perturbed and unperturbed averaging superprojectors allows for a description of ambiguities in the generator and block-diagonalized Hamiltonian. We compare the efficiency of the corresponding computational algorithm with the efficiencies of the Van Vleck and Magnus methods for high perturbative orders.

  7. Sudden headache, third nerve palsy and visual deficit: thinking outside the subarachnoid haemorrhage box.

    Science.gov (United States)

    Ní Chróinín, Danielle; Lambert, John

    2013-11-01

    A 75-year-old lady presented with sudden severe headache and vomiting. Examination was normal, and CT and lumbar puncture not convincing for subarachnoid haemorrhage. Shortly thereafter, she developed painless diplopia. Examination confirmed right third cranial nerve palsy plus homonymous left inferior quadrantanopia. Urgent cerebral MRI with angiography was requested to assess for a possible posterior communicating artery aneurysm, but revealed an unsuspected pituitary mass. Pituitary adenoma with pituitary apoplexy was diagnosed. Pituitary apopolexy is a syndrome comprising sudden headache, meningism, visual and/or oculomotor deficits, with an intrasellar mass. It is commonly due to haemorrhage or infarction within a pituitary adenoma. Treatment includes prompt steroid administration, and potentially surgical decompression. While subarachnoid haemorrhage is an important, well-recognised cause of sudden severe headache, other aetiologies, including pituitary apoplexy, should be considered and sought.

  8. Invariant exchange perturbation theory for multicenter systems: Time-dependent perturbations

    International Nuclear Information System (INIS)

    Orlenko, E. V.; Evstafev, A. V.; Orlenko, F. E.

    2015-01-01

    A formalism of exchange perturbation theory (EPT) is developed for the case of interactions that explicitly depend on time. Corrections to the wave function obtained in any order of perturbation theory and represented in an invariant form include exchange contributions due to intercenter electron permutations in complex multicenter systems. For collisions of atomic systems with an arbitrary type of interaction, general expressions are obtained for the transfer (T) and scattering (S) matrices in which intercenter electron permutations between overlapping nonorthogonal states belonging to different centers (atoms) are consistently taken into account. The problem of collision of alpha particles with lithium atoms accompanied by the redistribution of electrons between centers is considered. The differential and total charge-exchange cross sections of lithium are calculated

  9. Strings as perturbations of evolving spin networks

    International Nuclear Information System (INIS)

    Smolin, Lee

    2000-01-01

    One step in the construction of a background independent formulation of string theory is detailed, in which it is shown how perturbative strings may arise as small fluctuations around histories in a formulation of non-perturbative dynamics of spin networks due to Markopoulou. In this formulation the dynamics of spin network states and their generalizations is described in terms of histories which have discrete analogues of the causal structure and many fingered time of Lorentzian spacetimes. Perturbations of these histories turn out to be described in terms of spin systems defined on 2-dimensional timelike surfaces embedded in the discrete spacetime. When the history has a classical limit which is Minkowski spacetime, the action of the perturbation theory is given to leading order by the spacetime area of the surface, as in bosonic string theory. This map between a non-perturbative formulation of quantum gravity and a 1+1 dimensional theory generalizes to a large class of theories in which the group SU(2) i s extended to any quantum group or supergroup. It is argued that a necessary condition for the non-perturbative theory to have a good classical limit is that the resulting 1+1 dimensional theory defines a consistent and stable perturbative string theory

  10. Acoustic anisotropic wavefields through perturbation theory

    KAUST Repository

    Alkhalifah, Tariq Ali

    2013-09-01

    Solving the anisotropic acoustic wave equation numerically using finite-difference methods introduces many problems and media restriction requirements, and it rarely contributes to the ability to resolve the anisotropy parameters. Among these restrictions are the inability to handle media with η<0 and the presence of shear-wave artifacts in the solution. Both limitations do not exist in the solution of the elliptical anisotropic acoustic wave equation. Using perturbation theory in developing the solution of the anisotropic acoustic wave equation allows direct access to the desired limitation-free solutions, that is, solutions perturbed from the elliptical anisotropic background medium. It also provides a platform for parameter estimation because of the ability to isolate the wavefield dependency on the perturbed anisotropy parameters. As a result, I derive partial differential equations that relate changes in the wavefield to perturbations in the anisotropy parameters. The solutions of the perturbation equations represented the coefficients of a Taylor-series-type expansion of the wavefield as a function of the perturbed parameter, which is in this case η or the tilt of the symmetry axis. The expansion with respect to the symmetry axis allows use of an acoustic transversely isotropic media with a vertical symmetry axis (VTI) kernel to estimate the background wavefield and the corresponding perturbation coefficients. The VTI extrapolation kernel is about one-fourth the cost of the transversely isotropic model with a tilt in the symmetry axis kernel. Thus, for a small symmetry axis tilt, the cost of migration using a first-order expansion can be reduced. The effectiveness of the approach was demonstrated on the Marmousi model.

  11. Effects of Dicto-Comp and Dictation on the Writing Skill of Female Adult Iranian EFL Learners

    Science.gov (United States)

    Adel, Rahil; Hashemian, Mahmood

    2015-01-01

    This study was an attempt to clarify and remind L2 learners/teachers of 2 kinds of writing: dicto-comp and dictation. We explored the effect of controlled writing on the accuracy of the writing of adult Iranian EFL learners. Prior to the study, the homogeneity of 30 adult EFL learners was checked through an OPT test. Thirty participants were…

  12. Sudden oak death disease progression in oaks and tanoaks

    Science.gov (United States)

    Brice A. McPherson; Sylvia R. Mori; David L. Wood; Andrew J. Storer; Pavel Svihra; N. Maggi Kelly; Richard B. Standiford

    2006-01-01

    In March 2000, we established twenty disease progression plots in Marin County to monitor the progress of sudden oak death symptoms in coast live oak (Quercus agrifolia), California black oak (Q. kelloggii), and tanoak (Lithocarpus densiflorus) (McPherson and others 2005). Plots were located to encompass a...

  13. Sudden aortic death-proposal for a comprehensive diagnostic approach in forensic and in clinical pathology practice

    NARCIS (Netherlands)

    de Boer, Hans H.; Dedouit, Fabrice; Chappex, Nina; van der Wal, Allard C.; Michaud, Katarzyna

    2017-01-01

    Backgrounds Aortic rupture or dissection as immediate cause of sudden death is encountered in forensic and clinical autopsy practice. Despite a common denominator of 'sudden aortic death' (SAD), we expect that in both settings the diagnostic workup, being either primarily legal or primarily disease

  14. Excess sudden cardiac deaths after short-term clarithromycin administration in the CLARICOR trial

    DEFF Research Database (Denmark)

    Winkel, Per; Hilden, J; Hansen, Jørgen Fischer

    2011-01-01

    Objectives: To elucidate potential mechanisms for the clarithromycin-induced excess mortality observed in the CLARICOR trial during 2.6 year follow-up of patients with stable coronary artery disease. Methods: Cox analyses using out-of-hospital death as a proxy for sudden death compared to in-hospital...... CV death in patients not on statins at trial entry (HR: 2.61, 95% CI: 1.69–4.05, p administration was significantly associated with increased risk of sudden CV death in stable...

  15. The selector gene Pax7 dictates alternate pituitary cell fates through its pioneer action on chromatin remodeling

    NARCIS (Netherlands)

    Budry, L.; Balsalobre, A.; Gauthier, Y.; Khetchoumian, K.; L'Honore, A.; Vallette-Kasic, S.; Brue, T; Figarella-Branger, D.; Meij, B.P.; Drouin, J.

    2012-01-01

    Genes Dev. 2012 Oct 15;26(20):2299-310. doi: 10.1101/gad.200436.112. The selector gene Pax7 dictates alternate pituitary cell fates through its pioneer action on chromatin remodeling. Budry L, Balsalobre A, Gauthier Y, Khetchoumian K, L'honoré A, Vallette S, Brue T, Figarella-Branger D, Meij B,

  16. Perturbations of higher-dimensional spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Durkee, Mark; Reall, Harvey S, E-mail: M.N.Durkee@damtp.cam.ac.uk, E-mail: H.S.Reall@damtp.cam.ac.uk [DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)

    2011-02-07

    We discuss linearized gravitational perturbations of higher-dimensional spacetimes. For algebraically special spacetimes (e.g. Myers-Perry black holes), we show that there exist local gauge invariant quantities linear in the metric perturbation. These are the higher-dimensional generalizations of the 4D Newman-Penrose scalars that (in an algebraically special vacuum spacetime) satisfy decoupled equations of motion. We show that decoupling occurs in more than four dimensions if, and only if, the spacetime admits a null geodesic congruence with vanishing expansion, rotation and shear. Decoupling of electromagnetic perturbations occurs under the same conditions. Although these conditions are not satisfied in black hole spacetimes, they are satisfied in the near-horizon geometry of an extreme black hole.

  17. Catatonia Secondary to Sudden Clozapine Withdrawal: A Case with Three Repeated Episodes and a Literature Review

    Directory of Open Access Journals (Sweden)

    John Bilbily

    2017-01-01

    Full Text Available A literature search identified 9 previously published cases that were considered as possible cases of catatonia secondary to sudden clozapine withdrawal. Two of these 9 cases did not provide enough information to make a diagnosis of catatonia according to the Diagnostic and Statistical Manual, 5th Edition (DSM-5. The Liverpool Adverse Drug Reaction (ADR Causality Scale was modified to assess ADRs secondary to drug withdrawal. From the 7 published cases which met DSM-5 catatonia criteria, using the modified scale, we established that 3 were definitive and 4 were probable cases of catatonia secondary to clozapine withdrawal. A new definitive case is described with three catatonic episodes which (1 occurred after sudden discontinuation of clozapine in the context of decades of follow-up, (2 had ≥3 of 12 DSM-5 catatonic symptoms and serum creatinine kinase elevation, and (3 required medical hospitalization and intravenous fluids. Clozapine may be a gamma-aminobutyric acid (GABA receptor agonist; sudden clozapine withdrawal may explain a sudden decrease in GABA activity that may contribute to the development of catatonic symptoms in vulnerable patients. Based on the limited information from these cases, the pharmacological treatment for catatonia secondary to sudden clozapine withdrawal can include benzodiazepines and/or restarting clozapine.

  18. Application of linear and higher perturbation theory in reactor physics

    International Nuclear Information System (INIS)

    Woerner, D.

    1978-01-01

    For small perturbations in the material composition of a reactor according to the first approximation of perturbation theory the eigenvalue perturbation is proportional to the perturbation of the system. This assumption is true for the neutron flux not influenced by the perturbance. The two-dimensional code LINESTO developed for such problems in this paper on the basis of diffusion theory determines the relative change of the multiplication constant. For perturbations varying the neutron flux in the space of energy and position the eigenvalue perturbation is also influenced by this changed neutron flux. In such cases linear perturbation theory yields larger errors. Starting from the methods of calculus of variations there is additionally developed in this paper a perturbation method of calculation permitting in a quick and simple manner to assess the influence of flux perturbation on the eigenvalue perturbation. While the source of perturbations is evaluated in isotropic approximation of diffusion theory the associated inhomogeneous equation may be used to determine the flux perturbation by means of diffusion or transport theory. Possibilities of application and limitations of this method are studied in further systematic investigations on local perturbations. It is shown that with the integrated code system developed in this paper a number of local perturbations may be checked requiring little computing time. With it flux perturbations in first approximation and perturbations of the multiplication constant in second approximation can be evaluated. (orig./RW) [de

  19. 't Hooft loops and perturbation theory

    CERN Document Server

    De Forcrand, Philippe; Noth, D; Forcrand, Philippe de; Lucini, Biagio; Noth, David

    2005-01-01

    We show that high-temperature perturbation theory describes extremely well the area law of SU(N) spatial 't Hooft loops, or equivalently the tension of the interface between different Z_N vacua in the deconfined phase. For SU(2), the disagreement between Monte Carlo data and lattice perturbation theory for sigma(T)/T^2 is less than 2%, down to temperatures O(10) T_c. For SU(N), N>3, the ratios of interface tensions, (sigma_k/sigma_1)(T), agree with perturbation theory, which predicts tiny deviations from the ratio of Casimirs, down to nearly T_c. In contrast, individual tensions differ markedly from the perturbative expression. In all cases, the required precision Monte Carlo measurements are made possible by a simple but powerful modification of the 'snake' algorithm.

  20. From Windfall Sharing to Property Ownership: Prosocial Personality Traits in Giving and Taking Dictator Games

    Directory of Open Access Journals (Sweden)

    Kun Zhao

    2018-05-01

    Full Text Available The dictator game is a well-known task measuring prosocial preferences, in which one person divides a fixed amount of windfall money with a recipient. A key factor in real-world transfers of wealth is the concept of property ownership and consequently the related acts of giving and taking. Using a variation of the traditional dictator game (N = 256, we examined whether individual differences under different game frames corresponded with prosocial personality traits from the Big Five (politeness, compassion and HEXACO (Honesty-Humility, Emotionality, eXtraversion, Agreeableness, Conscientiousness, Openness to Experience (honesty-humility, agreeableness models. In the Big Five model, the effects of prosocial personality traits were generally stronger and more consistent for taking than for giving, in line with a “do-no-harm” explanation, whereby prosocial individuals felt less entitled to and less willing to infringe on the endowments of others. In contrast, HEXACO honesty-humility predicted allocations across both frames, consistent with its broad association with fair-mindedness, and providing further evidence of its role in allocations of wealth more generally. These findings highlight the utility of integrating personality psychology with behavioral economics, in which the discriminant validity across prosocial traits can shed light on the distinct motivations underpinning social decisions.

  1. Attentional strategic control over nonlexical and lexical processing in written spelling to dictation in adults.

    Science.gov (United States)

    Bonin, Patrick; Collay, Sandra; Fayol, Michel; Méot, Alain

    2005-01-01

    We conducted four experiments to investigate whether adults can exert attentional strategic control over nonlexical and lexical processing in written spelling to dictation. In Experiment 1, regular and irregular words were produced either in a nonword context (regular and irregular nonwords) or in a word context (high-frequency regular and irregular words), whereas in Experiment 2, the same set of words was produced either in a regular nonword or in an irregular low-frequency word context. Experiment 3 was a replication of Experiment 2 but with increased manipulation of the context. In Experiment 4, participants had to produce either under time pressure or in response to standard written spelling instructions. Regularity effects were found in all the experiments, but their size was not reliably affected by manipulations intended to increase or decrease reliance on nonlexical processing. More particularly, the results from Experiment 4 show that adults can speed up the initialization of their writing responses to a substantial degree without altering regularity effects on either latencies or spelling errors. Our findings suggest that, although adults are able to generate an internal deadline criterion of when to initialize the writing responses, nonlexical processing is a mandatory process that is not subject to attentional strategic control in written spelling to dictation.

  2. Propagation of Ion Acoustic Perturbations

    DEFF Research Database (Denmark)

    Pécseli, Hans

    1975-01-01

    Equations describing the propagation of ion acoustic perturbations are considered, using the assumption that the electrons are Boltzman distributed and isothermal at all times. Quasi-neutrality is also considered.......Equations describing the propagation of ion acoustic perturbations are considered, using the assumption that the electrons are Boltzman distributed and isothermal at all times. Quasi-neutrality is also considered....

  3. Constraint-induced sound therapy for sudden sensorineural hearing loss – behavioral and neurophysiological outcomes

    OpenAIRE

    Hidehiko Okamoto; Munehisa Fukushima; Henning Teismann; Lothar Lagemann; Tadashi Kitahara; Hidenori Inohara; Ryusuke Kakigi; Christo Pantev

    2014-01-01

    Sudden sensorineural hearing loss is characterized by acute, idiopathic hearing deterioration. We report here the development and evaluation of “constraint-induced sound therapy”, which is based on a well-established neuro-rehabilitation approach, and which is characterized by the plugging of the intact ear (“constraint”) and the simultaneous, extensive stimulation of the affected ear with music. The sudden sensorineural hearing loss patients who received the constraint-induced sound therapy ...

  4. EDITORIAL: Non-linear and non-Gaussian cosmological perturbations Non-linear and non-Gaussian cosmological perturbations

    Science.gov (United States)

    Sasaki, Misao; Wands, David

    2010-06-01

    In recent years there has been a resurgence of interest in the study of non-linear perturbations of cosmological models. This has been the result of both theoretical developments and observational advances. New theoretical challenges arise at second and higher order due to mode coupling and the need to develop new gauge-invariant variables beyond first order. In particular, non-linear interactions lead to deviations from a Gaussian distribution of primordial perturbations even if initial vacuum fluctuations are exactly Gaussian. These non-Gaussianities provide an important probe of models for the origin of structure in the very early universe. We now have a detailed picture of the primordial distribution of matter from surveys of the cosmic microwave background, notably NASA's WMAP satellite. The situation will continue to improve with future data from the ESA Planck satellite launched in 2009. To fully exploit these data cosmologists need to extend non-linear cosmological perturbation theory beyond the linear theory that has previously been sufficient on cosmological scales. Another recent development has been the realization that large-scale structure, revealed in high-redshift galaxy surveys, could also be sensitive to non-linearities in the primordial curvature perturbation. This focus section brings together a collection of invited papers which explore several topical issues in this subject. We hope it will be of interest to theoretical physicists and astrophysicists alike interested in understanding and interpreting recent developments in cosmological perturbation theory and models of the early universe. Of course it is only an incomplete snapshot of a rapidly developing field and we hope the reader will be inspired to read further work on the subject and, perhaps, fill in some of the missing pieces. This focus section is dedicated to the memory of Lev Kofman (1957-2009), an enthusiastic pioneer of inflationary cosmology and non-Gaussian perturbations.

  5. Comparative study of turbulence model performance for axisymmetric sudden expansion flow

    International Nuclear Information System (INIS)

    Bae, Youngmin; Kim, Young In; Kim, Keung Koo; Yoon, Juhyeon

    2013-01-01

    In this study, the performance of turbulence models in predicting the turbulent flow in an axisymmetric sudden expansion with an expansion ratio of 4 is assessed for a Reynolds number of 5.6 Χ 10 4 . The comparisons show that the standard k-ε and RSM models provide the best agreement with the experimental data, whereas the standard k-ω model gives poor predictions. Owing to its computational efficiency, the Reynolds Averaged Navier-Stokes (RANS) approach has been widely used for the prediction of turbulent flows and associated pressure losses in a variety of internal flow systems such as a diffuser, orifice, converging nozzle, and pipes with sudden expansion. However, the lack of a general turbulence model often leads to limited applications of a RANS approach, i. e., the accuracy and validity of solutions obtained from RANS equations vary with the turbulence model, flow regime, near-wall treatment, and configuration of the problem. In light of the foregoing, a large amount of turbulence research has been conducted to assess the performance of existing turbulence models for different flow fields. In this paper, the turbulent flow in an axisymmetric sudden expansion is numerically investigated for a Reynolds number of 5.6 Χ 10 4 , with the aim of examining the performance of several turbulence models

  6. Frequency and analysis of non-clinical errors made in radiology reports using the National Integrated Medical Imaging System voice recognition dictation software.

    Science.gov (United States)

    Motyer, R E; Liddy, S; Torreggiani, W C; Buckley, O

    2016-11-01

    Voice recognition (VR) dictation of radiology reports has become the mainstay of reporting in many institutions worldwide. Despite benefit, such software is not without limitations, and transcription errors have been widely reported. Evaluate the frequency and nature of non-clinical transcription error using VR dictation software. Retrospective audit of 378 finalised radiology reports. Errors were counted and categorised by significance, error type and sub-type. Data regarding imaging modality, report length and dictation time was collected. 67 (17.72 %) reports contained ≥1 errors, with 7 (1.85 %) containing 'significant' and 9 (2.38 %) containing 'very significant' errors. A total of 90 errors were identified from the 378 reports analysed, with 74 (82.22 %) classified as 'insignificant', 7 (7.78 %) as 'significant', 9 (10 %) as 'very significant'. 68 (75.56 %) errors were 'spelling and grammar', 20 (22.22 %) 'missense' and 2 (2.22 %) 'nonsense'. 'Punctuation' error was most common sub-type, accounting for 27 errors (30 %). Complex imaging modalities had higher error rates per report and sentence. Computed tomography contained 0.040 errors per sentence compared to plain film with 0.030. Longer reports had a higher error rate, with reports >25 sentences containing an average of 1.23 errors per report compared to 0-5 sentences containing 0.09. These findings highlight the limitations of VR dictation software. While most error was deemed insignificant, there were occurrences of error with potential to alter report interpretation and patient management. Longer reports and reports on more complex imaging had higher error rates and this should be taken into account by the reporting radiologist.

  7. Immunization safety review: vaccinations and sudden unexpected death in infancy

    National Research Council Canada - National Science Library

    Institute of Medicine (U.S.). Immunization Safety Review Committee; Stratton, Kathleen R

    2003-01-01

    ...), and neonatal death (infant death, whether sudden or not, during the first 4 weeks of life). Based on this review, the committee concluded that the evidence favors rejection of a causal relationship between some vaccines and SIDS...

  8. Perturbation methods for power and reactivity reconstruction

    International Nuclear Information System (INIS)

    Palmiotti, G.; Salvatores, M.; Estiot, J.C.; Broccoli, U.; Bruna, G.; Gomit, J.M.

    1987-01-01

    This paper deals with recent developments and applications in perturbation methods. Two types of methods are used. The first one is an explicit method, which allows the explicit reconstruction of a perturbed flux using a linear combination of a library of functions. In our application, these functions are the harmonics (i.e. the high order eigenfunctions of the system). The second type is based on the Generalized Perturbation Theory GPT and needs the calculation of an importance function for each integral parameter of interest. Recent developments of a particularly useful high order formulation allows to obtain satisfactory results also for very large perturbations

  9. On adiabatic perturbations in the ekpyrotic scenario

    International Nuclear Information System (INIS)

    Linde, A.; Mukhanov, V.; Vikman, A.

    2010-01-01

    In a recent paper, Khoury and Steinhardt proposed a way to generate adiabatic cosmological perturbations with a nearly flat spectrum in a contracting Universe. To produce these perturbations they used a regime in which the equation of state exponentially rapidly changed during a short time interval. Leaving aside the singularity problem and the difficult question about the possibility to transmit these perturbations from a contracting Universe to the expanding phase, we will show that the methods used in Khoury are inapplicable for the description of the cosmological evolution and of the process of generation of perturbations in this scenario

  10. Application of functional analysis to perturbation theory of differential equations. [nonlinear perturbation of the harmonic oscillator

    Science.gov (United States)

    Bogdan, V. M.; Bond, V. B.

    1980-01-01

    The deviation of the solution of the differential equation y' = f(t, y), y(O) = y sub O from the solution of the perturbed system z' = f(t, z) + g(t, z), z(O) = z sub O was investigated for the case where f and g are continuous functions on I x R sup n into R sup n, where I = (o, a) or I = (o, infinity). These functions are assumed to satisfy the Lipschitz condition in the variable z. The space Lip(I) of all such functions with suitable norms forms a Banach space. By introducing a suitable norm in the space of continuous functions C(I), introducing the problem can be reduced to an equivalent problem in terminology of operators in such spaces. A theorem on existence and uniqueness of the solution is presented by means of Banach space technique. Norm estimates on the rate of growth of such solutions are found. As a consequence, estimates of deviation of a solution due to perturbation are obtained. Continuity of the solution on the initial data and on the perturbation is established. A nonlinear perturbation of the harmonic oscillator is considered a perturbation of equations of the restricted three body problem linearized at libration point.

  11. Sarcomeric gene mutations in sudden infant death syndrome (SIDS).

    Science.gov (United States)

    Brion, Maria; Allegue, Catarina; Santori, Montserrat; Gil, Rocio; Blanco-Verea, Alejandro; Haas, Cordula; Bartsch, Christine; Poster, Simone; Madea, Burkhard; Campuzano, Oscar; Brugada, Ramon; Carracedo, Angel

    2012-06-10

    In developed countries, sudden infant death syndrome (SIDS) represents the most prevalent cause of death in children between 1 month and 1 year of age. SIDS is a diagnosis of exclusion, a negative autopsy which requires the absence of structural organ disease. Although investigators have confirmed that a significant percentage of SIDS cases are actually channelopathies, no data have been made available as to whether other sudden cardiac death-associated diseases, such as hypertrophic cardiomyopathy (HCM), could be responsible for some cases of SIDS. The presence of a genetic mutation in the sarcomeric protein usually affects the force of contraction of the myocyte, whose weakness is compensated with progressive hypertrophy and disarray. However, it is unclear whether in the most incipient forms, that is, first years of life, the lack of these phenotypes still confers a risk of arrhythmogenesis. The main goal of the present study is to wonder whether genetic defects in the sarcomeric proteins, previously associated with HCM, could be responsible for SIDS. We have analysed 286 SIDS cases for the most common genes implicated in HCM in adults. A total of 680 mutations localised in 16 genes were analysed by semi-automated matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDITOF-MS) using the Sequenom MassARRAY(®) System. Ten subjects with completely normal hearts showed mutated alleles at nine of the genetic variants analysed, and one additional novel mutation was detected by conventional sequencing. Therefore, a genetic mutation associated with HCM may cause sudden cardiac death in the absence of an identifiable phenotype. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  12. Coronary atherosclerosis in sudden cardiac death: An autopsy study

    Directory of Open Access Journals (Sweden)

    Sudha M

    2009-10-01

    Full Text Available Background: The incidence of ischemic heart disease (IHD has markedly increased in India over the past few years. Considering the variations in racial, dietary and lifestyle patterns in our population, it is essential to study the biology of coronary atherosclerosis in our patients. Vulnerable plaques have a large number of foam cells, extracellular lipid, thin fibrous caps and clusters of inflammatory cells and are more prone to rupture. These plaques are nourished by the microvessels arising from the vasa vasorum of the blood vessels and by lumen-derived microvessels through the fibrous cap. This autopsy study was designed to analyse the coronary arterial tree in cases of sudden cardiac death, classify coronary atherosclerotic plaques and to assess the factors contributing to vulnerability of the plaques including inflammation, calcification and microvascular density. Materials and Methods: Seven cases of sudden cardiac death were included in the study. The hearts were perfusion-fixed and the coronary arteries along with their main branches were dissected and studied. The location of the plaques, type of plaques, presence of inflammation and calcification were assessed. The cap thickness and microvessel density per 1000um 2 were assessed. The statistical significance was estimated. Results and Conclusions: Extensive high-grade coronary atherosclerotic disease was seen in all sudden cardiac death cases. Majority of the plaques were vulnerable. High-grade inflammation was seen in most of the vulnerable and ruptured plaques. All the ruptured plaques were uncalcified indicating that calcification probably stabilizes the plaques and protects against rupture. Increased microvessel density was noted in ruptured plaques compared to vulnerable plaques. However, it was not statistically significant.

  13. Sudden death related to advanced coronary atherosclerosis in mini-pigs

    International Nuclear Information System (INIS)

    Jacobsson, L.; Lundholm, L.; Wingren, G.

    1984-01-01

    Advanced coronary atherosclerosis was produced in 30 mini-pigs by a combination of a hypercholesterolaemic diet and X-irradiation to the precordial region. Within 11-25 weeks after the irradiation, 13 of the 30 animals died a sudden death probably caused by coronary atherosclerosis. The contents of free and ester-bound cholesterol in the right coronary artery were significantly higher in the animals which died spontaneously than in surviving animals. In an untreated group of 12 animals 7 died whereas in a group treated with β-pyridylcarbinol only 1 out of 5 died. In the coronary arteries, the contents of both free and ester-bound cholesterol were significantly lower in the β-pyridylcarbinol-treated animals. In a sulfinpyrazontreated group 3 out of 8, and in a metoprolol-treated group 2 out of 5 animals died. None of these drugs reduced the accumulation of cholesterol in the coronary arteries. The rate of sudden death was 26 +- 6% (P<0.05) lower in the combined group of treated animals than in the untreated ones. By regular ECG recordings, signs which could predict the fatal outcome of the experiment were looked for. Although depressed ST segments were present before death in a few animals, this was not a regular phenomenon. It is concluded that advanced coronary atherosclerosis in mini-pigs often leads to sudden death and that this animal model seems suitable for testing the potential therapeutic effects of drugs. (author)

  14. Sudden post-traumatic sciatica caused by a thoracic spinal meningioma.

    Science.gov (United States)

    Mariniello, Giuseppe; Malacario, Francesca; Dones, Flavia; Severino, Rocco; Ugga, Lorenzo; Russo, Camilla; Elefante, Andrea; Maiuri, Francesco

    2016-10-01

    Spinal meningiomas usually present with slowly progressive symptoms of cord and root compression, while a sudden clinical onset is very rare. A 35-year-old previously symptom-free woman presented sudden right sciatica and weakness of her right leg following a fall with impact to her left foot. A neurological examination showed paresis of the right quadriceps, tibial and sural muscles, increased bilateral knee and ankle reflexes and positive Babinski sign. Magnetic resonance imaging (MRI) revealed the presence of a spinal T11 meningioma in the left postero-lateral compartment of the spinal canal; at this level, the spinal cord was displaced to the contralateral side with the conus in the normal position. At surgery, a meningioma with dural attachment of the left postero-lateral dural surface was removed. The intervention resulted in rapid remission of both pain and neurological deficits. Spinal meningiomas may exceptionally present with sudden pain and neurological deficits as result of tumour bleeding or post-traumatic injury of the already compressed nervous structures, both in normal patients and in those with conus displacement or tethered cord. In this case, the traumatic impact of the left foot was transmitted to the spine, resulting in stretching of the already compressed cord and of the contralateral lombosacral roots. This case suggests that low thoracic cord compression should be suspected in patients with post-traumatic radicular leg pain with normal lumbar spine MRI. © The Author(s) 2016.

  15. Sudden infant death syndrome: an unrecognized killer in developing countries

    Directory of Open Access Journals (Sweden)

    Ndu IK

    2016-02-01

    Full Text Available Ikenna Kingsley Ndu Department of Paediatrics, Enugu State University Teaching Hospital, Enugu, Nigeria Abstract: Sudden infant death syndrome (SIDS is defined as the sudden unexpected death of an infant <1 year of age, with onset of the fatal episode apparently occurring during sleep, that remains unexplained after a thorough investigation including performance of a complete autopsy and review of the circumstances of death and the clinical history. SIDS contributes to infant mortality and resulted in ~15,000 deaths globally in 2013. Most of the risk factors of SIDS are common in developing countries; yet, there has been little interest in SIDS by researchers in Africa. This review looks at the extent of the attention given to SIDS in a developing country like Nigeria, and factors responsible for the scarce data concerning this significant cause of mortality. Keywords: SIDS, mortality, Nigeria

  16. Analytic continuation in perturbative QCD

    International Nuclear Information System (INIS)

    Caprini, Irinel

    2002-01-01

    We discuss some attempts to improve standard perturbative expansion in QCD by using the analytic continuation in the momentum and the Borel complex planes. We first analyse the momentum-plane analyticity properties of the Borel-summed Green functions in perturbative QCD and the connection between the Landau singularities and the infrared renormalons. By using the analytic continuation in the Borel complex plane, we propose a new perturbative series replacing the standard expansion in powers of the normalized coupling constant a. The new expansion functions have branch point and essential singularities at the origin of the complex a-plane and divergent Taylor expansions in powers of a. On the other hand the modified expansion of the QCD correlators is convergent under rather conservative conditions. (author)

  17. Massive states in chiral perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    Mallik, S [Saha Inst. of Nuclear Physics, Calcutta (India)

    1995-08-01

    It is shown that the chiral nonanalytic terms generated by {Delta}{sub 33} resonance in the nucleon self-energy is reproduced in chiral perturbation theory by perturbing appropriate local operators contained in the pion-nucleon effective Lagrangian itself. (orig.)

  18. Sudden cardiac death and acute pathology of coronary arteries

    NARCIS (Netherlands)

    van Dantzig, J. M.; Becker, A. E.

    1986-01-01

    The pathology of sudden cardiac death still is a matter of controversy, particularly with respect to the state of the coronary arteries. A recent study has shown a high incidence of acute lesions and suggests a causal relationship. The present study has been designed to verify whether or not acute

  19. Geometry of perturbed Gaussian states and quantum estimation

    International Nuclear Information System (INIS)

    Genoni, Marco G; Giorda, Paolo; Paris, Matteo G A

    2011-01-01

    We address the non-Gaussianity (nG) of states obtained by weakly perturbing a Gaussian state and investigate the relationships with quantum estimation. For classical perturbations, i.e. perturbations to eigenvalues, we found that the nG of the perturbed state may be written as the quantum Fisher information (QFI) distance minus a term depending on the infinitesimal energy change, i.e. it provides a lower bound to statistical distinguishability. Upon moving on isoenergetic surfaces in a neighbourhood of a Gaussian state, nG thus coincides with a proper distance in the Hilbert space and exactly quantifies the statistical distinguishability of the perturbations. On the other hand, for perturbations leaving the covariance matrix unperturbed, we show that nG provides an upper bound to the QFI. Our results show that the geometry of non-Gaussian states in the neighbourhood of a Gaussian state is definitely not trivial and cannot be subsumed by a differential structure. Nevertheless, the analysis of perturbations to a Gaussian state reveals that nG may be a resource for quantum estimation. The nG of specific families of perturbed Gaussian states is analysed in some detail with the aim of finding the maximally non-Gaussian state obtainable from a given Gaussian one. (fast track communication)

  20. Children's Sharing Behavior in Mini-Dictator Games: The Role of In-Group Favoritism and Theory of Mind

    Science.gov (United States)

    Yu, Jing; Zhu, Liqi; Leslie, Alan M.

    2016-01-01

    This study investigated the motivational and social-cognitive foundations (i.e., inequality aversion, in-group bias, and theory of mind) that underlie the development of sharing behavior among 3- to 9-year-old Chinese children (N = 122). Each child played two mini-dictator games against an in-group member (friend) and an out-group member…

  1. Extended multi-configuration quasi-degenerate perturbation theory: the new approach to multi-state multi-reference perturbation theory.

    Science.gov (United States)

    Granovsky, Alexander A

    2011-06-07

    The distinctive desirable features, both mathematically and physically meaningful, for all partially contracted multi-state multi-reference perturbation theories (MS-MR-PT) are explicitly formulated. The original approach to MS-MR-PT theory, called extended multi-configuration quasi-degenerate perturbation theory (XMCQDPT), having most, if not all, of the desirable properties is introduced. The new method is applied at the second order of perturbation theory (XMCQDPT2) to the 1(1)A(')-2(1)A(') conical intersection in allene molecule, the avoided crossing in LiF molecule, and the 1(1)A(1) to 2(1)A(1) electronic transition in cis-1,3-butadiene. The new theory has several advantages compared to those of well-established approaches, such as second order multi-configuration quasi-degenerate perturbation theory and multi-state-second order complete active space perturbation theory. The analysis of the prevalent approaches to the MS-MR-PT theory performed within the framework of the XMCQDPT theory unveils the origin of their common inherent problems. We describe the efficient implementation strategy that makes XMCQDPT2 an especially useful general-purpose tool in the high-level modeling of small to large molecular systems. © 2011 American Institute of Physics

  2. Perturbation Theory for Open Two-Level Nonlinear Quantum Systems

    International Nuclear Information System (INIS)

    Zhang Zhijie; Jiang Dongguang; Wang Wei

    2011-01-01

    Perturbation theory is an important tool in quantum mechanics. In this paper, we extend the traditional perturbation theory to open nonlinear two-level systems, treating decoherence parameter γ as a perturbation. By this virtue, we give a perturbative solution to the master equation, which describes a nonlinear open quantum system. The results show that for small decoherence rate γ, the ratio of the nonlinear rate C to the tunneling coefficient V (i.e., r = C/V) determines the validity of the perturbation theory. For small ratio r, the perturbation theory is valid, otherwise it yields wrong results. (general)

  3. Strong, sudden cooling alleviates the inflammatory responses in heat-stressed dairy cows based on iTRAQ proteomic analysis

    Science.gov (United States)

    Cheng, Jianbo; Min, Li; Zheng, Nan; Fan, Caiyun; Zhao, Shengguo; Zhang, Yangdong; Wang, Jiaqi

    2018-02-01

    This study was designed to investigate the effects of sudden cooling on the physiological responses of 12 heat-stressed Holstein dairy cows using an isobaric tags for relative and absolute quantification (iTRAQ) labeling approach. Plasma samples were collected from these cows during heat stress (HS), and after strong, sudden cooling in the summer (16 days later). We compared plasma proteomic data before and after sudden cooling to identify the differentially abundant proteins. The results showed that sudden cooling in summer effectively alleviated the negative consequences of HS on body temperature and production variables. Expressions of plasma hemoglobin alpha and hemoglobin beta were upregulated, whereas lipopolysaccharide-binding protein (LBP) and haptoglobin were downregulated in this process. The increase of hemoglobin after cooling may improve oxygen transport and alleviate the rise in respiration rates in heat-stressed dairy cows. The decrease of LBP and haptoglobin suggests that the inflammatory responses caused by HS are relieved after cooling. Our findings provide new insight into the physiological changes that occur when heat-stressed dairy cows experience strong, sudden cooling.

  4. Nonlinear spherical perturbations in quintessence models of dark energy

    Science.gov (United States)

    Pratap Rajvanshi, Manvendra; Bagla, J. S.

    2018-06-01

    Observations have confirmed the accelerated expansion of the universe. The accelerated expansion can be modelled by invoking a cosmological constant or a dynamical model of dark energy. A key difference between these models is that the equation of state parameter w for dark energy differs from ‑1 in dynamical dark energy (DDE) models. Further, the equation of state parameter is not constant for a general DDE model. Such differences can be probed using the variation of scale factor with time by measuring distances. Another significant difference between the cosmological constant and DDE models is that the latter must cluster. Linear perturbation analysis indicates that perturbations in quintessence models of dark energy do not grow to have a significant amplitude at small length scales. In this paper we study the response of quintessence dark energy to non-linear perturbations in dark matter. We use a fully relativistic model for spherically symmetric perturbations. In this study we focus on thawing models. We find that in response to non-linear perturbations in dark matter, dark energy perturbations grow at a faster rate than expected in linear perturbation theory. We find that dark energy perturbation remains localised and does not diffuse out to larger scales. The dominant drivers of the evolution of dark energy perturbations are the local Hubble flow and a supression of gradients of the scalar field. We also find that the equation of state parameter w changes in response to perturbations in dark matter such that it also becomes a function of position. The variation of w in space is correlated with density contrast for matter. Variation of w and perturbations in dark energy are more pronounced in response to large scale perturbations in matter while the dependence on the amplitude of matter perturbations is much weaker.

  5. Determinants of occurrence and survival after sudden cardiac arrest-A European perspective

    DEFF Research Database (Denmark)

    Empana, Jean-Philippe; Blom, Marieke T; Bӧttiger, Bernd W

    2018-01-01

    AIMS: The ESCAPE-NET project ("European Sudden Cardiac Arrest network- towards Prevention, Education and New Effective Treatments") aims to study: (1) risk factors and mechanisms for the occurrence of sudden cardiac arrest (SCA) in the population, and (2) risk factors and treatment strategies...... for survival after SCA on a European scale. METHODS: This is an Horizon2020 funded program of the European Union, performed by a European public-private consortium of 16 partners across 10 EU countries. There are 11 deep-phenotyped SCA cohorts for the study of risk factors and treatment strategies for survival...... ongoing efforts on SCA outside Europe and within Europe including the EuReCa project....

  6. Very high order lattice perturbation theory for Wilson loops

    International Nuclear Information System (INIS)

    Horsley, R.

    2010-10-01

    We calculate perturbativeWilson loops of various sizes up to loop order n=20 at different lattice sizes for pure plaquette and tree-level improved Symanzik gauge theories using the technique of Numerical Stochastic Perturbation Theory. This allows us to investigate the behavior of the perturbative series at high orders. We observe differences in the behavior of perturbative coefficients as a function of the loop order. Up to n=20 we do not see evidence for the often assumed factorial growth of the coefficients. Based on the observed behavior we sum this series in a model with hypergeometric functions. Alternatively we estimate the series in boosted perturbation theory. Subtracting the estimated perturbative series for the average plaquette from the non-perturbative Monte Carlo result we estimate the gluon condensate. (orig.)

  7. Odd-parity perturbations of the self-similar LTB spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Duffy, Emily M; Nolan, Brien C, E-mail: emilymargaret.duffy27@mail.dcu.ie, E-mail: brien.nolan@dcu.ie [School of Mathematical Sciences, Dublin City University, Glasnevin, Dublin 9 (Ireland)

    2011-05-21

    We consider the behaviour of odd-parity perturbations of those self-similar LemaItre-Tolman-Bondi spacetimes which admit a naked singularity. We find that a perturbation which evolves from initially regular data remains finite on the Cauchy horizon. Finiteness is demonstrated by considering the behaviour of suitable energy norms of the perturbation (and pointwise values of these quantities) on natural spacelike hypersurfaces. This result holds for a general choice of initial data and initial data surface. Finally, we examine the perturbed Weyl scalars in order to provide a physical interpretation of our results. Taken on its own, this result does not support cosmic censorship; however, a full perturbation of this spacetime would include even-parity perturbations, so we cannot conclude that this spacetime is stable to all linear perturbations.

  8. Screening and risk evaluation for sudden cardiac death in ischaemic and non-ischaemic cardiomyopathy

    DEFF Research Database (Denmark)

    Proclemer, Alessandro; Lewalter, Thorsten; Bongiorni, Maria Grazia

    2013-01-01

    The purpose of this EHRA survey was to examine the current clinical practice of screening and risk evaluation for sudden cardiac death in ischaemic and non-ischaemic cardiomyopathy with a focus on selection of candidates for implantable cardioverter-defibrillator (ICD) therapy, timing of ICD...... implantation, and use of non-invasive and invasive diagnostic tests across Europe. A systematic screening programme for sudden cardiac death existed in 19 out of 31 centres (61.3%). Implantation of ICDs according to the inclusion criteria of MADIT-II and SCD-HeFT trials was reported in 30 and 29% of centres......, respectively, followed by MADIT-CRT (18%), COMPANION (16%), and combined MADIT and MUSTT (7%) indications. In patients with severe renal impairment, ICD implantation for primary prevention of sudden death was always avoided in 8 centres (33.3%), was not used only if creatinine level was >2.5 mg/dL in 10...

  9. Solitonic Integrable Perturbations of Parafermionic Theories

    CERN Document Server

    Fernández-Pousa, C R; Hollowood, Timothy J; Miramontes, J L

    1997-01-01

    The quantum integrability of a class of massive perturbations of the parafermionic conformal field theories associated to compact Lie groups is established by showing that they have quantum conserved densities of scale dimension 2 and 3. These theories are integrable for any value of a continuous vector coupling constant, and they generalize the perturbation of the minimal parafermionic models by their first thermal operator. The classical equations-of-motion of these perturbed theories are the non-abelian affine Toda equations which admit (charged) soliton solutions whose semi-classical quantization is expected to permit the identification of the exact S-matrix of the theory.

  10. Gauge-invariant perturbations in hybrid quantum cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Gomar, Laura Castelló; Marugán, Guillermo A. Mena [Instituto de Estructura de la Materia, CSIC, Serrano 121, 28006 Madrid (Spain); Martín-Benito, Mercedes, E-mail: laura.castello@iem.cfmac.csic.es, E-mail: m.martin@hef.ru.nl, E-mail: mena@iem.cfmac.csic.es [Institute for Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen, Heyendaalseweg 135, NL-6525 AJ Nijmegen (Netherlands)

    2015-06-01

    We consider cosmological perturbations around homogeneous and isotropic spacetimes minimally coupled to a scalar field and present a formulation which is designed to preserve covariance. We truncate the action at quadratic perturbative order and particularize our analysis to flat compact spatial sections and a field potential given by a mass term, although the formalism can be extended to other topologies and potentials. The perturbations are described in terms of Mukhanov-Sasaki gauge invariants, linear perturbative constraints, and variables canonically conjugate to them. This set is completed into a canonical one for the entire system, including the homogeneous degrees of freedom. We find the global Hamiltonian constraint of the model, in which the contribution of the homogeneous sector is corrected with a term quadratic in the perturbations, that can be identified as the Mukhanov-Sasaki Hamiltonian in our formulation. We then adopt a hybrid approach to quantize the model, combining a quantum representation of the homogeneous sector with a more standard field quantization of the perturbations. Covariance is guaranteed in this approach inasmuch as no gauge fixing is adopted. Next, we adopt a Born-Oppenheimer ansatz for physical states and show how to obtain a Schrödinger-like equation for the quantum evolution of the perturbations. This evolution is governed by the Mukhanov-Sasaki Hamiltonian, with the dependence on the homogeneous geometry evaluated at quantum expectation values, and with a time parameter defined also in terms of suitable expectation values on that geometry. Finally, we derive effective equations for the dynamics of the Mukhanov-Sasaki gauge invariants, that include quantum contributions, but have the same ultraviolet limit as the classical equations. They provide the master equation to extract predictions about the power spectrum of primordial scalar perturbations.

  11. Gauge-invariant perturbations in hybrid quantum cosmology

    International Nuclear Information System (INIS)

    Gomar, Laura Castelló; Marugán, Guillermo A. Mena; Martín-Benito, Mercedes

    2015-01-01

    We consider cosmological perturbations around homogeneous and isotropic spacetimes minimally coupled to a scalar field and present a formulation which is designed to preserve covariance. We truncate the action at quadratic perturbative order and particularize our analysis to flat compact spatial sections and a field potential given by a mass term, although the formalism can be extended to other topologies and potentials. The perturbations are described in terms of Mukhanov-Sasaki gauge invariants, linear perturbative constraints, and variables canonically conjugate to them. This set is completed into a canonical one for the entire system, including the homogeneous degrees of freedom. We find the global Hamiltonian constraint of the model, in which the contribution of the homogeneous sector is corrected with a term quadratic in the perturbations, that can be identified as the Mukhanov-Sasaki Hamiltonian in our formulation. We then adopt a hybrid approach to quantize the model, combining a quantum representation of the homogeneous sector with a more standard field quantization of the perturbations. Covariance is guaranteed in this approach inasmuch as no gauge fixing is adopted. Next, we adopt a Born-Oppenheimer ansatz for physical states and show how to obtain a Schrödinger-like equation for the quantum evolution of the perturbations. This evolution is governed by the Mukhanov-Sasaki Hamiltonian, with the dependence on the homogeneous geometry evaluated at quantum expectation values, and with a time parameter defined also in terms of suitable expectation values on that geometry. Finally, we derive effective equations for the dynamics of the Mukhanov-Sasaki gauge invariants, that include quantum contributions, but have the same ultraviolet limit as the classical equations. They provide the master equation to extract predictions about the power spectrum of primordial scalar perturbations

  12. Sudden versus gradual pressure wean from Nasal CPAP in preterm infants: a randomized controlled trial.

    Science.gov (United States)

    Amatya, S; Macomber, M; Bhutada, A; Rastogi, D; Rastogi, S

    2017-06-01

    In preterm infants, nasal continuous positive airway pressure (NCPAP) is widely used for treatment of respiratory distress syndrome. However, the strategies for successfully weaning infants off NCPAP are still not well defined and there remains considerable variation between the methods. The objective of this study is to determine whether gradual weaning of NCPAP pressure is more successful than sudden weaning off NCPAP to room air. A randomized controlled trial was conducted in a level 3 neonatal intensive care unit on 70 preterm neonates who were born between 26 and 32 weeks gestation and required NCPAP for at least 48 h. When infants were stable on NCPAP at 0.21 FiO 2 and 5 cm H 2 O positive end expiratory pressure, neonates were randomized to the gradual wean group (reduction in pressure by 1 cm every 8 h until 3 cm H 2 0 was reached) or to sudden wean group (one time NCPAP removal to room air). The primary outcome was a success at the first trial to wean to room air. Secondary outcomes were a number of trials, and weight and postmenstrual age (PMA) at the time of successful wean. Total number of days on NCPAP and length of stay (LOS) in the hospital were also compared between the groups. Of the 70 infants included in the study, 35 were randomized to sudden group and 33 infants to gradual group (2 excluded for protocol deviation). In sudden and gradual groups, 14 and 22 infants, respectively, were weaned successfully in the first attempt (P=0.03). The infants were successfully weaned at 32.7±1.7 weeks versus 33.1±2.4 weeks (P=0.39) PMA and at a weight of 1651±290 g versus 1589±398 g (P=0.46) in the sudden and gradual groups, respectively. The total number of days on NCPAP was 27±19 days versus 32±24 days (P=0.38) and LOS was 63±25 days versus 63±22 days (P=0.99) in the sudden and gradual groups, respectively. Gradual weaning method was more successful as compared to sudden weaning method in the initial trial off NCPAP. There was no

  13. Cosmological perturbations in the new Higgs inflation

    Energy Technology Data Exchange (ETDEWEB)

    Germani, Cristiano [Arnold Sommerfeld Center, Ludwig-Maximilians-University, Theresienstr, 37 80333 Muenchen (Germany); Kehagias, Alex, E-mail: cristiano.germani@lmu.de, E-mail: kehagias@central.ntua.gr [Physics Division, National Technical University of Athens, 15780 Zografou Campus, Athens (Greece)

    2010-05-01

    We study the cosmological perturbations created during the New Higgs inflationary phase. In the New Higgs Inflation, the Higgs boson is kinetically coupled to the Einstein tensor and only three perturbative degrees of freedom, a scalar and two tensorial (gravitational waves), propagate during Inflation. Scalar perturbations are found to match the latest WMAP-7yrs data within Standard Model Higgs parameters. Primordial gravitational waves also, although propagating with superluminal speed, are consistent with present data. Finally, we estimate the values of the parameter of the New Higgs Inflation in relation to the Higgs mass, the spectral index and amplitude of the primordial scalar perturbations showing that the unitarity bound of the theory is not violated.

  14. Inflationary perturbations in anisotropic, shear-free universes

    International Nuclear Information System (INIS)

    Pereira, Thiago S.; Carneiro, Saulo; Marugan, Guillermo A. Mena

    2012-01-01

    In this work, the linear and gauge-invariant theory of cosmological perturbations in a class of anisotropic and shear-free spacetimes is developed. After constructing an explicit set of complete eigenfunctions in terms of which perturbations can be expanded, we identify the effective degrees of freedom during a generic slow-roll inflationary phase. These correspond to the anisotropic equivalent of the standard Mukhanov-Sasaki variables. The associated equations of motion present a remarkable resemblance to those found in perturbed Friedmann-Robertson-Walker spacetimes with curvature, apart from the spectrum of the Laplacian, which exhibits the characteristic frequencies of the underlying geometry. In particular, it is found that the perturbations cannot develop arbitrarily large super-Hubble modes

  15. Sudden disruption of the cross-tail current in the magnetotail

    International Nuclear Information System (INIS)

    Ma, Z. W.

    2008-01-01

    A Hall magnetohydrodynamic simulation is used to study current dynamic processes with realistic magnetotail geometry. The simulation results indicate that sudden disruption of cross-tail current at the near Earth region inside 15R E is triggered by fast magnetic reconnection with the reconnection rate ∼0.15. The cross-tail current density exhibits an impulsive intensification in the late growth phase. The magnitude of the current increases more than one order within a few minutes. After the reconnection onset, the cross-tail current is suddenly disrupted in a few Alfven times, which is in good agreement with that from the satellite observations. Associated with the current disruption, the tail-like geometry becomes a dipolarlike structure with an impulsive enhancement of the magnetic field B z . Large increases of the electric field and Earthward bulk flow in this simulation are observed immediately after the reconnection onset

  16. Comparative study of turbulence model performance for axisymmetric sudden expansion flow

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Youngmin; Kim, Young In; Kim, Keung Koo; Yoon, Juhyeon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    In this study, the performance of turbulence models in predicting the turbulent flow in an axisymmetric sudden expansion with an expansion ratio of 4 is assessed for a Reynolds number of 5.6 Χ 10{sup 4}. The comparisons show that the standard k-ε and RSM models provide the best agreement with the experimental data, whereas the standard k-ω model gives poor predictions. Owing to its computational efficiency, the Reynolds Averaged Navier-Stokes (RANS) approach has been widely used for the prediction of turbulent flows and associated pressure losses in a variety of internal flow systems such as a diffuser, orifice, converging nozzle, and pipes with sudden expansion. However, the lack of a general turbulence model often leads to limited applications of a RANS approach, i. e., the accuracy and validity of solutions obtained from RANS equations vary with the turbulence model, flow regime, near-wall treatment, and configuration of the problem. In light of the foregoing, a large amount of turbulence research has been conducted to assess the performance of existing turbulence models for different flow fields. In this paper, the turbulent flow in an axisymmetric sudden expansion is numerically investigated for a Reynolds number of 5.6 Χ 10{sup 4}, with the aim of examining the performance of several turbulence models.

  17. Reporting a sudden death due to accidental gasoline inhalation.

    Science.gov (United States)

    Martínez, María Antonia; Ballesteros, Salomé; Alcaraz, Rafael

    2012-02-10

    The investigation of uncertain fatalities requires accurate determination of the cause of death, with assessment of all factors that may have contributed to it. Gasoline is a complex and highly variable mixture of aliphatic and aromatic hydrocarbons that can lead to cardiac arrhythmias due to sensitization of the myocardium to catecholamines or acts as a simple asphyxiant if the vapors displace sufficient oxygen from the breathing atmosphere. This work describes a sudden occupational fatality involving gasoline. The importance of this petroleum distillate detection and its quantitative toxicological significance is discussed using a validated analytical method. A 51 year-old Caucasian healthy man without significant medical history was supervising the repairs of the telephone lines in a manhole near to a gas station. He died suddenly after inhaling gasoline vapors from an accidental leak. Extensive blistering and peeling of skin were observed on the skin of the face, neck, anterior chest, upper and lower extremities, and back. The internal examination showed a strong odor of gasoline, specially detected in the respiratory tract. The toxicological screening and quantitation of gasoline was performed by means of gas chromatography with flame ionization detector and confirmation was performed using gas chromatography-mass spectrometry. Disposition of gasoline in different tissues was as follows: heart blood, 35.7 mg/L; urine, not detected; vitreous humor, 1.9 mg/L; liver, 194.7 mg/kg; lung, 147.6 mg/kg; and gastric content, 116,6 mg/L (2.7 mg total). Based upon the toxicological data along with the autopsy findings, the cause of death was determined to be gasoline poisoning and the manner of death was accidental. We would like to alert on the importance of testing for gasoline, and in general for volatile hydrocarbons, in work-related sudden deaths involving inhalation of hydrocarbon vapors and/or exhaust fumes. Copyright © 2011 Elsevier Ireland Ltd. All rights

  18. Collaboratively managing sudden oak death using tangible geospatial modeling

    Science.gov (United States)

    Ross K. Meentemeyer; Francesco Tonini; Douglas Shoemaker; Richard C. Cobb; Brendan A. Harmon; Vaclav Petras; Anna Petrasova; Helena Mitasova

    2017-01-01

    Failure to build consensus amongst stakeholders has been a primary obstacle barring progress in developing and implementing strategies to manage sudden oak death (SOD). Consensus as to the goals of in situ management of SOD has rarely been reached, because stakeholders’ visions of success vary widely and often compete with each other...

  19. Oscillating flow and heat transfer in a channel with sudden cross section change

    Science.gov (United States)

    Ibrahim, Mounir; Hashim, Waqar

    1993-01-01

    We have computationally examined oscillating flow (zero mean) between two parallel plates with a sudden change in cross section. The flow was assumed to be laminar incompressible with the inflow velocity uniform over the channel cross section but varying sinusoidally with time. The cases studied cover wide ranges of Re(sub max) (from 187.5 to 2000), Va (from 1 to 10.66), the expansion ratio (1:2 and 1:4) and A(sub r) (2 and 4). Also, three different geometric cases were discussed: (1) asymmetric expansion/contraction; (2) symmetric expansion/contraction; and (3) symmetric blunt body. For these oscillating flow conditions, the fluid undergoes sudden expansion in one-half of the cycle and sudden contraction inthe other half. The instantaneous friction factor, for some ranges of Re(sub max) and Va, deviated substantially from the steady-state friction factor for the same flow parameters. A region has been identified below which the flow is laminar quasi-steady. A videotape showing computer simulations of the oscillating flow demonstrates the usefulness of the current analyses in providing information on the transient hydraulic phenomena.

  20. Singular perturbations of empty Robertson-Walker cosmologies

    International Nuclear Information System (INIS)

    Newman, R.P.A.C.

    1979-02-01

    An investigation is presented which concerns a class of cosmological models defined by McVittie (1931): the universe is envisaged as a set of galaxies, idealised as point particles, which provide singular perturbations of Robertson-Walker cosmologies. The perturbations are considered only to first order in the gravitational coupling constant (8πG)/c 2 . Attention will only be given to such perturbations of empty Robertson-Walker cosmologies. Chapter 1 summarises the observational support for the type of model employed and for the smallness of the quantities to be used as perturbation coefficients. Chapter 2 provides the prerequisite analysis of Robertson-Walker cosmologies. Perturbations of empty Robertson-Walker cosmologies of non-vanishing cosmical constant are considered in general in Chapter 3. The structure of McVittie's singularly perturbed Robertson-Walker cosmologies are considered in detail in Chapter 4. The remaining chapters seek to investigate them further by way of their optical properties. Chapter 5 provides the necessary theory of geometric optics with particular regard to the intensity and distortion of a beam of light, and Chapter 6 applies this theory to the McVittie cosmologies. Chapter 7 sees the definition of an averaging procedure which leads to expressions for the intensity and distortion of a typical beam of light from a point source. (author)

  1. Perturbation Theory of the Cosmological Log-Density Field

    DEFF Research Database (Denmark)

    Wang, Xin; Neyrinck, Mark; Szapudi, István

    2011-01-01

    , motivating an analytic study of it. In this paper, we develop cosmological perturbation theory for the power spectrum of this field. Our formalism is developed in the context of renormalized perturbation theory, which helps to regulate the convergence behavior of the perturbation series, and of the Taylor...

  2. Divergence of perturbation theory in large scale structures

    Science.gov (United States)

    Pajer, Enrico; van der Woude, Drian

    2018-05-01

    We make progress towards an analytical understanding of the regime of validity of perturbation theory for large scale structures and the nature of some non-perturbative corrections. We restrict ourselves to 1D gravitational collapse, for which exact solutions before shell crossing are known. We review the convergence of perturbation theory for the power spectrum, recently proven by McQuinn and White [1], and extend it to non-Gaussian initial conditions and the bispectrum. In contrast, we prove that perturbation theory diverges for the real space two-point correlation function and for the probability density function (PDF) of the density averaged in cells and all the cumulants derived from it. We attribute these divergences to the statistical averaging intrinsic to cosmological observables, which, even on very large and "perturbative" scales, gives non-vanishing weight to all extreme fluctuations. Finally, we discuss some general properties of non-perturbative effects in real space and Fourier space.

  3. Coupled catastrophes: sudden shifts cascade and hop among interdependent systems

    Science.gov (United States)

    Barnett, George; D'Souza, Raissa M.

    2015-01-01

    An important challenge in several disciplines is to understand how sudden changes can propagate among coupled systems. Examples include the synchronization of business cycles, population collapse in patchy ecosystems, markets shifting to a new technology platform, collapses in prices and in confidence in financial markets, and protests erupting in multiple countries. A number of mathematical models of these phenomena have multiple equilibria separated by saddle-node bifurcations. We study this behaviour in its normal form as fast–slow ordinary differential equations. In our model, a system consists of multiple subsystems, such as countries in the global economy or patches of an ecosystem. Each subsystem is described by a scalar quantity, such as economic output or population, that undergoes sudden changes via saddle-node bifurcations. The subsystems are coupled via their scalar quantity (e.g. trade couples economic output; diffusion couples populations); that coupling moves the locations of their bifurcations. The model demonstrates two ways in which sudden changes can propagate: they can cascade (one causing the next), or they can hop over subsystems. The latter is absent from classic models of cascades. For an application, we study the Arab Spring protests. After connecting the model to sociological theories that have bistability, we use socioeconomic data to estimate relative proximities to tipping points and Facebook data to estimate couplings among countries. We find that although protests tend to spread locally, they also seem to ‘hop' over countries, like in the stylized model; this result highlights a new class of temporal motifs in longitudinal network datasets. PMID:26559684

  4. Non-hard sphere thermodynamic perturbation theory.

    Science.gov (United States)

    Zhou, Shiqi

    2011-08-21

    A non-hard sphere (HS) perturbation scheme, recently advanced by the present author, is elaborated for several technical matters, which are key mathematical details for implementation of the non-HS perturbation scheme in a coupling parameter expansion (CPE) thermodynamic perturbation framework. NVT-Monte Carlo simulation is carried out for a generalized Lennard-Jones (LJ) 2n-n potential to obtain routine thermodynamic quantities such as excess internal energy, pressure, excess chemical potential, excess Helmholtz free energy, and excess constant volume heat capacity. Then, these new simulation data, and available simulation data in literatures about a hard core attractive Yukawa fluid and a Sutherland fluid, are used to test the non-HS CPE 3rd-order thermodynamic perturbation theory (TPT) and give a comparison between the non-HS CPE 3rd-order TPT and other theoretical approaches. It is indicated that the non-HS CPE 3rd-order TPT is superior to other traditional TPT such as van der Waals/HS (vdW/HS), perturbation theory 2 (PT2)/HS, and vdW/Yukawa (vdW/Y) theory or analytical equation of state such as mean spherical approximation (MSA)-equation of state and is at least comparable to several currently the most accurate Ornstein-Zernike integral equation theories. It is discovered that three technical issues, i.e., opening up new bridge function approximation for the reference potential, choosing proper reference potential, and/or using proper thermodynamic route for calculation of f(ex-ref), chiefly decide the quality of the non-HS CPE TPT. Considering that the non-HS perturbation scheme applies for a wide variety of model fluids, and its implementation in the CPE thermodynamic perturbation framework is amenable to high-order truncation, the non-HS CPE 3rd-order or higher order TPT will be more promising once the above-mentioned three technological advances are established. © 2011 American Institute of Physics

  5. A vortex dynamics perspective on stratospheric sudden warmings

    OpenAIRE

    Matthewman, N. J.

    2009-01-01

    A vortex dynamics approach is used to study the underlying mechanisms leading to polar vortex breakdown during stratospheric sudden warmings (SSWs). Observational data are used in chapter 2 to construct climatologies of the Arctic polar vortex structure during vortex-splitting and vortex-displacement SSWs occurring between 1958 and 2002. During vortex-splitting SSWs, polar vortex breakdown is shown to be typically independent of height (barotropic), whereas breakdown during vor...

  6. Circumvention of suddenly appearing obstacles in young and older adults

    NARCIS (Netherlands)

    Pijnappels, M.; Kingma, I.; Van Dieën, J. H.

    2010-01-01

    Reduced ability to circumvent an obstacle, which is noticed only shortly before collision, could be a cause of falls and injury, especially in older adults. In this study, we investigated differences in strategies and their characteristics between young and older adults when circumventing a suddenly

  7. Effect of passenger position on fear of danger experienced during sudden bus stops.

    Science.gov (United States)

    Aoki, Takeo; Uetake, Teruo; Shimoda, Masahiro

    2009-06-01

    The purpose of this study was to identify the effect of bus passengers' positions on their fear of danger when a bus stopped suddenly. A temporary bus running course with one bus stop was set up on the campus of the Tokyo University of Agriculture and Technology (TUAT). The bus ran the course 14 times with the bus stopping twice during the course, once at the bus stop and again just after re-starting from the bus stop. The driver was asked to brake more strongly than usual when stopping. Sixteen students (15 males and 1 female) between the ages of 18 and 21 years participated. In turn, all participants were asked to take 14 different postures in the bus. Participants were also asked to report their level of fear on a rating scale each time the bus stopped. The study showed that (1) passengers' fear of danger at the first sudden stop was typically higher than that at the second stop, (2) standing passengers who held hand straps experienced more fear than those who held fixed safety devices, (3) bus passengers sitting on the centre of the rear seat had a great risk of injury if the bus stopped suddenly, and (4) when passengers faced the window and stood transversely with respect to from the moving direction of the bus and the bus stopped suddenly, passengers' fear of danger was affected by the side of the bus on which they stood as well as which hand they used to grasp a safety device.

  8. Operator Decomposition Framework for Perturbation Theory

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Khalik, Hany S.; Wang, Congjian; Bang, Young Suk [North Carolina State University, Raleigh (United States)

    2012-05-15

    This summary describes a new framework for perturbation theory intended to improve its performance, in terms of the associated computational cost and the complexity of implementation, for routine reactor calculations in support of design, analysis, and regulation. Since its first introduction in reactor analysis by Winger, perturbation theory has assumed an aura of sophistication with regard to its implementation and its capabilities. Only few reactor physicists, typically mathematically proficient, have contributed to its development, with the general body of the nuclear engineering community remaining unaware of its current status, capabilities, and challenges. Given its perceived sophistication and the small body of community users, the application of perturbation theory has been limited to investigatory analyses only. It is safe to say that the nuclear community is split into two groups, a small one which understands the theory and, and a much bigger group with the perceived notion that perturbation theory is nothing but a fancy mathematical approach that has very little use in practice. Over the past three years, research has demonstrated two goals. First, reduce the computational cost of perturbation theory in order to enable its use for routine reactor calculations. Second, expose some of the myth about perturbation theory and present it in a form that is simple and relatable in order to stimulate the interest of nuclear practitioners, especially those who are currently working on the development of next generation reactor design and analysis tools. The operator decomposition approach has its roots in linear algebra and can be easily understood by code developers, especially those involved in the design of iterative numerical solution strategies

  9. Perturbations of the Friedmann universe

    International Nuclear Information System (INIS)

    Novello, M.; Salim, J.M.; Heintzmann, H.

    1982-01-01

    Correcting and extending previous work by Hawking (1966) and Olson (1976) the complete set of perturbation equations of a Friedmann Universe in the quasi-Maxwellian form is derived and analized. The formalism is then applied to scalar, vector and tensor perturbations of a phenomenological fluid, which is modelled such as to comprise shear and heat flux. Depending on the equation of state of the background it is found that there exist unstable (growing) modes of purely rotational character. It is further found that (to linear order at least) any vortex perturbation is equivalent to a certain heat flux vector. The equation for the gravitational waves are derived in a completely equivalent method as in case of the propagation, in a curved space-time, of electromagnetic waves in a plasma endowed with some definite constitutive relations. (Author) [pt

  10. Solar flare effects and storm sudden commencement even in ...

    African Journals Online (AJOL)

    1998-05-08

    Variations in the three components of geomagnetic field were observed at the twenty-two geomagnetic Euro-African Observatories during the solar flare that occurred on the 6 May, 1998 at 0080UT and storm sudden commencement that took place on May 8, 1998 at 15.00 UT. The geomagnetic field on 6 May, 1998 was ...

  11. Linking sudden oak death with spatial economic value transfer

    Science.gov (United States)

    Tom Holmes; Bill Smith

    2008-01-01

    Sudden oak death (caused by Phytophthora ramorum) is currently having a dramatic impact on the flow of ecosystem services provided by trees and forests in California. Timber species in California are not thought to be at risk of mortality from this pathogen and, consequently, economic impacts accrue to non-market values of trees such as aesthetics,...

  12. Cardiomyopathies as a Cause of Sudden Cardiac Death (SCD in Egypt: Recognition and Preventive Strategies Needed

    Directory of Open Access Journals (Sweden)

    Nora Fnon

    2016-06-01

    Full Text Available This study aimed at evaluating the epidemiological characteristics and pathological features of different types of cardiomyopathies in Egypt, highlighting the role of the forensic pathologist in identifying cases of cardiomyopathies and initiating for their families a possible genetic study aiming at prevention of sudden death. All cases with sudden cardiac death (SCD due to cardiomyopathies during the period from the beginning of January 2010 until the end of December 2014 (5 years were included in this study. All hearts underwent detailed gross and histological examination. Circumstances of death, medical history, and post-mortem pathological findings were thoroughly  investigated. Out of 535 cases of sudden cardiac death, there were 22 cases (4.1% diagnosed as having cardiomyopathies; sudden death was their first presentation. Eighteen cases (81.8% were male, with the 4th decade (11 cases, 50% being the most affected age; severe physical activity and exertion were evident in death circumstances of 14 cases (63.6%; pathological evaluation revealed that hypertrophic cardiomyopathy was the most frequent type, being diagnosed in 10 cases (45%. Cardiomyopathies are an infrequent cause of sudden cardiac death. Most deaths are in children and adults, so cases are of high social impact that demands multidisciplinary research and resources. In all cases of SCD, forensic autopsy should be done. Forensic study is the key to identifying an affected family and the starting point regarding assessing them.

  13. Resolution of ambiguities in perturbative QCD

    International Nuclear Information System (INIS)

    Nakkagawa, Hisao; Niegawa, Akira.

    1984-01-01

    In the perturbative QCD analyses of the deeply inelastic processes, the coupling constant depends on at least two mass-scales, the renormalization scale and the factorization scale. By integrating the coupled renormalization group equations with respect to these two mass-scales, the running coupling constant is defined. A perturbative approximation then introduces a new ambiguity, the integration-path dependence, into the theory. We show that the problem of this new ambiguity is resolved by imposing Stevenson's principle of minimal sensitivity. Together with the analogous analysis of the operator matrix element or the cut vertex, we can completely solve the problem of getting an unambiguous perturbative QCD prediction. (author)

  14. Perturbation analysis of linear control problems

    International Nuclear Information System (INIS)

    Petkov, Petko; Konstantinov, Mihail

    2017-01-01

    The paper presents a brief overview of the technique of splitting operators, proposed by the authors and intended for perturbation analysis of control problems involving unitary and orthogonal matrices. Combined with the technique of Lyapunov majorants and the implementation of the Banach and Schauder fixed point principles, it allows to obtain rigorous non-local perturbation bounds for a set of sensitivity analysis problems. Among them are the reduction of linear systems into orthogonal canonical forms, the feedback synthesis problem and pole assignment problem in particular, as well as other important problems in control theory and linear algebra. Key words: perturbation analysis, canonical forms, feedback synthesis

  15. Cumulants in perturbation expansions for non-equilibrium field theory

    International Nuclear Information System (INIS)

    Fauser, R.

    1995-11-01

    The formulation of perturbation expansions for a quantum field theory of strongly interacting systems in a general non-equilibrium state is discussed. Non-vanishing initial correlations are included in the formulation of the perturbation expansion in terms of cumulants. The cumulants are shown to be the suitable candidate for summing up the perturbation expansion. Also a linked-cluster theorem for the perturbation series with cumulants is presented. Finally a generating functional of the perturbation series with initial correlations is studied. We apply the methods to a simple model of a fermion-boson system. (orig.)

  16. [Sudden death in Versailles: A review of a cardiovascular treatrise by Dionis (1710)].

    Science.gov (United States)

    Charlier, P

    2018-02-01

    In 1710, the surgeon Pierre Dionis publishes a Dissertation on sudden death. Echoing and expanding the work of his Roman colleague Jean Marie Lancisi, he describes and analyzes dozens of cases of sudden death observed by him. A large number of cases was followed by autopsies allowing clinicopathological confrontation. Are proposed causes of death (pulmonary embolism, myocardial infarction, hemorrhagic stroke, arterial rupture, etc.), pathophysiological mechanisms based on the ancient theory of humors, and preventive actions to avoid these unexpected deaths. In this article, we oppose these old data to those of current literature. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  17. Prevention of sudden cardiac death in athletes, sportspersons and marathoners in India

    Directory of Open Access Journals (Sweden)

    Amit Vora

    2018-01-01

    Full Text Available The annual incidence of sudden cardiac death (SCD in athletes is significantly lower than the general population. However, when SCD occurs in an athlete during sporting event or training, it sends shockwaves in the society and raises questions about cardiovascular effects of sports and exercise. This document reviews the causes and mechanism of SCD in sports and exercise in young and older athletes. In the Indian context, we suggest a ‘pre-participation screening’ of young and older athletes and consider a ‘supervised, graded exercise regime’ for the uninitiated, older sports participant. Finally, the document proposes medical infrastructure required to successfully revive a victim of sudden cardiac arrest during a sporting event.

  18. Effects of Dictation, Speech to Text, and Handwriting on the Written Composition of Elementary School English Language Learners

    Science.gov (United States)

    Arcon, Nina; Klein, Perry D.; Dombroski, Jill D.

    2017-01-01

    Previous research has shown that both dictation and speech-to-text (STT) software can increase the quality of writing for native English speakers. The purpose of this study was to investigate the effect of these modalities on the written composition and cognitive load of elementary school English language learners (ELLs). In a within-subjects…

  19. Traffic Perturbation

    CERN Multimedia

    C. Colloca TS/FM

    2004-01-01

    TS/FM group informs you that, for the progress of the works at the Prévessin site entrance, some perturbation of the traffic may occur during the week between the 14th and 18th of June for a short duration. Access will be assured at any time. For more information, please contact 160239. C. Colloca TS/FM

  20. Mode coupling of Schwarzschild perturbations: Ringdown frequencies

    International Nuclear Information System (INIS)

    Pazos, Enrique; Brizuela, David; Martin-Garcia, Jose M.; Tiglio, Manuel

    2010-01-01

    Within linearized perturbation theory, black holes decay to their final stationary state through the well-known spectrum of quasinormal modes. Here we numerically study whether nonlinearities change this picture. For that purpose we study the ringdown frequencies of gauge-invariant second-order gravitational perturbations induced by self-coupling of linearized perturbations of Schwarzschild black holes. We do so through high-accuracy simulations in the time domain of first and second-order Regge-Wheeler-Zerilli type equations, for a variety of initial data sets. We consider first-order even-parity (l=2, m=±2) perturbations and odd-parity (l=2, m=0) ones, and all the multipoles that they generate through self-coupling. For all of them and all the initial data sets considered we find that--in contrast to previous predictions in the literature--the numerical decay frequencies of second-order perturbations are the same ones of linearized theory, and we explain the observed behavior. This would indicate, in particular, that when modeling or searching for ringdown gravitational waves, appropriately including the standard quasinormal modes already takes into account nonlinear effects.

  1. Supersymmetry restoration in superstring perturbation theory

    International Nuclear Information System (INIS)

    Sen, Ashoke

    2015-01-01

    Superstring perturbation theory based on the 1PI effective theory approach has been useful for addressing the problem of mass renormalization and vacuum shift. We derive Ward identities associated with space-time supersymmetry transformation in this approach. This leads to a proof of the equality of renormalized masses of bosons and fermions and identities relating fermionic amplitudes to bosonic amplitudes after taking into account the effect of mass renormalization. This also relates unbroken supersymmetry to a given order in perturbation theory to absence of tadpoles of massless scalars to higher order. The results are valid at the perturbative vacuum as well as in the shifted vacuum when the latter describes the correct ground state of the theory. We apply this to SO(32) heterotic string theory on Calabi-Yau 3-folds where a one loop Fayet-Iliopoulos term apparently breaks supersymmetry at one loop, but analysis of the low energy effective field theory indicates that there is a nearby vacuum where supersymmetry is restored. We explicitly prove that the perturbative amplitudes of this theory around the shifted vacuum indeed satisfy the Ward identities associated with unbroken supersymmetry. We also test the general arguments by explicitly verifying the equality of bosonic and fermionic masses at one loop order in the shifted vacuum, and the appearance of two loop dilaton tadpole in the perturbative vacuum where supersymmetry is expected to be broken.

  2. Supersymmetry restoration in superstring perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Ashoke [Harish-Chandra Research Institute,Chhatnag Road, Jhusi, Allahabad 211019 (India)

    2015-12-14

    Superstring perturbation theory based on the 1PI effective theory approach has been useful for addressing the problem of mass renormalization and vacuum shift. We derive Ward identities associated with space-time supersymmetry transformation in this approach. This leads to a proof of the equality of renormalized masses of bosons and fermions and identities relating fermionic amplitudes to bosonic amplitudes after taking into account the effect of mass renormalization. This also relates unbroken supersymmetry to a given order in perturbation theory to absence of tadpoles of massless scalars to higher order. The results are valid at the perturbative vacuum as well as in the shifted vacuum when the latter describes the correct ground state of the theory. We apply this to SO(32) heterotic string theory on Calabi-Yau 3-folds where a one loop Fayet-Iliopoulos term apparently breaks supersymmetry at one loop, but analysis of the low energy effective field theory indicates that there is a nearby vacuum where supersymmetry is restored. We explicitly prove that the perturbative amplitudes of this theory around the shifted vacuum indeed satisfy the Ward identities associated with unbroken supersymmetry. We also test the general arguments by explicitly verifying the equality of bosonic and fermionic masses at one loop order in the shifted vacuum, and the appearance of two loop dilaton tadpole in the perturbative vacuum where supersymmetry is expected to be broken.

  3. Fragmentation of suddenly heated liquids

    International Nuclear Information System (INIS)

    Blink, J.A.

    1985-03-01

    Fragmentation of free liquids in Inertial Confinement Fusion reactors could determine the upper bound on reactor pulse rate. The x-ray ablated materials must cool and recondense to allow driver beam propagation. The increased surface area caused by fragmentation will enhance the cooling and condensation rates. Relaxation from the suddenly heated state will move a liquid into the negative pressure region under the liquid-vapor P-V dome. The lithium equation of state was used to demonstrate that neutron-induced vaporization uses only a minor fraction of the added heat, much less than would be required to drive the expansion. A 77% expansion of the lithium is required before the rapid vaporization process of spinodal decomposition could begin, and nucleation and growth are too slow to contribute to the expansion

  4. Left ventricular cardiac myxoma and sudden death in a dog

    NARCIS (Netherlands)

    de Nijs, M.I.; Vink, Aryan; Bergmann, W.; Szatmári, V.

    2016-01-01

    Background: Myxoma is a very rare benign cardiac tumor in dogs. This is the first description of a cardiac myxoma originating from the left ventricular outflow tract, presumably causing sudden death. Case presentation: A previously healthy 12-year-old male West Highland white terrier was found dead

  5. Left ventricular cardiac myxoma and sudden death in a dog

    NARCIS (Netherlands)

    de Nijs, Maria Irene; Vink, Aryan; Bergmann, Wilhelmina; Szatmári, Viktor

    2016-01-01

    BACKGROUND: Myxoma is a very rare benign cardiac tumor in dogs. This is the first description of a cardiac myxoma originating from the left ventricular outflow tract, presumably causing sudden death. CASE PRESENTATION: A previously healthy 12-year-old male West Highland white terrier was found dead

  6. Can the second order multireference perturbation theory be considered a reliable tool to study mixed-valence compounds?

    Science.gov (United States)

    Pastore, Mariachiara; Helal, Wissam; Evangelisti, Stefano; Leininger, Thierry; Malrieu, Jean-Paul; Maynau, Daniel; Angeli, Celestino; Cimiraglia, Renzo

    2008-05-07

    In this paper, the problem of the calculation of the electronic structure of mixed-valence compounds is addressed in the frame of multireference perturbation theory (MRPT). Using a simple mixed-valence compound (the 5,5(') (4H,4H('))-spirobi[ciclopenta[c]pyrrole] 2,2('),6,6(') tetrahydro cation), and the n-electron valence state perturbation theory (NEVPT2) and CASPT2 approaches, it is shown that the ground state (GS) energy curve presents an unphysical "well" for nuclear coordinates close to the symmetric case, where a maximum is expected. For NEVPT, the correct shape of the energy curve is retrieved by applying the MPRT at the (computationally expensive) third order. This behavior is rationalized using a simple model (the ionized GS of two weakly interacting identical systems, each neutral system being described by two electrons in two orbitals), showing that the unphysical well is due to the canonical orbital energies which at the symmetric (delocalized) conformation lead to a sudden modification of the denominators in the perturbation expansion. In this model, the bias introduced in the second order correction to the energy is almost entirely removed going to the third order. With the results of the model in mind, one can predict that all MRPT methods in which the zero order Hamiltonian is based on canonical orbital energies are prone to present unreasonable energy profiles close to the symmetric situation. However, the model allows a strategy to be devised which can give a correct behavior even at the second order, by simply averaging the orbital energies of the two charge-localized electronic states. Such a strategy is adopted in a NEVPT2 scheme obtaining a good agreement with the third order results based on the canonical orbital energies. The answer to the question reported in the title (is this theoretical approach a reliable tool for a correct description of these systems?) is therefore positive, but care must be exercised, either in defining the orbital

  7. Sudden acquired retinal degeneration syndrome in western Canada: 93 cases.

    Science.gov (United States)

    Leis, Marina L; Lucyshyn, Danica; Bauer, Bianca S; Grahn, Bruce H; Sandmeyer, Lynne S

    2017-11-01

    This study reviewed clinical data from dogs diagnosed with sudden acquired retinal degeneration syndrome (SARDS) in western Canada. Medical records from the Western College of Veterinary Medicine from 2002 to 2016 showed that 93 cases of SARDS were diagnosed based on presentation for sudden blindness and a bilaterally extinguished electroretinogram. The most common pure breeds were the miniature schnauzer, dachshund, and pug. The mean age at diagnosis was 8.1 years and males and females were equally affected. Most of the dogs were presented with normal non-chromatic, but abnormal chromatic pupillary light reflexes. The incidence of retinal degeneration as detected via ophthalmoscopy increased over time after SARDS diagnosis. Polyuria, polydipsia, polyphagia, weight gain, elevated liver enzyme values, isosthenuria, and proteinuria were common clinical and laboratory findings. Chromatic pupillary light reflex testing may be more valuable than non-chromatic pupillary light testing in detecting pupil response abnormalities in dogs with SARDS, although electroretinography remains the definitive diagnostic test.

  8. Sudden death and paroxysmal autonomic dysfunction in stiff-man syndrome.

    Science.gov (United States)

    Mitsumoto, H; Schwartzman, M J; Estes, M L; Chou, S M; La Franchise, E F; De Camilli, P; Solimena, M

    1991-04-01

    Two women with typical stiff-man syndrome (SMS) developed increasingly frequent attacks of muscle spasms with severe paroxysmal autonomic dysfunctions such as transient hyperpyrexia, diaphoresis, tachypnea, tachycardia, pupillary dilation, and arterial hypertension. Autoantibodies to GABA-ergic neurons were identified in the serum of both patients and in the cerebrospinal fluid of one. Both died suddenly and unexpectedly. General autopsy did not reveal the cause of death. Neuropathological studies revealed perivascular gliosis in the spinal cord and brain stem of one patient and lymphocytic perivascular infiltration in the spinal cord, brain stem, and basal ganglia of the other. The occurrence of a chronic inflammatory reaction in one of the two patients supports the idea that an autoimmune disease against GABA-ergic neurons may be involved in SMS. A review of the literature indicates that functional impairment in SMS is severe and prognosis is unpredictable because of the potential for sudden and unexpected death. Both muscular abnormalities and autonomic dysfunctions may result from autoimmunity directed against GABA-ergic neurons.

  9. Sudden acquired retinal degeneration syndrome in western Canada: 93 cases

    Science.gov (United States)

    Leis, Marina L.; Lucyshyn, Danica; Bauer, Bianca S.; Grahn, Bruce H.; Sandmeyer, Lynne S.

    2017-01-01

    This study reviewed clinical data from dogs diagnosed with sudden acquired retinal degeneration syndrome (SARDS) in western Canada. Medical records from the Western College of Veterinary Medicine from 2002 to 2016 showed that 93 cases of SARDS were diagnosed based on presentation for sudden blindness and a bilaterally extinguished electroretinogram. The most common pure breeds were the miniature schnauzer, dachshund, and pug. The mean age at diagnosis was 8.1 years and males and females were equally affected. Most of the dogs were presented with normal non-chromatic, but abnormal chromatic pupillary light reflexes. The incidence of retinal degeneration as detected via ophthalmoscopy increased over time after SARDS diagnosis. Polyuria, polydipsia, polyphagia, weight gain, elevated liver enzyme values, isosthenuria, and proteinuria were common clinical and laboratory findings. Chromatic pupillary light reflex testing may be more valuable than non-chromatic pupillary light testing in detecting pupil response abnormalities in dogs with SARDS, although electroretinography remains the definitive diagnostic test. PMID:29089658

  10. Nonperturbative Quantum Physics from Low-Order Perturbation Theory.

    Science.gov (United States)

    Mera, Héctor; Pedersen, Thomas G; Nikolić, Branislav K

    2015-10-02

    The Stark effect in hydrogen and the cubic anharmonic oscillator furnish examples of quantum systems where the perturbation results in a certain ionization probability by tunneling processes. Accordingly, the perturbed ground-state energy is shifted and broadened, thus acquiring an imaginary part which is considered to be a paradigm of nonperturbative behavior. Here we demonstrate how the low order coefficients of a divergent perturbation series can be used to obtain excellent approximations to both real and imaginary parts of the perturbed ground state eigenenergy. The key is to use analytic continuation functions with a built-in singularity structure within the complex plane of the coupling constant, which is tailored by means of Bender-Wu dispersion relations. In the examples discussed the analytic continuation functions are Gauss hypergeometric functions, which take as input fourth order perturbation theory and return excellent approximations to the complex perturbed eigenvalue. These functions are Borel consistent and dramatically outperform widely used Padé and Borel-Padé approaches, even for rather large values of the coupling constant.

  11. On the existence of perturbed Robertson-Walker universes

    International Nuclear Information System (INIS)

    D'Eath, P.D.

    1976-01-01

    Solutions of the full nonlinear field equations of general relativity near the Robertson-Walker universes are examined, together with their relation to linearized perturbations. A method due to Choquet-Bruhat and Deser is used to prove existence theorems for solutions near Robertson-Walker constraint data of the constraint equations on a spacelike hypersurface. These theorems allow one to regard the matter fluctuations as independent quantities, ranging over certain function spaces. In the k=-1 case the existence theory describes perturbations which may vary within uniform bounds throughout space. When k=+1 a modification of the method leads to a theorem which clarifies some unusual features of these constraint perturbations. The k=0 existence theorem refers only to perturbations which die away at large distances. The connection between linearized constraint solutions and solutions of the full constraints is discussed. For k= +- 1 backgrounds, solutions of the linearized constraints are analyzed using transverse-traceless decompositions of symmetric tensors. Finally the time-evolution of perturbed constraint data and the validity of linearized perturbation theory for Robertson-Walker universes are considered

  12. Finite field-dependent symmetries in perturbative quantum gravity

    International Nuclear Information System (INIS)

    Upadhyay, Sudhaker

    2014-01-01

    In this paper we discuss the absolutely anticommuting nilpotent symmetries for perturbative quantum gravity in general curved spacetime in linear and non-linear gauges. Further, we analyze the finite field-dependent BRST (FFBRST) transformation for perturbative quantum gravity in general curved spacetime. The FFBRST transformation changes the gauge-fixing and ghost parts of the perturbative quantum gravity within functional integration. However, the operation of such symmetry transformation on the generating functional of perturbative quantum gravity does not affect the theory on physical ground. The FFBRST transformation with appropriate choices of finite BRST parameter connects non-linear Curci–Ferrari and Landau gauges of perturbative quantum gravity. The validity of the results is also established at quantum level using Batalin–Vilkovisky (BV) formulation. -- Highlights: •The perturbative quantum gravity is treated as gauge theory. •BRST and anti-BRST transformations are developed in linear and non-linear gauges. •BRST transformation is generalized by making it finite and field dependent. •Connection between linear and non-linear gauges is established. •Using BV formulation the results are established at quantum level also

  13. High-order perturbations of a spherical collapsing star

    International Nuclear Information System (INIS)

    Brizuela, David; Martin-Garcia, Jose M.; Sperhake, Ulrich; Kokkotas, Kostas D.

    2010-01-01

    A formalism to deal with high-order perturbations of a general spherical background was developed in earlier work [D. Brizuela, J. M. Martin-Garcia, and G. A. Mena Marugan, Phys. Rev. D 74, 044039 (2006); D. Brizuela, J. M. Martin-Garcia, and G. A. Mena Marugan, Phys. Rev. D 76, 024004 (2007)]. In this paper, we apply it to the particular case of a perfect fluid background. We have expressed the perturbations of the energy-momentum tensor at any order in terms of the perturbed fluid's pressure, density, and velocity. In general, these expressions are not linear and have sources depending on lower-order perturbations. For the second-order case we make the explicit decomposition of these sources in tensor spherical harmonics. Then, a general procedure is given to evolve the perturbative equations of motions of the perfect fluid for any value of the harmonic label. Finally, with the problem of a spherical collapsing star in mind, we discuss the high-order perturbative matching conditions across a timelike surface, in particular, the surface separating the perfect fluid interior from the exterior vacuum.

  14. The spectrum of density perturbations in an expanding universe

    Science.gov (United States)

    Silk, J.

    1974-01-01

    The basic dynamic equations that govern the evolution of perturbations in a Friedmann-Lemaitre universe are derived. General solutions describing the evolution of adiabatic perturbations in the density of matter are obtained, and the choice of the appropriate initial conditions is examined. The various perturbation modes are compared, and the effects of decoupling on the perturbation spectrum are studied. The scheme used to follow the evolution of density perturbations through decoupling is based on an extension of the Eddington approximation to the radiative transfer equation, and is strictly valid in both optically thick and thin limits.

  15. Interaction between bedding and sleeping position in the sudden infant death syndrome: a population based case-control study.

    Science.gov (United States)

    Fleming, P J; Gilbert, R; Azaz, Y; Berry, P J; Rudd, P T; Stewart, A; Hall, E

    1990-01-01

    OBJECTIVE--To determine the relation between sleeping position and quantity of bedding and the risk of sudden unexpected infant death. DESIGN--A study of all infants dying suddenly and unexpectedly and of two controls matched for age and date with each index case. The parents of control infants were interviewed within 72 hours of the index infant's death. Information was collected on bedding, sleeping position, heating, and recent signs of illness for index and control infants. SETTING--A defined geographical area comprising most of the county of Avon and part of Somerset. SUBJECTS--72 Infants who had died suddenly and unexpectedly (of whom 67 had died from the sudden infant death syndrome) and 144 control infants. RESULTS--Compared with the control infants the infants who had died from the sudden infant death syndrome were more likely to have been sleeping prone (relative risk 8.8; 95% confidence interval 7.0 to 11.0; p less than 0.001), to have been more heavily wrapped (relative risk 1.14 per tog above 8 tog; 1.03 to 1.28; p less than 0.05), and to have had the heating on all night (relative risk 2.7; 1.4 to 5.2; p less than 0.01). These differences were less pronounced in the younger infants (less than 70 days) than the older ones. The risk of sudden unexpected death among infants older than 70 days, nursed prone, and with clothing and bedding of total thermal resistance greater than 10 tog was increased by factors of 15.1 (2.6 to 89.6) and 25.2 (3.7 to 169.0) respectively compared with the risk in infants of the same age nursed supine or on their side and under less than 6 tog of bedding. CONCLUSIONS--Overheating and the prone position are independently associated with an increased risk of sudden unexpected infant death, particularly in infants aged more than 70 days. Educating parents about appropriate thermal care and sleeping position of infants may help to reduce the incidence of the sudden infant death syndrome. PMID:2390588

  16. A perturbation-based model for rectifier circuits

    Directory of Open Access Journals (Sweden)

    Vipin B. Vats

    2006-01-01

    Full Text Available A perturbation-theoretic analysis of rectifier circuits is presented. The governing differential equation of the half-wave rectifier with capacitor filter is analyzed by expanding the output voltage as a Taylor series with respect to an artificially introduced parameter in the nonlinearity of the diode characteristic as is done in quantum theory. The perturbation parameter introduced in the analysis is independent of the circuit components as compared to the method presented by multiple scales. The various terms appearing in the perturbation series are then modeled in the form of an equivalent circuit. This model is subsequently used in the analysis of full-wave rectifier. Matlab simulation results are included which confirm the validity of the theoretical formulations. Perturbation analysis acts a helpful tool in analyzing time-varying systems and chaotic systems.

  17. SHARP ENTRYWISE PERTURBATION BOUNDS FOR MARKOV CHAINS.

    Science.gov (United States)

    Thiede, Erik; VAN Koten, Brian; Weare, Jonathan

    For many Markov chains of practical interest, the invariant distribution is extremely sensitive to perturbations of some entries of the transition matrix, but insensitive to others; we give an example of such a chain, motivated by a problem in computational statistical physics. We have derived perturbation bounds on the relative error of the invariant distribution that reveal these variations in sensitivity. Our bounds are sharp, we do not impose any structural assumptions on the transition matrix or on the perturbation, and computing the bounds has the same complexity as computing the invariant distribution or computing other bounds in the literature. Moreover, our bounds have a simple interpretation in terms of hitting times, which can be used to draw intuitive but rigorous conclusions about the sensitivity of a chain to various types of perturbations.

  18. Schroedinger operators with singular perturbation potentials

    International Nuclear Information System (INIS)

    Harrell, E.M. II.

    1976-01-01

    This is a perturbative analysis of the eigenvalues and eigenfunctions of Schroedinger operators of the form -Δ + A + lambda V, defined on the Hilbert space L 2 (R/sup n/). A is a potential function (a smooth, real multiplication operator), and V is a ''spikelike'' perturbation, i.e., a perturbative potential function which diverges at some finite point. Lambda is a small real or complex parameter. The emphasis is on one-dimensional problems, and in particular the typical example is the ''spiked harmonic oscillator'' Hamiltonian, -d 2 /dx 2 + x 2 + lambda x/sup -α/, where α is a positive constant. An earlier study by L. Detwiler and J. R. Klauder [Phys. Rev. D 11 (1975) 1436] indicated that the lowest-order corrections to the ground-state eigenvalue of the spiked harmonic oscillator with lambda greater than 0 were proportional to lambda ln lambda when α = 3, and to lambda/sup 1/(α-2) when α is greater than 3. These and analogous results for a large class of operators and arbitrary eigenvalues are proved. Explicit constants in a modified perturbation series with a complicated dependence on lambda are determined and exhibited. Higher-order corrections for real lambda and lowest-order corrections for complex lambda are also discussed. While the substance of the dissertation is mathematical, its main applications are to quantum physics. The immediate cause of interest in such problems was the use of their peculiar convergence properties by J. R. Klauder as models for the behavior of nonrenormalizable quantum field theories. However, the results of this study are likely to be of greater importance in chemical or nuclear physics, as positive spikelike perturbations represent repulsive core interactions for quantum mechanical particles. The modified perturbation series are a new calculation technique for this situation

  19. Wilson loops in very high order lattice perturbation theory

    International Nuclear Information System (INIS)

    Ilgenfritz, E.M.; Nakamura, Y.; Perlt, H.; Schiller, A.; Rakow, P.E.L.; Schierholz, G.; Regensburg Univ.

    2009-10-01

    We calculate Wilson loops of various sizes up to loop order n=20 for lattice sizes of L 4 (L=4,6,8,12) using the technique of Numerical Stochastic Perturbation Theory in quenched QCD. This allows to investigate the behaviour of the perturbative series at high orders. We discuss three models to estimate the perturbative series: a renormalon inspired fit, a heuristic fit based on an assumed power-law singularity and boosted perturbation theory. We have found differences in the behavior of the perturbative series for smaller and larger Wilson loops at moderate n. A factorial growth of the coefficients could not be confirmed up to n=20. From Monte Carlo measured plaquette data and our perturbative result we estimate a value of the gluon condensate left angle (α)/(π)GG right angle. (orig.)

  20. Exact perturbation theory of multiphoton processes at high intensities. [Schroedinger equation, perturbation theory, matrix

    Energy Technology Data Exchange (ETDEWEB)

    Faisal, F H.M. [Bielefeld Univ. (Germany, F.R.). Fakultaet fuer Physik

    1976-06-11

    In this work the perturbation theory for multiphoton processes at high intensities is investigated and it is described an analytical method of summing the perturbation series to extract the contribution from all terms that give rise to the absorption of N photons by an atomic system. The method is first applied to the solution of a simple model problem and the result is confirmed by direct integration of the model Schroedinger equation. The usual lowest (nonvanishing)-order perturbation-theoretical calculation is also carried out for this model to demonstrate explicitly that the full result correctly reproduces that of the lowest-order theory in the limit of low intensity. The method is then extended to the case of an atomic system with well-developed spectrum (e.g. H atom) and the N-photon T-matrix is derived in terms of a ''photon matrix'' asub(N), for which a three-term recurrence relation is established. Next, from the vantage point of the general result obtained here, A probe is made into the nature of several approximate nonperturbative solutions that have appeared in the literature in the past. It is shown here that their applicability is severely restricted by the requirement of the essential spectral degeneracy of the atomic system. Finally, appendix A outlines a prescription of computing the photon matrix asub(N), which (as in the usual lowest-order perturbation-theoretical calculation)requires a knowledge of the eigenfunctions and eigenvalues of the atomic Hamiltonian only.

  1. Introduction and overview to some topics in perturbative QCD and their relationship to non perturbative effects

    International Nuclear Information System (INIS)

    West, G.

    1990-01-01

    The main thrust of this talk is to review and discuss various topics in both perturbative and non-perturbative QCD that are, by and large, model independent. This inevitably means that we shall rely heavily on the renormalization group and asymptotic freedom. Although this usually means that one has to concentrate on high energy phenomena, there are some physical processes even involving bound states which are certainly highly non-perturbative, where one can make some progress without becoming overly model independent. Experience with the EMC effect, where there are about as many ''explanations'' as authors, has surely taught us that it may well be worth returning to ''basics'' and thinking about general properties of QCD rather than guessing, essentially arbitrarily, what we think is its low energy structure. No doubt we shall have to await further numerical progress or for some inspired theoretical insight before we can, with confidence, attack these extremely difficult problems. So, with this in mine, I shall review a smattering of problems which do have a non-perturbative component and where some rather modest progress can actually be made; I emphasize the adjective ''modest''exclamation point

  2. Effective field theory of cosmological perturbations

    International Nuclear Information System (INIS)

    Piazza, Federico; Vernizzi, Filippo

    2013-01-01

    The effective field theory of cosmological perturbations stems from considering a cosmological background solution as a state displaying spontaneous breaking of time translations and (adiabatic) perturbations as the related Nambu–Goldstone modes. With this insight, one can systematically develop a theory for the cosmological perturbations during inflation and, with minor modifications, also describe in full generality the gravitational interactions of dark energy, which are relevant for late-time cosmology. The formalism displays a unique set of Lagrangian operators containing an increasing number of cosmological perturbations and derivatives. We give an introductory description of the unitary gauge formalism for theories with broken gauge symmetry—that allows us to write down the most general Lagrangian—and of the Stückelberg ‘trick’—that allows to recover gauge invariance and to make the scalar field explicit. We show how to apply this formalism to gravity and cosmology and we reproduce the detailed analysis of the action in the ADM variables. We also review some basic applications to inflation and dark energy. (paper)

  3. Privacy Is Become with, Data Perturbation

    Science.gov (United States)

    Singh, Er. Niranjan; Singhai, Niky

    2011-06-01

    Privacy is becoming an increasingly important issue in many data mining applications that deal with health care, security, finance, behavior and other types of sensitive data. Is particularly becoming important in counterterrorism and homeland security-related applications. We touch upon several techniques of masking the data, namely random distortion, including the uniform and Gaussian noise, applied to the data in order to protect it. These perturbation schemes are equivalent to additive perturbation after the logarithmic Transformation. Due to the large volume of research in deriving private information from the additive noise perturbed data, the security of these perturbation schemes is questionable Many artificial intelligence and statistical methods exist for data analysis interpretation, Identifying and measuring the interestingness of patterns and rules discovered, or to be discovered is essential for the evaluation of the mined knowledge and the KDD process as a whole. While some concrete measurements exist, assessing the interestingness of discovered knowledge is still an important research issue. As the tool for the algorithm implementations we chose the language of choice in industrial world MATLAB.

  4. Effective field theory of cosmological perturbations

    Science.gov (United States)

    Piazza, Federico; Vernizzi, Filippo

    2013-11-01

    The effective field theory of cosmological perturbations stems from considering a cosmological background solution as a state displaying spontaneous breaking of time translations and (adiabatic) perturbations as the related Nambu-Goldstone modes. With this insight, one can systematically develop a theory for the cosmological perturbations during inflation and, with minor modifications, also describe in full generality the gravitational interactions of dark energy, which are relevant for late-time cosmology. The formalism displays a unique set of Lagrangian operators containing an increasing number of cosmological perturbations and derivatives. We give an introductory description of the unitary gauge formalism for theories with broken gauge symmetry—that allows us to write down the most general Lagrangian—and of the Stückelberg ‘trick’—that allows to recover gauge invariance and to make the scalar field explicit. We show how to apply this formalism to gravity and cosmology and we reproduce the detailed analysis of the action in the ADM variables. We also review some basic applications to inflation and dark energy.

  5. Perturbation of an exact strong gravity solution

    International Nuclear Information System (INIS)

    Baran, S.A.

    1982-10-01

    Perturbations of an exact strong gravity solution are investigated. It is shown, by using the new multipole expansions previously presented, that this exact and static spherically symmetric solution is stable under odd parity perturbations. (author)

  6. On the singular perturbations for fractional differential equation.

    Science.gov (United States)

    Atangana, Abdon

    2014-01-01

    The goal of this paper is to examine the possible extension of the singular perturbation differential equation to the concept of fractional order derivative. To achieve this, we presented a review of the concept of fractional calculus. We make use of the Laplace transform operator to derive exact solution of singular perturbation fractional linear differential equations. We make use of the methodology of three analytical methods to present exact and approximate solution of the singular perturbation fractional, nonlinear, nonhomogeneous differential equation. These methods are including the regular perturbation method, the new development of the variational iteration method, and the homotopy decomposition method.

  7. Microfluidic mixing through oscillatory transverse perturbations

    Science.gov (United States)

    Wu, J. W.; Xia, H. M.; Zhang, Y. Y.; Zhu, P.

    2018-05-01

    Fluid mixing in miniaturized fluidic devices is a challenging task. In this work, the mixing enhancement through oscillatory transverse perturbations coupling with divergent circular chambers is studied. To simplify the design, an autonomous microfluidic oscillator is used to produce the oscillatory flow. It is then applied to four side-channels that intersect with a central channel of constant flow. The mixing performance is tested at high fluid viscosities of up to 16 cP. Results show that the oscillatory flow can cause strong transverse perturbations which effectively enhance the mixing. The influence of a fluidic capacitor in the central channel is also examined, which at low viscosities can intensify the perturbations and further improve the mixing.

  8. Vasculopathic Cranial Ocular Motor Neuropathy Following Sudden Emotional Stress

    OpenAIRE

    Purvin, Valerie

    2010-01-01

    We describe three patients who experienced onset of a microvascular ocular motor nerve palsy in the setting of sudden emotional stress. Such emotional states are accompanied by a marked increase in sympathetic tone in some individuals. Mechanisms by which these autonomic changes might produce an ischemic cranial nerve palsy include intra-cranial vasoconstriction and transient systemic hypotension due to alterations in cardiac function.

  9. Perturbative QCD and exclusive processes

    International Nuclear Information System (INIS)

    Bennett, J.; Hawes, F.; Zhao, M.; Zyla, P.

    1991-01-01

    The authors discuss perturbation theory as applied to particle physics calculations. In particle physics one is generally interested in the scattering amplitude for a system going from some initial state to a final state. The intermediate state or states are unknown. To get the scattering amplitude it is necessary to sum the contributions from processes which pass through all possible intermediate states. Intermediate states involve the exchange of intermediate vector bosons between the particles, and with this interaction is associated a coupling constant α. Each additional boson exchange involves an additional contribution of α to the coupling. If α is less than 1, one can see that the relative contribution of higher order processes is less and less important as α falls. In QCD the gluons serve as the intermediate vector bosons exchanged by quarks and gluons, and the interaction constant is not really a constant, but depends upon the distance between the particles. At short distances the coupling is small, and one can assume perturbative expansions may converge rapidly. Exclusive scattering processes, as opposed to inclusive, are those in which all of the final state products are detected. The authors then discuss the application of perturbative QCD to the deuteron. The issues of chiral conservation and color transparancy are also discussed, in the scheme of large Q 2 interations, where perturbative QCD should be applicable

  10. Perturbative analysis of multiple-field cosmological inflation

    International Nuclear Information System (INIS)

    Lahiri, Joydev; Bhattacharya, Gautam

    2006-01-01

    We develop a general formalism for analyzing linear perturbations in multiple-field cosmological inflation based on the gauge-ready approach. Our inflationary model consists of an arbitrary number of scalar fields with non-minimal kinetic terms. We solve the equations for scalar- and tensor-type perturbations during inflation to the first order in slow roll, and then obtain the super-horizon solutions for adiabatic and isocurvature perturbations after inflation. Analytic expressions for power-spectra and spectral indices arising from multiple-field inflation are presented

  11. Innovation and dedication underpin management of sudden oak death (Phytophthora ramorum) in California and Oregon forests

    Science.gov (United States)

    Susan J. Frankel

    2017-01-01

    This special issue of Forest Phytophthoras serves as part of the proceedings from the Sixth Sudden Oak Death Science Symposium held June 21 -23, 2016 at Fort Mason Center in San Francisco, CA, USA. The symposium marked almost 16 years to the day that David Rizzo (UC Davis) and Matteo Garbelotto (UC Berkeley) identified the cause of sudden oak death to be a previously...

  12. Exact Controllability and Perturbation Analysis for Elastic Beams

    International Nuclear Information System (INIS)

    Moreles, Miguel Angel

    2004-01-01

    The Rayleigh beam is a perturbation of the Bernoulli-Euler beam. We establish convergence of the solution of the Exact Controllability Problem for the Rayleigh beam to the corresponding solution of the Bernoulli-Euler beam. Convergence is related to a Singular Perturbation Problem. The main tool in solving this perturbation problem is a weak version of a lower bound for hyperbolic polynomials

  13. Modeling Small-Amplitude Perturbations in Inertial Confinement Fusion Pellets

    Science.gov (United States)

    Zalesak, Steven; Metzler, N.; Velikovich, A. L.; Gardner, J. H.; Manheimer, W.

    2005-10-01

    Recent advances in inertial confinement fusion (ICF) technology serve to ensure that imploding laser-driven ICF pellets will spend a significantly larger portion of their time in what is regarded as the ``linear'' portion of their perturbation evolution, i.e., in the presence of small-amplitude but nonetheless evolving perturbations. Since the evolution of these linear perturbations collectively form the initial conditions for the subsequent nonlinear evolution of the pellet, which in turn determines the energy yield of the pellet, the accurate numerical modeling of these small-amplitude perturbations has taken on an increased importance. This modeling is difficult despite the expected linear evolution of the perturbations themselves, because these perturbations are embedded in a highly nonlinear, strongly-shocked, and highly complex flow field which in and of itself stresses numerical computation capabilities, and whose simulation often employs numerical techniques which were not designed with the proper treatment of small-amplitude perturbations in mind. In this paper we will review some of the techniques that we have recently found to be of use toward this end.

  14. Cosmological perturbations on the phantom brane

    Energy Technology Data Exchange (ETDEWEB)

    Bag, Satadru; Sahni, Varun [Inter-University Centre for Astronomy and Astrophysics, Pune (India); Viznyuk, Alexander; Shtanov, Yuri, E-mail: satadru@iucaa.in, E-mail: viznyuk@bitp.kiev.ua, E-mail: shtanov@bitp.kiev.ua, E-mail: varun@iucaa.in [Bogolyubov Institute for Theoretical Physics, Kiev 03680 (Ukraine)

    2016-07-01

    We obtain a closed system of equations for scalar perturbations in a multi-component braneworld. Our braneworld possesses a phantom-like equation of state at late times, w {sub eff} < −1, but no big-rip future singularity. In addition to matter and radiation, the braneworld possesses a new effective degree of freedom—the 'Weyl fluid' or 'dark radiation'. Setting initial conditions on super-Hubble spatial scales at the epoch of radiation domination, we evolve perturbations of radiation, pressureless matter and the Weyl fluid until the present epoch. We observe a gradual decrease in the amplitude of the Weyl-fluid perturbations after Hubble-radius crossing, which results in a negligible effect of the Weyl fluid on the evolution of matter perturbations on spatial scales relevant for structure formation. Consequently, the quasi-static approximation of Koyama and Maartens provides a good fit to the exact results during the matter-dominated epoch. We find that the late-time growth of density perturbations on the brane proceeds at a faster rate than in ΛCDM. Additionally, the gravitational potentials Φ and Ψ evolve differently on the brane than in ΛCDM, for which Φ = Ψ. On the brane, by contrast, the ratio Φ/Ψ exceeds unity during the late matter-dominated epoch ( z ∼< 50). These features emerge as smoking gun tests of phantom brane cosmology and allow predictions of this scenario to be tested against observations of galaxy clustering and large-scale structure.

  15. Converting entropy to curvature perturbations after a cosmic bounce

    Energy Technology Data Exchange (ETDEWEB)

    Fertig, Angelika; Lehners, Jean-Luc; Mallwitz, Enno; Wilson-Ewing, Edward [Max Planck Institute for Gravitational Physics, Albert Einstein Institute,14476 Potsdam-Golm (Germany)

    2016-10-04

    We study two-field bouncing cosmologies in which primordial perturbations are created in either an ekpyrotic or a matter-dominated contraction phase. We use a non-singular ghost condensate bounce model to follow the perturbations through the bounce into the expanding phase of the universe. In contrast to the adiabatic perturbations, which on large scales are conserved across the bounce, entropy perturbations can grow significantly during the bounce phase. If they are converted into adiabatic/curvature perturbations after the bounce, they typically form the dominant contribution to the observed temperature fluctuations in the microwave background, which can have several beneficial implications. For ekpyrotic models, this mechanism loosens the constraints on the amplitude of the ekpyrotic potential while naturally suppressing the intrinsic amount of non-Gaussianity. For matter bounce models, the mechanism amplifies the scalar perturbations compared to the associated primordial gravitational waves.

  16. Perturbations of ultralight vector field dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Cembranos, J.A.R.; Maroto, A.L.; Jareño, S.J. Núñez [Departamento de Física Teórica I, Universidad Complutense de Madrid, E-28040 Madrid (Spain)

    2017-02-13

    We study the dynamics of cosmological perturbations in models of dark matter based on ultralight coherent vector fields. Very much as for scalar field dark matter, we find two different regimes in the evolution: for modes with k{sup 2}≪Hma, we have a particle-like behaviour indistinguishable from cold dark matter, whereas for modes with k{sup 2}≫Hma, we get a wave-like behaviour in which the sound speed is non-vanishing and of order c{sub s}{sup 2}≃k{sup 2}/m{sup 2}a{sup 2}. This implies that, also in these models, structure formation could be suppressed on small scales. However, unlike the scalar case, the fact that the background evolution contains a non-vanishing homogeneous vector field implies that, in general, the evolution of the three kinds of perturbations (scalar, vector and tensor) can no longer be decoupled at the linear level. More specifically, in the particle regime, the three types of perturbations are actually decoupled, whereas in the wave regime, the three vector field perturbations generate one scalar-tensor and two vector-tensor perturbations in the metric. Also in the wave regime, we find that a non-vanishing anisotropic stress is present in the perturbed energy-momentum tensor giving rise to a gravitational slip of order (Φ−Ψ)/Φ∼c{sub s}{sup 2}. Moreover in this regime the amplitude of the tensor to scalar ratio of the scalar-tensor modes is also h/Φ∼c{sub s}{sup 2}. This implies that small-scale density perturbations are necessarily associated to the presence of gravity waves in this model. We compare their spectrum with the sensitivity of present and future gravity waves detectors.

  17. Computer fan performance enhancement via acoustic perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Greenblatt, David, E-mail: davidg@technion.ac.il [Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa (Israel); Avraham, Tzahi; Golan, Maayan [Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa (Israel)

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Computer fan effectiveness was increased by introducing acoustic perturbations. Black-Right-Pointing-Pointer Acoustic perturbations controlled blade boundary layer separation. Black-Right-Pointing-Pointer Optimum frequencies corresponded with airfoils studies. Black-Right-Pointing-Pointer Exploitation of flow instabilities was responsible for performance improvements. Black-Right-Pointing-Pointer Peak pressure and peak flowrate were increased by 40% and 15% respectively. - Abstract: A novel technique for increasing computer fan effectiveness, based on introducing acoustic perturbations onto the fan blades to control boundary layer separation, was assessed. Experiments were conducted in a specially designed facility that simultaneously allowed characterization of fan performance and introduction of the perturbations. A parametric study was conducted to determine the optimum control parameters, namely those that deliver the largest increase in fan pressure for a given flowrate. The optimum reduced frequencies corresponded with those identified on stationary airfoils and it was thus concluded that the exploitation of Kelvin-Helmholtz instabilities, commonly observed on airfoils, was responsible for the fan blade performance improvements. The optimum control inputs, such as acoustic frequency and sound pressure level, showed some variation with different fan flowrates. With the near-optimum control conditions identified, the full operational envelope of the fan, when subjected to acoustic perturbations, was assessed. The peak pressure and peak flowrate were increased by up to 40% and 15% respectively. The peak fan efficiency increased with acoustic perturbations but the overall system efficiency was reduced when the speaker input power was accounted for.

  18. Computer fan performance enhancement via acoustic perturbations

    International Nuclear Information System (INIS)

    Greenblatt, David; Avraham, Tzahi; Golan, Maayan

    2012-01-01

    Highlights: ► Computer fan effectiveness was increased by introducing acoustic perturbations. ► Acoustic perturbations controlled blade boundary layer separation. ► Optimum frequencies corresponded with airfoils studies. ► Exploitation of flow instabilities was responsible for performance improvements. ► Peak pressure and peak flowrate were increased by 40% and 15% respectively. - Abstract: A novel technique for increasing computer fan effectiveness, based on introducing acoustic perturbations onto the fan blades to control boundary layer separation, was assessed. Experiments were conducted in a specially designed facility that simultaneously allowed characterization of fan performance and introduction of the perturbations. A parametric study was conducted to determine the optimum control parameters, namely those that deliver the largest increase in fan pressure for a given flowrate. The optimum reduced frequencies corresponded with those identified on stationary airfoils and it was thus concluded that the exploitation of Kelvin–Helmholtz instabilities, commonly observed on airfoils, was responsible for the fan blade performance improvements. The optimum control inputs, such as acoustic frequency and sound pressure level, showed some variation with different fan flowrates. With the near-optimum control conditions identified, the full operational envelope of the fan, when subjected to acoustic perturbations, was assessed. The peak pressure and peak flowrate were increased by up to 40% and 15% respectively. The peak fan efficiency increased with acoustic perturbations but the overall system efficiency was reduced when the speaker input power was accounted for.

  19. Monte Carlo technique for local perturbations in multiplying systems

    International Nuclear Information System (INIS)

    Bernnat, W.

    1974-01-01

    The use of the Monte Carlo method for the calculation of reactivity perturbations in multiplying systems due to changes in geometry or composition requires a correlated sampling technique to make such calculations economical or in the case of very small perturbations even feasible. The technique discussed here is suitable for local perturbations. Very small perturbation regions will be treated by an adjoint mode. The perturbation of the source distribution due to the changed system and its reaction on the reactivity worth or other values of interest is taken into account by a fission matrix method. The formulation of the method and its application are discussed. 10 references. (U.S.)

  20. Hypertrophic Cardiomyopathy Mimicking Acute Anterior Myocardial Infarction Associated with Sudden Cardiac Death

    Directory of Open Access Journals (Sweden)

    Y. Daralammouri

    2012-01-01

    Full Text Available Hypertrophic cardiomyopathy is the most common genetic disease of the heart. We report a rare case of hypertrophic obstructive cardiomyopathy mimicking an acute anterior myocardial infarction associated with sudden cardiac death. The patient presented with acute ST elevation myocardial infarction and significant elevation of cardiac enzymes. Cardiac catheterization showed some atherosclerotic coronary artery disease, without significant stenosis. Echocardiography showed left ventricular hypertrophy with a left ventricular outflow tract obstruction; the pressure gradient at rest was 20 mmHg and became severe with the Valsalva maneuver (100 mmHg. There was no family history of sudden cardiac death. Six days later, the patient suffered a syncope on his way to magnetic resonance imaging. He was successfully resuscitated by ventricular fibrillation.

  1. Coupling-parameter expansion in thermodynamic perturbation theory.

    Science.gov (United States)

    Ramana, A Sai Venkata; Menon, S V G

    2013-02-01

    An approach to the coupling-parameter expansion in the liquid state theory of simple fluids is presented by combining the ideas of thermodynamic perturbation theory and integral equation theories. This hybrid scheme avoids the problems of the latter in the two phase region. A method to compute the perturbation series to any arbitrary order is developed and applied to square well fluids. Apart from the Helmholtz free energy, the method also gives the radial distribution function and the direct correlation function of the perturbed system. The theory is applied for square well fluids of variable ranges and compared with simulation data. While the convergence of perturbation series and the overall performance of the theory is good, improvements are needed for potentials with shorter ranges. Possible directions for further developments in the coupling-parameter expansion are indicated.

  2. Stability under persistent perturbation by white noise

    International Nuclear Information System (INIS)

    Kalyakin, L

    2014-01-01

    Deterministic dynamical system which has an asymptotical stable equilibrium is considered under persistent perturbation by white noise. It is well known that if the perturbation does not vanish in the equilibrium position then there is not Lyapunov's stability. The trajectories of the perturbed system diverge from the equilibrium to arbitrarily large distances with probability 1 in finite time. New concept of stability on a large time interval is discussed. The length of interval agrees the reciprocal quantity of the perturbation parameter. The measure of stability is the expectation of the square distance from the trajectory till the equilibrium position. The method of parabolic equation is applied to both estimate the expectation and prove such stability. The main breakthrough is the barrier function derived for the parabolic equation. The barrier is constructed by using the Lyapunov function of the unperturbed system

  3. Prospects of inflation with perturbed throat geometry

    International Nuclear Information System (INIS)

    Ali, Amna; Chingangbam, R.; Panda, Sudhakar; Sami, M.

    2009-01-01

    We study brane inflation in a warped deformed conifold background that includes general possible corrections to the throat geometry sourced by coupling to the bulk of a compact Calabi-Yau space. We focus specifically, on the perturbation by chiral operator of dimension 3/2 in the CFT. We find that the effective potential in this case can give rise to required number of e-foldings and the spectral index n S consistent with observation. The tensor to scalar ratio of perturbations is generally very low in this scenario. The COBE normalization, however, poses certain difficulties which can be circumvented provided model parameters are properly fine tuned. We find the numerical values of parameters which can give rise to enough inflation, observationally consistent values of density perturbations, scalar to tensor ratio of perturbations and the spectral index n S .

  4. Non-perturbative materialization of ghosts

    International Nuclear Information System (INIS)

    Emparan, Roberto; Garriga, Jaume

    2006-01-01

    In theories with a hidden ghost sector that couples to visible matter through gravity only, empty space can decay into ghosts and ordinary matter by graviton exchange. Perturbatively, such processes can be very slow provided that the gravity sector violates Lorentz invariance above some cut-off scale. Here, we investigate non-perturbative decay processes involving ghosts, such as the spontaneous creation of self-gravitating lumps of ghost matter, as well as pairs of Bondi dipoles (i.e. lumps of ghost matter chasing after positive energy objects). We find the corresponding instantons and calculate their Euclidean action. In some cases, the instantons induce topology change or have negative Euclidean action. To shed some light on the meaning of such peculiarities, we also consider the nucleation of concentrical domain walls of ordinary and ghost matter, where the Euclidean calculation can be compared with the canonical (Lorentzian) description of tunneling. We conclude that non-perturbative ghost nucleation processes can be safely suppressed in phenomenological scenarios

  5. Non-Perturbative Quantum Geometry III

    CERN Document Server

    Krefl, Daniel

    2016-08-02

    The Nekrasov-Shatashvili limit of the refined topological string on toric Calabi-Yau manifolds and the resulting quantum geometry is studied from a non-perturbative perspective. The quantum differential and thus the quantum periods exhibit Stockes phenomena over the combined string coupling and quantized Kaehler moduli space. We outline that the underlying formalism of exact quantization is generally applicable to points in moduli space featuring massless hypermultiplets, leading to non-perturbative band splitting. Our prime example is local P1xP1 near a conifold point in moduli space. In particular, we will present numerical evidence that in a Stockes chamber of interest the string based quantum geometry reproduces the non-perturbative corrections for the Nekrasov-Shatashvili limit of 4d supersymmetric SU(2) gauge theory at strong coupling found in the previous part of this series. A preliminary discussion of local P2 near the conifold point in moduli space is also provided.

  6. How cancer cells dictate their microenvironment: present roles of extracellular vesicles.

    Science.gov (United States)

    Naito, Yutaka; Yoshioka, Yusuke; Yamamoto, Yusuke; Ochiya, Takahiro

    2017-02-01

    Intercellular communication plays an important role in cancer initiation and progression through secretory molecules, including growth factors and cytokines. Recent advances have revealed that small membrane vesicles, termed extracellular vesicles (EVs), served as a regulatory agent in the intercellular communication of cancer. EVs enable the transfer of functional molecules, including proteins, mRNA and microRNAs (miRNAs), into recipient cells. Cancer cells utilize EVs to dictate the unique phenotype of surrounding cells, thereby promoting cancer progression. Against such "education" by cancer cells, non-tumoral cells suppress cancer initiation and progression via EVs. Therefore, researchers consider EVs to be important cues to clarify the molecular mechanisms of cancer biology. Understanding the functions of EVs in cancer progression is an important aspect of cancer biology that has not been previously elucidated. In this review, we summarize experimental data that indicate the pivotal roles of EVs in cancer progression.

  7. Mass generation in perturbed massless integrable models

    International Nuclear Information System (INIS)

    Controzzi, D.; Mussardo, G.

    2005-01-01

    We extend form-factor perturbation theory to non-integrable deformations of massless integrable models, in order to address the problem of mass generation in such systems. With respect to the standard renormalisation group analysis this approach is more suitable for studying the particle content of the perturbed theory. Analogously to the massive case, interesting information can be obtained already at first order, such as the identification of the operators which create a mass gap and those which induce the confinement of the massless particles in the perturbed theory

  8. On perturbation theory for distance dependent statistics.

    Energy Technology Data Exchange (ETDEWEB)

    Mashkevich, S V

    1994-12-31

    It is known that perturbation theory for anyons has to be modified near Bose statistics in order to get correct finite results. For ``distance dependent statistics`` or anyons with smeared flux tubes, perturbation theory is in principle applicable directly but gives results which hold for too small values of the statistical parameter and, in particular, are not valid as the flux tube radius tends to zero. In this paper we discuss the way to modify perturbation theory for this situation, which allows to obtain the appropriate results. (author). 6 refs.

  9. Non-adiabatic perturbations in Ricci dark energy model

    International Nuclear Information System (INIS)

    Karwan, Khamphee; Thitapura, Thiti

    2012-01-01

    We show that the non-adiabatic perturbations between Ricci dark energy and matter can grow both on superhorizon and subhorizon scales, and these non-adiabatic perturbations on subhorizon scales can lead to instability in this dark energy model. The rapidly growing non-adiabatic modes on subhorizon scales always occur when the equation of state parameter of dark energy starts to drop towards -1 near the end of matter era, except that the parameter α of Ricci dark energy equals to 1/2. In the case where α = 1/2, the rapidly growing non-adiabatic modes disappear when the perturbations in dark energy and matter are adiabatic initially. However, an adiabaticity between dark energy and matter perturbations at early time implies a non-adiabaticity between matter and radiation, this can influence the ordinary Sachs-Wolfe (OSW) effect. Since the amount of Ricci dark energy is not small during matter domination, the integrated Sachs-Wolfe (ISW) effect is greatly modified by density perturbations of dark energy, leading to a wrong shape of CMB power spectrum. The instability in Ricci dark energy is difficult to be alleviated if the effects of coupling between baryon and photon on dark energy perturbations are included

  10. Non-linear perturbations of a spherically collapsing star

    International Nuclear Information System (INIS)

    Brizuela, David

    2009-01-01

    Linear perturbation theory has been a successful tool in General Relativity, and can be considered as complementary to full nonlinear simulations. Going to second and higher perturbative orders improves the approximation and offers a controlled way to analyze the nonlinearities of the theory, though the problem becomes much harder computationally. We present a systematic approach to the treatment of high order metric perturbations, focusing on the scenario of nonspherical perturbations of a dynamical spherical background. It is based on the combination of adapted geometrical variables and the use of efficient computer algebra techniques. After dealing with a number of theoretical issues, like the construction of gauge invariants, we apply the formalism to the particular case of a perfect fluid star surrounded by a vacuum exterior. We describe the regularization of the divergences of the perturbations at null infinity and the matching conditions through the surface of the star.

  11. Duality between QCD perturbative series and power corrections

    International Nuclear Information System (INIS)

    Narison, S.; Zakharov, V.I.

    2009-01-01

    We elaborate on the relation between perturbative and power-like corrections to short-distance sensitive QCD observables. We confront theoretical expectations with explicit perturbative calculations existing in literature. As is expected, the quadratic correction is dual to a long perturbative series and one should use one of them but not both. However, this might be true only for very long perturbative series, with number of terms needed in most cases exceeding the number of terms available. What has not been foreseen, the quartic corrections might also be dual to the perturbative series. If confirmed, this would imply a crucial modification of the dogma. We confront this quadratic correction against existing phenomenology (QCD (spectral) sum rules scales, determinations of light quark masses and of α s from τ-decay). We find no contradiction and (to some extent) better agreement with the data and with recent lattice calculations.

  12. Duality between QCD perturbative series and power corrections

    Energy Technology Data Exchange (ETDEWEB)

    Narison, S. [Laboratoire de Physique Theorique et Astroparticules, CNRS-IN2P3 and Universite de Montpellier II, Case 070, Place Eugene, 34095 Montpellier Cedex 05 (France)], E-mail: snarison@yahoo.fr; Zakharov, V.I. [Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Munich (Germany); Institute of Theoretical and Experimental Physics, B. Cheremushkinskaya 25, Moscow 117218 (Russian Federation)], E-mail: xxz@mppmu.mpg.de

    2009-08-31

    We elaborate on the relation between perturbative and power-like corrections to short-distance sensitive QCD observables. We confront theoretical expectations with explicit perturbative calculations existing in literature. As is expected, the quadratic correction is dual to a long perturbative series and one should use one of them but not both. However, this might be true only for very long perturbative series, with number of terms needed in most cases exceeding the number of terms available. What has not been foreseen, the quartic corrections might also be dual to the perturbative series. If confirmed, this would imply a crucial modification of the dogma. We confront this quadratic correction against existing phenomenology (QCD (spectral) sum rules scales, determinations of light quark masses and of {alpha}{sub s} from {tau}-decay). We find no contradiction and (to some extent) better agreement with the data and with recent lattice calculations.

  13. On the Singular Perturbations for Fractional Differential Equation

    Directory of Open Access Journals (Sweden)

    Abdon Atangana

    2014-01-01

    Full Text Available The goal of this paper is to examine the possible extension of the singular perturbation differential equation to the concept of fractional order derivative. To achieve this, we presented a review of the concept of fractional calculus. We make use of the Laplace transform operator to derive exact solution of singular perturbation fractional linear differential equations. We make use of the methodology of three analytical methods to present exact and approximate solution of the singular perturbation fractional, nonlinear, nonhomogeneous differential equation. These methods are including the regular perturbation method, the new development of the variational iteration method, and the homotopy decomposition method.

  14. Singularly perturbed volterra integro-differential equations | Bijura ...

    African Journals Online (AJOL)

    Several investigations have been made on singularly perturbed integral equations. This paper aims at presenting an algorithm for the construction of asymptotic solutions and then provide a proof asymptotic correctness to singularly perturbed systems of Volterra integro-differential equations. Mathematics Subject

  15. MCNP perturbation technique for criticality analysis

    International Nuclear Information System (INIS)

    McKinney, G.W.; Iverson, J.L.

    1995-01-01

    The differential operator perturbation technique has been incorporated into the Monte Carlo N-Particle transport code MCNP and will become a standard feature of future releases. This feature includes first and/or second order terms of the Taylor Series expansion for response perturbations related to cross-section data (i.e., density, composition, etc.). Criticality analyses can benefit from this technique in that predicted changes in the track-length tally estimator of K eff may be obtained for multiple perturbations in a single run. A key advantage of this method is that a precise estimate of a small change in response (i.e., < 1%) is easily obtained. This technique can also offer acceptable accuracy, to within a few percent, for up to 20-30% changes in a response

  16. Boundary Layer Instabilities Generated by Freestream Laser Perturbations

    Science.gov (United States)

    Chou, Amanda; Schneider, Steven P.

    2015-01-01

    A controlled, laser-generated, freestream perturbation was created in the freestream of the Boeing/AFOSR Mach-6 Quiet Tunnel (BAM6QT). The freestream perturbation convected downstream in the Mach-6 wind tunnel to interact with a flared cone model. The geometry of the flared cone is a body of revolution bounded by a circular arc with a 3-meter radius. Fourteen PCB 132A31 pressure transducers were used to measure a wave packet generated in the cone boundary layer by the freestream perturbation. This wave packet grew large and became nonlinear before experiencing natural transition in quiet flow. Breakdown of this wave packet occurred when the amplitude of the pressure fluctuations was approximately 10% of the surface pressure for a nominally sharp nosetip. The initial amplitude of the second mode instability on the blunt flared cone is estimated to be on the order of 10 -6 times the freestream static pressure. The freestream laser-generated perturbation was positioned upstream of the model in three different configurations: on the centerline, offset from the centerline by 1.5 mm, and offset from the centerline by 3.0 mm. When the perturbation was offset from the centerline of a blunt flared cone, a larger wave packet was generated on the side toward which the perturbation was offset. The offset perturbation did not show as much of an effect on the wave packet on a sharp flared cone as it did on a blunt flared cone.

  17. Sudden oak death effects on the dynamics of dead wood

    Science.gov (United States)

    Richard C. Cobb; Jo& atilde; o Filipe A.N.; Margaret R. Metz; Ross K. Meentemeyer; David M. Rizzo

    2013-01-01

    Sudden oak death has impacted forests notable for high-fire risk and contiguous host communities in California and Oregon coastal forest ecosystems. The disease continues to emerge in stands and landscapes with a large biomass of tanoak (Notholithocarpus densiflorus (Hook.&Arn.) Manos, Cannon & S.H.Oh), and we show that woody debris also...

  18. Local measurement and numerical calculation on turbulent two-phase flow in a vertical pipe with sudden expansion

    International Nuclear Information System (INIS)

    Kondo, Koichi; Yoshida, Kenji; Okawa, Tomio; Kataoka, Isao

    2004-01-01

    Experiment and numerical calculation were carried out for upward, turbulent bubbly two-phase flow in a vertical pipe with an axisymmetric sudden expansion, which is one of the typical multi-dimensional channel geometries. The void fraction, the liquid velocity and turbulent intensity along the flow direction below and the above the sudden expansion point were measured for various turbulent flow conditions by using a point-electrode resistivity probe and a hot-film anemometry probe. They showed quite complicated behaviors depending upon flow rates of gas and liquid phases and bubble size. In particular, the geometry of sudden expansion affected on the bubble behaviors in multi-dimensional two-phase flow, such as the bubble-stagnation, the bubble-deformation, the enhancement and suppression effects due to the two-phase turbulence etc. Through the measurements, fundamental parameters of the two-phase flow were clarified for the sudden expansion channel. Moreover, a three-dimensional one-way bubble tracking simulation of a single bubble behavior in turbulent flow field along the downstream of the sudden expansion was also demonstrated where equation of motion of bubble was solved by assuming appropriate constitutive models and turbulence model. Based on the trajectories of large number of bubbles, the void fraction distribution was predicted in this calculation. It concretely revealed that the lift force and the two-phase turbulence model were the most important parameters in determining the multi-dimensional void fraction distribution and the calculation should be considered by using the measured experimental data. (author)

  19. Cosmological perturbations from quantum fluctuations to large scale structure

    International Nuclear Information System (INIS)

    Bardeen, J.M.

    1988-01-01

    Classical perturbation theory is developed from the 3 + 1 form of the Einstein equations. A somewhat unusual form of the perturbation equations in the synchronous gauge is recommended for carrying out computations, but interpretation is based on certain hypersurface-invariant combinations of the variables. The formalism is used to analyze the origin of density perturbations from quantum fluctuations during inflation, with particular emphasis on dealing with 'double inflation' and deviations from the Zel'dovich spectrum. The evolution of the density perturbation to the present gives the final density perturbation power spectrum, whose relationship to observed large scale structure is discussed in the context of simple cold-dark-matter biasing schemes. 86 refs

  20. Phenotype-driven molecular autopsy for sudden cardiac death.

    Science.gov (United States)

    Cann, F; Corbett, M; O'Sullivan, D; Tennant, S; Hailey, H; Grieve, J H K; Broadhurst, P; Rankin, R; Dean, J C S

    2017-01-01

    A phenotype-driven approach to molecular autopsy based in a multidisciplinary team comprising clinical and laboratory genetics, forensic medicine and cardiology is described. Over a 13 year period, molecular autopsy was undertaken in 96 sudden cardiac death cases. A total of 46 cases aged 1-40 years had normal hearts and suspected arrhythmic death. Seven (15%) had likely pathogenic variants in ion channelopathy genes [KCNQ1 (1), KCNH2 (4), SCN5A (1), RyR2(1)]. Fifty cases aged between 2 and 67 had a cardiomyopathy. Twenty-five had arrhythmogenic right ventricular cardiomyopathy (ARVC), 10 dilated cardiomyopathy (DCM) and 15 hypertrophic cardiomyopathy (HCM). Likely pathogenic variants were found in three ARVC cases (12%) in PKP2, DSC2 or DSP, two DCM cases (20%) in MYH7, and four HCM cases (27%) in MYBPC3 (3) or MYH7 (1). Uptake of cascade screening in relatives was higher when a molecular diagnosis was made at autopsy. In three families, variants previously published as pathogenic were detected, but clinical investigation revealed no abnormalities in carrier relatives. With a conservative approach to defining pathogenicity of sequence variants incorporating family phenotype information and population genomic data, a molecular diagnosis was made in 15% of sudden arrhythmic deaths and 18% of cardiomyopathy deaths. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.