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Sample records for human theta class

  1. Molecular cloning of a cDNA and chromosomal localization of a human theta-class glutathione S-transferase gene (GSTT2) to chromosome 22

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    Tan, K.L.; Baker, R.T.; Board, P.G. [Australian National Univ., Canberra (Australia)] [and others

    1995-01-20

    Until recently the Theta-class glutathione S-transferases (GSTs) were largely overlooked due to their low activity with the model substrate 1-chloro-2,4-dinitrobenzene (CDNB) and their failure to bind to immobilized glutathione affinity matrices. Little is known about the number of genes in this class. Recently, Pemble et al. reported the cDNA cloning of a human Theta-class GST, termed GSTT1. In this study, we describe the molecular cloning of a cDNA encoding a second human Theta-class GST (GSTT2) from a {lambda}gt11 human liver 5{prime}-stretch cDNA library. The encoded protein contains 244 amino acids and has 78.3% sequence identity with the rat subunit 12 and only 55.0% identity with human GSTT1. GSTT2 has been mapped to chromosome 22 by somatic cell hybrid analysis. The precise position of the gene was localized to subband 22q11.2 by in situ hybridization. The absence of other regions of hybridization suggests that there are no closely related sequences (e.g., reverse transcribed pseudogenes) scattered throughout the genome and that if there are closely related genes, they must be clustered near GSTT2. Southern blot analysis of human DNA digested with BamHI shows that the size of the GSTT2 gene is relatively small, as the coding sequence falls within a 3.6-kb BamHI fragment. 35 refs., 6 figs.

  2. Traveling Theta Waves in the Human Hippocampus

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    Zhang, Honghui

    2015-01-01

    The hippocampal theta oscillation is strongly correlated with behaviors such as memory and spatial navigation, but we do not understand its specific functional role. One hint of theta's function came from the discovery in rodents that theta oscillations are traveling waves that allow parts of the hippocampus to simultaneously exhibit separate oscillatory phases. Because hippocampal theta oscillations in humans have different properties compared with rodents, we examined these signals directly using multielectrode recordings from neurosurgical patients. Our findings confirm that human hippocampal theta oscillations are traveling waves, but also show that these oscillations appear at a broader range of frequencies compared with rodents. Human traveling waves showed a distinctive pattern of spatial propagation such that there is a consistent phase spread across the hippocampus regardless of the oscillations' frequency. This suggests that traveling theta oscillations are important functionally in humans because they coordinate phase coding throughout the hippocampus in a consistent manner. SIGNIFICANCE STATEMENT We show for the first time in humans that hippocampal theta oscillations are traveling waves, moving along the length of the hippocampus in a posterior–anterior direction. The existence of these traveling theta waves is important for understanding hippocampal neural coding because they cause neurons at separate positions in the hippocampus to experience different theta phases simultaneously. The theta phase that a neuron measures is a key factor in how that cell represents behavioral information. Therefore, the existence of traveling theta waves indicates that, to fully understand how a hippocampal neuron represents information, it is vital to also account for that cell's location in addition to conventional measures of neural activity. PMID:26354915

  3. Pre-stimulus thalamic theta power predicts human memory formation.

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    Sweeney-Reed, Catherine M; Zaehle, Tino; Voges, Jürgen; Schmitt, Friedhelm C; Buentjen, Lars; Kopitzki, Klaus; Richardson-Klavehn, Alan; Hinrichs, Hermann; Heinze, Hans-Jochen; Knight, Robert T; Rugg, Michael D

    2016-09-01

    Pre-stimulus theta (4-8Hz) power in the hippocampus and neocortex predicts whether a memory for a subsequent event will be formed. Anatomical studies reveal thalamus-hippocampal connectivity, and lesion, neuroimaging, and electrophysiological studies show that memory processing involves the dorsomedial (DMTN) and anterior thalamic nuclei (ATN). The small size and deep location of these nuclei have limited real-time study of their activity, however, and it is unknown whether pre-stimulus theta power predictive of successful memory formation is also found in these subcortical structures. We recorded human electrophysiological data from the DMTN and ATN of 7 patients receiving deep brain stimulation for refractory epilepsy. We found that greater pre-stimulus theta power in the right DMTN was associated with successful memory encoding, predicting both behavioral outcome and post-stimulus correlates of successful memory formation. In particular, significant correlations were observed between right DMTN theta power and both frontal theta and right ATN gamma (32-50Hz) phase alignment, and frontal-ATN theta-gamma cross-frequency coupling. We draw the following primary conclusions. Our results provide direct electrophysiological evidence in humans of a role for the DMTN as well as the ATN in memory formation. Furthermore, prediction of subsequent memory performance by pre-stimulus thalamic oscillations provides evidence that post-stimulus differences in thalamic activity that index successful and unsuccessful encoding reflect brain processes specifically underpinning memory formation. Finally, the findings broaden the understanding of brain states that facilitate memory encoding to include subcortical as well as cortical structures. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Movement-related theta rhythm in humans: coordinating self-directed hippocampal learning.

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    Raphael Kaplan

    Full Text Available The hippocampus is crucial for episodic or declarative memory and the theta rhythm has been implicated in mnemonic processing, but the functional contribution of theta to memory remains the subject of intense speculation. Recent evidence suggests that the hippocampus might function as a network hub for volitional learning. In contrast to human experiments, electrophysiological recordings in the hippocampus of behaving rodents are dominated by theta oscillations reflecting volitional movement, which has been linked to spatial exploration and encoding. This literature makes the surprising cross-species prediction that the human hippocampal theta rhythm supports memory by coordinating exploratory movements in the service of self-directed learning. We examined the links between theta, spatial exploration, and memory encoding by designing an interactive human spatial navigation paradigm combined with multimodal neuroimaging. We used both non-invasive whole-head Magnetoencephalography (MEG to look at theta oscillations and Functional Magnetic Resonance Imaging (fMRI to look at brain regions associated with volitional movement and learning. We found that theta power increases during the self-initiation of virtual movement, additionally correlating with subsequent memory performance and environmental familiarity. Performance-related hippocampal theta increases were observed during a static pre-navigation retrieval phase, where planning for subsequent navigation occurred. Furthermore, periods of the task showing movement-related theta increases showed decreased fMRI activity in the parahippocampus and increased activity in the hippocampus and other brain regions that strikingly overlap with the previously observed volitional learning network (the reverse pattern was seen for stationary periods. These fMRI changes also correlated with participant's performance. Our findings suggest that the human hippocampal theta rhythm supports memory by coordinating

  5. Exponential mean-square stability of two classes of theta Milstein methods for stochastic delay differential equations

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    Rouz, Omid Farkhondeh; Ahmadian, Davood; Milev, Mariyan

    2017-12-01

    This paper establishes exponential mean square stability of two classes of theta Milstein methods, namely split-step theta Milstein (SSTM) method and stochastic theta Milstein (STM) method, for stochastic differential delay equations (SDDEs). We consider the SDDEs problem under a coupled monotone condition on drift and diffusion coefficients, as well as a necessary linear growth condition on the last term of theta Milstein method. It is proved that the SSTM method with θ ∈ [0, ½] can recover the exponential mean square stability of the exact solution with some restrictive conditions on stepsize, but for θ ∈ (½, 1], we proved that the stability results hold for any stepsize. Then, based on the stability results of SSTM method, we examine the exponential mean square stability of the STM method and obtain the similar stability results to that of the SSTM method. In the numerical section the figures show thevalidity of our claims.

  6. Glutathione-binding site of a bombyx mori theta-class glutathione transferase.

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    M D Tofazzal Hossain

    Full Text Available The glutathione transferase (GST superfamily plays key roles in the detoxification of various xenobiotics. Here, we report the isolation and characterization of a silkworm protein belonging to a previously reported theta-class GST family. The enzyme (bmGSTT catalyzes the reaction of glutathione with 1-chloro-2,4-dinitrobenzene, 1,2-epoxy-3-(4-nitrophenoxy-propane, and 4-nitrophenethyl bromide. Mutagenesis of highly conserved residues in the catalytic site revealed that Glu66 and Ser67 are important for enzymatic function. These results provide insights into the catalysis of glutathione conjugation in silkworm by bmGSTT and into the metabolism of exogenous chemical agents.

  7. Transient reduction in theta power caused by interictal spikes in human temporal lobe epilepsy.

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    Manling Ge; Jundan Guo; Yangyang Xing; Zhiguo Feng; Weide Lu; Xinxin Ma; Yuehua Geng; Xin Zhang

    2017-07-01

    The inhibitory impacts of spikes on LFP theta rhythms(4-8Hz) are investigated around sporadic spikes(SSs) based on intracerebral EEG of 4 REM sleep patients with temporal lobe epilepsy(TLE) under the pre-surgical monitoring. Sequential interictal spikes in both genesis area and extended propagation pathway are collected, that, SSs genesis only in anterior hippocampus(aH)(possible propagation pathway in Entorhinal cortex(EC)), only in EC(possible propagation pathway in aH), and in both aH and EC synchronously. Instantaneous theta power was estimated by using Gabor wavelet transform, and theta power level was estimated by averaged over time and frequency before SSs(350ms pre-spike) and after SSs(350ms post-spike). The inhibitory effect around spikes was evaluated by the ratio of theta power level difference between pre-spike and post-spike to pre-spike theta power level. The findings were that theta power level was reduced across SSs, and the effects were more sever in the case of SSs in both aH and EC synchronously than either SSs only in EC or SSs only in aH. It is concluded that interictal spikes impair LFP theta rhythms transiently and directly. The work suggests that the reduction of theta power after the interictal spike might be an evaluation indicator of damage of epilepsy to human cognitive rhythms.

  8. Independent delta/theta rhythms in the human hippocampus and entorhinal cortex

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    Florian Mormann

    2008-05-01

    Full Text Available Theta oscillations in the medial temporal lobe (MTL of mammals are involved in various functions such as spatial navigation, sensorimotor integration, and cognitive processing. While the theta rhythm was originally assumed to originate in the medial septum, more recent studies suggest autonomous theta generation in the MTL. Although coherence between entorhinal and hippocampal theta activity has been found to influence memory formation, it remains unclear whether these two structures can generate theta independently. In this study we analyzed intracranial electroencephalographic (EEG recordings from 22 patients with unilateral hippocampal sclerosis undergoing presurgical evaluation prior to resection of the epileptic focus. Using a wavelet-based, frequency-band-specific measure of phase synchronization, we quantified synchrony between 10 different recording sites along the longitudinal axis of the hippocampal formation in the non-epileptic brain hemisphere. We compared EEG synchrony between adjacent recording sites (i within the entorhinal cortex, (ii within the hippocampus, and (iii between the hippocampus and entorhinal cortex. We observed a significant interregional gap in synchrony for the delta and theta band, indicating the existence of independent delta/theta rhythms in different subregions of the human MTL. The interaction of these rhythms could represent the temporal basis for the information processing required for mnemonic encoding and retrieval.

  9. Theta Phase Synchronization Is the Glue that Binds Human Associative Memory.

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    Clouter, Andrew; Shapiro, Kimron L; Hanslmayr, Simon

    2017-10-23

    Episodic memories are information-rich, often multisensory events that rely on binding different elements [1]. The elements that will constitute a memory episode are processed in specialized but distinct brain modules. The binding of these elements is most likely mediated by fast-acting long-term potentiation (LTP), which relies on the precise timing of neural activity [2]. Theta oscillations in the hippocampus orchestrate such timing as demonstrated by animal studies in vitro [3, 4] and in vivo [5, 6], suggesting a causal role of theta activity for the formation of complex memory episodes, but direct evidence from humans is missing. Here, we show that human episodic memory formation depends on phase synchrony between different sensory cortices at the theta frequency. By modulating the luminance of visual stimuli and the amplitude of auditory stimuli, we directly manipulated the degree of phase synchrony between visual and auditory cortices. Memory for sound-movie associations was significantly better when the stimuli were presented in phase compared to out of phase. This effect was specific to theta (4 Hz) and did not occur in slower (1.7 Hz) or faster (10.5 Hz) frequencies. These findings provide the first direct evidence that episodic memory formation in humans relies on a theta-specific synchronization mechanism. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Theta oscillations at encoding mediate the context-dependent nature of human episodic memory.

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    Staudigl, Tobias; Hanslmayr, Simon

    2013-06-17

    Human episodic memory is highly context dependent. Therefore, retrieval benefits when a memory is recalled in the same context compared to a different context. This implies that items and contexts are bound together during encoding, such that the reinstatement of the initial context at test improves retrieval. Animal studies suggest that theta oscillations and theta-to-gamma cross-frequency coupling modulate such item-context binding, but direct evidence from humans is scarce. We investigated this issue by manipulating the overlap of contextual features between encoding and retrieval. Participants studied words superimposed on movie clips and were later tested by presenting the word with either the same or a different movie. The results show that memory performance and the oscillatory correlates of memory formation crucially depend on the overlap of the context between encoding and test. When the context matched, high theta power during encoding was related to successful recognition, whereas the opposite pattern emerged in the context-mismatch condition. In addition, cross-frequency coupling analysis revealed a context-dependent theta-to-gamma memory effect specifically in the left hippocampus. These results reveal for the first time that context-dependent episodic memory effects are mediated by theta oscillatory activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Genetic variability in the human cannabinoid receptor 1 is associated with resting state EEG theta power in humans.

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    Heitland, I; Kenemans, J L; Böcker, K B E; Baas, J M P

    2014-11-01

    It has long been postulated that exogenous cannabinoids have a profound effect on human cognitive functioning. These cannabinoid effects are thought to depend, at least in parts, on alterations of phase-locking of local field potential neuronal firing. The latter can be measured as activity in the theta frequency band (4-7Hz) by electroencephalogram. Theta oscillations are supposed to serve as a mechanism in neural representations of behaviorally relevant information. However, it remains unknown whether variability in endogenous cannabinoid activity is involved in theta rhythms and therefore, may serve as an individual differences index of human cognitive functioning. To clarify this issue, we recorded resting state EEG activity in 164 healthy human subjects and extracted EEG power across frequency bands (δ, θ, α, and β). To assess variability in the endocannabinoid system, two genetic polymorphisms (rs1049353, rs2180619) within the cannabinoid receptor 1 (CB1) were determined in all participants. As expected, we observed significant effects of rs1049353 on EEG power in the theta band at frontal, central and parietal electrode regions. Crucially, these effects were specific for the theta band, with no effects on activity in the other frequency bands. Rs2180619 showed no significant associations with theta power after Bonferroni correction. Taken together, we provide novel evidence in humans showing that genetic variability in the cannabinoid receptor 1 is associated with resting state EEG power in the theta frequency band. This extends prior findings of exogenous cannabinoid effects on theta power to the endogenous cannabinoid system. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. The effects of individualized theta burst stimulation on the excitability of the human motor system.

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    Brownjohn, Philip W; Reynolds, John N J; Matheson, Natalie; Fox, Jonathan; Shemmell, Jonathan B H

    2014-01-01

    Theta burst stimulation (TBS) is a pattern of repetitive transcranial magnetic stimulation that has been demonstrated to facilitate or suppress human corticospinal excitability when applied intermittently (iTBS) or continuously (cTBS), respectively. While the fundamental pattern of TBS, consisting of bursts of 50 Hz stimulation repeated at a 5 Hz theta frequency, induces synaptic plasticity in animals and in vitro preparations, the relationship between TBS and underlying cortical firing patterns in the human cortex has not been elucidated. To compare the effects of 5 Hz iTBS and cTBS with individualized TBS paradigms on corticospinal excitability and intracortical inhibitory circuits. Participants received standard and individualized iTBS (iTBS 5; iTBS I) and cTBS (cTBS 5; cTBS I), and sham TBS, in a randomised design. For individualized paradigms, the 5 Hz theta component of the TBS pattern was replaced by the dominant cortical frequency (4-16 Hz; upper frequency restricted by technical limitations) for each individual. We report that iTBS 5 and iTBS I both significantly facilitated motor evoked potential (MEP) amplitude to a similar extent. Unexpectedly, cTBS 5 and cTBS I failed to suppress MEP amplitude. None of the active TBS protocols had any significant effects on intracortical circuits when compared with sham TBS. In summary, iTBS facilitated MEP amplitude, an effect that was not improved by individualizing the theta component of the TBS pattern, while cTBS, a reportedly inhibitory paradigm, produced no change, or facilitation of MEP amplitude in our hands. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Molecular evolution of Theta-class glutathione transferase for enhanced activity with the anticancer drug 1,3-bis-(2-chloroethyl)-1-nitrosourea and other alkylating agents.

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    Larsson, Anna-Karin; Shokeer, Abeer; Mannervik, Bengt

    2010-05-01

    Glutathione transferase (GST) displaying enhanced activity with the cytostatic drug 1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU) and structurally related alkylating agents was obtained by molecular evolution. Mutant libraries created by recursive recombination of cDNA coding for human and rodent Theta-class GSTs were heterologously expressed in Escherichia coli and screened with the surrogate substrate 4-nitrophenethyl bromide (NPB) for enhanced alkyltransferase activity. A mutant with a 70-fold increased catalytic efficiency with NPB, compared to human GST T1-1, was isolated. The efficiency in degrading BCNU had improved 170-fold, significantly more than with the model substrate NPB. The enhanced catalytic activity of the mutant GST was also 2-fold higher with BCNU than wild-type mouse GST T1-1, which is 80-fold more efficient than wild-type human GST T1-1. We propose that GSTs catalyzing inactivation of anticancer drugs may find clinical use in protecting sensitive normal tissues to toxic side-effects in treated patients, and as selectable markers in gene therapy. Copyright 2010 Elsevier Inc. All rights reserved.

  14. Power of theta waves in the EEG of human subjects increases during recall of haptic information.

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    Grunwald, M; Weiss, T; Krause, W; Beyer, L; Rost, R; Gutberlet, I; Gertz, H J

    1999-02-05

    Several studies have reported a functional relationship between spectral power within the theta-band of the EEG (theta-power) and memory load while processing visual or semantic information. We investigated theta power during the processing of different complex haptic stimuli using a delayed recall design. The haptic explorations consisted of palpating the structure of twelve sunken reliefs with closed eyes. Subjects had to reproduce each relief by drawing it 10 s after the end of the exploration. The relationship between mean theta power and mean exploration time was analysed using a regression model. A linear relationship was found between the exploration time and theta power over fronto-central regions (Fp1, Fp2, F3, F7, F8, Fz, C3) directly before the recall of the relief. This result is interpreted in favour of the hypothesis that fronto-central theta power of the EEG correlates with the load of working memory independent of stimulus modality.

  15. Enhancing early consolidation of human episodic memory by theta EEG neurofeedback.

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    Rozengurt, Roman; Shtoots, Limor; Sheriff, Aviv; Sadka, Ofir; Levy, Daniel A

    2017-11-01

    Consolidation of newly formed memories is readily disrupted, but can it be enhanced? Given the prominent role of hippocampal theta oscillations in memory formation and retrieval, we hypothesized that upregulating theta power during early stages of consolidation might benefit memory stability and persistence. We used EEG neurofeedback to enable participants to selectively increase theta power in their EEG spectra following episodic memory encoding, while other participants engaged in low beta-focused neurofeedback or passively viewed a neutral nature movie. Free recall assessments immediately following the interventions, 24h later and 7d later all indicated benefit to memory of theta neurofeedback, relative to low beta neurofeedback or passive movie-viewing control conditions. The degree of benefit to memory was correlated with the extent of theta power modulation, but not with other spectral changes. Theta enhancement may provide optimal conditions for stabilization of new hippocampus-dependent memories. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Human Relations Class. A Syllabus.

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    Guillen, Mary A.

    A junior high level human relations class develops human interaction and oral communication skills. A week-by-week syllabus contains the following components: introduction of the students to each other and to the principles of body language, transactional analysis, and group interaction; behavior contracts; group dynamics topics and exercises;…

  17. Fast entrainment of human electroencephalogram to a theta-band photic flicker during successful memory encoding

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    Naoyuki eSato

    2013-05-01

    Full Text Available Theta band power (4-8Hz in the scalp electroencephalogram (EEG is thought to be stronger during memory encoding for subsequently remembered items than for forgotten items. According to simultaneous EEG-functional magnetic resonance imaging (fMRI measurements, the memory-dependent EEG theta is associated with multiple regions of the brain. This suggests that the multiple regions cooperate with EEG theta synchronization during successful memory encoding. However, a question still remains: What kind of neural dynamic organizes such a memory-dependent global network? In this study, the modulation of the EEG theta entrainment property during successful encoding was hypothesized to lead to EEG theta synchronization among a distributed network. Then, a transient response of EEG theta to a theta-band photic flicker with a short duration was evaluated during memory encoding. In the results, flicker-induced EEG power increased and decreased with a time constant of several hundred milliseconds following the onset and the offset of the flicker, respectively. Importantly, the offset response of EEG power was found to be significantly decreased during successful encoding. Moreover, the offset response of the phase locking index was also found to associate with memory performance. According to computational simulations, the results are interpreted as a smaller time constant (i.e., faster response of a driven harmonic oscillator rather than a change in the spontaneous oscillatory input. This suggests that the fast response of EEG theta forms a global EEG theta network among memory-related regions during successful encoding, and it contributes to a flexible formation of the network along the time course.

  18. Fast entrainment of human electroencephalogram to a theta-band photic flicker during successful memory encoding.

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    Sato, Naoyuki

    2013-01-01

    Theta band power (4-8 Hz) in the scalp electroencephalogram (EEG) is thought to be stronger during memory encoding for subsequently remembered items than for forgotten items. According to simultaneous EEG-functional magnetic resonance imaging (fMRI) measurements, the memory-dependent EEG theta is associated with multiple regions of the brain. This suggests that the multiple regions cooperate with EEG theta synchronization during successful memory encoding. However, a question still remains: What kind of neural dynamic organizes such a memory-dependent global network? In this study, the modulation of the EEG theta entrainment property during successful encoding was hypothesized to lead to EEG theta synchronization among a distributed network. Then, a transient response of EEG theta to a theta-band photic flicker with a short duration was evaluated during memory encoding. In the results, flicker-induced EEG power increased and decreased with a time constant of several hundred milliseconds following the onset and the offset of the flicker, respectively. Importantly, the offset response of EEG power was found to be significantly decreased during successful encoding. Moreover, the offset response of the phase locking index was also found to associate with memory performance. According to computational simulations, the results are interpreted as a smaller time constant (i.e., faster response) of a driven harmonic oscillator rather than a change in the spontaneous oscillatory input. This suggests that the fast response of EEG theta forms a global EEG theta network among memory-related regions during successful encoding, and it contributes to a flexible formation of the network along the time course.

  19. Probing changes in corticospinal excitability following theta burst stimulation of the human primary motor cortex.

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    Goldsworthy, Mitchell R; Vallence, Ann-Maree; Hodyl, Nicolette A; Semmler, John G; Pitcher, Julia B; Ridding, Michael C

    2016-01-01

    To determine whether the intensity of transcranial magnetic stimulation (TMS) used to probe changes in corticospinal excitability influences the measured plasticity response to theta burst stimulation (TBS) of the human primary motor cortex. Motor evoked potential (MEP) input/output (I/O) curves were recorded before and following continuous TBS (cTBS) (Experiment 1; n=18) and intermittent TBS (iTBS) (Experiment 2; n=18). The magnitude and consistency of MEP depression induced by cTBS was greatest when probed using stimulus intensities at or above 150% of resting motor threshold (RMT). In contrast, facilitation of MEPs following iTBS was strongest and most consistent at 110% of RMT. The plasticity response to both cTBS and iTBS is influenced by the stimulus intensity used to probe the induced changes in corticospinal excitability. The results highlight the importance of the test stimulus intensity used to assess TBS-induced changes in corticospinal excitability when interpreting neuroplasticity data, and suggest that a number of test intensities may be required to reliably probe the plasticity response. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  20. Remote effects of intermittent theta burst stimulation of the human pharyngeal motor system.

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    Mistry, Satish; Michou, Emilia; Rothwell, John; Hamdy, Shaheen

    2012-08-01

    Intermittent theta burst stimulation (iTBS) is a novel, non-invasive form of brain stimulation capable of facilitating excitability of the human primary motor cortex with therapeutic potential in the treatment of neurological conditions, such as multiple sclerosis. The objectives of this study were to evaluate the effects of iTBS on cortical properties in the human pharyngeal motor system. Transcranial magnetic stimulation (TMS)-evoked pharyngeal motor responses were recorded via a swallowed intra-luminal catheter and used to assess motor cortical pathways to the pharynx in both hemispheres before and for up to 90 min after iTBS in 15 healthy adults (nine male/six female, 22-59 years old). Active/sham iTBS comprised 600 intermittent repetitive TMS pulses, delivered in a double-blind pseudo-randomised order over each hemisphere on separate days at least 1 week apart. Abductor pollicis brevis (APB) recordings were used as control. Hemispheric interventional data were compared with sham using repeated-measures anova. iTBS was delivered at an average intensity of 43±1% of stimulator output. Compared with sham, iTBS to the hemisphere with stronger pharyngeal projections induced increased responses only in the contralateral weaker projection 60-90 min post-iTBS (maximum 54±19%, P≤0.007), with no change in stronger hemisphere responses. By contrast, iTBS to weaker projections had no significant effects (P=0.39) on either hemisphere. APB responses similarly did not change significantly (P=0.78) across all study arms. We conclude that iTBS can induce remote changes in corticobulbar excitability. While further studies will clarify the extent of these changes, iTBS holds promise as a potential treatment for dysphagia after unilateral brain damage. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  1. Efficacy and Time Course of Theta Burst Stimulation in Healthy Humans

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    Wischnewski, M.; Schutter, D.J.L.G.

    2015-01-01

    BACKGROUND: In the past decade research has shown that continuous (cTBS) and intermittent theta burst stimulation (iTBS) alter neuronal excitability levels in the primary motor cortex. OBJECTIVE: Quantitatively review the magnitude and time course on cortical excitability of cTBS and iTBS. METHODS:

  2. Deqi Induction by HT7 Acupuncture Alters Theta and Alpha Band Coherence in Human Healthy Subjects

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    Go-Eun Lee

    2017-01-01

    Full Text Available The aim of this preliminary study is to investigate the changes in phase synchronization in the theta and alpha bands before and during the performance of classical acupuncture on the Sinmun (HT7. The electroencephalogram (EEG signals from nine healthy young subjects were recorded before and during acupuncture in the “closed-eye” state. The EEG signals were acquired from 19 surface scalp electrodes (FP1, FP2, F7, F3, Fz F4, F8, T3, C3, Cz, C4, T4, T5, P3, Pz, P4, T6, O1, and O2. Needles were inserted into the HT7 bilaterally and were then manipulated to induce deqi and retained for 15 minutes. Phase synchronization was measured by phase coherence. In the theta band, coherence significantly increased between the temporal (T5, T6 and occipital areas (O1, O2 during the acupuncture stimulation. In the alpha band, coherence significantly increased between the left temporal area (T5 and other areas (frontal, parietal, and occipital. Phase coherence in the theta and alpha bands tended to increase during the retention of the acupuncture needles after deqi. Therefore, it can be concluded that acupuncture stimulation with deqi is clinically effective via the central nervous system (CNS.

  3. Theta vectors and quantum theta functions

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    Chang-Young, Ee; Kim, Hoil

    2005-01-01

    In this paper, we clarify the relation between Manin's quantum theta function and Schwarz's theta vector. We do this in comparison with the relation between the kq representation, which is equivalent to the classical theta function, and the corresponding coordinate space wavefunction. We first explain the equivalence relation between the classical theta function and the kq representation in which the translation operators of the phase space are commuting. When the translation operators of the phase space are not commuting, then the kq representation is no longer meaningful. We explain why Manin's quantum theta function, obtained via algebra (quantum torus) valued inner product of the theta vector, is a natural choice for the quantum version of the classical theta function. We then show that this approach holds for a more general theta vector containing an extra linear term in the exponent obtained from a holomorphic connection of constant curvature than the simple Gaussian one used in Manin's construction

  4. Cortical theta wanes for language.

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    Hermes, Dora; Miller, Kai J; Vansteensel, Mariska J; Edwards, Erik; Ferrier, Cyrille H; Bleichner, Martin G; van Rijen, Peter C; Aarnoutse, Erik J; Ramsey, Nick F

    2014-01-15

    The role of low frequency oscillations in language areas is not yet understood. Using ECoG in six human subjects, we studied whether different language regions show prominent power changes in a specific rhythm, in similar manner as the alpha rhythm shows the most prominent power changes in visual areas. Broca's area and temporal language areas were localized in individual subjects using fMRI. In these areas, the theta rhythm showed the most pronounced power changes and theta power decreased significantly during verb generation. To better understand the role of this language-related theta decrease, we then studied the interaction between low frequencies and local neuronal activity reflected in high frequencies. Amplitude-amplitude correlations showed that theta power correlated negatively with high frequency activity, specifically across verb generation trials. Phase-amplitude coupling showed that during control trials, high frequency power was coupled to theta phase, but this coupling decreased significantly during verb generation trials. These results suggest a dynamic interaction between the neuronal mechanisms underlying the theta rhythm and local neuronal activity in language areas. As visual areas show a pronounced alpha rhythm that may reflect pulsed inhibition, language regions show a pronounced theta rhythm with highly similar features. © 2013.

  5. Long lasting effects of daily theta burst rTMS sessions in the human amblyopic cortex.

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    Clavagnier, Simon; Thompson, Benjamin; Hess, Robert F

    2013-11-01

    It has been reported that a single session of 1 Hz or 10 Hz repetitive transcranial magnetic stimulation (rTMS) of the visual cortex can temporarily improve contrast sensitivity in adults with amblyopia. More recently, continuous theta burst stimulation (cTBS) of the visual cortex has been found to improve contrast sensitivity in observers with normal vision. The aims of this study were to assess whether cTBS of the visual cortex could improve contrast sensitivity in adults with amblyopia and whether repeated sessions of cTBS would lead to more pronounced and/or longer lasting effects. cTBS was delivered to the visual cortex while patients viewed a high contrast stimulus with their non-amblyopic eye. This manipulation was designed to bias the effects of cTBS toward inputs from the amblyopic eye. Contrast sensitivity was measured before and after stimulation. The effects of one cTBS session were measured in five patients and the effects of five consecutive daily sessions were measured in four patients. Three patients were available for follow-up at varying intervals after the final session. cTBS improved amblyopic eye contrast sensitivity to high spatial frequencies (P enduring visual function improvements in adults with amblyopia. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. The effects of theta-burst stimulation on vigilance in humans

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    Armand eMensen

    2014-06-01

    Full Text Available Repetitive transcranial magnetic stimulation has become a popular tool to modulate neuronal networks and associated brain functions in both clinical and basic research. Yet few studies have examined the potential effects of cortical stimulation on general levels of vigilance. In this exploratory study, we used theta-burst protocols, both continuous (cTBS and intermittent (iTBS patterns, to examine whether inhibition or excitation of the left dorso-lateral prefrontal cortex (dlPFC was able to induce reliable and acute changes to vigilance measures, compared to the left dorso-lateral associative visual cortex (dlAVC as a control site in line with previous work. Partially sleep restricted participants underwent four separate sessions in a single day, in a between subjects design for TBS stimulation type and within subjects for locaton, each consisting of maintenance of wakefulness test, a sleep latency test, and a psychomotor vigilance task. TBS significantly affected measures of sleep consolidation, namely latency to sleep stage 2 and sleep efficiency, but had no effects on sleep drive or psychomotor vigilance levels for either TBS type or location. Contrary to our initial hypothesis of the dlAVC as a control site, stimulation to this region resulted in the largest differential effects between stimulation types. Moreover, the effect of TBS was found to be consistent throughout the day. These data may provide the basis for further investigation into therapeutic applications of TBS in sleep disorders.

  7. The physiological basis of the effects of intermittent theta burst stimulation of the human motor cortex.

    Science.gov (United States)

    Di Lazzaro, V; Pilato, F; Dileone, M; Profice, P; Oliviero, A; Mazzone, P; Insola, A; Ranieri, F; Meglio, M; Tonali, P A; Rothwell, J C

    2008-08-15

    Theta burst stimulation (TBS) is a form of repetitive transcranial magnetic stimulation (TMS). When applied to motor cortex it leads to after-effects on corticospinal and corticocortical excitability that may reflect LTP/LTD-like synaptic effects. An inhibitory form of TBS (continuous, cTBS) suppresses MEPs, and spinal epidural recordings show this is due to suppression of the I1 volley evoked by TMS. Here we investigate whether the excitatory form of TBS (intermittent, iTBS) affects the same I-wave circuitry. We recorded corticospinal volleys evoked by single pulse TMS of the motor cortex before and after iTBS in three conscious patients who had an electrode implanted in the cervical epidural space for the control of pain. As in healthy subjects, iTBS increased MEPs, and this was accompanied by a significant increase in the amplitude of later I-waves, but not the I1 wave. In two of the patients we tested the excitability of the contralateral cortex and found a significant suppression of the late I-waves. The extent of the changes varied between the three patients, as did their age. To investigate whether age might be a significant contributor to the variability we examined the effect of iTBS on MEPs in 18 healthy subjects. iTBS facilitated MEPs evoked by TMS of the conditioned hemisphere and suppressed MEPs evoked by stimulation of the contralateral hemisphere. There was a slight but non-significant decline in MEP facilitation with age, suggesting that interindividual variability was more important than age in explaining our data. In a subgroup of 10 subjects we found that iTBS had no effect on the duration of the ipsilateral silent period suggesting that the reduction in contralateral MEPs was not due to an increase in ongoing transcallosal inhibition. In conclusion, iTBS affects the excitability of excitatory synaptic inputs to pyramidal tract neurones that are recruited by a TMS pulse, both in the stimulated hemisphere and in the contralateral hemisphere

  8. Differential substrate behaviours of ethylene oxide and propylene oxide towards human glutathione transferase theta hGSTT1-1.

    Science.gov (United States)

    Thier, R; Wiebel, F A; Bolt, H M

    1999-11-01

    The transformation of ethylene oxide (EO), propylene oxide (PO) and 1-butylene oxide (1-BuO) by human glutathione transferase theta (hGSTT1-1) was studied comparatively using 'conjugator' (GSTT1 + individuals) erythrocyte lysates. The relative sequence of velocity of enzymic transformation was PO > EO > 1-BuO. The faster transformation of PO compared to EO was corroborated in studies with human and rat GSTT1-1 (hGSTT1-1 and rGSTT1-1, respectively) expressed by Salmonella typhimurium TA1535. This sequence of reactivities of homologous epoxides towards GSTT1-1 contrasts to the sequence observed in homologous alkyl halides (methyl bromide, MBr; ethyl bromide, EtBr; n-propyl bromide, PrBr) where the relative sequence MeBr > EtBr > PrBr is observed. The higher reactivity towards GSTT1-1 of propylene oxide compared to ethylene oxide is consistent with a higher chemical reactivity. This is corroborated by experimental data of acid-catalysed hydrolysis of a number of aliphatic epoxides, including ethylene oxide and propylene oxide and consistent with semi-empirical molecular orbital modelings.

  9. Quadri-Pulse Theta Burst Stimulation using Ultra-High Frequency Bursts - A New Protocol to Induce Changes in Cortico-Spinal Excitability in Human Motor Cortex

    DEFF Research Database (Denmark)

    Jung, Nikolai H; Gleich, Bernhard; Gattinger, Norbert

    2016-01-01

    Patterned transcranial magnetic stimulation (TMS) such as theta burst stimulation (TBS) or quadri-pulse stimulation (QPS) can induce changes in cortico-spinal excitability, commonly referred to as long-term potentiation (LTP)-like and long-term depression (LTD)-like effects in human motor cortex (M...... of sinusoidal TMS pulses elicited either a posterior-anterior (PA) or anterior-posterior (AP) directed current in M1. Motor evoked potentials (MEPs) were recorded before and after qTBS to probe changes in cortico-spinal excitability. PA-qTBS at 666 Hz caused a decrease in PA-MEP amplitudes, whereas AP...... in cortico-spinal excitability. Induced current direction in the brain appears to be relevant when qTBS targets I-wave periodicity, corroborating that high-fidelity spike timing mechanisms are critical for inducing bi-directional plasticity in human M1....

  10. Inferring modules from human protein interactome classes

    Directory of Open Access Journals (Sweden)

    Chaurasia Gautam

    2010-07-01

    Full Text Available Abstract Background The integration of protein-protein interaction networks derived from high-throughput screening approaches and complementary sources is a key topic in systems biology. Although integration of protein interaction data is conventionally performed, the effects of this procedure on the result of network analyses has not been examined yet. In particular, in order to optimize the fusion of heterogeneous interaction datasets, it is crucial to consider not only their degree of coverage and accuracy, but also their mutual dependencies and additional salient features. Results We examined this issue based on the analysis of modules detected by network clustering methods applied to both integrated and individual (disaggregated data sources, which we call interactome classes. Due to class diversity, we deal with variable dependencies of data features arising from structural specificities and biases, but also from possible overlaps. Since highly connected regions of the human interactome may point to potential protein complexes, we have focused on the concept of modularity, and elucidated the detection power of module extraction algorithms by independent validations based on GO, MIPS and KEGG. From the combination of protein interactions with gene expressions, a confidence scoring scheme has been proposed before proceeding via GO with further classification in permanent and transient modules. Conclusions Disaggregated interactomes are shown to be informative for inferring modularity, thus contributing to perform an effective integrative analysis. Validation of the extracted modules by multiple annotation allows for the assessment of confidence measures assigned to the modules in a protein pathway context. Notably, the proposed multilayer confidence scheme can be used for network calibration by enabling a transition from unweighted to weighted interactomes based on biological evidence.

  11. Theta-burst stimulation-induced plasticity over primary somatosensory cortex changes somatosensory temporal discrimination in healthy humans.

    Directory of Open Access Journals (Sweden)

    Antonella Conte

    Full Text Available BACKGROUND: The somatosensory temporal discrimination threshold (STDT measures the ability to perceive two stimuli as being sequential. Precisely how the single cerebral structures contribute in controlling the STDT is partially known and no information is available about whether STDT can be modulated by plasticity-inducing protocols. METHODOLOGY/PRINCIPAL FINDINGS: To investigate how the cortical and cerebellar areas contribute to the STDT we used transcranial magnetic stimulation and a neuronavigation system. We enrolled 18 healthy volunteers and 10 of these completed all the experimental sessions, including the control experiments. STDT was measured on the left hand before and after applying continuous theta-burst stimulation (cTBS on the right primary somatosensory area (S1, pre-supplementary motor area (pre-SMA, right dorsolateral prefrontal cortex (DLPFC and left cerebellar hemisphere. We then investigated whether intermittent theta-burst stimulation (iTBS on the right S1 improved the STDT. After right S1 cTBS, STDT values increased whereas after iTBS to the same cortical site they decreased. cTBS over the DLPFC and left lateral cerebellum left the STDT statistically unchanged. cTBS over the pre-SMA also left the STDT statistically unchanged, but it increased the number of errors subjects made in distinguishing trials testing a single stimulus and those testing paired stimuli. CONCLUSIONS/SIGNIFICANCE: Our findings obtained by applying TBS to the cortical areas involved in processing sensory discrimination show that the STDT is encoded in S1, possibly depends on intrinsic S1 neural circuit properties, and can be modulated by plasticity-inducing TBS protocols delivered over S1. Our findings, giving further insight into mechanisms involved in somatosensory temporal discrimination, help interpret STDT abnormalities in movement disorders including dystonia and Parkinson's disease.

  12. Theta-Burst Stimulation-Induced Plasticity over Primary Somatosensory Cortex Changes Somatosensory Temporal Discrimination in Healthy Humans

    Science.gov (United States)

    Conte, Antonella; Rocchi, Lorenzo; Nardella, Andrea; Dispenza, Sabrina; Scontrini, Alessandra; Khan, Nashaba; Berardelli, Alfredo

    2012-01-01

    Background The somatosensory temporal discrimination threshold (STDT) measures the ability to perceive two stimuli as being sequential. Precisely how the single cerebral structures contribute in controlling the STDT is partially known and no information is available about whether STDT can be modulated by plasticity-inducing protocols. Methodology/Principal Findings To investigate how the cortical and cerebellar areas contribute to the STDT we used transcranial magnetic stimulation and a neuronavigation system. We enrolled 18 healthy volunteers and 10 of these completed all the experimental sessions, including the control experiments. STDT was measured on the left hand before and after applying continuous theta-burst stimulation (cTBS) on the right primary somatosensory area (S1), pre-supplementary motor area (pre-SMA), right dorsolateral prefrontal cortex (DLPFC) and left cerebellar hemisphere. We then investigated whether intermittent theta-burst stimulation (iTBS) on the right S1 improved the STDT. After right S1 cTBS, STDT values increased whereas after iTBS to the same cortical site they decreased. cTBS over the DLPFC and left lateral cerebellum left the STDT statistically unchanged. cTBS over the pre-SMA also left the STDT statistically unchanged, but it increased the number of errors subjects made in distinguishing trials testing a single stimulus and those testing paired stimuli. Conclusions/Significance Our findings obtained by applying TBS to the cortical areas involved in processing sensory discrimination show that the STDT is encoded in S1, possibly depends on intrinsic S1 neural circuit properties, and can be modulated by plasticity-inducing TBS protocols delivered over S1. Our findings, giving further insight into mechanisms involved in somatosensory temporal discrimination, help interpret STDT abnormalities in movement disorders including dystonia and Parkinson's disease. PMID:22412964

  13. Converging social classes through humanized urban edges

    Science.gov (United States)

    Abuan, M. V.; Galingan, Z. D.

    2017-10-01

    Urban open spaces are created to be used by people. It is a place of convergence and social activity. However, these places have transformed into places of divergence. When spaces become dehumanized, it separates social classes. As a result, underused spaces contribute to urban decay. Particularly an urban edge, the JP Rizal Makati Waterfront Area is the center of this paper. The JP Rizal Makati Waterfront Area is a waterfront development situated along the banks of one of Metro Manila’s major water thoroughfare --- Pasig River. The park and its physical form, urban design and landscape tend to deteriorate over time --- creating a further division of social convergence. Social hostility, crime, negligent maintenance and poor urban design are contributing factors to this sprawling decay in what used to be spaces of bringing people together. Amidst attempts to beautify and renew this portion of Makati City’s edge, the urban area still remains misspent.This paper attempts to re-humanize the waterfront development. It uses the responsive environment design principles to be able to achieve this goal.

  14. VICTORIA Class Submarine Human-in-the-Loop Experimentation Plan

    Science.gov (United States)

    2014-06-01

    1472G. VICTORIA Class Submarine Human-in-the-Loop Experimentation Plan and Preliminary Results © Her Majesty the Queen in Right of...19 th International Command and Control Research and Technology Symposium Title: VICTORIA Class Submarine Human-in-the-Loop...TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE VICTORIA Class Submarine Human-in-the-Loop Experimentation Plan 5a. CONTRACT

  15. Current direction-dependent modulation of human hand motor function by intermittent theta burst stimulation (iTBS).

    Science.gov (United States)

    Shirota, Yuichiro; Dhaka, Suman; Paulus, Walter; Sommer, Martin

    2017-05-22

    Transcranial magnetic stimulation (TMS) with different current directions can activate different sets of neurons. Current direction can also affect the results of repetitive TMS. To test the influence of uni-directional intermittent theta burst stimulation (iTBS) using different current directions, namely posteroanterior (PA) and anteroposterior (AP), on motor behaviour. In a cross-over design, PA- and AP-iTBS was applied over the left primary motor cortex in 19 healthy, right-handed volunteers. Performance of a finger-tapping task was recorded before and 0, 10, 20, and 30min after the iTBS. The task was conducted with the right and left hands separately at each time point. As a control, AP-iTBS with reduced intensity was applied to 14 participants in a separate session (AP weak condition). The finger-tapping count with the left hand was decreased after PA-iTBS. Neither AP- nor AP weak -iTBS altered the performance. Current direction had a significant impact on the after-effects of iTBS. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Frontoparietal regions may become hypoactive after intermittent theta burst stimulation over the contralateral homologous cortex in humans.

    Science.gov (United States)

    He, Xiaofei; Lan, Yue; Xu, Guangqing; Mao, Yurong; Chen, Zhenghong; Huang, Dongfeng; Pei, Zhong

    2013-12-01

    Brain injury to the dorsal frontoparietal networks, including the posterior parietal cortex (PPC) and dorsolateral prefrontal cortex (DLPFC), commonly cause spatial neglect. However, the interaction of these different regions in spatial attention is unclear. The aim of the present study was to investigate whether hyperexcitable neural networks can cause an abnormal interhemispheric inhibition. The Attention Network Test was used to test subjects following intermittent theta burst stimulation (iTBS) to the left or right frontoparietal networks. During the Attention Network Test task, all subjects tolerated each conditioning iTBS without any obvious iTBS-related side effects. Subjects receiving real-right-PPC iTBS showed significant enhancement in both alerting and orienting efficiency compared with those receiving either sham-right-PPC iTBS or real-left-PPC iTBS. Moreover, subjects exposed to the real-right-DLPFC iTBS exhibited significant improvement in both alerting and executive control efficiency, compared with those exposed to either the sham-right-DLPFC or real-left-DLPFC conditioning. Interestingly, compared with subjects exposed to the sham-left-PPC stimuli, subjects exposed to the real-left-PPC iTBS had a significant deficit in the orienting index. The present study indicates that iTBS over the contralateral homologous cortex may induce the hypoactivity of the right PPC through interhemispheric competition in spatial orienting attention.

  17. Stage theta pinch experiments

    International Nuclear Information System (INIS)

    Linford, R.K.; Downing, J.N.; Gribble, R.F.; Jacobson, A.R.; Platts, D.A.; Thomas, K.S.

    1975-01-01

    The Staged Theta Pinch program is designed to study the technological and physics problems associated with producing fat plasmas and separating the implosion heating from the adiabatic compression. Several methods of implosion heating are discussed. Circuit diagrams and theoretical magnetic field behavior are described for the STP and resonant heating experiments. (MOW)

  18. Ramanujan's theta functions

    CERN Document Server

    Cooper, Shaun

    2017-01-01

    Theta functions were studied extensively by Ramanujan. This book provides a systematic development of Ramanujan’s results and extends them to a general theory. The author’s treatment of the subject is comprehensive, providing a detailed study of theta functions and modular forms for levels up to 12. Aimed at advanced undergraduates, graduate students, and researchers, the organization, user-friendly presentation, and rich source of examples, lends this book to serve as a useful reference, a pedagogical tool, and a stimulus for further research. Topics, especially those discussed in the second half of the book, have been the subject of much recent research; many of which are appearing in book form for the first time. Further results are summarized in the numerous exercises at the end of each chapter.

  19. Neural rhythmic symphony of human walking observation: Upside-down and Uncoordinated condition on cortical theta, alpha, beta and gamma oscillations.

    Directory of Open Access Journals (Sweden)

    David eZarka

    2014-09-01

    Full Text Available Biological motion observation has been recognized to produce dynamic change in sensorimotor activation according to the observed kinematics. Physical plausibility of the spatial-kinematic relationship of human movement may play a major role in the top-down processing of human motion recognition. Here, we investigated the time course of scalp activation during observation of human gait in order to extract and use it on future integrated brain-computer interface using virtual reality (VR. We analyzed event related potentials (ERP, the event related spectral perturbation (ERSP and the inter-trial coherence (ITC from high-density EEG recording during video display onset (-200 to 600 ms and the steady state visual evoked potentials (SSVEP inside the video of human walking 3D-animation in three conditions: Normal; Upside-down (inverted images; and Uncoordinated (pseudo-randomly mixed images. We found that early visual evoked response P120 was decreased in Upside-down condition. The N170 and P300b amplitudes were decreased in Uncoordinated condition. In Upside-down and Uncoordinated conditions, we found decreased alpha power and theta phase-locking. As regards gamma oscillation, power was increased during the Upside-down animation and decreased during the Uncoordinated animation. An SSVEP-like response oscillating at about 10 Hz was also described showing that the oscillating pattern is enhanced 300 ms after the heel strike event only in the Normal but not in the Upside-down condition. Our results are consistent with most of previous point-light display studies, further supporting possible use of virtual reality for neurofeedback applications.

  20. Staged theta pinch experiments

    International Nuclear Information System (INIS)

    Linford, R.K.; Downing, J.N.; Gribble, R.F.; Jacobson, A.R.; Platts, D.A.; Thomas, K.S.

    1976-01-01

    Two implosion heating circuits are being experimentally tested. The principal experiment in the program is the 4.5-m-long Staged Theta Pinch (STP). It uses two relatively low energy (50kJ and 100 kJ), high voltage (125 kV) capacitor banks to produce the theta pinch plasma inside the 20 cm i.d. quartz discharge tube. A lower voltage (50 kV), higher energy (750 kJ) capacitor bank is used to contain the plasma and provide a variable amount of adiabatic compression. Because the experiment produces a higher ratio of implosion heating to compressional heating than conventional theta pinches, it should be capable of producing high temperature plasmas with a much larger ratio of plasma radius to discharge tube radius than has been possible in the past. The Resonant Heating Experiment (RHX) in its initial configuration is the same as a 0.9-m-long section of the high voltage part of the STP experiment and all the plasma results here were obtained with the experiment in that configuration. Part of the implosion bank will be removed and a low inductance crowbar added to convert it to the resonant heating configuration. (U.K.)

  1. Ramanujan's mock theta functions.

    Science.gov (United States)

    Griffin, Michael; Ono, Ken; Rolen, Larry

    2013-04-09

    In his famous deathbed letter, Ramanujan introduced the notion of a mock theta function, and he offered some alleged examples. Recent work by Zwegers [Zwegers S (2001) Contemp Math 291:268-277 and Zwegers S (2002) PhD thesis (Univ of Utrecht, Utrecht, The Netherlands)] has elucidated the theory encompassing these examples. They are holomorphic parts of special harmonic weak Maass forms. Despite this understanding, little attention has been given to Ramanujan's original definition. Here, we prove that Ramanujan's examples do indeed satisfy his original definition.

  2. Dose-dependent effects of theta burst rTMS on cortical excitability and resting-state connectivity of the human motor system.

    Science.gov (United States)

    Nettekoven, Charlotte; Volz, Lukas J; Kutscha, Martha; Pool, Eva-Maria; Rehme, Anne K; Eickhoff, Simon B; Fink, Gereon R; Grefkes, Christian

    2014-05-14

    Theta burst stimulation (TBS), a specific protocol of repetitive transcranial magnetic stimulation (rTMS), induces changes in cortical excitability that last beyond stimulation. TBS-induced aftereffects, however, vary between subjects, and the mechanisms underlying these aftereffects to date remain poorly understood. Therefore, the purpose of this study was to investigate whether increasing the number of pulses of intermittent TBS (iTBS) (1) increases cortical excitability as measured by motor-evoked potentials (MEPs) and (2) alters functional connectivity measured using resting-state fMRI, in a dose-dependent manner. Sixteen healthy, human subjects received three serially applied iTBS blocks of 600 pulses over the primary motor cortex (M1 stimulation) and the parieto-occipital vertex (sham stimulation) to test for dose-dependent iTBS effects on cortical excitability and functional connectivity (four sessions in total). iTBS over M1 increased MEP amplitudes compared with sham stimulation after each stimulation block. Although the increase in MEP amplitudes did not differ between the first and second block of M1 stimulation, we observed a significant increase after three blocks (1800 pulses). Furthermore, iTBS enhanced resting-state functional connectivity between the stimulated M1 and premotor regions in both hemispheres. Functional connectivity between M1 and ipsilateral dorsal premotor cortex further increased dose-dependently after 1800 pulses of iTBS over M1. However, no correlation between changes in MEP amplitudes and functional connectivity was detected. In summary, our data show that increasing the number of iTBS stimulation blocks results in dose-dependent effects at the local level (cortical excitability) as well as at a systems level (functional connectivity) with a dose-dependent enhancement of dorsal premotor cortex-M1 connectivity. Copyright © 2014 the authors 0270-6474/14/346849-11$15.00/0.

  3. Indefinite theta series and generalized error functions

    CERN Document Server

    Alexandrov, Sergei; Manschot, Jan; Pioline, Boris

    2016-01-01

    Theta series for lattices with indefinite signature $(n_+,n_-)$ arise in many areas of mathematics including representation theory and enumerative algebraic geometry. Their modular properties are well understood in the Lorentzian case ($n_+=1$), but have remained obscure when $n_+\\geq 2$. Using a higher-dimensional generalization of the usual (complementary) error function, discovered in an independent physics project, we construct the modular completion of a class of `conformal' holomorphic theta series ($n_+=2$). As an application, we determine the modular properties of a generalized Appell-Lerch sum attached to the lattice ${\\operatorname A}_2$, which arose in the study of rank 3 vector bundles on $\\mathbb{P}^2$. The extension of our method to $n_+>2$ is outlined.

  4. Mapping the after-effects of theta burst stimulation on the human auditory cortex with functional imaging.

    Science.gov (United States)

    Andoh, Jamila; Zatorre, Robert J

    2012-09-12

    Auditory cortex pertains to the processing of sound, which is at the basis of speech or music-related processing. However, despite considerable recent progress, the functional properties and lateralization of the human auditory cortex are far from being fully understood. Transcranial Magnetic Stimulation (TMS) is a non-invasive technique that can transiently or lastingly modulate cortical excitability via the application of localized magnetic field pulses, and represents a unique method of exploring plasticity and connectivity. It has only recently begun to be applied to understand auditory cortical function. An important issue in using TMS is that the physiological consequences of the stimulation are difficult to establish. Although many TMS studies make the implicit assumption that the area targeted by the coil is the area affected, this need not be the case, particularly for complex cognitive functions which depend on interactions across many brain regions. One solution to this problem is to combine TMS with functional Magnetic resonance imaging (fMRI). The idea here is that fMRI will provide an index of changes in brain activity associated with TMS. Thus, fMRI would give an independent means of assessing which areas are affected by TMS and how they are modulated. In addition, fMRI allows the assessment of functional connectivity, which represents a measure of the temporal coupling between distant regions. It can thus be useful not only to measure the net activity modulation induced by TMS in given locations, but also the degree to which the network properties are affected by TMS, via any observed changes in functional connectivity. Different approaches exist to combine TMS and functional imaging according to the temporal order of the methods. Functional MRI can be applied before, during, after, or both before and after TMS. Recently, some studies interleaved TMS and fMRI in order to provide online mapping of the functional changes induced by TMS. However, this

  5. Lecture classes in human anatomy: the students' perceptions.

    Science.gov (United States)

    Kar, Maitreyee; Roy, Hironmoy; Ghosh, Anasuya; Tapadar, Arunabha; Chowdhury, Subhramoy; Mukherjee, Pranab; Jana, Tapan Kumar

    2013-06-01

    The human anatomy, or in brief, the body structure has fascinated man for ages. Due to the information explosion and the increase in specializations, this knowledge is available in a very sketchy manner in high school biology courses. The first comprehensive course on the human anatomy is taught to the first year medical students in medical colleges. This is in keeping with the regulations of the Medical Council of India. The anatomy lecture classes occupy a considerable time of the course, to provide the students with an effective knowledge of the gross anatomy, histology, embryology and the clinical anatomy. On the other hand, the students' feedback regarding the lecture methods and the teaching environment is crucial in judging the efficacy of the present curriculum. To obtain the students' feedback about the environment of the lecture classes, as regards the venue, the teaching and learning aids which are used, the lecture class schedule of the university (the number of classes per week, the durations of the lecture classes, etc.) and the existing departmental practices (display of the class routine in advance, synchronization between the lecture and the practical classes), so that their suggestions could help the faculty in planning the most effective teaching procedures. A semi structured questionnaire was supplied to the students to get their feedback. Most of the students found the air conditioned seminar room's environment to be more comfortable and they supported the existing durations of the lecture hours with the combined use of chalk and a board and overhead projectors (OHPs). The perceptions of the learners helped in modifying the departmental practice in the desired way.

  6. Theta oscillations locked to intended actions rhythmically modulate perception.

    Science.gov (United States)

    Tomassini, Alice; Ambrogioni, Luca; Medendorp, W Pieter; Maris, Eric

    2017-07-07

    Ongoing brain oscillations are known to influence perception, and to be reset by exogenous stimulations. Voluntary action is also accompanied by prominent rhythmic activity, and recent behavioral evidence suggests that this might be coupled with perception. Here, we reveal the neurophysiological underpinnings of this sensorimotor coupling in humans. We link the trial-by-trial dynamics of EEG oscillatory activity during movement preparation to the corresponding dynamics in perception, for two unrelated visual and motor tasks. The phase of theta oscillations (~4 Hz) predicts perceptual performance, even >1 s before movement. Moreover, theta oscillations are phase-locked to the onset of the movement. Remarkably, the alignment of theta phase and its perceptual relevance unfold with similar non-monotonic profiles, suggesting their relatedness. The present work shows that perception and movement initiation are automatically synchronized since the early stages of motor planning through neuronal oscillatory activity in the theta range.

  7. Kinetic description of linear theta-pinch equilibria

    International Nuclear Information System (INIS)

    Batchelor, D.B.; Davidson, R.C.

    1975-01-01

    Equilibrium properties of linear theta-pinch plasmas are studied within the framework of the steady-state (o/x=0) Vlasov-Maxwell equations. The analysis is carried out for an infinitely long plasma column aligned parallel to an externally applied axial magnetic field Bsub(z)sup(ext)esub(z). Equilibrium properties are calculated for the class of rigid-rotor Vlasov equilibria, in which the th component distribution function (Hsub(perpendicular), Psub(theta), upsilonsub(z) depends on perpendicular energy H and canonical angular momentum Psub(theta), exclusively through the linear combination Hsub(perpendicular)-ωsub(j)Psub(theta), where ω;=const.=angular velocity of mean rotation. General equilibrium relations that pertain to the entire class of rigid-rotor Vlasov equilibria are discussed; and specific examples of sharp- and diffuse-boundary equilibrium configurations are considered. Rigid-rotor density and magnetic field profiles are compared with experimentally observed profiles. A general prescription is given for determining the functional dependence of the equilibrium distribution function on Hsub(perpendicular)-ωsub(j)Psub(theta) in circumstances, where the density profile or magnetic field profile is specified. (author)

  8. Theta power is reduced in healthy cognitive aging.

    Science.gov (United States)

    Cummins, Tarrant D R; Finnigan, Simon

    2007-10-01

    The effects of healthy cognitive aging on electroencephalographic (EEG) theta (4.9-6.8 Hz) power were examined during performance of a modified Sternberg, S., 1966. High-speed scanning in human memory. Science 153, 652-654.) word recognition task. In a sample of fourteen young (mean age 21.9 years, range=18-27) and fourteen older (mean age 68.4 years, range=60-80) participants, theta power was found to be significantly lower in older adults during both the retention and recognition intervals. This theta power difference was greatest at the fronto-central midline electrode and occurred in parallel with a small, non-significant decrease in recognition accuracy in the older sample. A significant decrease in older adults' mean theta power was also observed in resting EEG, however, it was of substantially smaller magnitude than the task-related theta difference. It is proposed that a neurophysiological measure(s), such as task-specific frontal midline theta (fmtheta) power, may be a more sensitive marker of cognitive aging than task performance measures. Furthermore, as recent research indicates that fmtheta is generated primarily in the anterior cingulate cortex, the current findings support evidence that the function of brain networks incorporating this structure may be affected in cognitive aging.

  9. The small mixing angle $\\theta_{13}$ and the lepton asymmetry

    CERN Document Server

    Lee, S H; Lee, Song-Haeng; Siyeon, Kim

    2005-01-01

    We present the correlation of low energy CP phases, both Dirac and Majorana, and the lepton asymmetry for the baryon asymmetry in the universe, with a certain class of Yukawa matrices that consist of two right-handed neutrinos and include one texture zero in themselves. For cases in which the amount of the lepton asymmetry $Y_L$ turns out to be proportional to $\\theta_{13}^2$, we consider the relation between two types of CP phases and the relation of $Y_L$ versus the Jarlskog invariant or the amplitude of neutrinoless double beta decay as $\\theta_{13}$ varies.

  10. Distinct slow and fast cortical theta dynamics in episodic memory retrieval.

    Science.gov (United States)

    Pastötter, Bernhard; Bäuml, Karl-Heinz T

    2014-07-01

    Brain oscillations in the theta frequency band (3-8 Hz) have been shown to be critically involved in human episodic memory retrieval. In prior work, both positive and negative relationships between cortical theta power and retrieval success have been reported. This study examined the hypothesis that slow and fast cortical theta oscillations at the edges of the traditional theta frequency band are differentially related to retrieval success. Scalp EEG was recorded in healthy human participants as they performed a cued-recall episodic memory task. Slow (~3 Hz) and fast (~7 Hz) theta oscillations at retrieval were examined as a function of whether an item was recalled or not and as a function of the items' output position at test. Recall success typically declines with output position, due to increases in interference level. The results showed that slow theta power was positively related but fast theta power was negatively related to retrieval success. Concurrent positive and negative episodic memory effects for slow and fast theta oscillations were dissociable in time and space, showing different time courses and different spatial locations on the scalp. Moreover, fast theta power increased from early to late output positions, whereas slow theta power was unaffected by items' output position. Together with prior work, the results suggest that slow and fast theta oscillations have distinct functional roles in episodic memory retrieval, with slow theta oscillations being related to processes of recollection and conscious awareness, and fast theta oscillations being linked to processes of interference and interference resolution. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Identifying Effective Enzyme Activity Targets for Recombinant Class I and Class II Collagenase for Successful Human Islet Isolation

    OpenAIRE

    Balamurugan, Appakalai N.; Green, Michael L.; Breite, Andrew G.; Loganathan, Gopalakrishnan; Wilhelm, Joshua J.; Tweed, Benjamin; Vargova, Lenka; Lockridge, Amber; Kuriti, Manikya; Hughes, Michael G.; Williams, Stuart K.; Hering, Bernhard J.; Dwulet, Francis E.; McCarthy, Robert C.

    2015-01-01

    Isolation following a good manufacturing practice-compliant, human islet product requires development of a robust islet isolation procedure where effective limits of key reagents are known. The enzymes used for islet isolation are critical but little is known about the doses of class I and class II collagenase required for successful islet isolation.

  12. Some theorems on the explicit evaluation of Ramanujan's theta-functions

    Directory of Open Access Journals (Sweden)

    Nayandeep Deka Baruah

    2004-01-01

    Full Text Available Bruce C. Berndt et al. and Soon-Yi Kang have proved many of Ramanujan's formulas for the explicit evaluation of the Rogers-Ramanujan continued fraction and theta-functions in terms of Weber-Ramanujan class invariants. In this note, we give alternative proofs of some of these identities of theta-functions recorded by Ramanujan in his notebooks and deduce some formulas for the explicit evaluation of his theta-functions in terms of Weber-Ramanujan class invariants.

  13. swot: Super W Of Theta

    Science.gov (United States)

    Coupon, Jean; Leauthaud, Alexie; Kilbinger, Martin; Medezinski, Elinor

    2017-07-01

    SWOT (Super W Of Theta) computes two-point statistics for very large data sets, based on “divide and conquer” algorithms, mainly, but not limited to data storage in binary trees, approximation at large scale, parellelization (open MPI), and bootstrap and jackknife resampling methods “on the fly”. It currently supports projected and 3D galaxy auto and cross correlations, galaxy-galaxy lensing, and weighted histograms.

  14. MHC class II molecules regulate growth in human T cells

    DEFF Research Database (Denmark)

    Nielsen, M; Odum, Niels; Bendtzen, K

    1994-01-01

    MHC-class-II-positive T cells are found in tissues involved in autoimmune disorders. Stimulation of class II molecules by monoclonal antibodies (mAbs) or bacterial superantigens induces protein tyrosine phosphorylation through activation of protein tyrosine kinases in T cells, and class II signals...... lines tested. Only one of three CD4+, CD45RAhigh, ROhigh T cells responded to class II costimulation. There was no correlation between T cell responsiveness to class II and the cytokine production profile of the T cell in question. Thus, T cell lines producing interferon (IFN)-gamma but not IL-4 (TH1...... modulate several T cell responses. Here, we studied further the role of class II molecules in the regulation of T cell growth. Costimulation of class II molecules by immobilized HLA-DR mAb significantly enhanced interleukin (IL)-2-supported T cell growth of the majority of CD4+, CD45RAlow, ROhigh T cell...

  15. Intrahemispheric theta rhythm desynchronization impairs working memory.

    Science.gov (United States)

    Alekseichuk, Ivan; Pabel, Stefanie Corinna; Antal, Andrea; Paulus, Walter

    2017-01-01

    There is a growing interest in large-scale connectivity as one of the crucial factors in working memory. Correlative evidence has revealed the anatomical and electrophysiological players in the working memory network, but understanding of the effective role of their connectivity remains elusive. In this double-blind, placebo-controlled study we aimed to identify the causal role of theta phase connectivity in visual-spatial working memory. The frontoparietal network was over- or de-synchronized in the anterior-posterior direction by multi-electrode, 6 Hz transcranial alternating current stimulation (tACS). A decrease in memory performance and increase in reaction time was caused by frontoparietal intrahemispheric desynchronization. According to the diffusion drift model, this originated in a lower signal-to-noise ratio, known as the drift rate index, in the memory system. The EEG analysis revealed a corresponding decrease in phase connectivity between prefrontal and parietal areas after tACS-driven desynchronization. The over-synchronization did not result in any changes in either the behavioral or electrophysiological levels in healthy participants. Taken together, we demonstrate the feasibility of manipulating multi-site large-scale networks in humans, and the disruptive effect of frontoparietal desynchronization on theta phase connectivity and visual-spatial working memory.

  16. Homotypic aggregation of human cell lines by HLA class II-, class Ia- and HLA-G-specific monoclonal antibodies

    DEFF Research Database (Denmark)

    Odum, Niels; Ledbetter, J A; Martin, P

    1991-01-01

    Major histocompatibility complex (MHC) class II molecules have been implicated in cell adhesion in two ways. In addition to the well-established role of class II antigens in low-affinity adhesion provided by interactions between class II and CD4, recent data indicated that class II may also induce...... adhesion between T and B cells by activating the CD18/CD11a (LFA-1) adhesion pathway. Here we report that monoclonal antibodies (mAb) against HLA-DR (L243, p4.1, HB10a, VI15) and certain broad class II reacting mAb (TU35, TU39), but not anti-DQ (TU22, Leu-10) mAb, induced homotypic aggregation of human...... class II-positive monocytic (I937) and T leukemic (HUT78) tumor cell lines and Epstein-Barr virus (EBV) transformed B-lymphoid cell lines (EBV-LCL). Class II-negative cell lines (U-937 and the EBV-LCL mutant line 616) were not induced to aggregate. An HLA-G-transfected EBV-LCL, 221-AGN...

  17. Task-related modulation of anterior theta and posterior alpha EEG reflects top-down preparation

    Directory of Open Access Journals (Sweden)

    Park Hae-Jeong

    2010-06-01

    Full Text Available Abstract Background Prestimulus EEG alpha activity in humans has been considered to reflect ongoing top-down preparation for the performance of subsequent tasks. Since theta oscillations may be related to poststimulus top-down processing, we investigated whether prestimulus EEG theta activity also reflects top-down cognitive preparation for a stimulus. Results We recorded EEG data from 15 healthy controls performing a color and shape discrimination task, and used the wavelet transformation to investigate the time course and power of oscillatory activity in the signals. We observed a relationship between both anterior theta and posterior alpha power in the prestimulus period and the type of subsequent task. Conclusions Since task-differences were reflected in both theta and alpha activities prior to stimulus onset, both prestimulus theta (particularly around the anterior region and prestimulus alpha (particularly around the posterior region activities may reflect prestimulus top-down preparation for the performance of subsequent tasks.

  18. Algebraic geometry and theta functions

    CERN Document Server

    Coble, Arthur B

    1929-01-01

    This book is the result of extending and deepening all questions from algebraic geometry that are connected to the central problem of this book: the determination of the tritangent planes of a space curve of order six and genus four, which the author treated in his Colloquium Lecture in 1928 at Amherst. The first two chapters recall fundamental ideas of algebraic geometry and theta functions in such fashion as will be most helpful in later applications. In order to clearly present the state of the central problem, the author first presents the better-known cases of genus two (Chapter III) and

  19. Theta function identities associated with Ramanujan's modular ...

    Indian Academy of Sciences (India)

    In Chapter 20 of his second notebook [6], Ramanujan recorded several theta function identities associated with modular equations of composite degree 15. These identities have previously been proved by Berndt in [3]. But he proved most of these theta function identities using modular equations. These identities can also ...

  20. Social Class and the Motivational Relevance of Other Human Beings: Evidence From Visual Attention.

    Science.gov (United States)

    Dietze, Pia; Knowles, Eric D

    2016-11-01

    We theorize that people's social class affects their appraisals of others' motivational relevance-the degree to which others are seen as potentially rewarding, threatening, or otherwise worth attending to. Supporting this account, three studies indicate that social classes differ in the amount of attention their members direct toward other human beings. In Study 1, wearable technology was used to film the visual fields of pedestrians on city streets; higher-class participants looked less at other people than did lower-class participants. In Studies 2a and 2b, participants' eye movements were tracked while they viewed street scenes; higher class was associated with reduced attention to people in the images. In Study 3, a change-detection procedure assessed the degree to which human faces spontaneously attract visual attention; faces proved less effective at drawing the attention of high-class than low-class participants, which implies that class affects spontaneous relevance appraisals. The measurement and conceptualization of social class are discussed. © The Author(s) 2016.

  1. Identifying Effective Enzyme Activity Targets for Recombinant Class I and Class II Collagenase for Successful Human Islet Isolation.

    Science.gov (United States)

    Balamurugan, Appakalai N; Green, Michael L; Breite, Andrew G; Loganathan, Gopalakrishnan; Wilhelm, Joshua J; Tweed, Benjamin; Vargova, Lenka; Lockridge, Amber; Kuriti, Manikya; Hughes, Michael G; Williams, Stuart K; Hering, Bernhard J; Dwulet, Francis E; McCarthy, Robert C

    2016-01-01

    Isolation following a good manufacturing practice-compliant, human islet product requires development of a robust islet isolation procedure where effective limits of key reagents are known. The enzymes used for islet isolation are critical but little is known about the doses of class I and class II collagenase required for successful islet isolation. We used a factorial approach to evaluate the effect of high and low target activities of recombinant class I (rC1) and class II (rC2) collagenase on human islet yield. Consequently, 4 different enzyme formulations with divergent C1:C2 collagenase mass ratios were assessed, each supplemented with the same dose of neutral protease. Both split pancreas and whole pancreas models were used to test enzyme targets (n = 20). Islet yield/g pancreas was compared with historical enzymes (n = 42). Varying the Wunsch (rC2) and collagen degradation activity (CDA, rC1) target dose, and consequently the C1:C2 mass ratio, had no significant effect on tissue digestion. Digestions using higher doses of Wunsch and CDA resulted in comparable islet yields to those obtained with 60% and 50% of those activities, respectively. Factorial analysis revealed no significant main effect of Wunsch activity or CDA for any parameter measured. Aggregate results from 4 different collagenase formulations gave 44% higher islet yield (>5000 islet equivalents/g) in the body/tail of the pancreas (n = 12) when compared with those from the same segment using a standard natural collagenase/protease mixture (n = 6). Additionally, islet yields greater than 5000 islet equivalents/g pancreas were also obtained in whole human pancreas. A broader C1:C2 ratio can be used for human islet isolation than has been used in the past. Recombinant collagenase is an effective replacement for the natural enzyme and we have determined that high islet yield can be obtained even with low doses of rC1:rC2, which is beneficial for the survival of islets.

  2. The role of REM theta activity in emotional memory

    Directory of Open Access Journals (Sweden)

    Isabel Camilla Hutchison

    2015-10-01

    Full Text Available While NREM sleep has been strongly implicated in the reactivation and consolidation of memory traces, the role of REM sleep remains unclear. A growing body of research on humans and animals provide behavioral evidence for a role of REM sleep in the strengthening and modulation of emotional memories. Theta activity – which describes low frequency oscillations in the local field potential within the hippocampus, amygdala and neocortex – is a prominent feature of both wake and REM sleep in humans and rodents. Theta coherence between the hippocampus and amygdala drives large-scale PGO waves, the density of which predicts increases in plasticity-related gene expression. This could potentially facilitate the processing of emotional memory traces within the hippocampus during REM sleep. Further, the timing of hippocampal activity in relation to theta phase is vital in determining subsequent potentiation of neuronal activity. This could allow the emotionally modulated strengthening of novel and the gradual weakening of consolidated hippocampal memory traces observed in both wake and REM sleep. Hippocampal theta activity is also correlated with REM sleep acetylcholine levels – which are thought to reduce hippocampal afferent inputs in the neocortex. The additional low levels of noradrenaline during REM sleep, which facilitate recurrent activation within the neocortex, could allow the integration of novel memory traces previously consolidated during NREM sleep. We therefore propose that REM sleep mediates the prioritized processing of emotional memories within the hippocampus, the integration of previously consolidated memory traces within the neocortex, as well as the disengagement of consolidated neocortical memory traces from the hippocampus.

  3. Theta-Generalized closed sets in fuzzy topological spaces

    International Nuclear Information System (INIS)

    El-Shafei, M.E.; Zakari, A.

    2006-01-01

    In this paper we introduce the concepts of theta-generalized closed fuzzy sets and generalized fuzzy sets in topological spaces. Furthermore, generalized fuzzy sets are extended to theta-generalized fuzzy sets. Also, we introduce the concepts of fuzzy theta-generalized continuous and fuzzy theta-generalized irresolute mappings. (author)

  4. Other characterizations of $\\beta$-$\\theta$-R0 topological spaces

    OpenAIRE

    Miguel Caldas Cueva

    2013-01-01

    In this paper we give other characterizations of $\\beta$-$\\theta$-$%R_0$ and also introduce a new separation axiom called$\\beta$-$\\theta$-$R_1$. It turns out that $\\beta$-$\\theta$-$R_1$ isstronger that $\\beta$-$\\theta$-$R_0$

  5. Chemotherapy disrupts learning, neurogenesis and theta activity in the adult brain.

    Science.gov (United States)

    Nokia, Miriam S; Anderson, Megan L; Shors, Tracey J

    2012-12-01

    Chemotherapy, especially if prolonged, disrupts attention, working memory and speed of processing in humans. Most cancer drugs that cross the blood-brain barrier also decrease adult neurogenesis. Because new neurons are generated in the hippocampus, this decrease may contribute to the deficits in working memory and related thought processes. The neurophysiological mechanisms that underlie these deficits are generally unknown. A possible mediator is hippocampal oscillatory activity within the theta range (3-12 Hz). Theta activity predicts and promotes efficient learning in healthy animals and humans. Here, we hypothesised that chemotherapy disrupts learning via decreases in hippocampal adult neurogenesis and theta activity. Temozolomide was administered to adult male Sprague-Dawley rats in a cyclic manner for several weeks. Treatment was followed by training with different types of eyeblink classical conditioning, a form of associative learning. Chemotherapy reduced both neurogenesis and endogenous theta activity, as well as disrupted learning and related theta-band responses to the conditioned stimulus. The detrimental effects of temozolomide only occurred after several weeks of treatment, and only on a task that requires the association of events across a temporal gap and not during training with temporally overlapping stimuli. Chemotherapy did not disrupt the memory for previously learned associations, a memory independent of (new neurons in) the hippocampus. In conclusion, prolonged systemic chemotherapy is associated with a decrease in hippocampal adult neurogenesis and theta activity that may explain the selective deficits in processes of learning that describe the 'chemobrain'. © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  6. Completely X-symmetric S-matrices corresponding to theta functions and models of statistical mechanics

    International Nuclear Information System (INIS)

    Chudnovsky, D.V.; Chudnovsky, G.V.

    1981-01-01

    We consider general expressions of factorized S-matrices with Abelian symmetry expressed in terms of theta-functions. These expressions arise from representations of the Heisenberg group. New examples of factorized S-matrices lead to a large class of completely integrable models of statistical mechanics which generalize the XYZ-model of the eight-vertex model. (orig.)

  7. A pedagogical introduction to theta functions

    International Nuclear Information System (INIS)

    Koh, I.G.; Shin, H.J.

    1988-01-01

    This paper reports on revolutions in physics that have been frequently accompanied by new developments in mathematics. In seventeenth century, Newton has initiated a program of describing celestial motion by classical mechanics. Integral and differential calculus was essential tool. Orbits of the moon and the earth are given by solving the differential equation of Newton's equation. Imagine a situation where one tries to solve such orbits without integral and differential calculus. Similar revolutions in understanding quantum gravity and in making deep connections between statistical and string physics are under progresses. One of indispensible tools are the theory of theta functions on Riemann surfaces. Since the literature of theta functions is mainly written by professional mathematician, physicists feel somewhat uneasy to begin to read a long chapters of lemmas and theorems, but it is now generally accepted that theta function is essential in understanding two-dimensional conformal field theory as the integral and differential calculus was indispensible in Newtonian mechanics

  8. Search for the exotic $\\Theta^+$ resonance in the NOMAD experiment

    CERN Document Server

    Samoylov, O; Autiero, D; Baldisseri, Alberto; Baldo-Ceolin, M; Banner, M; Bassompierre, G; Benslama, K; Besson, N; Bird, I; Blumenfeld, B; Bobisut, F; Bouchez, J; Boyd, S; Bueno, A; Bunyatov, S; Camilleri, L L; Cardini, A; Cattaneo, P W; Cavasinni, V; Cervera-Villanueva, A; Challis, R; Chukanov, A; Collazuol, G; Conforto, G; Conta, C; Contalbrigo, M; Cousins, R; Daniels, D; De Santo, A; Degaudenzi, H M; Del Prete, T; Di Lella, L; Dignan, T; Do Couto e Silva, E; Dumarchez, J; Ellis, M; Feldman, G J; Ferrari, R; Ferrère, D; Flaminio, V; Fraternali, M; Gaillard, J M; Gangler, E; Geiser, A; Geppert, D; Gibin, D; Gninenko, S; Godley, A; Gosset, J; Gouanère, M; Grant, A; Graziani, G; Guglielmi, A M; Gómez-Cadenas, J J; Gössling, C; Hagner, C; Hernando, J; Hubbard, D; Hurst, P; Hyett, N; Iacopini, E; Joseph, C; Juget, F; Kent, N; Kirsanov, M; Klimov, O; Kokkonen, J; Kovzelev, A; Krasnoperov, A V; La Rotonda, L; Lacaprara, S; Lachaud, C; Lakic, B; Lanza, A; Laveder, M; Letessier-Selvon, A A; Linssen, L; Ljubicic, A; Long, J; Lupi, A; Lyubushkin, V; Lévy, J M; Marchionni, A; Martelli, F; Mendiburu, J P; Meyer, J P; Mezzetto, M; Mishra, S R; Moorhead, G F; Méchain, X; Naumov, D; Nefedov, Yu; Nguyen-Mau, C; Nédélec, P; Orestano, D; Pastore, F; Peak, L S; Pennacchio, E; Pessard, H; Petti, R; Placci, A; Polesello, G; Pollmann, D; Polyarush, A Yu; Popov, B; Poulsen, C; Rebuffi, L; Rico, J; Riemann, P; Roda, C; Rubbia, André; Salvatore, F; Schahmaneche, K; Schmidt, B; Schmidt, T; Sconza, A; Sevior, M; Sillou, D; Soler, F J P; Sozzi, G; Steele, D; Stiegler, U; Stipcevic, M; Stolarczyk, T; Tareb-Reyes, M; Taylor, G N; Tereshchenko, V V; Toropin, A; Touchard, A M; Tovey, S N; Tran, M T; Tsesmelis, E; Ulrichs, J; Vacavant, L; Valdata-Nappi, M; Valuev, V; Vannucci, F; Varvell, K E; Veltri, M; Vercesi, V; Vidal-Sitjes, G; Vieira, J M; Vinogradova, T; Weber, F V; Weisse, T; Wilson, F F; Winton, L J; Yabsley, B D; Zaccone, Henri; Zuber, K; Zuccon, P

    2007-01-01

    A search for exotic Theta baryon via Theta -> proton +Ks decay mode in the NOMAD muon neutrino DIS data is reported. The special background generation procedure was developed. The proton identification criteria are tuned to maximize the sensitivity to the Theta signal as a function of xF which allows to study the Theta production mechanism. We do not observe any evidence for the Theta state in the NOMAD data. We provide an upper limit on Theta production rate at 90% CL as 2.13 per 1000 of neutrino interactions.

  9. Cubic metaplectic forms and theta functions

    CERN Document Server

    Proskurin, Nikolai

    1998-01-01

    The book is an introduction to the theory of cubic metaplectic forms on the 3-dimensional hyperbolic space and the author's research on cubic metaplectic forms on special linear and symplectic groups of rank 2. The topics include: Kubota and Bass-Milnor-Serre homomorphisms, cubic metaplectic Eisenstein series, cubic theta functions, Whittaker functions. A special method is developed and applied to find Fourier coefficients of the Eisenstein series and cubic theta functions. The book is intended for readers, with beginning graduate-level background, interested in further research in the theory of metaplectic forms and in possible applications.

  10. Engineering prototypes for theta-pinch devices

    International Nuclear Information System (INIS)

    Hansborough, L.D.; Hammer, C.F.; Hanks, K.W.; McDonald, T.E.; Nunnally, W.C.

    1975-01-01

    Past, present, and future engineering prototypes for theta-pinch plasma-physics devices at Los Alamos Scientific Laboratory are discussed. Engineering prototypes are designed to test and evaluate all components under system conditions expected on actual plasma-physics experimental devices. The importance of engineering prototype development increases as the size and complexity of the plasma-physics device increases. Past experiences with the Scyllac prototype and the Staged Theta-Pinch prototype are discussed and evaluated. The design of the proposed Staged Scyllac prototype and the Large Staged Scyllac implosion prototype assembly are discussed

  11. Kilowatt-Class Fission Power Systems for Science and Human Precursor Missions

    Science.gov (United States)

    Mason, Lee S.; Gibson, Marc Andrew; Poston, Dave

    2013-01-01

    Nuclear power provides an enabling capability for NASA missions that might otherwise be constrained by power availability, mission duration, or operational robustness. NASA and the Department of Energy (DOE) are developing fission power technology to serve a wide range of future space uses. Advantages include lower mass, longer life, and greater mission flexibility than competing power system options. Kilowatt-class fission systems, designated "Kilopower," were conceived to address the need for systems to fill the gap above the current 100-W-class radioisotope power systems being developed for science missions and below the typical 100-k We-class reactor power systems being developed for human exploration missions. This paper reviews the current fission technology project and examines some Kilopower concepts that could be used to support future science missions or human precursors.

  12. Naïve and Robust: Class-Conditional Independence in Human Classification Learning

    Science.gov (United States)

    Jarecki, Jana B.; Meder, Björn; Nelson, Jonathan D.

    2018-01-01

    Humans excel in categorization. Yet from a computational standpoint, learning a novel probabilistic classification task involves severe computational challenges. The present paper investigates one way to address these challenges: assuming class-conditional independence of features. This feature independence assumption simplifies the inference…

  13. The Human Relations Class at Sir Winston Churchill Secondary School. Research Report.

    Science.gov (United States)

    Gilbert, Katherine J.

    Human Relations was a program offered to Grade 10 students at Churchill Secondary School during the 1971-72 school year in lieu of four courses. The emphasis of the program was on the development of students as people who were more aware of themselves, of other people, and of the environment. The class took part in a variety of activities during…

  14. Improving Wellness on Campus: Service Learning in a Human Nutrition Class

    Science.gov (United States)

    Wood, Bonnie

    2003-01-01

    In a human nutrition class, students are paired with university faculty or staff volunteer participants. Students teach their service learning partners how to record their food consumption and physical activity during a typical 7-day period. Using these data, students complete nutritional assessments of their partners. (Contains 2 figures.)

  15. Understanding Protein Synthesis: A Role-Play Approach in Large Undergraduate Human Anatomy and Physiology Classes

    Science.gov (United States)

    Sturges, Diana; Maurer, Trent W.; Cole, Oladipo

    2009-01-01

    This study investigated the effectiveness of role play in a large undergraduate science class. The targeted population consisted of 298 students enrolled in 2 sections of an undergraduate Human Anatomy and Physiology course taught by the same instructor. The section engaged in the role-play activity served as the study group, whereas the section…

  16. Human Capital, Social Classes, and the Earnings Determination Process in Brazilian Agriculture.

    Science.gov (United States)

    Neves, Jorge A.; Haller, Archibald O.; Fernandes, Danielle C.

    This paper examines the process of earnings determination in the agricultural sector of Brazil. Among the main causal factors analyzed are human capital (education and work experience), labor market segmentation, gender, social class position, level of development/modernization, and concentration of land ownership. Data on individuals employed in…

  17. Ih tunes theta/gamma oscillations and cross-frequency coupling in an in silico CA3 model.

    Directory of Open Access Journals (Sweden)

    Samuel A Neymotin

    Full Text Available Ih channels are uniquely positioned to act as neuromodulatory control points for tuning hippocampal theta (4-12 Hz and gamma (25 Hz oscillations, oscillations which are thought to have importance for organization of information flow. contributes to neuronal membrane resonance and resting membrane potential, and is modulated by second messengers. We investigated oscillatory control using a multiscale computer model of hippocampal CA3, where each cell class (pyramidal, basket, and oriens-lacunosum moleculare cells, contained type-appropriate isoforms of . Our model demonstrated that modulation of pyramidal and basket allows tuning theta and gamma oscillation frequency and amplitude. Pyramidal also controlled cross-frequency coupling (CFC and allowed shifting gamma generation towards particular phases of the theta cycle, effected via 's ability to set pyramidal excitability. Our model predicts that in vivo neuromodulatory control of allows flexibly controlling CFC and the timing of gamma discharges at particular theta phases.

  18. Better than sleep: theta neurofeedback training accelerates memory consolidation.

    Science.gov (United States)

    Reiner, Miriam; Rozengurt, Roman; Barnea, Anat

    2014-01-01

    Consistent empirical results showed that both night and day sleep enhanced memory consolidation. In this study we explore processes of consolidation of memory during awake hours. Since theta oscillations have been shown to play a central role in exchange of information, we hypothesized that elevated theta during awake hours will enhance memory consolidation. We used a neurofeedback protocol, to enhance the relative power of theta or beta oscillations. Participants trained on a tapping task, were divided into three groups: neurofeedback theta; neurofeedback beta; control. We found a significant improvement in performance in the theta group, relative to the beta and control groups, immediately after neurofeedback. Performance was further improved after night sleep in all groups, with a significant advantage favoring the theta group. Theta power during training was correlated with the level of improvement, indicating a clear relationship between memory consolidation, and theta neurofeedback. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Quantum thetas on noncommutative T4 from embeddings into lattice

    International Nuclear Information System (INIS)

    Chang-Young, Ee; Kim, Hoil

    2007-01-01

    In this paper, we investigate the theta vector and quantum theta function over noncommutative T 4 from the embedding of RxZ 2 . Manin has constructed the quantum theta functions from the lattice embedding into vector space (x finite group). We extend Manin's construction of the quantum theta function to the embedding of vector space x lattice case. We find that the holomorphic theta vector exists only over the vector space part of the embedding, and over the lattice part we can only impose the condition for the Schwartz function. The quantum theta function built on this partial theta vector satisfies the requirement of the quantum theta function. However, two subsequent quantum translations from the embedding into the lattice part are nonadditive, contrary to the additivity of those from the vector space part

  20. Leptogenesis, $\\mu - \\tau$ Symmetry and $\\theta_{13}$

    CERN Document Server

    Mohapatra, Rabindra N; Yu, H; Yu, Haibo

    2005-01-01

    We show that in theories where neutrino masses arise from type I seesaw formula with three right handed neutrinos and where large atmospheric mixing angle owes its origin to an approximate leptonic $\\mu-\\tau$ interchange symmetry, the primordial lepton asymmetry of the Universe, $\\epsilon_l$ can be expressed in a simple form in terms of low energy neutrino oscillation parameters as $\\epsilon_l = (a \\Delta m^2_\\odot+ b \\Delta m^2_A \\theta^2_{13})$, where $a$ and $b$ are parameters characterizing high scale physics and are each of order $\\leq 10^{-2} $ eV$^{-2}$. We also find that for the case of two right handed neutrinos, $\\epsilon_l \\propto \\theta^2_{13}$ as a result of which, the observed value of baryon to photon ratio implies a lower limit on $\\theta_{13}$. For specific choices of the CP phase $\\delta$ we find $\\theta_{13}$ is predicted to be between $0.10-0.15$.

  1. Hippocampal theta frequency shifts and operant behaviour

    NARCIS (Netherlands)

    Lopes da Silva, F.H.; Kamp, A.

    1. 1. A shift of hippocampal dominant theta frequency to 6 c/sec has been demonstrated in the post-reward period in two dogs, which occurs consistently related in time to a well defined behavioural pattern in the course of an operant conditioning paradigm. 2. 2. The frequency shift was detected and

  2. Scylla IV-P theta pinch

    International Nuclear Information System (INIS)

    Bailey, A.G.; Chandler, G.I.; Ekdahl, C.A. Jr.; Lillberg, J.W.; Machalek, M.D.; Seibel, F.T.

    1976-01-01

    Scylla IV-P is a flexible, linear theta pinch designed to investigate high-density linear concepts, end-stoppering, alternate heating methods, and plasma injection techniques relevant to a pure fusion reactor and/or a fusion-fission hybrid system. The construction and experimental arrangement of the device are briefly described

  3. Three-dimensional ideal theta(1)/theta(2) angular transformer and its uses in fiber optics.

    Science.gov (United States)

    Ning, X

    1988-10-01

    A 3-D ideal theta(1)/theta(2) angular transformer in nonimaging optics is introduced. The axially symmetric transformer, combining a portion of a hyperbolic concentrator with two lenses, transforms an input limited Lambertian over an angle theta(1) to an output limited Lambertian over an angle theta(2) without losing throughput. This is the first known transformer with such ideal properties. Results of computer simulations of a transformer with planospherical lenses are presented. Because of its ideal angular transforming property, the transformer offers an excellent solution for power launching and fiber-fiber coupling in optical fiber systems. In principle, the theoretical maximum coupling efficiency based on radiance conservation can be achieved with this transformer. Several conceptual designs of source-fiber and fiber-fiber couplers using the transformer are given.

  4. The theta-structure in string theories - 1: bosonic strings

    International Nuclear Information System (INIS)

    Li Miao.

    1985-09-01

    We explored the theta-structures in bosonic string theories which are similar to those in gauge field theories. The theta-structure of string is due to the multiply connected spatial compact subspace of space-time. The work of this paper shows that there is an energy band E(theta) in the string theory and one may move the tachyon out in theory by choosing some proper theta parameters. (author)

  5. Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory

    OpenAIRE

    Masahiro eKawasaki; Masahiro eKawasaki; Masahiro eKawasaki; Keiichi eKitajo; Keiichi eKitajo; Yoko eYamaguchi

    2014-01-01

    In humans, theta phase (4–8 Hz) synchronization observed on electroencephalography (EEG) plays an important role in the manipulation of mental representations during working memory (WM) tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from...

  6. Increase in short-term memory capacity induced by down-regulating individual theta frequency via transcranial alternating current stimulation.

    Science.gov (United States)

    Vosskuhl, Johannes; Huster, René J; Herrmann, Christoph S

    2015-01-01

    Working memory (WM) and short-term memory (STM) supposedly rely on the phase-amplitude coupling (PAC) of neural oscillations in the theta and gamma frequency ranges. The ratio between the individually dominant gamma and theta frequencies is believed to determine an individual's memory capacity. The aim of this study was to establish a causal relationship between the gamma/theta ratio and WM/STM capacity by means of transcranial alternating current stimulation (tACS). To achieve this, tACS was delivered at a frequency below the individual theta frequency. Thereby the individual ratio of gamma to theta frequencies was changed, resulting in an increase of STM capacity. Healthy human participants (N = 33) were allocated to two groups, one receiving verum tACS, the other underwent a sham control protocol. The electroencephalogram (EEG) was measured before stimulation and analyzed with regard to the properties of PAC between theta and gamma frequencies to determine individual stimulation frequencies. After stimulation, EEG was recorded again in order to find after-effects of tACS in the oscillatory features of the EEG. Measures of STM and WM were obtained before, during and after stimulation. Frequency spectra and behavioral data were compared between groups and different measurement phases. The tACS- but not the sham stimulated group showed an increase in STM capacity during stimulation. WM was not affected in either groups. An increase in task-related theta amplitude after stimulation was observed only for the tACS group. These augmented theta amplitudes indicated that the manipulation of individual theta frequencies was successful and caused the increase in STM capacity.

  7. Increase in short-term memory capacity induced by down-regulating individual theta frequency via transcranial alternating current stimulation

    Directory of Open Access Journals (Sweden)

    Johannes eVosskuhl

    2015-05-01

    Full Text Available Working memory (WM and short-term memory (STM supposedly rely on the phase-amplitude coupling of neural oscillations in the theta and gamma frequency ranges. The ratio between the individually dominant gamma and theta frequencies is believed to determine an individual’s memory capacity. The aim of this study was to establish a causal relationship between the gamma/theta ratio and WM/STM capacity by means of transcranial alternating current stimulation (tACS. To achieve this, tACS was delivered at a frequency below the individual theta frequency. Thereby the individual ratio of gamma to theta frequencies was changed, resulting in an increase of STM capacity. Healthy human participants (N=33 were allocated to two groups, one receiving verum tACS, the other underwent a sham control protocol. The electroencephalogram (EEG was measured before stimulation and analyzed with regard to the properties of phase-amplitude coupling between theta and gamma frequencies to determine individual stimulation frequencies. After stimulation, EEG was recorded again in order to find after-effects of tACS in the oscillatory features of the EEG. Measures of STM and WM were obtained before, during and after stimulation. Frequency spectra and behavioral data were compared between groups and different measurement phases. The tACS- but not the sham stimulated group showed an increase in STM capacity during stimulation. WM was not affected in either groups. An increase in task-related theta amplitude after stimulation was observed only for the tACS group. These augmented theta amplitudes indicated that the manipulation of individual theta frequencies was successful and caused the increase in STM capacity.

  8. Episodic sequence memory is supported by a theta-gamma phase code.

    Science.gov (United States)

    Heusser, Andrew C; Poeppel, David; Ezzyat, Youssef; Davachi, Lila

    2016-10-01

    The meaning we derive from our experiences is not a simple static extraction of the elements but is largely based on the order in which those elements occur. Models propose that sequence encoding is supported by interactions between high- and low-frequency oscillations, such that elements within an experience are represented by neural cell assemblies firing at higher frequencies (gamma) and sequential order is encoded by the specific timing of firing with respect to a lower frequency oscillation (theta). During episodic sequence memory formation in humans, we provide evidence that items in different sequence positions exhibit greater gamma power along distinct phases of a theta oscillation. Furthermore, this segregation is related to successful temporal order memory. Our results provide compelling evidence that memory for order, a core component of an episodic memory, capitalizes on the ubiquitous physiological mechanism of theta-gamma phase-amplitude coupling.

  9. Resolution improvement by nonconfocal theta microscopy.

    Science.gov (United States)

    Lindek, S; Stelzer, E H

    1999-11-01

    We present a novel scanning fluorescence microscopy technique, nonconfocal theta microscopy (NCTM), that provides almost isotropic resolution. In NCTM, multiphoton absorption from two orthogonal illumination directions is used to induce fluorescence emission. Therefore the point-spread function of the microscope is described by the product of illumination point-spread functions with reduced spatial overlap, which provides the resolution improvement and the more isotropic observation volume. We discuss the technical details of this new method.

  10. Frontal Theta Activity Supports Detecting Mismatched Information in Visual Working Memory.

    Science.gov (United States)

    Liang, Tengfei; Hu, Zhonghua; Liu, Qiang

    2017-01-01

    During the comparison stage of visual working memory (VWM) processing, detecting the mismatch between the external sensory input and internal representations is a crucial cognitive ability for human, but the neural mechanism behind it remains largely unclear. The present study investigated the role of frontal theta power in detecting the mismatched information in VWM in a delayed matching task. A control task required to compare two simultaneously presented visual figures was also designed as a contrast to exclude the possibility that frontal theta activity just reflecting the non-memory-related behavioral conflicts. To better characterize the control mechanisms shaped by the frontal theta oscillation in human VWM, colored shapes were adopted as materials while both the task-relevant shape feature and task-irrelevant color feature could be mismatched. We found that the response times of participants were significantly delayed under the relevant- and irrelevant-mismatch conditions in both tasks and the conjunction-mismatch condition in delayed matching task. While our EEG data showed that increased frontal theta power was only observed under the relevant- and conjunction-mismatch conditions in the delayed matching task, but not the control task. These findings suggest that the frontal distributed theta activity observed here reflects the detection of mismatched information during the comparison stage of VWM, rather than the response-related conflicts. Furthermore, it is consistent with the proposal that theta-band oscillation can act as a control mechanism in working memory function so that the target-mismatched information in VWM could be successfully tracked. We also propose a possible processing structure to explain the neural dynamics underlying the mismatch detection process in VWM.

  11. Frontal Theta Activity Supports Detecting Mismatched Information in Visual Working Memory

    Directory of Open Access Journals (Sweden)

    Tengfei Liang

    2017-10-01

    Full Text Available During the comparison stage of visual working memory (VWM processing, detecting the mismatch between the external sensory input and internal representations is a crucial cognitive ability for human, but the neural mechanism behind it remains largely unclear. The present study investigated the role of frontal theta power in detecting the mismatched information in VWM in a delayed matching task. A control task required to compare two simultaneously presented visual figures was also designed as a contrast to exclude the possibility that frontal theta activity just reflecting the non-memory-related behavioral conflicts. To better characterize the control mechanisms shaped by the frontal theta oscillation in human VWM, colored shapes were adopted as materials while both the task-relevant shape feature and task-irrelevant color feature could be mismatched. We found that the response times of participants were significantly delayed under the relevant- and irrelevant-mismatch conditions in both tasks and the conjunction-mismatch condition in delayed matching task. While our EEG data showed that increased frontal theta power was only observed under the relevant- and conjunction-mismatch conditions in the delayed matching task, but not the control task. These findings suggest that the frontal distributed theta activity observed here reflects the detection of mismatched information during the comparison stage of VWM, rather than the response-related conflicts. Furthermore, it is consistent with the proposal that theta-band oscillation can act as a control mechanism in working memory function so that the target-mismatched information in VWM could be successfully tracked. We also propose a possible processing structure to explain the neural dynamics underlying the mismatch detection process in VWM.

  12. MHC Class II and CD9 in Human Eosinophils Localize to Detergent-Resistant Membrane Microdomains

    Science.gov (United States)

    Akuthota, Praveen; Melo, Rossana C. N.; Spencer, Lisa A.

    2012-01-01

    Eosinophils function in murine allergic airways inflammation as professional antigen-presenting cells (APCs). In murine professional APC cell types, optimal functioning of MHC Class II depends on its lateral association in plasma membranes and colocalization with the tetraspanin CD9 into detergent-resistant membrane microdomains (DRMs). With human eosinophils, we evaluated the localization of MHC Class II (HLA-DR) to DRMs and the functional significance of such localization. In granulocyte-macrophage colony-stimulating factor–stimulated human eosinophils, antibody cross-linked HLA-DR colocalized by immunofluorescence microscopy focally on plasma membranes with CD9 and the DRM marker ganglioside GM1. In addition, HLA-DR coimmunoprecipitates with CD9 after chemical cross-linking of CD9. HLA-DR and CD9 were localized by Western blotting in eosinophil DRM subcellular fractions. DRM disruption with the cholesterol-depleting agent methyl-β-cyclodextrin decreased eosinophil surface expression of HLA-DR and CD9. We show that CD9 is abundant on the surface of eosinophils, presenting the first electron microscopy data of the ultrastructural immunolocalization of CD9 in human eosinophils. Disruption of HLA-DR–containing DRMs decreased the ability of superantigen-loaded human eosinophils to stimulate CD4+ T-cell activation (CD69 expression), proliferation, and cytokine production. Our results, which demonstrate that eosinophil MHC Class II localizes to DRMs in association with CD9 in a functionally significant manner, represent a novel insight into the organization of the antigen presentation complex of human eosinophils. PMID:21885678

  13. MHC Class II and CD9 in human eosinophils localize to detergent-resistant membrane microdomains.

    Science.gov (United States)

    Akuthota, Praveen; Melo, Rossana C N; Spencer, Lisa A; Weller, Peter F

    2012-02-01

    Eosinophils function in murine allergic airways inflammation as professional antigen-presenting cells (APCs). In murine professional APC cell types, optimal functioning of MHC Class II depends on its lateral association in plasma membranes and colocalization with the tetraspanin CD9 into detergent-resistant membrane microdomains (DRMs). With human eosinophils, we evaluated the localization of MHC Class II (HLA-DR) to DRMs and the functional significance of such localization. In granulocyte-macrophage colony-stimulating factor-stimulated human eosinophils, antibody cross-linked HLA-DR colocalized by immunofluorescence microscopy focally on plasma membranes with CD9 and the DRM marker ganglioside GM1. In addition, HLA-DR coimmunoprecipitates with CD9 after chemical cross-linking of CD9. HLA-DR and CD9 were localized by Western blotting in eosinophil DRM subcellular fractions. DRM disruption with the cholesterol-depleting agent methyl-β-cyclodextrin decreased eosinophil surface expression of HLA-DR and CD9. We show that CD9 is abundant on the surface of eosinophils, presenting the first electron microscopy data of the ultrastructural immunolocalization of CD9 in human eosinophils. Disruption of HLA-DR-containing DRMs decreased the ability of superantigen-loaded human eosinophils to stimulate CD4(+) T-cell activation (CD69 expression), proliferation, and cytokine production. Our results, which demonstrate that eosinophil MHC Class II localizes to DRMs in association with CD9 in a functionally significant manner, represent a novel insight into the organization of the antigen presentation complex of human eosinophils.

  14. Persistence of hepatitis C virus in a white population: associations with human leukocyte antigen class 1.

    LENUS (Irish Health Repository)

    Fanning, Liam J

    2012-02-03

    The aim of this study was to define novel associations between human leukocyte antigen (HLA) class 1 alleles and persistence or clearance of the hepatitis C virus (HCV) in a white population. All individuals in the study were seropositive for anti-HCV antibodies. Viral status was determined by the Roche HCV Amplicor test. HLA-A, -B, -C allelic group profile was molecularly defined by reverse line probe hybridization. The strongest individual allelic group associations with persistent HCV infection were HLA A*11 (p = 0.044) and Cw*04 (p = 0.006). However, only the HLA C*04 association survived correction for multiple comparisons. Further analysis of alleles in linkage with HLA Cw*04 revealed that the haplotype HLA A*11, Cw*04 was present in 11 individuals, 10 of whom were viremic (p = 0.05). No gene dosage effect was observed. No association between HLA class 1 allelic groups and aviremia and virus load was evident in this white population. HLA B*44 is associated with low virus load in human immunodeficiency virus disease, but this association was not evident in this HCV-infected population. Novel HLA class 1 alleles associated with persistence of HCV have been identified.

  15. Trades Between Opposition and Conjunction Class Trajectories for Early Human Missions to Mars

    Science.gov (United States)

    Mattfeld, Bryan; Stromgren, Chel; Shyface, Hilary; Komar, David R.; Cirillo, William; Goodliff, Kandyce

    2014-01-01

    Candidate human missions to Mars, including NASA's Design Reference Architecture 5.0, have focused on conjunction-class missions with long crewed durations and minimum energy trajectories to reduce total propellant requirements and total launch mass. However, in order to progressively reduce risk and gain experience in interplanetary mission operations, it may be desirable that initial human missions to Mars, whether to the surface or to Mars orbit, have shorter total crewed durations and minimal stay times at the destination. Opposition-class missions require larger total energy requirements relative to conjunction-class missions but offer the potential for much shorter mission durations, potentially reducing risk and overall systems performance requirements. This paper will present a detailed comparison of conjunction-class and opposition-class human missions to Mars vicinity with a focus on how such missions could be integrated into the initial phases of a Mars exploration campaign. The paper will present the results of a trade study that integrates trajectory/propellant analysis, element design, logistics and sparing analysis, and risk assessment to produce a comprehensive comparison of opposition and conjunction exploration mission constructs. Included in the trade study is an assessment of the risk to the crew and the trade offs between the mission duration and element, logistics, and spares mass. The analysis of the mission trade space was conducted using four simulation and analysis tools developed by NASA. Trajectory analyses for Mars destination missions were conducted using VISITOR (Versatile ImpulSive Interplanetary Trajectory OptimizeR), an in-house tool developed by NASA Langley Research Center. Architecture elements were evaluated using EXploration Architecture Model for IN-space and Earth-to-orbit (EXAMINE), a parametric modeling tool that generates exploration architectures through an integrated systems model. Logistics analysis was conducted using

  16. Characterizing the roles of alpha and theta oscillations in multisensory attention.

    Science.gov (United States)

    Keller, Arielle S; Payne, Lisa; Sekuler, Robert

    2017-05-01

    Cortical alpha oscillations (8-13Hz) appear to play a role in suppressing distractions when just one sensory modality is being attended, but do they also contribute when attention is distributed over multiple sensory modalities? For an answer, we examined cortical oscillations in human subjects who were dividing attention between auditory and visual sequences. In Experiment 1, subjects performed an oddball task with auditory, visual, or simultaneous audiovisual sequences in separate blocks, while the electroencephalogram was recorded using high-density scalp electrodes. Alpha oscillations were present continuously over posterior regions while subjects were attending to auditory sequences. This supports the idea that the brain suppresses processing of visual input in order to advantage auditory processing. During a divided-attention audiovisual condition, an oddball (a rare, unusual stimulus) occurred in either the auditory or the visual domain, requiring that attention be divided between the two modalities. Fronto-central theta band (4-7Hz) activity was strongest in this audiovisual condition, when subjects monitored auditory and visual sequences simultaneously. Theta oscillations have been associated with both attention and with short-term memory. Experiment 2 sought to distinguish these possible roles of fronto-central theta activity during multisensory divided attention. Using a modified version of the oddball task from Experiment 1, Experiment 2 showed that differences in theta power among conditions were independent of short-term memory load. Ruling out theta's association with short-term memory, we conclude that fronto-central theta activity is likely a marker of multisensory divided attention. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. The viral transcription group determines the HLA class I cellular immune response against human respiratory syncytial virus.

    Science.gov (United States)

    Johnstone, Carolina; Lorente, Elena; Barriga, Alejandro; Barnea, Eilon; Infantes, Susana; Lemonnier, François A; David, Chella S; Admon, Arie; López, Daniel

    2015-04-01

    The cytotoxic T-lymphocyte-mediated killing of virus-infected cells requires previous recognition of short viral antigenic peptides bound to human leukocyte antigen class I molecules that are exposed on the surface of infected cells. The cytotoxic T-lymphocyte response is critical for the clearance of human respiratory syncytial virus infection. In this study, naturally processed viral human leukocyte antigen class I ligands were identified with mass spectrometry analysis of complex human leukocyte antigen-bound peptide pools isolated from large amounts of human respiratory syncytial virus-infected cells. Acute antiviral T-cell response characterization showed that viral transcription determines both the immunoprevalence and immunodominance of the human leukocyte antigen class I response to human respiratory syncytial virus. These findings have clear implications for antiviral vaccine design. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. The Viral Transcription Group Determines the HLA Class I Cellular Immune Response Against Human Respiratory Syncytial Virus*

    Science.gov (United States)

    Johnstone, Carolina; Lorente, Elena; Barriga, Alejandro; Barnea, Eilon; Infantes, Susana; Lemonnier, François A.; David, Chella S.; Admon, Arie; López, Daniel

    2015-01-01

    The cytotoxic T-lymphocyte-mediated killing of virus-infected cells requires previous recognition of short viral antigenic peptides bound to human leukocyte antigen class I molecules that are exposed on the surface of infected cells. The cytotoxic T-lymphocyte response is critical for the clearance of human respiratory syncytial virus infection. In this study, naturally processed viral human leukocyte antigen class I ligands were identified with mass spectrometry analysis of complex human leukocyte antigen-bound peptide pools isolated from large amounts of human respiratory syncytial virus-infected cells. Acute antiviral T-cell response characterization showed that viral transcription determines both the immunoprevalence and immunodominance of the human leukocyte antigen class I response to human respiratory syncytial virus. These findings have clear implications for antiviral vaccine design. PMID:25635267

  19. Lower trait frontal theta activity in mindfulness meditators

    Directory of Open Access Journals (Sweden)

    Guaraci Ken Tanaka

    2014-09-01

    Full Text Available Acute and long-term effects of mindfulness meditation on theta-band activity are not clear. The aim of this study was to investigate frontal theta differences between long- and short-term mindfulness practitioners before, during, and after mindfulness meditation. Twenty participants were recruited, of which 10 were experienced Buddhist meditators. Despite an acute increase in the theta activity during meditation in both the groups, the meditators showed lower trait frontal theta activity. Therefore, we suggested that this finding is a neural correlate of the expert practitioners’ ability to limit the processing of unnecessary information (e.g., discursive thought and increase the awareness of the essential content of the present experience. In conclusion, acute changes in the theta band throughout meditation did not appear to be a specific correlate of mindfulness but were rather related to the concentration properties of the meditation. Notwithstanding, lower frontal theta activity appeared to be a trait of mindfulness practices.

  20. {theta}-Compactness in L-topological spaces

    Energy Technology Data Exchange (ETDEWEB)

    Hanafy, I.M. [Department of Mathematics, Faculty of Education, Suez Canal University, El-Arish (Egypt)], E-mail: ihanafy@hotmail.com

    2009-12-15

    Recently, El-Naschie has shown that the notion of fuzzy topology may be relevant to quantum particle physics in connection with string theory and e{sup {infinity}} theory. In 2005, Caldas and Jafari have introduced {theta}-compact fuzzy topological spaces. In this paper, the concepts of{theta}-compactness, countable{theta}-compactness and the{theta}-Lindeloef property are introduced and studied in L-topological spaces, where L is a complete de Morgan algebra. They are defined by means of{theta}-openL-sets and their inequalities. They does not rely on the structure of basis lattice L and no distributivity in L is required. They can also be characterized by{theta}-closedL-sets and their inequalities. When L is a completely de Morgan algebra, their many characterizations are presented.

  1. Artificial theta stimulation impairs encoding of contextual fear memory.

    Directory of Open Access Journals (Sweden)

    Arto Lipponen

    Full Text Available Several experiments have demonstrated an intimate relationship between hippocampal theta rhythm (4-12 Hz and memory. Lesioning the medial septum or fimbria-fornix, a fiber track connecting the hippocampus and the medial septum, abolishes the theta rhythm and results in a severe impairment in declarative memory. To assess whether there is a causal relationship between hippocampal theta and memory formation we investigated whether restoration of hippocampal theta by electrical stimulation during the encoding phase also restores fimbria-fornix lesion induced memory deficit in rats in the fear conditioning paradigm. Male Wistar rats underwent sham or fimbria-fornix lesion operation. Stimulation electrodes were implanted in the ventral hippocampal commissure and recording electrodes in the septal hippocampus. Artificial theta stimulation of 8 Hz was delivered during 3-min free exploration of the test cage in half of the rats before aversive conditioning with three foot shocks during 2 min. Memory was assessed by total freezing time in the same environment 24 h and 28 h after fear conditioning, and in an intervening test session in a different context. As expected, fimbria-fornix lesion impaired fear memory and dramatically attenuated hippocampal theta power. Artificial theta stimulation produced continuous theta oscillations that were almost similar to endogenous theta rhythm in amplitude and frequency. However, contrary to our predictions, artificial theta stimulation impaired conditioned fear response in both sham and fimbria-fornix lesioned animals. These data suggest that restoration of theta oscillation per se is not sufficient to support memory encoding after fimbria-fornix lesion and that universal theta oscillation in the hippocampus with a fixed frequency may actually impair memory.

  2. Eta Products and Theta Series Identities

    CERN Document Server

    Kohler, Gunter

    2011-01-01

    This monograph deals with products of Dedekind's eta function, with Hecke theta series on quadratic number fields, and with "Eisenstein series." The author brings to the public the large number of identities that have been discovered over the past 20 years, the majority of which have not been published elsewhere. This book will be of interest to graduate students and scholars in the field of number theory and, in particular, modular forms. It is not an introductory text in this field. Nevertheless, some theoretical background material is presented that is important for understanding

  3. Numerical studies of the linear theta pinch

    International Nuclear Information System (INIS)

    Brackbill, J.U.; Menzel, M.T.; Barnes, D.C.

    1975-01-01

    Aspects of several physical problems associated with linear theta pinches were studied using recently developed numerical methods for the solution of the nonlinear equations for time-dependent magnetohydrodynamic flow in two- and three-dimensions. The problems studied include the propagation of end-loss produced rarefaction waves, the flow produced in a proposed injection experiment geometry, and the linear growth and nonlinear saturation of instabilities in rotating plasmas, all in linear geometries. The studies illustrate how numerical computations aid in flow visualization, and how the small amplitude behavior and nonlinear fate of plasmas in unstable equilibria can be connected through the numerical solution of the dynamical equations. (auth)

  4. Ramanujan’s mock theta functions

    Science.gov (United States)

    Griffin, Michael; Ono, Ken; Rolen, Larry

    2013-01-01

    In his famous deathbed letter, Ramanujan introduced the notion of a mock theta function, and he offered some alleged examples. Recent work by Zwegers [Zwegers S (2001) Contemp Math 291:268–277 and Zwegers S (2002) PhD thesis (Univ of Utrecht, Utrecht, The Netherlands)] has elucidated the theory encompassing these examples. They are holomorphic parts of special harmonic weak Maass forms. Despite this understanding, little attention has been given to Ramanujan’s original definition. Here, we prove that Ramanujan’s examples do indeed satisfy his original definition. PMID:23536292

  5. Quantum thetas on noncommutative Td with general embeddings

    International Nuclear Information System (INIS)

    Chang-Young, Ee; Kim, Hoil

    2008-01-01

    In this paper, we construct quantum theta functions over noncommutative T d with general embeddings. Manin has constructed quantum theta functions from the lattice embedding into vector space x finite group. We extend Manin's construction of quantum thetas to the case of general embedding of vector space x lattice x torus. It turns out that only for the vector space part of the embedding there exists the holomorphic theta vector, while for the lattice part there does not. Furthermore, the so-called quantum translations from embedding into the lattice part become non-additive, while those from the vector space part are additive

  6. Quantum Thetas on Noncommutative T^d with General Embeddings

    OpenAIRE

    Chang-Young, Ee; Kim, Hoil

    2007-01-01

    In this paper we construct quantum theta functions over noncommutative T^d with general embeddings. Manin has constructed quantum theta functions from the lattice embedding into vector space x finite group. We extend Manin's construction of quantum thetas to the case of general embedding of vector space x lattice x torus. It turns out that only for the vector space part of the embedding there exists the holomorphic theta vector, while for the lattice part there does not. Furthermore, the so-c...

  7. Material testing in a linear theta pinch

    International Nuclear Information System (INIS)

    Alani, R.; Azodi, H.; Naraghi, M.; Safaii, B.; Torabi-Fard, A.

    1983-01-01

    The interaction of stainless steel 316 and Inconel 625 alloys has been investigated with a thermonuclear-like plasma, n = 10 16 cm -3 and Tsub(i) = 1 keV, generated in the Alvand I linear theta pinch. The average power flux is 10 7 W/cm 2 and the interaction time nearly one μs. A theoretical analysis based on the formation of an observed impurity layer near the material, has been used to determine the properties of the impurity layer and the extent of the damage on the material. Although arcing has been observed, the dominant damage mechanism has been assessed to be due to evaporation. Exposure to single shots has produced very heavily defective areas and even surface cracks on the SS 316 sample, but no cracks were observed on Inconel 625 after exposure to even 18 shots. On the basis of temperature rise and evaporation a comparison is made among materials exposed to plasmas of a theta pinch, shock tube, present generation tokamak and an anticipated tokamak reactor. (orig.)

  8. Human leukocyte antigen class II susceptibility conferring alleles among non-insulin dependent diabetes mellitus patients

    International Nuclear Information System (INIS)

    Tipu, H.N.; Ahmed, T.A.; Bashir, M.M.

    2010-01-01

    To determine the frequency of Human Leukocyte Antigen (HLA) class II susceptibility conferring alleles among type 2 Diabetes mellitus patients, in comparison with healthy controls. Cross-sectional comparative study. Patients with non-insulin dependent Diabetes mellitus meeting World Health Organization criteria were studied. These were compared with age and gender matched healthy control subjects. For each subject (patients as well as controls), DNA was extracted from ethylene diamine tetra-acetate sample and HLA class II DRB1 typing was carried out at allele group level (DRB1*01-DRB1*16) by sequence specific primers. Human leukocyte antigen DRB1 type was determined by agarose gel electrophoresis and results were recorded. Frequencies were determined as number of an allele divided by total number of alleles per group; p-value was computed using Pearson's chi-square test. Among the 100 patients, there were 63 males and 37 females with 68 controls. A total of 13 different HLA DRB1 alleles were detected, with DRB1*15 being the commonest in both the groups. The allele DRB1*13 had statistically significant higher frequency in patient group as compared to controls (p 0.005). HLA DRB1*13 was found with a significantly increased frequency in non-insulin dependent Diabetes mellitus. (author)

  9. A Novel Class of Small Molecule Agonists with Preference for Human over Mouse TLR4 Activation.

    Directory of Open Access Journals (Sweden)

    Jason D Marshall

    Full Text Available The best-characterized Toll-like receptor 4 (TLR4 ligands are lipopolysaccharide (LPS and its chemically modified and detoxified variant, monophosphoryl lipid A (MPL. Although both molecules are active for human TLR4, they demonstrate a potency preference for mouse TLR4 based on data from transfected cell lines and primary cells of both species. After a high throughput screening process of small molecule libraries, we have discovered a new class of TLR4 agonist with a species preference profile differing from MPL. Products of the 4-component Ugi synthesis reaction were demonstrated to potently trigger human TLR4-transfected HEK cells but not mouse TLR4, although inclusion of the human MD2 with mTLR4 was able to partially recover activity. Co-expression of CD14 was not required for optimal activity of Ugi compounds on transfected cells, as it is for LPS. The species preference profile for the panel of Ugi compounds was found to be strongly active for human and cynomolgus monkey primary cells, with reduced but still substantial activity for most Ugi compounds on guinea pig cells. Mouse, rat, rabbit, ferret, and cotton rat cells displayed little or no activity when exposed to Ugi compounds. However, engineering the human versions of TLR4 and MD2 to be expressed in mTLR4/MD2 deficient mice allowed for robust activity by Ugi compounds both in vitro and in vivo. These findings extend the range of compounds available for development as agonists of TLR4 and identify novel molecules which reverse the TLR4 triggering preference of MPL for mouse TLR4 over human TLR4. Such compounds may be amenable to formulation as more potent human-specific TLR4L-based adjuvants than typical MPL-based adjuvants.

  10. Theta oscillations orchestrate medial temporal lobe and neocortex in remembering autobiographical memories.

    Science.gov (United States)

    Fuentemilla, L; Barnes, G R; Düzel, E; Levine, B

    2014-01-15

    Remembering autobiographical events can be associated with detailed visual imagery. The medial temporal lobe (MTL), precuneus and prefrontal cortex are held to jointly enable such vivid retrieval, but how these regions are orchestrated remains unclear. An influential prediction from animal physiology is that neural oscillations in theta frequency may be important. In this experiment, participants prospectively collected audio recordings describing personal autobiographical episodes or semantic knowledge over 2 to 7 months. These were replayed as memory retrieval cues while recording brain activity with magnetoencephalography (MEG). We identified a peak of theta power within a left MTL region of interest during both autobiographical and General Semantic retrieval. This MTL region was selectively phase-synchronized with theta oscillations in precuneus and medial prefrontal cortex, and this synchrony was higher during autobiographical as compared to General Semantic knowledge retrieval. Higher synchrony also predicted more detailed visual imagery during retrieval. Thus, theta phase-synchrony orchestrates in humans the MTL with a distributed neocortical memory network when vividly remembering autobiographical experiences. © 2013.

  11. Distribution of class ii major histocompatibility complex antigenexpressing cells in human dental pulp with carious lesions

    Directory of Open Access Journals (Sweden)

    Tetiana Haniastuti

    2012-09-01

    Full Text Available Background: Dental caries is a bacterial infection which causes destruction of the hard tissues of the tooth. Exposure of the dentin to the oral environment as a result of caries inevitably results in a cellular response in the pulp. The major histocompatibility complex (MHC is a group of genes that code for cell-surface histocompatibility antigens. Cells expressing class II MHC molecules participate in the initial recognition and the processing of antigenic substances to serve as antigen-presenting cells. Purpose: The aim of the study was to elucidate the alteration in the distribution of class II MHC antigen-expressing cells in human dental pulp as carious lesions progressed toward the pulp. Methods: Fifteen third molars with caries at the occlusal site at various stages of decay and 5 intact third molars were extracted and used in this study. Before decalcifying with 10% EDTA solution (pH 7.4, all the samples were observed by micro-computed tomography to confirm the lesion condition three-dimensionally. The specimens were then processed for cryosection and immunohistochemistry using an anti-MHC class II monoclonal antibody. Results: Class II MHC antigen-expressing cells were found both in normal and carious specimens. In normal tooth, the class II MHC-immunopositive cells were observed mainly at the periphery of the pulp tissue. In teeth with caries, class II MHC-immunopositive cells were located predominantly subjacent to the carious lesions. As the caries progressed, the number of class II MHC antigen-expressing cells was increased. Conclusion: The depth of carious lesions affects the distribution of class II MHC antigen-expressing cells in the dental pulp.Latar belakang: Karies merupakan penyakit infeksi bakteri yang mengakibatkan destruksi jaringan keras gigi. Dentin yang terbuka akibat karies akan menginduksi respon imun seluler pada pulpa. Kompleks histokompatibilitas utama (MHC merupakan sekumpulan gen yang mengkode histokompatibilitas

  12. Enhancement of motor learning by focal intermittent theta burst stimulation (iTBS) of either the primary motor (M1) or somatosensory area (S1) in healthy human subjects.

    Science.gov (United States)

    Platz, Thomas; Adler-Wiebe, Marija; Roschka, Sybille; Lotze, Martin

    2018-01-01

    Motor rehabilitation after brain damage relies on motor re-learning as induced by specific training. Non-invasive brain stimulation (NIBS) can alter cortical excitability and thereby has a potential to enhance subsequent training-induced learning. Knowledge about any priming effects of NIBS on motor learning in healthy subjects can help to design targeted therapeutic applications in brain-damaged subjects. To examine whether complex motor learning in healthy subjects can be enhanced by intermittent theta burst stimulation (iTBS) to primary motor or sensory cortical areas. Eighteen young healthy subjects trained eight different arm motor tasks (arm ability training, AAT) once a day for 5 days using their left non-dominant arm. Except for day 1 (baseline), training was performed after applying an excitatory form of repetitive transcranial magnetic stimulation (iTBS) to either (I) right M1 or (II) S1, or (III) sham stimulation to the right M1. Subjects were randomly assigned to conditions I, II, or III. A principal component analysis of the motor behaviour data suggested eight independent motor abilities corresponding to the 8 trained tasks. AAT induced substantial motor learning across abilities with generalisation to a non-trained test of finger dexterity (Nine-Hole-Peg-Test, NHPT). Participants receiving iTBS (to either M1 or S1) showed better performance with the AAT tasks over the period of training compared to sham stimulation as well as a bigger improvement with the generalisation task (NHPT) for the trained left hand after training completion. Priming with an excitatory repetitive transcranial magnetic stimulation as iTBS of either M1 or S1 can enhance motor learning across different sensorimotor abilities.

  13. Coupling between Theta Oscillations and Cognitive Control Network during Cross-Modal Visual and Auditory Attention: Supramodal vs Modality-Specific Mechanisms.

    Science.gov (United States)

    Wang, Wuyi; Viswanathan, Shivakumar; Lee, Taraz; Grafton, Scott T

    2016-01-01

    Cortical theta band oscillations (4-8 Hz) in EEG signals have been shown to be important for a variety of different cognitive control operations in visual attention paradigms. However the synchronization source of these signals as defined by fMRI BOLD activity and the extent to which theta oscillations play a role in multimodal attention remains unknown. Here we investigated the extent to which cross-modal visual and auditory attention impacts theta oscillations. Using a simultaneous EEG-fMRI paradigm, healthy human participants performed an attentional vigilance task with six cross-modal conditions using naturalistic stimuli. To assess supramodal mechanisms, modulation of theta oscillation amplitude for attention to either visual or auditory stimuli was correlated with BOLD activity by conjunction analysis. Negative correlation was localized to cortical regions associated with the default mode network and positively with ventral premotor areas. Modality-associated attention to visual stimuli was marked by a positive correlation of theta and BOLD activity in fronto-parietal area that was not observed in the auditory condition. A positive correlation of theta and BOLD activity was observed in auditory cortex, while a negative correlation of theta and BOLD activity was observed in visual cortex during auditory attention. The data support a supramodal interaction of theta activity with of DMN function, and modality-associated processes within fronto-parietal networks related to top-down theta related cognitive control in cross-modal visual attention. On the other hand, in sensory cortices there are opposing effects of theta activity during cross-modal auditory attention.

  14. Chasing theta-13 with the Double Chooz experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lasserre, Thierry [CEA/DSM/IRFU/SPP, Gif-sur-Yvette (France)

    2009-07-01

    Neutrino oscillation physics is entering a precision measurement area. The smallness of the theta-13 neutrino mixing angle is still enigmatic and should be resolved. Double Chooz will use two identical detectors near the Chooz nuclear power station to search for a non vanishing theta-13, and hopefully open the way to experiments aspiring to discover CP violation in the leptonic sector.

  15. Developing and Evaluating Medical Humanities Problem-Based Learning Classes Facilitated by the Teaching Assistants Majored in the Liberal Arts

    Science.gov (United States)

    Tseng, Fen-Yu; Shieh, Jeng-Yi; Kao, Tze-Wah; Wu, Chau-Chung; Chu, Tzong-Shinn; Chen, Yen-Yuan

    2016-01-01

    Abstract Although medical humanities courses taught by teachers from nonmedical backgrounds are not unusual now, few studies have compared the outcome of medical humanities courses facilitated by physicians to that by teaching assistants majored in the liberal arts. The objectives of this study were to (1) analyze the satisfaction of medical students with medical humanities problem-based learning (PBL) classes facilitated by nonmedical teaching assistants (TAF) majored in the liberal arts, and those facilitated by the attending physicians (APF) and (2) examine the satisfaction of medical students with clinical medicine-related and clinical medicine-unrelated medical humanities PBL classes. A total of 123 medical students, randomly assigned to 16 groups, participated in this study. There were 16 classes in the course: 8 of them were TAF classes; and the others were APF classes. Each week, each group rotated from 1 subject of the 16 subjects of PBL to another subject. All of the 16 groups went through all the 16 subjects in the 2013 spring semester. We examined the medical students’ satisfaction with each class, based on a rating score collected after each class was completed, using a scale from 0 (the lowest satisfaction) to 100 (the highest satisfaction). We also conducted multivariate linear regression analysis to examine the association between the independent variables and the students’ satisfaction. Medical students were more satisfied with the TAF (91.35 ± 7.75) medical humanities PBL classes than APF (90.40 ± 8.42) medical humanities PBL classes (P = 0.01). Moreover, medical students were more satisfied with the clinical medicine-unrelated topics (92.00 ± 7.10) than the clinical medicine-related topics (90.36 ± 7.99) in the medical humanities PBL course (P = 0.01). This medical humanities PBL course, including nonmedical subjects and topics, and nonmedical teaching assistants from the liberal arts as class facilitators, was

  16. Assessing the Biohazard Potential of Putative Martian Organisms for Exploration Class Human Space Missions

    Science.gov (United States)

    Warmflash, David; Larios-Sanz, Maia; Jones, Jeffrey; Fox, George E.; McKay, David S.

    2007-01-01

    Exploration Class missions to Mars will require precautions against potential contamination by any native microorganisms that may be incidentally pathogenic to humans. While the results of NASA's Viking biology experiments of 1976 have been generally interpreted as inconclusive for surface organisms, the possibility of native surface life has never been ruled out and more recent studies suggest that the case for biological interpretation of the Viking Labeled Release data may now be stronger than it was when the experiments were originally conducted. It is possible that, prior to the first human landing on Mars, robotic craft and sample return missions will provide enough data to know with certainty whether or not future human landing sites harbor extant life forms. However, if native life is confirmed, it will be problematic to determine whether any of its species may present a medical risk to astronauts. Therefore, it will become necessary to assess empirically the risk that the planet contains pathogens based on terrestrial examples of pathogenicity and to take a reasonably cautious approach to bio-hazard protection. A survey of terrestrial pathogens was conducted with special emphasis on those pathogens whose evolution has not depended on the presence of animal hosts. The history of the development and implementation of Apollo anticontamination protocol and recent recommendations of the NRC Space Studies Board regarding Mars were reviewed. Organisms can emerge in nature in the absence of indigenous animal hosts and both infectious and non-infectious human pathogens are theoretically possible on Mars. The prospect of Martian surface life, together with the existence of a diversity of routes by which pathogenicity has emerged on Earth, suggests that the possibility of human pathogens on Mars, while low, is not zero. Since the discovery and study of Martian life can have long-term benefits for humanity, the risk that Martian life might include pathogens should not

  17. Antigen presentation and MHC class II expression by human esophageal epithelial cells: role in eosinophilic esophagitis.

    Science.gov (United States)

    Mulder, Daniel J; Pooni, Aman; Mak, Nanette; Hurlbut, David J; Basta, Sameh; Justinich, Christopher J

    2011-02-01

    Professional antigen-presenting cells (APCs) play a crucial role in initiating immune responses. Under pathological conditions, epithelial cells at mucosal surfaces act as nonprofessional APCs, thereby regulating immune responses at the site of exposure. Epithelial cells in the esophagus may contribute to the pathogenesis of eosinophilic esophagitis (EoE) by presenting antigens on the major histocompatibility complex (MHC) class II. Our goal was to demonstrate the ability of esophageal epithelial cells to process and present antigens on the MHC class II system and to investigate the contribution of epithelial cell antigen presentation to EoE. Immunohistochemistry detected HLA-DR, CD80, and CD86 expression and enzyme-linked immunosorbent assay detected interferon-γ (IFNγ) in esophageal biopsies. Antigen presentation was studied using the human esophageal epithelial cell line HET-1A by reverse transcriptase-PCR, flow cytometry, and confocal microscopy. T helper cell lymphocyte proliferation was assessed by flow cytometry and IL-2 secretion. IFNγ and MHC class II were increased in mucosa of patients with EoE. IFNγ increased mRNA of HLA-DP, HLA-DQ, HLA-DR, and CIITA in HET-1A cells. HET-1A engulfed cell debris and processed ovalbumin. HET-1A cells expressed HLA-DR after IFNγ treatment. HET-1A stimulated T helper cell activation. In this study, we demonstrated the ability of esophageal epithelial cells to act as nonprofessional APCs in the presence of IFNγ. Esophageal epithelial cell antigen presentation may contribute to the pathophysiology of eosinophilic esophagitis. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  18. Superconformal algebras and mock theta functions

    International Nuclear Information System (INIS)

    Eguchi, Tohru; Hikami, Kazuhiro

    2009-01-01

    It is known that characters of BPS representations of extended superconformal algebras do not have good modular properties due to extra singular vectors coming from the BPS condition. In order to improve their modular properties we apply the method of Zwegers which has recently been developed to analyze modular properties of mock theta functions. We consider the case of the N=4 superconformal algebra at general levels and obtain the decomposition of characters of BPS representations into a sum of simple Jacobi forms and an infinite series of non-BPS representations. We apply our method to study elliptic genera of hyper-Kaehler manifolds in higher dimensions. In particular, we determine the elliptic genera in the case of complex four dimensions of the Hilbert scheme of points on K3 surfaces K [2] and complex tori A [[3

  19. Superconformal algebras and mock theta functions

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, Tohru [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Hikami, Kazuhiro [Department of Mathematics, Naruto University of Education, Tokushima 772-8502 (Japan)], E-mail: eguchi@yukawa.kyoto-u.ac.jp, E-mail: hikami@naruto-u.ac.jp

    2009-07-31

    It is known that characters of BPS representations of extended superconformal algebras do not have good modular properties due to extra singular vectors coming from the BPS condition. In order to improve their modular properties we apply the method of Zwegers which has recently been developed to analyze modular properties of mock theta functions. We consider the case of the N=4 superconformal algebra at general levels and obtain the decomposition of characters of BPS representations into a sum of simple Jacobi forms and an infinite series of non-BPS representations. We apply our method to study elliptic genera of hyper-Kaehler manifolds in higher dimensions. In particular, we determine the elliptic genera in the case of complex four dimensions of the Hilbert scheme of points on K3 surfaces K{sup [2]} and complex tori A{sup [[3

  20. Dynamics of major histocompatibility complex class I association with the human peptide-loading complex.

    Science.gov (United States)

    Panter, Michaela S; Jain, Ankur; Leonhardt, Ralf M; Ha, Taekjip; Cresswell, Peter

    2012-09-07

    Although the human peptide-loading complex (PLC) is required for optimal major histocompatibility complex class I (MHC I) antigen presentation, its composition is still incompletely understood. The ratio of the transporter associated with antigen processing (TAP) and MHC I to tapasin, which is responsible for MHC I recruitment and peptide binding optimization, is particularly critical for modeling of the PLC. Here, we characterized the stoichiometry of the human PLC using both biophysical and biochemical approaches. By means of single-molecule pulldown (SiMPull), we determined a TAP/tapasin ratio of 1:2, consistent with previous studies of insect-cell microsomes, rat-human chimeric cells, and HeLa cells expressing truncated TAP subunits. We also report that the tapasin/MHC I ratio varies, with the PLC population comprising both 2:1 and 2:2 complexes, based on mutational and co-precipitation studies. The MHC I-saturated PLC may be particularly prevalent among peptide-selective alleles, such as HLA-C4. Additionally, MHC I association with the PLC increases when its peptide supply is reduced by inhibiting the proteasome or by blocking TAP-mediated peptide transport using viral inhibitors. Taken together, our results indicate that the composition of the human PLC varies under normal conditions and dynamically adapts to alterations in peptide supply that may arise during viral infection. These findings improve our understanding of the quality control of MHC I peptide loading and may aid the structural and functional modeling of the human PLC.

  1. The E5 protein of human papillomavirus type 16 perturbs MHC class II antigen maturation in human foreskin keratinocytes treated with interferon-γ

    International Nuclear Information System (INIS)

    Zhang Benyue; Li Ping; Wang Exing; Brahmi, Zacharie; Dunn, Kenneth W.; Blum, Janice S.; Roman, Ann

    2003-01-01

    Major histocompatibility complex (MHC) class II antigens are expressed on human foreskin keratinocytes (HFKs) following exposure to interferon gamma. The expression of MHC class II proteins on the cell surface may allow keratinocytes to function as antigen-presenting cells and induce a subsequent immune response to virus infection. Invariant chain (Ii) is a chaperone protein which plays an important role in the maturation of MHC class II molecules. The sequential degradation of Ii within acidic endocytic compartments is a key process required for the successful loading of antigenic peptide onto MHC class II molecules. Since human papillomavirus (HPV) 16 E5 can inhibit the acidification of late endosomes in HFKs, the E5 protein may be able to affect proper peptide loading onto the MHC class II molecule. To test this hypothesis, HFKs were infected with either control virus or a recombinant virus expressing HPV16 E5 and the infected cells were subsequently treated with interferon-γ. ELISAs revealed a decrease of MHC class II expression on the surface of E5-expressing cells compared with control virus-infected cells after interferon treatment. Western blot analysis showed that, in cells treated with interferon gamma, E5 could prevent the breakdown of Ii and block the formation of peptide-loaded, SDS-stable mature MHC class II dimers, correlating with diminished surface MHC class II expression. These data suggest that HPV16 E5 may be able to decrease immune recognition of infected keratinocytes via disruption of MHC class II protein function

  2. Human HOX Proteins Use Diverse and Context-Dependent Motifs to Interact with TALE Class Cofactors.

    Science.gov (United States)

    Dard, Amélie; Reboulet, Jonathan; Jia, Yunlong; Bleicher, Françoise; Duffraisse, Marilyne; Vanaker, Jean-Marc; Forcet, Christelle; Merabet, Samir

    2018-03-13

    HOX proteins achieve numerous functions by interacting with the TALE class PBX and MEIS cofactors. In contrast to this established partnership in development and disease, how HOX proteins could interact with PBX and MEIS remains unclear. Here, we present a systematic analysis of HOX/PBX/MEIS interaction properties, scanning all paralog groups with human and mouse HOX proteins in vitro and in live cells. We demonstrate that a previously characterized HOX protein motif known to be critical for HOX-PBX interactions becomes dispensable in the presence of MEIS in all except the two most anterior paralog groups. We further identify paralog-specific TALE-binding sites that are used in a highly context-dependent manner. One of these binding sites is involved in the proliferative activity of HOXA7 in breast cancer cells. Together these findings reveal an extraordinary level of interaction flexibility between HOX proteins and their major class of developmental cofactors. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  3. JC polyomavirus infection is strongly controlled by human leucocyte antigen class II variants.

    Directory of Open Access Journals (Sweden)

    Emilie Sundqvist

    2014-04-01

    Full Text Available JC polyomavirus (JCV carriers with a compromised immune system, such as in HIV, or subjects on immune-modulating therapies, such as anti VLA-4 therapy may develop progressive multifocal leukoencephalopathy (PML which is a lytic infection of oligodendrocytes in the brain. Serum antibodies to JCV mark infection occur only in 50-60% of infected individuals, and high JCV-antibody titers seem to increase the risk of developing PML. We here investigated the role of human leukocyte antigen (HLA, instrumental in immune defense in JCV antibody response. Anti-JCV antibody status, as a surrogate for JCV infection, were compared to HLA class I and II alleles in 1621 Scandinavian persons with MS and 1064 population-based Swedish controls and associations were replicated in 718 German persons with MS. HLA-alleles were determined by SNP imputation, sequence specific (SSP kits and a reverse PCR sequence-specific oligonucleotide (PCR-SSO method. An initial GWAS screen displayed a strong HLA class II region signal. The HLA-DRB1*15 haplotype was strongly negatively associated to JCV sero-status in Scandinavian MS cases (OR = 0.42, p = 7×10(-15 and controls (OR = 0.53, p = 2×10(-5. In contrast, the DQB1*06:03 haplotype was positively associated with JCV sero-status, in Scandinavian MS cases (OR = 1.63, p = 0.006, and controls (OR = 2.69, p = 1×10(-5. The German dataset confirmed these findings (OR = 0.54, p = 1×10(-4 and OR = 1.58, p = 0.03 respectively for these haplotypes. HLA class II restricted immune responses, and hence CD4+ T cell immunity is pivotal for JCV infection control. Alleles within the HLA-DR1*15 haplotype are associated with a protective effect on JCV infection. Alleles within the DQB1*06:03 haplotype show an opposite association. These associations between JC virus antibody response and human leucocyte antigens supports the notion that CD4+ T cells are crucial in the immune defence to JCV and

  4. Bilateral theta-burst TMS to influence global gestalt perception.

    Directory of Open Access Journals (Sweden)

    Bernd Ritzinger

    Full Text Available While early and higher visual areas along the ventral visual pathway in the inferotemporal cortex are critical for the recognition of individual objects, the neural representation of human perception of complex global visual scenes remains under debate. Stroke patients with a selective deficit in the perception of a complex global Gestalt with intact recognition of individual objects - a deficit termed simultanagnosia - greatly helped to study this question. Interestingly, simultanagnosia typically results from bilateral lesions of the temporo-parietal junction (TPJ. The present study aimed to verify the relevance of this area for human global Gestalt perception. We applied continuous theta-burst TMS either unilaterally (left or right or bilateral simultaneously over TPJ. Healthy subjects were presented with hierarchically organized visual stimuli that allowed parametrical degrading of the object at the global level. Identification of the global Gestalt was significantly modulated only for the bilateral TPJ stimulation condition. Our results strengthen the view that global Gestalt perception in the human brain involves TPJ and is co-dependent on both hemispheres.

  5. Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory.

    Science.gov (United States)

    Kawasaki, Masahiro; Kitajo, Keiichi; Yamaguchi, Yoko

    2014-01-01

    In humans, theta phase (4-8 Hz) synchronization observed on electroencephalography (EEG) plays an important role in the manipulation of mental representations during working memory (WM) tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from subjects who were performing auditory-verbal and visual WM tasks; we compared the theta synchronizations when subjects performed either auditory-verbal or visual manipulations in separate WM tasks, or performed both two manipulations in the same WM task. The auditory-verbal WM task required subjects to calculate numbers presented by an auditory-verbal stimulus, whereas the visual WM task required subjects to move a spatial location in a mental representation in response to a visual stimulus. The dual WM task required subjects to manipulate auditory-verbal, visual, or both auditory-verbal and visual representations while maintaining auditory-verbal and visual representations. Our time-frequency EEG analyses revealed significant fronto-temporal theta phase synchronization during auditory-verbal manipulation in both auditory-verbal and auditory-verbal/visual WM tasks, but not during visual manipulation tasks. Similarly, we observed significant fronto-parietal theta phase synchronization during visual manipulation tasks, but not during auditory-verbal manipulation tasks. Moreover, we observed significant synchronization in both the fronto-temporal and fronto-parietal theta signals during simultaneous auditory-verbal/visual manipulations. These findings suggest that theta synchronization seems to flexibly connect the brain areas that manipulate WM.

  6. Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory

    Directory of Open Access Journals (Sweden)

    Masahiro eKawasaki

    2014-03-01

    Full Text Available In humans, theta phase (4–8 Hz synchronization observed on electroencephalography (EEG plays an important role in the manipulation of mental representations during working memory (WM tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from subjects who were performing auditory-verbal and visual WM tasks; we compared the theta synchronizations when subjects performed either auditory-verbal or visual manipulations in separate WM tasks, or performed both two manipulations in the same WM task. The auditory-verbal WM task required subjects to calculate numbers presented by an auditory-verbal stimulus, whereas the visual WM task required subjects to move a spatial location in a mental representation in response to a visual stimulus. The dual WM task required subjects to manipulate auditory-verbal, visual, or both auditory-verbal and visual representations while maintaining auditory-verbal and visual representations. Our time-frequency EEG analyses revealed significant fronto-temporal theta phase synchronization during auditory-verbal manipulation in both auditory-verbal and auditory-verbal/visual WM tasks, but not during visual manipulation tasks. Similarly, we observed significant fronto-parietal theta phase synchronization during visual manipulation tasks, but not during auditory-verbal manipulation tasks. Moreover, we observed significant synchronization in both the fronto-temporal and fronto-parietal theta signals during simultaneous auditory-verbal/visual manipulations. These findings suggest that theta synchronization seems to flexibly connect the brain areas that manipulate WM.

  7. Debye classes in A15 compounds

    International Nuclear Information System (INIS)

    Staudenmann, J.; DeFacio, B.; Testardi, L.R.; Werner, S.A.; Fluekiger, R.; Muller, J.

    1981-01-01

    The comparison between electron charge-density distribution of V 3 Si, Cr 3 Si, and V 3 Ge at room temperature leads us to study the Debye temperatures at 0 0 K THETA 0 from specific-heat measurements for over 100 A15 compounds. A phenomenological THETA 0 (M), M the molecular mass, is obtained from the static scaling relation THETA 0 (M) = aM/sup b/ and this organizes all of the data into five Debye classes: V(V 3 Si), V-G, G(V 3 Ge), G-C, and C(Cr 3 Si). In contrast, the Debye temperature THETA 0 (V), with V as the unit-cell volume does not relate alloys as THETA 0 (M) does, with the exception of the C class. This latter case leads to the surprising result MproportionalV/sup approximately1/3/ and to a Grueneisen constant of 1.6 +- 0.1 for all compounds of this class. In the V class where V 3 Si and Nb 3 Sn are found, THETA 0 (V) labels these two alloys differently, as does their martensitic c/a ratios. With T-bar/sub c/ denoting the average superconducting transition temperature within a Debye class, interesting correlations are shown. One is the maximum of T-bar/sub c/ which exists in the V class where the strongest anharmonicity occurs. Another is the case of compounds formed only by transition elements up to and including Au. This interesting case shows that approx.3.2< T-bar/sub c/< approx.5.0 K in all of the five classes and that there is no correlation between T/sub c/ and the thermal properties. The implications of these observations for creating better models for the A15 compounds are briefly discussed

  8. Eisenstein Series Identities Involving the Borweins' Cubic Theta Functions

    Directory of Open Access Journals (Sweden)

    Ernest X. W. Xia

    2012-01-01

    Full Text Available Based on the theories of Ramanujan's elliptic functions and the (p, k-parametrization of theta functions due to Alaca et al. (2006, 2007, 2006 we derive certain Eisenstein series identities involving the Borweins' cubic theta functions with the help of the computer. Some of these identities were proved by Liu based on the fundamental theory of elliptic functions and some of them may be new. One side of each identity involves Eisenstein series, the other products of the Borweins' cubic theta functions. As applications, we evaluate some convolution sums. These evaluations are different from the formulas given by Alaca et al.

  9. Human Activity Recognition from Smart-Phone Sensor Data using a Multi-Class Ensemble Learning in Home Monitoring.

    Science.gov (United States)

    Ghose, Soumya; Mitra, Jhimli; Karunanithi, Mohan; Dowling, Jason

    2015-01-01

    Home monitoring of chronically ill or elderly patient can reduce frequent hospitalisations and hence provide improved quality of care at a reduced cost to the community, therefore reducing the burden on the healthcare system. Activity recognition of such patients is of high importance in such a design. In this work, a system for automatic human physical activity recognition from smart-phone inertial sensors data is proposed. An ensemble of decision trees framework is adopted to train and predict the multi-class human activity system. A comparison of our proposed method with a multi-class traditional support vector machine shows significant improvement in activity recognition accuracies.

  10. Rotational instability in a linear theta pinch

    International Nuclear Information System (INIS)

    Ekdahl, C.; Bartsch, R.R.; Commisso, R.J.; Gribble, R.F.; McKenna, K.F.; Miller, G.; Siemon, R.E.

    1980-01-01

    The m=1 ''wobble'' instability of the plasma column in a 5-m linear theta pinch has been studied using an axial array of orthogonally viewing position detectors to resolve the wavelength and frequency of the column motion. The experimental results are compared with recent theoretical predictions that include finite Larmor orbit effects. The frequency and wavelength characteristics at saturation agree with the predicted dispersion relation for a plasma rotating faster than the diamagnetic drift speed. Measurements of the magnetic fields at the ends of the pinch establish the existence of currents flowing in such a way that they short out the radial electric fields in the plasma column. The magnitude of rotation, the observed delay in the onset of m=1 motion, and the magnitude of end-shorting currents can all be understood in terms of the torsional Alfven waves that communicate to the central plasma column the information that the ends have been shorted. The same waves are responsible for the torque which rotates the plasma and leads to the observed m=1 instability. Observations of the plasma in the presence of solid end plugs indicate a stabilization of high-m number modes and a reduction of the m=1 amplitude

  11. Using theta and alpha band power to assess cognitive workload in multitasking environments.

    Science.gov (United States)

    Puma, Sébastien; Matton, Nadine; Paubel, Pierre-V; Raufaste, Éric; El-Yagoubi, Radouane

    2018-01-01

    Cognitive workload is of central importance in the fields of human factors and ergonomics. A reliable measurement of cognitive workload could allow for improvements in human machine interface designs and increase safety in several domains. At present, numerous studies have used electroencephalography (EEG) to assess cognitive workload, reporting the rise in cognitive workload to be associated with increases in theta band power and decreases in alpha band power. However, results have been inconsistent with some failing to reach the required level of significance. We hypothesized that the lack of consistency could be related to individual differences in task performance and/or to the small sample sizes in most EEG studies. In the present study we used EEG to assess the increase in cognitive workload occurring in a multitasking environment while taking into account differences in performance. Twenty participants completed a task commonly used in airline pilot recruitment, which included an increasing number of concurrent sub-tasks to be processed from one to four. Subjective ratings, performances scores, pupil size and EEG signals were recorded. Results showed that increases in EEG alpha and theta band power reflected increases in the involvement of cognitive resources for the completion of one to three subtasks in a multitasking environment. These values reached a ceiling when performances dropped. Consistent differences in levels of alpha and theta band power were associated to levels of task performance: highest performance was related to lowest band power. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Simple UHV offset manipulator with independent theta and phi rotations

    International Nuclear Information System (INIS)

    Jamison, K.D.; Dunning, F.B.

    1984-01-01

    A simple UHV offset manipulator is described that not only allows a target crystal to be moved to any point on a circle centered on the manipulator axis but also provides indepedent theta and phi rotations at each position

  13. Justice, fairness, and membership in a class: conceptual confusions and moral puzzles in the regulation of human subjects research.

    Science.gov (United States)

    Iltis, Ana S

    2011-01-01

    This essay examines conceptual difficulties with one of the ways in which justice has been understood and applied the ethical and regulatory review of human research. Justice requires the fair distribution of the benefits and burdens of research. Class membership is seen as justifying inclusion in higher hazard-no benefit research from which members of potentially vulnerable classes, such as children, typically would be excluded. I argue that class membership does not do the justificatory work it is thought to do and that the use of class membership to justify inclusion in higher hazard-no benefit research leads to unjustified discrimination of sick children and offers special protections to healthy children. © 2011 American Society of Law, Medicine & Ethics, Inc.

  14. Human immune responses to H. pylori HLA Class II epitopes identified by immunoinformatic methods.

    Directory of Open Access Journals (Sweden)

    Songhua Zhang

    Full Text Available H. pylori persists in the human stomach over decades and promotes several adverse clinical sequelae including gastritis, peptic ulcers and gastric cancer that are linked to the induction and subsequent evasion of chronic gastric inflammation. Emerging evidence indicates that H. pylori infection may also protect against asthma and some other immune-mediated conditions through regulatory T cell effects outside the stomach. To characterize the complexity of the CD4+ T cell response generated during H. pylori infection, computational methods were previously used to generate a panel of 90 predicted epitopes conserved among H. pylori genomes that broadly cover HLA Class II diversity for maximum population coverage. Here, these sequences were tested individually for their ability to induce in vitro responses in peripheral blood mononuclear cells by interferon-γ ELISpot assay. The average number of spot-forming cells/million PBMCs was significantly elevated in H. pylori-infected subjects over uninfected persons. Ten of the 90 peptides stimulated IFN-γ secretion in the H. pylori-infected group only, whereas two out of the 90 peptides elicited a detectable IFN-γ response in the H. pylori-uninfected subjects but no response in the H. pylori-infected group. Cytokine ELISA measurements performed using in vitro PBMC culture supernatants demonstrated significantly higher levels of TNF-α, IL-2, IL-4, IL-6, IL-10, and TGF-β1 in the H. pylori-infected subjects, whereas IL-17A expression was not related to the subjects H. pylori-infection status. Our results indicate that the human T cell responses to these 90 peptides are generally increased in actively H. pylori-infected, compared with H. pylori-naïve, subjects. This information will improve understanding of the complex immune response to H. pylori, aiding rational epitope-driven vaccine design as well as helping identify other H. pylori epitopes with potentially immunoregulatory effects.

  15. Are the iota(1440) and theta(1640) glueballs or quarkonia

    International Nuclear Information System (INIS)

    Ono, S.; Pene, O.

    1982-01-01

    We study the possibility that the iota (1440) and theta (1640) are radially excited quarkonium states (2S and 2P). Their masses, total decay rates and psi → iotaγ, thetaγ branching ratios are roughly in agreement with this hypothesis but deltaπ dominance in iota decay is difficult to explain. We propose clear tests to check if they are quarkonium states. (orig.)

  16. Long-term plasticity is proportional to theta-activity.

    Directory of Open Access Journals (Sweden)

    Marian Tsanov

    Full Text Available BACKGROUND: Theta rhythm in the hippocampal formation is a main feature of exploratory behaviour and is believed to enable the encoding of new spatial information and the modification of synaptic weights. Cyclic changes of dentate gyrus excitability during theta rhythm are related to its function, but whether theta epochs per se are able to alter network properties of dentate gyrus for long time-periods is still poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: We used low-frequency stimulation protocols that amplify the power of endogenous theta oscillations, in order to estimate the plasticity effect of endogenous theta oscillations on a population level. We found that stimulation-induced augmentation of the theta rhythm is linked to a subsequent increase of neuronal excitability and decrease of the synaptic response. This EPSP-to-Spike uncoupling is related to an increased postsynaptic spiking on the positive phases of theta frequency oscillations. Parallel increase of the field EPSP slope and the population spike occurs only after concurrent pre- and postsynaptic activation. Furthermore, we observed that long-term potentiation (>24 h occurs in the dentate gyrus of freely behaving adult rats after phasic activity of entorhinal afferents in the theta-frequency range. This plasticity is proportional to the field bursting activity of granule cells during the stimulation, and may comprise a key step in spatial information transfer. Long-term potentiation of the synaptic component occurs only when the afferent stimulus precedes the evoked population burst, and is input-specific. CONCLUSIONS/SIGNIFICANCE: Our data confirm the role of the dentate gyrus in filtering information to the subsequent network during the activated state of the hippocampus.

  17. Accurate Typing of Human Leukocyte Antigen Class I Genes by Oxford Nanopore Sequencing.

    Science.gov (United States)

    Liu, Chang; Xiao, Fangzhou; Hoisington-Lopez, Jessica; Lang, Kathrin; Quenzel, Philipp; Duffy, Brian; Mitra, Robi David

    2018-04-03

    Oxford Nanopore Technologies' MinION has expanded the current DNA sequencing toolkit by delivering long read lengths and extreme portability. The MinION has the potential to enable expedited point-of-care human leukocyte antigen (HLA) typing, an assay routinely used to assess the immunologic compatibility between organ donors and recipients, but the platform's high error rate makes it challenging to type alleles with accuracy. We developed and validated accurate typing of HLA by Oxford nanopore (Athlon), a bioinformatic pipeline that i) maps nanopore reads to a database of known HLA alleles, ii) identifies candidate alleles with the highest read coverage at different resolution levels that are represented as branching nodes and leaves of a tree structure, iii) generates consensus sequences by remapping the reads to the candidate alleles, and iv) calls the final diploid genotype by blasting consensus sequences against the reference database. Using two independent data sets generated on the R9.4 flow cell chemistry, Athlon achieved a 100% accuracy in class I HLA typing at the two-field resolution. Copyright © 2018 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  18. Class I and II histone deacetylase expression in human chronic periodontitis gingival tissue.

    Science.gov (United States)

    Cantley, M D; Dharmapatni, A A S S K; Algate, K; Crotti, T N; Bartold, P M; Haynes, D R

    2016-04-01

    Histone deacetylase inhibitors (HDACi) are being considered to treat chronic inflammatory diseases at low doses. Currently HDACi that are more specific are being developed to target particular HDACs; therefore, this study aimed to determine levels and distribution of class I and II HDAC in human gingival samples obtained from patients with chronic periodontitis. Gingival biopsies were obtained from patients with and without (mild inflammation, no bone loss) periodontitis. Total RNA was isolated for real-time quantitative polymerase chain reaction to determine expression of HDACs 1-10. Immunohistochemistry was used to determine protein distribution of HDACs 1, 5, 8 and 9. Factor VIII, CD3 and tartrate resistant acid phosphatase (TRAP) were detected in serial sections to identify blood vessels, lymphocytes, pre-osteoclasts and osteoclasts cells respectively. Tumour necrosis factor α (TNF-α) expression was also assessed. mRNA for HDAC 1, 5, 8 and 9 were significantly upregulated in chronic periodontitis gingival tissues compared to non-periodontitis samples (p chronic periodontitis samples (p chronic periodontitis gingival tissues. HDAC 1, 5, 8 and 9 expression was higher in gingival tissues from patients with chronic periodontitis compared to non-periodontitis samples. Results suggest that these HDACs could therefore be targeted with specific acting HDACi. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Academic Performance in Human Anatomy and Physiology Classes: A 2-Yr Study of Academic Motivation and Grade Expectation

    Science.gov (United States)

    Sturges, Diana; Maurer, Trent W.; Allen, Deborah; Gatch, Delena Bell; Shankar, Padmini

    2016-01-01

    This project used a nonexperimental design with a convenience sample and studied the relationship between academic motivation, grade expectation, and academic performance in 1,210 students enrolled in undergraduate human anatomy and physiology (HAP) classes over a 2-yr period. A 42-item survey that included 28 items of the adapted academic…

  20. Two-Year Community: Human Anatomy Software Use in Traditional and Online Anatomy Laboratory Classes: Student-Perceived Learning Benefits

    Science.gov (United States)

    Kuyatt, Brian L.; Baker, Jason D.

    2014-01-01

    This study evaluates the effectiveness of human anatomy software in face-to-face and online anatomy laboratory classes. Cognitive, affective, and psychomotor perceived learning was measured for students using Pearson Education's Practice Anatomy Laboratory 2.0 software. This study determined that student-perceived learning was significantly…

  1. Lipoprotein profiles in human heterozygote carriers of a functional mutation P297S in scavenger receptor class B1

    NARCIS (Netherlands)

    Ljunggren, Stefan A.; Levels, Johannes H. M.; Hovingh, Kees; Holleboom, Adriaan G.; Vergeer, Menno; Argyri, Letta; Gkolfinopoulou, Christina; Chroni, Angeliki; Sierts, Jeroen A.; Kastelein, John J.; Kuivenhoven, Jan Albert; Lindahl, Mats; Karlsson, Helen

    2015-01-01

    The scavenger receptor class B type 1 (SR-B1) is an important HDL receptor involved in cholesterol uptake and efflux, but its physiological role in human lipoprotein metabolism is not fully understood. Heterozygous carriers of the SR-B1(P297S) mutation are characterized by increased HDL cholesterol

  2. Arginine (Di)methylated Human Leukocyte Antigen Class I Peptides Are Favorably Presented by HLA-B*07

    NARCIS (Netherlands)

    Marino, Fabio; Mommen, Geert P M; Jeko, Anita; Meiring, Hugo D; van Gaans-van den Brink, Jacqueline A M; Scheltema, Richard A; van Els, Cécile A C M; Heck, Albert J R

    Alterations in protein post-translational modification (PTM) are recognized hallmarks of diseases. These modifications potentially provide a unique source of disease-related human leukocyte antigen (HLA) class I-presented peptides that can elicit specific immune responses. While phosphorylated HLA

  3. Metabolomics and Ionomics of Potato Tuber Reveals an Influence of Cultivar and Market Class on Human Nutrients and Bioactive Compounds

    Directory of Open Access Journals (Sweden)

    Jacqueline M. Chaparro

    2018-05-01

    Full Text Available Potato (Solanum tuberosum L. is an important global food crop that contains phytochemicals with demonstrated effects on human health. Understanding sources of chemical variation of potato tuber can inform breeding for improved health attributes of the cooked food. Here, a comprehensive metabolomics (UPLC- and GC-MS and ionomics (ICP-MS analysis of raw and cooked potato tuber was performed on 60 unique potato genotypes that span 5 market classes including russet, red, yellow, chip, and specialty potatoes. The analyses detected 2,656 compounds that included known bioactives (43 compounds, nutrients (42, lipids (76, and 23 metals. Most nutrients and bioactives were partially degraded during cooking (44 out of 85; 52%, however genotypes with high quantities of bioactives remained highest in the cooked tuber. Chemical variation was influenced by genotype and market class. Specifically, ~53% of all detected compounds from cooked potato varied among market class and 40% varied by genotype. The most notable metabolite profiles were observed in yellow-flesh potato which had higher levels of carotenoids and specialty potatoes which had the higher levels of chlorogenic acid as compared to the other market classes. Variation in several molecules with known association to health was observed among market classes and included vitamins (e.g., pyridoxal, ~2-fold variation, bioactives (e.g., chlorogenic acid, ~40-fold variation, medicinals (e.g., kukoamines, ~6-fold variation, and minerals (e.g., calcium, iron, molybdenum, ~2-fold variation. Furthermore, more metabolite variation was observed within market class than among market class (e.g., α-tocopherol, ~1-fold variation among market class vs. ~3-fold variation within market class. Taken together, the analysis characterized significant metabolite and mineral variation in raw and cooked potato tuber, and support the potential to breed new cultivars for improved health traits.

  4. Metabolomics and Ionomics of Potato Tuber Reveals an Influence of Cultivar and Market Class on Human Nutrients and Bioactive Compounds

    Science.gov (United States)

    Chaparro, Jacqueline M.; Holm, David G.; Broeckling, Corey D.; Prenni, Jessica E.; Heuberger, Adam L.

    2018-01-01

    Potato (Solanum tuberosum L.) is an important global food crop that contains phytochemicals with demonstrated effects on human health. Understanding sources of chemical variation of potato tuber can inform breeding for improved health attributes of the cooked food. Here, a comprehensive metabolomics (UPLC- and GC-MS) and ionomics (ICP-MS) analysis of raw and cooked potato tuber was performed on 60 unique potato genotypes that span 5 market classes including russet, red, yellow, chip, and specialty potatoes. The analyses detected 2,656 compounds that included known bioactives (43 compounds), nutrients (42), lipids (76), and 23 metals. Most nutrients and bioactives were partially degraded during cooking (44 out of 85; 52%), however genotypes with high quantities of bioactives remained highest in the cooked tuber. Chemical variation was influenced by genotype and market class. Specifically, ~53% of all detected compounds from cooked potato varied among market class and 40% varied by genotype. The most notable metabolite profiles were observed in yellow-flesh potato which had higher levels of carotenoids and specialty potatoes which had the higher levels of chlorogenic acid as compared to the other market classes. Variation in several molecules with known association to health was observed among market classes and included vitamins (e.g., pyridoxal, ~2-fold variation), bioactives (e.g., chlorogenic acid, ~40-fold variation), medicinals (e.g., kukoamines, ~6-fold variation), and minerals (e.g., calcium, iron, molybdenum, ~2-fold variation). Furthermore, more metabolite variation was observed within market class than among market class (e.g., α-tocopherol, ~1-fold variation among market class vs. ~3-fold variation within market class). Taken together, the analysis characterized significant metabolite and mineral variation in raw and cooked potato tuber, and support the potential to breed new cultivars for improved health traits. PMID:29876353

  5. The morphology of midcingulate cortex predicts frontal-midline theta neurofeedback success

    Directory of Open Access Journals (Sweden)

    Stefanie eEnriquez-Geppert

    2013-08-01

    Full Text Available Humans differ in their ability to learn how to control their own brain activity by neurofeedback. However, neural mechanisms underlying these inter-individual differences, which may determine training success and associated cognitive enhancement, are not well understood. Here, it is asked whether neurofeedback success of frontal-midline (fm theta, an oscillation related to higher cognitive functions, could be predicted by the morphology of brain structures known to be critically involved in fm-theta generation. Nineteen young, right-handed participants underwent magnetic resonance imaging of T1-weighted brain images, and took part in an individualized, eight-session neurofeedback training in order to learn how to enhance activity in their fm-theta frequency band. Initial training success, measured at the second training session, was correlated with the final outcome measure. We found that the inferior, superior and middle frontal cortices were not associated with training success. However, volume of the midcingulate cortex as well as volume and concentration of the underlying white matter structures act as predictor variables for the general responsiveness to training. These findings suggest a neuroanatomical foundation for the ability to learn to control one’s own brain activity.

  6. Distinct roles of theta and alpha oscillations in the involuntary capture of goal-directed attention.

    Science.gov (United States)

    Harris, Anthony M; Dux, Paul E; Jones, Caelyn N; Mattingley, Jason B

    2017-05-15

    Mechanisms of attention assign priority to sensory inputs on the basis of current task goals. Previous studies have shown that lateralized neural oscillations within the alpha (8-14Hz) range are associated with the voluntary allocation of attention to the contralateral visual field. It is currently unknown, however, whether similar oscillatory signatures instantiate the involuntary capture of spatial attention by goal-relevant stimulus properties. Here we investigated the roles of theta (4-8Hz), alpha, and beta (14-30Hz) oscillations in human goal-directed visual attention. Across two experiments, we had participants respond to a brief target of a particular color among heterogeneously colored distractors. Prior to target onset, we cued one location with a lateralized, non-predictive cue that was either target- or non-target-colored. During the behavioral task, we recorded brain activity using electroencephalography (EEG), with the aim of analyzing cue-elicited oscillatory activity. We found that theta oscillations lateralized in response to all cues, and this lateralization was stronger if the cue matched the target color. Alpha oscillations lateralized relatively later, and only in response to target-colored cues, consistent with the capture of spatial attention. Our findings suggest that stimulus induced changes in theta and alpha amplitude reflect task-based modulation of signals by feature-based and spatial attention, respectively. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Lateralized theta wave connectivity and language performance in 2- to 5-year-old children.

    Science.gov (United States)

    Kikuchi, Mitsuru; Shitamichi, Kiyomi; Yoshimura, Yuko; Ueno, Sanae; Remijn, Gerard B; Hirosawa, Tetsu; Munesue, Toshio; Tsubokawa, Tsunehisa; Haruta, Yasuhiro; Oi, Manabu; Higashida, Haruhiro; Minabe, Yoshio

    2011-10-19

    Recent neuroimaging studies support the view that a left-lateralized brain network is crucial for language development in children. However, no previous studies have demonstrated a clear link between lateralized brain functional network and language performance in preschool children. Magnetoencephalography (MEG) is a noninvasive brain imaging technique and is a practical neuroimaging method for use in young children. MEG produces a reference-free signal, and is therefore an ideal tool to compute coherence between two distant cortical rhythms. In the present study, using a custom child-sized MEG system, we investigated brain networks while 78 right-handed preschool human children (32-64 months; 96% were 3-4 years old) listened to stories with moving images. The results indicated that left dominance of parietotemporal coherence in theta band activity (6-8 Hz) was specifically correlated with higher performance of language-related tasks, whereas this laterality was not correlated with nonverbal cognitive performance, chronological age, or head circumference. Power analyses did not reveal any specific frequencies that contributed to higher language performance. Our results suggest that it is not the left dominance in theta oscillation per se, but the left-dominant phase-locked connectivity via theta oscillation that contributes to the development of language ability in young children.

  8. Gender difference in the theta/alpha ratio during the induction of peaceful audiovisual modalities.

    Science.gov (United States)

    Yang, Chia-Yen; Lin, Ching-Po

    2015-09-01

    Gender differences in emotional perception have been found in numerous psychological and psychophysiological studies. The conducting modalities in diverse characteristics of different sensory systems make it interesting to determine how cooperation and competition contribute to emotional experiences. We have previously estimated the bias from the match attributes of auditory and visual modalities and revealed specific brain activity frequency patterns related to a peaceful mood. In that multimodality experiment, we focused on how inner-quiet information is processed in the human brain, and found evidence of auditory domination from the theta-band activity. However, a simple quantitative description of these three frequency bands is lacking, and no studies have assessed the effects of peacefulness on the emotional state. Therefore, the aim of this study was to use magnetoencephalography to determine if gender differences exist (and when and where) in the frequency interactions underpinning the perception of peacefulness. This study provides evidence of auditory and visual domination in perceptual bias during multimodality processing of peaceful consciousness. The results of power ratio analyses suggest that the values of the theta/alpha ratio are associated with a modality as well as hemispheric asymmetries in the anterior-to-posterior direction, which shift from right to left with the auditory to visual stimulations in a peaceful mood. This means that the theta/alpha ratio might be useful for evaluating emotion. Moreover, the difference was found to be most pronounced for auditory domination and visual sensitivity in the female group.

  9. Human cytomegalovirus alters localization of MHC class II and dendrite morphology in mature Langerhans cells.

    Science.gov (United States)

    Lee, Andrew W; Hertel, Laura; Louie, Ryan K; Burster, Timo; Lacaille, Vashti; Pashine, Achal; Abate, Davide A; Mocarski, Edward S; Mellins, Elizabeth D

    2006-09-15

    Hemopoietic stem cell-derived mature Langerhans-type dendritic cells (LC) are susceptible to productive infection by human CMV (HCMV). To investigate the impact of infection on this cell type, we examined HLA-DR biosynthesis and trafficking in mature LC cultures exposed to HCMV. We found decreased surface HLA-DR levels in viral Ag-positive as well as in Ag-negative mature LC. Inhibition of HLA-DR was independent of expression of unique short US2-US11 region gene products by HCMV. Indeed, exposure to UV-inactivated virus, but not to conditioned medium from infected cells, was sufficient to reduce HLA-DR on mature LC, implicating particle binding/penetration in this effect. Reduced surface levels reflected an altered distribution of HLA-DR because total cellular HLA-DR was not diminished. Accumulation of HLA-DR was not explained by altered cathepsin S activity. Mature, peptide-loaded HLA-DR molecules were retained within cells, as assessed by the proportion of SDS-stable HLA-DR dimers. A block in egress was implicated, as endocytosis of surface HLA-DR was not increased. Immunofluorescence microscopy corroborated the intracellular retention of HLA-DR and revealed markedly fewer HLA-DR-positive dendritic projections in infected mature LC. Unexpectedly, light microscopic analyses showed a dramatic loss of the dendrites themselves and immunofluorescence revealed that cytoskeletal elements crucial for the formation and maintenance of dendrites are disrupted in viral Ag-positive cells. Consistent with these dendrite effects, HCMV-infected mature LC exhibit markedly reduced chemotaxis in response to lymphoid chemokines. Thus, HCMV impedes MHC class II molecule trafficking, dendritic projections, and migration of mature LC. These changes likely contribute to the reduced activation of CD4+ T cells by HCMV-infected mature LC.

  10. RxClass

    Data.gov (United States)

    U.S. Department of Health & Human Services — The RxClass Browser is a web application for exploring and navigating through the class hierarchies to find the RxNorm drug members associated with each class....

  11. Expression, refolding and crystallization of murine MHC class I H-2Db in complex with human β2-microglobulin

    International Nuclear Information System (INIS)

    Sandalova, Tatyana; Michaëlsson, Jakob; Harris, Robert A.; Ljunggren, Hans-Gustaf; Kärre, Klas; Schneider, Gunter; Achour, Adnane

    2005-01-01

    Mouse MHC class I H-2Db in complex with human β2m and the LCMV-derived peptide gp33 has been produced and crystallized. Resolution of the structure of this complex combined with the structural comparison with the previously solved crystal structure of H-2Db/mβ2m/gp33 should lead to a better understanding of how the β2m subunit affects the overall conformation of MHC complexes as well as the stability of the presented peptides. β 2 -Microglobulin (β 2 m) is non-covalently linked to the major histocompatibility (MHC) class I heavy chain and interacts with CD8 and Ly49 receptors. Murine MHC class I can bind human β 2 m (hβ 2 m) and such hybrid molecules are often used in structural and functional studies. The replacement of mouse β 2 m (mβ 2 m) by hβ 2 m has important functional consequences for MHC class I complex stability and specificity, but the structural basis for this is unknown. To investigate the impact of species-specific β 2 m subunits on MHC class I conformation, murine MHC class I H-2D b in complex with hβ 2 m and the peptide gp33 derived from lymphocytic choriomeningitis virus (LCMV) has been expressed, refolded in vitro and crystallized. Crystals containing two complexes per asymmetric unit and belonging to the space group P2 1 , with unit-cell parameters a = 68.1, b = 65.2, c = 101.9 Å, β = 102.4°, were obtained

  12. Harnessing the power of theta: natural manipulations of cognitive performance during hippocampal theta-contingent eyeblink conditioning

    Science.gov (United States)

    Hoffmann, Loren C.; Cicchese, Joseph J.; Berry, Stephen D.

    2015-01-01

    Neurobiological oscillations are regarded as essential to normal information processing, including coordination and timing of cells and assemblies within structures as well as in long feedback loops of distributed neural systems. The hippocampal theta rhythm is a 3–12 Hz oscillatory potential observed during cognitive processes ranging from spatial navigation to associative learning. The lower range, 3–7 Hz, can occur during immobility and depends upon the integrity of cholinergic forebrain systems. Several studies have shown that the amount of pre-training theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning. Our lab has used a brain-computer interface (BCI) that delivers eyeblink conditioning trials contingent upon the explicit presence or absence of hippocampal theta. A behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to four-fold increase in learning speed. This behavioral effect is accompanied by enhanced amplitude and synchrony of hippocampal local field potential (LFP)s, multi-unit excitation, and single-unit response patterns that depend on theta state. Additionally, training in the presence of hippocampal theta has led to increases in the salience of tone-induced unit firing patterns in the medial prefrontal cortex, followed by persistent multi-unit activity during the trace interval. In cerebellum, rhythmicity and precise synchrony of stimulus time-locked LFPs with those of hippocampus occur preferentially under the theta condition. Here we review these findings, integrate them into current models of hippocampal-dependent learning and suggest how improvement in our understanding of neurobiological oscillations is critical for theories of medial temporal lobe processes underlying intact and pathological learning. PMID:25918501

  13. Harnessing the power of theta: natural manipulations of cognitive performance during hippocampal theta-contingent eyeblink conditioning.

    Science.gov (United States)

    Hoffmann, Loren C; Cicchese, Joseph J; Berry, Stephen D

    2015-01-01

    Neurobiological oscillations are regarded as essential to normal information processing, including coordination and timing of cells and assemblies within structures as well as in long feedback loops of distributed neural systems. The hippocampal theta rhythm is a 3-12 Hz oscillatory potential observed during cognitive processes ranging from spatial navigation to associative learning. The lower range, 3-7 Hz, can occur during immobility and depends upon the integrity of cholinergic forebrain systems. Several studies have shown that the amount of pre-training theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning. Our lab has used a brain-computer interface (BCI) that delivers eyeblink conditioning trials contingent upon the explicit presence or absence of hippocampal theta. A behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to four-fold increase in learning speed. This behavioral effect is accompanied by enhanced amplitude and synchrony of hippocampal local field potential (LFP)s, multi-unit excitation, and single-unit response patterns that depend on theta state. Additionally, training in the presence of hippocampal theta has led to increases in the salience of tone-induced unit firing patterns in the medial prefrontal cortex, followed by persistent multi-unit activity during the trace interval. In cerebellum, rhythmicity and precise synchrony of stimulus time-locked LFPs with those of hippocampus occur preferentially under the theta condition. Here we review these findings, integrate them into current models of hippocampal-dependent learning and suggest how improvement in our understanding of neurobiological oscillations is critical for theories of medial temporal lobe processes underlying intact and pathological learning.

  14. The Influence of Class II Division 2 Malocclusions on the Harmony of the Human Face Profile.

    Science.gov (United States)

    Perović, Tatjana

    2017-11-24

    BACKGROUND Persons with class II division 2 malocclusion are characterized by a very specific dento-skeletal and soft-tissue profile (a profile in which a protruding nose and chin, retruding lips, concave and shortened lower third of the face, and gummy smile are dominant), which is the opposite of the currently modern profiles (convex profile of protruding lips and small chin). The aim of this research was to determine the differences in parameters of harmonies of facial profiles between persons with class II division 2 malocclusions and class I, and to establish the significance of those differences. MATERIAL AND METHODS For this study, 50 patients with class II division 2 malocclusions and 50 patients with class I were selected; profile photos were recorded and a photometric analysis was done: a type of profile according to Schwarz, the shape of a nose, the prominence of chin, biometrical field, the position of lips in relation to the tangent Sn-Pg, S-line (Steiner), E-line (Riketts) and a facial angle according to Arnett. RESULTS The significant differences in profiles of persons with class II division 2 compared to class I were: position and prominence of the chin, the position of the lower and upper lip in relation to the S-line, and smaller value of a facial angle in relation to persons with class I. CONCLUSIONS The differences seen in skeletal profiles were not associated with significant differences in the profiled facial contours of the examined groups. The compensatory role of the fullness of soft tissues of the lips is probably the reason why there were not significant deviations in all the examined parameters.

  15. Two putative subunits of a peptide pump encoded in the human major histocompatability complex class 2 region

    International Nuclear Information System (INIS)

    Bahram, S.; Arnold, D.; Bresnahan, M.; Strominger, J.L.; Spies, T.

    1991-01-01

    The class 2 region of the human major histocompatibility complex (MHC) may encode several genes controlling the processing of endogenous antigen and the presentation of peptide epitopes by MHC class 1 molecules to cytotoxic T lymphocytes. A previously described peptide supply factor (PSF1) is a member of the multidrug-resistance family of transporters and may pump cytosolic peptides into the membrane-bound compartment where class 1 molecules assemble. A second transporter gene, PSF2, was identified 10 kilobases (kb) from PSF1, near the class 2 DOB gene. The complete sequences of PSF1 and PSF2 were determined from cDNA clones. The translation products are closely related in sequence and predicted secondary structure. Both contain a highly conserved ATP-binding fold and share 25% homology in a hydrophobic domain with a tentative number of eight membrane-spanning segments. Based on the principle dimeric organization of these two domains in other transporters, PSF1 and PSF2 may function as complementary subunits, independently as homodimers, or both. Taken together with previous genetic evidence, the coregulation of PSF1 and PSF2 by γ interferon and the to-some-degree coordinate transcription of these genes suggest a common role in peptide-loading of class 1 molecules, although a distinct function of PSF2 cannot be ruled out

  16. Network models provide insights into how oriens–lacunosum-moleculare and bistratified cell interactions influence the power of local hippocampal CA1 theta oscillations

    Directory of Open Access Journals (Sweden)

    Katie A Ferguson

    2015-08-01

    Full Text Available Hippocampal theta is a 4-12 Hz rhythm associated with episodic memory, and although it has been studied extensively, the cellular mechanisms underlying its generation are unclear. The complex interactions between different interneuron types, such as those between oriens--lacunosum-moleculare (OLM interneurons and bistratified cells (BiCs, make their contribution to network rhythms difficult to determine experimentally. We created network models that are tied to experimental work at both cellular and network levels to explore how these interneuron interactions affect the power of local oscillations. Our cellular models were constrained with properties from patch clamp recordings in the CA1 region of an intact hippocampus preparation in vitro. Our network models are composed of three different types of interneurons: parvalbumin-positive (PV+ basket and axo-axonic cells (BC/AACs, PV+ BiCs, and somatostatin-positive OLM cells. Also included is a spatially extended pyramidal cell model to allow for a simplified local field potential representation, as well as experimentally-constrained, theta frequency synaptic inputs to the interneurons. The network size, connectivity, and synaptic properties were constrained with experimental data. To determine how the interactions between OLM cells and BiCs could affect local theta power, we explored a number of OLM-BiC connections and connection strengths.We found that our models operate in regimes in which OLM cells minimally or strongly affected the power of network theta oscillations due to balances that, respectively, allow compensatory effects or not. Inactivation of OLM cells could result in no change or even an increase in theta power. We predict that the dis-inhibitory effect of OLM cells to BiCs to pyramidal cell interactions plays a critical role in the power of network theta oscillations. Our network models reveal a dynamic interplay between different classes of interneurons in influencing local theta

  17. Chasing {theta}{sub 13} with new reactor neutrino experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lasserre, Th. [DSM/DAPNIA/SPP, CEA/Saclay, 91191 Gif-sur-Yvette (France)

    2005-12-15

    It is now widely accepted that a new middle baseline disappearance reactor neutrino experiment with multiple detectors could provide a clean measurement of the {theta}{sub 13} mixing angle, free from any parameter degeneracies and correlations induced by matter effect and the unknown leptonic Dirac CP phase. The current best constraint on the third mixing angle comes from the Chooz reactor neutrino experiment sin{sup 2}(2{theta}{sub 13})<0.2 (90 % C.L., {delta}m{sub atm}{sup 2}=2.010{sup -3} eV{sup 2}). Several projects of experiment, with different timescales, have been proposed over the last two years all around the world. Their sensitivities range from sin{sup 2}(2{theta}{sub 13})<0.01 to 0.03, having thus an excellent discovery potential of the {nu}{sub e} fraction of {nu}{sub 3}.

  18. Simplified scaling model for the THETA-pinch

    Science.gov (United States)

    Ewing, K. J.; Thomson, D. B.

    1982-02-01

    A simple ID scaing model for the fast Theta pinch was developed and written as a code that would be flexible, inexpensive in computer time, and readily available for use with the Los Alamos explosive-driven high magnetic field program. The simplified model uses three successive separate stages: (1) a snowplow-like radial implosion, (2) an idealized resistive annihilation of reverse bias field, and (3) an adiabatic compression stage of a Beta = 1 plasma for which ideal pressure balance is assumed to hold. The code uses one adjustable fitting constant whose value was first determined by comparison with results from the Los Alamos Scylla III, Scyllacita, and Scylla IA Theta pinches.

  19. Energy transfer efficiency measurements in a theta-pinch

    International Nuclear Information System (INIS)

    Cavalcanti, G.H.; Luna, F.R.T.; Trigueiros, A.G.

    1993-01-01

    An increase in energy transfer efficiency of the capacitor bank to the plasma was obtained when the electrical system of a theta-pinch was changed so that the ratio of total inductance to coil inductance was switched of 1/6 to 1/2. A further increase about 20% was obtained for 16/1 ratio. The measurements were made through the current discharge decay, and the spectral analysis of the emitted light from theta-pinch shows a correspondent efficiency increase. (author)

  20. Distinguishing stimulus and response codes in theta oscillations in prefrontal areas during inhibitory control of automated responses.

    Science.gov (United States)

    Mückschel, Moritz; Dippel, Gabriel; Beste, Christian

    2017-11-01

    Response inhibition mechanisms are mediated via cortical and subcortical networks. At the cortical level, the superior frontal gyrus, including the supplementary motor area (SMA) and inferior frontal areas, is important. There is an ongoing debate about the functional roles of these structures during response inhibition as it is unclear whether these structures process different codes or contents of information during response inhibition. In the current study, we examined this question with a focus on theta frequency oscillations during response inhibition processes. We used a standard Go/Nogo task in a sample of human participants and combined different EEG signal decomposition methods with EEG beamforming approaches. The results suggest that stimulus coding during inhibitory control is attained by oscillations in the upper theta frequency band (∼7 Hz). In contrast, response selection codes during inhibitory control appear to be attained by the lower theta frequency band (∼4 Hz). Importantly, these different codes seem to be processed in distinct functional neuroanatomical structures. Although the SMA may process stimulus codes and response selection codes, the inferior frontal cortex may selectively process response selection codes during inhibitory control. Taken together, the results suggest that different entities within the functional neuroanatomical network associated with response inhibition mechanisms process different kinds of codes during inhibitory control. These codes seem to be reflected by different oscillations within the theta frequency band. Hum Brain Mapp 38:5681-5690, 2017. © 2017 Wiley-Liss, Inc. © 2017 Wiley Periodicals, Inc.

  1. Continuous theta burst stimulation of angular gyrus reduces subjective recollection.

    Directory of Open Access Journals (Sweden)

    Yasemin Yazar

    Full Text Available The contribution of lateral parietal regions such as the angular gyrus to human episodic memory has been the subject of much debate following widespread observations of left parietal activity in healthy volunteers during functional neuroimaging studies of memory retrieval. Patients with lateral parietal lesions are not amnesic, but recent evidence indicates that their memory abilities may not be entirely preserved. Whereas recollection appears intact when objective measures such as source accuracy are used, patients often exhibit reduced subjective confidence in their accurate recollections. When asked to recall autobiographical memories, they may produce spontaneous narratives that lack richness and specificity, but can remember specific details when prompted. Two distinct theoretical accounts have been proposed to explain these results: that the patients have a deficit in the bottom-up capturing of attention by retrieval output, or that they have an impairment in the subjective experience of recollection. The present study aimed to differentiate between these accounts using continuous theta burst stimulation (cTBS in healthy participants to disrupt function of specific left parietal subregions, including angular gyrus. Inconsistent with predictions of the attentional theory, angular gyrus cTBS did not result in greater impairment of free recall than cued recall. Supporting predictions of the subjective recollection account, temporary disruption of angular gyrus was associated with highly accurate source recollection accuracy but a selective reduction in participants' rated source confidence. The findings are consistent with a role for angular gyrus in the integration of memory features into a conscious representation that enables the subjective experience of remembering.

  2. Mechanical Stress Downregulates MHC Class I Expression on Human Cancer Cell Membrane

    KAUST Repository

    La Rocca, Rosanna; Tallerico, Rossana; Talib Hassan, Almosawy; Das, Gobind; Tadepally, Lakshmikanth; Matteucci, Marco; Liberale, Carlo; Mesuraca, Maria; Scumaci, Domenica; Gentile, Francesco; Cojoc, Gheorghe; Perozziello, Gerardo; Ammendolia, Antonio; Gallo, Adriana; Kä rre, Klas; Cuda, Giovanni; Candeloro, Patrizio; Di Fabrizio, Enzo M.; Carbone, Ennio

    2014-01-01

    bar (1 bar = 100.000 Pascal), depending on the devices used. Moreover, Raman spectroscopy analysis, after mechanical treatment, in the range between 700–1800 cm−1, indicated a relative concentration variation of MHC class I. PCA analysis was also

  3. Defining the HLA class I-associated viral antigen repertoire from HIV-1-infected human cells

    DEFF Research Database (Denmark)

    Ternette, Nicola; Yang, Hongbing; Partridge, Thomas

    2016-01-01

    Recognition and eradication of infected cells by cytotoxic T lymphocytes is a key defense mechanism against intracellular pathogens. High-throughput definition of HLA class I-associated immunopeptidomes by mass spectrometry is an increasingly important analytical tool to advance our understanding...

  4. Human leucocyte antigen class Ib molecules in pregnancy success and early pregnancy loss

    DEFF Research Database (Denmark)

    Dahl, Mette; Hviid, Thomas Vauvert F

    2013-01-01

    AND CONCLUSIONS The HLA class Ib molecules seem to induce suppression of the maternal immune system, but are not necessarily fundamental factors for pregnancy success. However, evidence points towards low expression of these proteins, especially HLA-G, being associated with reduced fertility. To clarify...

  5. NetMHCpan, a method for MHC class I binding prediction beyond humans

    DEFF Research Database (Denmark)

    Hoof, Ilka; Peters, B; Sidney, J

    2009-01-01

    molecules. We show that the NetMHCpan-2.0 method can accurately predict binding to uncharacterized HLA molecules, including HLA-C and HLA-G. Moreover, NetMHCpan-2.0 is demonstrated to accurately predict peptide binding to chimpanzee and macaque MHC class I molecules. The power of NetMHCpan-2.0 to guide...

  6. Academic performance in human anatomy and physiology classes: a 2-yr study of academic motivation and grade expectation.

    Science.gov (United States)

    Sturges, Diana; Maurer, Trent W; Allen, Deborah; Gatch, Delena Bell; Shankar, Padmini

    2016-03-01

    This project used a nonexperimental design with a convenience sample and studied the relationship between academic motivation, grade expectation, and academic performance in 1,210 students enrolled in undergraduate human anatomy and physiology (HAP) classes over a 2-yr period. A 42-item survey that included 28 items of the adapted academic motivation scale for HAP based on self-determination theory was administered in class during the first 3 wk of each semester. Students with higher grade point averages, who studied for longer hours and reported to be more motivated to succeed, did better academically in these classes. There was a significant relationship between students' scores on the adapted academic motivation scale and performance. Students were more extrinsically motivated to succeed in HAP courses than intrinsically motivated to succeed, and the analyses revealed that the most significant predictor of final grade was within the extrinsic scale (introjected and external types). Students' motivations remained stable throughout the course sequence. The data showed a significant relationship between HAP students' expected grade and their final grade in class. Finally, 65.5% of students overestimated their final grade, with 29% of students overestimating by two to four letter grades. Copyright © 2016 The American Physiological Society.

  7. Anionic Sites, Fucose Residues and Class I Human Leukocyte Antigen Fate During Interaction of Toxoplasma gondii with Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Stumbo Ana Carolina

    2002-01-01

    Full Text Available Toxoplasma gondii invades and proliferates in human umbilical vein endothelial cells where it resides in a parasitophorous vacuole. In order to analyze which components of the endothelial cell plasma membrane are internalized and become part of the parasitophorous vacuole membrane, the culture of endothelial cells was labeled with cationized ferritin or UEA I lectin or anti Class I human leukocytte antigen (HLA before or after infection with T. gondii. The results showed no cationized ferritin and UEA I lectin in any parasitophorous vacuole membrane, however, the Class I HLA molecule labeling was observed in some endocytic vacuoles containing parasite until 1 h of interaction with T. gondii. After 24 h parasite-host cell interaction, the labeling was absent on the vacuolar membrane, but presents only in small vesicles near parasitophorous vacuole. These results suggest the anionic site and fucose residues are excluded at the time of parasitophorous vacuole formation while Class I HLA molecules are present only on a minority of Toxoplasma-containig vacuoles.

  8. A clinical evaluation of a bioresorbable membrane and porous hydroxyapatite in the treatment of human molar class II furcations

    Directory of Open Access Journals (Sweden)

    K Gita Malathi

    2013-01-01

    Full Text Available Background: The ultimate goal of periodontal therapy is predictable regeneration of a functional attachment apparatus destroyed as a result of periodontitis. Reconstructive procedures have been used with varying success during the past decades to accomplish this goal. Aim: To evaluate whether the use of porous hydroxyapatite alone or a bioresorbable membrane alone would enhance the clinical results in the treatment of class II furcation defects in human lower molars. Materials and Methods: Fifteen patients with chronic periodontitis, aged between 39 and 49 years, with a pair of similar bilateral class II furcation defects (classification of Hamp et al. in mandibular first molars were selected. A split-mouth design was incorporated and the selected 30 furcation defects were assigned to one of the two treatment groups, i.e., Group I treated with a bioresorbable membrane from bovine-derived collagen guided tissue regeneration membrane and Group II treated using porous hydroxyapatite bone graft material on the contralateral sides. Evaluation of clinical parameters, probing depths and attachment levels, and radiographs was done preoperatively and 6 months postoperatively. Results: Both the groups showed statistically significant mean reduction in probing depths and gain in clinical attachment levels and linear bone fill. Comparison between Group I and Group II showed insignificant difference. Conclusion: Within the limits of this study, both the treatment modalities are beneficial for the treatment of human mandibular class II furcation defects.

  9. Investigation of plasma turbulence in a theta-pinch-discharge

    International Nuclear Information System (INIS)

    Lins, G.

    1980-01-01

    This thesis is concerned with investigations of plasma turbulence in a 3 KJ Theta-Pinch during implosion by high-frequency Stark-effect and Thomson scattering. The next points are modifications of electron-distribution function by ionization in low preionizized turbulent plasma and energy losses by particle flow and heat flow at the ends. (HT)

  10. Oscillatory frontal theta responses are increased upon bisensory stimulation.

    Science.gov (United States)

    Sakowitz, O W; Schürmann, M; Başar, E

    2000-05-01

    To investigate the functional correlation of oscillatory EEG components with the interaction of sensory modalities following simultaneous audio-visual stimulation. In an experimental study (15 subjects) we compared auditory evoked potentials (AEPs) and visual evoked potentials (VEPs) to bimodal evoked potentials (BEPs; simultaneous auditory and visual stimulation). BEPs were assumed to be brain responses to complex stimuli as a marker for intermodal associative functioning. Frequency domain analysis of these EPs showed marked theta-range components in response to bimodal stimulation. These theta components could not be explained by linear addition of the unimodal responses in the time domain. Considering topography the increased theta-response showed a remarkable frontality in proximity to multimodal association cortices. Referring to methodology we try to demonstrate that, even if various behavioral correlates of brain oscillations exist, common patterns can be extracted by means of a systems-theoretical approach. Serving as an example of functionally relevant brain oscillations, theta responses could be interpreted as an indicator of associative information processing.

  11. Classical Conditioning of Hippocampal Theta Patterns in the Rat.

    Science.gov (United States)

    1976-08-01

    associated with changes in performance of learned tasks , 1,4,5, 8,9 there have been very few studies of neurona l plasticity of the hippocampus It self...rapid development of a conditioned hippocampal theta response to a visual sti mulus demonstrates tha t there is considerable neurona l plasticity in the

  12. Combinatorial identities for tenth order mock theta functions

    Indian Academy of Sciences (India)

    44

    which lead us to one 4-way and one 3-way combinatorial identity. ... mock theta functions, partition identities and different combinatorial parameters, see for ... 3. Example 1.1. There are twelve (n + 1)–color partitions of 2: 21, 21 + 01, 11 + 11, ...

  13. Double-Chooz: a search for {theta}{sub 13}

    Energy Technology Data Exchange (ETDEWEB)

    Lasserre, Th. [DSM/DAPNIA/SPP, CEA/Saclay, 91191 Gif-sur-Yvette (France)

    2005-12-15

    The Double-Chooz experiment goal is to search for a non-vanishing value of the {theta}{sub 13} neutrino mixing angle. This is the last step to accomplish prior moving towards a new era of precision measurements in the lepton sector. The current best constraint on the third mixing angle comes from the CHOOZ reactor neutrino experiment sin{sup 2}(2{theta}{sub 13})<0.2 (90% C.L., {delta}m{sub atm}{sup 2}=2.0eV{sup 2}). Double-Chooz will explore the range of sin{sup 2}(2{theta}{sub 13}) from 0.2 to 0.03-0.02, within three years of data taking. The improvement of the CHOOZ result requires an increase in the statistics, a reduction of the systematic error below one percent, and a careful control of the backgrounds. Therefore, Double-Chooz will use two identical detectors, one at 150 m and another at 1.05 km distance from the Chooz nuclear cores. In addition, we will use the near detector as a ''state of the art'' prototype to investigate the potential of neutrinos for monitoring the civil nuclear power plants. The plan is to start operation with two detectors in 2008, and to reach a sensitivity sin{sup 2}(2{theta}{sub 13}) of 0.05 in 2009, and 0.03-0.02 in 2011.

  14. Instability study during implosion in the Tupa Theta-Pinch

    International Nuclear Information System (INIS)

    Kayama, M.E.; Boeckelmann, H.K.

    1986-01-01

    The importance of instabilities which occur during plasma heating in a Theta Pinch, in the implosion phase, is analysed. The plasma diagnostic was done by ultrafast photography and diamagnetic probe. The implosion time and the current layer thickness were calculated using a hybrid code for plasma simulation. The theoretical data were compared with the experimental ones. (M.C.K.) [pt

  15. Steady state theta pinch concept for slow formation of FRC

    International Nuclear Information System (INIS)

    Hirano, K.

    1987-05-01

    A steady state high beta plasma flow through a channel along the magnetic field increasing downstream can be regarded as a ''steady state theta pinch'', because if we see the plasma riding on the flow we should observe very similar process taking place in a theta pinch. Anticipating to produce an FRC without using very high voltage technics such as the ones required in a conventional theta pinch, we have studied after the analogy a ''steady state reversed field theta pinch'' which is brought about by steady head-on collision of counter plasma streams along the channel as ejected from two identical co-axial plasma sources mounted at the both ends of the apparatus. The ideal Poisson and shock adiabatic flow models are employed for the analysis of the steady colliding process. It is demonstrated that an FRC involving large numbers of particles is produced only by the weak shock mode which is achieved in case energetic plasma flow is decelerated almost to be stagnated through Poisson adiabatic process before the streams are collided. (author)

  16. Electrical insulators for the theta-pinch fusion reactor

    International Nuclear Information System (INIS)

    Clinard, F.W. Jr.

    1976-01-01

    The five major applications for electrical insulators in the Reference Theta Pinch Reactor are as follows: (1) first-wall insulator, (2) blanket intersegment insulator, (3) graphite encapsulating insulator, (4) implosion coil insulator, and (5) compression coil insulator. Insulator design proposals and some preliminary test results are given for each application

  17. Mechanical Stress Downregulates MHC Class I Expression on Human Cancer Cell Membrane

    DEFF Research Database (Denmark)

    La Rocca, Rosanna; Tallerico, Rossana; Hassan, Almosawy Talib

    2014-01-01

    In our body, cells are continuously exposed to physical forces that can regulate different cell functions such as cell proliferation, differentiation and death. In this work, we employed two different strategies to mechanically stress cancer cells. The cancer and healthy cell populations were...... treated either with mechanical stress delivered by a micropump (fabricated by deep X-ray nanolithography) or by ultrasound wave stimuli. A specific down-regulation of Major Histocompatibility Complex (MHC) class I molecules expression on cancer cell membrane compared to different kinds of healthy cells...... between 700–1800 cm-1, indicated a relative concentration variation of MHC class I. PCA analysis was also performed to distinguish control and stressed cells within different cell lines. These mechanical induced phenotypic changes increase the tumor immunogenicity, as revealed by the related increased...

  18. JC Polyomavirus Infection Is Strongly Controlled by Human Leucocyte Antigen Class II Variants

    DEFF Research Database (Denmark)

    Sundqvist, Emilie; Buck, Dorothea; Warnke, Clemens

    2014-01-01

    sequence-specific oligonucleotide (PCR-SSO) method. An initial GWAS screen displayed a strong HLA class II region signal. The HLA-DRB1*15 haplotype was strongly negatively associated to JCV sero-status in Scandinavian MS cases (OR = 0.42, p = 7×10(-15)) and controls (OR = 0.53, p = 2×10(-5)). In contrast...

  19. Selective changes in expression of HLA class I polymorphic determinants in human solid tumors

    International Nuclear Information System (INIS)

    Natali, P.G.; Nicotra, M.R.; Bigotti, A.; Venturo, I.; Giacomini, P.; Marcenaro, L.; Russo, C.

    1989-01-01

    Analysis of surgical biopsies with monoclonal antibodies (mAbs) to framework determinants of major histocompatibility complex class I antigens has shown that malignant transformation is frequently associated with a marked loss of these cell surface molecules. The present study sought to determine whether more selective losses of major histocompatibility complex class I expression occur. Multiple specimens from 13 different types of primary and metastatic tumors were tested utilizing mAb BB7.2, which recognizes a polymorphic HLA-A2 epitope. In each case, expression of HLA-A,B,C molecules was determined by testing with mAb W6/32 directed to a framework HLA class I determinant. The authors have found that in HLA-A2-positive patients, HLA-A2 products are not detectable or are reduced in their expression in 70-80% of endometrial, colorectal, mammary, and renal tumors; in 40-60% of soft-tissue, skin, ovary, urinary bladder, prostate, and stomach tumors; and in 25-30% of melanomas and lung carcinomas tested. All tumors expressed the framework HLA-A,B.C determinant. The HLA-A2 epitope recognized by mAb BB7.2 is located in a portion of the HLA-A2 molecule postulated to react with the T-cell receptor. The selective loss of an HLA class I polymorphic epitope shown in this study may explain the mechanism by which tumor cells escape both T-cell recognition and natural killer cell surveillance

  20. Lee weight enumerators of self-dual codes and theta functions

    NARCIS (Netherlands)

    Asch, van A.G.; Martens, F.J.L.

    2008-01-01

    The theory of modular forms, in particular theta functions, and coding theory are in a remarkable way connected. The connection is established by defining a suitable lattice corresponding to the given code, and considering its theta function. First we define some special theta functions, and

  1. Modulation of Hippocampal Theta Oscillations and Spatial Memory by Relaxin-3 Neurons of the Nucleus Incertus

    Science.gov (United States)

    Ma, Sherie; Olucha-Bordonau, Francisco E.; Hossain, M. Akhter; Lin, Feng; Kuei, Chester; Liu, Changlu; Wade, John D.; Sutton, Steven W.; Nunez, Angel; Gundlach, Andrew L.

    2009-01-01

    Hippocampal theta rhythm is thought to underlie learning and memory, and it is well established that "pacemaker" neurons in medial septum (MS) modulate theta activity. Recent studies in the rat demonstrated that brainstem-generated theta rhythm occurs through a multisynaptic pathway via the nucleus incertus (NI), which is the primary source of the…

  2. Impact of Prefrontal Theta Burst Stimulation on Clinical Neuropsychological Tasks

    Directory of Open Access Journals (Sweden)

    Raquel Viejo-Sobera

    2017-08-01

    Full Text Available Theta burst stimulation (TBS protocols hold high promise in neuropsychological rehabilitation. Nevertheless, their ability to either decrease (continuous, cTBS or increase (intermittent, iTBS cortical excitability in areas other than the primary motor cortex, and their consistency modulating human behaviors with clinically relevant tasks remain to be fully established. The behavioral effects of TBS over the dorsolateral prefrontal cortex (dlPFC are particularly interesting given its involvement in working memory (WM and executive functions (EF, often impaired following frontal brain damage. We aimed to explore the ability of cTBS and iTBS to modulate WM and EF in healthy individuals, assessed with clinical neuropsychological tests (Digits Backward, 3-back task, Stroop Test, and Tower of Hanoi. To this end, 36 participants were assessed using the four tests 1 week prior to stimulation and immediately following a single session of either cTBS, iTBS, or sham TBS, delivered to the left dlPFC. No significant differences were found across stimulation conditions in any of the clinical tasks. Nonetheless, in some of them, active stimulation induced significant pre/post performance modulations, which were not found for the sham condition. More specifically, sham stimulation yielded improvements in the 3-back task and the Color, Color-Word, and Interference Score of the Stroop Test, an effect likely caused by task practice. Both, iTBS and cTBS, produced improvements in Digits Backward and impairments in 3-back task accuracy. Moreover, iTBS increased Interference Score in the Stroop Test in spite of the improved word reading and impaired color naming, whereas cTBS decreased the time required to complete the Tower of Hanoi. Differing from TBS outcomes reported for cortico-spinal measures on the primary motor cortex, our analyses did not reveal any of the expected performance differences across stimulation protocols. However, if one considers independently

  3. Human umbilical cord mesenchymal stromal cells suppress MHC class II expression on rat vascular endothelium and prolong survival time of cardiac allograft

    Science.gov (United States)

    Qiu, Ying; Yun, Mark M; Han, Xia; Zhao, Ruidong; Zhou, Erxia; Yun, Sheng

    2014-01-01

    Background: Human umbilical cord mesenchymal stromal cells (UC-MSCs) have low immunogenicity and immune regulation. To investigate immunomodulatory effects of human UC-MSCs on MHC class II expression and allograft, we transplanted heart of transgenic rats with MHC class II expression on vascular endothelium. Methods: UC-MSCs were obtained from human umbilical cords and confirmed with flow cytometry analysis. Transgenic rat line was established using the construct of human MHC class II transactivator gene (CIITA) under mouse ICAM-2 promoter control. The induced MHC class II expression on transgenic rat vascular endothelial cells (VECs) was assessed with immunohistological staining. And the survival time of cardiac allograft was compared between the recipients with and without UC-MSC transfusion. Results: Flow cytometry confirmed that the human UC-MSCs were positive for CD29, CD44, CD73, CD90, CD105, CD271, and negative for CD34 and HLA-DR. Repeated infusion of human UC-MSCs reduced MHC class II expression on vascular endothelia of transplanted hearts, and increased survival time of allograft. The UC-MSCs increased regulatory cytokines IL10, transforming growth factor (TGF)-β1 and suppressed proinflammatory cytokines IL2 and IFN-γ in vivo. The UC-MSC culture supernatant had similar effects on cytokine expression, and decreased lymphocyte proliferation in vitro. Conclusions: Repeated transfusion of the human UC-MSCs reduced MHC class II expression on vascular endothelia and prolonged the survival time of rat cardiac allograft. PMID:25126177

  4. Human Leukocyte Antigen (HLA) Class I Restricted Epitope Discovery in Yellow Fewer and Dengue Viruses: Importance of HLA Binding Strength

    DEFF Research Database (Denmark)

    Lund, Ole; Nascimento, Eduardo J. M.; Maciel, Milton, Jr

    2011-01-01

    Epitopes from all available full-length sequences of yellow fever virus (YFV) and dengue fever virus (DENV) restricted by Human Leukocyte Antigen class I (HLA-I) alleles covering 12 HLA-I supertypes were predicted using the NetCTL algorithm. A subset of 179 predicted YFV and 158 predicted DENV...... inoculated twice with the 17DD YFV vaccine strain. Three of the YFV A*02:01 restricted peptides activated T-cells from the infected mice in vitro. All three peptides that elicited responses had an HLA binding affinity of 2 nM or less. The results indicate the importance of the strength of HLA binding...

  5. Ex vivo analysis of human memory CD4 T cells specific for hepatitis C virus using MHC class II tetramers

    OpenAIRE

    Day, Cheryl L.; Seth, Nilufer P.; Lucas, Michaela; Appel, Heiner; Gauthier, Laurent; Lauer, Georg M.; Robbins, Gregory K.; Szczepiorkowski, Zbigniew M.; Casson, Deborah R.; Chung, Raymond T.; Bell, Shannon; Harcourt, Gillian; Walker, Bruce D.; Klenerman, Paul; Wucherpfennig, Kai W.

    2003-01-01

    Containment of hepatitis C virus (HCV) and other chronic human viral infections is associated with persistence of virus-specific CD4 T cells, but ex vivo characterization of circulating CD4 T cells has not been achieved. To further define the phenotype and function of these cells, we developed a novel approach for the generation of tetrameric forms of MHC class II/peptide complexes that is based on the cellular peptide-exchange mechanism. HLA-DR molecules were expressed as precursors with a c...

  6. Associations among Epstein-Barr virus subtypes, human leukocyte antigen class I alleles, and the development of posttransplantation lymphoproliferative disorder in bone marrow transplant recipients

    NARCIS (Netherlands)

    Görzer, Irene; Puchhammer-Stöckl, Elisabeth; van Esser, Joost W J; Niesters, Hubert G M; Cornelissen, Jan J

    2007-01-01

    The association between Epstein-Barr virus subtype, human leukocyte antigen class I alleles, and the development of posttransplantation lymphoproliferative disorder was examined in a group of 25 bone marrow transplant recipients. A highly statistically significant correlation was observed between

  7. Kay Warren on Gender, Class, and the Unwilling Victims of Human Trafficking Law

    OpenAIRE

    Rothenberg, Janell

    2009-01-01

    Over the last decade, human trafficking has emerged as a legal category of prosecutable criminal behavior. The 2000 Protocol to Prevent, Suppress and Punish Trafficking in Persons, adopted by the United Nations General Assembly, created international guidelines for the identification and prosecution of human trafficking under the auspices of the UN Office on Drugs and Crime. More than 110 UN member states are signatories to this protocol while actual attempts to translate it into practice con...

  8. MHC class I–associated peptides derive from selective regions of the human genome

    Science.gov (United States)

    Pearson, Hillary; Granados, Diana Paola; Durette, Chantal; Bonneil, Eric; Courcelles, Mathieu; Rodenbrock, Anja; Laverdure, Jean-Philippe; Côté, Caroline; Thibault, Pierre

    2016-01-01

    MHC class I–associated peptides (MAPs) define the immune self for CD8+ T lymphocytes and are key targets of cancer immunosurveillance. Here, the goals of our work were to determine whether the entire set of protein-coding genes could generate MAPs and whether specific features influence the ability of discrete genes to generate MAPs. Using proteogenomics, we have identified 25,270 MAPs isolated from the B lymphocytes of 18 individuals who collectively expressed 27 high-frequency HLA-A,B allotypes. The entire MAP repertoire presented by these 27 allotypes covered only 10% of the exomic sequences expressed in B lymphocytes. Indeed, 41% of expressed protein-coding genes generated no MAPs, while 59% of genes generated up to 64 MAPs, often derived from adjacent regions and presented by different allotypes. We next identified several features of transcripts and proteins associated with efficient MAP production. From these data, we built a logistic regression model that predicts with good accuracy whether a gene generates MAPs. Our results show preferential selection of MAPs from a limited repertoire of proteins with distinctive features. The notion that the MHC class I immunopeptidome presents only a small fraction of the protein-coding genome for monitoring by the immune system has profound implications in autoimmunity and cancer immunology. PMID:27841757

  9. Mechanical Stress Downregulates MHC Class I Expression on Human Cancer Cell Membrane

    KAUST Repository

    La Rocca, Rosanna

    2014-12-26

    In our body, cells are continuously exposed to physical forces that can regulate different cell functions such as cell proliferation, differentiation and death. In this work, we employed two different strategies to mechanically stress cancer cells. The cancer and healthy cell populations were treated either with mechanical stress delivered by a micropump (fabricated by deep X-ray nanolithography) or by ultrasound wave stimuli. A specific down-regulation of Major Histocompatibility Complex (MHC) class I molecules expression on cancer cell membrane compared to different kinds of healthy cells (fibroblasts, macrophages, dendritic and lymphocyte cells) was observed, stimulating the cells with forces in the range of nano-newton, and pressures between 1 and 10 bar (1 bar = 100.000 Pascal), depending on the devices used. Moreover, Raman spectroscopy analysis, after mechanical treatment, in the range between 700–1800 cm−1, indicated a relative concentration variation of MHC class I. PCA analysis was also performed to distinguish control and stressed cells within different cell lines. These mechanical induced phenotypic changes increase the tumor immunogenicity, as revealed by the related increased susceptibility to Natural Killer (NK) cells cytotoxic recognition.

  10. Mechanical stress downregulates MHC class I expression on human cancer cell membrane.

    Directory of Open Access Journals (Sweden)

    Rosanna La Rocca

    Full Text Available In our body, cells are continuously exposed to physical forces that can regulate different cell functions such as cell proliferation, differentiation and death. In this work, we employed two different strategies to mechanically stress cancer cells. The cancer and healthy cell populations were treated either with mechanical stress delivered by a micropump (fabricated by deep X-ray nanolithography or by ultrasound wave stimuli. A specific down-regulation of Major Histocompatibility Complex (MHC class I molecules expression on cancer cell membrane compared to different kinds of healthy cells (fibroblasts, macrophages, dendritic and lymphocyte cells was observed, stimulating the cells with forces in the range of nano-newton, and pressures between 1 and 10 bar (1 bar = 100.000 Pascal, depending on the devices used. Moreover, Raman spectroscopy analysis, after mechanical treatment, in the range between 700-1800 cm(-1, indicated a relative concentration variation of MHC class I. PCA analysis was also performed to distinguish control and stressed cells within different cell lines. These mechanical induced phenotypic changes increase the tumor immunogenicity, as revealed by the related increased susceptibility to Natural Killer (NK cells cytotoxic recognition.

  11. Working memory performance inversely predicts spontaneous delta and theta-band scaling relations.

    Science.gov (United States)

    Euler, Matthew J; Wiltshire, Travis J; Niermeyer, Madison A; Butner, Jonathan E

    2016-04-15

    Electrophysiological studies have strongly implicated theta-band activity in human working memory processes. Concurrently, work on spontaneous, non-task-related oscillations has revealed the presence of long-range temporal correlations (LRTCs) within sub-bands of the ongoing EEG, and has begun to demonstrate their functional significance. However, few studies have yet assessed the relation of LRTCs (also called scaling relations) to individual differences in cognitive abilities. The present study addressed the intersection of these two literatures by investigating the relation of narrow-band EEG scaling relations to individual differences in working memory ability, with a particular focus on the theta band. Fifty-four healthy adults completed standardized assessments of working memory and separate recordings of their spontaneous, non-task-related EEG. Scaling relations were quantified in each of the five classical EEG frequency bands via the estimation of the Hurst exponent obtained from detrended fluctuation analysis. A multilevel modeling framework was used to characterize the relation of working memory performance to scaling relations as a function of general scalp location in Cartesian space. Overall, results indicated an inverse relationship between both delta and theta scaling relations and working memory ability, which was most prominent at posterior sensors, and was independent of either spatial or individual variability in band-specific power. These findings add to the growing literature demonstrating the relevance of neural LRTCs for understanding brain functioning, and support a construct- and state-dependent view of their functional implications. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. (No) time for control: Frontal theta dynamics reveal the cost of temporally guided conflict anticipation.

    Science.gov (United States)

    van Driel, Joram; Swart, Jennifer C; Egner, Tobias; Ridderinkhof, K Richard; Cohen, Michael X

    2015-12-01

    During situations of response conflict, cognitive control is characterized by prefrontal theta-band (3- to 8-Hz) activity. It has been shown that cognitive control can be triggered proactively by contextual cues that predict conflict. Here, we investigated whether a pretrial preparation interval could serve as such a cue. This would show that the temporal contingencies embedded in the task can be used to anticipate upcoming conflict. To this end, we recorded electroencephalography (EEG) from 30 human subjects while they performed a version of a Simon task in which the duration of a fixation cross between trials predicted whether the next trial would contain response conflict. Both their behavior and EEG activity showed a consistent but unexpected pattern of results: The conflict effect (increased reaction times and decreased accuracy on conflict as compared to nonconflict trials) was stronger when conflict was cued, and this was associated with stronger conflict-related midfrontal theta activity and functional connectivity. Interestingly, intervals that predicted conflict did show a pretarget increase in midfrontal theta power. These findings suggest that temporally guided expectations of conflict do heighten conflict anticipation, but also lead to less efficiently applied reactive control. We further explored this post-hoc interpretation by means of three behavioral follow-up experiments, in which we used nontemporal cues, semantically informative cues, and neutral cues. Together, this body of results suggests that the counterintuitive cost of conflict cueing may not be uniquely related to the temporal domain, but may instead be related to the implicitness and validity of the cue.

  13. Latent classes of polydrug and polyroute use and associations with human immunodeficiency virus risk behaviours and overdose among people who inject drugs in Tijuana, Baja California, Mexico.

    Science.gov (United States)

    Meacham, Meredith C; Roesch, Scott C; Strathdee, Steffanie A; Lindsay, Suzanne; Gonzalez-Zuniga, Patricia; Gaines, Tommi L

    2018-01-01

    Patterns of polydrug use among people who inject drugs (PWID) may be differentially associated with overdose and unique human immunodeficiency virus (HIV) risk factors. Subgroups of PWID in Tijuana, Mexico, were identified based on substances used, route of administration, frequency of use and co-injection indicators. Participants were PWID residing in Tijuana age ≥18 years sampled from 2011 to 2012 who reported injecting an illicit substance in the past month (n = 735). Latent class analysis identified discrete classes of polydrug use characterised by 11 indicators of past 6 months substance use. Multinomial logistic regression examined class membership association with HIV risk behaviours, overdose and other covariates using an automated three-step procedure in mplus to account for classification error. Participants were classified into five subgroups. Two polydrug and polyroute classes were defined by use of multiple substances through several routes of administration and were primarily distinguished from each other by cocaine use (class 1: 5%) or no cocaine use (class 2: 29%). The other classes consisted primarily of injectors: cocaine, methamphetamine and heroin injection (class 3: 4%); methamphetamine and heroin injection (class 4: 10%); and heroin injection (class 5: 52%). Compared with the heroin-only injection class, memberships in the two polydrug and polyroute use classes were independently associated with both HIV injection and sexual risk behaviours. Substance use patterns among PWID in Tijuana are highly heterogeneous, and polydrug and polyroute users are a high-risk subgroup who may require more tailored prevention and treatment interventions. [Meacham MC, Roesch SC, Strathdee SA, Lindsay S, Gonzalez-Zuniga P, Gaines TL. Latent classes of polydrug and polyroute use and associations with human immunodeficiency virus risk behaviours and overdose among people who inject drugs in Tijuana, Baja California, Mexico. Drug Alcohol Rev 2018;37:128-136].

  14. Structure of the human glucagon class B G-protein-coupled receptor

    NARCIS (Netherlands)

    Siu, F.Y.; He, M.; de Graaf, C.; Yang, D; Zhang, Z.; Zhou, C.; Han, G.W.; Xu, Q.; Wacker, D.; Joseph, J.S.; Wei, Liu; Lau, J.F.; Cherezov, V.; Katritch, V; Wang, M.W.; Stevens, R.C.

    2013-01-01

    Binding of the glucagon peptide to the glucagon receptor (GCGR) triggers the release of glucose from the liver during fasting; thus GCGR plays an important role in glucose homeostasis. Here we report the crystal structure of the seven transmembrane helical domain of human GCGR at 3.4 Å resolution,

  15. Donaldson-Witten theory and indefinite theta functions

    Science.gov (United States)

    Korpas, Georgios; Manschot, Jan

    2017-11-01

    We consider partition functions with insertions of surface operators of topologically twisted N=2 , SU(2) supersymmetric Yang-Mills theory, or Donaldson-Witten theory for short, on a four-manifold. If the metric of the compact four-manifold has positive scalar curvature, Moore and Witten have shown that the partition function is completely determined by the integral over the Coulomb branch parameter a, while more generally the Coulomb branch integral captures the wall-crossing behavior of both Donaldson polynomials and Seiberg-Witten invariants. We show that after addition of a \\overlineQ -exact surface operator to the Moore-Witten integrand, the integrand can be written as a total derivative to the anti-holomorphic coordinate ā using Zwegers' indefinite theta functions. In this way, we reproduce Göttsche's expressions for Donaldson invariants of rational surfaces in terms of indefinite theta functions for any choice of metric.

  16. Riemann-Theta Boltzmann Machine arXiv

    CERN Document Server

    Krefl, Daniel; Haghighat, Babak; Kahlen, Jens

    A general Boltzmann machine with continuous visible and discrete integer valued hidden states is introduced. Under mild assumptions about the connection matrices, the probability density function of the visible units can be solved for analytically, yielding a novel parametric density function involving a ratio of Riemann-Theta functions. The conditional expectation of a hidden state for given visible states can also be calculated analytically, yielding a derivative of the logarithmic Riemann-Theta function. The conditional expectation can be used as activation function in a feedforward neural network, thereby increasing the modelling capacity of the network. Both the Boltzmann machine and the derived feedforward neural network can be successfully trained via standard gradient- and non-gradient-based optimization techniques.

  17. Imploding to equilibrium of helically symmetric theta pinches

    International Nuclear Information System (INIS)

    Sharky, N.N.

    1978-01-01

    The time-dependent, single-fluid, dissipative magnetohydrodynamic equations are solved in helical coordinates (r,phi), where phi = THETA-kz, k = 2π/L and L is the periodicity length in the z-direction. The two-dimensional numerical calculations simulate theta pinches which have an l = 1 helical field added to them. Given the applied magnetic fields and the initial state of the plasma, we study the time evolution of the system. The plasma is found to experience two kinds of oscillations, occurring on different time scales. These are the radial compression oscillations, and the slower helical oscillations of the plasma column. The plasma motion is followed until these oscillations disappear and an equilibrium is nearly reached. Hence given the amplitude and the rise time of the applied magnetic fields, the calculations allow one to relate the initial state of a cold, homogeneous plasma to its final equilibrium state where it is heated and compressed

  18. High resolution human leukocyte antigen (HLA) class I and class II allele typing in Mexican mestizo women with sporadic breast cancer: case-control study

    International Nuclear Information System (INIS)

    Cantú de León, David; Yu, Neng; Yunis, Edmond J; Granados, Julio; Pérez-Montiel, Delia; Villavicencio, Verónica; Carranca, Alejandro García; Betancourt, Alejandro Mohar; Acuña-Alonzo, Victor; López-Tello, Alberto; Vargas-Alarcón, Gilberto; Barquera, Rodrigo

    2009-01-01

    The development of breast cancer is multifactorial. Hormonal, environmental factors and genetic predisposition, among others, could interact in the presentation of breast carcinoma. Human leukocyte antigen (HLA) alleles play an important role in immunity (cellular immunity) and may be important genetic traits. HLAAllele-specific interaction has not been well established. Recently, several studies had been conducted in order to do so, but the results are controversial and in some instances contradictory. We designed a case-control study to quantify the association of HLA class I and II genes and breast cancer. HLA typing was performed by high resolution sequence-specific oligotyping after DNA amplification (PCR-SSOP) of 100 breast cancer Mexican mestizo patients and 99 matched healthy controls. HLA-A frequencies that we were able to observe that there was no difference between both groups from the statistical viewpoint. HLA-B*1501 was found three times more common in the case group (OR, 3.714; p = 0.031). HLA-Cw is not a marker neither for risk, nor protection for the disease, because we did not find significant statistical differences between the two groups. DRB1*1301, which is expressed in seven cases and in only one control, observing an risk increase of up to seven times and DRB1*1602, which behaves similarly in being present solely in the cases (OR, 16.701; 95% CI, 0.947 – 294.670). DQ*0301-allele expression, which is much more common in the control group and could be protective for the presentation of the disease (OR, 0.078; 95% CI, 0.027–0.223, p = 0.00001). Our results reveal the role of the MHC genes in the pathophysiology of breast cancer, suggesting that in the development of breast cancer exists a disorder of immune regulation. The triggering factor seems to be restricted to certain ethnic groups and certain geographical regions since the relevant MHC alleles are highly diverse. This is the first study in Mexican population where high resolutions HLA

  19. Combinatorics of tenth-order mock theta functions

    Indian Academy of Sciences (India)

    θ(q) there is some root of unity ζ for which f (q) − θ(q) is unbounded as q → ζ rapidly. In the long list of 17 mock theta functions given by Ramanujan, few have been interpreted combinatorially. For example, (q) defined by (1.1) below, has been interpreted by Fine. [8] as a generating function for partitions into odd parts without ...

  20. Double-Chooz: a search for {theta}{sub 13}

    Energy Technology Data Exchange (ETDEWEB)

    Mention, G. [APC/PCC, College de France, 75005 Paris (France)

    2005-08-15

    The Double-Chooz experiment goal is to search for a non-vanishing value of the {theta}{sub 13} neutrino mixing angle. This is the last step to accomplish prior moving towards a new era of precision measurements in the lepton sector. The current best constraint on the third mixing angle comes from the CHOOZ reactor neutrino experiment sin{sup 2}(2{theta}{sub 13}) < 0.2-0.14 (90% C.L., {delta}m{sub atm}{sup 2}=2.0-2.410{sup -3} eV{sup 2}). Double-Chooz will explore the range of sin{sup 2}(2{theta}{sub 13}) from 0.2 to 0.03-0.02, within three years of data taking. The improvement of the CHOOZ result requires an increase in the statistics, a reduction of the systematic error below one percent, and a careful control of the backgrounds. Therefore, Double-Chooz will use two identical detectors, one at 150 m and another at 1.05 km distance from the Chooz nuclear cores. In addition, we will use the near detector as a 'state of the art' prototype to investigate the potential of neutrinos for monitoring the civil nuclear power plants. The plan is to start operation with two detectors in 2008, and to reach a sin{sup 2}(2{theta}{sub 13}) sensitivity of 0.05 in 2009, and 0.03-0.02 in 2011.

  1. A reversed-field theta-pinch plasma machine

    International Nuclear Information System (INIS)

    Yasojima, Yoshiyuki; Ueda, Yoshihiro; Sasao, Hiroyuki; Ueno, Noboru; Tanaka, Toshihide

    1984-01-01

    Mitsubishi Electric has constructed a reversed-field theta-pinch machine at its Central Research Laboratory and initiated a series of plasma diagnostics and control studies for development of nuclear-fusion technology. Although the device has a linear configuration, a stable high-temperature, high-density toroidal plasma can be generated. The article describes the overall structure, vacuum system, power-supply system, and diagnostics and control system of the plasma machine. (author)

  2. Theta coordinated error-driven learning in the hippocampus.

    Directory of Open Access Journals (Sweden)

    Nicholas Ketz

    Full Text Available The learning mechanism in the hippocampus has almost universally been assumed to be Hebbian in nature, where individual neurons in an engram join together with synaptic weight increases to support facilitated recall of memories later. However, it is also widely known that Hebbian learning mechanisms impose significant capacity constraints, and are generally less computationally powerful than learning mechanisms that take advantage of error signals. We show that the differential phase relationships of hippocampal subfields within the overall theta rhythm enable a powerful form of error-driven learning, which results in significantly greater capacity, as shown in computer simulations. In one phase of the theta cycle, the bidirectional connectivity between CA1 and entorhinal cortex can be trained in an error-driven fashion to learn to effectively encode the cortical inputs in a compact and sparse form over CA1. In a subsequent portion of the theta cycle, the system attempts to recall an existing memory, via the pathway from entorhinal cortex to CA3 and CA1. Finally the full theta cycle completes when a strong target encoding representation of the current input is imposed onto the CA1 via direct projections from entorhinal cortex. The difference between this target encoding and the attempted recall of the same representation on CA1 constitutes an error signal that can drive the learning of CA3 to CA1 synapses. This CA3 to CA1 pathway is critical for enabling full reinstatement of recalled hippocampal memories out in cortex. Taken together, these new learning dynamics enable a much more robust, high-capacity model of hippocampal learning than was available previously under the classical Hebbian model.

  3. Instantons, theta-vacua, confinement..... a pedagogical introduction

    International Nuclear Information System (INIS)

    Teper, M.J.

    1980-01-01

    In this series of lectures the concept of the instanton and its various ramifications, such as the dilute gas and theta-vacua, are introduced through the relatively simple dynamical system of 1 + 1 dimensional quantum mechanics and the 1 + 1 abelian Higgs model. Although QCD is not dealt with explicitly those aspects of the argument which are relevant to that much more complicated theory are noted. (UK)

  4. Index of Theta/Alpha Ratio of the Quantitative Electroencephalogram in Alzheimer's Disease: A Case-Control Study.

    Science.gov (United States)

    Fahimi, Golshan; Tabatabaei, Seyed Mahmoud; Fahimi, Elnaz; Rajebi, Hamid

    2017-08-01

    Alzheimer's disease (AD) is a devastating neurodegenerative disorder in human beings associated with cognitive, behavioral and motor impairments. The main symptom of AD is dementia, which causes difficulties in carrying out daily practices. Brain waves are altered in people with AD. Relative indices of brain waves can be beneficial in the diagnosis of AD. In this case-control study, 50 patients with AD and 50 matched healthy individuals were enrolled in case and control groups respectively. With recording and analyzing of brain waves with the utilization of quantitative electroencephalogram (QEEG), index of theta/alpha ratio was assessed in both groups. The index of theta/alpha ratio was significantly higher in patients with AD in comparison to healthy individuals (Pratio obtained by QEEG provides a non-invasive diagnostic marker of AD, which may be helpful in identification of non-advanced disease in susceptible individuals.

  5. Delta-gamma-theta Hedging of Crude Oil Asian Options

    Directory of Open Access Journals (Sweden)

    Juraj Hruška

    2015-01-01

    Full Text Available Since Black-Scholes formula was derived, many methods have been suggested for vanilla as well as exotic options pricing. More of investing and hedging strategies have been developed based on these pricing models. Goal of this paper is to derive delta-gamma-theta hedging strategy for Asian options and compere its efficiency with gamma-delta-theta hedging combined with predictive model. Fixed strike Asian options are type of exotic options, whose special feature is that payoff is calculated from the difference of average market price and strike price for call options and vice versa for the put options. Methods of stochastic analysis are used to determine deltas, gammas and thetas of Asian options. Asian options are cheaper than vanilla options and therefore they are more suitable for precise portfolio creation. On the other hand their deltas are also smaller as well as profits. That means that they are also less risky and more suitable for hedging. Results, conducted on chosen commodity, confirm better feasibility of Asian options compering with vanilla options in sense of gamma hedging.

  6. Dendritic brushes under theta and poor solvent conditions

    Science.gov (United States)

    Gergidis, Leonidas N.; Kalogirou, Andreas; Charalambopoulos, Antonios; Vlahos, Costas

    2013-07-01

    The effects of solvent quality on the internal stratification of polymer brushes formed by dendron polymers up to third generation were studied by means of molecular dynamics simulations with Langevin thermostat. The distributions of polymer units, of the free ends, the radii of gyration, and the back folding probabilities of the dendritic spacers were studied at the macroscopic states of theta and poor solvent. For high grafting densities we observed a small decrease in the height of the brush as the solvent quality decreases. The internal stratification in theta solvent was similar to the one we found in good solvent, with two and in some cases three kinds of populations containing short dendrons with weakly extended spacers, intermediate-height dendrons, and tall dendrons with highly stretched spacers. The differences increase as the grafting density decreases and single dendron populations were evident in theta and poor solvent. In poor solvent at low grafting densities, solvent micelles, polymeric pinned lamellae, spherical and single chain collapsed micelles were observed. The scaling dependence of the height of the dendritic brush at high density brushes for both solvents was found to be in agreement with existing analytical results.

  7. Theta series, wall-crossing and quantum dilogarithm identities

    CERN Document Server

    Alexandrov, Sergei

    2016-01-01

    Motivated by mathematical structures which arise in string vacua and gauge theories with N=2 supersymmetry, we study the properties of certain generalized theta series which appear as Fourier coefficients of functions on a twisted torus. In Calabi-Yau string vacua, such theta series encode instanton corrections from $k$ Neveu-Schwarz five-branes. The theta series are determined by vector-valued wave-functions, and in this work we obtain the transformation of these wave-functions induced by Kontsevich-Soibelman symplectomorphisms. This effectively provides a quantum version of these transformations, where the quantization parameter is inversely proportional to the five-brane charge $k$. Consistency with wall-crossing implies a new five-term relation for Faddeev's quantum dilogarithm $\\Phi_b$ at $b=1$, which we prove. By allowing the torus to be non-commutative, we obtain a more general five-term relation valid for arbitrary $b$ and $k$, which may be relevant for the physics of five-branes at finite chemical po...

  8. Theta signal as the neural signature of social exclusion.

    Science.gov (United States)

    Cristofori, Irene; Moretti, Laura; Harquel, Sylvain; Posada, Andres; Deiana, Gianluca; Isnard, Jean; Mauguière, François; Sirigu, Angela

    2013-10-01

    The feeling of being excluded from a social interaction triggers social pain, a sensation as intense as actual physical pain. Little is known about the neurophysiological underpinnings of social pain. We addressed this issue using intracranial electroencephalography in 15 patients performing a ball game where inclusion and exclusion blocks were alternated. Time-frequency analyses showed an increase in power of theta-band oscillations during exclusion in the anterior insula (AI) and posterior insula, the subgenual anterior cingulate cortex (sACC), and the fusiform "face area" (FFA). Interestingly, the AI showed an initial fast response to exclusion but the signal rapidly faded out. Activity in the sACC gradually increased and remained significant thereafter. This suggests that the AI may signal social pain by detecting emotional distress caused by the exclusion, whereas the sACC may be linked to the learning aspects of social pain. Theta activity in the FFA was time-locked to the observation of a player poised to exclude the participant, suggesting that the FFA encodes the social value of faces. Taken together, our findings suggest that theta activity represents the neural signature of social pain. The time course of this signal varies across regions important for processing emotional features linked to social information.

  9. Theta and Alpha Oscillations in Attentional Interaction during Distracted Driving

    Directory of Open Access Journals (Sweden)

    Yu-Kai Wang

    2018-02-01

    Full Text Available Performing multiple tasks simultaneously usually affects the behavioral performance as compared with executing the single task. Moreover, processing multiple tasks simultaneously often involve more cognitive demands. Two visual tasks, lane-keeping task and mental calculation, were utilized to assess the brain dynamics through 32-channel electroencephalogram (EEG recorded from 14 participants. A 400-ms stimulus onset asynchrony (SOA factor was used to induce distinct levels of attentional requirements. In the dual-task conditions, the deteriorated behavior reflected the divided attention and the overlapping brain resources used. The frontal, parietal and occipital components were decomposed by independent component analysis (ICA algorithm. The event- and response-related theta and alpha oscillations in selected brain regions were investigated first. The increased theta oscillation in frontal component and decreased alpha oscillations in parietal and occipital components reflect the cognitive demands and attentional requirements as executing the designed tasks. Furthermore, time-varying interactive over-additive (O-Add, additive (Add and under-additive (U-Add activations were explored and summarized through the comparison between the summation of the elicited spectral perturbations in two single-task conditions and the spectral perturbations in the dual task. Add and U-Add activations were observed while executing the dual tasks. U-Add theta and alpha activations dominated the posterior region in dual-task situations. Our results show that both deteriorated behaviors and interactive brain activations should be comprehensively considered for evaluating workload or attentional interaction precisely.

  10. Adaptive [theta]-methods for pricing American options

    Science.gov (United States)

    Khaliq, Abdul Q. M.; Voss, David A.; Kazmi, Kamran

    2008-12-01

    We develop adaptive [theta]-methods for solving the Black-Scholes PDE for American options. By adding a small, continuous term, the Black-Scholes PDE becomes an advection-diffusion-reaction equation on a fixed spatial domain. Standard implementation of [theta]-methods would require a Newton-type iterative procedure at each time step thereby increasing the computational complexity of the methods. Our linearly implicit approach avoids such complications. We establish a general framework under which [theta]-methods satisfy a discrete version of the positivity constraint characteristic of American options, and numerically demonstrate the sensitivity of the constraint. The positivity results are established for the single-asset and independent two-asset models. In addition, we have incorporated and analyzed an adaptive time-step control strategy to increase the computational efficiency. Numerical experiments are presented for one- and two-asset American options, using adaptive exponential splitting for two-asset problems. The approach is compared with an iterative solution of the two-asset problem in terms of computational efficiency.

  11. Substituted 2-Phenyl-Imidazopyridines: A New Class of Drug Leads for Human African Trypanosomiasis

    Science.gov (United States)

    Tatipaka, Hari Babu; Gillespie, J. Robert; Chatterjee, Arnab K.; Norcross, Neil R.; Hulverson, Matthew A.; Ranade, Ranae M.; Nagendar, Pendem; Creason, Sharon A.; McQueen, Joshua; Duster, Nicole A.; Nagle, Advait; Supek, Frantisek; Molteni, Valentina; Wenzler, Tanja; Brun, Reto; Glynne, Richard; Buckner, Frederick S.; Gelb, Michael H.

    2014-01-01

    A phenotypic screen of a compound library for antiparasitic activity on Trypanosoma brucei, the causative agent of human African trypanosomiasis, led to the identification of substituted 2-(3-aminophenyl) oxazolopyridines as a starting point for hit-to-lead medicinal chemistry. A total of 110 analogues were prepared, which led to the identification of 64, a substituted 2-(3-aminophenyl) imidazopyridine. This compound showed antiparasitic activity in vitro with an EC50 of 2 nM and displayed reasonable drug-like properties when tested in a number of in vitro assays. The compound was orally bioavailable and displayed good plasma and brain exposure in mice. Compound 64 cured mice infected with Trypanosoma brucei when dosed orally down to 2.5 mg/kg. Given its potent anti-parasitic properties and its ease of synthesis, compound 64 represents a new lead for the development of drugs to treat human African trypanosomiasis. PMID:24354316

  12. Understanding of human metabolic pathways of different sub-classes of phenols from Arbutus unedo fruit after an acute intake.

    Science.gov (United States)

    Mosele, Juana I; Macià, Alba; Motilva, María-José

    2016-03-01

    Arbutus unedo is a small Mediterranean fruit, commonly named strawberry tree, which is a rich source of different sub-classes of phenolic compounds, the more representative being the gallic acid derivatives, including its mono and oligomeric forms esterified with quinic and shikimic acids. In addition, galloyl derivatives, particularly gallotannins, described in A. unedo, are part of a very selective phenolic group, present in a reduced number of plant-products. The aim of the present study is to provide a better understanding of human metabolic pathways of different sub-classes of phenols from the A. unedo fruit after an acute intake by healthy adults. Therefore, the A. unedo phenolic metabolites were studied in whole blood samples (0 to 24 h), urine (24 h) and feces (12 and 24 h). Special focus was placed on the application of dried blood spot (DBS) cards for the sample collection and for the analysis of phenolic metabolites in whole blood samples. The results of the blood analysis revealed two peaks for the maximum concentrations of the main phenolic metabolites. Furthermore, it is appropriate to highlight the application of DBS cards as an efficient and accurate way to collect blood samples in post-prandial bioavailability studies. The analysis of urine (24 h) gave a wide range of phenolic metabolites showing the extensive metabolism that A. unedo phenolic compounds underwent in the human body. The results of the study provide a relevant contribution to the understanding of the in vivo human bioavailability of phenolic compounds, especially galloyl derivatives, a singular phenolic sub-group present in the A. unedo fruit.

  13. Metastatic MHC class I-negative mouse cells derived by transformation with human papillomavirus type 16

    Czech Academy of Sciences Publication Activity Database

    Šmahel, M.; Sobotková, E.; Bubeník, Jan; Šímová, Jana; Žák, R.; Ludvíková, V.; Mikyšková, Romana; Kovařík, J.; Jelínek, F.; Povýšil, C.; Marinov, J.; Vonka, V.

    2001-01-01

    Roč. 84, č. 3 (2001), s. 374-380 ISSN 0007-0920 R&D Projects: GA MZd NC5900; GA MZd NC5526; GA ČR GA312/99/0542; GA ČR GA312/98/0826 Institutional research plan: CEZ:AV0Z5052915 Keywords : human papillomavirus * E6/E7 oncogenes * cell transformation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.942, year: 2001

  14. MHC class I phenotype and function of human beta 2-microglobulin transgenic murine lymphocytes

    DEFF Research Database (Denmark)

    Bjerager, L; Pedersen, L O; Bregenholt, S

    1996-01-01

    . Based on data from cellular binding studies, Scatchard analyses and flow cytometry, it is concluded that exogenous h beta 2m does not bind to hybrid MHC class I (MHC-I) molecules composed of mouse heavy chain/h beta 2m molecules expressed on lymphocytes of transgenic mice. Immunoprecipitation and SDS......-PAGE analysis of metabolically labelled normal C57BL/6 lymph node cells showed binding of exogenous h beta 2m to MHC-I, in particular, to the H-2Db molecule through an exchange with endogenous mouse beta 2m. In contrast to normal H-2Db molecules, hybrid H-2Db expressed on the surface of transgenic lymphocytes...... binds radiolabelled peptide in the absence of exogenous added h beta 2m suggesting that a stable fraction of hybrid H-2Db molecules is empty or contain peptides with very low affinity. In a one-way allogenic mixed lymphocyte culture, transgenic splenocytes were found to be far less stimulatory than...

  15. Data Acquisition and Preprocessing in Studies on Humans: What Is Not Taught in Statistics Classes?

    Science.gov (United States)

    Zhu, Yeyi; Hernandez, Ladia M; Mueller, Peter; Dong, Yongquan; Forman, Michele R

    2013-01-01

    The aim of this paper is to address issues in research that may be missing from statistics classes and important for (bio-)statistics students. In the context of a case study, we discuss data acquisition and preprocessing steps that fill the gap between research questions posed by subject matter scientists and statistical methodology for formal inference. Issues include participant recruitment, data collection training and standardization, variable coding, data review and verification, data cleaning and editing, and documentation. Despite the critical importance of these details in research, most of these issues are rarely discussed in an applied statistics program. One reason for the lack of more formal training is the difficulty in addressing the many challenges that can possibly arise in the course of a study in a systematic way. This article can help to bridge this gap between research questions and formal statistical inference by using an illustrative case study for a discussion. We hope that reading and discussing this paper and practicing data preprocessing exercises will sensitize statistics students to these important issues and achieve optimal conduct, quality control, analysis, and interpretation of a study.

  16. Cognitive control during audiovisual working memory engages frontotemporal theta-band interactions.

    Science.gov (United States)

    Daume, Jonathan; Graetz, Sebastian; Gruber, Thomas; Engel, Andreas K; Friese, Uwe

    2017-10-03

    Working memory (WM) maintenance of sensory information has been associated with enhanced cross-frequency coupling between the phase of low frequencies and the amplitude of high frequencies, particularly in medial temporal lobe (MTL) regions. It has been suggested that these WM maintenance processes are controlled by areas of the prefrontal cortex (PFC) via frontotemporal phase synchronisation in low frequency bands. Here, we investigated whether enhanced cognitive control during audiovisual WM as compared to visual WM alone is associated with increased low-frequency phase synchronisation between sensory areas maintaining WM content and areas from PFC. Using magnetoencephalography, we recorded neural oscillatory activity from healthy human participants engaged in an audiovisual delayed-match-to-sample task. We observed that regions from MTL, which showed enhanced theta-beta phase-amplitude coupling (PAC) during the WM delay window, exhibited stronger phase synchronisation within the theta-band (4-7 Hz) to areas from lateral PFC during audiovisual WM as compared to visual WM alone. Moreover, MTL areas also showed enhanced phase synchronisation to temporooccipital areas in the beta-band (20-32 Hz). Our results provide further evidence that a combination of long-range phase synchronisation and local PAC might constitute a mechanism for neuronal communication between distant brain regions and across frequencies during WM maintenance.

  17. Recalling and forgetting dreams: theta and alpha oscillations during sleep predict subsequent dream recall.

    Science.gov (United States)

    Marzano, Cristina; Ferrara, Michele; Mauro, Federica; Moroni, Fabio; Gorgoni, Maurizio; Tempesta, Daniela; Cipolli, Carlo; De Gennaro, Luigi

    2011-05-04

    Under the assumption that dream recall is a peculiar form of declarative memory, we have hypothesized that (1) the encoding of dream contents during sleep should share some electrophysiological mechanisms with the encoding of episodic memories of the awake brain and (2) recalling a dream(s) after awakening from non-rapid eye movement (NREM) and rapid eye movement (REM) sleep should be associated with different brain oscillations. Here, we report that cortical brain oscillations of human sleep are predictive of successful dream recall. In particular, after morning awakening from REM sleep, a higher frontal 5-7 Hz (theta) activity was associated with successful dream recall. This finding mirrors the increase in frontal theta activity during successful encoding of episodic memories in wakefulness. Moreover, in keeping with the different EEG background, a different predictive relationship was found after awakening from stage 2 NREM sleep. Specifically, a lower 8-12 Hz (alpha) oscillatory activity of the right temporal area was associated with a successful dream recall. These findings provide the first evidence of univocal cortical electroencephalographic correlates of dream recall, suggesting that the neurophysiological mechanisms underlying the encoding and recall of episodic memories may remain the same across different states of consciousness.

  18. Reduced ERPs and theta oscillations underlie working memory deficits in Toxoplasma gondii infected seniors.

    Science.gov (United States)

    Gajewski, Patrick D; Falkenstein, Michael; Hengstler, Jan G; Golka, Klaus

    2016-10-01

    Toxoplasma gondii is one of the most widespread infections in humans. Recent studies give evidence for memory deficits in infected older adults. To investigate working memory dysfunction in infected elderly, a double-blinded electrophysiological study was conducted. 84 persons derived from a sample of 131 healthy participants with the mean age of 70 years were assigned to two groups of 42 non-infected and 42 infected individuals. The outcome measures were behavioral performance, target and response-related ERPs, and time-frequency wavelets during performance in a n-back working-memory task. The infected individuals showed a reduced rate of detected targets and diminished P3b amplitude both in target-locked as well as response-locked data compared to the non-infected group. Time-frequency decomposition of the EEG-signals revealed lower evoked power in the theta frequency range in the target-locked as well as in the response-locked data in infected individuals. The reported effects were comparable with differences between healthy young and old adults described previously. Taking together, the reduced working-memory performance accompanied by an attenuated P3b and frontal theta activity may suggest neurotransmitter imbalance like dopamine and norepinephrine in T. gondii infected individuals. In face of a high prevalence of T. gondii infection and the increasing ratio of older population their accelerated memory decline may have substantial socioeconomic consequences. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Developing and Evaluating Medical Humanities Problem-Based Learning Classes Facilitated by the Teaching Assistants Majored in the Liberal Arts: A Longitudinal Crossover Study.

    Science.gov (United States)

    Tseng, Fen-Yu; Shieh, Jeng-Yi; Kao, Tze-Wah; Wu, Chau-Chung; Chu, Tzong-Shinn; Chen, Yen-Yuan

    2016-02-01

    Although medical humanities courses taught by teachers from nonmedical backgrounds are not unusual now, few studies have compared the outcome of medical humanities courses facilitated by physicians to that by teaching assistants majored in the liberal arts. The objectives of this study were to (1) analyze the satisfaction of medical students with medical humanities problem-based learning (PBL) classes facilitated by nonmedical teaching assistants (TAF) majored in the liberal arts, and those facilitated by the attending physicians (APF) and (2) examine the satisfaction of medical students with clinical medicine-related and clinical medicine-unrelated medical humanities PBL classes.A total of 123 medical students, randomly assigned to 16 groups, participated in this study. There were 16 classes in the course: 8 of them were TAF classes; and the others were APF classes. Each week, each group rotated from 1 subject of the 16 subjects of PBL to another subject. All of the 16 groups went through all the 16 subjects in the 2013 spring semester. We examined the medical students' satisfaction with each class, based on a rating score collected after each class was completed, using a scale from 0 (the lowest satisfaction) to 100 (the highest satisfaction). We also conducted multivariate linear regression analysis to examine the association between the independent variables and the students' satisfaction.Medical students were more satisfied with the TAF (91.35 ± 7.75) medical humanities PBL classes than APF (90.40 ± 8.42) medical humanities PBL classes (P = 0.01). Moreover, medical students were more satisfied with the clinical medicine-unrelated topics (92.00 ± 7.10) than the clinical medicine-related topics (90.36 ± 7.99) in the medical humanities PBL course (P = 0.01).This medical humanities PBL course, including nonmedical subjects and topics, and nonmedical teaching assistants from the liberal arts as class facilitators, was satisfactory. This

  20. Intermittent Theta-Burst Stimulation of the Lateral Cerebellum Increases Functional Connectivity of the Default Network

    Science.gov (United States)

    Farzan, Faranak; Eldaief, Mark C.; Schmahmann, Jeremy D.; Pascual-Leone, Alvaro

    2014-01-01

    Cerebral cortical intrinsic connectivity networks share topographically arranged functional connectivity with the cerebellum. However, the contribution of cerebellar nodes to distributed network organization and function remains poorly understood. In humans, we applied theta-burst transcranial magnetic stimulation, guided by subject-specific connectivity, to regions of the cerebellum to evaluate the functional relevance of connections between cerebellar and cerebral cortical nodes in different networks. We demonstrate that changing activity in the human lateral cerebellar Crus I/II modulates the cerebral default mode network, whereas vermal lobule VII stimulation influences the cerebral dorsal attention system. These results provide novel insights into the distributed, but anatomically specific, modulatory impact of cerebellar effects on large-scale neural network function. PMID:25186750

  1. Brain Responses to a 6-Hz Binaural Beat: Effects on General Theta Rhythm and Frontal Midline Theta Activity.

    Science.gov (United States)

    Jirakittayakorn, Nantawachara; Wongsawat, Yodchanan

    2017-01-01

    A binaural beat is a beat phenomenon that is generated by the dichotic presentation of two almost equivalent pure tones but with slightly different frequencies. The brain responses to binaural beats remain controversial; therefore, the aim of this study was to investigate theta activity responses to a binaural beat by controlling factors affecting localization, including beat frequency, carrier tone frequency, exposure duration, and recording procedure. Exposure to a 6-Hz binaural beat on a 250 Hz carrier tone for 30 min was utilized in this study. Quantitative electroencephalography (QEEG) was utilized as the recording modality. Twenty-eight participants were divided into experimental and control groups. Emotional states were evaluated by Brunel Mood Scale (BRMUS) before and after exposing to the stimulus. The results showed that theta activity was induced in the entire cortex within 10 min of exposure to the stimulus in the experimental group. Compared to the control group, theta activity was also induced at the frontal and parietal-central regions, which included the Fz position, and left hemisphere dominance was presented for other exposure durations. The pattern recorded for 10 min of exposure appeared to be brain functions of a meditative state. Moreover, tension factor of BRUMS was decreased in experimental group compared to control group which resembled the meditation effect. Thus, a 6-Hz binaural beat on a 250 Hz carrier tone was suggested as a stimulus for inducing a meditative state.

  2. Brain Responses to a 6-Hz Binaural Beat: Effects on General Theta Rhythm and Frontal Midline Theta Activity

    Directory of Open Access Journals (Sweden)

    Nantawachara Jirakittayakorn

    2017-06-01

    Full Text Available A binaural beat is a beat phenomenon that is generated by the dichotic presentation of two almost equivalent pure tones but with slightly different frequencies. The brain responses to binaural beats remain controversial; therefore, the aim of this study was to investigate theta activity responses to a binaural beat by controlling factors affecting localization, including beat frequency, carrier tone frequency, exposure duration, and recording procedure. Exposure to a 6-Hz binaural beat on a 250 Hz carrier tone for 30 min was utilized in this study. Quantitative electroencephalography (QEEG was utilized as the recording modality. Twenty-eight participants were divided into experimental and control groups. Emotional states were evaluated by Brunel Mood Scale (BRMUS before and after exposing to the stimulus. The results showed that theta activity was induced in the entire cortex within 10 min of exposure to the stimulus in the experimental group. Compared to the control group, theta activity was also induced at the frontal and parietal-central regions, which included the Fz position, and left hemisphere dominance was presented for other exposure durations. The pattern recorded for 10 min of exposure appeared to be brain functions of a meditative state. Moreover, tension factor of BRUMS was decreased in experimental group compared to control group which resembled the meditation effect. Thus, a 6-Hz binaural beat on a 250 Hz carrier tone was suggested as a stimulus for inducing a meditative state.

  3. GABAergic contributions to gating, timing, and phase precession of hippocampal neuronal activity during theta oscillations.

    Science.gov (United States)

    Cutsuridis, Vassilis; Hasselmo, Michael

    2012-07-01

    Successful spatial exploration requires gating, storage, and retrieval of spatial memories in the correct order. The hippocampus is known to play an important role in the temporal organization of spatial information. Temporally ordered spatial memories are encoded and retrieved by the firing rate and phase of hippocampal pyramidal cells and inhibitory interneurons with respect to ongoing network theta oscillations paced by intra- and extrahippocampal areas. Much is known about the anatomical, physiological, and molecular characteristics as well as the connectivity and synaptic properties of various cell types in the hippocampal microcircuits, but how these detailed properties of individual neurons give rise to temporal organization of spatial memories remains unclear. We present a model of the hippocampal CA1 microcircuit based on observed biophysical properties of pyramidal cells and six types of inhibitory interneurons: axo-axonic, basket, bistratistified, neurogliaform, ivy, and oriens lacunosum-moleculare cells. The model simulates a virtual rat running on a linear track. Excitatory transient inputs come from the entorhinal cortex (EC) and the CA3 Schaffer collaterals and impinge on both the pyramidal cells and inhibitory interneurons, whereas inhibitory inputs from the medial septum impinge only on the inhibitory interneurons. Dopamine operates as a gate-keeper modulating the spatial memory flow to the PC distal dendrites in a frequency-dependent manner. A mechanism for spike-timing-dependent plasticity in distal and proximal PC dendrites consisting of three calcium detectors, which responds to the instantaneous calcium level and its time course in the dendrite, is used to model the plasticity effects. The model simulates the timing of firing of different hippocampal cell types relative to theta oscillations, and proposes functional roles for the different classes of the hippocampal and septal inhibitory interneurons in the correct ordering of spatial memories

  4. Insights on the neural basis of motor plasticity induced by theta burst stimulation from TMS-EEG

    Science.gov (United States)

    VERNET, Marine; BASHIR, Shahid; YOO, Woo-Kyoung; PEREZ, Jennifer M.; NAJIB, Umer; PASCUAL-LEONE, Alvaro

    2014-01-01

    Transcranial magnetic stimulation (TMS) is a useful tool to induce and measure plasticity in the human brain. However, the cortical effects are generally indirectly evaluated with motor-evoked potentials (MEPs) reflective of modulation of cortico-spinal excitability. In this study, we aim to provide direct measures of cortical plasticity by combining TMS with electroencephalography (EEG). Continuous theta-burst stimulation (cTBS) was applied over the primary motor cortex (M1) of young healthy adults; and we measured modulation of (i) motor evoked-potentials (MEPs), (ii) TMS-induced EEG evoked potentials (TEPs), (iii) TMS-induced EEG synchronization and (iv) eyes-closed resting EEG. Our results show the expected cTBS-induced decrease in MEPs size, which we found to be paralleled by a modulation of a combination of TEPs. Furthermore, we found that cTBS increased the power in the theta band of eyes-closed resting EEG, whereas it decreased single-pulse TMS-induced power in the theta and alpha bands. In addition, cTBS decreased the power in the beta band of eyes-closed resting EEG, whereas it increased single-pulse TMS-induced power in the beta band. We suggest that cTBS acts by modulating the phase alignment between already active oscillators; it synchronizes low frequency (theta and/or alpha) oscillators and desynchronizes high frequency (beta) oscillators. These results provide novel insights into the cortical effects of cTBS and could be useful for exploring cTBS-induced plasticity outside of the motor cortex. PMID:23190020

  5. Atmospheric, long baseline, and reactor neutrino data constraints on theta_{13}.

    Science.gov (United States)

    Roa, J E; Latimer, D C; Ernst, D J

    2009-08-07

    An atmospheric neutrino oscillation tool that uses full three-neutrino oscillation probabilities and a full three-neutrino treatment of the Mikheyev-Smirnov-Wolfenstein effect, together with an analysis of the K2K, MINOS, and CHOOZ data, is used to examine the bounds on theta_{13}. The recent, more finely binned, Super-K atmospheric data are employed. For L/E_{nu} greater, similar 10;{4} km/GeV, we previously found significant linear in theta_{13} terms. This analysis finds theta_{13} bounded from above by the atmospheric data while bounded from below by CHOOZ. The origin of this result arises from data in the previously mentioned very long baseline region; here, matter effects conspire with terms linear in theta_{13} to produce asymmetric bounds on theta_{13}. Assuming CP conservation, we find theta_{13} = -0.07_{-0.11};{+0.18} (90% C.L.).

  6. Increased theta band EEG power in sickle cell disease patients

    Directory of Open Access Journals (Sweden)

    Case M

    2017-12-01

    Full Text Available Michelle Case,1 Sina Shirinpour,1 Huishi Zhang,1 Yvonne H Datta,2 Stephen C Nelson,3 Karim T Sadak,4 Kalpna Gupta,2 Bin He1,5 1Department of Biomedical Engineering, 2Department of Medicine, University of Minnesota, 3Pediatric Hematology-Oncology, Children’s Hospitals and Clinics of Minnesota, 4Pediatric Hematology-Oncology, University of Minnesota Masonic Children’s Hospital, 5Institute for Engineering in Medicine, University of Minnesota, Minneapolis, MN, USA Objective: Pain is a major issue in the care of patients with sickle cell disease (SCD. The mechanisms behind pain and the best way to treat it are not well understood. We studied how electroencephalography (EEG is altered in SCD patients. Methods: We recruited 20 SCD patients and compared their resting state EEG to that of 14 healthy controls. EEG power was found across frequency bands using Welch’s method. Electrophysiological source imaging was assessed for each frequency band using the eLORETA algorithm. Results: SCD patients had increased theta power and decreased beta2 power compared to controls. Source localization revealed that areas of greater theta band activity were in areas related to pain processing. Imaging parameters were significantly correlated to emergency department visits, which indicate disease severity and chronic pain intensity. Conclusion: The present results support the pain mechanism referred to as thalamocortical dysrhythmia. This mechanism causes increased theta power in patients. Significance: Our findings show that EEG can be used to quantitatively evaluate differences between controls and SCD patients. Our results show the potential of EEG to differentiate between different levels of pain in an unbiased setting, where specific frequency bands could be used as biomarkers for chronic pain. Keywords: sickle cell disease, electroencephalography, chronic pain, electrophysiological source imaging, thalamocortical dysrhythmia

  7. Human β satellite DNA: Genomic organization and sequence definition of a class of highly repetitive tandem DNA

    International Nuclear Information System (INIS)

    Waye, J.S.; Willard, H.F.

    1989-01-01

    The authors describe a class of human repetitive DNA, called β satellite, that, at a most fundamental level, exists as tandem arrays of diverged ∼68-base-pair monomer repeat units. The monomer units are organized as distinct subsets, each characterized by a multimeric higher-order repeat unit that is tandemly reiterated and represents a recent unit of amplification. They have cloned, characterized, and determined the sequence of two β satellite higher-order repeat units: one located on chromosome 9, the other on the acrocentric chromosomes (13, 14, 15, 21, and 22) and perhaps other sites in the genome. Analysis by pulsed-field gel electrophoresis reveals that these tandem arrays are localized in large domains that are marked by restriction fragment length polymorphisms. In total, β-satellite sequences comprise several million base pairs of DNA in the human genome. Analysis of this DNA family should permit insights into the nature of chromosome-specific and nonspecific modes of satellite DNA evolution and provide useful tools for probing the molecular organization and concerted evolution of the acrocentric chromosomes

  8. Field reversed theta pinch TC-I UNICAMP

    International Nuclear Information System (INIS)

    Honda, R.Y.; Machida, M.; Aramaki, E.A.; Porto, P.; Berni, L.A.

    1990-01-01

    Field reversed configuration TC-I device is 16 cm diameter, 1 meter long with two mirror coils and 30 kJ field reversed theta pinch working for over two years at University of Campinas. Its implosion dynamics and field reversal parameters have been studied using flux excluded loops, internal magnetic probe, visible spectroscopy, photodiode array and image converter camera. The vacuum vessel is a pyrex tube of 14,5 cm diameter pumped with a liquid nitrogen cooled diffusion pump to a base pressure of 6 x 10 -7 Torr. The schematic view of the machine and experimental set up are shown. (Author)

  9. Dynamical stability of the alpha and theta phases of alumina

    DEFF Research Database (Denmark)

    Lodziana, Zbigniew; Parlinski, K.

    2003-01-01

    Using density functional calculations the phonon dispersion relations, phonon density of states, and free energy of theta and alpha phases of alumina are investigated. The temperature dependence of the free energy indicates that entropy contributes to the destabilization of the alpha phase...... cations in alumina, and suggest that some other than entropic mechanism exists, which stabilizes transition aluminas up to 1400 K. The present calculations go beyond the ground state energy calculations [C. Wolverton and K.C. Hass, Phys. Rev. B 63, 24102 (2001)], and give an additional understanding...... of the stability of transition alumina at finite temperatures....

  10. Brandt matrices and theta series over global function fields

    CERN Document Server

    Chuang, Chih-Yun; Wei, Fu-Tsun; Yu, Jing

    2015-01-01

    The aim of this article is to give a complete account of the Eichler-Brandt theory over function fields and the basis problem for Drinfeld type automorphic forms. Given arbitrary function field k together with a fixed place \\infty, the authors construct a family of theta series from the norm forms of "definite" quaternion algebras, and establish an explicit Hecke-module homomorphism from the Picard group of an associated definite Shimura curve to a space of Drinfeld type automorphic forms. The "compatibility" of these homomorphisms with different square-free levels is also examined. These Heck

  11. Theta variation and spatiotemporal scaling along the septotemporal axis of the hippocampus

    Directory of Open Access Journals (Sweden)

    Lauren L Long

    2015-03-01

    Full Text Available Hippocampal theta has been related to locomotor speed, attention, anxiety, sensorimotor integration and memory among other emergent phenomena. One difficulty in understanding the function of theta is that the hippocampus (HPC modulates voluntary behavior at the same time that it processes sensory input. Both functions are correlated with characteristic changes in theta indices. The current review highlights a series of studies examining theta local field potential (LFP signals across the septotemporal or longitudinal axis of the HPC. While the theta signal is coherent throughout the entirety of the HPC, the amplitude, but not the frequency, of theta varies significantly across its three-dimensional expanse. We suggest that the theta signal offers a rich vein of information about how distributed neuronal ensembles support emergent function. Further, we speculate that emergent function across the long axis varies with respect to spatiotemporal scale. Thus, septal hippocampus processes details of the proximal spatiotemporal environment while more temporal aspects process larger spaces and wider time-scales. The degree to which emergent functions are supported by the synchronization of theta across the septotemporal axis is an open question. Our working model is that theta synchrony serves to bind ensembles representing varying resolutions of spatiotemporal information at interdependent septotemporal areas of the HPC. Such synchrony and cooperative interactions along the septotemporal axis likely support memory formation and subsequent consolidation and retrieval.

  12. A computational study on altered theta-gamma coupling during learning and phase coding.

    Directory of Open Access Journals (Sweden)

    Xuejuan Zhang

    Full Text Available There is considerable interest in the role of coupling between theta and gamma oscillations in the brain in the context of learning and memory. Here we have used a neural network model which is capable of producing coupling of theta phase to gamma amplitude firstly to explore its ability to reproduce reported learning changes and secondly to memory-span and phase coding effects. The spiking neural network incorporates two kinetically different GABA(A receptor-mediated currents to generate both theta and gamma rhythms and we have found that by selective alteration of both NMDA receptors and GABA(A,slow receptors it can reproduce learning-related changes in the strength of coupling between theta and gamma either with or without coincident changes in theta amplitude. When the model was used to explore the relationship between theta and gamma oscillations, working memory capacity and phase coding it showed that the potential storage capacity of short term memories, in terms of nested gamma-subcycles, coincides with the maximal theta power. Increasing theta power is also related to the precision of theta phase which functions as a potential timing clock for neuronal firing in the cortex or hippocampus.

  13. Expected reward modulates encoding-related theta activity before an event.

    Science.gov (United States)

    Gruber, Matthias J; Watrous, Andrew J; Ekstrom, Arne D; Ranganath, Charan; Otten, Leun J

    2013-01-01

    Oscillatory brain activity in the theta frequency range (4-8 Hz) before the onset of an event has been shown to affect the likelihood of successfully encoding the event into memory. Recent work has also indicated that frontal theta activity might be modulated by reward, but it is not clear how reward expectancy, anticipatory theta activity, and memory formation might be related. Here, we used scalp electroencephalography (EEG) to assess the relationship between these factors. EEG was recorded from healthy adults while they memorized a series of words. Each word was preceded by a cue that indicated whether a high or low monetary reward would be earned if the word was successfully remembered in a later recognition test. Frontal theta power between the presentation of the reward cue and the onset of a word was predictive of later memory for the word, but only in the high reward condition. No theta differences were observed before word onset following low reward cues. The magnitude of prestimulus encoding-related theta activity in the high reward condition was correlated with the number of high reward words that were later confidently recognized. These findings provide strong evidence for a link between reward expectancy, theta activity, and memory encoding. Theta activity before event onset seems to be especially important for the encoding of motivationally significant stimuli. One possibility is that dopaminergic activity during reward anticipation mediates frontal theta activity related to memory. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Impaired theta-gamma coupling during working memory performance in schizophrenia.

    Science.gov (United States)

    Barr, Mera S; Rajji, Tarek K; Zomorrodi, Reza; Radhu, Natasha; George, Tony P; Blumberger, Daniel M; Daskalakis, Zafiris J

    2017-11-01

    Working memory deficits represent a core feature of schizophrenia. These deficits have been associated with dysfunctional dorsolateral prefrontal cortex (DLPFC) cortical oscillations. Theta-gamma coupling describes the modulation of gamma oscillations by theta phasic activity that has been directly associated with the ordering of information during working memory performance. Evaluating theta-gamma coupling may provide greater insight into the neural mechanisms mediating working memory deficits in this disorder. Thirty-eight patients diagnosed with schizophrenia or schizoaffective disorder and 38 healthy controls performed the verbal N-Back task administered at 4 levels, while EEG was recorded. Theta (4-7Hz)-gamma (30-50Hz) coupling was calculated for target and non-target correct trials for each working memory load. The relationship between theta-gamma coupling and accuracy was determined. Theta-gamma coupling was significantly and selectively impaired during correct responses to target letters among schizophrenia patients compared to healthy controls. A significant and positive relationship was found between theta-gamma coupling and 3-Back accuracy in controls, while this relationship was not observed in patients. These findings suggest that impaired theta-gamma coupling contribute to working memory dysfunction in schizophrenia. Future work is needed to evaluate the predictive utility of theta-gamma coupling as a neurophysiological marker for functional outcomes in this disorder. Copyright © 2017. Published by Elsevier B.V.

  15. Hippocampal theta activity in the acute cerveau isolé cat.

    Science.gov (United States)

    Gottesmann, C; Zernicki, B; Gandolfo, G

    1981-01-01

    In three cerveau isole cats, cortical and hippocampal EEG activity were recorded. In the cortical records, spindles alternated with low-voltage activity, whereas theta activity dominated in the hippocampus. The amount and frequency of theta were similar to those described previously for the pretrigeminal cat. In confirmation of previous results on rats, although cortical EEG activity differs in cerveau isole cat and pretrigeminal cat, both preparations show domination of theta activity in the hippocampus. It is concluded that the mesencephalic transection eliminates inhibitory effects from the lower brainstem on generators of the theta rhythm.

  16. Quantitative Profiling of Major Neutral Lipid Classes in Human Meibum by Direct Infusion Electrospray Ionization Mass Spectrometry

    Science.gov (United States)

    Chen, Jianzhong; Green, Kari B.; Nichols, Kelly K.

    2013-01-01

    Purpose. The purpose of this investigation was to better understand lipid composition in human meibum. Methods. Intact lipids in meibum samples were detected by direct infusion electrospray ionization mass spectrometry (ESI-MS) analysis in positive detection mode using sodium iodide (NaI) as an additive. The peak intensities of all major types of lipid species, that is, wax esters (WEs), cholesteryl esters (CEs), and diesters (DEs) were corrected for peak overlapping and isotopic distribution; an additional ionization efficiency correction was performed for WEs and CEs, which was simplified by the observation that the corresponding ionization efficiency was primarily dependent on the specific lipid class and saturation degree of the lipids while independent of the carbon chain length. A set of WE and CE standards was spiked in meibum samples for ionization efficiency determination and absolute quantitation. Results. The absolute amount (μmol/mg) for each of 51 WEs and 31 CEs in meibum samples was determined. The summed masses for 51 WEs and 31 CEs accounted for 48 ± 4% and 40 ± 2%, respectively, of the total meibum lipids. The mass percentages of saturated and unsaturated species were determined to be 75 ± 2% and 25 ± 1% for CEs and 14 ± 1% and 86 ± 1% for WEs. The profiles for two types of DEs were also obtained, which include 42 α,ω Type II DEs, and 21 ω Type I-St DEs. Conclusions. Major neutral lipid classes in meibum samples were quantitatively profiled by ESI-MS analysis with NaI additive. PMID:23847307

  17. Human leukocyte antigen class I, class II, and tumor necrosis factor-alpha polymorphisms in a healthy elder Mexican Mestizo population

    Directory of Open Access Journals (Sweden)

    Llorente Luis

    2005-11-01

    Full Text Available Abstract Background There is strong evidence that an individual's genetic background is an important predisposing factor to longevity. In the present study we analysed the frequency of HLA class I, class II, as well as the TNF-α -308 polymorphism that may be related to an increased life span in Mexican Mestizo healthy elders. Results HLA typing was performed by polymerase chain reaction sequence specific oligonucleotide (PCR SSO reverse dot blot. The TNF-α -308 polymorphism was assessed by PCR restriction fragment length polymorphism. A significant increased frequency of HLA-DRB1*11 was found in elderly women whereas this allele was not present in elderly males. The TNF2 allele was also increased in the elder group when compared to young controls. The frequencies of the remaining alleles tested were not statistically different among groups. Conclusion These data suggest an ethnicity independent tendency of HLA-DRB1*11 in elder females to increase life span and a possible role of the TNF2 allele with the successful remodelling of senescent immune system.

  18. Statistical properties of multi-theta polymer chains

    Science.gov (United States)

    Uehara, Erica; Deguchi, Tetsuo

    2018-04-01

    We study statistical properties of polymer chains with complex structures whose chemical connectivities are expressed by graphs. The multi-theta curve of m subchains with two branch points connected by them is one of the simplest graphs among those graphs having closed paths, i.e. loops. We denoted it by θm , and for m  =  2 it is given by a ring. We derive analytically the pair distribution function and the scattering function for the θm -shaped polymer chains consisting of m Gaussian random walks of n steps. Surprisingly, it is shown rigorously that the mean-square radius of gyration for the Gaussian θm -shaped polymer chain does not depend on the number m of subchains if each subchain has the same fixed number of steps. For m  =  3 we show the Kratky plot for the theta-shaped polymer chain consisting of hard cylindrical segments by the Monte-Carlo method including reflection at trivalent vertices.

  19. Opacity test using a neon-seeded theta pinch

    International Nuclear Information System (INIS)

    Thomson, D.B.

    1980-02-01

    Vacuum ultraviolet (VUV) emission from a neon-seeded high-density theta-pinch has been observed for comparison with theoretical radiation emission calculations. The plasma was created in a 25-cm-long theta-coil with 90-kG field having a 3.0-μs quarter period. A gas fill of 1 torr of helium + 2% neon was used. Observation of the HeII 4686 line/continuum ratio gave an electron temperature of 25 +- 4 eV. Shadowgraphs of the plasma radius, taken with a ruby laser, gave an electron density of 0.9 +- 0.09 x 10 18 cm -3 . The VUV emission was observed in radial view and with time resolution with a 2.2-m grazing-incidence monochromator equipped with a photomultiplier and p-terphenyl scintillator. Thin foils of carbon and aluminum were used as filters to absorb stray light and pass emission in the 44- to 100-A region

  20. A viral, transporter associated with antigen processing (TAP)-independent, high affinity ligand with alternative interactions endogenously presented by the nonclassical human leukocyte antigen E class I molecule.

    Science.gov (United States)

    Lorente, Elena; Infantes, Susana; Abia, David; Barnea, Eilon; Beer, Ilan; García, Ruth; Lasala, Fátima; Jiménez, Mercedes; Mir, Carmen; Morreale, Antonio; Admon, Arie; López, Daniel

    2012-10-12

    The transporter associated with antigen processing (TAP) enables the flow of viral peptides generated in the cytosol by the proteasome and other proteases to the endoplasmic reticulum, where they complex with nascent human leukocyte antigen (HLA) class I. Later, these peptide-HLA class I complexes can be recognized by CD8(+) lymphocytes. Cancerous cells and infected cells in which TAP is blocked, as well as individuals with unusable TAP complexes, are able to present peptides on HLA class I by generating them through TAP-independent processing pathways. Here, we identify a physiologically processed HLA-E ligand derived from the D8L protein in TAP-deficient vaccinia virus-infected cells. This natural high affinity HLA-E class I ligand uses alternative interactions to the anchor motifs previously described to be presented on nonclassical HLA class I molecules. This octameric peptide was also presented on HLA-Cw1 with similar binding affinity on both classical and nonclassical class I molecules. In addition, this viral peptide inhibits HLA-E-mediated cytolysis by natural killer cells. Comparison between the amino acid sequences of the presenting HLA-E and HLA-Cw1 alleles revealed a shared structural motif in both HLA class molecules, which could be related to their observed similar cross-reactivity affinities. This motif consists of several residues located on the floor of the peptide-binding site. These data expand the role of HLA-E as an antigen-presenting molecule.

  1. Establishing the Thematic Structure and Investigating the most Prominent Theta Roles Used in Sindhi Language

    Directory of Open Access Journals (Sweden)

    Zahid Ali Veesar

    2015-07-01

    Full Text Available This study focuses on the thematic structure of the Sindhi verbs to find theta roles in the Sindhi language. The study tries to answer the research questions; “What are the thematic structures of Sindhi verbs?” and “What are the prominent theta roles in the Sindhi language?” It examines the argument/thematic structure of Sindhi verbs and also finds the theta roles assigned by the Sindhi verbs to their arguments along with the most prominent theta roles used in the Sindhi language. The data come from the two interviews taken from two young native Sindhi speakers, which consist of 2 hours conversation having 1,669 sentences in natural spoken version of the Sindhi language. Towards the end, it has been found that the Sindhi language has certain theta roles which are assigned by the verbs to their arguments in sentences. Each verb phrase in our data is thus examined and studied in detail in terms of Argument/Thematic structure in order to find theta roles in Sindhi language. Thus, in this regard, each verb phrase (in a sentence has been examined with the help of Carnie’s theoretical framework (Thematic Relation and Theta Roles: 2006 in order to find the prominent theta roles in the Sindhi language. The data have been examined and analysed on the basis of the Carnie’s theoretical framework. The study finds that the Sindhi language has all (09 theta roles which have been proposed by Carnie (2006. It has been found that six prominent theta roles out of nine are used prominently in Sindhi. The six prominent theta roles in Sindhi language are: agent, theme, beneficiary, recipient, locative and goal.

  2. Identification of neurotensin-related peptides in human thymic epithelial cell membranes and relationship with major histocompatibility complex class I molecules.

    Science.gov (United States)

    Vanneste, Y; Thome, A N; Vandersmissen, E; Charlet, C; Franchimont, D; Martens, H; Lhiaubet, A M; Schimpff, R M; Rostène, W; Geenen, V

    1997-06-01

    This study shows the expression at the cell surface of human thymic epithelial cells (TEC) of a neurotensin (NT)-like immunoreactivity. NT radio-immunoassay (RIA) revealed that cultured human TEC contain +/-5 ng immunoreactive (ir) NT/10(6) cells, of which 5% is associated with plasma cell membranes. HPLC analysis of NT-ir present in human TEC showed a major peak of NT-ir corresponding to NT1-13. NT-ir was not detected in the supernatant of human TEC cultures. Using an affinity column prepared with a anti-MHC class I monoclonal antibody, NT-ir-related peptides were retained on the column and eluted together with MHC class I-related proteins. According to the elution time on HPLC of these peptides, they correspond to intact NT1-13, as well as to smaller fragments of NT1-13.

  3. Expression of a Chimeric Antigen Receptor Specific for Donor HLA Class I Enhances the Potency of Human Regulatory T Cells in Preventing Human Skin Transplant Rejection.

    Science.gov (United States)

    Boardman, D A; Philippeos, C; Fruhwirth, G O; Ibrahim, M A A; Hannen, R F; Cooper, D; Marelli-Berg, F M; Watt, F M; Lechler, R I; Maher, J; Smyth, L A; Lombardi, G

    2017-04-01

    Regulatory T cell (Treg) therapy using recipient-derived Tregs expanded ex vivo is currently being investigated clinically by us and others as a means of reducing allograft rejection following organ transplantation. Data from animal models has demonstrated that adoptive transfer of allospecific Tregs offers greater protection from graft rejection compared to polyclonal Tregs. Chimeric antigen receptors (CAR) are clinically translatable synthetic fusion proteins that can redirect the specificity of T cells toward designated antigens. We used CAR technology to redirect human polyclonal Tregs toward donor-MHC class I molecules, which are ubiquitously expressed in allografts. Two novel HLA-A2-specific CARs were engineered: one comprising a CD28-CD3ζ signaling domain (CAR) and one lacking an intracellular signaling domain (ΔCAR). CAR Tregs were specifically activated and significantly more suppressive than polyclonal or ΔCAR Tregs in the presence of HLA-A2, without eliciting cytotoxic activity. Furthermore, CAR and ΔCAR Tregs preferentially transmigrated across HLA-A2-expressing endothelial cell monolayers. In a human skin xenograft transplant model, adoptive transfer of CAR Tregs alleviated the alloimmune-mediated skin injury caused by transferring allogeneic peripheral blood mononuclear cells more effectively than polyclonal Tregs. Our results demonstrated that the use of CAR technology is a clinically applicable refinement of Treg therapy for organ transplantation. © 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

  4. Bacterial superantigens promote acute nasopharyngeal infection by Streptococcus pyogenes in a human MHC Class II-dependent manner.

    Directory of Open Access Journals (Sweden)

    Katherine J Kasper

    2014-05-01

    Full Text Available Establishing the genetic determinants of niche adaptation by microbial pathogens to specific hosts is important for the management and control of infectious disease. Streptococcus pyogenes is a globally prominent human-specific bacterial pathogen that secretes superantigens (SAgs as 'trademark' virulence factors. SAgs function to force the activation of T lymphocytes through direct binding to lateral surfaces of T cell receptors and class II major histocompatibility complex (MHC-II molecules. S. pyogenes invariably encodes multiple SAgs, often within putative mobile genetic elements, and although SAgs are documented virulence factors for diseases such as scarlet fever and the streptococcal toxic shock syndrome (STSS, how these exotoxins contribute to the fitness and evolution of S. pyogenes is unknown. Here we show that acute infection in the nasopharynx is dependent upon both bacterial SAgs and host MHC-II molecules. S. pyogenes was rapidly cleared from the nasal cavity of wild-type C57BL/6 (B6 mice, whereas infection was enhanced up to ∼10,000-fold in B6 mice that express human MHC-II. This phenotype required the SpeA superantigen, and vaccination with an MHC -II binding mutant toxoid of SpeA dramatically inhibited infection. Our findings indicate that streptococcal SAgs are critical for the establishment of nasopharyngeal infection, thus providing an explanation as to why S. pyogenes produces these potent toxins. This work also highlights that SAg redundancy exists to avoid host anti-SAg humoral immune responses and to potentially overcome host MHC-II polymorphisms.

  5. Crystal structure of a Gammadelta T-cell Receptor Specific for the Human MHC class I Homolog MICA

    Energy Technology Data Exchange (ETDEWEB)

    B Xu; J Pizarro; M Holmes; C McBeth; V Groh; T Spies; R Strong

    2011-12-31

    {gamma}{delta} T cells play important roles in bridging innate and adaptive immunity, but their recognition mechanisms remain poorly understood. Human {gamma}{delta} T cells of the V{sub {delta}}1 subset predominate in intestinal epithelia and respond to MICA and MICB (MHC class I chain-related, A and B; MIC) self-antigens, mediating responses to tumorigenesis or viral infection. The crystal structure of an MIC-reactive V{sub {delta}}1 {gamma}{delta} T-cell receptor (TCR) showed expected overall structural homology to antibodies, {alpha}{beta}, and other {gamma}{delta} TCRs, but complementary determining region conformations and conservation of V{sub {delta}}1 use revealed an uncharacteristically flat potential binding surface. MIC, likewise, serves as a ligand for the activating immunoreceptor natural killer group 2, D (NKG2D), also expressed on {gamma}{delta} T cells. Although MIC recognition drives both the TCR-dependent stimulatory and NKG2D-dependent costimulatory signals necessary for activation, interaction analyses showed that MIC binding by the two receptors was mutually exclusive. Analysis of relative binding kinetics suggested sequential recognition, defining constraints for the temporal organization of {gamma}{delta} T-cell/target cell interfaces.

  6. Enterocin C, a class IIb bacteriocin produced by E. faecalis C901, a strain isolated from human colostrum.

    Science.gov (United States)

    Maldonado-Barragán, Antonio; Caballero-Guerrero, Belén; Jiménez, Esther; Jiménez-Díaz, Rufino; Ruiz-Barba, José L; Rodríguez, Juan M

    2009-07-31

    Enterocin C (EntC), a class IIb bacteriocin was purified from culture supernatants of Enterococcus faecalis C901, a strain isolated from human colostrum. Enterocin C consists of two distinct peptides, named EntC1 and EntC2, whose complementary action is required for full antimicrobial activity. The structural genes entC1 and entC2 encoding enterocins EntC1 and EntC2, respectively, and that encoding the putative immunity protein (EntCI) are located in the 9-kb plasmid pEntC, harboured by E. faecalis C901. The N-terminal sequence of both antimicrobial peptides revealed that EntC1 (4284 Da) is identical to Ent1071A, one of the two peptides that form enterocin 1071 (Ent1071), a bacteriocin produced by E. faecalis BFE 1071. In contrast, EntC2 (3867 Da) presents the non-polar alanine residue at position 17 (Ala(17)) instead of the polar threonine residue (Thr(17)) in Ent1071B, the second peptide constituting Ent1071. In spite of peptide similarities, EntC differs from Ent1071 in major aspects, including the complementary activity among its constitutive peptides and its wider inhibitory spectrum of activity. Different amphiphilic alpha-helical conformations between EntC2 and Ent1071B could explain both, acquired complementary activity and increased antimicrobial spectrum.

  7. Crystal structure of a gammadelta T-cell receptor specific for the human MHC class I homolog MICA.

    Science.gov (United States)

    Xu, Bin; Pizarro, Juan C; Holmes, Margaret A; McBeth, Christine; Groh, Veronika; Spies, Thomas; Strong, Roland K

    2011-02-08

    γδ T cells play important roles in bridging innate and adaptive immunity, but their recognition mechanisms remain poorly understood. Human γδ T cells of the V(δ)1 subset predominate in intestinal epithelia and respond to MICA and MICB (MHC class I chain-related, A and B; MIC) self-antigens, mediating responses to tumorigenesis or viral infection. The crystal structure of an MIC-reactive V(δ)1 γδ T-cell receptor (TCR) showed expected overall structural homology to antibodies, αβ, and other γδ TCRs, but complementary determining region conformations and conservation of V(δ)1 use revealed an uncharacteristically flat potential binding surface. MIC, likewise, serves as a ligand for the activating immunoreceptor natural killer group 2, D (NKG2D), also expressed on γδ T cells. Although MIC recognition drives both the TCR-dependent stimulatory and NKG2D-dependent costimulatory signals necessary for activation, interaction analyses showed that MIC binding by the two receptors was mutually exclusive. Analysis of relative binding kinetics suggested sequential recognition, defining constraints for the temporal organization of γδ T-cell/target cell interfaces.

  8. MHC class II molecules deliver costimulatory signals in human T cells through a functional linkage with IL-2-receptors

    DEFF Research Database (Denmark)

    Odum, Niels; Kanner, S B; Ledbetter, J A

    1993-01-01

    MHC class II-positive T cells are found in tissues involved in autoimmune and infectious disorders. Because stimulation of class II molecules by mAb or bacterial superantigens induces protein tyrosine phosphorylation through activation of PTK3 in T cells, we hypothesized that class II signals play...... tyrosine phosphorylation of specific substrates including PLC-gamma 1. Combined stimulation of IL-2R and class II molecules had an additive effect on tyrosine phosphorylation. Pretreatment of T cells with a protein tyrosine kinase inhibitor, herbimycin A, inhibited IL-2 and class II-induced proliferation...... a regulatory function in T cell activation. Here, we show that cross-linking HLA-DR and -DP but not -DQ molecules by immobilized mAb enhanced proliferative T cell responses to IL-2. In contrast, class II stimulation had no effect on IL-4-induced proliferation. The costimulatory effect was most pronounced...

  9. Loss of balance during balance beam walking elicits a multifocal theta band electrocortical response.

    Science.gov (United States)

    Sipp, Amy R; Gwin, Joseph T; Makeig, Scott; Ferris, Daniel P

    2013-11-01

    Determining the neural correlates of loss of balance during walking could lead to improved clinical assessment and treatment for individuals predisposed to falls. We used high-density electroencephalography (EEG) combined with independent component analysis (ICA) to study loss of balance during human walking. We examined 26 healthy young subjects performing heel-to-toe walking on a treadmill-mounted balance beam as well as walking on the treadmill belt (both at 0.22 m/s). ICA identified clusters of electrocortical EEG sources located in or near anterior cingulate, anterior parietal, superior dorsolateral-prefrontal, and medial sensorimotor cortex that exhibited significantly larger mean spectral power in the theta band (4-7 Hz) during walking on the balance beam compared with treadmill walking. Left and right sensorimotor cortex clusters produced significantly less power in the beta band (12-30 Hz) during walking on the balance beam compared with treadmill walking. For each source cluster, we also computed a normalized mean time/frequency spectrogram time locked to the gait cycle during loss of balance (i.e., when subjects stepped off the balance beam). All clusters except the medial sensorimotor cluster exhibited a transient increase in theta band power during loss of balance. Cluster spectrograms demonstrated that the first electrocortical indication of impending loss of balance occurred in the left sensorimotor cortex at the transition from single support to double support prior to stepping off the beam. These findings provide new insight into the neural correlates of walking balance control and could aid future studies on elderly individuals and others with balance impairments.

  10. Theta dynamics in rat: speed and acceleration across the Septotemporal axis.

    Directory of Open Access Journals (Sweden)

    Lauren L Long

    Full Text Available Theta (6-12 Hz rhythmicity in the local field potential (LFP reflects a clocking mechanism that brings physically isolated neurons together in time, allowing for the integration and segregation of distributed cell assemblies. Variation in the theta signal has been linked to locomotor speed, sensorimotor integration as well as cognitive processing. Previously, we have characterized the relationship between locomotor speed and theta power and how that relationship varies across the septotemporal (long axis of the hippocampus (HPC. The current study investigated the relationship between whole body acceleration, deceleration and theta indices at CA1 and dentate gyrus (DG sites along the septotemporal axis of the HPC in rats. Results indicate that whole body acceleration and deceleration predicts a significant amount of variability in the theta signal beyond variation in locomotor speed. Furthermore, deceleration was more predictive of variation in theta amplitude as compared to acceleration as rats traversed a linear track. Such findings highlight key variables that systematically predict the variability in the theta signal across the long axis of the HPC. A better understanding of the relative contribution of these quantifiable variables and their variation as a function of experience and environmental conditions should facilitate our understanding of the relationship between theta and sensorimotor/cognitive functions.

  11. Recent developments in linear theta-pinch research: experiment and theory

    International Nuclear Information System (INIS)

    McKenna, K.F.; Bartsch, R.R.; Commisso, R.J.

    1978-01-01

    High energy plasmas offusion interest can be generated in linear theta pinches. However, end losses present a fundamental limitation on the plasma containment time. This paper discusses recent progress in end-loss and end-stoppering experiments and in the theoretical understanding of linear theta-pinch physics

  12. The fermion boundary condition and the THETA-angle in QED2

    International Nuclear Information System (INIS)

    Hrasko, P.

    1983-09-01

    The order parameter of the Schwinger model is calculated in the Euclidean functional integral approach. It is shown that the symmetry breaking angle THETA is intimately connected to the boundary condition imposed on the fermions. The transition to the Euclidean description involves both imaginary time and imaginary THETA. (author)

  13. Torus C-I field reversed theta-pinch at UNICAMP

    International Nuclear Information System (INIS)

    Machida, M.; Collares, M.P.; Honda, R.Y.; Sakanaka, P.H.; Scheid, V.H.B.

    1984-01-01

    The influence of multipole fields (octopole and quadrupole) on supressing the n=2 rotational instability, field reconnection, particle loss effects is studied, and the viability of transforming the theta-pinch from Campinas, Brazil (100Kv, 55Kj) to the field reversed theta-pinch with plasma translation program is analyzed. (E.G.) [pt

  14. Patterns of coupled theta activity in amygdala-hippocampal-prefrontal cortical circuits during fear extinction.

    Directory of Open Access Journals (Sweden)

    Jörg Lesting

    Full Text Available Signals related to fear memory and extinction are processed within brain pathways involving the lateral amygdala (LA for formation of aversive stimulus associations, the CA1 area of the hippocampus for context-dependent modulation of these associations, and the infralimbic region of the medial prefrontal cortex (mPFC for extinction processes. While many studies have addressed the contribution of each of these modules individually, little is known about their interactions and how they function as an integrated system. Here we show, by combining multiple site local field potential (LFP and unit recordings in freely behaving mice in a fear conditioning paradigm, that theta oscillations may provide a means for temporally and functionally connecting these modules. Theta oscillations occurred with high specificity in the CA1-LA-mPFC network. Theta coupling increased between all areas during retrieval of conditioned fear, and declined during extinction learning. During extinction recall, theta coupling partly rebounded in LA-mPFC and CA1-mPFC, and remained at a low level in CA1-LA. Interfering with theta coupling through local electrical microstimulation in CA1-LA affected conditioned fear and extinction recall depending on theta phase. These results support the hypothesis that theta coupling provides a means for inter-areal coordination in conditioned behavioral responsiveness. More specifically, theta oscillations seem to contribute to a population code indicating conditioned stimuli during recall of fear memory before and after extinction.

  15. Completely X-symmetric S-matrices corresponding to theta functions

    International Nuclear Information System (INIS)

    Chudnovsky, D.V.

    1981-01-01

    We consider the realization of the classical Weyl commutation relations using THETA-functions. The representations of the Heisenberg group enable us to realize completely symmetric factorized S-matrices in terms of THETA-functions corresponding to the torsion subgroup of an abelian variety. (orig.)

  16. Mixing angle theta and magnetic monopole in Weinberg's unified gauge theory

    International Nuclear Information System (INIS)

    Hsu, J.P.

    1975-01-01

    Gauge symmetry admits a local unit isovector and leads to the magnetic monopoles in Weinberg's unified theory. One predicts sin 2 theta = 1 / 2 for the mixing angle theta on the basis of Dirac's condition for charge quantization. This interesting result should be tested experimentally

  17. Signaling via class IA Phosphoinositide 3-kinases (PI3K in human, breast-derived cell lines.

    Directory of Open Access Journals (Sweden)

    Veronique Juvin

    Full Text Available We have addressed the differential roles of class I Phosphoinositide 3-kinases (PI3K in human breast-derived MCF10a (and iso-genetic derivatives and MDA-MB 231 and 468 cells. Class I PI3Ks are heterodimers of p110 catalytic (α, β, δ and γ and p50-101 regulatory subunits and make the signaling lipid, phosphatidylinositol (3,4,5-trisphosphate (PtdIns(3,4,5P3 that can activate effectors, eg protein kinase B (PKB, and responses, eg migration. The PtdIns(3,4,5P3-3-phosphatase and tumour-suppressor, PTEN inhibits this pathway. p110α, but not other p110s, has a number of onco-mutant variants that are commonly found in cancers. mRNA-seq data shows that MCF10a cells express p110β>>α>δ with undetectable p110γ. Despite this, EGF-stimulated phosphorylation of PKB depended upon p110α-, but not β- or δ- activity. EGF-stimulated chemokinesis, but not chemotaxis, was also dependent upon p110α, but not β- or δ- activity. In the presence of single, endogenous alleles of onco-mutant p110α (H1047R or E545K, basal, but not EGF-stimulated, phosphorylation of PKB was increased and the effect of EGF was fully reversed by p110α inhibitors. Cells expressing either onco-mutant displayed higher basal motility and EGF-stimulated chemokinesis.This latter effect was, however, only partially-sensitive to PI3K inhibitors. In PTEN(-/- cells, basal and EGF-stimulated phosphorylation of PKB was substantially increased, but the p110-dependency was variable between cell types. In MDA-MB 468s phosphorylation of PKB was significantly dependent on p110β, but not α- or δ- activity; in PTEN(-/- MCF10a it remained, like the parental cells, p110α-dependent. Surprisingly, loss of PTEN suppressed basal motility and EGF-stimulated chemokinesis. These results indicate that; p110α is required for EGF signaling to PKB and chemokinesis, but not chemotaxis; onco-mutant alleles of p110α augment signaling in the absence of EGF and may increase motility, in part, via acutely

  18. Human leukocyte antigen class I and II alleles and cervical adenocarcinoma: a pooled analysis of two epidemiologic studies

    Directory of Open Access Journals (Sweden)

    Mahboobeh eSafaeian

    2014-06-01

    Full Text Available Associations between human leukocyte antigens (HLA alleles and cervical cancer are largely representative of squamous cell carcinoma (SCC, the major histologic subtype. We evaluated the association between HLA class I (A, B, and C and class II (DRB1 and DQB1 loci and risk of cervical adenocarcinoma (ADC, a less common but aggressive histologic subtype.We pooled data from the Eastern and Western US cervical cancer studies, and evaluated the association between individual alleles and allele combinations and ADC (n=630 ADC; n=775 controls. Risk estimates were calculated for 11 a priori (based on known associations with cervical cancer regardless of histologic type and 38 non a priori common alleles, as odds ratios (OR and 95% confidence intervals (CI, adjusted for age and study. In exploratory analysis, we compared the risk associations between subgroups with HPV16 or HPV18 DNA in ADC tumor tissues in the Western US study cases and controls. Three of the a priori alleles were significantly associated with decreased risk of ADC (DRB1*13:01 (OR=0.61; 95%CI:0.41-0.93, DRB1*13:02 (OR=0.49; 95%CI:0.31-0.77, and DQB1*06:03 (OR=0.64; 95%CI:0.42-0.95; one was associated with increased risk (B*07:02(OR=1.39; 95%CI:1.07-1.79. Among alleles not previously reported, DQB1*06:04 (OR=0.46; 95%CI: 0.27-0.78 was associated with decreased risk of ADC and C*07:02 (OR=1.41; 95%CI:1.09-1.81 was associated with increased risk. We did not observe a difference by histologic subtype. ADC was most strongly associated with increased risk with B*07:02/C*07:02 alleles (OR=1.33; 95%CI:1.01-1.76 and decreased risk with DRB1*13:02/DQB1*06:04 (OR=0.41; 95%CI:0.21-0.80. Results suggest that HLA allele associations with cervical ADC are similar to those for cervical SCC. An intriguing finding was the difference in risk associated with several alleles restricted to HPV16 or HPV18 related tumors, consistent with the hypothesis that HLA recognition is HPV type specific.

  19. Transmitter release in the neuromuscular synapse of the protein kinase C theta-deficient adult mouse.

    Science.gov (United States)

    Besalduch, Núria; Santafé, Manel M; Garcia, Neus; Gonzalez, Carmen; Tomás, Marta; Tomás, Josep; Lanuza, Maria A

    2011-04-01

    We studied structural and functional features of the neuromuscular junction in adult mice (P30) genetically deficient in the protein kinase C (PKC) theta isoform. Confocal and electron microscopy shows that there are no differences in the general morphology of the endplates between PKC theta-deficient and wild-type (WT) mice. Specifically, there is no difference in the density of the synaptic vesicles. However, the myelin sheath is not as thick in the intramuscular nerve fibers of the PKC theta-deficient mice. We found a significant reduction in the size of evoked endplate potentials and in the frequency of spontaneous, asynchronous, miniature endplate potentials in the PKC theta-deficient neuromuscular preparations in comparison with the WT, but the mean amplitude of the spontaneous potentials is not different. These changes indicate that PKC theta has a presynaptic role in the function of adult neuromuscular synapses. Copyright © 2010 Wiley-Liss, Inc.

  20. Humanizing π-class glutathione S-transferase regulation in a mouse model alters liver toxicity in response to acetaminophen overdose.

    Directory of Open Access Journals (Sweden)

    Matthew P Vaughn

    Full Text Available Glutathione S-transferases (GSTs metabolize drugs and xenobiotics. Yet despite high protein sequence homology, expression of π-class GSTs, the most abundant of the enzymes, varies significantly between species. In mouse liver, hepatocytes exhibit high mGstp expression, while in human liver, hepatocytes contain little or no hGSTP1 mRNA or hGSTP1 protein. π-class GSTs are known to be critical determinants of liver responses to drugs and toxins: when treated with high doses of acetaminophen, mGstp1/2+/+ mice suffer marked liver damage, while mGstp1/2-/- mice escape liver injury.To more faithfully model the contribution of π-class GSTs to human liver toxicology, we introduced hGSTP1, with its exons, introns, and flanking sequences, into the germline of mice carrying disrupted mGstp genes. In the resultant hGSTP1+mGstp1/2-/- strain, π-class GSTs were regulated differently than in wild-type mice. In the liver, enzyme expression was restricted to bile duct cells, Kupffer cells, macrophages, and endothelial cells, reminiscent of human liver, while in the prostate, enzyme production was limited to basal epithelial cells, reminiscent of human prostate. The human patterns of hGSTP1 transgene regulation were accompanied by human patterns of DNA methylation, with bisulfite genomic sequencing revealing establishment of an unmethylated CpG island sequence encompassing the gene promoter. Unlike wild-type or mGstp1/2-/- mice, when hGSTP1+mGstp1/2-/- mice were overdosed with acetaminophen, liver tissues showed limited centrilobular necrosis, suggesting that π-class GSTs may be critical determinants of toxin-induced hepatocyte injury even when not expressed by hepatocytes.By recapitulating human π-class GST expression, hGSTP1+mGstp1/2-/- mice may better model human drug and xenobiotic toxicology.

  1. The Dynamics of Networks of Identical Theta Neurons.

    Science.gov (United States)

    Laing, Carlo R

    2018-02-05

    We consider finite and infinite all-to-all coupled networks of identical theta neurons. Two types of synaptic interactions are investigated: instantaneous and delayed (via first-order synaptic processing). Extensive use is made of the Watanabe/Strogatz (WS) ansatz for reducing the dimension of networks of identical sinusoidally-coupled oscillators. As well as the degeneracy associated with the constants of motion of the WS ansatz, we also find continuous families of solutions for instantaneously coupled neurons, resulting from the reversibility of the reduced model and the form of the synaptic input. We also investigate a number of similar related models. We conclude that the dynamics of networks of all-to-all coupled identical neurons can be surprisingly complicated.

  2. LTPF: a linear theta-pinch neutron source

    International Nuclear Information System (INIS)

    Ellis, W.R.

    1975-07-01

    The linear theta pinch is optimized with respect to maximum neutron current on a sample located between the discharge tube and the compression coil wall. Emphasis throughout is placed on physics and technology considerations which govern the choice of parameters. Technological demands are (hopefully) kept to a minimum. Two ''point designs'' are developed which are distinguished by their compressional magnetic field (i.e., coil current) wave-forms: one is sinusoidal and continuous, the other trapezoidal and pulsed intermittently. Both point designs give an average neutron current of approximately 5 x 10 13 n/cm 2 /s. Both devices are characterized by short lengths (approximately 1 m), rapid cycling (2 to 30 kHz), and magnetic mirrors (2 to 5:1) at the ends. A crucial item is the power supply, which is discussed in detail. (U.S.)

  3. Fermion Wavefunctions in Magnetized branes Theta identities and Yukawa couplings

    CERN Document Server

    Antoniadis, Ignatios; Panda, Binata

    2009-01-01

    Computation of Yukawa couplings, determining superpotentials as well as the Kähler metric, with oblique (non-commuting) fluxes in magnetized brane constructions is an interesting unresolved issue, in view of the importance of such fluxes for obtaining phenomenologically viable models. In order to perform this task, fermion (scalar) wavefunctions on toroidally compactified spaces are presented for general fluxes, parameterized by Hermitian matrices with eigenvalues of arbitrary signatures. We also give explicit mappings among fermion wavefunctions, of different internal chiralities on the tori, which interchange the role of the flux components with the complex structure of the torus. By evaluating the overlap integral of the wavefunctions, we give the expressions for Yukawa couplings among chiral multiplets arising from an arbitrary set of branes (or their orientifold images). The method is based on constructing certain mathematical identities for general Riemann theta functions with matrix valued modular par...

  4. Cost estimation for a theta-pinch reactor

    International Nuclear Information System (INIS)

    Coultas, T.A.; Cook, J.M.; Crnkovich, P.; Dauzvardis, P.

    1976-02-01

    A simulation of a theta-pinch fusion power plant has been completed to the point where economic feasibility can be examined. A PL/I cost subprogram is presented for interfacing with the computer code TPFPP. This code is then used to obtain a first approximation of the costs for the reactor. Independent geometrical and plant design parameters are varied over a wide range, with simultaneous variation of magnetic field, minor first wall radius, and plasma maximum compression. The study indicates that the plant energy balance must be favorable, availability must be high, and major component costs must be low to achieve economical results. Although costing uncertainties remain, it is clear that development of easy and rapid replacement methods for reactor components is essential and that new staging concepts to reduce the implosion energy requirement must be pursued

  5. Laser--plasma interaction in a theta-pinch geometry

    International Nuclear Information System (INIS)

    Armstrong, W.T.

    1978-06-01

    Prompt stimulated Brillouin scatter (SBS) is studied in an experiment wherein a high power, pulsed CO 2 laser irradiates an independently produced, theta-pinch plasma. SBS does not significantly affect laser heating of the plasma. Measurements of density profiles and temperature histories permitted examination of laser refraction, local heating and net absorption. Refractive containment of the CO 2 laser beam by an on-axis density minimum was observed at early times during the laser pulse. However, refractive containment was lost at late times due to the diffusive loss of the density minimum. Classical modeling of the expected heating required ''bleached'' absorption to account for the observed heating. A plasma absorptivity of approximately 46% was inferred from calorimetry measurements at 250 mtorr fill pressure. These results confirm that classical heating and refraction dominated the laser-plasma interaction

  6. Simulation of the implosion of a theta pinch

    International Nuclear Information System (INIS)

    Busnardo Neto, J.; Leite Neto, J.P.; Jesus Paes, A.C. de

    1982-01-01

    A two-fluid model was used to simulate the implosion of a theta-pinch, with initial densities varying from 10 12 to 10 16 cm -3 . The gases used were hydrogen, helium, neon and argon; initial temperatures of 2 eV and total ionization were assumed. For hydrogen the anomalous resistivity is dominant everywhere when the density is low (ν sub(eff) - ω sub(pi)). For high densities both resistivities are not high enough to allow diffusion of the magnetic field during the time of the implosion (ν sub(eff) approximatelly 0.3 ω sub(pi)). For heavier gases a surprisingly high value of the anomalous resistivity was found, due to the greater mass, (ν sub(eff) approximatelly 10-12 ω sub(pi)). (Author) [pt

  7. Fluctuating inhibitory inputs promote reliable spiking at theta frequencies in hippocampal interneurons

    Directory of Open Access Journals (Sweden)

    Duluxan eSritharan

    2012-05-01

    Full Text Available Theta frequency (4-12 Hz rhythms in the hippocampus play important roles in learning and memory. CA1 interneurons located at the stratum lacunosum-moleculare and radiatum junction (LM/RAD are thought to contribute to hippocampal theta population activities by rhythmically pacing pyramidal cells with inhibitory postsynaptic potentials. This implies that LM/RAD cells need to fire reliably at theta frequencies in vivo. To determine whether this could occur, we use biophysically-based LM/RAD model cells and apply different cholinergic and synaptic inputs to simulate in vivo-like network environments. We assess spike reliabilities and spiking frequencies, identifying biophysical properties and network conditions that best promote reliable theta spiking. We find that synaptic background activities that feature large inhibitory, but not excitatory, fluctuations are essential. This suggests that strong inhibitory input to these cells is vital for them to be able to contribute to population theta activities. Furthermore, we find that Type I-like oscillator models produced by augmented persistent sodium currents (INap or diminished A type potassium currents (IA enhance reliable spiking at lower theta frequencies. These Type I-like models are also the most responsive to large inhibitory fluctuations and can fire more reliably under such conditions. In previous work, we showed that INap and IA are largely responsible for establishing LM/RAD cells’ subthreshold activities. Taken together with this study, we see that while both these currents are important for subthreshold theta fluctuations and reliable theta spiking, they contribute in different ways – INap to reliable theta spiking and subthreshold activity generation, and IA to subthreshold activities at theta frequencies. This suggests that linking subthreshold and suprathreshold activities should be done with consideration of both in vivo contexts and biophysical specifics.

  8. The male-specific region of the human Y chromosome is a mosaic of discrete sequence classes

    NARCIS (Netherlands)

    Skaletsky, Helen; Kuroda-Kawaguchi, Tomoko; Minx, Patrick J.; Cordum, Holland S.; Hillier, LaDeana; Brown, Laura G.; Repping, Sjoerd; Pyntikova, Tatyana; Ali, Johar; Bieri, Tamberlyn; Chinwalla, Asif; Delehaunty, Andrew; Delehaunty, Kim; Du, Hui; Fewell, Ginger; Fulton, Lucinda; Fulton, Robert; Graves, Tina; Hou, Shun-Fang; Latrielle, Philip; Leonard, Shawn; Mardis, Elaine; Maupin, Rachel; McPherson, John; Miner, Tracie; Nash, William; Nguyen, Christine; Ozersky, Philip; Pepin, Kymberlie; Rock, Susan; Rohlfing, Tracy; Scott, Kelsi; Schultz, Brian; Strong, Cindy; Tin-Wollam, Aye; Yang, Shiaw-Pyng; Waterston, Robert H.; Wilson, Richard K.; Rozen, Steve; Page, David C.

    2003-01-01

    The male-specific region of the Y chromosome, the MSY, differentiates the sexes and comprises 95% of the chromosome's length. Here, we report that the MSY is a mosaic of heterochromatic sequences and three classes of euchromatic sequences: X-transposed, X-degenerate and ampliconic. These classes

  9. From neural oscillations to reasoning ability: Simulating the effect of the theta-to-gamma cycle length ratio on individual scores in a figural analogy test.

    Science.gov (United States)

    Chuderski, Adam; Andrelczyk, Krzysztof

    2015-02-01

    Several existing computational models of working memory (WM) have predicted a positive relationship (later confirmed empirically) between WM capacity and the individual ratio of theta to gamma oscillatory band lengths. These models assume that each gamma cycle represents one WM object (e.g., a binding of its features), whereas the theta cycle integrates such objects into the maintained list. As WM capacity strongly predicts reasoning, it might be expected that this ratio also predicts performance in reasoning tasks. However, no computational model has yet explained how the differences in the theta-to-gamma ratio found among adult individuals might contribute to their scores on a reasoning test. Here, we propose a novel model of how WM capacity constraints figural analogical reasoning, aimed at explaining inter-individual differences in reasoning scores in terms of the characteristics of oscillatory patterns in the brain. In the model, the gamma cycle encodes the bindings between objects/features and the roles they play in the relations processed. Asynchrony between consecutive gamma cycles results from lateral inhibition between oscillating bindings. Computer simulations showed that achieving the highest WM capacity required reaching the optimal level of inhibition. When too strong, this inhibition eliminated some bindings from WM, whereas, when inhibition was too weak, the bindings became unstable and fell apart or became improperly grouped. The model aptly replicated several empirical effects and the distribution of individual scores, as well as the patterns of correlations found in the 100-people sample attempting the same reasoning task. Most importantly, the model's reasoning performance strongly depended on its theta-to-gamma ratio in same way as the performance of human participants depended on their WM capacity. The data suggest that proper regulation of oscillations in the theta and gamma bands may be crucial for both high WM capacity and effective complex

  10. Human leukocyte antigen (HLA class I restricted epitope discovery in yellow fewer and dengue viruses: importance of HLA binding strength.

    Directory of Open Access Journals (Sweden)

    Ole Lund

    Full Text Available Epitopes from all available full-length sequences of yellow fever virus (YFV and dengue fever virus (DENV restricted by Human Leukocyte Antigen class I (HLA-I alleles covering 12 HLA-I supertypes were predicted using the NetCTL algorithm. A subset of 179 predicted YFV and 158 predicted DENV epitopes were selected using the EpiSelect algorithm to allow for optimal coverage of viral strains. The selected predicted epitopes were synthesized and approximately 75% were found to bind the predicted restricting HLA molecule with an affinity, K(D, stronger than 500 nM. The immunogenicity of 25 HLA-A*02:01, 28 HLA-A*24:02 and 28 HLA-B*07:02 binding peptides was tested in three HLA-transgenic mice models and led to the identification of 17 HLA-A*02:01, 4 HLA-A*2402 and 4 HLA-B*07:02 immunogenic peptides. The immunogenic peptides bound HLA significantly stronger than the non-immunogenic peptides. All except one of the immunogenic peptides had K(D below 100 nM and the peptides with K(D below 5 nM were more likely to be immunogenic. In addition, all the immunogenic peptides that were identified as having a high functional avidity had K(D below 20 nM. A*02:01 transgenic mice were also inoculated twice with the 17DD YFV vaccine strain. Three of the YFV A*02:01 restricted peptides activated T-cells from the infected mice in vitro. All three peptides that elicited responses had an HLA binding affinity of 2 nM or less. The results indicate the importance of the strength of HLA binding in shaping the immune response.

  11. Changes in hippocampal theta rhythm and their correlations with speed during different phases of voluntary wheel running in rats.

    Science.gov (United States)

    Li, J-Y; Kuo, T B J; Hsieh, I-T; Yang, C C H

    2012-06-28

    Hippocampal theta rhythm (4-12 Hz) can be observed during locomotor behavior, but findings on the relationship between locomotion speed and theta frequency are inconsistent if not contradictory. The inconsistency may be because of the difficulties that previous analyses and protocols have had excluding the effects of behavior training. We recorded the first or second voluntary wheel running each day, and assumed that theta frequency and activity are correlated with speed in different running phases. By simultaneously recording electroencephalography, physical activity, and wheel running speed, this experiment explored the theta oscillations during spontaneous running of the 12-h dark period. The recording was completely wireless and allowed the animal to run freely while being recorded in the wheel. Theta frequency and theta power of middle frequency were elevated before running and theta frequency, theta power of middle frequency, physical activity, and running speed maintained persistently high levels during running. The slopes of the theta frequency and theta activity (4-9.5 Hz) during the initial running were different compared to the same values during subsequent running. During the initial running, the running speed was positively correlated with theta frequency and with theta power of middle frequency. Over the 12-h dark period, the running speed did not positively correlate with theta frequency but was significantly correlated with theta power of middle frequency. Thus, theta frequency was associated with running speed only at the initiation of running. Furthermore, theta power of middle frequency was associated with speed and with physical activity during running when chronological order was not taken into consideration. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

  12. Event-related delta, theta, alpha and gamma correlates to auditory oddball processing during Vipassana meditation

    Science.gov (United States)

    Delorme, Arnaud; Polich, John

    2013-01-01

    Long-term Vipassana meditators sat in meditation vs. a control (instructed mind wandering) states for 25 min, electroencephalography (EEG) was recorded and condition order counterbalanced. For the last 4 min, a three-stimulus auditory oddball series was presented during both meditation and control periods through headphones and no task imposed. Time-frequency analysis demonstrated that meditation relative to the control condition evinced decreased evoked delta (2–4 Hz) power to distracter stimuli concomitantly with a greater event-related reduction of late (500–900 ms) alpha-1 (8–10 Hz) activity, which indexed altered dynamics of attentional engagement to distracters. Additionally, standard stimuli were associated with increased early event-related alpha phase synchrony (inter-trial coherence) and evoked theta (4–8 Hz) phase synchrony, suggesting enhanced processing of the habituated standard background stimuli. Finally, during meditation, there was a greater differential early-evoked gamma power to the different stimulus classes. Correlation analysis indicated that this effect stemmed from a meditation state-related increase in early distracter-evoked gamma power and phase synchrony specific to longer-term expert practitioners. The findings suggest that Vipassana meditation evokes a brain state of enhanced perceptual clarity and decreased automated reactivity. PMID:22648958

  13. On the irrationality of Ramanujan's mock theta functions and other q-series at an infinite number of points

    OpenAIRE

    Mingarelli, Angelo B.

    2007-01-01

    We show that all of Ramanujan's mock theta functions of order 3, Watson's three additional mock theta functions of order 3, the Rogers-Ramanujan q-series, and 6 mock theta functions of order 5 take on irrational values at the points q=\\pm 1/2,\\pm 1/3,\\pm 1/4,...

  14. Dependent Classes

    DEFF Research Database (Denmark)

    Gasiunas, Vaidas; Mezini, Mira; Ostermann, Klaus

    2007-01-01

    of dependent classes and a machine-checked type soundness proof in Isabelle/HOL [29], the first of this kind for a language with virtual classes and path-dependent types. [29] T.Nipkow, L.C. Poulson, and M. Wenzel. Isabelle/HOL -- A Proof Assistant for Higher-Order Logic, volume 2283 of LNCS, Springer, 2002......Virtual classes allow nested classes to be refined in subclasses. In this way nested classes can be seen as dependent abstractions of the objects of the enclosing classes. Expressing dependency via nesting, however, has two limitations: Abstractions that depend on more than one object cannot...... be modeled and a class must know all classes that depend on its objects. This paper presents dependent classes, a generalization of virtual classes that expresses similar semantics by parameterization rather than by nesting. This increases expressivity of class variations as well as the flexibility...

  15. Comprehensive Analysis of Cytomegalovirus pp65 Antigen-Specific CD8+ T Cell Responses According to Human Leukocyte Antigen Class I Allotypes and Intraindividual Dominance

    Directory of Open Access Journals (Sweden)

    Seung-Joo Hyun

    2017-11-01

    Full Text Available To define whether individual human leukocyte antigen (HLA class I allotypes are used preferentially in human cytomegalovirus (CMV-specific cytotoxic T lymphocyte responses, CD8+ T cell responses restricted by up to six HLA class I allotypes in an individual were measured in parallel using K562-based artificial antigen-presenting cells expressing both CMV pp65 antigen and one of 32 HLA class I allotypes (7 HLA-A, 14 HLA-B, and 11 HLA-C present in 50 healthy Korean donors. The CD8+ T cell responses to pp65 in the HLA-C allotypes were lower than responses to those in HLA-A and -B allotypes and there was no difference between the HLA-A and HLA-B loci. HLA-A*02:01, -B*07:02, and -C*08:01 showed the highest magnitude and frequency of immune responses to pp65 at each HLA class I locus. However, HLA-A*02:07, -B*59:01, -B*58:01, -B*15:11, -C*03:02, and -C*02:02 did not show any immune responses. Although each individual has up to six different HLA allotypes, 46% of the donors showed one allotype, 24% showed two allotypes, and 2% showed three allotypes that responded to pp65. Interestingly, the frequencies of HLA-A alleles were significantly correlated with the positivity of specific allotypes. Our results demonstrate that specific HLA class I allotypes are preferentially used in the CD8+ T cell immune response to pp65 and that a hierarchy among HLA class I allotypes is present in an individual.

  16. Testing the effects of adolescent alcohol use on adult conflict-related theta dynamics.

    Science.gov (United States)

    Harper, Jeremy; Malone, Stephen M; Iacono, William G

    2017-11-01

    Adolescent alcohol use (AAU) is associated with brain anomalies, but less is known about long-term neurocognitive effects. Despite theoretical models linking AAU to diminished cognitive control, empirical work testing this relationship with specific cognitive control neural correlates (e.g., prefrontal theta-band EEG dynamics) remains scarce. A longitudinal twin design was used to test the hypothesis that greater AAU is associated with reduced conflict-related EEG theta-band dynamics in adulthood, and to examine the genetic/environmental etiology of this association. In a large (N=718) population-based prospective twin sample, AAU was assessed at ages 11/14/17. Twins completed a flanker task at age 29 to elicit EEG theta-band medial frontal cortex (MFC) power and medial-dorsal prefrontal cortex (MFC-dPFC) connectivity. Two complementary analytic methods (cotwin control analysis; biometric modeling) were used to disentangle the genetic/shared environmental risk towards AAU from possible alcohol exposure effects on theta dynamics. AAU was negatively associated with adult cognitive control-related theta-band MFC power and MFC-dPFC functional connectivity. Genetic influences primarily underlie these associations. Findings provide strong evidence that genetic factors underlie the comorbidity between AAU and diminished cognitive control-related theta dynamics in adulthood. Conflict-related theta-band dynamics appear to be candidate brain-based endophenotypes/mechanisms for AAU. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  17. Spatial-area selective retrieval of multiple object-place associations in a hierarchical cognitive map formed by theta phase coding.

    Science.gov (United States)

    Sato, Naoyuki; Yamaguchi, Yoko

    2009-06-01

    The human cognitive map is known to be hierarchically organized consisting of a set of perceptually clustered landmarks. Patient studies have demonstrated that these cognitive maps are maintained by the hippocampus, while the neural dynamics are still poorly understood. The authors have shown that the neural dynamic "theta phase precession" observed in the rodent hippocampus may be capable of forming hierarchical cognitive maps in humans. In the model, a visual input sequence consisting of object and scene features in the central and peripheral visual fields, respectively, results in the formation of a hierarchical cognitive map for object-place associations. Surprisingly, it is possible for such a complex memory structure to be formed in a few seconds. In this paper, we evaluate the memory retrieval of object-place associations in the hierarchical network formed by theta phase precession. The results show that multiple object-place associations can be retrieved with the initial cue of a scene input. Importantly, according to the wide-to-narrow unidirectional connections among scene units, the spatial area for object-place retrieval can be controlled by the spatial area of the initial cue input. These results indicate that the hierarchical cognitive maps have computational advantages on a spatial-area selective retrieval of multiple object-place associations. Theta phase precession dynamics is suggested as a fundamental neural mechanism of the human cognitive map.

  18. Theta-rhythmic drive between medial septum and hippocampus in slow-wave sleep and microarousal: a Granger causality analysis.

    Science.gov (United States)

    Kang, D; Ding, M; Topchiy, I; Shifflett, L; Kocsis, B

    2015-11-01

    Medial septum (MS) plays a critical role in controlling the electrical activity of the hippocampus (HIPP). In particular, theta-rhythmic burst firing of MS neurons is thought to drive lasting HIPP theta oscillations in rats during waking motor activity and REM sleep. Less is known about MS-HIPP interactions in nontheta states such as non-REM sleep, in which HIPP theta oscillations are absent but theta-rhythmic burst firing in subsets of MS neurons is preserved. The present study used Granger causality (GC) to examine the interaction patterns between MS and HIPP in slow-wave sleep (SWS, a nontheta state) and during its short interruptions called microarousals (a transient theta state). We found that during SWS, while GC revealed a unidirectional MS→HIPP influence over a wide frequency band (2-12 Hz, maximum: ∼8 Hz), there was no theta peak in the hippocampal power spectra, indicating a lack of theta activity in HIPP. In contrast, during microarousals, theta peaks were seen in both MS and HIPP power spectra and were accompanied by bidirectional GC with MS→HIPP and HIPP→MS theta drives being of equal magnitude. Thus GC in a nontheta state (SWS) vs. a theta state (microarousal) primarily differed in the level of HIPP→MS. The present findings suggest a modification of our understanding of the role of MS as the theta generator in two regards. First, a MS→HIPP theta drive does not necessarily induce theta field oscillations in the hippocampus, as found in SWS. Second, HIPP theta oscillations entail bidirectional theta-rhythmic interactions between MS and HIPP. Copyright © 2015 the American Physiological Society.

  19. Effects of irradiation on the expression of major histocompatibility complex class I antigen and adhesion costimulation molecules ICAM-1 in human cervical cancer

    International Nuclear Information System (INIS)

    Santin, Alessandro D.; Hermonat, Paul L.; Hiserodt, John C.; Chiriva-Internati, Maurizio; Woodliff, Jeff; Theus, John W.; Barclay, David; Pecorelli, Sergio; Parham, Groesbeck P.

    1997-01-01

    Purpose: We initiated studies to analyze the effects of high doses of gamma irradiation on the surface antigen expression of MHC Class I, Class II, and ICAM-1 on human cervical carcinoma cell lines. Methods and Materials: The expression of surface antigens (MHC Class I, Class II, and ICAM-1) was evaluated by FACS analysis on two cervical cell lines at different time points, following their exposure to high doses of gamma irradiation (i.e., 25.00, 50.00, and 100.00 Gy). Results: The CaSki and SiHa cervical cancer cells we analyzed in this study expressed variable levels of MHC Class I and ICAM-1 antigens, while Class II surface antigens were not detectable. Whereas irradiation doses of 25.00 Gy were not sufficient to totally block cell replication in both cell lines, exposure to 50.00 or 100.00 Gy was able to completely inhibit cell replication. Range doses from 25.00 to 100.00 Gy significantly and consistently increased the expression of all surface antigens present on the cells prior to irradiation but were unable to induce neoexpression of antigens previously not expressed by these cells (i.e., MHC Class II). Importantly, such upregulation was shown to be dose dependent, with higher radiation doses associated with increased antigen expression. Moreover, when the kinetic of this upregulation was studied after 2 and 6 days after irradiation, it was shown to be persistent and lasted until all the cells died. Conclusions: These findings may partially explain the increased immunogenicity of tumor cells following irradiation and may suggest enhanced immune recognition in tumor tissue in patients receiving radiation therapy

  20. Intermittent theta-burst transcranial magnetic stimulation for treatment of Parkinson disease.

    Science.gov (United States)

    Benninger, D H; Berman, B D; Houdayer, E; Pal, N; Luckenbaugh, D A; Schneider, L; Miranda, S; Hallett, M

    2011-02-15

    To investigate the safety and efficacy of intermittent theta-burst stimulation (iTBS) in the treatment of motor symptoms in Parkinson disease (PD). Progression of PD is characterized by the emergence of motor deficits, which eventually respond less to dopaminergic therapy and pose a therapeutic challenge. Repetitive transcranial magnetic stimulation (rTMS) has shown promising results in improving gait, a major cause of disability, and may provide a therapeutic alternative. iTBS is a novel type of rTMS that may be more efficacious than conventional rTMS. In this randomized, double-blind, sham-controlled study, we investigated safety and efficacy of iTBS of the motor and dorsolateral prefrontal cortices in 8 sessions over 2 weeks (evidence Class I). Assessment of safety and clinical efficacy over a 1-month period included timed tests of gait and bradykinesia, Unified Parkinson's Disease Rating Scale (UPDRS), and additional clinical, neuropsychological, and neurophysiologic measures. We investigated 26 patients with mild to moderate PD: 13 received iTBS and 13 sham stimulation. We found beneficial effects of iTBS on mood, but no improvement of gait, bradykinesia, UPDRS, and other measures. EEG/EMG monitoring recorded no pathologic increase of cortical excitability or epileptic activity. Few reported discomfort or pain and one experienced tinnitus during real stimulation. iTBS of the motor and prefrontal cortices appears safe and improves mood, but failed to improve motor performance and functional status in PD. This study provides Class I evidence that iTBS was not effective for gait, upper extremity bradykinesia, or other motor symptoms in PD.

  1. Study on creep behavior of Grade 91 heat-resistant steel using theta projection method

    Science.gov (United States)

    Ren, Facai; Tang, Xiaoying

    2017-10-01

    Creep behavior of Grade 91 heat-resistant steel used for steam cooler was characterized using the theta projection method. Creep tests were conducted at the temperature of 923K under the stress ranging from 100-150MPa. Based on the creep curve results, four theta parameters were established using a nonlinear least square fitting method. Four theta parameters showed a good linearity as a function of stress. The predicted curves coincided well with the experimental data and creep curves were also modeled to the low stress level of 60MPa.

  2. Experimental study of CF4 conical theta pinch plasma expanding into vacuum

    International Nuclear Information System (INIS)

    Pedrow, P.D.; Nasiruddin, A.M.

    1989-01-01

    Langmuir probe, photodiode, and optical multichannel analyzer (OMA) measurements have been made on a pulsed CF 4 conical theta pinch plasma. A cloud of CF 4 gas was puffed into a conical theta pinch coil, converted to plasma, and propelled into the vacuum region ahead of the expanding gas cloud. At a position 67 cm away from the conical theta pinch coil, the plasma arrived in separate packets that were about 20 μs in duration. The average drift velocity of these packets corresponded to an energy of about 3 eV. The OMA measurements showed that the second packet contained neutral atomic fluorine as well as charged particles

  3. The electric dipole moment of the deuteron from the QCD {theta}-term

    Energy Technology Data Exchange (ETDEWEB)

    Bsaisou, J.; Liebig, S. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Hanhart, C.; Nogga, A.; Wirzba, A. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich (Germany); Forschungszentrum Juelich, JARA - Forces And Matter Experiments, Juelich (Germany); Meissner, U.G. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich (Germany); Forschungszentrum Juelich, JARA - Forces And Matter Experiments, Juelich (Germany); Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Universitaet Bonn, Bethe Center for Theoretical Physics, Bonn (Germany)

    2013-03-15

    The two-nucleon contributions to the electric dipole moment (EDM) of the deuteron, induced by the QCD {theta}-term, are calculated in the framework of effective field theory up-to-and-including next-to-next-to-leading order. In particular we find for the difference of the deuteron EDM and the sum of proton and neutron EDM induced by the QCD {theta}-term a value of (- 5.4 {+-}3.9) anti {theta} x 10{sup -} {sup 4} e fm. The by far dominant uncertainty comes from the CP- and isospin-violating {pi}NN coupling constant. (orig.)

  4. The facilitatory effects of intermittent theta burst stimulation on corticospinal excitability are enhanced by nicotine.

    Science.gov (United States)

    Swayne, Orlando B C; Teo, James T H; Greenwood, Richard J; Rothwell, John C

    2009-08-01

    Intermittent theta burst stimulation (iTBS) is increasingly widely used as a means of facilitating corticospinal excitability in the human primary motor cortex. This form of facilitatory plasticity within the stimulated cortex may occur by induction of long term potentiation (LTP). In animal models, agonists of nicotinic acetylcholine receptors have been shown to modulate or induce LTP; we thus sought to test whether nicotine may modulate the effects of iTBS on corticospinal excitability in humans. A double-blind placebo-controlled cross-over design study was conducted with 10 healthy subjects. iTBS was delivered 60min after subjects took either 4mg nicotine or placebo lozenges, and motor-evoked potentials (MEPs) were then recorded for 40min after the end of stimulation. In the placebo arm, iTBS produced an increase in the amplitudes of MEPs which lasted for 5min. In the nicotine arm, iTBS produced a more pronounced facilitation of MEPs that was still present at 40min. In a control experiment, nicotine alone had no effect on MEP amplitudes when given in the absence of iTBS. These data indicate that the effects of iTBS can be enhanced and prolonged by nicotine. These results are consistent with animal models demonstrating nicotinic modulation of facilitatory plasticity, and will be of interest to investigators seeking to enhance artificially induced changes in cortical excitability.

  5. Expression of HLA Class II Molecules in Humanized NOD.Rag1KO.IL2RgcKO Mice is Critical for Development and Function of Human T and B Cells

    Science.gov (United States)

    2011-05-17

    class switch was preserved in DRAG mice. The human identity of Ig heavy and Figure 4. Human T cells developed by DRAG mice are functional. At 6 months...HSC-infused DRAG and control mice were immunized with 1 flocculation unit of TT vaccine (Sanofi Pasteur ) by the intramuscular route, and the titers...and CD8 T cells with preserved integrity of both TCR and non-TCR signaling pathways. It has been suggested that low frequency and functional

  6. The relationship between hippocampal EEG theta activity and locomotor behaviour in freely moving rats: effects of vigabatrin.

    Science.gov (United States)

    Bouwman, B M; van Lier, H; Nitert, H E J; Drinkenburg, W H I M; Coenen, A M L; van Rijn, C M

    2005-01-30

    The relationship between hippocampal electroencephalogram (EEG) theta activity and locomotor speed in both spontaneous and forced walking conditions was studied in rats after vigabatrin injection (500 mg/kg i.p.). Vigabatrin increased the percentage of time that rats spent being immobile. During spontaneous walking in the open field, the speed of locomotion was increased by vigabatrin, while theta peak frequency was decreased. Vigabatrin also reduced the theta peak frequency during forced (speed controlled) walking. There was only a weak positive correlation (r=0.22) between theta peak frequency and locomotor speed for the saline condition. Furthermore, vigabatrin abolishes the weak relationship between speed of locomotion and theta peak frequency. Vigabatrin and saline did not differ in the slope of the regression line, but showed different offset points at the theta peak frequency axis. Thus, other factors than speed of locomotion seem to be involved in determination of the theta peak frequency.

  7. Measurement of the ion temperature in a diffuse theta pinch

    International Nuclear Information System (INIS)

    Kudo, Koichi; Watanabe, Yukio; Ogi, Sukeomi; Sumikawa, Toshio; Akazaki, Masanori

    1979-01-01

    The Doppler broadening of helium ion spectra was observed, and the ion temperature of theta pinch plasma was obtained. The apparatus for the measurement consists of a spectroscope, a photomultiplier and an oscilloscope. The time variation of initial plasma density was obtained. The doppler broadening of the spectra was observed in case of the plasma density of 2 x 10 13 /cm 3 and 3 x 10 12 /cm 3 . The analyses of the spectra gave the ion temperature. The double temperature distribution was seen. The temperature of the low temperature part was 5 to 9 electron-volt, and that of the high temperature part several hundred electron-volt. The high temperature is caused by the thermalization of particles accelerated by the magnetic piston. The decay of high temperature ions is due to the charge exchange with the neutral particles. The time of the highest temperature corresponds to the time at which the luminescent layer reaches to the central axis. (Kato, T.)

  8. ''Theta gun,'' a multistage, coaxial, magnetic induction projectile accelerator

    International Nuclear Information System (INIS)

    Burgess, T.J.; Duggin, B.W.; Cowan, M. Jr.

    1985-11-01

    We experimentally and theoretically studied a multistage coaxial magnetic induction projectile accelerator. We call this system a ''theta gun'' to differentiate it from other coaxial accelerator concepts such as the mass driver. We conclude that this system can theoretically attain railgun performance only for large caliber or very high injection velocity and, even then, only for long coil geometry. Our experiments with a three-stage, capactor bank-driven accelerator are described. The experiments are modeled with a 1-1/2 dimensional equivalent circuit-hydrodynamics code which is also described. We derive an expression for the conditions of coaxial accelerator-railgun ''velocity breakeven'' in the absence of ohmic and hydrodynamic effects. This, in conjunction with an expression for the magnetic coupling coefficient, defines a set of geometric relations which the coaxial system must simultaneously satisfy. Conclusions concerning both the existence and configuration of a breakeven coaxial system follow from this requirement. The relative advantages and disadvantages of the coaxial induction projectile accelerator, previously cited in the literature, are critiqued from the viewpoint of our analysis and experimental results. We find that the advantages vis-a-vis the railgun have been overstated. 13 refs., 17 figs

  9. Continuous theta-burst stimulation modulates tactile synchronization.

    Science.gov (United States)

    Lee, Kevin Gh; Jacobs, Mark F; Asmussen, Michael J; Zapallow, Christopher M; Tommerdahl, Mark; Nelson, Aimee J

    2013-08-23

    Temporal order judgement (TOJ) is the ability to detect the order of occurrence of two sequentially delivered stimuli. Previous research has shown that TOJ in the presence of synchronized periodic conditioning stimuli impairs TOJ performance, and this phenomenon is suggested to be mediated by GABAergic interneurons that cause perceptual binding across the two skin sites. Application of continuous theta-burst repetitive TMS (cTBS) over primary somatosensory cortex (SI) alters temporal and spatial tactile perception. The purpose of this study was to examine TOJ perception in the presence and absence of synchronized periodic conditioning stimuli before and after cTBS applied over left-hemisphere SI. A TOJ task was administered on the right index and middle finger (D2 and D3) in two separate sessions in the presence and absence of conditioning stimuli (a background low amplitude sinusoidal vibration). CTBS reduced the impact of the conditioning stimuli on TOJ performance for up to 18 minutes following stimulation while sham cTBS did not affect TOJ performance. In contrast, the TOJ task performed in the absence of synchronized conditioning stimulation was unaltered following cTBS. We conclude that cTBS suppresses inhibitory networks in SI that mediate perceptual binding during TOJ synchronization. CTBS offers one method to suppress cortical excitability in the cortex and potentially benefit clinical populations with altered inhibitory cortical circuits. Additionally, TOJ measures with conditioning stimuli may provide an avenue to assess sensory processing in neurologically impaired patient populations.

  10. Developmental differences in beta and theta power during sentence processing

    Directory of Open Access Journals (Sweden)

    Julie M. Schneider

    2016-06-01

    Full Text Available Although very young children process ongoing language quickly and effortlessly, research indicates that they continue to improve and mature in their language skills through adolescence. This prolonged development may be related to differing engagement of semantic and syntactic processes. This study used event related potentials and time frequency analysis of EEG to identify developmental differences in neural engagement as children (ages 10–12 and adults performed an auditory verb agreement grammaticality judgment task. Adults and children revealed very few differences in comprehending grammatically correct sentences. When identifying grammatical errors, however, adults displayed widely distributed beta and theta power decreases that were significantly less pronounced in children. Adults also demonstrated a significant P600 effect, while children exhibited an apparent N400 effect. Thus, when identifying subtle grammatical errors in real time, adults display greater neural activation that is traditionally associated with syntactic processing whereas children exhibit greater activity more commonly associated with semantic processing. These findings support previous claims that the cognitive and neural underpinnings of syntactic processing are still developing in adolescence, and add to them by more clearly identifying developmental changes in the neural oscillations underlying grammatical processing.

  11. Liner of a thermonuclear pulse THETA-pinch reactor

    International Nuclear Information System (INIS)

    Baranov, G.A.; Izotov, E.N.; Karasev, B.G.; Komin, A.V.; Krivosheev, M.V.; Levashov, A.D.

    1975-01-01

    Some possible constructive solutions to the problem of fabrication of the theta-pinch reactor liner by the method of centrifugal casting in a casting mould are considered. A scheme for liner manufacturing is presented, which includes the following elements: 1) a casting mould of dielectric material presenting a hollow cylinder of 4 m in diam., 3 m in length and 12 t in weight, which rotates at 8 rps in the reactor chamber; 2) a system for heat protection of the casting mould; the volume heat of the mould is suggested to remove by gaseous helium flowing under pressure along axial cooling channels of 5 mm in diam.; the channels are evenly distributed throughout the thickness of the mould shell; 3) a system for preparation and supply of a liquid metal to the casting mould, the metal is being supplied into the casting mould from its both ends at a rate of 1.7 t of the melt per second; 4) a system for rotation of the mould, which comprises two gas turbines mounted on both ends of the mould and two main stop-radial slip supports with gas lubrication

  12. Results from TRX-2 slow field-reversed-theta-pinch

    International Nuclear Information System (INIS)

    Slough, J.T.; Harding, D.; Hoffman, A.L.

    1984-01-01

    FRCs have been successfully generated in the TRX-2 slow risetime theta pinch. Initial studies indicate that the flux trapping through field reversal is about as good (''50%) as on TRX-1, although the quarter cycle time of the main coil was increased from 3 to 10 μsec. Formation studies have been started using the programmed formation techniques developed on TRX-1. The plasma dynamics are very similar to those exhibited in the faster rise TRX-1 experiments. The formation phase shows the same high degree of symmetry and reproducibility that was observed in TRX-1. Equilibrium behaviour of the FRCs formed is very similar to that observed on TRX-1, as long as impurity content is kept low. T/sub e/ + T/sub i/ temperatures of 400 to 500 eV are obtained and confirmed by impurity line broadening and decay rates. Flux and particle lifetimes ≅ 100 μsec have been observed and show the same strong scaling with x/sub s/ that was observed on TRX-1

  13. Effects of intermittent theta burst stimulation on spasticity after stroke.

    Science.gov (United States)

    Kim, Dae Hyun; Shin, Ji Cheol; Jung, Seungsoo; Jung, Tae-Min; Kim, Deog Young

    2015-07-08

    Spasticity is a common cause of long-term disability in poststroke hemiplegic patients. We investigated whether intermittent theta burst stimulation (iTBS) could reduce upper-limb spasticity after a stroke. Fifteen hemiplegic stroke patients were recruited for a double-blind sham-controlled cross-over design study. A single session of iTBS or sham stimulation was delivered on the motor hotspot of the affected flexor carpi radialis muscle in a random and counterbalanced order with a 1-week interval. Modified Ashworth scale (MAS), modified Tardieu scale (MTS), H-wave/M-wave amplitude ratio, peak torque (PT), peak torque angle (PTA), work of affected wrist flexor, and rectified integrated electromyographic activity of the flexor carpi radialis muscle were measured before, immediately after, 30 min after, and 1 week after iTBS or sham stimulation. Repeated-measures analysis of variance showed a significant interaction between time and intervention for the MAS, MTS, PT, PTA, and rectified integrated electromyographic activity (PiTBS compared with sham stimulation. However, the H-wave/M-wave amplitude ratio and work were not affected. MAS and MTS significantly improved for at least 30 min after iTBS, but the other parameters only improved immediately after iTBS (PiTBS on the affected hemisphere may help to reduce poststroke spasticity transiently.

  14. Fermion wavefunctions in magnetized branes: Theta identities and Yukawa couplings

    International Nuclear Information System (INIS)

    Antoniadis, Ignatios; Kumar, Alok; Panda, Binata

    2009-01-01

    Computation of Yukawa couplings, determining superpotentials as well as the Kaehler metric, with oblique (non-commuting) fluxes in magnetized brane constructions is an interesting unresolved issue, in view of the importance of such fluxes for obtaining phenomenologically viable models. In order to perform this task, fermion (scalar) wavefunctions on toroidally compactified spaces are presented for general fluxes, parameterized by Hermitian matrices with eigenvalues of arbitrary signatures. We also give explicit mappings among fermion wavefunctions, of different internal chiralities on the tori, which interchange the role of the flux components with the complex structure of the torus. By evaluating the overlap integral of the wavefunctions, we give the expressions for Yukawa couplings among chiral multiplets arising from an arbitrary set of branes (or their orientifold images). The method is based on constructing certain mathematical identities for general Riemann theta functions with matrix valued modular parameter. We briefly discuss an application of the result, for the mass generation of non-chiral fermions, in the SU(5) GUT model presented by us in Antoniadis, Kumar and Panda (2008) .

  15. Modulation of EEG Theta Band Signal Complexity by Music Therapy

    Science.gov (United States)

    Bhattacharya, Joydeep; Lee, Eun-Jeong

    The primary goal of this study was to investigate the impact of monochord (MC) sounds, a type of archaic sounds used in music therapy, on the neural complexity of EEG signals obtained from patients undergoing chemotherapy. The secondary goal was to compare the EEG signal complexity values for monochords with those for progressive muscle relaxation (PMR), an alternative therapy for relaxation. Forty cancer patients were randomly allocated to one of the two relaxation groups, MC and PMR, over a period of six months; continuous EEG signals were recorded during the first and last sessions. EEG signals were analyzed by applying signal mode complexity, a measure of complexity of neuronal oscillations. Across sessions, both groups showed a modulation of complexity of beta-2 band (20-29Hz) at midfrontal regions, but only MC group showed a modulation of complexity of theta band (3.5-7.5Hz) at posterior regions. Therefore, the neuronal complexity patterns showed different changes in EEG frequency band specific complexity resulting in two different types of interventions. Moreover, the different neural responses to listening to monochords and PMR were observed after regular relaxation interventions over a short time span.

  16. Production of $\\Theta^{+}$ (1540) and $\\Xi$ pentaquark states in proton- proton interactions

    CERN Document Server

    Bleicher, M; Liu, F M; Pierog, T; Werner, K; 10.1016/j.physletb.2004.05.010

    2004-01-01

    The production of strange pentaquark states (e.g., Theta baryons and Xi /sup --/states) in hadronic interactions within a Gribov-Regge approach is explored. In this approach the Theta /sup +/(1540) and the Xi are produced by disintegration of remnants formed by the exchange of pomerons between the two protons. We predict the rapidity and transverse momentum distributions as well as the 4 pi multiplicity of the Theta /sup +/, Xi /sup --/ , Xi /sup -/, Xi /sup 0/ and Xi /sup +/ for square root s=17 GeV (SPS) and 200 GeV (RHIC). For both energies more than 10/sup -3/ Theta /sup +/ and more than 10 /sup -5/ Xi per pp event should be observed by the present experiments.

  17. Validation Study of CODES Dragonfly Network Model with Theta Cray XC System

    Energy Technology Data Exchange (ETDEWEB)

    Mubarak, Misbah [Argonne National Lab. (ANL), Argonne, IL (United States); Ross, Robert B. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-05-31

    This technical report describes the experiments performed to validate the MPI performance measurements reported by the CODES dragonfly network simulation with the Theta Cray XC system at the Argonne Leadership Computing Facility (ALCF).

  18. A Precision Measurement of sin$^{2}\\theta$$_{w}$ from Semileptonic Neutrino Scattering

    CERN Document Server

    Wotschack, Jorg

    1987-01-01

    There is considerable interest in measuring the electroweak mixing parameter sin$^{2}\\Theta$$_{w}$, of the Glashow-Salam-Weinberg theory $^{1}$ as precisely as possible: first, its value may be predicted by models of Grand Unification;$^{2}$ second, precise measurements of sin$^{2}\\Theta$$_{w}$ from different processes would test the validity of electroweak radiative corrections. $^{3,$}$. Different methods have been used to determine sin$^{2}\\Theta$$_{w}$, over a large range of $Q^{2}$ values. FIGURE 1 gives a compilation of sin$^{2}\\Theta$$_{w}$ with remarkable agreement between the results. At present, it is most precisely determined in semileptonic neutrino-nucleon scattering from the ratio of neutral current (NC) to charged current (CC) cross and in proton-antiproton collisions from the W boson mass. $^{10,11}$.

  19. TAO/TRITON, RAMA, and PIRATA Buoys, Quarterly, 1992-present, Sigma-Theta

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has quarterly Sigma-Theta (Potential Density Anomaly) data from the TAO/TRITON (Pacific Ocean, https://www.pmel.noaa.gov/gtmba/ ), RAMA (Indian Ocean,...

  20. What is the functional relevance of prefrontal cortex entrainment to hippocampal theta rhythms?

    Directory of Open Access Journals (Sweden)

    James Michael Hyman

    2011-03-01

    Full Text Available There has been considerable interest in the importance of oscillations in the brain and in how these oscillations relate to the firing of single neurons. Recently a number of studies have shown that the spiking of individual neurons in the medial prefrontal cortex (mPFC become entrained to the hippocampal (HPC theta rhythm. We recently showed that theta-entrained mPFC cells lost theta-entrainment specifically on error trials even though the firing rates of these cells did not change (Hyman et al., 2010. This implied that the level of HPC theta-entrainment of mPFC units was more predictive of trial outcome than differences in firing rates and that there is more information encoded by the mPFC on working memory tasks than can be accounted for by a simple rate code. Nevertheless, the functional meaning of mPFC entrainment to HPC theta remains a mystery. It is also unclear as to whether there are any differences in the nature of the information encoded by theta-entrained and non-entrained mPFC cells. In this review we discuss mPFC entrainment to HPC theta within the context of previous results as well as provide a more detailed analysis of the Hyman et al. (2010 data set. This re-analysis revealed that theta-entrained mPFC cells selectively encoded a variety of task relevant behaviors and stimuli while never theta-entrained mPFC cells were most strongly attuned to errors or the lack of expected rewards. In fact, these error responsive neurons were responsible for the error representations exhibited by the entire ensemble of mPFC neurons. A theta reset was also detected in the post-error period. While it is becoming increasingly evident that mPFC neurons exhibit correlates to virtually all cues and behaviors, perhaps phase-locking directs attention to the task-relevant representations required to solve a spatially based working memory task while the loss of theta-entrainment at the start of error trials may represent a shift of attention away from

  1. The electric dipole moment of the nucleon from simulations at imaginary vacuum angle theta

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, S. [RIKEN-BNL Research Center, Brookhaven National Laboratory, Upton (United States)]|[Tsukuba Univ. (Japan). Graduate School of Pure and Applied Sciences; Horsley, R.; Zanotti, J. [Edinburgh Univ. (United Kingdom). School of Physics; Izubuchi, T. [RIKEN-BNL Research Center, Brookhaven National Laboratory, Upton (United States)]|[Kanazawa Univ. (Japan). Inst. for Theoretical Physics; Nakamura, Y.; Pleiter, D.; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Division. Dept. of Mathematical Sciences

    2008-07-15

    We compute the electric dipole moment of proton and neutron from lattice QCD simulations with N{sub f}=2 flavors of dynamical quarks at imaginary vacuum angle {theta}. The calculation proceeds via the CP odd form factor F{sub 3}. A novel feature of our calculation is that we use partially twisted boundary conditions to extract F{sub 3} at zero momentum transfer. As a byproduct, we test the QCD vacuum at nonvanishing {theta}. (orig.)

  2. The Effects of Theta and Gamma tACS on Working Memory and Electrophysiology

    Directory of Open Access Journals (Sweden)

    Anja Pahor

    2018-01-01

    Full Text Available A single blind sham-controlled study was conducted to explore the effects of theta and gamma transcranial alternating current stimulation (tACS on offline performance on working memory tasks. In order to systematically investigate how specific parameters of tACS affect working memory, we manipulated the frequency of stimulation (theta frequency vs. gamma frequency, the type of task (n-back vs. change detection task and the content of the tasks (verbal vs. figural stimuli. A repeated measures design was used that consisted of three sessions: theta tACS, gamma tACS and sham tACS. In total, four experiments were conducted which differed only with respect to placement of tACS electrodes (bilateral frontal, bilateral parietal, left fronto-parietal and right-fronto parietal. Healthy female students (N = 72 were randomly assigned to one of these groups, hence we were able to assess the efficacy of theta and gamma tACS applied over different brain areas, contrasted against sham stimulation. The pre-post/sham resting electroencephalogram (EEG analysis showed that theta tACS significantly affected theta amplitude, whereas gamma tACS had no significant effect on EEG amplitude in any of the frequency bands of interest. Gamma tACS did not significantly affect working memory performance compared to sham, and theta tACS led to inconsistent changes in performance on the n-back tasks. Active theta tACS significantly affected P3 amplitude and latency during performance on the n-back tasks in the bilateral parietal and right-fronto parietal protocols.

  3. A Data-Driven Approach to Responder Subgroup Identification after Paired Continuous Theta Burst Stimulation

    Directory of Open Access Journals (Sweden)

    Tonio Heidegger

    2017-08-01

    Full Text Available Background: Modulation of cortical excitability by transcranial magnetic stimulation (TMS is used for investigating human brain functions. A common observation is the high variability of long-term depression (LTD-like changes in human (motor cortex excitability. This study aimed at analyzing the response subgroup distribution after paired continuous theta burst stimulation (cTBS as a basis for subject selection.Methods: The effects of paired cTBS using 80% active motor threshold (AMT in 31 healthy volunteers were assessed at the primary motor cortex (M1 corresponding to the representation of the first dorsal interosseous (FDI muscle of the left hand, before and up to 50 min after plasticity induction. The changes in motor evoked potentials (MEPs were analyzed using machine-learning derived methods implemented as Gaussian mixture modeling (GMM and computed ABC analysis.Results: The probability density distribution of the MEP changes from baseline was tri-modal, showing a clear separation at 80.9%. Subjects displaying at least this degree of LTD-like changes were n = 6 responders. By contrast, n = 7 subjects displayed a paradox response with increase in MEP. Reassessment using ABC analysis as alternative approach led to the same n = 6 subjects as a distinct category.Conclusion: Depressive effects of paired cTBS using 80% AMT endure at least 50 min, however, only in a small subgroup of healthy subjects. Hence, plasticity induction by paired cTBS might not reflect a general mechanism in human motor cortex excitability. A mathematically supported criterion is proposed to select responders for enrolment in assessments of human brain functional networks using virtual brain lesions.

  4. Cutting Classes

    Science.gov (United States)

    Hacker, Andrew

    1976-01-01

    Provides critical reviews of three books, "The Political Economy of Social Class", "Ethnicity: Theory and Experience," and "Ethnicity in the United States," focusing on the political economy of social class and ethnicity. (Author/AM)

  5. A novel class I HDAC inhibitor, MPT0G030, induces cell apoptosis and differentiation in human colorectal cancer cells via HDAC1/PKCδ and E-cadherin.

    Science.gov (United States)

    Wang, Li-Ting; Liou, Jing-Ping; Li, Yu-Hsuan; Liu, Yi-Min; Pan, Shiow-Lin; Teng, Che-Ming

    2014-07-30

    Accumulation of genetic and epigenetic changes contributes to cancer development and progression. Compared with gene mutations or deletions, epigenetic changes are reversible, which alter the chromatin structure remodeling instead of changes in DNA sequence, and therefore become a promising strategy for chemotherapy. Histone deacetylases (HDACs) are a class of enzymes that responsible for the epigenetic regulation of gene expression. MPT0G030 is a potent and selective class I HDAC inhibitor which showed broad-spectrum cytotoxicity against various human cancer cell lines. in vitro fluorometric HDAC activity assay showed that MPT0G030 effectively inhibited Class I HDACs (HDAC1~3), which were overexpressed in many malignant neoplasms. Interestingly, MPT0G030 not only induced histone acetylation and tumor suppressor p21 transcription, but also redistributed E-cadherin and activated Protein Kinase C δ (PKCδ), which was linked to cell apoptosis and differentiation. Further, activation of PKCδ was demonstrated to be modulated through HDAC1. The in vivo anticancer activity of MPT0G030 and the importance of PKCδ were confirmed in the HT-29 tumor xenograft models. Taken together, those results indicate that MPT0G030, a class I HDAC inhibitor, has great potential as a new drug candidate for cancer therapy.

  6. Dynamic links between theta executive functions and alpha storage buffers in auditory and visual working memory.

    Science.gov (United States)

    Kawasaki, Masahiro; Kitajo, Keiichi; Yamaguchi, Yoko

    2010-05-01

    Working memory (WM) tasks require not only distinct functions such as a storage buffer and central executive functions, but also coordination among these functions. Neuroimaging studies have revealed the contributions of different brain regions to different functional roles in WM tasks; however, little is known about the neural mechanism governing their coordination. Electroencephalographic (EEG) rhythms, especially theta and alpha, are known to appear over distributed brain regions during WM tasks, but the rhythms associated with task-relevant regional coupling have not been obtained thus far. In this study, we conducted time-frequency analyses for EEG data in WM tasks that include manipulation periods and memory storage buffer periods. We used both auditory WM tasks and visual WM tasks. The results successfully demonstrated function-specific EEG activities. The frontal theta amplitudes increased during the manipulation periods of both tasks. The alpha amplitudes increased during not only the manipulation but also the maintenance periods in the temporal area for the auditory WM and the parietal area for the visual WM. The phase synchronization analyses indicated that, under the relevant task conditions, the temporal and parietal regions show enhanced phase synchronization in the theta bands with the frontal region, whereas phase synchronization between theta and alpha is significantly enhanced only within the individual areas. Our results suggest that WM task-relevant brain regions are coordinated by distant theta synchronization for central executive functions, by local alpha synchronization for the memory storage buffer, and by theta-alpha coupling for inter-functional integration.

  7. Theta Neurofeedback Effects on Motor Memory Consolidation and Performance Accuracy: An Apparent Paradox?

    Science.gov (United States)

    Reiner, Miriam; Lev, Dror D; Rosen, Amit

    2018-05-15

    Previous studies have shown that theta neurofeedback enhances motor memory consolidation on an easy-to-learn finger-tapping task. However, the simplicity of the finger-tapping task precludes evaluating the putative effects of elevated theta on performance accuracy. Mastering a motor sequence is classically assumed to entail faster performance with fewer errors. The speed-accuracy tradeoff (SAT) principle states that as action speed increases, motor performance accuracy decreases. The current study investigated whether theta neurofeedback could improve both performance speed and performance accuracy, or would only enhance performance speed at the cost of reduced accuracy. A more complex task was used to study the effects of parietal elevated theta on 45 healthy volunteers The findings confirmed previous results on the effects of theta neurofeedback on memory consolidation. In contrast to the two control groups, in the theta-neurofeedback group the speed-accuracy tradeoff was reversed. The speed-accuracy tradeoff patterns only stabilized after a night's sleep implying enhancement in terms of both speed and accuracy. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  8. Palmitic acid mediates hypothalamic insulin resistance by altering PKC-theta subcellular localization in rodents.

    Science.gov (United States)

    Benoit, Stephen C; Kemp, Christopher J; Elias, Carol F; Abplanalp, William; Herman, James P; Migrenne, Stephanie; Lefevre, Anne-Laure; Cruciani-Guglielmacci, Céline; Magnan, Christophe; Yu, Fang; Niswender, Kevin; Irani, Boman G; Holland, William L; Clegg, Deborah J

    2009-09-01

    Insulin signaling can be modulated by several isoforms of PKC in peripheral tissues. Here, we assessed whether one specific isoform, PKC-theta, was expressed in critical CNS regions that regulate energy balance and whether it mediated the deleterious effects of diets high in fat, specifically palmitic acid, on hypothalamic insulin activity in rats and mice. Using a combination of in situ hybridization and immunohistochemistry, we found that PKC-theta was expressed in discrete neuronal populations of the arcuate nucleus, specifically the neuropeptide Y/agouti-related protein neurons and the dorsal medial nucleus in the hypothalamus. CNS exposure to palmitic acid via direct infusion or by oral gavage increased the localization of PKC-theta to cell membranes in the hypothalamus, which was associated with impaired hypothalamic insulin and leptin signaling. This finding was specific for palmitic acid, as the monounsaturated fatty acid, oleic acid, neither increased membrane localization of PKC-theta nor induced insulin resistance. Finally, arcuate-specific knockdown of PKC-theta attenuated diet-induced obesity and improved insulin signaling. These results suggest that many of the deleterious effects of high-fat diets, specifically those enriched with palmitic acid, are CNS mediated via PKC-theta activation, resulting in reduced insulin activity.

  9. Engineering chimeric human and mouse major histocompatibility complex (MHC) class I tetramers for the production of T-cell receptor (TCR) mimic antibodies

    Science.gov (United States)

    Bentley, Carol; Yates, Jenna; Salimi, Maryam; Greig, Jenny; Wiblin, Sarah; Hassanali, Tasneem; Banham, Alison H.

    2017-01-01

    Therapeutic monoclonal antibodies targeting cell surface or secreted antigens are among the most effective classes of novel immunotherapies. However, the majority of human proteins and established cancer biomarkers are intracellular. Peptides derived from these intracellular proteins are presented on the cell surface by major histocompatibility complex class I (MHC-I) and can be targeted by a novel class of T-cell receptor mimic (TCRm) antibodies that recognise similar epitopes to T-cell receptors. Humoural immune responses to MHC-I tetramers rarely generate TCRm antibodies and many antibodies recognise the α3 domain of MHC-I and β2 microglobulin (β2m) that are not directly involved in presenting the target peptide. Here we describe the production of functional chimeric human-murine HLA-A2-H2Dd tetramers and modifications that increase their bacterial expression and refolding efficiency. These chimeric tetramers were successfully used to generate TCRm antibodies against two epitopes derived from wild type tumour suppressor p53 (RMPEAAPPV and GLAPPQHLIRV) that have been used in vaccination studies. Immunisation with chimeric tetramers yielded no antibodies recognising the human α3 domain and β2m and generated TCRm antibodies capable of specifically recognising the target peptide/MHC-I complex in fully human tetramers and on the cell surface of peptide pulsed T2 cells. Chimeric tetramers represent novel immunogens for TCRm antibody production and may also improve the yield of tetramers for groups using these reagents to monitor CD8 T-cell immune responses in HLA-A2 transgenic mouse models of immunotherapy. PMID:28448627

  10. [Diagnostic inquiries in patients with a theta ground rhythm variant in the EEG].

    Science.gov (United States)

    Wendland, K L; Fenzel, G

    1992-09-01

    Basing on the examination of 82.767 EEGs, 118 patients with theta rhythm variant (GRV) were found out. From their case-histories all particulars taken to be important were gathered by means of a questionnaire. In addition to this 70 of these patients were interviewed, mostly in the course of a visit at home, in order to supplement the data by catamnestic informations. Moreover, attending family doctors were asked for informations, and from 14 patients elsewhere recorded EEGs were evaluated. With regard to its cycles per second, the GRV proved to be stable even for long periods, but as to its coming to the fore a slight changeability revealed. Concerning physical complaints, the patients primarily suffered from headache, giddiness, and liability to fainting fits, secondary they frequently were affected with vegetative disorders and stomach complaints. In view of the psychic aspect striking often came to light unrest, lack of vitality, disturbed social contacts, sexual problems, anxiety fits, depressive reactions, and suicidal thoughts. High sensitiveness and insufficient self-sureness in many cases were conspicuous attributes. In particular men often failed in establishing or maintaining intimate human relations, so that many of them remained single, made at best only few friends, and easily became outsiders. Inability to enforce own desires against opposition, liability of mood, ill-humor, discontent, or even jealousy frequently made their appearance. As to gainful employment and professional status several of them were less successful than their siblings and their parents.

  11. Laboratory-induced learned helplessness attenuates approach motivation as indexed by posterior versus frontal theta activity.

    Science.gov (United States)

    Reznik, Samantha J; Nusslock, Robin; Pornpattananangkul, Narun; Abramson, Lyn Y; Coan, James A; Harmon-Jones, Eddie

    2017-08-01

    Research suggests that midline posterior versus frontal electroencephalographic (EEG) theta activity (PFTA) may reflect a novel neurophysiological index of approach motivation. Elevated PFTA has been associated with approach-related tendencies both at rest and during laboratory tasks designed to enhance approach motivation. PFTA is sensitive to changes in dopamine signaling within the fronto-striatal neural circuit, which is centrally involved in approach motivation, reward processing, and goal-directed behavior. To date, however, no studies have examined PFTA during a laboratory task designed to reduce approach motivation or goal-directed behavior. Considerable animal and human research supports the hypothesis put forth by the learned helplessness theory that exposure to uncontrollable aversive stimuli decreases approach motivation by inducing a state of perceived uncontrollability. Accordingly, the present study examined the effect of perceived uncontrollability (i.e., learned helplessness) on PFTA. EEG data were collected from 74 participants (mean age = 19.21 years; 40 females) exposed to either Controllable (n = 26) or Uncontrollable (n = 25) aversive noise bursts, or a No-Noise Condition (n = 23). In line with prediction, individuals exposed to uncontrollable aversive noise bursts displayed a significant decrease in PFTA, reflecting reduced approach motivation, relative to both individuals exposed to controllable noise bursts or the No-Noise Condition. There was no relationship between perceived uncontrollability and frontal EEG alpha asymmetry, another commonly used neurophysiological index of approach motivation. Results have implications for understanding the neurophysiology of approach motivation and establishing PFTA as a neurophysiological index of approach-related tendencies.

  12. Reduced multimodal integration of memory features following continuous theta burst stimulation of angular gyrus.

    Science.gov (United States)

    Yazar, Yasemin; Bergström, Zara M; Simons, Jon S

    Lesions of the angular gyrus (AnG) region of human parietal cortex do not cause amnesia, but appear to be associated with reduction in the ability to consciously experience the reliving of previous events. We used continuous theta burst stimulation to test the hypothesis that the cognitive mechanism implicated in this memory deficit might be the integration of retrieved sensory event features into a coherent multimodal memory representation. Healthy volunteers received stimulation to AnG or a vertex control site after studying stimuli that each comprised a visual object embedded in a scene, with the name of the object presented auditorily. Participants were then asked to make memory judgments about the studied stimuli that involved recollection of single event features (visual or auditory), or required integration of event features within the same modality, or across modalities. Participants' ability to retrieve context features from across multiple modalities was significantly reduced after AnG stimulation compared to stimulation of the vertex. This effect was observed only for the integration of cross-modal context features but not for integration of features within the same modality, and could not be accounted for by task difficulty as performance was matched across integration conditions following vertex stimulation. These results support the hypothesis that AnG is necessary for the multimodal integration of distributed cortical episodic features into a unified conscious representation that enables the experience of remembering. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Distributed Attention Is Implemented through Theta-Rhythmic Gamma Modulation.

    Science.gov (United States)

    Landau, Ayelet Nina; Schreyer, Helene Marianne; van Pelt, Stan; Fries, Pascal

    2015-08-31

    When subjects monitor a single location, visual target detection depends on the pre-target phase of an ∼8 Hz brain rhythm. When multiple locations are monitored, performance decrements suggest a division of the 8 Hz rhythm over the number of locations, indicating that different locations are sequentially sampled. Indeed, when subjects monitor two locations, performance benefits alternate at a 4 Hz rhythm. These performance alternations were revealed after a reset of attention to one location. Although resets are common and important events for attention, it is unknown whether, in the absence of resets, ongoing attention samples stimuli in alternation. Here, we examined whether spatially specific attentional sampling can be revealed by ongoing pre-target brain rhythms. Visually induced gamma-band activity plays a role in spatial attention. Therefore, we hypothesized that performance on two simultaneously monitored stimuli can be predicted by a 4 Hz modulation of gamma-band activity. Brain rhythms were assessed with magnetoencephalography (MEG) while subjects monitored bilateral grating stimuli for a unilateral target event. The corresponding contralateral gamma-band responses were subtracted from each other to isolate spatially selective, target-related fluctuations. The resulting lateralized gamma-band activity (LGA) showed opposite pre-target 4 Hz phases for detected versus missed targets. The 4 Hz phase of pre-target LGA accounted for a 14.5% modulation in performance. These findings suggest that spatial attention is a theta-rhythmic sampling process that is continuously ongoing, with each sampling cycle being implemented through gamma-band synchrony. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Activation of GABAergic pathway by hypocretin in the median raphe nucleus (MRN) mediates stress-induced theta rhythm in rats.

    Science.gov (United States)

    Hsiao, Yi-Tse; Jou, Shuo-Bin; Yi, Pei-Lu; Chang, Fang-Chia

    2012-07-15

    The frequency of electroencephalograms (EEGs) is predominant in theta rhythm during stress (e.g., footshock) in rats. Median raphe nucleus (MRN) desynchronizes hippocampal theta waves via activation of GABAergic neurons in the medial septum-diagonal band of Broca (MS-DBB), a theta rhythm pacemaker. Increased hypocretin mediates stress responses in addition to the maintenance of wakefulness. Hypocretin receptors are abundant in the MRN, suggesting a possible role of hypocretin in modulating stress-induced theta rhythm. Our results indicated that the intensity of theta waves was enhanced by footshock and that a hypocretin receptor antagonist (TCS1102) suppressed the footshock-induced theta waves. Administration of hypocretin-1 (1 and 10 μg) and hypocretin-2 (10 μg) directly into the MRN simulated the effect of footshock and significantly increased theta waves. Co-administration of GABA(A) receptor antagonist, bicuculline, into the MRN blocked the increase of theta waves induced by hypocretins or footshock. These results suggested that stress enhances the release of hypocretins, activates GABAergic neurons in the MRN, blocks the ability of MRN to desynchronize theta waves, and subsequently increases the intensity of theta rhythm. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Optogenetic activation of septal cholinergic neurons suppresses sharp wave ripples and enhances theta oscillations in the hippocampus.

    Science.gov (United States)

    Vandecasteele, Marie; Varga, Viktor; Berényi, Antal; Papp, Edit; Barthó, Péter; Venance, Laurent; Freund, Tamás F; Buzsáki, György

    2014-09-16

    Theta oscillations in the limbic system depend on the integrity of the medial septum. The different populations of medial septal neurons (cholinergic and GABAergic) are assumed to affect different aspects of theta oscillations. Using optogenetic stimulation of cholinergic neurons in ChAT-Cre mice, we investigated their effects on hippocampal local field potentials in both anesthetized and behaving mice. Cholinergic stimulation completely blocked sharp wave ripples and strongly suppressed the power of both slow oscillations (0.5-2 Hz in anesthetized, 0.5-4 Hz in behaving animals) and supratheta (6-10 Hz in anesthetized, 10-25 Hz in behaving animals) bands. The same stimulation robustly increased both the power and coherence of theta oscillations (2-6 Hz) in urethane-anesthetized mice. In behaving mice, cholinergic stimulation was less effective in the theta (4-10 Hz) band yet it also increased the ratio of theta/slow oscillation and theta coherence. The effects on gamma oscillations largely mirrored those of theta. These findings show that medial septal cholinergic activation can both enhance theta rhythm and suppress peri-theta frequency bands, allowing theta oscillations to dominate.

  16. Upsilon NU: Our chapter in Sigma Theta Tau Internacional Upsilon NU: nuestro capítulo en Sigma Theta Tau International

    Directory of Open Access Journals (Sweden)

    GARZÓN ALARCÓN NELLY

    2008-07-01

    Full Text Available ALa Sociedad de Honor de Enfermería, Sigma Theta Tau Internacional, es una organización que nace y vive para desarrollar el conocimiento y la ciencia de enfermería como fundamentos del liderazgo y la búsqueda de la excelencia en el cuidado de la persona, la familia y la comunidad.

  17. A comparison of student performance in human development classes using three different modes of delivery: Online, face-to-face, and combined

    Science.gov (United States)

    Kalsow, Susan Christensen

    1999-11-01

    The problem. The dual purposes of this research were to determine if there is a difference in student performance in three Human Development classes when the modes of delivery are different and to analyze student perceptions of using Web-based learning as all or part of their course experience. Procedures. Data for this study were collected from three Human Development courses taught at Drake University. Grades from five essays, projects, and overall grades were used in the three classes and analyzed using a single factor analysis of variance to determine if there was a significant difference. Content analysis was used on the evaluation comments of the participants in the online and combined classes to determine their perceptions of Web-based learning. Findings. The single factor analysis of variance measuring student performance showed no significant difference among the online, face-to-face, and combined scores at the .05 level of significance, however, the difference was significant at the .06. The content analysis of the online and combined course showed the three major strengths of learning totally or partly online to be increased comfort in using the computer, the quality of the overall experience, and convenience in terms of increased access to educational opportunities. The barriers included lack of human interaction and access to the professor. Conclusions. The study indicates that Web-based learning is a viable option for postsecondary educational delivery in terms of student performance and learning. On the average, performance is at least as good as performance in traditional face-to-face classrooms. Improved performance, however, is contingent on adequate access to equipment, faculty skill in teaching using a new mode of delivery, and the personality of the student. The convenient access to educational opportunities and becoming more comfortable with technology are benefits that were important to these two groups. Web-based learning is not for everyone

  18. Genetic influences on functional connectivity associated with feedback processing and prediction error: Phase coupling of theta-band oscillations in twins.

    Science.gov (United States)

    Demiral, Şükrü Barış; Golosheykin, Simon; Anokhin, Andrey P

    2017-05-01

    Detection and evaluation of the mismatch between the intended and actually obtained result of an action (reward prediction error) is an integral component of adaptive self-regulation of behavior. Extensive human and animal research has shown that evaluation of action outcome is supported by a distributed network of brain regions in which the anterior cingulate cortex (ACC) plays a central role, and the integration of distant brain regions into a unified feedback-processing network is enabled by long-range phase synchronization of cortical oscillations in the theta band. Neural correlates of feedback processing are associated with individual differences in normal and abnormal behavior, however, little is known about the role of genetic factors in the cerebral mechanisms of feedback processing. Here we examined genetic influences on functional cortical connectivity related to prediction error in young adult twins (age 18, n=399) using event-related EEG phase coherence analysis in a monetary gambling task. To identify prediction error-specific connectivity pattern, we compared responses to loss and gain feedback. Monetary loss produced a significant increase of theta-band synchronization between the frontal midline region and widespread areas of the scalp, particularly parietal areas, whereas gain resulted in increased synchrony primarily within the posterior regions. Genetic analyses showed significant heritability of frontoparietal theta phase synchronization (24 to 46%), suggesting that individual differences in large-scale network dynamics are under substantial genetic control. We conclude that theta-band synchronization of brain oscillations related to negative feedback reflects genetically transmitted differences in the neural mechanisms of feedback processing. To our knowledge, this is the first evidence for genetic influences on task-related functional brain connectivity assessed using direct real-time measures of neuronal synchronization. Copyright © 2016

  19. Theta-Gamma Coupling and Working Memory in Alzheimer’s Dementia and Mild Cognitive Impairment

    Directory of Open Access Journals (Sweden)

    Michelle S. Goodman

    2018-04-01

    Full Text Available Working memory deficits are common among individuals with Alzheimer’s dementia (AD or mild cognitive impairment (MCI. Yet, little is known about the mechanisms underlying these deficits. Theta-gamma coupling—the modulation of high-frequency gamma oscillations by low-frequency theta oscillations—is a neurophysiologic process underlying working memory. We assessed the relationship between theta-gamma coupling and working memory deficits in AD and MCI. We hypothesized that: (1 individuals with AD would display the most significant working memory impairments followed by MCI and finally healthy control (HC participants; and (2 there would be a significant association between working memory performance and theta-gamma coupling across all participants. Ninety-eight participants completed the N-back working memory task during an electroencephalography (EEG recording: 33 with AD (mean ± SD age: 76.5 ± 6.2, 34 with MCI (mean ± SD age: 74.8 ± 5.9 and 31 HCs (mean ± SD age: 73.5 ± 5.2. AD participants performed significantly worse than control and MCI participants on the 1- and 2-back conditions. Regarding theta-gamma coupling, AD participants demonstrated the lowest level of coupling followed by the MCI and finally control participants on the 2-back condition. Finally, a linear regression analysis demonstrated that theta-gamma coupling (β = 0.69, p < 0.001 was the most significant predictor of 2-back performance. Our results provide evidence for a relationship between altered theta-gamma coupling and working memory deficits in individuals with AD and MCI. They also provide insight into a potential mechanism underlying working memory impairments in these individuals.

  20. Age-related changes of frontal-midline theta is predictive of efficient memory maintenance.

    Science.gov (United States)

    Kardos, Z; Tóth, B; Boha, R; File, B; Molnár, M

    2014-07-25

    Frontal areas are thought to be the coordinators of working memory processes by controlling other brain areas reflected by oscillatory activities like frontal-midline theta (4-7 Hz). With aging substantial changes can be observed in the frontal brain areas, presumably leading to age-associated changes in cortical correlates of cognitive functioning. The present study aimed to test whether altered frontal-midline theta dynamics during working memory maintenance may underlie the capacity deficits observed in older adults. 33-channel EEG was recorded in young (18-26 years, N=20) and old (60-71 years, N=16) adults during the retention period of a visual delayed match-to-sample task, in which they had to maintain arrays of 3 or 5 colored squares. An additional visual odd-ball task was used to be able to measure the electrophysiological indices of sustained attentional processes. Old participants showed reduced frontal theta activity during both tasks compared to the young group. In the young memory maintenance-related frontal-midline theta activity was shown to be sensitive both to the increased memory demands and to efficient subsequent memory performance, whereas the old adults showed no such task-related difference in the frontal theta activity. The decrease of frontal-midline theta activity in the old group indicates that cerebral aging may alter the cortical circuitries of theta dynamics, thereby leading to age-associated decline of working memory maintenance function. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  1. Different types of theta rhythmicity are induced by social and fearful stimuli in a network associated with social memory.

    Science.gov (United States)

    Tendler, Alex; Wagner, Shlomo

    2015-02-16

    Rhythmic activity in the theta range is thought to promote neuronal communication between brain regions. In this study, we performed chronic telemetric recordings in socially behaving rats to monitor electrophysiological activity in limbic brain regions linked to social behavior. Social encounters were associated with increased rhythmicity in the high theta range (7-10 Hz) that was proportional to the stimulus degree of novelty. This modulation of theta rhythmicity, which was specific for social stimuli, appeared to reflect a brain-state of social arousal. In contrast, the same network responded to a fearful stimulus by enhancement of rhythmicity in the low theta range (3-7 Hz). Moreover, theta rhythmicity showed different pattern of coherence between the distinct brain regions in response to social and fearful stimuli. We suggest that the two types of stimuli induce distinct arousal states that elicit different patterns of theta rhythmicity, which cause the same brain areas to communicate in different modes.

  2. Galactolipids from Bauhinia racemosa as a new class of antifilarial agents against human lymphatic filarial parasite, Brugia malayi.

    Science.gov (United States)

    Sashidhara, Koneni V; Singh, Suriya P; Misra, Sweta; Gupta, Jyoti; Misra-Bhattacharya, Shailja

    2012-04-01

    Bioassay guided fractionation of ethanolic extract of the leaves of Bauhinia racemosa led to the isolation of galactolipid and catechin class of the compounds (1-7) from the most active n-butanol fraction (F4). Among the active galactolipids, 1 emerged as the lead molecule which was active on both forms of lymphatic filarial parasite, Brugia malayi. It was found to be better than the standard drug ivermectin and diethylcarbamazine (DEC) in terms of dose and efficacy. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  3. Facilitation of speech repetition accuracy by theta burst stimulation of the left posterior inferior frontal gyrus.

    Science.gov (United States)

    Restle, Julia; Murakami, Takenobu; Ziemann, Ulf

    2012-07-01

    The posterior part of the inferior frontal gyrus (pIFG) in the left hemisphere is thought to form part of the putative human mirror neuron system and is assigned a key role in mapping sensory perception onto motor action. Accordingly, the pIFG is involved in motor imitation of the observed actions of others but it is not known to what extent speech repetition of auditory-presented sentences is also a function of the pIFG. Here we applied fMRI-guided facilitating intermittent theta burst transcranial magnetic stimulation (iTBS), or depressant continuous TBS (cTBS), or intermediate TBS (imTBS) over the left pIFG of healthy subjects and compared speech repetition accuracy of foreign Japanese sentences before and after TBS. We found that repetition accuracy improved after iTBS and, to a lesser extent, after imTBS, but remained unchanged after cTBS. In a control experiment, iTBS was applied over the left middle occipital gyrus (MOG), a region not involved in sensorimotor processing of auditory-presented speech. Repetition accuracy remained unchanged after iTBS of MOG. We argue that the stimulation type and stimulation site specific facilitating effect of iTBS over left pIFG on speech repetition accuracy indicates a causal role of the human left-hemispheric pIFG in the translation of phonological perception to motor articulatory output for repetition of speech. This effect may prove useful in rehabilitation strategies that combine repetitive speech training with iTBS of the left pIFG in speech disorders, such as aphasia after cerebral stroke. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Reward Expectancy Strengthens CA1 Theta and Beta Band Synchronization and Hippocampal-Ventral Striatal Coupling.

    Science.gov (United States)

    Lansink, Carien S; Meijer, Guido T; Lankelma, Jan V; Vinck, Martin A; Jackson, Jadin C; Pennartz, Cyriel M A

    2016-10-12

    The use of information from the hippocampal memory system in motivated behavior depends on its communication with the ventral striatum. When an animal encounters cues that signal subsequent reward, its reward expectancy is raised. It is unknown, however, how this process affects hippocampal dynamics and their influence on target structures, such as ventral striatum. We show that, in rats, reward-predictive cues result in enhanced hippocampal theta and beta band rhythmic activity during subsequent action, compared with uncued goal-directed navigation. The beta band component, also labeled theta's harmonic, involves selective hippocampal CA1 cell groups showing frequency doubling of firing periodicity relative to theta rhythmicity and it partitions the theta cycle into segments showing clear versus poor spike timing organization. We found that theta phase precession occurred over a wider range than previously reported. This was apparent from spikes emitted near the peak of the theta cycle exhibiting large "phase precessing jumps" relative to spikes in foregoing cycles. Neither this phenomenon nor the regular manifestation of theta phase precession was affected by reward expectancy. Ventral striatal neuronal firing phase-locked not only to hippocampal theta, but also to beta band activity. Both hippocampus and ventral striatum showed increased synchronization between neuronal firing and local field potential activity during cued compared with uncued goal approaches. These results suggest that cue-triggered reward expectancy intensifies hippocampal output to target structures, such as the ventral striatum, by which the hippocampus may gain prioritized access to systems modulating motivated behaviors. Here we show that temporally discrete cues raising reward expectancy enhance both theta and beta band activity in the hippocampus once goal-directed navigation has been initiated. These rhythmic activities are associated with increased synchronization of neuronal firing

  5. Abnormal-induced theta activity supports early directed-attention network deficits in progressive MCI.

    Science.gov (United States)

    Deiber, Marie-Pierre; Ibañez, Vicente; Missonnier, Pascal; Herrmann, François; Fazio-Costa, Lara; Gold, Gabriel; Giannakopoulos, Panteleimon

    2009-09-01

    The electroencephalography (EEG) theta frequency band reacts to memory and selective attention paradigms. Global theta oscillatory activity includes a posterior phase-locked component related to stimulus processing and a frontal-induced component modulated by directed attention. To investigate the presence of early deficits in the directed attention-related network in elderly individuals with mild cognitive impairment (MCI), time-frequency analysis at baseline was used to assess global and induced theta oscillatory activity (4-6Hz) during n-back working memory tasks in 29 individuals with MCI and 24 elderly controls (EC). At 1-year follow-up, 13 MCI patients were still stable and 16 had progressed. Baseline task performance was similar in stable and progressive MCI cases. Induced theta activity at baseline was significantly reduced in progressive MCI as compared to EC and stable MCI in all n-back tasks, which were similar in terms of directed attention requirements. While performance is maintained, the decrease of induced theta activity suggests early deficits in the directed-attention network in progressive MCI, whereas this network is functionally preserved in stable MCI.

  6. Search for $\\Theta^{++}$ Pentaquarks in the Exclusive Reaction $\\gamma p\\to K^+K^-p$

    Energy Technology Data Exchange (ETDEWEB)

    V. Kubarovsky; Marco Battaglieri; Raffaella De Vita; John Goett; Lei Guo; Gordon Mutchler; Paul Stoler; Dennis Weygand; Pawel Ambrozewicz; Marco Anghinolfi; Gegham Asryan; Harutyun AVAKIAN; Harutyun Avakian; H. Bagdasaryan; Nathan Baillie; Jacques Ball; Nathan Baltzell; V. Batourine; Ivan Bedlinski; Ivan Bedlinskiy; Matthew Bellis; Nawal Benmouna; Barry Berman; Angela Biselli; Sylvain Bouchigny; Sergey Boyarinov; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; Sharon Careccia; Daniel Carman; Shifeng Chen; Eric Clinton; Philip Cole; Patrick Collins; Philip Coltharp; Donald Crabb; Hall Crannell; Volker Crede; John Cummings; Rita De Masi; Daniel Dale; Enzo De Sanctis; Pavel Degtiarenko; Alexandre Deur; Kahanawita Dharmawardane; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; Latifa Elouadrhiri; Paul Eugenio; Gleb Fedotov; Herbert Funsten; Marianna Gabrielyan; Liping Gan; Michel Garcon; Ashot Gasparian; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; Oleksandr Glamazdin; John Goetz; Evgueni Golovatch; Atilla Gonenc; Christopher Gordon; Ralf Gothe; Keith Griffioen; Michel Guidal; Nevzat Guler; Vardan Gyurjyan; Cynthia Hadjidakis; Kawtar Hafidi; Rafael Hakobyan; John Hardie; F. Hersman; Kenneth Hicks; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; David Jenkins; Hyon-Suk Jo; Kyungseon Joo; Henry Juengst; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Franz Klein; Friedrich Klein; Alexei Klimenko; Mikhail Kossov; Laird Kramer; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Jeff Lachniet; Jean Laget; Jorn Langheinrich; David Lawrence; Tsung-shung Lee; Ji Li; Kenneth Livingston; Hai-jiang Lu; Marion MacCormick; Nikolai Markov; Bryan McKinnon; Bernhard Mecking; Joseph Melone; Mac Mestayer; Curtis Meyer; Tsutomu Mibe; Konstantin Mikhaylov; Ralph Minehart; Marco Mirazita; Rory Miskimen; Vasiliy Mochalov; Viktor Mokeev; Ludyvine Morand; Steven Morrow; Maryam Moteabbed; Pawel Nadel-Turonski; Itaru Nakagawa; Rakhsha Nasseripour; Silvia Niccolai; Gabriel Niculescu; Maria-Ioana Niculescu; Bogdan Niczyporuk; Megh Niroula; Rustam Niyazov; Mina Nozar; Mikhail Osipenko; Alexander Ostrovidov; Kijun Park; Evgueni Pasyuk; Craig Paterson; Joshua Pierce; Nikolay Pivnyuk; Dinko Pocanic; Oleg Pogorelko; Sergey Pozdnyakov; John Price; Yelena Prok; Dan Protopopescu; Brian Raue; Gregory Riccardi; Giovanni Ricco; Marco Ripani; Barry Ritchie; Federico Ronchetti; Guenther Rosner; Patrizia Rossi; Franck Sabatie; Carlos Salgado; Joseph Santoro; Vladimir Sapunenko; Reinhard Schumacher; Vladimir Serov; Youri Sharabian; Nikolay Shvedunov; Elton Smith; Lee Smith; Daniel Sober; Aleksey Stavinskiy; Samuel Stepanyan; Stepan Stepanyan; Burnham Stokes; Igor Strakovski; Steffen Strauch; Mauro Taiuti; David Tedeschi; Aram Teymurazyan; Ulrike Thoma; Avtandil Tkabladze; Svyatoslav Tkachenko; Luminita Todor; Clarisse Tur; Maurizio Ungaro; Michael Vineyard; Alexander Vlassov; Lawrence Weinstein; Michael Williams; Elliott Wolin; Michael Wood; Amrit Yegneswaran; Lorenzo Zana; Jixie Zhang; Bo Zhao

    2006-04-28

    The reaction {gamma}p {yields} K{sup +}K{sup -}p was studied at Jefferson Lab with photon energies from 1.8 to 3.8 GeV using a tagged photon beam. The goal was to search for a {Theta}{sup ++} pentaquark, a narrow doubly charged baryon state having strangeness S = +1 and isospin I = 1, in the pK{sup +} invariant mass spectrum. No statistically significant evidence of a {Theta}{sup ++} was found. Upper limits on the total and differential production cross section for the reaction {gamma}p {yields} K{sup -}{Theta}{sup ++} were obtained in the mass range from 1.5 to 2.0 GeV/c{sup 2}, with an upper limit of about 0.15 nb, 95% C.L. for a narrow resonance with a mass M{sub {Theta}{sup ++}} = 1.54 GeV/c{sup 2}. This result places a very stringent upper limit on the {Theta}{sup ++} width.

  7. The Coupling between Gamma and Theta Oscillation and Visuotactile Integration Process

    Directory of Open Access Journals (Sweden)

    Noriaki Kanayama

    2011-10-01

    Full Text Available Some researches revealed the relationship between multisensory integration and EEG oscillations. Previous studies revealed that the visuotactile integration process could be explained by gamma and theta band oscillation. In addition, recent studies have showed the possibility that a coupling between oscillations at the different frequency bands plays an important role on the multisensory integration system. This study aimed to investigate whether the gamma and theta oscillations show the coupling during the visuotactile integration. Using congruency effect paradigm only for left hand, we measured scalp EEG during simultaneous presentation of “spatially congruent” or “spatially incongruent” visuotactile stimuli. In Experiment 1, the proportion of the spatially congruent trials (80% vs 20% was changed across the experimental blocks. The results showed that the relationship between gamma power and theta phase at the parietal area was modulated by the proportion. In Experiment 2, the saliency of the vibration stimulus (0dB vs −20dB was changed across trials. The results showed that the relationship between gamma power and theta phase was immune to the saliency. These results suggest that multisensory integration process has a plasticity, which is modulated by the proportion of congruent trial, and the process could be explained by the coupling between gamma/theta oscillations.

  8. Hippocampal Theta-Gamma Coupling Reflects State-Dependent Information Processing in Decision Making.

    Science.gov (United States)

    Amemiya, Seiichiro; Redish, A David

    2018-03-20

    During decision making, hippocampal activity encodes information sometimes about present and sometimes about potential future plans. The mechanisms underlying this transition remain unknown. Building on the evidence that gamma oscillations at different frequencies (low gamma [LG], 30-55 Hz; high gamma [HG], 60-90 Hz; and epsilon, 100-140 Hz) reflect inputs from different circuits, we identified how changes in those frequencies reflect different information-processing states. Using a unique noradrenergic manipulation by clonidine, which shifted both neural representations and gamma states, we found that future representations depended on gamma components. These changes were identifiable on each cycle of theta as asymmetries in the theta cycle, which arose from changes within the ratio of LG and HG power and the underlying phases of those gamma rhythms within the theta cycle. These changes in asymmetry of the theta cycle reflected changes in representations of present and future on each theta cycle. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  9. Contribution of Arginine 13 to the Catalytic Activity of Human Class Pi Glutathione Transferase P1-1

    International Nuclear Information System (INIS)

    Kong, Ji Na; Jo, Dong Hyeon; Do, Hyun Dong; Lee, Jin Ju; Kong, Kwang Hoon

    2010-01-01

    Arg13 is a conserved active-site residue in all known Pi class glutathione S-transferases (GSTs) and in most Alpha class GSTs. To evaluate its contribution to substrate binding and catalysis of this residue, three mutants (R13A, R13K, and R13L) were expressed in Escherichia coli and purified by GSH affinity chromatography. The substitutions of Arg13 significantly affected GSH-conjugation activity, while scarcely affecting glutathione peroxidase or steroid isomerase activities. Mutation of Arg13 into Ala largely reduced the GSH-conjugation activity by approximately 85 - 95%, whereas substitutions by Lys and Leu barely affected activity. These results suggest that, in the GSH-conjugation activity of hGST P1-1, the contribution of Arg13 toward catalytic activity is highly dependent on substrate specificities and the size of the side chain at position 13. From the kinetic parameters, introduction of larger side chains at position 13 results in stronger affinity (Leu > Lys, Arg > Ala) towards GSH. The substitutions of Arg13 with alanine and leucine significantly affected k cat , whereas substitution with Lys was similar to that of the wild type, indicating the significance of a positively charged residue at position 13. From the plots of log (k cat /K m CDNB ) against pH, the pK a values of the thiol group of GSH bound in R13A, R13K, and R13L were estimated to be 1.8, 1.4, and 1.8 pK units higher than the pK a value of the wildtype enzyme, demonstrating the contribution of the Arg13 guanidinium group to the electrostatic field in the active site. From these results, we suggest that contribution of Arg13 in substrate binding is highly dependent on the nature of the electrophilic substrates, while in the catalytic mechanism, it stabilizes the GSH thiolate through hydrogen bonding

  10. The interaction of beta 2-microglobulin (beta 2m) with mouse class I major histocompatibility antigens and its ability to support peptide binding. A comparison of human and mouse beta 2m

    DEFF Research Database (Denmark)

    Pedersen, L O; Stryhn, A; Holter, T L

    1995-01-01

    of class I molecules are involved in peptide binding, whereas most of class I molecules are involved in beta 2m binding. We propose that mouse beta 2m interacts with the minor peptide binding (i.e. the "empty") fraction with a lower affinity than human beta 2m does, whereas mouse and human beta 2m interact......The function of major histocompatibility complex (MHC) class I molecules is to sample peptides derived from intracellular proteins and to present these peptides to CD8+ cytotoxic T lymphocytes. In this paper, biochemical assays addressing MHC class I binding of both peptide and beta 2-microglobulin...... (beta 2m) have been used to examine the assembly of the trimolecular MHC class I/beta 2m/peptide complex. Recombinant human beta 2m and mouse beta 2ma have been generated to compare the binding of the two beta 2m to mouse class I. It is frequently assumed that human beta 2m binds to mouse class I heavy...

  11. Theta coupling between V4 and prefrontal cortex predicts visual short-term memory performance.

    Science.gov (United States)

    Liebe, Stefanie; Hoerzer, Gregor M; Logothetis, Nikos K; Rainer, Gregor

    2012-01-29

    Short-term memory requires communication between multiple brain regions that collectively mediate the encoding and maintenance of sensory information. It has been suggested that oscillatory synchronization underlies intercortical communication. Yet, whether and how distant cortical areas cooperate during visual memory remains elusive. We examined neural interactions between visual area V4 and the lateral prefrontal cortex using simultaneous local field potential (LFP) recordings and single-unit activity (SUA) in monkeys performing a visual short-term memory task. During the memory period, we observed enhanced between-area phase synchronization in theta frequencies (3-9 Hz) of LFPs together with elevated phase locking of SUA to theta oscillations across regions. In addition, we found that the strength of intercortical locking was predictive of the animals' behavioral performance. This suggests that theta-band synchronization coordinates action potential communication between V4 and prefrontal cortex that may contribute to the maintenance of visual short-term memories.

  12. Cueing vocabulary during sleep increases theta activity during later recognition testing.

    Science.gov (United States)

    Schreiner, Thomas; Göldi, Maurice; Rasch, Björn

    2015-11-01

    Neural oscillations in the theta band have repeatedly been implicated in successful memory encoding and retrieval. Several recent studies have shown that memory retrieval can be facilitated by reactivating memories during their consolidation during sleep. However, it is still unknown whether reactivation during sleep also enhances subsequent retrieval-related neural oscillations. We have recently demonstrated that foreign vocabulary cues presented during sleep improve later recall of the associated translations. Here, we examined the effect of cueing foreign vocabulary during sleep on oscillatory activity during subsequent recognition testing after sleep. We show that those words that were replayed during sleep after learning (cued words) elicited stronger centroparietal theta activity during recognition as compared to noncued words. The reactivation-induced increase in theta oscillations during later recognition testing might reflect a strengthening of individual memory traces and the integration of the newly learned words into the mental lexicon by cueing during sleep. © 2015 Society for Psychophysiological Research.

  13. Cloning and expression of a cDNA coding for the human platelet-derived growth factor receptor: Evidence for more than one receptor class

    International Nuclear Information System (INIS)

    Gronwald, R.G.K.; Grant, F.J.; Haldeman, B.A.; Hart, C.E.; O'Hara, P.J.; Hagen, F.S.; Ross, R.; Bowen-Pope, D.F.; Murray, M.J.

    1988-01-01

    The complete nucleotide sequence of a cDNA encoding the human platelet-derived growth factor (PDGF) receptor is presented. The cDNA contains an open reading frame that codes for a protein of 1106 amino acids. Comparison to the mouse PDGF receptor reveals an overall amino acid sequence identity of 86%. This sequence identity rises to 98% in the cytoplasmic split tyrosine kinase domain. RNA blot hybridization analysis of poly(A) + RNA from human dermal fibroblasts detects a major and a minor transcript using the cDNA as a probe. Baby hamster kidney cells, transfected with an expression vector containing the receptor cDNA, express an ∼ 190-kDa cell surface protein that is recognized by an anti-human PDGF receptor antibody. The recombinant PDGF receptor is functional in the transfected baby hamster kidney cells as demonstrated by ligand-induced phosphorylation of the receptor. Binding properties of the recombinant PDGF receptor were also assessed with pure preparations of BB and AB isoforms of PDGF. Unlike human dermal fibroblasts, which bind both isoforms with high affinity, the transfected baby hamster kidney cells bind only the BB isoform of PDGF with high affinity. This observation is consistent with the existence of more than one PDGF receptor class

  14. Word class and context affect alpha-band oscillatory dynamics in an older population

    Directory of Open Access Journals (Sweden)

    Monika eMellem

    2012-04-01

    Full Text Available Differences in the oscillatory EEG dynamics of reading open class and closed class words have previously been found (Bastiaansen et al., 2005 and are thought to reflect differences in lexical-semantic content between these word classes. In particular, the theta band (4–7 Hz seems to play a prominent role in lexical-semantic retrieval. We tested whether this theta effect is robust in an older population of subjects. Additionally, we examined how the context of a word can modulate the oscillatory dynamics underlying retrieval for the two different classes of words. Older participants (mean age 55 read words presented in either syntactically-correct sentences or in a scrambled order (scrambled sentence while their EEG was recorded. We performed time-frequency analysis to examine how power varied based on the context or class of the word. We observed larger power decreases in the alpha (8–12Hz band between 200–700 ms for the open class compared to closed class words, but this was true only for the scrambled sentence context. We did not observe differences in theta power between these conditions. Context exerted an effect on the alpha and low beta (13–18 Hz bands between 0–700 ms. These results suggest that the previously observed word class effects on theta power changes in a younger participant sample do not seem to be a robust effect in this older population. Though this is an indirect comparison between studies, it may suggest the existence of aging effects on word retrieval dynamics for different populations. Additionally, the interaction between word class and context suggests that word retrieval mechanisms interact with sentence-level comprehension mechanisms in the alpha band.

  15. Self-regulation of frontal-midline theta facilitates memory updating and mental set shifting

    Directory of Open Access Journals (Sweden)

    Stefanie eEnriquez-Geppert

    2014-12-01

    Full Text Available Frontal-midline (fm theta oscillations as measured via the electroencephalogram (EEG have been suggested as neural working language of executive functioning. Their power has been shown to increase when cognitive processing or task performance is enhanced. Thus, the question arises whether learning to increase fm-theta amplitudes would functionally impact the behavioral performance in tasks probing executive functions (EFs. Here, the effects of neurofeedback, a learning method to self-up-regulate fm-theta over frontal-midline electrodes, on the four most representative EFs, memory updating, set shifting, conflict monitoring, and motor inhibition are presented. Before beginning and after completing an individualized, eight-session gap-spaced neurofeedback intervention, the three-back, letter/number task-switching, Stroop, and stop-signal tasks were tested while measuring the EEG. Self-determined up-regulation of fm-theta and its putative role for executive functioning were compared to an active control group, the so-called pseudo-neurofeedback group. Task-related fm-theta activity after training differed significantly between groups. More importantly, though, after neurofeedback significantly enhanced behavioral performance was observed. The training group showed higher accuracy scores in the three-back task and reduced mixing and shifting costs in letter/number task-switching. However, this specific protocol type did not affect performance in tasks probing conflict monitoring and motor inhibition. Thus, our results suggest a modulation of proactive but not reactive mechanisms of cognitive control. In sum, the modulation of fm-theta via neurofeedback may serve as potent treatment approach for executive dysfunctions.

  16. Effects of intermittent theta burst stimulation on cerebral blood flow and cerebral vasomotor reactivity.

    Science.gov (United States)

    Pichiorri, Floriana; Vicenzini, Edoardo; Gilio, Francesca; Giacomelli, Elena; Frasca, Vittorio; Cambieri, Chiara; Ceccanti, Marco; Di Piero, Vittorio; Inghilleri, Maurizio

    2012-08-01

    To determine whether intermittent theta burst stimulation influences cerebral hemodynamics, we investigated changes induced by intermittent theta burst stimulation on the middle cerebral artery cerebral blood flow velocity and vasomotor reactivity to carbon dioxide (CO(2)) in healthy participants. The middle cerebral artery flow velocity and vasomotor reactivity were monitored by continuous transcranial Doppler sonography. Changes in cortical excitability were tested by transcranial magnetic stimulation. In 11 healthy participants, before and immediately after delivering intermittent theta burst stimulation, we tested cortical excitability measured by the resting motor threshold and motor evoked potential amplitude over the stimulated hemisphere and vasomotor reactivity to CO(2) bilaterally. The blood flow velocity was monitored in both middle cerebral arteries throughout the experimental session. In a separate session, we tested the effects of sham stimulation under the same experimental conditions. Whereas the resting motor threshold remained unchanged before and after stimulation, motor evoked potential amplitudes increased significantly (P = .04). During and after stimulation, middle cerebral artery blood flow velocities also remained bilaterally unchanged, whereas vasomotor reactivity to CO(2) increased bilaterally (P = .04). The sham stimulation left all variables unchanged. The expected intermittent theta burst stimulation-induced changes in cortical excitability were not accompanied by changes in cerebral blood flow velocities; however, the bilateral increased vasomotor reactivity suggests that intermittent theta burst stimulation influences the cerebral microcirculation, possibly involving subcortical structures. These findings provide useful information on hemodynamic phenomena accompanying intermittent theta burst stimulation, which should be considered in research aimed at developing this noninvasive, low-intensity stimulation technique for safe

  17. Theta oscillations are sensitive to both early and late conflict processing stages: effects of alcohol intoxication.

    Science.gov (United States)

    Kovacevic, Sanja; Azma, Sheeva; Irimia, Andrei; Sherfey, Jason; Halgren, Eric; Marinkovic, Ksenija

    2012-01-01

    Prior neuroimaging evidence indicates that decision conflict activates medial and lateral prefrontal and parietal cortices. Theoretical accounts of cognitive control highlight anterior cingulate cortex (ACC) as a central node in this network. However, a better understanding of the relative primacy and functional contributions of these areas to decision conflict requires insight into the neural dynamics of successive processing stages including conflict detection, response selection and execution. Moderate alcohol intoxication impairs cognitive control as it interferes with the ability to inhibit dominant, prepotent responses when they are no longer correct. To examine the effects of moderate intoxication on successive processing stages during cognitive control, spatio-temporal changes in total event-related theta power were measured during Stroop-induced conflict. Healthy social drinkers served as their own controls by participating in both alcohol (0.6 g/kg ethanol for men, 0.55 g/kg women) and placebo conditions in a counterbalanced design. Anatomically-constrained magnetoencephalography (aMEG) approach was applied to complex power spectra for theta (4-7 Hz) frequencies. The principal generator of event-related theta power to conflict was estimated to ACC, with contributions from fronto-parietal areas. The ACC was uniquely sensitive to conflict during both early conflict detection, and later response selection and execution stages. Alcohol attenuated theta power to conflict across successive processing stages, suggesting that alcohol-induced deficits in cognitive control may result from theta suppression in the executive network. Slower RTs were associated with attenuated theta power estimated to ACC, indicating that alcohol impairs motor preparation and execution subserved by the ACC. In addition to their relevance for the currently prevailing accounts of cognitive control, our results suggest that alcohol-induced impairment of top-down strategic processing

  18. Multifractal Detrended Fluctuation Analysis of alpha and theta EEG rhythms with musical stimuli

    International Nuclear Information System (INIS)

    Maity, Akash Kumar; Pratihar, Ruchira; Mitra, Anubrato; Dey, Subham; Agrawal, Vishal; Sanyal, Shankha; Banerjee, Archi; Sengupta, Ranjan; Ghosh, Dipak

    2015-01-01

    Highlights: • EEG was done to record the brain electrical activity of 10 subjects in response to simple acoustical tanpura stimuli. • Empirical Mode Decomposition (EMD) technique used to make the EEG signal free from blink and other muscular artifacts. • Multifractal Detrended Fluctuation Analysis (MFDFA) performed to assess the complexity of extracted alpha and theta brain rhythms. • The findings show spectral width i.e. complexity of alpha and theta rhythms increase in all the seven frontal locations studied, under the effect of musical stimuli. - Abstract: Electroencephalography (EEG) was performed on 10 participants using a simple acoustical stimuli i.e. a tanpura drone. The tanpura drone is free from any semantic content and is used with a hypothesis that it provides a specific resting environment for the listeners. The EEG data was extracted for all the frontal electrodes viz. F3, F4, F7, F8, Fp1, Fp2 and Fz. Empirical Mode Decomposition (EMD) was applied on the acquired raw EEG signal to make it free from blink as well as other muscular artifacts. Wavelet Transform (WT) technique was used to segregate alpha and theta waves from the denoised EEG signal. Non-linear analysis in the form of Multifractal Detrended Fluctuation Analysis (MFDFA) was carried out on the extracted alpha and theta time series data to study the variation of their complexity. It was found that in all the frontal electrodes alpha as well as theta complexity increases as is evident from the increase of multifractal spectral width. This study is entirely new and gives interesting data regarding neural activation of the alpha and theta brain rhythms while listening to simple acoustical stimuli. The importance of this study lies in the context of emotion quantification using multifractal spectral width as a parameter as well as in the field of cognitive music therapy. The results are discussed in detail.

  19. Bi-Directional Theta Modulation between the Septo-Hippocampal System and the Mammillary Area in Free-Moving Rats

    Directory of Open Access Journals (Sweden)

    Ming Ruan

    2017-09-01

    Full Text Available Hippocampal (HPC theta oscillations have long been linked to various functions of the brain. Many cortical and subcortical areas that also exhibit theta oscillations have been linked to functional circuits with the hippocampus on the basis of coupled activities at theta frequencies. We examine, in freely moving rats, the characteristics of diencephalic theta local field potentials (LFPs recorded in the supramammillary/mammillary (SuM/MM areas that are bi-directionally connected to the HPC through the septal complex. Using partial directed coherence (PDC, we find support for previous suggestions that SuM modulates HPC theta at higher frequencies. We find weak separation of SuM and MM by dominant theta frequency recorded locally. Contrary to oscillatory cell activities under anesthesia where SuM is insensitive, but MM is sensitive to medial septal (MS inactivation, theta LFPs persisted and became indistinguishable after MS-inactivation. However, MS-inactivation attenuated SuM/MM theta power, while increasing the frequency of SuM/MM theta. MS-inactivation also reduced root mean squared power in both HPC and SuM/MM equally, but reduced theta power differentially in the time domain. We provide converging evidence that SuM is preferentially involved in coding HPC theta at higher frequencies, and that the MS-HPC circuit normally imposes a frequency-limiting modulation over the SuM/MM area as suggested by cell-based recordings in anesthetized animals. In addition, we provide evidence that the postulated SuM-MS-HPC-MM circuit is under complex bi-directional control, rather than SuM and MM having roles as unidirectional relays in the network.

  20. Double Chooz and non Asian efforts towards {theta}{sub 13}

    Energy Technology Data Exchange (ETDEWEB)

    Lasserre, Thierry [CEA/Saclay and Laboratoire Astroparticle and Cosmologie Institut de Recherche des Lois Fondamentales de l' Univers Service de Physique des Particules 91191 Gif-s-Yvette (France)], E-mail: thierry.lasserre@cea.fr

    2008-11-01

    Neutrino oscillation physics is entering a precision measurement area. The smallness of the {theta}{sub 13} neutrino mixing angle is still enigmatic and should be resolved. Double Chooz will use two identical detectors near the Chooz nuclear power station to search for a non vanishing {theta}{sub 13}, and hopefully open the way to experiments aspiring to discover CP violation in the leptonic sector. The Angra project aims to prevail over the Double Chooz experiment if the third neutrino oscillation channel is not discovered in the forthcoming years.

  1. Transient loss of plasma from a theta pinch having an initially reversed magnetic field

    International Nuclear Information System (INIS)

    Heidrich, J.E.

    1981-01-01

    The results of an experimental study of the transient loss of plasma from a 25-cm-long theta pinch initially containing a reversed trapped magnetic field are presented. The plasma, amenable to MHD analyses, was a doubly ionized helium plasma characterized by an ion density N/sub i/ = 2 x 10 16 cm -3 and an ion temperature T/sub i/ = 15 eV at midcoil and by N/sub i/ = 0.5 x 10 16 cm -3 and T/sub i/ = 6 eV at a position 2.5 cm beyond the end of the theta coil

  2. VE-cadherin expression allows identification of a new class of hematopoietic stem cells within human embryonic liver.

    Science.gov (United States)

    Oberlin, Estelle; Fleury, Maud; Clay, Denis; Petit-Cocault, Laurence; Candelier, Jean-Jacques; Mennesson, Benoît; Jaffredo, Thierry; Souyri, Michèle

    2010-11-25

    Edification of the human hematopoietic system during development is characterized by the production of waves of hematopoietic cells separated in time, formed in distinct embryonic sites (ie, yolk sac, truncal arteries including the aorta, and placenta). The embryonic liver is a major hematopoietic organ wherein hematopoietic stem cells (HSCs) expand, and the future, adult-type, hematopoietic cell hierarchy becomes established. We report herein the identification of a new, transient, and rare cell population in the human embryonic liver, which coexpresses VE-cadherin, an endothelial marker, CD45, a pan-hematopoietic marker, and CD34, a common endothelial and hematopoietic marker. This population displays an outstanding self-renewal, proliferation, and differentiation potential, as detected by in vitro and in vivo hematopoietic assays compared with its VE-cadherin negative counterpart. Based on VE-cadherin expression, our data demonstrate the existence of 2 phenotypically and functionally separable populations of multipotent HSCs in the human embryo, the VE-cadherin(+) one being more primitive than the VE-cadherin(-) one, and shed a new light on the hierarchical organization of the embryonic liver HSC compartment.

  3. Building a World-Class Safety Culture: The National Ignition Facility and the Control of Human and Organizational Error

    International Nuclear Information System (INIS)

    Bennett, C T; Stalnaker, G

    2002-01-01

    Accidents in complex systems send us signals. They may be harbingers of a catastrophe. Some even argue that a ''normal'' consequence of operations in a complex organization may not only be the goods it produces, but also accidents and--inevitably--catastrophes. We would like to tell you the story of a large, complex organization, whose history questions the argument ''that accidents just happen.'' Starting from a less than enviable safety record, the National Ignition Facility (NIF) has accumulated over 2.5 million safe hours. The story of NIF is still unfolding. The facility is still being constructed and commissioned. But the steps NIF has taken in achieving its safety record provide a principled blueprint that may be of value to others. Describing that principled blueprint is the purpose of this paper. The first part of this paper is a case study of NIF and its effort to achieve a world-class safety record. This case study will include a description of (1) NIF's complex systems, (2) NIF's early safety history, (3) factors that may have initiated its safety culture change, and (4) the evolution of its safety blueprint. In the last part of the paper, we will compare NIF's safety culture to what safety industry experts, psychologists, and sociologists say about how to shape a culture and control organizational error

  4. The effect of stimulation interval on plasticity following repeated blocks of intermittent theta burst stimulation.

    Science.gov (United States)

    Tse, Nga Yan; Goldsworthy, Mitchell R; Ridding, Michael C; Coxon, James P; Fitzgerald, Paul B; Fornito, Alex; Rogasch, Nigel C

    2018-06-04

    This study assessed the effect of interval duration on the direction and magnitude of changes in cortical excitability and inhibition when applying repeated blocks of intermittent theta burst stimulation (iTBS) over motor cortex. 15 participants received three different iTBS conditions on separate days: single iTBS; repeated iTBS with a 5 minute interval (iTBS-5-iTBS); and with a 15 minute interval (iTBS-15-iTBS). Changes in cortical excitability and short-interval cortical inhibition (SICI) were assessed via motor-evoked potentials (MEPs) before and up to 60 mins following stimulation. iTBS-15-iTBS increased MEP amplitude for up to 60 mins post stimulation, whereas iTBS-5-iTBS decreased MEP amplitude. In contrast, MEP amplitude was not altered by single iTBS. Despite the group level findings, only 53% of individuals showed facilitated MEPs following iTBS-15-iTBS, and only 40% inhibited MEPs following iTBS-5-iTBS. Modulation of SICI did not differ between conditions. These results suggest interval duration between spaced iTBS plays an important role in determining the direction of plasticity on excitatory, but not inhibitory circuits in human motor cortex. While repeated iTBS can increase the magnitude of MEP facilitation/inhibition in some individuals compared to single iTBS, the response to repeated iTBS appears variable between individuals in this small sample.

  5. Word classes

    DEFF Research Database (Denmark)

    Rijkhoff, Jan

    2007-01-01

    in grammatical descriptions of some 50 languages, which together constitute a representative sample of the world’s languages (Hengeveld et al. 2004: 529). It appears that there are both quantitative and qualitative differences between word class systems of individual languages. Whereas some languages employ...... a parts-of-speech system that includes the categories Verb, Noun, Adjective and Adverb, other languages may use only a subset of these four lexical categories. Furthermore, quite a few languages have a major word class whose members cannot be classified in terms of the categories Verb – Noun – Adjective...... – Adverb, because they have properties that are strongly associated with at least two of these four traditional word classes (e.g. Adjective and Adverb). Finally, this article discusses some of the ways in which word class distinctions interact with other grammatical domains, such as syntax and morphology....

  6. Why don't you like me? : Midfrontal theta power in response to unexpected peer rejection feedback

    NARCIS (Netherlands)

    van der Molen, M.J.W.; Dekkers, L.M.S.; Westenberg, P.M.; van der Veen, F.M.; van der Molen, M.W.

    2017-01-01

    Social connectedness theory posits that the brain processes social rejection as a threat to survival. Recent electrophysiological evidence suggests that midfrontal theta (4–8 Hz) oscillations in the EEG provide a window on the processing of social rejection. Here we examined midfrontal theta

  7. Theta-alpha EEG phase distributions in the frontal area for dissociation of visual and auditory working memory.

    Science.gov (United States)

    Akiyama, Masakazu; Tero, Atsushi; Kawasaki, Masahiro; Nishiura, Yasumasa; Yamaguchi, Yoko

    2017-03-07

    Working memory (WM) is known to be associated with synchronization of the theta and alpha bands observed in electroencephalograms (EEGs). Although frontal-posterior global theta synchronization appears in modality-specific WM, local theta synchronization in frontal regions has been found in modality-independent WM. How frontal theta oscillations separately synchronize with task-relevant sensory brain areas remains an open question. Here, we focused on theta-alpha phase relationships in frontal areas using EEG, and then verified their functional roles with mathematical models. EEG data showed that the relationship between theta (6 Hz) and alpha (12 Hz) phases in the frontal areas was about 1:2 during both auditory and visual WM, and that the phase distributions between auditory and visual WM were different. Next, we used the differences in phase distributions to construct FitzHugh-Nagumo type mathematical models. The results replicated the modality-specific branching by orthogonally of the trigonometric functions for theta and alpha oscillations. Furthermore, mathematical and experimental results were consistent with regards to the phase relationships and amplitudes observed in frontal and sensory areas. These results indicate the important role that different phase distributions of theta and alpha oscillations have in modality-specific dissociation in the brain.

  8. Urea Derivatives of 2-Aryl-benzothiazol-5-amines: A New Class of Potential Drugs for Human African Trypanosomiasis.

    Science.gov (United States)

    Patrick, Donald A; Gillespie, J Robert; McQueen, Joshua; Hulverson, Matthew A; Ranade, Ranae M; Creason, Sharon A; Herbst, Zackary M; Gelb, Michael H; Buckner, Frederick S; Tidwell, Richard R

    2017-02-09

    A previous publication from this lab (Patrick, et al. Bioorg. Med. Chem. 2016, 24 , 2451 - 2465 ) explored the antitrypanosomal activities of novel derivatives of 2-(2-benzamido)ethyl-4-phenylthiazole (1), which had been identified as a hit against Trypanosoma brucei, the causative agent of human African trypanosomiasis. While a number of these compounds, particularly the urea analogues, were quite potent, these molecules as a whole exhibited poor metabolic stability. The present work describes the synthesis of 65 new analogues arising from medicinal chemistry optimization at different sites on the molecule. The most promising compounds were the urea derivatives of 2-aryl-benzothiazol-5-amines. One such analogue, (S)-2-(3,4-difluorophenyl)-5-(3-fluoro-N-pyrrolidylamido)benzothiazole (57) was chosen for in vivo efficacy studies based upon in vitro activity, metabolic stability, and brain penetration. This compound attained 5/5 cures in murine models of both early and late stage human African trypanosomiasis, representing a new lead for the development of drugs to combat this neglected disease.

  9. Class size versus class composition

    DEFF Research Database (Denmark)

    Jones, Sam

    Raising schooling quality in low-income countries is a pressing challenge. Substantial research has considered the impact of cutting class sizes on skills acquisition. Considerably less attention has been given to the extent to which peer effects, which refer to class composition, also may affect...... bias from omitted variables, the preferred IV results indicate considerable negative effects due to larger class sizes and larger numbers of overage-for-grade peers. The latter, driven by the highly prevalent practices of grade repetition and academic redshirting, should be considered an important...

  10. Human CD4+ T cells lyse target cells via granzyme/perforin upon circumvention of MHC class II restriction by an antibody-like immunoreceptor.

    Science.gov (United States)

    Hombach, Andreas; Köhler, Heike; Rappl, Gunter; Abken, Hinrich

    2006-10-15

    Immune elimination of tumor cells requires the close cooperation between CD8+ CTL and CD4+ Th cells. We circumvent MHC class II-restriction of CD4+ T cells by expression of a recombinant immunoreceptor with an Ab-derived binding domain redirecting specificity. Human CD4+ T cells grafted with an immunoreceptor specific for carcinoembryonic Ag (CEA) are activated to proliferate and secrete cytokines upon binding to CEA+ target cells. Notably, redirected CD4+ T cells mediate cytolysis of CEA+ tumor cells with high efficiencies. Lysis by redirected CD4+ T cells is independent of death receptor signaling via TNF-alpha or Fas, but mediated by perforin and granzyme because cytolysis is inhibited by blocking the release of cytotoxic granules, but not by blocking of Fas ligand or TNF-alpha. CD4+ T cells redirected by Ab-derived immunoreceptors in a MHC class II-independent fashion substantially extend the power of an adoptive, Ag-triggered immunotherapy not only by CD4+ T cell help, but also by cytolytic effector functions. Because cytolysis is predominantly mediated via granzyme/perforin, target cells that are resistant to death receptor signaling become sensitive to a cytolytic attack by engineered CD4+ T cells.

  11. Human Leukocyte Antigen Class II Alleles (DQB1 and DRB1 as Predictors for Response to Interferon Therapy in HCV Genotype 4

    Directory of Open Access Journals (Sweden)

    Olfat Shaker

    2013-01-01

    Full Text Available Human leukocyte antigens class II play an important role in immune response against HCV. We investigated whether HLA class II alleles influence susceptibility to HCV infection and response to interferon therapy. HLA-DRB1 and -DQB1 loci were genotyped using PCR-SSO Luminex technology. According to our regimen, 41 (66% of patients achieved sustained virological response to combined treatment of IFN and ribavirin. Frequencies of DQB1*0313 allele and DRB1*04-DRB1*11, DQB1*0204-DQB1*0313, DQB1*0309-DQB1*0313, and DQB1*0313-DQB1*0319 haplotypes were significantly more frequent in nonresponders than in responders. In contrast, DQB1*02, DQB1*06, DRB1*13, and DRB1*15 alleles were significantly more frequent in responders than in nonresponders. Similarly, DRB1*1301, DRB1*1361, and DRB1*1369 alleles and DRB1*1301-DRB1*1328, DRB1*1301-DRB1*1361, DRB1*1301-DRB1*1369, DRB1*1328-DRB1*1361, and DRB1*1328-DRB1*1369 haplotypes were significantly found only in responders. Some alleles and linkages showed significantly different distributions between patient and healthy groups. These alleles may be used as predictors for response to treatment or to susceptibility to HCV infection in the Egyptian population.

  12. Increasing human Th17 differentiation through activation of orphan nuclear receptor retinoid acid-related orphan receptor γ (RORγ) by a class of aryl amide compounds.

    Science.gov (United States)

    Zhang, Wei; Zhang, Jing; Fang, Leiping; Zhou, Ling; Wang, Shuai; Xiang, Zhijun; Li, Yuan; Wisely, Bruce; Zhang, Guifeng; An, Gang; Wang, Yonghui; Leung, Stewart; Zhong, Zhong

    2012-10-01

    In a screen for small-molecule inhibitors of retinoid acid-related orphan receptor γ (RORγ), we fortuitously discovered that a class of aryl amide compounds behaved as functional activators of the interleukin 17 (IL-17) reporter in Jurkat cells. Three of these compounds were selected for further analysis and found to activate the IL-17 reporter with potencies of ∼0.1 μM measured by EC₅₀. These compounds were shown to directly bind to RORγ by circular dichroism-based thermal stability experiments. Furthermore, they can enhance an in vitro Th17 differentiation process in human primary T cells. As RORγ remains an orphan nuclear receptor, discovery of these aryl amide compounds as functional agonists will now provide pharmacological tools for us to dissect functions of RORγ and facilitate drug discovery efforts for immune-modulating therapies.

  13. Enhanced Constraints on theta13 from A Three-Flavor Oscillation Analysis of Reactor Antineutrinos at KamLAND

    Energy Technology Data Exchange (ETDEWEB)

    The KamLAND Collaboration; Gando, A.; Gando, Y.; Ichimura, K.; Ikeda, H.; Inoue, K.; Kibe, Y.; Kishimoto, Y.; Koga, M.; Minekawa, Y.; Mitsui, T.; Morikawa, T.; Nagai, N.; Nakajima, K.; Nakamura, K.; Narita, K.; Shimizu, I.; Shimizu, Y.; Shirai, J.; Suekane, F.; Suzuki, A.; Takahashi, H.; Takahashi, N.; Takemoto, Y.; Tamae, K.; Watanabe, H.; Xu, B. D.; Yabumoto, H.; Yoshida, H.; Yoshida, S.; Enomoto, S.; Kozlov, A.; Murayama, H.; Grant, C.; Keefer, G.; Piepke, A.; Banks, T. I.; Bloxham, T.; Detwiler, J. A.; Freedman, S. J.; Fujikawa, B. K.; Han, K.; Kadel, R.; O' Donnell, T.; Steiner, H. M.; Dwyer, D. A.; McKeown, R. D.; Zhang, C.; Berger, B. E.; Lane, C. E.; Maricic, J.; Miletic, T.; Batygov, M.; Learned, J. G.; Matsuno, S.; Sakai, M.; Horton-Smith, G. A.; Downum, K. E.; Gratta, G.; Efremenko, Y.; Perevozchikov, O.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Heeger, K. M.; Decowski, M. P.

    2010-09-24

    We present new constraints on the neutrino oscillation parameters {Delta}m{sub 21}{sup 2}, {theta}{sub 12}, and {theta}{sub 13} from a three-flavor analysis of solar and KamLAND data. The KamLAND data set includes data acquired following a radiopurity upgrade and amounts to a total exposure of 3.49 x 10{sup 32} target-proton-year. Under the assumption of CPT invariance, a two-flavor analysis ({theta}{sub 13} = 0) of the KamLAND and solar data yields the best-fit values tan{sup 2} {theta}{sub 12} = 0.444{sub -0.030}{sup +0.036} and {Delta}m{sub 21}{sup 2} = 7.50{sub -0.20}{sup +0.19} x 10{sup -5} eV{sup 2}; a three-flavor analysis with {theta}{sub 13} as a free parameter yields the best-fit values tan{sup 2} {theta}{sub 12} = 0.452{sub -0.033}{sup +0.035}, {Delta}m{sub 21}{sup 2} = 7.50{sub -0.20}{sup +0.19} x 10{sup -5}eV{sup 2}, and sin{sup 2} {theta}{sub 13} = 0.020{sub -0.016}{sup +0.016}. This {theta}{sub 13} interval is consistent with other recent work combining the CHOOZ, atmospheric and long-baseline accelerator experiments. We also present a new global {theta}{sub 13} analysis, incorporating the CHOOZ, atmospheric and accelerator data, which indicates sin{sup 2} {theta}{sub 13} = 0.017{sub -0.009}{sup +0.010}, a nonzero value at the 93% C.L. This finding will be further tested by upcoming accelerator and reactor experiments.

  14. Plasma resistivity in a slow rising current theta-pinch device

    International Nuclear Information System (INIS)

    Kayama, Milton Eiji; Dobrowolsky, Marcelo Shubert; Honda, Roberto Yzumi; Aramaki, Emilia Akemi; Algatti, Mauricio Antonio

    1998-01-01

    Anomalous behavior of plasma resistivity was observed in a Theta-pinch plasma. A comparative analysis was performed with a hybrid numerical code where the Chodura s resistivity algorithm is included. Good agreement was found in the radial plasma dynamic description. The experimental value of resistivity at null field point was found to be one order of magnitude greater than the theoretical prediction. (author)

  15. EEG theta and gamma responses to semantic violations in online sentence processing

    NARCIS (Netherlands)

    Hald, L.A.; Bastiaansen, M.C.M.; Hagoort, P.

    2006-01-01

    We explore the nature of the oscillatory dynamics in the EEG of subjects reading sentences that contain a semantic violation. More specifically, we examine whether increases in theta (≈3–7 Hz) and gamma (around 40 Hz) band power occur in response to sentences that were either semantically correct or

  16. Complementary theta resonance filtering by two spatially segregated mechanisms in CA1 hippocampal pyramidal neurons.

    Science.gov (United States)

    Hu, Hua; Vervaeke, Koen; Graham, Lyle J; Storm, Johan F

    2009-11-18

    Synaptic input to a neuron may undergo various filtering steps, both locally and during transmission to the soma. Using simultaneous whole-cell recordings from soma and apical dendrites from rat CA1 hippocampal pyramidal cells, and biophysically detailed modeling, we found two complementary resonance (bandpass) filters of subthreshold voltage signals. Both filters favor signals in the theta (3-12 Hz) frequency range, but have opposite location, direction, and voltage dependencies: (1) dendritic H-resonance, caused by h/HCN-channels, filters signals propagating from soma to dendrite when the membrane potential is close to rest; and (2) somatic M-resonance, caused by M/Kv7/KCNQ and persistent Na(+) (NaP) channels, filters signals propagating from dendrite to soma when the membrane potential approaches spike threshold. Hippocampal pyramidal cells participate in theta network oscillations during behavior, and we suggest that that these dual, polarized theta resonance mechanisms may convey voltage-dependent tuning of theta-mediated neural coding in the entorhinal/hippocampal system during locomotion, spatial navigation, memory, and sleep.

  17. Energy- and particle-confinement properties of an end-plugged, linear, theta pinch

    International Nuclear Information System (INIS)

    Commisso, R.J.; Bartsch, R.R.; Ekdahl, C.A.; McKenna, K.F.; Siemon, R.E.

    1979-01-01

    Experiments show that axial confinement of plasma in a straight theta-pinch solenoid is improved by placing solid lithium deuteride plugs at the ends. The energy confinement is increased nearly threefold in agreement with theoretical estimates which assume classical electron thermal conduction and no convective losses. The confinement of deuterium ions is explained by classical Coulomb collisions in the ablated lithium deuteride plasma

  18. Selective Entrainment of Theta Oscillations in the Dorsal Stream Causally Enhances Auditory Working Memory Performance.

    Science.gov (United States)

    Albouy, Philippe; Weiss, Aurélien; Baillet, Sylvain; Zatorre, Robert J

    2017-04-05

    The implication of the dorsal stream in manipulating auditory information in working memory has been recently established. However, the oscillatory dynamics within this network and its causal relationship with behavior remain undefined. Using simultaneous MEG/EEG, we show that theta oscillations in the dorsal stream predict participants' manipulation abilities during memory retention in a task requiring the comparison of two patterns differing in temporal order. We investigated the causal relationship between brain oscillations and behavior by applying theta-rhythmic TMS combined with EEG over the MEG-identified target (left intraparietal sulcus) during the silent interval between the two stimuli. Rhythmic TMS entrained theta oscillation and boosted participants' accuracy. TMS-induced oscillatory entrainment scaled with behavioral enhancement, and both gains varied with participants' baseline abilities. These effects were not seen for a melody-comparison control task and were not observed for arrhythmic TMS. These data establish theta activity in the dorsal stream as causally related to memory manipulation. VIDEO ABSTRACT. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. White paper report on using nuclear reactors to search for a value of theta13

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, K.; Anjos, J.C.; Ayres, D.; Beacom, J.; Bediaga, I.; de Bellefon, A.; Berger, B.E.; Bilenky, S.; Blucher, E.; Bolton, T.; Buck, C.; Bugg, W.; Busenitz, J.; Choubey, S.; Conrad, J.; Cribier, M.; Dadoun, O.; Dalnoki-Veress, F.; Decowski, M.; de Gouvea, Andre; Demutrh, D.; Dessages-Ardellier, F.; Efremenko, Y.; von Feilitzsch, F.; Finley, D.; Formaggio, J.A.; Freedman, S.J.; Fujikawa, B.K.; Garbini, M.; Giusti, P.; Goger-Neff, M.; Goodman, M.; Gray, F.; Grieb, C.; Grudzinski, J.J.; Guarino, V.J.; Hartmann, F.; Hagner, C.; Heeger, K.M.; Hofmann, W.; Horton-Smith, G.; Huber, P.; Inzhechik, L.; Jochum, J.; Jostlein, H.; Kadel, R.; Kamyshkov, Y.; Kaplan, D.; Kasper, P.; de Kerret, H.; Kersten, J.; Klein, J.; Knopfle, K.T.; Kopeikin, V.; Kozlov, Yu.; Kryn, D.; Kuchler, V.; Kuze, M.; Lachenmaier, T.; Lasserre, T.; Laughton, C.; Lendvai, C.; Li, J.; Lindner, M.; Link, J.; Longo, M.; Lu, Y.S.; Luk, K.B.; Ma, Y.Q.; Martemyanov, V.P.; Mauger, C.; Manghetti, H.; McKeown, R.; Mention, G.; Meyer, J.P.; Mikaelyan, L.; Minakata, H.; Naples, D.; Nunokawa, H.; Oberauer, L.; Obolensky, M.; Parke, S.; Petcov, S.T.; Peres, O.L.G.; Potzel, W.; Pilcher, J.; Plunkett, R.; Raffelt, G.; Rapidis, P.; Reyna, D.; Roe, B.; Rolinec, M.; Sakamoto, Y.; Sartorelli, G.; Schonert, S.; Schwertz, T.; Selvi, M.; Shaevitz, M.; Shellard, R.; Shrock, R.; Sidwell, R.; Sims, J.; Sinev, V.; Stanton, N.; Stancu, I.; Stefanski, R.; Seukane, F.; Sugiyama, H.; Sukhotin, S.; Sumiyoshi, T.; Svoboda, R.; Talaga, R.; Tamura, N.; Tanimoto, M.; Thron, J.; von Toerne, E.; Vignaud, D.; Wagner, C.; Wang, Y.F.; Wang, Z.; Winter, W.; Wong, H.; Yakushev, E.; Yang, C.G.; Yasuda, O.

    2004-02-26

    There has been superb progress in understanding the neutrino sector of elementary particle physics in the past few years. It is now widely recognized that the possibility exists for a rich program of measuring CP violation and matter effects in future accelerator {nu} experiments, which has led to intense efforts to consider new programs at neutrino superbeams, off-axis detectors, neutrino factories and beta beams. However, the possibility of measuring CP violation can be fulfilled only if the value of the neutrino mixing parameter {theta}{sub 13} is such that sin{sup 2} (2{theta}{sub 13}) greater than or equal to on the order of 0.01. The authors of this white paper are an International Working Group of physicists who believe that a timely new experiment at a nuclear reactor sensitive to the neutrino mixing parameter {theta}{sub 13} in this range has a great opportunity for an exciting discovery, a non-zero value to {theta}{sub 13}. This would be a compelling next step of this program. We are studying possible new reactor experiments at a variety of sites around the world, and we have collaborated to prepare this document to advocate this idea and describe some of the issues that are involved.

  20. High precision measurement of sin2theta/sub W/ in semi-leptonic neutrino interactions

    International Nuclear Information System (INIS)

    Guyot, C.

    1985-01-01

    The experiment has provided what is presently the most accurate measurement of sin 2 theta/sub W/. The errors are still too large for a significant test of the standard model and the measured value is in agreement with the measured values of M/sub W/ and M/sub Z/. On the other hand, this result can constrain the Grand Unified models. The standard SU(5) model predicts sin 2 theta/sub W//sup MS/ = 0.214 +/- 0.004 (the error comes from the uncertainty on Lambda/sub MS/), in very good agreement with the measured value. While this model has big problems with the proton lifetime, it could be saved by its supersymmetric extension. In the minimal SU(5) SUSY model (with 2 Higgs supermultiplets) sin 2 theta/sub W//sup MS/ = 0.233 +/- 0.004, [12] in bad agreement with the measured value. The addition of other Higgs supermultiplets increases the value of sin 2 theta/sub W/. Unless some unexpected large contribution from higher-twist terms occurs, the present measurement can already bring a significant constraint on Grand Unified models

  1. A spectroscopic study of radiation produced in a theta-pinch

    International Nuclear Information System (INIS)

    Trigueiros, A.; Machida, M.; Pagan, C.J.B.

    1988-01-01

    Preliminary results of the analysis of the spectra of four times ionized Krypton, Kr-V, are presented. 28 transitions were classified and for five of then the classification is new. We also present the UNICAMP theta-pinch for the study of highly ionized atoms. This device is now in testing. (author) [pt

  2. Continuous theta burst demonstrates a causal role of premotor homunculus in action interpretation

    DEFF Research Database (Denmark)

    Michael, John Andrew

    2014-01-01

    Although it is well established that regions of premotor cortex (PMC) are active during action observation, it remains controversial whether they play a causal role in action understanding. In the experiment reported here, we used off-line continuous theta-burst stimulation (cTBS) to investigate ...

  3. Engineering and physics considerations for a linear theta-pinch hybrid reactor (LTPHR)

    International Nuclear Information System (INIS)

    Krakowski, R.A.; Miller, R.L.; Hagenson, R.L.

    1976-01-01

    A fusion-fission hybrid reactor based on pulsed, high-β, linear theta-pinch magnetic confinement is considered. A preliminary design which incorporates key physics, engineering and economic considerations is presented. An extensive presentation of the system energy balance is made, and this energy balance is evaluated parametrically. The feasibility of end-loss reduction is addressed

  4. Frontal theta accounts for individual differences in the cost of conflict on decision making.

    Science.gov (United States)

    Pinner, John F L; Cavanagh, James F

    2017-10-01

    Cognitive conflict is often experienced as a difficult, frustrating, and aversive state. Recent studies have indicated that conflict acts as an implicit cost during learning, valuation, and the instantiation of cognitive control. Here we investigated if an implicit manipulation of conflict also influences explicit decision making to risk. Participants were required to perform a Balloon Analogue Risk Task wherein the virtual balloon was inflated by performing a flankers task. By varying the percent of incongruent flanker trials between balloons, we hypothesized that participants would pump the balloon fewer times in conditions of higher conflict and that frontal midline theta would account for significant variance in this relationship. Across two studies, we demonstrate that conflict did not elicit reliable behavioral changes in this task across participants. However, individual differences in frontal theta power accounted for significant variance by predicting diminished balloon pumps. Thus, while conflict costs may act as investments to some individuals (invigorating behavior), it is aversive to others (diminishing behavior), and frontal midline theta power accounts for these varying behavioral tendencies between individuals. These findings demonstrate how frontal midline theta is not only a candidate mechanism for implementing cognitive control, but it is sensitive to the inherent costs therein. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Plasma behaviors in the open field region of reversed-field theta-pinch

    International Nuclear Information System (INIS)

    Aso, Yoshiyuki; Hirano, Keiichi.

    1983-03-01

    A characteristic behavior of the plasma in an open field region of reversed field theta pinch has been studied with the guide field (GF) which extends the field line along the axial direction. The experimental result suggests that the rotaional instability may be induced in FRC after the plasma touches the wall at the ends of the open field. (author)

  6. Theta-paced flickering between place-cell maps in the hippocampus

    Czech Academy of Sciences Publication Activity Database

    Ježek, Karel; Henriksen, E. J.; Treves, A.; Moser, E. I.; Moser, M.B.

    2011-01-01

    Roč. 478, č. 7368 (2011), s. 246-249 ISSN 0028-0836 R&D Projects: GA MŠk(CZ) LC554; GA MŠk(CZ) 1M0517 Institutional research plan: CEZ:AV0Z50110509 Keywords : memory * theta * hippocampus * place cells * teleportation Subject RIV: FH - Neurology Impact factor: 36.280, year: 2011

  7. (No) Time for control: Frontal theta dynamics reveal the cost of temporally guided conflict anticipation

    NARCIS (Netherlands)

    van Driel, J.; Swart, J.C.; Egner, T.; Ridderinkhof, K.R.; Cohen, M.

    2015-01-01

    During situations of response conflict, cognitive control is characterized by prefrontal theta-band (3- to 8-Hz) activity. It has been shown that cognitive control can be triggered proactively by contextual cues that predict conflict. Here, we investigated whether a pretrial preparation interval

  8. (No) time for control: frontal theta dynamics reveal the cost of temporally guided conflict anticipation

    NARCIS (Netherlands)

    van Driel, J.; Swart, J.C.; Egner, T.; Ridderinkhof, K.R.; Cohen, M.X.

    2015-01-01

    During situations of response conflict, cognitive control is characterized by prefrontal theta-band (3- to 8-Hz) activity. It has been shown that cognitive control can be triggered proactively by contextual cues that predict conflict. Here, we investigated whether a pretrial preparation interval

  9. Frontal theta and beta synchronizations for monetary reward increase visual working memory capacity.

    Science.gov (United States)

    Kawasaki, Masahiro; Yamaguchi, Yoko

    2013-06-01

    Visual working memory (VWM) capacity is affected by motivational influences; however, little is known about how reward-related brain activities facilitate the VWM systems. To investigate the dynamic relationship between VWM- and reward-related brain activities, we conducted time-frequency analyses using electroencephalograph (EEG) data obtained during a monetary-incentive delayed-response task that required participants to memorize the position of colored disks. In case of a correct answer, participants received a monetary reward (0, 10 or 50 Japanese yen) announced at the beginning of each trial. Behavioral results showed that VWM capacity under high-reward condition significantly increased compared with that under low- or no-reward condition. EEG results showed that frontal theta (6 Hz) amplitudes enhanced during delay periods and positively correlated with VWM capacity, indicating involvement of theta local synchronizations in VWM. Moreover, frontal beta activities (24 Hz) were identified as reward-related activities, because delay-period amplitudes correlated with increases in VWM capacity between high-reward and no-reward conditions. Interestingly, cross-frequency couplings between frontal theta and beta phases were observed only under high-reward conditions. These findings suggest that the functional dynamic linking between VWM-related theta and reward-related beta activities on the frontal regions plays an integral role in facilitating increases in VWM capacity.

  10. Operating point considerations for the Reference Theta-Pinch Reactor (RTPR)

    International Nuclear Information System (INIS)

    Krakowski, R.A.; Miller, R.L.; Hagenson, R.L.

    1976-01-01

    Aspects of the continuing engineering design-point reassessment and optimization of the Reference Theta-Pinch Reactor (RTPR) are discussed. An updated interim design point which achieves a favorable energy balance and involves relaxed technological requirements, which nonetheless satisfy more rigorous physics and engineering constraints, is presented

  11. Measuring $\\theta_{13}$ via Muon Neutrino to Electron Neutrino Oscillations in the MINOS Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Toner, Ruth B. [Univ. of Cambridge (United Kingdom). Pembroke College

    2011-01-01

    One of the primary goals in neutrino physics at the present moment is to make a measurement of the neutrino oscillation parameter $\\theta_{13}$. This parameter, in addition to being unknown, could potentially allow for the introduction of CP violation into the lepton sector. The MINOS long-baseline neutrino oscillation experiment has the ability to make a measurement of this parameter, by looking for the oscillation of muon neutrinos to electron neutrinos between a Near and Far Detector over a distance of 735 km. This thesis discusses the development of an analysis framework to search for this oscillation mode. Two major improvements to pre-existing analysis techniques have been implemented by the author. First, a novel particle ID technique based on strip topology, known as the Library Event Matching (LEM) method, is optimized for use in MINOS. Second, a multiple bin likelihood method is developed to fit the data. These two improvements, when combined, increase MINOS' sensitivity to $\\sin^2(2\\theta_{13})$ by 27\\% over previous analyses. This thesis sees a small excess over background in the Far Detector. A Frequentist interpretation of the data rules out $\\theta_{13}=0$ at 91\\%. A Bayesian interpretation of the data is also presented, placing the most stringent upper boundary on the oscillation parameter to date, at $\\sin^2(2\\theta_{13})<0.09(0.015)$ for the Normal (Inverted) Hierarchy and $\\delta_{CP}=0$.

  12. Effective pathfinding for four-wheeled robot based on combining Theta* and hybrid A* algorithms

    Directory of Open Access Journals (Sweden)

    Віталій Геннадійович Михалько

    2016-07-01

    Full Text Available Effective pathfinding algorithm based on Theta* and Hybrid A* algorithms was developed for four-wheeled robot. Pseudocode for algorithm was showed and explained. Algorithm and simulator for four-wheeled robot were implemented using Java programming language. Algorithm was tested on U-obstacles, complex maps and for parking problem

  13. Seasonal variation of Sigma sub(Theta) with wind speed, direction and stability

    Digital Repository Service at National Institute of Oceanography (India)

    Sadhuram, Y.

    For an airport site near Visakhapatnam, India, and based on 10 years of data for the months of January, April, August and October, values of Sigma sub(Theta) are given as a function of wind speed, wind direction and Pasquill diffusion category...

  14. Alcohol Hits You When It Is Hard: Intoxication, Task Difficulty, and Theta Brain Oscillations.

    Science.gov (United States)

    Rosen, Burke Q; Padovan, Nevena; Marinkovic, Ksenija

    2016-04-01

    Alcohol intoxication is known to impair decision making in a variety of situations. Previous neuroimaging evidence suggests that the neurofunctional system subserving controlled processing is especially vulnerable to alcohol in conflict-evoking tasks. The present study investigated the effects of moderate alcohol intoxication on the spatiotemporal neural dynamics of event-related total theta (4 to 7 Hz) power as a function of task difficulty. Two variants of the Simon task manipulated incongruity via simple spatial stimulus-response mismatch and, in a more difficult version, by combining spatial and semantic interference. Healthy social drinkers participated in both alcohol (0.6 g/kg ethanol for men, 0.55 g/kg for women) and placebo conditions in a counterbalanced design. Whole-head magnetoencephalography (MEG) signals were acquired and event-related total theta power was calculated on each trial with Morlet wavelets. MEG sources were estimated using anatomically constrained, noise-normalized, spectral dynamic statistical parametric mapping. Longer reaction times and lower accuracy confirmed the difficulty manipulation. Response conflict (incongruity) increased and alcohol intoxication decreased event-related theta power overall during both tasks bilaterally in the medial and ventrolateral prefrontal cortices. However, alcohol-induced theta suppression was selective for conflict only in the more difficult task which engaged the dorsal anterior cingulate (dAC) and anterior inferolateral prefrontal cortices. Theta power correlated negatively with drinking levels and disinhibition, suggesting that cognitive control is susceptible in more impulsive individuals with higher alcohol intake. The spatiotemporal theta profile across the 2 tasks supports the concept of a rostrocaudal activity gradient in the medial prefrontal cortex that is modulated by task difficulty, with the dAC as the key node in the network subserving cognitive control. Conflict-related theta power was

  15. Creep curve modeling of hastelloy-X alloy by using the theta projection method

    International Nuclear Information System (INIS)

    Woo Gon, Kim; Woo-Seog, Ryu; Jong-Hwa, Chang; Song-Nan, Yin

    2007-01-01

    To model the creep curves of the Hastelloy-X alloy which is being considered as a candidate material for the VHTR (Very High Temperature gas-cooled Reactor) components, full creep curves were obtained by constant-load creep tests for different stress levels at 950 C degrees. Using the experimental creep data, the creep curves were modeled by applying the Theta projection method. A number of computing processes of a nonlinear least square fitting (NLSF) analysis was carried out to establish the suitably of the four Theta parameters. The results showed that the Θ 1 and Θ 2 parameters could not be optimized well with a large error during the fitting of the full creep curves. On the other hand, the Θ 3 and Θ 4 parameters were optimized well without an error. For this result, to find a suitable cutoff strain criterion, the NLSF analysis was performed with various cutoff strains for all the creep curves. An optimum cutoff strain range for defining the four Theta parameters accurately was found to be a 3% cutoff strain. At the 3% cutoff strain, the predicted curves coincided well with the experimental ones. The variation of the four Theta parameters as the function of a stress showed a good linearity, and the creep curves were modeled well for the low stress levels. Predicted minimum creep rate showed a good agreement with the experimental data. Also, for a design usage of the Hastelloy-X alloy, the plot of the log stress versus log the time to a 1% strain was predicted, and the creep rate curves with time and a cutoff strain at 950 C degrees were constructed numerically for a wide rang of stresses by using the Theta projection method. (authors)

  16. Oscillatory theta activity during memory formation and its impact on overnight consolidation: a missing link?

    Science.gov (United States)

    Heib, Dominik P J; Hoedlmoser, Kerstin; Anderer, Peter; Gruber, Georg; Zeitlhofer, Josef; Schabus, Manuel

    2015-08-01

    Sleep has been shown to promote memory consolidation driven by certain oscillatory patterns, such as sleep spindles. However, sleep does not consolidate all newly encoded information uniformly but rather "selects" certain memories for consolidation. It is assumed that such selection depends on salience tags attached to the new memories before sleep. However, little is known about the underlying neuronal processes reflecting presleep memory tagging. The current study sought to address the question of whether event-related changes in spectral theta power (theta ERSP) during presleep memory formation could reflect memory tagging that influences subsequent consolidation during sleep. Twenty-four participants memorized 160 word pairs before sleep; in a separate laboratory visit, they performed a nonlearning control task. Memory performance was tested twice, directly before and after 8 hr of sleep. Results indicate that participants who improved their memory performance overnight displayed stronger theta ERSP during the memory task in comparison with the control task. They also displayed stronger memory task-related increases in fast sleep spindle activity. Furthermore, presleep theta activity was directly linked to fast sleep spindle activity, indicating that processes during memory formation might indeed reflect memory tagging that influences subsequent consolidation during sleep. Interestingly, our results further indicate that the suggested relation between sleep spindles and overnight performance change is not as direct as once believed. Rather, it appears to be mediated by processes beginning during presleep memory formation. We conclude that theta ERSP during presleep memory formation reflects cortico-hippocampal interactions that lead to a better long-term accessibility by tagging memories for sleep spindle-related reprocessing.

  17. Social Classes

    DEFF Research Database (Denmark)

    Aktor, Mikael

    2018-01-01

    . Although this social structure was ideal in nature and not equally confirmed in other genres of ancient and medieval literature, it has nevertheless had an immense impact on Indian society. The chapter presents an overview of the system with its three privileged classes, the Brahmins, the Kṣatriyas......The notions of class (varṇa) and caste (jāti) run through the dharmaśāstra literature (i.e. Hindu Law Books) on all levels. They regulate marriage, economic transactions, work, punishment, penance, entitlement to rituals, identity markers like the sacred thread, and social interaction in general...

  18. Human leucocyte antigens class II allele and haplotype association with Type 1 Diabetes in Madeira Island (Portugal).

    Science.gov (United States)

    Spínola, H; Lemos, A; Couto, A R; Parreira, B; Soares, M; Dutra, I; Bruges-Armas, J; Brehm, A; Abreu, S

    2017-12-01

    This study confirms for Madeira Island (Portugal) population the Type 1 Diabetes (T1D) susceptible and protective Human leucocyte antigens (HLA) markers previously reported in other populations and adds some local specificities. Among the strongest T1D HLA associations, stands out, as susceptible, the alleles DRB1*04:05 (OR = 7.3), DQB1*03:02 (OR = 6.1) and DQA1*03:03 (OR = 4.5), as well as the haplotypes DRB1*04:05-DQA1*03:03-DQB1*03:02 (OR = 100.9) and DRB1*04:04-DQA1*03:01-DQB1*03:02 (OR = 22.1), and DQB1*06:02 (OR = 0.07) and DRB1*15:01-DQA1*01:02-DQB1*06:02 (OR = 0.04) as protective. HLA-DQA1 positive for Arginine at position 52 (Arg52) (OR = 15.2) and HLA-DQB1 negative for Aspartic acid at the position 57 (Asp57) (OR = 9.0) alleles appear to be important genetic markers for T1D susceptibility, with higher odds ratio values than any single allele and than most of the haplotypes. Genotypes generated by the association of markers Arg52 DQA1 positive and Asp57 DQB1 negative increase T1D susceptibility much more than one would expected by a simple additive effect of those markers separately (OR = 26.9). This study also confirms an increased risk for DRB1*04/DRB1*03 heterozygote genotypes (OR = 16.8) and also a DRB1*04-DQA1*03:01-DQB1*03:02 haplotype susceptibility dependent on the DRB1*04 allele (DRB1*04:01, OR = 7.9; DRB1*04:02, OR = 3.2; DRB1*04:04, OR = 22.1). © 2017 John Wiley & Sons Ltd.

  19. Distribution of class 1 integrons with IS26-mediated deletions in their 3'-conserved segments in Escherichia coli of human and animal origin.

    Directory of Open Access Journals (Sweden)

    Fay E Dawes

    Full Text Available Class 1 integrons play a role in the emergence of multi-resistant bacteria by facilitating the recruitment of gene cassettes encoding antibiotic resistance genes. 512 E. coli strains sourced from humans (n = 202, animals (n = 304 and the environment (n = 6 were screened for the presence of the intI1 gene. In 31/79 integron positive E. coli strains, the gene cassette regions could not be PCR amplified using standard primers. DNA sequence analysis of 6 serologically diverse strains revealed atypical integrons harboured the dfrA5 cassette gene and only 24 bp of the integron 3'-conserved segment (CS remained, due to the insertion of IS26. PCR targeting intI1 and IS26 followed by restriction fragment length polymorphism (RFLP analysis identified the integron-dfrA5-IS26 element in 27 E. coli strains of bovine origin and 4 strains of human origin. Southern hybridization and transformation studies revealed the integron-dfrA5-IS26 gene arrangement was either chromosomally located or plasmid borne. Plasmid location in 4/9 E. coli strains and PCR linkage of Tn21 transposition genes with the intI1 gene in 20/31 strains, suggests this element is readily disseminated by horizontal transfer.

  20. Inhibition of human T cell leukemia virus type 2 replication by the suppressive action of class II transactivator and nuclear factor Y.

    Science.gov (United States)

    Tosi, Giovanna; Pilotti, Elisabetta; Mortara, Lorenzo; De Lerma Barbaro, Andrea; Casoli, Claudio; Accolla, Roberto S

    2006-08-22

    The master regulator of MHC-II gene transcription, class II transactivator (CIITA), acts as a potent inhibitor of human T cell leukemia virus type 2 (HTLV-2) replication by blocking the activity of the viral Tax-2 transactivator. Here, we show that this inhibitory effect takes place at the nuclear level and maps to the N-terminal 1-321 region of CIITA, where we identified a minimal domain, from positions 64-144, that is strictly required to suppress Tax-2 function. Furthermore, we show that Tax-2 specifically cooperates with cAMP response element binding protein-binding protein (CBP) and p300, but not with p300/CBP-associated factor, to enhance transcription from the viral promoter. This finding represents a unique difference with respect to Tax-1, which uses all three coactivators to transactivate the human T cell leukemia virus type 1 LTR. Direct sequestering of CBP or p300 is not the primary mechanism by which CIITA causes suppression of Tax-2. Interestingly, we found that the transcription factor nuclear factor Y, which interacts with CIITA to increase transcription of MHC-II genes, exerts a negative regulatory action on the Tax-2-mediated HTLV-2 LTR transactivation. Thus, CIITA may inhibit Tax-2 function, at least in part, through nuclear factor Y. These findings demonstrate the dual defensive role of CIITA against pathogens: it increases the antigen-presenting function for viral determinants and suppresses HTLV-2 replication in infected cells.

  1. NetMHC-3.0: accurate web accessible predictions of human, mouse and monkey MHC class I affinities for peptides of length 8-11.

    Science.gov (United States)

    Lundegaard, Claus; Lamberth, Kasper; Harndahl, Mikkel; Buus, Søren; Lund, Ole; Nielsen, Morten

    2008-07-01

    NetMHC-3.0 is trained on a large number of quantitative peptide data using both affinity data from the Immune Epitope Database and Analysis Resource (IEDB) and elution data from SYFPEITHI. The method generates high-accuracy predictions of major histocompatibility complex (MHC): peptide binding. The predictions are based on artificial neural networks trained on data from 55 MHC alleles (43 Human and 12 non-human), and position-specific scoring matrices (PSSMs) for additional 67 HLA alleles. As only the MHC class I prediction server is available, predictions are possible for peptides of length 8-11 for all 122 alleles. artificial neural network predictions are given as actual IC(50) values whereas PSSM predictions are given as a log-odds likelihood scores. The output is optionally available as download for easy post-processing. The training method underlying the server is the best available, and has been used to predict possible MHC-binding peptides in a series of pathogen viral proteomes including SARS, Influenza and HIV, resulting in an average of 75-80% confirmed MHC binders. Here, the performance is further validated and benchmarked using a large set of newly published affinity data, non-redundant to the training set. The server is free of use and available at: http://www.cbs.dtu.dk/services/NetMHC.

  2. Birthing Classes

    Science.gov (United States)

    ... management options. Breastfeeding basics. Caring for baby at home. Birthing classes are not just for new parents, though. ... midwife. Postpartum care. Caring for your baby at home, including baby first aid. Lamaze One of the most popular birthing techniques in the U.S., Lamaze has been around ...

  3. Temporal correlation between auditory neurons and the hippocampal theta rhythm induced by novel stimulations in awake guinea pigs.

    Science.gov (United States)

    Liberman, Tamara; Velluti, Ricardo A; Pedemonte, Marisa

    2009-11-17

    The hippocampal theta rhythm is associated with the processing of sensory systems such as touch, smell, vision and hearing, as well as with motor activity, the modulation of autonomic processes such as cardiac rhythm, and learning and memory processes. The discovery of temporal correlation (phase locking) between the theta rhythm and both visual and auditory neuronal activity has led us to postulate the participation of such rhythm in the temporal processing of sensory information. In addition, changes in attention can modify both the theta rhythm and the auditory and visual sensory activity. The present report tested the hypothesis that the temporal correlation between auditory neuronal discharges in the inferior colliculus central nucleus (ICc) and the hippocampal theta rhythm could be enhanced by changes in sensory stimulation. We presented chronically implanted guinea pigs with auditory stimuli that varied over time, and recorded the auditory response during wakefulness. It was observed that the stimulation shifts were capable of producing the temporal phase correlations between the theta rhythm and the ICc unit firing, and they differed depending on the stimulus change performed. Such correlations disappeared approximately 6 s after the change presentation. Furthermore, the power of the hippocampal theta rhythm increased in half of the cases presented with a stimulation change. Based on these data, we propose that the degree of correlation between the unitary activity and the hippocampal theta rhythm varies with--and therefore may signal--stimulus novelty.

  4. Computational study of hippocampal-septal theta rhythm changes due to β-amyloid-altered ionic channels.

    Directory of Open Access Journals (Sweden)

    Xin Zou

    Full Text Available Electroencephagraphy (EEG of many dementia patients has been characterized by an increase in low frequency field potential oscillations. One of the characteristics of early stage Alzheimer's disease (AD is an increase in theta band power (4-7 Hz. However, the mechanism(s underlying the changes in theta oscillations are still unclear. To address this issue, we investigate the theta band power changes associated with β-Amyloid (Aβ peptide (one of the main markers of AD using a computational model, and by mediating the toxicity of hippocampal pyramidal neurons. We use an established biophysical hippocampal CA1-medial septum network model to evaluate four ionic channels in pyramidal neurons, which were demonstrated to be affected by Aβ. They are the L-type Ca²⁺ channel, delayed rectifying K⁺ channel, A-type fast-inactivating K⁺ channel and large-conductance Ca²⁺-activated K⁺ channel. Our simulation results demonstrate that only the Aβ inhibited A-type fast-inactivating K⁺ channel can induce an increase in hippocampo-septal theta band power, while the other channels do not affect theta rhythm. We further deduce that this increased theta band power is due to enhanced synchrony of the pyramidal neurons. Our research may elucidate potential biomarkers and therapeutics for AD. Further investigation will be helpful for better understanding of AD-induced theta rhythm abnormalities and associated cognitive deficits.

  5. Impact of economic development on quality of life and human happiness: a study on urban socio economic classes of suburban Mumbai

    Directory of Open Access Journals (Sweden)

    Debjani Banerjee

    2016-11-01

    Full Text Available This paper emphasizes that for a nation to revitalize in terms of development, not only does it need to evaluate in terms of GDP growth rate, but also has to consider the Quality of Life of its citizen and their human happiness. There is strong correlation between macro-economic development parameters like health, education, GDP growth rate and Quality of Life Index, expressed through HDI. It also has correlation with subjective quality of life based on the perception of urban socio economic classes, as measured in this study. The subjective quality of life is studied through five parameters like Quality of house, education, health care, transportation and recreation facilities. Human happiness is evaluated through the perception of respondents towards change in their financial conditions and consumption expenditure influencing their quality of life. This empirical research through spearman’s rank correlation tried to establish the relationship between macro-economic indicators with the quality of life parameters as perceived by people. The study was conducted in Mumbai, and its suburban areas .with a sample of 850 respondents taken through structured questionnaire, during 2012-13. It was observed from A. T. Kearney’s GRDI report that India was ranking between first five positions, consistently in terms of Modern Trade Retail Business since 2000. The managerial implication of the study highlights the association of quantitative economic development with larger aspect of human development, for the policy makers to understand the various areas which needs to be taken care to cater towards revitalizing the development of the nation

  6. Theta oscillations during holeboard training in rats: different learning strategies entail different context-dependent modulations in the hippocampus.

    Science.gov (United States)

    Woldeit, M L; Korz, V

    2010-02-03

    A functional connection between theta rhythms, information processing, learning and memory formation is well documented by studies focusing on the impact of theta waves on motor activity, global context or phase coding in spatial learning. In the present study we analyzed theta oscillations during a spatial learning task and assessed which specific behavioral contexts were connected to changes in theta power and to the formation of memory. Therefore, we measured hippocampal dentate gyrus theta modulations in male rats that were allowed to establish a long-term spatial reference memory in a holeboard (fixed pattern of baited holes) in comparison to rats that underwent similar training conditions but could not form a reference memory (randomly baited holes). The first group established a pattern specific learning strategy, while the second developed an arbitrary search strategy, visiting increasingly more holes during training. Theta power was equally influenced during the training course in both groups, but was significantly higher when compared to untrained controls. A detailed behavioral analysis, however, revealed behavior- and context-specific differences within the experimental groups. In spatially trained animals theta power correlated with the amounts of reference memory errors in the context of the inspection of unbaited holes and exploration in which, as suggested by time frequency analyses, also slow wave (delta) power was increased. In contrast, in randomly trained animals positive correlations with working memory errors were found in the context of rearing behavior. These findings indicate a contribution of theta/delta to long-lasting memory formation in spatially trained animals, whereas in pseudo trained animals theta seems to be related to attention in order to establish trial specific short-term working memory. Implications for differences in neuronal plasticity found in earlier studies are discussed. Copyright 2010 IBRO. Published by Elsevier Ltd

  7. Why don't you like me? Midfrontal theta power in response to unexpected peer rejection feedback.

    Science.gov (United States)

    van der Molen, M J W; Dekkers, L M S; Westenberg, P M; van der Veen, F M; van der Molen, M W

    2017-02-01

    Social connectedness theory posits that the brain processes social rejection as a threat to survival. Recent electrophysiological evidence suggests that midfrontal theta (4-8Hz) oscillations in the EEG provide a window on the processing of social rejection. Here we examined midfrontal theta dynamics (power and inter-trial phase synchrony) during the processing of social evaluative feedback. We employed the Social Judgment paradigm in which 56 undergraduate women (mean age=19.67 years) were asked to communicate their expectancies about being liked vs. disliked by unknown peers. Expectancies were followed by feedback indicating social acceptance vs. rejection. Results revealed a significant increase in EEG theta power to unexpected social rejection feedback. This EEG theta response could be source-localized to brain regions typically reported during activation of the saliency network (i.e., dorsal anterior cingulate cortex, insula, inferior frontal gyrus, frontal pole, and the supplementary motor area). Theta phase dynamics mimicked the behavior of the time-domain averaged feedback-related negativity (FRN) by showing stronger phase synchrony for feedback that was unexpected vs. expected. Theta phase, however, differed from the FRN by also displaying stronger phase synchrony in response to rejection vs. acceptance feedback. Together, this study highlights distinct roles for midfrontal theta power and phase synchrony in response to social evaluative feedback. Our findings contribute to the literature by showing that midfrontal theta oscillatory power is sensitive to social rejection but only when peer rejection is unexpected, and this theta response is governed by a widely distributed neural network implicated in saliency detection and conflict monitoring. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Study of CP(N-1) theta-vacua by cluster simulation of SU(N) quantum spin ladders.

    Science.gov (United States)

    Beard, B B; Pepe, M; Riederer, S; Wiese, U-J

    2005-01-14

    D-theory provides an alternative lattice regularization of the 2D CP(N-1) quantum field theory in which continuous classical fields emerge from the dimensional reduction of discrete SU(N) quantum spins. Spin ladders consisting of n transversely coupled spin chains lead to a CP(N-1) model with a vacuum angle theta=npi. In D-theory no sign problem arises and an efficient cluster algorithm is used to investigate theta-vacuum effects. At theta=pi there is a first order phase transition with spontaneous breaking of charge conjugation symmetry for CP(N-1) models with N>2.

  9. Coding Class

    DEFF Research Database (Denmark)

    Ejsing-Duun, Stine; Hansbøl, Mikala

    Denne rapport rummer evaluering og dokumentation af Coding Class projektet1. Coding Class projektet blev igangsat i skoleåret 2016/2017 af IT-Branchen i samarbejde med en række medlemsvirksomheder, Københavns kommune, Vejle Kommune, Styrelsen for IT- og Læring (STIL) og den frivillige forening...... Coding Pirates2. Rapporten er forfattet af Docent i digitale læringsressourcer og forskningskoordinator for forsknings- og udviklingsmiljøet Digitalisering i Skolen (DiS), Mikala Hansbøl, fra Institut for Skole og Læring ved Professionshøjskolen Metropol; og Lektor i læringsteknologi, interaktionsdesign......, design tænkning og design-pædagogik, Stine Ejsing-Duun fra Forskningslab: It og Læringsdesign (ILD-LAB) ved Institut for kommunikation og psykologi, Aalborg Universitet i København. Vi har fulgt og gennemført evaluering og dokumentation af Coding Class projektet i perioden november 2016 til maj 2017...

  10. NetMHCIIpan-3.0, a common pan-specific MHC class II prediction method including all three human MHC class II isotypes, HLA-DR, HLA-DP and HLA-DQ

    DEFF Research Database (Denmark)

    Karosiene, Edita; Rasmussen, Michael; Blicher, Thomas

    2013-01-01

    Major histocompatibility complex class II (MHCII) molecules play an important role in cell-mediated immunity. They present specific peptides derived from endosomal proteins for recognition by T helper cells. The identification of peptides that bind to MHCII molecules is therefore of great importa......MHCIIpan-3.0 method is the first pan-specific predictor covering all HLA class II molecules with known sequences including HLA-DR, HLA-DP, and HLA-DQ. The NetMHCpan-3.0 method is available at http://www.cbs.dtu.dk/services/NetMHCIIpan-3.0....

  11. Persistent hyperdopaminergia decreases the peak frequency of hippocampal theta oscillations during quiet waking and REM sleep.

    Directory of Open Access Journals (Sweden)

    Kafui Dzirasa

    Full Text Available Long-term changes in dopaminergic signaling are thought to underlie the pathophysiology of a number of psychiatric disorders. Several conditions are associated with cognitive deficits such as disturbances in attention processes and learning and memory, suggesting that persistent changes in dopaminergic signaling may alter neural mechanisms underlying these processes. Dopamine transporter knockout (DAT-KO mice exhibit a persistent five-fold increase in extracellular dopamine levels. Here, we demonstrate that DAT-KO mice display lower hippocampal theta oscillation frequencies during baseline periods of waking and rapid-eye movement sleep. These altered theta oscillations are not reversed via treatment with the antidopaminergic agent haloperidol. Thus, we propose that persistent hyperdopaminergia, together with secondary alterations in other neuromodulatory systems, results in lower frequency activity in neural systems responsible for various cognitive processes.

  12. Search for the Theta+ pentaquark in the gamma d -> Lambda n K+ reaction measured with CLAS

    Energy Technology Data Exchange (ETDEWEB)

    Silvia Niccolai; Marco Mirazita; Patrizia Rossi; Nathan Baltzell; Daniel Carman; Kenneth Hicks; Bryan McKinnon; Tsutomu Mibe; Stepan Stepanyan; David Tedeschi; Gary Adams; Pawel Ambrozewicz; Sergio Pereira; Marco Anghinolfi; Gegham Asryan; Harutyun AVAKIAN; H. Bagdasaryan; Nathan Baillie; Jacques Ball; V. Batourine; Marco Battaglieri; Ivan Bedlinski; Ivan Bedlinskiy; Ivan Bedlinski; Ivan Bedlinskiy; Mehmet Bektasoglu; Matthew Bellis; Nawal Benmouna; Barry Berman; Angela Biselli; Sergey Boyarinov; Sylvain Bouchigny; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; S.L. Careccia; Bryan Carnahan; Shifeng Chen; Philip Cole; Patrick Collins; Philip Coltharp; Donald Crabb; Hall Crannell; V. Crede; John Cummings; Natalya Dashyan; Pavel Degtiarenko; Rita De Masi; Airton Deppman; Enzo De Sanctis; Alexandre Deur; Raffaella De Vita; Kahanawita Dharmawardane; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; L. El Fassi; Latifa Elouadrhiri; Paul Eugenio; Gleb Fedotov; Gerald Feldman; Herbert Funsten; Michel Garcon; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; John Goetz; Atilla Gonenc; Christopher Gordon; Ralf Gothe; Keith Griffioen; Michel Guidal; Nevzat Guler; Lei Guo; Vardan Gyurjyan; Cynthia Hadjidakis; Kawtar Hafidi; Hayk Hakobyan; Rafael Hakobyan; John Hardie; F. Hersman; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; David Jenkins; Hyon-Suk Jo; Kyungseon Joo; Henry Juengst; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Andreas Klein; Franz Klein; Alexei Klimenko; Mikhail Kossov; Laird Kramer; V. Kubarovsky; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Jeff Lachniet; Jorn Langheinrich; David Lawrence; Tsung-shung Lee; Kenneth Livingston; H. Lu; Marion MacCormick; Nikolai Markov; Bernhard Mecking; Jonathan Mellor; Joseph Melone; Mac Mestayer; Curtis Meyer; Konstantin Mikhaylov; Ralph Minehart; Rory Miskimen; Viktor Mokeev; Ludyvine Morand; Steven Morrow; Maryam Moteabbed; Gordon Mutchler; Pawel Nadel-Turonski; James Napolitano; Rakhsha Nasseripour; Gabriel Niculescu; Maria-Ioana Niculescu; Bogdan Niczyporuk; Megh Niroula; Rustam Niyazov; Mina Nozar; Jorge De Olivei Echeimberg; Mikhail Osipenko; Alexander Ostrovidov; K. Park; Evgueni Pasyuk; Craig Paterson; Joshua Pierce; Nikolay Pivnyuk; Dinko Pocanic; Oleg Pogorelko; Sergey Pozdnyakov; Barry Preedom; John Price; Yelena Prok; Dan Protopopescu; Brian Raue; Gregory Riccardi; Giovanni Ricco; Marco Ripani; Barry Ritchie; Federico Ronchetti; Guenther Rosner; Franck Sabatie; Carlos Salgado; Joseph Santoro; Vladimir Sapunenko; Reinhard Schumacher; Vladimir Serov; Youri Sharabian; Nikolay Shvedunov; Elton Smith; Lee Smith; Daniel Sober; Aleksey Stavinskiy; Stepan Stepanyan; Burnham Stokes; Paul Stoler; Igor Strakovski; Steffen Strauch; Mauro Taiuti; Ulrike Thoma; Avtandil Tkabladze; Svyatoslav Tkachenko; Luminita Todor; Clarisse Tur; Maurizio Ungaro; Michael Vineyard; Alexander Vlassov; Daniel Watts; Lawrence Weinstein; Dennis Weygand; M. Williams; Elliott Wolin; Michael Wood; Amrit Yegneswaran; Lorenzo Zana; Jixie Zhang; Bo Zhao; Zhiwen Zhao

    2006-04-26

    For the first time, the reaction gamma d -> Lambda n K+ has been analyzed in order to search for the exotic pentaquark baryon Theta+(1540). The data were taken at Jefferson Lab, using the Hall-B tagged-photon beam of energy between 0.8 and 3.6 GeV and the CEBAF Large Acceptance Spectrometer (CLAS). No statistically significant structures were observed in the nK+ invariant mass distribution. The upper limit on the gamma d -> Lambda Theta+ integrated cross section has been calculated and found to be between 5 and 25 nb, depending on the production model assumed. The upper limit on the differential cross section is also reported.

  13. Search for the Theta+ pentaquark in the gamma d -> Lambda n K+ reaction measured with CLAS

    International Nuclear Information System (INIS)

    Silvia Niccolai; Marco Mirazita; Patrizia Rossi; Nathan Baltzell; Daniel Carman; Kenneth Hicks; Bryan McKinnon; Tsutomu Mibe; Stepan Stepanyan; David Tedeschi; Gary Adams; Pawel Ambrozewicz; Sergio Pereira; Marco Anghinolfi; Gegham Asryan; Harutyun AVAKIAN; H. Bagdasaryan; Nathan Baillie; Jacques Ball; V. Batourine; Marco Battaglieri; Ivan Bedlinski; Ivan Bedlinskiy; Ivan Bedlinski; Ivan Bedlinskiy; Mehmet Bektasoglu; Matthew Bellis; Nawal Benmouna; Barry Berman; Angela Biselli; Sergey Boyarinov; Sylvain Bouchigny; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; S.L. Careccia; Bryan Carnahan; Shifeng Chen; Philip Cole; Patrick Collins; Philip Coltharp; Donald Crabb; Hall Crannell; V. Crede; John Cummings; Natalya Dashyan; Pavel Degtiarenko; Rita De Masi; Airton Deppman; Enzo De Sanctis; Alexandre Deur; Raffaella De Vita; Kahanawita Dharmawardane; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; L. El Fassi; Latifa Elouadrhiri; Paul Eugenio; Gleb Fedotov; Gerald Feldman; Herbert Funsten; Michel Garcon; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; John Goetz; Atilla Gonenc; Christopher Gordon; Ralf Gothe; Keith Griffioen; Michel Guidal; Nevzat Guler; Lei Guo; Vardan Gyurjyan; Cynthia Hadjidakis; Kawtar Hafidi; Hayk Hakobyan; Rafael Hakobyan; John Hardie; F. Hersman; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; David Jenkins; Hyon-Suk Jo; Kyungseon Joo; Henry Juengst; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Andreas Klein; Franz Klein; Alexei Klimenko; Mikhail Kossov; Laird Kramer; V. Kubarovsky; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Jeff Lachniet; Jorn Langheinrich; David Lawrence; Tsung-shung Lee; Kenneth Livingston; H. Lu; Marion MacCormick; Nikolai Markov; Bernhard Mecking

    2006-01-01

    For the first time, the reaction gamma d -> Lambda n K+ has been analyzed in order to search for the exotic pentaquark baryon Theta+(1540). The data were taken at Jefferson Lab, using the Hall-B tagged-photon beam of energy between 0.8 and 3.6 GeV and the CEBAF Large Acceptance Spectrometer (CLAS). No statistically significant structures were observed in the nK+ invariant mass distribution. The upper limit on the gamma d -> Lambda Theta+ integrated cross section has been calculated and found to be between 5 and 25 nb, depending on the production model assumed. The upper limit on the differential cross section is also reported

  14. High-Field Nb3Sn Cos-theta Dipole with Stress Management

    Energy Technology Data Exchange (ETDEWEB)

    Novitski, Igor [Fermilab; Carmichael, Justin [Fermilab; Kashikhin, Vadim V. [Fermilab; Zlobin, Alexander V. [Fermilab

    2017-01-01

    Cost-effective superconducting dipole magnets with operating fields up to 16 T are being considered for the LHC en-ergy upgrade (HE-LHC) and a Future Circular Collider (FCC). To demonstrate feasibility of 15 T accelerator quality dipole mag-nets, FNAL as a part of the US-MDP is developing a single-aper-ture Nb3Sn dipole demonstrator based on a 4-layer graded cos-theta coil with 60 mm aperture and cold iron yoke. In parallel, to explore the limit of the Nb3Sn accelerator magnet technology, op-timize magnet design and performance parameters, and reduce magnet cost, magnet design studies are also being performed to push the nominal bore field to 16 T in a 60-mm aperture cos-theta dipole. Results of these studies are reported and discussed in this paper.

  15. Plasma experiments on staged theta pinch, implosion heating experiment and Scyllac feedback-sector experiment

    International Nuclear Information System (INIS)

    Bartsch, R.R.; Buchenauer, C.J.; Cantrell, E.L.

    1977-01-01

    Results of the Los Alamos theta-pinch program in three areas of investigation are summarized: 1) In the Staged Theta Pinch, results are reported on the effects of magnetic field amplitude and time history of plasma formation. 2) In the Implosion Heating Experiment, density, internal-magnetic field and neutron measurements yield a consistent picture of the implosion which agrees with kinetic computations and with a simple dynamic model of the ions and magnetic piston. 3) In the Scyllac Feedback-Sector Experiment, the l=1, 0 equilibrium plasma parameters have been adjusted to accommodate the feedback stabilization system. With a uniform toroidal discharge tube the m=1 instability is feedback-stabilized in the vertical direction, and confinement in the toroidal direction is extended by feedback control. Results with a helical discharge tube are also reported. (author)

  16. Search for {theta}(1540){sup +} in the exclusive proton-induced reaction p+C(N){yields}{theta}{sup +} anti K{sup 0}+C(N) at the energy of 70 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Antipov, Yu.M.; Artamonov, A.V.; Batarin, V.A.; Eroshin, O.V. [Inst. for High Energy Physics, Protvino (Russian Federation); Kolgamov, V.Z. [Inst. of Theoretical and Experimental Physics, Moscow (RU)] [and others

    2004-09-01

    A search for narrow {theta}(1540){sup +}, a candidate for pentaquark baryon with positive strangeness, has been performed in an exclusive proton-induced reaction p+C(N){yields}{theta}{sup +} anti K{sup 0}+C(N) on carbon nuclei or quasifree nucleons at E{sub beam}=70 GeV ({radical}(s)=11.5 GeV) studying nK{sup +}, pK{sub S}{sup 0} and pK{sub L}{sup 0} decay channels of {theta}(1540){sup +} in four different final states of the {theta}{sup +} anti K{sup 0} system. In order to assess the quality of the identification of the final states with neutron or K {sup 0} {sub L}, we reconstructed {lambda}(1520){yields}nK{sup 0}{sub S} and {phi}{yields}K{sup 0}{sub L}K{sup 0}{sub S} decays in the calibration reactions p+C(N){yields}{lambda}(1520)K{sup +}+C(N) and p+C(N){yields}p{phi}+C(N). We found no evidence for narrow pentaquark peak in any of the studied final states and decay channels. Assuming that the production characteristics of the {theta}{sup +} anti K{sup 0} system are not drastically different from those of the {lambda}(1520)K{sup +} and p{phi} systems, we established upper limits on the cross-section ratios {sigma}({theta}{sup +} anti K{sup 0})/{sigma}({lambda}(1520)K{sup +})< 0.02 and {sigma}({theta}{sup +} anti K{sup 0})/{sigma}(p{phi})< 0.15 at 90% CL and a preliminary upper limit for the forward hemisphere cross-section {sigma}({theta}{sup +} anti K{sup 0})< 30 nb/nucleon. (orig.)

  17. The theta-pinch - a versatile tool for the generation and study of high temperature plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Hintz, E. [Inst. fuer Plasmaphysik, Forschungszentrum-Juelich GmbH (Germany)

    2004-07-01

    The more general technical and physical features of theta-pinches are described. Special field of their application are high-ss plasmas. Two examples are analysed and studied in more detail: a high density plasma near thermal equilibrium and a low density plasma far from equilibrium. The latter is of special interest for future investigations. Possibilities of field-reversed configurations are pointed out. (orig.)

  18. Is the hippocampal theta rhythm related to cognition in a non-locomotor place recognition task?

    Czech Academy of Sciences Publication Activity Database

    Kelemen, Edo; Morón, I.; Fenton, André Antonio

    2005-01-01

    Roč. 15, č. 4 (2005), s. 472-479 ISSN 1050-9631 Grant - others:5th Framework Development Program(XE) QLG3-CT-1999-00192; McDonnell Foundation(US) 98-38-CNS-QUA.05; Ministerio de Ciencia y Tecnologia (ES) BS02002-01215 Institutional research plan: CEZ:AV0Z5011922 Keywords : theta rhythm * cognition * place recognition Subject RIV: FH - Neurology Impact factor: 3.781, year: 2005

  19. Semantic congruence enhances memory of episodic associations: role of theta oscillations.

    Science.gov (United States)

    Atienza, Mercedes; Crespo-Garcia, Maite; Cantero, Jose L

    2011-01-01

    Growing evidence suggests that theta oscillations play a crucial role in episodic encoding. The present study evaluates whether changes in electroencephalographic theta source dynamics mediate the positive influence of semantic congruence on incidental associative learning. Here we show that memory for episodic associations (face-location) is more accurate when studied under semantically congruent contexts. However, only participants showing RT priming effect in a conceptual priming test (priming group) also gave faster responses when recollecting source information of semantically congruent faces as compared with semantically incongruent faces. This improved episodic retrieval was positively correlated with increases in theta power during the study phase mainly in the bilateral parahippocampal gyrus, left superior temporal gyrus, and left lateral posterior parietal lobe. Reconstructed signals from the estimated sources showed higher theta power for congruent than incongruent faces and also for the priming than the nonpriming group. These results are in agreement with the attention to memory model. Besides directing top-down attention to goal-relevant semantic information during encoding, the dorsal parietal lobe may also be involved in redirecting attention to bottom-up-driven memories thanks to connections between the medial-temporal and the left ventral parietal lobe. The latter function can either facilitate or interfere with encoding of face-location associations depending on whether they are preceded by semantically congruent or incongruent contexts, respectively, because only in the former condition retrieved representations related to the cue and the face are both coherent with the person identity and are both associated with the same location.

  20. The theta-pinch - a versatile tool for the generation and study of high temperature plasmas

    International Nuclear Information System (INIS)

    Hintz, E.

    2004-01-01

    The more general technical and physical features of theta-pinches are described. Special field of their application are high-ss plasmas. Two examples are analysed and studied in more detail: a high density plasma near thermal equilibrium and a low density plasma far from equilibrium. The latter is of special interest for future investigations. Possibilities of field-reversed configurations are pointed out. (orig.)

  1. Theta frequency background tunes transmission but not summation of spiking responses.

    Directory of Open Access Journals (Sweden)

    Dhanya Parameshwaran

    Full Text Available Hippocampal neurons are known to fire as a function of frequency and phase of spontaneous network rhythms, associated with the animal's behaviour. This dependence is believed to give rise to precise rate and temporal codes. However, it is not well understood how these periodic membrane potential fluctuations affect the integration of synaptic inputs. Here we used sinusoidal current injection to the soma of CA1 pyramidal neurons in the rat brain slice to simulate background oscillations in the physiologically relevant theta and gamma frequency range. We used a detailed compartmental model to show that somatic current injection gave comparable results to more physiological synaptically driven theta rhythms incorporating excitatory input in the dendrites, and inhibitory input near the soma. We systematically varied the phase of synaptic inputs with respect to this background, and recorded changes in response and summation properties of CA1 neurons using whole-cell patch recordings. The response of the cell was dependent on both the phase of synaptic inputs and frequency of the background input. The probability of the cell spiking for a given synaptic input was up to 40% greater during the depolarized phases between 30-135 degrees of theta frequency current injection. Summation gain on the other hand, was not affected either by the background frequency or the phasic afferent inputs. This flat summation gain, coupled with the enhanced spiking probability during depolarized phases of the theta cycle, resulted in enhanced transmission of summed inputs during the same phase window of 30-135 degrees. Overall, our study suggests that although oscillations provide windows of opportunity to selectively boost transmission and EPSP size, summation of synaptic inputs remains unaffected during membrane oscillations.

  2. Multidimensional coincidence point results for generalized $(\\psi ,\\theta ,\\varphi$-contraction on ordered metric spaces

    Directory of Open Access Journals (Sweden)

    Bhavana Deshpande

    2017-11-01

    Full Text Available The main objective of this research article is to establish some coincidence point theorem for $g$-non-decreasing mappings under generalized $(\\psi ,\\theta ,\\varphi $-contraction on a partially ordered metric space. Furthermore, we show how multidimensional results can be seen as a simple consequences of our unidimensional coincidence point theorem. Our results modify, improve, sharpen, enrich and generalize various known results.

  3. Alpha and theta brain oscillations index dissociable processes in spoken word recognition.

    Science.gov (United States)

    Strauß, Antje; Kotz, Sonja A; Scharinger, Mathias; Obleser, Jonas

    2014-08-15

    Slow neural oscillations (~1-15 Hz) are thought to orchestrate the neural processes of spoken language comprehension. However, functional subdivisions within this broad range of frequencies are disputed, with most studies hypothesizing only about single frequency bands. The present study utilizes an established paradigm of spoken word recognition (lexical decision) to test the hypothesis that within the slow neural oscillatory frequency range, distinct functional signatures and cortical networks can be identified at least for theta- (~3-7 Hz) and alpha-frequencies (~8-12 Hz). Listeners performed an auditory lexical decision task on a set of items that formed a word-pseudoword continuum: ranging from (1) real words over (2) ambiguous pseudowords (deviating from real words only in one vowel; comparable to natural mispronunciations in speech) to (3) pseudowords (clearly deviating from real words by randomized syllables). By means of time-frequency analysis and spatial filtering, we observed a dissociation into distinct but simultaneous patterns of alpha power suppression and theta power enhancement. Alpha exhibited a parametric suppression as items increasingly matched real words, in line with lowered functional inhibition in a left-dominant lexical processing network for more word-like input. Simultaneously, theta power in a bilateral fronto-temporal network was selectively enhanced for ambiguous pseudowords only. Thus, enhanced alpha power can neurally 'gate' lexical integration, while enhanced theta power might index functionally more specific ambiguity-resolution processes. To this end, a joint analysis of both frequency bands provides neural evidence for parallel processes in achieving spoken word recognition. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Sustained frontal midline theta enhancements during effortful listening track working memory demands.

    Science.gov (United States)

    Wisniewski, Matthew G; Iyer, Nandini; Thompson, Eric R; Simpson, Brian D

    2017-11-27

    Recent studies demonstrate that frontal midline theta power (4-8 Hz) enhancements in the electroencephalogram (EEG) relate to effortful listening. It has been proposed that these enhancements reflect working memory demands. Here, the need to retain auditory information in working memory was manipulated in a 2-interval 2-alternative forced-choice delayed pitch discrimination task ("Which interval contained the higher pitch?"). On each trial, two square wave stimuli differing in pitch at an individual's ∼70.7% correct threshold were separated by a 3-second ISI. In a 'Roving' condition, the lowest pitch stimulus was randomly selected on each trial (uniform distribution from 840 to 1160 Hz). In a 'Fixed' condition, the lowest pitch was always 979 Hz. Critically, the 'Fixed' condition allowed one to know the correct response immediately following the first stimulus (e.g., if the first stimulus is 979 Hz, the second must be higher). In contrast, the 'Roving' condition required retention of the first tone for comparison to the second. Frontal midline theta enhancements during the ISI were only observed for the 'Roving' condition. Alpha (8-13 Hz) enhancements were apparent during the ISI, but did not differ significantly between conditions. Since conditions were matched for accuracy at threshold, results suggest that frontal midline theta enhancements will not always accompany difficult listening. Mixed results in the literature regarding frontal midline theta enhancements may be related to differences between tasks in regards to working memory demands. Alpha enhancements may reflect task general effortful listening processes. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Probability laws related to the Jacobi theta and Riemann zeta function and Brownian excursions

    OpenAIRE

    Biane, P.; Pitman, J.; Yor, M.

    1999-01-01

    This paper reviews known results which connect Riemann's integral representations of his zeta function, involving Jacobi's theta function and its derivatives, to some particular probability laws governing sums of independent exponential variables. These laws are related to one-dimensional Brownian motion and to higher dimensional Bessel processes. We present some characterizations of these probability laws, and some approximations of Riemann's zeta function which are related to these laws.

  6. Theta and Alpha Alterations in Amnestic Mild Cognitive Impairment in Semantic Go/NoGo Tasks

    Directory of Open Access Journals (Sweden)

    Lydia T. Nguyen

    2017-05-01

    Full Text Available Growing evidence suggests that cognitive control processes are impaired in amnestic mild cognitive impairment (aMCI; however the nature of these alterations needs further examination. The current study examined differences in electroencephalographic theta and alpha power related to cognitive control processes involving response execution and response inhibition in 22 individuals with aMCI and 22 age-, sex-, and education-matched cognitively normal controls. Two Go/NoGo tasks involving semantic categorization were used. In the basic categorization task, Go/NoGo responses were made based on exemplars of a single car (Go and a single dog (NoGo. In the superordinate categorization task, responses were made based on multiple exemplars of objects (Go and animals (NoGo. Behavioral data showed that the aMCI group had more false alarms during the NoGo trials compared to controls. The EEG data revealed between group differences related to response type in theta (4–7 Hz and low-frequency alpha (8–10 Hz power. In particular, the aMCI group differed from controls in theta power during the NoGo trials at frontal and parietal electrodes, and in low-frequency alpha power during Go trials at parietal electrodes. These results suggest that alterations in theta power converge with behavioral deterioration in response inhibition, whereas alterations in low-frequency alpha power appear to precede behavioral changes in response execution. Both behavioral and electrophysiological correlates combined provide a more comprehensive characterization of cognitive control deficits in aMCI.

  7. Computer simulation of a staging system for a theta-pinch reactor (RTPR)

    International Nuclear Information System (INIS)

    Crnkovich, P.G.

    1976-02-01

    To reduce excessive energy requirements for the implosion heating system of a theta-pinch reactor, two staging methods, the brute force and bucking field options, were proposed. A Marshall coil and a segmented coil were also considered. Calculations involved in coding these coil designs and staging options into a PL/I subprogram are described. A marked savings in the energy required for the IH system is realized with the bucking option and others

  8. The UNICAMP theta-pinch for spectroscopic study of plasma radiations

    International Nuclear Information System (INIS)

    Trigueiros, A.G.; Luna, F.R.T.; Holanda Cavalcanti, G. de; Mania, A.J.

    1993-01-01

    The emission spectrum of six times ionized xenon (Xe VII), has been observed in the vacuum ultraviolet (VUV) using a theta-pinch discharge. The spectrum was recorded with a 2-meter normal incidence spectrograph in the 300-2000 A region. Preliminary results allow the identification of transitions in the n=5 complex. Ten of these transitions were identified. The identifications are supported by relativistic Hartree-Fock calculations. (author)

  9. Resting-state theta band connectivity and graph analysis in generalized social anxiety disorder

    Directory of Open Access Journals (Sweden)

    Mengqi Xing

    2017-01-01

    Conclusions: Theta-dependent interconnectivity was associated with state anxiety in gSAD and an increase in information processing efficiency in gSAD (compared to controls. Results may represent enhanced baseline self-focused attention, which is consistent with cognitive models of gSAD and fMRI studies implicating emotion dysregulation and disturbances in task negative networks (e.g., default mode network in gSAD.

  10. Transient Global Amnesia Deteriorates the Network Efficiency of the Theta Band.

    Directory of Open Access Journals (Sweden)

    Young Ho Park

    Full Text Available Acute perturbation of the hippocampus, one of the connector hubs in the brain, is a key step in the pathophysiological cascade of transient global amnesia (TGA. We tested the hypothesis that network efficiency, meaning the efficiency of information exchange over a network, is impaired during the acute stage of TGA. Graph theoretical analysis was applied to resting-state EEG data collected from 21 patients with TGA. The EEG data were obtained twice, once during the acute stage ( 2 months after symptom onset of TGA. Characteristic path lengths and clustering coefficients of functional networks constructed using phase-locking values were computed and normalized as a function of the degree in the delta, theta, alpha, beta 1, beta 2 and gamma frequency bands of the EEG. We investigated whether the normalized characteristic path length (nCPL and normalized clustering coefficients (nCC differed significantly between the acute and resolved stages of TGA at each frequency band using the Wilcoxon signed-rank test. For networks where the nCPL or nCC differed significantly between the two stages, we also evaluated changes in the connections of the brain networks. During the acute stage of TGA, the nCPL of the theta band networks with mean degrees of 8, 8.5, 9 and 9.5 significantly increased (P < 0.05. During the acute stage, the lost edges for these networks were mostly found between the anterior (frontal and anterior temporal and posterior (parieto-occipital and posterior temporal brain regions, whereas newly developed edges were primarily found between the left and right frontotemporal regions. The nCC of the theta band with a mean degree of 5.5 significantly decreased during the acute stage (P < 0.05. Our results indicate that TGA deteriorates the network efficiency of the theta frequency band. This effect might be related to the desynchronization between the anterior and posterior brain areas.

  11. 2-Triazenoazaindoles: α novel class of triazenes inducing transcriptional down-regulation of EGFR and HER-2 in human pancreatic cancer cells.

    Science.gov (United States)

    Kreutzer, Jan N; Salvador, Alessia; Diana, Patrizia; Cirrincione, Girolamo; Vedaldi, Daniela; Litchfield, David W; Issinger, Olaf-Georg; Guerra, Barbara

    2012-04-01

    Pancreatic cancer is a complex malignancy arising from the accumulation of genetic and epigenetic defects in the affected cells. Standard chemotherapy for patients with advanced disease shows only modest effects and is associated with considerable toxicity. Overexpression or aberrant activation of members of the epidermal growth factor receptor tyrosine kinase family, which includes EGFR and HER-2, occurs frequently and is associated with multiple drug resistance and decreased patient survival. In this study, we have investigated the therapeutic potential of AS104, a novel compound of the triazene class, with potential inhibitory effects on EGFR. We found that treatment of cells with AS104 causes significant reduction of cell growth and metabolic activity in four human pancreatic cancer cell lines. Furthermore, we show that the AS104-mediated induction of apoptotic cell death is associated with stimulation of autophagy in a dose-dependent manner. Treatment of cells with AS104 results in significant down-regulation of EGFR and HER-2 expression and activity and subsequent inhibition of downstream signaling proteins. Quantitative RT-PCR analysis and assays with proteasome inhibitors revealed that AS104 regulates the expression of EGFR and HER-2 at the transcriptional level. These findings provide for the first time experimental evidence for efficacy of AS104 in the simultaneous transcriptional repression of EGFR and HER-2 genes and suggest that AS104 may have therapeutic potential in the treatment of pancreatic cancers that express high levels of the aforementioned receptor tyrosine kinases.

  12. 2-Triazenoazaindoles: A novel class of triazenes inducing transcriptional down-regulation of EGFR and HER-2 in human pancreatic cancer cells

    Science.gov (United States)

    KREUTZER, JAN N.; SALVADOR, ALESSIA; DIANA, PATRIZIA; CIRRINCIONE, GIROLAMO; VEDALDI, DANIELA; LITCHFIELD, DAVID W.; ISSINGER, OLAF-GEORG; GUERRA, BARBARA

    2012-01-01

    Pancreatic cancer is a complex malignancy arising from the accumulation of genetic and epigenetic defects in the affected cells. Standard chemotherapy for patients with advanced disease shows only modest effects and is associated with considerable toxicity. Overexpression or aberrant activation of members of the epidermal growth factor receptor tyrosine kinase family, which includes EGFR and HER-2, occurs frequently and is associated with multiple drug resistance and decreased patient survival. In this study, we have investigated the therapeutic potential of AS104, a novel compound of the triazene class, with potential inhibitory effects on EGFR. We found that treatment of cells with AS104 causes significant reduction of cell growth and metabolic activity in four human pancreatic cancer cell lines. Furthermore, we show that the AS104-mediated induction of apoptotic cell death is associated with stimulation of autophagy in a dose-dependent manner. Treatment of cells with AS104 results in significant down-regulation of EGFR and HER-2 expression and activity and subsequent inhibition of downstream signaling proteins. Quantitative RT-PCR analysis and assays with proteasome inhibitors revealed that AS104 regulates the expression of EGFR and HER-2 at the transcriptional level. These findings provide for the first time experimental evidence for efficacy of AS104 in the simultaneous transcriptional repression of EGFR and HER-2 genes and suggest that AS104 may have therapeutic potential in the treatment of pancreatic cancers that express high levels of the aforementioned receptor tyrosine kinases. PMID:22134789

  13. Decreased rhythmic GABAergic septal activity and memory-associated theta oscillations after hippocampal amyloid-beta pathology in the rat.

    Science.gov (United States)

    Villette, Vincent; Poindessous-Jazat, Frédérique; Simon, Axelle; Léna, Clément; Roullot, Elodie; Bellessort, Brice; Epelbaum, Jacques; Dutar, Patrick; Stéphan, Aline

    2010-08-18

    The memory deficits associated with Alzheimer's disease result to a great extent from hippocampal network dysfunction. The coordination of this network relies on theta (symbol) oscillations generated in the medial septum. Here, we investigated in rats the impact of hippocampal amyloid beta (Abeta) injections on the physiological and cognitive functions that depend on the septohippocampal system. Hippocampal Abeta injections progressively impaired behavioral performances, the associated hippocampal theta power, and theta frequency response in a visuospatial recognition test. These alterations were associated with a specific reduction in the firing of the identified rhythmic bursting GABAergic neurons responsible for the propagation of the theta rhythm to the hippocampus, but without loss of medial septal neurons. Such results indicate that hippocampal Abeta treatment leads to a specific functional depression of inhibitory projection neurons of the medial septum, resulting in the functional impairment of the temporal network.

  14. The analyzing power Asub(y)(theta) for the elastic scattering of 12 MeV neutrons from deuterons

    International Nuclear Information System (INIS)

    Tornow, W.; Lisowski, P.W.; Byrd, R.C.; Walter, R.L.

    1978-01-01

    The analyzing power Asub(y)(theta) was obtained at 10 0 intervals between 30 0 (lab) to 120 0 (lab) for 2 H(n, n) 2 H at 12.0 MeV. The polarized neutron beam employed in the measurement was obtained by using neutrons emitted at 0 0 from the polarization transfer reaction 2 H(d(pol), n(pol)) 3 He. The accuracy in the Asub(y)(theta) values that was achieved ranged from +- 0.006 to +- 0.013. Comparison of the data to Asub(y)(theta) results obtained at 12 MeV for the charge symmetric reaction 2 H(p, p) 2 H shows that the two Asub(y)(theta) distributions are equal to within the above accuracy. (Auth.)

  15. Optical Interferometric Observations of Theta1 Orionis C from NPOI and Implications for the System Orbit (Preprint)

    National Research Council Canada - National Science Library

    Patience, J; Zavala, R. T; Prato, L; Franz, O; Wasserman, L; Tycner, C; Hutter, D. J; Hummel, C. A

    2007-01-01

    With the Navy Prototype Optical Interferometer (NPOI), the binary system Theta 1 Orionis C, the most massive member of the Trapezium, was spatially resolved over a time period extending from February 2006 to March 2007...

  16. Theta Burst Transcranial Magnetic Stimulation for Auditory Verbal Hallucinations : Negative Findings From a Double-Blind-Randomized Trial

    NARCIS (Netherlands)

    Koops, Sanne; van Dellen, Edwin; Schutte, Maya J L; Nieuwdorp, Wendy; Neggers, Sebastiaan F W; Sommer, Iris E C

    BACKGROUND: Auditory verbal hallucinations (AVH) in schizophrenia are resistant to antipsychotic medication in approximately 25% of patients. Treatment with repetitive transcranial magnetic stimulation (rTMS) for refractory AVH has shown varying results. A stimulation protocol using continuous theta

  17. Theta-Gamma Coding Meets Communication-through-Coherence: Neuronal Oscillatory Multiplexing Theories Reconciled.

    Science.gov (United States)

    McLelland, Douglas; VanRullen, Rufin

    2016-10-01

    Several theories have been advanced to explain how cross-frequency coupling, the interaction of neuronal oscillations at different frequencies, could enable item multiplexing in neural systems. The communication-through-coherence theory proposes that phase-matching of gamma oscillations between areas enables selective processing of a single item at a time, and a later refinement of the theory includes a theta-frequency oscillation that provides a periodic reset of the system. Alternatively, the theta-gamma neural code theory proposes that a sequence of items is processed, one per gamma cycle, and that this sequence is repeated or updated across theta cycles. In short, both theories serve to segregate representations via the temporal domain, but differ on the number of objects concurrently represented. In this study, we set out to test whether each of these theories is actually physiologically plausible, by implementing them within a single model inspired by physiological data. Using a spiking network model of visual processing, we show that each of these theories is physiologically plausible and computationally useful. Both theories were implemented within a single network architecture, with two areas connected in a feedforward manner, and gamma oscillations generated by feedback inhibition within areas. Simply increasing the amplitude of global inhibition in the lower area, equivalent to an increase in the spatial scope of the gamma oscillation, yielded a switch from one mode to the other. Thus, these different processing modes may co-exist in the brain, enabling dynamic switching between exploratory and selective modes of attention.

  18. Theta oscillation and neuronal activity in rat hippocampus areinvolved in temporal discrimination of time in seconds

    Directory of Open Access Journals (Sweden)

    Tomoaki eNakazono

    2015-06-01

    Full Text Available The discovery of time cells revealed that the rodent hippocampus has information of time.Previous studies have suggested that a role of hippocampal time cells is to integratetemporally segregated events into a sequence using working memory with time perception.However, it is unclear that hippocampal cells contribute to time perception itself becausemost previous studies employed delayed matching-to-sample tasks that did not evaluatetime perception separately from working memory processes. Here, we investigated thefunction of the rat hippocampus in time perception using a temporal discrimination task. Inthe task, rats had to discriminate between durations of 1 and 3 sec to get a reward, andmaintaining task-related information as working memory was not required. We found thatsome hippocampal neurons showed firing rate modulation similar to that of time cells.Moreover, theta oscillation of local field potentials (LFPs showed a transient enhancementof power during time discrimination periods. However, there were little relationshipsbetween the neuronal activities and theta oscillations. These results suggest that both theindividual neuronal activities and theta oscillations of LFPs in the hippocampus have a possibility to be engaged in seconds order time perception; however, they participate in different ways.

  19. Differential effects of ongoing EEG beta and theta power on memory formation.

    Directory of Open Access Journals (Sweden)

    Sebastian Scholz

    Full Text Available Recently, elevated ongoing pre-stimulus beta power (13-17 Hz at encoding has been associated with subsequent memory formation for visual stimulus material. It is unclear whether this activity is merely specific to visual processing or whether it reflects a state facilitating general memory formation, independent of stimulus modality. To answer that question, the present study investigated the relationship between neural pre-stimulus oscillations and verbal memory formation in different sensory modalities. For that purpose, a within-subject design was employed to explore differences between successful and failed memory formation in the visual and auditory modality. Furthermore, associative memory was addressed by presenting the stimuli in combination with background images. Results revealed that similar EEG activity in the low beta frequency range (13-17 Hz is associated with subsequent memory success, independent of stimulus modality. Elevated power prior to stimulus onset differentiated successful from failed memory formation. In contrast, differential effects between modalities were found in the theta band (3-7 Hz, with an increased oscillatory activity before the onset of later remembered visually presented words. In addition, pre-stimulus theta power dissociated between successful and failed encoding of associated context, independent of the stimulus modality of the item itself. We therefore suggest that increased ongoing low beta activity reflects a memory promoting state, which is likely to be moderated by modality-independent attentional or inhibitory processes, whereas high ongoing theta power is suggested as an indicator of the enhanced binding of incoming interlinked information.

  20. Differential effects of ongoing EEG beta and theta power on memory formation.

    Science.gov (United States)

    Scholz, Sebastian; Schneider, Signe Luisa; Rose, Michael

    2017-01-01

    Recently, elevated ongoing pre-stimulus beta power (13-17 Hz) at encoding has been associated with subsequent memory formation for visual stimulus material. It is unclear whether this activity is merely specific to visual processing or whether it reflects a state facilitating general memory formation, independent of stimulus modality. To answer that question, the present study investigated the relationship between neural pre-stimulus oscillations and verbal memory formation in different sensory modalities. For that purpose, a within-subject design was employed to explore differences between successful and failed memory formation in the visual and auditory modality. Furthermore, associative memory was addressed by presenting the stimuli in combination with background images. Results revealed that similar EEG activity in the low beta frequency range (13-17 Hz) is associated with subsequent memory success, independent of stimulus modality. Elevated power prior to stimulus onset differentiated successful from failed memory formation. In contrast, differential effects between modalities were found in the theta band (3-7 Hz), with an increased oscillatory activity before the onset of later remembered visually presented words. In addition, pre-stimulus theta power dissociated between successful and failed encoding of associated context, independent of the stimulus modality of the item itself. We therefore suggest that increased ongoing low beta activity reflects a memory promoting state, which is likely to be moderated by modality-independent attentional or inhibitory processes, whereas high ongoing theta power is suggested as an indicator of the enhanced binding of incoming interlinked information.

  1. Medial septal GABAergic projection neurons promote object exploration behavior and type 2 theta rhythm

    Science.gov (United States)

    Gangadharan, Gireesh; Shin, Jonghan; Kim, Seong-Wook; Kim, Angela; Paydar, Afshin; Kim, Duk-Soo; Miyazaki, Taisuke; Watanabe, Masahiko; Yanagawa, Yuchio; Kim, Jinhyun; Kim, Yeon-Soo; Kim, Daesoo; Shin, Hee-Sup

    2016-01-01

    Exploratory drive is one of the most fundamental emotions, of all organisms, that are evoked by novelty stimulation. Exploratory behavior plays a fundamental role in motivation, learning, and well-being of organisms. Diverse exploratory behaviors have been described, although their heterogeneity is not certain because of the lack of solid experimental evidence for their distinction. Here we present results demonstrating that different neural mechanisms underlie different exploratory behaviors. Localized Cav3.1 knockdown in the medial septum (MS) selectively enhanced object exploration, whereas the null mutant (KO) mice showed enhanced-object exploration as well as open-field exploration. In MS knockdown mice, only type 2 hippocampal theta rhythm was enhanced, whereas both type 1 and type 2 theta rhythm were enhanced in KO mice. This selective effect was accompanied by markedly increased excitability of septo-hippocampal GABAergic projection neurons in the MS lacking T-type Ca2+ channels. Furthermore, optogenetic activation of the septo-hippocampal GABAergic pathway in WT mice also selectively enhanced object exploration behavior and type 2 theta rhythm, whereas inhibition of the same pathway decreased the behavior and the rhythm. These findings define object exploration distinguished from open-field exploration and reveal a critical role of T-type Ca2+ channels in the medial septal GABAergic projection neurons in this behavior. PMID:27208094

  2. Frontal theta EEG dynamics in a real-world air traffic control task.

    Science.gov (United States)

    Shou, Guofa; Ding, Lei

    2013-01-01

    Mental workload and time-on-task effect are two major factors expediting fatigue progress, which leads to performance decline and/or failure in real-world tasks. In the present study, electroencephalography (EEG) is applied to study mental fatigue development during an air traffic control (ATC) task. Specifically, the frontal theta EEG dynamics are firstly dissolved into a unique frontal independent component (IC) through a novel time-frequency independent component analysis (tfICA) method. Then the temporal fluctuations of the identified frontal ICs every minute are compared to workload (reflected by number of clicks per minute) and time-on-task effect by correlational analysis and linear regression analysis. It is observed that the frontal theta activity significantly increase with workload augment and time-on-task. The present study demonstrates that the frontal theta EEG activity identified by tfICA method is a sensitive and reliable metric to assess mental workload and time-on-task effect in a real-world task, i.e., ATC task, at the resolution of minute(s).

  3. Increased coherence among striatal regions in the theta range during attentive wakefulness

    Directory of Open Access Journals (Sweden)

    G. Lepski

    2012-08-01

    Full Text Available The striatum, the largest component of the basal ganglia, is usually subdivided into associative, motor and limbic components. However, the electrophysiological interactions between these three subsystems during behavior remain largely unknown. We hypothesized that the striatum might be particularly active during exploratory behavior, which is presumably associated with increased attention. We investigated the modulation of local field potentials (LFPs in the striatum during attentive wakefulness in freely moving rats. To this end, we implanted microelectrodes into different parts of the striatum of Wistar rats, as well as into the motor, associative and limbic cortices. We then used electromyograms to identify motor activity and analyzed the instantaneous frequency, power spectra and partial directed coherence during exploratory behavior. We observed fine modulation in the theta frequency range of striatal LFPs in 92.5 ± 2.5% of all epochs of exploratory behavior. Concomitantly, the theta power spectrum increased in all striatal channels (P 0.7 between the primary motor cortex and the rostral part of the caudatoputamen nucleus, as well as among all striatal channels (P < 0.001. Conclusively, we observed a pattern of strong theta band activation in the entire striatum during attentive wakefulness, as well as a strong coherence between the motor cortex and the entire striatum. We suggest that this activation reflects the integration of motor, cognitive and limbic systems during attentive wakefulness.

  4. Magnitude of Alloresponses to MHC Class I/II Expressing Human Cardiac Myocytes is Limited by their Intrinsic Ability to Process and Present Antigenic Peptides

    Directory of Open Access Journals (Sweden)

    Aftab A. Ansari

    2003-01-01

    Full Text Available In this investigation we have explored the relationship between the weak allogenicity of cardiac myocytes and their capacity to present allo-antigens by examining the ability of a human cardiac myocyte cell line (W-1 to process and present nominal antigens. W-1 cells (HLA-A*0201 and HLA-DR β1*0301 pulsed with the influenza A matrix 1 (58-66 peptide (M1 were able to serve as targets for the HLA-A*0201 restricted CTL line PG, specific for M1-peptide. However, PG-CTLs were unable to lyse W-1 target cells infected with a recombinant vaccinia virus expressing the M1 protein (M1-VAC. Pretreatment of these M1-VAC targets with IFN-γ partially restored their ability to process and present the M1 peptide. However, parallel studies demonstrated that IFN-γ pretreated W-1's could not process tetanus toxin (TT or present the TT(830-843 peptide to HLA-DR3 restricted TT-primed T cells. Semi-quantitative RT-PCR measurements revealed significantly lower constitutive levels of expression for MHC class I, TAP-1/2, and LMP-2/7 genes in W-1s that could be elevated by pretreatment with IFN-γ to values equal to or greater than those expressed in EBV-PBLs. However, mRNA levels for the genes encoding MHC class II, Ii, CIITA, and DMA/B were markedly lower in both untreated and IFN-γ pretreated W-1s relative to EBV-PBLs. Furthermore, pulse-chase analysis of the corresponding genes revealed significantly lower protein levels and longer half-life expression in W-1s relative to EBV-PBLs. These results suggest that weak allogenicity of cardiac myocytes may be governed by their limited expression of MHC genes and gene products critical for antigen processing and presentation.

  5. Behavioural Inhibition System (BIS) sensitivity differentiates EEG theta responses during goal conflict in a continuous monitoring task.

    Science.gov (United States)

    Moore, Roger A; Mills, Matthew; Marshman, Paul; Corr, Philip J

    2012-08-01

    Previous research has revealed that EEG theta oscillations are affected during goal conflict processing. This is consistent with the behavioural inhibition system (BIS) theory of anxiety (Gray & McNaughton, 2000). However, studies have not attempted to relate these BIS-related theta effects to BIS personality measures. Confirmation of such an association would provide further support for BIS theory, especially as it relates to trait differences. EEG was measured (32 electrodes) from extreme groups (low/high trait BIS) engaged in a target detection task. Goal conflicts were introduced throughout the task. Results show that the two groups did not differ in behavioural performance. The major EEG result was that a stepwise discriminant analysis indicated discrimination by 6 variables derived from coherence and power, with 5 of the 6 in the theta range as predicted by BIS theory and one in the beta range. Also, across the whole sample, EEG theta coherence increased at a variety of regions during primary goal conflict and showed a general increase during response execution; EEG theta power, in contrast, was primarily reactive to response execution. This is the first study to reveal a three-way relationship between the induction of goal conflict, the induction of theta power and coherence, and differentiation by psychometrically-defined low/high BIS status. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Increased frontal electroencephalogram theta amplitude in patients with anorexia nervosa compared to healthy controls

    Directory of Open Access Journals (Sweden)

    Hestad KA

    2016-09-01

    Full Text Available Knut A Hestad,1–3 Siri Weider,3,4 Kristian Bernhard Nilsen,5–7 Marit Sæbø Indredavik,8,9 Trond Sand7,10 1Department of Research, Innlandet Hospital Trust, Brumunddal, Norway; 2Department of Public Health, Hedmark University of Applied Sciences, Elverum, Norway; 3Department of Psychology, Faculty of Social Sciences and Technology Management, Norwegian University of Science and Technology (NTNU, Trondheim, Norway; 4Department of Psychiatry, Specialised Unit for Eating Disorder Patients, Levanger Hospital, Health Trust Nord-Trøndelag, Levanger, Norway; 5Department of Neuroscience, Norwegian University of Science and Technology (NTNU, Trondheim, Norway; 6Department of Work Psychology and Physiology, National Institute of Occupational Health, Oslo, Norway; 7Department of Neurology, Section for Clinical Neurophysiology, Oslo University Hospital, Ullevål, Oslo, Norway; 8Regional Centre for Child and Youth Mental Health and Child Welfare, Faculty of Medicine, Norwegian University of Science and Technology (NTNU, Trondheim, Norway; 9Department of Child and Adolescent Psychiatry, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway; 10Department of Neurology and Clinical Neurophysiology, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway Objective: To conduct a blind study of quantitative electroencephalogram-band amplitudes in patients with anorexia nervosa (AN and healthy controls.Methods: Twenty-one patients with AN and 24 controls were examined with eyes-closed 16-channel electroencephalogram. Main variables were absolute alpha, theta, and delta amplitudes in frontal, temporal, and posterior regions.Results: There were no significant differences between the AN patients and controls regarding absolute regional band amplitudes in µV. Borderline significance was found for anterior theta (P=0.051. Significantly increased left and right frontal electrode theta amplitude was found in AN patients (F3, P=0.014; F4, P

  7. The noncommutative standard model. Construction beyond leading order in {theta} and collider phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Alboteanu, A.M.

    2007-07-01

    Within this work we study the phenomenological consequences of a possible realization of QFT on noncommutative space-time. In the first part we performed a phenomenological analysis of the hadronic process pp {yields} Z{sub {gamma}} {yields} l{sup +}l{sup -}{gamma} at the LHC and of electron-positron pair annihilation into a Z boson and a photon at the International Linear Collider (ILC). The noncommutative extension of the SM considered within this work relies on two building blocks: the Moyal-Weyl *-product of functions on ordinary space-time and the Seiberg-Witten maps. A consequence of the noncommutativity of space-time is the violation of rotational invariance with respect to the beam axis. This effect shows up in the azimuthal dependence of cross sections, which is absent in the SM as well as in other models beyond the SM. We have found this dependence to be best suited for deriving the sensitivity bounds on the noncommutative scale NC. By studying pp{yields}Z{sub {gamma}} {yields}l{sup +}l{sup -}{gamma} to first order in the noncommutative parameter {theta}, we show in the first part of this work that measurements at the LHC are sensitive to noncommutative effects only in certain cases, giving bounds on the noncommutative scale of {lambda}{sub NC} >or similar 1.2 TeV. By means of e{sup +}e{sup -} {yields} Z{sub {gamma}} {yields} l{sup +}l{sup -}{gamma} to O({theta}) we have shown that ILC measurements are complementary to LHC measurements of the noncommutative parameters. In addition, the bounds on {lambda}{sub NC} derived from the ILC are significantly higher and reach {lambda}{sub NC} >or similar 6 TeV. In the second part of this work we expand the neutral current sector of the noncommutative SM to second order in {theta}. We found that, against the general expectation, the theory must be enlarged by additional parameters. The new parameters enter the theory as ambiguities of the Seiberg-Witten maps. The latter are not uniquely determined and differ by

  8. Boosting the LTP-like plasticity effect of intermittent theta-burst stimulation using gamma transcranial alternating current stimulation.

    Science.gov (United States)

    Guerra, Andrea; Suppa, Antonio; Bologna, Matteo; D'Onofrio, Valentina; Bianchini, Edoardo; Brown, Peter; Di Lazzaro, Vincenzo; Berardelli, Alfredo

    2018-03-24

    Transcranial Alternating Current Stimulation (tACS) consists in delivering electric current to the brain using an oscillatory pattern that may entrain the rhythmic activity of cortical neurons. When delivered at gamma frequency, tACS modulates motor performance and GABA-A-ergic interneuron activity. Since interneuronal discharges play a crucial role in brain plasticity phenomena, here we co-stimulated the primary motor cortex (M1) in healthy subjects by means of tACS during intermittent theta-burst stimulation (iTBS), a transcranial magnetic stimulation paradigm known to induce long-term potentiation (LTP)-like plasticity. We measured and compared motor evoked potentials before and after gamma, beta and sham tACS-iTBS. While we delivered gamma-tACS, we also measured short-interval intracortical inhibition (SICI) to detect any changes in GABA-A-ergic neurotransmission. Gamma, but not beta and sham tACS, significantly boosted and prolonged the iTBS-induced after-effects. Interestingly, the extent of the gamma tACS-iTBS after-effects correlated directly with SICI changes. Overall, our findings point to a link between gamma oscillations, interneuronal GABA-A-ergic activity and LTP-like plasticity in the human M1. Gamma tACS-iTBS co-stimulation might represent a new strategy to enhance and prolong responses to plasticity-inducing protocols, thereby lending itself to future applications in the neurorehabilitation setting. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Treatment of advanced gastrointestinal cancer with genetically modified autologous mesenchymal stem cells - TREAT-ME-1 - a phase I, first in human, first in class trial.

    Science.gov (United States)

    von Einem, Jobst C; Peter, Sylvia; Günther, Christine; Volk, Hans-Dieter; Grütz, Gerald; Salat, Christoph; Stoetzer, Oliver; Nelson, Peter J; Michl, Marlies; Modest, Dominik P; Holch, Julian W; Angele, Martin; Bruns, Christiane; Niess, Hanno; Heinemann, Volker

    2017-10-06

    This phase I, first in human, first in class clinical study aimed at evaluating the safety, tolerability and efficacy of treatment with genetically modified mesenchymal stromal cells (MSC) in combination with ganciclovir (GCV). MSC_apceth_101 are genetically modified autologous MSCs used as vehicles for a cell-based gene therapy in patients with advanced gastrointestinal adenocarcinoma. The study design consisted of a dose-escalation 3 + 3 design. All patients ( n = 6) were treated with up to three applications of MSC_apceth_101, followed by GCV infusions given on three consecutive days starting 48 hours after injection of MSC_apceth_101. Three of six patients received a total dose of 1.5 × 10 6 cells/kg. Two patients received three doses of 1 × 10 6 cells/kg, while one patient received only two doses of 1 × 10 6 cells/kg due to a SADR. Six patients received MSC_apceth_101. No IMP-related serious adverse events occurred. Adverse-events related to IMP-injection were increased creatinine, cough, fever, and night sweat. TNF, IL-6, IL-8, IL-10 and sE-Selectin, showed that repeated application is immunologically safe, but induces a switch of the functional properties of monocytes to an inflammatory phenotype. Treatment induced stable disease in 4/6 patients, and progressive disease in 2/6 patients. Treatment with MSC_apceth_101 in combination with GCV demonstrated acceptable safety and tolerability in patients with advanced gastrointestinal adenocarcinoma.

  10. Differential production of immunoglobulin classes and subclasses by mucosal-type human B-lymphocytes exposed in vitro to CpG oligodeoxynucleotides.

    Science.gov (United States)

    Cognasse, Fabrice; Acquart, Sophie; Beniguel, Lydie; Sabido, Odile; Chavarin, Patricia; Genin, Christian; Garraud, Olivier

    2005-01-01

    As B-lymphocytes play an important role in innate and adaptive immunity, we aimed to examine the effects of CpG oligodeoxynucleotides (ODNs) on purified tonsil-originating CD19+ B-cells, representing mucosal B-cells. We screened various K-type ODNs, reactive with human B-cells, and tested for the production of immunoglobulins in vitro. Using one CpG-ODN, DSP30, we observed that it could upregulate not only Toll-like receptor 9 (TLR9) mRNA expression in activated B-cells, but also the early expression of CD69 followed by the sequential expression of CD80, CD86 and the nuclear factor (NF)-kappaB pathway. Furthermore, mRNA expression of certain B-cell-derived cytokines was influenced by exposure to DSP30, with a strong upregulation of interleukin 6 (IL-6) and downregulation of IL1-beta. Stimulation of B-cells, co-stimulated with IL-2, IL-10 and soluble CD40 ligand (sCD40L) with different CpG-ODNs, had differing effects on the terminal differentiation in vitro of B-cells into immunoglobulin-secreting cells. TLR9 is involved in innate immunity and the recognition of bound CpG DNA from invading bacterial pathogens. As tonsillar B-cells are mucosal-type B-lymphocytes, this study suggests that CpG-ODNs show promise as mucosal adjuvants in modulating the local production of immunoglobulins of certain classes and subclasses, a crucial issue in vaccine perspectives.

  11. Encoding of physics concepts: concreteness and presentation modality reflected by human brain dynamics.

    Directory of Open Access Journals (Sweden)

    Kevin Lai

    Full Text Available Previous research into working memory has focused on activations in different brain areas accompanying either different presentation modalities (verbal vs. non-verbal or concreteness (abstract vs. concrete of non-science concepts. Less research has been conducted investigating how scientific concepts are learned and further processed in working memory. To bridge this gap, the present study investigated human brain dynamics associated with encoding of physics concepts, taking both presentation modality and concreteness into account. Results of this study revealed greater theta and low-beta synchronization in the anterior cingulate cortex (ACC during encoding of concrete pictures as compared to the encoding of both high and low imageable words. In visual brain areas, greater theta activity accompanying stimulus onsets was observed for words as compared to pictures while stronger alpha suppression was observed in responses to pictures as compared to words. In general, the EEG oscillation patterns for encoding words of different levels of abstractness were comparable but differed significantly from encoding of pictures. These results provide insights into the effects of modality of presentation on human encoding of scientific concepts and thus might help in developing new ways to better teach scientific concepts in class.

  12. Encoding of physics concepts: concreteness and presentation modality reflected by human brain dynamics.

    Science.gov (United States)

    Lai, Kevin; She, Hsiao-Ching; Chen, Sheng-Chang; Chou, Wen-Chi; Huang, Li-Yu; Jung, Tzyy-Ping; Gramann, Klaus

    2012-01-01

    Previous research into working memory has focused on activations in different brain areas accompanying either different presentation modalities (verbal vs. non-verbal) or concreteness (abstract vs. concrete) of non-science concepts. Less research has been conducted investigating how scientific concepts are learned and further processed in working memory. To bridge this gap, the present study investigated human brain dynamics associated with encoding of physics concepts, taking both presentation modality and concreteness into account. Results of this study revealed greater theta and low-beta synchronization in the anterior cingulate cortex (ACC) during encoding of concrete pictures as compared to the encoding of both high and low imageable words. In visual brain areas, greater theta activity accompanying stimulus onsets was observed for words as compared to pictures while stronger alpha suppression was observed in responses to pictures as compared to words. In general, the EEG oscillation patterns for encoding words of different levels of abstractness were comparable but differed significantly from encoding of pictures. These results provide insights into the effects of modality of presentation on human encoding of scientific concepts and thus might help in developing new ways to better teach scientific concepts in class.

  13. Expression of bovine non-classical major histocompatibility complex class I proteins in mouse P815 and human K562 cells.

    Science.gov (United States)

    Parasar, Parveen; Wilhelm, Amanda; Rutigliano, Heloisa M; Thomas, Aaron J; Teng, Lihong; Shi, Bi; Davis, William C; Suarez, Carlos E; New, Daniel D; White, Kenneth L; Davies, Christopher J

    2016-08-01

    Major histocompatibility complex class I (MHC-I) proteins can be expressed as cell surface or secreted proteins. To investigate whether bovine non-classical MHC-I proteins are expressed as cell surface or secreted proteins, and to assess the reactivity pattern of monoclonal antibodies with non-classical MHC-I isoforms, we expressed the MHC proteins in murine P815 and human K562 (MHC-I deficient) cells. Following antibiotic selection, stably transfected cell lines were stained with H1A or W6/32 antibodies to detect expression of the MHC-I proteins by flow cytometry. Two non-classical proteins (BoLA-NC1*00501 and BoLA-NC3*00101) were expressed on the cell surface in both cell lines. Surprisingly, the BoLA-NC4*00201 protein was expressed on the cell membrane of human K562 but not mouse P815 cells. Two non-classical proteins (BoLA-NC1*00401, which lacks a transmembrane domain, and BoLA-NC2*00102) did not exhibit cell surface expression. Nevertheless, Western blot analyses demonstrated expression of the MHC-I heavy chain in all transfected cell lines. Ammonium-sulfate precipitation of proteins from culture supernatants showed that BoLA-NC1*00401 was secreted and that all surface expressed proteins where shed from the cell membrane by the transfected cells. Interestingly, the surface expressed MHC-I proteins were present in culture supernatants at a much higher concentration than BoLA-NC1*00401. This comprehensive study shows that bovine non-classical MHC-I proteins BoLA-NC1*00501, BoLA-NC3*00101, and BoLA-NC4*00201 are expressed as surface isoforms with the latter reaching the cell membrane only in K562 cells. Furthermore, it demonstrated that BoLA-NC1*00401 is a secreted isoform and that significant quantities of membrane associated MHC-I proteins can be shed from the cell membrane. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Class I Underground Injection Control Program: Study of the Risks Associated with Class I Underground Injection Wells

    Science.gov (United States)

    The document provides describes the current Class I UIC program, the history of Class I injection, and studies of human health risks associated with Class I injection wells, which were conducted for past regulatory efforts and policy documentation.

  15. High-risk human papillomavirus E7 expression reduces cell-surface MHC class I molecules and increases susceptibility to natural killer cells

    DEFF Research Database (Denmark)

    Bottley, G; Watherston, O G; Hiew, Y-L

    2007-01-01

    a role for E7 in tumour immune evasion. We show that knockdown of E7 expression in HPV16- and HPV18-transformed cervical carcinoma cells by RNA interference increased expression of major histocompatibility complex (MHC) class I at the cell surface and reduced susceptibility of these cells to natural...... killer (NK) cells. Tetracycline-regulated induction of HPV16 E7 resulted in reduced expression of cell surface MHC class I molecules and increased NK cell killing. Our results suggest that, for HPV-associated malignancies, reduced MHC class I expression is the result of an active immune evasion strategy...

  16. A Comparison of Frontal Theta Activity During Shooting among Biathletes and Cross-Country Skiers before and after Vigorous Exercise.

    Directory of Open Access Journals (Sweden)

    Harri Luchsinger

    Full Text Available Previous studies using electroencephalography (EEG to monitor brain activity have linked higher frontal theta activity to more focused attention and superior performance in goal-directed precision tasks. In biathlon, shooting performance requires focused attention after high-intensity cross-country skiing.To compare biathletes (serving as experts and cross-country skiers (novices and examine the effect of vigorous exercise on frontal theta activity during shooting.EEG frontal theta (4-7 Hz activity was compared between nine biathletes and eight cross-country skiers at comparable skiing performance levels who fired 100 shots on a 5-m indoor shooting range in quiescent condition followed by 20 shots after each of five 6-min high-intensity roller skiing sessions in the skating technique on a treadmill.Biathletes hit 80±14% and 81±10% before and after the roller skiing sessions, respectively. For the cross-country skiers these values were significantly lower than for the biathletes and amounted to 39±13% and 44±11% (p<0.01. Biathletes had on average 6% higher frontal theta activity during shooting as compared to cross-country skiers (F1,15 = 4.82, p = 0.044, but no significant effect of vigorous exercise on frontal theta activity in either of the two groups were found (F1,15 = 0.14, p = 0.72.Biathletes had significantly higher frontal theta activity than cross-country skiers during shooting, indicating higher focused attention in biathletes. Vigorous exercise did not decrease shooting performance or frontal theta activity during shooting in biathletes and cross-country skiers.

  17. Functional localization and effective connectivity of cortical theta and alpha oscillatory activity during an attention task

    Directory of Open Access Journals (Sweden)

    Yuichi Kitaura

    Full Text Available Objectives: The aim of this paper is to investigate cortical electric neuronal activity as an indicator of brain function, in a mental arithmetic task that requires sustained attention, as compared to the resting state condition. The two questions of interest are the cortical localization of different oscillatory activities, and the directional effective flow of oscillatory activity between regions of interest, in the task condition compared to resting state. In particular, theta and alpha activity are of interest here, due to their important role in attention processing. Methods: We adapted mental arithmetic as an attention ask in this study. Eyes closed 61-channel EEG was recorded in 14 participants during resting and in a mental arithmetic task (“serial sevens subtraction”. Functional localization and connectivity analyses were based on cortical signals of electric neuronal activity estimated with sLORETA (standardized low resolution electromagnetic tomography. Functional localization was based on the comparison of the cortical distributions of the generators of oscillatory activity between task and resting conditions. Assessment of effective connectivity was based on the iCoh (isolated effective coherence method, which provides an appropriate frequency decomposition of the directional flow of oscillatory activity between brain regions. Nine regions of interest comprising nodes from the dorsal and ventral attention networks were selected for the connectivity analysis. Results: Cortical spectral density distribution comparing task minus rest showed significant activity increase in medial prefrontal areas and decreased activity in left parietal lobe for the theta band, and decreased activity in parietal-occipital regions for the alpha1 band. At a global level, connections among right hemispheric nodes were predominantly decreased during the task condition, while connections among left hemispheric nodes were predominantly increased. At more

  18. Invention class

    International Nuclear Information System (INIS)

    Wang, Yeon Jung

    1990-03-01

    This book gives descriptions of whole conception of patent, which includes invention and human, the way to invent, ten commandments of invention, 50 well-known inventions and inventors, conception of industrial property right system, measures on industrial property right practice, measures on industrial property right invasion, the best 10 patent dispute in history, the best 10 real patent cases in history, field of patent invention, inventions and supporting system of technical development ; supporting by the patent and trademark office and the commerce-industry ministry.

  19. Effects of semantic relatedness on age-related associative memory deficits: the role of theta oscillations.

    Science.gov (United States)

    Crespo-Garcia, Maite; Cantero, Jose L; Atienza, Mercedes

    2012-07-16

    Growing evidence suggests that age-related deficits in associative memory are alleviated when the to-be-associated items are semantically related. Here we investigate whether this beneficial effect of semantic relatedness is paralleled by spatio-temporal changes in cortical EEG dynamics during incidental encoding. Young and older adults were presented with faces at a particular spatial location preceded by a biographical cue that was either semantically related or unrelated. As expected, automatic encoding of face-location associations benefited from semantic relatedness in the two groups of age. This effect correlated with increased power of theta oscillations over medial and anterior lateral regions of the prefrontal cortex (PFC) and lateral regions of the posterior parietal cortex (PPC) in both groups. But better-performing elders also showed increased brain-behavior correlation in the theta band over the right inferior frontal gyrus (IFG) as compared to young adults. Semantic relatedness was, however, insufficient to fully eliminate age-related differences in associative memory. In line with this finding, poorer-performing elders relative to young adults showed significant reductions of theta power in the left IFG that were further predictive of behavioral impairment in the recognition task. All together, these results suggest that older adults benefit less than young adults from executive processes during encoding mainly due to neural inefficiency over regions of the left ventrolateral prefrontal cortex (VLPFC). But this associative deficit may be partially compensated for by engaging preexistent semantic knowledge, which likely leads to an efficient recruitment of attentional and integration processes supported by the left PPC and left anterior PFC respectively, together with neural compensatory mechanisms governed by the right VLPFC. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Event-related theta synchronization predicts deficit in facial affect recognition in schizophrenia.

    Science.gov (United States)

    Csukly, Gábor; Stefanics, Gábor; Komlósi, Sarolta; Czigler, István; Czobor, Pál

    2014-02-01

    Growing evidence suggests that abnormalities in the synchronized oscillatory activity of neurons in schizophrenia may lead to impaired neural activation and temporal coding and thus lead to neurocognitive dysfunctions, such as deficits in facial affect recognition. To gain an insight into the neurobiological processes linked to facial affect recognition, we investigated both induced and evoked oscillatory activity by calculating the Event Related Spectral Perturbation (ERSP) and the Inter Trial Coherence (ITC) during facial affect recognition. Fearful and neutral faces as well as nonface patches were presented to 24 patients with schizophrenia and 24 matched healthy controls while EEG was recorded. The participants' task was to recognize facial expressions. Because previous findings with healthy controls showed that facial feature decoding was associated primarily with oscillatory activity in the theta band, we analyzed ERSP and ITC in this frequency band in the time interval of 140-200 ms, which corresponds to the N170 component. Event-related theta activity and phase-locking to facial expressions, but not to nonface patches, predicted emotion recognition performance in both controls and patients. Event-related changes in theta amplitude and phase-locking were found to be significantly weaker in patients compared with healthy controls, which is in line with previous investigations showing decreased neural synchronization in the low frequency bands in patients with schizophrenia. Neural synchrony is thought to underlie distributed information processing. Our results indicate a less effective functioning in the recognition process of facial features, which may contribute to a less effective social cognition in schizophrenia. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  1. Resting-state theta band connectivity and graph analysis in generalized social anxiety disorder.

    Science.gov (United States)

    Xing, Mengqi; Tadayonnejad, Reza; MacNamara, Annmarie; Ajilore, Olusola; DiGangi, Julia; Phan, K Luan; Leow, Alex; Klumpp, Heide

    2017-01-01

    Functional magnetic resonance imaging (fMRI) resting-state studies show generalized social anxiety disorder (gSAD) is associated with disturbances in networks involved in emotion regulation, emotion processing, and perceptual functions, suggesting a network framework is integral to elucidating the pathophysiology of gSAD. However, fMRI does not measure the fast dynamic interconnections of functional networks. Therefore, we examined whole-brain functional connectomics with electroencephalogram (EEG) during resting-state. Resting-state EEG data was recorded for 32 patients with gSAD and 32 demographically-matched healthy controls (HC). Sensor-level connectivity analysis was applied on EEG data by using Weighted Phase Lag Index (WPLI) and graph analysis based on WPLI was used to determine clustering coefficient and characteristic path length to estimate local integration and global segregation of networks. WPLI results showed increased oscillatory midline coherence in the theta frequency band indicating higher connectivity in the gSAD relative to HC group during rest. Additionally, WPLI values positively correlated with state anxiety levels within the gSAD group but not the HC group. Our graph theory based connectomics analysis demonstrated increased clustering coefficient and decreased characteristic path length in theta-based whole brain functional organization in subjects with gSAD compared to HC. Theta-dependent interconnectivity was associated with state anxiety in gSAD and an increase in information processing efficiency in gSAD (compared to controls). Results may represent enhanced baseline self-focused attention, which is consistent with cognitive models of gSAD and fMRI studies implicating emotion dysregulation and disturbances in task negative networks (e.g., default mode network) in gSAD.

  2. Kinesthetic motor imagery training modulates frontal midline theta during imagination of a dart throw.

    Science.gov (United States)

    Weber, E; Doppelmayr, M

    2016-12-01

    Motor imagery (MI) is a frequently used and effective method for motor learning in sports as well as in other domains. Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) studies indicated that experts within a certain sport exhibit a more pronounced brain activity during MI as compared to novices. Similar to the execution, during MI the motor sequence has to be planned. Thus, the frontal attentional system, in part represented by the frontal midline theta (4-7Hz), is closely related to these processes and presumably plays a major role in MI as well. In this study, a MI dart training and its impact on frontal midline theta activity (fmt) during MI are examined. 53 healthy subjects with no prior dart experience were randomly allocated to a kinesthetic training group (KinVis) or to a control group (Control). Both groups performed 15 training sessions. While in the KinVis group dart throwing was accompanied by MI, the Control group trained without MI. Dart performance and fmt activity during MI within the first and the 15th session were compared. As expected, the performance increase was more pronounced in the KinVis group. Furthermore, frontal theta amplitude was significantly increased in the KinVis group during MI in the 15th training session as compared to the baseline. These results confirm the effectivity of MI. The enhanced fmt activity in the KinVis group can be interpreted as a better allocation of the requested resources in the frontal attentional network after MI. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. END effects on the n = 2 rotational instability in the reversed field theta-pinch

    International Nuclear Information System (INIS)

    Aso, Y.; Wu, Ch.; Himeno, S.; Hirano, K.

    1981-07-01

    It is observed that n = 2 rotational mode which appears in the field reversed configuration created by a theta-pinch can be stabilized if the ejected plasmas from the ends are guided out to the far ends of the apparatus by long axial solenoidal fields. This is understood from the fact that endshorting becomes no longer possible before the ejecting plasma tips reach to the ends. Measurement of plasma rotations just outside the separatrix suggests that both preferential diffusion loss and endshorting play a very important role for the n = 2 mode. (author)

  4. Double phi-Step theta-Scanning Technique for Spherical Near-Field Antenna Measurements

    DEFF Research Database (Denmark)

    Laitinen, Tommi

    2008-01-01

    Probe-corrected spherical near-field antenna measurements with an arbitrary probe set certain requirements on an applicable scanning technique. The computational complexity of the general high-order probe correction technique for an arbitrary probe, that is based on the Phi scanning, is O(N4...... a specific double Phi-step thetas scanning technique for spherical near-field antenna measurements. This technique not only constitutes an alternative spherical scanning technique, but it also enables formulating an associated probe correction technique for arbitrary probes with the computational complexity...

  5. Velocity-space particle loss in field-reversed theta pinches

    International Nuclear Information System (INIS)

    Hsiao, M.Y.

    1983-01-01

    A field-reversed theta pinch (FRTP) is a compact device for magnetic fusion. It has attracted much attention in recent years since encouraging experimental results have been obtained. However, the definite causes for the observed particle loss rate and plasma rotation are not well known. In this work, we study the velocity-space particle loss (VSPL), i.e., particle loss due to the existence of a loss region in velocity space, in FRTP's in order to have a better understanding about the characteristics of this device

  6. A new formulation of theta pinch implosions - a collisionless wave model

    International Nuclear Information System (INIS)

    Tsui, K.H.

    Previous work in theta pinch implosions is characterized by anomalous resistivity owing its origin to plasma instabilities. A diametrically opposite collisionless model is proposed here that consists of an inhomogeneous wave equation. The electron velocities are solved by guiding center approximation. This model offers qualitative explanations to various effects like experimental Alfven scaling law, Alfven penetration time, sheath thickness, shock formation, shock width, piston thickness, Alfven Mach number. Although collision is not essential, the plasma has an apparent resistivity with an effective collision frequency of roughly the same as those anomalous ones used in turbulent model. (Author) [pt

  7. Refrigeration requirements for fusion reactors based upon the theta-pinch concept

    International Nuclear Information System (INIS)

    Williamson, K.D. Jr.; King, C.R.

    1976-01-01

    Two refrigeration systems applicable to the theta-pinch fusion concept are described. The first is a 1100 W, 4.5 K refrigerator which will be used for testing superconducting NbTi Magnetic Energy Transfer and Storage (METS) coil systems. This unit is currently being installed and is to be operational by April 1977. The second unit is applicable to the Syllac Fusion Test Reactor (SFTR) and has been conceptually designed. This liquefier-refrigerator is about 22 times larger than those in existence at present and will require 12-MW input electrical power. It will provide 3045 kg/h of liquid helium at 4.5 K

  8. Vacuum ultraviolet emission from argon, krypton, and xenon in a radial-viewed theta pinch

    International Nuclear Information System (INIS)

    Engleman, R. Jr.; Thomson, D.B.; Monaghan, D.A.

    1976-03-01

    Vacuum ultraviolet line emission from argon, krypton, and xenon (5 percent in deuterium) has been observed from a plasma (approximately 50 eV and N/sub e/ approximately 10 17 /cm 3 ) produced by the Scyllar linear theta-pinch device. More than 50 emission lines in the 30- to 500-A region have been measured for each gas mixture. Some lines have been identified as due to Ar VII through XI, Kr IX and X, and Xe IX, but many lines remain unassigned

  9. Chromatically unique 6-bridge graph theta(a,a,a,b,b,c

    Directory of Open Access Journals (Sweden)

    N.S.A. Karim

    2016-04-01

    Full Text Available For a graph $G$, let $P(G,\\lambda$ denote the chromatic polynomial of $G$. Two graphs $G$ and $H$ are chromatically equivalent if they share the same chromatic polynomial. A graph $G$ is chromatically unique if for any graph chromatically equivalent to $G$ is isomorphic to $G$. In this paper, the chromatically unique of a new family of 6-bridge graph $\\theta(a,a,a,b,b,c$ where $2\\le a\\le b\\le c$ is investigated.

  10. Experimental study of the initial plasma formation stage in a linear theta pinch of inverted field

    International Nuclear Information System (INIS)

    Casin, G.C.; Alvarez, Ricardo; Rojkind, R.H.; Rodrigo, A.B.

    1986-01-01

    The initial stage of the plasma formation was studied in a linear theta pinch. Experiments were made to determine the machine operating conditions for good shot-to-shot reproducibility. Spectroscopic measurements of electron density and of electron and ion temperature were made afterwards to characterize the plasma at different stages of its heating process. The results obtained indicate that shot-to-shot reproducibility is strongly influenced by the presence of impurities and by the plasma preionization technique used. Under proper operating conditions, excellent reproducibility was observed. The measured values of the plasma parameters are compatible with those determined for similar machines. (Author) [es

  11. Impaired theta phase-resetting underlying auditory N1 suppression in chronic alcoholism.

    Science.gov (United States)

    Fuentemilla, Lluis; Marco-Pallarés, Josep; Gual, Antoni; Escera, Carles; Polo, Maria Dolores; Grau, Carles

    2009-02-18

    It has been suggested that chronic alcoholism may lead to altered neural mechanisms related to inhibitory processes. Here, we studied auditory N1 suppression phenomena (i.e. amplitude reduction with repetitive stimuli) in chronic alcoholic patients as an early-stage information-processing brain function involving inhibition by the analysis of the N1 event-related potential and time-frequency computation (spectral power and phase-resetting). Our results showed enhanced neural theta oscillatory phase-resetting underlying N1 generation in suppressed N1 event-related potential. The present findings suggest that chronic alcoholism alters neural oscillatory synchrony dynamics at very early stages of information processing.

  12. Modulation of inhibitory activity markers by intermittent theta-burst stimulation in rat cortex is NMDA-receptor dependent.

    Science.gov (United States)

    Labedi, Adnan; Benali, Alia; Mix, Annika; Neubacher, Ute; Funke, Klaus

    2014-01-01

    Intermittent theta-burst stimulation (iTBS) applied via transcranial magnetic stimulation has been shown to increase cortical excitability in humans. In the rat brain it strongly reduced the number of neurons expressing the 67-kD isoform of the GABA-synthesizing enzyme glutamic acid decarboxylase (GAD67) and those expressing the calcium-binding proteins parvalbumin (PV) and calbindin (CB), specific markers of fast-spiking (FS) and non-FS inhibitory interneurons, respectively, an indication of modified cortical inhibition. Since iTBS effects in humans have been shown to be NMDA receptor sensitive, we wondered whether the iTBS-induced changes in the molecular phenotype of interneurons may be also sensitive to glutamatergic synaptic transmission mediated by NMDA receptors. In a sham-controlled fashion, five iTBS-blocks of 600 stimuli were applied to rats either lightly anesthetized by only urethane or by an additional low (subnarcotic) or high dose of the NMDA receptor antagonist ketamine before immunohistochemical analysis. iTBS reduced the number of neurons expressing GAD67, PV and CB. Except for CB, a low dose of ketamine partially prevented these effects while a higher dose almost completely abolished the iTBS effects. Our findings indicate that iTBS modulates the molecular, and likely also the electric, activity of cortical inhibitory interneurons and that the modulation of FS-type but less that of non-FS-type neurons is mediated by NMDA receptors. A combination of iTBS with pharmacological interventions affecting distinct receptor subtypes may thus offer options to enhance its selectivity in modulating the activity of distinct cell types and preventing others from being modulated. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Continuous theta-burst stimulation over the dorsal premotor cortex interferes with associative learning during object lifting.

    Science.gov (United States)

    Nowak, Dennis A; Berner, Julia; Herrnberger, Bärbel; Kammer, Thomas; Grön, Georg; Schönfeldt-Lecuona, Carlos

    2009-04-01

    When lifting objects of different mass, humans scale grip force according to the expected mass. In this context, humans are able to associate a sensory cue, such as a colour, to a particular mass of an object and link this association to the grip forces necessary for lifting. Here, we study the role of the dorsal premotor cortex (PMd) in setting-up an association between a colour cue and a particular mass to be lifted. Healthy right-handed subjects used a precision grip between the index finger and thumb to lift two different masses. Colour cues provided information about which of the two masses subjects would have to lift. Subjects first performed a series of lifts with the right hand to establish a stable association between a colour cue and a mass, followed by 20sec of continuous high frequency repetitive trancranial magnetic stimulation using a recently developed protocol (continuous theta-burst stimulation, cTBS) over (i) the left primary motor cortex, (ii) the left PMd and (iii) the left occipital cortex to be commenced by another series of lifts with either the right or left hand. cTBS over the PMd, but not over the primary motor cortex or O1, disrupted the predictive scaling of isometric finger forces based on colour cues, irrespective of whether the right or left hand performed the lifts after the stimulation. Our data highlight the role of the PMd to generalize and maintain associative memory processes relevant for predictive control of grip forces during object manipulation.

  14. Supramodal Theta, Gamma, and Sustained Fields Predict Modality-specific Modulations of Alpha and Beta Oscillations during Visual and Tactile Working Memory.

    Science.gov (United States)

    van Ede, Freek; Jensen, Ole; Maris, Eric

    2017-08-01

    Flexible control over currently relevant sensory representations is an essential feature of primate cognition. We investigated the neurophysiological bases of such flexible control in humans during an intermodal working memory task in which participants retained visual or tactile sequences. Using magnetoencephalography, we first show that working memory retention engages early visual and somatosensory areas, as reflected in the sustained load-dependent suppression of alpha and beta oscillations. Next, we identify three components that are also load dependent but modality independent: medial prefrontal theta synchronization, frontoparietal gamma synchronization, and sustained parietal event-related fields. Critically, these domain-general components predict (across trials and within load conditions) the modality-specific suppression of alpha and beta oscillations, with largely unique contributions per component. Thus, working memory engages multiple complementary frontoparietal components that have discernible neuronal dynamics and that flexibly modulate retention-related activity in sensory areas in a manner that tracks the current contents of working memory.

  15. Theta synchronization between medial prefrontal cortex and cerebellum is associated with adaptive performance of associative learning behavior

    Science.gov (United States)

    Chen, Hao; Wang, Yi-jie; Yang, Li; Sui, Jian-feng; Hu, Zhi-an; Hu, Bo

    2016-01-01

    Associative learning is thought to require coordinated activities among distributed brain regions. For example, to direct behavior appropriately, the medial prefrontal cortex (mPFC) must encode and maintain sensory information and then interact with the cerebellum during trace eyeblink conditioning (TEBC), a commonly-used associative learning model. However, the mechanisms by which these two distant areas interact remain elusive. By simultaneously recording local field potential (LFP) signals from the mPFC and the cerebellum in guinea pigs undergoing TEBC, we found that theta-frequency (5.0–12.0 Hz) oscillations in the mPFC and the cerebellum became strongly synchronized following presentation of auditory conditioned stimulus. Intriguingly, the conditioned eyeblink response (CR) with adaptive timing occurred preferentially in the trials where mPFC-cerebellum theta coherence was stronger. Moreover, both the mPFC-cerebellum theta coherence and the adaptive CR performance were impaired after the disruption of endogenous orexins in the cerebellum. Finally, association of the mPFC -cerebellum theta coherence with adaptive CR performance was time-limited occurring in the early stage of associative learning. These findings suggest that the mPFC and the cerebellum may act together to contribute to the adaptive performance of associative learning behavior by means of theta synchronization. PMID:26879632

  16. Hippocampal theta activity is selectively associated with contingency detection but not discrimination in rabbit discrimination-reversal eyeblink conditioning.

    Science.gov (United States)

    Nokia, Miriam S; Wikgren, Jan

    2010-04-01

    The relative power of the hippocampal theta-band ( approximately 6 Hz) activity (theta ratio) is thought to reflect a distinct neural state and has been shown to affect learning rate in classical eyeblink conditioning in rabbits. We sought to determine if the theta ratio is mostly related to the detection of the contingency between the stimuli used in conditioning or also to the learning of more complex inhibitory associations when a highly demanding delay discrimination-reversal eyeblink conditioning paradigm is used. A high hippocampal theta ratio was not only associated with a fast increase in conditioned responding in general but also correlated with slow emergence of discriminative responding due to sustained responding to the conditioned stimulus not paired with an unconditioned stimulus. The results indicate that the neural state reflected by the hippocampal theta ratio is specifically linked to forming associations between stimuli rather than to the learning of inhibitory associations needed for successful discrimination. This is in line with the view that the hippocampus is responsible for contingency detection in the early phase of learning in eyeblink conditioning. (c) 2009 Wiley-Liss, Inc.

  17. Detecting Site-Specific Physicochemical Selective Pressures: Applications to the Class I HLA of the Human Major Histocompatibility Complex and the SRK of the Plant Sporophytic Self-Incompatibility System

    DEFF Research Database (Denmark)

    Sainudiin, Raazesh; Wong, Wendy Shuk Wan; Yogeeswaran, Krithika

    2005-01-01

    :transversion biases. Here, we apply this method to two positively selected receptors involved in ligand-recognition: the class I alleles of the human major histocompatibility complex (MHC) of known structure and the S-locus receptor kinase (SRK) of the sporophytic self-incompatibility system (SSI) in cruciferous...... Bayes approach is used to identify sites that may be important for ligand recognition in these proteins....

  18. A novel one-class SVM based negative data sampling method for reconstructing proteome-wide HTLV-human protein interaction networks.

    Science.gov (United States)

    Mei, Suyu; Zhu, Hao

    2015-01-26

    Protein-protein interaction (PPI) prediction is generally treated as a problem of binary classification wherein negative data sampling is still an open problem to be addressed. The commonly used random sampling is prone to yield less representative negative data with considerable false negatives. Meanwhile rational constraints are seldom exerted on model selection to reduce the risk of false positive predictions for most of the existing computational methods. In this work, we propose a novel negative data sampling method based on one-class SVM (support vector machine, SVM) to predict proteome-wide protein interactions between HTLV retrovirus and Homo sapiens, wherein one-class SVM is used to choose reliable and representative negative data, and two-class SVM is used to yield proteome-wide outcomes as predictive feedback for rational model selection. Computational results suggest that one-class SVM is more suited to be used as negative data sampling method than two-class PPI predictor, and the predictive feedback constrained model selection helps to yield a rational predictive model that reduces the risk of false positive predictions. Some predictions have been validated by the recent literature. Lastly, gene ontology based clustering of the predicted PPI networks is conducted to provide valuable cues for the pathogenesis of HTLV retrovirus.

  19. A comparative study of long-baseline superbeams within LAGUNA for large $\\theta_{13}$

    CERN Document Server

    Coloma, Pilar; Pascoli, Silvia

    2012-01-01

    The Daya Bay and RENO experiments have recently observed a non-zero $\\theta_{13}$ at more than $5\\sigma$ CL. This has important consequences for future neutrino oscillation experiments. We analyze these within the LAGUNA design study which considers seven possible locations for a European neutrino observatory for proton decay, neutrino, and astroparticle physics. The megaton-scale detector would be an ideal target for a CERN-based neutrino beam with baselines ranging from 130 km to 2300 km. We perform a detailed study to assess the physics reach of the three detector options - a 440 kton water \\v{C}erenkov, a 100 kton liquid argon and a 50 kton liquid scintillator detector - at each of the possible locations, taking into account the recent measurement of $\\theta_{13}$. We study the impact of the beam properties and detector performances on the sensitivity to CP-violation and the mass hierarchy. We find that a liquid argon or water \\v{C}erenkov detector can make a $3\\sigma$ discovery of CP violation for $60%-7...

  20. Theta, mental flexibility, and post-traumatic stress disorder: connecting in the parietal cortex.

    Directory of Open Access Journals (Sweden)

    Benjamin T Dunkley

    Full Text Available Post-traumatic stress disorder (PTSD is a mental health injury characterised by re-experiencing, avoidance, numbing and hyperarousal. Whilst the aetiology of the disorder is relatively well understood, there is debate about the prevalence of cognitive sequelae that manifest in PTSD. In particular, there are conflicting reports about deficits in executive function and mental flexibility. Even less is known about the neural changes that underlie such deficits. Here, we used magnetoencephalography to study differences in functional connectivity during a mental flexibility task in combat-related PTSD (all males, mean age = 37.4, n = 18 versus a military control (all males, mean age = 33.05, n = 19 group. We observed large-scale increases in theta connectivity in the PTSD group compared to controls. The PTSD group performance was compromised in the more attentionally-demanding task and this was characterised by 'late-stage' theta hyperconnectivity, concentrated in network connections involving right parietal cortex. Furthermore, we observed significant correlations with the connectivity strength in this region with a number of cognitive-behavioural outcomes, including measures of attention, depression and anxiety. These findings suggest atypical coordination of neural synchronisation in large scale networks contributes to deficits in mental flexibility for PTSD populations in timed, attentionally-demanding tasks, and this propensity toward network hyperconnectivity may play a more general role in the cognitive sequelae evident in this disorder.

  1. A neural signature of fairness in altruism: a game of theta?

    Science.gov (United States)

    Rodrigues, Johannes; Ulrich, Natalie; Hewig, Johannes

    2015-04-01

    In the dictator game, a proposer can share a certain amount of money between himself or herself and a receiver, who has no opportunity of influencing the offer. Rational choice theory predicts that dictators keep all money for themselves. But people often are offering money to receivers, despite their opportunity to maximize their own profit and therefore showing altruistic behavior. In this study, we investigated the influence of the altruism of the dictator, the anonymity of the decision and the income of the receiver on the offer made by a dictator. Additionally, we were interested in the influence of midfrontal theta activity prior to the offer, indicating the upcoming decision. The height of the offer made by the dictator was dependent on all variables investigated: Altruism of the dictator led to higher offers and income of the receiver led to higher offer the poorer the receivers are. The anonymity of the decision had two effects, depending on the altruism of the dictator, with higher offers for highly altruistic dictators, when they were not observed, and lower offers for less altruistic dictators in this condition. Finally, midfrontal theta activity predicts upcoming fair offers, maybe indicating altruistic motivation or empathy on physiological basis.

  2. Lexical tonal discrimination in Zapotec children. A study of the theta rhythm.

    Science.gov (United States)

    Poblano, Adrián; Castro-Sierra, Eduardo; Arteaga, Carmina; Pérez-Ruiz, Santiago J

    Zapotec is a language used mainly in the state of Oaxaca in Mexico of tonal characteristic; homophone words with difference in fundamental frequency with different meanings. Our objective was to analyze changes in the electroencephalographic (EEG) theta rhythm during word discrimination of lexical tonal bi-syllabic homophone word samples of Zapotec. We employed electroencephalography analysis during lexical tonal discrimination in 12 healthy subjects 9-16 years of age. We observed an increase in theta relative power between lexical discrimination and at rest eyes-open state in right temporal site. We also observed several significant intra- and inter-hemispheric correlations in several scalp sites, mainly in left fronto-temporal and right temporal areas when subjects were performing lexical discrimination. Our data suggest more engagement of neural networks of the right hemisphere are involved in Zapotec language discrimination. Copyright © 2015 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

  3. Single-trial regression elucidates the role of prefrontal theta oscillations in response conflict

    Directory of Open Access Journals (Sweden)

    Michael X Cohen

    2011-02-01

    Full Text Available In most cognitive neuroscience experiments there are many behavioral and experimental dynamics, and many indices of brain activity, that vary from trial to trial. For example, in studies of response conflict, conflict is usually treated as a binary variable (i.e., response conflict exists or does not in any given trial, whereas some evidence and intuition suggests that conflict may vary in intensity from trial to trial. Here we demonstrate that single-trial multiple regression of time-frequency electrophysiological activity reveals neural mechanisms of cognitive control that are not apparent in cross-trial averages. We also introduce a novel extension to oscillation phase coherence and synchronization analyses, based on weighted phase modulation, that has advantages over standard coherence measures in terms of linking electrophysiological dynamics to trial-varying behavior and experimental variables. After replicating previous response conflict findings using trial-averaged data, we extend these findings using single trial analytic methods to provide novel evidence for the role of medial frontal-lateral prefrontal theta-band synchronization in conflict-induced response time dynamics, including a role for lateral prefrontal theta-band activity in biasing response times according to perceptual conflict. Given that these methods shed new light on the prefrontal mechanisms of response conflict, they are also likely to be useful for investigating other neurocognitive processes.

  4. Is theta burst stimulation applied to visual cortex able to modulate peripheral visual acuity?

    Directory of Open Access Journals (Sweden)

    Sabrina Brückner

    Full Text Available Repetitive transcranial magnetic stimulation is usually applied to visual cortex to explore the effects on cortical excitability. Most researchers therefore concentrate on changes of phosphene threshold, rarely on consequences for visual performance. Thus, we investigated peripheral visual acuity in the four quadrants of the visual field using Landolt C optotypes before and after repetitive stimulation of the visual cortex. We applied continuous and intermittend theta burst stimulation with various stimulation intensities (60%, 80%, 100%, 120% of individual phosphene threshold as well as monophasic and biphasic 1 Hz stimulation, respectively. As an important result, no serious adverse effects were observed. In particular, no seizure was induced, even with theta burst stimulation applied with 120% of individual phosphene threshold. In only one case stimulation was ceased because the subject reported intolerable pain. Baseline visual acuity decreased over sessions, indicating a continuous training effect. Unexpectedly, none of the applied transcranial magnetic stimulation protocols had an effect on performance: no change in visual acuity was found in any of the four quadrants of the visual field. Binocular viewing as well as the use of peripheral instead of foveal presentation of the stimuli might have contributed to this result. Furthermore, intraindividual variability could have masked the TMS- induced effects on visual acuity.

  5. Electron temperature in field reversed configurations and theta pinches with closed magnetic field lines

    International Nuclear Information System (INIS)

    Newton, A.A.

    1986-01-01

    Field-reversed configurations (FRC) and theta pinches with trapped reversed bias field are essentially the same magnetic confinement systems using closed magnetic field lines inside an open-ended magnetic flux tube. A simple model of joule heating and parallel electron thermal conduction along the open flux lines to an external heat sink gives the electron temperature as Tsub(e)(eV) approx.= 0.05 Bsup(2/3)(G)Lsup(1/3)(cm), where B is the magnetic field and L is the coil length. This model appears to agree with measurements from present FRC experiments and past theta-pinch experiments which cover a range of 40-900 eV. The energy balance in the model is dominated by (a) parallel electron thermal conduction along the open field lines which has a steep temperature dependence, Q is proportional to Tsub(e)sup(7/2), and (b) the assumed rapid perpendicular transport in the plasma bulk which, in experiments to date, may be due to the small number of ion gyroradii across the plasma. (author)

  6. Learning curves of theta/beta neurofeedback in children with ADHD.

    Science.gov (United States)

    Janssen, Tieme W P; Bink, Marleen; Weeda, Wouter D; Geladé, Katleen; van Mourik, Rosa; Maras, Athanasios; Oosterlaan, Jaap

    2017-05-01

    Neurofeedback is widely applied as non-pharmacological intervention aimed at reducing symptoms of ADHD, even though efficacy has not been unequivocally established. Neuronal changes during the neurofeedback intervention that resemble learning can provide crucial evidence for the feasibility and specificity of this intervention. A total of 38 children (aged between 7 and 13 years) with a DSM-IV-TR diagnosis of ADHD, completed on average 29 sessions of theta (4-8 Hz)/beta (13-20 Hz) neurofeedback training. Dependent variables included training-related measures as well as theta and beta power during baseline and training runs for each session. Learning effects were analyzed both within and between sessions. To further specify findings, individual learning curves were explored and correlated with behavioral changes in ADHD symptoms. Over the course of the training, there was a linear increase in participants' mean training level, highest obtained training level and the number of earned credits (range b = 0.059, -0.750, p neurofeedback, although a lack of behavioral correlates may indicate insufficient transfer to daily functioning, or to confounding reinforcement of electromyographic activity. This trial is registered at the US National Institutes of Health (ClinicalTrials.gov, ref. no: NCT01363544); https://clinicaltrials.gov/show/NCT01363544 .

  7. The neuronal mechanisms underlying improvement of impulsivity in ADHD by theta/beta neurofeedback.

    Science.gov (United States)

    Bluschke, Annet; Broschwitz, Felicia; Kohl, Simon; Roessner, Veit; Beste, Christian

    2016-08-12

    Neurofeedback is increasingly recognized as an intervention to treat core symptoms of attention deficit hyperactivity disorder (ADHD). Despite the large number of studies having been carried out to evaluate its effectiveness, it is widely elusive what neuronal mechanisms related to the core symptoms of ADHD are modulated by neurofeedback. 19 children with ADHD undergoing 8 weeks of theta/beta neurofeedback and 17 waiting list controls performed a Go/Nogo task in a pre-post design. We used neurophysiological measures combining high-density EEG recording with source localization analyses using sLORETA. Compared to the waiting list ADHD control group, impulsive behaviour measured was reduced after neurofeedback treatment. The effects of neurofeedback were very specific for situations requiring inhibitory control over responses. The neurophysiological data shows that processes of perceptual gating, attentional selection and resource allocation processes were not affected by neurofeedback. Rather, neurofeedback effects seem to be based on the modulation of response inhibition processes in medial frontal cortices. The study shows that specific neuronal mechanisms underlying impulsivity are modulated by theta/beta neurofeedback in ADHD. The applied neurofeedback protocol could be particularly suitable to address inhibitory control. The study validates assumed functional neuroanatomical target regions of an established neurofeedback protocol on a neurophysiological level.

  8. A Virtual Class Calculus

    DEFF Research Database (Denmark)

    Ernst, Erik; Ostermann, Klaus; Cook, William Randall

    2006-01-01

    Virtual classes are class-valued attributes of objects. Like virtual methods, virtual classes are defined in an object's class and may be redefined within subclasses. They resemble inner classes, which are also defined within a class, but virtual classes are accessed through object instances...... model for virtual classes has been a long-standing open question. This paper presents a virtual class calculus, vc, that captures the essence of virtual classes in these full-fledged programming languages. The key contributions of the paper are a formalization of the dynamic and static semantics of vc...

  9. Corticostriatal field potentials are modulated at delta and theta frequencies during interval-timing task in rodents

    Directory of Open Access Journals (Sweden)

    Eric B Emmons

    2016-04-01

    Full Text Available Organizing movements in time is a critical and highly conserved feature of mammalian behavior. Temporal control of action requires corticostriatal networks. We investigate these networks in rodents using a two-interval timing task while recording local field potentials in medial frontal cortex or dorsomedial striatum. Consistent with prior work, we found cue-triggered delta (1-4 Hz and theta activity (4-8 Hz primarily in rodent medial frontal cortex. We observed delta activity across temporal intervals in medial frontal cortex and dorsomedial striatum. Rewarded responses were associated with increased delta activity in medial frontal cortex. Activity in theta bands in medial frontal cortex and delta bands in the striatum was linked with the timing of responses. These data suggest both delta and theta activity in frontostriatal networks are modulated during interval timing and that activity in these bands may be involved in the temporal control of action.

  10. PAL(TM) 2.0 Human Anatomy Software Tool Use in Community College Traditional and Online Anatomy Laboratory Classes: Student-Perceived Learning Benefits

    Science.gov (United States)

    Kuyatt, Brian Lee

    2012-01-01

    Human anatomy courses, with laboratory, are curricular requirements in graduate medical, undergraduate nursing, and all allied health science programs. Anatomy laboratory courses engage students in hands-on activities, including human cadaver or mammalian dissection, supported by photos from textbooks, detailed plastic models or human anatomical…

  11. Preventing an identity crisis: unexpected co-expression of class III beta-tubulin and glial fibrillary acidic protein in human fetal astrocytes in culture

    Czech Academy of Sciences Publication Activity Database

    Katsetos, C.D.; Dráberová, Eduarda; Del Valle, L.; Bertrand, L.; Agamanolis, D.P.; de Chadarévian, J.-P.; Legido, A.; Dráber, Pavel

    2007-01-01

    Roč. 26, č. 11 (2007), s. 107-107 ISSN 0364-5134 R&D Projects: GA MŠk LC545; GA ČR GA204/05/2375 Institutional research plan: CEZ:AV0Z50520514 Keywords : class III beta-tubulin * fetal glia Subject RIV: EB - Genetics ; Molecular Biology

  12. Effect of human scavenger receptor class A overexpression in bone marrow-derived cells on cholesterol levels and atherosclerosis in ApoE-deficient mice

    NARCIS (Netherlands)

    van Eck, M.; de Winther, M. P.; Herijgers, N.; Havekes, L. M.; Hofker, M. H.; Groot, P. H.; van Berkel, T. J.

    2000-01-01

    In the arterial wall, scavenger receptor class A (SRA) is implicated in pathological lipid deposition. In contrast, in the liver, SRA is suggested to remove modified lipoproteins from the circulation, thereby protecting the body from their pathological action. The role of SRA on bone marrow-derived

  13. Effect of human scavenger receptor class A overexpression in bone marrow-derived cells on cholesterol levels and atherosclerosis in apoE-deficient mice

    NARCIS (Netherlands)

    Eck, M. van; Winther, M.P.J. de; Herijgers, N.; Havekes, L.M.; Hofker, M.H.; Groot, P.H.E.; Berkel, T.J.C. van

    2000-01-01

    In the arterial wall, scavenger receptor class A (SRA) is implicated in pathological lipid deposition. In contrast, in the liver, SRA is suggested to remove modified lipoproteins from the circulation, thereby protecting the body from their pathological action. The role of SRA on bone marrow-derived

  14. Complex modulation of fingertip forces during precision grasp and lift after theta burst stimulation over the dorsal premotor cortex

    Directory of Open Access Journals (Sweden)

    Drljačić Dragana

    2017-01-01

    Full Text Available Background/Aim. Adaptive control and fingertip force synchronization of precise grasp stability during unimanual manipulation of small objects represents an illustrative example of highly fractionated movements that are foundation of fine motor control. It is assumed that this process is controlled by several motor areas of the frontal lobe, particularly applicable to the primary motor (M-1 and dorsal premotor cortex (PMd. Aiming to examine the role of PMd during fine coordination of fingertip forces we applied theta burst repetitive magnetic stimulation (TBS to disrupt neural processing in that cortical area. Methods. Using a single-blind, randomized, crossover design, 10 healthy subjects (29 ± 3.9 years received single sessions of continuous TBS (cTBS600, intermittent TBS (iTBS600, or sham stimulation, separate from one another at least one week, over the PMd region of dominant hemisphere. Precision grasp and lift were assessed by instrumented device, recording grip (G and load (L forces, during three manipulation tasks (ramp-and-hold, oscillation force producing and simple lifting tasks, with each hand separately, before and after interventions. Results. We observed the improvement of task performance related to constant error (CE in oscillation task with the dominant hand (DH after the iTBS (p = 0.009. On the contrary, the cTBS reduced variable error (VE for non-dominant hand (NH, p = 0.005. Considering force coordination we found that iTBS worsened variables for NH (G/L ratio, p = 0.017; cross-correlation of the G and L, p = 0.047; Gain, p = 0.047. Conclusion. These results demonstrate the ability of TBS to modulate fingertip forces during precision grasping and lifting, when applied over PMd. These findings support the role of PMd in human motor control and forces generation required to hold small objects stable in our hands.

  15. Modulation of left primary motor cortex excitability after bimanual training and intermittent theta burst stimulation to left dorsal premotor cortex.

    Science.gov (United States)

    Neva, Jason L; Vesia, Michael; Singh, Amaya M; Staines, W Richard

    2014-03-15

    Bimanual visuomotor movement training (BMT) enhances the excitability of human preparatory premotor and primary motor (M1) cortices compared to unimanual movement. This occurs when BMT involves mirror symmetrical movements of both upper-limbs (in-phase) but not with non-symmetrical movements (anti-phase). The neural mechanisms mediating the effect of BMT is unclear, but may involve interhemispheric connections between homologous M1 representations as well as the dorsal premotor cortices (PMd). The purpose of this study is to assess how intermittent theta burst stimulation (iTBS) of the left PMd affects left M1 excitability, and the possible combined effects of iTBS to left PMd applied before a single session of BMT. Left M1 excitability was quantified using transcranial magnetic stimulation (TMS) in terms of both the amplitudes and spatial extent of motor evoked potentials (MEPs) for the extensor carpi radialis (ECR) before and multiple time points following (1) BMT, (2) iTBS to left PMd or (3) iTBS to left PMd and BMT. Although there was not a greater increase in either specific measure of M1 excitability due to the combination of the interventions, iTBS applied before BMT showed that both the spatial extent and global MEP amplitude for the ECR became larger in parallel, whereas the spatial extent was enhanced with BMT alone and global MEP amplitude was enhanced with iTBS to left PMd alone. These results suggest that the modulation of rapid functional M1 excitability associated with BMT and iTBS of the left PMd could operate under related early markers of neuro-plastic mechanisms, which may be expressed in concurrent and distinct patterns of M1 excitability. Critically, this work may guide rehabilitation training and stimulation techniques that modulate cortical excitability after brain injury. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Continuous and intermittent transcranial magnetic theta burst stimulation modify tactile learning performance and cortical protein expression in the rat differently.

    Science.gov (United States)

    Mix, Annika; Benali, Alia; Eysel, Ulf T; Funke, Klaus

    2010-11-01

    Repetitive transcranial magnetic stimulation (rTMS) can modulate cortical excitability in a stimulus-frequency-dependent manner. Two kinds of theta burst stimulation (TBS) [intermittent TBS (iTBS) and continuous TBS (cTBS)] modulate human cortical excitability differently, with iTBS increasing it and cTBS decreasing it. In rats, we recently showed that this is accompanied by changes in the cortical expression of proteins related to the activity of inhibitory neurons. Expression levels of the calcium-binding protein parvalbumin (PV) and of the 67-kDa isoform of glutamic acid decarboxylase (GAD67) were strongly reduced following iTBS, but not cTBS, whereas both increased expression of the 65-kDa isoform of glutamic acid decarboxylase. In the present study, to investigate possible functional consequences, we applied iTBS and cTBS to rats learning a tactile discrimination task. Conscious rats received either verum or sham rTMS prior to the task. Finally, to investigate how rTMS and learning effects interact, protein expression was determined for cortical areas directly involved in the task and for those either not, or indirectly, involved. We found that iTBS, but not cTBS, improved learning and strongly reduced cortical PV and GAD67 expression. However, the combination of learning and iTBS prevented this effect in those cortical areas involved in the task, but not in unrelated areas. We conclude that the improved learning found following iTBS is a result of the interaction of two effects, possibly in a homeostatic manner: a general weakening of inhibition mediated by the fast-spiking interneurons, and re-established activity in those neurons specifically involved in the learning task, leading to enhanced contrast between learning-induced and background activity. © 2010 The Authors. European Journal of Neuroscience © 2010 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  17. Intermittent Theta-Burst Transcranial Magnetic Stimulation Alters Electrical Properties of Fast-Spiking Neocortical Interneurons in an Age-Dependent Fashion

    Directory of Open Access Journals (Sweden)

    Kathrin eHoppenrath

    2016-03-01

    Full Text Available Modulation of human cortical excitability by repetitive transcranial magnetic stimulation (rTMS appears to be in part related to changed activity of inhibitory systems. Our own studies showed that intermittent theta-burst stimulation (iTBS applied via rTMS to rat cortex primarily affects the parvalbumin-expressing (PV fast-spiking interneurons (FSIs, evident via a strongly reduced PV expression. We further found the iTBS effect on PV to be age-dependent since no reduction in PV could be induced before the perineuronal nets (PNNs of FSIs start to grow around postnatal day 30. To elucidate possible iTBS-induced changes in the electrical properties of FSIs and cortical network activity during cortical critical period, we performed ex vivo – in vitro whole-cell patch clamp recordings from pre-labelled FSIs in the current study. FSIs of verum iTBS-treated rats displayed a higher excitability than sham-treated controls at PD29-38, evident as higher rates of induced action potential firing at low current injections (100-200 pA and a more depolarized resting membrane potential. This effect was absent in younger (PD26-28 and older animals (PD40-62. Slices of verum iTBS-treated rats further showed higher rates of spontaneous EPSCs. Based on these and previous findings we conclude that FSIs are particularly sensitive to theta-burst stimulation during early cortical development, when FSIs show an activity-driven step of maturation which is paralleled by intense growth of the PNNs and subsequent closure of the cortical critical period. Although to be proven further, rTMS may be a possible early intervention to compensate for hypo-activity related mal-development of cortical neuronal circuits.

  18. A Randomized Trial of Comparing the Efficacy of Two Neurofeedback Protocols for Treatment of Clinical and Cognitive Symptoms of ADHD: Theta Suppression/Beta Enhancement and Theta Suppression/Alpha Enhancement

    Directory of Open Access Journals (Sweden)

    Arash Mohagheghi

    2017-01-01

    Full Text Available Introduction. Neurofeedback (NF is an adjuvant or alternative therapy for children with Attention Deficit Hyperactivity Disorder (ADHD. This study intended to compare the efficacy of two different NF protocols on clinical and cognitive symptoms of ADHD. Materials and Methods. In this clinical trial, sixty children with ADHD aged 7 to 10 years old were randomly grouped to receive two different NF treatments (theta suppression/beta enhancement protocol and theta suppression/alpha enhancement protocol. Clinical and cognitive assessments were conducted prior to and following the treatment and also after an eight-week follow-up. Results. Both protocols alleviated the symptoms of ADHD in general (p<0.001, hyperactivity (p<0.001, inattention (p<0.001, and omission errors (p<0.001; however, they did not affect the oppositional and impulsive scales nor commission errors. These effects were maintained after an eight-week intervention-free period. The only significant difference between the two NF protocols was that high-frequency alpha enhancement protocol performed better in suppressing omission errors (p<0.001. Conclusion. The two NF protocols with theta suppression/beta enhancement and theta suppression/alpha enhancement have considerable and comparable effect on clinical symptoms of ADHD. Alpha enhancement protocol was more effective in suppressing omission errors.

  19. The production and crystallization of the human leukocyte antigen class II molecules HLA-DQ2 and HLA-DQ8 complexed with deamidated gliadin peptides implicated in coeliac disease

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, Kate N.; Reid, Hugh H.; Borg, Natalie A.; Broughton, Sophie E.; Huyton, Trevor [The Protein Crystallography Unit, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800 (Australia); Anderson, Robert P. [Autoimmunity and Transplantation Division, Walter and Eliza Hall Institute, 1G Royal Parade, Parkville, Victoria 3050 (Australia); Department of Gastroenterology, The Royal Melbourne Hospital, Grattan Street, Parkville, Victoria 3050 (Australia); McCluskey, James [Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria 3010 (Australia); Rossjohn, Jamie, E-mail: jamie.rossjohn@med.monash.edu.au [The Protein Crystallography Unit, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800 (Australia)

    2007-12-01

    The production and crystallization of human leukocyte antigen class II molecules HLA-DQ2 and HLA-DQ8 in complex with deamidated gliadin peptides is reported. Crystals of HLA-DQ2{sup PQPELPYPQ} diffracted to 3.9 Å, while the HLA-DQ8{sup EGSFQPSQE} crystals diffracted to 2.1 Å, allowing structure determination by molecular replacement. The major histocompatibility complex (MHC) class II molecules HLA-DQ2 and HLA-DQ8 are key risk factors in coeliac disease, as they bind deamidated gluten peptides that are subsequently recognized by CD4{sup +} T cells. Here, the production and crystallization of both HLA-DQ2 and HLA-DQ8 in complex with the deamidated gliadin peptides DQ2 α-I (PQPELPYPQ) and DQ8 α-I (EGSFQPSQE), respectively, are reported.

  20. Class III beta-tubulin is constitutively coexpressed with glial fibrillary acidic protein and nestin in midgestational human fetal astrocytes: implications for phenotypic identity

    Czech Academy of Sciences Publication Activity Database

    Dráberová, Eduarda; Del Valle, L.; Gordon, J.; Marková, Vladimíra; Šmejkalová, Barbora; Bertrand, L.; de Chadarévian, J.-P.; Agamanolis, D.P.; Legido, A.; Khalili, K.; Dráber, Pavel; Katsetos, C.D.

    2008-01-01

    Roč. 67, č. 4 (2008), s. 341-354 ISSN 0022-3069 R&D Projects: GA MŠk LC545; GA ČR GA204/05/2375 Institutional research plan: CEZ:AV0Z50520514 Keywords : astrocytes * class III beta-tubulin * fetal glia Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.140, year: 2008

  1. Killing of Human Melanoma Cells Induced by Activation of Class I Interferon–Regulated Signaling Pathways via MDA-7/IL-24

    Science.gov (United States)

    Ekmekcioglu, Suhendan; Mumm, John B.; Udtha, Malini; Chada, Sunil; Grimm, Elizabeth A.

    2008-01-01

    Restoration of the tumor-suppression function by gene transfer of the melanoma differentiation-associated gene 7 (MDA7)/interleukin 24 (IL-24) successfully induces apoptosis in melanoma tumors in vivo. To address the molecular mechanisms involved, we previously revealed that MDA7/IL-24 treatment of melanoma cells down-regulates interferon regulatory factor (IRF)-1 expression and concomitantly up-regulates IRF-2 expression, which competes with the activity of IRF-1 and reverses the induction of IRF-1–regulated inducible nitric oxide synthase (iNOS). Interferons (IFNs) influence melanoma cell survival by modulating apoptosis. A class I IFN (IFN alfa) has been approved for the treatment of advanced melanoma with some limited success. A class II IFN (IFN gamma), on the other hand, supports melanoma cell survival, possibly through constitutive activation of iNOS expression. We therefore conducted this study to explore the molecular pathways of MDA7/IL-24 regulation of apoptosis via the intracellular induction of IFNs in melanoma. We hypothesized that the restoration of the MDA7/IL-24 axis leads to upregulation of Class I IFNs and induction of the apoptotic cascade. We found that MDA7/IL-24 induces the secretion of endogenous IFN beta, another class I IFN, leading to the arrest of melanoma cell growth and apoptosis. We also identified a series of apoptotic markers that play a role in this pathway, including the regulation of tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) and Fas-FasL. In summary, we described a novel pathway of MDA7/IL-24 regulation of apoptosis in melanoma tumors via endogenous IFN beta induction followed by IRF regulation and TRAIL/FasL system activation. PMID:18511292

  2. Slow oscillation electrical brain stimulation during waking promotes EEG theta activity and memory encoding

    DEFF Research Database (Denmark)

    Kirov, Roumen; Weiss, Carsten; Siebner, Hartwig R

    2009-01-01

    typically occurring during this state of sleep were also enhanced. Here, we show that the same tSOS applied in the waking brain also induced an increase in endogenous EEG slow oscillations (0.4-1.2 Hz), although in a topographically restricted fashion. Applied during wakefulness tSOS, additionally, resulted......The application of transcranial slow oscillation stimulation (tSOS; 0.75 Hz) was previously shown to enhance widespread endogenous EEG slow oscillatory activity when applied during a sleep period characterized by emerging endogenous slow oscillatory activity. Processes of memory consolidation...... induced by tSOS critically depend on brain state. In response to tSOS during wakefulness the brain transposes stimulation by responding preferentially with theta oscillations and facilitated encoding....

  3. Implosion measurements in a high voltage, large diameter, medium density theta pinch

    International Nuclear Information System (INIS)

    Henins, I.; Hammel, J.E.; Jarboe, T.E.; Marshall, J.; Sherwood, A.R.

    1975-01-01

    Extensive sets of density measurements were obtained for two preionization levels with other parameters held constant (B = 0.5 T, n 0 = 4.8 x 10 14 cm -3 , E/sub theta/ = 1 kV/cm). The gross features of the implosion are similar in the two cases, but the density front is double-peaked for the higher preionization case. Generally, the particles move ahead of the driving magnetic field front, but some are also within this front. After reaching the axis the imploding plasma is observed to move outward again through the magnetic field in a manner suggesting anomalous transport. The particles stop at the outer radii. The total number of particles increases during the implosion and thereafter remains about constant. (auth)

  4. Energy storage and transfer with homopolar machine for a linear theta-pinch hybrid reactor

    International Nuclear Information System (INIS)

    Vogel, H.F.; Brennan, M.; Dase, W.G.; Tolk, K.M.; Weldon, W.F.

    1976-01-01

    The energy storage and transfer system for the compression coils of a linear theta-pinch hybrid reactor (LTPHR) are described. High efficiency and low cost are the principal requirements for the energy storage and transfer of 25MJ/m or 25GJ for a 1-km LTPHR. The circuit efficiency must be approximately 90%, and the cost for the circuit 5-6c/J. Scaling laws and simple relationships between circuit efficiency and cost-per-unit energy as a function of the half cycle time are presented. An important consideration concerns the pulse repetition rate of 2.25 pulses per second, 70x10 6 shots/yr, or 1.7x10 9 shots over the 25-yr plant life. Current interruption to initiate energy transfer is not feasible at this rate. Therefore, a simple ringing circuit with contactors to make and break at the periodically occurring zero-current instances, is considered

  5. Compact-Toroid Fusion Reactor (CTOR) based on the Field-Reversed Theta Pinch

    International Nuclear Information System (INIS)

    Hagenson, R.L.; Krakowski, R.A.

    1981-01-01

    Scoping studies of a translating Compact Torus Reactor (CTOR) have been made on the basis of a dynamic plasma model and an overall systems approach. This CTOR embodiment uses a Field-Reversed Theta Pinch as a plasma source. The field-reversed plasmoid would be formed and compressionally heated to ignition prior to injection into and translation through a linear burn chamber, thereby removing the high-technology plamoid source from the hostile reactor environment. Stabilization of the field-reversed plasmoid would be provided by a passive conducting shell located outside the high-temperature blanket but within the low-field superconducting magnets and associated radition shielding. On the basis of this batch-burn but thermally steady-state approach, a reactor concept emerges with a length below approx. 40 m that generates 300 to 400 MWe of net electrical power with a recirculating power fraction less than 0.15

  6. Compact-Toroid fusion reactor based on the field-reversed theta pinch

    International Nuclear Information System (INIS)

    Hagenson, R.L.; Krakowski, R.A.

    1981-03-01

    Early scoping studies based on approximate, analytic models have been extended on the basis of a dynamic plasma model and an overall systems approach to examine a Compact Toroid (CTOR) reactor embodiment that uses a Field-Reversed Theta Pinch as a plasma source. The field-reversed plasmoid would be formed and compressionally heated to ignition prior to injection into and translation through a linear burn chamber, thereby removing the high-technology plasmoid source from the hostile reactor environment. Stabilization of the field-reversed plasmoid would be provided by a passive conducting shell located outside the high-temperature blanket but within the low-field superconducting magnets and associated radiation shielding. On the basis of this batch-burn but thermally steady-state approach, a reactor concept emerges with a length below approx. 40 m that generates 300 to 400 MWe of net electrical power with a recirculating power fraction less than 0.15

  7. Bilateral somatosensory evoked potentials following intermittent theta-burst repetitive transcranial magnetic stimulation.

    Science.gov (United States)

    Premji, Azra; Ziluk, Angela; Nelson, Aimee J

    2010-08-05

    Intermittent theta-burst stimulation (iTBS) is a form of repetitive transcranial magnetic stimulation that may alter cortical excitability in the primary somatosensory cortex (SI). The present study investigated the effects of iTBS on subcortical and early cortical somatosensory evoked potentials (SEPs) recorded over left, iTBS stimulated SI and the right-hemisphere non-stimulated SI. SEPs were recorded before and at 5, 15, and 25 minutes following iTBS. Compared to pre-iTBS, the amplitude of cortical potential N20/P25 was significantly increased for 5 minutes from non-stimulated SI and for 15 to 25 minutes from stimulated SI. Subcortical potentials recorded bilaterally remained unaltered following iTBS. We conclude that iTBS increases the cortical excitability of SI bilaterally and does not alter thalamocortical afferent input to SI. ITBS may provide one avenue to induce cortical plasticity in the somatosensory cortex.

  8. Obtaining Msub(W)-Msub(Z) cos theta in technicolor theories

    International Nuclear Information System (INIS)

    Grady, M.

    1983-01-01

    We show that the successful relation Msub(w) = Msub(z) cos theta is preserved in the technicolor formulation of the dynamical Higgs mechanism provided only that the creation operators for Goldstone bosons associated with broken generators belong to the Isub(w)=1/2 representation of the weak isospin group. We present a plausibility argument that this is indeed the case. No additional isospin or isospin-like global SU(2) symmetries are then required allowing isospin to be spontaneously broken. This may be of help in producing a large msub(c)/msub(s) splitting. It is also shown how the weak hypercharge interaction can produce substantial vacuum isospin breaking in a theory which is only marginally asymptotically free. This mechanism predicts msub(#betta#)μ/msub(μ)approx.=(msub(s)/msub(c)) 3 , providing a natural explanation for small neutrino masses. (orig.)

  9. Cognitive-Neural Effects of Brush Writing of Chinese Characters: Cortical Excitation of Theta Rhythm

    Directory of Open Access Journals (Sweden)

    Min Xu

    2013-01-01

    Full Text Available Chinese calligraphy has been scientifically investigated within the contexts and principles of psychology, cognitive science, and the cognitive neuroscience. On the basis of vast amount of research in the last 30 years, we have developed a cybernetic theory of handwriting and calligraphy to account for the intricate interactions of several psychological dimensions involved in the dynamic act of graphic production. Central to this system of writing are the role of sensory, bio-, cognitive, and neurofeedback mechanisms for the initiation, guidance, and regulation of the writing motions vis-a-vis visual-geometric variations of Chinese characters. This experiment provided the first evidence of cortical excitation in EEG theta wave as a neural hub that integrates information coming from changes in the practitioner’s body, emotions, and cognition. In addition, it has also confirmed neurofeedback as an essential component of the cybernetic theory of handwriting and calligraphy.

  10. Energy storage and transfer with homopolar machine for a linear theta-pinch hybrid reactor

    International Nuclear Information System (INIS)

    Vogel, H.F.; Brennan, M.; Dase, W.G.; Tolk, K.M.; Weldon, W.F.

    1975-12-01

    This report describes the energy storage and transfer system for the compression coil system of a linear theta-pinch hybrid reactor (LTPHR). High efficiency and low cost are the principal requirements for the energy storage and transfer of 25 MJ/m or 25 GJ for a 1-km LTPHR. The circuit efficiency must be approximately 90 percent, and the cost for the circuit 5 to 6 cents/J. Scaling laws and simple relationships between circuit efficiency and cost per unit energy as a function of the half cycle time are presented. Capacitors and homopolor machines are considered as energy storage elements with both functioning basically as capacitors. The advantage of the homopolar machine in this application is its relatively low cost, whereas that of capacitors is better efficiency

  11. Field-reversed configuration produced by a linear theta-pinch, Tupa-1

    International Nuclear Information System (INIS)

    Kayama, M.E.; Boeckelmann, H.K.; Sakanaka, P.H.; Machida, M.

    1987-01-01

    The formation of field reversed configuration, FRC, in one meter mirrorless linear theta-pinch device Tupa-I was observed. This configuration was studied during the first half magnetic cycle of ringing main bank discharge using magnetic probes. The separatrix radius by the exclude flux probe and the ion temperature by visible spectroscopy were measured. The plasma dynamics was observed by the image converter camera. A clear indication of the formation of FRC due to reconnection of the antiparallel bias to the main field and a fast reconnection, less than 0.2 microsec, that is explained in terms of forced reconnection driven by the Kruskal-Schwarzschild instability, are also observed. (author) [pt

  12. FRC formation studies in a field reversed theta pinch with a variable length coil

    International Nuclear Information System (INIS)

    Maqueda, R.; Sobehart, J.; Rodrigo, A.B.

    1987-01-01

    The formation phase of field reversed configurations (FRC) produced using a theta pinch has received considerable attention lately in connection with the possibility of developing formation methods in time scales longer than the Alven radial time, which would permit the use of low-voltage technology and represent an important engineering simplification in the trend towards larger scale machines sup (1)). The mechanisms leading to the loss of trapped reversed flux during the preheating 2 ) and formation sup (3,4)) stages, looking for maximization of this quantity in order to improve on the stability and transport properties of the configuration in its final equilibrium state are investigated. As a result, semi-emperical scaling laws have been obtained relating the reversed flux loss with experimental operating parameters during the early stages of the formation process 1 ). (author) [pt

  13. Predicting {theta}{sub 13} and the neutrino mass scale from quark lepton mass hierarchies

    Energy Technology Data Exchange (ETDEWEB)

    Buchmueller, W.; Domcke, V.; Schmitz, K.

    2011-11-15

    Flavour symmetries of Froggatt-Nielsen type can naturally reconcile the large quark and charged lepton mass hierarchies and the small quark mixing angles with the observed small neutrino mass hierarchies and their large mixing angles. We point out that such a flavour structure, together with the measured neutrino mass squared differences and mixing angles, strongly constrains yet undetermined parameters of the neutrino sector. Treating unknown O(1) parameters as random variables, we obtain surprisingly accurate predictions for the smallest mixing angle, sin{sup 2}2{theta}{sub 13}=0.07{sup +0.11}{sub -0.05}, the smallest neutrino mass, m{sub 1}=2.5{sup +1.7}{sub -1.6} x 10{sup -3} eV, and one Majorana phase, {alpha}{sub 21}/{pi}=1.0{sup +0.2}{sub -0.2}. (orig.)

  14. Immediate effects of Alpha/theta and Sensory-Motor Rhythm feedback on music performance.

    Science.gov (United States)

    Gruzelier, J H; Hirst, L; Holmes, P; Leach, J

    2014-07-01

    This is one of a series of investigations comparing two EEG-neurofeedback protocols - Alpha/theta (A/T) and Sensory-Motor Rhythm (SMR) - for performance enhancement in the Arts, here with the focus on music. The original report (Egner and Gruzelier, 2003) established a beneficial outcome for elite conservatoire musicians following A/T training in two investigations. Subsequently this A/T advantage was replicated for both advanced instrumental and novice singing abilities, including improvisation, while SMR training benefited novice performance only (Gruzelier, Holmes et al., 2014). Here we report a replication of the latter study in university instrumentalists who as before were novice singers with one design change - post-training performances were conducted within the tenth final session instead of on a subsequent occasion. As before expert judges rated the domains of Creativity/Musicality, Communication/Presentation and Technique. The proximity to training of the music performances within the last session likely compromised gains from A/T learning, but perhaps reinforced the impact of SMR training efficacy. In support of validation there was evidence of strong within- and across-session A/T learning and positive linear trends for across-session SMR/theta and SMR/beta-2 ratio learning. In support of mediation learning correlated with music performance. The A/T outcome was markedly discrepant from previous studies and should dispel any impression that the hypnogogic state itself is transferred to the performance context. The effects of SMR ratio training are consistent with an impact on lower-order abilities required in novice performance such as sustained attention and memory, and benefiting all three domains of music assessment. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Impaired cognitive discrimination and discoordination of coupled theta-gamma oscillations in Fmr1 knockout mice

    Science.gov (United States)

    Radwan, Basma; Dvorak, Dino; Fenton, André

    2016-01-01

    Fragile X syndrome (FXS) patients do not make the fragile X mental retardation protein (FMRP). Absence of FMRP causes dysregulated translation, abnormal synaptic plasticity and the most common form of inherited intellectual disability. But FMRP loss has minimal effects on memory itself, making it difficult to understand why absence of FMRP impairs memory discrimination and increases risk of autistic symptoms in patients, such as exaggerated responses to environmental changes. While Fmr1 knockout (KO) and wild-type (WT) mice perform cognitive discrimination tasks, we find abnormal patterns of coupling between theta and gamma oscillations in perisomatic and dendritic hippocampal CA1 local field potentials of the KO. Perisomatic CA1 theta-gamma phase-amplitude coupling (PAC) decreases with familiarity in both the WT and KO, but activating an invisible shock zone, subsequently changing its location, or turning it off, changes the pattern of oscillatory events in the LFPs recorded along the somato-dendritic axis of CA1. The cognition-dependent changes of this pattern of neural activity are relatively constrained in WT mice compared to KO mice, which exhibit abnormally weak changes during the cognitive challenge caused by changing the location of the shock zone and exaggerated patterns of change when the shock zone is turned off. Such pathophysiology might explain how dysregulated translation leads to intellectual disability in FXS. These findings demonstrate major functional abnormalities after the loss of FMRP in the dynamics of neural oscillations and that these impairments would be difficult to detect by steady-state measurements with the subject at rest or in steady conditions. PMID:26792400

  16. Change in hippocampal theta oscillation associated with multiple lever presses in a bimanual two-lever choice task for robot control in rats.

    Directory of Open Access Journals (Sweden)

    Norifumi Tanaka

    Full Text Available Hippocampal theta oscillations have been implicated in working memory and attentional process, which might be useful for the brain-machine interface (BMI. To further elucidate the properties of the hippocampal theta oscillations that can be used in BMI, we investigated hippocampal theta oscillations during a two-lever choice task. During the task body-restrained rats were trained with a food reward to move an e-puck robot towards them by pressing the correct lever, ipsilateral to the robot several times, using the ipsilateral forelimb. The robot carried food and moved along a semicircle track set in front of the rat. We demonstrated that the power of hippocampal theta oscillations gradually increased during a 6-s preparatory period before the start of multiple lever pressing, irrespective of whether the correct lever choice or forelimb side were used. In addition, there was a significant difference in the theta power after the first choice, between correct and incorrect trials. During the correct trials the theta power was highest during the first lever-releasing period, whereas in the incorrect trials it occurred during the second correct lever-pressing period. We also analyzed the hippocampal theta oscillations at the termination of multiple lever pressing during the correct trials. Irrespective of whether the correct forelimb side was used, the power of hippocampal theta oscillations gradually decreased with the termination of multiple lever pressing. The frequency of theta oscillation also demonstrated an increase and decrease, before and after multiple lever pressing, respectively. There was a transient increase in frequency after the first lever press during the incorrect trials, while no such increase was observed during the correct trials. These results suggested that hippocampal theta oscillations reflect some aspects of preparatory and cognitive neural activities during the robot controlling task, which could be used for BMI.

  17. Entorhinal-CA3 Dual-Input Control of Spike Timing in the Hippocampus by Theta-Gamma Coupling.

    Science.gov (United States)

    Fernández-Ruiz, Antonio; Oliva, Azahara; Nagy, Gergő A; Maurer, Andrew P; Berényi, Antal; Buzsáki, György

    2017-03-08

    Theta-gamma phase coupling and spike timing within theta oscillations are prominent features of the hippocampus and are often related to navigation and memory. However, the mechanisms that give rise to these relationships are not well understood. Using high spatial resolution electrophysiology, we investigated the influence of CA3 and entorhinal inputs on the timing of CA1 neurons. The theta-phase preference and excitatory strength of the afferent CA3 and entorhinal inputs effectively timed the principal neuron activity, as well as regulated distinct CA1 interneuron populations in multiple tasks and behavioral states. Feedback potentiation of distal dendritic inhibition by CA1 place cells attenuated the excitatory entorhinal input at place field entry, coupled with feedback depression of proximal dendritic and perisomatic inhibition, allowing the CA3 input to gain control toward the exit. Thus, upstream inputs interact with local mechanisms to determine theta-phase timing of hippocampal neurons to support memory and spatial navigation. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. The relationship between hippocampal EEG theta activity and locomotr behaviour in freely moving rats: effects of vigabatrin

    NARCIS (Netherlands)

    Bouwman, B.M.; Lier, H. van; Nitert, H.E.J.; Drinkenburg, W.H.I.M.; Coenen, A.M.L.; Rijn, C.M. van

    2005-01-01

    The relationship between hippocampal electroencephalogram (EEG) theta activity and locomotor speed in both spontaneous and forced walking conditions was studied in rats after vigabatrin injection (500 mg/kg i.p.). Vigabatrin increased the percentage of time that rats spent being immobile. During

  19. Index of alpha/theta ratio of the electroencephalogram: a new marker for Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Magali eSchmidt

    2013-10-01

    Full Text Available Objective: We evaluated quantitative EEG measures to determine a screening index to discriminate AD patients from normal individuals. Methods: Two groups of individuals older than 50 years, comprising a control group of 57 normal volunteers and a study group of 50 patients with probable AD, were compared. EEG recordings were obtained from subjects in a wake state with eyes closed at rest for 30 min. Logistic regression analysis was conducted. Results: Spectral potentials of the alpha and theta bands were computed for all electrodes and the alpha/theta ratio calculated. Logistic regression of alpha/theta of the mean potential of the C3 and O1 electrodes was carried out. A formula was calculated to aid the diagnosis of AD yielding 76.4 % sensitivity and 84.6 specificity for AD with an area under the ROC curve of 0.92. Conclusions: Logistic regression of alpha/theta of the spectrum of the mean potential of EEG represents a good marker discriminating AD patients from normal controls.

  20. Optical design and performance of F-Theta lenses for high-power and high-precision applications

    Science.gov (United States)

    Yurevich, V. I.; Grimm, V. A.; Afonyushkin, A. A.; Yudin, K. V.; Gorny, S. G.

    2015-09-01

    F-Theta lenses are widely used in remote laser processing. Nowadays, a large variety of scanning systems utilizing these devices are commercially available. In this paper, we demonstrate that all practical issues lose their triviality in designing high-performance F-Theta scanning systems. Laser power scaling requires attention to thermally-induced phenomena and ghost reflections. This requirement considerably complicates optimization of the optical configuration of the system and primary aberration correction, even during preliminary design. Obtaining high positioning accuracy requires taking into consideration all probable reasons for processing field distortion. We briefly describe the key engineering relationships and invariants as well as the typical design of a scanner lens and the main field-flattening techniques. Specific emphasis is directed to consideration of the fundamental nonlinearity of two-mirror scanners. To the best of our knowledge, this issue has not been yet studied. We also demonstrate the benefits of our F-Theta lens optimization technique, which uses a plurality of entrance pupils. The problems of eliminating focused ghost reflections and the effects of thermally-induced processes in high-power F-Theta lenses are considered. A set of multi-path 3D processing and laser cutting experiments were conducted and are presented herein to demonstrate the impact of laser beam degradation on the process performance. A selection of our non-standard optical designs is presented.