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Sample records for intrinsic subthreshold oscillations

  1. Neuropeptide S-mediated facilitation of synaptic transmission enforces subthreshold theta oscillations within the lateral amygdala.

    Directory of Open Access Journals (Sweden)

    Susanne Meis

    Full Text Available The neuropeptide S (NPS receptor system modulates neuronal circuit activity in the amygdala in conjunction with fear, anxiety and the expression and extinction of previously acquired fear memories. Using in vitro brain slice preparations of transgenic GAD67-GFP (Δneo mice, we investigated the effects of NPS on neural activity in the lateral amygdala as a key region for the formation and extinction of fear memories. We are able to demonstrate that NPS augments excitatory glutamatergic synaptic input onto both projection neurons and interneurons of the lateral amygdala, resulting in enhanced spike activity of both types of cells. These effects were at least in part mediated by presynaptic mechanisms. In turn, inhibition of projection neurons by local interneurons was augmented by NPS, and subthreshold oscillations were strengthened, leading to their shift into the theta frequency range. These data suggest that the multifaceted effects of NPS on amygdaloid circuitry may shape behavior-related network activity patterns in the amygdala and reflect the peptide's potent activity in various forms of affective behavior and emotional memory.

  2. Intrinsic 1/f device noise reduction and its effect on phase noise in CMOS ring oscillators

    NARCIS (Netherlands)

    Gierkink, Sander L.J.; Klumperink, Eric A.M.; van der Wel, A.P.; Hoogzaad, G.; Hoogzaad, Gian; van Tuijl, Adrianus Johannes Maria; Nauta, Bram

    1999-01-01

    This paper gives experimental proof of an intriguing physical effect: periodic on-off switching of MOS transistors in a CMOS ring oscillator reduces their intrinsic 1/f noise and hence the oscillator's close-in phase noise. More specifically, it is shown that the 1/f3 phase noise is dependent on the

  3. Reduction of Intrinsic 1/f Device Noise in a CMOS Ring Oscillator

    NARCIS (Netherlands)

    Gierkink, Sander L.J.; Klumperink, Eric A.M.; Ikkink, T.J.; Ikkink, T.J.; van Tuijl, Adrianus Johannes Maria

    1998-01-01

    The implications of intrinsic 1/f device noise reduction in MOS transistors due to periodic on-off switching in a CMOS ring oscillator are explored. It is shown that maximising the amplitude of oscillation helps to reduce the close-in phase noise. Measurement results, corrected for

  4. Conditional intrinsic voltage oscillations in mature vertebrate neurons undergo specific changes in culture

    DEFF Research Database (Denmark)

    Guertin, Pierre A; Hounsgaard, Jørn

    2006-01-01

    Although intrinsic neuronal properties in invertebrates are well known to undergo specific adaptive changes in culture, long-term adaptation of similar properties in mature vertebrate neurons remain poorly understood. To investigate this, we used an organotypic slice preparation from the spinal...... cord of adult turtles maintainable for several weeks in culture conditions. N-methyl-D-aspartate (NMDA)-induced-tetrodotoxin (TTX)-resistant voltage oscillations in motoneurons were approximately 10 times faster in culture than in acute preparations. Oscillations in culture were abolished by NMDA...... to understanding further the potential for plasticity of mature vertebrate neurons....

  5. Intrinsic and Extrinsic Neuronal Mechanisms in Temporal Coding: A Further Look at Neuronal Oscillations

    Science.gov (United States)

    Lestienne, Rémy

    1999-01-01

    Many studies in recent years have been devoted to the detection of fast oscillations in the Central Nervous System (CNS), interpreting them as synchronizing devices. We should, however, refrain from associating too closely the two concepts of synchronization and oscillation. Whereas synchronization is a relatively well-defined concept, by contrast oscillation of a population of neurones in the CNS looks loosely defined, in the sense that both its frequency sharpness and the duration of the oscillatory episodes vary widely from case to case. Also, the functions of oscillations in the brain are multiple and are not confined to synchronization. The paradigmatic instantiation of oscillation in physics is given by the harmonic oscillator, a device particularly suited to tell the time, as in clocks. We will thus examine first the case of oscillations or cycling discharges of neurones, which provide a clock or impose a “tempo” for various kinds of information processing. Neuronal oscillators are rarely just clocks clicking at a fixed frequency. Instead, their frequency is often adjustable and controllable, as in the example of the “chattering cells” discovered in the superficial layers of the visual cortex. Moreover, adjustable frequency oscillators are suitable for use in “phase locked loops” (PLL) networks, a device that can convert time coding to frequency coding; such PLL units have been found in the somatosensory cortex of guinea pigs. Finally, are oscillations stricto sensu necessary to induce synchronization in the discharges of downstream neurones? We know that this is not the case, at least not for local populations of neurones. As a contribution to this question, we propose that repeating patterns in neuronal discharges production may be looked at as one such alternative solution in relation to the processing of information. We review here the case of precisely repeating triplets, detected in the discharges of olfactory mitral cells of a freely

  6. Intrinsic and Extrinsic Neuronal Mechanisms in Temporal Coding: A Further Look at Neuronal Oscillations

    Directory of Open Access Journals (Sweden)

    Rémy Lestienne

    1999-01-01

    case to case. Also, the functions of oscillations in the brain are multiple and are not confined to synchronization. The paradigmatic instantiation of oscillation in physics is given by the harmonic oscillator, a device particularly suited to tell the time, as in clocks. We will thus examine first the case of oscillations or cycling discharges of neurones, which provide a clock or impose a “tempo” for various kinds of information processing. Neuronal oscillators are rarely just clocks clicking at a fixed frequency. Instead, their frequency is often adjustable and controllable, as in the example of the “chattering cells” discovered in the superficial layers of the visual cortex. Moreover, adjustable frequency oscillators are suitable for use in “phase locked loops” (PLL networks, a device that can convert time coding to frequency coding; such PLL units have been found in the somatosensory cortex of guinea pigs. Finally, are oscillations stricto sensu necessary to induce synchronization in the discharges of downstream neurones? We know that this is not the case, at least not for local populations of neurones. As a contribution to this question, we propose that repeating patterns in neuronal discharges production may be looked at as one such alternative solution in relation to the processing of information. We review here the case of precisely repeating triplets, detected in the discharges of olfactory mitral cells of a freely breathing rat under odor stimulation.

  7. Analysis of the role of the low threshold currents IT and Ih in intrinsic delta oscillations of thalamocortical neurons

    Directory of Open Access Journals (Sweden)

    Yimy eAmarillo

    2015-05-01

    Full Text Available Thalamocortical neurons are involved in the generation and maintenance of brain rhythms associated with global functional states. The repetitive burst firing of TC neurons at delta frequencies (1-4 Hz has been linked to the oscillations recorded during deep sleep and during episodes of absence seizures. To get insight into the biophysical properties that are the basis for intrinsic delta oscillations in these neurons, we performed a bifurcation analysis of a minimal conductance-based thalamocortical neuron model including only the IT channel and the sodium and potassium leak channels. This analysis unveils the dynamics of repetitive burst firing of TC neurons, and describes how the interplay between the amplifying variable mT and the recovering variable hT of the calcium channel IT is sufficient to generate low threshold oscillations in the delta band. We also explored the role of the hyperpolarization activated cationic current Ih in this reduced model and determine that, albeit not required, Ih amplifies and stabilizes the oscillation.

  8. Quantum simulations and experiments on Rabi oscillations of spin qubits : Intrinsic vs extrinsic damping

    NARCIS (Netherlands)

    De Raedt, Hans; Barbara, Bernard; Miyashita, Seiji; Michielsen, Kristel; Bertaina, Sylvain; Gambarelli, Serge

    2012-01-01

    Electron paramagnetic resonance experiments show that the decay of Rabi oscillations of ensembles of spin qubits depends noticeably on the microwave power, and more precisely on the Rabi frequency, an effect recently called "driven decoherence." By direct numerical solution of the time-dependent

  9. Synchronous Oscillations Intrinsic to Water: Applications to Cellular Time Keeping and Water Treatment

    Directory of Open Access Journals (Sweden)

    D. James Morré

    2015-05-01

    Full Text Available A homodimeric, growth-related and time-keeping hydroquinone oxidase (ENOX1 of the eukaryotic cell surface capable of oxidizing intracellular NADH exhibits properties of the ultradian driver of the biological 24 h circadian clock by exhibiting a complex 2 + 3 set of oscillations of copper salts and appear to derive from periodic variations in the ratio of ortho and para nuclear spins of the paired hydrogen atoms of the elongated octahedral structure of the ENOX1 protein bound copper II hexahydrates. A corollary of these observations is that the ortho/para oscillations must occur in a highly synchronized matter. Our findings suggest that water molecules communicate with each other via very low frequency electromagnetic fields and that these fields also appear to be generated by the energetics of the synchronous ortho to para interconversions of the nuclear spin pairs of the water hydrogens. Further evidence for energy absorbed and emitted by water and correlated with ortho/para oscillations of ortho/para spin pairs of water hydrogens is indicated from the auto-oscillations in water luminescence. The emissions oscillate with period lengths of 18.8 min that agree with our previously found period of oscillation of about 18 min for pure water, reflective of ortho to para spin isomers based on measurements of redox potential. The period length of pure water (increased by about 25% in D2O and varies depending on the dominant cation present (copper salts in solution are unique in that the period length is exactly 24 min. Synchrony is maintained through generation of and response to LFEMF generated by the ortho-para spin pairs. Changes in redox potential sufficient to catalyze NADH oxidation were used to monitor synchronous water oscillations that appear to extend indefinitely over great distances in contiguous bodies of either still or flowing water. Adjacent out-of-phase water samples contained in thin plastic cuvettes auto-synchronize in a matter of

  10. Intrinsic synchronization of an array of spin-torque oscillators driven by the spin-Hall effect

    International Nuclear Information System (INIS)

    Siracusano, G.; Puliafito, V.; Giordano, A.; Azzerboni, B.; Finocchio, G.; Tomasello, R.; La Corte, A.; Carpentieri, M.

    2015-01-01

    This paper micromagnetically studies the magnetization dynamics driven by the spin-Hall effect in a Platinum/Permalloy bi-layer. For a certain field and current range, the excitation of a uniform mode, characterized by a power with a spatial distribution in the whole ferromagnetic cross section, is observed. We suggest to use the ferromagnet of the bi-layer as basis for the realization of an array of spin-torque oscillators (STOs): the Permalloy ferromagnet will act as shared free layer, whereas the spacers and the polarizers are built on top of it. Following this strategy, the frequency of the uniform mode will be the same for the whole device, creating an intrinsic synchronization. The synchronization of an array of parallely connected STOs will allow to increase the output power, as necessary for technological applications

  11. Inhibitory coherence in a heterogeneous population of subthreshold and suprathreshold type-I neurons

    International Nuclear Information System (INIS)

    Kim, Sang-Yoon; Hong, Duk-Geun; Kim, Jean; Lim, Woochang

    2012-01-01

    We study inhibitory coherence (i.e. collective coherence by synaptic inhibition) in a population of globally coupled type-I neurons, which can fire at arbitrarily low frequency. No inhibitory coherence is observed in a homogeneous population composed of only subthreshold neurons, which exhibit noise-induced firings. In addition to subthreshold neurons, there exist spontaneously firing suprathreshold neurons in a noisy environment of a real brain. To take into consideration the effect of suprathreshold neurons on inhibitory coherence, we consider a heterogeneous population of subthreshold and suprathreshold neurons and investigate the inhibitory coherence by increasing the fraction of suprathreshold neurons P supra . As P supra passes a threshold P* supra , suprathreshold neurons begin to synchronize and play the role of coherent inhibitors for the emergence of inhibitory coherence. Thus, regularly oscillating population-averaged global potential appears for P supra > P* supra . For this coherent case, suprathreshold neurons exhibit sparse spike synchronization (i.e. individual potentials of suprathreshold neurons consist of coherent sparse spikings and coherent subthreshold small-amplitude hoppings). By virtue of their coherent inhibition, sparsely synchronized suprathreshold neurons suppress the noisy activity of subthreshold neurons. Thus, subthreshold neurons exhibit hopping synchronization (i.e. only coherent subthreshold hopping oscillations without spikings appear in the individual potentials of subthreshold neurons). We also characterize the inhibitory coherence in terms of the ‘statistical-mechanical’ spike-based and correlation-based measures, which quantify the average contributions of the microscopic individual spikes and individual potentials to the macroscopic global potential. Finally, the effect of sparse randomness of synaptic connectivity on the inhibitory coherence is briefly discussed. (paper)

  12. Subthreshold olfactory stimulation can enhance sweetness.

    Science.gov (United States)

    Labbe, D; Rytz, A; Morgenegg, C; Ali, S; Martin, N

    2007-03-01

    The impact of olfactory perception on sweetness was explored in a model solution using odorants at subthreshold concentrations. First, the impact of 6 odorants, previously described in the literature as congruent with sweetness, was investigated at suprathreshold level in a sucrose solution. Ethyl butyrate and maltol were selected as they had the highest and the lowest sweetness-enhancing properties, respectively. Second, the impact on sweetness of the 2 odorants was investigated at subthreshold concentrations. A system delivering a continuous liquid flow at the same sucrose level, but with varying odorant concentrations, was used. At a subthreshold level, ethyl butyrate but not maltol significantly enhanced the sweetness of the sucrose solution. This study highlights that olfactory perception induced by odorants at a subthreshold level can significantly modulate taste perception. Finally, contrary to results observed with ethyl butyrate at suprathreshold levels, at subthreshold levels, the intensity of sweetness enhancement was not proportional to ethyl butyrate concentration.

  13. Patients with Chronic Visceral Pain Show Sex-Related Alterations in Intrinsic Oscillations of the Resting Brain

    Science.gov (United States)

    Hong, Jui-Yang; Kilpatrick, Lisa A.; Labus, Jennifer; Gupta, Arpana; Jiang, Zhiguo; Ashe-McNalley, Cody; Stains, Jean; Heendeniya, Nuwanthi; Ebrat, Bahar; Smith, Suzanne; Tillisch, Kirsten; Naliboff, Bruce

    2013-01-01

    Abnormal responses of the brain to delivered and expected aversive gut stimuli have been implicated in the pathophysiology of irritable bowel syndrome (IBS), a visceral pain syndrome occurring more commonly in women. Task-free resting-state functional magnetic resonance imaging (fMRI) can provide information about the dynamics of brain activity that may be involved in altered processing and/or modulation of visceral afferent signals. Fractional amplitude of low-frequency fluctuation is a measure of the power spectrum intensity of spontaneous brain oscillations. This approach was used here to identify differences in the resting-state activity of the human brain in IBS subjects compared with healthy controls (HCs) and to identify the role of sex-related differences. We found that both the female HCs and female IBS subjects had a frequency power distribution skewed toward high frequency to a greater extent in the amygdala and hippocampus compared with male subjects. In addition, female IBS subjects had a frequency power distribution skewed toward high frequency in the insula and toward low frequency in the sensorimotor cortex to a greater extent than male IBS subjects. Correlations were observed between resting-state blood oxygen level-dependent signal dynamics and some clinical symptom measures (e.g., abdominal discomfort). These findings provide the first insight into sex-related differences in IBS subjects compared with HCs using resting-state fMRI. PMID:23864686

  14. Neurodynamic oscillators

    Science.gov (United States)

    Espinosa, Ismael; Gonzalez, Hortensia; Quiza, Jorge; Gonazalez, J. Jesus; Arroyo, Ruben; Lara, Ritaluz

    1995-01-01

    Oscillation of electrical activity has been found in many nervous systems, from invertebrates to vertebrates including man. There exists experimental evidence of very simple circuits with the capability of oscillation. Neurons with intrinsic oscillation have been found and also neural circuits where oscillation is a property of the network. These two types of oscillations coexist in many instances. It is nowadays hypothesized that behind synchronization and oscillation there is a system of coupled oscillators responsible for activities that range from locomotion and feature binding in vision to control of sleep and circadian rhythms. The huge knowledge that has been acquired on oscillators from the times of Lord Rayleigh has made the simulation of neural oscillators a very active endeavor. This has been enhanced with more recent physiological findings about small neural circuits by means of intracellular and extracellular recordings as well as imaging methods. The future of this interdisciplinary field looks very promising; some researchers are going into quantum mechanics with the idea of trying to provide a quantum description of the brain. In this work we describe some simulations using neuron models by means of which we form simple neural networks that have the capability of oscillation. We analyze the oscillatory activity with root locus method, cross-correlation histograms, and phase planes. In the more complicated neural network models there is the possibility of chaotic oscillatory activity and we study that by means of Lyapunov exponents. The companion paper shows an example of that kind.

  15. Subthreshold depression in children and adolescents

    DEFF Research Database (Denmark)

    Wesselhoeft, Rikke; Sørensen, Merete Juul; Heiervang, Einar

    2013-01-01

    Depressive disorders are disabling conditions striking at all ages. In adults, subthreshold depression (SD) is viewed as being on a continuum with major depressive disorder (MDD). Whether this holds for children and adolescents, is still unclear. We performed the first systematic review of SD...

  16. Subthreshold FIR Filter Architecture for Ultra Low Power Applications

    OpenAIRE

    Mishra, Biswajit; M. Al-Hashimi, Bashir

    2008-01-01

    Subthreshold design has been proposed as an effective technique for designing signal processing circuits needed in wireless sensor nodes powered by sources with limited energy. In this paper we propose a subthreshold FIR architecture which brings the benefits of reducedleakage energy, reduced minimum energy point, reduced operating voltage and increased operating frequency when compared with recently reported subthreshold designs. We shall demonstrate this through the design of a 9-tap FIR fi...

  17. Computed tomography image using sub-terahertz waves generated from a high-T{sub c} superconducting intrinsic Josephson junction oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Kashiwagi, T., E-mail: kashiwagi@ims.tsukuba.ac.jp; Minami, H.; Kadowaki, K. [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba (Japan); Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Nakade, K.; Saiwai, Y.; Kitamura, T.; Watanabe, C.; Ishida, K.; Sekimoto, S.; Asanuma, K.; Yasui, T.; Shibano, Y. [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba (Japan); Tsujimoto, M. [Department of Electronic Science and Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan); Yamamoto, T. [Wide Bandgap Materials Group, Optical and Electronic Materials Unit, Environment and Energy Materials Division, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Marković, B. [Faculty of Sciences, University of Montenegro, George Washington Str., 81000 Podgorica (Montenegro); Mirković, J. [Faculty of Science, University of Montenegro, and CETI, Put Radomira Ivanovica, 81000 Podgorica (Montenegro); Klemm, R. A. [Department of Physics, University of Central Florida, 4000 Central Florida Blvd., Orlando, Florida 32816-2385 (United States)

    2014-02-24

    A computed tomography (CT) imaging system using monochromatic sub-terahertz coherent electromagnetic waves generated from a device constructed from the intrinsic Josephson junctions in a single crystalline mesa structure of the high-T{sub c} superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+δ} was developed and tested on three samples: Standing metallic rods supported by styrofoam, a dried plant (heart pea) containing seeds, and a plastic doll inside an egg shell. The images obtained strongly suggest that this CT imaging system may be useful for a variety of practical applications.

  18. Preventing Depression in Adults With Subthreshold Depression

    DEFF Research Database (Denmark)

    Buntrock, Claudia; Berking, Matthias; Smit, Filip

    2017-01-01

    BACKGROUND: Psychological interventions for the prevention of depression might be a cost-effective way to reduce the burden associated with depressive disorders. OBJECTIVE: To evaluate the cost-effectiveness of a Web-based guided self-help intervention to prevent major depressive disorder (MDD......) in people with subthreshold depression (sD). METHODS: A pragmatic randomized controlled trial was conducted with follow-up at 12 months. Participants were recruited from the general population via a large statutory health insurance company and an open access website. Participants were randomized to a Web......-based guided self-help intervention (ie, cognitive-behavioral therapy and problem-solving therapy assisted by supervised graduate students or health care professionals) in addition to usual care or to usual care supplemented with Web-based psycho-education (enhanced usual care). Depression-free years (DFYs...

  19. 2-D analytical modeling of subthreshold current and subthreshold swing for ion-implanted strained-Si double-material double-gate (DMDG) MOSFETs

    Science.gov (United States)

    Goel, Ekta; Singh, Kunal; Singh, Balraj; Kumar, Sanjay; Jit, Satyabrata

    2017-09-01

    In this paper, the subthreshold behavior of ion-implanted strained-Si double-material double-gate (DMDG) MOSFETs has been analyzed by means of subthreshold current and subthreshold swing. The surface potential based formulation of subthreshold current and subthreshold swing is done by solving the 2-D Poisson's equations in the channel region using parabolic approximation method. The dependence of subthreshold characteristics on various device parameters such as gate length ratio, Ge mole fraction, peak doping concentration, projected range, straggle parameter etc. has been studied. The modeling results are found to be well matched with the simulation data obtained by a 2-D device simulator, ATLAS™, from SILVACO.

  20. Ultra-Low-Energy Sub-Threshold Circuits: Program Overview

    National Research Council Canada - National Science Library

    Chandrakasan, Anantha

    2007-01-01

    .... This concept was demonstrated with a UWB baseband processor. We have developed a DC-DC converter to efficiently deliver sub-threshold voltage and minimize the power dissipation of an arbitrary digital circuit...

  1. Assessment of Global Variability in UTBB MOSFETs in Subthreshold Regime

    Directory of Open Access Journals (Sweden)

    Sergej Makovejev

    2014-07-01

    Full Text Available The global variability of ultra-thin body and buried oxide (UTBB MOSFETs in subthreshold and off regimes of operation is analyzed. The variability of the off-state drain current, subthreshold slope, drain-induced barrier lowering (DIBL, gate leakage current, threshold voltage and their correlations are considered. Two threshold voltage extraction techniques were used. It is shown that the transconductance over drain current (gm/Id method is preferable for variability studies. It is demonstrated that the subthreshold drain current variability in short channel devices cannot be described by threshold voltage variability. It is suggested to include the effective body factor incorporating short channel effects in order to properly model the subthreshold drain current variability.

  2. Subthreshold body dysmorphic disorder in adolescents: Prevalence and impact.

    Science.gov (United States)

    Schneider, Sophie C; Mond, Jonathan; Turner, Cynthia M; Hudson, Jennifer L

    2017-05-01

    The aim of the current study was to establish the prevalence of subthreshold body dysmorphic disorder (subthreshold-BDD) in a community sample of adolescents, and to compare disorder correlates in individuals with subthreshold-BDD to those with probable full-syndrome BDD (probable-BDD) and those without BDD (non-BDD). Self-report questionnaires assessing DSM-IV BDD criteria, past mental health service use, and symptoms of body dysmorphic disorder, anxiety, depression, obsessive-compulsive disorder and eating disorders, were completed by 3149 Australian high school students (mean age =14.6 years, 63.5% male). Male participants also completed measures assessing quality of life, muscularity concerns, emotional symptoms, conduct problems, hyperactivity, and peer problems. The prevalence of subthreshold-BDD was 3.4%, and probable-BDD was 1.7%. Compared to the non-BDD group, subthreshold-BDD was associated with elevated symptoms of comorbid psychopathology and greater past mental health service use, and in male-only measures, with poorer quality of life and elevated muscularity concerns. Subthreshold-BDD participants reported significantly lower mental health service use, and fewer symptoms of depression, eating disorders, and hyperactivity than probable-BDD participants, however, other comorbid symptoms did not differ significantly between these groups. These findings indicate that subthreshold-BDD is associated with substantial difficulties for adolescents in the general community. BDD screening should include subthreshold presentations, as these may be an important target for early intervention programs. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  3. Depression and coping in subthreshold eating disorders.

    Science.gov (United States)

    Dennard, E Eliot; Richards, C Steven

    2013-08-01

    The eating disorder literature has sought to understand the role of comorbid psychiatric diagnoses and coping in relation to eating disorders. The present research extends these findings by studying the relationships among depression, coping, and the entire continuum of disordered eating behaviors, with an emphasis on subthreshold eating disorders. 109 undergraduate females completed questionnaires to assess disordered eating symptoms, depressive symptoms, and the use of active and avoidant coping mechanisms. Hypotheses were tested using bivariate linear regression and multivariate linear regression. Results indicated that depression was a significant predictor of disordered eating symptoms after controlling for relationships between depression and coping. Although avoidant coping was positively associated with disordered eating, it was not a significant predictor after controlling for depression and coping. Previous research has found associations between depression and diagnosable eating disorders, and this research extends those findings to the entire continuum of disordered eating. Future research should continue to investigate the predictors and correlates of the disordered eating continuum using more diverse samples. Testing for mediation and moderation among these variables may also be a fruitful area of investigation. Published by Elsevier Ltd.

  4. Intrinsic Motivation.

    Science.gov (United States)

    the activity. There has been very little research and theorizing which considers the topic of intrinsic motivation , yet there is a substantial amount...reported within the framework of intrinsic motivation , yet the paper reinterprets the work within that framework. It considers several approaches of

  5. Analytical modeling of subthreshold current and subthreshold swing of Gaussian-doped strained-Si-on-insulator MOSFETs

    International Nuclear Information System (INIS)

    Rawat, Gopal; Kumar, Sanjay; Goel, Ekta; Kumar, Mirgender; Jit, S.; Dubey, Sarvesh

    2014-01-01

    This paper presents the analytical modeling of subthreshold current and subthreshold swing of short-channel fully-depleted (FD) strained-Si-on-insulator (SSOI) MOSFETs having vertical Gaussian-like doping profile in the channel. The subthreshold current and subthreshold swing have been derived using the parabolic approximation method. In addition to the effect of strain on silicon layer, various other device parameters such as channel length (L), gate-oxide thickness (t ox ), strained-Si channel thickness (t s-Si ), peak doping concentration (N P ), project range (R p ) and straggle (σ p ) of the Gaussian profile have been considered while predicting the device characteristics. The present work may help to overcome the degradation in subthreshold characteristics with strain engineering. These subthreshold current and swing models provide valuable information for strained-Si MOSFET design. Accuracy of the proposed models is verified using the commercially available ATLAS™, a two-dimensional (2D) device simulator from SILVACO. (semiconductor devices)

  6. Threshold and subthreshold Generalized Anxiety Disorder (GAD) and suicide ideation.

    Science.gov (United States)

    Gilmour, Heather

    2016-11-16

    Subthreshold Generalized Anxiety Disorder (GAD) has been reported to be at least as prevalent as threshold GAD and of comparable clinical significance. It is not clear if GAD is uniquely associated with the risk of suicide, or if psychiatric comorbidity drives the association. Data from the 2012 Canadian Community Health Survey-Mental Health were used to estimate the prevalence of threshold and subthreshold GAD in the household population aged 15 or older. As well, the relationship between GAD and suicide ideation was studied. Multivariate logistic regression was used in a sample of 24,785 people to identify significant associations, while adjusting for the confounding effects of sociodemographic factors and other mental disorders. In 2012, an estimated 722,000 Canadians aged 15 or older (2.6%) met the criteria for threshold GAD; an additional 2.3% (655,000) had subthreshold GAD. For people with threshold GAD, past 12-month suicide ideation was more prevalent among men than women (32.0% versus 21.2% respectively). In multivariate models that controlled sociodemographic factors, the odds of past 12-month suicide ideation among people with either past 12-month threshold or subthreshold GAD were significantly higher than the odds for those without GAD. When psychiatric comorbidity was also controlled, associations between threshold and subthreshold GAD and suicidal ideation were attenuated, but remained significant. Threshold and subthreshold GAD affect similar percentages of the Canadian household population. This study adds to the literature that has identified an independent association between threshold GAD and suicide ideation, and demonstrates that an association is also apparent for subthreshold GAD.

  7. Adult Autism Subthreshold Spectrum (AdAS Spectrum): Validation of a questionnaire investigating subthreshold autism spectrum.

    Science.gov (United States)

    Dell'Osso, L; Gesi, C; Massimetti, E; Cremone, I M; Barbuti, M; Maccariello, G; Moroni, I; Barlati, S; Castellini, G; Luciano, M; Bossini, L; Rocchetti, M; Signorelli, M; Aguglia, E; Fagiolini, A; Politi, P; Ricca, V; Vita, A; Carmassi, C; Maj, M

    2017-02-01

    Increasing literature has shown the usefulness of a dimensional approach to autism. The present study aimed to determine the psychometric properties of the Adult Autism Subthreshold Spectrum (AdAS Spectrum), a new questionnaire specifically tailored to assess subthreshold forms of autism spectrum disorder (ASD) in adulthood. 102 adults endorsing at least one DSM-5 symptom criterion for ASD (ASDc), 143 adults diagnosed with a feeding and eating disorder (FED), and 160 subjects with no mental disorders (CTL), were recruited from 7 Italian University Departments of Psychiatry and administered the following: SCID-5, Autism-Spectrum Quotient (AQ), Ritvo Autism and Asperger Diagnostic Scale 14-item version (RAADS-14), and AdAS Spectrum. The AdAS Spectrum demonstrated excellent internal consistency for the total score (Kuder-Richardson's coefficient=.964) as well as for five out of seven domains (all coefficients>.80) and sound test-retest reliability (ICC=.976). The total and domain AdAS Spectrum scores showed a moderate to strong (>.50) positive correlation with one another and with the AQ and RAADS-14 total scores. ASDc subjects reported significantly higher AdAS Spectrum total scores than both FED (pAdAS Spectrum scores from CTL subjects to ASD patients, across FED 0 , ASD 1 , FED 1 was shown. The AdAS Spectrum showed excellent internal consistency and test-retest reliability and strong convergent validity with alternative dimensional measures of ASD. The questionnaire performed differently among the three diagnostic groups and enlightened some significant effects of gender in the expression of autistic traits. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Pattern segmentation with activity dependent natural frequency shift and sub-threshold resonance.

    Science.gov (United States)

    Shtrahman, E; Zochowski, M

    2015-03-09

    Understanding the mechanisms underlying distributed pattern formation in brain networks and its content driven dynamical segmentation is an area of intense study. We investigate a theoretical mechanism for selective activation of diverse neural populations that is based on dynamically shifting cellular resonances in functionally or structurally coupled networks. We specifically show that sub-threshold neuronal depolarization from synaptic coupling or external input can shift neurons into and out of resonance with specific bands of existing extracellular oscillations, and this can act as a dynamic readout mechanism during information storage and retrieval. We find that this mechanism is robust and suggest it as a general coding strategy that can be applied to any network with oscillatory nodes.

  9. Compact models and performance investigations for subthreshold interconnects

    CERN Document Server

    Dhiman, Rohit

    2014-01-01

    The book provides a detailed analysis of issues related to sub-threshold interconnect performance from the perspective of analytical approach and design techniques. Particular emphasis is laid on the performance analysis of coupling noise and variability issues in sub-threshold domain to develop efficient compact models. The proposed analytical approach gives physical insight of the parameters affecting the transient behavior of coupled interconnects. Remedial design techniques are also suggested to mitigate the effect of coupling noise. The effects of wire width, spacing between the wires, wi

  10. Association of perfectionistic and dependent dysfunctional attitudes with subthreshold depression

    Directory of Open Access Journals (Sweden)

    Horiuchi S

    2017-08-01

    Full Text Available Satoshi Horiuchi,1 Shuntaro Aoki,2,3 Koki Takagaki,4 Fumihito Shoji5 1Faculty of Social Welfare, Iwate Prefectural University, Iwate, Japan; 2Graduate School of Psychological Science, Health Sciences University of Hokkaido, Hokkaido, Japan; 3Japan Society for the Promotion of Science, Tokyo, Japan; 4Department of Psychiatry and Neurosciences, Hiroshima University, Hiroshima, Japan; 5Graduate School of Social Welfare, Iwate Prefectural University, Iwate, Japan Background: Dysfunctional attitudes are beliefs and attitudes that induce negative thoughts about the self, others, and the future, leading to depression. Perfectionistic dysfunctional attitudes are beliefs and attitudes about achievement and excessive fear of failure, while dependent dysfunctional attitudes are beliefs and attitudes about dependency on, and approval from, others. Subthreshold depression refers to a depressive state that does not meet the diagnostic criteria for a major depressive episode. This study examined whether the difference in perfectionistic dysfunctional attitudes between college students with subthreshold depression and those with no depression would be greater than that of dependent dysfunctional attitudes.Methods: Participants were defined as having subthreshold depression if they scored 16 or higher on the Japanese version of the Center for Epidemiologic Studies Depression Scale but did not meet the diagnostic criteria for a major depressive episode, as assessed by the major depressive episode module of the Mini-International Neuropsychiatric Interview. The participants included 21 male and 87 female college students, with a mean age of 20.3 years. Dysfunctional attitudes were evaluated with the Japanese version of the 24-item Dysfunctional Attitude Scale.Results: Of the 108 students, 34 had subthreshold depression while 74 had no depression. The magnitudes of the differences in perfectionistic and dependent dysfunctional attitudes between the students with

  11. Contributions of Gerard de Saussure to fission physics: Subthreshold and near-subthreshold measurements at the ORELA

    International Nuclear Information System (INIS)

    Perez, R.B.; Difilippo, F.C.

    1992-01-01

    In the late 1960s, Strutinsky's theoretical work on the structure of the fission barrier, together with some new neutron cross-section measurements performed at Saclay and Gel, was called to Gerard de Saussure's attention, and he immediately recognized the importance of those developments. Indeed, de Saussure was quick to note that for neutron energies in the range of the fission barrier potential energy, fission cross-section measurements would yield direct information about the physical properties of the fission barrier. Under his leadership, a set of extensive and precise measurements was performed at the Oak Ridge Electron Linear Accelerator (ORELA) by an international group of researchers, lasting over two decades. Those measurements were unique in many respects: Fission widths were determined for many previously unreported resonances in the subthreshold region, and a detailed study was performed on the physical properties of the fission barrier at high nuclear deformations. In this paper, we report a specific part of the de Saussure's extensive involvement in the area of subthreshold fission physics: the 1979 measurement of the 238 U(n,f) cross ection in the subthreshold and near-subthreshold regions. This cross section was measured in the energy region between 5 eV and 3.5 MeV using a large fission chamber loaded with high-purity 238 U, which had 235 U

  12. Dependence of synchronization frequency of Kuramoto oscillators ...

    Indian Academy of Sciences (India)

    journal of. December 2014 physics pp. 945–953. Dependence of synchronization frequency of Kuramoto oscillators on symmetry of intrinsic frequency in ring ... In this article, we study the difference between networks with sym- ... The dynamics of a general ith oscillator in a system of N Kuramoto oscillators is given as.

  13. Device and Circuit Design Challenges in the Digital Subthreshold Region for Ultralow-Power Applications

    Directory of Open Access Journals (Sweden)

    Ramesh Vaddi

    2009-01-01

    Full Text Available In recent years, subthreshold operation has gained a lot of attention due to ultra low-power consumption in applications requiring low to medium performance. It has also been shown that by optimizing the device structure, power consumption of digital subthreshold logic can be further minimized while improving its performance. Therefore, subthreshold circuit design is very promising for future ultra low-energy sensor applications as well as high-performance parallel processing. This paper deals with various device and circuit design challenges associated with the state of the art in optimal digital subthreshold circuit design and reviews device design methodologies and circuit topologies for optimal digital subthreshold operation. This paper identifies the suitable candidates for subthreshold operation at device and circuit levels for optimal subthreshold circuit design and provides an effective roadmap for digital designers interested to work with ultra low-power applications.

  14. Executive function in individuals with subthreshold autism traits.

    Science.gov (United States)

    Christ, Shawn E; Kanne, Stephen M; Reiersen, Angela M

    2010-09-01

    Recent research has documented increased psychosocial difficulties in individuals who report higher-than-typical autistic traits but without an Autism Spectrum Disorder (ASD) diagnosis. Less is known, however, regarding the cognitive profile of individuals with subthreshold autism symptomatology. The objective of the present study was to provide additional insight into this issue and examine whether young adults who report higher degrees of autism traits also report experiencing increased difficulties with executive control. The Behavior Rating Inventory of Executive Function was utilized to evaluate behavioral aspects of executive functioning in 66 and 28 individuals who endorsed high and low subthreshold levels of autism symptomatology, respectively. After accounting for Attention Deficit/Hyperactivity Disorder (ADHD) symptomatology at both the group and individual participant levels, we found that autism traits continued to explain a significant amount of variance in participants' overall level of executive function (Global Executive Composite) as well as within most individual executive domains. Interestingly, the high and low trait groups did not differ on the inhibitory control and organization of materials scales, areas of functioning that appears to be largely spared in individuals with ASD as well. Findings from the present study are consistent with past research linking ASD and executive control impairment. In addition, ASD and ADHD traits were associated with unique contributions to the executive control profile of individuals with subthreshold autism symptomatology. This finding underscores the importance of accounting for ADHD symptomatology in studying ASD. Copyright 2010 APA, all rights reserved.

  15. Analytical Subthreshold Current and Subthreshold Swing Models for a Fully Depleted (FD) Recessed-Source/Drain (Re-S/D) SOI MOSFET with Back-Gate Control

    Science.gov (United States)

    Saramekala, Gopi Krishna; Tiwari, Pramod Kumar

    2017-08-01

    Two-dimensional (2D) analytical models for the subthreshold current and subthreshold swing of the back-gated fully depleted recessed-source/drain (Re-S/D) silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistor (MOSFET) are presented. The surface potential is determined by solving the 2D Poisson equation in both channel and buried-oxide (BOX) regions, considering suitable boundary conditions. To derive closed-form expressions for the subthreshold characteristics, the virtual cathode potential expression has been derived in terms of the minimum of the front and back surface potentials. The effect of various device parameters such as gate oxide and Si film thicknesses, thickness of source/drain penetration into BOX, applied back-gate bias voltage, etc. on the subthreshold current and subthreshold swing has been analyzed. The validity of the proposed models is established using the Silvaco ATLAS™ 2D device simulator.

  16. Analytical model for subthreshold current and subthreshold swing of short-channel double-material-gate MOSFETs with strained-silicon channel on silicon—germanium substrates

    International Nuclear Information System (INIS)

    Tiwari Pramod Kumar; Saramekala Gopi Krishna; Mukhopadhyay Anand Kumar; Dubey Sarvesh

    2014-01-01

    The present work gives some insight into the subthreshold behaviour of short-channel double-material-gate strained-silicon on silicon—germanium MOSFETs in terms of subthreshold swing and off-current. The formulation of subthreshold current and, thereupon, the subthreshold swing have been done by exploiting the expression of potential distribution in the channel region of the device. The dependence of the subthreshold characteristics on the device parameters, such as Ge mole fraction, gate length ratio, work function of control gate metal and gate length, has been tested in detail. The analytical models have been validated by the numerical simulation results that were obtained from the device simulation software ATLAS™ by Silvaco Inc. (semiconductor devices)

  17. A new compact subthreshold behavior model for dual-material surrounding gate (DMSG) MOSFETs

    Science.gov (United States)

    Chiang, T. K.

    2009-05-01

    On the basis of exact resultant solution of two-dimensional Poisson equation, a new compact subthreshold behavior model comprising two-dimensional potential, threshold voltage, subthreshold current and subthreshold swing for the dual-material surrounding gate (DMSG) MOSFETs is successfully developed. The model shows its validity by a good agreement with the simulated results from published device simulation software MEDICI. Besides offering the physical insight into device physics, the model provides the basic designing guidance for the DMSG MOSFETs.

  18. The Effects of Subthreshold Priming Alerts on Pilots in the USAARL TH-67 Microsim

    Science.gov (United States)

    2009-06-01

    subthreshold priming, subliminal messaging , cockpit displays UNCLAS UNCLAS UNCLAS SAR 46 Loraine Parish St. Onge, PhD 334-255-6906 Reset...this experiment influenced your opinion of sub-threshold priming/ subliminal messaging ? Five participants responded that they felt that...participation in this experiment influenced your opinion of sub-threshold priming/ subliminal messaging ? Please explain. 4. In your opinion, do

  19. Subthreshold autism spectrum disorder in patients with eating disorders.

    Science.gov (United States)

    Dell'Osso, L; Carpita, B; Gesi, C; Cremone, I M; Corsi, M; Massimetti, E; Muti, D; Calderani, E; Castellini, G; Luciano, M; Ricca, V; Carmassi, C; Maj, M

    2018-02-01

    Increasingly data suggest a possible overlap between psychopathological manifestations of eating disorders (EDs) and autism spectrum disorders (ASD). The aim of the present study was to assess the presence of subthreshold autism spectrum symptoms, by means of a recently validated instrument, in a sample of participants with EDs, particularly comparing participants with or without binge eating behaviours. 138 participants meeting DSM-5 criteria for EDs and 160 healthy control participants (HCs), were recruited at 3 Italian University Departments of Psychiatry and assessed by the SCID-5, the Adult Autism Subthreshold Spectrum (AdAS Spectrum) and the Eating Disorders Inventory, version 2 (EDI-2). ED participants included: 46 with restrictive anorexia (AN-R); 24 with binge-purging type of Anorexia Nervosa (AN-BP); 34 with Bulimia Nervosa (BN) and 34 with Binge Eating Disorder (BED). The sample was split in two groups: participants with binge eating behaviours (BEB), in which were included participants with AN-BP, BN and BED, and participants with restrictive behaviours (AN-R). participants with EDs showed significantly higher AdAS Spectrum total scores than HCs. Moreover, EDs participants showed significantly higher scores on all AdAS Spectrum domains with the exception of Non verbal communication and Hyper-Hypo reactivity to sensory input for AN-BP participants, and Childhood/Adolescence domain for AN-BP and BED participants. Participants with AN-R scored significantly higher than participants with BEB on the AdAS Spectrum total score, and on the Inflexibility and adherence to routine and Restricted interest/rumination AdAS Spectrum domain scores. Significant correlations emerged between the Interpersonal distrust EDI-2 sub-scale and the Non verbal communication and the Restricted interest and rumination AdAS Spectrum domains; as well as between the Social insecurity EDI-2 sub-scale and the Inflexibility and adherence to routine and Restricted interest and rumination

  20. Subthreshold Psychosis in 22q11.2 Deletion Syndrome: Multisite Naturalistic Study.

    Science.gov (United States)

    Weisman, Omri; Guri, Yael; Gur, Raquel E; McDonald-McGinn, Donna M; Calkins, Monica E; Tang, Sunny X; Emanuel, Beverly; Zackai, Elaine H; Eliez, Stephan; Schneider, Maude; Schaer, Marie; Kates, Wendy R; Antshel, Kevin M; Fremont, Wanda; Shashi, Vandana; Hooper, Stephen R; Armando, Marco; Vicari, Stefano; Pontillo, Maria; Kushan, Leila; Jalbrzikowski, Maria; Bearden, Carrie E; Cubells, Joseph F; Ousley, Opal Y; Walker, Elaine F; Simon, Tony J; Stoddard, Joel; Niendam, Tara A; van den Bree, Marianne B M; Gothelf, Doron

    2017-09-01

    Nearly one-third of individuals with 22q11.2 deletion syndrome (22q11.2DS) develop a psychotic disorder during life, most of them by early adulthood. Importantly, a full-blown psychotic episode is usually preceded by subthreshold symptoms. In the current study, 760 participants (aged 6-55 years) with a confirmed hemizygous 22q11.2 microdeletion have been recruited through 10 medical sites worldwide, as part of an international research consortium. Of them, 692 were nonpsychotic and with complete measurement data. Subthreshold psychotic symptoms were assessed using the Structured Interview for Prodromal Syndromes (SIPS). Nearly one-third of participants met criteria for positive subthreshold psychotic symptoms (32.8%), less than 1% qualified for acute positive subthreshold symptoms, and almost a quarter met criteria for negative/disorganized subthreshold symptoms (21.7%). Adolescents and young adults (13-25 years) showed the highest rates of subthreshold psychotic symptoms. Additionally, higher rates of anxiety disorders and attention deficit/hyperactivity disorder (ADHD) were found among the study participants with subthreshold psychotic symptoms compared to those without. Full-scale IQ, verbal IQ, and global functioning (GAF) scores were negatively associated with participants' subthreshold psychotic symptoms. This study represents the most comprehensive analysis reported to date on subthreshold psychosis in 22q11.2DS. Novel findings include age-related changes in subthreshold psychotic symptoms and evidence that cognitive deficits are associated with subthreshold psychosis in this population. Future studies should longitudinally follow these symptoms to detect whether and how early identification and treatment of these manifestations can improve long-term outcomes in those that eventually develop a psychotic disorder. © The Author 2017. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For

  1. Olfactory-visual integration facilitates perception of subthreshold negative emotion.

    Science.gov (United States)

    Novak, Lucas R; Gitelman, Darren R; Schuyler, Brianna; Li, Wen

    2015-10-01

    A fast growing literature of multisensory emotion integration notwithstanding, the chemical senses, intimately associated with emotion, have been largely overlooked. Moreover, an ecologically highly relevant principle of "inverse effectiveness", rendering maximal integration efficacy with impoverished sensory input, remains to be assessed in emotion integration. Presenting minute, subthreshold negative (vs. neutral) cues in faces and odors, we demonstrated olfactory-visual emotion integration in improved emotion detection (especially among individuals with weaker perception of unimodal negative cues) and response enhancement in the amygdala. Moreover, while perceptual gain for visual negative emotion involved the posterior superior temporal sulcus/pSTS, perceptual gain for olfactory negative emotion engaged both the associative olfactory (orbitofrontal) cortex and amygdala. Dynamic causal modeling (DCM) analysis of fMRI timeseries further revealed connectivity strengthening among these areas during crossmodal emotion integration. That multisensory (but not low-level unisensory) areas exhibited both enhanced response and region-to-region coupling favors a top-down (vs. bottom-up) account for olfactory-visual emotion integration. Current findings thus confirm the involvement of multisensory convergence areas, while highlighting unique characteristics of olfaction-related integration. Furthermore, successful crossmodal binding of subthreshold aversive cues not only supports the principle of "inverse effectiveness" in emotion integration but also accentuates the automatic, unconscious quality of crossmodal emotion synthesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Two-dimensional model for subthreshold current and subthreshold swing of graded-channel dual-material double-gate (GCDMDG) MOSFETs

    Science.gov (United States)

    Goel, Ekta; Kumar, Sanjay; Singh, Balraj; Singh, Kunal; Jit, Satyabrata

    2017-06-01

    The subthreshold performance of graded-channel dual-material double-gate (GCDMDG) MOSFETs is examined through two-dimensional (2D) analytical modeling of subthreshold-current (SC) and subthreshold-swing (SS). The potential function obtained by using the parabolic approach to solve the 2D Poisson's equation, has been used to formulate SC and SS characteristics of the device. The variations of SS against different device parameters have been obtained with the help of effective conduction path parameter. The SC and SS characteristics of the GCDMDG MOS transistor have been compared with those of the dual-material double-gate (DMDG) and simple graded-channel double-gate (GCDG) MOS structures to show its better subthreshold characteristics over the latter two devices. The results of the developed model are well-agreed with the commercially available SILVACO ATLAS™ simulator data.

  3. The predictive value of childhood subthreshold manic symptoms for adolescent and adult psychiatric outcomes

    NARCIS (Netherlands)

    Papachristou, Efstathios; Oldehinkel, Albertine J.; Ormel, Johan; Raven, Dennis; Hartman, Catharina A.; Frangou, Sophia; Reichenberg, Abraham

    2017-01-01

    Background: Childhood subthreshold manic symptoms may represent a state of developmental vulnerability to Bipolar Disorder (BD) and may also be associated with other adverse psychiatric outcomes. To test this hypothesis we examined the structure and predictive value of childhood subthreshold manic

  4. Differential mortality rates in major and subthreshold depression: meta-analysis of studies that measured both

    NARCIS (Netherlands)

    Cuijpers, P.; Vogelzangs, N.; Twisk, J.; Kleiboer, A.M.; Li, J.; Penninx, B.W.J.H.

    2013-01-01

    Background: Although the association between depression and excess mortality has been well established, it is not clear whether this is greater in major depression than in subthreshold depression. Aims: To compare excess mortality in major depression with that in subthreshold depression. Method: We

  5. Adolescent Subthreshold-Depression and Anxiety: Psychopathology, Functional Impairment and Increased Suicide Risk

    Science.gov (United States)

    Balazs, Judit; Miklosi, Monika; Kereszteny, Agnes; Hoven, Christina W.; Carli, Vladimir; Wasserman, Camilla; Apter, Alan; Bobes, Julio; Brunner, Romuald; Cosman, Doina; Cotter, Padraig; Haring, Christian; Iosue, Miriam; Kaess, Michael; Kahn, Jean-Pierre; Keeley, Helen; Marusic, Dragan; Postuvan, Vita; Resch, Franz; Saiz, Pilar A.; Sisask, Merike; Snir, Avigal; Tubiana, Alexandra; Varnik, Airi; Sarchiapone, Marco; Wasserman, Danuta

    2013-01-01

    Background: Subthreshold-depression and anxiety have been associated with significant impairments in adults. This study investigates the characteristics of adolescent subthreshold-depression and anxiety with a focus on suicidality, using both categorical and dimensional diagnostic models. Methods: Data were drawn from the Saving and Empowering…

  6. Subthreshold anxiety better defined by symptom self-report than by diagnostic interview

    NARCIS (Netherlands)

    Karsten, J.; Nolen, W. A.; Penninx, B. W. J. H.; Hartman, C. A.

    Background: There is no consensus on how to define subthreshold anxiety. Based on functional impairment, we aim to evaluate the use of a diagnostic instrument and an anxiety severity questionnaire to derive an empirical cut-off for defining clinically relevant, subthreshold anxiety. Methods: Our

  7. Predictors of incident major depression in diabetic outpatients with subthreshold depression

    NARCIS (Netherlands)

    Bot, Mariska; Pouwer, Francois; Ormel, Johan; Slaets, Joris P. J.; de Jonge, Peter

    2010-01-01

    P>Aims The objective of the study was to determine rates and risks of major depression in diabetes outpatients with subthreshold depression. Methods This study is based on data of a stepped care-based intervention study in which diabetic patients with subthreshold depression were randomly allocated

  8. Analytical Model of Subthreshold Drain Current Characteristics of Ballistic Silicon Nanowire Transistors

    Directory of Open Access Journals (Sweden)

    Wanjie Xu

    2015-01-01

    Full Text Available A physically based subthreshold current model for silicon nanowire transistors working in the ballistic regime is developed. Based on the electric potential distribution obtained from a 2D Poisson equation and by performing some perturbation approximations for subband energy levels, an analytical model for the subthreshold drain current is obtained. The model is further used for predicting the subthreshold slopes and threshold voltages of the transistors. Our results agree well with TCAD simulation with different geometries and under different biasing conditions.

  9. Neutrino Oscillations

    Indian Academy of Sciences (India)

    Neutrino Oscillations: New Windows to the Particle World. General Article Volume 21 Issue 10 ... Neutrino oscillation is a quantum mechanicalphenomenon whereby a neutrino created witha specific lepton flavour (electron, muon, or tau) can later bemeasured to have a different flavour. Historical developmentof the field in ...

  10. Chemical Oscillations

    Indian Academy of Sciences (India)

    The law of mass-action led chemists to the belief that reactions approach equilibrium steadily. So the discovery of chemical oscillations came as a surprise. Now chemists are very familiar with reactions that oscillate in time and/or space. Experimental and theoretical studies of such reac- tions showing temporal and spatial ...

  11. Sub-threshold signal processing in arrays of non-identical nanostructures

    International Nuclear Information System (INIS)

    Cervera, Javier; Manzanares, Jose A; Mafe, Salvador

    2011-01-01

    . We demonstrate also that circuits composed of coupled non-identical nanoparticles can act as elementary nano-oscillators that show synchronization properties for sub-threshold stimuli. The results obtained should be of conceptual interest for the design of reliable signal processing schemes with non-identical nanostructures.

  12. Adaptive Supply Voltage Management for Low Power Logic Circuitry Operating at Subthreshold

    OpenAIRE

    Rehan Ahmed

    2015-01-01

    With the rise in demand of portable hand held devices and with the rise in application of wireless sensor networks and RFID reduction of total power consumption has become a necessity. To save power we operate the logic circuitry of our devices at sub-threshold. In sub-threshold the drain current is exponentially dependent on the threshold voltage hence the threshold variation causes profound variation of ION and IOFF the ratio of which affect the speed of a circuit drastically. S...

  13. Examining various subthreshold definitions of PTSD using the Clinician Administered PTSD Scale for DSM-5.

    Science.gov (United States)

    Franklin, C Laurel; Raines, Amanda M; Chambliss, Jessica L; Walton, Jessica L; Maieritsch, Kelly P

    2018-07-01

    The Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5; American Psychiatric Association [APA], 2013) includes Other- and Unspecified- Trauma and Stressor-Related Disorders to capture subthreshold Posttraumatic Stress Disorder (PTSD) symptoms. However, the DSM-5 does not specify the number or type of symptoms needed to assign them. The purpose of the current study was to extend our understanding of subthreshold PTSD by comparing four commonly used definitions adapted to the DSM-5 PTSD criteria in an outpatient treatment-seeking sample. Veterans (N = 193) presenting to PTSD clinics were assessed using the Clinician Administered PTSD Scale for DSM-5 (CAPS-5). Participants reported a criterion A traumatic event, but did not meet criteria for threshold-PTSD. We hypothesized that the number of veterans captured would be highest when fewer specific criterion sets were required by the subthreshold definition. Our hypothesis was upheld in that the more criteria required by the subthreshold PTSD definition, the lower the number of veterans counted within the group. The study consisted primarily of trauma treatment-seeking male veterans, with chronic PTSD symptoms. In addition, the sample size was small and was collected as part of routine clinical care. These results support previous contentions around careful decision making when defining what constitutes subthreshold PTSD in research and clinical work. It also points to the need for continued research to better understand the diagnostic and treatment implications of subthreshold PTSD. Published by Elsevier B.V.

  14. Panic disorder and subthreshold panic in the light of comorbidity: a follow-up study.

    Science.gov (United States)

    Oral, Elif; Aydin, Nazan; Gulec, Mustafa; Oral, Meltem

    2012-10-01

    Especially in the presence of agoraphobia and comorbid conditions, panic disorder causes significant impairment in life quality. Although there are several studies about epidemiology and clinical features, subthreshold symptoms and courses of comorbidity have not been studied sufficiently in panic disorder. The current study assessed the courses of panic disorder and subthreshold panic symptoms in consideration of the major and subthreshold comorbid conditions. Patients with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-diagnosed panic disorder were assessed using the panic disorder follow-up questionnaire, Panic and Agoraphobia Scale, Hamilton Depression Rating Scale, and State-Trait Anxiety Inventory. Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders was used to determine comorbidity, and all participants were received to 1-year follow-up. Comorbidity assessment showed that the threshold comorbidity decreased, while the subthreshold comorbidity increased at 1-year follow-up. Panic disorder symptom severity was decreased, but subthreshold panic symptoms continued to be present within the course of the illness. Presence of agoraphobia and duration of disease were significantly related with higher Panic and Agoraphobia Scale scores in the second assessment, and these relationships were independent from the treatment process. Even if the comorbidity and the severity of panic decrease with treatment, subthreshold panic and comorbid symptoms may still resist in panic disorder. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. An Ultra-Low Energy Subthreshold SRAM Bitcell for Energy Constrained Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Arijit Banerjee

    2014-05-01

    Full Text Available Energy consumption is a key issue in portable biomedical devices that require uninterrupted biomedical data processing. As the battery life is critical for the user, these devices impose stringent energy constraints on SRAMs and other system on chip (SoC components. Prior work shows that operating CMOS circuits at subthreshold supply voltages minimizes energy per operation. However, at subthreshold voltages, SRAM bitcells are sensitive to device variations, and conventional 6T SRAM bitcell is highly vulnerable to readability related errors in subthreshold operation due to lower read static noise margin (RSNM and half-select issue problems. There are many robust subthreshold bitcells proposed in the literature that have some improvements in RSNM, write static noise margin (WSNM, leakage current, dynamic energy, and other metrics. In this paper, we compare our proposed bitcell with the state of the art subthreshold bitcells across various SRAM design knobs and show their trade-offs in a column mux scenario from the energy and delay metrics and the energy per operation metric standpoint. Our 9T half-select-free subthreshold bitcell has 2.05× lower mean read energy, 1.12× lower mean write energy, and 1.28× lower mean leakage current than conventional 8T bitcells at the TT_0.4V_27C corner. Our bitcell also supports the bitline interleaving technique that can cope with soft errors.

  16. A Technique for Designing Variation Resilient Subthreshold Sram Cell

    Directory of Open Access Journals (Sweden)

    Aminul Islam

    2013-04-01

    Full Text Available This paper presents a technique for designing a variability aware subthreshold SRAM cell. The architecture of the proposed cell is similar to the standard read-decoupled 8-transistor (RD8T SRAM cell with the exception that the access FETS are replaced with transmission gates (TGs. In this work, various design metrics are assessed and compared with RD8T SRAM cell. The proposed design offers 2.14× and 1.75× improvement in TRA (read access time and TWA (write access time respectively compared with RD8T. It proves its robustness against process variations by featuring narrower spread in TRA distribution (2.35× and TWA distribution (3.79× compared with RD8T. The proposed bitcell offers 1.16× higher read current (IREAD and 1.64× lower bitline leakage current (ILEAK respectively compared with RD8T. It also shows its robustness by offering 1.34× (1.58× tighter spread in IREAD (ILEAK compared with RD8T. It exhibits 1.42× larger IREAD to ILEAK ratio. It shows 2.2× higher frequency @ 250 mV with read bitline capacitance of 10 fF. Besides, the proposed bitcell achieves same read stability and write-ability as that of RD8T at the cost of 3 extra transistors. The leakage power of the proposed design is close to that of RD8T.   ABSTRAK: Kertas kerja ini membentangkan teknik merekabentuk sel bawah ambang SRAM yang bolehubah. Senibina sel yang dicadangkan adalah sama dengan sel SRAM 8-transistor (RD8T “pisahan-bacaan” piawai kecuali FET akses  digantikan dengan sel pintu transmisi (TGs. Di dalam kajian ini, beberapa metrik rekabentuk dinilai dan dibandingkan dengan sel RD8T SRAM. Rekabentuk yang dicadangkan menawarkan  peningkatan 2.14× dan 1.75×  dalam TRA (masa akses baca dan TWA (masa akses tulis berbanding dengan RD8T. Ia membuktikan kekukuhan variasi proses dengan menampilkan tebaran yang lebih sempit dalam pengagihan TRA (2.35 × dan pengagihan TWA (3.79 × berbanding dengan RD8T. Sel-Bit yang dicadangkan mempunyai arus baca 1.16

  17. Nonlinear oscillations

    CERN Document Server

    Nayfeh, Ali Hasan

    1995-01-01

    Nonlinear Oscillations is a self-contained and thorough treatment of the vigorous research that has occurred in nonlinear mechanics since 1970. The book begins with fundamental concepts and techniques of analysis and progresses through recent developments and provides an overview that abstracts and introduces main nonlinear phenomena. It treats systems having a single degree of freedom, introducing basic concepts and analytical methods, and extends concepts and methods to systems having degrees of freedom. Most of this material cannot be found in any other text. Nonlinear Oscillations uses sim

  18. Hardened Flip-Flop Optimized for Subthreshold Operation Heavy Ion Characterization of a Radiation

    Directory of Open Access Journals (Sweden)

    Eric Bozeman

    2012-05-01

    Full Text Available A novel Single Event Upset (SEU tolerant flip-flop design is proposed, which is well suited for very-low power electronics that operate in subthreshold ( < Vt ≈ 500 mV. The proposed flip-flop along with a traditional (unprotected flip-flop, a Sense-Amplifier-based Rad-hard Flip-Flop (RSAFF and a Dual Interlocked storage Cell (DICE flip-flop were all fabricated in MIT Lincoln Lab’s XLP 0.15 μm fully-depleted SOI CMOS technology—a process optimized for subthreshold operation. At the Cyclotron Institute at Texas A&M University, all four cells were subjected to heavy ion characterization in which the circuits were dynamically updated with alternating data and then checked for SEUs at both subthreshold (450 mV and superthreshold (1.5 V levels. The proposed flip-flop never failed, while the traditional and DICE designs did demonstrate faulty behavior. Simulations were conducted with the XLP process and the proposed flip-flop provided an improved energy delay product relative to the other non-faulty rad-hard flip-flop at subthreshold voltage operation. According to the XLP models operating in subthreshold at 250 mV, performance was improved by 31% and energy consumption was reduced by 27%.

  19. Subthreshold depressive disorder in adolescents: predictors of escalation to full-syndrome depressive disorders.

    Science.gov (United States)

    Klein, Daniel N; Shankman, Stewart A; Lewinsohn, Peter M; Seeley, John R

    2009-07-01

    Subthreshold depressive disorder is one of the best established risk factors for the onset of full-syndrome depressive disorders. However, many youths with subthreshold depressive disorder do not develop full-syndrome depression. We examined predictors of escalation to full-syndrome depressive disorders in a community sample of 225 adolescents with subthreshold depressive disorder. Criteria for subthreshold depressive disorder were an episode of depressed mood or loss of interest or pleasure lasting at least 1 week and at least two of the seven other DSM-IV-associated symptoms for major depression. Participants were assessed four times from mid-adolescence to age 30 years using semistructured diagnostic interviews. The estimated risk for escalation to full-syndrome depressive disorders was 67%. Five variables accounted for unique variance in predicting escalation: severity of depressive symptoms, medical conditions/symptoms, history of suicidal ideation, history of anxiety disorder, and familial loading for depression. Adolescents with three or more risk factors had an estimated 90% chance of escalating to full-syndrome depressive disorder, compared with 47% of adolescents with fewer than three risk factors. These data may be useful in identifying a subgroup of youths with subthreshold depressive disorder who are at especially high risk for escalating to full-syndrome depressive disorders.

  20. Chemical Oscillations

    Indian Academy of Sciences (India)

    behaviour of a few complex chemical systems. We observed that these chemical oscillators are basically .... Kutta fourth order integration method to solve the Lotka-. Volterra equation as per the Fortran program given in ... This is known as the phase plane represen- tation. We have obtained these plots using the software.

  1. Chemical Oscillations

    Indian Academy of Sciences (India)

    relevant species is zero. So, oscillations can appear only if the inhibition step is somehow .... the value of such an experimental parameter can possi- bly move the system between the steady states. Per- ... states for different values of [X], obtained far from equilibrium. Figure 2. System showing. The concentrations [X] ...

  2. Entrainment of two coupled van der Pol oscillators by an external oscillation. As a base of "holonic control".

    Science.gov (United States)

    Ohsuga, M; Yamaguchi, Y; Shimizu, H

    1985-01-01

    A system composed of two coupled internal oscillators and an external oscillation is studied as a model of biological control systems. The type of interaction between the internal oscillators is a mutual and dissipative one. Three macroscopic states of the internal oscillators are demonstrated in the absence of the external oscillation. Strict and loose entrainment regions of the internal oscillators by the external oscillation are shown in respect to the intensity of the mutual interaction, the intrinsic frequency difference of the internal oscillations, and the magnitude and frequency of the external oscillation. On the other hand, an idea of "holonic system" is introduced and the fundamental properties of the model as a holonic system are elucidated.

  3. Estimation of Synaptic Conductances in Presence of Nonlinear Effects Caused by Subthreshold Ionic Currents

    DEFF Research Database (Denmark)

    Vich, Catalina; Berg, Rune W.; Guillamon, Antoni

    2017-01-01

    Subthreshold fluctuations in neuronal membrane potential traces contain nonlinear components, and employing nonlinear models might improve the statistical inference. We propose a new strategy to estimate synaptic conductances, which has been tested using in silico data and applied to in vivo...... recordings. The model is constructed to capture the nonlinearities caused by subthreshold activated currents, and the estimation procedure can discern between excitatory and inhibitory conductances using only one membrane potential trace. More precisely, we perform second order approximations of biophysical...... models to capture the subthreshold nonlinearities, resulting in quadratic integrate-and-fire models, and apply approximate maximum likelihood estimation where we only suppose that conductances are stationary in a 50–100 ms time window. The results show an improvement compared to existent procedures...

  4. Subthreshold posttraumatic stress disorder in the world health organization world mental health surveys.

    Science.gov (United States)

    McLaughlin, Katie A; Koenen, Karestan C; Friedman, Matthew J; Ruscio, Ayelet Meron; Karam, Elie G; Shahly, Victoria; Stein, Dan J; Hill, Eric D; Petukhova, Maria; Alonso, Jordi; Andrade, Laura Helena; Angermeyer, Matthias C; Borges, Guilherme; de Girolamo, Giovanni; de Graaf, Ron; Demyttenaere, Koen; Florescu, Silvia E; Mladenova, Maya; Posada-Villa, Jose; Scott, Kate M; Takeshima, Tadashi; Kessler, Ronald C

    2015-02-15

    Although only a few people exposed to a traumatic event (TE) develop posttraumatic stress disorder (PTSD), symptoms that do not meet full PTSD criteria are common and often clinically significant. Individuals with these symptoms sometimes have been characterized as having subthreshold PTSD, but no consensus exists on the optimal definition of this term. Data from a large cross-national epidemiologic survey are used in this study to provide a principled basis for such a definition. The World Health Organization World Mental Health Surveys administered fully structured psychiatric diagnostic interviews to community samples in 13 countries containing assessments of PTSD associated with randomly selected TEs. Focusing on the 23,936 respondents reporting lifetime TE exposure, associations of approximated DSM-5 PTSD symptom profiles with six outcomes (distress-impairment, suicidality, comorbid fear-distress disorders, PTSD symptom duration) were examined to investigate implications of different subthreshold definitions. Although consistently highest outcomes for distress-impairment, suicidality, comorbidity, and PTSD symptom duration were observed among the 3.0% of respondents with DSM-5 PTSD rather than other symptom profiles, the additional 3.6% of respondents meeting two or three of DSM-5 criteria B-E also had significantly elevated scores for most outcomes. The proportion of cases with threshold versus subthreshold PTSD varied depending on TE type, with threshold PTSD more common following interpersonal violence and subthreshold PTSD more common following events happening to loved ones. Subthreshold DSM-5 PTSD is most usefully defined as meeting two or three of DSM-5 criteria B-E. Use of a consistent definition is critical to advance understanding of the prevalence, predictors, and clinical significance of subthreshold PTSD. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  5. Sub-threshold Post Traumatic Stress Disorder in the WHO World Mental Health Surveys

    Science.gov (United States)

    McLaughlin, Katie A.; Koenen, Karestan C.; Friedman, Matthew J.; Ruscio, Ayelet Meron; Karam, Elie G.; Shahly, Victoria; Stein, Dan J.; Hill, Eric D.; Petukhova, Maria; Alonso, Jordi; Andrade, Laura Helena; Angermeyer, Matthias C.; Borges, Guilherme; de Girolamo, Giovanni; de Graaf, Ron; Demyttenaere, Koen; Florescu, Silvia E.; Mladenova, Maya; Posada-Villa, Jose; Scott, Kate M.; Takeshima, Tadashi; Kessler, Ronald C.

    2014-01-01

    Background Although only a minority of people exposed to a traumatic event (TE) develops PTSD, symptoms not meeting full PTSD criteria are common and often clinically significant. Individuals with these symptoms have sometimes been characterized as having sub-threshold PTSD, but no consensus exists on the optimal definition of this term. Data from a large cross-national epidemiological survey are used to provide a principled basis for such a definition. Methods The WHO World Mental Health (WMH) Surveys administered fully-structured psychiatric diagnostic interviews to community samples in 13 countries containing assessments of PTSD associated with randomly selected TEs. Focusing on the 23,936 respondents reporting lifetime TE exposure, associations of approximated DSM-5 PTSD symptom profiles with six outcomes (distress-impairment, suicidality, comorbid fear-distress disorders, PTSD symptom duration) were examined to investigate implications of different sub-threshold definitions. Results Although consistently highest distress-impairment, suicidality, comorbidity, and symptom duration were observed among the 3.0% of respondents with DSM-5 PTSD than other symptom profiles, the additional 3.6% of respondents meeting two or three of DSM-5 Criteria BE also had significantly elevated scores for most outcomes. The proportion of cases with threshold versus sub-threshold PTSD varied depending on TE type, with threshold PTSD more common following interpersonal violence and sub-threshold PTSD more common following events happening to loved ones. Conclusions Sub-threshold DSM-5 PTSD is most usefully defined as meeting two or three of the DSM-5 Criteria B-E. Use of a consistent definition is critical to advance understanding of the prevalence, predictors, and clinical significance of sub-threshold PTSD. PMID:24842116

  6. Tunnel field-effect transistor with two gated intrinsic regions

    Directory of Open Access Journals (Sweden)

    Y. Zhang

    2014-07-01

    Full Text Available In this paper, we propose and validate (using simulations a novel design of silicon tunnel field-effect transistor (TFET, based on a reverse-biased p+-p-n-n+ structure. 2D device simulation results show that our devices have significant improvements of switching performance compared with more conventional devices based on p-i-n structure. With independent gate voltages applied to two gated intrinsic regions, band-to-band tunneling (BTBT could take place at the p-n junction, and no abrupt degenerate doping profile is required. We developed single-side-gate (SSG structure and double-side-gate (DSG structure. SSG devices with HfO2 gate dielectric have a point subthreshold swing of 9.58 mV/decade, while DSG devices with polysilicon gate electrode material and HfO2 gate dielectric have a point subthreshold swing of 16.39 mV/decade. These DSG devices have ON-current of 0.255 μA/μm, while that is lower for SSG devices. Having two nano-scale independent gates will be quite challenging to realize with good uniformity across the wafer and the improved behavior of our TFET makes it a promising steep-slope switch candidate for further investigations.

  7. The Effects of Subthreshold Visual Cues on Flight Performance in the NUH-60FS Black Hawk Research Simulator

    Science.gov (United States)

    2011-08-01

    influenced your opinion of subthreshold priming/ subliminal messaging ...0%) Table 9. Has participating in this experiment influenced your opinion of subthreshold priming/ subliminal messaging ? Yes No Other...priming/ subliminal messaging ? Positive Negative Other Frequency (%) 14 (46.7%) 8 (26.7%) 8 (26.7%)5 Table 11. In your opinion, do you

  8. Reading Disability Spectrum: Early and Late Recognition, Subthreshold, and Full Comorbidity

    Science.gov (United States)

    Töro, Krisztina Tárnokiné; Miklósi, Mónika; Horanyi, Eszter; Kovács, Gábor Pers; Balázs, Judit

    2018-01-01

    Several studies have reported high comorbidity for reading disability (RD) and psychiatric disorders. The aim of this study was to investigate the comorbidity of subthreshold and full psychiatric disorders with RD while comparing subgroups based on age of RD recognition (early vs. late). We analyzed data from 130 children with RD and 82 typically…

  9. Usage and reported helpfulness of self-help strategies by adults with sub-threshold depression.

    Science.gov (United States)

    Morgan, Amy J; Jorm, Anthony F; Mackinnon, Andrew J

    2012-02-01

    Informal self-help has the potential to reduce the population burden from sub-threshold forms of depression. Evaluating the effectiveness of self-help is difficult in controlled trials, but can be assessed with direct ratings by consumers. Depression experts have previously rated the likely effectiveness of self-help for sub-threshold depression but it is unclear whether the strategies are helpful in practice. We report ratings of the effectiveness of self-help as used by adults with sub-threshold depression. 1326 adults with sub-threshold depression were recruited over the internet and completed questionnaires about their use of 26 self-help strategies for depression symptoms. Strategies that had been used were then assessed for their perceived helpfulness. Reported strategy helpfulness tended to be consistent with expert ratings of likely helpfulness. Exercise or physical activity was rated as most helpful while spending time alone was rated as least helpful. There was little association at the sample level between how helpful a strategy was rated and how frequently it was used. This suggests that the use of self-help is not optimal at the population level. Limitations The sample was self-selected and frequency of use of self-help was self-rated. There is room for improvement in the use of self-help through increasing the usage of strategies that are likely to be helpful and reducing the use of strategies that are unhelpful. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Power oscillation damping controller

    DEFF Research Database (Denmark)

    2012-01-01

    A power oscillation damping controller is provided for a power generation device such as a wind turbine device. The power oscillation damping controller receives an oscillation indicating signal indicative of a power oscillation in an electricity network and provides an oscillation damping control...... signal in response to the oscillation indicating signal, by processing the oscillation damping control signal in a signal processing chain. The signal processing chain includes a filter configured for passing only signals within a predetermined frequency range....

  11. Opposing Effects of Intrinsic Conductance and Correlated Synaptic Input on V-Fluctuations during Network Activity

    DEFF Research Database (Denmark)

    Kolind, Jens; Hounsgaard, Jørn Dybkjær; Berg, Rune W

    2012-01-01

    Neurons often receive massive concurrent bombardment of synaptic inhibition and excitation during functional network activity. This increases membrane conductance and causes fluctuations in membrane potential (V(m)) and spike timing. The conductance increase is commonly attributed to synaptic...... conductance, but also includes the intrinsic conductances recruited during network activity. These two sources of conductance have contrasting dynamic properties at sub-threshold membrane potentials. Synaptic transmitter gated conductance changes abruptly and briefly with each presynaptic action potential...... input we find that the magnitude of the membrane fluctuations uniquely determines the relative contribution of synaptic and intrinsic conductance. We also quantify how V(m)-fluctuations vary with synaptic correlations for fixed ratios of synaptic and intrinsic conductance. Interestingly, the levels of V...

  12. Subthreshold membrane currents confer distinct tuning properties that enable neurons to encode the integral or derivative of their input

    Directory of Open Access Journals (Sweden)

    Stephanie eRatté

    2015-01-01

    Full Text Available Neurons rely on action potentials, or spikes, to encode information. But spikes can encode different stimulus features in different neurons. We show here through simulations and experiments how neurons encode the integral or derivative of their input based on the distinct tuning properties conferred upon them by subthreshold currents. Slow-activating subthreshold inward (depolarizing current mediates positive feedback control of subthreshold voltage, sustaining depolarization and allowing the neuron to spike on the basis of its integrated stimulus waveform. Slow-activating subthreshold outward (hyperpolarizing current mediates negative feedback control of subthreshold voltage, truncating depolarization and forcing the neuron to spike on the basis of its differentiated stimulus waveform. Depending on its direction, slow-activating subthreshold current cooperates or competes with fast-activating inward current during spike initiation. This explanation predicts that sensitivity to the rate of change of stimulus intensity differs qualitatively between integrators and differentiators. This was confirmed experimentally in spinal sensory neurons that naturally behave as specialized integrators or differentiators. Predicted sensitivity to different stimulus features was confirmed by covariance analysis. Integration and differentiation, which are themselves inverse operations, are thus shown to be implemented by the slow feedback mediated by oppositely directed subthreshold currents expressed in different neurons.

  13. Full syndrome and subthreshold attention-deficit/hyperactivity disorder in a Korean community sample: comorbidity and temperament findings.

    Science.gov (United States)

    Cho, Soo-Churl; Kim, Boong-Nyun; Kim, Jae-Won; Rohde, Luis Augusto; Hwang, Jun-Won; Chungh, Dong-Seon; Shin, Min-Sup; Lyoo, In Kyoon; Go, Bock-Ja; Lee, Sang-Eun; Kim, Hyo-Won

    2009-07-01

    The main objective of this study was to investigate the comorbid disorders and temperamental profiles of full syndrome and subthreshold attention-deficit/hyperactivity disorder (ADHD). A sample of 2,493 students was randomly selected from six representative elementary schools in Seoul, Korea. Among 245 children with full syndrome and subthreshold ADHD diagnosed by the diagnostic interview schedule for children-4th version, parents of 185 subjects (mean age 9.0 +/- 1.7 years) and of a random sample of 185 age- and gender-matched non-ADHD children have completed the parent's version of the children behavior checklist (CBCL) and the juvenile temperament and character inventory (JTCI). The prevalence rates of full syndrome and subthreshold ADHD were, respectively, 5.90% (95% confidence interval = 4.74-7.06) and 9.00% (95% confidence interval = 7.58-10.41). Subthreshold ADHD cases did not differ from full syndrome ADHD in any JTCI profile, showing high novelty seeking/low persistence/low self-directedness than controls. Subthreshold ADHD also showed increased risk for externalizing disorders and higher scores in eight CBCL scales (somatic complaints, anxious/depressed, social problems, attention problems, delinquent behaviors, aggressive behaviors, externalizing problems and total behavioral problems) compared to the controls. These results support the clinical relevance of subthreshold ADHD in Asian culture. Increased clinical awareness for children with subthreshold ADHD is needed.

  14. P3-9: Roles of Subthreshold LFP Induced by Receptive Field Surround for Response Modulation in Monkey V1

    Directory of Open Access Journals (Sweden)

    Kayeon Kim

    2012-10-01

    Full Text Available A focal stimulus outside the receptive field robustly induces LFP change, while the same stimulus evokes no spike activity. We determined how this subthreshold LFP change interacted with spike response to the RF stimulus. Specifically, we sequentially presented two identical Gabor stimuli with a variable stimulus onset asynchrony (SOA; the first one (S1 was presented outside RF inducing a subthreshold LFP change, and the second one (S2 was subsequently presented within RF generating a spiking response. This enabled us to manipulate the temporal relation between subthreshold LFP and evoked spike activity and to determine whether subthreshold LFP contributed to modulation of spike activity in a SOA-dependent manner. We found that the subthreshold LFP propagated a considerably long distance, estimated to be more than 10 mm of cortical distance. The cross-correlation between the time course of subthreshold LFP and the pattern of SOA-dependency of spike activity was significant. These results indicate that signal integration is farther beyond the RF than previously estimated based on spike-triggered average, and suggest that subthreshold LFP modulate spike activity in a SOA-dependent manner.

  15. Stochastic synchronization of neuronal populations with intrinsic and extrinsic noise.

    KAUST Repository

    Bressloff, Paul C

    2011-05-03

    We extend the theory of noise-induced phase synchronization to the case of a neural master equation describing the stochastic dynamics of an ensemble of uncoupled neuronal population oscillators with intrinsic and extrinsic noise. The master equation formulation of stochastic neurodynamics represents the state of each population by the number of currently active neurons, and the state transitions are chosen so that deterministic Wilson-Cowan rate equations are recovered in the mean-field limit. We apply phase reduction and averaging methods to a corresponding Langevin approximation of the master equation in order to determine how intrinsic noise disrupts synchronization of the population oscillators driven by a common extrinsic noise source. We illustrate our analysis by considering one of the simplest networks known to generate limit cycle oscillations at the population level, namely, a pair of mutually coupled excitatory (E) and inhibitory (I) subpopulations. We show how the combination of intrinsic independent noise and extrinsic common noise can lead to clustering of the population oscillators due to the multiplicative nature of both noise sources under the Langevin approximation. Finally, we show how a similar analysis can be carried out for another simple population model that exhibits limit cycle oscillations in the deterministic limit, namely, a recurrent excitatory network with synaptic depression; inclusion of synaptic depression into the neural master equation now generates a stochastic hybrid system.

  16. Oscillations of void lattices

    International Nuclear Information System (INIS)

    Akhiezer, A.I.; Davydov, L.N.; Spol'nik, Z.A.

    1976-01-01

    Oscillations of a nonideal crystal are studied, in which macroscopic defects (pores) form a hyperlattice. It is shown that alongside with acoustic and optical phonons (relative to the hyperlattice), in such a crystal oscillations of the third type are possible which are a hydridization of sound oscillations of atoms and surface oscillations of a pore. Oscillation spectra of all three types were obtained

  17. A three-dimensional (3D) analytical model for subthreshold characteristics of uniformly doped FinFET

    Science.gov (United States)

    Tripathi, Shweta; Narendar, Vadthiya

    2015-07-01

    In this paper, three dimensional (3D) analytical model for subthreshold characteristics of doped FinFET has been presented. The separation of variables technique is used to solve the 3D Poisson's equation analytically with appropriate boundary conditions so as to obtain the expression for channel potential. The thus obtained potential distribution function has been employed in deriving subthreshold current and subthreshold slope model. The channel potential characteristics have been studied as a function of various device parameters such as gate length, gate oxide thickness and channel doping. The proposed analytical model results have been validated by comparing with the simulation data obtained by the 3D device simulator ATLAS™ from Silvaco.

  18. Thermoelastic loss in microscale oscillators

    Science.gov (United States)

    Houston, B. H.; Photiadis, D. M.; Marcus, M. H.; Bucaro, J. A.; Liu, Xiao; Vignola, J. F.

    2002-02-01

    A simple model of thermoelastic dissipation is proposed for general, free standing microelectromechanical (MEMS) and nanoelectromechanical (NEMS) oscillators. The theory defines a flexural modal participation factor, the fraction of potential energy stored in flexure, and approximates the internal friction by assuming the energy loss to occur solely via classical thermoelastic dissipation of this component of the motion. The theory is compared to the measured internal friction of a high Q mode of a single-crystal silicon double paddle oscillator. The loss at high temperature (above 150 K) is found to be in good agreement with the theoretical prediction. The importance of this dissipation mechanism as a function of scale is briefly discussed. We find that the relative importance of this mechanism scales with the size of the structure, and that for nanoscale structures it is less important than intrinsic phonon-phonon scattering.

  19. Intrinsic contractures of the hand.

    Science.gov (United States)

    Paksima, Nader; Besh, Basil R

    2012-02-01

    Contractures of the intrinsic muscles of the fingers disrupt the delicate and complex balance of intrinsic and extrinsic muscles, which allows the hand to be so versatile and functional. The loss of muscle function primarily affects the interphalangeal joints but also may affect etacarpophalangeal joints. The resulting clinical picture is often termed, intrinsic contracture or intrinsic-plus hand. Disruption of the balance between intrinsic and extrinsic muscles has many causes and may be secondary to changes within the intrinsic musculature or the tendon unit. This article reviews diagnosis, etiology, and treatment algorithms in the management of intrinsic contractures of the fingers. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Temporal structure of neuronal population oscillations with empirical model decomposition

    International Nuclear Information System (INIS)

    Li Xiaoli

    2006-01-01

    Frequency analysis of neuronal oscillation is very important for understanding the neural information processing and mechanism of disorder in the brain. This Letter addresses a new method to analyze the neuronal population oscillations with empirical mode decomposition (EMD). Following EMD of neuronal oscillation, a series of intrinsic mode functions (IMFs) are obtained, then Hilbert transform of IMFs can be used to extract the instantaneous time frequency structure of neuronal oscillation. The method is applied to analyze the neuronal oscillation in the hippocampus of epileptic rats in vivo, the results show the neuronal oscillations have different descriptions during the pre-ictal, seizure onset and ictal periods of the epileptic EEG at the different frequency band. This new method is very helpful to provide a view for the temporal structure of neural oscillation

  1. Oscillators - a simple introduction

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2013-01-01

    Oscillators are kernel components of electrical and electronic circuits. Discussion of history, mechanisms and design based on Barkhausens observation. Discussion of a Wien Bridge oscillator based on the question: Why does this circuit oscillate ?......Oscillators are kernel components of electrical and electronic circuits. Discussion of history, mechanisms and design based on Barkhausens observation. Discussion of a Wien Bridge oscillator based on the question: Why does this circuit oscillate ?...

  2. Predicting Intrinsic Motivation

    Science.gov (United States)

    Martens, Rob; Kirschner, Paul A.

    2004-01-01

    Intrinsic motivation can be predicted from participants' perceptions of the social environment and the task environment (Ryan & Deci, 2000)in terms of control, relatedness and competence. To determine the degree of independence of these factors 251 students in higher vocational education (physiotherapy and hotel management) indicated the…

  3. Oscillating Permanent Magnets.

    Science.gov (United States)

    Michaelis, M. M.; Haines, C. M.

    1989-01-01

    Describes several ways to partially levitate permanent magnets. Computes field line geometries and oscillation frequencies. Provides several diagrams illustrating the mechanism of the oscillation. (YP)

  4. Use of the subthreshold behavior to compare X-ray and Co-60 radiation-induced defects in MOS transistors

    Science.gov (United States)

    Dozier, C. M.; Brown, D. B.; Freitag, R. K.; Throckmorton, J. L.

    1986-12-01

    Transistor behavior in the subthreshold region is used to compare the production of oxide trapped charge and interface states produced by X-ray and Co-60 radiation. For the oxides used in this study, the subthreshold data indicates the presence of two types of interface states. One of these interface states appears to differ from the more commonly observed amphoteric defect. The characteristics of these states suggest that they are donor defects. These states further complicate testing protocols because they anneal at room temperature. A modification to the subthreshold measurement technique of McWhorter and Winokur is proposed for oxides in which these donor states occur. Using this revised subthreshold technique, less interface dose enhancement occurs during X-ray exposures than was observed previously with thick-oxide-capacitor measurements.

  5. Predictors of incident major depression in diabetic outpatients with subthreshold depression

    DEFF Research Database (Denmark)

    Bot, Mariska; Pouwer, Francois; Ormel, Johan

    2010-01-01

    patients were available at 2-year follow-up. The 2-year incidence of major depression was 42% (n=31). Higher baseline anxiety levels [odds ratio (OR)=1.25; 95% confidence interval (CI), 1.04-1.50; P=0.018] and depression severity levels (OR=1.09; 95% CI, 1.00-1.18; P=0.045) were predictors of incident...... major depression. Stepped care allocation was not related to incident major depression. In multivariable models, similar results were found. CONCLUSIONS: Having a higher baseline level of anxiety and depression appeared to be related to incident major depression during 2-year follow-up in diabetic...... patients with subthreshold depression. A stepped care intervention aimed at depression alone did not prevent the onset of depression in these patients. Besides level of depression, anxiety might be taken into account in the prevention of major depression in diabetic patients with subthreshold depression....

  6. Static Standing Trunk Sway Assessment in Amputees – Effects of Sub-Threshold Stimulation

    Directory of Open Access Journals (Sweden)

    L. Ming-Yih

    2007-01-01

    Full Text Available Sub-threshold electrical stimulation can enhance the sensitivity of the human somatosensory system to improve the balance control capability of elderly was shown in recent rehabilitation articles. The purpose of this study was to evaluate the postural sway of trans-tibial amputees when performing single leg quiet standing on firm surface. Four unilateral trans-tibial amputees who consecutively wore prosthetics over 2 years were recruited in this study. Subjects performed single leg quiet standing trails with sub-threshold electrical stimulation applied at the quadriceps muscle during the trails. Spatial co-ordinates for the determination kinematic data (sway distance of the center of mass (COM on second sacral (S2 were collected using an ultrasound-based Zebris CMS-HS system. The single leg quiet standing test is measure considered to assess postural steadiness in a static position by a spatial measurement. The common notion is that a better postural steadiness, i.e. less postural sway, allows for longer time single leg quiet standing. However, there is lack of evidence how postural steadiness during single leg quiet standing changes over time. In this article, we hypothesized that the static balance of single leg quiet standing could be improved for providing proprioceptive neuromuscular facilitation using sub-sensory stimulation in amputees. To test this hypothesis, a computerized sub-threshold low-level electrical stimulation device was developed and proposed for clinical study. Experimental results show that reduction in all of the postural sway indices (constant time sway length, max sway distance and average sway distance and increase in single leg support time index during single leg quiet standing by applying sub-sensory stimulation. The single leg quiet standing test findings suggest that sub-threshold electrical stimulation rehabilitation strategies may be effective in improving static balance performance for amputees.

  7. "Subthreshold" depression: is the distinction between depressive disorder not otherwise specified and adjustment disorder valid?

    Science.gov (United States)

    Zimmerman, Mark; Martinez, Jennifer H; Dalrymple, Kristy; Chelminski, Iwona; Young, Diane

    2013-05-01

    Patients with clinically significant symptoms of depression who do not meet the criteria for major depressive disorder or dysthymic disorder are considered to have subthreshold depression. According to DSM-IV, such patients should be diagnosed with depressive disorder not otherwise specified (NOS) if the development of the symptoms is not attributable to a stressful event or with adjustment disorder if the symptoms follow a stressor. Research on the treatment of subthreshold depression rarely addresses the distinction between depressive disorder NOS and adjustment disorder. In the present report from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project, we examined the validity of this distinction. From December 1995 to June 2011, 3,400 psychiatric patients presenting to the Rhode Island Hospital outpatient practice were evaluated with semistructured diagnostic interviews for DSM-IV Axis I and Axis II disorders and measures of psychosocial morbidity. Slightly less than 10% (n = 300) of the 3,400 patients were diagnosed with depressive disorder NOS or adjustment disorder with depressed mood. The patients with depressive disorder NOS were significantly more often diagnosed with social phobia (P depressive disorder NOS reported more anhedonia, increased appetite, increased sleep, and indecisiveness, whereas the patients with adjustment disorder reported more weight loss, reduced appetite, and insomnia. There was no significant difference between the groups in overall level of severity of depression or impaired functioning. The patients with depressive disorder NOS had a nonsignificantly elevated morbid risk of depression in their first-degree relatives. Clinically significant subthreshold depression was common in psychiatric outpatients, and the present results support the validity of distinguishing between depressive disorder NOS and adjustment disorder with depressed mood. Future studies of the treatment of subthreshold depression

  8. Panic disorder and subthreshold panic in the UK general population: epidemiology, comorbidity and functional limitation.

    Science.gov (United States)

    Skapinakis, P; Lewis, G; Davies, S; Brugha, T; Prince, M; Singleton, N

    2011-09-01

    The epidemiology of panic disorder has not been investigated in the past in the UK using a nationally representative sample of the population. The aim of the present paper was to examine the epidemiology, comorbidity and functional impairment of subthreshold panic and panic disorder with or without agoraphobia. We used data from the 2000 Office for National Statistics Psychiatric Morbidity survey (N=8580). Panic disorder and agoraphobia were assessed with the Revised Clinical Interview Schedule (CIS-R). The prevalence of panic disorder with or without agoraphobia was 1.70% (95% confidence interval: 1.41-2.03%). Subthreshold panic was more common. Economic inactivity was consistently associated with all syndromes. The comorbidity pattern of the panic syndromes and the associated functional impairment show that panic-related conditions are important public health problems, even in subthreshold status. The findings show that efforts to reduce the disability associated with psychiatric disorders should include detection and management of panic disorder. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  9. Intrinsic and Extrinsic Motivation

    OpenAIRE

    Roland Bénabou; Jean Tirole

    2003-01-01

    A central tenet of economics is that individuals respond to incentives. For psychologists and sociologists, in contrast, rewards and punishments are often counterproductive, because they undermine "intrinsic motivation". We reconcile these two views, showing how performance incentives offered by an informed principal (manager, teacher, parent) can adversely impact an agent's (worker, child) perception of the task, or of his own abilities. Incentives are then only weak reinforcers in the short...

  10. Intrinsic and extrinsic mortality reunited

    DEFF Research Database (Denmark)

    Koopman, Jacob J E; Wensink, Maarten J; Rozing, Maarten P

    2015-01-01

    Intrinsic and extrinsic mortality are often separated in order to understand and measure aging. Intrinsic mortality is assumed to be a result of aging and to increase over age, whereas extrinsic mortality is assumed to be a result of environmental hazards and be constant over age. However......, allegedly intrinsic and extrinsic mortality have an exponentially increasing age pattern in common. Theories of aging assert that a combination of intrinsic and extrinsic stressors underlies the increasing risk of death. Epidemiological and biological data support that the control of intrinsic as well...... as extrinsic stressors can alleviate the aging process. We argue that aging and death can be better explained by the interaction of intrinsic and extrinsic stressors than by classifying mortality itself as being either intrinsic or extrinsic. Recognition of the tight interaction between intrinsic and extrinsic...

  11. Large-spot subthreshold transpupillary thermotherapy for chronic serous macular detachment

    Directory of Open Access Journals (Sweden)

    Giuseppe Lo Giudice

    2011-03-01

    Full Text Available Giuseppe Lo Giudice1, Valentina de Belvis2, Marco Tavolato1, Alessandro Galan11San Paolo Ophthalmic Center, San Antonio Hospital, Padova, Italy; 2Paediatric Low Vision Center, Paediatric Rare Eye Disease Center, Department of Paediatrics, University of Padova, ItalyPurpose: To report the effect of subthreshold transpupillary thermotherapy (TTT in treating serous detachment of the neurosensory retina secondary to chronic central serous chorioretinopathy (CCSC.Methods: Seven eyes from five patients with CCSC, persistent serous detachment of the neurosensory retina and a clinical course of between 12 and 60 months were treated. All eyes received large-spot TTT guided by indocyanine green angiography (ICGA. Subthreshold TTT was performed using an 810 nm diode laser with a spot size of 3.0 mm (power was set at 350 mW. Treatment was applied for 60 seconds to the areas of choroidal hyperfluorescence on ICGA.Results: The mean number of TTT sessions was 1.4 ± 0.5. All eyes were followed up for at least 6 months (mean 9.6 ± 3.2 standard deviation; range 6–12 months. The mean logarithm of the minimum angle of resolution best-corrected visual acuity was significantly better compared with baseline. All TTT-treated eyes had stable or improved vision (P < 0.001. Mean optical coherence tomography (OCT central foveal thickness was significantly lower in all patients (P < 0.001 compared with pretreatment OCT, with a reduction in subretinal fluid and resolution of serous detachment associated with anatomical fovea restoration. No patient had any treatment-related side effects.Conclusion: Modified subthreshold TTT appears to have a beneficial effect in treating patients with CCSC and persistent neurosensory detachment. The encouraging results and lack of visually significant complications suggest that further investigation is warranted.Keywords: central serous chorioretinopathy, indocyanine green angiography, neurosensory detachment, transpupillary

  12. Watchful waiting for subthreshold depression and anxiety in visually impaired older adults.

    Science.gov (United States)

    van der Aa, Hilde P A; Krijnen-de Bruin, Esther; van Rens, Ger H M B; Twisk, Jos W R; van Nispen, Ruth M A

    2015-12-01

    Immediate treatment of depression and anxiety may not always be necessary in resilient patients. This study aimed to determine remission rates of subthreshold depression and anxiety, incidence rates of major depressive and anxiety disorders, and predictors of these remission and incidence rates in visually impaired older adults after a three-month 'watchful waiting' period. A pretest-posttest study in 265 visually impaired older adults (mean age 74 years), from outpatient low-vision rehabilitation services, with subthreshold depression and/or anxiety was performed as part of a randomised controlled trial on the cost-effectiveness of a stepped-care intervention. An ordinal logistic regression analysis was conducted. Main outcome measures were: (1) subthreshold depression and anxiety measured with the Centre for Epidemiologic Studies Depression Scale (CES-D) and the anxiety subscale of the Hospital Anxiety and Depression Scale (HADS-A), and (2) depressive and anxiety disorders measured with the Mini International Neuropsychiatric Interview. After a three-month watchful waiting period, depression and anxiety decreased significantly by 3.8 (CES-D) and 1.4 points (HADS-A) (p depression and/or anxiety and 18 % developed a depressive and/or anxiety disorder. Female gender [odds ratio (OR) 0.49, 95 % confidence interval (CI) 0.28-0.86], more problems with adjustment to vision loss at baseline (OR 1.02, 95 % CI 1.00-1.03), more symptoms of depression and anxiety at baseline (OR 1.06, 95 % CI 1.02-1.10), and a history of major depressive, dysthymic, and/or panic disorder (OR 2.28, 95 % CI 1.28-4.07) were associated with lower odds of remitting from subthreshold depression and/or anxiety and higher odds of developing a disorder after watchful waiting. Watchful waiting can be an appropriate step in managing depression and anxiety in visually impaired older adults. However, female gender, problems with adjustment to vision loss, higher depression and anxiety symptoms

  13. Telephone Cognitive-Behavioral Therapy for Subthreshold Depression and Presenteeism in Workplace: A Randomized Controlled Trial

    Science.gov (United States)

    Furukawa, Toshi A.; Horikoshi, Masaru; Kawakami, Norito; Kadota, Masayo; Sasaki, Megumi; Sekiya, Yuki; Hosogoshi, Hiroki; Kashimura, Masami; Asano, Kenichi; Terashima, Hitomi; Iwasa, Kazunori; Nagasaku, Minoru; Grothaus, Louis C.

    2012-01-01

    Background Subthreshold depression is highly prevalent in the general population and causes great loss to society especially in the form of reduced productivity while at work (presenteeism). We developed a highly-structured manualized eight-session cognitive-behavioral program with a focus on subthreshold depression in the workplace and to be administered via telephone by trained psychotherapists (tCBT). Methods We conducted a parallel-group, non-blinded randomized controlled trial of tCBT in addition to the pre-existing Employee Assistance Program (EAP) versus EAP alone among workers with subthreshold depression at a large manufacturing company in Japan. The primary outcomes were depression severity as measured with Beck Depression Inventory-II (BDI-II) and presenteeism as measured with World Health Organization Health and Work Productivity Questionnaire (HPQ). In the course of the trial the follow-up period was shortened in order to increase acceptability of the study. Results The planned sample size was 108 per arm but the trial was stopped early due to low accrual. Altogether 118 subjects were randomized to tCBT+EAP (n = 58) and to EAP alone (n = 60). The BDI-II scores fell from the mean of 17.3 at baseline to 11.0 in the intervention group and to 15.7 in the control group after 4 months (p<0.001, Effect size = 0.69, 95%CI: 0.32 to 1.05). However, there was no statistically significant decrease in absolute and relative presenteeism (p = 0.44, ES = 0.15, −0.21 to 0.52, and p = 0.50, ES = 0.02, −0.34 to 0.39, respectively). Conclusion Remote CBT, including tCBT, may provide easy access to quality-assured effective psychotherapy for people in the work force who present with subthreshold depression. Further studies are needed to evaluate the effectiveness of this approach in longer terms. The study was funded by Sekisui Chemicals Co. Ltd. Trial Registration ClinicalTrials.gov NCT00885014 PMID:22532849

  14. Subthreshold displacement damage in copper--aluminum alloys during electron irradiation

    International Nuclear Information System (INIS)

    Drosd, R.; Kosel, T.; Washburn, J.

    1976-12-01

    During electron irradiation at low energies which results in a negligible damage rate in a pure material, lighter solute atoms are displaced, which may in turn indirectly displace solvent atoms by a focussed replacement collision or an interstitial diffusion jump. The extent to which lighter solute atoms contribute to the subthreshold damage rate has been examined by irradiating copper--aluminum alloys at high temperatures in a high voltage electron microscope. The damage rate, as measured by monitoring the growth rate of dislocation loops, at 300 kV was found to increase linearly with the aluminum concentration

  15. A temperature monitor circuit with small voltage sensitivity using a topology-reconfigurable ring oscillator

    Science.gov (United States)

    Kishimoto, Tadashi; Ishihara, Tohru; Onodera, Hidetoshi

    2018-04-01

    In this paper, we propose a temperature monitor circuit that exhibits a small supply voltage sensitivity adopting a circuit topology of a reconfigurable ring oscillator. The circuit topology of the monitor is crafted such that the oscillation frequency is determined by the amount of subthreshold leakage current, which has an exponential dependence on temperature. Another important characteristic of the monitor is its small supply voltage sensitivity. The measured oscillation frequency of a test chip fabricated in a 65 nm CMOS process varies only 2.6% under a wide range of supply voltages from 0.4 to 1.0 V at room temperature. The temperature estimation error ranges from ‑0.3 to 0.4 °C over a temperature range of 10 to 100 °C.

  16. Oscillating heat pipes

    CERN Document Server

    Ma, Hongbin

    2015-01-01

    This book presents the fundamental fluid flow and heat transfer principles occurring in oscillating heat pipes and also provides updated developments and recent innovations in research and applications of heat pipes. Starting with fundamental presentation of heat pipes, the focus is on oscillating motions and its heat transfer enhancement in a two-phase heat transfer system. The book covers thermodynamic analysis, interfacial phenomenon, thin film evaporation,  theoretical models of oscillating motion and heat transfer of single phase and two-phase flows, primary  factors affecting oscillating motions and heat transfer,  neutron imaging study of oscillating motions in an oscillating heat pipes, and nanofluid’s effect on the heat transfer performance in oscillating heat pipes.  The importance of thermally-excited oscillating motion combined with phase change heat transfer to a wide variety of applications is emphasized. This book is an essential resource and learning tool for senior undergraduate, gradua...

  17. Phenomenology of neutrino oscillations

    Indian Academy of Sciences (India)

    Abstract. The phenomenology of solar, atmospheric, supernova and laboratory neutrino oscillations is described. Analytical formulae for matter effects are reviewed. The results from oscillations are confronted with neutrinoless double beta decay.

  18. Subthreshold Current and Swing Modeling of Gate Underlap DG MOSFETs with a Source/Drain Lateral Gaussian Doping Profile

    Science.gov (United States)

    Singh, Kunal; Kumar, Sanjay; Goel, Ekta; Singh, Balraj; Kumar, Mirgender; Dubey, Sarvesh; Jit, Satyabrata

    2017-01-01

    This paper proposes a new model for the subthreshold current and swing of the short-channel symmetric underlap ultrathin double gate metal oxide field effect transistors with a source/drain lateral Gaussian doping profile. The channel potential model already reported earlier has been utilized to formulate the closed form expression for the subthreshold current and swing of the device. The effects of the lateral straggle and geometrical parameters such as the channel length, channel thickness, and oxide thickness on the off current and subthreshold slope have been demonstrated. The devices with source/drain lateral Gaussian doping profiles in the underlap structure are observed to be highly resistant to short channel effects while improving the current drive. The proposed model is validated by comparing the results with the numerical simulation data obtained by using the commercially available ATLAS™, a two-dimensional (2-D) device simulator from SILVACO.

  19. The colpitts oscillator family

    DEFF Research Database (Denmark)

    Lindberg, Erik; Murali, K.; Tamasevicius, A.

    A tutorial study of the Colpitts oscillator family defined as all oscillators based on a nonlinear amplifier and a three- terminal linear resonance circuit with one coil and two capacitors. The original patents are investigated. The eigenvalues of the linearized Jacobian for oscillators based...

  20. Analysis and Modeling of Subthreshold Neural Multi-Electrode Array Data by Statistical Field Theory.

    Science.gov (United States)

    Henningson, Måns; Illes, Sebastian

    2017-01-01

    Multi-electrode arrays (MEA) are increasingly used to investigate spontaneous neuronal network activity. The recorded signals comprise several distinct components: Apart from artifacts without biological significance, one can distinguish between spikes (action potentials) and subthreshold fluctuations (local fields potentials). Here we aim to develop a theoretical model that allows for a compact and robust characterization of subthreshold fluctuations in terms of a Gaussian statistical field theory in two spatial and one temporal dimension. What is usually referred to as the driving noise in the context of statistical physics is here interpreted as a representation of the neural activity. Spatial and temporal correlations of this activity give valuable information about the connectivity in the neural tissue. We apply our methods on a dataset obtained from MEA-measurements in an acute hippocampal brain slice from a rat. Our main finding is that the empirical correlation functions indeed obey the logarithmic behavior that is a general feature of theoretical models of this kind. We also find a clear correlation between the activity and the occurrence of spikes. Another important insight is the importance of correctly separating out certain artifacts from the data before proceeding with the analysis.

  1. Subthreshold Photocoagulation Using Endpoint Management in the PASCAL® System for Diffuse Diabetic Macular Edema

    Directory of Open Access Journals (Sweden)

    Masafumi Hamada

    2018-01-01

    Full Text Available We evaluated subthreshold photocoagulation using endpoint management (EPM for the treatment of diabetic macular edema (DME. The study enrolled 10 eyes from 10 patients (6 men and 4 women with DME. The entry criteria included central macular thickness (CMT ≥ 300 μm and decimal visual acuity (VA ≤ 0.5. The primary endpoints were VA (logMAR and CMT at 6 months follow-up. Secondary endpoints included fundus autofluorescence, macular volume (MV, and macular sensitivity (MS. We used the PASCAL Streamline Yellow® (wavelength, 577 nm system to perform grid pattern laser photocoagulation at 50% of the threshold (size, 100 μm; duration, 0.015 s; spacing, 0.5; and energy, 4.5–7.8 mJ. At 6 months posttreatment, CMT was significantly decreased, while there were no significant changes in macular sensitivity, mean BCVA (logMAR, or macular volume. Autofluorescence imaging revealed no changes after treatment in 6 of 10 eyes. No eyes exhibited subjective symptoms of scotoma after photocoagulation. Optical coherence tomography showed the complete resolution of macular edema in 4 eyes (40% after a single treatment; MS was increased in all 4 of these eyes at 6 months posttreatment. In conclusion, subthreshold photocoagulation using EPM is safe and effective for DME treatment and preserves MS. This trial is registered with UMIN000012401.

  2. Exact subthreshold integration with continuous spike times in discrete-time neural network simulations.

    Science.gov (United States)

    Morrison, Abigail; Straube, Sirko; Plesser, Hans Ekkehard; Diesmann, Markus

    2007-01-01

    Very large networks of spiking neurons can be simulated efficiently in parallel under the constraint that spike times are bound to an equidistant time grid. Within this scheme, the subthreshold dynamics of a wide class of integrate-and-fire-type neuron models can be integrated exactly from one grid point to the next. However, the loss in accuracy caused by restricting spike times to the grid can have undesirable consequences, which has led to interest in interpolating spike times between the grid points to retrieve an adequate representation of network dynamics. We demonstrate that the exact integration scheme can be combined naturally with off-grid spike events found by interpolation. We show that by exploiting the existence of a minimal synaptic propagation delay, the need for a central event queue is removed, so that the precision of event-driven simulation on the level of single neurons is combined with the efficiency of time-driven global scheduling. Further, for neuron models with linear subthreshold dynamics, even local event queuing can be avoided, resulting in much greater efficiency on the single-neuron level. These ideas are exemplified by two implementations of a widely used neuron model. We present a measure for the efficiency of network simulations in terms of their integration error and show that for a wide range of input spike rates, the novel techniques we present are both more accurate and faster than standard techniques.

  3. Reward abnormalities among women with full and subthreshold bulimia nervosa: a functional magnetic resonance imaging study.

    Science.gov (United States)

    Bohon, Cara; Stice, Eric

    2011-11-01

    To test the hypothesis that women with full and subthreshold bulimia nervosa show abnormal neural activation in response to food intake and anticipated food intake relative to healthy control women. Females with and without full/subthreshold bulimia nervosa recruited from the community (N = 26) underwent functional magnetic resonance imaging (fMRI) during receipt and anticipated receipt of chocolate milkshake and a tasteless control solution. Women with bulimia nervosa showed trends for less activation than healthy controls in the right anterior insula in response to anticipated receipt of chocolate milkshake (vs. tasteless solution) and in the left middle frontal gyrus, right posterior insula, right precentral gyrus, and right mid dorsal insula in response to consumptions of milkshake (vs. tasteless solution). Bulimia nervosa may be related to potential hypofunctioning of the brain reward system, which may lead these individuals to binge eat to compensate for this reward deficit, though the hypo-responsivity might be a result of a history of binge eating highly palatable foods. Copyright © 2010 Wiley Periodicals, Inc.

  4. The effect of subthreshold continuous electrical stimulation on the facial function of patients with Bell's palsy.

    Science.gov (United States)

    Kim, Jin; Choi, Jae Young

    2016-01-01

    The drug regimen plus electrical stimulation was more effective in treating Bell's palsy than the conventional drug treatment alone. The effectiveness of such a sub-threshold, continuous, low frequency electrical stimulation suggests a new therapeutic approach to accelerate nerve regeneration and improve functional recovery after injury. The purpose of this study was to determine whether sub-threshold, continuous electrical stimulation at 20 Hz facilitates functional recovery of patients with Bell's palsy. The authors performed a prospective randomized study that included 60 patients with mild-to-moderate grade Bell's palsy (HB grade ≤4, SB grade ≥40), to evaluate the effect of developed electrical stimulation on the resolution of symptoms. Thirty patients were treated with prednisolone or/and acyclovir plus electrical stimulation within 7 days of the onset of symptoms. The other 30 patients were treated with only prednisolone or/and acyclovir as a control group. The overall rate of patient recovery among those treated with prednisolone or/and acyclovir plus electrical stimulation (96%) was significantly better (p < 0.05) than the rate among those treated with only prednisolone or/and acyclovir (88%).

  5. Cognitive-behavioral therapy for subthreshold bulimia nervosa: A case series.

    Science.gov (United States)

    Peterson, C B; Miller, K B; Willer, M G; Ziesmer, J; Durkin, N; Arikian, A; Crow, S J

    2011-09-01

    The extent to which cognitive-behavioral therapy (CBT) is helpful in treating individuals with bulimic symptoms who do not meet full criteria for bulimia nervosa is unclear. The purpose of this investigation was to examine the potential efficacy of CBT for eating disorder individuals with bulimic symptoms who do not meet full criteria for bulimia nervosa. Twelve participants with subthreshold bulimia nervosa were treated in a case series with 20 sessions of CBT. Ten of the 12 participants (83.3%) completed treatment. Intent-to-treat abstinent percentages were 75.0% for objectively large episodes of binge eating (OBEs), 33.3% for subjectively large episodes of binge eating (SBEs), and 50% for purging at end of treatment. At one year follow-up, 66.7% were abstinent for OBEs, 41.7% for SBEs, and 50.0% for purging. The majority also reported improvements in associated symptoms. This case series provides support for the use of CBT with individuals with subthreshold bulimia nervosa.

  6. Design of a Low-Power Universal Gm-C Filter in Sub-Threshold Region

    Directory of Open Access Journals (Sweden)

    Mohammad Aghaei Jeshvaghani

    2013-10-01

    Full Text Available In this paper, a second order universal filter with the ability of electronically tuning central frequency (ω0 and quality factor (Q, based on the inverter as transconductance block which realizes multi-mode responses (voltage, current, transconductance, transresistance in sub-threshold region, is presented. Biasing transistors in sub-threshold region, reduces the power consumption of the proposed filter and the grounded capacitors are used to reduce the parasitic effects which is another advantage of the proposed filter circuit. Furthermore, low sensitivity of the performance of the proposed filter to the values of gmi , Ci is considered as another advantage of the proposed circuit. In addition, realizing the proposed filter based on the inverter circuit leads to a reduced value of layout area as well as power consumption. Finally, the proposed filter performance is simulated in HSPICE using 0.18 µm (LEVEL49 CMOS technology parameters. As it is shown in the paper, the proposed filter consumes only 64.69 nW power in a ±0.3V supply voltage.

  7. Polysubstance and Behavioral Addictions in a Patient with Bipolar Disorder: Role of Lifetime Subthreshold Autism Spectrum

    Directory of Open Access Journals (Sweden)

    Liliana Dell’Osso

    2018-01-01

    Full Text Available This case report draws attention to the potential relevance of undetected autism spectrum symptoms in a bipolar patient with high work functioning showing a peculiar addictive profile with impulsive and antisocial behaviors. A 23-year-old man with a diagnosis of Bipolar Disorder (BD and Substance Use Disorder (SUD was hospitalized at the Psychiatric Clinic of the University of Pisa for diuretics and β-2 adrenergic agonist abuse in a remission phase of benzodiazepines and substance abuse. He reported a history of behavioral addictions in the framework of a global high work functioning with particular skills in computer science. When assessed for adult autism spectrum symptoms, despite not fulfilling a DSM-5 diagnosis of Autism Spectrum Disorder (ASD, he reported a score of 93/240 at the Ritvo Autism and Asperger Diagnostic Scale (RAADS-r and of 88/160 at the Adult Autism Subthreshold Spectrum (AdAS Spectrum, both indicative of ASD. We argue the possible role of adult subthreshold autism spectrum features, generally disregarded in adult psychiatry, in the peculiar addictive profile developed by this patient with BD that may deserve appropriate treatment.

  8. The Effect of Interpersonal Counseling for Subthreshold Depression in Undergraduates: An Exploratory Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Ami Yamamoto

    2018-01-01

    Full Text Available Background. Subthreshold depression and poor stress coping strategies are major public health problems among undergraduates. Interpersonal counseling (IPC is a brief structured psychological intervention originally designed for use in primary care to treat depressive patients whose symptoms arose from current life stress. Objectives. This study examined the efficacy of IPC in treating subthreshold depression and coping strategies among undergraduates in school counseling. Materials and Methods. We carried out an exploratory randomized controlled trial comparing the efficacy of IPC with counseling as usual (CAU. Participants were 31 undergraduates exhibiting depression without a psychiatric diagnosis. Results. The Zung Self-Rating Depression Scale total score decreased significantly in the IPC group (n=15; Z=-2.675, p=.007, but not in the CAU group (n=16. The task-oriented coping score of the Coping Inventory for Stressful Situations showed a tendency towards a greater increase in the IPC group than in the CAU group (t=1.919, df=29, p=.065. Conclusions. The IPC might be more useful for student counseling because it can teach realistic coping methods and reduce depressive symptoms in a short period. Further studies using more participants are required.

  9. Intrinsic Chevrolets at the SSC

    International Nuclear Information System (INIS)

    Brodsky, S.J.; Collins, J.C.; Ellis, S.D.; Gunion, J.F.; Mueller, A.H.

    1984-01-01

    The possibility of the production at high energy of heavy quarks, supersymmetric particles and other large mass colored systems via the intrinsic twist-six components in the proton wave function is discussed. While the existing data do not rule out the possible relevance of intrinsic charm production at present energies, the extrapolation of such intrinsic contributions to very high masses and energies suggests that they will not play an important role at the SSC

  10. Subthreshold-swing-adjustable tunneling-field-effect-transistor-based random-access memory for nonvolatile operation

    Science.gov (United States)

    Huh, In; Cheon, Woo Young; Choi, Woo Young

    2016-04-01

    A subthreshold-swing-adjustable tunneling-field-effect-transistor-based random-access memory (SAT RAM) has been proposed and fabricated for low-power nonvolatile memory applications. The proposed SAT RAM cell demonstrates adjustable subthreshold swing (SS) depending on stored information: small SS in the erase state ("1" state) and large SS in the program state ("0" state). Thus, SAT RAM cells can achieve low read voltage (Vread) with a large memory window in addition to the effective suppression of ambipolar behavior. These unique features of the SAT RAM are originated from the locally stored charge, which modulates the tunneling barrier width (Wtun) of the source-to-channel tunneling junction.

  11. Anxiofit-1 and reduction of subthreshold and mild anxiety: evaluation of a health claim pursuant to Article 14 of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Sjödin, Anders Mikael

    2016-01-01

    of the health claim, is sufficiently characterised. The Panel considers that reduction of subthreshold and mild anxiety is a beneficial physiological effect. Subthreshold and mild anxiety is a risk factor for anxiety and depressive disorders. One human intervention study with a small number of participants...

  12. Internet-based cognitive behavioural therapy for subthreshold depression in people over 50 years old:a randomized controlled clinical trial

    NARCIS (Netherlands)

    Spek, V.; Nyklicek, I.; Smits, N.; Cuijpers, P.; Riper, H.; Keyzer, J.; Pop, V.

    2007-01-01

    Background. Subthreshold depression is a highly prevalent condition and a risk factor for developing a major depressive episode. Internet-based cognitive behaviour therapy may be a promising approach for the treatment of subthreshold depression. The current study had two aims: (1) to determine

  13. Nature's Autonomous Oscillators

    Science.gov (United States)

    Mayr, H. G.; Yee, J.-H.; Mayr, M.; Schnetzler, R.

    2012-01-01

    Nonlinearity is required to produce autonomous oscillations without external time dependent source, and an example is the pendulum clock. The escapement mechanism of the clock imparts an impulse for each swing direction, which keeps the pendulum oscillating at the resonance frequency. Among nature's observed autonomous oscillators, examples are the quasi-biennial oscillation and bimonthly oscillation of the Earth atmosphere, and the 22-year solar oscillation. The oscillations have been simulated in numerical models without external time dependent source, and in Section 2 we summarize the results. Specifically, we shall discuss the nonlinearities that are involved in generating the oscillations, and the processes that produce the periodicities. In biology, insects have flight muscles, which function autonomously with wing frequencies that far exceed the animals' neural capacity; Stretch-activation of muscle contraction is the mechanism that produces the high frequency oscillation of insect flight, discussed in Section 3. The same mechanism is also invoked to explain the functioning of the cardiac muscle. In Section 4, we present a tutorial review of the cardio-vascular system, heart anatomy, and muscle cell physiology, leading up to Starling's Law of the Heart, which supports our notion that the human heart is also a nonlinear oscillator. In Section 5, we offer a broad perspective of the tenuous links between the fluid dynamical oscillators and the human heart physiology.

  14. Intrinsically dynamic population models

    Directory of Open Access Journals (Sweden)

    Robert Schoen

    2005-03-01

    Full Text Available Intrinsically dynamic models (IDMs depict populations whose cumulative growth rate over a number of intervals equals the product of the long term growth rates (that is the dominant roots or dominant eigenvalues associated with each of those intervals. Here the focus is on the birth trajectory produced by a sequence of population projection (Leslie matrices. The elements of a Leslie matrix are represented as straightforward functions of the roots of the matrix, and new relationships are presented linking the roots of a matrix to its Net Reproduction Rate and stable mean age of childbearing. Incorporating mortality changes in the rates of reproduction yields an IDM when the subordinate roots are held constant over time. In IDMs, the birth trajectory generated by any specified sequence of Leslie matrices can be found analytically. In the Leslie model with 15 year age groups, the constant subordinate root assumption leads to reasonable changes in the age pattern of fertility, and equations (27 and (30 provide the population size and structure that result from changing levels of net reproduction. IDMs generalize the fixed rate stable population model. They can characterize any observed population, and can provide new insights into dynamic demographic behavior, including the momentum associated with gradual or irregular paths to zero growth.

  15. Detection of sub-threshold periodic signal by multiplicative and additive cross-correlated sine-Wiener noises in the FitzHugh-Nagumo neuron

    Science.gov (United States)

    Yao, Yuangen; Ma, Chengzhang; Wang, Canjun; Yi, Ming; Gui, Rong

    2018-02-01

    We study the effects of multiplicative and additive cross-correlated sine-Wiener (CCSW) noises on the performance of sub-threshold periodic signal detection in the FitzHugh-Nagumo (FHN) neuron by calculating Fourier coefficients Q for measuring synchronization between sub-threshold input signal and the response of system. CCSW noises-induced transitions of electrical activity in the FHN neuron model can be observed. Moreover, the performance of sub-threshold periodic signal detection is achieved at moderate noise strength, cross-correlation time and cross-correlation strength of CCSW noises, which indicate the occurrence of CCSW noises-induced stochastic resonance. Furthermore, the performance of sub-threshold signal detection is strongly sensitive to cross-correlation time of CCSW noises. Therefore, the performance can be effectively controlled by regulating cross-correlation time of CCSW noises. These results provide a possible mechanism for amplifying or detecting the sub-threshold signal in the nervous system.

  16. Method of normal coordinates in the formulation of a system with dissipation: The harmonic oscillator

    International Nuclear Information System (INIS)

    Mshelia, E.D.

    1994-07-01

    The method of normal coordinates of the theory of vibrations is used in decoupling the motion of n oscillators (1 ≤ n ≤4) representing intrinsic degrees of freedom coupled to collective motion in a quantum mechanical model that allows the determination of the probability for energy transfer from collective to intrinsic excitations in a dissipative system. (author). 21 refs

  17. A memristor-based third-order oscillator: beyond oscillation

    KAUST Repository

    Talukdar, Abdul Hafiz Ibne

    2012-10-06

    This paper demonstrates the first third-order autonomous linear time variant circuit realization that enhances parametric oscillation through the usage of memristor in conventional oscillators. Although the output has sustained oscillation, the linear features of the conventional oscillators become time dependent. The poles oscillate in nonlinear behavior due to the oscillation of memristor resistance. The mathematical formulas as well as SPICE simulations are introduced for the memristor-based phase shift oscillator showing a great matching.

  18. A memristor-based third-order oscillator: beyond oscillation

    Science.gov (United States)

    Talukdar, A.; Radwan, A. G.; Salama, K. N.

    2011-09-01

    This paper demonstrates the first third-order autonomous linear time variant circuit realization that enhances parametric oscillation through the usage of memristor in conventional oscillators. Although the output has sustained oscillation, the linear features of the conventional oscillators become time dependent. The poles oscillate in nonlinear behavior due to the oscillation of memristor resistance. The mathematical formulas as well as SPICE simulations are introduced for the memristor-based phase shift oscillator showing a great matching.

  19. [Pregnancy-related anxiety and subthreshold autism trait in preschool children based a birth cohort study].

    Science.gov (United States)

    Sun, Yanli; Shao, Ting; Yao, Yuyou; Tao, Huihui; Ni, Lingling; Yan, Shuangqin; Gu, Chunli; Cao, Hui; Huang, Kun; Tao, Fangbiao

    2016-02-01

    To analyze the associations between pregnancy-related anxiety and the prevalence of subthreshold autism trait (SAT) in preschool children. Baseline data came from the Ma'anshan Birth Cohort Study, a part of the China-Anhui Birth Cohort Study (C-ABCS). All the participants were enrolled among pregnant women who received prenatal health care in 4 municipal medical centers during Oct. 2008 to Oct. 2010. A total of 5 084 pregnant women were recruited at the beginning and 4 669 singleton live births were included until childbirth. The situation about pregnancy-specific anxiety during trimester and third trimester of women were evaluated by Pregnancy-specific Anxiety Questionnaire (PAQ). Between April 2014 and April 2015, the cohort was followed up again, and the Clancy Autism Behavior Scale (CABRS) filled out by parents was used for telling the SAT children from the healthy children among 3 663 preschool children. Univariate and binary regression model was used to estimate associations between the pregnancy-related anxiety during trimester and third trimester and the subthreshold autism trait in children. During the pregnancy, the detected rates of women with pregnancy-specific anxiety in trimester and the third trimester were 25.5%(935/3 663), 13.9%(501/3 592) respectively, and the detected rate of maternal pregnancy-specific anxiety in both periods was 7.7%(278/3 592). There were 290 positive children with SAT and the detection rate was 7.9%. After controlling possible confounding factors including children's genders, place of residence, supplement folic acid during pregnancy, preterm birth, exposure to second-hand smoke during pregnancy, the father (mother) cultural levels, the father (mother) nature of work and family income, the results of multinomial logistic regression analysis showed that maternal pregnancy-specific anxiety in trimester was the risk factor for SAT in preschool children (OR=1.51, 95% CI: 1.11-2.04), and there was no association between maternal

  20. Progress in neutrino oscillation searches and their implications

    Indian Academy of Sciences (India)

    Abstract. Neutrino oscillation, in which a given flavor of neutrino transforms into another is a powerful tool for probing small neutrino masses. The intrinsic neutrino properties involved are neu- trino mass squared difference ∆m2 and the mixing angle in vacuum θ. In this paper I will summarize the progress that we have ...

  1. Predicting the onset of major depression in subjects with subthreshold depression in primary care: A prospective study.

    NARCIS (Netherlands)

    Cuijpers, P.; Smit, H.F.E.; Willemse, G.

    2005-01-01

    Objective: That subjects with subthreshold depression have an increased probability of developing major depression has been confirmed by many studies. However, the factors which may predict the onset of major depression have yet to be fully examined. Method: We examined the control group of a

  2. Oscillations of disks

    CERN Document Server

    Kato, Shoji

    2016-01-01

    This book presents the current state of research on disk oscillation theory, focusing on relativistic disks and tidally deformed disks. Since the launch of the Rossi X-ray Timing Explorer (RXTE) in 1996, many high-frequency quasiperiodic oscillations (HFQPOs) have been observed in X-ray binaries. Subsequently, similar quasi-periodic oscillations have been found in such relativistic objects as microquasars, ultra-luminous X-ray sources, and galactic nuclei. One of the most promising explanations of their origin is based on oscillations in relativistic disks, and a new field called discoseismology is currently developing. After reviewing observational aspects, the book presents the basic characteristics of disk oscillations, especially focusing on those in relativistic disks. Relativistic disks are essentially different from Newtonian disks in terms of several basic characteristics of their disk oscillations, including the radial distributions of epicyclic frequencies. In order to understand the basic processes...

  3. Towards a better understanding of deep subthreshold photofission of 238U

    International Nuclear Information System (INIS)

    Bellia, G.; Del Zoppo, A.; Maiolino, C.; Misneco, E.; Russo, G.

    1983-01-01

    Deep subthreshold photofission data of 238 U are analysed. Spectroscopic properties of highly deformed states from experiments in the literature are introduced into a model calculation based on the doorway state formalism which is extended to fission at energies as low as the isomeric level. It is shown that starting from the results of a detailed analysis of the photofission measurements near the top of the fission barrier it is possible to describe the process in the energy range covered by the intermediate well in the double-humped deformation potential. In particular, the so-called ''shelf effect'' in the low energy photofission is reproduced in terms of delayed isomeric fission through a few undamped vibrational states localised in the pairing gap region above the isomer. (orig.)

  4. Towards a better understanding of deep subthreshold photofission of /sup 238/U

    Energy Technology Data Exchange (ETDEWEB)

    Bellia, G.; Del Zoppo, A.; Maiolino, C.; Misneco, E.; Russo, G.

    1983-11-01

    Deep subthreshold photofission data of /sup 238/U are analysed. Spectroscopic properties of highly deformed states from experiments in the literature are introduced into a model calculation based on the doorway state formalism which is extended to fission at energies as low as the isomeric level. It is shown that starting from the results of a detailed analysis of the photofission measurements near the top of the fission barrier it is possible to describe the process in the energy range covered by the intermediate well in the double-humped deformation potential. In particular, the so-called ''shelf effect'' in the low energy photofission is reproduced in terms of delayed isomeric fission through a few undamped vibrational states localised in the pairing gap region above the isomer.

  5. Fermi motion versus co-operative effects in subthreshold pion and energetic gamma production

    International Nuclear Information System (INIS)

    Knoll, J.

    1986-06-01

    Various reaction mechanisms proposed to explain the production of pions at 'sub-threshold' energies and of energetic gammas are examined. They range from the nucleon-nucleon single collision mechanism to a co-operative multi-nucleon process. With a shell model prescription for the initial state energies the single collision picture cannot explain the data. The participation of many nucleons in the pion production process appears to be necessary. We present a statistical model which demands the co-operative action of several of the target and projectile nucleons in the pion production process. The formation of composite fragments alongside with the produced pion is seen to be vital to understand the experimental data within this model. (orig.)

  6. Chronic subthreshold cortical stimulation: a therapeutic and potentially restorative therapy for focal epilepsy.

    Science.gov (United States)

    Lundstrom, Brian Nils; Worrell, Gregory A; Stead, Matt; Van Gompel, Jamie J

    2017-07-01

    Approximately one third of patients with focal epilepsy continue to have ongoing seizures despite adequate trials of anti-seizure medications. Surgery to remove the epileptogenic zone remains the most efficacious treatment option for focal drug-resistant epilepsy. However, when cortical areas are eloquent or there are multiple epileptogenic zones, surgical resection is not an ideal approach. Cortical stimulation provides an attractive alternative. Area covered: Here, the authors describe Chronic Subthreshold Cortical Stimulation (CSCS), which uses continuous intracranial electrical stimulation applied near the epileptogenic zone to lower seizure probability. The authors review literature related to CSCS. One challenge is finding the most efficacious set of stimulation parameters for each patient. Expert commentary: Data supporting CSCS are limited but promising for the treatment of patients with focal drug resistant epilepsy who are not surgical candidates. Additional electrophysiological biomarkers to estimate cortical excitability are needed.

  7. A Digital Auto-Zeroing Circuit to Reduce Offset in Sub-Threshold Sense Amplifiers

    Directory of Open Access Journals (Sweden)

    Benton H. Calhoun

    2013-05-01

    Full Text Available Device variability in modern processes has become a major concern in SRAM design leading to degradation of both performance and yield. Variation induced offset in the sense amplifiers requires a larger bitline differential, which slows down SRAM access times and causes increased power consumption. The effect aggravated in the sub-threshold region. In this paper, we propose a circuit that reduces the sense amp offset using an auto-zeroing scheme with automatic temperature, voltage, and aging tracking. The circuit enables flexible tuning of the offset voltage. Measurements taken from a 45 nm test chip show the circuit is able to limit the offset to 20 mV. A 16kB SRAM is designed using the auto-zeroing circuit for the sense amps. The reduction in the total read energy and delay is reported for various configurations of the memory.

  8. Self-oscillation

    Science.gov (United States)

    Jenkins, Alejandro

    2013-04-01

    Physicists are very familiar with forced and parametric resonance, but usually not with self-oscillation, a property of certain dynamical systems that gives rise to a great variety of vibrations, both useful and destructive. In a self-oscillator, the driving force is controlled by the oscillation itself so that it acts in phase with the velocity, causing a negative damping that feeds energy into the vibration: no external rate needs to be adjusted to the resonant frequency. The famous collapse of the Tacoma Narrows bridge in 1940, often attributed by introductory physics texts to forced resonance, was actually a self-oscillation, as was the swaying of the London Millennium Footbridge in 2000. Clocks are self-oscillators, as are bowed and wind musical instruments. The heart is a “relaxation oscillator”, i.e., a non-sinusoidal self-oscillator whose period is determined by sudden, nonlinear switching at thresholds. We review the general criterion that determines whether a linear system can self-oscillate. We then describe the limiting cycles of the simplest nonlinear self-oscillators, as well as the ability of two or more coupled self-oscillators to become spontaneously synchronized (“entrained”). We characterize the operation of motors as self-oscillation and prove a theorem about their limit efficiency, of which Carnot’s theorem for heat engines appears as a special case. We briefly discuss how self-oscillation applies to servomechanisms, Cepheid variable stars, lasers, and the macroeconomic business cycle, among other applications. Our emphasis throughout is on the energetics of self-oscillation, often neglected by the literature on nonlinear dynamical systems.

  9. Subthreshold attention-deficit/hyperactivity disorder is associated with functional impairments across domains: a comprehensive analysis in a large-scale community study.

    Science.gov (United States)

    Hong, Soon-Beom; Dwyer, Dominic; Kim, Jae-Won; Park, Eun-Jin; Shin, Min-Sup; Kim, Boong-Nyun; Yoo, Hee-Jeong; Cho, In-Hee; Bhang, Soo-Young; Hong, Yun-Chul; Pantelis, Christos; Cho, Soo-Churl

    2014-08-01

    This study compared children who experience attention-deficit/hyperactivity disorder (ADHD) symptoms but do not meet criteria (i.e., subthreshold ADHD) with those with the full syndrome and healthy controls. Presence of ADHD symptoms was determined in a nationwide community sample of 921 children, aged 8-11 years. The main outcome measures comprised attentional symptoms, comorbidity profiles, academic performance, and neurocognitive ability (i.e., ADHD Rating Scale, Child Behavior Checklist, Learning Disability Evaluation Scale, and Stroop Color-Word Test, respectively). Subthreshold ADHD was equally prevalent in boys and girls, and more prevalent in low-income families. Throughout all the outcome measurements, subthreshold ADHD was both a significantly milder condition than full syndrome ADHD and a significantly more severe condition than non-ADHD status. The findings were consistent across the total as well as the subtest scores, and after correction for multiple comparisons (p < 0.0017). Children with subthreshold ADHD were found to experience significant symptoms and functional impairments. The results of this study support the clinical relevance of subthreshold ADHD in a childhood population. Subthreshold diagnostic criteria for ADHD may be more sensitive in detecting ADHD symptoms in girls than the full syndrome criteria, and subthreshold clinical, cognitive, and behavioral symptoms of ADHD may occur in a subset of children who are possibly more sensitive to their environment. Further consideration about the diagnostic threshold for ADHD may particularly benefit girls and children in low-income families.

  10. Intrinsically Passive Handling and Grasping

    NARCIS (Netherlands)

    Stramigioli, Stefano; Scherpen, Jacquelien M.A.; Khodabandehloo, Koorosh

    2000-01-01

    The paper presents a control philosophy called Intrinsically Passive Control, which has the feature to properly behave during interaction with any passive objects. The controlled robot will never become unstable due to the physical structure of the controller.

  11. Phenomenology of neutrino oscillations

    Indian Academy of Sciences (India)

    In this talk, I shall try to give a bird's eye view of the current status of neutrino oscillations. ..... the night effect. An asymmetry between the night and day rates would be an unambiguous signal for neutrino oscillations independent of the details of the solar ... It is particularly important to see the effect of the core of the earth [19].

  12. Active-bridge oscillator

    Science.gov (United States)

    Wessendorf, Kurt O.

    2001-01-01

    An active bridge oscillator is formed from a differential amplifier where positive feedback is a function of the impedance of one of the gain elements and a relatively low value common emitter resistance. This use of the nonlinear transistor parameter h stabilizes the output and eliminates the need for ALC circuits common to other bridge oscillators.

  13. On the Dirac oscillator

    International Nuclear Information System (INIS)

    Rodrigues, R. de Lima

    2007-01-01

    In the present work we obtain a new representation for the Dirac oscillator based on the Clifford algebra C 7. The symmetry breaking and the energy eigenvalues for our model of the Dirac oscillator are studied in the non-relativistic limit. (author)

  14. Grazing Impact Oscillations

    NARCIS (Netherlands)

    Weger, J.G.; Water, van de W.; Molenaar, J.

    2000-01-01

    An impact oscillator is a periodically driven system that hits a wall when its amplitude exceeds a critical value. We study impact oscillations where collisions with the wall are with near-zero velocity (grazing impacts). A characteristic feature of grazing impact dynamics is a geometrically

  15. Line width of Josephson flux flow oscillators

    DEFF Research Database (Denmark)

    Koshelets, V.P.; Dmitriev, P.N.; Sobolev, A.S.

    2002-01-01

    A combination of wide-band electronic tunability and moderate free-running line width makes the Josephson flux flow oscillator (FFO) a perfect on-chip local oscillator for integrated submillimeter-wave SIS receivers. The possibility of FFO phase locking at all frequencies of interest has...... to be proven before one initiates real FFO applications. To achieve this goal a comprehensive set of line width measurements of the FFO operating in different regimes has been performed. FFOs with tapered shape have been successfully implemented in order to avoid the superfine resonant structure with voltage...... spacing of about 20 nV and extremely low differential resistance, recently observed in the IVC of the standard rectangular geometry. The obtained results have been compared with existing theories and FFO models in order to understand and possibly eliminate excess noise in the FFO. The intrinsic line width...

  16. A coupled-oscillator model of olfactory bulb gamma oscillations.

    Directory of Open Access Journals (Sweden)

    Guoshi Li

    2017-11-01

    Full Text Available The olfactory bulb transforms not only the information content of the primary sensory representation, but also its underlying coding metric. High-variance, slow-timescale primary odor representations are transformed by bulbar circuitry into secondary representations based on principal neuron spike patterns that are tightly regulated in time. This emergent fast timescale for signaling is reflected in gamma-band local field potentials, presumably serving to efficiently integrate olfactory sensory information into the temporally regulated information networks of the central nervous system. To understand this transformation and its integration with interareal coordination mechanisms requires that we understand its fundamental dynamical principles. Using a biophysically explicit, multiscale model of olfactory bulb circuitry, we here demonstrate that an inhibition-coupled intrinsic oscillator framework, pyramidal resonance interneuron network gamma (PRING, best captures the diversity of physiological properties exhibited by the olfactory bulb. Most importantly, these properties include global zero-phase synchronization in the gamma band, the phase-restriction of informative spikes in principal neurons with respect to this common clock, and the robustness of this synchronous oscillatory regime to multiple challenging conditions observed in the biological system. These conditions include substantial heterogeneities in afferent activation levels and excitatory synaptic weights, high levels of uncorrelated background activity among principal neurons, and spike frequencies in both principal neurons and interneurons that are irregular in time and much lower than the gamma frequency. This coupled cellular oscillator architecture permits stable and replicable ensemble responses to diverse sensory stimuli under various external conditions as well as to changes in network parameters arising from learning-dependent synaptic plasticity.

  17. An efficient method for simulation of noisy coupled multi-dimensional oscillators

    Science.gov (United States)

    Stinchcombe, Adam R.; Forger, Daniel B.

    2016-09-01

    We present an efficient computational method for the study of populations of noisy coupled oscillators. By taking a population density approach in which the probability density of observing an oscillator at a point of state space is the primary variable instead of the states of all of the oscillators, we are able to seamlessly account for intrinsic noise within the oscillators and global coupling within the population. The population is assumed to consist of a large number of oscillators so that the noise process is well sampled over the population. Our numerical method is able to solve the governing equation even in the challenging case of limit cycle oscillators with a large number of state variables. Instead of simulating a prohibitive number of oscillators, our particle method simulates relatively few particles allowing for the efficient solution of the governing equation.

  18. Neuroelectric Tuning of Cortical Oscillations by Apical Dendrites in Loop Circuits

    Directory of Open Access Journals (Sweden)

    David LaBerge

    2017-06-01

    Full Text Available Bundles of relatively long apical dendrites dominate the neurons that make up the thickness of the cerebral cortex. It is proposed that a major function of the apical dendrite is to produce sustained oscillations at a specific frequency that can serve as a common timing unit for the processing of information in circuits connected to that apical dendrite. Many layer 5 and 6 pyramidal neurons are connected to thalamic neurons in loop circuits. A model of the apical dendrites of these pyramidal neurons has been used to simulate the electric activity of the apical dendrite. The results of that simulation demonstrated that subthreshold electric pulses in these apical dendrites can be tuned to specific frequencies and also can be fine-tuned to narrow bandwidths of less than one Hertz (1 Hz. Synchronous pulse outputs from the circuit loops containing apical dendrites can tune subthreshold membrane oscillations of neurons they contact. When the pulse outputs are finely tuned, they function as a local “clock,” which enables the contacted neurons to synchronously communicate with each other. Thus, a shared tuning frequency can select neurons for membership in a circuit. Unlike layer 6 apical dendrites, layer 5 apical dendrites can produce burst firing in many of their neurons, which increases the amplitude of signals in the neurons they contact. This difference in amplitude of signals serves as basis of selecting a sub-circuit for specialized processing (e.g., sustained attention within the typically larger layer 6-based circuit. After examining the sustaining of oscillations in loop circuits and the processing of spikes in network circuits, we propose that cortical functioning can be globally viewed as two systems: a loop system and a network system. The loop system oscillations influence the network system’s timing and amplitude of pulse signals, both of which can select circuits that are momentarily dominant in cortical activity.

  19. Clinical importance of personality difficulties: diagnostically sub-threshold personality disorders.

    Science.gov (United States)

    Karukivi, Max; Vahlberg, Tero; Horjamo, Kalle; Nevalainen, Minna; Korkeila, Jyrki

    2017-01-14

    Current categorical classification of personality disorders has been criticized for overlooking the dimensional nature of personality and that it may miss some sub-threshold personality disturbances of clinical significance. We aimed to evaluate the clinical importance of these conditions. For this, we used a simple four-level dimensional categorization based on the severity of personality disturbance. The sample consisted of 352 patients admitted to mental health services. All underwent diagnostic assessments (SCID-I and SCID-II) and filled in questionnaires concerning their social situation and childhood adversities, and other validated tools, including the Beck Depression Inventory (BDI), Alcohol Use Disorders Identification Test (AUDIT), health-related quality of life (15D), and the five-item Mental Health Index (MHI-5). The patients were categorized into four groups according to the level of personality disturbance: 0 = No personality disturbance, 1 = Personality difficulty (one criterion less than threshold for one or more personality disorders), 2 = Simple personality disorder (one personality disorder), and 3 = Complex/Severe personality disorder (two or more personality disorders or any borderline and antisocial personality disorder). The proportions of the groups were as follows: no personality disturbance 38.4% (n = 135), personality difficulty 14.5% (n = 51), simple personality disorder 19.9% (n = 70), and complex/severe personality disorder 24.4% (n = 86). Patients with no personality disturbance were significantly differentiated (p personality disorders stood out as being worst off. Social dysfunction was related to the severity of the personality disturbance. Patients with a personality difficulty or a simple personality disorder had prominent symptoms and difficulties, but the differences between these groups were mostly non-significant. An elevated severity level of personality disturbance is associated with an

  20. Experimental verification of subthreshold laser therapy using conventional pattern scan laser.

    Directory of Open Access Journals (Sweden)

    Tomoyasu Shiraya

    Full Text Available Leading-edge therapeutic laser technologies are not available at every medical facility; therefore, alternative approaches incorporating novel advances in digital and laser technology into more readily available conventional methods have generated significant research interest. Using a rabbit model, this study investigated whether the algorithm used in the Endpoint Management (EM software system of the latest devices could enable subthreshold laser treatment in conventional retinal tissue laser therapy systems.Two types of devices were used, the PASCAL Streamline 577 and the MC 500-Vixi™, and the laser method was classified into three categories: EM; single-shot using PASCAL with arbitrary energy settings (PSS-SDM; and MC500-VixiTM (VX-SDM, which were performed in eight eyes from four Dutch-Belted rabbits. In EM, 100 mW (100% was set as a landmark, and the laser energy parameters were gradually decreased to 80%, 60%, 50%, 40%, 30%, 20%, and 10%, using a 2 × 3 square pattern. In PSS-SDM and VX-SDM, as control, the laser energy was gradually decreased to 100, 80, 60, 50, 40, 30, 20, and 10 mW. The laser settings were fixed at 200 μm, 20 ms, and a wavelength of 577 μm. To identify and compare the extent of tissue damage at each spot size, optical coherence tomography (OCT and histological findings were used to construct a three-dimensional histopathology image using a confocal laser scanning fluorescence microscope.The spot size at 50% setting on EM was 7183 μm2; PSS-SDM required 50 mW (5503 μm2 to 60 mW (10279 μm2 and VX-SDM required 50 mW (7423 μm2 to create the approximate spot size. Furthermore, at 50 mW of PSS-SDM and VX-SDM, the extent of tissue damage in all three methods was generally in accord with the outer nuclear layer by OCT and inner nuclear layer by histopathological imaging.These findings suggest that it may be possible to perform subthreshold laser therapy using approximations from the EM algorithm.

  1. Harmonic oscillator Green's function

    International Nuclear Information System (INIS)

    Macek, J.H.; Ovchinnikov, S.Yu.; Khrebtukov, D.B.

    2000-01-01

    The Green's function for the harmonic oscillator in three dimensions plays an important role in the theory of atomic collisions. One representation of low-energy ion-atom collisions involves harmonic oscillator potentials. A closed-form expression for the harmonic oscillator Green's function, needed to exploit this representation, is derived. This expression is similar to the expression for the Coulomb Green's function obtained by Hostler and Pratt. Calculations of electron distributions for a model system of ion-atom collisions are reported to illustrate the theory.

  2. Oscillating foil propulsion

    OpenAIRE

    Hauge, Jacob

    2013-01-01

    Unsteady foil theory is discussed and applied on several cases of an oscillating foil. The oscillating foil is meant as a propulsion system for a platform supply vessel.Four case studies of foil oscillation have been performed. A thrust coefficient of 0.1 was achieved at an efficiency of 0.75. A thrust coefficient of minimum 0.184 is necessary to overcome the calm water resistance of the foil.Issues connected to coupled vessel-foil models are discussed.

  3. Neutrino Oscillation Physics

    CERN Document Server

    Kayser, Boris

    2014-04-10

    To complement the neutrino-physics lectures given at the 2011 International School on Astro Particle Physics devoted to Neutrino Physics and Astrophysics (ISAPP 2011; Varenna, Italy), at the 2011 European School of High Energy Physics (ESHEP 2011; Cheila Gradistei, Romania), and, in modified form, at other summer schools, we present here a written description of the physics of neutrino oscillation. This description is centered on a new way of deriving the oscillation probability. We also provide a brief guide to references relevant to topics other than neutrino oscillation that were covered in the lectures.

  4. Oscillator, neutron modulator

    International Nuclear Information System (INIS)

    Agaisse, R.; Leguen, R.; Ombredane, D.

    1960-01-01

    The authors present a mechanical device and an electronic control circuit which have been designed to sinusoidally modulate the reactivity of the Proserpine atomic pile. The mechanical device comprises an oscillator and a mechanism assembly. The oscillator is made of cadmium blades which generate the reactivity oscillation. The mechanism assembly comprises a pulse generator for cycle splitting, a gearbox and an engine. The electronic device comprises or performs pulse detection, an on-off device, cycle pulse shaping, phase separation, a dephasing amplifier, electronic switches, counting scales, and control devices. All these elements are briefly presented

  5. Tunnel field-effect transistor charge-trapping memory with steep subthreshold slope and large memory window

    Science.gov (United States)

    Kino, Hisashi; Fukushima, Takafumi; Tanaka, Tetsu

    2018-04-01

    Charge-trapping memory requires the increase of bit density per cell and a larger memory window for lower-power operation. A tunnel field-effect transistor (TFET) can achieve to increase the bit density per cell owing to its steep subthreshold slope. In addition, a TFET structure has an asymmetric structure, which is promising for achieving a larger memory window. A TFET with the N-type gate shows a higher electric field between the P-type source and the N-type gate edge than the conventional FET structure. This high electric field enables large amounts of charges to be injected into the charge storage layer. In this study, we fabricated silicon-oxide-nitride-oxide-semiconductor (SONOS) memory devices with the TFET structure and observed a steep subthreshold slope and a larger memory window.

  6. Modeling of subthreshold characteristics of short channel junctionless cylindrical surrounding-gate nanowire metal–oxide–silicon field effect transistors

    International Nuclear Information System (INIS)

    Jin, Xiaoshi; Liu, Xi; Lee, Jung-Hee; Lee, Jong-Ho

    2014-01-01

    A subthreshold model of short-channel junctionless field effect transistors with cylindrical surrounding-gate nanowire structure has been proposed. It was based on an approximated solution of two-dimensional Poisson's equation. The derivation of this model was introduced and the accuracy of the proposed models have been verified by comparison with both previous models and the SILVACO Atlas TCAD simulation results, which show good agreement. (paper)

  7. Oscillating fluid power generator

    Science.gov (United States)

    Morris, David C

    2014-02-25

    A system and method for harvesting the kinetic energy of a fluid flow for power generation with a vertically oriented, aerodynamic wing structure comprising one or more airfoil elements pivotably attached to a mast. When activated by the moving fluid stream, the wing structure oscillates back and forth, generating lift first in one direction then in the opposite direction. This oscillating movement is converted to unidirectional rotational movement in order to provide motive power to an electricity generator. Unlike other oscillating devices, this device is designed to harvest the maximum aerodynamic lift forces available for a given oscillation cycle. Because the system is not subjected to the same intense forces and stresses as turbine systems, it can be constructed less expensively, reducing the cost of electricity generation. The system can be grouped in more compact clusters, be less evident in the landscape, and present reduced risk to avian species.

  8. Fluctuations in LC Oscillators

    Directory of Open Access Journals (Sweden)

    O. Ondracek

    1994-03-01

    Full Text Available An analysis of the phase and amplitude fluctuations in oscillators with simple resonant circuit is presented. Negative feedback is used to minimize effect of the inherent noise produced by bipolar transistor on fluctuation characteristics.

  9. High frequency nanotube oscillator

    Science.gov (United States)

    Peng, Haibing [Houston, TX; Zettl, Alexander K [Kensington, TX

    2012-02-21

    A tunable nanostructure such as a nanotube is used to make an electromechanical oscillator. The mechanically oscillating nanotube can be provided with inertial clamps in the form of metal beads. The metal beads serve to clamp the nanotube so that the fundamental resonance frequency is in the microwave range, i.e., greater than at least 1 GHz, and up to 4 GHz and beyond. An electric current can be run through the nanotube to cause the metal beads to move along the nanotube and changing the length of the intervening nanotube segments. The oscillator can operate at ambient temperature and in air without significant loss of resonance quality. The nanotube is can be fabricated in a semiconductor style process and the device can be provided with source, drain, and gate electrodes, which may be connected to appropriate circuitry for driving and measuring the oscillation. Novel driving and measuring circuits are also disclosed.

  10. Hetero-gate-dielectric double gate junctionless transistor (HGJLT) with reduced band-to-band tunnelling effects in subthreshold regime

    Science.gov (United States)

    Ghosh, Bahniman; Mondal, Partha; Akram, M. W.; Bal, Punyasloka; Salimath, Akshay Kumar

    2014-06-01

    We propose a hetero-gate-dielectric double gate junctionless transistor (HGJLT), taking high-k gate insulator at source side and low-k gate insulator at drain side, which reduces the effects of band-to-band tunnelling (BTBT) in the sub-threshold region. A junctionless transistor (JLT) is turned off by the depletion of carriers in the highly doped thin channel (device layer) which results in a significant band overlap between the valence band of the channel region and the conduction band of the drain region, due to off-state drain bias, that triggers electrons to tunnel from the valence band of the channel region to the conduction band of the drain region leaving behind holes in the channel. These effects of band-to-band tunnelling increase the sub-threshold leakage current, and the accumulation of holes in the channel forms a parasitic bipolar junction transistor (n-p-n BJT for channel JLT) in the lateral direction by the source (emitter), channel (base) and drain (collector) regions in JLT structure in off-state. The proposed HGJLT reduces the subthreshold leakage current and suppresses the parasitic BJT action in off-state by reducing the band-to-band tunnelling probability.

  11. Dopa therapy and action impulsivity: subthreshold error activation and suppression in Parkinson's disease.

    Science.gov (United States)

    Fluchère, Frédérique; Deveaux, Manon; Burle, Borís; Vidal, Franck; van den Wildenberg, Wery P M; Witjas, Tatiana; Eusebio, Alexandre; Azulay, Jean-Philippe; Hasbroucq, Thierry

    2015-05-01

    Impulsive actions entail (1) capture of the motor system by an action impulse, which is an urge to act and (2) failed suppression of that impulse in order to prevent a response error. Several studies indicate that dopaminergic treatment can induce action impulsivity in patients diagnosed with Parkinson's disease (PD). Whether this effect is due to increased impulse expression or to decreased impulse suppression remains to be deciphered. We used a novel approach based on electromyographic (EMG) analyses to decipher the effects of the patient's usual dopaminergic therapy on the expression and suppression of subliminal erroneous impulses. To this end, we used a within-subject design and took advantage of the Simon task, that elicits prepotent response tendencies. The patients (N = 15) performed the task on their usual dopaminergic medication and after complete medication withdrawal (for at least 12 h). The correction rate that measures the ability to suppress subthreshold impulsive muscle activity was lower when the patients were on medication as compared to their off medication state (p < 0.05). The incorrect activation rate that measures the capture of the motor system by action impulses was unaffected by medication. Dopa therapy affected action impulsivity. Although medication did not influence the incidence of fast action impulses, it significantly reduced patients' ability to abort and suppress muscle activation related to the incorrect response alternative.

  12. Depressed intracortical inhibition after long trains of subthreshold repetitive magnetic stimuli at low frequency.

    Science.gov (United States)

    Modugno, Nicola; Currà, Antonio; Conte, Antonella; Inghilleri, Maurizio; Fofi, Luisa; Agostino, Rocco; Manfredi, Mario; Berardelli, Alfredo

    2003-12-01

    Repetitive transcranial magnetic stimulation (rTMS) modulates cortical excitability. These effects outlast the rTMS train, and range from inhibition to facilitation according to the variables used for rTMS. Several studies have demonstrated short and long-term effects on motor evoked potential (MEP) size, whereas the effects on intracortical inhibition (ICI) and facilitation (ICF) are still unclear. We investigated short- (1-15 min), intermediate- (16-30 min), and long-term (6 h) effects on intracortical excitability. Fourteen healthy subjects were stimulated with rTMS trains of 900 pulses (1 Hz, 90% resting motor threshold (rMTh)), delivered over the primary motor cortex and the occipital area. MTh, MEP size, silent period, intracortical inhibition at short (ICI) and long inter-stimulus intervals, and ICF were tested before and after rTMS. ICI was reduced 16-30 min after 1 Hz rTMS trains over the primary motor area, whereas the other response variables remained unchanged. The ICI reduction at 16-30 min was reproducible on different days in the same subjects; it was absent at 6 h and after stimulation of the occipital area. Subthreshold 1 Hz rTMS decreases ICI by reducing the excitability of intracortical inhibitory interneurones or by altering the electrical properties of the facilitatory chain of neurons responsible for the I waves.

  13. Low-Voltage Organic Single-Crystal Field-Effect Transistor with Steep Subthreshold Slope.

    Science.gov (United States)

    Yang, Fangxu; Sun, Lingjie; Han, Jiangli; Li, Baili; Yu, Xi; Zhang, Xiaotao; Ren, Xiaochen; Hu, Wenping

    2018-03-06

    Anodization is a promising technique to form high- k dielectrics for low-power organic field-effect transistor (OFET) applications. However, the surface quality of the dielectric, which is mainly inherited from the metal electrode, can be improved further than other fabrication techniques, such as sol-gel. In this study, we applied the template stripping method to fabricate a low-power single-crystalline OFET based on the anodized AlO x dielectric. We found that the template stripping method largely improves the surface roughness of the deposited Al and allows for the formation of a high-quality AlO x high- k dielectric by anodization. The ultraflat AlO x /SAM dielectric combined with a single-crystal 2,6-diphenylanthracene (DPA) semiconductor produced a nearly defect-free interface with a steep subthreshold swing (SS) of 66 mV/decade. The current device is a promising candidate for future ultralow-power applications. Other than metal deposition, template stripping could provide a general approach to improve thin-film quality for many other types of materials and processes.

  14. Enhanced default mode network connectivity with ventral striatum in subthreshold depression individuals.

    Science.gov (United States)

    Hwang, J W; Xin, S C; Ou, Y M; Zhang, W Y; Liang, Y L; Chen, J; Yang, X Q; Chen, X Y; Guo, T W; Yang, X J; Ma, W H; Li, J; Zhao, B C; Tu, Y; Kong, J

    2016-05-01

    Subthreshold depression (StD) is a highly prevalent condition associated with increased service utilization and social morbidity. Nevertheless, due to limitations in current diagnostic systems that set the boundary for major depressive disorder (MDD), very few brain imaging studies on the neurobiology of StD have been carried out, and its underlying neurobiological mechanism remains unclear. In recent years, accumulating evidence suggests that the disruption of the default mode network (DMN), a network involved in self-referential processing, affective cognition, and emotion regulation, is involved in major depressive disorder. Using independent component analysis, we investigated resting-state default mode network (DMN) functional connectivity (FC) changes in two cohorts of StD patients with different age ranges (young and middle-aged, n = 57) as well as matched controls (n = 79). We found significant FC increase between the DMN and ventral striatum (key region in the reward network), in both cohorts of StD patients in comparison with controls. In addition, we also found the FC between the DMN and ventral striatum was positively and significantly associated with scores on the Center for Epidemiologic Studies Depression Scale (CES-D), a measurement of depressive symptomatology. We speculate that this enhanced FC between the DMN and the ventral striatum may reflect a self-compensation to ameliorate the lowered reward function. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Efficient transmission of subthreshold signals in complex networks of spiking neurons.

    Directory of Open Access Journals (Sweden)

    Joaquin J Torres

    Full Text Available We investigate the efficient transmission and processing of weak, subthreshold signals in a realistic neural medium in the presence of different levels of the underlying noise. Assuming Hebbian weights for maximal synaptic conductances--that naturally balances the network with excitatory and inhibitory synapses--and considering short-term synaptic plasticity affecting such conductances, we found different dynamic phases in the system. This includes a memory phase where population of neurons remain synchronized, an oscillatory phase where transitions between different synchronized populations of neurons appears and an asynchronous or noisy phase. When a weak stimulus input is applied to each neuron, increasing the level of noise in the medium we found an efficient transmission of such stimuli around the transition and critical points separating different phases for well-defined different levels of stochasticity in the system. We proved that this intriguing phenomenon is quite robust, as it occurs in different situations including several types of synaptic plasticity, different type and number of stored patterns and diverse network topologies, namely, diluted networks and complex topologies such as scale-free and small-world networks. We conclude that the robustness of the phenomenon in different realistic scenarios, including spiking neurons, short-term synaptic plasticity and complex networks topologies, make very likely that it could also occur in actual neural systems as recent psycho-physical experiments suggest.

  16. Enhancing analog performance and suppression of subthreshold swing using hetero-junctionless double gate TFETs

    Science.gov (United States)

    Chauhan, Sudakar Singh; Sharma, Neha

    2017-12-01

    This paper proposes hetero-junctionless double gate tunnel field effect transistor (HJLDG-TFETs) for suppression of subthreshold swing (SS) using an InAs compound semiconductor material. The proposed device with high dielectric material, gives an excellent performance when InAs uses at source side. Because of low band gap of 0.36 eV , it reduces the potential barrier height of source channel interface causing higher band to band tunneling. Whereas, Si at the drain side with higher band gap of 1.12 eV , increasing the barrier height of drain channel interface causing lower quantum tunneling. As a result, the proposed device with high-k (HfO2) at 30 nm channel section provides a tremendous characteristics with high ION /IOFF ratio of 2 ×1011 , a point SS of 43.30 mV / decade and moderate SS of 56.75 mV / decade . All the above results show that the proposed device is assured for a low power switching application. The variation in gate supply voltage also analyzed for transconductance property of the device.

  17. Subthreshold radiation-induced processes in the bulk and on surfaces and interfaces of solids

    International Nuclear Information System (INIS)

    Itoh, N.

    1998-01-01

    A review is given on the processes induced under irradiation by electronic encounters and by elastic encounters below the knock-on threshold. It is pointed out that electronic encounters cause bond scission that results in defect formation and sputtering in a variety of materials. The conditions for generation of permanent radiation-induced process as a consequence of electronic encounters are critically examined. Two critical issues are localization of electronic excitation energy and energetics. Self-trapping of excitons is one way of localization; otherwise defects are involved in localization and therefore in radiation-induced processes (RIP) by electronic excitation. Arguments on energetics indicate presence of linear and nonlinear electronic process with respect to the density of excitation. The registration of energetic heavy-ion tracks is explained in terms of non-linear electronic processes. The difference in the processes in the bulk, on surfaces and at interfaces is critically discussed. The possible contribution of subthreshold elastic encounters to thermodynamically driven interface reaction is also discussed. (orig.)

  18. Treatment of emotional dysregulation in full syndrome and subthreshold binge eating disorder.

    Science.gov (United States)

    Clyne, Courtney; Latner, Janet D; Gleaves, David H; Blampied, Neville M

    2010-01-01

    The link between negative affect and binge eating in those with binge eating disorder (BED) has been well established. The present study examined the efficacy of a treatment for BED designed to increase recognition and regulation of negative emotion, replicating and extending a previous investigation (Clyne, C., & Blampied, N.M. [2004]. Training in emotion regulation as a treatment for binge eating: A preliminary study. Behaviour Change, 21, 269-281) by including a control group, a larger number of participants, and formal diagnoses rather than classifying binge eating symptomatology from self-report questionnaires. Twenty-three women diagnosed with subthreshold or full syndrome BED (using the Eating Disorders Examination) participated in a treatment program that focused on increasing emotional regulation skills. Each participant completed the Eating Disorders Examination Questionnaire, the Binge Eating Scale, the Emotional Eating Scale, and completed self-monitoring records of binge episodes. Binge abstinence rates following treatment (post-treatment and 1 year follow-up were 78% and 87% respectively) were comparable to other empirically supported treatments for BED. Other positive changes in eating and general pathology were observed. These effects were well-maintained up to 1 year later.

  19. Subthreshold Psychiatric Psychopathology in Functional Gastrointestinal Disorders: Can It Be the Bridge between Gastroenterology and Psychiatry?

    Science.gov (United States)

    Stasi, Cristina; Nisita, Cristiana; Cortopassi, Sonia; Corretti, Giorgio; Gambaccini, Dario; De Bortoli, Nicola; Fani, Bernardo; Simonetti, Natalia; Ricchiuti, Angelo; Dell'Osso, Liliana; Marchi, Santino; Bellini, Massimo

    2017-01-01

    Functional gastrointestinal disorders (FGDs) are multifactorial disorders of the gut-brain interaction. This study investigated the prevalence of Axis I and spectrum disorders in patients with FGD and established the link between FGDs and psychopathological dimensions. A total of 135 consecutive patients with FGD were enrolled. The symptoms' severity was evaluated using questionnaires, while the psychiatric evaluation by clinical interviews established the presence/absence of mental (Diagnostic and Statistical Manual-4th edition, Axis I Diagnosis) or spectrum disorders. Of the 135 patients, 42 (32.3%) had functional dyspepsia, 52 (40.0%) had irritable bowel syndrome, 21 (16.2%) had functional bloating, and 20 (15.4%) had functional constipation. At least one psychiatric disorder was present in 46.9% of the patients, while a suprathreshold panic spectrum was present in 26.2%. Functional constipation was associated with depressive disorders ( p < 0.05), while functional dyspepsia was related to the current major depressive episode ( p < 0.05). Obsessive-compulsive spectrum was correlated with the presence of functional constipation and irritable bowel syndrome ( p < 0.05). The high prevalence of subthreshold psychiatric symptomatology in patients with FGD, which is likely to influence the expression of gastrointestinal symptoms, suggested the usefulness of psychological evaluation in patients with FGDs.

  20. Again on neutrino oscillations

    International Nuclear Information System (INIS)

    Bilenky, S.M.; Pontecorvo, B.

    1976-01-01

    The general case is treated of a weak interaction theory in which a term violating lepton charges is present. In such a scheme the particles with definite masses are Majorana neutrinos (2N if in the weak interaction participate N four-component neutrinos). Neutrino oscillations are discussed and it is shown that the minimum average intensity at the earth of solar neutrinos is 1/2N of the intensity expected when oscillations are absent

  1. Robustness of synthetic oscillators in growing and dividing cells

    Science.gov (United States)

    Paijmans, Joris; Lubensky, David K.; Rein ten Wolde, Pieter

    2017-05-01

    Synthetic biology sets out to implement new functions in cells, and to develop a deeper understanding of biological design principles. Elowitz and Leibler [Nature (London) 403, 335 (2000), 10.1038/35002125] showed that by rational design of the reaction network, and using existing biological components, they could create a network that exhibits periodic gene expression, dubbed the repressilator. More recently, Stricker et al. [Nature (London) 456, 516 (2008), 10.1038/nature07389] presented another synthetic oscillator, called the dual-feedback oscillator, which is more stable. Detailed studies have been carried out to determine how the stability of these oscillators is affected by the intrinsic noise of the interactions between the components and the stochastic expression of their genes. However, as all biological oscillators reside in growing and dividing cells, an important question is how these oscillators are perturbed by the cell cycle. In previous work we showed that the periodic doubling of the gene copy numbers due to DNA replication can couple not only natural, circadian oscillators to the cell cycle [Paijmans et al., Proc. Natl. Acad. Sci. (USA) 113, 4063 (2016), 10.1073/pnas.1507291113], but also these synthetic oscillators. Here we expand this study. We find that the strength of the locking between oscillators depends not only on the positions of the genes on the chromosome, but also on the noise in the timing of gene replication: noise tends to weaken the coupling. Yet, even in the limit of high levels of noise in the replication times of the genes, both synthetic oscillators show clear signatures of locking to the cell cycle. This work enhances our understanding of the design of robust biological oscillators inside growing and diving cells.

  2. Neutrino oscillations with LSND

    International Nuclear Information System (INIS)

    Stancu, Ion

    2000-01-01

    The Liquid Scintillator Neutrino Detector (LSND) at the Los Alamos Meson Physics Facility (LAMPF) has conducted searches for ν-bar μ → ν-bar e oscillations using ν-bar μ from μ + decay at rest (DAR) and for ν μ → ν e oscillations using ν μ from π + decay in flight (DIF). For the 1993-1995 data taking period, significant beam-excess events have been found in both oscillation channels. For the DAR search, a total excess of 51.8 +18.7 -16.9 ± 8.0 events from the ν-bar e p → e + n inverse β-decay reaction is observed, with e + energies between 20-60 MeV. For the DIF search, a total excess of 18.1 ± 6.6 ± 4.0 events from the ν e C → e - X inclusive reaction is observed, with e - energies between 60-200 MeV. If interpreted as neutrino oscillations, these excesses correspond to oscillation probabilities of (3.1±1.2±0.5) x 10 -3 and (2.6 ± 1.0 ± 0.5) x 10 -3 , respectively. Additional data collected during the 1996-1998 runs has been preliminarily analyzed for the DAR channel and yields very good agreement with the previously obtained results, for a combined oscillation probability of (3.3±0.9±0.5) x 10 -3

  3. Characterization of Partial Intrinsic Symmetries

    NARCIS (Netherlands)

    Shehu, Aurela; Brunton, Alan; Wuhrer, Stefanie; Wand, Michael

    2014-01-01

    We present a mathematical framework and algorithm for characterizing and extracting partial intrinsic symmetries of surfaces, which is a fundamental building block for many modern geometry processing algorithms. Our goal is to compute all “significant” symmetry information of the shape, which we

  4. Reading: Intrinsic versus Extrinsic Motivation.

    Science.gov (United States)

    Ediger, Marlow

    Much debate centers on motivating student in reading achievement. Should students feel motivated from within (intrinsic motivation), or is it better to have extrinsic motivation whereby external stimuli are used to help learners achieve optimally in reading? This paper aims to analyze the two points of view about motivating students in reading…

  5. Intrinsic volumes of symmetric cones

    OpenAIRE

    Amelunxen, Dennis; Bürgisser, Peter

    2012-01-01

    We compute the intrinsic volumes of the cone of positive semidefinite matrices over the real numbers, over the complex numbers, and over the quaternions, in terms of integrals related to Mehta's integral. Several applications for the probabilistic analysis of semidefinite programming are given.

  6. Acoustic resonance spectroscopy intrinsic seals

    International Nuclear Information System (INIS)

    Olinger, C.T.; Burr, T.; Vnuk, D.R.

    1994-01-01

    We have begun to quantify the ability of acoustic resonance spectroscopy (ARS) to detect the removal and replacement of the lid of a simulated special nuclear materials drum. Conceptually, the acoustic spectrum of a container establishcs a baseline fingerprint, which we refer to as an intrinsic seal, for the container. Simply removing and replacing the lid changes some of the resonant frequencies because it is impossible to exactly duplicate all of the stress patterns between the lid and container. Preliminary qualitative results suggested that the ARS intrinsic seal could discriminate between cases where a lid has or has not been removed. The present work is directed at quantifying the utility of the ARS intrinsic seal technique, including the technique's sensitivity to ''nuisance'' effects, such as temperature swings, movement of the container, and placement of the transducers. These early quantitative tests support the potential of the ARS intrinsic seal application, but also reveal a possible sensitivity to nuisance effects that could limit environments or conditions under which the technique is effective

  7. Intrinsic Motivation in Physical Education

    Science.gov (United States)

    Davies, Benjamin; Nambiar, Nathan; Hemphill, Caroline; Devietti, Elizabeth; Massengale, Alexandra; McCredie, Patrick

    2015-01-01

    This article describes ways in which educators can use Harter's perceived competence motivation theory, the achievement goal theory, and self-determination theory to develop students' intrinsic motivation to maintain physical fitness, as demonstrated by the Sound Body Sound Mind curriculum and proven effective by the 2013 University of…

  8. Contribution of the primary motor cortex to motor imagery: a subthreshold TMS study.

    Science.gov (United States)

    Pelgrims, Barbara; Michaux, Nicolas; Olivier, Etienne; Andres, Michael

    2011-09-01

    Motor imagery (MI) mostly activates the same brain regions as movement execution (ME) including the primary motor cortex (Brodmann area 4, BA4). However, whether BA4 is functionally relevant for MI remains controversial. The finding that MI tasks are impaired by BA4 virtual lesions induced by transcranial magnetic stimulation (TMS) supports this view, though previous studies do not permit to exclude that BA4 is also involved in other processes such as hand recognition. Additionally, previous works largely underestimated the possible negative consequences of TMS-induced muscle twitches on MI task performance. Here we investigated the role of BA4 in MI by interfering with the function of the left or right BA4 in healthy subjects performing a MI task in which they had to make laterality judgements on rotated hand drawings. We used a subthreshold repetitive TMS protocol and monitored electromyographic activity to exclude undesirable effects of hand muscle twitches. We found that BA4 virtual lesions selectively increased reaction times in laterality judgments on hand drawings, leaving unaffected a task of equal difficulty, involving judgments on letters. Interestingly, the effects of virtual lesions of left and right BA4 on MI task performance were the same irrespective of the laterality (left/right) of hand drawings. A second experiment allowed us to rule out the possibility that BA4 lesions affect visual or semantic processing of hand drawings. Altogether, these results indicate that BA4 contribution to MI tasks is specifically related to the mental simulation process and further emphasize the functional coupling between ME and MI. Copyright © 2010 Wiley-Liss, Inc.

  9. Plasma kallikrein enhances platelet aggregation response by subthreshold doses of ADP.

    Science.gov (United States)

    Ottaiano, Tatiana F; Andrade, Sheila S; de Oliveira, Cleide; Silva, Mariana C C; Buri, Marcus V; Juliano, Maria A; Girão, Manoel J B C; Sampaio, Misako U; Schmaier, Alvin H; Wlodawer, Alexander; Maffei, Francisco H A; Oliva, Maria Luiza V

    2017-04-01

    Human plasma kallikrein (huPK) potentiates platelet responses to subthreshold doses of ADP, although huPK itself, does not induce platelet aggregation. In the present investigation, we observe that huPK pretreatment of platelets potentiates ADP-induced platelet activation by prior proteolysis of the G-protein-coupled receptor PAR-1. The potentiation of ADP-induced platelet activation by huPK is mediated by the integrin α IIb β 3 through interactions with the KGD/KGE sequence motif in huPK. Integrin α IIb β 3 is a cofactor for huPK binding to platelets to support PAR-1 hydrolysis that contributes to activation of the ADP signaling pathway. This activation pathway leads to phosphorylation of Src, AktS 473 , ERK1/2, and p38 MAPK, and to Ca 2+ release. The effect of huPK is blocked by specific antagonists of PAR-1 (SCH 19197) and α IIb β 3 (abciximab) and by synthetic peptides comprising the KGD and KGE sequence motifs of huPK. Further, recombinant plasma kallikrein inhibitor, rBbKI, also blocks this entire mechanism. These results suggest a new function for huPK. Formation of plasma kallikrein lowers the threshold for ADP-induced platelet activation. The present observations are consistent with the notion that plasma kallikrein promotes vascular disease and thrombosis in the intravascular compartment and its inhibition may ameliorate cardiovascular disease and thrombosis. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  10. Sleep problems and disorders among adolescents with persistent and subthreshold attention-deficit/hyperactivity disorders.

    Science.gov (United States)

    Gau, Susan Shur-Fen; Chiang, Huey-Ling

    2009-05-01

    To investigate the sleep schedules, problems, and disorders among adolescents with persistent attention-deficit/hyperactivity disorder (ADHD) and those with partially remitted ADHD symptoms. A case-control study. National Taiwan University and schools in Taipei Patients or Participants: The sample included 281 adolescents (male, 85.4%; 145 with persistent ADHD, 136 with subthreshold ADHD), aged 11 to 17, who were diagnosed with ADHD, according to DSM-IV criteria, at the mean age of 6.7 years (SD = 3.0) and 185 unaffected control subjects. N/A. We conducted psychiatric interviews of participants and their mothers using the Chinese Kiddie-Schedule for Affective Disorders and Schizophrenia-Epidemiology version for making the diagnoses of ADHD, other psychiatric disorders, and sleep problems or disorders. We also collected the medication treatment data and parent and teacher reports of ADHD-related symptoms. Our results showed that adolescents with a childhood diagnosis of ADHD according to DSM-IV criteria, regardless of persistent ADHD, were more likely to have current and lifetime sleep problems and sleep disorders according to DSM-IV (insomnia, sleep terrors, nightmares, bruxism, and snoring). The presence of at least 1 psychiatric comorbid condition increased the risks for insomnia and nightmares. The use of methylphenidate was not associated with further increased risk of sleep problems, except bruxism. Our findings support a relationship between ADHD and sleep problems, which can be partially explained by the psychiatric comorbidities, but did not support a disturbed sleep schedule. Our study suggests that mental health professionals should screen for sleep problems and psychiatric comorbidities among adolescents with a childhood diagnosis of ADHD regardless of the severity of current ADHD symptoms.

  11. Sub-threshold spinal cord stimulation facilitates spontaneous motor activity in spinal rats

    Science.gov (United States)

    2013-01-01

    Background Epidural stimulation of the spinal cord can be used to enable stepping on a treadmill (electrical enabling motor control, eEmc) after a complete mid-thoracic spinal cord transection in adult rats. Herein we have studied the effects of eEmc using a sub-threshold intensity of stimulation combined with spontaneous load-bearing proprioception to facilitate hindlimb stepping and standing during daily cage activity in paralyzed rats. Methods We hypothesized that eEmc combined with spontaneous cage activity would greatly increase the frequency and level of activation of the locomotor circuits in paralyzed rats. Spontaneous cage activity was recorded using a specially designed swivel connector to record EMG signals and an IR based camcorder to record video. Results and conclusion The spinal rats initially were very lethargic in their cages showing little movement. Without eEmc, the rats remained rather inactive with the torso rarely being elevated from the cage floor. When the rats used their forelimbs to move, the hindlimbs were extended and dragged behind with little or no flexion. In contrast, with eEmc the rats were highly active and the hindlimbs showed robust alternating flexion and extension resulting in step-like movements during forelimb-facilitated locomotion and often would stand using the sides of the cages as support. The mean and summed integrated EMG levels in both a hindlimb flexor and extensor muscle were higher with than without eEmc. These data suggest that eEmc, in combination with the associated proprioceptive input, can modulate the spinal networks to significantly amplify the amount and robustness of spontaneous motor activity in paralyzed rats. PMID:24156340

  12. Oscillations in neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Hoeye, Gudrun Kristine

    1999-07-01

    We have studied radial and nonradial oscillations in neutron stars, both in a general relativistic and non-relativistic frame, for several different equilibrium models. Different equations of state were combined, and our results show that it is possible to distinguish between the models based on their oscillation periods. We have particularly focused on the p-, f-, and g-modes. We find oscillation periods of II approx. 0.1 ms for the p-modes, II approx. 0.1 - 0.8 ms for the f-modes and II approx. 10 - 400 ms for the g-modes. For high-order (l (>{sub )} 4) f-modes we were also able to derive a formula that determines II{sub l+1} from II{sub l} and II{sub l-1} to an accuracy of 0.1%. Further, for the radial f-mode we find that the oscillation period goes to infinity as the maximum mass of the star is approached. Both p-, f-, and g-modes are sensitive to changes in the central baryon number density n{sub c}, while the g-modes are also sensitive to variations in the surface temperature. The g-modes are concentrated in the surface layer, while p- and f-modes can be found in all parts of the star. The effects of general relativity were studied, and we find that these are important at high central baryon number densities, especially for the p- and f-modes. General relativistic effects can therefore not be neglected when studying oscillations in neutron stars. We have further developed an improved Cowling approximation in the non-relativistic frame, which eliminates about half of the gap in the oscillation periods that results from use of the ordinary Cowling approximation. We suggest to develop an improved Cowling approximation also in the general relativistic frame. (Author)

  13. Oscillating Finite Sums

    KAUST Repository

    Alabdulmohsin, Ibrahim M.

    2018-03-07

    In this chapter, we use the theory of summability of divergent series, presented earlier in Chap. 4, to derive the analogs of the Euler-Maclaurin summation formula for oscillating sums. These formulas will, in turn, be used to perform many remarkable deeds with ease. For instance, they can be used to derive analytic expressions for summable divergent series, obtain asymptotic expressions of oscillating series, and even accelerate the convergence of series by several orders of magnitude. Moreover, we will prove the notable fact that, as far as the foundational rules of summability calculus are concerned, summable divergent series behave exactly as if they were convergent.

  14. Non-linear oscillations

    CERN Document Server

    Hagedorn, Peter

    1982-01-01

    Thoroughly revised and updated, the second edition of this concise text provides an engineer's view of non-linear oscillations, explaining the most important phenomena and solution methods. Non-linear descriptions are important because under certain conditions there occur large deviations from the behaviors predicted by linear differential equations. In some cases, completely new phenomena arise that are not possible in purely linear systems. The theory of non-linear oscillations thus has important applications in classical mechanics, electronics, communications, biology, and many other branches of science. In addition to many other changes, this edition has a new section on bifurcation theory, including Hopf's theorem.

  15. Friedel oscillations in graphene

    DEFF Research Database (Denmark)

    Lawlor, J. A.; Power, S. R.; Ferreira, M.S.

    2013-01-01

    Symmetry breaking perturbations in an electronically conducting medium are known to produce Friedel oscillations in various physical quantities of an otherwise pristine material. Here we show in a mathematically transparent fashion that Friedel oscillations in graphene have a strong sublattice...... asymmetry. As a result, the presence of impurities and/or defects may impact the distinct graphene sublattices very differently. Furthermore, such an asymmetry can be used to explain the recent observations that nitrogen atoms and dimers are not randomly distributed in graphene but prefer to occupy one...

  16. Oscillators from nonlinear realizations

    Science.gov (United States)

    Kozyrev, N.; Krivonos, S.

    2018-02-01

    We construct the systems of the harmonic and Pais-Uhlenbeck oscillators, which are invariant with respect to arbitrary noncompact Lie algebras. The equations of motion of these systems can be obtained with the help of the formalism of nonlinear realizations. We prove that it is always possible to choose time and the fields within this formalism in such a way that the equations of motion become linear and, therefore, reduce to ones of ordinary harmonic and Pais-Uhlenbeck oscillators. The first-order actions, that produce these equations, can also be provided. As particular examples of this construction, we discuss the so(2, 3) and G 2(2) algebras.

  17. High performance ring oscillators from 10-nm wide silicon nanowire field-effect transistors

    KAUST Repository

    Huang, Ruo-Gu

    2011-06-24

    We explore 10-nm wide Si nanowire (SiNW) field-effect transistors (FETs) for logic applications, via the fabrication and testing of SiNW-based ring oscillators. We report on SiNW surface treatments and dielectric annealing, for producing SiNW FETs that exhibit high performance in terms of large on/off-state current ratio (~108), low drain-induced barrier lowering (~30 mV) and low subthreshold swing (~80 mV/decade). The performance of inverter and ring-oscillator circuits fabricated from these nanowire FETs are also explored. The inverter demonstrates the highest voltage gain (~148) reported for a SiNW-based NOT gate, and the ring oscillator exhibits near rail-to-rail oscillation centered at 13.4 MHz. The static and dynamic characteristics of these NW devices indicate that these SiNW-based FET circuits are excellent candidates for various high-performance nanoelectronic applications. © 2011 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

  18. Renormalization group method for predicting frequency clusters in a chain of nearest-neighbor Kuramoto oscillators.

    Science.gov (United States)

    Kogan, Oleg; Refael, Gil; Cross, Michael; Rogers, Jeffrey

    2008-03-01

    We develop a renormalization group (RG) method to predict frequency clusters and their statistical properties in a 1-dimensional chain of nearest-neighbor coupled Kuramoto oscillators. The intrinsic frequencies and couplings are random numbers chosen from a distribution. The method is designed to work in the regime of strong randomness, where the distribution of intrinsic frequencies and couplings has long tails. Two types of decimation steps are possible: elimination of oscillators with exceptionally large frequency and renormalization of two oscillators bonded by a very large coupling into a single one. Based on these steps, we perform a numerical RG calculation. The oscillators in the renormalized chain correspond to frequency clusters. We compare the RG results with those obtained directly from the numerical solution of the chain's equations of motion.

  19. Layer- and cell-type-specific subthreshold and suprathreshold effects of long-term monocular deprivation in rat visual cortex.

    Science.gov (United States)

    Medini, Paolo

    2011-11-23

    Connectivity and dendritic properties are determinants of plasticity that are layer and cell-type specific in the neocortex. However, the impact of experience-dependent plasticity at the level of synaptic inputs and spike outputs remains unclear along vertical cortical microcircuits. Here I compared subthreshold and suprathreshold sensitivity to prolonged monocular deprivation (MD) in rat binocular visual cortex in layer 4 and layer 2/3 pyramids (4Ps and 2/3Ps) and in thick-tufted and nontufted layer 5 pyramids (5TPs and 5NPs), which innervate different extracortical targets. In normal rats, 5TPs and 2/3Ps are the most binocular in terms of synaptic inputs, and 5NPs are the least. Spike responses of all 5TPs were highly binocular, whereas those of 2/3Ps were dominated by either the contralateral or ipsilateral eye. MD dramatically shifted the ocular preference of 2/3Ps and 4Ps, mostly by depressing deprived-eye inputs. Plasticity was profoundly different in layer 5. The subthreshold ocular preference shift was sevenfold smaller in 5TPs because of smaller depression of deprived inputs combined with a generalized loss of responsiveness, and was undetectable in 5NPs. Despite their modest ocular dominance change, spike responses of 5TPs consistently lost their typically high binocularity during MD. The comparison of MD effects on 2/3Ps and 5TPs, the main affected output cells of vertical microcircuits, indicated that subthreshold plasticity is not uniquely determined by the initial degree of input binocularity. The data raise the question of whether 5TPs are driven solely by 2/3Ps during MD. The different suprathreshold plasticity of the two cell populations could underlie distinct functional deficits in amblyopia.

  20. Subthreshold resonances and resonances in the R -matrix method for binary reactions and in the Trojan horse method

    Science.gov (United States)

    Mukhamedzhanov, A. M.; Shubhchintak, Bertulani, C. A.

    2017-08-01

    In this paper we discuss the R -matrix approach to treat the subthreshold resonances for the single-level and one-channel and for the single-level and two-channel cases. In particular, the expression relating the asymptotic normalization coefficient (ANC) with the observable reduced width, when the subthreshold bound state is the only channel or coupled with an open channel, which is a resonance, is formulated. Since the ANC plays a very important role in nuclear astrophysics, these relations significantly enhance the power of the derived equations. We present the relationship between the resonance width and the ANC for the general case and consider two limiting cases: wide and narrow resonances. Different equations for the astrophysical S factors in the R -matrix approach are presented. After that we discuss the Trojan horse method (THM) formalism. The developed equations are obtained using the surface-integral formalism and the generalized R -matrix approach for the three-body resonant reactions. It is shown how the Trojan horse (TH) double-differential cross section can be expressed in terms of the on-the-energy-shell astrophysical S factor for the binary subreaction. Finally, we demonstrate how the THM can be used to calculate the astrophysical S factor for the neutron generator 13C(α ,n )16O in low-mass AGB stars. At astrophysically relevant energies this astrophysical S factor is controlled by the threshold level 1 /2+,Ex=6356 keV. Here, we reanalyzed recent TH data taking into account more accurately the three-body effects and using both assumptions that the threshold level is a subthreshold bound state or it is a resonance state.

  1. Modeling microtubule oscillations

    DEFF Research Database (Denmark)

    Jobs, E.; Wolf, D.E.; Flyvbjerg, H.

    1997-01-01

    Synchronization of molecular reactions in a macroscopic volume may cause the volume's physical properties to change dynamically and thus reveal much about the reactions. As an example, experimental time series for so-called microtubule oscillations are analyzed in terms of a minimal model for thi...

  2. Neutrino oscillation experiments

    International Nuclear Information System (INIS)

    Camilleri, L.

    1996-01-01

    Neutrino oscillation experiments (ν μ →ν e and ν μ →ν τ ) currently being performed at accelerators are reviewed. Future plans for short and long base-line experiments are summarized. (author) 10 figs., 2 tabs., 29 refs

  3. A simple violin oscillator

    Science.gov (United States)

    Jones, R. T.

    1976-01-01

    For acoustic tests the violin is driven laterally at the bridge by a small speaker of the type commonly found in pocket transistor radios. An audio oscillator excites the tone which is picked up by a sound level meter. Gross patterns of vibration modes are obtained by the Chladni method.

  4. The variational spiked oscillator

    International Nuclear Information System (INIS)

    Aguilera-Navarro, V.C.; Ullah, N.

    1992-08-01

    A variational analysis of the spiked harmonic oscillator Hamiltonian -d 2 / d x 2 + x 2 + δ/ x 5/2 , δ > 0, is reported in this work. A trial function satisfying Dirichlet boundary conditions is suggested. The results are excellent for a large range of values of the coupling parameter. (author)

  5. From excitability to oscillations

    DEFF Research Database (Denmark)

    Postnov, D. E.; Neganova, A. Y.; Jacobsen, J. C. B.

    2013-01-01

    One consequence of cell-to-cell communication is the appearance of synchronized behavior, where many cells cooperate to generate new dynamical patterns. We present a simple functional model of vasomotion based on the concept of a two-mode oscillator with dual interactions: via relatively slow...

  6. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, Sidse M; Hansen, Lars Kai; Parnas, Josef

    2007-01-01

    A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able...

  7. Neutrino oscillation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Camilleri, L. [European Organization for Nuclear Research, Geneva (Switzerland)

    1996-11-01

    Neutrino oscillation experiments ({nu}{sub {mu}}{yields}{nu}{sub e} and {nu}{sub {mu}}{yields}{nu}{sub {tau}}) currently being performed at accelerators are reviewed. Future plans for short and long base-line experiments are summarized. (author) 10 figs., 2 tabs., 29 refs.

  8. Nonlinearity in oscillating bridges

    Directory of Open Access Journals (Sweden)

    Filippo Gazzola

    2013-09-01

    Full Text Available We first recall several historical oscillating bridges that, in some cases, led to collapses. Some of them are quite recent and show that, nowadays, oscillations in suspension bridges are not yet well understood. Next, we survey some attempts to model bridges with differential equations. Although these equations arise from quite different scientific communities, they display some common features. One of them, which we believe to be incorrect, is the acceptance of the linear Hooke law in elasticity. This law should be used only in presence of small deviations from equilibrium, a situation which does not occur in widely oscillating bridges. Then we discuss a couple of recent models whose solutions exhibit self-excited oscillations, the phenomenon visible in real bridges. This suggests a different point of view in modeling equations and gives a strong hint how to modify the existing models in order to obtain a reliable theory. The purpose of this paper is precisely to highlight the necessity of revisiting the classical models, to introduce reliable models, and to indicate the steps we believe necessary to reach this target.

  9. Solar neutrino oscillations

    International Nuclear Information System (INIS)

    Haxton, W.C.

    1993-01-01

    The special properties of solar neutrinos that render this flux so uniquely important in searches for neutrino masses and flavor mixing are reviewed. The effects of matter, including density fluctuations and turbulence, on solar neutrino oscillations are explained through analogies with more familiar atomic physics phenomena

  10. Charge oscillations in orbitrons

    International Nuclear Information System (INIS)

    Porto, M.; Gomes, L.C.

    1981-01-01

    A statistical model for the electron distribution in orbitrons is constructed where the effect of the end plates is considered. A comparison is made with the measured density of charge. The electromagnetic oscillations generated by orbitrons are calculated as pressure waves and the results obtained are compared with the data. (Author) [pt

  11. solar neutrino oscillation phenomenology

    Indian Academy of Sciences (India)

    sRUBABATI GOsWAMI. Harish-Chandra Research Institute, Chhatnag Road, Jhusi, Allahabad 211 019, India. Email: sruba@mri.ernet.in. Abstract. This article summarises the status of the solar neutrino oscillation phe- nomenology at the end of 2002 in the light of the SNO and KamLAND results. We first present the allowed ...

  12. Suitability of FinFET introduction into eDRAM cells for operate at sub-threshold level

    OpenAIRE

    Amat, Esteve; Calomarde Palomino, Antonio; Canal Corretger, Ramon; Rubio Sola, Jose Antonio

    2017-01-01

    This paper explores the feasibility, in terms of performance and reliability, of gain-cell embedded DRAM (eDRAM) to be operative at sub-threshold range, when they are implemented with 10 nm FinFET devices. The use of individual transistor resizing in order to achieve better cell performance (i.e. retention time, access time, and energy consumption) at the sub-VT operating level is studied. In this scenario, asymmetrically resizing the memory cell, since we modify the channel length of the wri...

  13. Detecting Nosocomial Intrinsic Infections through Relating Bacterial ...

    African Journals Online (AJOL)

    Sierra Leone Journal of Biomedical Research ... Surgical procedures often lead to both intrinsic and extrinsic infections. ... This study demonstrated surgical procedures as precursory to intrinsic infections and that bacterial pathogens found on wounds and endogenous indicators of surgery are links to intrinsic infection.

  14. Analysis of subthreshold pace-maker currents in chick embryonic heart cells.

    Science.gov (United States)

    Clay, J R; Shrier, A

    1981-03-01

    1. Small re-aggregates of cells dissociated from the ventricles of 7-day-old chick embryonic hearts beat spontaneously in low external potassium concentration (Ko = 1.3 mM) tissue culture medium. This activity was blocked by the addition of tetrodotoxin (TTX) or potassium ions to the external medium. 2. A two-micro-electrode voltage-clamp technique was used to analyse the subthreshold currents responsible for the pace-maker depolarization. 3. Voltage-clamp steps 6-10 sec in duration revealed a time-dependent current having first order kinetics. Its membrane potential range of steady-state activation was -90 to -60 mV. 4. The current kinetics were qualitatively similar to those of Hodgkin & Huxley (1952b) with a peak time constant of approximately 1 sec at V = -75 mV. The kinetics were independent of Ko. 5. The time-dependent current was attributed to gated membrane channels. The fully activated current-voltage (I-V) relation of the channels was determined from the ratio of the amplitudes of the time-dependent currents during and after voltage-clamp steps following the procedure of Noble & Tsien (1968). 6. The fully activated I-V relation displayed inward rectification with negative slope conductance at potentials more than 15 mV positive to its reversal potential. Changes of Ko shifted the I-V curve along the voltage axis like a potassium electrode. 7. The time-independent (background) current was obtained by subtracting the gated channel current from the steady-state I-V curve. This current also rectified in the inward direction. 8. The inwardly rectifying I-V relations were theoretically described by a channel having a row of ion-selective sites along which ions move in a single file (Hodgkin & Keynes, 1955), and a membrane-bound particle which blocked the channel in a voltage-dependent manner. 9. The relationship of the voltage-clamp results to spontaneous activity is discussed and comparisons are made with measurements from whole embryonic heart and other

  15. Bimodal oscillations in nephron autoregulation

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Pavlov, A N; Mosekilde, E

    2002-01-01

    The individual functional unit of the kidney (the nephron) displays oscillations in its pressure and flow regulation at two different time scales: fast oscillations associated with a myogenic dynamics of the afferent arteriole, and slower oscillations arising from a delay in the tubuloglomerular ...

  16. Effects of the gate dielectric on the subthreshold transport of carbon nanotube network transistors grown by using plasma-enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    Jeong, Seung Geun; Park, Wan Jun

    2010-01-01

    In this study, we investigated the subthreshold slope of random network carbon nanotube transistors with different geometries and passivations. Single-wall carbon nanotubes with lengths of 1-2 m were grown by using plasma-enhanced chemical vapor deposition to form the transistor channels. A critical channel length, where the subthreshold slope was saturated, of 7 μm was obtained. This was due to the percolational behavior of the nanotube random networks. With the dielectric passivation, the subthreshold slope was dramatically reduced from 9 V/decade to 0.9 V/decade by reducing interfacial trap sites, which then reduced the interface capacitance between the nanotube network and the gate dielectric.

  17. Observation and analysis of oscillations in linear accelerators

    International Nuclear Information System (INIS)

    Seeman, J.T.

    1991-11-01

    This report discusses the following on oscillation in linear accelerators: Betatron Oscillations; Betatron Oscillations at High Currents; Transverse Profile Oscillations; Transverse Profile Oscillations at High Currents.; Oscillation and Profile Transient Jitter; and Feedback on Transverse Oscillations

  18. Intrinsic cylindrical and spherical waves

    International Nuclear Information System (INIS)

    Ludlow, I K

    2008-01-01

    Intrinsic waveforms associated with cylindrical and spherical Bessel functions are obtained by eliminating the factors responsible for the inverse radius and inverse square radius laws of wave power per unit area of wavefront. The resulting expressions are Riccati-Bessel functions for both cases and these can be written in terms of amplitude and phase functions of order v and wave variable z. When z is real, it is shown that a spatial phase angle of the intrinsic wave can be defined and this, together with its amplitude function, is systematically investigated for a range of fixed orders and varying z. The derivatives of Riccati-Bessel functions are also examined. All the component functions exhibit different behaviour in the near field depending on the order being less than, equal to or greater than 1/2. Plots of the phase angle can be used to display the locations of the zeros of the general Riccati-Bessel functions and lead to new relations concerning the ordering of the real zeros of Bessel functions and the occurrence of multiple zeros when the argument of the Bessel function is fixed

  19. The neuroanatomy of subthreshold depressive symptoms in Huntington's disease: a combined diffusion tensor imaging (DTI) and voxel-based morphometry (VBM) study.

    Science.gov (United States)

    Sprengelmeyer, R; Orth, M; Müller, H-P; Wolf, R C; Grön, G; Depping, M S; Kassubek, J; Justo, D; Rees, E M; Haider, S; Cole, J H; Hobbs, N Z; Roos, R A C; Dürr, A; Tabrizi, S J; Süssmuth, S D; Landwehrmeyer, G B

    2014-07-01

    Depressive symptoms are prominent psychopathological features of Huntington's disease (HD), making a negative impact on social functioning and well-being. We compared the frequencies of a history of depression, previous suicide attempts and current subthreshold depression between 61 early-stage HD participants and 40 matched controls. The HD group was then split based on the overall HD group's median Hospital Anxiety and Depression Scale-depression score into a group of 30 non-depressed participants (mean 0.8, s.d. = 0.7) and a group of 31 participants with subthreshold depressive symptoms (mean 7.3, s.d. = 3.5) to explore the neuroanatomy underlying subthreshold depressive symptoms in HD using voxel-based morphometry (VBM) and diffusion tensor imaging (DTI). Frequencies of history of depression, previous suicide attempts or current subthreshold depressive symptoms were higher in HD than in controls. The severity of current depressive symptoms was also higher in HD, but not associated with the severity of HD motor signs or disease burden. Compared with the non-depressed HD group DTI revealed lower fractional anisotropy (FA) values in the frontal cortex, anterior cingulate cortex, insula and cerebellum of the HD group with subthreshold depressive symptoms. In contrast, VBM measures were similar in both HD groups. A history of depression, the severity of HD motor signs or disease burden did not correlate with FA values of these regions. Current subthreshold depressive symptoms in early HD are associated with microstructural changes - without concomitant brain volume loss - in brain regions known to be involved in major depressive disorder, but not those typically associated with HD pathology.

  20. Black Phosphorus Based Field Effect Transistors with Simultaneously Achieved Near Ideal Subthreshold Swing and High Hole Mobility at Room Temperature.

    Science.gov (United States)

    Liu, Xinke; Ang, Kah-Wee; Yu, Wenjie; He, Jiazhu; Feng, Xuewei; Liu, Qiang; Jiang, He; Dan Tang; Wen, Jiao; Lu, Youming; Liu, Wenjun; Cao, Peijiang; Han, Shun; Wu, Jing; Liu, Wenjun; Wang, Xi; Zhu, Deliang; He, Zhubing

    2016-04-22

    Black phosphorus (BP) has emerged as a promising two-dimensional (2D) material for next generation transistor applications due to its superior carrier transport properties. Among other issues, achieving reduced subthreshold swing and enhanced hole mobility simultaneously remains a challenge which requires careful optimization of the BP/gate oxide interface. Here, we report the realization of high performance BP transistors integrated with HfO2 high-k gate dielectric using a low temperature CMOS process. The fabricated devices were shown to demonstrate a near ideal subthreshold swing (SS) of ~69 mV/dec and a room temperature hole mobility of exceeding >400 cm(2)/Vs. These figure-of-merits are benchmarked to be the best-of-its-kind, which outperform previously reported BP transistors realized on traditional SiO2 gate dielectric. X-ray photoelectron spectroscopy (XPS) analysis further reveals the evidence of a more chemically stable BP when formed on HfO2 high-k as opposed to SiO2, which gives rise to a better interface quality that accounts for the SS and hole mobility improvement. These results unveil the potential of black phosphorus as an emerging channel material for future nanoelectronic device applications.

  1. From Asperger's Autistischen Psychopathen to DSM-5 Autism Spectrum Disorder and Beyond: A Subthreshold Autism Spectrum Model.

    Science.gov (United States)

    Dell'Osso, Liliana; Luche, Riccardo Dalle; Gesi, Camilla; Moroni, Ilenia; Carmassi, Claudia; Maj, Mario

    2016-01-01

    Growing interest has recently been devoted to partial forms of autism, lying at the diagnostic boundaries of those conditions previously diagnosed as Asperger's Disorder. This latter includes an important retrieval of the European classical psychopathological concepts of adult autism to which Hans Asperger referred in his work. Based on the review of Asperger's Autistische Psychopathie , from first descriptions through the DSM-IV Asperger's Disorder and up to the recent DSM-5 Autism Spectrum Disorder, the paper aims to propose a Subthreshold Autism Spectrum Model that encompasses not only threshold-level manifestations but also mild/atypical symptoms, gender-specific features, behavioral manifestations and personality traits associated with Autism Spectrum Disorder. This model includes, but is not limited to, the so-called broad autism phenotype spanning across the general population that does not fully meet Autism Spectrum Disorder criteria. From this perspective, we propose a subthreshold autism as a unique psychological/behavioral model for research that could help to understand the neurodevelopmental trajectories leading from autistic traits to a broad range of mental disorders.

  2. Impact of novel olfactory stimuli at supra and subthreshold concentrations on the perceived sweetness of sucrose after associative learning.

    Science.gov (United States)

    Labbe, David; Martin, Nathalie

    2009-10-01

    The impact of coexposure to a novel olfactory stimulation in combination with sweet taste on the construction of perceptual interaction was studied. The first objective was to explore whether a new flavoring perceived retronasally at a subthreshold concentration could enhance the perceived sweetness after a coexposure with sucrose using an approach encouraging associative learning. After validating the associative learning by showing an increase of the perceived sweetness by the flavoring at a suprathreshold concentration, we showed that the flavoring stimulation did not impact the perceived sweetness when presented at a subthreshold concentration. The second objective was to validate the absence of associative learning when subjects were exposed to the sucrose flavored solution in a context of coexposure akin to sensory profiling training. As expected, we confirmed that coexposure following sensory profiling training did not promote associative learning, probably because this approach encouraged subjects to consider the olfactory and sweet taste combination as a set of distinct qualities. The potential role of neural integration processes in these results was discussed.

  3. Subthreshold psychotic symptom distress, self-stigma, and peer social support among college students with mental health concerns.

    Science.gov (United States)

    Denenny, Danielle; Thompson, Elizabeth; Pitts, Steven C; Dixon, Lisa B; Schiffman, Jason

    2015-06-01

    The primary aim of this study was to explore the potential moderating effect of social support on the relation between distress caused by psychosis risk symptoms and self-stigma among college students with mental health diagnoses. Participants were young adult college students who endorsed having a past or present mental health diagnosis (n = 63). Self-report data were examined from the Prodromal Questionnaire-Brief, a measure of subthreshold psychosis risk symptoms; the Self-Concurrence/Application subscale of the Self-Stigma of Mental Illness Scale, a measure of self-stigma; and the Friendships subscale of the Lubben Social Network Scale-Revised, a measure of social support from peers. There was a modest direct relation between distress associated with psychosis risk symptoms and self-stigma. There was a larger relation between distress from risk symptoms and self-stigma for those with low social support compared to those with mean and high social support. Although causality cannot be determined based on this study, a strong relation between symptom distress and stigma was found among those reporting low peer social support. Interventions that target both self-stigma and social support might be relevant for young adults with a history of mental health concerns who currently endorse subthreshold psychotic symptoms. (c) 2015 APA, all rights reserved).

  4. From Asperger's Autistischen Psychopathen to DSM-5 Autism Spectrum Disorder and Beyond: A Subthreshold Autism Spectrum Model

    Science.gov (United States)

    Dell’Osso, Liliana; Luche, Riccardo Dalle; Gesi, Camilla; Moroni, Ilenia; Carmassi, Claudia; Maj, Mario

    2016-01-01

    Growing interest has recently been devoted to partial forms of autism, lying at the diagnostic boundaries of those conditions previously diagnosed as Asperger’s Disorder. This latter includes an important retrieval of the European classical psychopathological concepts of adult autism to which Hans Asperger referred in his work. Based on the review of Asperger's Autistische Psychopathie, from first descriptions through the DSM-IV Asperger’s Disorder and up to the recent DSM-5 Autism Spectrum Disorder, the paper aims to propose a Subthreshold Autism Spectrum Model that encompasses not only threshold-level manifestations but also mild/atypical symptoms, gender-specific features, behavioral manifestations and personality traits associated with Autism Spectrum Disorder. This model includes, but is not limited to, the so-called broad autism phenotype spanning across the general population that does not fully meet Autism Spectrum Disorder criteria. From this perspective, we propose a subthreshold autism as a unique psychological/behavioral model for research that could help to understand the neurodevelopmental trajectories leading from autistic traits to a broad range of mental disorders. PMID:27867417

  5. Acoustics waves and oscillations

    CERN Document Server

    Sen, S.N.

    2013-01-01

    Parameters of acoustics presented in a logical and lucid style Physical principles discussed with mathematical formulations Importance of ultrasonic waves highlighted Dispersion of ultrasonic waves in viscous liquids explained This book presents the theory of waves and oscillations and various applications of acoustics in a logical and simple form. The physical principles have been explained with necessary mathematical formulation and supported by experimental layout wherever possible. Incorporating the classical view point all aspects of acoustic waves and oscillations have been discussed together with detailed elaboration of modern technological applications of sound. A separate chapter on ultrasonics emphasizes the importance of this branch of science in fundamental and applied research. In this edition a new chapter ''Hypersonic Velocity in Viscous Liquids as revealed from Brillouin Spectra'' has been added. The book is expected to present to its readers a comprehensive presentation of the subject matter...

  6. Nonlinear (Anharmonic Casimir Oscillator

    Directory of Open Access Journals (Sweden)

    Habibollah Razmi

    2011-01-01

    Full Text Available We want to study the dynamics of a simple linear harmonic micro spring which is under the influence of the quantum Casimir force/pressure and thus behaves as a (an nonlinear (anharmonic Casimir oscillator. Generally, the equation of motion of this nonlinear micromechanical Casimir oscillator has no exact solvable (analytical solution and the turning point(s of the system has (have no fixed position(s; however, for particular values of the stiffness of the micro spring and at appropriately well-chosen distance scales and conditions, there is (are approximately sinusoidal solution(s for the problem (the variable turning points are collected in a very small interval of positions. This, as a simple and elementary plan, may be useful in controlling the Casimir stiction problem in micromechanical devices.

  7. Plasma oscillations in porous samples

    Directory of Open Access Journals (Sweden)

    Kornyushin Y.

    2004-01-01

    Full Text Available The influence of the shape of a sample on the type of uniform dipole collective electrons oscillations is discussed. In samples of a bulk shape uniform bulk dipole oscillations cannot exist. They exist in samples of a thin slab shape only. However in essentially porous materials the electrostatic energy of the oscillation in a sample is considerably larger thus leading to stronger restoring force and higher frequency of the oscillation. When this frequency exceeds the Langmuir frequency, the oscillation becomes of a bulk type. .

  8. Neutrino Masses and Oscillations

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit; Treille, Daniel

    2002-01-01

    This course will not cover its subject in the customary way. The emphasis will be on the simple theoretical concepts (helicity, handedness, chirality, Majorana masses) which are obscure in most of the literature, and on the quantum mechanics of oscillations, that ALL books get wrong. Which, hopefully, will not deter me from discussing some of the most interesting results from the labs and from the cosmos.

  9. Oscillations in quasineutral plasmas

    International Nuclear Information System (INIS)

    Grenier, E.

    1996-01-01

    The purpose of this article is to describe the limit, as the vacuum electric permittivity goes to zero, of a plasma physics system, deduced from the Vlasov-Poisson system for special initial data (distribution functions which are analytic in the space variable, with compact support in velocity), a limit also called open-quotes quasineutral regimeclose quotes of the plasma, and the related oscillations of the electric field, with high frequency in time. 20 refs

  10. Oscillations with laboratory neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Saitta, Biagio

    2001-05-01

    The status of searches for oscillations using neutrinos produced in the laboratory is reviewed. The most recent results from experiments approaching completion are reported and the potential capabilities of long baseline projects being developed in USA and Europe are considered and compared. The steps that should naturally follow this new generation of experiments are outlined and the impact of future facilities - such as neutrino factories or conventional superbeams - in precision measurements of elements of the neutrino mixing matrix is discussed.

  11. A New Analytical Subthreshold Behavior Model for Single-Halo, Dual-Material Gate Silicon-on-Insulator Metal Oxide Semiconductor Field Effect Transistor

    Science.gov (United States)

    Chiang, Te-Kuang

    2008-11-01

    On the basis of the exact solution of the two-dimensional Poisson equation, a new analytical subthreshold behavior model consisting of the two-dimensional potential, threshold voltage, and subthreshold current for the single-halo, dual-material gate (SHDMG) silicon-on-insulator (SOI) metal oxide semiconductor field effect transistor (MOSFET) is developed. The model is verified by the good agreement with a numerical simulation using the device simulator MEDICI. The model not only offers a physical insight into device physics but is also an efficient device model for the circuit simulation.

  12. Role of spin-transfer torques on synchronization and resonance phenomena in stochastic magnetic oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Accioly, Artur [Instituto de Física, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre (Brazil); Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay (France); Locatelli, Nicolas; Querlioz, Damien; Kim, Joo-Von [Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay (France); Mizrahi, Alice [Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay (France); Unité Mixte de Physique CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, F91767 Palaiseau (France); Pereira, Luis G. [Instituto de Física, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre (Brazil); Grollier, Julie [Unité Mixte de Physique CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, F91767 Palaiseau (France)

    2016-09-07

    A theoretical study on how synchronization and resonance-like phenomena in superparamagnetic tunnel junctions can be driven by spin-transfer torques is presented. We examine the magnetization of a superparamagnetic free layer that reverses randomly between two well-defined orientations due to thermal fluctuations, acting as a stochastic oscillator. When subject to an external ac forcing, this system can present stochastic resonance and noise-enhanced synchronization. We focus on the roles of the mutually perpendicular damping-like and field-like torques, showing that the response of the system is very different at low and high frequencies. We also demonstrate that the field-like torque can increase the efficiency of the current-driven forcing, especially at sub-threshold electric currents. These results can be useful for possible low-power, more energy efficient applications.

  13. Inhibition of Intrinsic Thrombin Generation

    Directory of Open Access Journals (Sweden)

    Thomas W. Stief MD

    2006-01-01

    Full Text Available Background The contact phase of coagulation is of physiologic/pathophysiologic importance, whenever unphysiologic polynegative substances such as cell fragments (microparticles get in contact with blood. There are several clinically used inhibitors of intrinsic thrombin generation. Here the inhibitory concentrations 50% (IC50 of these anticoagulants are measured by the highly specific thrombin generation assay INCA. Methods Unfrozen pooled normal citrated plasma in polystyrole tubes was supplemented at 23°C in duplicate with 0–2 IU/ml low molecular weight heparin (dalteparin, 0–2 IU/ml unfractionated heparin, 0–500 KIU/ml aprotinin, or 0–40 mM arginine. 50 μl plasma or 1 IU/ml thrombin standard were pipetted into a polystyrole microtiter plate with flat bottom. 5 μl SiO 2 /CaCl 2 - reagent (INCA activator were added and after 0–30 min incubation at 37°C 100 μl 2.5 M arginine, pH 8.6, were added; arginine inhibits hemostasis activation and depolymerizes generated fibrin within 20 min at 23°C. The in the physiologic 37°C incubation phase generated thrombin was then chromogenically detected. The intra-assay CV values were < 5%. Results and Discussion The approximate IC50 were 0.01 IU/ml dalteparin, 0.02 IU/ml heparin, 25 KIU/ml aprotinin, and 12 mM arginine. The efficiency of any anticoagulant on intrinsic thrombin generation should be measured for each individual patient. Abbreviations IIa, thrombin; δA, increase in absorbance; APTT, activated partial thromboplastin time; CRT, coagulation reaction time (at 37°C in water-bath; F-wells, polystyrole microtiter plates with flat bottom; IC50, inhibitory concentration 50%; INCA, intrinsic coagulation activity assay; IU, international units; KIU, kallikrein inhibiting unis; LMWH, low molecular weight heparin; mA, milli-absorbance units; PSL, pathromtin SL®; RT, room temperature (23°C; U-wells, polystyrole microtiter plates with round bottom.

  14. Digital signal processing reveals circadian baseline oscillation in majority of mammalian genes.

    Directory of Open Access Journals (Sweden)

    Andrey A Ptitsyn

    2007-06-01

    Full Text Available In mammals, circadian periodicity has been described for gene expression in the hypothalamus and multiple peripheral tissues. It is accepted that 10%-15% of all genes oscillate in a daily rhythm, regulated by an intrinsic molecular clock. Statistical analyses of periodicity are limited by the small size of datasets and high levels of stochastic noise. Here, we propose a new approach applying digital signal processing algorithms separately to each group of genes oscillating in the same phase. Combined with the statistical tests for periodicity, this method identifies circadian baseline oscillation in almost 100% of all expressed genes. Consequently, circadian oscillation in gene expression should be evaluated in any study related to biological pathways. Changes in gene expression caused by mutations or regulation of environmental factors (such as photic stimuli or feeding should be considered in the context of changes in the amplitude and phase of genetic oscillations.

  15. Intrinsic rotation with gyrokinetic models

    International Nuclear Information System (INIS)

    Parra, Felix I.; Barnes, Michael; Catto, Peter J.; Calvo, Iván

    2012-01-01

    The generation of intrinsic rotation by turbulence and neoclassical effects in tokamaks is considered. To obtain the complex dependences observed in experiments, it is necessary to have a model of the radial flux of momentum that redistributes the momentum within the tokamak in the absence of a preexisting velocity. When the lowest order gyrokinetic formulation is used, a symmetry of the model precludes this possibility, making small effects in the gyroradius over scale length expansion necessary. These effects that are usually small become important for momentum transport because the symmetry of the lowest order gyrokinetic formulation leads to the cancellation of the lowest order momentum flux. The accuracy to which the gyrokinetic equation needs to be obtained to retain all the physically relevant effects is discussed.

  16. Bifurcations of mixed-mode oscillations in a stellate cell model

    Science.gov (United States)

    Wechselberger, Martin; Weckesser, Warren

    2009-08-01

    Experimental recordings of the membrane potential of stellate cells within the entorhinal cortex show a transition from subthreshold oscillations (STOs) via mixed-mode oscillations (MMOs) to relaxation oscillations under increased injection of depolarizing current. Acker et al. introduced a 7D conductance based model which reproduces many features of the oscillatory patterns observed in these experiments. For the first time, we present a comprehensive bifurcation analysis of this model by using the software package AUTO. In particular, we calculate the stable MMO branches within the bifurcation diagram of this model, as well as other MMO patterns which are unstable. We then use geometric singular perturbation theory to demonstrate how the bifurcations are governed by a 3D reduced model introduced by Rotstein et al. We extend their analysis to explain all observed MMO patterns within the bifurcation diagram. A key role in this bifurcation analysis is played by a novel homoclinic bifurcation structure connecting to a saddle equilibrium on the unstable branch of the corresponding critical manifold. This type of homoclinic connection is possible due to canards of folded node (folded saddle-node) type.

  17. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, S.M.; Hansen, Lars Kai; Parnas, J.

    2007-01-01

    A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able...... contralateral to stimulus side and additionally an unexpected 20 Hz activity was observed slightly lateralized in the frontal central region. The gamma phase locking may be a manifestation of early somatosensory feature integration. The analyses suggest that the high frequency activity consists of two distinct...

  18. Neutrino oscillations at LAMPF

    International Nuclear Information System (INIS)

    Carlini, R.; Choi, C.; Donohue, J.

    1985-01-01

    Work at Argonne continues on the construction of the neutrino oscillation experiment (E645). Construction of detector supports and active shield components were completed at the Provo plant of the principal contractor for the project (the Pittsburgh-Des Moines Corporation). Erection of the major experimental components was completed at the LAMPF experimental site in mid-March 1985. Work continues on the tunnel which will house the detector. Construction of detector components (scintillators and proportional drift tubes) is proceeding at Ohio State University and Louisiana State University. Consolidation of these components into the 20-ton neutrino detector is beginning at LAMPF

  19. Theory of oscillators

    CERN Document Server

    Andronov, Aleksandr Aleksandrovich; Vitt, Aleksandr Adolfovich

    1966-01-01

    Theory of Oscillators presents the applications and exposition of the qualitative theory of differential equations. This book discusses the idea of a discontinuous transition in a dynamic process. Organized into 11 chapters, this book begins with an overview of the simplest type of oscillatory system in which the motion is described by a linear differential equation. This text then examines the character of the motion of the representative point along the hyperbola. Other chapters consider examples of two basic types of non-linear non-conservative systems, namely, dissipative systems and self-

  20. Incentives and intrinsic motivation in healthcare

    Directory of Open Access Journals (Sweden)

    Mikel Berdud

    2016-11-01

    Conclusions: The conclusions could act as a guide to support the optimal design of incentive policies and schemes within health organisations when healthcare professionals are intrinsically motivated.

  1. Algebraic description of intrinsic modes in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Leviatan, A. (Los Alamos National Lab., NM (USA))

    1990-01-01

    We present a procedure for extracting normal modes in algebraic number-conserving systems of interacting bosons relevant for collective states in even-even nuclei. The Hamiltonian is resolved into intrinsic (bandhead related) and collective (in-band related) parts. Shape parameters are introduced through non-spherical boson bases. Intrinsic modes decoupled from the spurious modes are obtained from the intrinsic part of the Hamiltonian in the limit of large number of bosons. Intrinsic states are constructed and serve to evaluate electromagnetic transition rates. The method is illustrated for systems with one type of boson as well as with proton-neutron bosons. (author).

  2. Algebraic description of intrinsic modes in nuclei

    International Nuclear Information System (INIS)

    Leviatan, A.

    1990-01-01

    We present a procedure for extracting normal modes in algebraic number-conserving systems of interacting bosons relevant for collective states in even-even nuclei. The Hamiltonian is resolved into intrinsic (bandhead related) and collective (in-band related) parts. Shape parameters are introduced through non-spherical boson bases. Intrinsic modes decoupled from the spurious modes are obtained from the intrinsic part of the Hamiltonian in the limit of large number of bosons. Intrinsic states are constructed and serve to evaluate electromagnetic transition rates. The method is illustrated for systems with one type of boson as well as with proton-neutron bosons. (author)

  3. Brain Oscillations, Hypnosis, and Hypnotizability

    Science.gov (United States)

    Jensen, Mark P.; Adachi, Tomonori; Hakimian, Shahin

    2014-01-01

    In this article, we summarize the state-of-science knowledge regarding the associations between hypnosis and brain oscillations. Brain oscillations represent the combined electrical activity of neuronal assemblies, and are usually measured as specific frequencies representing slower (delta, theta, alpha) and faster (beta, gamma) oscillations. Hypnosis has been most closely linked to power in the theta band and changes in gamma activity. These oscillations are thought to play a critical role in both the recording and recall of declarative memory and emotional limbic circuits. Here we propose that it is this role that may be the mechanistic link between theta (and perhaps gamma) oscillations and hypnosis; specifically that theta oscillations may facilitate, and that changes in gamma activity observed with hypnosis may underlie, some hypnotic responses. If these hypotheses are supported, they have important implications for both understanding the effects of hypnosis, and for enhancing response to hypnotic treatments. PMID:25792761

  4. Brain Oscillations, Hypnosis, and Hypnotizability.

    Science.gov (United States)

    Jensen, Mark P; Adachi, Tomonori; Hakimian, Shahin

    2015-01-01

    This article summarizes the state-of-science knowledge regarding the associations between hypnosis and brain oscillations. Brain oscillations represent the combined electrical activity of neuronal assemblies, usually measured as specific frequencies representing slower (delta, theta, alpha) and faster (beta, gamma) oscillations. Hypnosis has been most closely linked to power in the theta band and changes in gamma activity. These oscillations are thought to play a critical role in both the recording and recall of declarative memory and emotional limbic circuits. The authors propose that this role may be the mechanistic link between theta (and perhaps gamma) oscillations and hypnosis, specifically, that the increases in theta oscillations and changes in gamma activity observed with hypnosis may underlie some hypnotic responses. If these hypotheses are supported, they have important implications for both understanding the effects of hypnosis and for enhancing response to hypnotic treatments.

  5. Bounded-oscillation Pushdown Automata

    Directory of Open Access Journals (Sweden)

    Pierre Ganty

    2016-09-01

    Full Text Available We present an underapproximation for context-free languages by filtering out runs of the underlying pushdown automaton depending on how the stack height evolves over time. In particular, we assign to each run a number quantifying the oscillating behavior of the stack along the run. We study languages accepted by pushdown automata restricted to k-oscillating runs. We relate oscillation on pushdown automata with a counterpart restriction on context-free grammars. We also provide a way to filter all but the k-oscillating runs from a given PDA by annotating stack symbols with information about the oscillation. Finally, we study closure properties of the defined class of languages and the complexity of the k-emptiness problem asking, given a pushdown automaton P and k >= 0, whether P has a k-oscillating run. We show that, when k is not part of the input, the k-emptiness problem is NLOGSPACE-complete.

  6. An Artificial Muscle Ring Oscillator

    OpenAIRE

    O’Brien, Benjamin Marc; Anderson, Iain Alexander

    2012-01-01

    Dielectric elastomer artificialmuscles have great potential for the creation of novel pumps, motors, and circuitry. Control of these devices requires an oscillator, either as a driver or clock circuit, which is typically provided as part of bulky, rigid, and costly external electronics. Oscillator circuits based on piezo-resistive dielectric elastomer switch technology provide a way to embed oscillatory behavior into artificial muscle devices. Previous oscillator circuits were not digital, ab...

  7. Nanoscale relaxation oscillator

    Science.gov (United States)

    Zettl, Alexander K.; Regan, Brian C.; Aloni, Shaul

    2009-04-07

    A nanoscale oscillation device is disclosed, wherein two nanoscale droplets are altered in size by mass transport, then contact each other and merge through surface tension. The device may also comprise a channel having an actuator responsive to mechanical oscillation caused by expansion and contraction of the droplets. It further has a structure for delivering atoms between droplets, wherein the droplets are nanoparticles. Provided are a first particle and a second particle on the channel member, both being made of a chargeable material, the second particle contacting the actuator portion; and electrodes connected to the channel member for delivering a potential gradient across the channel and traversing the first and second particles. The particles are spaced apart a specified distance so that atoms from one particle are delivered to the other particle by mass transport in response to the potential (e.g. voltage potential) and the first and second particles are liquid and touch at a predetermined point of growth, thereby causing merging of the second particle into the first particle by surface tension forces and reverse movement of the actuator. In a preferred embodiment, the channel comprises a carbon nanotube and the droplets comprise metal nanoparticles, e.g. indium, which is readily made liquid.

  8. Noise induced regularity of porous silicon nanostructures electrochemically etched in the presence of a sub-threshold periodic signal

    Science.gov (United States)

    Roy, Tanushree; Rumandla, Sravya; Agarwal, V.; Parmananda, P.

    2017-09-01

    In the present work, regularity of the pores generated during the electrochemical etching of silicon wafer is analyzed. The wafer-electrolyte (ethanolic hydrofluoric acid) composite is placed in an electrochemical cell operated galvanostatically at a fixed (set-point) anodic current. This set-point current is subsequently perturbed by a sub-threshold periodic current signal. Numerous experiments were performed for diverse experimental configurations. Some of the experimental parameters varied were hydrofluoric concentration, set-points, and the properties of the input periodic signal (i.e., duty cycle and amplitude). The regularity of the generated pore size distribution was quantified by calculating the spatial normalized variance (NV). For certain experimental configurations, as described later, the phenomena of Periodic Stochastic Resonance (PSR) could be provoked. In PSR, enhanced regularity of the Porous Silicon nanostructures for an optimal HF concentration is observed. Consequently, the spatial NV versus the HF concentration curve exhibits a unimodal profile.

  9. Theoretical spectral distributions and total cross sections for neutral subthreshold pion production in carbon-carbon collisions

    Science.gov (United States)

    Norbury, J. W.; Cucinotta, F. A.; Deutchman, P. A.; Townsend, L. W.

    1985-01-01

    A coherent isobar formalism is employed to model subthreshold production of neutral pions in carbon-carbon collisions at energies below 100 MeV/nucleon. No arbitrary scale factors or adjustable free parameters are used in calculation of the Lorentz-invariant cross sections for pion production in the projectile, which produces an excited state that goes to M1 resonance in the target by conservation of spin and isospin. Pion production is also modeled for the projectile, which also reaches M1 resonance. The overall pion spectral distribution in the center of mass system is then integrated over the energy range 35-84 MeV/nucleon. The results expose an energy loss in the incident ions, as observed experimentally, and indicate that an isobar mechanism is responsible for higher energy pion production. Lower energy pions are a result of thermal processes.

  10. A current-mode voltage regulator with an embedded sub-threshold reference for a passive UHF RFID transponder

    International Nuclear Information System (INIS)

    Liu Zhongqi; Zhang Chun; Li Yongming; Wang Zhihua

    2010-01-01

    This paper presents a current-mode voltage regulator for a passive UHF RFID transponder. The passive tag power is extracted from RF energy through the RF-to-DC rectifier. Due to huge variations of the incoming RF power, the rectifier output voltage should be regulated to achieve a stable power supply. By accurately controlling the current flowing into the load with an embedded sub-threshold reference, the regulated voltage varies in a range of 1-1.3 V from -20 to 80 0 C, and a bandwidth of about 100 kHz is achieved for a fast power recovery. The circuit is fabricated in UMC 0.18 μm mixed-mode CMOS technology, and the current consumption is only 1 μA. (semiconductor integrated circuits)

  11. Unstable oscillators based hyperchaotic circuit

    DEFF Research Database (Denmark)

    Murali, K.; Tamasevicius, A.; G. Mykolaitis, A.

    1999-01-01

    A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations in the circ......A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations...

  12. Spatial computation with gamma oscillations

    Science.gov (United States)

    Engelhard, Ben; Vaadia, Eilon

    2014-01-01

    Gamma oscillations in cortex have been extensively studied with relation to behavior in both humans and animal models; however, their computational role in the processing of behaviorally relevant signals is still not clear. One oft-overlooked characteristic of gamma oscillations is their spatial distribution over the cortical space and the computational consequences of such an organization. Here, we advance the proposal that the spatial organization of gamma oscillations is of major importance for their function. The interaction of specific spatial distributions of oscillations with the functional topography of cortex enables select amplification of neuronal signals, which supports perceptual and cognitive processing. PMID:25249950

  13. The Duffing oscillator with damping

    DEFF Research Database (Denmark)

    Johannessen, Kim

    2015-01-01

    An analytical solution to the differential equation describing the Duffing oscillator with damping is presented. The damping term of the differential equation and the initial conditions satisfy an algebraic equation, and thus the solution is specific for this type of damping. The nonlinear term....... It is established that the period of oscillation is shorter compared to that of a linearized model but increasing with time and asymptotically approaching the period of oscillation of the linear damped model. An explicit expression for the period of oscillation has been derived, and it is found to be very accurate....

  14. Geochemical indicators of intrinsic bioremediation

    International Nuclear Information System (INIS)

    Borden, R.C.; Gomez, C.A.; Becker, M.T.

    1995-01-01

    A detailed field investigation has been completed at a gasoline-contaminated aquifer near Rocky Point, NC, to examine possible indicators of intrinsic bioremediation and identify factors that may significantly influence the rae and extent of bioremediation. The dissolved plume of benzene, toluene, ethylbenzene, and xylene (BTEX) in ground water is naturally degrading. Toluene and o-xylene are most rapidly degraded followed by m-, p-xylene, and benzene. Ethylbenzene appears to degrade very slowly under anaerobic conditions present in the center of the plume. The rate and extent of biodegradation appears to be strongly influenced by the type and quantity of electron acceptors present in the aquifer. At the upgradient edge of the plume, nitrate, ferric iron, and oxygen are used as terminal electron acceptors during hydrocarbon biodegradation. The equivalent of 40 to 50 mg/l of hydrocarbon is degraded based on the increase in dissolved CO 2 relative to background ground water. Immediately downgradient of the source area, sulfate and iron are the dominant electron acceptors. Toluene and o-xylene are rapidly removed in this region. Once the available oxygen, nitrate, and sulfate are consumed, biodegradation is limited and appears to be controlled by mixing and aerobic biodegradation at the plume fringes

  15. Protein intrinsic disorder in plants.

    Science.gov (United States)

    Pazos, Florencio; Pietrosemoli, Natalia; García-Martín, Juan A; Solano, Roberto

    2013-09-12

    To some extent contradicting the classical paradigm of the relationship between protein 3D structure and function, now it is clear that large portions of the proteomes, especially in higher organisms, lack a fixed structure and still perform very important functions. Proteins completely or partially unstructured in their native (functional) form are involved in key cellular processes underlain by complex networks of protein interactions. The intrinsic conformational flexibility of these disordered proteins allows them to bind multiple partners in transient interactions of high specificity and low affinity. In concordance, in plants this type of proteins has been found in processes requiring these complex and versatile interaction networks. These include transcription factor networks, where disordered proteins act as integrators of different signals or link different transcription factor subnetworks due to their ability to interact (in many cases simultaneously) with different partners. Similarly, they also serve as signal integrators in signaling cascades, such as those related to response to external stimuli. Disordered proteins have also been found in plants in many stress-response processes, acting as protein chaperones or protecting other cellular components and structures. In plants, it is especially important to have complex and versatile networks able to quickly and efficiently respond to changing environmental conditions since these organisms cannot escape and have no other choice than adapting to them. Consequently, protein disorder can play an especially important role in plants, providing them with a fast mechanism to obtain complex, interconnected and versatile molecular networks.

  16. Protein intrinsic disorder in plants

    Directory of Open Access Journals (Sweden)

    Florencio ePazos

    2013-09-01

    Full Text Available To some extent contradicting the classical paradigm of the relationship between protein 3D structure and function, now it is clear that large portions of the proteomes, especially in higher organisms, lack a fixed structure and still perform very important functions. Proteins completely or partially unstructured in their native (functional form are involved in key cellular processes underlain by complex networks of protein interactions. The intrinsic conformational flexibility of these disordered proteins allows them to bind multiple partners in transient interactions of high specificity and low affinity. In concordance, in plants this type of proteins has been found in processes requiring these complex and versatile interaction networks. These include transcription factor networks, where disordered proteins act as integrators of different signals or link different transcription factor subnetworks due to their ability to interact (in many cases simultaneously with different partners. Similarly, they also serve as signal integrators in signalling cascades, such as those related to response to external stimuli. Disordered proteins have also been found in plants in many stress-response processes, acting as protein chaperones or protecting other cellular components and structures. In plants, it is especially important to have complex and versatile networks able to quickly and efficiently respond to changing environmental conditions since these organisms can not escape and have no other choice than adapting to them. Consequently, protein disorder can play an especially important role in plants, providing them with a fast mechanism to obtain complex, interconnected and versatile molecular networks.

  17. Severity of complicated versus uncomplicated subthreshold depression: New evidence on the "Monotonicity Thesis" from the national comorbidity survey.

    Science.gov (United States)

    Wakefield, Jerome C; Schmitz, Mark F

    2017-04-01

    "Complicated" subthreshold depression (CsD) includes at least one of six pathosuggestive "complicated" symptoms: >6 months duration, marked role impairment, sense of worthlessness, suicidal ideation, psychotic ideation, and psychomotor retardation. "Uncomplicated" subthreshold depression (UsD) has no complicated features. Whereas studies show that complicated (CMDD) versus uncomplicated (UMDD) major depression differ substantially in severity and prognosis, UsD and CsD severity has not been previously compared. This study evaluates UsD and CsD pathology validator levels and examines whether the complicated/uncomplicated distinction offers incremental concurrent validity over the standard number-of-symptoms dimension as a depression severity measure. Using nationally representative community data from the National Comorbidity Survey, seven depression lifetime history subgroups were identified: one MDD screener symptom (n=1432); UsD (n=430); CsD (n=611); UMDD (n=182); and CMDD with 5-6 symptoms (n=518), 7 symptoms (n=217), and 8-9 symptoms (n=291). Severity was evaluated using five concurrent pathology validators: suicide attempt, interference with life, help seeking, hospitalization, and generalized anxiety disorder. CsD validator levels are substantially higher than both UsD and UMDD levels, and similar to mild CMDD, disconfirming the "monotonicity thesis" that severity increase with symptom number. Complicated/uncomplicated status predicts severity, and when complicatedness is controlled, number of symptoms no longer predicts validator levels. Diagnoses were based on respondents' fallible retrospective symptom reports during a lay-administered structured interview, which may not yield diagnoses comparable to clinicians' assessments. CsD is more severe than UsD and comparable to mild MDD. Complicated status more validly indicates depression severity than the standard number-of-symptoms measure. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Evaluation of the oscillatory interference model of grid cell firing through analysis and measured period variance of some biological oscillators.

    Directory of Open Access Journals (Sweden)

    Eric A Zilli

    2009-11-01

    Full Text Available Models of the hexagonally arrayed spatial activity pattern of grid cell firing in the literature generally fall into two main categories: continuous attractor models or oscillatory interference models. Burak and Fiete (2009, PLoS Comput Biol recently examined noise in two continuous attractor models, but did not consider oscillatory interference models in detail. Here we analyze an oscillatory interference model to examine the effects of noise on its stability and spatial firing properties. We show analytically that the square of the drift in encoded position due to noise is proportional to time and inversely proportional to the number of oscillators. We also show there is a relatively fixed breakdown point, independent of many parameters of the model, past which noise overwhelms the spatial signal. Based on this result, we show that a pair of oscillators are expected to maintain a stable grid for approximately t = 5mu(3/(4pisigma(2 seconds where mu is the mean period of an oscillator in seconds and sigma(2 its variance in seconds(2. We apply this criterion to recordings of individual persistent spiking neurons in postsubiculum (dorsal presubiculum and layers III and V of entorhinal cortex, to subthreshold membrane potential oscillation recordings in layer II stellate cells of medial entorhinal cortex and to values from the literature regarding medial septum theta bursting cells. All oscillators examined have expected stability times far below those seen in experimental recordings of grid cells, suggesting the examined biological oscillators are unfit as a substrate for current implementations of oscillatory interference models. However, oscillatory interference models can tolerate small amounts of noise, suggesting the utility of circuit level effects which might reduce oscillator variability. Further implications for grid cell models are discussed.

  19. LEADERSHIP STYLE AND EMPLOYEES' INTRINSIC JOB ...

    African Journals Online (AJOL)

    Abstract. This study investigates the impact of leadership style on employees' intrinsic job satisfaction in the Cross River State Newspaper Corporation, Calabar,. Nigeria. The study examined the problem of dissatisfaction in the work place as far as intrinsic factors of job satisfaction are concerned. Structured questionnaire ...

  20. Intrinsic bioremediation of landfills interim report

    International Nuclear Information System (INIS)

    Brigmon, R.L.; Fliermans, C.B.

    1997-01-01

    Intrinsic bioremediation is a risk management option that relies on natural biological and physical processes to contain the spread of contamination from a source. Evidence is presented in this report that intrinsic bioremediation is occurring at the Sanitary Landfill is fundamental to support incorportion into a Corrective Action Plan (CAP)

  1. Differential scanning microcalorimetry of intrinsically disordered proteins.

    Science.gov (United States)

    Permyakov, Sergei E

    2012-01-01

    Ultrasensitive differential scanning calorimetry (DSC) is an indispensable thermophysical technique enabling to get direct information on enthalpies accompanying heating/cooling of dilute biopolymer solutions. The thermal dependence of protein heat capacity extracted from DSC data is a valuable source of information on intrinsic disorder level of a protein. Application details and limitations of DSC technique in exploration of protein intrinsic disorder are described.

  2. Intrinsic bioremediation of landfills interim report

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R.L. [Westinghouse Savannah River Company, Aiken, SC (United States); Fliermans, C.B.

    1997-07-14

    Intrinsic bioremediation is a risk management option that relies on natural biological and physical processes to contain the spread of contamination from a source. Evidence is presented in this report that intrinsic bioremediation is occurring at the Sanitary Landfill is fundamental to support incorportion into a Corrective Action Plan (CAP).

  3. An Intrinsic Coordinate System for Fingerprint Matching

    NARCIS (Netherlands)

    Bazen, A.M.; Gerez, Sabih H.; Bigun, J.; Smeraldi, F.

    2001-01-01

    In this paper, an intrinsic coordinate system is proposed for fingerprints. First the fingerprint is partitioned in regular regions, which are regions that contain no singular points. In each regular region, the intrinsic coordinate system is defined by the directional field. When using the

  4. Numerical Investigation and Experimental Demonstration of Chaos from Two-Stage Colpitts Oscillator in the Ultrahigh Frequency Range

    DEFF Research Database (Denmark)

    Bumeliene, S.; Tamasevicius, A.; Mykolaitis, G.

    2006-01-01

    A hardware prototype of the two-stage Colpitts oscillator employing the microwave BFG520 type transistors with the threshold frequency of 9 GHz and designed to operate in the ultrahigh frequency range (300–1000 MHz) is described. The practical circuit in addition to the intrinsic two-stage oscill......A hardware prototype of the two-stage Colpitts oscillator employing the microwave BFG520 type transistors with the threshold frequency of 9 GHz and designed to operate in the ultrahigh frequency range (300–1000 MHz) is described. The practical circuit in addition to the intrinsic two......-stage oscillator contains an emitter follower acting as a buffer and minimizing the influence of the load. The circuit is investigated both numerically and experimentally. Typical phase portraits, Lyapunov exponents, Lyapunov dimension and broadband continuous power spectra are presented. The main advantage...

  5. Coronal Waves and Oscillations

    Directory of Open Access Journals (Sweden)

    Nakariakov Valery M.

    2005-07-01

    Full Text Available Wave and oscillatory activity of the solar corona is confidently observed with modern imaging and spectral instruments in the visible light, EUV, X-ray and radio bands, and interpreted in terms of magnetohydrodynamic (MHD wave theory. The review reflects the current trends in the observational study of coronal waves and oscillations (standing kink, sausage and longitudinal modes, propagating slow waves and fast wave trains, the search for torsional waves, theoretical modelling of interaction of MHD waves with plasma structures, and implementation of the theoretical results for the mode identification. Also the use of MHD waves for remote diagnostics of coronal plasma - MHD coronal seismology - is discussed and the applicability of this method for the estimation of coronal magnetic field, transport coefficients, fine structuring and heating function is demonstrated.

  6. Acetylcholine modulates gamma frequency oscillations in the hippocampus by activation of muscarinic M1 receptors.

    Science.gov (United States)

    Betterton, Ruth T; Broad, Lisa M; Tsaneva-Atanasova, Krasimira; Mellor, Jack R

    2017-06-01

    Modulation of gamma oscillations is important for the processing of information and the disruption of gamma oscillations is a prominent feature of schizophrenia and Alzheimer's disease. Gamma oscillations are generated by the interaction of excitatory and inhibitory neurons where their precise frequency and amplitude are controlled by the balance of excitation and inhibition. Acetylcholine enhances the intrinsic excitability of pyramidal neurons and suppresses both excitatory and inhibitory synaptic transmission, but the net modulatory effect on gamma oscillations is not known. Here, we find that the power, but not frequency, of optogenetically induced gamma oscillations in the CA3 region of mouse hippocampal slices is enhanced by low concentrations of the broad-spectrum cholinergic agonist carbachol but reduced at higher concentrations. This bidirectional modulation of gamma oscillations is replicated within a mathematical model by neuronal depolarisation, but not by reducing synaptic conductances, mimicking the effects of muscarinic M1 receptor activation. The predicted role for M1 receptors was supported experimentally; bidirectional modulation of gamma oscillations by acetylcholine was replicated by a selective M1 receptor agonist and prevented by genetic deletion of M1 receptors. These results reveal that acetylcholine release in CA3 of the hippocampus modulates gamma oscillation power but not frequency in a bidirectional and dose-dependent manner by acting primarily through muscarinic M1 receptors. © 2017 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  7. Hyperchaos in coupled Colpitts oscillators

    DEFF Research Database (Denmark)

    Cenys, Antanas; Tamasevicius, Arunas; Baziliauskas, Antanas

    2003-01-01

    The paper suggests a simple solution of building a hyperchaotic oscillator. Two chaotic Colpitts oscillators, either identical or non-identical ones are coupled by means of two linear resistors R-k. The hyperchaotic output signal v(t) is a linear combination, specifically the mean of the individual...

  8. Oscillating solitons in nonlinear optics

    Indian Academy of Sciences (India)

    ... are derived, and the relevant properties and features of oscillating solitons are illustrated. Oscillating solitons are controlled by the reciprocal of the group velocity and Kerr nonlinearity. Results of this paper will be valuable to the study of dispersion-managed optical communication system and mode-locked fibre lasers.

  9. The Wien Bridge Oscillator Family

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2006-01-01

    A tutorial in which the Wien bridge family of oscillators is defined and investigated. Oscillators which do not fit into the Barkhausen criterion topology may be designed. A design procedure based on initial complex pole quality factor is reported. The dynamic transfer characteristic...

  10. Mechanical Parametric Oscillations and Waves

    Science.gov (United States)

    Dittrich, William; Minkin, Leonid; Shapovalov, Alexander S.

    2013-01-01

    Usually parametric oscillations are not the topic of general physics courses. Probably it is because the mathematical theory of this phenomenon is relatively complicated, and until quite recently laboratory experiments for students were difficult to implement. However parametric oscillations are good illustrations of the laws of physics and can be…

  11. Stochastic and Chaotic Relaxation Oscillations

    NARCIS (Netherlands)

    Grasman, J.; Roerdink, J.B.T.M.

    1988-01-01

    For relaxation oscillators stochastic and chaotic dynamics are investigated. The effect of random perturbations upon the period is computed. For an extended system with additional state variables chaotic behavior can be expected. As an example, the Van der Pol oscillator is changed into a

  12. Oscillator strengths for neutral technetium

    International Nuclear Information System (INIS)

    Garstang, R.H.

    1981-01-01

    Oscillator strengths have been calculated for most of the spectral lines of TcI which are of interest in the study of stars of spectral type S. Oscillator strengths have been computed for the corresponding transitions in MnI as a partial check of the technetium calculations

  13. Quasi Periodic Oscillations in Blazars

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Home; Journals; Journal of Astrophysics and Astronomy; Volume 35; Issue 3. Quasi Periodic Oscillations in Blazars ... Here we report our recent discoveries of Quasi-Periodic Oscillations (QPOs) in blazars time series data in X-ray and optical electromagnetic bands. Any such detection can give important ...

  14. GA-based Design Algorithms for the Robust Synthetic Genetic Oscillators with Prescribed Amplitude, Period and Phase

    Directory of Open Access Journals (Sweden)

    Bor-Sen Chen

    2010-05-01

    Full Text Available In the past decade, the development of synthetic gene networks has attracted much attention from many researchers. In particular, the genetic oscillator known as the repressilator has become a paradigm for how to design a gene network with a desired dynamic behaviour. Even though the repressilator can show oscillatory properties in its protein concentrations, their amplitudes, frequencies and phases are perturbed by the kinetic parametric fluctuations (intrinsic molecular perturbations and external disturbances (extrinsic molecular noises of the environment. Therefore, how to design a robust genetic oscillator with desired amplitude, frequency and phase under stochastic intrinsic and extrinsic molecular noises is an important topic for synthetic biology. In this study, based on periodic reference signals with arbitrary amplitudes, frequencies and phases, a robust synthetic gene oscillator is designed by tuning the kinetic parameters of repressilator via a genetic algorithm (GA so that the protein concentrations can track the desired periodic reference signals under intrinsic and extrinsic molecular noises. GA is a stochastic optimization algorithm which was inspired by the mechanisms of natural selection and evolution genetics. By the proposed GA-based design algorithm, the repressilator can track the desired amplitude, frequency and phase of oscillation under intrinsic and extrinsic noises through the optimization of fitness function. The proposed GA-based design algorithm can mimic the natural selection in evolutionary process to select adequate kinetic parameters for robust genetic oscillators. The design method can be easily extended to any synthetic gene network design with prescribed behaviours.

  15. Oscillating nonlinear acoustic shock waves

    DEFF Research Database (Denmark)

    Gaididei, Yuri; Rasmussen, Anders Rønne; Christiansen, Peter Leth

    2016-01-01

    We investigate oscillating shock waves in a tube using a higher order weakly nonlinear acoustic model. The model includes thermoviscous effects and is non isentropic. The oscillating shock waves are generated at one end of the tube by a sinusoidal driver. Numerical simulations show...... that at resonance a stationary state arise consisting of multiple oscillating shock waves. Off resonance driving leads to a nearly linear oscillating ground state but superimposed by bursts of a fast oscillating shock wave. Based on a travelling wave ansatz for the fluid velocity potential with an added 2'nd order...... polynomial in the space and time variables, we find analytical approximations to the observed single shock waves in an infinitely long tube. Using perturbation theory for the driven acoustic system approximative analytical solutions for the off resonant case are determined....

  16. Oscillating universe with quintom matter

    International Nuclear Information System (INIS)

    Xiong Huahui; Cai Yifu; Qiu Taotao; Piao Yunsong; Zhang Xinmin

    2008-01-01

    In this Letter, we study the possibility of building a model of the oscillating universe with quintom matter in the framework of 4-dimensional Friedmann-Robertson-Walker background. Taking the two-scalar-field quintom model as an example, we find in the model parameter space there are five different types of solutions which correspond to: (I) a cyclic universe with the minimal and maximal values of the scale factor remaining the same in every cycle, (II) an oscillating universe with its minimal and maximal values of the scale factor increasing cycle by cycle, (III) an oscillating universe with its scale factor always increasing, (IV) an oscillating universe with its minimal and maximal values of the scale factor decreasing cycle by cycle, and (V) an oscillating universe with its scale factor always decreasing

  17. Fast equilibrium switch of a micro mechanical oscillator

    Science.gov (United States)

    Le Cunuder, Anne; Martínez, Ignacio A.; Petrosyan, Artyom; Guéry-Odelin, David; Trizac, Emmanuel; Ciliberto, Sergio

    2016-09-01

    We demonstrate an accurate method to control the motion of a micromechanical oscillator in contact with a thermal bath. The experiment is carried out on the cantilever tip of an atomic force microscope. Applying an appropriate time dependent external force, we decrease the time necessary to reach equilibrium by two orders of magnitude compared to the intrinsic equilibration time. Finally, we analyze the energetic cost of such a fast equilibration, by measuring with kB T accuracy the energy exchanges along the process.

  18. Microwave oscillator based on an intrinsic BSCCO-type Josephson junction

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Madsen, Søren Peder

    2005-01-01

    The electrical behavior of anisotropic BSCCO single crystals is modeled by mutually coupled long Josephson junctions. For the basic fluxon modes with one fluxon per layer, the fluxons will arrange themselves in an anti phase configuration (triangular lattice) because of the mutual repulsion. We a...

  19. Predictors of drusen reduction after subthreshold infrared (810 nm) diode laser macular grid photocoagulation for nonexudative age-related macular degeneration.

    Science.gov (United States)

    Rodanant, Nuttawut; Friberg, Thomas R; Cheng, Lingyun; Aurora, Ajay; Bartsch, Dirk; Toyoguchi, Mitsuko; Corbin, Patricia S; El-Bradey, Mohamed H; Freeman, William R

    2002-10-01

    To determine the predictors of drusen reduction in eyes with nonexudative age-related macular degeneration (ARMD) treated with subthreshold infrared (810 nm) diode laser macular grid photocoagulation. Additionally, to determine the relationship of laser-induced drusen reduction and best-corrected visual acuity (BCVA) 18 months after laser treatment. Randomized controlled clinical trial. Fifty patients (100 eyes) with bilateral nonexudative ARMD were enrolled at two centers. One eye of each patient was randomized to the observation; the other eye was treated with 48 subthreshold (invisible end point) applications of infrared (810 nm) diode laser in a macular grid pattern. The eyes that received subthreshold laser treatment were compared with the eyes that received no treatment. The baseline fundus characteristics (number, size, and distribution of drusen, as well as focal hyperpigmentation) from two macula areas (central 1500 micro diameter, pericentral 1500 micro ring area) on stereo color photographs, the number of laser-induced lesions, and the area of laser induced retinal pigment epithelial (RPE) lesions on fluorescein angiography 3 months after treatment were studied as predictors of major drusen reduction (> or = 50% drusen reduction from baseline) 18 months after laser treatment. BCVA at baseline and 18 months later was compared in observation eyes and in laser-treated eyes. Eighteen months after randomization, 24 (48%) of 50 eyes treated with subthreshold laser had major drusen reduction compared with three (6%) of 50 observation eyes (P =.00001). At 3 months post-treatment in laser-treated eyes with major drusen reduction, the mean number of laser-induced lesions on fluorescein angiography was 30.7 and the mean area of RPE change was 0.81 mm(2) compared with 14.8 laser-induced lesions and 0.35 mm(2) area of RPE change in eyes without major drusen reduction (P =.0001 and P =.0003, respectively). At baseline, fundus characteristics were not significantly

  20. Oscillations of atomic nuclei in crystals

    OpenAIRE

    Vdovenkov, V. A.

    2002-01-01

    Oscillations of atomic nuclei in crystals are considered in this paper. It is shown that elastic nuclei oscillations relatively electron envelops (inherent, I-oscillations) and waves of such oscillations can exist in crystals at adiabatic condition. The types and energy quantums of I-oscillations for different atoms are determined. In this connection the adiabatic crystal model is offered. Each atom in the adiabatic model is submitted as I-oscillator whose stationary oscillatory terms are sho...

  1. Algebraic description of intrinsic modes in nuclei

    International Nuclear Information System (INIS)

    Leviatan, A.

    1989-01-01

    We present a procedure for extracting normal modes in algebraic number-conserving systems of interacting bosons relevant for collective states in even-even nuclei. The Hamiltonian is resolved into intrinsic (bandhead related) and collective (in-band related) parts. Shape parameters are introduced through non-spherical boson bases. Intrinsic modes decoupled from the spurious modes are obtained from the intinsic part of the Hamiltonian in the limit of large number of bosons. Intrinsic states are constructed and serve to evaluate electromagnetic transition rates. The method is illustrated for systems with one type of boson as well as with proton-neutron bosons. 28 refs., 1 fig

  2. Algebraic description of intrinsic modes in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Leviatan, A.

    1989-01-01

    We present a procedure for extracting normal modes in algebraic number-conserving systems of interacting bosons relevant for collective states in even-even nuclei. The Hamiltonian is resolved into intrinsic (bandhead related) and collective (in-band related) parts. Shape parameters are introduced through non-spherical boson bases. Intrinsic modes decoupled from the spurious modes are obtained from the intinsic part of the Hamiltonian in the limit of large number of bosons. Intrinsic states are constructed and serve to evaluate electromagnetic transition rates. The method is illustrated for systems with one type of boson as well as with proton-neutron bosons. 28 refs., 1 fig.

  3. Heat transfer with oscillating pressure and oscillating flow

    Science.gov (United States)

    Kornhauser, Alan A.; Smith, Joseph L., Jr.

    Heat exchangers in Stirling engines and many other reciprocating machines operating under conditions of both oscillating pressure and oscillating flow are discussed. Experiments were done on an apparatus consisting of a piston-cylinder space connected to an annular dead-end heat exchanger space. Instantaneous heat flux and center gas temperature were measured at six locations along the heat exchanger. The results were used to test the model, with the complex Nusselt number correlated against oscillating-flow Peclet number. The experimental results showed that the complex Nusselt number was capable of predicting the heat flux, but that there was at least one other important independent variable besides oscillating-flow Peclet number. Dimensional analysis suggested that this was either the ratio of gas thermal properties to those of the wall or a measure of compressibility effects.

  4. Contributions of intrinsic motor neuron properties to the production of rhythmic motor output in the mammalian spinal cord

    DEFF Research Database (Denmark)

    Kiehn, O; Kjaerulff, O; Tresch, M C

    2000-01-01

    showing that the neonatal rat spinal cord can produce a stable motor rhythm in the absence of spike activity in premotor interneuronal networks. These coordinated motor neuron oscillations are dependent on NMDA-evoked pacemaker properties, which are synchronized across gap junctions. We discuss...... the functional relevance for such coordinated oscillations in immature and mature spinal motor systems.......Motor neurons are endowed with intrinsic and conditional membrane properties that may shape the final motor output. In the first half of this paper we present data on the contribution of I(h), a hyperpolarization-activated inward cation current, to phase-transition in motor neurons during rhythmic...

  5. Neutrino oscillation: status and outlooks

    International Nuclear Information System (INIS)

    Nedelec, P.

    1994-01-01

    Whether the neutrinos are massive or not is one of the most puzzling question of physics today. If they are massive, they can contribute significantly to the Dark Matter of the Universe. An other consequence of a non-zero mass of neutrinos is that they might oscillate from one flavor to another. This oscillation process is by now the only way to detect a neutrino with a mass in the few eV range. Several neutrino experiments are currently looking for such an oscillation, in different modes, using different techniques. An overview of the experimental situation for neutrino experiments at accelerators is given. (author). 9 refs., 5 figs., 5 tabs

  6. Collective oscillations in a plasma

    CERN Document Server

    Akhiezer, A I; Polovin, R V; ter Haar, D

    2013-01-01

    International Series of Monographs in Natural Philosophy: Collective Oscillations in a Plasma, Volume 7 presents specific topics within the general field of radio waves propagation. This book contains five chapters that address the theory of linear oscillations in a plasma, the spectra of the eigen oscillations, and the mechanism of high-frequency heating. The opening chapters deal with the self-consistent fields; development of initial perturbation; dispersion permittivity tensor of a plasma in a magnetic field; effect of thermal motion of particles on low-frequency resonances; excitation of

  7. Oscillations in Mathematical Biology

    CERN Document Server

    1983-01-01

    The papers in this volume are based on talks given at a one day conference held on the campus of Adelphi University in April 1982. The conference was organized with the title "Oscillations in Mathematical Biology;" however the speakers were allowed considerable latitutde in their choice of topics. In the event, the talks all concerned the dynamics of non-linear systems arising in biology so that the conference achieved a good measure of cohesion. Some of the speakers cho~e not to submit a manuscript for these proceedings, feeling that their material was too conjectural to be committed to print. Also the paper of Rinzel and Troy is a distillation of the two separate talks that the authors gave. Otherwise the material reproduces the conference proceedings. The conference was made possible by the generous support of the Office of the Dean of the College of Arts and Sciences at Adelphi. The bulk of the organization of the conference was carried out by Dr. Ronald Grisell whose energy was in large measure responsib...

  8. Principal oscillation patterns

    International Nuclear Information System (INIS)

    Storch, H. von; Buerger, G.; Storch, J.S. von

    1993-01-01

    The Principal Oscillation Pattern (POP) analysis is a technique which is used to simultaneously infer the characteristic patterns and time scales of a vector time series. The POPs may be seen as the normal modes of a linearized system whose system matrix is estimated from data. The concept of POP analysis is reviewed. Examples are used to illustrate the potential of the POP technique. The best defined POPs of tropospheric day-to-day variability coincide with the most unstable modes derived from linearized theory. POPs can be derived even from a space-time subset of data. POPs are successful in identifying two independent modes with similar time scales in the same data set. The POP method can also produce forecasts which may potentially be used as a reference for other forecast models. The conventional POP analysis technique has been generalized in various ways. In the cyclostationary POP analysis, the estimated system matrix is allowed to vary deterministically with an externally forced cycle. In the complex POP analysis not only the state of the system but also its ''momentum'' is modeled. Associated correlation patterns are a useful tool to describe the appearance of a signal previously identified by a POP analysis in other parameters. (orig.)

  9. Rabi oscillation between states of a coupled harmonic oscillator

    International Nuclear Information System (INIS)

    Park, Tae Jun

    2003-01-01

    Rabi oscillation between bound states of a single potential is well known. However the corresponding formula between the states of two different potentials has not been obtained yet. In this work, we derive Rabi formula between the states of a coupled harmonic oscillator which may be used as a simple model for the electron transfer. The expression is similar to typical Rabi formula for a single potential. This result may be used to describe transitions between coupled diabatic potential curves

  10. Intrinsic endometriosis of ureter: a case report

    International Nuclear Information System (INIS)

    Hong, Myung Sun; Kim, Ho Chul; Yun, Ku Sup; Choi, Chul Soon; Bae, Sang Hoon; Kim, Sung Yong; Shin, Hyung Sik

    1995-01-01

    Endometriosis is a rare cause of an ureteral obstruction. We report a case of intrinsic ureteral endometriosis resulting in severe hydroureteronephrosis. The diagnosis of ureteral endometriosis may be considered in women with flank pain and ureteric obstruction within true pelvis

  11. The Intrinsic Dynamics of Psychological Process

    NARCIS (Netherlands)

    Vallacher, Robin R.; van Geert, Paul; Nowak, Andrzej

    2015-01-01

    Psychological processes unfold on various timescales in accord with internally generated patterns. The intrinsic dynamism of psychological process is difficult to investigate using traditional methods emphasizing cause–effect relations, however, and therefore is rarely incorporated into social

  12. Deuterium NMR, induced and intrinsic cholesteric lyomesophases

    International Nuclear Information System (INIS)

    Alcantara, M.R.

    1982-01-01

    Induced and intrinsic cholesteric lyotropic mesophases were studied. Induced cholesteric lyomesophases based on potassium laurate (KL) system, with small amounts of cholesterol added, were studied by deuterium NMR and by polarizing microscopy. Order profiles obtained from deuterium NMR of KL perdenderated chains in both induced cholesteric and normal mesophases were compared. The intrinsic cholesteric lyotropic mesophases were based on the amphiphile potassium N-lauroyl serinate (KLNS) in the resolved levo form. The study of the type I intrinsic cholesteric mesophase was made by optical microscopy under polarized light and the type II intrinsic cholesteric lyomesophase was characterized by deuterium NMR. The new texture was explained by the use of the theory of disclinations developed for thermotropic liquid crystals, specially for cholesteric type. (M.J.C.) [pt

  13. Cocaine sensitization increases subthreshold activity in dopamine neurons from the ventral tegmental area.

    Science.gov (United States)

    Arencibia-Albite, Francisco; Vázquez-Torres, Rafael; Jiménez-Rivera, Carlos A

    2017-02-01

    The progressive escalation of psychomotor responses that results from repeated cocaine administration is termed sensitization. This phenomenon alters the intrinsic properties of dopamine (DA) neurons from the ventral tegmental area (VTA), leading to enhanced dopaminergic transmission in the mesocorticolimbic network. The mechanisms underlying this augmented excitation are nonetheless poorly understood. DA neurons display the hyperpolarization-activated, nonselective cation current, dubbed I h We recently demonstrated that I h and membrane capacitance are substantially reduced in VTA DA cells from cocaine-sensitized rats. The present study shows that 7 days of cocaine withdrawal did not normalize I h and capacitance. In cells from cocaine-sensitized animals, the amplitude of excitatory synaptic potentials, at -70 mV, was ∼39% larger in contrast to controls. Raise and decay phases of the synaptic signal were faster under cocaine, a result associated with a reduced membrane time constant. Synaptic summation was paradoxically elevated by cocaine exposure, as it consisted of a significantly reduced summation indexed but a considerably increased depolarization. These effects are at least a consequence of the reduced capacitance. I h attenuation is unlikely to explain such observations, since at -70 mV, no statistical differences exist in I h or input resistance. The neuronal shrinkage associated with a diminished capacitance may help to understand two fundamental elements of drug addiction: incentive sensitization and negative emotional states. A reduced cell size may lead to substantial enhancement of cue-triggered bursting, which underlies drug craving and reward anticipation, whereas it could also result in DA depletion, as smaller neurons might express low levels of tyrosine hydroxylase. This work uses a new approach that directly extracts important biophysical parameters from alpha function-evoked synaptic potentials. Two of these parameters are the cell membrane

  14. Intrinsic and acquired resistance mechanisms in enterococcus

    Science.gov (United States)

    Hollenbeck, Brian L.; Rice, Louis B.

    2012-01-01

    Enterococci have the potential for resistance to virtually all clinically useful antibiotics. Their emergence as important nosocomial pathogens has coincided with increased expression of antimicrobial resistance by members of the genus. The mechanisms underlying antibiotic resistance in enterococci may be intrinsic to the species or acquired through mutation of intrinsic genes or horizontal exchange of genetic material encoding resistance determinants. This paper reviews the antibiotic resistance mechanisms in Enterococcus faecium and Enterococcus faecalis and discusses treatment options. PMID:23076243

  15. Manic Episode after Ventricular-Peritoneal Shunt Replacement in a Patient with Radiation-Induced Hydrocephalus: The Role of Lifetime Subthreshold Bipolar Features

    Directory of Open Access Journals (Sweden)

    Antonio Callari

    2014-01-01

    Full Text Available We present a case report of a woman hospitalized for a ventricular-peritoneal shunting replacement, who developed a manic episode with psychotic symptoms after hydrocephalus resolution. We have no knowledge of cases of manic episodes due to hydrocephalus resolution by ventricular-peritoneal shunt replacement, although previous case reports have suggested that hydrocephalus might induce rapid-onset affective episodes or mood cycles. The patient’s history revealed the lifetime presence of signs and features belonging to the subthreshold bipolar spectrum, in absence of previous full-blown episodes of a bipolar disorder. Our hypothesis is that such lifetime sub-threshold bipolar features represented precursors of the subsequent full-blown manic episode, triggered by an upregulated binding of striatum D2 receptors after the ventricular-peritoneal shunt replacement.

  16. Manic Episode after Ventricular-Peritoneal Shunt Replacement in a Patient with Radiation-Induced Hydrocephalus: The Role of Lifetime Subthreshold Bipolar Features

    Science.gov (United States)

    Callari, Antonio; Mantua, Valentina; Miniati, Mario; Benvenuti, Antonella; Mauri, Mauro; Dell'Osso, Liliana

    2014-01-01

    We present a case report of a woman hospitalized for a ventricular-peritoneal shunting replacement, who developed a manic episode with psychotic symptoms after hydrocephalus resolution. We have no knowledge of cases of manic episodes due to hydrocephalus resolution by ventricular-peritoneal shunt replacement, although previous case reports have suggested that hydrocephalus might induce rapid-onset affective episodes or mood cycles. The patient's history revealed the lifetime presence of signs and features belonging to the subthreshold bipolar spectrum, in absence of previous full-blown episodes of a bipolar disorder. Our hypothesis is that such lifetime sub-threshold bipolar features represented precursors of the subsequent full-blown manic episode, triggered by an upregulated binding of striatum D2 receptors after the ventricular-peritoneal shunt replacement. PMID:24527253

  17. Mentalization-based treatment in groups for adolescents with borderline personality disorder (BPD) or subthreshold BPD versus treatment as usual (M-GAB)

    DEFF Research Database (Denmark)

    Beck, Emma; Bo, Sune; Gondan, Matthias

    2016-01-01

    mentalization-based treatment in groups is an efficacious treatment for adolescents with BPD or subthreshold BPD compared to treatment as usual. The trial is a four-center, two-armed, parallel-group, assessor-blinded randomized clinical superiority trial. One hundred twelve patients aged 14 to 17 referred...... to Child and Adolescent Psychiatric Clinics in Region Zealand are randomized to 1 year of either mentalization-based treatment in groups or treatment as usual. Patients will be included if they meet at least four DSM-5 criteria for BPD. The primary outcome is self-reported borderline features at discharge...... variables. Follow-up assessment will take place at 3 and 12 months after end of treatment. Discussion This is the first randomized controlled trial to test the efficacy of a group-based mentalization-based treatment for adolescents with BPD or subthreshold BPD. If the results confirm our hypothesis...

  18. The intrinsic resistome of bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Jorge Andrés Olivares Pacheco

    2013-04-01

    Full Text Available Intrinsically resistant bacteria have emerged as a relevant health problem in the last years. Those bacterial species, several of them with an environmental origin, present naturally a low-level susceptibility to several drugs. It has been proposed that intrinsic resistance is mainly the consequence of the impermeability of cellular envelopes, the activity of multidrug efflux pumps or the lack of appropriate targets for a given family of drugs. However, recently published articles indicate that the characteristic phenotype of susceptibility to antibiotics of a given bacterial species depends on the concerted activity of several elements, what has been named as intrinsic resistome. These determinants comprise not just classical resistance genes. Other elements, several of them involved in basic bacterial metabolic processes, are of relevance for the intrinsic resistance of bacterial pathogens. In the present review we analyse recent publications on the intrinsic resistomes of Escherichia coli and Pseudomonas aeruginosa. We present as well information on the role that global regulators of bacterial metabolism, as Crc from P. aeruginosa, may have on modulating bacterial susceptibility to antibiotics. Finally, we discuss the possibility of searching inhibitors of the intrinsic resistome in the aim of improving the activity of drugs currently in use for clinical practice.

  19. Incentives and intrinsic motivation in healthcare.

    Science.gov (United States)

    Berdud, Mikel; Cabasés, Juan M; Nieto, Jorge

    It has been established in the literature that workers within public organisations are intrinsically motivated. This paper is an empirical study of the healthcare sector using methods of qualitative analysis research, which aims to answer the following hypotheses: 1) doctors are intrinsically motivated; 2) economic incentives and control policies may undermine doctors' intrinsic motivation; and 3) well-designed incentives may encourage doctors' intrinsic motivation. We conducted semi-structured interviews à-la-Bewley with 16 doctors from Navarre's Healthcare Service (Servicio Navarro de Salud-Osasunbidea), Spain. The questions were based on current theories of intrinsic motivation and incentives to test the hypotheses. Interviewees were allowed to respond openly without time constraints. Relevant information was selected, quantified and analysed by using the qualitative concepts of saturation and codification. The results seem to confirm the hypotheses. Evidence supporting hypotheses 1 and 2 was gathered from all interviewees, as well as indications of the validity of hypothesis 3 based on interviewees' proposals of incentives. The conclusions could act as a guide to support the optimal design of incentive policies and schemes within health organisations when healthcare professionals are intrinsically motivated. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Study of Gaussian Doped Double Gate JunctionLess (GD-DG-JL) transistor including source drain depletion length: Model for sub-threshold behavior

    Science.gov (United States)

    Kumari, Vandana; Kumar, Ayush; Saxena, Manoj; Gupta, Mridula

    2018-01-01

    The sub-threshold model formulation of Gaussian Doped Double Gate JunctionLess (GD-DG-JL) FET including source/drain depletion length is reported in the present work under the assumption that the ungated regions are fully depleted. To provide deeper insight into the device performance, the impact of gaussian straggle, channel length, oxide and channel thickness and high-k gate dielectric has been studied using extensive TCAD device simulation.

  1. A sub-threshold dose of pilocarpine increases glutamine synthetase in reactive astrocytes and enhances the progression of amygdaloid-kindling epilepsy in rats.

    Science.gov (United States)

    Sun, Hong-Liu; Deng, Da-Ping; Pan, Xiao-Hong; Wang, Chao-Yun; Zhang, Xiu-Li; Chen, Xiang-Ming; Wang, Chun-Hua; Liu, Yu-Xia; Li, Shu-Cui; Bai, Xian-Yong; Zhu, Wei

    2016-03-02

    The prognosis of patients exposed to a sub-threshold dose of a proconvulsant is difficult to establish. In this study, we investigated the effect of a single sub-threshold dose of the proconvulsant pilocarpine (PILO) on the progression of seizures that were subsequently induced by daily electrical stimulation (kindling) of the amygdaloid formation. Male Sprague–Dawley rats were each implanted with an electrode in the right basolateral amygdala and an indwelling cannula in the right ventricle. The animals were randomized into groups and were administered one of the following treatments: saline, PILO, saline+L-α-aminoadipic acid (L-AAA; one dosage tested), PILO+L-AAA, or PILO+L-methionine sulfoximine (three dosages tested). Amygdaloid stimulation and electroencephalography were performed once daily. We performed immunohistochemistry and western blot for glial fibrillary acidic protein and glutamine synthetase (GS). We also assayed the enzymic activity of GS in discrete brain regions. An intraperitoneal injection of a sub-threshold PILO dose enhanced the progression of amygdaloid-kindling seizures and was accompanied by an increase in reactive-astrocyte and GS (content and activity) in the hippocampus and piriform cortex. L-AAA and L-methionine sulfoximine, inhibitors of astrocytic and GS function, respectively, abolished the effect of PILO on amygdaloid-kindling seizures. We conclude that one sub-threshold dose of a proconvulsant may enhance the progression of subsequent epilepsy and astrocytic GS may play a role in this phenomenon. Thus, a future therapy for epilepsy could be inhibition of astrocytes and/or GS.

  2. Global Status of Neutrino Oscillation

    Indian Academy of Sciences (India)

    monojit

    2014-11-08

    Outline of talk. Neutrino Oscillations: the context. Solar and geo neutrino physics. Reactor neutrino physics. Atmospheric and long-baseline neutrino physics. Atmospheric neutrinos and INO. Nov 8, 2014, IASc Annual Meeting, IIT-Madras, Chennai – p. 2 ...

  3. Strongly nonlinear oscillators analytical solutions

    CERN Document Server

    Cveticanin, Livija

    2014-01-01

    This book provides the presentation of the motion of pure nonlinear oscillatory systems and various solution procedures which give the approximate solutions of the strong nonlinear oscillator equations. The book presents the original author’s method for the analytical solution procedure of the pure nonlinear oscillator system. After an introduction, the physical explanation of the pure nonlinearity and of the pure nonlinear oscillator is given. The analytical solution for free and forced vibrations of the one-degree-of-freedom strong nonlinear system with constant and time variable parameter is considered. Special attention is given to the one and two mass oscillatory systems with two-degrees-of-freedom. The criteria for the deterministic chaos in ideal and non-ideal pure nonlinear oscillators are derived analytically. The method for suppressing chaos is developed. Important problems are discussed in didactic exercises. The book is self-consistent and suitable as a textbook for students and also for profess...

  4. Modelling solar-like oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Eggenberger, P; Miglio, A [Institut d' Astrophysique et de Geophysique de l' Universite de Liege, 17 Allee du 6 Aout, B-4000 Liege (Belgium); Carrier, F [Institute of Astronomy, University of Leuven, Celestijnenlaan 200 D, B-3001 Leuven (Belgium); Mathis, S [CEA/DSM/DAPNIA/Service d' Astrophysique, CEA/Saclay, AIM-Unite Mixte de Recherche CEA-CNRS-Universite Paris VII, UMR 7158, 91191 Gif-sur-Yvette Cedex (France)], E-mail: eggenberger@Qastro.ulg.ac.be

    2008-10-15

    The computation of models of stars for which solar-like oscillations have been observed is discussed. After a brief intoduction on the observations of solar-like oscillations, the modelling of isolated stars and of stars belonging to a binary system is presented with specific examples of recent theoretical calibrations. Finally the input physics introduced in stellar evolution codes for the computation of solar-type stars is discussed with a peculiar emphasis on the modelling of rotation for these stars.

  5. Dynamic analysis of the conditional oscillator underlying slow waves in thalamocortical neurons

    Directory of Open Access Journals (Sweden)

    Francois eDavid

    2016-02-01

    Full Text Available During non-REM sleep the EEG shows characteristics waves that are generated by the dynamic interactions between cortical and thalamic oscillators. In thalamic neurons, low-threshold T-type Ca2+ channels play a pivotal role in almost every type of neuronal oscillations, including slow (<1 Hz waves, sleep spindles and delta waves. The transient opening of T channels gives rise to the low threshold spikes (LTSs, and associated high frequency bursts of action potentials, that are characteristically present during sleep spindles and delta waves, whereas the persistent opening of a small fraction of T channels, (i.e. ITwindow is responsible for the membrane potential bistability underlying sleep slow oscillations. Surprisingly thalamocortical (TC neurons express a very high density of T channels that largely exceed the amount required to generate LTSs and therefore, to support certain, if not all, sleep oscillations. Here, to clarify the relationship between T current density and sleep oscillations, we systematically investigated the impact of the T conductance level on the intrinsic rhythmic activities generated in TC neurons, combining in vitro experiments and TC neuron simulation. Using bifurcation analysis, we provide insights into the dynamical processes taking place at the transition between slow and delta oscillations. Our results show that although stable delta oscillations can be evoked with minimal T conductance, the full range of slow oscillation patterns, including groups of delta oscillations separated by Up states (grouped-delta slow waves requires a high density of T channels. Moreover, high levels of T conductance ensure the robustness of different types of slow oscillations.

  6. Within-trial economic evaluation of diabetes-specific cognitive behaviour therapy in patients with type 2 diabetes and subthreshold depression

    Directory of Open Access Journals (Sweden)

    Ohmann Christian

    2010-10-01

    Full Text Available Abstract Background Despite the high prevalence of subthreshold depression in patients with type 2 diabetes, evidence on cost-effectiveness of different therapy options for these patients is currently lacking. Methods/Design Within-trial economic evaluation of the diabetes-specific cognitive behaviour therapy for subthreshold depression. Patients with diabetes and subthreshold depression are randomly assigned to either 2 weeks of diabetes-specific cognitive behaviour group therapy (n = 104 or to standard diabetes education programme only (n = 104. Patients are followed for 12 months. During this period data on total health sector costs, patient costs and societal productivity costs are collected in addition to clinical data. Health related quality of life (the SF-36 and the EQ-5D is measured at baseline, immediately after the intervention, at 6 and at 12 months after the intervention. Quality adjusted life years (QALYs, and cumulative costs will be estimated for each arm of the trial. Cost-effectiveness of the diabetes-specific cognitive behaviour group therapy will be analysed from the perspective of the German statutory health insurance and from the societal perspective. To this end, incremental cost-effectiveness ratio (ICER in terms of cost per QALY gained will be calculated. Discussion Some methodological issues of the described economic evaluation are discussed. Trial registration The trial has been registered at the Clinical Trials Register (NCT01009138.

  7. Adult Autism Subthreshold Spectrum (AdAS Spectrum) in parents of pediatric patients with epilepsy: Correlations with post-traumatic stress symptoms.

    Science.gov (United States)

    Dell'Osso, L; Corsi, M; Gesi, C; Bertelloni, C A; Massimetti, G; Peroni, D; Bonuccelli, A; Orsini, A; Carmassi, C

    2018-05-01

    Increasing literature has shown the usefulness of a dimensional approach to mental disorders, particularly when exploring subjects exposed to traumatic experiences such as a severe illness in one's child. Recent evidence suggests an increased vulnerability in subjects with autism spectrum symptoms to develop post-traumatic stress symptoms. The aim of the present study was to evaluate the presence of adult autism subthreshold spectrum in a sample of parents of children with epilepsy and its impact on post-traumatic stress spectrum symptoms in the same study sample. Results revealed noteworthy correlations between post-traumatic stress symptoms and adult autism subthreshold spectrum (AdAS Spectrum) only in the subgroup of the fathers. In particular, were evidenced correlations between AdAS Spectrum domain of rumination and narrow interests and some TALS-SR nuclear domains: reaction to traumatic events, reexperiencing and arousal. These findings corroborate the hypothesis that subthreshold autistic features may influence the possible psychopathological reaction to trauma. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Modeling nonlinearities in MEMS oscillators.

    Science.gov (United States)

    Agrawal, Deepak K; Woodhouse, Jim; Seshia, Ashwin A

    2013-08-01

    We present a mathematical model of a microelectromechanical system (MEMS) oscillator that integrates the nonlinearities of the MEMS resonator and the oscillator circuitry in a single numerical modeling environment. This is achieved by transforming the conventional nonlinear mechanical model into the electrical domain while simultaneously considering the prominent nonlinearities of the resonator. The proposed nonlinear electrical model is validated by comparing the simulated amplitude-frequency response with measurements on an open-loop electrically addressed flexural silicon MEMS resonator driven to large motional amplitudes. Next, the essential nonlinearities in the oscillator circuit are investigated and a mathematical model of a MEMS oscillator is proposed that integrates the nonlinearities of the resonator. The concept is illustrated for MEMS transimpedance-amplifier- based square-wave and sine-wave oscillators. Closed-form expressions of steady-state output power and output frequency are derived for both oscillator models and compared with experimental and simulation results, with a good match in the predicted trends in all three cases.

  9. Modulation of sub-threshold properties of InGaAs MOSFETs by La2O3 gate dielectrics

    Directory of Open Access Journals (Sweden)

    C.-Y. Chang

    2017-09-01

    Full Text Available We have found the ferroelectric-like characteristics in atomic layer deposition (ALD La2O3 films with thermal budget lower than 300oC in polarization-electric field (P-E and capacitance-gate voltage (C-V measurements on W/La2O3/W and W/La2O3/InGaAs capacitors. The observed hysteresis and saturation of polarization in the P-E characteristics of the W/La2O3/W and the W/La2O3/InGaAs capacitors, and the counter-clockwise C-V hysteresis in the C-V curves of the W/La2O3/InGaAs capacitors suggest a possibility of ferroelectricity in the present La2O3 films. By using this gate stack, W/La2O3/InGaAs metal-oxide-semiconductor field-effect transistors (MOSFETs were fabricated in order to examine the negative capacitance (NC effect due to La2O3. It is found that the sub-threshold swing (SS of W/La2O3/InGaAs MOSFETs is lower at low temperature than the theoretical limit of MOSFETs. This result strongly suggests that the W/La2O3/InGaAs MOSFETs can work as a steep-slope III-V negative capacitance field-effect transistor (NCFET.

  10. An App a Day Keeps the Doctor Away: Guided Education and Training via Smartphones in Subthreshold Post Traumatic Stress Disorder.

    Science.gov (United States)

    Roy, Michael J; Costanzo, Michelle E; Highland, Krista B; Olsen, Cara; Clayborne, Denece; Law, Wendy

    2017-08-01

    Post traumatic stress disorder (PTSD) symptoms are common in military service members (SMs), but stigma can impede treatment initiation. Smartphone applications (apps) are available anywhere, anytime, with the potential to both mitigate the impact of stigma and reduce PTSD symptom severity. We provided 144 SMs or family members, with subthreshold PTSD symptoms (PTSD Checklist [PCL] scores of 28-49), with apps promoting psychoeducation, social engagement, and relaxation and randomized them to 6 weeks of resilience enhancement (brief cognitive-behavioral session, followed by daily text messages directing app use) or a control group (daily text messages of inspirational quotes). Participants (54 percent males, 87 percent SMs) in both groups reported reductions in PTSD, anxiety, and depression symptoms during the 6-week intervention, which were sustained at 3 months, but exhibited partial rebound at 6-12 months. Our preliminary results suggest that app use, with or without specific direction, feasibly and effectively reduces symptom severity. Future studies should consider a longer intervention, enhanced compliance tracking, or boosters to sustain benefits.

  11. Racial discrimination is associated with distressing subthreshold positive psychotic symptoms among US urban ethnic minority young adults.

    Science.gov (United States)

    Anglin, Deidre M; Lighty, Quenesha; Greenspoon, Michelle; Ellman, Lauren M

    2014-10-01

    Racial discrimination is related to depression, anxiety, and severe psychological distress, and evidence drawn from studies emanating from the United Kingdom and The Netherlands suggest racial discrimination is also related to clinical psychosis and subthreshold psychotic symptoms in racial and ethnic minority (REM) populations. The present study sought to determine the association between racial discrimination experiences and attenuated positive psychotic symptoms (APPS) in a United States (US) urban, predominantly immigrant and REM young adult population. A cohort of 650 young adults was administered a self-report inventory for psychosis risk [i.e., Prodromal Questionnaire (PQ)], and the Experiences of Discrimination Questionnaire. The PQ allowed the dimensional assessment of APPS, as well as the categorical assessment of a potentially "high risk" group (i.e., 8 or more APPS endorsed as distressing), the latter of which was based on previous validation studies using the structured interview for prodromal syndromes. The relations between self-reported racial discrimination and APPS, and racial discrimination and "high" distressing positive PQ endorsement were determined, while accounting for anxiety and depression symptoms. Racial discrimination was significantly associated with APPS and with significantly higher odds of endorsing eight or more distressing APPS, even after adjusting for anxiety and depression symptoms. The present study provides preliminary evidence that racial discrimination among US ethnic minorities may be associated with APPS, as well as potentially higher risk for psychosis.

  12. Sub-threshold panic attacks and agoraphobic avoidance increase comorbidity of mental disorders: results from an adult general population sample.

    Science.gov (United States)

    Pané-Farré, Christiane A; Fenske, Kristin; Stender, Jan P; Meyer, Christian; John, Ulrich; Rumpf, Hans-Jürgen; Hapke, Ulfert; Hamm, Alfons O

    2013-06-01

    Full-blown panic attacks are frequently associated with other mental disorders. Most comorbidity analyses did not discriminate between isolated panic attacks vs. panic attacks that occurred in the context of a panic disorder and rarely evaluated the impact of comorbid agoraphobia. Moreover, there are no larger scale epidemiological studies regarding the influence of sub-threshold panic attacks. 4075 German-speaking respondents aged 18-64 were interviewed using the fully structured Munich Composite International Diagnostic Interview. Limited symptom attacks, isolated panic attacks, and panic disorder were associated with other lifetime DSM-IV disorders with monotonically increasing odds and increasing tendency for multiple comorbidities across the three groups. The presence of agoraphobia was associated with more frequent comorbidity in all panic subgroups and also in persons who never experienced panic attacks. The present study suggests that populations with isolated or limited symptom should be carefully attended to in clinical practice, especially if agoraphobia is present. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. A GM-CSF/IL-33 pathway facilitates allergic airway responses to sub-threshold house dust mite exposure.

    Directory of Open Access Journals (Sweden)

    Alba Llop-Guevara

    Full Text Available Allergic asthma is a chronic immune-inflammatory disease of the airways. Despite aeroallergen exposure being universal, allergic asthma affects only a fraction of individuals. This is likely related, at least in part, to the extent of allergen exposure. Regarding house dust mite (HDM, we previously identified the threshold required to elicit allergic responses in BALB/c mice. Here, we investigated the impact of an initial immune perturbation on the response to sub-threshold HDM exposure. We show that transient GM-CSF expression in the lung facilitated robust eosinophilic inflammation, long-lasting antigen-specific Th2 responses, mucus production and airway hyperresponsiveness. This was associated with increased IL-33 levels and activated CD11b(+ DCs expressing OX40L. GM-CSF-driven allergic responses were significantly blunted in IL-33-deficient mice. IL-33 was localized on alveolar type II cells and in vitro stimulation of human epithelial cells with GM-CSF enhanced intracellular IL-33 independently of IL-1α. Likewise, GM-CSF administration in vivo resulted in increased levels of IL-33 but not IL-1α. These findings suggest that exposures to environmental agents associated with GM-CSF production, including airway infections and pollutants, may decrease the threshold of allergen responsiveness and, hence, increase the susceptibility to develop allergic asthma through a GM-CSF/IL-33/OX40L pathway.

  14. Effects of band-tails on the subthreshold characteristics of nanowire band-to-band tunneling transistors

    Science.gov (United States)

    Khayer, M. Abul; Lake, Roger K.

    2011-10-01

    High source doping is required to support the high electric fields necessary to provide sufficient drive currents in interband tunnel field effect transistors (TFETs). High doping is associated with band-tails in the density of states that decay exponentially into the bandgap with decay constants that can be comparable to the room temperature thermal energy kBT. This compromises the core operational principal of a TFET of a hard energy cut-off to the injected channel carrier distribution provided by the source valence band edge. If the band-tails are limited to the source region, they have minimal effect for short channels ≤10 nm, since the leakage current is dominated by direct, coherent tunneling through the channel. For longer 20 nm channels, source band-tails can double the inverse subthreshold slope but still leave it below the ideal 60 mV/decade value with on-off current ratios greater than 106 using a supply voltage of 0.4 V. Band-tails both in the source and channel are more detrimental for both 10 and 20 nm channels. On-off current ratios are reduced to ≥103 and ≥104 for the 10 nm and 20 nm channel devices, respectively.

  15. Subthreshold self-sustained discharge initiated by a microwave beam in a large volume of high-pressure gas

    Science.gov (United States)

    Artem’ev, K. V.; Batanov, G. M.; Berezhetskaya, N. K.; Davydov, A. M.; Kossyi, I. A.; Nefedov, V. I.; Sarksyan, K. A.; Kharchev, N. K.

    2017-10-01

    The presented results are based on the experimental studies of generating a long plasma column in gas (or gas mixtures) at atmospheric pressure both in free space and in a closed chamber. The microwave generator GYROTRON was used as an energy source. Its parameters were as follows: the microwave pulse power was in the range of 200 ≤ P ≤ 600 kW, the wavelength was λ ≈ 0.4 cm, and the pulse duration was in the range of 0.5 ≤ τi ≤ 20 ms. Under strong subthreshold conditions, a plasma column with a length of up to L ≤ 50 cm was created using a microwave beam that was formed using a quasi-optical mirror system. The discharge initiation system had an original design. Based on the discharge structure, expansion dynamics and typical discharge plasma parameters, this discharge can be attributed to the type of microwave discharges that are known as self/non-self-sustained discharges. The discharge properties and advantages of using this discharge as a basis of a plasma-chemical reactor are discussed.

  16. Analyzing Sub-Threshold Bitcell Topologies and the Effects of Assist Methods on SRAM VMIN

    Directory of Open Access Journals (Sweden)

    James Boley

    2012-04-01

    Full Text Available The need for ultra low power circuits has forced circuit designers to scale voltage supplies into the sub-threshold region where energy per operation is minimized [1]. The problem with this is that the traditional 6T SRAM bitcell, used for data storage, becomes unreliable at voltages below about 700 mV due to process variations and decreased device drive strength [2]. In order to achieve reliable operation, new bitcell topologies and assist methods have been proposed. This paper provides a comparison of four different bitcell topologies using read and write VMIN as the metrics for evaluation. In addition, read and write assist methods were tested using the periphery voltage scaling techniques discussed in [4–13]. Measurements taken from a 180 nm test chip show read functionality (without assist methods down to 500 mV and write functionality down to 600 mV. Using assist methods can reduce both read and write VMIN by 100 mV over the unassisted test case.

  17. Anatomical and functional assemblies of brain BOLD oscillations

    Science.gov (United States)

    Baria, Alexis T.; Baliki, Marwan N.; Parrish, Todd; Apkarian, A. Vania

    2011-01-01

    Brain oscillatory activity has long been thought to have spatial properties, the details of which are unresolved. Here we examine spatial organizational rules for the human brain oscillatory activity as measured by blood oxygen level-dependent (BOLD). Resting state BOLD signal was transformed into frequency space (Welch’s method), averaged across subjects, and its spatial distribution studied as a function of four frequency bands, spanning the full bandwidth of BOLD. The brain showed anatomically constrained distribution of power for each frequency band. This result was replicated on a repository dataset of 195 subjects. Next, we examined larger-scale organization by parceling the neocortex into regions approximating Brodmann Areas (BAs). This indicated that BAs of simple function/connectivity (unimodal), vs. complex properties (transmodal), are dominated by low frequency BOLD oscillations, and within the visual ventral stream we observe a graded shift of power to higher frequency bands for BAs further removed from the primary visual cortex (increased complexity), linking frequency properties of BOLD to hodology. Additionally, BOLD oscillation properties for the default mode network demonstrated that it is composed of distinct frequency dependent regions. When the same analysis was performed on a visual-motor task, frequency-dependent global and voxel-wise shifts in BOLD oscillations could be detected at brain sites mostly outside those identified with general linear modeling. Thus, analysis of BOLD oscillations in full bandwidth uncovers novel brain organizational rules, linking anatomical structures and functional networks to characteristic BOLD oscillations. The approach also identifies changes in brain intrinsic properties in relation to responses to external inputs. PMID:21613505

  18. Magnetically Coupled Magnet-Spring Oscillators

    Science.gov (United States)

    Donoso, G.; Ladera, C. L.; Martin, P.

    2010-01-01

    A system of two magnets hung from two vertical springs and oscillating in the hollows of a pair of coils connected in series is a new, interesting and useful example of coupled oscillators. The electromagnetically coupled oscillations of these oscillators are experimentally and theoretically studied. Its coupling is electromagnetic instead of…

  19. On the nonlinear modeling of ring oscillators

    KAUST Repository

    Elwakil, Ahmed S.

    2009-06-01

    We develop higher-order nonlinear models of three-stage and five-stage ring oscillators based on a novel inverter model. The oscillation condition and oscillation frequency are derived and compared to classical linear model analysis. Two important special cases for five-stage ring oscillators are also studied. Numerical simulations are shown. © 2009 World Scientific Publishing Company.

  20. On the mechanism of oscillations in neutrophils

    DEFF Research Database (Denmark)

    Brasen, Jens Christian; Barington, Torben; Olsen, Lars Folke

    2010-01-01

    We have investigated the regulation of the oscillatory generation of H(2)O(2) and oscillations in shape and size in neutrophils in suspension. The oscillations are independent of cell density and hence do not represent a collective phenomena. Furthermore, the oscillations are independent...... of the external glucose concentration and the oscillations in H(2)O(2) production are 180 degrees out of phase with the oscillations in NAD(P)H. Cytochalasin B blocked the oscillations in shape and size whereas it increased the period of the oscillations in H(2)O(2) production. 1- and 2-butanol also blocked...... the oscillations in shape and size, but only 1-butanol inhibited the oscillations in H(2)O(2) production. We conjecture that the oscillations are likely to be due to feedback regulations in the signal transduction cascade involving phosphoinositide 3-kinases (PI3K). We have tested this using a simple mathematical...

  1. Short-range correlations in carbon-12, oxygen-16, and neon-20: Intrinsic properties

    Science.gov (United States)

    Braley, R. C.; Ford, W. F.; Becker, R. L.; Patterson, M. R.

    1972-01-01

    The Brueckner-Hartree-Fock (BHF) method has been applied to nuclei whose intrinsic structure is nonspherical. Reaction matrix elements were calculated as functions of starting energy for the Hamada-Johnston interaction using the Pauli operator appropriate to O-16 and a shifted oscillator spectrum for virtual excited states. Binding energies, single particle energies, radii, and shape deformations of the intrinsic state, in ordinary as well as renormalized BHF, are discussed and compared with previous HF studies and with experiment when possible. Results are presented for C-12, 0-16 and Ne-20. It is found that the binding energies and radii are too small, but that separation energies are well reproduced when the renormalized theory is used.

  2. Discomfort caused by low-frequency lateral oscillation, roll oscillation and roll-compensated lateral oscillation.

    Science.gov (United States)

    Beard, George F; Griffin, Michael J

    2013-01-01

    Roll compensation during cornering (aligning the feet-to-head axis of the body with the resultant force) reduces lateral acceleration, but how any improvement in comfort depends on the frequency of the acceleration has not previously been investigated. Seated subjects judged the discomfort caused by lateral oscillation, roll oscillation and fully roll-compensated lateral oscillation at each of seven frequencies (0.25-1.0 Hz). Irrespective of whether it was caused by pure lateral acceleration or gravitational acceleration due to pure roll, acceleration in the plane of the seat caused similar discomfort at frequencies less than 0.4 Hz. From 0.4 to 1.0 Hz, with the same lateral acceleration in the plane of the seat, there was greater discomfort from roll oscillation than from lateral acceleration. With fully roll-compensated lateral oscillation, discomfort was less than with either the lateral component or the roll component of the motion from 0.2 to 0.5 Hz, but discomfort increased with increasing frequency and caused similar discomfort to pure roll oscillation at 1.0 Hz. Tilting can reduce passenger exposure to vehicle lateral acceleration when cornering, but how comfort depends on the frequency of motion was unknown. This study shows 'tilt-compensation' only improves comfort at frequencies less than 0.5 Hz. The findings affect tilting vehicles and the prediction of discomfort caused by low-frequency motions.

  3. Functions of intrinsic disorder in transmembrane proteins

    DEFF Research Database (Denmark)

    Kjaergaard, Magnus; Kragelund, Birthe B.

    2017-01-01

    mechanisms. (3) Trafficking of membrane proteins. (4) Transient membrane associations. (5) Post-translational modifications most notably phosphorylation and (6) disorder-linked isoform dependent function. We finish the review by discussing the future challenges facing the membrane protein community regarding......Intrinsic disorder is common in integral membrane proteins, particularly in the intracellular domains. Despite this observation, these domains are not always recognized as being disordered. In this review, we will discuss the biological functions of intrinsically disordered regions of membrane...... proteins, and address why the flexibility afforded by disorder is mechanistically important. Intrinsically disordered regions are present in many common classes of membrane proteins including ion channels and transporters; G-protein coupled receptors (GPCRs), receptor tyrosine kinases and cytokine...

  4. Management Control, Intrinsic Motivation and Creativity

    DEFF Research Database (Denmark)

    Godt Gregersen, Mikkel

    of the conclusion is that intrinsic motivation and management control can coexist under the conditions that all three basic needs, i.e. autonomy, competence and relatedness, are supported. This can happen when control takes point of departure in the individual employee. The second part of the conclusion......This thesis consists of a cape and three papers. The overall research question is: How can intrinsic motivation and management control coexist in a creative environment and how can coordination be possible in such a context? The cape ties together the research done in the three papers....... It is divided into six sections. The first section introduces the concepts of intrinsic motivation, creativity and management control. This is followed by a section on management control in a creative context. These two sections frame the thesis and introduce the setting in which the research has been done...

  5. Cell intrinsic control of axon regeneration

    Science.gov (United States)

    Mar, Fernando M; Bonni, Azad; Sousa, Mónica M

    2014-01-01

    Although neurons execute a cell intrinsic program of axonal growth during development, following the establishment of connections, the developmental growth capacity declines. Besides environmental challenges, this switch largely accounts for the failure of adult central nervous system (CNS) axons to regenerate. Here, we discuss the cell intrinsic control of axon regeneration, including not only the regulation of transcriptional and epigenetic mechanisms, but also the modulation of local protein translation, retrograde and anterograde axonal transport, and microtubule dynamics. We further explore the causes underlying the failure of CNS neurons to mount a vigorous regenerative response, and the paradigms demonstrating the activation of cell intrinsic axon growth programs. Finally, we present potential mechanisms to support axon regeneration, as these may represent future therapeutic approaches to promote recovery following CNS injury and disease. PMID:24531721

  6. Analytical insights on theta-gamma coupled neural oscillators.

    Science.gov (United States)

    Fontolan, Lorenzo; Krupa, Maciej; Hyafil, Alexandre; Gutkin, Boris

    2013-08-14

    In this paper, we study the dynamics of a quadratic integrate-and-fire neuron, spiking in the gamma (30-100 Hz) range, coupled to a delta/theta frequency (1-8 Hz) neural oscillator. Using analytical and semianalytical methods, we were able to derive characteristic spiking times for the system in two distinct regimes (depending on parameter values): one regime where the gamma neuron is intrinsically oscillating in the absence of theta input, and a second one in which gamma spiking is directly gated by theta input, i.e., windows of gamma activity alternate with silence periods depending on the underlying theta phase. In the former case, we transform the equations such that the system becomes analogous to the Mathieu differential equation. By solving this equation, we can compute numerically the time to the first gamma spike, and then use singular perturbation theory to find successive spike times. On the other hand, in the excitable condition, we make direct use of singular perturbation theory to obtain an approximation of the time to first gamma spike, and then extend the result to calculate ensuing gamma spikes in a recursive fashion. We thereby give explicit formulas for the onset and offset of gamma spike burst during a theta cycle, and provide an estimation of the total number of spikes per theta cycle both for excitable and oscillator regimes.

  7. Linear stability analysis of collective neutrino oscillations without spurious modes

    Science.gov (United States)

    Morinaga, Taiki; Yamada, Shoichi

    2018-01-01

    Collective neutrino oscillations are induced by the presence of neutrinos themselves. As such, they are intrinsically nonlinear phenomena and are much more complex than linear counterparts such as the vacuum or Mikheyev-Smirnov-Wolfenstein oscillations. They obey integro-differential equations, for which it is also very challenging to obtain numerical solutions. If one focuses on the onset of collective oscillations, on the other hand, the equations can be linearized and the technique of linear analysis can be employed. Unfortunately, however, it is well known that such an analysis, when applied with discretizations of continuous angular distributions, suffers from the appearance of so-called spurious modes: unphysical eigenmodes of the discretized linear equations. In this paper, we analyze in detail the origin of these unphysical modes and present a simple solution to this annoying problem. We find that the spurious modes originate from the artificial production of pole singularities instead of a branch cut on the Riemann surface by the discretizations. The branching point singularities on the Riemann surface for the original nondiscretized equations can be recovered by approximating the angular distributions with polynomials and then performing the integrals analytically. We demonstrate for some examples that this simple prescription does remove the spurious modes. We also propose an even simpler method: a piecewise linear approximation to the angular distribution. It is shown that the same methodology is applicable to the multienergy case as well as to the dispersion relation approach that was proposed very recently.

  8. ALG-2 oscillates in subcellular localization, unitemporally with calcium oscillations

    DEFF Research Database (Denmark)

    la Cour, Jonas Marstrand; Mollerup, Jens; Berchtold, Martin Werner

    2007-01-01

    A variety of stimuli can trigger intracellular calcium oscillations. Relatively little is known about the molecular mechanisms decoding these events. We show that ALG-2, a Ca2+-binding protein originally isolated as a protein associated with apoptosis, is directly linked to Ca2+ signalling. We...... localization in an oscillatory fashion unitemporally with Ca2+ oscillations, whereas a Ca2+-binding deficient mutant of ALG-2 did not redistribute. Using tagged ALG-2 as bait we identified its novel target protein Sec31A and based on the partial colocalization of endogenous ALG-2 and Sec31A we propose that ALG...

  9. Depletion-mode quantum dots in intrinsic silicon

    Science.gov (United States)

    Amitonov, Sergey V.; Spruijtenburg, Paul C.; Vervoort, Max W. S.; van der Wiel, Wilfred G.; Zwanenburg, Floris A.

    2018-01-01

    We report the fabrication and electrical characterization of depletion-mode quantum dots in a two-dimensional hole gas (2DHG) in intrinsic silicon. We use fixed charge in a SiO2/Al2O3 dielectric stack to induce a 2DHG at the Si/SiO2 interface. Fabrication of the gate structures is accomplished with a single layer metallization process. Transport spectroscopy reveals regular Coulomb oscillations with charging energies of 10-15 meV and 3-5 meV for the few- and many-hole regimes, respectively. This depletion-mode design avoids complex multilayer architectures requiring precision alignment and allows us to adopt directly best practices already developed for depletion dots in other material systems. We also demonstrate a method to deactivate fixed charge in the SiO2/Al2O3 dielectric stack using deep ultraviolet light, which may become an important procedure to avoid unwanted 2DHG build-up in Si MOS quantum bits.

  10. Halo Intrinsic Alignment: Dependence on Mass, Formation Time, and Environment

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Qianli; Kang, Xi; Wang, Peng; Luo, Yu [Purple Mountain Observatory, the Partner Group of MPI für Astronomie, 2 West Beijing Road, Nanjing 210008 (China); Yang, Xiaohu; Jing, Yipeng [Center for Astronomy and Astrophysics, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang, Huiyuan [Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026 (China); Mo, Houjun, E-mail: kangxi@pmo.ac.cn [Astronomy Department and Center for Astrophysics, Tsinghua University, Beijing 10084 (China)

    2017-10-10

    In this paper we use high-resolution cosmological simulations to study halo intrinsic alignment and its dependence on mass, formation time, and large-scale environment. In agreement with previous studies using N -body simulations, it is found that massive halos have stronger alignment. For the first time, we find that for a given halo mass older halos have stronger alignment and halos in cluster regions also have stronger alignment than those in filaments. To model these dependencies, we extend the linear alignment model with inclusion of halo bias and find that the halo alignment with its mass and formation time dependence can be explained by halo bias. However, the model cannot account for the environment dependence, as it is found that halo bias is lower in clusters and higher in filaments. Our results suggest that halo bias and environment are independent factors in determining halo alignment. We also study the halo alignment correlation function and find that halos are strongly clustered along their major axes and less clustered along the minor axes. The correlated halo alignment can extend to scales as large as 100 h {sup −1} Mpc, where its feature is mainly driven by the baryon acoustic oscillation effect.

  11. Insulin aggregation tracked by its intrinsic TRES

    Science.gov (United States)

    Chung, Li Hung C.; Birch, David J. S.; Vyshemirsky, Vladislav; Ryadnov, Maxim G.; Rolinski, Olaf J.

    2017-12-01

    Time-resolved emission spectra (TRES) have been used to detect conformational changes of intrinsic tyrosines within bovine insulin at a physiological pH. The approach offers the ability to detect the initial stages of insulin aggregation at the molecular level. The data analysis has revealed the existence of at least three fluorescent species undergoing dielectric relaxation and significant spectral changes due to insulin aggregation. The results indicate the suitability of the intrinsic TRES approach for insulin studies and for monitoring its stability during storage and aggregation in insulin delivery devices.

  12. Intrinsic viscosity of a suspension of cubes

    KAUST Repository

    Mallavajula, Rajesh K.

    2013-11-06

    We report on the viscosity of a dilute suspension of cube-shaped particles. Irrespective of the particle size, size distribution, and surface chemistry, we find empirically that cubes manifest an intrinsic viscosity [η]=3.1±0.2, which is substantially higher than the well-known value for spheres, [η]=2.5. The orientation-dependent intrinsic viscosity of cubic particles is determined theoretically using a finite-element solution of the Stokes equations. For isotropically oriented cubes, these calculations show [η]=3.1, in excellent agreement with our experimental observations. © 2013 American Physical Society.

  13. Intrinsic entropy perturbations from the dark sector

    Science.gov (United States)

    Celoria, Marco; Comelli, Denis; Pilo, Luigi

    2018-03-01

    Perfect fluids are modeled by using an effective field theory approach which naturally gives a self-consistent and unambiguous description of the intrinsic non-adiabatic contribution to pressure variations. We study the impact of intrinsic entropy perturbation on the superhorizon dynamics of the curvature perturbation Script R in the dark sector. The dark sector, made of dark matter and dark energy is described as a single perfect fluid. The non-perturbative vorticity's dynamics and the Weinberg theorem violation for perfect fluids are also studied.

  14. A model of intrinsic symmetry breaking

    International Nuclear Information System (INIS)

    Ge, Li; Li, Sheng; George, Thomas F.; Sun, Xin

    2013-01-01

    Different from the symmetry breaking associated with a phase transition, which occurs when the controlling parameter is manipulated across a critical point, the symmetry breaking presented in this Letter does not need parameter manipulation. Instead, the system itself suddenly undergoes symmetry breaking at a certain time during its evolution, which is intrinsic symmetry breaking. Through a polymer model, it is revealed that the origin of the intrinsic symmetry breaking is nonlinearity, which produces instability at the instance when the evolution crosses an inflexion point, where this instability breaks the original symmetry

  15. Escalation to Major Depressive Disorder among adolescents with subthreshold depressive symptoms: evidence of distinct subgroups at risk.

    Science.gov (United States)

    Hill, Ryan M; Pettit, Jeremy W; Lewinsohn, Peter M; Seeley, John R; Klein, Daniel N

    2014-04-01

    The presence of subthreshold depressive symptoms (SubD) in adolescence is associated with high prospective risk of developing Major Depressive Disorder (MDD). Little is known about variables that predict escalation from SubD to MDD. This study used a longitudinal prospective design in a community sample of adolescents to identify combinations of risk factors that predicted escalation from SubD to MDD. Classification tree analysis was used to identify combinations of risk factors that improved the sensitivity and specificity of prediction of MDD onset among 424 adolescents with a lifetime history of SubD. Of the 424, 144 developed MDD during the follow-up period. Evidence for multiple subgroups was found: among adolescents with poor friend support, the highest risk of escalation was among participants with lifetime histories of an anxiety or substance use disorder. Among adolescents with high friend support, those reporting multiple major life events in the past year or with a history of an anxiety disorder were at highest risk of escalation. Study findings may not inform prevention efforts for individuals who first develop SubD during adulthood. This study did not examine the temporal ordering of predictors involved in escalation from SubD to MDD. Adolescents with a history of SubD were at highest risk of escalation to MDD in the presence of poor friend support and an anxiety or substance use disorder, or in the presence of better friend support, multiple major life events, and an anxiety disorder. Findings may inform case identification approaches for adolescent depression prevention programs. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Real oscillations of virtual neutrinos

    International Nuclear Information System (INIS)

    Grimus, W.; Stockinger, P.

    1996-01-01

    We study the conditions for neutrino oscillations in a field-theoretical approach by taking into account that only the neutrino production and detection processes, which are localized in space around the coordinates x searrow P and x searrow D , respectively, can be manipulated. In this sense the neutrinos whose oscillations are investigated appear as virtual lines connecting production with detection in the total Feynman graph and all neutrino fields or states to be found in the discussion are mass eigenfields or eigenstates. We perform a thorough examination of the integral over the spatial components of the inner neutrino momentum and show that in the asymptotic limit L=|x searrow D -x searrow P |→∞ the virtual neutrinos become open-quote open-quote real close-quote close-quote and under certain conditions the usual picture of neutrino oscillations emerges without ambiguities. copyright 1996 The American Physical Society

  17. Damping of coupled harmonic oscillators

    Science.gov (United States)

    Dolfo, Gilles; Vigué, Jacques

    2018-03-01

    When two harmonic oscillators are coupled in the presence of damping, their dynamics exhibit two very different regimes depending on the relative magnitude of the coupling and damping terms At resonance, when the coupling has its largest effect, if the coupling dominates the damping, there is a periodic exchange of energy between the two oscillators while, in the opposite case, the energy transfer from one oscillator to the other one is irreversible. We prove that the border between these two regimes goes through an exceptional point and we briefly explain what is an exceptional point. The present paper is written for undergraduate students, with some knowledge in classical mechanics, but it may also be of interest for graduate students.

  18. Prediction of pilot induced oscillations

    Directory of Open Access Journals (Sweden)

    Valentin PANĂ

    2011-03-01

    Full Text Available An important problem in the design of flight-control systems for aircraft under pilotedcontrol is the determination of handling qualities and pilot-induced oscillations (PIO tendencieswhen significant nonlinearities exist in the vehicle description. The paper presents a method to detectpossible pilot-induced oscillations of Category II (with rate and position limiting, a phenomenonusually due to a misadaptation between the pilot and the aircraft response during some tasks in whichtight closed loop control of the aircraft is required from the pilot. For the analysis of Pilot in the LoopOscillations an approach, based on robust stability analysis of a system subject to uncertainparameters, is proposed. In this analysis the nonlinear elements are substituted by linear uncertainparameters. This approach assumes that PIO are characterized by a limit cycle behavior.

  19. On the origin of interdecadal oscillations in a coupled ocean–atmosphere model

    OpenAIRE

    Arzel, Olivier; De Verdière, Alain Colin; Huck, Thierry

    2007-01-01

    Interdecadal oscillations are analysed in a coupled ocean–atmosphere model made of a planetary geostrophic ocean model within an idealized geometry, coupled to a zonally-averaged tropospheric atmosphere model. The interdecadal variability that arises spontaneously in this coupled system is caused by intrinsic ocean dynamics, the coupled air-sea feedbacks being not essential. The spatial pattern of the variability bears some resemblance with observations and results obtained with atmosphere-oc...

  20. Decoding temporally encoded sensory input by cortical oscillations and thalamic phase comparators

    OpenAIRE

    Ahissar, Ehud; Haidarliu, Sebastian; Zacksenhouse, Miriam

    1997-01-01

    The temporally encoded information obtained by vibrissal touch could be decoded “passively,” involving only input-driven elements, or “actively,” utilizing intrinsically driven oscillators. A previous study suggested that the trigeminal somatosensory system of rats does not obey the bottom-up order of activation predicted by passive decoding. Thus, we have tested whether this system obeys the predictions of active decoding. We have studied cortical single units in ...

  1. DIGITAL SELF-OSCILLATING MODULATOR

    DEFF Research Database (Denmark)

    2007-01-01

    A digital self-oscillating modulator (1) having a digital reference signal as input (Vref) comprises a forward loop with a first output and a feedback loop. The feedback loop comprises a feedback block (18) having a transfer function (MFB) and a digital output. The forward loop comprises an alter......A digital self-oscillating modulator (1) having a digital reference signal as input (Vref) comprises a forward loop with a first output and a feedback loop. The feedback loop comprises a feedback block (18) having a transfer function (MFB) and a digital output. The forward loop comprises...

  2. Spontaneous oscillations in microfluidic networks

    Science.gov (United States)

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

    2017-11-01

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

  3. Frustration-induced protein intrinsic disorder.

    Science.gov (United States)

    Matsushita, Katsuyoshi; Kikuchi, Macoto

    2013-03-14

    Spontaneous folding into a specific native structure is the most important property of protein to perform their biological functions within organisms. Spontaneous folding is understood on the basis of an energy landscape picture based on the minimum frustration principle. Therefore, frustration seemingly only leads to protein functional disorder. However, frustration has recently been suggested to have a function in allosteric regulation. Functional frustration has the possibility to be a key to our deeper understanding of protein function. To explore another functional frustration, we theoretically examined structural frustration, which is designed to induce intrinsic disorder of a protein and its function through the coupled folding and binding. We extended the Wako-Saitô-Muñoz-Eaton model to take into account a frustration effect. With the model, we analyzed the binding part of neuron-restrictive silencer factor and showed that designed structural frustration in it induces intrinsic disorder. Furthermore, we showed that the folding and the binding are cooperative in interacting with a target protein. The cooperativity enables an intrinsically disordered protein to exhibit a sharp switch-like folding response to binding chemical potential change. Through this switch-like response, the structural frustration may contribute to the regulation function of interprotein interaction of the intrinsically disordered protein.

  4. Simple intrinsic defects in InAs :

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, Peter Andrew

    2013-03-01

    This Report presents numerical tables summarizing properties of intrinsic defects in indium arsenide, InAs, as computed by density functional theory using semi-local density functionals, intended for use as reference tables for a defect physics package in device models.

  5. INTRINSIC AND EXTRINSIC MOTIVATION IN THE SELECTION ...

    African Journals Online (AJOL)

    A psychological perspective is considered that applies intrinsic and extrinsic motivational concepts to communication phenomena. The paper also tries to develop an analytical understanding of human communication-related behavior with respect to the two types of motives. Proposals are also put forward to communication ...

  6. Intrinsic and Extrinsic Motivation among Collegiate Instrumentalists

    Science.gov (United States)

    Diaz, Frank M.

    2010-01-01

    The purpose of this study was to gather and compare information on measures of intrinsic and extrinsic motivation among instrumentalists enrolled in collegiate ensembles. A survey instrument was developed to gather information concerning demographic data and responses to questions on motivational preference. Participants were undergraduate and…

  7. A rotational integral formula for intrinsic volumes

    DEFF Research Database (Denmark)

    Jensen, Eva Bjørn Vedel; Rataj, J.

    2008-01-01

    A rotational version of the famous Crofton formula is derived. The motivation for deriving the formula comes from local stereology, a new branch of stereology based on sections through fixed reference points. The formula shows how rotational averages of intrinsic volumes measured on sections...

  8. Original Paper Detecting Nosocomial Intrinsic Infections through ...

    African Journals Online (AJOL)

    2011-04-20

    Apr 20, 2011 ... Key Words: Bacterial pathogens, Endogenous indicators, NosocomiaI infection, Surgery. Received 30 October 2010/ Accepted 30 March 2011. INTRODUCTION. Micro-organisms from intrinsic and extrinsic sources have been known to cause nosocomial infections (CDC, 1991). The human body enables.

  9. Organisational Learning and Employees' Intrinsic Motivation

    Science.gov (United States)

    Remedios, Richard; Boreham, Nick

    2004-01-01

    This study examined the effects of organisational learning initiatives on employee motivation. Four initiatives consistent with theories of organisational learning were a priori ranked in terms of concepts that underpin intrinsic-motivation theory. Eighteen employees in a UK petrochemical company were interviewed to ascertain their experiences of…

  10. Intrinsic Motivation, Organizational Justice, and Creativity

    Science.gov (United States)

    Hannam, Kalli; Narayan, Anupama

    2015-01-01

    For employees to generate creative ideas that are not only original, but also useful to their company, they must interact with their workplace environment to determine organizational needs. Therefore, it is important to consider aspects of the individual as well as their environment when studying creativity. Intrinsic motivation, a predictor of…

  11. Discovery of Intrinsic Primitives on Triangle Meshes

    KAUST Repository

    Solomon, Justin

    2011-04-01

    The discovery of meaningful parts of a shape is required for many geometry processing applications, such as parameterization, shape correspondence, and animation. It is natural to consider primitives such as spheres, cylinders and cones as the building blocks of shapes, and thus to discover parts by fitting such primitives to a given surface. This approach, however, will break down if primitive parts have undergone almost-isometric deformations, as is the case, for example, for articulated human models. We suggest that parts can be discovered instead by finding intrinsic primitives, which we define as parts that posses an approximate intrinsic symmetry. We employ the recently-developed method of computing discrete approximate Killing vector fields (AKVFs) to discover intrinsic primitives by investigating the relationship between the AKVFs of a composite object and the AKVFs of its parts. We show how to leverage this relationship with a standard clustering method to extract k intrinsic primitives and remaining asymmetric parts of a shape for a given k. We demonstrate the value of this approach for identifying the prominent symmetry generators of the parts of a given shape. Additionally, we show how our method can be modified slightly to segment an entire surface without marking asymmetric connecting regions and compare this approach to state-of-the-art methods using the Princeton Segmentation Benchmark. © 2011 The Author(s).

  12. TOWARDS THRESHOLD FREQUENCY IN CHAOTIC COLPITTS OSCILLATOR

    DEFF Research Database (Denmark)

    Lindberg, Erik; Tamasevicius, Arunas; Mykolaitis, Gytis

    2007-01-01

    A novel version of chaotic Colpitts oscillator is described. Instead of a linear loss resistor, it includes an extra inductor and diode in the collector circuit of the transistor. The modified circuit in comparison with the common Colpitts oscillator may generate chaotic oscillations at the funda......A novel version of chaotic Colpitts oscillator is described. Instead of a linear loss resistor, it includes an extra inductor and diode in the collector circuit of the transistor. The modified circuit in comparison with the common Colpitts oscillator may generate chaotic oscillations...

  13. Quantized impedance dealing with the damping behavior of the one-dimensional oscillator

    Directory of Open Access Journals (Sweden)

    Jinghao Zhu

    2015-11-01

    Full Text Available A quantized impedance is proposed to theoretically establish the relationship between the atomic eigenfrequency and the intrinsic frequency of the one-dimensional oscillator in this paper. The classical oscillator is modified by the idea that the electron transition is treated as a charge-discharge process of a suggested capacitor with the capacitive energy equal to the energy level difference of the jumping electron. The quantized capacitance of the impedance interacting with the jumping electron can lead the resonant frequency of the oscillator to the same as the atomic eigenfrequency. The quantized resistance reflects that the damping coefficient of the oscillator is the mean collision frequency of the transition electron. In addition, the first and third order electric susceptibilities based on the oscillator are accordingly quantized. Our simulation of the hydrogen atom emission spectrum based on the proposed method agrees well with the experimental one. Our results exhibits that the one-dimensional oscillator with the quantized impedance may become useful in the estimations of the refractive index and one- or multi-photon absorption coefficients of some nonmagnetic media composed of hydrogen-like atoms.

  14. Oscillation and noise determine signal transduction in shark multimodal sensory cells.

    Science.gov (United States)

    Braun, H A; Wissing, H; Schäfer, K; Hirsch, M C

    1994-01-20

    Oscillating membrane potentials that generate rhythmic impulse patterns are considered to be of particular significance for neuronal information processing. In contrast, noise is usually seen as a disturbance which limits the accuracy of information transfer. We show here, however, that noise in combination with intrinsic oscillations can provide neurons with particular encoding properties, a discovery we made when recording from single electro-sensory afferents of a fish. The temporal sequence of the impulse trains indicates oscillations that operate near the spike-triggering threshold. The oscillation frequency determines the basic rhythm of impulse generation, but whether or not an impulse is actually triggered essentially depends on superimposed noise. The probability of impulse generation can be altered considerably by minor modifications of oscillation baseline and amplitude, which may underlie the exquisite sensitivity of these receptors to thermal and electrical stimuli. Additionally, thermal, but not electrical, stimuli alter the oscillation frequency, allowing dual sensory messages to be conveyed in a single spike train. These findings demonstrate novel properties of sensory transduction which may be relevant for neuronal signalling in general.

  15. Emergence of noise-induced oscillations in the central circadian pacemaker.

    Directory of Open Access Journals (Sweden)

    Caroline H Ko

    2010-10-01

    Full Text Available Bmal1 is an essential transcriptional activator within the mammalian circadian clock. We report here that the suprachiasmatic nucleus (SCN of Bmal1-null mutant mice, unexpectedly, generates stochastic oscillations with periods that overlap the circadian range. Dissociated SCN neurons expressed fluctuating levels of PER2 detected by bioluminescence imaging but could not generate circadian oscillations intrinsically. Inhibition of intercellular communication or cyclic-AMP signaling in SCN slices, which provide a positive feed-forward signal to drive the intracellular negative feedback loop, abolished the stochastic oscillations. Propagation of this feed-forward signal between SCN neurons then promotes quasi-circadian oscillations that arise as an emergent property of the SCN network. Experimental analysis and mathematical modeling argue that both intercellular coupling and molecular noise are required for the stochastic rhythms, providing a novel biological example of noise-induced oscillations. The emergence of stochastic circadian oscillations from the SCN network in the absence of cell-autonomous circadian oscillatory function highlights a previously unrecognized level of circadian organization.

  16. Synaptic NMDA Receptor-Dependent Ca2+ Entry Drives Membrane Potential and Ca2+ Oscillations in Spinal Ventral Horn Neurons

    Science.gov (United States)

    Alpert, Michael H.; Alford, Simon

    2013-01-01

    During vertebrate locomotion, spinal neurons act as oscillators when initiated by glutamate release from descending systems. Activation of NMDA receptors initiates Ca2+-mediated intrinsic membrane potential oscillations in central pattern generator (CPG) neurons. NMDA receptor-dependent intrinsic oscillations require Ca2+-dependent K+ (KCa2) channels for burst termination. However, the location of Ca2+ entry mediating KCa2 channel activation, and type of Ca2+ channel – which includes NMDA receptors and voltage-gated Ca2+ channels (VGCCs) – remains elusive. NMDA receptor-dependent Ca2+ entry necessitates presynaptic release of glutamate, implying a location at active synapses within dendrites, whereas VGCC-dependent Ca2+ entry is not similarly constrained. Where Ca2+ enters relative to KCa2 channels is crucial to information processing of synaptic inputs necessary to coordinate locomotion. We demonstrate that Ca2+ permeating NMDA receptors is the dominant source of Ca2+ during NMDA-dependent oscillations in lamprey spinal neurons. This Ca2+ entry is synaptically located, NMDA receptor-dependent, and sufficient to activate KCa2 channels at excitatory interneuron synapses onto other CPG neurons. Selective blockade of VGCCs reduces whole-cell Ca2+ entry but leaves membrane potential and Ca2+ oscillations unaffected. Furthermore, repetitive oscillations are prevented by fast, but not slow, Ca2+ chelation. Taken together, these results demonstrate that KCa2 channels are closely located to NMDA receptor-dependent Ca2+ entry. The close spatial relationship between NMDA receptors and KCa2 channels provides an intrinsic mechanism whereby synaptic excitation both excites and subsequently inhibits ventral horn neurons of the spinal motor system. This places the components necessary for oscillation generation, and hence locomotion, at glutamatergic synapses. PMID:23646190

  17. Dynamics of decadal variability in the Atlantic subpolar gyre: a stochastically forced oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Born, Andreas [University of Bern, Climate and Environmental Physics, Physics Institute, Bern (Switzerland); Oeschger Centre for Climate Change Research, Bern (Switzerland); Bjerknes Centre for Climate Research, Bergen (Norway); University of Bergen, Geophysical Institute, Bergen (Norway); Mignot, Juliette [IPSL/UPMC/CNRS/IRD/MNHN, Laboratoire d' Oceanographie et du Climat, Experimentation et Approches Numeriques, Paris (France)

    2012-07-15

    Internal variability of the Atlantic subpolar gyre is investigated in a 600 years control simulation of a comprehensive coupled climate model. The subpolar gyre shows irregular oscillations of decadal time scale with most spectral power between 15 and 20 years. Positive and negative feedback mechanisms act successively on the circulation leading to an internal oscillation. This involves periodically enhanced deep convection in the subpolar gyre center and intermittently enhanced air-sea thermal coupling. As a result, anomalies of the large-scale atmospheric circulation can be transferred to the ocean on the ocean's intrinsic time scale, exciting the oscillator stochastically. A detailed understanding of oscillatory mechanisms of the ocean and their sensitivity to atmospheric forcing holds considerable potential for decadal predictions as well as for the interpretation of proxy data records. (orig.)

  18. Ellipsoidal basis for isotropic oscillator

    International Nuclear Information System (INIS)

    Kallies, W.; Lukac, I.; Pogosyan, G.S.; Sisakyan, A.N.

    1994-01-01

    The solutions of the Schroedinger equation are derived for the isotropic oscillator potential in the ellipsoidal coordinate system. The explicit expression is obtained for the ellipsoidal integrals of motion through the components of the orbital moment and Demkov's tensor. The explicit form of the ellipsoidal basis is given for the lowest quantum numbers. 10 refs.; 1 tab. (author)

  19. Oscillating solitons in nonlinear optics

    Indian Academy of Sciences (India)

    Abstract. Oscillating solitons are obtained in nonlinear optics. Analytical study of the variable- coefficient nonlinear Schrödinger equation, which is used to describe the soliton propagation in those systems, is carried out using the Hirota's bilinear method. The bilinear forms and analytic soliton solutions are derived, and the ...

  20. Low-Vibration Oscillating Compressor

    Science.gov (United States)

    Studer, P. A.

    1984-01-01

    Oscillating compressor momentum compensated: produces little vibration in its supporting structure. Compressure requires no lubrication and virtually free of wear. Compresses working fluids such as helium, nitrogen or chlorfluorocarbons for Stirling-cycle refrigeration or other purposes. Compressor includes two mutually opposed ferromagnetic pistons of same shape and mass. Electromagnetic flux links both pistons, causing magnetic attraction between them.

  1. Sound oscillation of dropwise cluster

    Energy Technology Data Exchange (ETDEWEB)

    Shavlov, A.V., E-mail: shavlov@ikz.ru [Institute of the Earth Cryosphere, RAS Siberian Branch, P.O. 1230, 625000 Tyumen (Russian Federation); Dzhumandzhi, V.A.; Romanyuk, S.N. [Institute of the Earth Cryosphere, RAS Siberian Branch, P.O. 1230, 625000 Tyumen (Russian Federation)

    2012-06-04

    There was registered sound oscillation of a dropwise cluster formed over the warmed-up water surface. We have calculated the electrical charge of drops on the basis of experimental data on ion-sound oscillation. It was demonstrated that the charge is proportional to surface area of the drops and does not depend on intensity of their evaporation (condensation) in the range of 60–100 °C. The charge of drops reaches 10{sup 2}–10{sup 3} units of elementary charge and coincides on magnitude order with the literary value of a charge calculated by another method. -- Highlights: ► The present investigation registered short-wave sound oscillations of water drops in a dropwise cluster in the range of 60–100 °C. ► We have found autocorrelation functions and Fourier transforms of time series of interdroplet distance; defined oscillation frequencies. ► Calculated electrical charge of drops and specified that the charge is proportional to the drop surface area.

  2. Sound oscillation of dropwise cluster

    International Nuclear Information System (INIS)

    Shavlov, A.V.; Dzhumandzhi, V.A.; Romanyuk, S.N.

    2012-01-01

    There was registered sound oscillation of a dropwise cluster formed over the warmed-up water surface. We have calculated the electrical charge of drops on the basis of experimental data on ion-sound oscillation. It was demonstrated that the charge is proportional to surface area of the drops and does not depend on intensity of their evaporation (condensation) in the range of 60–100 °C. The charge of drops reaches 10 2 –10 3 units of elementary charge and coincides on magnitude order with the literary value of a charge calculated by another method. -- Highlights: ► The present investigation registered short-wave sound oscillations of water drops in a dropwise cluster in the range of 60–100 °C. ► We have found autocorrelation functions and Fourier transforms of time series of interdroplet distance; defined oscillation frequencies. ► Calculated electrical charge of drops and specified that the charge is proportional to the drop surface area.

  3. Treatment response in relation to subthreshold bipolarity in patients with major depressive disorder receiving antidepressant monotherapy: a post hoc data analysis (KOMDD study

    Directory of Open Access Journals (Sweden)

    Park YM

    2016-05-01

    Full Text Available Young-Min Park,1 Bun-Hee Lee2 1Department of Psychiatry, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, 2Department of Psychiatry, Seoul Eunpyeong Hospital, Seoul, Republic of Korea Background: The aim of this observational study was to determine whether subthreshold bipolarity affects treatment response and remission in patients with major depressive disorder receiving antidepressant (AD monotherapy over a 6-month follow-up period. Methods: Seventy-eight patients with major depressive disorder were stratified into two subgroups according to the presence of subthreshold bipolarity, identified using the Korean version of the Mood Disorder Questionnaire (K-MDQ, which classifies patients as positive for a screening of bipolarity based on the cutoff for the total K-MDQ score (ie, 7 points. They received AD monotherapy such as escitalopram, sertraline, paroxetine, or tianeptine for 6 months. The Beck Depression Inventory (BDI, Hamilton Depression Rating Scale (HAMD, Hamilton Anxiety Scale, and Beck Scale for Suicide Ideation were applied at baseline, 1 week, 3 weeks, 2 months, 3 months, and 6 months. Results: The mean HAMD, BDI, and Beck Scale for Suicide Ideation scores were higher in the bipolarity group than in the nonbipolarity group at 3 weeks. The mean BDI score was also higher in the bipolarity group than in the nonbipolarity group at 6 months. Evaluation of the ratio of improvement for each scale revealed different patterns of percentage changes between the two groups over the 6-month follow-up period. Furthermore, the response and remission rates (as assessed using BDI and HAMD scores were higher in the nonbipolarity group than in the bipolarity group, with the exception of HAMD scores at the 3-week follow-up time point. Conclusion: The findings of this study showed that depressed patients with bipolarity had a worse response to AD monotherapy than did those without bipolarity. Keywords: subthreshold bipolarity

  4. Method of Obtaining High Resolution Intrinsic Wire Boom Damping Parameters for Multi-Body Dynamics Simulations

    Science.gov (United States)

    Yew, Alvin G.; Chai, Dean J.; Olney, David J.

    2010-01-01

    The goal of NASA's Magnetospheric MultiScale (MMS) mission is to understand magnetic reconnection with sensor measurements from four spinning satellites flown in a tight tetrahedron formation. Four of the six electric field sensors on each satellite are located at the end of 60- meter wire booms to increase measurement sensitivity in the spin plane and to minimize motion coupling from perturbations on the main body. A propulsion burn however, might induce boom oscillations that could impact science measurements if oscillations do not damp to values on the order of 0.1 degree in a timely fashion. Large damping time constants could also adversely affect flight dynamics and attitude control performance. In this paper, we will discuss the implementation of a high resolution method for calculating the boom's intrinsic damping, which was used in multi-body dynamics simulations. In summary, experimental data was obtained with a scaled-down boom, which was suspended as a pendulum in vacuum. Optical techniques were designed to accurately measure the natural decay of angular position and subsequently, data processing algorithms resulted in excellent spatial and temporal resolutions. This method was repeated in a parametric study for various lengths, root tensions and vacuum levels. For all data sets, regression models for damping were applied, including: nonlinear viscous, frequency-independent hysteretic, coulomb and some combination of them. Our data analysis and dynamics models have shown that the intrinsic damping for the baseline boom is insufficient, thereby forcing project management to explore mitigation strategies.

  5. Characterizing brain oscillations in cognition and disease

    NARCIS (Netherlands)

    Jiang, H.

    2016-01-01

    It has been suggested that neuronal oscillations play a fundamental role for shaping the functional architecture of the working brain. This thesis investigates brain oscillations in rat, human healthy population and major depressive disorder (MDD) patients. A novel measurement termed

  6. Cyanohydrin reactions enhance glycolytic oscillations in yeast

    DEFF Research Database (Denmark)

    Hald, Bjørn Olav; Nielsen, Astrid Gram; Tortzen, Christian

    2015-01-01

    Synchronous metabolic oscillations can be induced in yeast by addition of glucose and removal of extracellular acetaldehyde (ACAx). Compared to other means of ACAx removal, cyanide robustly induces oscillations, indicating additional cyanide reactions besides ACA to lactonitrile conversion. Here...

  7. Analytic Neutrino Oscillation Probabilities in Matter: Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Parke, Stephen J. [Fermilab; Denton, Peter B. [Copenhagen U.; Minakata, Hisakazu [Madrid, IFT

    2018-01-02

    We summarize our recent paper on neutrino oscillation probabilities in matter, explaining the importance, relevance and need for simple, highly accurate approximations to the neutrino oscillation probabilities in matter.

  8. Identifying the neural substrates of intrinsic motivation during task performance.

    Science.gov (United States)

    Lee, Woogul; Reeve, Johnmarshall

    2017-10-01

    Intrinsic motivation is the inherent tendency to seek out novelty and challenge, to explore and investigate, and to stretch and extend one's capacities. When people imagine performing intrinsically motivating tasks, they show heightened anterior insular cortex (AIC) activity. To fully explain the neural system of intrinsic motivation, however, requires assessing neural activity while people actually perform intrinsically motivating tasks (i.e., while answering curiosity-inducing questions or solving competence-enabling anagrams). Using event-related functional magnetic resonance imaging, we found that the neural system of intrinsic motivation involves not only AIC activity, but also striatum activity and, further, AIC-striatum functional interactions. These findings suggest that subjective feelings of intrinsic satisfaction (associated with AIC activations), reward processing (associated with striatum activations), and their interactions underlie the actual experience of intrinsic motivation. These neural findings are consistent with the conceptualization of intrinsic motivation as the pursuit and satisfaction of subjective feelings (interest and enjoyment) as intrinsic rewards.

  9. Internal dynamics of long Josephson junction oscillators

    DEFF Research Database (Denmark)

    Christiansen, Peter Leth; Lomdahl, P. S.; Scott, Alwyn C.

    1981-01-01

    Numerical computations on a sine-Gordon model of the Josephson junction fluxon oscillator are compared with experimental measurements. Good agreement is found for the voltage current characteristic, oscillator power output, and range of current bias over which oscillation is observed. Our numeric...... results imply a ''bunched-fluxon'' mode of oscillation at larger values of bias current. Applied Physics Letters is copyrighted by The American Institute of Physics....

  10. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

    Ge, Xiaoqing

    2010-06-01

    Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.

  11. A theory of generalized Bloch oscillations

    DEFF Research Database (Denmark)

    Duggen, Lars; Lew Yan Voon, L. C.; Lassen, Benny

    2016-01-01

    Bloch oscillations of electrons are shown to occur for cases when the energy spectrum does not consist of the traditional evenly-spaced ladders and the potential gradient does not result from an external electric field. A theory of such generalized Bloch oscillations is presented and an exact...... oscillations. We stipulate that the presented theory of generalized Bloch oscillations can be extended to other systems such as acoustics and photonics....

  12. Psychoeducation versus treatment as usual in diabetic patients with subthreshold depression: preliminary results of a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Pibernik-Okanovic Mirjana

    2009-08-01

    Full Text Available Abstract Background Research on the effects of treating sub-threshold depression in persons with diabetes is scarce in spite of the findings indicating that this condition is highly prevalent in the diabetic population and may increase the risk of developing a subsequent major depression. This study was aimed at exploring the effects of a psycho-educational intervention on depression- and diabetes-related outcomes in patients with mild to moderate depressive symptoms. Methods A randomized controlled study design with a one-year follow-up was used. Fifty patients with mild to moderate depressive symptoms (74% female, aged 57 ± 9 yrs, diabetes duration of 10 ± 8 yrs, BMI 31 ± 6 kg/m2, HbA1C 7.7% ± 1.4, 53% insulin treated were randomly assigned to either an intervention or a control group. The intervention group underwent four psycho-educational sessions aimed at enabling self-management of depressive symptoms. The control group was informed about the screening results and depression treatment options while continuing diabetes treatment as usual. Both groups were contacted by phone in 2–3-month intervals, and re-assessed for depression after 6 and 12 months. Changes in depressive symptoms and glycaemic control were considered primary outcomes. Mann-Whitney U test and Friedman ANOVA were used to compare between- and within-group indicators at 6- and 12-month follow-ups. Results Both the intervention and the control group reported a significant decrease in depressive symptoms as measured by the CES-D scale (Friedman ANOVA χ2 = 10.8 p = .004 and χ2 = 7.3 p = 0.03, respectively. The 6-month and 1-year indicators of glycaemic control as compared to baseline HbA1C values were also improved in both groups (χ2 = 11.6 p = 0.003 and χ2 = 17.1 p = 0.0002, respectively. Between-group differences in depressive symptoms and HbA1C values were not statistically significant either at 6- or at 12-month follow-up (all p > 0.05. Conclusion Psycho

  13. Kv4 channels underlie the subthreshold-operating A-type K+-current in nociceptive dorsal root ganglion neurons

    Directory of Open Access Journals (Sweden)

    Thanawath R Na Phuket

    2009-07-01

    Full Text Available The dorsal root ganglion (DRG contains heterogeneous populations of sensory neurons including primary nociceptive neurons and C-fibers implicated in pain signaling.  Recent studies have demonstrated DRG hyperexcitability associated with downregulation of A-type K+ channels; however, the molecular correlate of the corresponding A-type K+ current (IA has remained hypothetical.  Kv4 channels may underlie the IA in DRG neurons.  We combined electrophysiology, molecular biology (whole-tissue and single-cell RT-PCR and immunohistochemistry to investigate the molecular basis of the IA in acutely dissociated DRG neurons from 7-8 day-old rats.  Whole-cell recordings demonstrate a robust tetraethylammonium-resistant (20 mM and 4-aminopyridine-sensitive (5 mM IA.  Matching Kv4 channel properties, activation and inactivation of this IA occur in the subthreshold range of membrane potentials and the rate of recovery from inactivation is rapid and voltage-dependent.  Among Kv4 transcripts, the DRG expresses significant levels of Kv4.1 and Kv4.3 mRNAs.  Also, single small-medium diameter DRG neurons (~30 mm exhibit correlated frequent expression of mRNAs encoding Kv4.1 and Nav1.8, a known nociceptor marker.  In contrast, the expressions of Kv1.4 and Kv4.2 mRNAs at the whole-tissue and single-cell levels are relatively low and infrequent.  Kv4 protein expression in nociceptive DRG neurons was confirmed by immunohistochemistry, which demonstrates colocalization of Kv4.3 and Nav1.8, and negligible expression of Kv4.2.  Furthermore, specific dominant-negative suppression and overexpression strategies confirmed the contribution of Kv4 channels to IA in DRG neurons.  Contrasting the expression patterns of Kv4 channels in the central and peripheral nervous systems, we discuss possible functional roles of these channels in primary sensory neurons.

  14. Effect of Intrinsic Stress on Structural and Optical Properties of Amorphous Si-Doped SnO₂ Thin-Film.

    Science.gov (United States)

    Ning, Honglong; Liu, Xianzhe; Zhang, Hongke; Fang, Zhiqiang; Cai, Wei; Chen, Jianqiu; Yao, Rihui; Xu, Miao; Wang, Lei; Lan, Linfeng; Peng, Junbiao; Wang, Xiaofeng; Zhang, Zichen

    2017-01-01

    The effect of intrinsic stress on the structure and physical properties of silicon-tin-oxide (STO) films have been investigated. Since a state of tensile stress is available in as-deposited films, the value of stress can be exponentially enhanced when the annealing temperature is increased. The tensile stress is able to not only suppress the crystallization and widen the optical band gap of STO films, but also reduce defects of STO films. In this report, the good electrical performance of STO thin-film transistors (TFTs) can be obtained when annealing temperature is 450 °C. This includes a value of saturation mobility that can be reached at 6.7 cm²/Vs, a ratio of I on /I off as 7.34 × 107, a steep sub-threshold swing at 0.625 V/decade, and a low trap density of 7.96 × 10 11 eV -1 ·cm -2 , respectively.

  15. Effective harmonic oscillator description of anharmonic molecular ...

    Indian Academy of Sciences (India)

    Administrator

    The effective harmonic oscillator is constructed variationally, by taking the trial wave function as a harmonic oscillator eigenfunction with the centroid and width parameter as variational para- eters. It is found that the effective harmonic oscillator approximation provides a description of the anharmonic eigenstates very similar ...

  16. Assessing the quality of stochastic oscillations

    Indian Academy of Sciences (India)

    Population dynamics; stochastic oscillations. ... We propose a quantification of the oscillatory appearance of the fluctuating populations, and show that good stochastic oscillations are present if a parameter of the macroscopic model is small, and that no microscopic model will show oscillations if that parameter is large.

  17. Neutrino oscillations in the early universe

    International Nuclear Information System (INIS)

    Enqvist, K.

    1990-01-01

    The oscillations of electron neutrinos into inert neutrinos may have resonant behaviour in the heat bath of the early Universe. It is shown that any initial neutrino asymmetry will be washed away by the oscillations. Neutrino oscillations would affect also primordial helium production, which implies stringent limits on the neutrino mixing parameters. (orig.)

  18. The supersymmetric Pegg-Barnett oscillator

    International Nuclear Information System (INIS)

    Shen, Jian Qi

    2005-01-01

    The su(n) Lie algebraic structure of the Pegg-Barnett oscillator that possesses a finite-dimensional number-state space is demonstrated. The supersymmetric generalization of the Pegg-Barnett oscillator is suggested. it is shown that such a supersymmetric Pegg-Barnett oscillator may have some potential applications, e.g., the mass spectrum of the charged leptons

  19. Three flavour oscillation interpretation of neutrino data

    Indian Academy of Sciences (India)

    To explain the atmospheric neutrino problem in terms of neutrino oscillations, ЖС¾ of about 10-¿. eV. ¾. [8] is needed whereas the neutrino oscil- lation solution to the solar neutrino problem requires ЖС¾ ~10- eV. ¾ . Hence both solar and atmospheric neutrino problems cannot be explained in terms of e ° μ oscillations.

  20. Comparison of Methods for Oscillation Detection

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Trangbæk, Klaus

    2006-01-01

    This paper compares a selection of methods for detecting oscillations in control loops. The methods are tested on measurement data from a coal-fired power plant, where some oscillations are occurring. Emphasis is put on being able to detect oscillations without having a system model and without u...

  1. Intrinsic Motivation in Open Source Software Development

    DEFF Research Database (Denmark)

    Bitzer, J.; W., Schrettl,; Schröder, Philipp

    2004-01-01

    This papers sheds light on the puzzling evidence that even though open source software (OSS) is a public good, it is developed for free by highly qualified, young and motivated individuals, and evolves at a rapid pace. We show that once OSS development is understood as the private provision...... of a public good, these features emerge quite naturally. We adapt a dynamic private-provision-of-public-goods model to reflects key aspects of the OSS phenomenon. In particular, instead of relying on extrinsic motives for programmers (e.g. signaling) the present model is driven by intrinsic motives of OSS...... programmers, such as user-programmers, play value or \\emph{homo ludens} payoff, and gift culture benefits. Such intrinsic motives feature extensively in the wider OSS literature and turn out to add new insights to the economic analysis....

  2. Does Aerobic Exercise Influence Intrinsic Brain Activity?

    DEFF Research Database (Denmark)

    Flodin, Pär; Jonasson, Lars S; Riklund, Katrin

    2017-01-01

    Previous studies have indicated that aerobic exercise could reduce age related decline in cognition and brain functioning. Here we investigated the effects of aerobic exercise on intrinsic brain activity. Sixty sedentary healthy males and females (64-78 years) were randomized into either an aerobic...... exercise group or an active control group. Both groups recieved supervised training, 3 days a week for 6 months. Multimodal brain imaging data was acquired before and after the intervention, including 10 min of resting state brain functional magnetic resonance imaging (rs-fMRI) and arterial spin labeling...... group improved more. Contrary to our hypothesis, we did not observe any significant group by time interactions with regard to any measure of intrinsic activity. To further probe putative relationships between fitness and brain activity, we performed post hoc analyses disregarding group belongings...

  3. Documentation Requirements, Intrinsic Motivation, and Worker Absence

    DEFF Research Database (Denmark)

    Andersen, Lotte Bøgh; Kristensen, Nicolai; Pedersen, Lene Holm

    2015-01-01

    Command systems are widely used to monitor public service provision, but little is known about unintended effects on individual workers’ motivation and work effort. Using insights from motivation crowding theory, we estimate a SEM model that captures how Danish childcare assistants and social...... and higher sickness absence. The association is statistically significant, but very small in substantive terms. The result is nevertheless consistent with the expectation in motivation crowding theory and contributes to the literature by including a new, reliable behavioral variable—sickness absence....../healthcare assistants perceive documentation requirements. We analyze how this perception relates to intrinsic motivation measured in a survey and sickness absence as reported in administrative registers, and find that individuals who perceive documentation requirements as controlling have lower intrinsic motivation...

  4. Extrinsic and intrinsic determinants of nerve regeneration

    Directory of Open Access Journals (Sweden)

    Toby A. Ferguson

    2011-01-01

    Full Text Available After central nervous system (CNS injury axons fail to regenerate often leading to persistent neurologic deficit although injured peripheral nervous system (PNS axons mount a robust regenerative response that may lead to functional recovery. Some of the failures of CNS regeneration arise from the many glial-based inhibitory molecules found in the injured CNS, whereas the intrinsic regenerative potential of some CNS neurons is actively curtailed during CNS maturation and limited after injury. In this review, the molecular basis for extrinsic and intrinsic modulation of axon regeneration within the nervous system is evaluated. A more complete understanding of the factors limiting axonal regeneration will provide a rational basis, which is used to develop improved treatments for nervous system injury.

  5. Intrinsic point defects in aluminum antimonide

    OpenAIRE

    Åberg, Daniel; Erhart, Paul; Williamson, Andrew J.; Lordi, Vincenzo

    2010-01-01

    Calculations within density functional theory on the basis of the local density approximation are carried out to study the properties of intrinsic point defects in aluminum antimonide. Special care is taken to address finite-size effects, band gap error, and symmetry reduction in the defect structures. The correction of the band gap is based on a set of GW calculations. The most important defects are identified to be the aluminum interstitial $Al_{i,Al}^{1+}$, the antimony antisites $Sb_{Al}^...

  6. Intrinsic luminescence of alkali silicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Arbuzov, V.I.; Grabovskis, V.Y.; Tolstoi, M.N.; Vitol, I.K.

    1986-09-01

    This study obtains additional information on L centers and their role in electron excitation and intrinsic luminescence of a whole series. (Li, Na, K, Rb, and Cs) of alkali silicate glasses. The authors compare the features of the interaction with radiation of specimens of glass and crystal of a similar chemical composition, since silicates of alkali metals can be obtained in both the glassy and crystalline states.

  7. Intrinsic work motivation and pension reform acceptance

    OpenAIRE

    Heinemann, Friedrich; Hennighausen, Tanja; Moessinger, Marc-Daniel

    2011-01-01

    Although demographic change leaves pay-as-you-go pension systems unsustainable, reforms, such as a higher pension age, are highly unpopular. This contribution looks into the role of intrinsic motivation as a driver for pension reform acceptance. Theoretical reasoning suggests that this driver should be relevant: The choice among different pension reform options (increasing pension age, increasing contributions, cutting pensions) can be analyzed within the framework of an optimal job separatio...

  8. A structural model of intrinsic motivation

    OpenAIRE

    Aguilar, Javier; González, Daniel; Aguilar, Amira

    2017-01-01

    The main purpose of this research was to develop and test a structural model of intrinsic motivation among students of the University of Sonora to the curriculum of their careers. A secondary objective was to overcome the limitations of the model developed among students of the UNAM. Eight psychometric scales developed by the authors in previous studies were used, which showed satisfactory reliability and validity values. The model tested was similar to the sample of the UNAM, except for the ...

  9. Measuring neutrino oscillation parameters using $\

    Energy Technology Data Exchange (ETDEWEB)

    Backhouse, Christopher James [Oriel College, Oxford (United Kingdom)

    2011-01-01

    MINOS is a long-baseline neutrino oscillation experiment. It consists of two large steel-scintillator tracking calorimeters. The near detector is situated at Fermilab, close to the production point of the NuMI muon-neutrino beam. The far detector is 735 km away, 716m underground in the Soudan mine, Northern Minnesota. The primary purpose of the MINOS experiment is to make precise measurements of the 'atmospheric' neutrino oscillation parameters (Δmatm2 and sin2atm). The oscillation signal consists of an energy-dependent deficit of vμ interactions in the far detector. The near detector is used to characterize the properties of the beam before oscillations develop. The two-detector design allows many potential sources of systematic error in the far detector to be mitigated by the near detector observations. This thesis describes the details of the vμ-disappearance analysis, and presents a new technique to estimate the hadronic energy of neutrino interactions. This estimator achieves a significant improvement in the energy resolution of the neutrino spectrum, and in the sensitivity of the neutrino oscillation fit. The systematic uncertainty on the hadronic energy scale was re-evaluated and found to be comparable to that of the energy estimator previously in use. The best-fit oscillation parameters of the vμ-disappearance analysis, incorporating this new estimator were: Δm2 = 2.32-0.08+0.12 x 10-3 eV2, sin 2 2θ > 0.90 (90% C.L.). A similar analysis, using data from a period of running where the NuMI beam was operated in a configuration producing a predominantly $\\bar{v}$μ beam, yielded somewhat different best-fit parameters Δ$\\bar{m}${sup 2} = (3.36-0.40+0.46(stat.) ± 0.06(syst.)) x 10-3eV2, sin2 2$\\bar{θ}$ = 0.86-0.12_0

  10. Time domain oscillating poles: Stability redefined in Memristor based Wien-oscillators

    KAUST Repository

    Talukdar, Abdul Hafiz Ibne

    2012-07-28

    Traditionally, the necessary and sufficient condition for any system to be oscillating is that its poles are located on the imaginary (jω) axis. In this paper, for the first time, we have shown that systems can oscillate with time-domain oscillating poles. The idea is verified using a Memristor based Wien oscillator. Sustained oscillations are observed without having the poles of the system fixed on the imaginary axis and the oscillating behavior of the system poles is reported. The oscillating resistance and triangular shape of FFT are also demonstrated with mathematical reasoning and simulation results to support the unusual and surprising characteristics. © 2009 IEEE.

  11. Moral Distress, Workplace Health, and Intrinsic Harm.

    Science.gov (United States)

    Weber, Elijah

    2016-05-01

    Moral distress is now being recognized as a frequent experience for many health care providers, and there's good evidence that it has a negative impact on the health care work environment. However, contemporary discussions of moral distress have several problems. First, they tend to rely on inadequate characterizations of moral distress. As a result, subsequent investigations regarding the frequency and consequences of moral distress often proceed without a clear understanding of the phenomenon being discussed, and thereby risk substantially misrepresenting the nature, frequency, and possible consequences of moral distress. These discussions also minimize the intrinsically harmful aspects of moral distress. This is a serious omission. Moral distress doesn't just have a negative impact on the health care work environment; it also directly harms the one who experiences it. In this paper, I claim that these problems can be addressed by first clarifying our understanding of moral distress, and then identifying what makes moral distress intrinsically harmful. I begin by identifying three common mistakes that characterizations of moral distress tend to make, and explaining why these mistakes are problematic. Next, I offer an account of moral distress that avoids these mistakes. Then, I defend the claim that moral distress is intrinsically harmful to the subject who experiences it. I conclude by explaining how acknowledging this aspect of moral distress should reshape our discussions about how best to deal with this phenomenon. © 2015 John Wiley & Sons Ltd.

  12. Intrinsic electron trapping in amorphous oxide

    Science.gov (United States)

    Strand, Jack; Kaviani, Moloud; Afanas’ev, Valeri V.; Lisoni, Judit G.; Shluger, Alexander L.

    2018-03-01

    We demonstrate that electron trapping at intrinsic precursor sites is endemic in non-glass-forming amorphous oxide films. The energy distributions of trapped electron states in ultra-pure prototype amorphous (a)-HfO2 insulator obtained from exhaustive photo-depopulation experiments demonstrate electron states in the energy range of 2–3 eV below the oxide conduction band. These energy distributions are compared to the results of density functional calculations of a-HfO2 models of realistic density. The experimental results can be explained by the presence of intrinsic charge trapping sites formed by under-coordinated Hf cations and elongated Hf–O bonds in a-HfO2. These charge trapping states can capture up to two electrons, forming polarons and bi-polarons. The corresponding trapping sites are different from the dangling-bond type defects responsible for trapping in glass-forming oxides, such as SiO2, in that the traps are formed without bonds being broken. Furthermore, introduction of hydrogen causes formation of somewhat energetically deeper electron traps when a proton is immobilized next to the trapped electron bi-polaron. The proposed novel mechanism of intrinsic charge trapping in a-HfO2 represents a new paradigm for charge trapping in a broad class of non-glass-forming amorphous insulators.

  13. Learning intrinsic excitability in medium spiny neurons.

    Science.gov (United States)

    Scheler, Gabriele

    2013-01-01

    We present an unsupervised, local activation-dependent learning rule for intrinsic plasticity (IP) which affects the composition of ion channel conductances for single neurons in a use-dependent way. We use a single-compartment conductance-based model for medium spiny striatal neurons in order to show the effects of parameterization of individual ion channels on the neuronal membrane potential-curent relationship (activation function). We show that parameter changes within the physiological ranges are sufficient to create an ensemble of neurons with significantly different activation functions. We emphasize that the effects of intrinsic neuronal modulation on spiking behavior require a distributed mode of synaptic input and can be eliminated by strongly correlated input. We show how modulation and adaptivity in ion channel conductances can be utilized to store patterns without an additional contribution by synaptic plasticity (SP). The adaptation of the spike response may result in either "positive" or "negative" pattern learning. However, read-out of stored information depends on a distributed pattern of synaptic activity to let intrinsic modulation determine spike response. We briefly discuss the implications of this conditional memory on learning and addiction.

  14. Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence

    International Nuclear Information System (INIS)

    Jian, Zhang; Bin, Shao; Jian, Zou

    2009-01-01

    In this paper, we investigate the entropy squeezing for a two-level atom interacting with two quantized fields through Raman coupling. We obtain the dynamical evolution of the total system under the influence of intrinsic decoherence when the two quantized fields are prepared in a two-mode squeezing vacuum state initially. The effects of the field squeezing factor, the two-level atomic transition frequency, the second field frequency and the intrinsic decoherence on the entropy squeezing are discussed. Without intrinsic decoherence, the increase of field squeezing factor can break the entropy squeezing. The two-level atomic transition frequency changes only the period of oscillation but not the strength of entropy squeezing. The influence of the second field frequency is complicated. With the intrinsic decoherence taken into consideration, the results show that the stronger the intrinsic decoherence is, the more quickly the entropy squeezing will disappear. The increase of the atomic transition frequency can hasten the disappearance of entropy squeezing. (classical areas of phenomenology)

  15. Altered intrinsic excitability of hippocampal CA1 pyramidal neurons in aged PDAPP mice

    Directory of Open Access Journals (Sweden)

    Francesco eTamagnini

    2015-10-01

    Full Text Available Amyloidopathy involves the accumulation of insoluble amyloid β (Aβ species in the brain’s parenchyma and is a key histopathological hallmark of Alzheimer’s disease (AD. Work on transgenic mice that overexpress A suggests that elevated A levels in the brain are associated with aberrant epileptiform activity and increased intrinsic excitability of CA1 hippocampal neurons. In this study we examined if similar changes could be observed in hippocampal CA1 pyramidal neurons from aged PDAPP mice (20-23 month old, Indiana mutation: V717F on APP gene compared to their age-matched WT littermate controls. Whole-cell current clamp recordings revealed that sub-threshold intrinsic properties, such as input resistance, resting membrane potential and hyperpolarization activated sag were unaffected, but capacitance was significantly decreased in the transgenic animals. No differences between genotypes were observed in the overall number of action potentials (AP elicited by 500 ms supra-threshold current stimuli. PDAPP neurons, however, exhibited higher instantaneous firing frequencies after accommodation in response to high intensity current injections. The AP waveform was narrower and shorter in amplitude in PDAPP mice: these changes, according to our in silico model of a CA1/3 pyramidal neuron, depended on the respective reduction and increase of Na+ and K+ voltage-gated channels maximal conductances. Finally, the after-hyperpolarization (AHP, seen after the first AP evoked by a +300 pA current injection and after 50 Hz AP bursts, was more pronounced in PDAPP mice.These data show that Aβ-overexpression in aged mice altered the capacitance, the neuronal firing and the AP waveform of CA1 pyramidal neurons. Some of these findings are consistent with previous work on younger PDAPP, they also show important differences that can be potentially ascribed to the interaction between amyloidopathy and ageing. Such a change of IE properties over time

  16. Neuronal oscillations in Parkinson's disease.

    Science.gov (United States)

    Witcher, Mark; Moran, Rosalyn; Tatter, Stephen B; Laxton, Adrian W

    2014-06-01

    Parkinson's Disease (PD), characterized by tremor, rigidity, and bradykinesia, is one of the most prevalent neurodegenerative disorders in the world. The pathological hallmark of PD is the loss of dopaminergic cells in the substantia nigra and other brain regions. The pathophysiological mechanisms by which dopaminergic cell loss leads to the motor manifestations of PD are yet to be fully elucidated. A growing body of evidence has revealed abnormal neuronal oscillations within and between multiple brain regions in PD. Unique oscillatory patterns are associated with specific motor abnormalities in PD. Therapies, such as dopaminergic medication and deep brain stimulation that disrupt these abnormal neuronal oscillatory patterns produce symptomatic improvement in PD patients. These findings emphasize the importance of abnormal neuronal oscillations in the pathophysiology of PD, making the disruption of these oscillatory patterns a promising target in the development of effective PD treatments.

  17. Neutrino oscillations in deconstructed dimensions

    International Nuclear Information System (INIS)

    Haellgren, Tomas; Ohlsson, Tommy; Seidl, Gerhart

    2005-01-01

    We present a model for neutrino oscillations in the presence of a deconstructed non-gravitational large extra dimension compactified on the boundary of a two-dimensional disk. In the deconstructed phase, sub-mm lattice spacings are generated from the hierarchy of energy scales between ∼ 1 TeV and the usual B-L breaking scale ∼ 10 15 GeV. Here, short-distance cutoffs down to ∼ 1 eV are motivated by the strong coupling behavior of gravity in local discrete extra dimensions. This could make it possible to probe the discretization of extra dimensions and non-trivial field configurations in theory spaces which have only a few sites, i.e., for coarse latticizations. Thus, the model has relevance to present and future precision neutrino oscillation experiments. (author)

  18. Experimental studies of neutrino oscillations

    CERN Document Server

    Kajita, Takaaki

    2016-01-01

    The 2015 Nobel Prize in physics has been awarded to Takaaki Kajita and Arthur McDonald "for the discovery of neutrino oscillations, which shows that neutrinos have mass". Takaaki Kajita of Tokyo University is a Japanese physicist, known for neutrino experiments at the Kamiokande and its successor, Super-Kamiokande. This volume of collected works of Kajita on neutrino oscillations provides a good glimpse into as well as a record of the rise and the role of Asian research in the frontiers of neutrino physics. Japan is now a major force in the study of the 3 families of neutrinos. Much remains to be done to clarify the Dirac vs. Majorana nature of the neutrino, and the cosmological implications of the neutrino. The collected works of Kajita and his Super-Kamiokande group will leave an indelible foot-print in the history of big and better science.

  19. Memristor-based reactance-less oscillator

    KAUST Repository

    Zidan, Mohammed A.

    2012-10-02

    The first reactance-less oscillator is introduced. By using a memristor, the oscillator can be fully implemented on-chip without the need for any capacitors or inductors, which results in an area-efficient fully integrated solution. The concept of operation of the proposed oscillator is explained and detailed mathematical analysis is introduced. Closed-form expressions for the oscillation frequency and oscillation conditions are derived. Finally, the derived equations are verified with circuit simulations showing excellent agreement. © 2011 The Institution of Engineering and Technology.

  20. Quantum oscillations of conductivity in bismuth wires

    International Nuclear Information System (INIS)

    Condrea, Elena

    2011-01-01

    Measurements of the resistance of bismuth nanowires with several diameters and different quality reveal oscillations on the dependence of resistance under uniaxial strain at T = 4.2 K. Amplitude of oscillations is significant (38 %) at helium temperature and becomes smearing at T = 77 K. Observed oscillations originate from quantum size effect. A simple evaluation of period of oscillations allows us to identify the groups of carriers involved in transport. Calculated periods of 42.2 and 25.9 nm satisfy approximately the ratio 2:1 for two experimentally observed sets of oscillations from light and heavy electrons.

  1. A silicon doped hafnium oxide ferroelectric p–n–p–n SOI tunneling field–effect transistor with steep subthreshold slope and high switching state current ratio

    Directory of Open Access Journals (Sweden)

    Saeid Marjani

    2016-09-01

    Full Text Available In this paper, a silicon–on–insulator (SOI p–n–p–n tunneling field–effect transistor (TFET with a silicon doped hafnium oxide (Si:HfO2 ferroelectric gate stack is proposed and investigated via 2D device simulation with a calibrated nonlocal band–to–band tunneling model. Utilization of Si:HfO2 instead of conventional perovskite ferroelectrics such as lead zirconium titanate (PbZrTiO3 and strontium bismuth tantalate (SrBi2Ta2O9 provides compatibility to the CMOS process as well as improved device scalability. By using Si:HfO2 ferroelectric gate stack, the applied gate voltage is effectively amplified that causes increased electric field at the tunneling junction and reduced tunneling barrier width. Compared with the conventional p–n–p–n SOI TFET, the on–state current and switching state current ratio are appreciably increased; and the average subthreshold slope (SS is effectively reduced. The simulation results of Si:HfO2 ferroelectric p–n–p–n SOI TFET show significant improvement in transconductance (∼9.8X enhancement at high overdrive voltage and average subthreshold slope (∼35% enhancement over nine decades of drain current at room temperature, indicating that this device is a promising candidate to strengthen the performance of p–n–p–n and conventional TFET for a switching performance.

  2. Low sub-threshold swing realization with contacts of graphene/h-BN/MoS2 heterostructures in MoS2 transistors

    Science.gov (United States)

    Li, Chao; Yan, Xiao; Bao, Wenzhong; Ding, Shijin; Zhang, David Wei; Zhou, Peng

    2017-11-01

    MoS2 and other atomically thin-layered semiconductors have attracted intensive interest for their unique characteristics and have become promising candidates for short-channel transistor devices. In this work, we demonstrate an MoS2 transistor with a graphene/hBN/MoS2 heterostructure contact so as to achieve a low sub-threshold swing (SS) and expand the scope of the drain current with a low SS. By inserting an h-BN tunneling layer between graphene and MoS2, the carrier transport with a tunneling effect across h-BN makes the transistor exhibit a less than 80 mV/dec sub-threshold swing over 4 orders of magnitude of the drain current at room temperature. Meanwhile, the MoS2 transistor achieves a maximum on/off ratio of ˜107, and the heterostructure contact shows fairly good ohmic characteristics. Furthermore, the thickness of the h-BN tunneling layer in the heterostructure is optimized, which is essential for the tunneling current and the performance of an MoS2 transistor. This study of an MoS2 transistor based on a graphene/h-BN/MoS2 heterostructure contact may pave the way for the development of thin-layered semiconductors in low-power electronic applications.

  3. Ultrastructural changes of chorioretinal complex under sub-threshold laser exposure at wavelengths of 0.81 and 0.532 μm (experimental study

    Directory of Open Access Journals (Sweden)

    N. A. Fedoruk

    2014-01-01

    Full Text Available Aim: To reveal ultrastructural changes of chorioretinal complex and their possible reversibility under sub-threshold laser exposure at wavelengths of 0.81 and 0.532 μm in 1, 8 and 30 days. Methods: Experimental study was performed on 16 chinchilla rabbits (32 eyes using laser at wavelengths of 0.532 and 0.81 μm in CW, micropulse, and transpupillary thermotherapy modes. Transmission electron microscope EM-10C (Opton, Oberkochen, Germany was used to perform ultrastructural study of retina following laser exposure. Results: In a day after sub-threshold laser exposure, ultrastructural changes were mainly detected in retinal pigment epithelium (RPE, choriocapillaries, and photoreceptors. In 8 days, intracellular regeneration of RPE and partial restoration of choriocapillary blood flow and RPE macrophages were observed. In 30 days, RPE morphology, the number and the structure of photoreceptor outer segments were re-established. Mitochondria of photoreceptor inner segments regenerated as well. Conclusion: Ultrastructural changes of chorioretinal complex following sub-threshold laser radiation were reversible. Intracellular regeneration provided almost complete recovery of chorioretinal complex structure by day 30.

  4. Ultrastructural changes of chorioretinal complex under sub-threshold laser exposure at wavelengths of 0.81 and 0.532 μm (experimental study

    Directory of Open Access Journals (Sweden)

    N. A. Fedoruk

    2015-01-01

    Full Text Available Aim: To reveal ultrastructural changes of chorioretinal complex and their possible reversibility under sub-threshold laser exposure at wavelengths of 0.81 and 0.532 μm in 1, 8 and 30 days. Methods: Experimental study was performed on 16 chinchilla rabbits (32 eyes using laser at wavelengths of 0.532 and 0.81 μm in CW, micropulse, and transpupillary thermotherapy modes. Transmission electron microscope EM-10C (Opton, Oberkochen, Germany was used to perform ultrastructural study of retina following laser exposure. Results: In a day after sub-threshold laser exposure, ultrastructural changes were mainly detected in retinal pigment epithelium (RPE, choriocapillaries, and photoreceptors. In 8 days, intracellular regeneration of RPE and partial restoration of choriocapillary blood flow and RPE macrophages were observed. In 30 days, RPE morphology, the number and the structure of photoreceptor outer segments were re-established. Mitochondria of photoreceptor inner segments regenerated as well. Conclusion: Ultrastructural changes of chorioretinal complex following sub-threshold laser radiation were reversible. Intracellular regeneration provided almost complete recovery of chorioretinal complex structure by day 30.

  5. Does age moderate the relationship between depressive symptoms and suicidal ideation in middle-aged and older patients with schizophrenia and subthreshold depression?

    Science.gov (United States)

    Kasckow, John; Golshan, Shahrokh; Zisook, Sidney

    2014-05-01

    Suicidal deaths in middle-aged and older individuals with schizophrenia are a public health concern. Depression and schizophrenia are major risk factors for suicide. However, it is unknown whether age moderates the relationship between depression and suicidal ideation in patients with schizophrenia and subthreshold depression. Suicidal ideation was assessed with the InterSePT Scale for Suicidal Ideation and the Clinical Global Impression-Suicide Severity Scale in outpatients older than 39 years with schizophrenia and subthreshold depression (n = 213). Using linear regression, we examined whether depression (based on Calgary Depression Rating Scale scores), age, and "age by depressive symptoms" predicted suicidal ideation. Depressive symptoms predicted suicidal ideation. Neither age nor "depressive symptoms by age" predicted suicidal ideation. In this population, age does not appear to moderate the relationship between depressive symptoms and suicidal behavior. Thus, assessing depressive symptoms as a risk factor is important at all ages in this population. Copyright © 2014 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

  6. Harmonic oscillator and nuclear pseudospin

    International Nuclear Information System (INIS)

    Lisboa, Ronai; Malheiro, Manuel; Castro, Antonio S. de; Alberto, Pedro; Fiolhais, Manuel

    2004-01-01

    A generalized relativistic harmonic oscillator for spin 1/2 particles is studied. The Dirac Hamiltonian contains a scalar S and a vector V quadratic potentials in the radial coordinate, as well as a tensor potential U, linear in r. Setting either Σ = S + V or Δ = V - S to zero, analytical solutions for bound states are found. The eingenenergies and their nonrelativistic limits are presented and particular cases are discussed, especially the case Σ = 0, for which pseudospin symmetry is exact

  7. Global Status of Neutrino Oscillation

    Indian Academy of Sciences (India)

    monojit

    Number Games. The defining element in the oscillation (or survival probability) is sin. 2. ∆m2. 21L/(4E) ≡ sin. 2. 1.27(∆m2. 21eV. 2) ((L/E)km/GeV OR m/MeV). .... The 90% CL contours with 10 years' simulated ICAL in comparison with results ... Simulation showing improvement in sensitivity to the unknown CP phase.

  8. Harmonic oscillator on a lattice

    International Nuclear Information System (INIS)

    Ader, J.P.; Bonnier, B.; Hontebeyrie, M.; Meyers, C.

    1983-01-01

    The continuum limit of the ground state energy for the harmonic oscillator with discrete time is derived for all possible choices of the lattice derivative. The occurrence of unphysical values is shown to arise whenever the lattice laplacian is not strictly positive on its Brillouin zone. These undesirable limits can either be finite and arbitrary (multiple spectrum) or infinite (overlapping sublattices with multiple spectrum). (orig.)

  9. Lepton asymmetries from neutrino oscillations

    International Nuclear Information System (INIS)

    Volkas, R.R.

    2000-01-01

    Reasonably large relic neutrino asymmetries can be generated by active-sterile neutrino oscillations. After briefly discussing possible applications, I describe the Quantum Kinetic Equation formalism used to compute the asymmetry growth curves. I then show how the basic features of these curves can be understood on the basis of the adiabatic limit approximation in the collision dominated epoch, and the pure MSW effect at lower temperatures (author)

  10. Coherence effects in neutrino oscillations

    International Nuclear Information System (INIS)

    Kiers, K.; Weiss, N.

    1996-01-01

    We study the effect of coherent and incoherent broadening on neutrino oscillations both in vacuum and in the presence of matter (the MSW effect). We show under very general assumptions that it is not possible to distinguish experimentally neutrinos produced in some region of space as wave packets from those produced in the same region of space as plane waves with the same energy distribution. copyright 1995 The American Physical Society

  11. Oscillations and Waves in Sunspots

    Directory of Open Access Journals (Sweden)

    Elena Khomenko

    2015-11-01

    Full Text Available A magnetic field modifies the properties of waves in a complex way. Significant advances have been made recently in our understanding of the physics of sunspot waves with the help of high-resolution observations, analytical theories, as well as numerical simulations. We review the current ideas in the field, providing the most coherent picture of sunspot oscillations as by present understanding.

  12. Neutrino Oscillation Experiment at JHF

    CERN Multimedia

    2002-01-01

    T2K is a long baseline neutrino experiment designed to investigate how neutrinos change from one flavor to another as they travel (neutrino oscillations). An intense beam of muon neutrinos is generated at the J-PARC nuclear physics site on the East coast of Japan and directed across the country to the Super-Kamiokande neutrino detector in the mountains of western Japan. The beam is measured once before it leaves the J-PARC site, using the near detector ND280, and again at Super-K, 295 km away: the change in the measured intensity and composition of the beam is used to provide information on the properties of neutrinos. The high intensity neutrino beam is produced in an off-axis configuration. The peak neutrino energy is tuned to the oscillation maximum of ∼ 0.6 GeV to maximize the sensitivity to neutrino oscillations. The science goals of T2K can be summarized as follows: •\tsearch for CP violation in the neutrino sector •\tdiscovery of νμ → νe ( i.e. the confirmation that θ13 > 0 ) •\tprecision ...

  13. Drifting oscillations in axion monodromy

    International Nuclear Information System (INIS)

    Flauger, Raphael; Westphal, Alexander

    2014-12-01

    We study the pattern of oscillations in the primordial power spectrum in axion monodromy inflation, accounting for drifts in the oscillation period that can be important for comparing to cosmological data. In these models the potential energy has a monomial form over a super-Planckian field range, with superimposed modulations whose size is model-dependent. The amplitude and frequency of the modulations are set by the expectation values of moduli fields. We show that during the course of inflation, the diminishing energy density can induce slow adjustments of the moduli, changing the modulations. We provide templates capturing the effects of drifting moduli, as well as drifts arising in effective field theory models based on softly broken discrete shift symmetries, and we estimate the precision required to detect a drifting period. A non-drifting template suffices over a wide range of parameters, but for the highest frequencies of interest, or for sufficiently strong drift, it is necessary to include parameters characterizing the change in frequency over the e-folds visible in the CMB. We use these templates to perform a preliminary search for drifting oscillations in a part of the parameter space in the Planck nominal mission data.

  14. Micro-machined resonator oscillator

    Science.gov (United States)

    Koehler, Dale R.; Sniegowski, Jeffry J.; Bivens, Hugh M.; Wessendorf, Kurt O.

    1994-01-01

    A micro-miniature resonator-oscillator is disclosed. Due to the miniaturization of the resonator-oscillator, oscillation frequencies of one MHz and higher are utilized. A thickness-mode quartz resonator housed in a micro-machined silicon package and operated as a "telemetered sensor beacon" that is, a digital, self-powered, remote, parameter measuring-transmitter in the FM-band. The resonator design uses trapped energy principles and temperature dependence methodology through crystal orientation control, with operation in the 20-100 MHz range. High volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Unique design features include squeeze-film damping for robust vibration and shock performance, capacitive coupling through micro-machined diaphragms allowing resonator excitation at the package exterior, circuit integration and extremely small (0.1 in. square) dimensioning. A family of micro-miniature sensor beacons is also disclosed with widespread applications as bio-medical sensors, vehicle status monitors and high-volume animal identification and health sensors. The sensor family allows measurement of temperatures, chemicals, acceleration and pressure. A microphone and clock realization is also available.

  15. Drifting oscillations in axion monodromy

    Energy Technology Data Exchange (ETDEWEB)

    Flauger, Raphael [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); McAllister, Liam [Department of Physics, Cornell University, Ithaca, NY 14853 (United States); Silverstein, Eva [Stanford Institute for Theoretical Physics, Stanford University, Stanford, CA 94305 (United States); Westphal, Alexander, E-mail: flauger@physics.ucsd.edu, E-mail: mcallister@cornell.edu, E-mail: evas@stanford.edu, E-mail: alexander.westphal@desy.de [Theory Group, Deutsches Elektronen-Synchrotron DESY, D-22603 Hamburg (Germany)

    2017-10-01

    We study the pattern of oscillations in the primordial power spectrum in axion monodromy inflation, accounting for drifts in the oscillation period that can be important for comparing to cosmological data. In these models the potential energy has a monomial form over a super-Planckian field range, with superimposed modulations whose size is model-dependent. The amplitude and frequency of the modulations are set by the expectation values of moduli fields. We show that during the course of inflation, the diminishing energy density can induce slow adjustments of the moduli, changing the modulations. We provide templates capturing the effects of drifting moduli, as well as drifts arising in effective field theory models based on softly broken discrete shift symmetries, and we estimate the precision required to detect a drifting period. A non-drifting template suffices over a wide range of parameters, but for the highest frequencies of interest, or for sufficiently strong drift, it is necessary to include parameters characterizing the change in frequency over the e-folds visible in the CMB. We use these templates to perform a preliminary search for drifting oscillations in a part of the parameter space in the Planck nominal mission data.

  16. Health related quality of life and psychopathological distress in risk taking and self-harming adolescents with full-syndrome, subthreshold and without borderline personality disorder: rethinking the clinical cut-off?

    Science.gov (United States)

    Kaess, Michael; Fischer-Waldschmidt, Gloria; Resch, Franz; Koenig, Julian

    2017-01-01

    Diagnostic standards do not acknowledge developmental specifics and differences in the clinical presentation of adolescents with borderline personality disorder (BPD). BPD is associated with severe impairments in health related quality of life (HRQoL) and increased psychopathological distress. Previously no study addressed differences in HRQoL and psychopathology in adolescents with subthreshold and full-syndrome BPD as well as adolescents at-risk for the development but no current BPD. Drawing on data from a consecutive sample of N  = 264 adolescents (12-17 years) presenting with risk-taking and self-harming behavior at a specialized outpatient clinic, we investigated differences in HRQoL (KIDSCREEN-52) and psychopathological distress (SCL-90-R) comparing adolescents with no BPD (less than 3 criteria fulfilled), to those with subthreshold (3-4 BPD criteria) and full-syndrome BPD (5 or more BPD criteria). Group differences were analyzed using one-way analysis of variance with Sidak corrected contrasts or Chi-Square test for categorical variables. Adolescents with subthreshold and full-syndrome BPD presented one year later at our clinic and were more likely female. Adolescents with subthreshold and full-syndrome BPD showed greater Axis-I and Axis-II comorbidity compared to adolescents with no BPD, and reported greater risk-taking behaviour, self-injury and suicidality. Compared to those without BPD, adolescents with subthreshold and full-syndrome BPD reported significantly reduced HRQoL. Adolescents with sub-threshold BPD and those with full-syndrome BPD did not differ on any HRQoL dimension, with the exception of Self-Perception . Similar, groups with sub-threshold and full-syndrome BPD showed no significant differences on any dimension of self-reported psychopathological distress, with the exception of Hostility . Findings highlight that subthreshold BPD in adolescents is associated with impairments in HRQoL and psychopathological distress comparable to full

  17. Importance and challenges of measuring intrinsic foot muscle strength

    Science.gov (United States)

    2012-01-01

    Background Intrinsic foot muscle weakness has been implicated in a range of foot deformities and disorders. However, to establish a relationship between intrinsic muscle weakness and foot pathology, an objective measure of intrinsic muscle strength is needed. The aim of this review was to provide an overview of the anatomy and role of intrinsic foot muscles, implications of intrinsic weakness and evaluate the different methods used to measure intrinsic foot muscle strength. Method Literature was sourced from database searches of MEDLINE, PubMed, SCOPUS, Cochrane Library, PEDro and CINAHL up to June 2012. Results There is no widely accepted method of measuring intrinsic foot muscle strength. Methods to estimate toe flexor muscle strength include the paper grip test, plantar pressure, toe dynamometry, and the intrinsic positive test. Hand-held dynamometry has excellent interrater and intrarater reliability and limits toe curling, which is an action hypothesised to activate extrinsic toe flexor muscles. However, it is unclear whether any method can actually isolate intrinsic muscle strength. Also most methods measure only toe flexor strength and other actions such as toe extension and abduction have not been adequately assessed. Indirect methods to investigate intrinsic muscle structure and performance include CT, ultrasonography, MRI, EMG, and muscle biopsy. Indirect methods often discriminate between intrinsic and extrinsic muscles, but lack the ability to measure muscle force. Conclusions There are many challenges to accurately measure intrinsic muscle strength in isolation. Most studies have measured toe flexor strength as a surrogate measure of intrinsic muscle strength. Hand-held dynamometry appears to be a promising method of estimating intrinsic muscle strength. However, the contribution of extrinsic muscles cannot be excluded from toe flexor strength measurement. Future research should clarify the relative contribution of intrinsic and extrinsic muscles

  18. Add-drop double bus microresonator array local oscillators for sharp multiple Fano resonance engineering

    Science.gov (United States)

    Li, Jiahua; Qu, Ye; Wu, Ying

    2018-03-01

    Asymmetric resonances are currently the subject of considerable research efforts in photonic nanostructures. Here we propose a feasible method to achieve multiple Fano resonances and their control in an optical compound system consisting of an array of on-chip microresonators without mutual coupling and two parallel fiber waveguides side-coupled to the microresonator array by means of a local oscillator. We derive analytical and transparent expressions for the power transmission function summing over the two light transporting paths within the framework of quantum optics. It is clearly shown that introducing the local oscillator as an additional light propagating path plays an important role in the formation of narrow and multiple Fano resonance lineshapes. The power transmission spectrum through the combination of both the microresonator array and the local oscillator is very sensitive to the system parameters, for example, the intrinsic decay rate of the resonator, the phase shift factor of the local oscillator, the transmission coefficient of the fiber beam splitter, and the total number of the microresonators. Through detailed analysis, we identify the optimums for generating Fano resonance lineshapes. Also, we assess the experimental feasibility of the scheme using currently available technology. The proposed method is relatively straightforward as it requires only one local oscillator as one interferometer arm and it is mostly fiber-based. We believe that our work will help to understand and improve multiple Fano resonance engineering.

  19. Reduction theories elucidate the origins of complex biological rhythms generated by interacting delay-induced oscillations.

    Directory of Open Access Journals (Sweden)

    Ikuhiro Yamaguchi

    Full Text Available Time delay is known to induce sustained oscillations in many biological systems such as electroencephalogram (EEG activities and gene regulations. Furthermore, interactions among delay-induced oscillations can generate complex collective rhythms, which play important functional roles. However, due to their intrinsic infinite dimensionality, theoretical analysis of interacting delay-induced oscillations has been limited. Here, we show that the two primary methods for finite-dimensional limit cycles, namely, the center manifold reduction in the vicinity of the Hopf bifurcation and the phase reduction for weak interactions, can successfully be applied to interacting infinite-dimensional delay-induced oscillations. We systematically derive the complex Ginzburg-Landau equation and the phase equation without delay for general interaction networks. Based on the reduced low-dimensional equations, we demonstrate that diffusive (linearly attractive coupling between a pair of delay-induced oscillations can exhibit nontrivial amplitude death and multimodal phase locking. Our analysis provides unique insights into experimentally observed EEG activities such as sudden transitions among different phase-locked states and occurrence of epileptic seizures.

  20. Noise promotes independent control of gamma oscillations and grid firing within recurrent attractor networks

    Science.gov (United States)

    Solanka, Lukas; van Rossum, Mark CW; Nolan, Matthew F

    2015-01-01

    Neural computations underlying cognitive functions require calibration of the strength of excitatory and inhibitory synaptic connections and are associated with modulation of gamma frequency oscillations in network activity. However, principles relating gamma oscillations, synaptic strength and circuit computations are unclear. We address this in attractor network models that account for grid firing and theta-nested gamma oscillations in the medial entorhinal cortex. We show that moderate intrinsic noise massively increases the range of synaptic strengths supporting gamma oscillations and grid computation. With moderate noise, variation in excitatory or inhibitory synaptic strength tunes the amplitude and frequency of gamma activity without disrupting grid firing. This beneficial role for noise results from disruption of epileptic-like network states. Thus, moderate noise promotes independent control of multiplexed firing rate- and gamma-based computational mechanisms. Our results have implications for tuning of normal circuit function and for disorders associated with changes in gamma oscillations and synaptic strength. DOI: http://dx.doi.org/10.7554/eLife.06444.001 PMID:26146940

  1. Positive consequences of intrinsically rewarding work: A model to ...

    African Journals Online (AJOL)

    This study sought to empirically test a theoretical model outlining the relationships between intrinsic rewards, intrinsic motivation, work engagement and intention to quit, in an attempt to empirically assess whether intrinsic rewards result in improved levels of motivation, engagement and retention. Using a sample of 587 ...

  2. The value of nature: Economic, intrinsic, or both?

    Science.gov (United States)

    There has been a long standing argument that ecosystems have intrinsic value and therefore there is no need to put a price tag on Mother Nature. The concept of intrinsic value reflects the perspective that nature has value in its own right, independent of human uses. Intrinsic va...

  3. Personalizing Sample Databases with Facebook Information to Increase Intrinsic Motivation

    Science.gov (United States)

    Marzo, Asier; Ardaiz, Oscar; Sanz de Acedo, María Teresa; Sanz de Acedo, María Luisa

    2017-01-01

    Motivation is fundamental for students to achieve successful and complete learning. Motivation can be extrinsic, i.e., driven by external rewards, or intrinsic, i.e., driven by internal factors. Intrinsic motivation is the most effective and must be inspired by the task at hand. Here, a novel strategy is presented to increase intrinsic motivation…

  4. Intrinsic Motivation: An Overlooked Component for Student Success

    Science.gov (United States)

    Augustyniak, Robert A.; Ables, Adrienne Z.; Guilford, Philip; Lujan, Heidi L.; Cortright, Ronald N.; DiCarlo, Stephen E.

    2016-01-01

    Intrinsic motivation to learn involves engaging in learning opportunities because they are seen as enjoyable, interesting, or relevant to meeting one's core psychological needs. As a result, intrinsic motivation is associated with high levels of effort and task performance. Students with greater levels of intrinsic motivation demonstrate strong…

  5. The Development of Intrinsic Motivation for Physical Activity

    Science.gov (United States)

    2005-07-01

    The Development of Intrinsic Motivation for Physical Activity by James Dunigan Beaty Bachelor of Science Central Washington...2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE The Development of Intrinsic Motivation for Physical Activity 5a. CONTRACT...Government." 3 ABSTRACT The Development of Intrinsic Motivation for Physical Activity by James Dunigan Beaty Cynthia Carruthers, Ph.D

  6. Elements of the Competitive Situation That Affect Intrinsic Motivation.

    Science.gov (United States)

    Reeve, Johnmarshall; Deci, Edward L.

    1996-01-01

    Explores the effects of three elements of the competitive situation (competitive set, competitive outcome, and interpersonal context) on intrinsic motivation in a sample of college students (n=100). Competitive outcome and interpersonal context affected intrinsic motivation: winning increased intrinsic motivation, while pressured interpersonal…

  7. Innate and intrinsic antiviral immunity in skin.

    Science.gov (United States)

    Kawamura, Tatsuyoshi; Ogawa, Youichi; Aoki, Rui; Shimada, Shinji

    2014-09-01

    As the body's most exposed interface with the environment, the skin is constantly challenged by potentially pathogenic microbes, including viruses. To sense the invading viruses, various types of cells resident in the skin express many different pattern-recognition receptors (PRRs) such as C-type lectin receptors (CLRs), Toll-like receptors (TLRs), nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs), retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) and cytosolic DNA sensors, that can detect the pathogen-associated molecular patterns (PAMPs) of the viruses. The detection of viral PAMPs initiates two major innate immune signaling cascades: the first involves the activation of the downstream transcription factors, such as interferon regulatory factors (IRFs), nuclear factor kappa B (NF-κB) and activator protein 1 (AP-1), which cooperate to induce the transcription of type I interferons and pro-inflammatory cytokines. The second signaling pathway involves the caspase-1-mediated processing of IL-1β and IL-18 through the formation of an inflammasome complex. Cutaneous innate immunity including the production of the innate cytokines constitutes the first line of host defence that limits the virus dissemination from the skin, and also plays an important role in the activation of adaptive immune response, which represents the second line of defence. More recently, the third immunity "intrinsic immunity" has emerged, that provides an immediate and direct antiviral defense mediated by host intrinsic restriction factors. This review focuses on the recent advances regarding the antiviral immune systems, highlighting the innate and intrinsic immunity against the viral infections in the skin, and describes how viral components are recognized by cutaneous immune systems. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. Metacognitive mastery and intrinsic motivation in schizophrenia.

    Science.gov (United States)

    Vohs, Jenifer L; Lysaker, Paul H

    2014-01-01

    Deficits in intrinsic motivation (IM) have been linked to poorer outcome in schizophrenia, but its proximal mechanisms remain poorly understood. This study examined whether metacognitive mastery, or the capacity to use knowledge of self, others, and context to identify and cope with psychological difficulties, predicted levels of IM for 6 months among 75 participants with prolonged schizophrenia. Repeated-measures analysis of variance revealed that high metacognitive mastery predicted consistently higher levels of IM; however, intermediate and low mastery did not produce unique IM profiles. The findings suggest that metacognitive mastery may have an important role in IM over time and could be a meaningful treatment target.

  9. Symplectic Structure of Intrinsic Time Gravity

    Directory of Open Access Journals (Sweden)

    Eyo Eyo Ita

    2016-08-01

    Full Text Available The Poisson structure of intrinsic time gravity is analysed. With the starting point comprising a unimodular three-metric with traceless momentum, a trace-induced anomaly results upon quantization. This leads to a revision of the choice of momentum variable to the (mixed index traceless momentric. This latter choice unitarily implements the fundamental commutation relations, which now take on the form of an affine algebra with SU(3 Lie algebra amongst the momentric variables. The resulting relations unitarily implement tracelessness upon quantization. The associated Poisson brackets and Hamiltonian dynamics are studied.

  10. Intrinsically conductive polymer thin film piezoresistors

    DEFF Research Database (Denmark)

    Lillemose, Michael; Spieser, Martin; Christiansen, N.O.

    2008-01-01

    We report on the piezoresistive effect in the intrinsically conductive polymer, polyaniline. A process recipe for indirect patterning of thin film polyaniline has been developed. Using a specially designed chip, the polyaniline thin films have been characterised with respect to resistivity...... and strain sensitivity using two- and four-point measurement method. We have found that polyaniline has a negative gauge factor of K = -4.9, which makes it a candidate for piezoresistive read-out in polymer based MEMS-devices. (C) 2007 Elsevier B.V. All rights reserved....

  11. Intrinsic chirp of single-cycle pulses

    International Nuclear Information System (INIS)

    Lin Qiang; Zheng Jian; Dai Jianming; Ho, I-Chen; Zhang, X.-C.

    2010-01-01

    The Fourier transform-limited electromagnetic pulse has been regarded to be free of chirps for a long time. This is no longer true if the pulse duration goes down to or less than one optical cycle. We report the experimental observation of intrinsic chirps in such pulses with the sub-single-cycle terahertz (THz) waveforms obtained with a standard THz time-domain spectroscopy system. The results confirm the break down of the carrier-envelope (CE) expression for single-cycle optical pulses, and may influence the experimental measurements and theoretical modeling with single-cycle pulses.

  12. Oscillations

    Directory of Open Access Journals (Sweden)

    Qinghua Wu

    2015-01-01

    equivalent to the GMRES method proposed by Olver (2009. Moreover, the simpler GMRES does not require upper Hessenberg matrix factorization, which leads to much simpler program and requires less work. Numerical experiments are conducted to illustrate the performance of the new method and show that in some cases the simpler GMRES method could achieve higher accuracy than GMRES.

  13. Separation control with fluidic oscillators in water

    Science.gov (United States)

    Schmidt, H.-J.; Woszidlo, R.; Nayeri, C. N.; Paschereit, C. O.

    2017-08-01

    The present study assesses the applicability of fluidic oscillators for separation control in water. The first part of this work evaluates the properties of the fluidic oscillators including frequency, cavitation effects, and exerted thrust. Derived from the governing internal dynamics, the oscillation frequency is found to scale directly with the jet's exit velocity and the size of the fluidic oscillator independent of the working fluid. Frequency data from various experiments collapse onto a single curve. The occurrence of cavitation is examined by visual inspection and hydrophone measurements. The oscillation frequency is not affected by cavitation because it does not occur inside the oscillators. The spectral information obtained with the hydrophone provide a reliable indicator for the onset of cavitation at the exit. The performance of the fluidic oscillators for separation control on a bluff body does not seem to be affected by the presence of cavitation. The thrust exerted by an array of fluidic oscillators with water as the working fluid is measured to be even larger than theoretically estimated values. The second part of the presented work compares the performance of fluidic oscillators for separation control in water with previous results in air. The array of fluidic oscillators is installed into the rear end of a bluff body model. The drag improvements based on force balance measurements agree well with previous wind tunnel experiments on the same model. The flow field is examined by pressure measurements and with particle image velocimetry. Similar performance and flow field characteristics are observed in both water and air.

  14. A novel retinal oscillation mechanism in an autosomal dominant photoreceptor degeneration mouse model

    Directory of Open Access Journals (Sweden)

    Hung-Ya eTu

    2016-01-01

    Full Text Available It has been shown in rd1 and rd10 models of photoreceptor degeneration (PD that inner retinal neurons display spontaneous and rhythmic activities. Furthermore, the rhythmic activity has been shown to require the gap junction protein connexin 36, which is likely located in AII amacrine cells (AII-ACs. In the present study, an autosomal dominant PD model called rhoΔCTA, whose rods overexpress a C-terminally truncated mutant rhodopsin and degenerate with a rate similar to that of rd1, was used to investigate the generality and mechanisms of heightened inner retinal activity following PD. To fluorescently identify cholinergic starburst amacrine cells (SACs, the rhoΔCTA mouse was introduced into a combined ChAT-IRES-Cre and Ai9 background. In this mouse, we observed large amplitude excitatory postsynaptic currents (EPSCs oscillations and non-rhythmic inhibitory postsynaptic currents (IPSCs in both ON- and OFF-SACs. The IPSCs were more noticeable in OFF- than in ON-SACs. Similar to reported retinal ganglion cell (RGC oscillation in rd1 mice, EPSC oscillation was synaptically driven by glutamate and sensitive to blockade of NaV channels and gap junctions. These data suggest that akin to rd1 mice, AII-AC is a prominent oscillator in rhoΔCTA mice. Surprisingly, OFF-SAC but not ON-SAC EPSC oscillation could readily be enhanced by GABAergic blockade. More importantly, weakening the AII-AC gap junction network by activating retinal dopamine receptors abolished oscillations in ON-SACs but not in OFF-SACs. Furthermore, the latter persisted in the presence of flupirtine, an M-type potassium channel activator recently reported to dampen intrinsic AII-AC bursting. These data suggest the existence of a novel oscillation mechanism in mice with PD.

  15. Noninvasive iPhone Measurement of Left Ventricular Ejection Fraction Using Intrinsic Frequency Methodology.

    Science.gov (United States)

    Pahlevan, Niema M; Rinderknecht, Derek G; Tavallali, Peyman; Razavi, Marianne; Tran, Thao T; Fong, Michael W; Kloner, Robert A; Csete, Marie; Gharib, Morteza

    2017-07-01

    The study is based on previously reported mathematical analysis of arterial waveform that extracts hidden oscillations in the waveform that we called intrinsic frequencies. The goal of this clinical study was to compare the accuracy of left ventricular ejection fraction derived from intrinsic frequencies noninvasively versus left ventricular ejection fraction obtained with cardiac MRI, the most accurate method for left ventricular ejection fraction measurement. After informed consent, in one visit, subjects underwent cardiac MRI examination and noninvasive capture of a carotid waveform using an iPhone camera (The waveform is captured using a custom app that constructs the waveform from skin displacement images during the cardiac cycle.). The waveform was analyzed using intrinsic frequency algorithm. Outpatient MRI facility. Adults able to undergo MRI were referred by local physicians or self-referred in response to local advertisement and included patients with heart failure with reduced ejection fraction diagnosed by a cardiologist. Standard cardiac MRI sequences were used, with periodic breath holding for image stabilization. To minimize motion artifact, the iPhone camera was held in a cradle over the carotid artery during iPhone measurements. Regardless of neck morphology, carotid waveforms were captured in all subjects, within seconds to minutes. Seventy-two patients were studied, ranging in age from 20 to 92 years old. The main endpoint of analysis was left ventricular ejection fraction; overall, the correlation between ejection fraction-iPhone and ejection fraction-MRI was 0.74 (r = 0.74; p iPhone] + 1.9). Analysis of carotid waveforms using intrinsic frequency methods can be used to document left ventricular ejection fraction with accuracy comparable with that of MRI. The measurements require no training to perform or interpret, no calibration, and can be repeated at the bedside to generate almost continuous analysis of left ventricular ejection fraction

  16. The Neglected Intrinsic Resistome of Bacterial Pathogens

    Science.gov (United States)

    Fajardo, Alicia; Martínez-Martín, Nadia; Mercadillo, María; Galán, Juan C.; Ghysels, Bart; Matthijs, Sandra; Cornelis, Pierre; Wiehlmann, Lutz; Tümmler, Burkhard; Baquero, Fernando; Martínez, José L.

    2008-01-01

    Bacteria with intrinsic resistance to antibiotics are a worrisome health problem. It is widely believed that intrinsic antibiotic resistance of bacterial pathogens is mainly the consequence of cellular impermeability and activity of efflux pumps. However, the analysis of transposon-tagged Pseudomonas aeruginosa mutants presented in this article shows that this phenotype emerges from the action of numerous proteins from all functional categories. Mutations in some genes make P. aeruginosa more susceptible to antibiotics and thereby represent new targets. Mutations in other genes make P. aeruginosa more resistant and therefore define novel mechanisms for mutation-driven acquisition of antibiotic resistance, opening a new research field based in the prediction of resistance before it emerges in clinical environments. Antibiotics are not just weapons against bacterial competitors, but also natural signalling molecules. Our results demonstrate that antibiotic resistance genes are not merely protective shields and offer a more comprehensive view of the role of antibiotic resistance genes in the clinic and in nature. PMID:18286176

  17. A tonoplast intrinsic protein in Gardenia jasminoides

    Science.gov (United States)

    Gao, Lan; Li, Hao-Ming

    2017-08-01

    Physiological and molecular studies proved that plasma membrane intrinsic proteins (PIPs) and tonoplast intrinsic proteins (TIPs) subfamily of aquaporins play key functions in plant water homeostasis. Five specialized subgroups (TIP1-5) of TIPs have been found in higher plants, in which the TIP1 and TIP2 isoforms are the largest arbitrary groups. TIPs have high water-transport activity than PIPs, some TIPs can transport other small molecule such as urea, ammonia, hydrogen peroxide, and carbon dioxide. In this work, the structure of the putative tonoplast aquaporin from Gardenia jasminoides (GjTIP) was analyzed. Its transcript level has increased during fruit maturation. A phylogenetic analysis indicates that the protein belongs to TIP1 subfamily. A three-dimensional model structure of GjTIP was built based on crystal structure of an ammonia-permeable AtTIP2-1 from Arabidopsis thaliana. The model structure displayed as a homo-tetramer, each monomer has six trans-membrane and two half-membrane-spanning α helices. The data suggests that the GjTIP has tendency to be a mixed function aquaporin, might involve in water, urea and hydrogen peroxide transport, and the gating machanism founded in some AQPs involving pH and phosphorylation response have not been proved in GjTIP.

  18. Intrinsic regulation of enteroendocrine fate by Numb.

    Science.gov (United States)

    Sallé, Jérémy; Gervais, Louis; Boumard, Benjamin; Stefanutti, Marine; Siudeja, Katarzyna; Bardin, Allison J

    2017-07-03

    How terminal cell fates are specified in dynamically renewing adult tissues is not well understood. Here we explore terminal cell fate establishment during homeostasis using the enteroendocrine cells (EEs) of the adult Drosophila midgut as a paradigm. Our data argue against the existence of local feedback signals, and we identify Numb as an intrinsic regulator of EE fate. Our data further indicate that Numb, with alpha-adaptin, acts upstream or in parallel of known regulators of EE fate to limit Notch signaling, thereby facilitating EE fate acquisition. We find that Numb is regulated in part through its asymmetric and symmetric distribution during stem cell divisions; however, its de novo synthesis is also required during the differentiation of the EE cell. Thus, this work identifies Numb as a crucial factor for cell fate choice in the adult Drosophila intestine. Furthermore, our findings demonstrate that cell-intrinsic control mechanisms of terminal cell fate acquisition can result in a balanced tissue-wide production of terminally differentiated cell types. © 2017 The Authors.

  19. Intrinsic position uncertainty impairs overt search performance.

    Science.gov (United States)

    Semizer, Yelda; Michel, Melchi M

    2017-08-01

    Uncertainty regarding the position of the search target is a fundamental component of visual search. However, due to perceptual limitations of the human visual system, this uncertainty can arise from intrinsic, as well as extrinsic, sources. The current study sought to characterize the role of intrinsic position uncertainty (IPU) in overt visual search and to determine whether it significantly limits human search performance. After completing a preliminary detection experiment to characterize sensitivity as a function of visual field position, observers completed a search task that required localizing a Gabor target within a field of synthetic luminance noise. The search experiment included two clutter conditions designed to modulate the effect of IPU across search displays of varying set size. In the Cluttered condition, the display was tiled uniformly with feature clutter to maximize the effects of IPU. In the Uncluttered condition, the clutter at irrelevant locations was removed to attenuate the effects of IPU. Finally, we derived an IPU-constrained ideal searcher model, limited by the IPU measured in human observers. Ideal searchers were simulated based on the detection sensitivity and fixation sequences measured for individual human observers. The IPU-constrained ideal searcher predicted performance trends similar to those exhibited by the human observers. In the Uncluttered condition, performance decreased steeply as a function of increasing set size. However, in the Cluttered condition, the effect of IPU dominated and performance was approximately constant as a function of set size. Our findings suggest that IPU substantially limits overt search performance, especially in crowded displays.

  20. The neglected intrinsic resistome of bacterial pathogens.

    Directory of Open Access Journals (Sweden)

    Alicia Fajardo

    Full Text Available Bacteria with intrinsic resistance to antibiotics are a worrisome health problem. It is widely believed that intrinsic antibiotic resistance of bacterial pathogens is mainly the consequence of cellular impermeability and activity of efflux pumps. However, the analysis of transposon-tagged Pseudomonas aeruginosa mutants presented in this article shows that this phenotype emerges from the action of numerous proteins from all functional categories. Mutations in some genes make P. aeruginosa more susceptible to antibiotics and thereby represent new targets. Mutations in other genes make P. aeruginosa more resistant and therefore define novel mechanisms for mutation-driven acquisition of antibiotic resistance, opening a new research field based in the prediction of resistance before it emerges in clinical environments. Antibiotics are not just weapons against bacterial competitors, but also natural signalling molecules. Our results demonstrate that antibiotic resistance genes are not merely protective shields and offer a more comprehensive view of the role of antibiotic resistance genes in the clinic and in nature.

  1. Intrinsic terminators in Mycoplasma hyopneumoniae transcription.

    Science.gov (United States)

    Fritsch, Tiago Ebert; Siqueira, Franciele Maboni; Schrank, Irene Silveira

    2015-04-08

    Mycoplasma hyopneumoniae, an important pathogen of swine, exhibits a low guanine and cytosine (GC) content genome. M. hyopneumoniae genome is organised in long transcriptional units and promoter sequences have been mapped upstream of all transcription units. These analysis provided insights into the gene organisation and transcription initiation at the genome scale. However, the presence of transcriptional terminator sequences in the M. hyopneumoniae genome is poorly understood. In silico analyses demonstrated the presence of putative terminators in 82% of the 33 monocistronic units (mCs) and in 74% of the 116 polycistronic units (pCs) considering different classes of terminators. The functional activity of 23 intrinsic terminators was confirmed by RT-PCR and qPCR. Analysis of all terminators found by three software algorithms, combined with experimental results, allowed us to propose a pattern of RNA hairpin formation during the termination process and to predict the location of terminators in the M. hyopneumoniae genome sequence. The stem-loop structures of intrinsic terminators of mycoplasma diverge from the pattern of terminators found in other bacteria due the low content of guanine and cytosine. In M. hyopneumoniae, transcription can end after a transcriptional unit and before its terminator sequence and can also continue past the terminator sequence with RNA polymerases gradually releasing the RNA.

  2. Intrinsically disordered proteins drive membrane curvature.

    Science.gov (United States)

    Busch, David J; Houser, Justin R; Hayden, Carl C; Sherman, Michael B; Lafer, Eileen M; Stachowiak, Jeanne C

    2015-07-24

    Assembly of highly curved membrane structures is essential to cellular physiology. The prevailing view has been that proteins with curvature-promoting structural motifs, such as wedge-like amphipathic helices and crescent-shaped BAR domains, are required for bending membranes. Here we report that intrinsically disordered domains of the endocytic adaptor proteins, Epsin1 and AP180 are highly potent drivers of membrane curvature. This result is unexpected since intrinsically disordered domains lack a well-defined three-dimensional structure. However, in vitro measurements of membrane curvature and protein diffusivity demonstrate that the large hydrodynamic radii of these domains generate steric pressure that drives membrane bending. When disordered adaptor domains are expressed as transmembrane cargo in mammalian cells, they are excluded from clathrin-coated pits. We propose that a balance of steric pressure on the two surfaces of the membrane drives this exclusion. These results provide quantitative evidence for the influence of steric pressure on the content and assembly of curved cellular membrane structures.

  3. Clusters in nonsmooth oscillator networks

    Science.gov (United States)

    Nicks, Rachel; Chambon, Lucie; Coombes, Stephen

    2018-03-01

    For coupled oscillator networks with Laplacian coupling, the master stability function (MSF) has proven a particularly powerful tool for assessing the stability of the synchronous state. Using tools from group theory, this approach has recently been extended to treat more general cluster states. However, the MSF and its generalizations require the determination of a set of Floquet multipliers from variational equations obtained by linearization around a periodic orbit. Since closed form solutions for periodic orbits are invariably hard to come by, the framework is often explored using numerical techniques. Here, we show that further insight into network dynamics can be obtained by focusing on piecewise linear (PWL) oscillator models. Not only do these allow for the explicit construction of periodic orbits, their variational analysis can also be explicitly performed. The price for adopting such nonsmooth systems is that many of the notions from smooth dynamical systems, and in particular linear stability, need to be modified to take into account possible jumps in the components of Jacobians. This is naturally accommodated with the use of saltation matrices. By augmenting the variational approach for studying smooth dynamical systems with such matrices we show that, for a wide variety of networks that have been used as models of biological systems, cluster states can be explicitly investigated. By way of illustration, we analyze an integrate-and-fire network model with event-driven synaptic coupling as well as a diffusively coupled network built from planar PWL nodes, including a reduction of the popular Morris-Lecar neuron model. We use these examples to emphasize that the stability of network cluster states can depend as much on the choice of single node dynamics as it does on the form of network structural connectivity. Importantly, the procedure that we present here, for understanding cluster synchronization in networks, is valid for a wide variety of systems in

  4. Harmonic oscillator and nuclear pseudospin

    International Nuclear Information System (INIS)

    Lisboa, Ronai; Malheiro, Manuel; Castro, Antonio S. de; Alberto, Pedro; Fiolhais, M.

    2004-01-01

    A generalized relativistic harmonic oscillator for spin 1/2 particles is studied. The Dirac Hamiltonians contains a scalar S and a vector V quadratic potentials in the radial coordinate, as well as a tensor potential U, linear in r. Setting either Σ=S+V or Δ=V - S to zero, analytical solutions for bound states are found. The eigenenergies and their nonrelativistic limits are present and particular cases are discussed, especially the case Σ=0, for which pseudospin symmetry is exact. (author)

  5. Wave Physics Oscillations - Solitons - Chaos

    CERN Document Server

    Nettel, Stephen

    2009-01-01

    This textbook is intended for those second year undergraduates in science and engineering who will later need an understanding of electromagnetic theory and quantum mechanics. The classical physics of oscillations and waves is developed at a more advanced level than has been customary for the second year, providing a basis for the quantum mechanics that follows. In this new edition the Green's function is explained, reinforcing the integration of quantum mechanics with classical physics. The text may also form the basis of an "introduction to theoretical physics" for physics majors. The concluding chapters give special attention to topics in current wave physics: nonlinear waves, solitons, and chaotic behavior.

  6. Pair creation and plasma oscillations

    International Nuclear Information System (INIS)

    We describe aspects of particle creation in strong fields using a quantum kinetic equation with a relaxation-time approximation to the collision term. The strong electric background field is determined by solving Maxwell's equation in tandem with the Vlasov equation. Plasma oscillations appear as a result of feedback between the background field and the field generated by the particles produced. The plasma frequency depends on the strength of the initial background fields and the collision frequency, and is sensitive to the necessary momentum-dependence of dressed-parton masses

  7. Making space for harmonic oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Michelotti, Leo; /Fermilab

    2004-11-01

    If we restrict the number of harmonic oscillator energy eigenstates to some finite value, N, then the discrete spectrum of the corresponding position operator comprise the roots of the Hermite polynomial H{sub N+1}. Its range is just large enough to accommodate classical motion at high energy. A negative energy term must be added to the Hamiltonian which affects only the last eigenstate, |N>, suggesting it is concentrated at the extrema of this finite ''space''. Calculations support a conjecture that, in the limit of large N, the global distribution of points approaches the differential form for classical action.

  8. Relaxation Oscillation and Canard Explosion

    Science.gov (United States)

    Krupa, M.; Szmolyan, P.

    2001-08-01

    We give a geometric analysis of relaxation oscillations and canard cycles in singularly perturbed planar vector fields. The transition from small Hopf-type cycles to large relaxation cycles, which occurs in an exponentially thin parameter interval, is described as a perturbation of a family of singular cycles. The results are obtained by means of two blow-up transformations combined with standard tools of dynamical systems theory. The efficient use of various charts is emphasized. The results are applied to the van der Pol equation.

  9. Intrinsically secure fast reactors with dense cores

    International Nuclear Information System (INIS)

    Slessarev, Igor

    2007-01-01

    Secure safety, resistance to weapons material proliferation and problems of long-lived wastes remain the most important 'painful points' of nuclear power. Many innovative reactor concepts have been developed aimed at a radical enhancement of safety. The promising potential of innovative nuclear reactors allows for shifting accents in current reactor safety 'strategy' to reveal this worth. Such strategy is elaborated focusing on the priority for intrinsically secure safety features as well as on sure protection being provided by the first barrier of defence. Concerning the potential of fast reactors (i.e. sodium cooled, lead-cooled, etc.), there are no doubts that they are able to possess many favourable intrinsically secure safety features and to lay the proper foundation for a new reactor generation. However, some of their neutronic characteristics have to be radically improved. Among intrinsically secure safety properties, the following core parameters are significantly important: reactivity margin values, reactivity feed-back and coolant void effects. Ways of designing intrinsically secure safety features in fast reactors (titled hereafter as Intrinsically Secure Fast Reactors - ISFR) can be found in the frame of current reactor technologies by radical enhancement of core neutron economy and by optimization of core compositions. Simultaneously, respecting resistance to proliferation, by using non-enriched fuel feed as well as a core breeding gain close to zero, are considered as the important features (long-lived waste problems will be considered in a separate paper). This implies using the following reactor design options as well as closed fuel cycles with natural U as the reactor feed: ·Ultra-plate 'dense cores' of the ordinary (monolithic) type with negative total coolant void effects. ·Modular type cores. Multiple dense modules can be embedded in the common reflector for achieving the desired NPP total power. The modules can be used also independently (as

  10. Real-time monitoring of circadian clock oscillations in primary cultures of mammalian cells using Tol2 transposon-mediated gene transfer strategy

    Directory of Open Access Journals (Sweden)

    Yamanaka Iori

    2010-01-01

    Full Text Available Abstract Background The circadian rhythm in mammals is orchestrated by a central pacemaker in the brain, but most peripheral tissues contain their own intrinsic circadian oscillators. The circadian rhythm is a fundamental biological system in mammals involved in the regulation of various physiological functions such as behavior, cardiovascular functions and energy metabolism. Thus, it is important to understand the correlation between circadian oscillator and physiological functions in peripheral tissues. However, it is still difficult to investigate the molecular oscillator in primary culture cells. Results In this study, we used a novel Tol2 transposon based Dbp promoter or Bmal1 promoter driven luciferase reporter vector system to detect and analyze the intrinsic molecular oscillator in primary culture cells (mouse embryonic fibroblasts, fetal bovine heart endothelial cells and rat astrocytes. The results showed circadian molecular oscillations in all examined primary culture cells. Moreover, the phase relationship between Dbp promoter driven and Bmal1 promoter driven molecular rhythms were almost anti-phase, which suggested that these reporters appropriately read-out the intrinsic cellular circadian clock. Conclusions Our results indicate that gene transfer strategy using the Tol2 transposon system of a useful and safe non-viral vector is a powerful tool for investigating circadian rhythms in peripheral tissues.

  11. The Neuroscience of Growth Mindset and Intrinsic Motivation.

    Science.gov (United States)

    Ng, Betsy

    2018-01-26

    Our actions can be triggered by intentions, incentives or intrinsic values. Recent neuroscientific research has yielded some results about the growth mindset and intrinsic motivation. With the advances in neuroscience and motivational studies, there is a global need to utilize this information to inform educational practice and research. Yet, little is known about the neuroscientific interplay between growth mindset and intrinsic motivation. This paper attempts to draw on the theories of growth mindset and intrinsic motivation, together with contemporary ideas in neuroscience, outline the potential for neuroscientific research in education. It aims to shed light on the relationship between growth mindset and intrinsic motivation in terms of supporting a growth mindset to facilitate intrinsic motivation through neural responses. Recent empirical research from the educational neuroscience perspective that provides insights into the interplay between growth mindset and intrinsic motivation will also be discussed.

  12. Phase noise and frequency stability in oscillators

    CERN Document Server

    Rubiola, Enrico

    2009-01-01

    Presenting a comprehensive account of oscillator phase noise and frequency stability, this practical text is both mathematically rigorous and accessible. An in-depth treatment of the noise mechanism is given, describing the oscillator as a physical system, and showing that simple general laws govern the stability of a large variety of oscillators differing in technology and frequency range. Inevitably, special attention is given to amplifiers, resonators, delay lines, feedback, and flicker (1/f) noise. The reverse engineering of oscillators based on phase-noise spectra is also covered, and end-of-chapter exercises are given. Uniquely, numerous practical examples are presented, including case studies taken from laboratory prototypes and commercial oscillators, which allow the oscillator internal design to be understood by analyzing its phase-noise spectrum. Based on tutorials given by the author at the Jet Propulsion Laboratory, international IEEE meetings, and in industry, this is a useful reference for acade...

  13. Driven, autoresonant three-oscillator interactions

    International Nuclear Information System (INIS)

    Yaakobi, O.; Friedland, L.; Henis, Z.

    2007-01-01

    An efficient control scheme of resonant three-oscillator interactions using an external chirped frequency drive is suggested. The approach is based on formation of a double phase-locked (autoresonant) state in the system, as the driving oscillation passes linear resonance with one of the interacting oscillators. When doubly phase locked, the amplitudes of the oscillators increase with time in proportion to the driving frequency deviation from the linear resonance. The stability of this phase-locked state and the effects of dissipation and of the initial three-oscillator frequency mismatch on the autoresonance are analyzed. The associated autoresonance threshold phenomenon in the driving amplitude is also discussed. In contrast to other nonlinear systems, driven, autoresonant three-oscillator excitations are independent of the sign of the driving frequency chirp rate

  14. Damping elastic oscillations of digging mechanism

    Science.gov (United States)

    Kuznetsov, N. K.; Makhno, D. E.; Iov, I. A.

    2017-10-01

    The article studies methods for reducing dynamic loading and elastic oscillations of excavator buckets using dampers. The authors suggest a structural scheme for damping bucket oscillations using a damping device installed in a running gear of the traction cable. The results of numerical efficiency simulation are presented. The article shows that the system helps to reduce intensity of elastic oscillations and a transition period in acceleration and deceleration modes.

  15. Oscillations of neutral B mesons systems

    CERN Document Server

    Boucrot, J.

    1999-01-01

    The oscillation phenomenon in the neutral B mesons systems is now well established. The motivations and principles of the measurements are given; then the most recent results from the LEP experiments, the CDF collaboration at Fermilab and the SLD collaboration at SLAC are reviewed. The present world average of the $\\bd$ meson oscillation frequency is $\\dmd = 0.471 \\pm 0.016 \\ps$ and the lower limit on the $\\bs$ oscillation frequency is

  16. Synchronization of weakly coupled canard oscillators

    OpenAIRE

    Köksal Ersöz, Elif; Desroches, Mathieu; Krupa, Martin

    2017-01-01

    International audience; Synchronization has been studied extensively in the context of weakly coupled oscillators using the so-called phase response curve (PRC) which measures how a change of the phase of an oscillator is affected by a small perturbation. This approach was based upon the work of Malkin, and it has been extended to relaxation oscillators. Namely, synchronization conditions were established under the weak coupling assumption, leading to a criterion for the existence of synchron...

  17. Cardiogenic oscillation induced ventilator autotriggering

    Directory of Open Access Journals (Sweden)

    Narender Kaloria

    2015-01-01

    Full Text Available Cardiogenic oscillation during mechanical ventilation can auto-trigger the ventilator resembling patient initiated breadth. This gives a false sense of intact respiratory drive and determination brain death, even if other tests are positive, is not appropriate in such a situation. It will prolong the ICU stay and confound the brain-death determination. In this case report, we describe a 35 year old man who was brought to the hospital after many hours of critical delay following multiple gun shot injuries. The patient suffered a cardiac arrest while on the way from another hospital. After an emergency laparotomy, patient was shifted to Intensive Care Unit (ICU with Glasgow Coma Scale (GCS score of E1VTM1 and was mechanically ventilated. Despite absence of brainstem reflexes, the ventilator continued to be triggered on continuous positive airway pressure (CPAP mode and the patient maintained normal oxygen saturation and acceptable levels of carbon dioxide. An apnoea test confirmed absent respiratory drive. Ventilatory waveform graph analysis, revealed cardiogenic oscillation as the cause for autotrigerring.

  18. Investigation of Transverse Oscillation Method

    DEFF Research Database (Denmark)

    Udesen, Jesper; Jensen, Jørgen Arendt

    2006-01-01

    Conventional ultrasound scanners can only display the axial component of the blood velocity vector, which is a significant limitation when vessels nearly parallel to the skin surface are scanned. The transverse oscillation method (TO) overcomes this limitation by introducing a transverse oscillat......Conventional ultrasound scanners can only display the axial component of the blood velocity vector, which is a significant limitation when vessels nearly parallel to the skin surface are scanned. The transverse oscillation method (TO) overcomes this limitation by introducing a transverse...... II. A virtual linear array transducer with center frequency 7 MHz and 128 active elements is created, and a virtual blood vessel of radius 6.4 mm is simulated. The performance of the TO method is found around an initial point in the parameter space. The parameters varied are: flow angle, transmit...... focus depth, receive apodization, pulse length, transverse wave length, number of emissions, signal to noise ratio, and type of echo canceling filter used. Using the experimental scanner RASMUS, the performance of the TO method is evaluated. An experimental flowrig is used to create laminar parabolic...

  19. Waves and oscillations in nature an introduction

    CERN Document Server

    Narayanan, A Satya

    2015-01-01

    Waves and oscillations are found in large scales (galactic) and microscopic scales (neutrino) in nature. Their dynamics and behavior heavily depend on the type of medium through which they propagate.Waves and Oscillations in Nature: An Introduction clearly elucidates the dynamics and behavior of waves and oscillations in various mediums. It presents different types of waves and oscillations that can be observed and studied from macroscopic to microscopic scales. The book provides a thorough introduction for researchers and graduate students in assorted areas of physics, such as fluid dynamics,

  20. High Reliability Oscillators for Terahertz Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Terahertz sources based on lower frequency oscillators and amplifiers plus a chain of frequency multipliers are the workhorse technology for NASA's terahertz...

  1. Introduction to classical and quantum harmonic oscillators

    CERN Document Server

    Bloch, Sylvan C

    2013-01-01

    From conch shells to lasers . harmonic oscillators, the timeless scientific phenomenon As intriguing to Galileo as they are to scientists today, harmonic oscillators have provided a simple and compelling paradigm for understanding the complexities that underlie some of nature's and mankind's most fascinating creations. From early string and wind instruments fashioned from bows and seashells to the intense precision of lasers, harmonic oscillators have existed in various forms, as objects of beauty and scientific use. And harmonic oscillation has endured as one of science's most fascinating con

  2. Strengthening and damping of synchrotron oscillations

    International Nuclear Information System (INIS)

    Taratin, A.M.

    2001-01-01

    Resonance strengthening and damping of synchrotron oscillations of collider bunch halo particles was studied by simulation. It was shown that the strengthening of particle synchrotron oscillations can be highly efficient with using a resonance pulse sequence. The resonance damping of particle synchrotron oscillations is only possible when the inverse population of the accelerated bunch halo is realized. Resonance method of synchrotron oscillation strengthening can be used for the extraction of beam halo particles with a bent crystal to improve the background conditions for colliding beam experiments and to fulfill simultaneously some fixed target experiments

  3. Scleronomic holonomic constraints and conservative nonlinear oscillators

    International Nuclear Information System (INIS)

    Munoz, R; Gonzalez-Garcia, G; Izquierdo-De La Cruz, E Izquierdo-De La; Fernandez-Anaya, G

    2011-01-01

    A bead sliding, under the sole influence of its own weight, on a rigid wire shaped in the fashion of a plane curve, will describe (generally anharmonic) oscillations around a local minimum. For given shapes, the bead will behave as a harmonic oscillator in the whole range, such as an unforced, undamped, Duffing oscillator, etc. We also present cases in which the effective potential acting on the bead is not analytical around a minimum. The small oscillation approximation cannot be applied to such pathological cases. Nonetheless, these latter instances are studied with other standard techniques.

  4. Scleronomic holonomic constraints and conservative nonlinear oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Munoz, R; Gonzalez-Garcia, G; Izquierdo-De La Cruz, E Izquierdo-De La [Universidad Autonoma de la Ciudad de Mexico, Centro Historico, Fray Servando Teresa de Mier 92, Col Centro, Del Cuauhtemoc, Mexico DF, CP 06080 (Mexico); Fernandez-Anaya, G, E-mail: rodrigo.munoz@uacm.edu.mx, E-mail: gggharper@gmail.com, E-mail: erickidc@gmail.com, E-mail: guillermo.fernandez@uia.mx [Universidad Iberoamericana, Departamento de Fisica y Matematicas, Prolongacon Paseo de de la Reforma 880, Col Lomas de Santa Fe, Del Alvaro Obregn, Mexico DF, CP 01219 (Mexico)

    2011-05-15

    A bead sliding, under the sole influence of its own weight, on a rigid wire shaped in the fashion of a plane curve, will describe (generally anharmonic) oscillations around a local minimum. For given shapes, the bead will behave as a harmonic oscillator in the whole range, such as an unforced, undamped, Duffing oscillator, etc. We also present cases in which the effective potential acting on the bead is not analytical around a minimum. The small oscillation approximation cannot be applied to such pathological cases. Nonetheless, these latter instances are studied with other standard techniques.

  5. Reentrant transition in coupled noisy oscillators.

    Science.gov (United States)

    Kobayashi, Yasuaki; Kori, Hiroshi

    2015-01-01

    We report on a synchronization-breaking instability observed in a noisy oscillator unidirectionally coupled to a pacemaker. Using a phase oscillator model, we find that, as the coupling strength is increased, the noisy oscillator lags behind the pacemaker more frequently and the phase slip rate increases, which may not be observed in averaged phase models such as the Kuramoto model. Investigation of the corresponding Fokker-Planck equation enables us to obtain the reentrant transition line between the synchronized state and the phase slip state. We verify our theory using the Brusselator model, suggesting that this reentrant transition can be found in a wide range of limit cycle oscillators.

  6. InGaAs tunnel FET with sub-nanometer EOT and sub-60 mV/dec sub-threshold swing at room temperature

    Science.gov (United States)

    Alian, A.; Mols, Y.; Bordallo, C. C. M.; Verreck, D.; Verhulst, A.; Vandooren, A.; Rooyackers, R.; Agopian, P. G. D.; Martino, J. A.; Thean, A.; Lin, D.; Mocuta, D.; Collaert, N.

    2016-12-01

    InGaAs homojunction Tunnel FET devices are demonstrated with sub-60 mV/dec Sub-threshold Swing (SS) measured in DC. A 54 mV/dec SS is achieved at 100 pA/μm over a drain voltage range of 0.2-0.5 V. The SS remains sub-60 mV/dec over 1.5 orders of magnitude of current at room temperature. Trap-Assisted Tunneling (TAT) is found to be negligible in the device evidenced by low temperature dependence of the transfer characteristics. Equivalent Oxide Thickness (EOT) is found to play the major role in achieving sub-60 mV/dec performance. The EOT of the demonstrated devices is 0.8 nm.

  7. Gate-all-around junctionless silicon transistors with atomically thin nanosheet channel (0.65 nm) and record sub-threshold slope (43 mV/dec)

    Science.gov (United States)

    Thirunavukkarasu, Vasanthan; Jhan, Yi-Ruei; Liu, Yan-Bo; Kurniawan, Erry Dwi; Lin, Yu Ru; Yang, Shang-Yi; Cheng, Che-Hsiang; Wu, Yung-Chun

    2017-01-01

    A silicon junctionless (JL) trench gate-all-around (GAA) nanowire field-effect transistor with an atomically thin channel thickness of 0.65 nm and a very thin oxide with a thickness of 12.3 nm are demonstrated experimentally. Experimental results indicate that this device with a channel thickness of 0.65 nm achieves a sub-threshold slope (SS) of 43 mV/decade, which is the best yet achieved by any reported JLFET. Owing to the atomically thin channel, this device has an extremely high ION/IOFF current ratio of >108. Furthermore, the atomically thin channel GAA JLFET exhibits a low threshold voltage (VTH) variation and negligible drain-induced barrier lowering (DIBL tunneling generation rate of 1.2 × 1024/cm2 s when the channel is scaled down to tunneling provides a means of achieving an SS value much lower than its fundamental physical limit.

  8. Effect of a web-based guided self-help intervention for prevention of major depression in adults with subthreshold depression

    DEFF Research Database (Denmark)

    Buntrock, C.; Ebert, D. D.; Lehr, D.

    2016-01-01

    -employee contributions). Participants included 406 self-selected adults with subthreshold depression (Centre for Epidemiologic Studies Depression Scale score≥16, no current MDD according to Diagnostic and Statistical Manual of Mental Disorders [Fourth Edition, Text Revision] criteria). INTERVENTIONS All participants had...... AND MEASURES The primary outcome was time to onset of MDD in the intervention group relative to the control group over a 12-month follow-up period as assessed by blinded diagnostic raters using the telephone-administered Structured Clinical Interview for DSM-IV Axis Disorders at 6-and 12-month follow......Importance Evidence-based treatments for major depressive disorder (MDD) are not very successful in improving functional and health outcomes. Attention has increasingly been focused on the prevention of MDD. OBJECTIVE To evaluate the effectiveness of a web-based guided self-help intervention...

  9. Associations between Tactile Sensory Threshold and Postural Performance and Effects of Healthy Aging and Subthreshold Vibrotactile Stimulation on Postural Outcomes in a Simple Dual Task.

    Science.gov (United States)

    Dettmer, Marius; Pourmoghaddam, Amir; Lee, Beom-Chan; Layne, Charles S

    2016-01-01

    Specific activities that require concurrent processing of postural and cognitive tasks may increase the risk for falls in older adults. We investigated whether peripheral receptor sensitivity was associated with postural performance in a dual-task and whether an intervention in form of subthreshold vibration could affect performance. Ten younger (age: 20-35 years) and ten older adults (70-85 years) performed repeated auditory-verbal 1-back tasks while standing quietly on a force platform. Foot sole vibration was randomly added during several trials. Several postural control and performance measures were assessed and statistically analyzed (significance set to α-levels of .05). There were moderate correlations between peripheral sensitivity and several postural performance and control measures (r = .45 to .59). Several postural performance measures differed significantly between older and younger adults (p stimulation should focus on older adults whose balance is significantly affected.

  10. Reduced Subthreshold Characteristics and Flicker Noise of an AlGaAs/InGaAs PHEMT Using Liquid Phase Deposited TiO2 as a Gate Dielectric

    Directory of Open Access Journals (Sweden)

    Kai-Yuen Lam

    2016-10-01

    Full Text Available This study presents the fabrication and improved properties of an AlGaAs/InGaAs metal-oxide-semiconductor pseudomorphic high-electron-mobility transistor (MOS-PHEMT using liquid phase deposited titanium dioxide (LPD-TiO2 as a gate dielectric. Sulfur pretreatment and postoxidation rapid thermal annealing (RTA were consecutively employed before and after the gate dielectric was deposited to fill dangling bonds and therefore release interface trapped charges. Compared with a benchmark PHEMT, the AlGaAs/InGaAs MOS-PHEMT using LPD-TiO2 exhibited larger gate bias operation, higher breakdown voltage, suppressed subthreshold characteristics, and reduced flicker noise. As a result, the device with proposed process and using LPD-TiO2 as a gate dielectric is promising for high-speed applications that demand little noise at low frequencies.

  11. [Electromagnetic radiation of non-thermal intensity and short exposition as a sub-threshold irritant for the central nervous system].

    Science.gov (United States)

    Luk'ianova, S N

    2013-01-01

    This work represents generalization and the analysis of the long-term own materials characterizing reaction of the brain on electromagnetic radiation of low intensity (energy flow density in the continuous regime or in the impulse approximately 500 microW/sm2) and a short exposition (approximately 30 min). A set of the experimental results received on separate neurons, formations and brain as a whole give an idea about the reaction of the central nervous system to the studied influence. Comparison of these data with the corresponding responses to the known incentives (light, sound, electric current) testifies to the electromagnetic radiation of low energy flow density and a short exposition as a sub-threshold irritant for the central nervous system.

  12. Oscillating shells and oscillating balls in AdS

    Science.gov (United States)

    Banerjee, Avik; Kundu, Arnab; Roy, Pratik; Virmani, Amitabh

    2017-07-01

    It has recently been reported that certain thin timelike shells undergo oscillatory motion in AdS. In this paper, we compute two-point function of a probe field in the geodesic approximation in such an oscillating shell background. We confirm that the two-point function exhibits an oscillatory behaviour following the motion of the shell. We show that similar oscillatory dynamics is possible when the perfect fluid on the shell has a polytropic equation of state. Moreover, we show that certain ball like configurations in AdS also exhibit oscillatory motion and comment on how such a solution can be smoothly matched to an appropriate exterior solution. We also demonstrate that the weak energy condition is satisfied for these oscillatory configurations.

  13. Oscillations of Difference Equations with Several Oscillating Coefficients

    Directory of Open Access Journals (Sweden)

    L. Berezansky

    2014-01-01

    Full Text Available We study the oscillatory behavior of the solutions of the difference equation Δx(n+∑i=1mpi(nx(τi(n=0,n∈N0[∇xn-∑i=1mpinxσin=0, n∈N] where (pi(n, 1≤i≤m are real sequences with oscillating terms, τi(n[σi(n], 1≤i≤m are general retarded (advanced arguments, and Δ[∇] denotes the forward (backward difference operator Δx(n=x(n+1-x(n[∇x(n=x(n-x(n-1]. Examples illustrating the results are also given.

  14. Systematic Review of Clinical Practice Guidelines for Failed Antidepressant Treatment Response in Major Depressive Disorder, Dysthymia, and Subthreshold Depression in Adults.

    Science.gov (United States)

    MacQueen, Glenda; Santaguida, Pasqualina; Keshavarz, Homa; Jaworska, Natalia; Levine, Mitchell; Beyene, Joseph; Raina, Parminder

    2017-01-01

    This systematic review critically evaluated clinical practice guidelines (CPGs) for treating adults with major depressive disorder, dysthymia, or subthreshold or minor depression for recommendations following inadequate response to first-line treatment with selective serotonin reuptake inhibitors (SSRIs). Searches for CPGs (January 2004 to November 2014) in English included 7 bibliographic databases and grey literature sources using CPG and depression as the keywords. Two raters selected CPGs on depression with a national scope. Data extraction included definitions of adequate response and recommended treatment options. Two raters assessed quality using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument. From 46,908 citations, 3167 were screened at full text. From these 21 CPG were applicable to adults in primary care and outpatient settings. Five CPGs consider patients with dysthymia or subthreshold or minor depression. None provides recommendations for those who do not respond to first-line SSRI treatment. For adults with MDD, most CPGs do not define an "inadequate response" or provide specific suggestions regarding how to choose alternative medications when switching to an alternative antidepressant. There is variability between CPGs in recommending combination strategies. AGREE II ratings for stakeholder involvement in CPG development, editorial independence, and rigor of development are domains in which depression guidelines are often less robust. About half of patients with depression require second-line treatment to achieve remission. Consistency and clarity in guidelines for second-line treatment of depression are therefore important for clinicians but lacking in most current guidelines. This may reflect a paucity of primary studies upon which to base conclusions.

  15. Treatment response in relation to subthreshold bipolarity in patients with major depressive disorder receiving antidepressant monotherapy: a post hoc data analysis (KOMDD study).

    Science.gov (United States)

    Park, Young-Min; Lee, Bun-Hee

    2016-01-01

    The aim of this observational study was to determine whether subthreshold bipolarity affects treatment response and remission in patients with major depressive disorder receiving antidepressant (AD) monotherapy over a 6-month follow-up period. Seventy-eight patients with major depressive disorder were stratified into two subgroups according to the presence of subthreshold bipolarity, identified using the Korean version of the Mood Disorder Questionnaire (K-MDQ), which classifies patients as positive for a screening of bipolarity based on the cutoff for the total K-MDQ score (ie, 7 points). They received AD monotherapy such as escitalopram, sertraline, paroxetine, or tianeptine for 6 months. The Beck Depression Inventory (BDI), Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Scale, and Beck Scale for Suicide Ideation were applied at baseline, 1 week, 3 weeks, 2 months, 3 months, and 6 months. The mean HAMD, BDI, and Beck Scale for Suicide Ideation scores were higher in the bipolarity group than in the nonbipolarity group at 3 weeks. The mean BDI score was also higher in the bipolarity group than in the nonbipolarity group at 6 months. Evaluation of the ratio of improvement for each scale revealed different patterns of percentage changes between the two groups over the 6-month follow-up period. Furthermore, the response and remission rates (as assessed using BDI and HAMD scores) were higher in the nonbipolarity group than in the bipolarity group, with the exception of HAMD scores at the 3-week follow-up time point. The findings of this study showed that depressed patients with bipolarity had a worse response to AD monotherapy than did those without bipolarity.

  16. Augmentation with citalopram for suicidal ideation in middle-aged and older outpatients with schizophrenia and schizoaffective disorder who have subthreshold depressive symptoms: a randomized controlled trial.

    Science.gov (United States)

    Zisook, Sidney; Kasckow, John W; Lanouette, Nicole M; Golshan, Shahrokh; Fellows, Ian; Vahia, Ipsit; Mohamed, Somaia; Rao, Sanjai

    2010-07-01

    To examine the effects of citalopram augmentation of antipsychotics on suicidal ideation in middle-aged and older people with schizophrenia and subthreshold depressive symptoms. In this placebo-controlled trial conducted from September 1, 2001, to August 31, 2007, 198 outpatients > or = 40 years old with DSM-IV-diagnosed schizophrenia or schizoaffective disorder and subthreshold depressive symptoms were randomly assigned to flexible-dose citalopram (n = 104) or placebo (n = 94) augmentation of their antipsychotic for 12 weeks. Depression was measured with the Hamilton Depression Rating Scale (HDRS) and Calgary Depression Rating Scale (CDRS). Primary suicidal ideation measures were the Clinical Global Impressions-Severity of Suicide scale (CGI-SS) and the InterSePT Scale for Suicidal Thinking (ISST); secondary outcomes were the Scale for Suicidal Ideation (SSI), Beck Hopelessness Scale (BHS), HDRS item 3, and CDRS item 8. Compared to placebo, at the final visit, citalopram was associated with lower BHS scores (4.21 vs 4.98; P suicidal ideation on the ISST (17.7% vs 38.7%; P suicidal ideation, there were no significant differences between citalopram and placebo regarding "emergent" ideation on either primary outcome. Among the 55 participants with baseline suicidal ideation, fewer treated with citalopram had endpoint ideation on the ISST (28.6% vs 66.7%; P suicidal ideation to no suicidal ideation on both the ISST (75.0% vs 31.4%; P suicidal ideation was no more common with citalopram than placebo. In participants with baseline suicidal ideation, citalopram reduced suicidal ideation, especially in those whose depressive symptoms responded to treatment. (c) Copyright 2010 Physicians Postgraduate Press, Inc.

  17. Quantum synchronization effects in intrinsic Josephson junctions

    International Nuclear Information System (INIS)

    Machida, M.; Kano, T.; Yamada, S.; Okumura, M.; Imamura, T.; Koyama, T.

    2008-01-01

    We investigate quantum dynamics of the superconducting phase in intrinsic Josephson junctions of layered high-T c superconductors motivated by a recent experimental observation for the switching rate enhancement in the low temperature quantum regime. We pay attention to only the capacitive coupling between neighboring junctions and perform large-scale simulations for the Schroedinger equation derived from the Hamiltonian considering the capacitive coupling alone. The simulation focuses on an issue whether the switching of a junction induces those of the other junctions or not. The results reveal that the superconducting phase dynamics show synchronous behavior with increasing the quantum character, e.g., decreasing the junction plane area and effectively the temperature. This is qualitatively consistent with the experimental result

  18. Intrinsic thermal expansion of crystal defects

    International Nuclear Information System (INIS)

    Ganne, J.-P.

    1981-02-01

    Although the phenomenon of thermal expansion has long been known, the intrinsic thermal expansion coefficient (ITEC) βsub(d) of a point defect, derived from its formation volume vsub(d), has never been measured directly. The differential dilatometer by interferometry built by ASTY and GILDER is described. It has allowed βsub(d) to be measured for several defects. Vacancies and small interstitial loops were produced in aluminium by low temperature (20 K) fast neutron irradiation followed by an anneal up to the beginning of stage III (160 K). The very high value of the measured ratio βsub(d)/β 0 (12+-4) is comparable with a lattice statics calculated (42) value (11.5 0 [fr

  19. Intrinsic topological superfluidity - fluctuations and response

    Science.gov (United States)

    Levin, K.; Wu, Chien-Te; Anderson, Brandon; Boyack, Rufus

    Recent interest in topological superconductivity is based primarily on exploiting proximity effects to obtain this important phase. However, in cold gases it is possible to contemplate ``intrinsic'' topological superfluidity produced with a synthetic spin-orbit coupling and Zeeman field. It is important for such future experiments to establish how low in temperature one needs to go to reach the ordered phase. Similarly, it will be helpful to have a probe of the normal (pseudogap) phase to determine if the ultimate superfluid order will be topological or trivial. In this talk, we address these issues by considering fluctuation effects in such a superfluid, and calculate the critical transition temperature and response functions. We see qualitative signatures of topological superfluidity in spin and charge response functions. We also explore the suppression of superfluidity due to fluctuations, and importantly find that the temperature scales necessary to reach topological superfluidity are reasonably accessible

  20. Major Intrinsic Proteins in Biomimetic Membranes

    DEFF Research Database (Denmark)

    Helix Nielsen, Claus

    2010-01-01

    will generally have finite permeabilities to both electrolytes and non-electrolytes. The feasibility of a biomimetic MIP device thus depends on the relative transport contribution from both protein and biomimetic support matrix. Also the biomimetic matrix must be encapsulated in order to protect it and make....../separation technology, a unique class of membrane transport proteins is especially interesting the major intrinsic proteins (MIPs). Generally, MIPs conduct water molecules and selected solutes in and out of the cell while preventing the passage of other solutes, a property critical for the conservation of the cells...... it sufficiently stable in a final application. Here, I specifically discuss the feasibility of developing osmotic biomimetic MIP membranes, but the technical issues are of general concern in the design of biomimetic membranes capable of supporting selective transmembrane fluxes....

  1. Intrinsic densitometry: In-plant evaluation

    International Nuclear Information System (INIS)

    Nishida, K.; Kurosawa, A.; Masui, J.; Hsue, S.T.

    1994-11-01

    A measurement of the plutonium concentration in a sample is always necessary for nuclear material control and accounting. This report describes the testing of the intrinsic densitometry (ID) technique for implant applications. The authors found that the ID method can determine the plutonium concentrations to between 2 and 3% at concentrations of 100 g/l to 200 g/l with quartz cells and a measurement time of 3600 s. The precision can be improved to 1 to 2% with a higher counting rate. The authors also found that nitric acid concentration and the impurity level of uranium in the product plutonium solution do not affect the concentration measurement. When this technique is applied to plutonium solutions in stainless steel pipes, they found that similar precision in plutonium concentration can be achieved using a high-count-rate detector. The precision, however, is reduced with aged plutonium solutions

  2. On the intrinsic colours of cepheids

    International Nuclear Information System (INIS)

    Efremov, Yu.N.

    1979-01-01

    Some consequences from new data on the photometrically obtained intrinsic colours are considered. It is shown that the small amplitude and almost sinusoidal light-curve cepheids (Cs-subtype) increase their pulsation amplitude towards the red instability strip edge, differing from the other galactic cepheids. This feature is discussed in connection with Efremov's (1968) hypothesis that the Cs-cepheids first cross the instability strip from left to right. The galactic cepheid period-colour relation obtained by Dean, Warren and Cousins (1978) satisfies rather well the LMC cepheid observations and, consequently, considerations for the period-luminosity relations are made. The residuals from the PL relation proposed by us correlate with the colour residuals from the DWC period-colour relation ΔV/delta(B-V) being equal to 2.7. The luminosity effect as a possible cause of the discrepancy between the spectroscopic cepheid colours and the photometric colours is briefly discussed. (Auth.)

  3. Intrinsic Dynamics of Quantum-Dash Lasers

    KAUST Repository

    Chen, Cheng

    2011-10-01

    Temperature-dependent intrinsic modulation response of InAs/InAlGaAs quantum-dash lasers was investigated by using pulse optical injection modulation to minimize the effects of parasitics and self-heating. Compared to typical quantum-well lasers, the quantum-dash lasers were found to have comparable differential gain but approximately twice the gain compression factor, probably due to carrier heating by free-carrier absorption, as opposed to stimulated transition. Therefore, the narrower modulation bandwidth of the quantum-dash lasers than that of quantum-well lasers was attributed to their higher gain compression factor. In addition, as expected, quantum-dash lasers with relatively long and uniform dashes exhibit higher temperature stability than quantum-well lasers. However, the lasers with relatively short and nonuniform dashes exhibit stronger temperature dependence, probably due to their higher surface-to-volume ratio and nonuniform dash sizes. © 2011 IEEE.

  4. Intrinsic thermoelectric power of group VB metals

    Directory of Open Access Journals (Sweden)

    Gunadhor Singh Okram

    2012-03-01

    Full Text Available We have reinvestigated the thermopower of group VB metals in polycrystalline forms in the temperature range of 6-300K, taking into account the critical nature of the sample surface and heat treatment especially for niobium. Strikingly small magnitude, negative sign, phonon drag dip and superconductivity not reported previously were observed in surface-cleaned single crystalline Nb. However, while thermopower magnitudes are small, mixed signs were found in the polycrystalline V, Nb and Ta samples. These properties were therefore interpreted as their intrinsic properties and were briefly discussed taking into account of the existing theory by fitting also the data that give the Fermi energies of 10.94 eV, 5.08 eV and 1.86eV, respectively.

  5. Computer Simulations of Intrinsically Disordered Proteins

    Science.gov (United States)

    Chong, Song-Ho; Chatterjee, Prathit; Ham, Sihyun

    2017-05-01

    The investigation of intrinsically disordered proteins (IDPs) is a new frontier in structural and molecular biology that requires a new paradigm to connect structural disorder to function. Molecular dynamics simulations and statistical thermodynamics potentially offer ideal tools for atomic-level characterizations and thermodynamic descriptions of this fascinating class of proteins that will complement experimental studies. However, IDPs display sensitivity to inaccuracies in the underlying molecular mechanics force fields. Thus, achieving an accurate structural characterization of IDPs via simulations is a challenge. It is also daunting to perform a configuration-space integration over heterogeneous structural ensembles sampled by IDPs to extract, in particular, protein configurational entropy. In this review, we summarize recent efforts devoted to the development of force fields and the critical evaluations of their performance when applied to IDPs. We also survey recent advances in computational methods for protein configurational entropy that aim to provide a thermodynamic link between structural disorder and protein activity.

  6. Intrinsic Ambipolarity and Rotation in Stellarators

    International Nuclear Information System (INIS)

    Helander, P.; Simakov, A. N.

    2008-01-01

    It is shown that collisional plasma transport is intrinsically ambipolar only in quasiaxisymmetric or quasihelically symmetric magnetic configurations. Only in such fields can the plasma rotate freely, and then only in the direction of quasisymmetry. In a non-quasi-symmetric magnetic field, the average radial electric field is determined by parallel viscosity, which in turn is usually governed by collisional processes. Locally, the radial electric field may be affected by turbulent Reynolds stress producing zonal flows, but on a radial average taken over several ion gyroradii, it is determined by parallel viscosity, at least if the turbulence is electrostatic and obeys the conventional gyrokinetic orderings. This differs from the situation in a tokamak, where there is no flow damping by parallel viscosity in the symmetry direction and the turbulent Reynolds stress may affect the global radial electric field

  7. IMPACT OF BARYONIC PHYSICS ON INTRINSIC ALIGNMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Tenneti, Ananth; Gnedin, Nickolay Y. [Particle Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Feng, Yu, E-mail: vat@andrew.cmu.edu [Berkeley Center for Cosmological Physics, Department of Physics, University of California Berkeley, Berkeley, CA 94720 (United States)

    2017-01-10

    We explore the effects of specific assumptions in the subgrid models of star formation and stellar and active galactic nucleus feedback on intrinsic alignments of galaxies in cosmological simulations of the “MassiveBlack-II” family. Using smaller-volume simulations, we explore the parameter space of the subgrid star formation and feedback model and find remarkable robustness of the observable statistical measures to the details of subgrid physics. The one observational probe most sensitive to modeling details is the distribution of misalignment angles. We hypothesize that the amount of angular momentum carried away by the galactic wind is the primary physical quantity that controls the orientation of the stellar distribution. Our results are also consistent with a similar study by the EAGLE simulation team.

  8. The importance of being top-heavy: Intrinsic stability of flapping flight

    Science.gov (United States)

    Ristroph, Leif; Liu, Bin; Zhang, Jun

    2011-11-01

    We explore the stability of flapping flight in a model system that consists of a pyramid-shaped object that freely hovers in a vertically oscillating airflow. Such a ``bug'' not only generates sufficient aerodynamic force to keep aloft but also robustly maintains balance during free-flight. Flow visualization reveals that both weight support and intrinsic stability result from the periodic shedding of dipolar vortices. Counter-intuitively, the observed pattern of vortex shedding suggests that stability requires a high center-of-mass, which we verify by comparing the performance of top- and bottom-heavy bugs. Finally, we visit a zoo of other flapping flyers, including Mary Poppins' umbrella, a flying saucer or UFO, and Da Vinci's helicopter.

  9. Personality traits associated with intrinsic academic motivation in medical students.

    Science.gov (United States)

    Tanaka, Masaaki; Mizuno, Kei; Fukuda, Sanae; Tajima, Seiki; Watanabe, Yasuyoshi

    2009-04-01

    Motivation is one of the most important psychological concepts in education and is related to academic outcomes in medical students. In this study, the relationships between personality traits and intrinsic academic motivation were examined in medical students. The study group consisted of 119 Year 2 medical students at Osaka City University Graduate School of Medicine. They completed questionnaires dealing with intrinsic academic motivation (the Intrinsic Motivation Scale toward Learning) and personality (the Temperament and Character Inventory [TCI]). On simple regression analyses, the TCI dimensions of persistence, self-directedness, co-operativeness and self-transcendence were positively associated with intrinsic academic motivation. On multiple regression analysis adjusted for age and gender, the TCI dimensions of persistence, self-directedness and self-transcendence were positively associated with intrinsic academic motivation. The temperament dimension of persistence and the character dimensions of self-directedness and self-transcendence are associated with intrinsic academic motivation in medical students.

  10. Phenomenology of coupled nonlinear oscillators

    Science.gov (United States)

    Estevez-Rams, E.; Estevez-Moya, D.; Aragón-Fernández, B.

    2018-02-01

    A recently introduced model of coupled nonlinear oscillators in a ring is revisited in terms of its information processing capabilities. The use of Lempel-Ziv based entropic measures allows to study thoroughly the complex patterns appearing in the system for different values of the control parameters. Such behaviors, resembling cellular automata, have been characterized both spatially and temporally. Information distance is used to study the stability of the system to perturbations in the initial conditions and in the control parameters. The latter is not an issue in cellular automata theory, where the rules form a numerable set, contrary to the continuous nature of the parameter space in the system studied in this contribution. The variation in the density of the digits, as a function of time is also studied. Local transitions in the control parameter space are also discussed.

  11. Optimal oscillation-center transformations

    International Nuclear Information System (INIS)

    Dewar, R.L.

    1984-08-01

    A variational principle is proposed for defining that canonical transformation, continuously connected with the identity transformation, which minimizes the residual, coordinate-dependent part of the new Hamiltonian. The principle is based on minimization of the mean-square generalized force. The transformation reduces to the action-angle transformation in that part of the phase space of an integrable system where the orbit topology is that of the unperturbed system, or on primary KAM surfaces. General arguments in favor of this definition are given, based on Galilean invariance, decay of the Fourier spectrum, and its ability to include external fields or inhomogeneous systems. The optimal oscillation-center transformation for the physical pendulum, or particle in a sinusoidal potential, is constructed

  12. Local hysteresis in relaxation oscillators

    International Nuclear Information System (INIS)

    Alstroem, P.; Christiansen, B.; Levinsen, M.T.

    1988-01-01

    Relaxation oscillations or 'integrate and fire' phenomena are very commonly found in nature. When modulated by an external force a global hysteresis connected with chaos is often encountered. Besides this kind of hysteresis a local form is found in some systems. We describe briefly the difference and the circumstances under which to observe local hysteresis. A specific system treated in detail is the Fohlmeister model, originally derived to describe a neuronal encoder. In the limit of small damping an analytical solution is obtained. Furthermore, we derive an upper limit to the hysteresis. The results are compared to numerical calculations on the full system and agree quite well. In contrast to e.g. the driven damped pendulum equation the hysteresis is limited in size as compared to the phase-locked region. (orig.)

  13. Oscillating spin-2 dark matter

    Science.gov (United States)

    Marzola, Luca; Raidal, Martti; Urban, Federico R.

    2018-01-01

    The negative outcomes of laboratory searches, juxtaposed with cosmological observations, may indicate that dark matter has a gravitational origin. We show that coherent oscillations of a massive spin-2 field emerging from bimetric theory can easily account for the observed dark matter abundance. The framework, based on the only known consistent extension of general relativity to interacting spin-2 fields, is testable in precision measurements of the electric charge variation by means of atomic clocks, molecular systems, dedicated resonant mass detectors, as well as gravity interferometers and axionlike-particle experiments. These searches, therefore, provide a new window into the phenomenology of gravity which complements the results of dedicated tests of gravitation. We also present a multimetric extension of the scenario that straightforwardly implements the clockwork mechanism for gravity, explaining the apparent weakness of this force.

  14. Quantum wormholes and harmonic oscillators

    Science.gov (United States)

    Garay, Luis J.

    1993-01-01

    The quantum state of a wormhole can be represented by a path integral over all asymptotically Euclidean four-geometries and all matter fields which have prescribed values, the arguments of the wave function, on a three-surface which divides the space time manifold into two disconnected parts. Minisuperspace models which consist of a homogeneous massless scalar field coupled to a Friedmann-Robertson-Walker space time are considered. Once the path integral over the lapse function is performed, the requirement that the space time be asymptotically Euclidean can be accomplished by fixing the asymptotic gravitational momentum in the remaining path integral. It is argued that there does not exist any wave function which corresponds to asymptotic field configurations such that the effective gravitational constant is negative in the asymptotic region. Then, the wormhole wave functions can be written as linear combinations of harmonic oscillator wave functions.

  15. Oscillating water column structural model

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, Guild [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bull, Diana L [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jepsen, Richard Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gordon, Margaret Ellen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    An oscillating water column (OWC) wave energy converter is a structure with an opening to the ocean below the free surface, i.e. a structure with a moonpool. Two structural models for a non-axisymmetric terminator design OWC, the Backward Bent Duct Buoy (BBDB) are discussed in this report. The results of this structural model design study are intended to inform experiments and modeling underway in support of the U.S. Department of Energy (DOE) initiated Reference Model Project (RMP). A detailed design developed by Re Vision Consulting used stiffeners and girders to stabilize the structure against the hydrostatic loads experienced by a BBDB device. Additional support plates were added to this structure to account for loads arising from the mooring line attachment points. A simplified structure was designed in a modular fashion. This simplified design allows easy alterations to the buoyancy chambers and uncomplicated analysis of resulting changes in buoyancy.

  16. Investigating Power Density and the Degree of Nonlinearity in Intrinsic Components of Anesthesia EEG by the Hilbert-Huang Transform: An Example Using Ketamine and Alfentanil.

    Directory of Open Access Journals (Sweden)

    Feng-Fang Tsai

    Full Text Available Empirical mode decomposition (EMD is an adaptive filter bank for processing nonlinear and non-stationary signals, such as electroencephalographic (EEG signals. EMD works well to decompose a time series into a set of intrinsic mode functions with specific frequency bands. An IMF therefore represents an intrinsic component on its correspondingly intrinsic frequency band. The word of 'intrinsic' means the frequency is totally adaptive to the nature of a signal. In this study, power density and nonlinearity are two critical parameters for characterizing the amplitude and frequency modulations in IMFs. In this study, a nonlinearity level is quantified using degree of waveform distortion (DWD, which represents the characteristic of waveform distortion as an assessment of the intra-wave modulation of an IMF. In the application of anesthesia EEG analysis, the assessments of power density and DWD for a set of IMFs represent dynamic responses in EEG caused by two different anesthesia agents, Ketamine and Alfentanil, on different frequency bands. Ketamine causes the increase of power density and the decrease of nonlinearity on γ-band neuronal oscillation, which cannot be found EEG responses of group B using Alfentanil. Both agents cause an increase of power density and a decrease of nonlinearity on β-band neuronal oscillation accompany with a loss of consciousness. Moreover, anesthesia agents cause the decreases of power density and nonlinearity (i.e. DWD for the low-frequency IMFs.

  17. Oscillating and rotating sine-Gordon system

    DEFF Research Database (Denmark)

    Olsen, O. H.; Samuelsen, Mogens Rugholm

    1986-01-01

    The interaction between a 2π kink and the background or vacuum is investigated in the pure sine-Gordon system. For an oscillating background (i.e., the k=0 part of the phonon spectrum) the 2π kink oscillates, while for increasing or decreasing vacuum two phenomena have been observed, depending on...... to a Mathieu equation explaining the excitation....

  18. Phase Multistability in Coupled Oscillator Systems

    DEFF Research Database (Denmark)

    Mosekilde, Erik; Postnov, D.E.; Sosnovtseva, Olga

    2003-01-01

    along the orbit of the individual oscillator. Focusing on the mechanisms underlying the appearance of phase multistability, the paper examines a variety of phase-locked patterns. In particular we demonstrate the nested structure of synchronization regions for oscillations with multicrest wave forms...

  19. Synchronization of oscillators in complex networks

    Indian Academy of Sciences (India)

    https://www.ias.ac.in/article/fulltext/pram/070/06/1175-1198 ... Abstract. Theory of identical or complete synchronization of identical oscillators in arbitrary networks is introduced. ... Combined theories are used to explore and compare three types of semirandom networks for their efficacy in synchronizing oscillators.

  20. Oscillating systems with cointegrated phase processes

    DEFF Research Database (Denmark)

    Østergaard, Jacob; Rahbek, Anders; Ditlevsen, Susanne

    2017-01-01

    We present cointegration analysis as a method to infer the network structure of a linearly phase coupled oscillating system. By defining a class of oscillating systems with interacting phases, we derive a data generating process where we can specify the coupling structure of a network that resemb...

  1. Electromagnetic Radiation Originating from Unstable Electron Oscillations

    DEFF Research Database (Denmark)

    Juul Rasmussen, Jens; Pécseli, Hans

    1975-01-01

    Electromagnetic oscillations in the range 300 – 700 MHz were observed from an unmagnetized argon discharge with an unstable electron velocity distribution function.......Electromagnetic oscillations in the range 300 – 700 MHz were observed from an unmagnetized argon discharge with an unstable electron velocity distribution function....

  2. Discontinuous Spirals of Stable Periodic Oscillations

    DEFF Research Database (Denmark)

    Sack, Achim; Freire, Joana G.; Lindberg, Erik

    2013-01-01

    We report the experimental discovery of a remarkable organization of the set of self-generated periodic oscillations in the parameter space of a nonlinear electronic circuit. When control parameters are suitably tuned, the wave pattern complexity of the periodic oscillations is found to increase...

  3. Lambda Oscillations and the Conservation Laws

    OpenAIRE

    Widom, A.; Srivastava, Y. N.

    1996-01-01

    Lowe, Bassalleck, Burkhardt, Rusek, Stephenson, and Goldman assert, under the assumption of decays at fixed space-time points, that Kaon induced Lambda oscillations disappear. We find, under the same assumption, that energy conservation and momentum conservation also disappear. Ordinary particles can exhibit quantum oscillations.

  4. Mass and oscillations of Dirac neutrinos

    International Nuclear Information System (INIS)

    Collot, J.

    1989-01-01

    In the most economical extension of the standard model, we have presented the theory of massive Dirac neutrinos. We have particularly emphasized that, in this model, a complete analogy between quarks and leptons can be erected and predicts neutrino flavor oscillations. We have reviewed the last experimental results concerning kinetic neutrino mass experiments and neutrino oscillation investigations

  5. Accelerator-based neutrino oscillation searches

    International Nuclear Information System (INIS)

    Whitehouse, D.; Rameika, G.

    1993-01-01

    This paper attempts to summarize the neutrino oscillation section of the Workshop on Future Directions in Particle and Nuclear Physics at Multi-GeV Hadron Beam Facilities. There were very lively discussions about the merits of the different oscillation channels, experiments, and facilities, but the authors believe a substantial consensus emerged

  6. Compensation of oscillation coupling induced by solenoids

    International Nuclear Information System (INIS)

    Zelinskij, A.Yu.; Karnaukhov, I.M.; Shcherbakov, A.A.

    1988-01-01

    Methods for construction of various schemes of oscillation coupling compensation, induced by solenoids in charged particle storage rings, are described. Peculiarities of magnetic structure, enabling to localize oscillation coupling in wide energy range are discussed. Results of calculation of compensation schemes for design of NR-2000 storage ring spin rotation are presented

  7. Natural oscillation frequencies for arbitrary piping systems

    International Nuclear Information System (INIS)

    Gale, J.; Tiselj, I.

    2007-01-01

    This paper concerns axial and lateral oscillations and oscillation frequencies of various empty (natural frequency of oscillation) and fluid filled (forced oscillation) piping systems. Forced oscillations of fluid filled piping systems and corresponding exchange of energy are denominated also Fluid-Structure-Interaction (FSI). Oscillations appear due to various external or internal impacts and are successfully described with eight-equation physical model for simulations of FSI during fast transients. The physical model is solved with characteristic upwind numerical method and is compiled into a computer code. Simulations were compared to the analytical solutions or solutions from the literature whenever was possible. Discussion on results and problems encountered is given. The proposed physical model gives accurate results, and it enables evaluation of natural frequency of arbitrarily loaded, arbitrarily shaped and arbitrarily supported piping systems. Piping systems are rarely empty, thus forced oscillations due to FSI effects were observed and simulated. Application of various fluids pointed out importance of the fluid's compressibility on pipe's axial oscillations. (author)

  8. Phase locking between Josephson soliton oscillators

    DEFF Research Database (Denmark)

    Holst, T.; Hansen, Jørn Bindslev; Grønbech-Jensen, N.

    1990-01-01

    We report observations of phase-locking phenomena between two Josephson soliton (fluxon) oscillators biased in self-resonant modes. The locking strength was measured as a function of bias conditions. A frequency tunability of the phase-locked oscillators up to 7% at 10 GHz was observed. Two coupled...

  9. The 2D κ-Dirac oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Fabiano M., E-mail: fmandrade@uepg.br [Departamento de Matemática e Estatística, Universidade Estadual de Ponta Grossa, 84030-900 Ponta Grossa-PR (Brazil); Silva, Edilberto O., E-mail: edilbertoo@gmail.com [Departamento de Física, Universidade Federal do Maranhão, Campus Universitário do Bacanga, 65085-580 São Luís-MA (Brazil)

    2014-11-10

    In this Letter, 2D Dirac oscillator in the quantum deformed framework generated by the κ-Poincaré–Hopf algebra is considered. The problem is formulated using the κ-deformed Dirac equation. The resulting theory reveals that the energies and wave functions of the oscillator are modified by the deformation parameter.

  10. TRANSVERSE OSCILLATIONS OF SYSTEMS OF CORONAL LOOPS

    International Nuclear Information System (INIS)

    Luna, M.; Oliver, R.; Ballester, J. L.; Terradas, J.

    2009-01-01

    We study the collective kinklike normal modes of a system of several cylindrical loops using the T-matrix theory. Loops that have similar kink frequencies oscillate collectively with a frequency which is slightly different from that of the individual kink mode. On the other hand, if the kink frequency of a loop is different from that of the others, it oscillates individually with its own frequency. Since the individual kink frequency depends on the loop density but not on its radius for typical 1 MK coronal loops, a coupling between kink oscillations of neighboring loops takes place when they have similar densities. The relevance of these results in the interpretation of the oscillations studied by Schrijver and Brown in 2000 and Verwichte et al. in 2004, in which transverse collective loop oscillations seem to be detected, is discussed. In the first case, two loops oscillating in antiphase are observed; interpreting this motion as a collective kink mode suggests that their densities are roughly equal. In the second case, there are almost three groups of tubes that oscillate with similar periods, and therefore their dynamics can be collective, which again seems to indicate that the loops of each group share a similar density. All the other loops seem to oscillate individually and their densities can be different from the rest.

  11. Neutrino oscillations: Present status and outlook

    Indian Academy of Sciences (India)

    Abstract. The status of neutrino oscillations from global data is summarized, with the focus on the three-flavour picture. The status of sterile neutrino oscillation interpretations of the LSND anomaly in the light of recent MiniBooNE results is also discussed. Further- more, an outlook on the measurement of the mixing angle θ13 ...

  12. Parametric resonance in neutrino oscillations in matter

    Indian Academy of Sciences (India)

    Neutrino oscillations in matter can exhibit a specific resonance enhancement - parametric resonance, which is different from the MSW resonance. Oscillations of atmospheric and solar neutrinos inside the earth can undergo parametric enhancement when neutrino trajectories cross the core of the earth. In this paper we ...

  13. Autonomous Duffing-Holmes Type Chaotic Oscillator

    DEFF Research Database (Denmark)

    Tamaševičius, A.; Bumelienė, S.; Kirvaitis, R.

    2009-01-01

    We have designed and built a novel Duffing type autonomous 3rd-order chaotic oscillator. In comparison with the common non-autonomous DuffingHolmes type oscillator the autonomous circuit has an internal positive feedback loop instead of an external periodic drive source. In addition...

  14. Effective harmonic oscillator description of anharmonic molecular ...

    Indian Academy of Sciences (India)

    ... a harmonic oscillator eigenfunction with the centroid and width parameter as variational paraeters. It is found that the effective harmonic oscillator approximation provides a description of the anharmonic eigenstates very similar to the vibrational self consistent field results. Coriolis coupling is also included in these studies.

  15. Experiments with elasto-plastic oscillator

    DEFF Research Database (Denmark)

    Randrup-Thomsen, S.; Ditlevsen, Ove Dalager

    1999-01-01

    Plastic displacements of a Gaussian white noise excited three degrees of freedom non-ideal elasto-plastic oscillator are measured in laboratory experiments and the plastic displacements are compared to computer simulated results for the corresponding ideal elasto-plastic oscillator. The comparative...

  16. Experiments with elasto-plastic oscillator

    DEFF Research Database (Denmark)

    Randrup-thomsen, Søren; Ditlevsen, Ove Dalager

    1996-01-01

    Plastic displacements of a Gaussian white noise excited three degrees of freedom non-ideal elasto-plastic oscillator are measured in laboratory experiments and the plastic displacements are compared to computer simulated results for the corresponding ideal elasto-plastic oscillator. The comparative...

  17. Half-linear discrete oscillation theory

    Directory of Open Access Journals (Sweden)

    P. Rehak

    2000-01-01

    where $\\alpha>1$, are investigated. A particular attention is devoted to the connection with oscillation theory of its continuous counterpart, half--linear differential equation and also with the theory of linear differential and difference equations. We present not only the overview of the existing results but we also establish new oscillation and nonoscillation criteria.

  18. Vibrational resonance in the Morse oscillator

    Indian Academy of Sciences (India)

    Abstract. The occurrence of vibrational resonance is investigated in both classical and quantum mechanical Morse oscillators driven by a biharmonic force. The biharmonic force consists of two forces of widely different frequencies ω and with. ≫ ω. In the damped and biharmoni- cally driven classical Morse oscillator, ...

  19. Effective harmonic oscillator description of anharmonic molecular ...

    Indian Academy of Sciences (India)

    Administrator

    function as a harmonic oscillator eigenfunction with the centroid and width parameter as variational para- eters. It is found that the effective harmonic oscillator approximation provides a description of the anharmonic eigenstates very similar to the vibrational self consistent field results. Coriolis coupling is also included in ...

  20. Modeling diauxic glycolytic oscillations in yeast

    DEFF Research Database (Denmark)

    Hald, Bjørn Olav; Sørensen, Preben Graae

    2010-01-01

    Glycolytic oscillations in a stirred suspension of starved yeast cells is an excellent model system for studying the dynamics of metabolic switching in living systems. In an open-flow system the oscillations can be maintained indefinitely at a constant operating point where they can be characteri...