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Sample records for integrating electrophysiology contraction

  1. A Computational Model Integrating Electrophysiology, Contraction, and Mitochondrial Bioenergetics in the Ventricular Myocyte

    PubMed Central

    Cortassa, Sonia; Aon, Miguel A.; O'Rourke, Brian; Jacques, Robert; Tseng, Hsiang-Jer; Marbán, Eduardo; Winslow, Raimond L.

    2006-01-01

    An intricate network of reactions is involved in matching energy supply with demand in the heart. This complexity arises because energy production both modulates and is modulated by the electrophysiological and contractile activity of the cardiac myocyte. Here, we present an integrated mathematical model of the cardiac cell that links excitation-contraction coupling with mitochondrial energy generation. The dynamics of the model are described by a system of 50 ordinary differential equations. The formulation explicitly incorporates cytoplasmic ATP-consuming processes associated with force generation and ion transport, as well as the creatine kinase reaction. Changes in the electrical and contractile activity of the myocyte are coupled to mitochondrial energetics through the ATP, Ca2+, and Na+ concentrations in the myoplasmic and mitochondrial matrix compartments. The pseudo steady-state relationship between force and oxygen consumption at various stimulus frequencies and external Ca2+ concentrations is reproduced in both model simulations and direct experiments in cardiac trabeculae under normoxic conditions, recapitulating the linearity between cardiac work and respiration in the heart. Importantly, the model can also reproduce the rapid time-dependent changes in mitochondrial NADH and Ca2+ in response to abrupt changes in workload. The steady-state and dynamic responses of the model were conferred by ADP-dependent stimulation of mitochondrial oxidative phosphorylation and Ca2+-dependent regulation of Krebs cycle dehydrogenases, illustrating how the model can be used as a tool for investigating mechanisms underlying metabolic control in the heart. PMID:16679365

  2. Integrated platform and API for electrophysiological data

    PubMed Central

    Sobolev, Andrey; Stoewer, Adrian; Leonhardt, Aljoscha; Rautenberg, Philipp L.; Kellner, Christian J.; Garbers, Christian; Wachtler, Thomas

    2014-01-01

    Recent advancements in technology and methodology have led to growing amounts of increasingly complex neuroscience data recorded from various species, modalities, and levels of study. The rapid data growth has made efficient data access and flexible, machine-readable data annotation a crucial requisite for neuroscientists. Clear and consistent annotation and organization of data is not only an important ingredient for reproducibility of results and re-use of data, but also essential for collaborative research and data sharing. In particular, efficient data management and interoperability requires a unified approach that integrates data and metadata and provides a common way of accessing this information. In this paper we describe GNData, a data management platform for neurophysiological data. GNData provides a storage system based on a data representation that is suitable to organize data and metadata from any electrophysiological experiment, with a functionality exposed via a common application programming interface (API). Data representation and API structure are compatible with existing approaches for data and metadata representation in neurophysiology. The API implementation is based on the Representational State Transfer (REST) pattern, which enables data access integration in software applications and facilitates the development of tools that communicate with the service. Client libraries that interact with the API provide direct data access from computing environments like Matlab or Python, enabling integration of data management into the scientist's experimental or analysis routines. PMID:24795616

  3. Integrative Systems Models of Cardiac Excitation Contraction Coupling

    PubMed Central

    Greenstein, Joseph L.; Winslow, Raimond L.

    2010-01-01

    Excitation-contraction coupling in the cardiac myocyte is mediated by a number of highly integrated mechanisms of intracellular Ca2+ transport. The complexity and integrative nature of heart cell electrophysiology and Ca2+-cycling has led to an evolution of computational models that have played a crucial role in shaping our understanding of heart function. An important emerging theme in systems biology is that the detailed nature of local signaling events, such as those that occur in the cardiac dyad, have important consequences at higher biological scales. Multi-scale modeling techniques have revealed many mechanistic links between micro-scale events, such as Ca2+ binding to a channel protein, and macro-scale phenomena, such as excitation-contraction coupling gain. Here we review experimentally based multi-scale computational models of excitation-contraction coupling and the insights that have been gained through their application. PMID:21212390

  4. Implementation of Contraction to Electrophysiological Ventricular Myocyte Models, and Their Quantitative Characterization via Post-Extrasystolic Potentiation

    PubMed Central

    Ji, Yanyan Claire; Gray, Richard A.; Fenton, Flavio H.

    2015-01-01

    Heart failure (HF) affects over 5 million Americans and is characterized by impairment of cellular cardiac contractile function resulting in reduced ejection fraction in patients. Electrical stimulation such as cardiac resynchronization therapy (CRT) and cardiac contractility modulation (CCM) have shown some success in treating patients with HF. Computer simulations have the potential to help improve such therapy (e.g. suggest optimal lead placement) as well as provide insight into the underlying mechanisms which could be beneficial. However, these myocyte models require a quantitatively accurate excitation-contraction coupling such that the electrical and contraction predictions are correct. While currently there are close to a hundred models describing the detailed electrophysiology of cardiac cells, the majority of cell models do not include the equations to reproduce contractile force or they have been added ad hoc. Here we present a systematic methodology to couple first generation contraction models into electrophysiological models via intracellular calcium and then compare the resulting model predictions to experimental data. This is done by using a post-extrasystolic pacing protocol, which captures essential dynamics of contractile forces. We found that modeling the dynamic intracellular calcium buffers is necessary in order to reproduce the experimental data. Furthermore, we demonstrate that in models the mechanism of the post-extrasystolic potentiation is highly dependent on the calcium released from the Sarcoplasmic Reticulum. Overall this study provides new insights into both specific and general determinants of cellular contractile force and provides a framework for incorporating contraction into electrophysiological models, both of which will be necessary to develop reliable simulations to optimize electrical therapies for HF. PMID:26317204

  5. Implementation of Contraction to Electrophysiological Ventricular Myocyte Models, and Their Quantitative Characterization via Post-Extrasystolic Potentiation.

    PubMed

    Ji, Yanyan Claire; Gray, Richard A; Fenton, Flavio H

    2015-01-01

    Heart failure (HF) affects over 5 million Americans and is characterized by impairment of cellular cardiac contractile function resulting in reduced ejection fraction in patients. Electrical stimulation such as cardiac resynchronization therapy (CRT) and cardiac contractility modulation (CCM) have shown some success in treating patients with HF. Computer simulations have the potential to help improve such therapy (e.g. suggest optimal lead placement) as well as provide insight into the underlying mechanisms which could be beneficial. However, these myocyte models require a quantitatively accurate excitation-contraction coupling such that the electrical and contraction predictions are correct. While currently there are close to a hundred models describing the detailed electrophysiology of cardiac cells, the majority of cell models do not include the equations to reproduce contractile force or they have been added ad hoc. Here we present a systematic methodology to couple first generation contraction models into electrophysiological models via intracellular calcium and then compare the resulting model predictions to experimental data. This is done by using a post-extrasystolic pacing protocol, which captures essential dynamics of contractile forces. We found that modeling the dynamic intracellular calcium buffers is necessary in order to reproduce the experimental data. Furthermore, we demonstrate that in models the mechanism of the post-extrasystolic potentiation is highly dependent on the calcium released from the Sarcoplasmic Reticulum. Overall this study provides new insights into both specific and general determinants of cellular contractile force and provides a framework for incorporating contraction into electrophysiological models, both of which will be necessary to develop reliable simulations to optimize electrical therapies for HF.

  6. Data integration: Combined Imaging and Electrophysiology data in the cloud

    PubMed Central

    Kini, Lohith G.; Davis, Kathryn A.; Wagenaar, Joost B.

    2015-01-01

    There has been an increasing effort to correlate electrophysiology data with imaging in patients with refractory epilepsy over recent years. IEEG.org provides a free-access, rapidly growing archive of imaging data combined with electrophysiology data and patient metadata. It currently contains over 1200 human and animal datasets, with multiple data modalities associated with each dataset (neuroimaging, EEG, EKG, de-identified clinical and experimental data, etc.). The platform is developed around the concept that scientific data sharing requires a flexible platform that allows sharing of data from multiple file-formats. IEEG.org provides high and low-level access to the data in addition to providing an environment in which domain experts can find, visualize, and analyze data in an intuitive manner. Here, we present a summary of the current infrastructure of the platform, available datasets and goals for the near future. PMID:26044858

  7. 48 CFR 3016.170 - Contracts with Lead System Integrators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 7 2011-10-01 2011-10-01 false Contracts with Lead System... Selecting Contract Types 3016.170 Contracts with Lead System Integrators. The contracting officer should... contracts with lead system integrators in the production, fielding and sustainment of complex systems....

  8. 48 CFR 3016.170 - Contracts with Lead System Integrators.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 7 2014-10-01 2014-10-01 false Contracts with Lead System... Selecting Contract Types 3016.170 Contracts with Lead System Integrators. The contracting officer should... contracts with lead system integrators in the production, fielding and sustainment of complex systems....

  9. 48 CFR 3016.170 - Contracts with Lead System Integrators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Contracts with Lead System... Selecting Contract Types 3016.170 Contracts with Lead System Integrators. The contracting officer should... contracts with lead system integrators in the production, fielding and sustainment of complex systems....

  10. 48 CFR 3016.170 - Contracts with Lead System Integrators.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 7 2012-10-01 2012-10-01 false Contracts with Lead System... Selecting Contract Types 3016.170 Contracts with Lead System Integrators. The contracting officer should... contracts with lead system integrators in the production, fielding and sustainment of complex systems....

  11. Electrophysiological and Mechanical Characteristics in Human Ileal Motility: Recordings of Slow Waves Conductions and Contractions, In vitro.

    PubMed

    Ryoo, Seung-Bum; Oh, Heung-Kwon; Moon, Sang Hui; Choe, Eun Kyung; Yu, Sung A; Park, Sung-Hye; Park, Kyu Joo

    2015-11-01

    Little human tissue data are available for slow waves and migrating motor complexes, which are the main components of small bowel motility. We investigated the electrophysiological and mechanical characteristics of human ileal motility, in vitro. Ileum was obtained from patients undergoing bowel resection. Electrophysiological microelectrode recordings for membrane potential changes and mechanical tension recordings for contraction from smooth muscle strips and ileal segments were performed. Drugs affecting the enteric nervous system were applied to measure the changes in activity. Slow waves were detected with a frequency of 9~10/min. There were no cross-sectional differences in resting membrane potential (RMP), amplitude or frequency between outer and inner circular muscle (CM), suggesting that electrical activities could be effectively transmitted from outer to inner CM. The presence of the interstitial cell of Cajal (ICC) at the linia septa was verified by immunohistochemistry. Contractions of strips and segments occurred at a frequency of 3~4/min and 1~2/min, respectively. The frequency, amplitude and area under the curve were similar between CM and LM. In segments, contractions of CM were associated with LM, but propagation varied with antegrade and retrograde directions. Atropine, N(W)-oxide-L-arginine, and sodium nitroprusside exhibited different effects on RMP and contractions. There were no cross-sectional differences with regard to the characteristics of slow waves in CM. The frequency of contractions in smooth muscle strips and ileal segments was lower than slow waves. The directions of propagation were diverse, indicating both mixing and transport functions of the ileum.

  12. ISPMER: Integrated system for combined PET, MRI, and electrophysiological recording in somatosensory studies in rats

    NASA Astrophysics Data System (ADS)

    Shih, Yen-Yu; Chen, You-Yin; Chen, Jyh-Cheng; Chang, Chen; Jaw, Fu-Shan

    2007-10-01

    The present study developed an integrated system for use in combined PET, MRI, and electrophysiological recording in somatosensory studies in rats, called ISPMER. A stereotaxic frame was designed for animal positioning that could be used in all three measurement modalities, and its dimensions complied with the gold standard of the Paxinos and Watson rat brain atlas. A graphical user interface was developed for analyzing the data using several signal processing algorithms. This integrated system provides a novel interface for the recording and processing of three-dimensional neuronal signals in three modalities.

  13. Privacy Impact Assessment for the Integrated Contracts Management System

    EPA Pesticide Factsheets

    The Integrated Contracts Management System collects contact information and other Personally Identifiable Information (PII). Learn how this data will be collected in the system, how it will be used, access to the data, and the purpose of data collection.

  14. Integrated, automated revenue management for managed care contracts.

    PubMed

    Burckhart, Kent

    2002-04-01

    Faced with increasing managed care penetration and declining net revenue in recent years, healthcare providers increasingly are emphasizing revenue management. To streamline processes and reduce costs in this area, many healthcare providers have implemented or are considering automated contract management systems. When selecting such a system, healthcare financial managers should make certain that the system can interface with both patient-accounting and decision-support systems of the organization. This integration enhances a healthcare provider's financial viability by providing integrated revenue-management capabilities to analyze projected performance of proposed managed care contracts and actual performance of existing contracts.

  15. Neuromuscular fatigue following isometric contractions with similar torque time integral.

    PubMed

    Rozand, V; Cattagni, T; Theurel, J; Martin, A; Lepers, R

    2015-01-01

    Torque time integral (TTI) is the combination of intensity and duration of a contraction. The aim of this study was to compare neuromuscular alterations following different isometric sub-maximal contractions of the knee extensor muscles but with similar TTI. Sixteen participants performed 3 sustained contractions at different intensities (25%, 50%, and 75% of Maximal Voluntary Contraction (MVC) torque) with different durations (68.5±33.4 s, 35.1±16.8 s and 24.8±12.9 s, respectively) but similar TTI value. MVC torque, maximal voluntary activation level (VAL), M-wave characteristics and potentiated doublet amplitude were assessed before and immediately after the sustained contractions. EMG activity of the vastus lateralis (VL) and -rectus femoris (RF) muscles was recorded during the sustained contractions. MVC torque reduction was similar in the 3 conditions after the exercise (-23.4±2.7%). VAL decreased significantly in a similar extent (-3.1±1.3%) after the 3 sustained contractions. Potentiated doublet amplitude was similarly reduced in the 3 conditions (-19.7±1.5%), but VL and RF M-wave amplitudes remained unchanged. EMG activity of VL and RF muscles increased in the same extent during the 3 contractions (VL: 54.5±40.4%; RF: 53.1±48.7%). These results suggest that central and peripheral alterations accounting for muscle fatigue are similar following isometric contractions with similar TTI. TTI should be considered in the exploration of muscle fatigue during sustained isometric contractions.

  16. Locally Contractive Dynamics in Generalized Integrate-and-Fire Neurons.

    PubMed

    Jimenez, Nicolas D; Mihalas, Stefan; Brown, Richard; Niebur, Ernst; Rubin, Jonathan

    2013-09-10

    Integrate-and-fire models of biological neurons combine differential equations with discrete spike events. In the simplest case, the reset of the neuronal voltage to its resting value is the only spike event. The response of such a model to constant input injection is limited to tonic spiking. We here study a generalized model in which two simple spike-induced currents are added. We show that this neuron exhibits not only tonic spiking at various frequencies but also the commonly observed neuronal bursting. Using analytical and numerical approaches, we show that this model can be reduced to a one-dimensional map of the adaptation variable and that this map is locally contractive over a broad set of parameter values. We derive a sufficient analytical condition on the parameters for the map to be globally contractive, in which case all orbits tend to a tonic spiking state determined by the fixed point of the return map. We then show that bursting is caused by a discontinuity in the return map, in which case the map is piecewise contractive. We perform a detailed analysis of a class of piecewise contractive maps that we call bursting maps and show that they robustly generate stable bursting behavior. To the best of our knowledge, this work is the first to point out the intimate connection between bursting dynamics and piecewise contractive maps. Finally, we discuss bifurcations in this return map, which cause transitions between spiking patterns.

  17. Phase Zero Contracting Operations (PZCO) -- Strategic and Integrative Planning for Contingency and Expeditionary Operations

    DTIC Science & Technology

    2012-05-02

    Tier Model ( TTM ) ........................... 15  A.  Credentialed Contract Planners Integrated with Operations Planners...Planners The Three-tier Model ( TTM ) was published to address the challenges inherent in contracting in complex military operations (Yoder, 2004). The...Contingency Contracting, Expeditionary Contracting, Humanitarian Aid, Disaster Relief, Advanced Planning, Three-tier Model , YTTM, APEX, JOPES, JCASO

  18. 48 CFR 3016.170 - Contracts with Lead System Integrators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., HOMELAND SECURITY ACQUISITION REGULATION (HSAR) CONTRACT METHODS AND CONTRACT TYPES TYPES OF CONTRACTS... negotiate the most appropriate contract type and fee structure based on risks inherent in the work to be... with the work to be performed and the risks assumed. Worthwhile existing guidance on contract...

  19. Salience-based integration of redundant signals in visual pop-out search: evidence from behavioral and electrophysiological measures.

    PubMed

    Krummenacher, Joseph; Grubert, Anna; Töllner, Thomas; Müller, Hermann J

    2014-03-19

    Behavioral and electrophysiological evidence is presented suggesting that, in visual search for feature singleton targets, multidimensional signals are integrated at a preselective stage of processing. Observers searched for a target that was consistently defined by the same features, but differed from the variable context either nonredundantly by one or redundantly by two dimensionally different features. The behavioral results showed reaction time redundancy gains and evidence of coactive processing, and the electrophysiological analyses revealed the latency of the N2pc component of the event-related potential (ERP) to be expedited by redundant relative to nonredundant displays, while the response-related lateralized readiness potential (LRP) remained unaffected. These findings suggest that target signal integration in singleton search paradigms occurs pre-attentively, that is, prior to focal-attentional target selection, with observers basing their responses on the detection of featureless saliency signals, even under conditions in which the target features remain constant and are known in advance. These results have implications for theories assuming top-down influences in feature detection.

  20. Mechanisms of Percept-Percept and Image-Percept Integration in Vision: Behavioral and Electrophysiological Evidence

    ERIC Educational Resources Information Center

    Dalvit, Silvia; Eimer, Martin

    2011-01-01

    Previous research has shown that the detection of a visual target can be guided not only by the temporal integration of two percepts, but also by integrating a percept and an image held in working memory. Behavioral and event-related brain potential (ERP) measures were obtained in a target detection task that required temporal integration of 2…

  1. Integration of electrophysiological recordings with single-cell RNA-seq data identifies neuronal subtypes.

    PubMed

    Fuzik, János; Zeisel, Amit; Máté, Zoltán; Calvigioni, Daniela; Yanagawa, Yuchio; Szabó, Gábor; Linnarsson, Sten; Harkany, Tibor

    2016-02-01

    Traditionally, neuroscientists have defined the identity of neurons by the cells' location, morphology, connectivity and excitability. However, the direct relationship between these parameters and the molecular phenotypes has remained largely unexplored. Here, we present a method for obtaining full transcriptome data from single neocortical pyramidal cells and interneurons after whole-cell patch-clamp recordings in mouse brain slices. In our approach, termed Patch-seq, a patch-clamp stimulus protocol is followed by the aspiration of the entire somatic compartment into the recording pipette, reverse transcription of RNA including addition of unique molecular identifiers, cDNA amplification, Illumina library preparation and sequencing. We show that Patch-seq reveals a close link between electrophysiological characteristics, responses to acute chemical challenges and RNA expression of neurotransmitter receptors and channels. Moreover, it distinguishes neuronal subpopulations that correspond to both well-established and, to our knowledge, hitherto undescribed neuronal subtypes. Our findings demonstrate the ability of Patch-seq to precisely map neuronal subtypes and predict their network contributions in the brain.

  2. Parametric design and correlational analyses help integrating fMRI and electrophysiological data during face processing.

    PubMed

    Horovitz, Silvina G; Rossion, Bruno; Skudlarski, Pawel; Gore, John C

    2004-08-01

    Face perception is typically associated with activation in the inferior occipital, superior temporal (STG), and fusiform gyri (FG) and with an occipitotemporal electrophysiological component peaking around 170 ms on the scalp, the N170. However, the relationship between the N170 and the multiple face-sensitive activations observed in neuroimaging is unclear. It has been recently shown that the amplitude of the N170 component monotonically decreases as gaussian noise is added to a picture of a face [Jemel et al., 2003]. To help clarify the sources of the N170 without a priori assumptions regarding their number and locations, ERPs and fMRI were recorded in five subjects in the same experiment, in separate sessions. We used a parametric paradigm in which the amplitude of the N170 was modulated by varying the level of noise in a picture, and identified regions where the percent signal change in fMRI correlated with the ERP data. N170 signals were observed for pictures of both cars and faces but were stronger for faces. A monotonic decrease with added noise was observed for the N170 at right hemisphere sites but was less clear on the left and occipital central sites. Correlations between fMRI signal and N170 amplitudes for faces were highly significant (P < 0.001) in bilateral fusiform gyrus and superior temporal gyrus. For cars, the strongest correlations were observed in the parahippocampal region and in the STG (P < 0.005). Besides contributing to clarify the spatiotemporal course of face processing, this study illustrates how ERP information may be used synergistically in fMRI analyses. Parametric designs may be developed further to provide some timing information on fMRI activity and help identify the generators of ERP signals.

  3. Electrophysiological Evidence for Incremental Lexical-Semantic Integration in Auditory Compound Comprehension

    ERIC Educational Resources Information Center

    Koester, Dirk; Holle, Henning; Gunter, Thomas C.

    2009-01-01

    The present study investigated the time-course of semantic integration in auditory compound word processing. Compounding is a productive mechanism of word formation that is used frequently in many languages. Specifically, we examined whether semantic integration is incremental or is delayed until the head, the last constituent in German, is…

  4. Contractions

    MedlinePlus

    ... feel tightening of your uterus muscles at irregular intervals or a squeezing sensation in your lower abdomen ... beginning of childbirth. These contractions come at regular intervals, usually move from the back to the lower ...

  5. Mechanisms of percept-percept and image-percept integration in vision: behavioral and electrophysiological evidence.

    PubMed

    Dalvit, Silvia; Eimer, Martin

    2011-02-01

    Previous research has shown that the detection of a visual target can be guided not only by the temporal integration of two percepts, but also by integrating a percept and an image held in working memory. Behavioral and event-related brain potential (ERP) measures were obtained in a target detection task that required temporal integration of 2 successively presented stimuli in the left or right hemifield. Task performance was good when both displays followed each other immediately (percept-percept integration) and when displays were separated by a 300- or 900-ms interval (image-percept integration), but was poor with intermediate interstimulus intervals. An enhanced posterior negativity at electrodes contralateral to the side of the target was observed for percept-percept and for image-percept integration, demonstrating that both are based on spatiotopic representations. However, this contralateral negativity emerged later and was more sustained on trials with long interstimulus intervals, indicating that image-percept integration is slower and involves a sustained activation of working memory.

  6. Contract-Based Integration of Cyber-Physical Analyses (Poster)

    DTIC Science & Technology

    2014-11-07

    for existential quan- tification). A universally ( existentially ) quantified contract is satisfied if and only if UNSAT (SAT) is returned. For...property specification in Promela. A universally ( existentially ) quantified contract is satisfied if and only if the LTL property holds for all (at

  7. Fall 2014 SEI Research Review Contract-Based Integration of CPS Analyses

    DTIC Science & Technology

    2014-10-28

    2014 Carnegie Mellon University Fall 2014 SEI Research Review Contract-Based Integration of CPS Analyses Software Engineering Institute...DATE 28 OCT 2014 2. REPORT TYPE N/A 3. DATES COVERED 4. TITLE AND SUBTITLE Contract-Based Integration of CPS Analyses - SEI Research Review...etc. Large CPS are integrated out of components developed by suppliers that use their own analysis methods and make their own assumptions

  8. Contract-Based Integration of Cyber-Physical Analyses

    DTIC Science & Technology

    2014-10-14

    Physical Analyses 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Ivan Ruchkin, Dionisio De Niz, Sagar Chaki, David Garlan...Architectural views tackle model consistency, not analytic tool consistency [3][4] ● Meta-level AADL languages do not allow domain-specific semantics [5...O- automata by over-approximation of continuous interaction, 2004 [2] Sangiovanni-Vincentelli et al. Taming Dr. Frankenstein: contract-based design

  9. Contract-Based Integration of Cyber-Physical Analyses

    DTIC Science & Technology

    2014-10-14

    Physical Analyses 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Dionisio de Niz Ivan Ruchkin; Sagar Chaki; David Garlan...Architectural views tackle model consistency, not analytic tool consistency [3][4] ● Meta-level AADL languages do not allow domain-specific semantics [5...O- automata by over-approximation of continuous interaction, 2004 [2] Sangiovanni-Vincentelli et al. Taming Dr. Frankenstein: contract-based design

  10. Electrophysiological Endophenotypes for Schizophrenia

    PubMed Central

    Owens, Emily; Bachman, Peter; Glahn, David C; Bearden, Carrie E

    2016-01-01

    Endophenotypes are quantitative, heritable traits that may help to elucidate the pathophysiologic mechanisms underlying complex disease syndromes, such as schizophrenia. They can be assessed at numerous levels of analysis; here, we review electrophysiological endophenotypes that have shown promise in helping us understand schizophrenia from a more mechanistic point of view. For each endophenotype, we describe typical experimental procedures, reliability, heritability, and reported gene and neurobiological associations. We discuss recent findings regarding the genetic architecture of specific electrophysiological endophenotypes, as well as converging evidence from EEG studies implicating disrupted balance of glutamatergic signaling and GABA-ergic inhibition in the pathophysiology of schizophrenia. We conclude that refining the measurement of electrophysiological endophenotypes, expanding genetic association studies, and integrating datasets are important next steps for understanding the mechanisms that connect identified genetic risk loci for schizophrenia to the disease phenotype. PMID:26954597

  11. Electrophysiological correlates of cross-linguistic semantic integration in hearing signers: N400 and LPC.

    PubMed

    Zachau, Swantje; Korpilahti, Pirjo; Hämäläinen, Jarmo A; Ervast, Leena; Heinänen, Kaisu; Suominen, Kalervo; Lehtihalmes, Matti; Leppänen, Paavo H T

    2014-07-01

    We explored semantic integration mechanisms in native and non-native hearing users of sign language and non-signing controls. Event-related brain potentials (ERPs) were recorded while participants performed a semantic decision task for priming lexeme pairs. Pairs were presented either within speech or across speech and sign language. Target-related ERP responses were subjected to principal component analyses (PCA), and neurocognitive basis of semantic integration processes were assessed by analyzing the N400 and the late positive complex (LPC) components in response to spoken (auditory) and signed (visual) antonymic and unrelated targets. Semantically-related effects triggered across modalities would indicate a similar tight interconnection between the signers׳ two languages like that described for spoken language bilinguals. Remarkable structural similarity of the N400 and LPC components with varying group differences between the spoken and signed targets were found. The LPC was the dominant response. The controls׳ LPC differed from the LPC of the two signing groups. It was reduced to the auditory unrelated targets and was less frontal for all the visual targets. The visual LPC was more broadly distributed in native than non-native signers and was left-lateralized for the unrelated targets in the native hearing signers only. Semantic priming effects were found for the auditory N400 in all groups, but only native hearing signers revealed a clear N400 effect to the visual targets. Surprisingly, the non-native signers revealed no semantically-related processing effect to the visual targets reflected in the N400 or the LPC; instead they appeared to rely more on visual post-lexical analyzing stages than native signers. We conclude that native and non-native signers employed different processing strategies to integrate signed and spoken semantic content. It appeared that the signers׳ semantic processing system was affected by group-specific factors like language

  12. Economic contraction and birth outcomes: an integrative review.

    PubMed

    Zilko, C E Margerison

    2010-01-01

    BACKGROUND Previous research has demonstrated an association between economic contraction at both the individual and aggregate level, and adverse health outcomes. Proposed mechanisms include increased psychosocial stress and loss of resources. The aim of this review is to assess the quantity, validity and consistency of empirical evidence examining economic contraction and birth outcomes. METHODS Empirical, English-language articles examining the effects of economic change at either the aggregate or individual level on birthweight, length of gestation, neonatal mortality and the secondary sex ratio were identified using PubMed and ISI Web of Knowledge. Studies were organized by level of analysis and birth outcome and evaluated for internal and external validity. RESULTS One individual-level study reported a strong association between individual shift to inadequate employment and decreased birthweight. Of seven aggregate-level studies on birthweight, five exhibited moderate to strong validity but reported inconsistent findings. Similarly, findings from five studies (four with moderate to strong validity) examining rates of neonatal mortality reported inconsistent findings. Three of four moderate to strong studies reported a reduced secondary sex ratio following economic contraction. CONCLUSIONS Associations between economic contraction and birthweight, neonatal mortality and the secondary sex ratio remain speculative. Consensus on methodology is needed to compare findings across studies. Further research on economic contraction and the secondary sex ratio, as well as individual-level birthweight and length of gestation, is warranted.

  13. Electrophysiological correlates reflect the integration of model-based and model-free decision information.

    PubMed

    Eppinger, Ben; Walter, Maik; Li, Shu-Chen

    2017-01-03

    In this study, we investigated the interplay of habitual (model-free) and goal-directed (model-based) decision processes by using a two-stage Markov decision task in combination with event-related potentials (ERPs) and computational modeling. To manipulate the demands on model-based decision making, we applied two experimental conditions with different probabilities of transitioning from the first to the second stage of the task. As we expected, when the stage transitions were more predictable, participants showed greater model-based (planning) behavior. Consistent with this result, we found that stimulus-evoked parietal (P300) activity at the second stage of the task increased with the predictability of the state transitions. However, the parietal activity also reflected model-free information about the expected values of the stimuli, indicating that at this stage of the task both types of information are integrated to guide decision making. Outcome-related ERP components only reflected reward-related processes: Specifically, a medial prefrontal ERP component (the feedback-related negativity) was sensitive to negative outcomes, whereas a component that is elicited by reward (the feedback-related positivity) increased as a function of positive prediction errors. Taken together, our data indicate that stimulus-locked parietal activity reflects the integration of model-based and model-free information during decision making, whereas feedback-related medial prefrontal signals primarily reflect reward-related decision processes.

  14. Promised and Delivered Inducements and Contributions: An Integrated View of Psychological Contract Appraisal

    ERIC Educational Resources Information Center

    Lambert, Lisa Schurer

    2011-01-01

    The reciprocal exchange of employees' work for pay that is central to employment relationships is viewed here through the lens of the psychological contract. A psychological contract involves promised inducements, promised contributions, delivered inducements, and delivered contributions: How an employee cognitively integrates these 4 elements is…

  15. Electrophysiological and Behavioral Outcomes of Berard Auditory Integration Training (AIT) in Children with Autism Spectrum Disorder.

    PubMed

    Sokhadze, Estate M; Casanova, Manuel F; Tasman, Allan; Brockett, Sally

    2016-12-01

    Autism is a pervasive developmental disorder of childhood characterized by deficits in social interaction, language, and stereotyped behaviors along with a restricted range of interests. It is further marked by an inability to perceive and respond to social and emotional signals in a typical manner. This might due to the functional disconnectivity of networks important for specific aspects of social cognition and behavioral control resulting in deficits of sensory information integration. According to several recent theories sensory processing and integration abnormalities may play an important role in impairments of perception, cognition, and behavior in individuals with autism. Among these sensory abnormalities, auditory perception distortion may contribute to many typical symptoms of autism. The present study used Berard's technique of auditory integration training (AIT) to improve sound integration in children with autism. It also aimed to understand the abnormal neural and functional mechanisms underlying sound processing distortion in autism by incorporating behavioral, psychophysiological and neurophysiological outcomes. It was proposed that exposure to twenty 30-min AIT sessions (total 10 h of training) would result in improved behavioral evaluation scores, improve profile of cardiorespiratory activity, and positively affect both early [N1, mismatch negativity (MMN)] and late (P3) components of evoked potentials in auditory oddball task. Eighteen children with autism spectrum disorder (ASD) participated in the study. A group of 16 typically developing children served as a contrast group in the auditory oddball task. Autonomic outcomes of the study reflected a linear increase of heart rate variability measures and respiration rate. Comparison of evoked potential characteristics of children with ASD versus typically developing children revealed several group difference findings, more specifically, a delayed latency of N1 to rare and frequent stimuli, larger

  16. Operational Contract Support: Actions Needed to Enhance the Collection, Integration, and Sharing of Lessons Learned

    DTIC Science & Technology

    2015-03-01

    Additionally, the Army’s Acquisition, Logistics and Technology-Integration Office has fully integrated with the Combined Arms Support Command’s Reverse ...Acquisition, Technology and Logistics ) Memorandum, Charter for the Department of Defense Operational Contract Support Functional Capabilities Integration...Secretary of Defense for Acquisition, Technology and Logistics has overall responsibility for establishing and publishing policies and procedures

  17. [Boundaries and integrity in the "Social Contract for Spanish Science", 1907-1939].

    PubMed

    Gómez, Amparo

    2014-01-01

    This article analyzes the relationship between science and politics in Spain in the early 20th century from the perspective of the Social Contract for Science. The article shows that a genuine social contract for science was instituted in Spain during this period, although some boundary and integrity problems emerged. These problems are analyzed, showing that the boundary problems were a product of the conservative viewpoint on the relationship between science and politics, while the integrity problems involved the activation of networks of influence in the awarding of scholarships to study abroad. Finally, the analysis reveals that these problems did not invalidate the Spanish social contract for science.

  18. Warfighter Support: DOD Needs Additional Steps to Fully Integrate Operational Contract Support into Contingency Planning

    DTIC Science & Technology

    2013-02-01

    Planning Report to the Chairman, Subcommittee on Contracting Oversight, Committee on Homeland Security and Governmental Affairs, U.S. Senate...TITLE AND SUBTITLE Warfighter Support: DOD Needs Additional Steps to Fully Integrate Operational Contract Support into Contingency Planning 5a...Support into Contingency Planning Why GAO Did This Study DOD has relied extensively on contractors for operations in Iraq and Afghanistan over the

  19. A Three-Dimensional Simulation Model of Cardiomyocyte Integrating Excitation-Contraction Coupling and Metabolism

    PubMed Central

    Hatano, Asuka; Okada, Jun-ichi; Washio, Takumi; Hisada, Toshiaki; Sugiura, Seiryo

    2011-01-01

    Recent studies have revealed that Ca2+ not only regulates the contraction of cardiomyocytes, but can also function as a signaling agent to stimulate ATP production by the mitochondria. However, the spatiotemporal resolution of current experimental techniques limits our investigative capacity to understand this phenomenon. Here, we created a detailed three-dimensional (3D) cardiomyocyte model to study the subcellular regulatory mechanisms of myocardial energetics. The 3D cardiomyocyte model was based on the finite-element method, with detailed subcellular structures reproduced, and it included all elementary processes involved in cardiomyocyte electrophysiology, contraction, and ATP metabolism localized to specific loci. The simulation results were found to be reproducible and consistent with experimental data regarding the spatiotemporal pattern of cytosolic, intrasarcoplasmic-reticulum, and mitochondrial changes in Ca2+; as well as changes in metabolite levels. Detailed analysis suggested that although the observed large cytosolic Ca2+ gradient facilitated uptake by the mitochondrial Ca2+ uniporter to produce cyclic changes in mitochondrial Ca2+ near the Z-line region, the average mitochondrial Ca2+ changes slowly. We also confirmed the importance of the creatine phosphate shuttle in cardiac energy regulation. In summary, our 3D model provides a powerful tool for the study of cardiac function by overcoming some of the spatiotemporal limitations of current experimental approaches. PMID:22261047

  20. Phase Zero Operations for Contingency and Expeditionary Contracting-Keys to Fully Integrating Contracting into Operational Planning and Execution

    DTIC Science & Technology

    2010-08-02

    based contracting ( EBC ) execution throughout all of the following phases of the Unified Combatant Commander’s campaign plan: shaping, deterring...General of the Joint Contracting Command-Iraq/Afghanistan (JCC–I/A) pioneered effects-based contracting ( EBC ) to align tactical contracting efforts...work based on the warfighters’ main efforts.” (Poree et al., 2008a, 2008b) This project applied EBC methodologies and the systems engineering

  1. Challenges of commissioning and contracting for integrated care in the National Health Service (NHS) in England.

    PubMed

    Addicott, Rachael

    2016-01-01

    For many years there has been a separation between purchasing and provision of services in the English National Health Service (NHS). Many studies report that this commissioning function has been weak: purchasers have had little impact or power in negotiations with large acute providers, and have had limited strategic control over the delivery of care. Nevertheless, commissioning has become increasingly embedded in the NHS structure since the arrival of Clinical Commissioning Groups (CCGs) in 2012. Recently, some of these CCGs have focused on how they can contract and commission in different ways to stimulate greater collaboration across providers. This paper examines experiences of commissioning and contracting for integrated care in the English NHS, based on a series of national-level interviews and case studies of five health economies that are implementing novel contracting models. The cases illustrated here demonstrate early experiments to drive innovation through contracting in the NHS that have largely relied on the vision of individual teams or leaders, in combination with external legal, procurement and actuarial support. It is unlikely that this approach will be sustainable or replicable across the country or internationally, despite the best intentions of commissioners. Designing and operating novel contractual approaches will require considerable determination, alongside advanced skills in procurement, contract management and commissioning. The cost of developing new contractual approaches is high, and as the process is difficult and resource-intensive, it is likely that dedicated teams or programs will be required to drive significant improvement.

  2. Promised and delivered inducements and contributions: an integrated view of psychological contract appraisal.

    PubMed

    Lambert, Lisa Schurer

    2011-07-01

    The reciprocal exchange of employees' work for pay that is central to employment relationships is viewed here through the lens of the psychological contract. A psychological contract involves promised inducements, promised contributions, delivered inducements, and delivered contributions: How an employee cognitively integrates these 4 elements is a central question in psychological contract theory. Three alternative approaches for integrating the 4 elements were drawn from discrepancy theory, from equity theory, and from need theories of satisfaction, respectively. Experimental findings disconfirmed the discrepancy and equity approaches. Findings were consistent with the premise of the needs model, which is that appraisal is driven by how psychological contract elements facilitate or hinder an employee's effort to fulfill personal needs. Results showed that promised and delivered pay and work contribute uniquely to appraisal but that they vary in their influence on appraisal. These findings were consistent with the needs model principle that elements proximal to need satisfaction matter more than distal elements. That is, what is delivered (for pay and for work) matters more than what is promised, and pay matters more than work.

  3. Liposome chaperon in cell-free membrane protein synthesis: one-step preparation of KcsA-integrated liposomes and electrophysiological analysis by the planar bilayer method.

    PubMed

    Ando, M; Akiyama, M; Okuno, D; Hirano, M; Ide, T; Sawada, S; Sasaki, Y; Akiyoshi, K

    2016-02-01

    Chaperoning functions of liposomes were investigated using cell-free membrane protein synthesis. KcsA potassium channel-reconstituted liposomes were prepared directly using cell-free protein synthesis. In the absence of liposomes, all synthesized KcsA protein aggregated. In the presence of liposomes, however, synthesized KcsA spontaneously integrated into the liposome membrane. The KscA-reconstituted liposomes were transferred to the planar bilayer across a small hole in a thin plastic sheet and the channel function of KcsA was examined. The original electrophysiological activities, such as voltage- and pH-dependence, were observed. These results suggested that in cell-free membrane protein synthesis, liposomes act as chaperones, preventing aggregation and assisting in folding and tetrameric formation, thereby allowing full channel activity.

  4. Is it me or is it you? Behavioral and electrophysiological effects of oxytocin administration on self-other integration during joint task performance.

    PubMed

    Ruissen, Margit I; de Bruijn, Ellen R A

    2015-09-01

    The neuropeptide oxytocin has been associated with promoting various social behaviors in humans including cooperation and trust. Surprisingly little, however, is known about the possible role of oxytocin in processes required for social interactive behavior such as joint task performance. The current study investigated whether intranasal administration of oxytocin leads to increased self-other integration using a social Simon task. A placebo-controlled double-blind between-subjects design was used. Behavioral and EEG measures were obtained from 63 healthy male volunteers who either received 24 intranasal units (IU) oxytocin or a placebo while they performed the social Simon task in an individual and a joint/social context. The behavioral results demonstrated an enhanced Simon effect in the social context after oxytocin administration. At the electrophysiological level, the stimulus-locked N2 component, reflecting response conflict, was increased in the social compared to the individual context for Go trials, but only after oxytocin administration. The P3 component, reflecting response inhibition, was increased for social compared to individual contexts, irrespective of condition. Both the behavioral and N2 findings suggest that oxytocin enhances self-other integration. While more inhibition is needed in the social context, this process seems less sensitive to changes in self-other integration. To conclude, the current study is the first to show oxytocin-induced modulations of processes that play a central role in joint task performance and thus importantly adds to our understanding of the neurocognitive mechanisms underlying the diverse social effects of oxytocin.

  5. Applying microfluidics to electrophysiology.

    PubMed

    Eddington, David T

    2007-01-01

    Microfluidics can be integrated with standard electrophysiology techniques to allow new experimental modalities. Specifically, the motivation for the microfluidic brain slice device is discussed including how the device docks to standard perfusion chambers and the technique of passive pumping which is used to deliver boluses of neuromodulators to the brain slice. By simplifying the device design, we are able to achieve a practical solution to the current unmet electrophysiology need of applying multiple neuromodulators across multiple regions of the brain slice. This is achieved by substituting the standard coverglass substrate of the perfusion chamber with a thin microfluidic device bonded to the coverglass substrate. This was then attached to the perfusion chamber and small holes connect the open-well of the perfusion chamber to the microfluidic channels buried within the microfluidic substrate. These microfluidic channels are interfaced with ports drilled into the edge of the perfusion chamber to access and deliver stimulants. This project represents how the field of microfluidics is transitioning away from proof-of concept device demonstrations and into practical solutions for unmet experimental and clinical needs.

  6. β-adrenergic effects on cardiac myofilaments and contraction in an integrated rabbit ventricular myocyte model

    PubMed Central

    Negroni, Jorge A.; Morotti, Stefano; Lascano, Elena C.; Gomes, Aldrin V.; Grandi, Eleonora; Puglisi, José L; Bers, Donald M.

    2015-01-01

    A five-state model of myofilament contraction was integrated into a well-established rabbit ventricular myocyte model of ion channels, Ca2+ transporters and kinase signaling to analyze the relative contribution of different phosphorylation targets to the overall mechanical response driven by β-adrenergic stimulation (β-AS). β-AS effect on sarcoplasmic reticulum Ca2+ handling, Ca2+, K+ and Cl− currents, and Na+/K+-ATPase properties were included based on experimental data. The inotropic effect on the myofilaments was represented as reduced myofilament Ca2+ sensitivity (XBCa) and titin stiffness, and increased cross-bridge (XB) cycling rate (XBcy). Assuming independent roles of XBCa and XBcy, the model reproduced experimental β-AS responses on action potentials and Ca2+ transient amplitude and kinetics. It also replicated the behavior of force-Ca2+, release-restretch, length-step, stiffness-frequency and force-velocity relationships, and increased force and shortening in isometric and isotonic twitch contractions. The β-AS effect was then switched off from individual targets to analyze their relative impact on contractility. Preventing β-AS effects on L-type Ca2+ channels or phospholamban limited Ca2+ transients and contractile responses in parallel, while blocking phospholemman and K+ channel (IKs) effects enhanced Ca2+ and inotropy. Removal of β-AS effects from XBCa enhanced contractile force while decreasing peak Ca2+ (due to greater Ca2+ buffering), but had less effect on shortening. Conversely, preventing β-AS effects on XBcy preserved Ca2+ transient effects, but blunted inotropy (both isometric force and especially shortening). Removal of titin effects had little impact on contraction. Finally, exclusion of β-AS from XBCa and XBcy while preserving effects on other targets resulted in preserved peak isometric force response (with slower kinetics) but nearly abolished enhanced shortening. β-AS effects on XBCa vs. XBcy have greater impact on isometric

  7. β-adrenergic effects on cardiac myofilaments and contraction in an integrated rabbit ventricular myocyte model.

    PubMed

    Negroni, Jorge A; Morotti, Stefano; Lascano, Elena C; Gomes, Aldrin V; Grandi, Eleonora; Puglisi, José L; Bers, Donald M

    2015-04-01

    A five-state model of myofilament contraction was integrated into a well-established rabbit ventricular myocyte model of ion channels, Ca(2+) transporters and kinase signaling to analyze the relative contribution of different phosphorylation targets to the overall mechanical response driven by β-adrenergic stimulation (β-AS). β-AS effect on sarcoplasmic reticulum Ca(2+) handling, Ca(2+), K(+) and Cl(-) currents, and Na(+)/K(+)-ATPase properties was included based on experimental data. The inotropic effect on the myofilaments was represented as reduced myofilament Ca(2+) sensitivity (XBCa) and titin stiffness, and increased cross-bridge (XB) cycling rate (XBcy). Assuming independent roles of XBCa and XBcy, the model reproduced experimental β-AS responses on action potentials and Ca(2+) transient amplitude and kinetics. It also replicated the behavior of force-Ca(2+), release-restretch, length-step, stiffness-frequency and force-velocity relationships, and increased force and shortening in isometric and isotonic twitch contractions. The β-AS effect was then switched off from individual targets to analyze their relative impact on contractility. Preventing β-AS effects on L-type Ca(2+) channels or phospholamban limited Ca(2+) transients and contractile responses in parallel, while blocking phospholemman and K(+) channel (IKs) effects enhanced Ca(2+) and inotropy. Removal of β-AS effects from XBCa enhanced contractile force while decreasing peak Ca(2+) (due to greater Ca(2+) buffering), but had less effect on shortening. Conversely, preventing β-AS effects on XBcy preserved Ca(2+) transient effects, but blunted inotropy (both isometric force and especially shortening). Removal of titin effects had little impact on contraction. Finally, exclusion of β-AS from XBCa and XBcy while preserving effects on other targets resulted in preserved peak isometric force response (with slower kinetics) but nearly abolished enhanced shortening. β-AS effects on XBCa and XBcy

  8. Auditory Integration Training: A Double-Blind Study of Behavioral and Electrophysiological Effects in People with Autism.

    ERIC Educational Resources Information Center

    Edelson, Stephen M.; Arin, Deborah; Bauman, Margaret; Lukas, Scott E.; Rudy, Jane H.; Sholar, Michelle; Rimland, Bernard

    1999-01-01

    Nineteen individuals with autism either listened to auditory integration training processed music or unprocessed music for 20 half-hour sessions. A significant decrease in Aberrant Behavior Checklist Scores was observed in the experimental group at the 30-month follow-up assessment. In addition, three experimental subjects but no controls showed a…

  9. Electrophysiological study of diaphragmatic myoclonus.

    PubMed Central

    Chen, R; Remtulla, H; Bolton, C F

    1995-01-01

    This is the first reported detailed electrophysiological study of diaphragmatic myoclonus. An 86 year old woman had rapid, intermittent epigastric pulsations. Neurological examination and imaging studies of the brain and spinal cord were normal. Needle EMG showed rhythmic contractions of the diaphragm and external intercostal muscles at 4 to 5 Hz. These contractions were often associated with suppression of normal breathing and were capable of maintaining adequate ventilation. Both diaphragms were involved but showed considerable variability in their relative latencies. Automated interference pattern analysis suggested a change in recruitment order, with selective activation of large phrenic motoneurons. The supraspinal mechanisms mediating diaphragmatic myoclonus are different from that of voluntary and involuntary rhythmic breathing, and seem to be unrelated to palatal myoclonus. The generator source is likely related to respiratory centres in the rostral medulla. PMID:7738561

  10. Macroscopic contraction of a gel induced by the integrated motion of light-driven molecular motors.

    PubMed

    Li, Quan; Fuks, Gad; Moulin, Emilie; Maaloum, Mounir; Rawiso, Michel; Kulic, Igor; Foy, Justin T; Giuseppone, Nicolas

    2015-02-01

    Making molecular machines that can be useful in the macroscopic world is a challenging long-term goal of nanoscience. Inspired by the protein machinery found in biological systems, and based on the theoretical understanding of the physics of motion at the nanoscale, organic chemists have developed a number of molecules that can produce work by contraction or rotation when triggered by various external chemical or physical stimuli. In particular, basic molecular switches that commute between at least two thermodynamic minima and more advanced molecular motors that behave as dissipative units working far from equilibrium when fuelled with external energy have been reported. However, despite recent progress, the ultimate challenge of coordinating individual molecular motors in a continuous mechanical process that can have a measurable effect at the macroscale has remained elusive. Here, we show that by integrating light-driven unidirectional molecular rotors as reticulating units in a polymer gel, it is possible to amplify their individual motions to achieve macroscopic contraction of the material. Our system uses the incoming light to operate under far-from-equilibrium conditions, and the work produced by the motor in the photostationary state is used to twist the entangled polymer chains up to the collapse of the gel. Our design could be a starting point to integrate nanomotors in metastable materials to store energy and eventually to convert it.

  11. Macroscopic contraction of a gel induced by the integrated motion of light-driven molecular motors

    NASA Astrophysics Data System (ADS)

    Li, Quan; Fuks, Gad; Moulin, Emilie; Maaloum, Mounir; Rawiso, Michel; Kulic, Igor; Foy, Justin T.; Giuseppone, Nicolas

    2015-02-01

    Making molecular machines that can be useful in the macroscopic world is a challenging long-term goal of nanoscience. Inspired by the protein machinery found in biological systems, and based on the theoretical understanding of the physics of motion at the nanoscale, organic chemists have developed a number of molecules that can produce work by contraction or rotation when triggered by various external chemical or physical stimuli. In particular, basic molecular switches that commute between at least two thermodynamic minima and more advanced molecular motors that behave as dissipative units working far from equilibrium when fuelled with external energy have been reported. However, despite recent progress, the ultimate challenge of coordinating individual molecular motors in a continuous mechanical process that can have a measurable effect at the macroscale has remained elusive. Here, we show that by integrating light-driven unidirectional molecular rotors as reticulating units in a polymer gel, it is possible to amplify their individual motions to achieve macroscopic contraction of the material. Our system uses the incoming light to operate under far-from-equilibrium conditions, and the work produced by the motor in the photostationary state is used to twist the entangled polymer chains up to the collapse of the gel. Our design could be a starting point to integrate nanomotors in metastable materials to store energy and eventually to convert it.

  12. Contract Research Organizations (CROs) in China: integrating Chinese research and development capabilities for global drug innovation.

    PubMed

    Shi, Yun-Zhen; Hu, Hao; Wang, Chunming

    2014-11-19

    The significance of R&D capabilities of China has become increasingly important as an emerging force in the context of globalization of pharmaceutical research and development (R&D). While China has prospered in its R&D capability in the past decade, how to integrate the rising pharmaceutical R&D capability of China into the global development chain for innovative drugs remains challenging. For many multinational corporations and research organizations overseas, their attempt to integrate China's pharmaceutical R&D capabilities into their own is always hindered by policy constraints and reluctance of local universities and pharmaceutical firms. In light of the situation, contract research organizations (CROs) in China have made great innovation in value proposition, value chain and value networking to be at a unique position to facilitate global and local R&D integration. Chinese CROs are now being considered as the essentially important and highly versatile integrator of local R&D capability for global drug discovery and innovation.

  13. “Reality” of near-death-experience memories: evidence from a psychodynamic and electrophysiological integrated study

    PubMed Central

    Palmieri, Arianna; Calvo, Vincenzo; Kleinbub, Johann R.; Meconi, Federica; Marangoni, Matteo; Barilaro, Paolo; Broggio, Alice; Sambin, Marco; Sessa, Paola

    2014-01-01

    The nature of near-death-experiences (NDEs) is largely unknown but recent evidence suggests the intriguing possibility that NDEs may refer to actually “perceived,” and stored, experiences (although not necessarily in relation to the external physical world). We adopted an integrated approach involving a hypnosis-based clinical protocol to improve recall and decrease memory inaccuracy together with electroencephalography (EEG) recording in order to investigate the characteristics of NDE memories and their neural markers compared to memories of both real and imagined events. We included 10 participants with NDEs, defined by the Greyson NDE scale, and 10 control subjects without NDE. Memories were assessed using the Memory Characteristics Questionnaire. Our hypnosis-based protocol increased the amount of details in the recall of all kind of memories considered (NDE, real, and imagined events). Findings showed that NDE memories were similar to real memories in terms of detail richness, self-referential, and emotional information. Moreover, NDE memories were significantly different from memories of imagined events. The pattern of EEG results indicated that real memory recall was positively associated with two memory-related frequency bands, i.e., high alpha and gamma. NDE memories were linked with theta band, a well-known marker of episodic memory. The recall of NDE memories was also related to delta band, which indexes processes such as the recollection of the past, as well as trance states, hallucinations, and other related portals to transpersonal experience. It is notable that the EEG pattern of correlations for NDE memory recall differed from the pattern for memories of imagined events. In conclusion, our findings suggest that, at a phenomenological level, NDE memories cannot be considered equivalent to imagined memories, and at a neural level, NDE memories are stored as episodic memories of events experienced in a peculiar state of consciousness. PMID:24994974

  14. Electrophysiological evaluation of psychogenic movement disorders.

    PubMed

    Kamble, Nitish L; Pal, Pramod Kumar

    2016-01-01

    Psychogenic movement disorders (PMD) include a group of neurological symptoms which cannot be explained by any organic syndrome. The diagnosis of PMD is challenging for both neurologist and psychiatrist. Electrophysiological examination is a useful tool to evaluate and support a diagnosis PMD. It includes a set of tests which are chosen appropriate to the clinical setting that provides objective criteria for the diagnosis of PMD. The various tests available include accelerometry, surface electromyography, electroencephalography, jerk locked back averaging and pre-movement potentials, somatosensory evoked potentials, transcranial magnetic stimulation (TMS) etc. Electrophysiologically psychogenic tremors display features of variability, entrainability, coactivation, distractibility and increase in the amplitude and frequency on mass loading. Movement related cortical potentials such as Bereitschaftspotential is seen in psychogenic myoclonus. Presence of triphasic contraction of muscles and absence of co-contraction suggests psychogenic myoclonus. Latency of C-reflex is longer in psychogenic myoclonus as compared to organic myoclonus. The role of TMS to differentiate psychogenic from organic dystonia is still not clear. In conclusion, electrophysiological tests are most useful for tremor, followed by jerks and least for dystonia. In patients with long-standing PMD or those with mixed pathology, electrophysiological tests may not be very useful.

  15. Electromagnetic integral equation approach based on contraction operator and solution optimization in Krylov subspace

    NASA Astrophysics Data System (ADS)

    Singer, B. Sh.

    2008-12-01

    The paper presents a new code for modelling electromagnetic fields in complicated 3-D environments and provides examples of the code application. The code is based on an integral equation (IE) for the scattered electromagnetic field, presented in the form used by the Modified Iterative Dissipative Method (MIDM). This IE possesses contraction properties that allow it to be solved iteratively. As a result, for an arbitrary earth model and any source of the electromagnetic field, the sequence of approximations converges to the solution at any frequency. The system of linear equations that represents a finite-dimensional counterpart of the continuous IE is derived using a projection definition of the system matrix. According to this definition, the matrix is calculated by integrating the Green's function over the `source' and `receiver' cells of the numerical grid. Such a system preserves contraction properties of the continuous equation and can be solved using the same iterative technique. The condition number of the system matrix and, therefore, the convergence rate depends only on the physical properties of the model under consideration. In particular, these parameters remain independent of the numerical grid used for numerical simulation. Applied to the system of linear equations, the iterative perturbation approach generates a sequence of approximations, converging to the solution. The number of iterations is significantly reduced by finding the best possible approximant inside the Krylov subspace, which spans either all accumulated iterates or, if it is necessary to save the memory, only a limited number of the latest iterates. Optimization significantly reduces the number of iterates and weakens its dependence on the lateral contrast of the model. Unlike more traditional conjugate gradient approaches, the iterations are terminated when the approximate solution reaches the requested relative accuracy. The number of the required iterates, which for simple

  16. Guide for Integrating Systems Engineering into DoD Acquisition Contracts Version 1.0

    DTIC Science & Technology

    2006-12-11

    Acquisition Contracts Version 1.0 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER...38 List of Figures UFigure 1-1 Simplified Government Acquisition ProcessU...Development ATL-ED@osd.mil ii List of Tables UTable 1-1 Summary of Contracting Activities and SE and PM RolesU

  17. Advances in Electrophysiological Research

    PubMed Central

    Kamarajan, Chella; Porjesz, Bernice

    2015-01-01

    Electrophysiological measures of brain function are effective tools to understand neurocognitive phenomena and sensitive indicators of pathophysiological processes associated with various clinical conditions, including alcoholism. Individuals with alcohol use disorder (AUD) and their high-risk offspring have consistently shown dysfunction in several electrophysiological measures in resting state (i.e., electroencephalogram) and during cognitive tasks (i.e., event-related potentials and event-related oscillations). Researchers have recently developed sophisticated signal-processing techniques to characterize different aspects of brain dynamics, which can aid in identifying the neural mechanisms underlying alcoholism and other related complex disorders. These quantitative measures of brain function also have been successfully used as endophenotypes to identify and help understand genes associated with AUD and related disorders. Translational research also is examining how brain electrophysiological measures potentially can be applied to diagnosis, prevention, and treatment. PMID:26259089

  18. Phase Zero Contracting Operations-Strategic and Integrative Planning for Contingency and Expeditionary Operations

    DTIC Science & Technology

    2013-10-01

    349–372 Phase Zero Contracting Operations (PZCO) FIGURE 4. CONTRACTING PHASE ZERO: PLAN, EXERCISE, REHEARSE, AND SYNCHRONIZE Note. BPA = Blanket...More Robust Construction Supplies; Oce Equipment; Quality of Life; and Morale, Welfare, and Recreation PO/TO/DO/ BPA Small Purchase Standard Vehicles PO...TO/DO/ BPA Small Purchase Standard Vehicles PO/TO/DO/ BPA Small Purchase Standard Vehicles PO/TO/DO/ BPA Small Purchase Food, Water, Billeting, Hygiene

  19. Cardiac Electrophysiology: Normal and Ischemic Ionic Currents and the ECG

    ERIC Educational Resources Information Center

    Klabunde, Richard E.

    2017-01-01

    Basic cardiac electrophysiology is foundational to understanding normal cardiac function in terms of rate and rhythm and initiation of cardiac muscle contraction. The primary clinical tool for assessing cardiac electrical events is the electrocardiogram (ECG), which provides global and regional information on rate, rhythm, and electrical…

  20. Electrophysiological studies in alcoholism

    PubMed Central

    Blackstock, Eileen; Rushworth, Geoffrey; Gath, Dennis

    1972-01-01

    Using a range of electrophysiological techniques, it has been possible to demonstrate impaired function in smaller calibre motor fibres and in distal large cutaneous sensory nerve fibres in both alcoholic patients without neuropathy and in those alcoholics with clinical manifestations of peripheral nerve disease. Evidence of more proximal involvement of Ia sensory fibres was obtained, but in the majority of our patients, large motor fibres functioned normally. The nature of the underlying pathological process is discussed. Images PMID:4338445

  1. The Integration of the Competition in Contracting Act of 1984 in Systems Acquisition.

    DTIC Science & Technology

    1986-04-01

    Representatives as House Resolution 5184. The act in its final ammended form hitchhiked with the Deficit Reduction Act of 1984 (Public Law 98-369) and the...to the CICA, and finally offers recommendations for further AFSC response. Anyone already familiar with the CICA will do well to skip the first ...enteri.g any contract. Therefor, it first requires _dvance pla,. .ing and market research before soliciting bids or proposals. Lack of advw.nced plrni

  2. The integrated supplier: key to cost management and multi-franchise capitation contracting.

    PubMed

    Schuweiler, R C

    1996-05-01

    Capitation...most healthcare providers do not work under it, comprehend it, or even want it, yet supply capitation contracting seminars are popping up everywhere creating the feeling that the bandwagon is leaving, and it might be time to get on board. Not true. Supply capitation is not for all organizations. Capitation contracting is not easy and there are not many successful models to help the uninitiated. If a panacea is sought for reducing supply costs, capitation is only one component of a systematic strategy to reduce materiel costs. This article suggests a direction using the Group Health Materiel Management (Group Health Cooperative of Puget Sound, WA) experience as a point of reference. It advocates a systematic approach that focuses on expense reduction in: cost of goods, holding cost of inventory, labor cost associated with all materiel processes, distribution cost (transportation and par stock pick, pack, and replenishment), product utilization, variation in product standards, and waste stream byproducts. At Group Health (GH) these issues are primarily addressed through the use of: information systems, supplier certification/selection processes, group purchasing compliance, supply channel management, supply capitation contracting programs, standardization, and utilization management. Because of managed care organizational structure, Group Health Cooperative supply capitation contracting, as performed at GH, is discussed not as a quick fix solution but in the spirit of sharing our experience with others who may be considering it as a cost savings tactic in the context of a broad-based materiel management strategy. This article highlights the experiences of GH beginning with materiel management's business process assumptions toward multiple-franchise supply capitation.

  3. Electrophysiology of autonomic neuromuscular transmission involving ATP.

    PubMed

    Sneddon, P

    2000-07-03

    Electrophysiological investigations of autonomic neuromuscular transmission have provided great insights into the role of ATP as a neurotransmitter. Burnstock and Holman made the first recordings of excitatory junction potentials (e.j.p.s) produced by sympathetic nerves innervating the smooth muscle of the guinea-pig vas deferens. This led to the identification of ATP as the mediator of e.j.p.s in this tissue, where ATP acts as a cotransmitter with noradrenaline. The e.j.p.s are mediated solely by ATP acting on P2X(1) receptors leading to action potentials and a rapid phasic contraction, whilst noradrenaline mediates a slower, tonic contraction which is not dependent on membrane depolarisation. Subsequent electrophysiological studies of the autonomic innervation of smooth muscles of the urogenital, gastrointestinal and cardiovascular systems have revealed a similar pattern of response, where ATP mediates a fast electrical and mechanical response, whilst another transmitter such as noradrenaline, acetylcholine, nitric oxide or a peptide mediates a slower response. The modulation of junction potentials by a variety of pre-junctional receptors and the mechanism of inactivation of ATP as a neurotransmitter will also be described.

  4. Synergistic Approach Integrating Joint Capabilities for USSOCOM Contingency Contracting: Construction Management Module

    DTIC Science & Technology

    2010-12-01

    of synergistic approach to integrating joint operations (lack of integration between military services doctrine, training, and skill sets). cp2 Lack...construction-related guidance. ap6, ap7, ap10, ap11, bp2, cp1, cp2 , cp3 3. Comprehend and apply the special funding authority to USSOCOM. ap7, cp1, cp2 ...ap1, ap2, ap3, ap7 11. Synthesize why why CCOs should focus on interoperability with other agencies. cp1, cp2 , cp5 12. Synthesize contracting’s

  5. 77 FR 42339 - Improving Contracting Officers' Access to Relevant Integrity Information

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-18

    .... Ryan Burnette, OFPP, at (202) 395- 7724 or rburnette@omb.eop.gov . SUPPLEMENTARY INFORMATION: To access.../omb/procurement/frn/frn-access-to-relevant-integrity-information-public-comments.pdf . Joseph G... From the Federal Register Online via the Government Publishing Office OFFICE OF MANAGEMENT...

  6. Gesundes Kinzigtal Integrated Care: improving population health by a shared health gain approach and a shared savings contract

    PubMed Central

    H., Hildebrandt; C., Hermann; R., Knittel; M., Richter-Reichhelm; A., Siegel; W., Witzenrath

    2010-01-01

    Introduction Integrated care solutions need supportive financial incentives. In this paper, we describe the financial architecture and operative details of the integrated pilot Gesundes Kinzigtal. Description of integrated care case Located in Southwest Germany, Gesundes Kinzigtal is one of the few population-based integrated care approaches in Germany, organising care across all health service sectors and indications. The system serving around half of the population of the region is run by a regional health management company (Gesundes Kinzigtal GmbH) in cooperation with the physicians' network in the region (MQNK), a German health care management company with a background in medical sociology and health economics (OptiMedis AG) and with two statutory health insurers (among them is the biggest health insurer in Southwest Germany: AOK Baden-Württemberg). Discussion and (preliminary) conclusion The shared savings contract between Gesundes Kinzigtal GmbH and the two health insurers, providing financial incentives for managers and health care providers to realize a substantial efficiency gain, could be an appropriate contractual base of Gesundes Kinzigtal's population health gain approach. This approach is based on the assumption that a more effective trans-sector organization of Germany's health care system and increased investments in well-designed preventive programmes will lead to a reduction in morbidity, and in particular to a reduced incidence and prevalence of chronic diseases. This, in turn, is to lead to a comparative reduction in health care cost. Although the comparative cost in the Kinzigtal region has been reduced from the onset of Gesundes Kinzigtal Integrated Care, only future research will have to demonstrate whether—and to what extent—cost reduction may be attributed to a real population health gain. PMID:20689772

  7. Construction Management Module: Contingency Contracting Synergistic Approach Integrating Joint Capabilities for USSOCOM

    DTIC Science & Technology

    2010-01-29

    integration between military services doctrine, training, skill sets). cp2 Lack of coordination between cross-functional areas (finance, engineering...Know where to find additional DoD construction-related guidance. ap6, ap7, ap10, ap11, bp2, cp1, cp2 , cp3 3. Comprehend and apply the special...funding authority to USSOCOM. ap7, cp1, cp2 , cp5 4. Comprehend the unique command structure and authority in which USSOCOM operates around the

  8. Advanced Electrophysiologic Mapping Systems

    PubMed Central

    2006-01-01

    integration of anatomic and electrical potential information that enable better visualization of areas of interest for ablation Advanced nonfluoroscopy mapping/navigation systems appear to be safe; they consistently shortened the fluoroscopy duration and radiation exposure. Evidence suggests that nonfluoroscopy mapping and navigation systems may be used as adjuncts to rather than replacements for fluoroscopy in guiding the ablation of complex arrhythmias. Most studies showed a nonsignificant trend toward lower overall failure rate for advanced mapping-guided ablation compared with fluoroscopy-guided mapping. Pooled analyses of small RCTs and non-RCTs that compared fluoroscopy- with nonfluoroscopy-guided ablation of atrial fibrillation and atrial flutter showed that advanced nonfluoroscopy mapping and navigational systems: Yielded acute success rates of 69% to 100%, not significantly different from fluoroscopy ablation. Had overall failure rates at 3 months to 19 months of 1% to 40% (median 25%). Resulted in a 10% relative reduction in overall failure rate for advanced mapping guided-ablation compared to fluoroscopy guided ablation for the treatment of atrial fibrillation. Yielded added benefit over fluoroscopy in guiding the ablation of complex arrhythmia. The advanced systems were shown to reduce the arrhythmia burden and the need for antiarrhythmic drugs in patients with complex arrhythmia who had failed fluoroscopy-guided ablation Based on predominantly observational studies, circumferential PV ablation guided by a nonfluoroscopy system was shown to do the following: Result in freedom from atrial fibrillation (with or without antiarrhythmic drug) in 75% to 95% of patients (median 79%). This effect was maintained up to 28 months. Result in freedom from atrial fibrillation without antiarrhythmic drugs in 47% to 95% of patients (median 63%). Improve patient survival at 28 months after the procedure as compared with drug therapy. Require special skills; patient outcomes are

  9. 76 FR 81807 - Operational Contract Support

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-29

    ... include: (1) Incorporation of lessons learned from current operations; (2) requirements for the... contract support (OCS). The ability to orchestrate and synchronize the provision of integrated contract..., integrate, and execute acquisition of, contracted support, including synchronizing and...

  10. Multiscale Interactions in a 3D Model of the Contracting Ventricle.

    PubMed

    Amar, Ani; Zlochiver, Sharon; Barnea, Ofer

    2015-12-01

    A biophysical detailed multiscale model of the myocardium is presented. The model was used to study the contribution of interrelated cellular mechanisms to global myocardial function. The multiscale model integrates cellular electrophysiology, excitation propagation dynamics and force development models into a geometrical fiber based model of the ventricle. The description of the cellular electrophysiology in this study was based on the Ten Tusscher-Noble-Noble-Panfilov heterogeneous model for human ventricular myocytes. A four-state model of the sarcomeric control of contraction developed by Negroni and Lascano was employed to model the intracellular mechanism of force generation. The propagation of electrical excitation was described by a reaction-diffusion equation. The 3D geometrical model of the ventricle, based on single fiber contraction was used as a platform for the evaluation of proposed models. The model represents the myocardium as an anatomically oriented array of contracting fibers with individual fiber parameters such as size, spatial location, orientation and mechanical properties. Moreover, the contracting ventricle model interacts with intraventricular blood elements linking the contractile elements to the heart's preload and afterload, thereby producing the corresponding pressure-volume loop. The results show that the multiscale ventricle model is capable of simulating mechanical contraction, pressure generation and load interactions as well as demonstrating the individual contribution of each ion current.

  11. Depth Attenuation Degree Based Visualization for Cardiac Ischemic Electrophysiological Feature Exploration

    PubMed Central

    Liu, Lei; Zuo, Wangmeng; Zhang, Henggui

    2016-01-01

    Although heart researches and acquirement of clinical and experimental data are progressively open to public use, cardiac biophysical functions are still not well understood. Due to the complex and fine structures of the heart, cardiac electrophysiological features of interest may be occluded when there is a necessity to demonstrate cardiac electrophysiological behaviors. To investigate cardiac abnormal electrophysiological features under the pathological condition, in this paper, we implement a human cardiac ischemic model and acquire the electrophysiological data of excitation propagation. A visualization framework is then proposed which integrates a novel depth weighted optic attenuation model into the pathological electrophysiological model. The hidden feature of interest in pathological tissue can be revealed from sophisticated overlapping biophysical information. Experiment results verify the effectiveness of the proposed method for intuitively exploring and inspecting cardiac electrophysiological activities, which is fundamental in analyzing and explaining biophysical mechanisms of cardiac functions for doctors and medical staff. PMID:28004002

  12. Perceived Control and Psychological Contract Breach as Explanations of the Relationships Between Job Insecurity, Job Strain and Coping Reactions: Towards a Theoretical Integration.

    PubMed

    Vander Elst, Tinne; De Cuyper, Nele; Baillien, Elfi; Niesen, Wendy; De Witte, Hans

    2016-04-01

    This study aims to further knowledge on the mechanisms through which job insecurity is related to negative outcomes. Based on appraisal theory, two explanations-perceived control and psychological contract breach-were theoretically integrated in a comprehensive model and simultaneously examined as mediators of the job insecurity-outcome relationship. Different categories of outcomes were considered, namely work-related (i.e. vigour and need for recovery) and general strain (i.e. mental and physical health complaints), as well as psychological (i.e. job satisfaction and organizational commitment) and behavioural coping reactions (i.e. self-rated performance and innovative work behaviour). The hypotheses were tested using data of a heterogeneous sample of 2413 Flemish employees by means of both single and multiple mediator structural equation modelling analyses (bootstrapping method). Particularly, psychological contract breach accounted for the relationship between job insecurity and strain. Both perceived control and psychological contract breach mediated the relationships between job insecurity and psychological coping reactions, although the indirect effects were larger for psychological contract breach. Finally, perceived control was more important than psychological contract breach in mediating the relationships between job insecurity and behavioural coping reactions. This study meets previous calls for a theoretical integration regarding mediators of the job insecurity-outcome relationship.

  13. Accompanying coordinate expansion and recurrence relation method using a transfer relation scheme for electron repulsion integrals with high angular momenta and long contractions

    SciTech Connect

    Hayami, Masao; Seino, Junji; Nakai, Hiromi

    2015-05-28

    An efficient algorithm for the rapid evaluation of electron repulsion integrals is proposed. The present method, denoted by accompanying coordinate expansion and transferred recurrence relation (ACE-TRR), is constructed using a transfer relation scheme based on the accompanying coordinate expansion and recurrence relation method. Furthermore, the ACE-TRR algorithm is extended for the general-contraction basis sets. Numerical assessments clarify the efficiency of the ACE-TRR method for the systems including heavy elements, whose orbitals have long contractions and high angular momenta, such as f- and g-orbitals.

  14. Impact of pay-for-performance contracts and network registry on diabetes and asthma HEDIS measures in an integrated delivery network.

    PubMed

    Levin-Scherz, Jeffrey; DeVita, Nicole; Timbie, Justin

    2006-02-01

    This article reviews the experience of a large, heterogeneous integrated delivery network that incorporated physician quality metrics into pay-for-performance contracts. The authors present criteria for including measures in pay-for-performance contracts and offer a practical approach to determining withhold return or bonus distribution based on improvement and performance. They demonstrate interventions undertaken to improve performance, including the development of a claims-based registry. Empirical data show that the network performance improved more than the comparable state and national performance during the period of this observational study. The authors conclude that pay-for-performance contracts led to development of medical management programs including a claims-based registry and nonphysician interventions, which helped significantly improve selected HEDIS scores.

  15. Resuscitation great. Luigi Galvani and the foundations of electrophysiology.

    PubMed

    Cajavilca, Christian; Varon, Joseph; Sternbach, George L

    2009-02-01

    Luigi Galvani became one of the greatest scientists of the 18th century with his research and the development of his theory on animal electricity. His work was appreciated by many scientists. Nevertheless, it gave rise to one of the most passionate scientific debates in history when Alessandro Volta postulated that Galvani had confused intrinsic animal electricity with small currents produced by metals. This debate would result in the creation of electrophysiology, electromagnetism, electrochemistry and the electrical battery. Galvani responded to each of the postulated theories of Volta giving irrefutable proof of the involvement of electricity in the contraction of muscles. However, his work was subsequently abandoned and silenced for many years but his ideas and theories were finally confirmed by the creation of new instruments and the interest of new scientists who helped position Galvani as the father of electrophysiology.

  16. Relationships between cortical myeloarchitecture and electrophysiological networks

    PubMed Central

    Hunt, Benjamin A. E.; Tewarie, Prejaas K.; Mougin, Olivier E.; Geades, Nicolas; Singh, Krish D.; Morris, Peter G.; Gowland, Penny A.; Brookes, Matthew J.

    2016-01-01

    The human brain relies upon the dynamic formation and dissolution of a hierarchy of functional networks to support ongoing cognition. However, how functional connectivities underlying such networks are supported by cortical microstructure remains poorly understood. Recent animal work has demonstrated that electrical activity promotes myelination. Inspired by this, we test a hypothesis that gray-matter myelin is related to electrophysiological connectivity. Using ultra-high field MRI and the principle of structural covariance, we derive a structural network showing how myelin density differs across cortical regions and how separate regions can exhibit similar myeloarchitecture. Building upon recent evidence that neural oscillations mediate connectivity, we use magnetoencephalography to elucidate networks that represent the major electrophysiological pathways of communication in the brain. Finally, we show that a significant relationship exists between our functional and structural networks; this relationship differs as a function of neural oscillatory frequency and becomes stronger when integrating oscillations over frequency bands. Our study sheds light on the way in which cortical microstructure supports functional networks. Further, it paves the way for future investigations of the gray-matter structure/function relationship and its breakdown in pathology. PMID:27830650

  17. Electrophysiology Tool Construction

    PubMed Central

    Ide, David

    2016-01-01

    This protocol documents the construction of a custom microscope stage system currently in widespread use by a wide variety of investigators. The current design and construction of this stage is the result of multiple iterations, integrating input from a number of electrophysiologists working with a variety of preparations. Thus, this tool is a generally applicable solution, suitable for a wide array of end-user requirements; its flexible design facilitates rapid and easy configuration, making it useful for multi-user microscopes, as individual researchers can reconfigure the stage system or have their own readily replaceable stage plates. Furthermore, the stage can be manufactured using equipment typically found in small research machine shops, and by keeping the various parts on hand, machinists can quickly satisfy new requests and/or modifications for a wide variety of applications. PMID:23315946

  18. Distribution of electrophysiological abnormality in Lambert-Eaton myasthenic syndrome

    PubMed Central

    Maddison, P.; Newsom-Davis, J.; Mills, K.

    1998-01-01

    OBJECTIVE—To assess the distribution of electrophysiological abnormality in Lambert-Eaton myasthenic syndrome (LEMS) to identify the most sensitive muscle to use in routine examination.
METHODS—Surface recorded compound muscle action potential (CMAP) amplitudes were made from abductor digiti minimi, abductor pollicis brevis, anconeus, biceps brachii, and trapezius in 10 patients with LEMS. The effect of 3,4-diaminopyridine (3,4-DAP) was recorded in each muscle in nine patients. CMAP amplitudes were measured at rest and immediately after 10 seconds maximal voluntary contraction in each muscle. Values were compared with results obtained from 12 healthy controls.
RESULTS—Resting CMAP amplitudes were reduced in at least one muscle in all patients compared with controls, most markedly in abductor digiti minimi and anconeus. The administration of 3,4-DAP resulted in significantly improved resting CMAP amplitudes in trapezius only. After maximal voluntary muscle contraction, characteristic increments in CMAP amplitude of over 100% above resting values were seen in abductor digiti minimi and abductor pollicis brevis in seven patients, anconeus and biceps brachii in five patients. No patient had this level of increment in trapezius.
CONCLUSION—Despite predominantly proximal limb weakness seen clinically in patients with LEMS, the most sensitive muscles for detecting characteristic electrophysiological abnormalities of low resting CMAP amplitude and increment of over 100% after 10 seconds maximal voluntary contraction are abductor digiti minimi, abductor pollicis brevis, and anconeus.

 PMID:9703174

  19. Electrophysiological and Ultrastructural Characterization of Neuromuscular Junctions in Diaphragm Muscle of Acetylcholinesterase Knockout Mice

    DTIC Science & Technology

    2008-04-01

    Electrophysiological and Ultrastructural Characterization of Neuromuscular Junctions in 5a. CONTRACT NUMBER Diaphragm Muscle of Acetylcholinesterase Knockout Mice...AChE +/+) and acetylcholinesterase knockout (AChE -/-) mice to determine the compensatory mechanism manifested by the neuromuscular junction to...had smaller nerve terminals and diminished pre- and postsynaptic surface contacts relative to neuromuscular junctions of AChE +/+ mice. The

  20. Olfaction in dragonflies: electrophysiological evidence.

    PubMed

    Rebora, Manuela; Salerno, Gianandrea; Piersanti, Silvana; Dell'otto, Alessandro; Gaino, Elda

    2012-02-01

    The problem of olfaction in Paleoptera (Odonata, Ephemeroptera) cannot be considered fully elucidated until now. These insects have been traditionally considered anosmic, because their brain lacks glomerular antennal lobes, typically involved in Neoptera odor perception. In order to understand if the presumed coeloconic olfactory receptors described on the antennal flagellum of adult Odonata are really functioning, we performed an electrophysiological investigation with electroantennogram (EAG) and single cell recordings (SCR), using Libellula depressa L. (Odonata, Libellulidae) as a model species. Odors representing different chemical classes such as (Z)-3-hexenyl acetate (acetate ester), (E)-2-hexenal, octanal (aldehydes), (Z)-3-hexen-1-ol (alcohol), propionic acid, butyric acid (carboxylic acids), and 1,4-diaminobutane (amine) were tested. Most of the tested chemicals elicited depolarizing EAG responses in both male and female antennae; SCR show unambiguously for the first time the presence of olfactory neurons in the antennae of L. depressa and strongly support the olfactory function of the coeloconic sensilla located on the antennal flagellum of this species. Electrophysiological activity may not necessarily indicate behavioral activity, and the biological role of olfactory responses in Odonata must be determined in behavioral bioassays. This study represents a starting point for further behavioral, electrophysiological, neuroanatomical and molecular investigation on Odonata olfaction, a research field particularly interesting owing to the basal position of Paleoptera, also for tracing evolutionary trends in insect olfaction.

  1. Intraoperative monitoring by imaging and electrophysiological techniques during giant intracranial aneurysm surgery.

    PubMed

    Durand, A; Penchet, G; Thines, L

    2016-02-01

    Difficulties in giant intracranial aneurysm surgery are the consequence of aneurysmal wall histology and the complex angioarchitecture of the vascular tree. In order to reduce complications and risks of those procedures, various imaging and electrophysiological techniques can be implemented perioperatively. The authors review the principles, goals and main results in this context of micro-Doppler and flowmeter techniques, near-infrared spectroscopy, operative microscope-integrated indocyanine green video-angiography, neuro-endoscopy, selective intraoperative angiography and electrophysiological monitoring.

  2. Personal miniature electrophysiological tape recorder

    NASA Technical Reports Server (NTRS)

    Green, H.

    1981-01-01

    The use of a personal miniature electrophysiological tape recorder to measure the physiological reactions of space flight personnel to space flight stress and weightlessness is described. The Oxford Instruments Medilog recorder, a battery-powered, four-channel cassette tape recorder with 24 hour endurance is carried on the person and will record EKG, EOG, EEG, and timing and event markers. The data will give information about heart rate and morphology changes, and document adaptation to zero gravity on the part of subjects who, unlike highly trained astronauts, are more representative of the normal population than were the subjects of previous space flight studies.

  3. Personal miniature electrophysiological tape recorder

    NASA Astrophysics Data System (ADS)

    Green, H.

    1981-11-01

    The use of a personal miniature electrophysiological tape recorder to measure the physiological reactions of space flight personnel to space flight stress and weightlessness is described. The Oxford Instruments Medilog recorder, a battery-powered, four-channel cassette tape recorder with 24 hour endurance is carried on the person and will record EKG, EOG, EEG, and timing and event markers. The data will give information about heart rate and morphology changes, and document adaptation to zero gravity on the part of subjects who, unlike highly trained astronauts, are more representative of the normal population than were the subjects of previous space flight studies.

  4. Electrophysiological and contractile function of cardiomyocytes derived from human embryonic stem cells

    PubMed Central

    Blazeski, Adriana; Zhu, Renjun; Hunter, David W.; Weinberg, Seth H.; Boheler, Kenneth R.; Zambidis, Elias T.; Tung, Leslie

    2013-01-01

    Human embryonic stem cells have emerged as the prototypical source from which cardiomyocytes can be derived for use in drug discovery and cell therapy. However, such applications require that these cardiomyocytes (hESC-CMs) faithfully recapitulate the physiology of adult cells, especially in relation to their electrophysiological and contractile function. We review what is known about the electrophysiology of hESC-CMs in terms of beating rate, action potential characteristics, ionic currents, and cellular coupling as well as their contractility in terms of calcium cycling and contraction. We also discuss the heterogeneity in cellular phenotypes that arises from variability in cardiac differentiation, maturation, and culture conditions, and summarize present strategies that have been implemented to reduce this heterogeneity. Finally, we present original electrophysiological data from optical maps of hESC-CM clusters. PMID:22958937

  5. The Psychological Contract

    DTIC Science & Technology

    2009-10-01

    employee commitment • Freedom to sign new contracts • Little learning • Low integration/identification Transitional • Ambiguity/uncertainty • High...turnover • Instability T im ef ra m e Lo ng T er m Balanced • High employee commitment • High integration/identification • Mutual employee...organization support • Dynamic Relational • High employee commitment • High affective commitment • High integration/identification • Stability 14

  6. Antivenom Evaluation by Electrophysiological Analysis.

    PubMed

    Restano-Cassulini, Rita; Garcia, Walter; Paniagua-Solís, Jorge F; Possani, Lourival D

    2017-02-23

    Scorpion stings on humans are medically relevant because they may contain toxins that specifically target ion channels. During antivenom production, pharmaceutical companies must use a large number of experimental animals to ensure the antivenom's efficacy according to pharmacopeia methods. Here we present an electrophysiological alternative for the evaluation of horse antivenoms produced against two species of Moroccan scorpions: Buthus mardochei and Androctonus mauretanicus. Human sodium and potassium channels and acetylcholine nicotinic receptors were analyzed by standard patch-clamp techniques. The results showed that the antivenom is capable of reversing ion current disruption caused by the venom application. We propose the use of this in vitro technique for antivenom evaluation as an alternative to using a large number of live animals.

  7. Electrophysiological correlates of change detection.

    PubMed

    Eimer, Martin; Mazza, Veronica

    2005-05-01

    To identify electrophysiological correlates of change detection, event-related brain potentials (ERPs) were recorded while participants monitored displays containing four faces in order to detect a face identity change across successive displays. Successful change detection was mirrored by an N2pc component at posterior electrodes contralateral to the side of a change, suggesting close links between conscious change detection and attention. ERPs on undetected-change trials differed from detected-change and no-change trials. We suggest that short-latency ERP differences between these trial types reflect trial-by-trial fluctuations in advance task preparation, whereas differences in the P3 time range are due to variations in the duration of perceptual and decision-related processing. Overall, these findings demonstrate that ERPs are a useful tool for dissociating processes underlying change blindness and change detection.

  8. Antivenom Evaluation by Electrophysiological Analysis

    PubMed Central

    Restano-Cassulini, Rita; Garcia, Walter; Paniagua-Solís, Jorge F.; Possani, Lourival D.

    2017-01-01

    Scorpion stings on humans are medically relevant because they may contain toxins that specifically target ion channels. During antivenom production, pharmaceutical companies must use a large number of experimental animals to ensure the antivenom’s efficacy according to pharmacopeia methods. Here we present an electrophysiological alternative for the evaluation of horse antivenoms produced against two species of Moroccan scorpions: Buthus mardochei and Androctonus mauretanicus. Human sodium and potassium channels and acetylcholine nicotinic receptors were analyzed by standard patch-clamp techniques. The results showed that the antivenom is capable of reversing ion current disruption caused by the venom application. We propose the use of this in vitro technique for antivenom evaluation as an alternative to using a large number of live animals. PMID:28241514

  9. Evolution of ventricular myocyte electrophysiology.

    PubMed

    Rosati, Barbara; Dong, Min; Cheng, Lan; Liou, Shian-Ren; Yan, Qinghong; Park, Ji Young; Shiang, Elaine; Sanguinetti, Michael; Wang, Hong-Sheng; McKinnon, David

    2008-11-12

    The relative importance of regulatory versus structural evolution for the evolution of different biological systems is a subject of controversy. The primacy of regulatory evolution in the diversification of morphological traits has been promoted by many evolutionary developmental biologists. For physiological traits, however, the role of regulatory evolution has received less attention or has been considered to be relatively unimportant. To address this issue for electrophysiological systems, we examined the importance of regulatory and structural evolution in the evolution of the electrophysiological function of cardiac myocytes in mammals. In particular, two related phenomena were studied: the change in action potential morphology in small mammals and the scaling of action potential duration across mammalian phylogeny. In general, the functional properties of the ion channels involved in ventricular action potential repolarization were found to be relatively invariant. In contrast, there were large changes in the expression levels of multiple ion channel and transporter genes. For the Kv2.1 and Kv4.2 potassium channel genes, which are primary determinants of the action potential morphology in small mammals, the functional properties of the proximal promoter regions were found to vary in concordance with species-dependent differences in mRNA expression, suggesting that evolution of cis-regulatory elements is the primary determinant of this trait. Scaling of action potential duration was found to be a complex phenomenon, involving changes in the expression of a large number of channels and transporters. In this case, it is concluded that regulatory evolution is the predominant mechanism by which the scaling is achieved.

  10. Architect's Contract.

    ERIC Educational Resources Information Center

    Ohio State Board of Education, Columbus.

    An actual contract form used for architectural services is presented. Fees, duties, and services are included. Services are listed in the following phases--(1) schematic design, (2) design development, (3) contract document, and (4) construction. Extra services are listed, and owner's responsibility with regard to cost estimates is given.…

  11. Microsystems for cell-based electrophysiology

    NASA Astrophysics Data System (ADS)

    Yobas, Levent

    2013-08-01

    Among the electrophysiology techniques, the voltage clamp and its subsequent scaling to smaller mammalian cells, the so-called patch clamp, led to fundamental discoveries in the last century, revealing the ionic mechanisms and the role of single-ion channels in the generation and propagation of action potentials through excitable membranes (e.g. nerves and muscles). Since then, these techniques have gained a reputation as the gold standard of studying cellular ion channels owing to their high accuracy and rich information content via direct measurements under a controlled membrane potential. However, their delicate and skill-laden procedure has put a serious constrain on the throughput and their immediate utilization in the discovery of new cures targeting ion channels until researchers discovered ‘lab-on-a-chip’ as a viable platform for the automation of these techniques into a reliable high-throughput screening functional assay on ion channels. This review examines the innovative ‘lab-on-a-chip’ microtechnologies demonstrated towards this target over a period of slightly more than a decade. The technologies are categorically reviewed according to their considerations for design, fabrication, as well as microfluidic integration from a performance perspective with reference to their ability to secure G Ω seals (gigaseals) on cells, the norm broadly accepted among electrophysiologists for quality recordings that reflect ion-channel activity with high fidelity.

  12. The tarsal taste of honey bees: behavioral and electrophysiological analyses.

    PubMed

    de Brito Sanchez, Maria Gabriela; Lorenzo, Esther; Su, Songkun; Liu, Fanglin; Zhan, Yi; Giurfa, Martin

    2014-01-01

    Taste plays a crucial role in the life of honey bees as their survival depends on the collection and intake of nectar and pollen, and other natural products. Here we studied the tarsal taste of honey bees through a series of behavioral and electrophysiological analyses. We characterized responsiveness to various sweet, salty and bitter tastants delivered to gustatory sensilla of the fore tarsi. Behavioral experiments showed that stimulation of opposite fore tarsi with sucrose and bitter substances or water yielded different outcomes depending on the stimulation sequence. When sucrose was applied first, thereby eliciting proboscis extension, no bitter substance could induce proboscis retraction, thus suggesting that the primacy of sucrose stimulation induced a central excitatory state. When bitter substances or water were applied first, sucrose stimulation could still elicit proboscis extension but to a lower level, thus suggesting central inhibition based on contradictory gustatory input on opposite tarsi. Electrophysiological experiments showed that receptor cells in the gustatory sensilla of the tarsomeres are highly sensitive to saline solutions at low concentrations. No evidence for receptors responding specifically to sucrose or to bitter substances was found in these sensilla. Receptor cells in the gustatory sensilla of the claws are highly sensitive to sucrose. Although bees do not possess dedicated bitter-taste receptors in the tarsi, indirect bitter detection is possible because bitter tastes inhibit sucrose receptor cells of the claws when mixed with sucrose solution. By combining behavioral and electrophysiological approaches, these results provide the first integrative study on tarsal taste detection in the honey bee.

  13. An Elective Course in Cardiovascular Electrophysiology for Pharmacy Learners

    PubMed Central

    2016-01-01

    Objective. To implement an integrated, comprehensive, and learner-centered elective course focused at exposing learners to the interpretation of electrocardiograms and highlighting the mechanisms underlining the abnormal electrophysiological events. Design. Learners were presented with foundational information on the mechanisms underlying electrophysiological changes associated with the development of arrhythmias. They then discussed the interpretation of electrocardiogram (ECG) recordings and diagnosis of cardiovascular events. Teaching formats included “chalk-talk” and didactic sessions, case-based exercises providing hands-on evaluation of ECG recordings, and high-fidelity simulation presenting cases of arrhythmias. The course design emphasized critical thinking, learner engagement, and development of problem-solving skills. Learners were assessed by formal assignments, examinations, and in-class quizzes. Assessment. Learner comprehension of the material was assessed using cumulative examinations, in-class quizzes, assignments, and in-class presentations. Learner evaluations showed that the case-based discussions, practice ECGs, review tables, and illustrations enhanced course performance and retention of complex material. Conclusion. The elective course provided in-depth exposure to the mechanisms underlying electrophysiological aberrations resulting in arrhythmias. It gave learners an opportunity to learn the art of ECG interpretation and to apply their knowledge in simulated scenarios. As clinical teams adopt a multidisciplinary team approach to patient care, acquiring these skills enriches learner experiences and allows them to expand their role and professional opportunities as pharmacists. PMID:27899826

  14. Hourglass-shaped aperture for cellular electrophysiological study

    NASA Astrophysics Data System (ADS)

    Chen, Chang-Yu; Liu, Kuan-Ting; Jong, De-Shien; Wo, Andrew M.

    2007-09-01

    This work presents a simple process of reflow of melted glass by CO2 laser to form an hourglass-shaped aperture for cellular electrophysiological study. The fabricated aperture proves to be smooth, circular, debris-free, and freshly activated. Two-phase flow simulation illuminates details of the reflow process. The resulting seal resistance quality is well suited to measure ion-channel activities; a seal resistance of 1.9GΩ for PC-12 cell and a typical resistance of 200MΩ for Chinese hamster ovary cells were achieved. This approach can be integrated with microfluidics in a single cell patch or array configuration.

  15. Historical perspectives on interventional electrophysiology.

    PubMed

    Lüderitz, Berndt

    2003-10-01

    The history of interventional electrophysiology is long and fascinating. In the beginning, there is not simply the anatomy and physiology of the heart, but also analysis of the pulse, which indicates the activity of the heart. The analysis of the (peripheral) pulse as a mechanical expression of heart activity goes back several millennia. In China, in 280 B.C., Wang Chu Ho wrote ten books about the pulse. The Greeks called the pulse "sphygmos", and the sphygmology thus deals with a theory of this natural occurrence. In Roman times, Galen interpreted the various types of pulse according to the widespread presumption of the time, that each organ in every disease has its own form of pulse. The basic tool for arrhythmia diagnosis became the electrocardiography introduced by Willem Einthoven who obtained the first human electrogram 1902 in Leiden, The Netherlands. The growing clinical importance of electrical cardiac stimulation has been recognized and renewed as Zoll (1911-1999) in 1952 reported a successful resuscitation in cardiac standstill by external stimulation. Meanwhile all over the world, millions of patients with cardiac arrhythmias have been treated with pacemakers in the last 45 years. The concept of a fully automatic implantable cardioverter-defibrillator system (ICD) for recognition and treatment of ventricular tachyarrhythmias was first suggested in 1970. The first implantation of the device in a human being was performed in February 1980. Further developments concern atrial and atrioventricular defibrillators, radiofrequency ablation, laser therapy and advanced antiarrhythmic surgery, new antiarrhythmic drugs and sophisticated devices for preventive pacing. The advances in the field of diagnostic and therapeutic application of pharmacologic and electrical tools as well as alternative methods will continue as rapidly as before in order to give us further significant aid in taking care of the patient.

  16. Integrative modeling of the cardiac ventricular myocyte

    PubMed Central

    Winslow, Raimond L.; Cortassa, Sonia; O'Rourke, Brian; Hashambhoy, Yasmin L.; Rice, John Jeremy; Greenstein, Joseph L.

    2011-01-01

    Cardiac electrophysiology is a discipline with a rich 50-year history of experimental research coupled with integrative modeling which has enabled us to achieve a quantitative understanding of the relationships between molecular function and the integrated behavior of the cardiac myocyte in health and disease. In this paper, we review the development of integrative computational models of the cardiac myocyte. We begin with a historical overview of key cardiac cell models that helped shape the field. We then narrow our focus to models of the cardiac ventricular myocyte and describe these models in the context of their subcellular functional systems including dynamic models of voltage-gated ion channels, mitochondrial energy production, ATP-dependent and electrogenic membrane transporters, intracellular Ca dynamics, mechanical contraction, and regulatory signal transduction pathways. We describe key advances and limitations of the models as well as point to new directions for future modeling research. PMID:20865780

  17. Extensional vs contractional Cenozoic deformation in Ibiza (Balearic Promontory, Spain): Integration in the West Mediterranean back-arc setting

    NASA Astrophysics Data System (ADS)

    Etheve, Nathalie; Frizon de Lamotte, Dominique; Mohn, Geoffroy; Martos, Raquel; Roca, Eduard; Blanpied, Christian

    2016-07-01

    Based on field work and seismic reflection data, we investigate the Cenozoic tectono-sedimentary evolution offshore and onshore Ibiza allowing the proposal of a new tectonic agenda for the region and its integration in the geodynamic history of the West Mediterranean. The late Oligocene-early Miocene rifting event, which characterizes the Valencia Trough and the Algerian Basin, located north and south of the study area respectively, is also present in Ibiza and particularly well-expressed in the northern part of the island. Among these two rifted basins initiated in the frame of the European Cenozoic Rift System, the Valencia Trough failed rapidly while the Algerian Basin evolved after as a back-arc basin related to the subduction of the Alpine-Maghrebian Tethys. The subsequent middle Miocene compressional deformation was localized by the previous extensional faults, which were either inverted or passively translated depending on their initial orientation. Despite the lateral continuity between the External Betics and the Balearic Promontory, it appears from restored maps that this tectonic event cannot be directly related to the Betic orogen, but results from compressive stresses transmitted through the Algerian Basin. A still active back-arc asthenospheric rise likely explains the stiff behavior of this basin, which has remained poorly deformed up to recent time. During the late Miocene a new extensional episode reworked the southern part of the Balearic Promontory. It is suggested that this extensional deformation developed in a trans-tensional context related to the westward translation of the Alboran Domain and the coeval right-lateral strike-slip movement along the Emile Baudot Escarpment bounding the Algerian Basin to the north.

  18. Electrophysiologic Evaluation of Psychogenic Movement Disorders

    PubMed Central

    Pal, Pramod Kumar

    2011-01-01

    Psychogenic movement disorders (PMD) are a group of disorders which are in the border zone between neurology and psychiatry. All necessary laboratory investigations should be done to rule out an underlying organic disorder. While clinical acumen of a trained movement disorder specialist may be sufficient to diagnose most PMD, there are clinical situations where electrophysiological tests are required either to rule out an organic movement disorder or even diagnose a PMD. Current electrophysiological test are most useful for tremor, followed by jerks and least for spasms or dystonia. Commonly used electrophysiologic tests include multichannel surface electromyography (EMG), accelerometry, electroencephalography time locked with EMG, premovement potential (Bereitschaftspotential), and somatosensory evoked potentials. Psychogenic tremor is a low frequency tremor with variable frequency and duration of EMG bursts, entrainable, has a high coherence with voluntary movements, and presence of coactivation sign. Patients with psychogenic jerks have well organized triphasic pattern of activation of agonist and antagonist muscles. The jerks are associated with EMG bursts of long duration (usually > 70 ms), long and variable latencies in stimulus induced jerks, absence of craniocaudal pattern of muscle recruitment in apparent startle response, and often a Breitschaftspotential (premovement potential) precedes the jerk. Electrophysiological characterization of psychogenic dystonia is difficult and the tests are usually performed to rule out organic dystonia with characteristic findings. Finally, caution should be exerted in interpreting the electrophysiological tests as both false positive and false negative diagnosis of PMD may still occur. PMID:24868388

  19. Individual differences in reinforcement learning: behavioral, electrophysiological, and neuroimaging correlates.

    PubMed

    Santesso, Diane L; Dillon, Daniel G; Birk, Jeffrey L; Holmes, Avram J; Goetz, Elena; Bogdan, Ryan; Pizzagalli, Diego A

    2008-08-15

    During reinforcement learning, phasic modulations of activity in midbrain dopamine neurons are conveyed to the dorsal anterior cingulate cortex (dACC) and basal ganglia (BG) and serve to guide adaptive responding. While the animal literature supports a role for the dACC in integrating reward history over time, most human electrophysiological studies of dACC function have focused on responses to single positive and negative outcomes. The present electrophysiological study investigated the role of the dACC in probabilistic reward learning in healthy subjects using a task that required integration of reinforcement history over time. We recorded the feedback-related negativity (FRN) to reward feedback in subjects who developed a response bias toward a more frequently rewarded ("rich") stimulus ("learners") versus subjects who did not ("non-learners"). Compared to non-learners, learners showed more positive (i.e., smaller) FRNs and greater dACC activation upon receiving reward for correct identification of the rich stimulus. In addition, dACC activation and a bias to select the rich stimulus were positively correlated. The same participants also completed a monetary incentive delay (MID) task administered during functional magnetic resonance imaging. Compared to non-learners, learners displayed stronger BG responses to reward in the MID task. These findings raise the possibility that learners in the probabilistic reinforcement task were characterized by stronger dACC and BG responses to rewarding outcomes. Furthermore, these results highlight the importance of the dACC to probabilistic reward learning in humans.

  20. Electrophysiological methods for Caenorhabditis elegans neurobiology.

    PubMed

    Goodman, Miriam B; Lindsay, Theodore H; Lockery, Shawn R; Richmond, Janet E

    2012-01-01

    Patch-clamp electrophysiology is a technique of choice for the biophysical analysis of the function of nerve, muscle, and synapse in Caenorhabditis elegans nematodes. Considerable technical progress has been made in C. elegans electrophysiology in the decade since the initial publication of this technique. Today, most, if not all, electrophysiological studies that can be done in larger animal preparations can also be done in C. elegans. This chapter has two main goals. The first is to present to a broad audience the many techniques available for patch-clamp analysis of neurons, muscles, and synapses in C. elegans. The second is to provide a methodological introduction to the techniques for patch clamping C. elegans neurons and body-wall muscles in vivo, including emerging methods for optogenetic stimulation coupled with postsynaptic recording. We also present samples of the cell-intrinsic and postsynaptic ionic currents that can be measured in C. elegans nerves and muscles.

  1. Electrophysiological characterization of membrane transport proteins.

    PubMed

    Grewer, Christof; Gameiro, Armanda; Mager, Thomas; Fendler, Klaus

    2013-01-01

    Active transport in biological membranes has been traditionally studied using a variety of biochemical and biophysical techniques, including electrophysiology. This review focuses on aspects of electrophysiological methods that make them particularly suited for the investigation of transporter function. Two major approaches to electrical recording of transporter activity are discussed: (a) artificial planar lipid membranes, such as the black lipid membrane and solid supported membrane, which are useful for studies on bacterial transporters and transporters of intracellular compartments, and (b) patch clamp and voltage clamp techniques, which investigate transporters in native cellular membranes. The analytical power of these methods is highlighted by several examples of mechanistic studies of specific membrane proteins, including cytochrome c oxidase, NhaA Na(+)/H(+) exchanger, ClC-7 H(+)/Cl(-) exchanger, glutamate transporters, and neutral amino acid transporters. These examples reveal the wealth of mechanistic information that can be obtained when electrophysiological methods are used in combination with rapid perturbation approaches.

  2. Electrophysiological Methods for C. elegans Neurobiology

    PubMed Central

    Goodman, Miriam B.; Lindsay, Theodore H.; Lockery, Shawn R.; Richmond, Janet E.

    2014-01-01

    Patch-clamp electrophysiology is the technique of choice for the biophysical analysis of the function of nerve, muscle, and synapse in C. elegans nematodes. Considerable technical progress has been made in C. elegans electrophysiology in the decade since the initial publication of this technique. Today, most, if not all electrophysiological studies that can be done in larger animal preparations can also be done in C. elegans. This chapter has two main goals. The first is to present to a broad audience the many techniques available for patch-clamp analysis of neurons, muscles, and synapses in C. elegans. The second is to provide a methodological introduction to the techniques for patch-clamping C. elegans neurons and body-wall muscles in vivo, including emerging methods for optogenetic stimulation coupled with post-synaptic recording. We also present samples of the cell-intrinsic and post-synaptic ionic currents that can be measured in C. elegans nerve and muscle. PMID:22226532

  3. [Interdisciplinarity and chronic pain therapy--implementation of a new Interdisciplinary Center at the University Hospital Dresden on the basis of an integrated health care contract].

    PubMed

    Michel, Sabine; Günther, Klaus-Peter; Joraschky, Peter; Reichmann, Heinz; Koch, Thea; Eberlein-Gonska, Maria

    2007-01-01

    Due to the bio-psycho-social complexity and presence of various health departments, chronic pain requires interdisciplinary cooperation which enables the accurate evaluation of the clinical findings and is a prerequisite for an individual and resource-oriented therapeutic concept focusing on both physical and mental activation. This concept forms the basis of medical care at the University Pain Center, which was founded in April 2004 at the Carl Gustav Carus University Hospital in Dresden. Since then, day care and inpatient services have been provided in addition to well-established outpatient care. The motive behind the foundation of the Pain Center was to sensitize health insurers to the complex problems of chronic pain and existing regional structural deficits. Following a draft version of a coherent multimodal, interdisciplinary healthcare concept along with full cost accounting after 1 1/2 years, an integrative healthcare contract got signed by two health insurances (AOK-Sachsen and VdAK) in June 2004. After two years of existence, the first experiences, results and especially the Pain Center's treatment spectrum ought to be demonstrated.

  4. Optic Nerve Dysfunction in Obstructive Sleep Apnea: An Electrophysiological Study

    PubMed Central

    Liguori, Claudio; Palmieri, Maria Giuseppina; Pierantozzi, Mariangela; Cesareo, Massimo; Romigi, Andrea; Izzi, Francesca; Marciani, Maria Grazia; Oliva, Corrado; Mercuri, Nicola Biagio; Placidi, Fabio

    2016-01-01

    Study Objectives: The aim of this study was to evaluate the integrity of the visual system in patients affected by obstructive sleep apnea (OSA) by means of electroretinogram (ERG) and visual evoked potential (VEP). Methods: We performed electrophysiological study of the visual system in a population of severe OSA (apnea-hypopnea events/time in bed ≥ 30/h) patients without medical comorbidities compared to a group of healthy controls similar for age, sex, and body mass index. Patients and controls did not have visual impairment or systemic disorders with known influence on the visual system. ERG and VEP were elicited by a reversal pattern generated on a television monitor at low (55') and high (15') spatial frequencies stimulation. Daytime sleepiness was assessed using the Epworth Sleepiness Scale (ESS) in both patients and controls. Results: In comparison with healthy controls (n = 27), patients with OSA (n = 27) showed a significant latency delay coupled with a significant amplitude reduction of P100 wave of VEP at all spatial frequencies in both eyes. No significant differences between groups were detected as concerning ERG components. No correlations were found between polygraphic parameters, ESS scores, or VEP and ERG components in OSA patients. Conclusions: This study documented that patients with OSA, without medical comorbidities, present VEP alteration as documented by lower amplitude and longer latency of the P100 component than healthy controls. These altered electrophysiological findings may be the expression of optic nerve dysfunction provoked by hypoxia, acidosis, hypercarbia and airway obstruction, frequently observed in patients with OSA. Hence, we hypothesize that OSA per se may impair optic nerve function. Citation: Liguori C, Palmieri MG, Pierantozzi M, Cesareo M, Romigi A, Izzi F, Marciani MG, Oliva C, Mercuri NB, Placidi F. Optic nerve dysfunction in obstructive sleep apnea: an electrophysiological study. SLEEP 2016;39(1):19–23. PMID

  5. Finding the locus of semantic satiation: an electrophysiological attempt.

    PubMed

    Frenck-Mestre, C; Besson, M; Pynte, J

    1997-05-01

    The present study examined the effect of massed repetition of an initial category name upon the subsequent semantic categorization of a target word by means of an electrophysiological measure of semantic processing: the N400. Results showed the classic N400 effect, whereby evoked potentials were more negative for targets that were not members of the repeated category than for member targets. Moreover, repetition of the category name led to an increased and sustained positivity. The N400 effect was not modified, however, by repetition. Hence, insomuch as the N400 reflects meaning integration processes, these results do not support the hypothesis that massed repetition exerts its influence at the level of meaning integration.

  6. Electrophysiology of connection current spikes.

    PubMed

    Fish, Raymond M; Geddes, Leslie A

    2008-12-01

    Connection to a 60-Hz or other voltage source can result in cardiac dysrhythmias, a startle reaction, muscle contractions, and a variety of other physiological responses. Such responses can lead to injury, especially if significant ventricular cardiac dysrhythmias occur, or if a person is working at some height above ground and falls as a result of a musculoskeletal response. Physiological reactions are known to relate to intensity and duration of current exposure. The connection current that flows is a function of the applied voltage at the instant of connection, and the electrical impedance encountered by the voltage source in contact with the skin or other body tissues. In this article we describe a rarely investigated phenomenon, namely a contact, or connection, current spike that is many times higher than the steady-state current. This current spike occurs when an electrical connection is made at a non-zero voltage time in a sine wave or other waveform. Such current spikes may occur when electronic or manual switching or connecting of conductors occurs in electronic instrumentation connected to a patient. These findings are relevant to medical devices and instrumentation and to electrical safety in general.

  7. Minimum Information about a Cardiac Electrophysiology Experiment (MICEE): standardised reporting for model reproducibility, interoperability, and data sharing.

    PubMed

    Quinn, T A; Granite, S; Allessie, M A; Antzelevitch, C; Bollensdorff, C; Bub, G; Burton, R A B; Cerbai, E; Chen, P S; Delmar, M; Difrancesco, D; Earm, Y E; Efimov, I R; Egger, M; Entcheva, E; Fink, M; Fischmeister, R; Franz, M R; Garny, A; Giles, W R; Hannes, T; Harding, S E; Hunter, P J; Iribe, G; Jalife, J; Johnson, C R; Kass, R S; Kodama, I; Koren, G; Lord, P; Markhasin, V S; Matsuoka, S; McCulloch, A D; Mirams, G R; Morley, G E; Nattel, S; Noble, D; Olesen, S P; Panfilov, A V; Trayanova, N A; Ravens, U; Richard, S; Rosenbaum, D S; Rudy, Y; Sachs, F; Sachse, F B; Saint, D A; Schotten, U; Solovyova, O; Taggart, P; Tung, L; Varró, A; Volders, P G; Wang, K; Weiss, J N; Wettwer, E; White, E; Wilders, R; Winslow, R L; Kohl, P

    2011-10-01

    Cardiac experimental electrophysiology is in need of a well-defined Minimum Information Standard for recording, annotating, and reporting experimental data. As a step towards establishing this, we present a draft standard, called Minimum Information about a Cardiac Electrophysiology Experiment (MICEE). The ultimate goal is to develop a useful tool for cardiac electrophysiologists which facilitates and improves dissemination of the minimum information necessary for reproduction of cardiac electrophysiology research, allowing for easier comparison and utilisation of findings by others. It is hoped that this will enhance the integration of individual results into experimental, computational, and conceptual models. In its present form, this draft is intended for assessment and development by the research community. We invite the reader to join this effort, and, if deemed productive, implement the Minimum Information about a Cardiac Electrophysiology Experiment standard in their own work.

  8. [Do We Still Need Electrophysiology in Ophthalmology?

    PubMed

    Tegetmeyer, H

    2016-12-01

    Electrophysiological methods in clinical ophthalmology include the full-field electroretinogram (ERG) for assessment of outer and middle retinal layers, pattern ERG (PERG) for assessment of ganglion cell function, the electrooculogram (EOG) for assessment of retinal pigment epithelium function, as well as visual evoked potentials (VEP) for assessment of the visual pathway, including the optic nerve and visual cortex. Multifocal recording techniques for ERG and VEP are used for tests within selected areas of the visual field. Technical progress in ocular imaging, especially optical coherence tomography (OCT) and fundus autofluorescence (FAF), allows high-resolution imaging of subtle morphological changes of the retina and posterior fundus. Typical retinal diseases may then be diagnosed at an early stage, without conventional electrophysiological investigations (e.g. x-linked retinoschisis, Stargardt disease, vitelliform macular dystrophy). OCT outclasses electrophysiological methods in the quantification of optic atrophies. With newly developed optic techniques, peripheral retinal structures (wide angle optics) and subtle structures up to the photoreceptor level (adaptive optics) can be imaged with increasing quality. However, differentiation of central retinal disorders (e.g. macular dystrophy) from generalised retinal diseases requires electrophysiological diagnostic testing. The same applies to discrimination between different functional disorders in generalised retinal diseases (e.g. enhanced S-cone syndrome, congenital stationary night blindness, achromatopsia).

  9. Electrophysiological assessment of retinal ganglion cell function

    PubMed Central

    Porciatti, Vittorio

    2015-01-01

    The function of retinal ganglion cells (RGCs) can be non-invasively assessed in experimental and genetic models of glaucoma by means of variants of the ERG technique that emphasize the activity of inner retina neurons. The best understood technique is the Pattern Electroretinogram (PERG) in response to contrast-reversing gratings or checkerboards, which selectively depends on the presence of functional RGCs. In glaucoma models, the PERG can be altered before histological loss of RGCs; PERG alterations may be either reversed with moderate IOP lowering or exacerbated with moderate IOP elevation. Under particular luminance-stimulus conditions, the Flash-ERG displays components that may reflect electrical activity originating in the proximal retina and be altered in some experimental glaucoma models (positive Scotopic Threshold response, pSTR; negative Scotopic Threshold Response, nSTR; Photopic Negative Response, PhNR; Oscillatory Potentials, OPs; multifocal ERG, mfERG). It is not yet known which of these components is most sensitive to glaucomatous damage. Electrophysiological assessment of RGC function appears to be a necessary outcome measure in experimental glaucoma models, which complements structural assessment and may even predict it. Neuroprotective strategies could be tested based on enhancement of baseline electrophysiological function that results in improved RGC survival. The use of electrophysiology in glaucoma models may be facilitated by specifically designed instruments that allow high throughput, robust assessment of electrophysiological function. PMID:25998495

  10. Electrophysiological Correlates of Observational Learning in Children

    ERIC Educational Resources Information Center

    Rodriguez Buritica, Julia M.; Eppinger, Ben; Schuck, Nicolas W.; Heekeren, Hauke R.; Li, Shu-Chen

    2016-01-01

    Observational learning is an important mechanism for cognitive and social development. However, the neurophysiological mechanisms underlying observational learning in children are not well understood. In this study, we used a probabilistic reward-based observational learning paradigm to compare behavioral and electrophysiological markers of…

  11. Portuguese National Registry on Cardiac Electrophysiology, 2013 and 2014.

    PubMed

    Cavaco, Diogo; Morgado, Francisco; Bonhorst, Daniel

    2016-01-01

    The authors present the results of the national registry of electrophysiology of the Portuguese Association for Arrhythmology, Pacing and Electrophysiology (APAPE) for 2013 and 2014. The registry is annual and voluntary, and data are collected retrospectively. Data for electrophysiological studies, ablations and cardioverter-defibrillator implantations for 2013 and 2014 are presented. Developments over the years and their implications are analyzed and discussed.

  12. Electrophysiological, histochemical, and hormonal adaptation of rat muscle after prolonged hindlimb suspension

    NASA Astrophysics Data System (ADS)

    Kourtidou-Papadeli, Chrysoula; Kyparos, Antonios; Albani, Maria; Frossinis, Athanasios; Papadelis, Christos L.; Bamidis, Panagiotis; Vivas, Ana; Guiba-Tziampiri, Olympia

    2004-05-01

    The perspective of long-duration flights for future exploration, imply more research in the field of human adaptation. Previous studies in rat muscles hindlimb suspension (HLS), indicated muscle atrophy and a change of fibre composition from slow-to-fast twitch types. However, the contractile responses to long-term unloading is still unclear. Fifteen adult Wistar rats were studied in 45 and 70 days of muscle unweighting and soleus (SOL) muscle as well as extensor digitorum longus (EDL) were prepared for electrophysiological recordings (single, twitch, tetanic contraction and fatigue) and histochemical stainings. The loss of muscle mass observed was greater in the soleus muscle. The analysis of electrophysiological properties of both EDL and SOL showed significant main effects of group, of number of unweighting days and fatigue properties. Single contraction for soleus muscle remained unchanged but there was statistically significant difference for tetanic contraction and fatigue. Fatigue index showed a decrease for the control rats, but increase for the HLS rats. According to the histochemical findings there was a shift from oxidative to glycolytic metabolism during HLS. The data suggested that muscles atrophied, but they presented an adaptation pattern, while their endurance in fatigue was decreased.

  13. The Impact of Opioids on Cardiac Electrophysiology.

    PubMed

    Wedam, Erich F; Haigney, Mark C

    2016-01-01

    Synthetic opioid agents have been used in modern medicine for over a century and for opioid addiction treatment for over a half-century. Liberal use of opioids in the United States has been attended by an extraordinary increase in opioid-related mortality, with over 16,000 deaths in 2012. As there have been advances in opioid agents for pain and addiction, so have there been advances in our understanding of the cardiac effects of these agents. In the last 10 years, significant data regarding electrophysiologic effects of these agents have been collected. We aim in this review to discuss the effects on cardiac electrophysiology of the various opioid agents currently in use and the evidence that these effects are contributing to the rise in opioid-related mortality.

  14. Re-visiting the electrophysiology of language.

    PubMed

    Obleser, Jonas

    2015-09-01

    This editorial accompanies a special issue of Brain and Language re-visiting old themes and new leads in the electrophysiology of language. The event-related potential (ERP) as a series of characteristic deflections ("components") over time and their distribution on the scalp has been exploited by speech and language researchers over decades to find support for diverse psycholinguistic models. Fortunately, methodological and statistical advances have allowed human neuroscience to move beyond some of the limitations imposed when looking at the ERP only. Most importantly, we currently witness a refined and refreshed look at "event-related" (in the literal sense) brain activity that relates itself more closely to the actual neurobiology of speech and language processes. It is this imminent change in handling and interpreting electrophysiological data of speech and language experiments that this special issue intends to capture.

  15. Python for large-scale electrophysiology.

    PubMed

    Spacek, Martin; Blanche, Tim; Swindale, Nicholas

    2008-01-01

    Electrophysiology is increasingly moving towards highly parallel recording techniques which generate large data sets. We record extracellularly in vivo in cat and rat visual cortex with 54-channel silicon polytrodes, under time-locked visual stimulation, from localized neuronal populations within a cortical column. To help deal with the complexity of generating and analysing these data, we used the Python programming language to develop three software projects: one for temporally precise visual stimulus generation ("dimstim"); one for electrophysiological waveform visualization and spike sorting ("spyke"); and one for spike train and stimulus analysis ("neuropy"). All three are open source and available for download (http://swindale.ecc.ubc.ca/code). The requirements and solutions for these projects differed greatly, yet we found Python to be well suited for all three. Here we present our software as a showcase of the extensive capabilities of Python in neuroscience.

  16. The Impact of Opioids on Cardiac Electrophysiology

    PubMed Central

    Wedam, Erich F.; Haigney, Mark C.

    2016-01-01

    Synthetic opioid agents have been used in modern medicine for over a century and for opioid addiction treatment for over a half-century. Liberal use of opioids in the United States has been attended by an extraordinary increase in opioid-related mortality, with over 16,000 deaths in 2012. As there have been advances in opioid agents for pain and addiction, so have there been advances in our understanding of the cardiac effects of these agents. In the last 10 years, significant data regarding electrophysiologic effects of these agents have been collected. We aim in this review to discuss the effects on cardiac electrophysiology of the various opioid agents currently in use and the evidence that these effects are contributing to the rise in opioid-related mortality. PMID:26818485

  17. Electrophysiological Characteristics of Fetal Atrioventricular Block

    PubMed Central

    Zhao, Hui; Cuneo, Bettina F.; Strasburger, Janette F.; Huhta, James C.; Gotteiner, Nina L.; Wakai, Ronald T.

    2012-01-01

    Objectives The purpose of our work was to define the complex electrophysiological characteristics seen in second- (2°) and third-degree (3°) atrioventricular block (AVB) and to longitudinally follow the development of atrial and ventricular heart rate and rhythm patterns with a goal of identifying heart rate and rhythm patterns associated with urgent delivery or neonatal pacing. Background The electrophysiological characteristics of congenital AVB before birth have not been extensively studied, yet the mortality from this disease is substantial. Along with advances in fetal therapies and interventions, a comprehensive natural history specific to the etiology of AVB, as well as the electrophysiological factors influencing outcome, are needed to best select treatment options. Methods Twenty-eight fetuses with AVB were evaluated by fetal magnetocardiography; 21 fetuses were evaluated serially. Results Fetuses with 2° AVB and isolated 3° AVB showed: 1) diverse atrial rhythms and mechanisms of atrioventricular conduction during 2° AVB; 2) junctional ectopic tachycardia and ventricular tachycardia during 3° AVB; 3) reactive ventricular and atrial fetal heart rate (FHR) tracings at ventricular rates >56 beats/min; and 4) flat ventricular FHR tracings at ventricular rates <56 beats/min despite reactive atrial FHR tracings. In contrast, fetuses with 3° AVB associated with structural cardiac disease exhibited predominantly nonreactive heart rate tracings and simpler rhythms. Conclusions Second-degree AVB, isolated 3° AVB, and 3° AVB associated with structural cardiac disease manifest distinctly different electrophysiological characteristics and outcome. Fetuses with 2° AVB or isolated 3° AVB commonly exhibited complex, changing heart rate and rhythm patterns; all 19 delivered fetuses are alive and healthy. Fetuses with structural cardiac disease and 3° AVB exhibited largely monotonous heart rate and rhythm patterns and poor prognosis. Junctional ectopic

  18. Pulsed linear acceleration as a vestibular stimulus in electrophysiological investigations.

    PubMed

    Jones, T A; Schiltz, T

    1989-03-01

    A simple method of generating precisely defined pulsed linear acceleration stimuli was developed and used to study vestibular responses to cranial acceleration. Electromechanical shakers were coupled to a stimulus platform. The platform, in turn, was used to couple stimuli to the skull. Movements were controlled by a voltage waveform (V(t] applied to shakers. Software algorithms were used to synthesize voltage functions (V(t]. The resulting acceleration was monitored [a(t)] and used to generate velocity [v(t)] and position [x(t)] functions (first and second integrals of a(t), respectively). The characteristics of stimuli used in physiological experiments are described. The system provides precise control of the timing and amplitude of acceleration, velocity and position pulses to the cranium and has proved to be valuable in developing noninvasive electrophysiological measures of peripheral and central vestibular function.

  19. The P300 as an Electrophysiological Probe of Alcohol Expectancy

    PubMed Central

    Fishman, Inna; Goldman, Mark S.; Donchin, Emanuel

    2008-01-01

    Language-based measures indicate that alcohol expectancies influence alcohol consumption. To relate these measures to brain actions that precede verbal output, the P300 component of the Event-related potentials (ERPs) was used to detect violations of individually held alcohol expectancies. As predicted, P300 amplitude elicited by negative alcohol expectancy stimuli was positively correlated with endorsement of positive/arousing alcohol expectancies on the language-based measure, such that the higher an individual's positive/arousing expectancies, the larger was the P300 elicited by negative alcohol expectancy stimuli. These results demonstrated concordance between language-based measures of alcohol expectancies and electrophysiological probes of expectancy. Although whether these expectancy processes are integral to decision pathways that influence consumption is unknown, these findings suggest that such processing can occur very quickly outside of conscious deliberation. PMID:18729689

  20. Electrophysiological methods for hearing assessment in pinnipeds

    NASA Astrophysics Data System (ADS)

    Reichmuth Kastak, Colleen; Kastak, David; Finneran, James J.; Houser, Dorian S.; Supin, Alexander

    2005-04-01

    Studies of auditory sensitivity in marine mammals generally rely on behavioral psychophysical methodologies. While these studies are the standard for hearing assessment in marine mammals, data are limited to only a few individuals representing a small proportion of species. Accumulating research on dolphin auditory physiology has resulted in the refinement of electrophysiological methods appropriate for odontocete cetaceans and an increase in available audiometric information. Electrophysiological methods have also been used with pinnipeds, but there are significant gaps in our understanding of pinniped auditory physiology that must be addressed before such appoaches can be broadly applied to investigations of pinniped hearing. We are taking a bottom-up approach to developing suitable methods for evoked potential audiometry in pinnipeds, including technology transfer from studies of cetaceans and other mammals, mapping of response amplitude with respect to recording positions on the skull, characterization of responses in relationship to various stimulus types and presentation parameters, and determination of whether useful frequency-specific data can be reliably obtained using electrophysiological methods. This approach is being taken with representative pinniped species including California sea lions (Zalophus californianus), harbor seals (Phoca vitulina), and northern elephant seals (Mirounga angustirostris) using both training and chemical immobilization techniques. [Work supported by NOPP.

  1. Benchmarking electrophysiological models of human atrial myocytes

    PubMed Central

    Wilhelms, Mathias; Hettmann, Hanne; Maleckar, Mary M.; Koivumäki, Jussi T.; Dössel, Olaf; Seemann, Gunnar

    2013-01-01

    Mathematical modeling of cardiac electrophysiology is an insightful method to investigate the underlying mechanisms responsible for arrhythmias such as atrial fibrillation (AF). In past years, five models of human atrial electrophysiology with different formulations of ionic currents, and consequently diverging properties, have been published. The aim of this work is to give an overview of strengths and weaknesses of these models depending on the purpose and the general requirements of simulations. Therefore, these models were systematically benchmarked with respect to general mathematical properties and their ability to reproduce certain electrophysiological phenomena, such as action potential (AP) alternans. To assess the models' ability to replicate modified properties of human myocytes and tissue in cardiac disease, electrical remodeling in chronic atrial fibrillation (cAF) was chosen as test case. The healthy and remodeled model variants were compared with experimental results in single-cell, 1D and 2D tissue simulations to investigate AP and restitution properties, as well as the initiation of reentrant circuits. PMID:23316167

  2. Cellular cardiac electrophysiology modeling with Chaste and CellML.

    PubMed

    Cooper, Jonathan; Spiteri, Raymond J; Mirams, Gary R

    2014-01-01

    Chaste is an open-source C++ library for computational biology that has well-developed cardiac electrophysiology tissue simulation support. In this paper, we introduce the features available for performing cardiac electrophysiology action potential simulations using a wide range of models from the Physiome repository. The mathematics of the models are described in CellML, with units for all quantities. The primary idea is that the model is defined in one place (the CellML file), and all model code is auto-generated at compile or run time; it never has to be manually edited. We use ontological annotation to identify model variables describing certain biological quantities (membrane voltage, capacitance, etc.) to allow us to import any relevant CellML models into the Chaste framework in consistent units and to interact with them via consistent interfaces. This approach provides a great deal of flexibility for analysing different models of the same system. Chaste provides a wide choice of numerical methods for solving the ordinary differential equations that describe the models. Fixed-timestep explicit and implicit solvers are provided, as discussed in previous work. Here we introduce the Rush-Larsen and Generalized Rush-Larsen integration techniques, made available via symbolic manipulation of the model equations, which are automatically rearranged into the forms required by these approaches. We have also integrated the CVODE solvers, a 'gold standard' for stiff systems, and we have developed support for symbolic computation of the Jacobian matrix, yielding further increases in the performance and accuracy of CVODE. We discuss some of the technical details of this work and compare the performance of the available numerical methods. Finally, we discuss how this is generalized in our functional curation framework, which uses a domain-specific language for defining complex experiments as a basis for comparison of model behavior.

  3. Computational models of atrial cellular electrophysiology and calcium handling, and their role in atrial fibrillation.

    PubMed

    Heijman, Jordi; Erfanian Abdoust, Pegah; Voigt, Niels; Nattel, Stanley; Dobrev, Dobromir

    2016-02-01

    The complexity of the heart makes an intuitive understanding of the relative contribution of ion channels, transporters and signalling pathways to cardiac electrophysiology challenging. Computational modelling of cardiac cellular electrophysiology has proven useful to integrate experimental findings, extrapolate results obtained in expression systems or animal models to other systems, test quantitatively ideas based on experimental data and provide novel hypotheses that are experimentally testable. While the bulk of computational modelling has traditionally been directed towards ventricular bioelectricity, increasing recognition of the clinical importance of atrial arrhythmias, particularly atrial fibrillation, has led to widespread efforts to apply computational approaches to understanding atrial electrical function. The increasing availability of detailed, atrial-specific experimental data has stimulated the development of novel computational models of atrial-cellular electrophysiology and Ca(2+) handling. To date, more than 300 studies have employed mathematical simulations to enhance our understanding of atrial electrophysiology, arrhythmogenesis and therapeutic responses. Future modelling studies are likely to move beyond current whole-cell models by incorporating new data on subcellular architecture, macromolecular protein complexes, and localized ion-channel regulation by signalling pathways. At the same time, more integrative multicellular models that take into account regional electrophysiological and Ca(2+) handling properties, mechano-electrical feedback and/or autonomic regulation will be needed to investigate the mechanisms governing atrial arrhythmias. A combined experimental and computational approach is expected to provide the more comprehensive understanding of atrial arrhythmogenesis that is required to develop improved diagnostic and therapeutic options. Here, we review this rapidly expanding area, with a particular focus on Ca(2+) handling, and

  4. Electrophysiologic features of fetal ventricular aneurysms and diverticula

    PubMed Central

    PETERS, CARLI; WACKER-GUSSMANN, ANNETTE; STRASBURGER, JANETTE F; CUNEO, BETTINA F; GOTTEINER, NINA; GULECYUZ, MEHEMET; WAKAI, RONALD T

    2014-01-01

    Objective Congenital ventricular wall defects are very rare and include congenital ventricular aneurysms (CVAs) and diverticula (CVDs). Method We report a series of five fetuses: three with CVAs and two with CVDs referred due to fetal arrhythmia. In addition to routine fetal echocardiography, fetal magnetocardiography (fMCG) was used. The literature in CVA and CVD is reviewed. Results Incessant premature ventricular contractions (PVC), mainly bigeminy and trigeminy were found in three fetuses with CVAs and in one with CVD, who also had ventricular couplets. The other fetus with CVD, referred because of PVCs, had only sinus tachycardia. ST elevation was noted in two. Fetal movement had a variable impact on PVC’s. Postnatal evaluation demonstrated two persistent left ventricular aneurysms and one persistent right CVD; one CVD resolved at 35 weeks gestation. Two neonates had incessant PVCs. Both arrhythmias resolved spontaneously while being treated with propranolol. Conclusion FMCG is complementary to echocardiographic imaging. In fetuses with left ventricular wall defects, additional electrophysiological diagnosis can be made by fMCG, including the complexity of ventricular ectopy, arrhythmic response to fetal movement, presence of ST-T wave abnormalities, and atrial amplitude increases. Prenatal risk factor assessment using fMCG can additionally support post-natal treatment and follow-up. PMID:25284224

  5. Procurement Integrity in Contingency Operations: A Case Study of Army Contracting Officer Corruption in Operations Iraqi and Enduring Freedom Utilizing Occupational Fraud Theory

    DTIC Science & Technology

    2011-12-01

    personnel incorrectly have been characterized as “ shoppers ,” by some both inside and outside of the Army (and, consequently, reduced in both quantity and...Publication 4-10). Retrieved from DTIC Online website: http://www.dtic.mil/doctrine/new_pubs/jp4_10.pdf Commission on Wartime Contracting in Iraq

  6. Electrophysiological endophenotypes in rodent models of schizophrenia and psychosis

    PubMed Central

    Rosen, Andrew M.; Spellman, Timothy; Gordon, Joshua A.

    2015-01-01

    Schizophrenia is caused by a diverse array of risk factors, and results in a similarly diverse set of symptoms. Electrophysiological endophenotypes lie between risks and symptoms, and have the potential to link the two. Electrophysiological studies in rodent models, described here, demonstrate that widely differing risk factors result in a similar set of core electrophysiological endophenotypes, suggesting the possibility of a shared neurobiological substrate. PMID:25910423

  7. Multifunctional Catheters Combining Intracardiac Ultrasound Imaging and Electrophysiology Sensing

    PubMed Central

    Stephens, Douglas N.; Cannata, Jonathan; Liu, Ruibin; Zhao, Jian Zhong; Shung, K. Kirk; Nguyen, Hien; Chia, Raymond; Dentinger, Aaron; Wildes, Douglas; Thomenius, Kai E.; Mahajan, Aman; Shivkumar, Kalyanam; Kim, Kang; O’Donnell, Matthew; Nikoozadeh, Amin; Oralkan, Omer; Khuri-Yakub, Pierre T.; Sahn, David J.

    2015-01-01

    A family of 3 multifunctional intracardiac imaging and electrophysiology (EP) mapping catheters has been in development to help guide diagnostic and therapeutic intracardiac EP procedures. The catheter tip on the first device includes a 7.5 MHz, 64-element, side-looking phased array for high resolution sector scanning. The second device is a forward-looking catheter with a 24-element 14 MHz phased array. Both of these catheters operate on a commercial imaging system with standard software. Multiple EP mapping sensors were mounted as ring electrodes near the arrays for electrocardiographic synchronization of ultrasound images and used for unique integration with EP mapping technologies. To help establish the catheters’ ability for integration with EP interventional procedures, tests were performed in vivo in a porcine animal model to demonstrate both useful intracardiac echocardiographic (ICE) visualization and simultaneous 3-D positional information using integrated electroanatomical mapping techniques. The catheters also performed well in high frame rate imaging, color flow imaging, and strain rate imaging of atrial and ventricular structures. The companion paper of this work discusses the catheter design of the side-looking catheter with special attention to acoustic lens design. The third device in development is a 10 MHz forward-looking ring array that is to be mounted at the distal tip of a 9F catheter to permit use of the available catheter lumen for adjunctive therapy tools. PMID:18986948

  8. High-throughput electrophysiology with Xenopus oocytes

    PubMed Central

    Papke, Roger L.; Smith-Maxwell, Cathy

    2010-01-01

    Voltage-clamp techniques are typically used to study the plasma membrane proteins, such as ion channels and transporters that control bioelectrical signals. Many of these proteins have been cloned and can now be studied as potential targets for drug development. The two approaches most commonly used for heterologous expression of cloned ion channels and transporters involve either transfection of the genes into small cells grown in tissue culture or the injection of the genetic material into larger cells. The standard large cells used for the expression of cloned cDNA or synthetic RNA are the egg progenitor cells (oocytes) of the African frog, Xenopus laevis. Until recently, cellular electrophysiology was performed manually, one cell at a time by a single operator. However, methods of high-throughput electrophysiology have been developed which are automated and permit data acquisition and analysis from multiple cells in parallel. These methods are breaking a bottleneck in drug discovery, useful in some cases for primary screening as well as for thorough characterization of new drugs. Increasing throughput of high-quality functional data greatly augments the efficiency of academic research and pharmaceutical drug development. Some examples of studies that benefit most from high-throughput electrophysiology include pharmaceutical screening of targeted compound libraries, secondary screening of identified compounds for subtype selectivity, screening mutants of ligand-gated channels for changes in receptor function, scanning mutagenesis of protein segments, and mutant-cycle analysis. We describe here the main features and potential applications of OpusXpress, an efficient commercially available system for automated recording from Xenopus oocytes. We show some types of data that have been gathered by this system and review realized and potential applications. PMID:19149490

  9. Cell-Specific Cardiac Electrophysiology Models

    PubMed Central

    Groenendaal, Willemijn; Ortega, Francis A.; Kherlopian, Armen R.; Zygmunt, Andrew C.; Krogh-Madsen, Trine; Christini, David J.

    2015-01-01

    The traditional cardiac model-building paradigm involves constructing a composite model using data collected from many cells. Equations are derived for each relevant cellular component (e.g., ion channel, exchanger) independently. After the equations for all components are combined to form the composite model, a subset of parameters is tuned, often arbitrarily and by hand, until the model output matches a target objective, such as an action potential. Unfortunately, such models often fail to accurately simulate behavior that is dynamically dissimilar (e.g., arrhythmia) to the simple target objective to which the model was fit. In this study, we develop a new approach in which data are collected via a series of complex electrophysiology protocols from single cardiac myocytes and then used to tune model parameters via a parallel fitting method known as a genetic algorithm (GA). The dynamical complexity of the electrophysiological data, which can only be fit by an automated method such as a GA, leads to more accurately parameterized models that can simulate rich cardiac dynamics. The feasibility of the method is first validated computationally, after which it is used to develop models of isolated guinea pig ventricular myocytes that simulate the electrophysiological dynamics significantly better than does a standard guinea pig model. In addition to improving model fidelity generally, this approach can be used to generate a cell-specific model. By so doing, the approach may be useful in applications ranging from studying the implications of cell-to-cell variability to the prediction of intersubject differences in response to pharmacological treatment. PMID:25928268

  10. Reentrant Information Flow in Electrophysiological Rat Default Mode Network

    PubMed Central

    Jing, Wei; Guo, Daqing; Zhang, Yunxiang; Guo, Fengru; Valdés-Sosa, Pedro A.; Xia, Yang; Yao, Dezhong

    2017-01-01

    Functional MRI (fMRI) studies have demonstrated that the rodent brain shows a default mode network (DMN) activity similar to that in humans, offering a potential preclinical model both for physiological and pathophysiological studies. However, the neuronal mechanism underlying rodent DMN remains poorly understood. Here, we used electrophysiological data to analyze the power spectrum and estimate the directed phase transfer entropy (dPTE) within rat DMN across three vigilance states: wakeful rest (WR), slow-wave sleep (SWS), and rapid-eye-movement sleep (REMS). We observed decreased gamma powers during SWS compared with WR in most of the DMN regions. Increased gamma powers were found in prelimbic cortex, cingulate cortex, and hippocampus during REMS compared with WR, whereas retrosplenial cortex showed a reverse trend. These changed gamma powers are in line with the local metabolic variation of homologous brain regions in humans. In the analysis of directional interactions, we observed well-organized anterior-to-posterior patterns of information flow in the delta band, while opposite patterns of posterior-to-anterior flow were found in the theta band. These frequency-specific opposite patterns were only observed in WR and REMS. Additionally, most of the information senders in the delta band were also the receivers in the theta band, and vice versa. Our results provide electrophysiological evidence that rat DMN is similar to its human counterpart, and there is a frequency-dependent reentry loop of anterior-posterior information flow within rat DMN, which may offer a mechanism for functional integration, supporting conscious awareness. PMID:28289373

  11. Opportunities and challenges of current electrophysiology research: a plea to establish 'translational electrophysiology' curricula.

    PubMed

    Lau, Dennis H; Volders, Paul G A; Kohl, Peter; Prinzen, Frits W; Zaza, Antonio; Kääb, Stefan; Oto, Ali; Schotten, Ulrich

    2015-05-01

    Cardiac electrophysiology has evolved into an important subspecialty in cardiovascular medicine. This is in part due to the significant advances made in our understanding and treatment of heart rhythm disorders following more than a century of scientific discoveries and research. More recently, the rapid development of technology in cellular electrophysiology, molecular biology, genetics, computer modelling, and imaging have led to the exponential growth of knowledge in basic cardiac electrophysiology. The paradigm of evidence-based medicine has led to a more comprehensive decision-making process and most likely to improved outcomes in many patients. However, implementing relevant basic research knowledge in a system of evidence-based medicine appears to be challenging. Furthermore, the current economic climate and the restricted nature of research funding call for improved efficiency of translation from basic discoveries to healthcare delivery. Here, we aim to (i) appraise the broad challenges of translational research in cardiac electrophysiology, (ii) highlight the need for improved strategies in the training of translational electrophysiologists, and (iii) discuss steps towards building a favourable translational research environment and culture.

  12. Contracts in radiology practices: contract types and key provisions.

    PubMed

    Muroff, Julie A; Muroff, Lawrence R

    2004-07-01

    A contract between a radiology group and its physician member(s) provides the foundation for the professional relationships in a group practice. The parties are not in positions of parity; contract provisions are structured to maintain the primacy of the group over the individual members. An integration clause should be included to preclude reliance on communications that are not memorialized by the language of the contract. Precise, unambiguous terms must be used to convey the intentions of the parties. The contract should have a clear date of initiation and, if applicable, an effective date of termination. Mechanisms for termination and modification should be expressed clearly to minimize the risk of judicial interference. The method of determining and adjusting the salary and other benefits of the radiologist should be stated, as consideration is necessary to support the existence of a legal contract. The obligations of the radiologist to the practice are often stated in general terms to maximize the group's flexibility. Finally, other key clauses that are discussed in the paper should be incorporated into the contract.

  13. Effects of bepridil on cardiac electrophysiologic properties.

    PubMed

    Prystowsky, E N

    1992-04-09

    The current classification system for antiarrhythmic drugs has several shortcomings; for example, electrophysiologic effects are defined in normal tissue, whereas antiarrhythmic drugs are often used clinically in diseased or injured tissue. Consideration of the electrophysiologic effects of bepridil in humans emphasizes the drawbacks of the classification system. Bepridil is primarily a calcium antagonist with class IV action. However, because the drug has class IA action as well, it should not be considered a typical class I or class IV agent. Bepridil has been observed to prolong the QT interval in the majority of patients in whom it is used for treatment of angina. However, in US clinical trials, including open extensions, only 7 cases of torsades de pointes have been recorded. In France, where the drug is approved for treatment of angina, the incidence of torsades de pointes was 0.01% in 1989. No consensus currently exists regarding what degree of QT prolongation constitutes increased risk for a ventricular proarrhythmic event. Based on current information, bepridil should be used cautiously in patients with a propensity toward hypokalemia, which can exacerbate or induce a proarrhythmic state. The drug should not be used in patients with a prolonged QT interval at baseline, a history of torsades de pointes, or long QT interval syndrome. Bepridil also should be avoided in patients with sinus node dysfunction or second- or third-degree atrioventricular block.

  14. A Motivation Contract Model of Employee Appraisal.

    ERIC Educational Resources Information Center

    Glenn, Robert B.

    The purpose of this paper is to develop a process model for identification and assessment of employee job performance, through motivation contracting. The model integrated various components of expectancy theories of motivation and performance contracting and is based on humanistic assumptions about the nature of people. More specifically, the…

  15. Audiovisual integration for speech during mid-childhood: electrophysiological evidence.

    PubMed

    Kaganovich, Natalya; Schumaker, Jennifer

    2014-12-01

    Previous studies have demonstrated that the presence of visual speech cues reduces the amplitude and latency of the N1 and P2 event-related potential (ERP) components elicited by speech stimuli. However, the developmental trajectory of this effect is not yet fully mapped. We examined ERP responses to auditory, visual, and audiovisual speech in two groups of school-age children (7-8-year-olds and 10-11-year-olds) and in adults. Audiovisual speech led to the attenuation of the N1 and P2 components in all groups of participants, suggesting that the neural mechanisms underlying these effects are functional by early school years. Additionally, while the reduction in N1 was largest over the right scalp, the P2 attenuation was largest over the left and midline scalp. The difference in the hemispheric distribution of the N1 and P2 attenuation supports the idea that these components index at least somewhat disparate neural processes within the context of audiovisual speech perception.

  16. Multiplexed, High Density Electrophysiology with Nanofabricated Neural Probes

    PubMed Central

    Du, Jiangang; Blanche, Timothy J.; Harrison, Reid R.; Lester, Henry A.; Masmanidis, Sotiris C.

    2011-01-01

    Extracellular electrode arrays can reveal the neuronal network correlates of behavior with single-cell, single-spike, and sub-millisecond resolution. However, implantable electrodes are inherently invasive, and efforts to scale up the number and density of recording sites must compromise on device size in order to connect the electrodes. Here, we report on silicon-based neural probes employing nanofabricated, high-density electrical leads. Furthermore, we address the challenge of reading out multichannel data with an application-specific integrated circuit (ASIC) performing signal amplification, band-pass filtering, and multiplexing functions. We demonstrate high spatial resolution extracellular measurements with a fully integrated, low noise 64-channel system weighing just 330 mg. The on-chip multiplexers make possible recordings with substantially fewer external wires than the number of input channels. By combining nanofabricated probes with ASICs we have implemented a system for performing large-scale, high-density electrophysiology in small, freely behaving animals that is both minimally invasive and highly scalable. PMID:22022568

  17. Embryonic amygdalar transplants in adult rats with motor cortex lesions: a molecular and electrophysiological analysis.

    PubMed

    Jiménez-Díaz, Lydia; Nava-Mesa, Mauricio O; Heredia, Margarita; Riolobos, Adelaida S; Gómez-Álvarez, Marcelo; Criado, José María; de la Fuente, Antonio; Yajeya, Javier; Navarro-López, Juan D

    2011-01-01

    Transplants of embryonic nervous tissue ameliorate motor deficits induced by motor cortex lesions in adult animals. Restoration of lost brain functions has been recently shown in grafts of homotopic cortical origin, to be associated with a functional integration of the transplant after development of reciprocal host-graft connections. Nevertheless little is known about physiological properties or gene expression profiles of cortical implants with functional restorative capacity but no cortical origin. In this study, we show molecular and electrophysiological evidence supporting the functional development and integration of heterotopic transplants of embryonic amygdalar tissue placed into pre-lesioned motor cortex of adult rats. Grafts were analyzed 3 months post-transplantation. Using reverse transcriptase quantitative polymerase chain reaction, we found that key glutamatergic, GABAergic, and muscarinic receptors transcripts were expressed at different quantitative levels both in grafted and host tissues, but were all continuously present in the graft. Parallel sharp electrode recordings of grafted neurons in brain slices showed a regular firing pattern of transplanted neurons similar to host amygdalar pyramidal neurons. Synaptic connections from the adjacent host cortex on grafted neurons were electrophysiologically investigated and confirmed our molecular results. Taken together, our findings indicate that grafted neurons from a non-cortical, non-motor-related, but ontogenetical similar source, not only received functionally effective contacts from the adjacent motor cortex, but also developed electrophysiological and gene expression patterns comparable to host pyramidal neurons; suggesting an interesting tool for the field of neural repair and donor tissue in adults.

  18. A Novel Long-term, Multi-Channel and Non-invasive Electrophysiology Platform for Zebrafish

    PubMed Central

    Hong, SoonGweon; Lee, Philip; Baraban, Scott C.; Lee, Luke P.

    2016-01-01

    Zebrafish are a popular vertebrate model for human neurological disorders and drug discovery. Although fecundity, breeding convenience, genetic homology and optical transparency have been key advantages, laborious and invasive procedures are required for electrophysiological studies. Using an electrode-integrated microfluidic system, here we demonstrate a novel multichannel electrophysiology unit to record multiple zebrafish. This platform allows spontaneous alignment of zebrafish and maintains, over days, close contact between head and multiple surface electrodes, enabling non-invasive long-term electroencephalographic recording. First, we demonstrate that electrographic seizure events, induced by pentylenetetrazole, can be reliably distinguished from eye or tail movement artifacts, and quantifiably identified with our unique algorithm. Second, we show long-term monitoring during epileptogenic progression in a scn1lab mutant recapitulating human Dravet syndrome. Third, we provide an example of cross-over pharmacology antiepileptic drug testing. Such promising features of this integrated microfluidic platform will greatly facilitate high-throughput drug screening and electrophysiological characterization of epileptic zebrafish. PMID:27305978

  19. Electrophysiological comparison between males and females in HNPP.

    PubMed

    Manganelli, Fiore; Pisciotta, Chiara; Dubbioso, Raffaele; Maruotti, Valerio; Iodice, Rosa; Notturno, Francesca; Ruggiero, Lucia; Vitale, Carmine; Nolano, Maria; Uncini, Antonino; Santoro, Lucio

    2013-08-01

    Some evidences highlighted a higher clinical expression of hereditary neuropathy with liability to pressure palsy (HNPP) in males, and a higher load of traumatic nerve injuries due to different occupational activity has been invoked to explain this observation. It is unknown whether this increased clinical impairment corresponds to a greater electrophysiological involvement. Thus, we compared clinical and electrophysiological features between men and women in a large cohort of HNPP patients. Nerve palsies and electrophysiological abnormalities were more frequent in men, and electrophysiological findings which differentiated males from females did not show any age-related worsening. In conclusion, our findings showed a higher clinical and electrophysiological involvement in males which does not seem related to different cumulative nerve damage over time. We believe that the higher disease expression may increase the chance to detect the disease in males and, thereby, to underestimate the HNPP diagnosis in females.

  20. Transparent, Flexible, Low Noise Graphene Electrodes for Simultaneous Electrophysiology and Neuroimaging

    PubMed Central

    Kuzum, Duygu; Takano, Hajime; Shim, Euijae; Reed, Jason C; Juul, Halvor; Richardson, Andrew G.; de Vries, Julius; Bink, Hank; Dichter, Marc A.; Lucas, Timothy H.; Coulter, Douglas A.; Cubukcu, Ertugrul; Litt, Brian

    2014-01-01

    Calcium imaging is a versatile experimental approach capable of resolving single neurons with single-cell spatial resolution in the brain. Electrophysiological recordings provide high temporal, but limited spatial resolution, due to the geometrical inaccessibility of the brain. An approach that integrates the advantages of both techniques could provide new insights into functions of neural circuits. Here, we report a transparent, flexible neural electrode technology based on graphene, which enables simultaneous optical imaging and electrophysiological recording. We demonstrate that hippocampal slices can be imaged through transparent graphene electrodes by both confocal and two-photon microscopy without causing any light-induced artifacts in the electrical recordings. Graphene electrodes record high frequency bursting activity and slow synaptic potentials that are hard to resolve by multi-cellular calcium imaging. This transparent electrode technology may pave the way for high spatio-temporal resolution electrooptic mapping of the dynamic neuronal activity. PMID:25327632

  1. Long-term synchronized electrophysiological and behavioral wireless monitoring of freely moving animals

    PubMed Central

    Grand, Laszlo; Ftomov, Sergiu; Timofeev, Igor

    2012-01-01

    Parallel electrophysiological recording and behavioral monitoring of freely moving animals is essential for a better understanding of the neural mechanisms underlying behavior. In this paper we describe a novel wireless recording technique, which is capable of synchronously recording in vivo multichannel electrophysiological (LFP, MUA, EOG, EMG) and activity data (accelerometer, video) from freely moving cats. The method is based on the integration of commercially available components into a simple monitoring system and is complete with accelerometers and the needed signal processing tools. LFP activities of freely moving group-housed cats were recorded from multiple intracortical areas and from the hippocampus. EMG, EOG, accelerometer and video were simultaneously acquired with LFP activities 24-h a day for 3 months. These recordings confirm the possibility of using our wireless method for 24-h long-term monitoring of neurophysiological and behavioral data of freely moving experimental animals such as cats, ferrets, rabbits and other large animals. PMID:23099345

  2. Stimfit: quantifying electrophysiological data with Python

    PubMed Central

    Guzman, Segundo J.; Schlögl, Alois; Schmidt-Hieber, Christoph

    2013-01-01

    Intracellular electrophysiological recordings provide crucial insights into elementary neuronal signals such as action potentials and synaptic currents. Analyzing and interpreting these signals is essential for a quantitative understanding of neuronal information processing, and requires both fast data visualization and ready access to complex analysis routines. To achieve this goal, we have developed Stimfit, a free software package for cellular neurophysiology with a Python scripting interface and a built-in Python shell. The program supports most standard file formats for cellular neurophysiology and other biomedical signals through the Biosig library. To quantify and interpret the activity of single neurons and communication between neurons, the program includes algorithms to characterize the kinetics of presynaptic action potentials and postsynaptic currents, estimate latencies between pre- and postsynaptic events, and detect spontaneously occurring events. We validate and benchmark these algorithms, give estimation errors, and provide sample use cases, showing that Stimfit represents an efficient, accessible and extensible way to accurately analyze and interpret neuronal signals. PMID:24600389

  3. Automatic Parameterization Strategy for Cardiac Electrophysiology Simulations.

    PubMed

    Costa, Caroline Mendonca; Hoetzl, Elena; Rocha, Bernardo Martins; Prassl, Anton J; Plank, Gernot

    2013-10-01

    Driven by recent advances in medical imaging, image segmentation and numerical techniques, computer models of ventricular electrophysiology account for increasingly finer levels of anatomical and biophysical detail. However, considering the large number of model parameters involved parameterization poses a major challenge. A minimum requirement in combined experimental and modeling studies is to achieve good agreement in activation and repolarization sequences between model and experiment or patient data. In this study, we propose basic techniques which aid in determining bidomain parameters to match activation sequences. An iterative parameterization algorithm is implemented which determines appropriate bulk conductivities which yield prescribed velocities. In addition, a method is proposed for splitting the computed bulk conductivities into individual bidomain conductivities by prescribing anisotropy ratios.

  4. Rheumatoid neuropathy: a histological and electrophysiological study

    PubMed Central

    Weller, R. O.; Bruckner, F. E.; Chamberlain, M. Anne

    1970-01-01

    Peripheral nerves in five patients with rheumatoid neuropathy were examined electrophysiologically and by sural nerve biopsy. There was close correlation between the clinical severity of the disease and the degree of nerve damage found histologically and by EMG. Group 1 patients with a mild distal sensory neuropathy showed varying degrees of axonal degeneration in the large myelinated fibres and some segmental demyelination. Group 2 patients with a severe, rapidly progressive sensori-motor neuropathy had extensive loss of myelinated fibres. In one case all the large fibres had degenerated. The second case had lost both large and small myelinated fibres together with many of the non-myelinated axons. The major nerve damage in both groups appeared to be axonal degeneration but some segmental demyelination was detected. Occlusive vascular disease in the vasa nervorum was considered to be the major cause of the nerve damage. Images PMID:4320255

  5. The electrophysiological signature of deliberate rule violations.

    PubMed

    Pfister, Roland; Wirth, Robert; Schwarz, Katharina A; Foerster, Anna; Steinhauser, Marco; Kunde, Wilfried

    2016-12-01

    Humans follow rules by default, and violating even simple rules induces cognitive conflict for the rule breaker. Previous studies revealed this conflict in various behavioral measures, including response times and movement trajectories. Based on these experiments, we investigated the electrophysiological signature of deliberately violating a simple stimulus-response mapping rule. Such rule violations were characterized by a delayed and attenuated P300 component when evaluating a rule-relevant stimulus, most likely reflecting increased response complexity. This parietal attenuation was followed by a frontal positivity for rule violations relative to correct response trials. Together, these results reinforce previous findings on the need to inhibit automatic S-R translation when committing a rule violation, and they point toward additional factors involved in rule violation. Candidate processes such as negative emotional responses and increased monitoring should be targeted by future investigations.

  6. Lyme carditis. Electrophysiologic and histopathologic study

    SciTech Connect

    Reznick, J.W.; Braunstein, D.B.; Walsh, R.L.; Smith, C.R.; Wolfson, P.M.; Gierke, L.W.; Gorelkin, L.; Chandler, F.W.

    1986-11-01

    To further define the nature of Lyme carditis, electrophysiologic study and endomyocardial biopsy were performed in a patient with Lyme disease, whose principal cardiac manifestation was high-degree atrioventricular block. Intracardiac recording demonstrated supra-Hisian block and complete absence of an escape mechanism. Gallium 67 scanning demonstrated myocardial uptake, and right ventricular endomyocardial biopsy revealed active lymphocytic myocarditis. A structure compatible with a spirochetal organism was demonstrated in one biopsy specimen. It is concluded that Lyme disease can produce active myocarditis, as suggested by gallium 67 imaging and confirmed by endomyocardial biopsy. Furthermore, the presence of high-grade atrioventricular block in this disease requires aggressive management with temporary pacemaker and corticosteroid therapy.

  7. Electrophysiological characterization of human rectal afferents

    PubMed Central

    Ng, Kheng-Seong; Brookes, Simon J.; Montes-Adrian, Noemi A.; Mahns, David A.

    2016-01-01

    It is presumed that extrinsic afferent nerves link the rectum to the central nervous system. However, the anatomical/functional existence of such nerves has never previously been demonstrated in humans. Therefore, we aimed to identify and make electrophysiological recordings in vitro from extrinsic afferents, comparing human rectum to colon. Sections of normal rectum and colon were procured from anterior resection and right hemicolectomy specimens, respectively. Sections were pinned and extrinsic nerves dissected. Extracellular visceral afferent nerve activity was recorded. Neuronal responses to chemical [capsaicin and “inflammatory soup” (IS)] and mechanical (Von Frey probing) stimuli were recorded and quantified as peak firing rate (range) in 1-s intervals. Twenty-eight separate nerve trunks from eight rectums were studied. Of these, spontaneous multiunit afferent activity was recorded in 24 nerves. Peak firing rates increased significantly following capsaicin [median 6 (range 3–25) spikes/s vs. 2 (1–4), P < 0.001] and IS [median 5 (range 2–18) spikes/s vs. 2 (1–4), P < 0.001]. Mechanosensitive “hot spots” were identified in 16 nerves [median threshold 2.0 g (range 1.4–6.0 g)]. In eight of these, the threshold decreased after IS [1.0 g (0.4–1.4 g)]. By comparison, spontaneous activity was recorded in only 3/30 nerves studied from 10 colons, and only one hot spot (threshold 60 g) was identified. This study confirms the anatomical/functional existence of extrinsic rectal afferent nerves and characterizes their chemo- and mechanosensitivity for the first time in humans. They have different electrophysiological properties to colonic afferents and warrant further investigation in disease states. PMID:27789454

  8. Electrophysiological correlates of voice learning and recognition.

    PubMed

    Zäske, Romi; Volberg, Gregor; Kovács, Gyula; Schweinberger, Stefan Robert

    2014-08-13

    Listeners can recognize familiar human voices from variable utterances, suggesting the acquisition of speech-invariant voice representations during familiarization. However, the neurocognitive mechanisms mediating learning and recognition of voices from natural speech are currently unknown. Using electrophysiology, we investigated how representations are formed during intentional learning of initially unfamiliar voices that were later recognized among novel voices. To probe the acquisition of speech-invariant voice representations, we compared a "same sentence" condition, in which speakers repeated the study utterances at test, and a "different sentence" condition. Although recognition performance was higher for same compared with different sentences, substantial voice learning also occurred for different sentences, with recognition performance increasing across consecutive study-test-cycles. During study, event-related potentials elicited by voices subsequently remembered elicited a larger sustained parietal positivity (∼250-1400 ms) compared with subsequently forgotten voices. This difference due to memory was unaffected by test sentence condition and may thus reflect the acquisition of speech-invariant voice representations. At test, voices correctly classified as "old" elicited a larger late positive component (300-700 ms) at Pz than voices correctly classified as "new." This event-related potential OLD/NEW effect was limited to the same sentence condition and may thus reflect speech-dependent retrieval of voices from episodic memory. Importantly, a speech-independent effect for learned compared with novel voices was found in beta band oscillations (16-17 Hz) between 290 and 370 ms at central and right temporal sites. Our results are a first step toward elucidating the electrophysiological correlates of voice learning and recognition.

  9. Effects of chronic treatment with statins and fenofibrate on rat skeletal muscle: a biochemical, histological and electrophysiological study

    PubMed Central

    Pierno, S; Didonna, M P; Cippone, V; De Luca, A; Pisoni, M; Frigeri, A; Nicchia, G P; Svelto, M; Chiesa, G; Sirtori, C; Scanziani, E; Rizzo, C; De Vito, D; Conte Camerino, D

    2006-01-01

    Background and purpose: Skeletal muscle injury by hypolipidemic drugs is not fully understood. An extensive analysis of the effect of chronic treatment with fluvastatin (5 mgkg-1 and 20 mgkg-1), atorvastatin (10 mgkg-1) and fenofibrate (60 mgkg-1) on rat skeletal muscle was undertaken. Experimental approach: Myoglobinemia as sign of muscle damage was measured by enzymatic assay. Histological and immunohistochemical techniques were used to estimate muscle integrity and the presence of aquaporin-4, a protein controlling water homeostasis. Electrophysiological evaluation of muscle Cl- conductance (gCl) and mechanical threshold (MT) for contraction, index of intracellular calcium homeostasis, was performed by the two-intracellular microelectrodes technique. Key results: Fluvastatin (20 mgkg-1) increased myoglobinemia. The lower dose of fluvastatin did not modify myoglobinemia, but reduced urinary electrolytes, suggesting direct effects on renal function. Atorvastatin also increased myoglobinemia, with slight effects on urinary parameters. No treatment caused any histological damage to muscle or modification in the number of fibres expressing aquaporin-4. Either fluvastatin (at both doses) or atorvastatin reduced sarcolemma gCl and changed MT. Both statins produced slight effects on total cholesterol, suggesting that the observed modifications occur independently of HMGCoA-reductase inhibition. Fenofibrate increased myoglobinemia and decreased muscle gCl, whereas it did not change the MT, suggesting a different mechanism of action from the statins. Conclusions and Implications This study identifies muscle gCl and MT as early targets of drugs action that may contribute to milder symptoms of myotoxicity, such as muscle cramps, while the increase of myoglobinemia is a later phenomenon. PMID:17031388

  10. The Electrophysiological Phenomenon of Alzheimer's Disease: A Psychopathology Theory.

    PubMed

    Holston, Ezra C

    2015-08-01

    The current understanding of Alzheimer's disease (AD) is based on the Aβ and tau pathology and the resulting neuropathological changes, which are associated with manifested clinical symptoms. However, electrophysiological brain changes may provide a more expansive understanding of AD. Hence, the objective of this systematic review is to propose a theory about the electrophysiological phenomenon of Alzheimer's disease (EPAD). The review of literature resulted from an extensive search of PubMed and MEDLINE databases. One-hundred articles were purposively selected. They provided an understanding of the concepts establishing the theory of EPAD (neuropathological changes, neurochemical changes, metabolic changes, and electrophysiological brain changes). Changes in the electrophysiology of the brain are foundational to the association or interaction of the concepts. Building on Berger's Psychophysical Model, it is evident that electrophysiological brain changes occur and affect cortical areas to generate or manifest symptoms from onset and across the stages of AD, which may be prior to pathological changes. Therefore, the interaction of the concepts demonstrates how the psychopathology results from affected electrophysiology of the brain. The theory of the EPAD provides a theoretical foundation for appropriate measurements of AD without dependence on neuropathological changes. Future research is warranted to further test this theory. Ultimately, this theory contributes to existing knowledge because it shows how electrophysiological changes are useful in understanding the risk and progression of AD across the stages.

  11. 76 FR 79565 - Management Contracts-Background Investigations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-22

    ... National Indian Gaming Commission 25 CFR Part 537 RIN 3141-AA46 Management Contracts--Background... management contracts. The proposed revision may reduce duplication of efforts while maintaining the integrity... contractor should be required to submit background information when the contract is for management of...

  12. The Acoustic Lens Design and in Vivo Use of a Multifunctional Catheter Combining Intracardiac Ultrasound Imaging and Electrophysiology Sensing

    PubMed Central

    Stephens, Douglas N.; Cannata, Jonathan; Liu, Ruibin; Zhao, Jian Zhong; Shung, K. Kirk; Nguyen, Hien; Chia, Raymond; Dentinger, Aaron; Wildes, Douglas; Thomenius, Kai E.; Mahajan, Aman; Shivkumar, Kalyanam; Kim, Kang; O’Donnell, Matthew; Sahn, David

    2009-01-01

    A multifunctional 9F intracardiac imaging and electrophysiology mapping catheter was developed and tested to help guide diagnostic and therapeutic intracardiac electrophysiology (EP) procedures. The catheter tip includes a 7.25-MHz, 64-element, side-looking phased array for high resolution sector scanning. Multiple electrophysiology mapping sensors were mounted as ring electrodes near the array for electrocardiographic synchronization of ultrasound images. The catheter array elevation beam performance in particular was investigated. An acoustic lens for the distal tip array designed with a round cross section can produce an acceptable elevation beam shape; however, the velocity of sound in the lens material should be approximately 155 m/s slower than in tissue for the best beam shape and wide bandwidth performance. To help establish the catheter’s unique ability for integration with electrophysiology interventional procedures, it was used in vivo in a porcine animal model, and demonstrated both useful intracardiac echocardiographic visualization and simultaneous 3-D positional information using integrated electroanatomical mapping techniques. The catheter also performed well in high frame rate imaging, color flow imaging, and strain rate imaging of atrial and ventricular structures. PMID:18407850

  13. Electrophysiological and functional connectivity of the human supplementary motor area.

    PubMed

    Narayana, Shalini; Laird, Angela R; Tandon, Nitin; Franklin, Crystal; Lancaster, Jack L; Fox, Peter T

    2012-08-01

    Neuro-imaging methods for detecting functional and structural inter-regional connectivity are in a rapid phase of development. While reports of regional connectivity patterns based on individual methods are becoming common, studies comparing the results of two or more connectivity-mapping methods remain rare. In this study, we applied transcranial magnetic stimulation during PET imaging (TMS/PET), a stimulation-based method, and meta-analytic connectivity modeling (MACM), a task-based method to map the connectivity patterns of the supplementary motor area (SMA). Further, we drew upon the behavioral domain meta-data of the BrainMap® database to characterize the behavioral domain specificity of two maps. Both MACM and TMS/PET detected multi-synaptic connectivity patterns, with the MACM-detected connections being more extensive. Both MACM and TMS/PET detected connections belonging to multiple behavioral domains, including action, cognition and perception. Finally, we show that the two connectivity-mapping methods are complementary in that, the MACM informed on the functional nature of SMA connections, while TMS/PET identified brain areas electrophysiologically connected with the SMA. Thus, we demonstrate that integrating multimodal database and imaging techniques can derive comprehensive connectivity maps of brain areas.

  14. The virtual intestine: in silico modeling of small intestinal electrophysiology and motility and the applications.

    PubMed

    Du, Peng; Paskaranandavadivel, Niranchan; Angeli, Timothy R; Cheng, Leo K; O'Grady, Gregory

    2016-01-01

    The intestine comprises a long hollow muscular tube organized in anatomically and functionally discrete compartments, which digest and absorb nutrients and water from ingested food. The intestine also plays key roles in the elimination of waste and protection from infection. Critical to all of these functions is the intricate, highly coordinated motion of the intestinal tract, known as motility, which is coregulated by hormonal, neural, electrophysiological and other factors. The Virtual Intestine encapsulates a series of mathematical models of intestinal function in health and disease, with a current focus on motility, and particularly electrophysiology. The Virtual Intestine is being cohesively established across multiple physiological scales, from sub/cellular functions to whole organ levels, facilitating quantitative evaluations that present an integrative in silico framework. The models are also now finding broad physiological applications, including in evaluating hypotheses of slow wave pacemaker mechanisms, smooth muscle electrophysiology, structure-function relationships, and electromechanical coupling. Clinical applications are also beginning to follow, including in the pathophysiology of motility disorders, diagnosing intestinal ischemia, and visualizing colonic dysfunction. These advances illustrate the emerging potential of the Virtual Intestine to effectively address multiscale research challenges in interdisciplinary gastrointestinal sciences.

  15. The Virtual Intestine: in-silico modeling of small intestinal electrophysiology and motility and the applications

    PubMed Central

    Du, Peng; Paskaranandavadivel, Niranchan; Angeli, Timothy R.; Cheng, Leo K; O'Grady, Gregory

    2016-01-01

    The intestine comprises a long hollow muscular tube organized in anatomically and functionally discrete compartments, which digest and absorb nutrients and water from ingested food. The intestine also plays key roles in the elimination of waste and protection from infection. Critical to all of these functions is the intricate, highly-coordinated motion of the intestinal tract, known as motility, which is co-regulated by hormonal, neural, electrophysiological and other factors. The Virtual Intestine encapsulates a series of mathematical models of intestinal function in health and disease, with a current focus on motility, and particularly electrophysiology. The Virtual Intestine is being cohesively established across multiple physiological scales, from sub/cellular functions to whole organ levels, facilitating quantitative evaluations that present an integrative in-silico framework. The models are also now finding broad physiological applications, including in evaluating hypotheses of slow wave pacemaker mechanisms, smooth muscle electrophysiology, structure-function relationships, and electromechanical coupling. Clinical applications are also beginning to follow, including in the pathophysiology of motility disorders, diagnosing intestinal ischemia, and visualizing colonic dysfunction. These advances illustrate the emerging potential of the Virtual Intestine to effectively address multi-scale research challenges in interdisciplinary gastrointestinal sciences. PMID:26562482

  16. Effects of transcranial direct current stimulation (tDCS) on behaviour and electrophysiology of language production.

    PubMed

    Wirth, Miranka; Rahman, Rasha Abdel; Kuenecke, Janina; Koenig, Thomas; Horn, Helge; Sommer, Werner; Dierks, Thomas

    2011-12-01

    Excitatory anodal transcranial direct current stimulation (A-tDCS) over the left dorsal prefrontal cortex (DPFC) has been shown to improve language production. The present study examined neurophysiological underpinnings of this effect. In a single-blinded within-subject design, we traced effects of A-tDCS compared to sham stimulation over the left DPFC using electrophysiological and behavioural correlates during overt picture naming. Online effects were examined during A-tDCS by employing the semantic interference (SI-)Effect - a marker that denotes the functional integrity of the language system. The behavioural SI-Effect was found to be reduced, whereas the electrophysiological SI-Effect was enhanced over left compared to right temporal scalp-electrode sites. This modulation is suggested to reflect a superior tuning of neural responses within language-related generators. After -(offline) effects of A-tDCS were detected in the delta frequency band, a marker of neural inhibition. After A-tDCS there was a reduction in delta activity during picture naming and the resting state, interpreted to indicate neural disinhibition. Together, these findings demonstrate electrophysiological modulations induced by A-tDCS of the left DPFC. They suggest that A-tDCS is capable of enhancing neural processes during and after application. The present functional and oscillatory neural markers could detect positive effects of prefrontal A-tDCS, which could be of use in the neuro-rehabilitation of frontal language functions.

  17. A new extracellular multirecording system for electrophysiological studies: application to hippocampal organotypic cultures.

    PubMed

    Stoppini, L; Duport, S; Corrèges, P

    1997-03-01

    The present paper describes a new multirecording device which performs continuous electrophysiological studies on organotypic cultures. This device is formed by a card (Physiocard) carrying the culture which is inserted into an electronic module. Electrical activities are recorded by an array of 30 biocompatible microelectrodes which are adjusted into close contact with the upper surface of the slice culture. The microelectrode array is integrated into the card enabling electrical stimulation and recording of neurons over periods ranging from several hours to a few days outside a Faraday cage. Neuronal responses are recorded and analyzed by a dedicated electronic and acquisition chain. A perfusion chamber is contained in the card, allowing continuous perfusion in sterile conditions. Electrophysiological extracellular recordings and some drugs' effects obtained with this system in hippocampal slice cultures were identical to conventional electrophysiological set-up results with tetrodotoxin, bicuculline, kainate, dexamethasone and NBQX. The Physiocard system allows new insights for studies on nervous tissue and allows sophisticated approaches to be used quicker and more easily. It could be used for various neurophysiological studies or screening tests such as neural network mapping, nervous recovery, epilepsy, neurotoxicity or neuropharmacology.

  18. Large-scale electrophysiology: acquisition, compression, encryption, and storage of big data.

    PubMed

    Brinkmann, Benjamin H; Bower, Mark R; Stengel, Keith A; Worrell, Gregory A; Stead, Matt

    2009-05-30

    The use of large-scale electrophysiology to obtain high spatiotemporal resolution brain recordings (>100 channels) capable of probing the range of neural activity from local field potential oscillations to single-neuron action potentials presents new challenges for data acquisition, storage, and analysis. Our group is currently performing continuous, long-term electrophysiological recordings in human subjects undergoing evaluation for epilepsy surgery using hybrid intracranial electrodes composed of up to 320 micro- and clinical macroelectrode arrays. DC-capable amplifiers, sampling at 32kHz per channel with 18-bits of A/D resolution are capable of resolving extracellular voltages spanning single-neuron action potentials, high frequency oscillations, and high amplitude ultra-slow activity, but this approach generates 3 terabytes of data per day (at 4 bytes per sample) using current data formats. Data compression can provide several practical benefits, but only if data can be compressed and appended to files in real-time in a format that allows random access to data segments of varying size. Here we describe a state-of-the-art, scalable, electrophysiology platform designed for acquisition, compression, encryption, and storage of large-scale data. Data are stored in a file format that incorporates lossless data compression using range-encoded differences, a 32-bit cyclically redundant checksum to ensure data integrity, and 128-bit encryption for protection of patient information.

  19. Electrophysiological correlates of the BOLD signal for EEG-informed fMRI.

    PubMed

    Murta, Teresa; Leite, Marco; Carmichael, David W; Figueiredo, Patrícia; Lemieux, Louis

    2015-01-01

    Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) are important tools in cognitive and clinical neuroscience. Combined EEG-fMRI has been shown to help to characterise brain networks involved in epileptic activity, as well as in different sensory, motor and cognitive functions. A good understanding of the electrophysiological correlates of the blood oxygen level-dependent (BOLD) signal is necessary to interpret fMRI maps, particularly when obtained in combination with EEG. We review the current understanding of electrophysiological-haemodynamic correlates, during different types of brain activity. We start by describing the basic mechanisms underlying EEG and BOLD signals and proceed by reviewing EEG-informed fMRI studies using fMRI to map specific EEG phenomena over the entire brain (EEG-fMRI mapping), or exploring a range of EEG-derived quantities to determine which best explain colocalised BOLD fluctuations (local EEG-fMRI coupling). While reviewing studies of different forms of brain activity (epileptic and nonepileptic spontaneous activity; cognitive, sensory and motor functions), a significant attention is given to epilepsy because the investigation of its haemodynamic correlates is the most common application of EEG-informed fMRI. Our review is focused on EEG-informed fMRI, an asymmetric approach of data integration. We give special attention to the invasiveness of electrophysiological measurements and the simultaneity of multimodal acquisitions because these methodological aspects determine the nature of the conclusions that can be drawn from EEG-informed fMRI studies. We emphasise the advantages of, and need for, simultaneous intracranial EEG-fMRI studies in humans, which recently became available and hold great potential to improve our understanding of the electrophysiological correlates of BOLD fluctuations.

  20. Integration

    ERIC Educational Resources Information Center

    Kalyn, Brenda

    2006-01-01

    Integrated learning is an exciting adventure for both teachers and students. It is not uncommon to observe the integration of academic subjects such as math, science, and language arts. However, educators need to recognize that movement experiences in physical education also can be linked to academic curricula and, may even lead the…

  1. Electrophysiological effects of semantic context in picture and word naming.

    PubMed

    Janssen, Niels; Carreiras, Manuel; Barber, Horacio A

    2011-08-01

    Recent language production studies have started to use electrophysiological measures to investigate the time course of word selection processes. An important contribution with respect to this issue comes from studies that have relied on an effect of semantic context in the semantic blocking task. Here we used this task to further establish the empirical pattern associated with the effect of semantic context, and whether the effect arises during output processing. Electrophysiological and reaction time measures were co-registered while participants overtly named picture and word stimuli in the semantic blocking task. The results revealed inhibitory reaction time effects of semantic context for both words and pictures, and a corresponding electrophysiological effect that could not be interpreted in terms of output processes. These data suggest that the electrophysiological effect of semantic context in the semantic blocking task does not reflect output processes, and therefore undermine an interpretation of this effect in terms of word selection.

  2. The Electrophysiology of Basic Phrase Building

    PubMed Central

    Lapinskaya, Natalia; Heffner, Christopher C.; Malko, Anton; Lau, Ellen F.

    2016-01-01

    A defining trait of linguistic competence is the ability to combine elements into increasingly complex structures to denote, and to comprehend, a potentially infinite number of meanings. Recent magnetoencephalography (MEG) work has investigated these processes by comparing the response to nouns in combinatorial (blue car) and non-combinatorial (rnsh car) contexts. In the current study we extended this paradigm using electroencephalography (EEG) to dissociate the role of semantic content from phonological well-formedness (yerl car). We used event-related potential (ERP) recordings in order to better relate the observed neurophysiological correlates of basic combinatorial operations to prior ERP work on comprehension. We found that nouns in combinatorial contexts (blue car) elicited a greater centro-parietal negativity between 180-400ms, independent of the phonological well-formedness of the context word. We discuss the potential relationship between this ‘combinatorial’ effect and classic N400 effects. We also report preliminary evidence for an early anterior negative deflection immediately preceding the critical noun in combinatorial contexts, which we tentatively interpret as an electrophysiological reflex of syntactic structure initialization. PMID:27711111

  3. Grafted dopamine neurons: Morphology, neurochemistry, and electrophysiology.

    PubMed

    Strömberg, Ingrid; Bickford, Paula; Gerhardt, Greg A

    2010-02-09

    Grafting of dopamine-rich tissue to counteract the symptoms in Parkinson's disease became a promising tool for future treatment. This article discusses how to improve the functional outcome with respect to graft outgrowth and functions of dopamine release and electrophysiological responses to graft implantation in the host brain striatal target. It has been documented that a subpopulation of the dopamine neurons innervates the host brain in a target-specific manner, while some of the grafted dopamine neurons never project to the host striatum. Neurochemical studies have demonstrated that the graft-induced outgrowth synthesize, store, metabolize and release dopamine and possibly other neurotransmitters such as 5-HT. Furthermore, the released dopamine affects the dopamine-depleted brain in areas that are larger than the graft-derived nerve fibers reach. While stem cells will most likely be the future source of cells to be used in grafting, it is important to find the guiding cues for how to reinnervate the dopamine-depleted striatum in a proper way with respect to the dopamine subpopulations of A9 and A10 to efficiently treat the motor abnormalities seen in Parkinson's disease.

  4. [On the first studies of electrophysiology].

    PubMed

    de Micheli, Alfredo

    2011-01-01

    A historical outline of the evolution of electrophysiology from the eighteenth century is shortly presented. Topics concerning the so called animal electricity starting from the observations on descharges of Torpedo fish until Bolognese Galvani's researches on the frogs are exposed. The points of view of their oppositionists also are examined. These ones, leaded by the physicist Alessandro Volta, professor in the University of Pavia, believed that electricity detected by galvanists was not inherent to animal but was due to the action of the metallic conductors present in the circuit: contact electricity. Only towards the middle of the nineteenth century the physicist Carlo Matteucci attained to demonstrate the existente of the real animal electricity in form of injury current. It was possible to determine that quantitatively thanks to the capillary electrometer built in 1872 by the French physicist Gabriel Lippmann. This instrument was used by the English physiologist Waller in order to obtain the primitive electrocardiographic tracings in humans (1887). At beginnings of the twentieth century, the Dutch professor Willem Einthoven, of the University of Leiden, introduced his string galvanometer which permitted to allow the modern electrocardiography. So it was possible to record the electrical potentials of myocardial cells, first in vitro, later in isolated and perfused heart, son after in dog's heart in situ and finally in human heart. Therefore now it is possible to effectuate endocardial and epicardial mappings, indispensable in order to diagnose and treat the cardiac arrhythmias.

  5. Electrophysiological study of Drosophila rhodopsin mutants

    PubMed Central

    1986-01-01

    Electrophysiological investigations were carried out on several independently isolated mutants of the ninaE gene, which encodes opsin in R1-6 photoreceptors, and a mutant of the ninaD gene, which is probably important in the formation of the rhodopsin chromophore. In these mutants, the rhodopsin content in R1-6 photoreceptors is reduced by 10(2)-10(6)-fold. Light-induced bumps recorded from even the most severely affected mutants are physiologically normal. Moreover, a detailed noise analysis shows that photoreceptor responses of both a ninaE mutant and a ninaD mutant follow the adapting bump model. Since any extensive rhodopsin-rhodopsin interactions are not likely in these mutants, the above results suggest that such interactions are not needed for the generation and adaptation of light-induced bumps. Mutant bumps are strikingly larger in amplitude than wild-type bumps. This difference is observed both in ninaD and ninaE mutants, which suggests that it is due to severe depletion of rhodopsin content, rather than to any specific alterations in the opsin protein. Lowering or buffering the intracellular calcium concentration by EGTA injection mimics the effects of the mutations on the bump amplitude, but, unlike the mutations, it also affects the latency and kinetics of light responses. PMID:3097245

  6. Electrophysiology of pumpkin seeds: Memristors in vivo

    PubMed Central

    Volkov, Alexander G.; Nyasani, Eunice K.; Tuckett, Clayton; Greeman, Esther A.; Markin, Vladislav S.

    2016-01-01

    ABSTRACT Leon Chua, the discoverer of a memristor, theoretically predicted that voltage gated ion channels can be memristors. We recently found memristors in different plants such as the Venus flytrap, Mimosa pudica, Aloe vera, apple fruits, and in potato tubers. There are no publications in literature about the existence of memristors in seeds. The goal of this work was to discover if pumpkin seeds might have memristors. We selected Cucurbita pepo L., cv. Cinderella, Cucurbita maxima L. cv Warty Goblin, and Cucurbita maxima L., cv. Jarrahdale seeds for this analysis. In these seeds, we found the presence of resistors with memory. The analysis was based on cyclic voltammetry where a memristor should manifest itself as a nonlinear two-terminal electrical element, which exhibits a pinched hysteresis loop on a current-voltage plane for any bipolar cyclic voltage input signal. Dry dormant pumpkin seeds have very high electrical resistance without memristive properties. The electrostimulation by bipolar sinusoidal or triangular periodic waves induces electrical responses in imbibed pumpkin seeds with fingerprints of memristors. Tetraethylammonium chloride, an inhibitor of voltage gated K+ channels, transforms a memristor to a resistor in pumpkin seeds. NPPB (5-Nitro-2-(3-phenylpropylamino)benzoic acid) inhibits the memristive properties of imbibed pumpkin seeds. The discovery of memristors in pumpkin seeds creates a new direction in the understanding of electrophysiological phenomena in seeds. PMID:26926652

  7. Organic transistors for electrophysiology (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Rivnay, Jonathan

    2015-10-01

    Efficient local transduction of biological signals is of critical importance for mapping brain activity and diagnosing pathological conditions. Traditional devices used to record electrophysiological signals are passive electrodes that require (pre)amplification with downstream electronics. Organic electrochemical transistors (OECTs) that utilize conducting polymer films as the channel have shown considerable promise as amplifying transducers due to their stability in aqueous conditions and high transconductance (>3 mS). The materials properties and physics of such transistors, however, remains largely unexplored thus limiting their potential. Here we show that the uptake of ionic charge from an electrolyte into a poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) OECT channel leads to a dependence of the effective capacitance on the entire volume of the film. Subsequently, device transconductance and time response vary with channel thickness, a defining characteristic that differentiates OECTs from field effect transistors, and provides a new degree of freedom for device engineering. Using this understanding we tailor OECTs for a variety of low (1-100 Hz) and high (1-10 kHz) frequency applications, including human electroencephalography, where high transconductance devices impart richer signal content without the need for additional amplification circuitry. We also show that the materials figure of merit OECTs is the product of hole mobility and volumetric capacitance of the channel, leading to design rules for novel high performance materials.

  8. Electrophysiology of pumpkin seeds: Memristors in vivo.

    PubMed

    Volkov, Alexander G; Nyasani, Eunice K; Tuckett, Clayton; Greeman, Esther A; Markin, Vladislav S

    2016-01-01

    Leon Chua, the discoverer of a memristor, theoretically predicted that voltage gated ion channels can be memristors. We recently found memristors in different plants such as the Venus flytrap, Mimosa pudica, Aloe vera, apple fruits, and in potato tubers. There are no publications in literature about the existence of memristors in seeds. The goal of this work was to discover if pumpkin seeds might have memristors. We selected Cucurbita pepo L., cv. Cinderella, Cucurbita maxima L. cv Warty Goblin, and Cucurbita maxima L., cv. Jarrahdale seeds for this analysis. In these seeds, we found the presence of resistors with memory. The analysis was based on cyclic voltammetry where a memristor should manifest itself as a nonlinear two-terminal electrical element, which exhibits a pinched hysteresis loop on a current-voltage plane for any bipolar cyclic voltage input signal. Dry dormant pumpkin seeds have very high electrical resistance without memristive properties. The electrostimulation by bipolar sinusoidal or triangular periodic waves induces electrical responses in imbibed pumpkin seeds with fingerprints of memristors. Tetraethylammonium chloride, an inhibitor of voltage gated K(+) channels, transforms a memristor to a resistor in pumpkin seeds. NPPB (5-Nitro-2-(3-phenylpropylamino)benzoic acid) inhibits the memristive properties of imbibed pumpkin seeds. The discovery of memristors in pumpkin seeds creates a new direction in the understanding of electrophysiological phenomena in seeds.

  9. Introduction to solid supported membrane based electrophysiology.

    PubMed

    Bazzone, Andre; Costa, Wagner Steuer; Braner, Markus; Călinescu, Octavian; Hatahet, Lina; Fendler, Klaus

    2013-05-11

    The electrophysiological method we present is based on a solid supported membrane (SSM) composed of an octadecanethiol layer chemisorbed on a gold coated sensor chip and a phosphatidylcholine monolayer on top. This assembly is mounted into a cuvette system containing the reference electrode, a chlorinated silver wire. After adsorption of membrane fragments or proteoliposomes containing the membrane protein of interest, a fast solution exchange is used to induce the transport activity of the membrane protein. In the single solution exchange protocol two solutions, one non-activating and one activating solution, are needed. The flow is controlled by pressurized air and a valve and tubing system within a faraday cage. The kinetics of the electrogenic transport activity is obtained via capacitive coupling between the SSM and the proteoliposomes or membrane fragments. The method, therefore, yields only transient currents. The peak current represents the stationary transport activity. The time dependent transporter currents can be reconstructed by circuit analysis. This method is especially suited for prokaryotic transporters or eukaryotic transporters from intracellular membranes, which cannot be investigated by patch clamp or voltage clamp methods.

  10. Electrophysiological effects of ATP on brain neurones.

    PubMed

    Illes, P; Nieber, K; Nörenberg, W

    1996-12-01

    1. The electrophysiological effects of ATP on brain neurones are either due to the direct activation of P2 purinoceptors by the unmetabolized nucleotide or to the indirect activation of P1. purinoceptors by the degradation product adenosine. 2. Two subtypes of P2 purinoceptors are involved, a ligand-activated ion channel (P2X) and a G protein-coupled receptor (P2Y). Hence, the stimulation of P2X purinoceptors leads to a cationic conductance increase, while the stimulation of P2Y purinoceptors leads to a G protein-mediated opening or closure of potassium channels. 3. ATP may induce a calcium-dependent potassium current by increasing the intracellular Ca2+ concentration. This is due either to the entry of Ca2+ via P2X purinoceptors or to the activation of metabotropic P2Y purinoceptors followed by signaling via the G protein/phospholipase C/inositol 1,4,5-trisphosphate (IP3) cascade. Eventually, IP3 releases Ca2+ from its intracellular pools. 4. There is no convincing evidence for the presence of P2U purinoceptors sensitive to both ATP and UTP, or pyrimidinoceptors sensitive to UTP only, in the central nervous system (CNS). 5. ATP-sensitive P2X and P2Y purinoceptors show a wide distribution in the CNS and appear to regulate important neuronal functions.

  11. Essentials of photometry for clinical electrophysiology of vision.

    PubMed

    McCulloch, Daphne L; Hamilton, Ruth

    2010-08-01

    Electrophysiological testing of the visual system requires familiarity with photometry. This technical note outlines the concepts of photometry with a focus on information relevant to clinical ERG and VEP testing. Topics include photometric quantities, consideration of pupil size, specification of brief extended flash stimuli, and the influence of the spectral composition of visual stimuli. Standard units and terms are explained in the context of the ISCEV standards and guidelines for clinical electrophysiology of vision.

  12. Ion channels at the nucleus: electrophysiology meets the genome.

    PubMed

    Matzke, Antonius J M; Weiger, Thomas M; Matzke, Marjori

    2010-07-01

    The nuclear envelope is increasingly viewed from an electrophysiological perspective by researchers interested in signal transduction pathways that influence gene transcription and other processes in the nucleus. Here, we describe evidence for ion channels and transporters in the nuclear membranes and for possible ion gating by the nuclear pores. We argue that a systems-level understanding of cellular regulation is likely to require the assimilation of nuclear electrophysiology into molecular and biochemical signaling pathways.

  13. Bayesian Quantitative Electrophysiology and Its Multiple Applications in Bioengineering

    PubMed Central

    Barr, Roger C.; Nolte, Loren W.; Pollard, Andrew E.

    2014-01-01

    Bayesian interpretation of observations began in the early 1700s, and scientific electrophysiology began in the late 1700s. For two centuries these two fields developed mostly separately. In part that was because quantitative Bayesian interpretation, in principle a powerful method of relating measurements to their underlying sources, often required too many steps to be feasible with hand calculation in real applications. As computer power became widespread in the later 1900s, Bayesian models and interpretation moved rapidly but unevenly from the domain of mathematical statistics into applications. Use of Bayesian models now is growing rapidly in electrophysiology. Bayesian models are well suited to the electrophysiological environment, allowing a direct and natural way to express what is known (and unknown) and to evaluate which one of many alternatives is most likely the source of the observations, and the closely related receiver operating characteristic (ROC) curve is a powerful tool in making decisions. Yet, in general, many people would ask what such models are for, in electrophysiology, and what particular advantages such models provide. So to examine this question in particular, this review identifies a number of electrophysiological papers in bio-engineering arising from questions in several organ systems to see where Bayesian electrophysiological models or ROC curves were important to the results that were achieved. PMID:22275206

  14. Multiple Option Grade Contracts.

    ERIC Educational Resources Information Center

    Partin, Ronald L.

    1979-01-01

    A flexible, point contract system is described which maximizes the advantages of a criterion-referenced contract system while eliminating some of the disadvantages of standard grade contracts. This model has been used by the author in a variety of high school and college courses. (Author/SJL)

  15. Teaching about Contracts.

    ERIC Educational Resources Information Center

    Froman, Michael; Kosnoff, Kathy

    1978-01-01

    Presents teaching strategies for introducing high school students to contract law. Offers as a case study a contract agreement between pro football players and team owners. Stresses basic elements of contracts (offer, acceptance, consideration, and understanding the bargaining process). Journal available from the American Bar Association, 1155…

  16. Traumatic Brain Injury Detection Using Electrophysiological Methods

    PubMed Central

    Rapp, Paul E.; Keyser, David O.; Albano, Alfonso; Hernandez, Rene; Gibson, Douglas B.; Zambon, Robert A.; Hairston, W. David; Hughes, John D.; Krystal, Andrew; Nichols, Andrew S.

    2015-01-01

    Measuring neuronal activity with electrophysiological methods may be useful in detecting neurological dysfunctions, such as mild traumatic brain injury (mTBI). This approach may be particularly valuable for rapid detection in at-risk populations including military service members and athletes. Electrophysiological methods, such as quantitative electroencephalography (qEEG) and recording event-related potentials (ERPs) may be promising; however, the field is nascent and significant controversy exists on the efficacy and accuracy of the approaches as diagnostic tools. For example, the specific measures derived from an electroencephalogram (EEG) that are most suitable as markers of dysfunction have not been clearly established. A study was conducted to summarize and evaluate the statistical rigor of evidence on the overall utility of qEEG as an mTBI detection tool. The analysis evaluated qEEG measures/parameters that may be most suitable as fieldable diagnostic tools, identified other types of EEG measures and analysis methods of promise, recommended specific measures and analysis methods for further development as mTBI detection tools, identified research gaps in the field, and recommended future research and development thrust areas. The qEEG study group formed the following conclusions: (1) Individual qEEG measures provide limited diagnostic utility for mTBI. However, many measures can be important features of qEEG discriminant functions, which do show significant promise as mTBI detection tools. (2) ERPs offer utility in mTBI detection. In fact, evidence indicates that ERPs can identify abnormalities in cases where EEGs alone are non-disclosing. (3) The standard mathematical procedures used in the characterization of mTBI EEGs should be expanded to incorporate newer methods of analysis including non-linear dynamical analysis, complexity measures, analysis of causal interactions, graph theory, and information dynamics. (4) Reports of high specificity in q

  17. [Electrophysiological testing in spinal cord tumors].

    PubMed

    André-Obadia, N; Mauguière, F

    2017-02-01

    Evoked potentials (EPs) are useful to evaluate the functional impairment of motor and somatosensory pathways in spinal cord tumors. Conduction through pyramidal tracts is evaluated by motor EPs (MEPs) elicited by transcranial stimulation, magnetic for awake patients or electric in the operating room. Somatosensory EPs (SEPs) and laser EPs (LEPs) are complementary procedures to explore conduction in dorsal columns and spinothalamic tracts, respectively. MEPs as well as SEPs show conduction abnormalities in about 60% of cases with a sensitivity that increases up to 70% when both procedures are carried out. Abnormalities are observed in the absence of any clinical sign in respectively 7% and 15% of cases for MEPs and SEPs. Multilevel stimulations for SEPs recordings permit to detect segmental dysfunction in 70% in case of cervical TIM, even in the absence of clinical signs. LEPs are useful in specific clinical situations: they allow a dermatomal stimulation and are correlated to segmental thermoalgic anaesthesia. Electrophysiological testing plays an important role in the diagnostic and therapeutic strategy: before surgery, MEPs and SEPs objectively evaluate the functional impairment directly related to the lesion. They also help by permitting a follow-up, either before surgery when the surgical decision is delayed because of a good clinical tolerance of the lesion, or after operation to evaluate the functional evolution. Intraoperative monitoring of MEPs and SEPs allows informing the surgeon about the impact on each surgical manipulation. No prospective randomized study has been performed to date to compare clinical evolution after surgery with or without monitoring. Nevertheless, a wide consensus became established in favor of monitoring to limit the risk of postoperative definite deficit and to permit an optimal surgical resection without risk when responses are preserved.

  18. Comparison of Electrophysiological Auditory Measures in Fishes.

    PubMed

    Maruska, Karen P; Sisneros, Joseph A

    2016-01-01

    Sounds provide fishes with important information used to mediate behaviors such as predator avoidance, prey detection, and social communication. How we measure auditory capabilities in fishes, therefore, has crucial implications for interpreting how individual species use acoustic information in their natural habitat. Recent analyses have highlighted differences between behavioral and electrophysiologically determined hearing thresholds, but less is known about how physiological measures at different auditory processing levels compare within a single species. Here we provide one of the first comparisons of auditory threshold curves determined by different recording methods in a single fish species, the soniferous Hawaiian sergeant fish Abudefduf abdominalis, and review past studies on representative fish species with tuning curves determined by different methods. The Hawaiian sergeant is a colonial benthic-spawning damselfish (Pomacentridae) that produces low-frequency, low-intensity sounds associated with reproductive and agonistic behaviors. We compared saccular potentials, auditory evoked potentials (AEP), and single neuron recordings from acoustic nuclei of the hindbrain and midbrain torus semicircularis. We found that hearing thresholds were lowest at low frequencies (~75-300 Hz) for all methods, which matches the spectral components of sounds produced by this species. However, thresholds at best frequency determined via single cell recordings were ~15-25 dB lower than those measured by AEP and saccular potential techniques. While none of these physiological techniques gives us a true measure of the auditory "perceptual" abilities of a naturally behaving fish, this study highlights that different methodologies can reveal similar detectable range of frequencies for a given species, but absolute hearing sensitivity may vary considerably.

  19. Electrophysiological correlates of remembering emotional pictures.

    PubMed

    Schaefer, Alexandre; Pottage, Claire L; Rickart, Adam J

    2011-01-01

    Extensive evidence shows that emotional events tend to be remembered in greater detail and with an enhanced sense of vividness compared to neutral events. The current study investigated the neural correlates of this phenomenon during retrieval using the event-related potentials technique (ERP). Participants were asked to perform a memory recognition test of previously studied ("Old") and unstudied ("New") emotional and neutral pictures encoded a week before the test session. Next, they were asked to perform a Remember-Know task (Gardiner and Java, 1993) for each "old" decision. ERPs were created for retrieval activity corresponding to six conditions: Remember-Emotional, Remember-Neutral, Know-Emotional, Know-Neutral, New-Emotional and New-Neutral. Results showed that negative emotion enhanced three distinct subtypes of the electrophysiological old-new effect specifically for old items associated with a "Remember" judgment. This effect was observed for ERP old-new effects conforming to an early frontal P2 old-new effect peaking at ~180 ms, a midfrontal old-new effect starting at ~300 ms (the "FN400") and a late positive complex (LPC) with parietal maxima observed at 500-700 ms. In addition, a breakdown of our data in different levels of emotional arousal revealed that the relationship between ERP correlates of retrieval and arousal conformed to a nonlinear, inverted U-shaped function for posterior late effects (500-700) and to a linear function for early effects (P2 and FN400). Taken together, these results suggest that multiple retrieval subprocesses contribute to the emotional enhancement of recollective experience.

  20. Management Levers That Drive Services Contracting Success

    DTIC Science & Technology

    2013-11-10

    unique process that provides a cradle-to-grave acquisition approach (Apte & Rendon, 2007). In their third exploratory research study , conducted in 2008...of the contactors ability to maintain qualified individuals in key positions as outlined in the contract. The utilization of small business rating...contains an assessment of the contractors’ ability to integrate small businesses in the execution of the contract. These ratings are completed and

  1. Integrating sodium reduction strategies in the procurement process and contracting of food venues in the County of Los Angeles government, 2010-2012.

    PubMed

    Cummings, Patricia L; Kuo, Tony; Gase, Lauren N; Mugavero, Kristy

    2014-01-01

    Since sodium is ubiquitous in the food supply, recent approaches to sodium reduction have focused on increasing the availability of lower-sodium products through system-level and environmental changes. This article reviews integrated efforts by the Los Angeles County Sodium Reduction Initiative to implement these strategies at food venues in the County of Los Angeles government. The review used mixed methods, including a scan of the literature, key informant interviews, and lessons learned during 2010-2012 to assess program progress. Leveraging technical expertise and shared resources, the initiative strategically incorporated sodium reduction strategies into the overall work plan of a multipartnership food procurement program in Los Angeles County. To date, 3 County departments have incorporated new or updated nutrition requirements that included sodium limits and other strategies. The strategic coupling of sodium reduction to food procurement and general health promotion allowed for simultaneous advancement and acceleration of the County's sodium reduction agenda.

  2. Final Technical Report for Contract No. DE-EE0006332, "Integrated Simulation Development and Decision Support Tool-Set for Utility Market and Distributed Solar Power Generation"

    SciTech Connect

    Cormier, Dallas; Edra, Sherwin; Espinoza, Michael; Daye, Tony; Kostylev, Vladimir; Pavlovski, Alexandre; Jelen, Deborah

    2014-12-29

    This project will enable utilities to develop long-term strategic plans that integrate high levels of renewable energy generation, and to better plan power system operations under high renewable penetration. The program developed forecast data streams for decision support and effective integration of centralized and distributed solar power generation in utility operations. This toolset focused on real time simulation of distributed power generation within utility grids with the emphasis on potential applications in day ahead (market) and real time (reliability) utility operations. The project team developed and demonstrated methodologies for quantifying the impact of distributed solar generation on core utility operations, identified protocols for internal data communication requirements, and worked with utility personnel to adapt the new distributed generation (DG) forecasts seamlessly within existing Load and Generation procedures through a sophisticated DMS. This project supported the objectives of the SunShot Initiative and SUNRISE by enabling core utility operations to enhance their simulation capability to analyze and prepare for the impacts of high penetrations of solar on the power grid. The impact of high penetration solar PV on utility operations is not only limited to control centers, but across many core operations. Benefits of an enhanced DMS using state-of-the-art solar forecast data were demonstrated within this project and have had an immediate direct operational cost savings for Energy Marketing for Day Ahead generation commitments, Real Time Operations, Load Forecasting (at an aggregate system level for Day Ahead), Demand Response, Long term Planning (asset management), Distribution Operations, and core ancillary services as required for balancing and reliability. This provided power system operators with the necessary tools and processes to operate the grid in a reliable manner under high renewable penetration.

  3. OptoDyCE: Automated system for high-throughput all-optical dynamic cardiac electrophysiology

    NASA Astrophysics Data System (ADS)

    Klimas, Aleksandra; Yu, Jinzhu; Ambrosi, Christina M.; Williams, John C.; Bien, Harold; Entcheva, Emilia

    2016-02-01

    In the last two decades, <30% of drugs withdrawals from the market were due to cardiac toxicity, where unintended interactions with ion channels disrupt the heart's normal electrical function. Consequently, all new drugs must undergo preclinical testing for cardiac liability, adding to an already expensive and lengthy process. Recognition that proarrhythmic effects often result from drug action on multiple ion channels demonstrates a need for integrative and comprehensive measurements. Additionally, patient-specific therapies relying on emerging technologies employing stem-cell derived cardiomyocytes (e.g. induced pluripotent stem-cell-derived cardiomyocytes, iPSC-CMs) require better screening methods to become practical. However, a high-throughput, cost-effective approach for cellular cardiac electrophysiology has not been feasible. Optical techniques for manipulation and recording provide a contactless means of dynamic, high-throughput testing of cells and tissues. Here, we consider the requirements for all-optical electrophysiology for drug testing, and we implement and validate OptoDyCE, a fully automated system for all-optical cardiac electrophysiology. We demonstrate the high-throughput capabilities using multicellular samples in 96-well format by combining optogenetic actuation with simultaneous fast high-resolution optical sensing of voltage or intracellular calcium. The system can also be implemented using iPSC-CMs and other cell-types by delivery of optogenetic drivers, or through the modular use of dedicated light-sensitive somatic cells in conjunction with non-modified cells. OptoDyCE provides a truly modular and dynamic screening system, capable of fully-automated acquisition of high-content information integral for improved discovery and development of new drugs and biologics, as well as providing a means of better understanding of electrical disturbances in the heart.

  4. Electrophysiology of globus pallidus neurons in vitro.

    PubMed

    Nambu, A; Llinaś, R

    1994-09-01

    1. We investigated the electrical properties of globus pallidus neurons intracellularly using brain slices from adult guinea pigs. Three types of neurons were identified according to their intrinsic electrophysiological properties. 2. Type I neurons (59%) were silent at the resting membrane level (-65 +/- 10 mV, mean +/- SD) and generated a burst of spikes, with strong accommodation, to depolarizing current injection. Calcium-dependent low-frequency (1-8 Hz) membrane oscillations were often elicited by membrane depolarization (-53 +/- 8 mV). A low-threshold calcium conductance and an A-current were also identified. The mean input resistance of this neuronal type was 70 +/- 22 M omega. 3. Type II neurons (37%) fired spontaneously at the resting membrane level (-59 +/- 9 mV). Their repetitive firing (< or = 200 Hz) was very sensitive to the amplitude of injected current and showed weak accommodation. Sodium-dependent high-frequency (20-100 Hz) subthreshold membrane oscillations were often elicited by membrane depolarization. This neuronal type demonstrated a low-threshold calcium spike and had the highest input resistance (134 +/- 62 M omega) of the three neuron types. 4. Type III neurons (4%) did not fire spontaneously at the resting membrane level (-73 +/- 5 mV). Their action potentials were characterized by a long duration (2.3 +/- 0.6 ms). Repetitive firing elicited by depolarizing current injection showed weak or no accommodation. This neuronal type had an A-current and showed the lowest input resistance (52 +/- 35 M omega) of the three neuron types. 5. Stimulation of the caudoputamen evoked inhibitory postsynaptic potentials (IPSPs) in Type I and II neurons. In Type II neurons the IPSPs were usually followed by rebound firing. Excitatory postsynaptic potentials and antidromic responses were also elicited in some Type I and II neurons. The estimated conduction velocity of the striopallidal projection was < 1 m/s (Type I neurons, 0.49 +/- 0.37 m/s; Type II

  5. Mechanobiology of lymphatic contractions.

    PubMed

    Munn, Lance L

    2015-02-01

    The lymphatic system is responsible for controlling tissue fluid pressure by facilitating flow of lymph (i.e. the plasma and cells that enter the lymphatic system). Because lymph contains cells of the immune system, its transport is not only important for fluid homeostasis, but also immune function. Lymph drainage can occur via passive flow or active pumping, and much research has identified the key biochemical and mechanical factors that affect output. Although many studies and reviews have addressed how tissue properties and fluid mechanics (i.e. pressure gradients) affect lymph transport [1-3] there is less known about lymphatic mechanobiology. As opposed to passive mechanical properties, mechanobiology describes the active coupling of mechanical signals and biochemical pathways. Lymphatic vasomotion is the result of a fascinating system affected by mechanical forces exerted by the flowing lymph, including pressure-induced vessel stretch and flow-induced shear stresses. These forces can trigger or modulate biochemical pathways important for controlling the lymphatic contractions. Here, I review the current understanding of lymphatic vessel function, focusing on vessel mechanobiology, and summarize the prospects for a comprehensive understanding that integrates the mechanical and biomechanical control mechanisms in the lymphatic system.

  6. Issues in physician contracting.

    PubMed

    Fanburg, John D; Leone, Alyson M

    2005-09-01

    Dermatologists will enter into a number of different contracts during their professional careers. It is important that in each agreement they enter, dermatologists reap the benefits that they aspire for and understand the consequences of each provision. This article addresses just a few of the different issues that arise in physician contracting, such as choosing the appropriate form of business entity; the importance of a writing; term and termination of the contract; compensation models; benefits, vacation and other time off included in the contract; malpractice insurance; and restrictive covenants. Each provision should be carefully analyzed to ensure that it will protect the best interests of the dermatologist in that situation.

  7. Electrophysiological signal analysis and visualization using Cloudwave for epilepsy clinical research.

    PubMed

    Jayapandian, Catherine P; Chen, Chien-Hung; Bozorgi, Alireza; Lhatoo, Samden D; Zhang, Guo-Qiang; Sahoo, Satya S

    2013-01-01

    Epilepsy is the most common serious neurological disorder affecting 50-60 million persons worldwide. Electrophysiological data recordings, such as electroencephalogram (EEG), are the gold standard for diagnosis and pre-surgical evaluation in epilepsy patients. The increasing trend towards multi-center clinical studies require signal visualization and analysis tools to support real time interaction with signal data in a collaborative environment, which cannot be supported by traditional desktop-based standalone applications. As part of the Prevention and Risk Identification of SUDEP Mortality (PRISM) project, we have developed a Web-based electrophysiology data visualization and analysis platform called Cloudwave using highly scalable open source cloud computing infrastructure. Cloudwave is integrated with the PRISM patient cohort identification tool called MEDCIS (Multi-modality Epilepsy Data Capture and Integration System). The Epilepsy and Seizure Ontology (EpSO) underpins both Cloudwave and MEDCIS to support query composition and result retrieval. Cloudwave is being used by clinicians and research staff at the University Hospital - Case Medical Center (UH-CMC) Epilepsy Monitoring Unit (EMU) and will be progressively deployed at four EMUs in the United States and the United Kingdomas part of the PRISM project.

  8. Toward the virtual stomach: progress in multiscale modeling of gastric electrophysiology and motility.

    PubMed

    Du, Peng; O'Grady, Gregory; Gao, Jerry; Sathar, Shameer; Cheng, Leo K

    2013-01-01

    Experimental progress in investigating normal and disordered gastric motility is increasingly being complimented by sophisticated multiscale modeling studies. Mathematical modeling has become a valuable tool in this effort, as there is an ever-increasing need to gain an integrative and quantitative understanding of how physiological mechanisms achieve coordinated functions across multiple biophysical scales. These interdisciplinary efforts have been particularly notable in the area of gastric electrophysiology, where they are beginning to yield a comprehensive and integrated in silico organ modeling framework, or 'virtual stomach'. At the cellular level, a number of biophysically based mathematical cell models have been developed, and these are now being applied in areas including investigations of gastric electrical pacemaker mechanisms, smooth muscle electrophysiology, and electromechanical coupling. At the tissue level, micro-structural models are being creatively developed and employed to investigate clinically significant questions, such as the functional effects of ICC degradation on gastrointestinal (GI) electrical activation. At the organ level, high-resolution electrical mapping and modeling studies are combined to provide improved insights into normal and dysrhythmic gastric electrical activation. These efforts are also enabling detailed forward and inverse modeling studies at the 'whole body' level, with implications for diagnostic techniques for gastric dysrhythmias. These recent advances, together with several others highlighted in this review, collectively demonstrate a powerful trend toward applying mathematical models to effectively investigate structure-function relationships and overcome multiscale challenges in basic and clinical GI research.

  9. Visualization of elusive structures using intracardiac echocardiography: Insights from electrophysiology

    PubMed Central

    Szili-Torok, T; McFadden, EP; Jordaens, LJ; Roelandt, JRTC

    2004-01-01

    Electrophysiological mapping and ablation techniques are increasingly used to diagnose and treat many types of supraventricular and ventricular tachycardias. These procedures require an intimate knowledge of intracardiac anatomy and their use has led to a renewed interest in visualization of specific structures. This has required collaborative efforts from imaging as well as electrophysiology experts. Classical imaging techniques may be unable to visualize structures involved in arrhythmia mechanisms and therapy. Novel methods, such as intracardiac echocardiography and three-dimensional echocardiography, have been refined and these technological improvements have opened new perspectives for more effective and accurate imaging during electrophysiology procedures. Concurrently, visualization of these structures noticeably improved our ability to identify intracardiac structures. The aim of this review is to provide electrophysiologists with an overview of recent insights into the structure of the heart obtained with intracardiac echocardiography and to indicate to the echo-specialist which structures are potentially important for the electrophysiologist. PMID:15253772

  10. Electrophysiological recordings from behaving animals--going beyond spikes.

    PubMed

    Chorev, Edith; Epsztein, Jérôme; Houweling, Arthur R; Lee, Albert K; Brecht, Michael

    2009-10-01

    Most of our current knowledge about the neural control of behavior is based on electrophysiology. Here we review advances and limitations of current electrophysiological recording techniques applied in behaving animals. Extracellular recording methods have improved with respect to sampling density and miniaturization, and our understanding of the nature of the recorded signals has advanced. Juxtacellular recordings have become increasingly popular as they allow identification of the recorded neurons. Juxtacellular recordings are relatively easy to apply in behaving animals and can be used to stimulate individual neurons. Methods for intracellular recordings in awake behaving animals also advanced, and it has become clear that long-duration intracellular recordings are possible even in freely moving animals. We conclude that the electrophysiological methods repertoire has greatly diversified in recent years and that the field has moved beyond what used to be a mere spike counting business.

  11. Electrophysiologic features of inherited demyelinating neuropathies: a reappraisal.

    PubMed

    Lewis, R A; Sumner, A J

    1999-09-14

    The observation that inherited demyelinating neuropathies tend to have uniform conduction slowing and acquired disorders (CIDP and variants) have nonuniform or multifocal slowing was made before the identification of genetic defects of specific myelin constituents that cause the different forms of Charcot-Marie-Tooth and other inherited disorders involving peripheral nerve myelin. It is becoming clear that the electrophysiologic aspects of these disorders are more complex than previously realized. We review the current information available on the electrophysiologic features of the inherited demyelinating neuropathies in hopes of clarifying the clinical electrodiagnostic features of these disorders as well as to shed light on the physiologic consequences of the different genetic mutations.

  12. Optrodes for combined optogenetics and electrophysiology in live animals

    PubMed Central

    Dufour, Suzie; De Koninck, Yves

    2015-01-01

    Abstract. Optical tissue properties limit visible light depth penetration in tissue. Because of this, the recent development of optogenetic tools was quickly followed by the development of light delivery devices for in vivo optogenetics applications. We summarize the efforts made in the last decade to design neural probes that combine conventional electrophysiological recordings and optical channel(s) for optogenetic activation, often referred to as optodes or optrodes. Several aspects including challenges for light delivery in living brain tissue, the combination of light delivery with electrophysiological recordings, probe designs, multimodality, wireless implantable system, and practical considerations guiding the choice of configuration depending on the questions one seeks to address are presented. PMID:26158014

  13. Tying the Contract Knot.

    ERIC Educational Resources Information Center

    Reeves, Kimberly

    2001-01-01

    An informal survey of state superintendent associations and lawyers representing superintendents reveals little change in top executives' contracts over the past decade. Mandatory evaluations and renewable (non-"evergreen") contracts are becoming common; pay-for-performance measures are emerging, yet limited. Contractual and job-leaving…

  14. Contract Teachers in India

    ERIC Educational Resources Information Center

    Goyal, Sangeeta; Pandey, Priyanka

    2013-01-01

    In this paper, we use non-experimental data from government schools in Uttar Pradesh and Madhya Pradesh, two of the largest Indian states, to present average school outcomes by contract status of teachers. We find that contract teachers are associated with higher effort than civil service teachers with permanent tenures, before as well as after…

  15. The New Employment Contract?

    ERIC Educational Resources Information Center

    Levine, David I.

    2002-01-01

    In the classic employment contract, especially at large companies, wages were not strongly responsive to the labor market. Instead, individual companies had distinctive company wage levels and patterns. An exhaustive study of employers and employees in the United States and Japan examined whether the "old employment contract" has been…

  16. Weighing the Contract Option.

    ERIC Educational Resources Information Center

    Dervarics, Charles

    1993-01-01

    Contracting for noneducational services is standard operating procedure in many school districts. Private contractors are involved in transportation, food service, maintenance, and even, in rare cases, instruction. Before deciding to contract out, school boards should examine improvement to school-run operations before making a final decision.…

  17. Electrophysiological correlates of the BOLD signal for EEG-informed fMRI

    PubMed Central

    Murta, Teresa; Leite, Marco; Carmichael, David W; Figueiredo, Patrícia; Lemieux, Louis

    2015-01-01

    Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) are important tools in cognitive and clinical neuroscience. Combined EEG–fMRI has been shown to help to characterise brain networks involved in epileptic activity, as well as in different sensory, motor and cognitive functions. A good understanding of the electrophysiological correlates of the blood oxygen level-dependent (BOLD) signal is necessary to interpret fMRI maps, particularly when obtained in combination with EEG. We review the current understanding of electrophysiological–haemodynamic correlates, during different types of brain activity. We start by describing the basic mechanisms underlying EEG and BOLD signals and proceed by reviewing EEG-informed fMRI studies using fMRI to map specific EEG phenomena over the entire brain (EEG–fMRI mapping), or exploring a range of EEG-derived quantities to determine which best explain colocalised BOLD fluctuations (local EEG–fMRI coupling). While reviewing studies of different forms of brain activity (epileptic and nonepileptic spontaneous activity; cognitive, sensory and motor functions), a significant attention is given to epilepsy because the investigation of its haemodynamic correlates is the most common application of EEG-informed fMRI. Our review is focused on EEG-informed fMRI, an asymmetric approach of data integration. We give special attention to the invasiveness of electrophysiological measurements and the simultaneity of multimodal acquisitions because these methodological aspects determine the nature of the conclusions that can be drawn from EEG-informed fMRI studies. We emphasise the advantages of, and need for, simultaneous intracranial EEG–fMRI studies in humans, which recently became available and hold great potential to improve our understanding of the electrophysiological correlates of BOLD fluctuations. PMID:25277370

  18. Clinical and electrophysiological assessment of inferior alveolar nerve function after lateral nerve transposition.

    PubMed

    Nocini, P F; De Santis, D; Fracasso, E; Zanette, G

    1999-04-01

    Inferior alveolar nerve (IAN) transposition surgery may cause some degree of sensory impairment. Accurate and reproducible tests are mandatory to assess IAN conduction capacity following nerve transposition. In this study subjective (heat, pain and tactile-discriminative tests) and objective (electrophysiological) assessments were performed in 10 patients receiving IAN transposition (bilaterally in 8 cases) in order to evaluate any impairment of the involved nerves one year post-operatively. All patients reported a tingling, well-tolerated sensation in the areas supplied by the mental nerve with no anaesthesia or burning paresthesia. Tactile discrimination was affected the most (all but 1 patient). No action potential was recorded in 4 patients' sides (23.5%); 12 sides showed a decreased nerve conduction velocity (NCV) (70.5%) and 1 side normal NCV values (6%). There was no significant difference in NCV decrease between partial and total transposition sides, if examined separately. Nerve conduction findings were related 2-point discrimination scores, but not to changes in pain and heat sensitivity. These findings show that lateral nerve transposition, though resulting in a high percentage of minor IAN injuries, as determined by electrophysiological testing, provides a viable surgical procedure to allow implant placement in the posterior mandible without causing severe sensory complaints. Considering ethical and forensic implications, patients should be fully informed that a certain degree of nerve injury might be expected to occur from the procedure. Electrophysiological evaluation is a reliable way to assess the degree of IAN dysfunction, especially if combined with a clinical examination. Intraoperative monitoring of IAN conduction might help identify the pathogenetic mechanisms of nerve injury and the surgical steps that are most likely to harm nerve integrity.

  19. Electrophysiological Indices of Response Inhibition in a Go/NoGo Task Predict Self-Control in a Social Context

    PubMed Central

    Nash, Kyle; Schiller, Bastian; Gianotti, Lorena R. R.; Baumgartner, Thomas; Knoch, Daria

    2013-01-01

    Recent research demonstrates that response inhibition—a core executive function—may subserve self-regulation and self-control. However, it is unclear whether response inhibition also predicts self-control in the multifaceted, high-level phenomena of social decision-making. Here we examined whether electrophysiological indices of response inhibition would predict self-control in a social context. Electroencephalography was recorded as participants completed a widely used Go/NoGo task (the cued Continuous Performance Test). Participants then interacted with a partner in an economic exchange game that requires self-control. Results demonstrated that greater NoGo-Anteriorization and larger NoGo-P300 peak amplitudes—two established electrophysiological indices of response inhibition—both predicted more self-control in this social game. These findings support continued integration of executive function and self-regulation and help extend prior research into social decision-making processes. PMID:24265773

  20. Managing the Contract Closeout Process

    DTIC Science & Technology

    1992-03-01

    also fulfilled its obligations (Ref. l:p. 267]. The closeout process completes all the individual actions started during earlier segments of the...taught as a segment in the Management of Defense Acquisition Contracts (MDAC) Advanced Contract Administration course. There is no separate course for... segment ir the Management of Defense Acquisiticn Contracts (MDAC) Advanced Contract Administration course. The National Contract Management Association

  1. Integrated Warfighter Biodefense Program (IWBP)

    DTIC Science & Technology

    2012-02-01

    In addition, further work was done on developing Pattern Based Prediction by implementing a predictive analytics methodology based on stochastic...integrating Pattern Based Prediction (to enable Predictive Analytics ) with Pattern Based Discovery. FINANCIAL SUMMARY: Contract Activity QLI Contract

  2. The Use of Electrophysiology in the Study of Early Development

    ERIC Educational Resources Information Center

    Szucs, Denes

    2005-01-01

    Electrophysiology is a timely and important tool in the study of early cognitive development. This commentary polishes the definition of event-related potential (ERP) components; often interpreted as expressions of mental processes. Further, attention is drawn to time-frequency analysis of the electroencephalogram (EEG) which conveys much more…

  3. Should we perform systematic electrophysiological study in Steinert's disease?

    PubMed

    Fayssoil, Abdallah

    2008-10-18

    Myotonic dystrophy type 1 (Steinert's disease) is a multisystem disorder with autosomal dominant inheritance. This disease is associated with the presence of an abnormal expansion of a cytosine thymine-guanine (CTG) trinucleotide repeat on chromosome 19q13.3. Because of rhythmic complications, the place for systematic electrophysiological study (EPS) has to be discussed.

  4. Should we perform systematic electrophysiological study in Steinert's disease?

    PubMed Central

    Fayssoil, Abdallah

    2008-01-01

    Myotonic dystrophy type 1 (Steinert's disease) is a multisystem disorder with autosomal dominant inheritance. This disease is associated with the presence of an abnormal expansion of a cytosine thymine-guanine (CTG) trinucleotide repeat on chromosome 19q13.3. Because of rhythmic complications, the place for systematic electrophysiological study (EPS) has to be discussed. PMID:18928563

  5. Electrophysiological features of POEMS syndrome and chronic inflammatory demyelinating polyneuropathy.

    PubMed

    Guo, Xiuming; Qin, Xinyue; Zhang, Yuping; Huang, Cheng; Yu, Gang

    2014-04-01

    Polyneuropathy is often an initial manifestation of polyneuropathy, organomegaly, endocrinopathy, M protein and skin changes (POEMS) syndrome and therefore this disorder is frequently misdiagnosed as chronic inflammatory demyelinating polyneuropathy (CIDP). We reviewed electrophysiological data in 20 patients with POEMS syndrome and 36 matched patients with CIDP to compare the electrophysiological features of POEMS syndrome and CIDP. Compared with CIDP controls, POEMS patients demonstrated (1) less prolonged distal motor latency and less reduced motor nerve and sensory nerve conduction velocities, (2) greater reduction of amplitudes of compound motor action potentials (CMAP) in distal stimulation, and similar reduction of amplitudes of CMAP in proximal stimulation, (3) similar reduction of amplitudes of sensory nerve action potentials (SNAP) in median and ulnar nerves, and a greater reduction of amplitudes of SNAP in tibial and peroneal nerves, (4) less temporal dispersion, (5) less frequent conduction block, (6) more frequent neurogenic injury in the muscles of the upper and lower limbs, and more frequent neurogenic injury in the muscles of the lower than upper limbs, (7) similar F wave and H reflex abnormalities, and (8) less frequent skin sympathetic response abnormalities. We concluded that before development of typical clinical manifestations, POEMS neuropathy can be distinguished from CIDP by neural electrophysiological examination. These electrophysiological features can be used for early diagnosis and initiating correct treatment of POEMS syndrome.

  6. Electrophysiological Signals of Familiarity and Recency in the Infant Brain

    ERIC Educational Resources Information Center

    Snyder, Kelly A.; Garza, John; Zolot, Liza; Kresse, Anna

    2010-01-01

    Electrophysiological work in nonhuman primates has established the existence of multiple types of signals in the temporal lobe that contribute to recognition memory, including information regarding a stimulus's relative novelty, familiarity, and recency of occurrence. We used high-density event-related potentials (ERPs) to examine whether young…

  7. The Electrophysiological Correlates of Scientific Innovation Induced by Heuristic Information

    ERIC Educational Resources Information Center

    Luo, Junlong; Du, Xiumin; Tang, Xiaochen; Zhang, Entao; Li, Haijiang; Zhang, Qinglin

    2013-01-01

    In this study, novel and old scientific innovations (NSI and OSI) were selected as materials to explore the electrophysiological correlates of scientific innovation induced by heuristic information. Using event-related brain potentials (ERPs) to do so, college students solved NSI problems (for which they did not know the answers) and OSI problems…

  8. A highly versatile and easily configurable system for plant electrophysiology.

    PubMed

    Gunsé, Benet; Poschenrieder, Charlotte; Rankl, Simone; Schröeder, Peter; Rodrigo-Moreno, Ana; Barceló, Juan

    2016-01-01

    In this study we present a highly versatile and easily configurable system for measuring plant electrophysiological parameters and ionic flow rates, connected to a computer-controlled highly accurate positioning device. The modular software used allows easy customizable configurations for the measurement of electrophysiological parameters. Both the operational tests and the experiments already performed have been fully successful and rendered a low noise and highly stable signal. Assembly, programming and configuration examples are discussed. The system is a powerful technique that not only gives precise measuring of plant electrophysiological status, but also allows easy development of ad hoc configurations that are not constrained to plant studies. •We developed a highly modular system for electrophysiology measurements that can be used either in organs or cells and performs either steady or dynamic intra- and extracellular measurements that takes advantage of the easiness of visual object-oriented programming.•High precision accuracy in data acquisition under electrical noisy environments that allows it to run even in a laboratory close to electrical equipment that produce electrical noise.•The system makes an improvement of the currently used systems for monitoring and controlling high precision measurements and micromanipulation systems providing an open and customizable environment for multiple experimental needs.

  9. Standardization of Electrophysiological Measures of Hearing in Marine Mammals

    DTIC Science & Technology

    2004-01-01

    modified for in-air testing of pinniped hearing. Two of three subjects involved in the study have been trained using operant conditioning and positive ... reinforcement techniques to voluntarily participate in electrophysiological testing procedures (i.e., enter the controlled acoustic environment of the

  10. Animal electricity and the birth of electrophysiology: the legacy of Luigi Galvani.

    PubMed

    Piccolino, M

    1998-07-15

    Preceded by a companion paper on Galvani's life, this article is written on the occasion of the bicentenary of the death of Luigi Galvani. From his studies on the effects of electricity on frogs, the scientist of Bologna derived the hypothesis that animal tissues are endowed with an intrinsic electricity that is involved in fundamental physiological processes such as nerve conduction and muscle contraction. Galvani's work swept away from life sciences mysterious fluids and elusive entities like "animal spirits" and led to the foundation of a new science, electrophysiology. Two centuries of research work have demonstrated how insightful was Galvani's conception of animal electricity. Nevertheless, the scholar of Bologna is still largely misrepresented in the history of science, because the importance of his researches seems to be limited to the fact that they opened the paths to the studies of the physicist Alessandro Volta, which culminated in 1800 with the invention of the electric battery. Volta strongly opposed Galvani's theories on animal electricity. The matter of the scientific controversy between Galvani and Volta is examined here in the light of two centuries of electrophysiological studies leading to the modern understanding of electrical excitability in nerve and muscle. By surveying the work of scientists such as Nobili, Matteucci, du Bois-Reymond, von Helmholtz, Bernstein, Hermann, Lucas, Adrian, Hodgkin, Huxley, and Katz, the real matter of the debate raised by Galvani's discoveries is here reconsidered. In addition, a revolutionary phase of the 18th century science that opened the way for the development of modern neurosciences is reevaluated.

  11. 48 CFR 3042.7000 - Contract clause.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SECURITY ACQUISITION REGULATION (HSAR) CONTRACT MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Contracting Officer's Technical Representative 3042.7000 Contract clause. The contracting officer shall insert the clause at (HSAR) 48 CFR 3052.242-72, Contracting Officer's Technical Representative,...

  12. Software and hardware infrastructure for research in electrophysiology

    PubMed Central

    Mouček, Roman; Ježek, Petr; Vařeka, Lukáš; Řondík, Tomáš; Brůha, Petr; Papež, Václav; Mautner, Pavel; Novotný, Jiří; Prokop, Tomáš; Štěbeták, Jan

    2014-01-01

    As in other areas of experimental science, operation of electrophysiological laboratory, design and performance of electrophysiological experiments, collection, storage and sharing of experimental data and metadata, analysis and interpretation of these data, and publication of results are time consuming activities. If these activities are well organized and supported by a suitable infrastructure, work efficiency of researchers increases significantly. This article deals with the main concepts, design, and development of software and hardware infrastructure for research in electrophysiology. The described infrastructure has been primarily developed for the needs of neuroinformatics laboratory at the University of West Bohemia, the Czech Republic. However, from the beginning it has been also designed and developed to be open and applicable in laboratories that do similar research. After introducing the laboratory and the whole architectural concept the individual parts of the infrastructure are described. The central element of the software infrastructure is a web-based portal that enables community researchers to store, share, download and search data and metadata from electrophysiological experiments. The data model, domain ontology and usage of semantic web languages and technologies are described. Current data publication policy used in the portal is briefly introduced. The registration of the portal within Neuroscience Information Framework is described. Then the methods used for processing of electrophysiological signals are presented. The specific modifications of these methods introduced by laboratory researches are summarized; the methods are organized into a laboratory workflow. Other parts of the software infrastructure include mobile and offline solutions for data/metadata storing and a hardware stimulator communicating with an EEG amplifier and recording software. PMID:24639646

  13. Age-Related Changes in 1/f Neural Electrophysiological Noise.

    PubMed

    Voytek, Bradley; Kramer, Mark A; Case, John; Lepage, Kyle Q; Tempesta, Zechari R; Knight, Robert T; Gazzaley, Adam

    2015-09-23

    Aging is associated with performance decrements across multiple cognitive domains. The neural noise hypothesis, a dominant view of the basis of this decline, posits that aging is accompanied by an increase in spontaneous, noisy baseline neural activity. Here we analyze data from two different groups of human subjects: intracranial electrocorticography from 15 participants over a 38 year age range (15-53 years) and scalp EEG data from healthy younger (20-30 years) and older (60-70 years) adults to test the neural noise hypothesis from a 1/f noise perspective. Many natural phenomena, including electrophysiology, are characterized by 1/f noise. The defining characteristic of 1/f is that the power of the signal frequency content decreases rapidly as a function of the frequency (f) itself. The slope of this decay, the noise exponent (χ), is often <-1 for electrophysiological data and has been shown to approach white noise (defined as χ = 0) with increasing task difficulty. We observed, in both electrophysiological datasets, that aging is associated with a flatter (more noisy) 1/f power spectral density, even at rest, and that visual cortical 1/f noise statistically mediates age-related impairments in visual working memory. These results provide electrophysiological support for the neural noise hypothesis of aging. Significance statement: Understanding the neurobiological origins of age-related cognitive decline is of critical scientific, medical, and public health importance, especially considering the rapid aging of the world's population. We find, in two separate human studies, that 1/f electrophysiological noise increases with aging. In addition, we observe that this age-related 1/f noise statistically mediates age-related working memory decline. These results significantly add to this understanding and contextualize a long-standing problem in cognition by encapsulating age-related cognitive decline within a neurocomputational model of 1/f noise-induced deficits in

  14. Marine Corps Contingency Contracting MCI

    DTIC Science & Technology

    2003-12-01

    unfamiliar, such as, foreign business practices, cultures, and language barriers . The importance of having a trained contingency contracting officer...practices, cultures, and language barriers . D. WHO PERFORMS CONTINGENCY CONTRACTING The individuals who perform contingency contracting within the

  15. Cloudwave: distributed processing of "big data" from electrophysiological recordings for epilepsy clinical research using Hadoop.

    PubMed

    Jayapandian, Catherine P; Chen, Chien-Hung; Bozorgi, Alireza; Lhatoo, Samden D; Zhang, Guo-Qiang; Sahoo, Satya S

    2013-01-01

    Epilepsy is the most common serious neurological disorder affecting 50-60 million persons worldwide. Multi-modal electrophysiological data, such as electroencephalography (EEG) and electrocardiography (EKG), are central to effective patient care and clinical research in epilepsy. Electrophysiological data is an example of clinical "big data" consisting of more than 100 multi-channel signals with recordings from each patient generating 5-10GB of data. Current approaches to store and analyze signal data using standalone tools, such as Nihon Kohden neurology software, are inadequate to meet the growing volume of data and the need for supporting multi-center collaborative studies with real time and interactive access. We introduce the Cloudwave platform in this paper that features a Web-based intuitive signal analysis interface integrated with a Hadoop-based data processing module implemented on clinical data stored in a "private cloud". Cloudwave has been developed as part of the National Institute of Neurological Disorders and Strokes (NINDS) funded multi-center Prevention and Risk Identification of SUDEP Mortality (PRISM) project. The Cloudwave visualization interface provides real-time rendering of multi-modal signals with "montages" for EEG feature characterization over 2TB of patient data generated at the Case University Hospital Epilepsy Monitoring Unit. Results from performance evaluation of the Cloudwave Hadoop data processing module demonstrate one order of magnitude improvement in performance over 77GB of patient data. (Cloudwave project: http://prism.case.edu/prism/index.php/Cloudwave).

  16. Neural ensemble communities: Open-source approaches to hardware for large-scale electrophysiology

    PubMed Central

    Siegle, Joshua H.; Hale, Gregory J.; Newman, Jonathan P.; Voigts, Jakob

    2014-01-01

    One often-overlooked factor when selecting a platform for large-scale electrophysiology is whether or not a particular data acquisition system is “open” or “closed”: that is, whether or not the system’s schematics and source code are available to end users. Open systems have a reputation for being difficult to acquire, poorly documented, and hard to maintain. With the arrival of more powerful and compact integrated circuits, rapid prototyping services, and web-based tools for collaborative development, these stereotypes must be reconsidered. We discuss some of the reasons why multichannel extracellular electrophysiology could benefit from open-source approaches and describe examples of successful community-driven tool development within this field. In order to promote the adoption of open-source hardware and to reduce the need for redundant development efforts, we advocate a move toward standardized interfaces that connect each element of the data processing pipeline. This will give researchers the flexibility to modify their tools when necessary, while allowing them to continue to benefit from the high-quality products and expertise provided by commercial vendors. PMID:25528614

  17. Electrophysiological Correlates of Rapid Auditory and Linguistic Processing in Adolescents with Specific Language Impairment

    PubMed Central

    Weber-Fox, Christine; Leonard, Laurence B.; Wray, Amanda Hampton; Tomblin, J. Bruce

    2010-01-01

    Brief tonal stimuli and spoken sentences were utilized to examine whether adolescents (aged 14;3-18;1) with specific language impairments (SLI) exhibit atypical neural activity for rapid auditory processing of non-linguistic stimuli and linguistic processing of verb-agreement and semantic constraints. Further, we examined whether the behavioral and electrophysiological indices for rapid auditory processing were correlated with those for linguistic processing. Fifteen adolescents with SLI and 15 adolescents with normal language met strict criteria for displaying consistent diagnoses from kindergarten through the eighth grade. The findings provide evidence that auditory processing for non-linguistic stimuli is atypical in a significant number of adolescents with SLI compared to peers with normal language and indicate that reduced efficiency in auditory processing in SLI is more vulnerable to rapid rates (200 ms ISI) of stimuli presentation (indexed by reduced accuracy, a tendency for longer RTs, reduced N100 over right anterior sites, and reduced amplitude P300). Many adolescents with SLI displayed reduced behavioral accuracy for detecting verb-agreement violations and semantic anomalies, along with less robust P600s elicited by verb-agreement violations. The results indicate that ERPs elicited by morphosyntactic aspects of language processing are atypical in many adolescents with SLI. Additionally, correlational analyses between behavioral and electrophysiological indices of processing non-linguistic stimuli and verb-agreement violations suggest that the integrity of neural functions for auditory processing may only account for a small proportion of the variance in morphosyntactic processing in some adolescents. PMID:20889197

  18. Neural ensemble communities: open-source approaches to hardware for large-scale electrophysiology.

    PubMed

    Siegle, Joshua H; Hale, Gregory J; Newman, Jonathan P; Voigts, Jakob

    2015-06-01

    One often-overlooked factor when selecting a platform for large-scale electrophysiology is whether or not a particular data acquisition system is 'open' or 'closed': that is, whether or not the system's schematics and source code are available to end users. Open systems have a reputation for being difficult to acquire, poorly documented, and hard to maintain. With the arrival of more powerful and compact integrated circuits, rapid prototyping services, and web-based tools for collaborative development, these stereotypes must be reconsidered. We discuss some of the reasons why multichannel extracellular electrophysiology could benefit from open-source approaches and describe examples of successful community-driven tool development within this field. In order to promote the adoption of open-source hardware and to reduce the need for redundant development efforts, we advocate a move toward standardized interfaces that connect each element of the data processing pipeline. This will give researchers the flexibility to modify their tools when necessary, while allowing them to continue to benefit from the high-quality products and expertise provided by commercial vendors.

  19. Neurointensive care unit system for continuous electrophysiological monitoring with remote web-based review.

    PubMed

    van der Kouwe, André J W; Burgess, Richard C

    2003-06-01

    There is a need in the neurological intensive care unit for a single integrated bedside monitor for continuously monitoring the function of the patient's central nervous system. In this paper, we demonstrate the feasibility of building such a system and operating it in the intensive care environment. We have developed a fully automated system that samples electrophysiological waveforms of various modalities according to a schedule of predefined intervals along with routinely monitored cardiac and respiratory parameters. The system provides stimulation and acquires responses without requiring supervision. The electrophysiological data include brainstem auditory and somatosensory evoked potentials and epochs of the electroencephalogram. The system applies peak detection and spectral analysis to extract salient parameters from the raw waveforms. The results are made available immediately in real time on the local network for local review and further analysis. A web-based interface makes review by a qualified neurologist possible anywhere within the hospital's secure intranet during and after monitoring. This system could potentially give an early warning of impending herniation, subclinical seizures, and brain or spinal cord ischemia. We demonstrate its application in a few diverse neurological intensive care cases and a case in the interventional neuroradiology suite.

  20. A computational model of Purkinje fibre single cell electrophysiology: implications for the long QT syndrome

    PubMed Central

    Sampson, K J; Iyer, V; Marks, A R; Kass, R S

    2010-01-01

    Computer modelling has emerged as a particularly useful tool in understanding the physiology and pathophysiology of cardiac tissues. Models of ventricular, atrial and nodal tissue have evolved and include detailed ion channel kinetics and intercellular Ca2+ handling. Purkinje fibre cells play a central role in the electrophysiology of the heart and in the genesis of cardiac arrhythmias. In this study, a new computational model has been constructed that incorporates the major membrane currents that have been isolated in recent experiments using Purkinje fibre cells. The model, which integrates mathematical models of human ion channels based on detailed biophysical studies of their kinetic and voltage-dependent properties, recapitulates distinct electrophysiological characteristics unique to Purkinje fibre cells compared to neighbouring ventricular myocytes. These characteristics include automaticity, hyperpolarized voltage range of the action potential plateau potential, and prolonged action potential duration. Simulations of selective ion channel blockade reproduce responses to pharmacological challenges characteristic of isolated Purkinje fibres in vitro, and importantly, the model predicts that Purkinje fibre cells are prone to severe arrhythmogenic activity in patients harbouring long QT syndrome 3 but much less so for other common forms of long QT. This new Purkinje cellular model can be a useful tool to study tissue-specific drug interactions and the effects of disease-related ion channel dysfunction on the cardiac conduction system. PMID:20498233

  1. An Association between Auditory-Visual Synchrony Processing and Reading Comprehension: Behavioral and Electrophysiological Evidence.

    PubMed

    Mossbridge, Julia; Zweig, Jacob; Grabowecky, Marcia; Suzuki, Satoru

    2017-03-01

    The perceptual system integrates synchronized auditory-visual signals in part to promote individuation of objects in cluttered environments. The processing of auditory-visual synchrony may more generally contribute to cognition by synchronizing internally generated multimodal signals. Reading is a prime example because the ability to synchronize internal phonological and/or lexical processing with visual orthographic processing may facilitate encoding of words and meanings. Consistent with this possibility, developmental and clinical research has suggested a link between reading performance and the ability to compare visual spatial/temporal patterns with auditory temporal patterns. Here, we provide converging behavioral and electrophysiological evidence suggesting that greater behavioral ability to judge auditory-visual synchrony (Experiment 1) and greater sensitivity of an electrophysiological marker of auditory-visual synchrony processing (Experiment 2) both predict superior reading comprehension performance, accounting for 16% and 25% of the variance, respectively. These results support the idea that the mechanisms that detect auditory-visual synchrony contribute to reading comprehension.

  2. ACTIVE: A Tool for Integrating Analysis Contracts

    DTIC Science & Technology

    2014-10-14

    for modeling systems in the Architecture Analysis and Design Language (AADL). In the paper we analyze the problems that occur when independently...5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Dionisio de Niz Ivan Ruchkin; Sagar Chaki; David Garlan 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT...tectural description language because AADL offers a con- venient way to represent the structural, design-time aspect of the system. In particular

  3. Simultaneous wireless electrophysiological and neurochemical monitoring

    NASA Astrophysics Data System (ADS)

    Murari, Kartikeya; Mollazadeh, Mohsen; Thakor, Nitish; Cauwenberghs, Gert

    2008-08-01

    Information processing and propagation in the central nervous system is mostly electrical in nature. At synapses, electrical signals cause the release of neurotransmitters like dopamine, glutamate etc., that are sensed by post-synaptic neurons resulting in signal propagation or inhibition. It can be very informative to monitor electrical and neurochemical signals simultaneously to understand the mechanisms underlying normal or abnormal brain function. We present an integrated system for the simultaneous wireless acquisition of neurophysiological and neurochemical activity. Applications of the system to neuroscience include monitoring EEG and glutamate in rat somatosensory cortex following global ischemia.

  4. Drafting the Superintendent's Contract.

    ERIC Educational Resources Information Center

    Clark, James F.

    1983-01-01

    A superintendent's contract should be individually designed and negotiated; however, necessary characteristics are suggested in the areas of duration, certification and responsibilities, compensation, vacation and fringe benefits, liability and indemnification, medical examination, evaluation, renewal and nonrenewal, termination, and a…

  5. Negotiating managed care contracts.

    PubMed

    Beckman, P A; Fischer, T J

    1997-08-01

    Physicians currently have a major opportunity to help guide the rapid evolution of managed care in the United States. General principles on how physicians can successfully negotiate a managed care contract are discussed.

  6. Superfund Contract Laboratory Program

    EPA Pesticide Factsheets

    The Contract Laboratory Program (CLP) is a national network of EPA personnel, commercial laboratories, and support contractors whose primary mission is to provide data of known and documented quality to the Superfund program.

  7. Mechanics of Vorticella Contraction

    PubMed Central

    Misra, Gaurav; Dickinson, Richard B.; Ladd, Anthony J.C.

    2010-01-01

    Abstract Vorticella convallaria is one of a class of fast-moving organisms that can traverse its body size in less than a millisecond by rapidly coiling a slender stalk anchoring it to a nearby surface. The stalk houses a fiber called the spasmoneme, which winds helically within the stalk and rapidly contracts in response to calcium signaling. We have developed a coupled mechanical-chemical model of the coiling process, accounting for the coiling of the elastic stalk and the binding of calcium to the protein spasmin. Simulations of the model describe the contraction and recovery processes quantitatively. The stalk-spasmoneme system is shown to satisfy geometric constraints, which explains why the cell body sometimes rotates during contraction. The shape of the collapsing and recovering stalk bounds its effective bending stiffness. Simulations suggest that recovery from the contracted state is driven by the stalk at a rate controlled by dissociation of calcium from spasmin. PMID:20550905

  8. Mechanics of Vorticella contraction.

    PubMed

    Misra, Gaurav; Dickinson, Richard B; Ladd, Anthony J C

    2010-06-16

    Vorticella convallaria is one of a class of fast-moving organisms that can traverse its body size in less than a millisecond by rapidly coiling a slender stalk anchoring it to a nearby surface. The stalk houses a fiber called the spasmoneme, which winds helically within the stalk and rapidly contracts in response to calcium signaling. We have developed a coupled mechanical-chemical model of the coiling process, accounting for the coiling of the elastic stalk and the binding of calcium to the protein spasmin. Simulations of the model describe the contraction and recovery processes quantitatively. The stalk-spasmoneme system is shown to satisfy geometric constraints, which explains why the cell body sometimes rotates during contraction. The shape of the collapsing and recovering stalk bounds its effective bending stiffness. Simulations suggest that recovery from the contracted state is driven by the stalk at a rate controlled by dissociation of calcium from spasmin.

  9. Premature Ventricular Contractions (PVCs)

    MedlinePlus

    ... in the body that may be caused by caffeine, tobacco, exercise or anxiety Injury to the heart ... may increase your risk of premature ventricular contractions: Caffeine, tobacco and alcohol Exercise High blood pressure (hypertension) ...

  10. 3 CFR - Government Contracting

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... contract oversight could reduce such sums significantly. Government outsourcing for services also raises... governmental functions. Agencies and departments must operate under clear rules prescribing when outsourcing is... oversee acquisitions appropriately; and (4) clarify when governmental outsourcing for services is and...

  11. Advanced Contract Administration. First Week

    DTIC Science & Technology

    1988-04-14

    administration. Keywords: Contracting/administrative contracting officer relations Financial management; Production management , Quality assurance; Subcontracting; Claims; Government property; Ethics data sources and modifications.

  12. Multiscale forward electromagnetic model of uterine contractions during pregnancy

    PubMed Central

    2012-01-01

    Background Analyzing and monitoring uterine contractions during pregnancy is relevant to the field of reproductive health assessment. Its clinical importance is grounded in the need to reliably predict the onset of labor at term and pre-term. Preterm births can cause health problems or even be fatal for the fetus. Currently, there are no objective methods for consistently predicting the onset of labor based on sensing of the mechanical or electrophysiological aspects of uterine contractions. Therefore, modeling uterine contractions could help to better interpret such measurements and to develop more accurate methods for predicting labor. In this work, we develop a multiscale forward electromagnetic model of myometrial contractions during pregnancy. In particular, we introduce a model of myometrial current source densities and compute its magnetic field and action potential at the abdominal surface, using Maxwell’s equations and a four-compartment volume conductor geometry. To model the current source density at the myometrium we use a bidomain approach. We consider a modified version of the Fitzhugh-Nagumo (FHN) equation for modeling ionic currents in each myocyte, assuming a plateau-type transmembrane potential, and we incorporate the anisotropic nature of the uterus by designing conductivity-tensor fields. Results We illustrate our modeling approach considering a spherical uterus and one pacemaker located in the fundus. We obtained a travelling transmembrane potential depolarizing from −56 mV to −16 mV and an average potential in the plateau area of −25 mV with a duration, before hyperpolarization, of 35 s, which is a good approximation with respect to the average recorded transmembrane potentials at term reported in the technical literature. Similarly, the percentage of myometrial cells contracting as a function of time had the same symmetric properties and duration as the intrauterine pressure waveforms of a pregnant human myometrium at term

  13. Joint Contingency Contracting

    DTIC Science & Technology

    2005-06-01

    Cdr (Head of Contracting Activity - HCA)FISC - Sigonella 5th Fleet AOR NAVSUP FISC Site - Dubai FISC Det-Bahrain Bahrain Seychelles CJOA Afghanistan...Services’ individual approaches for the accession of COs (and contracting specialists) is inconsistent and creates disparities between the breadth...and temperatures ranging from 130 degrees to below freezing. J42 AAdmin Clerk (Navy E-5) J4221 Fuels Ops Officer Navy

  14. Intrinsic electrophysiological properties of entorhinal cortex stellate cells and their contribution to grid cell firing fields

    PubMed Central

    Pastoll, Hugh; Ramsden, Helen L.; Nolan, Matthew F.

    2012-01-01

    The medial entorhinal cortex (MEC) is an increasingly important focus for investigation of mechanisms for spatial representation. Grid cells found in layer II of the MEC are likely to be stellate cells, which form a major projection to the dentate gyrus. Entorhinal stellate cells are distinguished by distinct intrinsic electrophysiological properties, but how these properties contribute to representation of space is not yet clear. Here, we review the ionic conductances, synaptic, and excitable properties of stellate cells, and examine their implications for models of grid firing fields. We discuss why existing data are inconsistent with models of grid fields that require stellate cells to generate periodic oscillations. An alternative possibility is that the intrinsic electrophysiological properties of stellate cells are tuned specifically to control integration of synaptic input. We highlight recent evidence that the dorsal-ventral organization of synaptic integration by stellate cells, through differences in currents mediated by HCN and leak potassium channels, influences the corresponding organization of grid fields. Because accurate cellular data will be important for distinguishing mechanisms for generation of grid fields, we introduce new data comparing properties measured with whole-cell and perforated patch-clamp recordings. We find that clustered patterns of action potential firing and the action potential after-hyperpolarization (AHP) are particularly sensitive to recording condition. Nevertheless, with both methods, these properties, resting membrane properties and resonance follow a dorsal-ventral organization. Further investigation of the molecular basis for synaptic integration by stellate cells will be important for understanding mechanisms for generation of grid fields. PMID:22536175

  15. Characterisation of Development and Electrophysiological Mechanisms Underlying Rhythmicity of the Avian Lymph Heart

    PubMed Central

    Jaffer, Sajjida; Valasek, Petr; Luke, Graham; Batarfi, Munirah; Whalley, Benjamin Jason; Patel, Ketan

    2016-01-01

    Despite significant advances in tissue engineering such as the use of scaffolds, bioreactors and pluripotent stem cells, effective cardiac tissue engineering for therapeutic purposes has remained a largely intractable challenge. For this area to capitalise on such advances, a novel approach may be to unravel the physiological mechanisms underlying the development of tissues that exhibit rhythmic contraction yet do not originate from the cardiac lineage. Considerable attention has been focused on the physiology of the avian lymph heart, a discrete organ with skeletal muscle origins yet which displays pacemaker properties normally only found in the heart. A functional lymph heart is essential for avian survival and growth in ovo. The histological nature of the lymph heart is similar to skeletal muscle although molecular and bioelectrical characterisation during development to assess mechanisms that contribute towards lymph heart contractile rhythmicity have not been undertaken. A better understanding of these processes may provide exploitable insights for therapeutic rhythmically contractile tissue engineering approaches in this area of significant unmet clinical need. Here, using molecular and electrophysiological approaches, we describe the molecular development of the lymph heart to understand how this skeletal muscle becomes fully functional during discrete in ovo stages of development. Our results show that the lymph heart does not follow the normal transitional programme of myogenesis as documented in most skeletal muscle, but instead develops through a concurrent programme of precursor expansion, commitment to myogenesis and functional differentiation which offers a mechanistic explanation for its rapid development. Extracellular electrophysiological field potential recordings revealed that the peak-to-peak amplitude of electrically evoked local field potentials elicited from isolated lymph heart were significantly reduced by treatment with carbachol; an

  16. Local control of β-adrenergic stimulation: Effects on ventricular myocyte electrophysiology and Ca2+-transient1

    PubMed Central

    Heijman, Jordi; Volders, Paul G.A.; Westra, Ronald L.; Rudy, Yoram

    2011-01-01

    Local signaling domains and numerous interacting molecular pathways and substrates contribute to the whole-cell response of myocytes during β-adrenergic stimulation (βARS). We aimed to elucidate the quantitative contribution of substrates and their local signaling environments during βARS to the canine epicardial ventricular myocyte electrophysiology and calcium transient (CaT). We present a computational compartmental model of βARS and its electrophysiological effects. Novel aspects of the model include localized signaling domains, incorporation of β1 and β2 receptor isoforms, a detailed population-based approach to integrate the βAR and Ca2+/Calmodulin kinase (CaMKII) signaling pathways and their effects on a wide range of substrates that affect whole-cell electrophysiology and CaT. The model identifies major roles for phosphodiesterases, adenylyl cyclases, PKA and restricted diffusion in the control of local cAMP levels and shows that activation of specific cAMP domains by different receptor isoforms allows for specific control of action potential and CaT properties. In addition, the model predicts increased CaMKII activity during βARS due to rate-dependent accumulation and increased Ca2+ cycling. CaMKII inhibition, reduced compartmentation, and selective blockade of β1AR are predicted to reduce the occurrence of delayed afterdepolarizations during βARS. Finally, the relative contribution of each PKA substrate to whole-cell electrophysiology is quantified by comparing simulations with and without phosphorylation of each target. In conclusion, this model enhances our understanding of localized βAR signaling and its whole-cell effects in ventricular myocytes by incorporating receptor isoforms, multiple pathways and a detailed representation of multiple-target phosphorylation; it provides a basis for further studies of βARS under pathological conditions. PMID:21345340

  17. Nanomaterial-Enabled Dry Electrodes for Electrophysiological Sensing: A Review

    NASA Astrophysics Data System (ADS)

    Yao, Shanshan; Zhu, Yong

    2016-04-01

    Long-term, continuous, and unsupervised tracking of physiological data is becoming increasingly attractive for health/wellness monitoring and ailment treatment. Nanomaterials have recently attracted extensive attention as building blocks for flexible/stretchable conductors and are thus promising candidates for electrophysiological electrodes. Here we provide a review on nanomaterial-enabled dry electrodes for electrophysiological sensing, focusing on electrocardiography (ECG). The dry electrodes can be classified into contact surface electrodes, contact-penetrating electrodes, and noncontact capacitive electrodes. Different types of electrodes including their corresponding equivalent electrode-skin interface models and the sources of the noise are first introduced, followed by a review on recent developments of dry ECG electrodes based on various nanomaterials, including metallic nanowires, metallic nanoparticles, carbon nanotubes, and graphene. Their fabrication processes and performances in terms of electrode-skin impedance, signal-to-noise ratio, resistance to motion artifacts, skin compatibility, and long-term stability are discussed.

  18. Breadboard Amplifier: Building and Using Simple Electrophysiology Equipment

    PubMed Central

    Crisp, Kevin M.; Lin, Hunter; Prosper, Issa

    2016-01-01

    Electrophysiology is a valuable skill for the neuroscientist, but the learning curve for students can be steep. Here we describe a very simple electromyography (EMG) amplifier that can be built from scratch by students with no electronics experience in about 30 minutes, making it ideal for incorporating into a laboratory activity. With few parts and no adjustments except the gain, students can begin physiology experiments quickly while having the satisfaction of having built the equipment themselves. Because the output of the circuit goes to a computer sound card, students can listen to electrophysiological activity as they see it on the computer screen, a feature many of our students greatly appreciated. Various applications are discussed, including dual channel recording, using streaming media platforms with remote lab partners and acquiring data in the field on a smart phone. Our students reported that they enjoyed being able to build a working device and using it to record from their own muscles. PMID:27385921

  19. Pants on fire: the electrophysiological signature of telling a lie.

    PubMed

    Pfister, Roland; Foerster, Anna; Kunde, Wilfried

    2014-01-01

    Even though electroencephalography has played a prominent role for lie detection via personally relevant information, the electrophysiological signature of active lying is still elusive. We addressed this signature with two experiments in which participants helped a virtual police officer to locate a knife. Crucially, before this response, they announced whether they would lie or tell the truth about the knife's location. This design allowed us to study the signature of lie-telling in the absence of rare and personally significant oddball stimuli that are typically used for lie detection via electrophysiological markers, especially the P300 component. Our results indicate that active lying attenuated P300 amplitudes as well as N200 amplitudes for such non-oddball stimuli. These results support accounts that stress the high cognitive demand of lie-telling, including the need to suppress the truthful response and to generate a lie.

  20. Zebrafish heart as a model for human cardiac electrophysiology.

    PubMed

    Vornanen, Matti; Hassinen, Minna

    2016-01-01

    The zebrafish (Danio rerio) has become a popular model for human cardiac diseases and pharmacology including cardiac arrhythmias and its electrophysiological basis. Notably, the phenotype of zebrafish cardiac action potential is similar to the human cardiac action potential in that both have a long plateau phase. Also the major inward and outward current systems are qualitatively similar in zebrafish and human hearts. However, there are also significant differences in ionic current composition between human and zebrafish hearts, and the molecular basis and pharmacological properties of human and zebrafish cardiac ionic currents differ in several ways. Cardiac ionic currents may be produced by non-orthologous genes in zebrafish and humans, and paralogous gene products of some ion channels are expressed in the zebrafish heart. More research on molecular basis of cardiac ion channels, and regulation and drug sensitivity of the cardiac ionic currents are needed to enable rational use of the zebrafish heart as an electrophysiological model for the human heart.

  1. Affine Contractions on the Plane

    ERIC Educational Resources Information Center

    Celik, D.; Ozdemir, Y.; Ureyen, M.

    2007-01-01

    Contractions play a considerable role in the theory of fractals. However, it is not easy to find contractions which are not similitudes. In this study, it is shown by counter examples that an affine transformation of the plane carrying a given triangle onto another triangle may not be a contraction even if it contracts edges, heights or medians.…

  2. Energetics of contraction.

    PubMed

    Barclay, C J

    2015-04-01

    Muscles convert energy from ATP into useful work, which can be used to move limbs and to transport ions across membranes. The energy not converted into work appears as heat. At the start of contraction heat is also produced when Ca(2+) binds to troponin-C and to parvalbumin. Muscles use ATP throughout an isometric contraction at a rate that depends on duration of stimulation, muscle type, temperature and muscle length. Between 30% and 40% of the ATP used during isometric contraction fuels the pumping Ca(2+) and Na(+) out of the myoplasm. When shortening, muscles produce less force than in an isometric contraction but use ATP at a higher rate and when lengthening force output is higher than the isometric force but rate of ATP splitting is lower. Efficiency quantifies the fraction of the energy provided by ATP that is converted into external work. Each ATP molecule provides 100 zJ of energy that can potentially be converted into work. The mechanics of the myosin cross-bridge are such that at most 50 zJ of work can be done in one ATP consuming cycle; that is, the maximum efficiency of a cross-bridge is ∼50%. Cross-bridges in tortoise muscle approach this limit, producing over 90% of the possible work per cycle. Other muscles are less efficient but contract more rapidly and produce more power.

  3. Human melanocytes mitigate keratinocyte-dependent contraction in an in vitro collagen contraction assay.

    PubMed

    Rakar, Jonathan; Krammer, Markus P; Kratz, Gunnar

    2015-08-01

    Scarring is an extensive problem in burn care, and treatment can be especially complicated in cases of hypertrophic scarring. Contraction is an important factor in scarring but the contribution of different cell types remains unclear. We have investigated the contractile behavior of keratinocytes, melanocytes and fibroblasts by using an in vitro collagen gel assay aimed at identifying a modulating role of melanocytes in keratinocyte-mediated contraction. Cells were seeded on a collagen type I gel substrate and the change in gel dimensions were measured over time. Hematoxylin & Eosin-staining and immunohistochemistry against pan-cytokeratin and microphthalmia-associated transcription factor showed that melanocytes integrated between keratinocytes and remained there throughout the experiments. Keratinocyte- and fibroblast-seeded gels contracted significantly over time, whereas melanocyte-seeded gels did not. Co-culture assays showed that melanocytes mitigate the keratinocyte-dependent contraction (significantly slower and 18-32% less). Fibroblasts augmented the contraction in most assays (approximately 6% more). Non-contact co-cultures showed some influence on the keratinocyte-dependent contraction. Results show that mechanisms attributable to melanocytes, but not fibroblasts, can mitigate keratinocyte contractile behavior. Contact-dependent mechanisms are stronger modulators than non-contact dependent mechanisms, but both modes carry significance to the contraction modulation of keratinocytes. Further investigations are required to determine the mechanisms involved and to determine the utility of melanocytes beyond hypopigmentation in improved clinical regimes of burn wounds and wound healing.

  4. Temporal and comparative outcomes of cardiac electrophysiology abstracts.

    PubMed

    Wong, Christopher X; Sun, Michelle T; Cheng, Yi Han; Dang, Jerry; Barlow, David S; Chia, Nicholas H; Wong, Nicole X; Wong, Michelle X; Lau, Dennis H; Brooks, Anthony G; Roberts-Thomson, Kurt C; Sanders, Prashanthan

    2013-07-15

    Although conferences are important vehicles for discussing scientific findings, the translation of presented research into peer-reviewed manuscripts is a crucial subsequent step in the research process. Given the evolving subspecialization of cardiology, we sought to characterize the temporal and comparative outcomes of abstracts presented at a subspecialty cardiac electrophysiology conference. Abstracts presented at the Heart Rhythm Society conference (1994 through 2006; HRS abstracts) and abstracts presented at the American Heart Association conference (2003; AHA abstracts) were studied. Subsequent publications, impact factors, and citation rates were determined. A total of 3,850 HRS and 1,000 AHA abstracts were studied. More human abstracts were presented at HRS than AHA (p <0.05). Compared with HRS abstracts, more AHA abstracts were published (p <0.001) and had higher impact factors and citation rates (p <0.001 for both). These differences were attributable in part to the greater proportion of human HRS abstracts. Compared with HRS abstracts, electrophysiology-related AHA abstracts were published less (p <0.001), and these publications had similar impact factors (p = 0.38) although greater citation rates (p = 0.001). The number and publication rate of HRS abstracts increased over the 15-year period, as did their publication impact factors and citation rates (p <0.001 for all). In conclusion, there are significant differences between AHA and HRS abstracts. Although AHA abstracts were more likely to be published overall, the publication rate and impact of electrophysiology abstracts presented at both a subspecialty (HRS) and a major cardiovascular conference (AHA) were comparable. There has also been a growth in the number and impact of cardiac electrophysiology abstracts presented at HRS in recent years.

  5. Space Motion Sickness and Stress Training Simulator using Electrophysiological Biofeedback

    NASA Astrophysics Data System (ADS)

    Gaudeau, C.; Golding, J. F.; Thevot, F.; Lucas, Y.; Bobola, P.; Thouvenot, J.

    2005-06-01

    An important problem in manned spaceflight is the nausea that typically appears during the first 3 days and then disappears after 5 days. Methods of detecting changes in electrophysiological signals are being studied in order to reduce susceptibility to space motion sickness through biofeedback training, and for the early detection of nausea during EVA. A simulator would allow subjects to control their body functions and to use biofeedback to control space motion sickness and stress.

  6. Electrophysiological Imaging of Brain Activity and Connectivity – Challenges and Opportunities

    PubMed Central

    He, Bin; Yang, Lin; Wilke, Christopher; Yuan, Han

    2011-01-01

    Unlocking the dynamic inner workings of the brain continues to remain a grand challenge of the 21st century. To this end, functional neuroimaging modalities represent an outstanding approach to better understand the mechanisms of both normal and abnormal brain function. The ability to image brain function with ever increasing spatial and temporal resolution utilizing minimal or non-invasive procedures has made a significant leap over the past several decades. Further delineation of functional networks could lead to improved understanding of brain function in both normal as well as diseased states. This article reviews recent advancements and current challenges in dynamic functional neuroimaging techniques, including electrophysiological source imaging, multimodal neuroimaging integrating fMRI with EEG/MEG, and functional connectivity imaging. PMID:21478071

  7. Materials for multifunctional balloon catheters with capabilities in cardiac electrophysiological mapping and ablation therapy

    NASA Astrophysics Data System (ADS)

    Kim, Dae-Hyeong; Lu, Nanshu; Ghaffari, Roozbeh; Kim, Yun-Soung; Lee, Stephen P.; Xu, Lizhi; Wu, Jian; Kim, Rak-Hwan; Song, Jizhou; Liu, Zhuangjian; Viventi, Jonathan; de Graff, Bassel; Elolampi, Brian; Mansour, Moussa; Slepian, Marvin J.; Hwang, Sukwon; Moss, Joshua D.; Won, Sang-Min; Huang, Younggang; Litt, Brian; Rogers, John A.

    2011-04-01

    Developing advanced surgical tools for minimally invasive procedures represents an activity of central importance to improving human health. A key challenge is in establishing biocompatible interfaces between the classes of semiconductor device and sensor technologies that might be most useful in this context and the soft, curvilinear surfaces of the body. This paper describes a solution based on materials that integrate directly with the thin elastic membranes of otherwise conventional balloon catheters, to provide diverse, multimodal functionality suitable for clinical use. As examples, we present sensors for measuring temperature, flow, tactile, optical and electrophysiological data, together with radiofrequency electrodes for controlled, local ablation of tissue. Use of such ‘instrumented’ balloon catheters in live animal models illustrates their operation, as well as their specific utility in cardiac ablation therapy. The same concepts can be applied to other substrates of interest, such as surgical gloves.

  8. Application of electrophysiological methods and magnetic resonance tomographic angiography in the differentiation between hemifacial spasm and Meige syndrome.

    PubMed

    Huang, Chuyi; Miao, Suhua; Chu, Heling; Muheremu, Aikeremujiang; Wu, Jinting; Zhou, Rongsong; Zuo, Huancong; Ma, Yu

    2016-05-01

    Bilateral hemifacial spasm and Meige syndrome can be easily confused due to their similar clinical manifestation. Here, we aimed to investigate the application of electrophysiological methods and magnetic resonance tomographic angiography (MRTA) in the differentiation between hemifacial spasm and Meige syndrome. 10 patients with bilateral hemifacial spasm and 9 patients with Meige syndrome received electrophysiological monitoring of nerves. There were two males and eight females with bilateral hemifacial spasm, aged 16-58 years with a course of 5-54 months. For the patients with Meige syndrome, there were three males and six females, aged 51-68 years with a course of 12-36 months. All patients received conventional MRTA of the brain blood vessels before decompression. We found that all patients with Meige syndrome showed synchronous contraction of bilateral orbicularis oculi muscles and (or) burst discharge from orbicularis oris muscles in surface electromyography (sEMG). However, those with hemifacial spasm presented with bilaterally asynchronous burst discharge. Electromyography for patients with Meige syndrome did not record abnormal muscle response (AMR), but recorded AMR for those with bilateral hemifacial spasm. The offending vessels were compressed in patients with hemifacial spasm in MRTA, while MRTA results were generally negative for those with Meige syndrome. Combining sEMG and AMR detection in EMG and MRTA, bilateral hemifacial spasm can be differentiated from Meige syndrome with a reduction of misdiagnosis rate.

  9. A Wireless Optogenetic Headstage with Multichannel Electrophysiological Recording Capability

    PubMed Central

    Gagnon-Turcotte, Gabriel; Avakh Kisomi, Alireza; Ameli, Reza; Dufresne Camaro, Charles-Olivier; LeChasseur, Yoan; Néron, Jean-Luc; Brule Bareil, Paul; Fortier, Paul; Bories, Cyril; de Koninck, Yves; Gosselin, Benoit

    2015-01-01

    We present a small and lightweight fully wireless optogenetic headstage capable of optical neural stimulation and electrophysiological recording. The headstage is suitable for conducting experiments with small transgenic rodents, and features two implantable fiber-coupled light-emitting diode (LED) and two electrophysiological recording channels. This system is powered by a small lithium-ion battery and is entirely built using low-cost commercial off-the-shelf components for better flexibility, reduced development time and lower cost. Light stimulation uses customizable stimulation patterns of varying frequency and duty cycle. The optical power that is sourced from the LED is delivered to target light-sensitive neurons using implantable optical fibers, which provide a measured optical power density of 70 mW/mm2 at the tip. The headstage is using a novel foldable rigid-flex printed circuit board design, which results into a lightweight and compact device. Recording experiments performed in the cerebral cortex of transgenic ChR2 mice under anesthetized conditions show that the proposed headstage can trigger neuronal activity using optical stimulation, while recording microvolt amplitude electrophysiological signals. PMID:26371006

  10. Functional identification of islet cell types by electrophysiological fingerprinting

    PubMed Central

    Zhang, Quan; Vergari, Elisa; Kellard, Joely A.; Rodriguez, Blanca; Ashcroft, Frances M.; Rorsman, Patrik

    2017-01-01

    The α-, β- and δ-cells of the pancreatic islet exhibit different electrophysiological features. We used a large dataset of whole-cell patch-clamp recordings from cells in intact mouse islets (N = 288 recordings) to investigate whether it is possible to reliably identify cell type (α, β or δ) based on their electrophysiological characteristics. We quantified 15 electrophysiological variables in each recorded cell. Individually, none of the variables could reliably distinguish the cell types. We therefore constructed a logistic regression model that included all quantified variables, to determine whether they could together identify cell type. The model identified cell type with 94% accuracy. This model was applied to a dataset of cells recorded from hyperglycaemic βV59M mice; it correctly identified cell type in all cells and was able to distinguish cells that co-expressed insulin and glucagon. Based on this revised functional identification, we were able to improve conductance-based models of the electrical activity in α-cells and generate a model of δ-cell electrical activity. These new models could faithfully emulate α- and δ-cell electrical activity recorded experimentally. PMID:28275121

  11. Effects of Morphology Constraint on Electrophysiological Properties of Cortical Neurons

    NASA Astrophysics Data System (ADS)

    Zhu, Geng; Du, Liping; Jin, Lei; Offenhäusser, Andreas

    2016-04-01

    There is growing interest in engineering nerve cells in vitro to control architecture and connectivity of cultured neuronal networks or to build neuronal networks with predictable computational function. Pattern technologies, such as micro-contact printing, have been developed to design ordered neuronal networks. However, electrophysiological characteristics of the single patterned neuron haven’t been reported. Here, micro-contact printing, using polyolefine polymer (POP) stamps with high resolution, was employed to grow cortical neurons in a designed structure. The results demonstrated that the morphology of patterned neurons was well constrained, and the number of dendrites was decreased to be about 2. Our electrophysiological results showed that alterations of dendritic morphology affected firing patterns of neurons and neural excitability. When stimulated by current, though both patterned and un-patterned neurons presented regular spiking, the dynamics and strength of the response were different. The un-patterned neurons exhibited a monotonically increasing firing frequency in response to injected current, while the patterned neurons first exhibited frequency increase and then a slow decrease. Our findings indicate that the decrease in dendritic complexity of cortical neurons will influence their electrophysiological characteristics and alter their information processing activity, which could be considered when designing neuronal circuitries.

  12. Atrial Electrophysiological Remodeling and Fibrillation in Heart Failure

    PubMed Central

    Pandit, Sandeep V.; Workman, Antony J.

    2016-01-01

    Heart failure (HF) causes complex, chronic changes in atrial structure and function, which can cause substantial electrophysiological remodeling and predispose the individual to atrial fibrillation (AF). Pharmacological treatments for preventing AF in patients with HF are limited. Improved understanding of the atrial electrical and ionic/molecular mechanisms that promote AF in these patients could lead to the identification of novel therapeutic targets. Animal models of HF have identified numerous changes in atrial ion currents, intracellular calcium handling, action potential waveform and conduction, as well as expression and signaling of associated proteins. These studies have shown that the pattern of electrophysiological remodeling likely depends on the duration of HF, the underlying cardiac pathology, and the species studied. In atrial myocytes and tissues obtained from patients with HF or left ventricular systolic dysfunction, the data on changes in ion currents and action potentials are largely equivocal, probably owing mainly to difficulties in controlling for the confounding influences of multiple variables, such as patient’s age, sex, disease history, and drug treatments, as well as the technical challenges in obtaining such data. In this review, we provide a summary and comparison of the main animal and human electrophysiological studies to date, with the aim of highlighting the consistencies in some of the remodeling patterns, as well as identifying areas of contention and gaps in the knowledge, which warrant further investigation. PMID:27812293

  13. A model of electrophysiological heterogeneity in periglomerular cells

    PubMed Central

    Sethupathy, Praveen; Rubin, Daniel B.; Li, Guoshi; Cleland, Thomas A.

    2013-01-01

    Olfactory bulb (OB) periglomerular (PG) cells are heterogeneous with respect to several features, including morphology, connectivity, patterns of protein expression, and electrophysiological properties. However, these features rarely correlate with one another, suggesting that the differentiating properties of PG cells may arise from multiple independent adaptive variables rather than representing discrete cell classes. We use computational modeling to assess this hypothesis with respect to electrophysiological properties. Specifically, we show that the heterogeneous electrophysiological properties demonstrated in PG cell recordings can be explained solely by differences in the relative expression levels of ion channel species in the cell, without recourse to modifying channel kinetic properties themselves. This PG cell model can therefore be used as the basis for diverse cellular and network-level analyses of OB computations. Moreover, this simple basis for heterogeneity contributes to an emerging hypothesis that glomerular-layer interneurons may be better described as a single population expressing distributions of partially independent, potentially plastic properties, rather than as a set of discrete cell classes. PMID:23637658

  14. Electrophysiological characterization of Nsc-34 cell line using Microelectrode Array.

    PubMed

    Sabitha, K R; Sanjay, D; Savita, B; Raju, T R; Laxmi, T R

    2016-11-15

    Neurons communicate with each other through intricate network to evolve higher brain functions. The electrical activity of the neurons plays a crucial role in shaping the connectivity. With motor neurons being vulnerable to neurodegenerative diseases, understanding the electrophysiological properties of motor neurons is the need of the hour, in order to comprehend the impairment of connectivity in these diseases. NSC-34 cell line serves as an excellent model to study the properties of motor neurons as they express Choline acetyltransferase (ChAT). Although NSC-34 cell lines have been used to study the effect of various toxicological, neurotrophic and neuroprotective agents, the electrical activity of these cells has not been elucidated. In the current study, we have characterized the electrophysiological properties of NSC-34 cell lines using Micro-Electrode Array (MEA) as a tool. Based on the spike waveform, firing frequency, auto- and cross-correlogram analysis, we demonstrate that NSC-34 cell culture has >2 distinct types of neuronal population: principal excitatory neurons, putative interneurons and unclassified neurons. The presence of interneurons in the NSC-34 culture was characterized by increased expression of GAD-67 markers. Thus, finding an understanding of the electrophysiological properties of different population of neurons in NSC-34 cell line, will have multiple applications in the treatment of neurological disorders.

  15. A Wireless Optogenetic Headstage with Multichannel Electrophysiological Recording Capability.

    PubMed

    Gagnon-Turcotte, Gabriel; Kisomi, Alireza Avakh; Ameli, Reza; Camaro, Charles-Olivier Dufresne; LeChasseur, Yoan; Néron, Jean-Luc; Bareil, Paul Brule; Fortier, Paul; Bories, Cyril; de Koninck, Yves; Gosselin, Benoit

    2015-09-09

    We present a small and lightweight fully wireless optogenetic headstage capable of optical neural stimulation and electrophysiological recording. The headstage is suitable for conducting experiments with small transgenic rodents, and features two implantable fiber-coupled light-emitting diode (LED) and two electrophysiological recording channels. This system is powered by a small lithium-ion battery and is entirely built using low-cost commercial off-the-shelf components for better flexibility, reduced development time and lower cost. Light stimulation uses customizable stimulation patterns of varying frequency and duty cycle. The optical power that is sourced from the LED is delivered to target light-sensitive neurons using implantable optical fibers, which provide a measured optical power density of 70 mW/mm² at the tip. The headstage is using a novel foldable rigid-flex printed circuit board design, which results into a lightweight and compact device. Recording experiments performed in the cerebral cortex of transgenic ChR2 mice under anesthetized conditions show that the proposed headstage can trigger neuronal activity using optical stimulation, while recording microvolt amplitude electrophysiological signals.

  16. Effects of Morphology Constraint on Electrophysiological Properties of Cortical Neurons.

    PubMed

    Zhu, Geng; Du, Liping; Jin, Lei; Offenhäusser, Andreas

    2016-04-07

    There is growing interest in engineering nerve cells in vitro to control architecture and connectivity of cultured neuronal networks or to build neuronal networks with predictable computational function. Pattern technologies, such as micro-contact printing, have been developed to design ordered neuronal networks. However, electrophysiological characteristics of the single patterned neuron haven't been reported. Here, micro-contact printing, using polyolefine polymer (POP) stamps with high resolution, was employed to grow cortical neurons in a designed structure. The results demonstrated that the morphology of patterned neurons was well constrained, and the number of dendrites was decreased to be about 2. Our electrophysiological results showed that alterations of dendritic morphology affected firing patterns of neurons and neural excitability. When stimulated by current, though both patterned and un-patterned neurons presented regular spiking, the dynamics and strength of the response were different. The un-patterned neurons exhibited a monotonically increasing firing frequency in response to injected current, while the patterned neurons first exhibited frequency increase and then a slow decrease. Our findings indicate that the decrease in dendritic complexity of cortical neurons will influence their electrophysiological characteristics and alter their information processing activity, which could be considered when designing neuronal circuitries.

  17. Clinical and electrophysiological characteristics of neuropathy associated with Tangier disease.

    PubMed

    Zyss, Julie; Béhin, Anthony; Couvert, Philippe; Bouhour, Françoise; Sassolas, Agnès; Kolev, Ivan; Denys, Violaine; Vial, Christophe; Lacour, A; Carrié, Alain; Stojkovic, Tanya

    2012-06-01

    Tangier disease (TD) (OMIM#205400) is a rare autosomal recessive disorder resulting from mutations in the ABCA1 gene, leading to decreased levels of plasma high-density lipoproteins (HDL). Peripheral neuropathy is a common finding in this disease, and may present as relapsing/remitting mono/polyneuropathies or as syringomyelia-like neuropathy. We retrospectively analyzed four patients, and report here their clinical, biological, electrophysiological, imaging, and genetic findings. Three patients had a typical pseudosyringomyelic neuropathy including facial diplegia, but asymmetrical onset was observed in one patient who had first been misdiagnosed with Lewis-Sumner syndrome. Electrophysiological pattern was heterogeneous, showing both signs of demyelination and axonal degeneration. Truncating mutations of the ABCA1 gene, including two previously undescribed mutations, were constantly found. Atypical symptom onset and demyelinating features on electrophysiological examination can be misleading in case of pseudosyringomyelic neuropathy. These reports illustrate two different neurological phenotypes in TD, namely the pseudosyringomyelic type and the Lewis-Sumner-like type, and advocate for a systematic assessment of lipid profile including HDL cholesterol in demyelinating neuropathies.

  18. Exploring the unknown: electrophysiological and behavioural measures of visuospatial learning.

    PubMed

    Quinlivan, Brendan; Butler, John S; Ridwan, Abdur Raquib; Beiser, Ines; Williams, Laura; McGovern, Eavan; O'Riordan, Sean; Hutchinson, Michael; Reilly, Richard B

    2016-05-01

    Visuospatial memory describes our ability to temporarily store and manipulate visual and spatial information and is employed for a wide variety of complex cognitive tasks. Here, a visuospatial learning task requiring fine motor control is employed to investigate visuospatial learning in a group of typically developing adults. Electrophysiological and behavioural data are collected during a target location task under two experimental conditions: Target Learning and Target Cued. Movement times (MTs) are employed as a behavioural metric of performance, while dynamic P3b amplitudes and power in the alpha band (approximately 10 Hz) are explored as electrophysiological metrics during visuospatial learning. Results demonstrate that task performance, as measured by MT, is highly correlated with P3b amplitude and alpha power at a consecutive trial level (trials 1-30). The current set of results, in conjunction with the existing literature, suggests that changes in P3b amplitude and alpha power could correspond to different aspects of the learning process. Here it is hypothesized that changes in P3b correspond to a diminishing inter-stimulus interval and reduced stimulus relevance, while the corresponding changes in alpha power represent an automation of response as habituation occurs in participants. The novel analysis presented in the current study demonstrates how gradual electrophysiological changes can be tracked during the visuospatial learning process under the current paradigm.

  19. Future Contracting for Availability

    DTIC Science & Technology

    2016-04-30

    qÜáêíÉÉåíÜ=^ååì~ä= ^Åèìáëáíáçå=oÉëÉ~êÅÜ= póãéçëáìã= qÜìêëÇ~ó=pÉëëáçåë= sçäìãÉ=ff= = Future Contracting for Availability Lou Kratz, Vice President and Managing ...Alpert, Analyst, Systecon North America Future Contracting for Availability Lou Kratz, Vice President and Managing Director, Logistics...êÉ~íáåÖ=póåÉêÖó=Ñçê=fåÑçêãÉÇ=`Ü~åÖÉ= - 18 - Future Contracting for Availability Lou Kratz—is the Vice President and Managing Director, Logistics

  20. Alfaxalone Anaesthesia Facilitates Electrophysiological Recordings of Nociceptive Withdrawal Reflexes in Dogs (Canis familiaris)

    PubMed Central

    Hunt, James; Murrell, Jo; Knazovicky, David; Harris, John; Kelly, Sara; Knowles, Toby G.; Lascelles, B. Duncan X.

    2016-01-01

    Naturally occurring canine osteoarthritis represents a welfare issue for affected dogs (Canis familiaris), but is also considered very similar to human osteoarthritis and has therefore been proposed as a model of disease in humans. Central sensitisation is recognized in human osteoarthritis sufferers but identification in dogs is challenging. Electromyographic measurement of responses to nociceptive stimulation represents a potential means of investigating alterations in central nociceptive processing, and has been evaluated in conscious experimental dogs, but is likely to be aversive. Development of a suitable anaesthetic protocol in experimental dogs, which facilitated electrophysiological nociceptive withdrawal reflex assessment, may increase the acceptability of using the technique in owned dogs with naturally occurring osteoarthritis. Seven purpose bred male hound dogs underwent electromyographic recording sessions in each of three states: acepromazine sedation, alfaxalone sedation, and alfaxalone anaesthesia. Electromyographic responses to escalating mechanical and electrical, and repeated electrical, stimuli were recorded. Subsequently the integral of both early and late rectified responses was calculated. Natural logarithms of the integral values were analysed within and between the three states using multi level modeling. Alfaxalone increased nociceptive thresholds and decreased the magnitude of recorded responses, but characteristics of increasing responses with increasing stimulus magnitude were preserved. Behavioural signs of anxiety were noted in two out of seven dogs during recordings in the acepromazine sedated state. There were few significant differences in response magnitude or nociceptive threshold between the two alfaxalone states. Following acepromazine premedication, induction of anaesthesia with 1–2 mg kg-1 alfaxalone, followed by a continuous rate infusion in the range 0.075–0.1 mg kg-1 min-1 produced suitable conditions to enable

  1. Professionalism and medicine's social contract with society.

    PubMed

    Cruess, Sylvia R

    2006-08-01

    Medicine's relationship with society has been described as a social contract: an "as if" contract with obligations and expectations on the part of both society and medicine, "each of the other". The term is often used without elaboration by those writing on professionalism in medicine. Based on the literature, society's expectations of medicine are: the services of the healer, assured competence, altruistic service, morality and integrity, accountability, transparency, objective advice, and promotion of the public good. Medicine's expectations of society are: trust, autonomy, self-regulation, a health care system that is value-driven and adequately funded, participation in public policy, shared responsibility for health, a monopoly, and both non-financial and financial rewards. The recognition of these expectations is important as they serve as the basis of a series of obligations which are necessary for the maintenance of medicine as a profession. Mutual trust and reasonable demands are required of both parties to the contract.

  2. 48 CFR 3416.701 - Contract clause.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Agreements 3416.701 Contract clause. The contracting... organizations that have fixed indirect cost rates with carryforward adjustments approved by the Government agency responsible for negotiating the organization's indirect cost rates....

  3. 48 CFR 3017.204 - Contracts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Contracts. 3017.204 Section... ACQUISITION REGULATION (HSAR) CONTRACT METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 3017.204 Contracts....

  4. 48 CFR 3017.204 - Contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 7 2011-10-01 2011-10-01 false Contracts. 3017.204... ACQUISITION REGULATION (HSAR) CONTRACT METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options. 3017.204 Contracts....

  5. 48 CFR 3017.204 - Contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Contracts. 3017.204... ACQUISITION REGULATION (HSAR) CONTRACT METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options. 3017.204 Contracts....

  6. 48 CFR 3017.204 - Contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 7 2014-10-01 2014-10-01 false Contracts. 3017.204... ACQUISITION REGULATION (HSAR) CONTRACT METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 3017.204 Contracts....

  7. 48 CFR 3017.204 - Contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 7 2012-10-01 2012-10-01 false Contracts. 3017.204... ACQUISITION REGULATION (HSAR) CONTRACT METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 3017.204 Contracts....

  8. Electrophysiological, vasoactive, and gastromodulatory effects of stevia in healthy Wistar rats.

    PubMed

    Yesmine, Saquiba; Connolly, Kylie; Hill, Nicholas; Coulson, Fiona R; Fenning, Andrew S

    2013-07-01

    Antihypertensive and antidiabetic effects of stevia, Stevia rebaudiana (Asteraceae), have been demonstrated in several human and animal models. The current study aims to define stevia's role in modifying the electrophysiological and mechanical properties of cardiomyocytes, blood vessels, and gastrointestinal smooth muscle. Tissues from thoracic aorta, mesenteric arteries, ileum, and left ventricular papillary muscles were excised from 8-week-old healthy Wistar rats. The effects of stevia (1 × 10-9 M to 1 × 10-4 M) were measured on these tissues. Stevia's effects in the presence of verapamil, 4-AP, and L-NAME were also assessed. In cardiomyocytes, stevia attenuated the force of contraction, decreased the average peak amplitude, and shortened the repolarisation phase of action potential - repolarisation phase of action potential20 by 25 %, repolarisation phase of action potential50 by 34 %, and repolarisation phase of action potential90 by 36 %. Stevia caused relaxation of aortic tissues which was significantly potentiated in the presence of verapamil. In mesenteric arteries, incubation with L-NAME failed to block stevia-induced relaxation indicating the mechanism of action may not be fully via nitric oxide-dependent pathways. Stevia concentration-dependently reduced electrical field stimulated and carbachol-induced contractions in the isolated ileum. This study is the first to show the effectiveness of stevia in reducing cardiac action potential duration at 20 %, 50 %, and 90 % of repolarisation. Stevia also showed beneficial modulatory effects on cardiovascular and gastrointestinal tissues via calcium channel antagonism, activation of the M2 muscarinic receptor function, and enhanced nitric oxide release.

  9. Analytic theory of orbit contraction

    NASA Technical Reports Server (NTRS)

    Vinh, N. X.; Longuski, J. M.; Busemann, A.; Culp, R. D.

    1977-01-01

    The motion of a satellite in orbit, subject to atmospheric force and the motion of a reentry vehicle are governed by gravitational and aerodynamic forces. This suggests the derivation of a uniform set of equations applicable to both cases. For the case of satellite motion, by a proper transformation and by the method of averaging, a technique appropriate for long duration flight, the classical nonlinear differential equation describing the contraction of the major axis is derived. A rigorous analytic solution is used to integrate this equation with a high degree of accuracy, using Poincare's method of small parameters and Lagrange's expansion to explicitly express the major axis as a function of the eccentricity. The solution is uniformly valid for moderate and small eccentricities. For highly eccentric orbits, the asymptotic equation is derived directly from the general equation. Numerical solutions were generated to display the accuracy of the analytic theory.

  10. Contracting with Teacher Partnerships.

    ERIC Educational Resources Information Center

    Shaten, Jessica; Kolderie, Ted

    This monograph describes the concept of school district contracts with teacher partnerships for educational services; taking the view of education as an industry, the document analyzes advantages, obstacles, and strategies of such a change. Section 1, "The Challenge," suggests that societal changes make an education industry outside the…

  11. Acting Out Muscle Contraction.

    ERIC Educational Resources Information Center

    Hudson, Margaret

    2003-01-01

    Describes a science activity that can be implemented into anatomy and physiology courses that demonstrates the interactions between action and myosin, the roles of sodium and calcium ions in the regulation of contraction, and the functions of the plasma membrane and the sarcoplasmic reticulum. (YDS)

  12. Model for Contingency Contracting.

    ERIC Educational Resources Information Center

    Prince George's Community Coll., Largo, MD. Dept. of Human Development.

    The Department of Human Development at Prince George's Community College has developed a contingency contracting model for the department's counseling and student services which presents planning and evaluation as interrelated parts of the same process of self-imposed accountability. The implementation of the model consisted of: (1) planning…

  13. Employee contract issues for dermatologists.

    PubMed

    Brown, Christopher E; Indest, George F

    2013-12-01

    Employees and employers routinely face negotiating and preparing physician employment contracts. It is important for both sides to know and understand the basic information on what a comprehensive employment contract for a dermatologist should contain. There are various employment contract provisions from both the employee's perspective and the employer's perspective that must be considered when preparing physician employment contracts. This article provides basic advice and recommendations on requirements that should be included in such contracts. It suggests legal pitfalls that can be avoided through various contract clauses.

  14. Contracting with the Enemy: The Contracting Officer’s Dilemma

    DTIC Science & Technology

    2015-06-01

    authority is the legal authority to enter into binding contracts and obligate funds on behalf of the U.S. Government (USG), while command authority includes...include authority to make binding contracts or modify existing contracts for the USG. It is also important to note that Geographical Combatant...Appointment, which provides the legal authorization to enter into binding contracts and obligate appropriated funds on behalf of the U.S. government

  15. Contract Audit Followup: Its Impact on Defense Contracting.

    DTIC Science & Technology

    1983-12-01

    UNIT NUERS Naval Postgraduate School Monterey, California 93943 11. CONTROLLING OFFICE WANE AND ADDRESS 12. REPORT DATE Naval Postgraduate School...of control " Although many procurement managers and contracting offi- 4 cers have privately expressed their opinions of the contract audit followup...Management/ACO: Pesi qnes a manager of Adainistrative Contract- ing Officers. Managesent /PCO: Manager of Procuring Contracting Officers. Mangement/PA

  16. Effects of Hydrazine on Electrophysiology, Behavior and Runway Performance in the Cat.

    DTIC Science & Technology

    HYDRAZINES, *ROCKET PROPELLANTS, ELECTROENCEPHALOGRAPHY, TOXICITY, BEHAVIOR, PERFORMANCE(HUMAN), CENTRAL NERVOUS SYSTEM, TOXIC TOLERANCES, PERMISSIBLE DOSAGE, BODY WEIGHT, ELECTROPHYSIOLOGY, BRAIN , CATS, EXPERIMENTAL DATA.

  17. Electrophysiological indices of target and distractor processing in visual search.

    PubMed

    Hickey, Clayton; Di Lollo, Vincent; McDonald, John J

    2009-04-01

    Attentional selection of a target presented among distractors can be indexed with an event-related potential (ERP) component known as the N2pc. Theoretical interpretation of the N2pc has suggested that it reflects a fundamental mechanism of attention that shelters the cortical representation of targets by suppressing neural activity stemming from distractors. Results from fields other than human electrophysiology, however, suggest that attention does not act solely through distractor suppression; rather, it modulates the processing of both target and distractors. We conducted four ERP experiments designed to investigate whether the N2pc reflects multiple attentional mechanisms. Our goal was to reconcile ostensibly conflicting outcomes obtained in electrophysiological studies of attention with those obtained using other methodologies. Participants viewed visual search arrays containing one target and one distractor. In Experiments 1 through 3, the distractor was isoluminant with the background, and therefore, did not elicit early lateralized ERP activity. This work revealed a novel contralateral ERP component that appears to reflect direct suppression of the cortical representation of the distractor. We accordingly name this component the distractor positivity (P(D)). In Experiment 4, an ERP component associated with target processing was additionally isolated. We refer to this component as the target negativity (N(T)). We believe that the N2pc reflects the summation of the P(D) and N(T), and that these discrete components may have been confounded in earlier electrophysiological studies. Overall, this study demonstrates that attention acts on both target and distractor representations, and that this can be indexed in the visual ERP.

  18. Electrophysiological Properties of Subventricular Zone Cells in Adult Mouse Brain

    PubMed Central

    Lai, Bin; Mao, Xiao Ou; Xie, Lin; Chang, Su-Youne; Xiong, Zhi-Gang; Jin, Kunlin; Greenberg, David A.

    2010-01-01

    The subventricular zone (SVZ) is a principal site of adult neurogenesis and appears to participate in the brain’s response to injury. Thus, measures that enhance SVZ neurogenesis may have a role in treatment of neurological disease. To better characterize SVZ cells and identify potential targets for therapeutic intervention, we studied electrophysiological properties of SVZ cells in adult mouse brain slices using patch-clamp techniques. Electrophysiology was correlated with immunohistochemical phenotype by injecting cells with lucifer yellow and by studying transgenic mice carrying green fluorescent protein under control of the doublecortin (DCX) or glial fibrillary acidic protein (GFAP) promoter. We identified five types of cells in the adult mouse SVZ: type 1 cells, with 4-aminopyridine (4-AP)/tetraethylammonium (TEA)-sensitive and CdCl2-sensitive inward currents; type 2 cells, with Ca2+-sensitive K+ and both 4-AP/TEA-sensitive and -insensitive currents; type 3 cells, with 4-AP/TEA-sensitive and -insensitive and small Na+ currents; type 4 cells, with slowly activating, large linear outward current and sustained outward current without fast-inactivating component; and type 5 cells, with a large outward rectifying current with a fast inactivating component. Type 2 and 3 cells expressed DCX, types 4 and 5 cells expressed GFAP, and type 1 cells expressed neither. We propose that SVZ neurogenesis involves a progression of electrophysiological cell phenotypes from types 4 and 5 cells (astrocytes) to type 1 cells (neuronal progenitors) to types 2 and 3 cells (nascent neurons), and that drugs acting on. ion channels expressed during neurogenesis might promote therapeutic neurogenesis in the injured brain. PMID:20434436

  19. [Electrophysiological characteristics of asymptomatic Wolff-Parkinson-White syndromes].

    PubMed

    Brembilla-Perrot, B; Ghawi, R; Dechaux, J P

    1991-11-01

    The management of the Wolff-Parkinson-White syndrome (WPW) is controversial especially when the patient is asymptomatic. The aim of this study was to evaluate the electrophysiological characteristics of such patients. Thirty two asymptomatic subjects with overt WPW on the surface ECG aged 14 to 68 years (average 36 +/- 15 years) underwent endocavitary or oesophageal electrophysiological study with the following protocol: programmed atrial stimulation using 1 or 2 extrastimuli over 3 cycles to evaluate the induction of paroxysmal junctional tachycardia and atrial fibrillation; atrial pacing at increasing frequencies to assess the shortest cycle conducted by the bundle of Kent. This protocol was repeated during intravenous infusion of 20 to 30 mg of Isoproterenol. Four electrophysiological characteristics were identified: the incidence of induction of junctional tachycardia was very low (2 cases, 6%); the incidence of induction of atrial fibrillation or tachycardia was similar to that of symptomatic WPW (9 cases 30%); the incidence of rapid conduction via the bundle of Kent (cycle conducted by the Kent less than 250 ms under basal conditions less than 200 ms with Isoproterenol) was 19% (6 cases); the incidence of potentially serious forms of WPW with rapid conduction in the bundle of Kent and atrial vulnerability (induction of atrial fibrillation at a frequency less than the Wenckebach point by programmed atrial stimulation) was similar to that in symptomatic WPW, 3 cases (10%). In conclusion, the asymptomatic character of the WPW is very probably due to the absence of junctional tachycardias. Nevertheless, these patients are at risk of atrial fibrillation with an incidence of potentially serious forms of 10%.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. 48 CFR 3443.107 - Contract clause.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Contract clause. 3443.107... CONTRACT MANAGEMENT CONTRACT MODIFICATIONS General 3443.107 Contract clause. The contracting officer must... cost-reimbursement contracts in which it will be essential for the contracting officer to be...

  1. 48 CFR 3416.307 - Contract clauses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Contract clauses. 3416.307... CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Cost-Reimbursement Contracts 3416.307 Contract clauses. (a) If the clause at FAR 52.216-7 (Allowable Cost and Payment) is used in a contract with...

  2. 48 CFR 3016.406 - Contract clauses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Contract clauses. 3016.406... ACQUISITION REGULATION (HSAR) CONTRACT METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Incentive Contracts 3016.406 Contract clauses. (e)(1)(i) The contracting officer shall insert a clause substantially the...

  3. Considerations for the use of cellular electrophysiology models within cardiac tissue simulations.

    PubMed

    Cooper, Jonathan; Corrias, Alberto; Gavaghan, David; Noble, Denis

    2011-10-01

    The use of mathematical models to study cardiac electrophysiology has a long history, and numerous cellular scale models are now available, covering a range of species and cell types. Their use to study emergent properties in tissue is also widespread, typically using the monodomain or bidomain equations coupled to one or more cell models. Despite the relative maturity of this field, little has been written looking in detail at the interface between the cellular and tissue-level models. Mathematically this is relatively straightforward and well-defined. There are however many details and potential inconsistencies that need to be addressed, in order to ensure correct operation of a cellular model within a tissue simulation. This paper will describe these issues and how to address them. Simply having models available in a common format such as CellML is still of limited utility, with significant manual effort being required to integrate these models within a tissue simulation. We will thus also discuss the facilities available for automating this in a consistent fashion within Chaste, our robust and high-performance cardiac electrophysiology simulator. It will be seen that a common theme arising is the need to go beyond a representation of the model mathematics in a standard language, to include additional semantic information required in determining the model's interface, and hence to enhance interoperability. Such information can be added as metadata, but agreement is needed on the terms to use, including development of appropriate ontologies, if reliable automated use of CellML models is to become common.

  4. Morphological Characteristics of Electrophysiologically Characterized Layer Vb Pyramidal Cells in Rat Barrel Cortex

    PubMed Central

    Loucif, Alexandre J. C.; Schubert, Dirk; Möck, Martin

    2016-01-01

    Layer Vb pyramidal cells are the major output neurons of the neocortex and transmit the outcome of cortical columnar signal processing to distant target areas. At the same time they contribute to local tactile information processing by emitting recurrent axonal collaterals into the columnar microcircuitry. It is, however, not known how exactly the two types of pyramidal cells, called slender-tufted and thick-tufted, contribute to the local circuitry. Here, we investigated in the rat barrel cortex the detailed quantitative morphology of biocytin-filled layer Vb pyramidal cells in vitro, which were characterized for their intrinsic electrophysiology with special emphasis on their action potential firing pattern. Since we stained the same slices for cytochrome oxidase, we could also perform layer- and column-related analyses. Our results suggest that in layer Vb the unambiguous action potential firing patterns "regular spiking (RS)" and "repetitive burst spiking (RB)" (previously called intrinsically burst spiking) correlate well with a distinct morphology. RS pyramidal cells are somatodendritically of the slender-tufted type and possess numerous local intralaminar and intracolumnar axonal collaterals, mostly reaching layer I. By contrast, their transcolumnar projections are less well developed. The RB pyramidal cells are somatodendritically of the thick-tufted type and show only relatively sparse local axonal collaterals, which are preferentially emitted as long horizontal or oblique infragranular collaterals. However, contrary to many previous slice studies, a substantial number of these neurons also showed axonal collaterals reaching layer I. Thus, electrophysiologically defined pyramidal cells of layer Vb show an input and output pattern which suggests RS cells to be more "locally segregating" signal processors whereas RB cells seem to act more on a "global integrative" scale. PMID:27706253

  5. Utility Energy Services Contracts Guide

    SciTech Connect

    2013-09-01

    The UESC Guide is a compilation of samples and templates developed as a resource to help contracting officers implement task orders for UESCs under existing U.S. General Services Administration areawide contracts.

  6. Electrophysiology in the Developing World: Challenges and Opportunities.

    PubMed

    Bestawros, Michael

    2017-02-01

    As a subset of the growing epidemic of cardiovascular morbidity and mortality in low-income and middle-income countries (LMICs), the significant burdens of heart rhythm disorders also increase. Effective diagnostic and treatment modalities exist, but financial resources and expertise are limited. Cost-effective strategies exist to address most of these limitations, but many surmountable barriers need to be overcome to introduce and improve electrophysiologic care in LMICs. In this article, current and potential solutions are offered for the diagnostic and therapeutic challenges of managing bradyarrhythmias and tachyarrhythmias.

  7. Electrophysiological studies of malaria parasite-infected erythrocytes: Current status

    PubMed Central

    Staines, Henry M.; Alkhalil, Abdulnaser; Allen, Richard J.; De Jonge, Hugo R.; Derbyshire, Elvira; Egée, Stéphane; Ginsburg, Hagai; Hill, David A.; Huber, Stephan M.; Kirk, Kiaran; Lang, Florian; Lisk, Godfrey; Oteng, Eugene; Pillai, Ajay D.; Rayavara, Kempaiah; Rouhani, Sherin; Saliba, Kevin J.; Shen, Crystal; Solomon, Tsione; Thomas, Serge L. Y.; Verloo, Patrick; Desai, Sanjay A.

    2009-01-01

    The altered permeability characteristics of erythrocytes infected with malaria parasites have been a source of interest for over 30 years. Recent electrophysiological studies have provided strong evidence that these changes reflect transmembrane transport through ion channels in the host erythrocyte plasma membrane. However, conflicting results and differing interpretations of the data have led to confusion in this field. In an effort to unravel these issues, the groups involved recently came together for a week of discussion and experimentation. In this article, the various models for altered transport are reviewed, together with the areas of consensus in the field and those that require a better understanding. PMID:17292372

  8. National Registry on Cardiac Electrophysiology 2007 and 2008.

    PubMed

    da Silva, Manuel Nogueira; Bonhorst, Daniel; de Sousa, João

    2009-11-01

    Clinical electrophysiology remains one of the most dynamic areas of cardiology, with continuing developments in equipping centers with more modern mapping and navigation systems. This has enabled an increase in the number and variety of interventions, resulting in significant improvements in results of therapeutic ablation of arrhythmias and prevention of sudden cardiac death. In this phase of transition towards implementation of a computerized national registry with nationwide data transmitted via the internet, publication of the registry in its previous form, although requiring more work, still seems justified, in order to appraise and disseminate qualitative and quantitative developments in this activity and enable comparisons with what is being done internationally, assess the centers' training capacity and inform national and European health authorities of the activities and real needs in this sector. The authors analyze the number and type of procedures performed during 2007 and 2008 based on a survey sent to centers performing diagnostic and interventional electrophysiology (16 centers in 2007 and 2008) and/or implanting cardioverter-defibrillators (ICDs) (19 centers in 2007 and 21 in 2008). Compared to 2006, one more center began interventional electrophysiology in 2007 and two centers began implanting ICDs in 2008. In the years under review, 2060 electrophysiological studies were performed in 2007 and 2007 were performed in 2008, of which 74 and 79.5% respectively were followed by therapeutic ablation, making totals of 1523 and 1596 ablations (increases of 10.7 and 4.6% from previous years). Atrioventricular nodal reentrant tachycardia was the main indication for ablation (28.4 and 28.7%), followed by accessory pathways (26.8 and 25.4%), atrial flutter (20.8 and 19.7%), atrial fibrillation (13.9 and 14.6%), ventricular tachycardia (4.7 and 5.1%), atrial tachycardia (2.8 and 2.6%) and atrioventricular junction ablation (2.7 and 3.9%). Regarding ICDs, a

  9. [Electrophysiological research on pain and itching in the clinic].

    PubMed

    Dallakian, I G; Zhukova, I K; Filina, T F; Samsonov, V A

    1988-01-01

    To study the central mechanisms of pain and itching, the authors performed electroencephalographic (EEG) examination in acupuncture-treated patients with diffuse neurodermatitis (n = 43) and trigeminal neuralgia (n = 25). The most characteristic EEG finding was increased synchronization of the cortical rhythm. The revealed EEG features point to the functional involvement of the thalamocortical system in the development of pain and itching. Changes of clinical and electrophysiological parameters in the course of acupuncture treatment is an additional evidence of the morphofunctional unity of the development of pain and itching.

  10. Clinical and electrophysiological observations in patients with low pressure retinopathy.

    PubMed Central

    Russell, R W; Ikeda, H

    1986-01-01

    The clinical, angiographic, and electrophysiological features of seven patients with transient visual loss and low-pressure retinopathy are presented. Six of the patients also had symptoms of cerebral ischaemia. The commonest provoking feature was bright light. Angiography showed multiple extracranial occlusions involving both internal and external carotid arteries in addition to occlusion or stenosis on the contralateral side. Electroretinography showed delay in the recovery of the b wave in the affected eye after exposure to bright light. This appears to be a valuable test for the detection of minor degrees of ischaemic damage to the retina caused by insufficiency of the retinal and choroidal circulation. Images PMID:3756120

  11. [A new method in fetal heart electrophysiology - fetal magnetocardiography].

    PubMed

    Wacker-Gussmann, A; Lim, M; Henes, J; Preissl, H; Abele, H; Kiefer, I

    2011-06-01

    Fetal magnetocardiography (fMCG) is used as a non-invasive method for registering the electrophysiological fetal heart activity. Superconducting quantum interference device-based magnetometers are currently used to make fMCG recordings. In contrast to fetal ECG, this method is independent of signal loss due to isolating factors such as, especially, the vernix caesaroa between the 27th and 34th weeks of gestation. We report about a term newborn with a third degree AV block, examined by this method.

  12. Molecular and Electrophysiological Mechanisms Underlying Cardiac Arrhythmogenesis in Diabetes Mellitus

    PubMed Central

    Tse, Vivian; Yeo, Jie Ming

    2016-01-01

    Diabetes is a common endocrine disorder with an ever increasing prevalence globally, placing significant burdens on our healthcare systems. It is associated with significant cardiovascular morbidities. One of the mechanisms by which it causes death is increasing the risk of cardiac arrhythmias. The aim of this article is to review the cardiac (ion channel abnormalities, electrophysiological and structural remodelling) and extracardiac factors (neural pathway remodelling) responsible for cardiac arrhythmogenesis in diabetes. It is concluded by an outline of molecular targets for future antiarrhythmic therapy for the diabetic population. PMID:27642609

  13. [Photophobic response in Stentor coeruleus--electrophysiologic investigations].

    PubMed

    Walerczyk, M; Fabczak, H; Fabczak, S

    2000-01-01

    It is widely known that the phototransduction process in vertebrate photoreceptor cells are mediated by cGMP-gated ionic channels. The recent electrophysiological study showed that the cGMP-gated channels are also present in light sensitive protozoan ciliate Stentor coeruleus. These channels might play a key role in phototransduction process which leads to the photophobic behavior in the ciliate. The basic biophysical and pharmaceutical properties of cGMP-gated channels in Stentor indicate high similarity to those in vertebrate photoreceptor cells.

  14. Computer simulation of fibrillation threshold measurements and electrophysiologic testing procedures

    NASA Technical Reports Server (NTRS)

    Grumbach, M. P.; Saxberg, B. E.; Cohen, R. J.

    1987-01-01

    A finite element model of cardiac conduction was used to simulate two experimental protocols: 1) fibrillation threshold measurements and 2) clinical electrophysiologic (EP) testing procedures. The model consisted of a cylindrical lattice whose properties were determined by four parameters: element length, conduction velocity, mean refractory period, and standard deviation of refractory periods. Different stimulation patterns were applied to the lattice under a given set of lattice parameter values and the response of the model was observed through a simulated electrocardiogram. The studies confirm that the model can account for observations made in experimental fibrillation threshold measurements and in clinical EP testing protocols.

  15. Russian Contract Procurement Document

    SciTech Connect

    Tobin, J G

    2010-03-29

    This contract supports the enhancement of physical protection or nuclear material control and accounting systems at institutes or enterprises of the newly independent states under the material protection control and accounting (MPC&A) program. The contract is entered into pursuant to the MPC&A Program, a gratuitous technical assistance program, in accordance with the bilateral Agreements between the Russian Federation and the United States of America concerning the Safe and Secure Transportation, Storage and Destruction of Weapons and the Prevention of Weapons Proliferation of June 1992, as extended and amended by Protocol signed of June 1999, Agreement between the Government of the Russian Federation regarding Cooperation in the Area of Nuclear Materials Physical Protection, Control and Accounting of October 1999 and the Russian Federation law of May 1999 on the taxation exemption of gratuitous technical assistance with Russian Federation under registration No.DOE001000.

  16. Dupuytren's Contracture: Fibroblast Contraction?

    PubMed Central

    Gabbiani, Giulio; Majno, Guido

    1972-01-01

    In 6 cases of Dupuytren's disease and 1 of Ledderhose's disease, the nodules of the palmar and plantar aponeurosis were examined by light and electron microscopy. The cells composing these nodules, presumably fibroblasts, showed three significant ultrastructural features: (1) a fibrillar system similar to that of smooth muscle cells; (2) nuclear deformations such as are found in contracted cells, the severest being recognizable by light microscopy (cross-banded nuclei); (3) cell-to-cell and cell-to-stroma attachments. Based on these data and on recent information about the biology of the fibroblasts, it is suggested that these cells are fibroblasts that have modulated into contractile cells (myofibroblasts), and that their contraction plays a role in the pathogenesis of the contracture observed clinically. ImagesFig 10Fig 5Fig 11Fig 6 and 7Fig 8Fig 1Fig 2Fig 9Fig 3Fig 4 PMID:5009249

  17. Contracts for dispatchable power

    SciTech Connect

    Kahn, E.P.; Stoft, S.; Marnay, C.; Berman, D.

    1990-10-01

    Competitive bidding for electric power is maturing. Increasing numbers of utilities are soliciting proposals from private suppliers. The amount of capacity being sought is increasing, and potential suppliers appear to be abundant. Analysis of these developments still remains limited. Evidence on the behavior of this market is scarce and sketchy. The underlying economic principles that are shaping the market have not clearly been articulated. In this report we examine the economics of competitive bidding both empirically and analytically. Previous study of this market has focused on the evaluation criteria specified in Requests for Proposals (RFPs), and highly aggregated summary statistics on participation and results. We continue the examination of RFPs, but also survey the details of long term contracts that have emerged from competitive bidding. Contracts provide a new level of specific detail that has not been previously available. 68 refs., 13 figs., 25 tabs.

  18. Electrophysiological recording from neurons controlling sensory and motor functions of the esophagus.

    PubMed

    Sengupta, J N

    2001-12-03

    contractions of the distal esophagus. This response undergoes inhibition in response to proximal distension. In addition, there is a second, nonrhythmic firing response that occurs both proximal and distal esophageal distension. This observation suggests that swallow-induced inhibition of the distal esophagus is controlled by the preganglionic motor neurons in the brain stem. Electrophysiological studies allow direct understanding of neuronal activities regulating esophageal functions. In vivo recording has an advantage for studying functional roles of the neurons in regulatory reflexes, whereas in vitro recording is useful for more accurate study of receptor pharmacology. Recordings from the central nervous system allow study of the neurotransmitters involved in neuronal function and the circuitry of different reflex mechanisms.

  19. The Value of Competitive Contracting

    DTIC Science & Technology

    2014-09-01

    Research & Engineering) BBP Better Buying Power BOA basic ordering agreement BPA basic purchase agreement CAE Component Acquisition Executive CDSA...Basic Ordering Agreement ( BOA ) c. Government wide acquisition contracts and IDIQ contracts d. BPAs and BPA calls under Federal Supply Schedules...contract actions ( BOAs , BPAs, FSS, and GWAC) contracts that are not required to report the number of competitive offers. The fiscal year 2011 DOD

  20. Army Contigency Contracting.

    DTIC Science & Technology

    1985-11-01

    r I I ;. - L U C A ,. . • - J 01 .1 .1 C.. - 0 . c s U- 101 1. L.J 1 L I.C w - L.. . 4-.- 22...and transportation services as well. The noble intentions of an occupying power would mean r little to a civilian population suffering from basic...PROPOSAL EVALUAT ION NEGOTIATION AWARD CONTRACT ADMINISTRATION * PERFORMANCE A r P C []"O’ PCD GOVERNMENT ACO CONTRACTOR EXPERIENCE COR EXPER I

  1. Construction Contract Provisions Analysis.

    DTIC Science & Technology

    1982-09-01

    bidding and contract docuents. These documents appear together in the bid package. After the bid, the IFB (or RFTP, RFP ) is extracted and the remainder...Corps personnel suggest that the original reason for the clause -- to prevent brokering - is anachronistic in the current construction market. However...amount of premiums paid for performance and payment * bonds (including coinsurance and reinsurance agreements, when applicable) after furnishing

  2. The Unwritten Contract

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Hosted by former STS-1 Astronaut Bob Crippen, this video highlights the Space Shuttle program team's commitment to quality assurance as being the unwritten contract all workers in the shuttle program have with the flight crews: To keep them and the whole Space Transportation System safe. The video is presented by the Marshall Space Flight Center's Safety, Reliability, Maintainability, and Quality Assurance Office (SRM&QA).

  3. Contracting As A Science

    DTIC Science & Technology

    2012-04-30

    disconfirmation of expectations theory to examine customer satisfaction in the procuring contracting officer ( PCO )–program manager (PM) relationship in...feedback to unsuccessful offerors reduces or eliminates feelings of inequity, a negotiated agreement is considered inequitable, company perception of...outcomes will be judged (Helson, 1964). Some of the areas to which researchers have applied adaptation- level theory include price perception and the

  4. Contracting as a Science

    DTIC Science & Technology

    2012-04-30

    disconfirmation of expectations theory to examine customer satisfaction in the procuring contracting officer ( PCO )–program manager (PM) relationship in...feedback to unsuccessful offerors reduces or eliminates feelings of inequity, a negotiated agreement is considered inequitable, company perception of...outcomes will be judged (Helson, 1964). Some of the areas to which researchers have applied adaptation- level theory include price perception and the

  5. Elements of gas contracts

    SciTech Connect

    O`Neal, J.

    1995-12-01

    The gas marketing scene has taken on a new look from the days of the {open_quotes}Long Term{close_quotes} or {open_quotes}Life of Lease{close_quotes} Contracts. In the past natural gas was of ten sold direct from the wellhead or a producer-owned facility to a pipeline company at a flat rate price and the only parties involved were producer or seller and buyer. Today, the parties involved in the marketing process might include a gathering entity to gather gas at a central point and provide gathering, compression and/or dehydration services; multiple pipeline companies for transportation; sales representatives or marketing brokers to negotiate a sale of the available gas on a monthly basis; and purchasers or end users. New terms have also been introduced in the process such as: {open_quotes}LDC{close_quotes} (local distribution company), {open_quotes}FERC Order 636{close_quotes}, {open_quotes}Price Delivered-to-Pipeline{close_quotes} and the various {open_quotes}levels of Service{close_quotes} under Gas Sales and Purchase Agreements. Four common levels of service are: {open_quotes}Firm{close_quotes}, {open_quotes}Baseload{close_quotes}, {open_quotes}Swing{close_quotes} and {open_quotes}Baseload/Operational{close_quotes}. It is evident that current marketing plans often require a separate contract for each service or commitment. Contract contents vary greatly, but most contain the following elements.

  6. Why radiologists lose their hospital contracts: is your contract secure?

    PubMed

    Muroff, Lawrence R

    2010-03-01

    Previously, a hospital contract meant tenure for the incumbent group of radiologists; however, those days are long gone. Exclusive contracts have morphed into exclusive contracts with carve-outs. Turf erosion has become a fact of life for radiology practices. Now radiologists are losing their hospital contracts in record numbers. Group size, though helpful for a variety of reasons, does not ensure that a practice will be secure in its hospital setting. The reasons that groups lose their hospital contracts are varied, and in this paper, the author discusses the most common ones. Suggestions to help practices avoid this unfortunate fate are presented.

  7. How Learning Contracts Motivate Students

    ERIC Educational Resources Information Center

    Greenwood, Scott C.; McCabe, Patrick P.

    2008-01-01

    In this article, the authors discuss how learning contracts can motivate students. "A learning contract is simply a written agreement between teacher and learner in which the learner undertakes to complete mutually agreed upon tasks in a specified amount of time on his or her own initiative" (Greenwood, 2003, p.1). Contracts are designed to…

  8. Health Contract in the Classroom

    ERIC Educational Resources Information Center

    Haber, David

    2007-01-01

    A health contract is a technique used by health professionals to help clients achieve a health goal. This article describes a course, "Changing Health Behaviors," in which a health contract strategy is taught and practiced with older adults. The health contract can also be included as a smaller educational component within a gerontology course…

  9. 48 CFR 2446.710 - Contract clauses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CONTRACT MANAGEMENT QUALITY ASSURANCE Warranties 2446.710 Contract clauses. (c)(1) The contracting officer... Performance Specifications or Design Criteria, whenever it is in the Government's interest....

  10. 48 CFR 2446.710 - Contract clauses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... CONTRACT MANAGEMENT QUALITY ASSURANCE Warranties 2446.710 Contract clauses. (c)(1) The contracting officer... Performance Specifications or Design Criteria, whenever it is in the Government's interest....

  11. 48 CFR 2446.710 - Contract clauses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... CONTRACT MANAGEMENT QUALITY ASSURANCE Warranties 2446.710 Contract clauses. (c)(1) The contracting officer... Performance Specifications or Design Criteria, whenever it is in the Government's interest....

  12. How do astrocytes shape synaptic transmission? Insights from electrophysiology

    PubMed Central

    Dallérac, Glenn; Chever, Oana; Rouach, Nathalie

    2013-01-01

    A major breakthrough in neuroscience has been the realization in the last decades that the dogmatic view of astroglial cells as being merely fostering and buffering elements of the nervous system is simplistic. A wealth of investigations now shows that astrocytes actually participate in the control of synaptic transmission in an active manner. This was first hinted by the intimate contacts glial processes make with neurons, particularly at the synaptic level, and evidenced using electrophysiological and calcium imaging techniques. Calcium imaging has provided critical evidence demonstrating that astrocytic regulation of synaptic efficacy is not a passive phenomenon. However, given that cellular activation is not only represented by calcium signaling, it is also crucial to assess concomitant mechanisms. We and others have used electrophysiological techniques to simultaneously record neuronal and astrocytic activity, thus enabling the study of multiple ionic currents and in depth investigation of neuro-glial dialogues. In the current review, we focus on the input such approach has provided in the understanding of astrocyte-neuron interactions underlying control of synaptic efficacy. PMID:24101894

  13. Electrophysiological fingerprints of OFF bipolar cells in rat retina

    PubMed Central

    Vielma, Alex H.; Schmachtenberg, Oliver

    2016-01-01

    Retinal bipolar cells (BCs) divide photoreceptor output into different channels for the parallel extraction of temporal and chromatic stimulus properties. In rodents, five types of OFF BCs have been differentiated, based on morphological and functional criteria, but their electrophysiological characterization remains incomplete. This study analyzed OFF BCs with the patch clamp technique in acute slices of rat retina. Their specific voltage-dependent currents and glutamate responses are shown to represent individual fingerprints which define the signal processing and filtering properties of each cell type and allow their unequivocal identification. Two additions to the rat BC repertoire are presented: OFF BC-2′, a variation of BC-2 with wider axonal arbours and prominent Na+ currents, is described for the first time in rodents, and OFF BC-3b, previously identified in mouse, is electrophysiologically characterized in rat. Moreover, the glutamate responses of rat OFF BCs are shown to be differentially sensitive to AMPA- and kainate-receptor blockers and to modulation by nitric oxide (NO) through a cGMP-dependent mechanism. These results contribute to our understanding of the diversity and function of bipolar cells in mammals. PMID:27457753

  14. Electrophysiological Recording in the Brain of Intact Adult Zebrafish

    PubMed Central

    Johnston, Lindsey; Ball, Rebecca E.; Acuff, Seth; Gaudet, John; Sornborger, Andrew; Lauderdale, James D.

    2013-01-01

    Previously, electrophysiological studies in adult zebrafish have been limited to slice preparations or to eye cup preparations and electrorentinogram recordings. This paper describes how an adult zebrafish can be immobilized, intubated, and used for in vivo electrophysiological experiments, allowing recording of neural activity. Immobilization of the adult requires a mechanism to deliver dissolved oxygen to the gills in lieu of buccal and opercular movement. With our technique, animals are immobilized and perfused with habitat water to fulfill this requirement. A craniotomy is performed under tricaine methanesulfonate (MS-222; tricaine) anesthesia to provide access to the brain. The primary electrode is then positioned within the craniotomy window to record extracellular brain activity. Through the use of a multitube perfusion system, a variety of pharmacological compounds can be administered to the adult fish and any alterations in the neural activity can be observed. The methodology not only allows for observations to be made regarding changes in neurological activity, but it also allows for comparisons to be made between larval and adult zebrafish. This gives researchers the ability to identify the alterations in neurological activity due to the introduction of various compounds at different life stages. PMID:24300281

  15. Shared electrophysiology mechanisms of body ownership and motor imagery.

    PubMed

    Evans, Nathan; Blanke, Olaf

    2013-01-01

    Although we feel, see, and experience our hands as our own (body or hand ownership), recent research has shown that illusory hand ownership can be induced for fake or virtual hands and may be useful for neuroprosthetics and brain-computer interfaces. Despite the vast amount of behavioral data on illusory hand ownership, neuroimaging studies are rare, in particular electrophysiological studies. Thus, while the neural systems underlying hand ownership are relatively well described, the spectral signatures of body ownership as measured by electroencephalography (EEG) remain elusive. Here we induced illusory hand ownership in an automated, computer-controlled manner using virtual reality while recording 64-channel EEG and found that illusory hand ownership is reflected by a body-specific modulation in the mu-band over fronto-parietal cortex. In a second experiment in the same subjects, we then show that mu as well as beta-band activity in highly similar fronto-parietal regions was also modulated during a motor imagery task often used in paradigms employing non-invasive brain-computer interface technology. These data provide insights into the electrophysiological brain mechanisms of illusory hand ownership and their strongly overlapping mechanisms with motor imagery in fronto-parietal cortex. They also highlight the potential of combining high-resolution EEG with virtual reality setups and automatized stimulation protocols for systematic, reproducible stimulus presentation in cognitive neuroscience, and may inform the design of non-invasive brain-computer interfaces.

  16. [Electrophysiology and calcium signalling in human bronchial smooth muscle].

    PubMed

    Marthan, R; Hyvelin, J M; Roux, E; Savineau, J P

    1999-01-01

    Recently, cells isolated from airways have been used to characterize precisely the electrophysiological properties of this smooth muscle and to describe the changes in cytosolic calcium concentration ([Ca2+]i) occurring upon agonist stimulation. Although most studies have produced consistent results in terms of types of ion channel and pathways of calcium signalling implicated in the mechanical activity of airways, there are differences according to (i) the site along the bronchial tree (trachea vs. bronchi); (ii) the proliferating status of the cells (freshly isolated vs. cultured) and (iii) the species (human vs. animals). With regard to the electrophysiological properties of airway smooth muscle, the contribution to [Ca2+]i rise of Ca2+ influx through L-type voltage-dependent calcium channels depends on the balance between depolarization related to non-specific cation channel and/or chloride channel activation and hyperpolarization related to activation of a variety of potassium channels. Most of the above-mentioned channels appear to be controlled, directly or indirectly, by agonists in human bronchial smooth muscle. With regard to calcium signalling, the pattern of agonist-induced [Ca2+]i responses, the so-called [Ca2+]i oscillations, has been observed recently in freshly isolated airway smooth muscle cells. The role and the calcium sources involved in these oscillations in human bronchial smooth muscle are currently being investigated.

  17. Electrophysiological heterogeneity and stability of reentry in simulated cardiac tissue.

    PubMed

    Xie, F; Qu, Z; Garfinkel, A; Weiss, J N

    2001-02-01

    Generation of wave break is a characteristic feature of cardiac fibrillation. In this study, we investigated how dynamic factors and fixed electrophysiological heterogeneity interact to promote wave break in simulated two-dimensional cardiac tissue, by using the Luo-Rudy (LR1) ventricular action potential model. The degree of dynamic instability of the action potential model was controlled by varying the maximal amplitude of the slow inward Ca(2+) current to produce spiral waves in homogeneous tissue that were either nearly stable, meandering, hypermeandering, or in breakup regimes. Fixed electrophysiological heterogeneity was modeled by randomly varying action potential duration over different spatial scales to create dispersion of refractoriness. We found that the degree of dispersion of refractoriness required to induce wave break decreased markedly as dynamic instability of the cardiac model increased. These findings suggest that reducing the dynamic instability of cardiac cells by interventions, such as decreasing the steepness of action potential duration restitution, may still have merit as an antifibrillatory strategy.

  18. Simultaneous electrophysiological recording and calcium imaging of suprachiasmatic nucleus neurons.

    PubMed

    Irwin, Robert P; Allen, Charles N

    2013-12-08

    Simultaneous electrophysiological and fluorescent imaging recording methods were used to study the role of changes of membrane potential or current in regulating the intracellular calcium concentration. Changing environmental conditions, such as the light-dark cycle, can modify neuronal and neural network activity and the expression of a family of circadian clock genes within the suprachiasmatic nucleus (SCN), the location of the master circadian clock in the mammalian brain. Excitatory synaptic transmission leads to an increase in the postsynaptic Ca(2+) concentration that is believed to activate the signaling pathways that shifts the rhythmic expression of circadian clock genes. Hypothalamic slices containing the SCN were patch clamped using microelectrodes filled with an internal solution containing the calcium indicator bis-fura-2. After a seal was formed between the microelectrode and the SCN neuronal membrane, the membrane was ruptured using gentle suction and the calcium probe diffused into the neuron filling both the soma and dendrites. Quantitative ratiometric measurements of the intracellular calcium concentration were recorded simultaneously with membrane potential or current. Using these methods it is possible to study the role of changes of the intracellular calcium concentration produced by synaptic activity and action potential firing of individual neurons. In this presentation we demonstrate the methods to simultaneously record electrophysiological activity along with intracellular calcium from individual SCN neurons maintained in brain slices.

  19. Obesity, Cardiovascular Fitness, and Inhibition Function: An Electrophysiological Study.

    PubMed

    Song, Tai-Fen; Chi, Lin; Chu, Chien-Heng; Chen, Feng-Tzu; Zhou, Chenglin; Chang, Yu-Kai

    2016-01-01

    The purpose of the present study was to examine how obesity and cardiovascular fitness are associated with the inhibition aspect of executive function from behavioral and electrophysiological perspectives. One hundred college students, aged 18-25 years, were categorized into four groups of equal size on the basis of body mass index and cardiovascular fitness: a normal-weight and high-fitness (NH) group, an obese-weight and high-fitness (OH) group, a normal-weight and low-fitness (NL) group, and an obese-weight and low-fitness (OL) group. Behavioral measures of response time and number of errors, as well as event-related potential measures of P3 and N1, were assessed during the Stroop Task. The results revealed that, in general, the NH group exhibited shorter response times and larger P3 amplitudes relative to the NL and OL groups, wherein the OL group exhibited the longest response time in the incongruent condition. No group differences in N1 indices were also revealed. These findings suggest that the status of being both normal weight and having high cardiovascular fitness is associated with better behavioral and later stages of electrophysiological indices of cognitive function.

  20. Analysis of electrophysiological properties and responses of neutrophils

    PubMed Central

    Morgan, Deri; DeCoursey, Thomas E.

    2014-01-01

    Summary The past decade has seen increasing use of the patch clamp technique on neutrophils and eosinophils. The main goal of these electrophysiological studies has been to elucidate the mechanisms underlying the phagocyte respiratory burst. NADPH oxidase activity, which defines the respiratory burst in granulocytes, is electrogenic because electrons from NADPH are transported across the cell membrane, where they reduce oxygen to form superoxide anion (O2−). This passage of electrons comprises an electrical current that would rapidly depolarize the membrane if the charge movement were not balanced by proton efflux. The patch clamp technique enables simultaneous recording of NADPH oxidase-generated electron current and H+ flux through the closely related H+ channel. Increasing evidence suggests that other ion channels may play crucial roles in degranulation, phagocytosis, and chemotaxis, highlighting the importance of electrophysiological studies to advance knowledge of granulocyte function. Several configurations of the patch clamp technique exist. Each has advantages and limitations that are discussed here. Meaningful measurements of ion channels cannot be achieved without an understanding of their fundamental properties. We describe the types of measurements that are necessary to characterize a particular ion channel. PMID:24504950

  1. Zebrafish heart as a model for human cardiac electrophysiology

    PubMed Central

    Vornanen, Matti; Hassinen, Minna

    2016-01-01

    ABSTRACT The zebrafish (Danio rerio) has become a popular model for human cardiac diseases and pharmacology including cardiac arrhythmias and its electrophysiological basis. Notably, the phenotype of zebrafish cardiac action potential is similar to the human cardiac action potential in that both have a long plateau phase. Also the major inward and outward current systems are qualitatively similar in zebrafish and human hearts. However, there are also significant differences in ionic current composition between human and zebrafish hearts, and the molecular basis and pharmacological properties of human and zebrafish cardiac ionic currents differ in several ways. Cardiac ionic currents may be produced by non-orthologous genes in zebrafish and humans, and paralogous gene products of some ion channels are expressed in the zebrafish heart. More research on molecular basis of cardiac ion channels, and regulation and drug sensitivity of the cardiac ionic currents are needed to enable rational use of the zebrafish heart as an electrophysiological model for the human heart. PMID:26671745

  2. Correlations of clinical, neuroimaging, and electrophysiological features in Hirayama disease

    PubMed Central

    Liao, Ming-Feng; Chang, Hong-Shiu; Chang, Kuo-Hsuan; Ro, Long-Sun; Chu, Chun-Che; Kuo, Hung-Chou; Lyu, Rong-Kuo

    2016-01-01

    Abstract Hirayama disease (HD) is characterized by development of asymmetric forearm muscle atrophy during adolescence with or without focal cervical spinal cord atrophy. The purpose of this study is to assess the correlation of clinical symptoms, disease progression, and electrophysiological findings with cervical spine magnetic resonance imaging (MRI) findings. The medical records, cervical spine MRIs, and electrophysiological findings of 44 HD patients were retrospectively reviewed and analyzed. Denervation changes in any single C5 to C7 root-innervated muscle (deltoid, biceps, triceps, or extensor digitorum communis) occurred more frequently in the 25 patients with cord atrophy than the 19 patients without cord atrophy (88% vs 53%, P = 0.02). Onset age, duration of disease progression, neurological examinations, nerve conduction study, and electromyographic findings from individual muscles were similar between patient groups. Compared with HD patients without cord atrophy, HD patients with cord atrophy experience a more severe denervation change in C5 to C7 root-innervated muscles. PMID:27428223

  3. Obesity, Cardiovascular Fitness, and Inhibition Function: An Electrophysiological Study

    PubMed Central

    Song, Tai-Fen; Chi, Lin; Chu, Chien-Heng; Chen, Feng-Tzu; Zhou, Chenglin; Chang, Yu-Kai

    2016-01-01

    The purpose of the present study was to examine how obesity and cardiovascular fitness are associated with the inhibition aspect of executive function from behavioral and electrophysiological perspectives. One hundred college students, aged 18–25 years, were categorized into four groups of equal size on the basis of body mass index and cardiovascular fitness: a normal-weight and high-fitness (NH) group, an obese-weight and high-fitness (OH) group, a normal-weight and low-fitness (NL) group, and an obese-weight and low-fitness (OL) group. Behavioral measures of response time and number of errors, as well as event-related potential measures of P3 and N1, were assessed during the Stroop Task. The results revealed that, in general, the NH group exhibited shorter response times and larger P3 amplitudes relative to the NL and OL groups, wherein the OL group exhibited the longest response time in the incongruent condition. No group differences in N1 indices were also revealed. These findings suggest that the status of being both normal weight and having high cardiovascular fitness is associated with better behavioral and later stages of electrophysiological indices of cognitive function. PMID:27512383

  4. Verification of computational models of cardiac electro-physiology.

    PubMed

    Pathmanathan, Pras; Gray, Richard A

    2014-05-01

    For computational models of cardiac activity to be used in safety-critical clinical decision-making, thorough and rigorous testing of the accuracy of predictions is required. The field of 'verification, validation and uncertainty quantification' has been developed to evaluate the credibility of computational predictions. The first stage, verification, is the evaluation of how well computational software correctly solves the underlying mathematical equations. The aim of this paper is to introduce novel methods for verifying multi-cellular electro-physiological solvers, a crucial first stage for solvers to be used with confidence in clinical applications. We define 1D-3D model problems with exact solutions for each of the monodomain, bidomain, and bidomain-with-perfusing-bath formulations of cardiac electro-physiology, which allow for the first time the testing of cardiac solvers against exact errors on fully coupled problems in all dimensions. These problems are carefully constructed so that they can be easily run using a general solver and can be used to greatly increase confidence that an implementation is correct, which we illustrate by testing one major solver, 'Chaste', on the problems. We then perform case studies on calculation verification (also known as solution verification) for two specific applications. We conclude by making several recommendations regarding verification in cardiac modelling.

  5. Electrophysiological Auditory Responses and Language Development in Infants with Periventricular Leukomalacia

    ERIC Educational Resources Information Center

    Avecilla-Ramirez, G. N.; Ruiz-Correa, S.; Marroquin, J. L.; Harmony, T.; Alba, A.; Mendoza-Montoya, O.

    2011-01-01

    This study presents evidence suggesting that electrophysiological responses to language-related auditory stimuli recorded at 46 weeks postconceptional age (PCA) are associated with language development, particularly in infants with periventricular leukomalacia (PVL). In order to investigate this hypothesis, electrophysiological responses to a set…

  6. 42 CFR 434.6 - General requirements for all contracts and subcontracts. P>(a) Contracts. All contracts under...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false General requirements for all contracts and subcontracts. P>(a) Contracts. All contracts under this part must include all of the following: 434.6 Section... contracts and subcontracts.P>(a) Contracts. All contracts under this part must include all of the...

  7. Interpretation of 2-probe turbulence measurements in an axisymmetric contraction

    NASA Technical Reports Server (NTRS)

    Marion-Moulin, C.; Tan-Atichat, J.; Nagib, H. M.

    1983-01-01

    Simultaneous measurements of the streamwise and radial velocity components at two points, one on and one off the centerline with variable radial separation, were digitally recorded and processed at several stations along a four to one contraction with controlled upstream turbulence conditions. Various statistical quantities are presented including spectra and coherence functions. The integral L sub ux, L sub um, L sub vx, L sub vm were also estimated and their variation along the contraction is examined.

  8. 48 CFR 2415.204 - Contract format.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CONTRACTING METHODS AND CONTRACTING TYPES CONTRACTING BY NEGOTIATION Solicitation and Receipt of Proposals and Information 2415.204 Contract format. (e) The cognizant HCA shall be responsible for making...

  9. 48 CFR 39.107 - Contract clause.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CONTRACTING ACQUISITION OF INFORMATION TECHNOLOGY General 39.107 Contract clause. The contracting officer..., in solicitations and contracts for information technology which require security of information... information technology services or support services....

  10. 48 CFR 2442.1107 - Contract clause.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... information technology services. ... CONTRACT MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Production Surveillance and Reporting 2442... clause at 2452.242-71, Contract Management System, in solicitations and contracts when all of...

  11. 48 CFR 3035.7000 - Contract clause.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SECURITY ACQUISITION REGULATION (HSAR) SPECIAL CATEGORIES OF CONTRACTING RESEARCH AND DEVELOPMENT CONTRACTING Information Dissemination by Educational Institutions 3035.7000 Contract clause. The contracting officer may use the clause at (HSAR) 48 CFR 3052.235-70, Dissemination of...

  12. 48 CFR 15.204-1 - Uniform contract format.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CONTRACTING METHODS AND CONTRACT TYPES CONTRACTING BY NEGOTIATION Solicitation and Receipt of Proposals and Information 15.204-1 Uniform contract format. (a) Contracting officers shall prepare solicitations...

  13. NeuroChip: A Microfluidic Electrophysiological Device for Genetic and Chemical Biology Screening of Caenorhabditis elegans Adult and Larvae

    PubMed Central

    Hu, Chunxiao; Dillon, James; Kearn, James; Murray, Caitriona; O’Connor, Vincent; Holden-Dye, Lindy; Morgan, Hywel

    2013-01-01

    Genetic and chemical biology screens of C. elegans have been of enormous benefit in providing fundamental insight into neural function and neuroactive drugs. Recently the exploitation of microfluidic devices has added greater power to this experimental approach providing more discrete and higher throughput phenotypic analysis of neural systems. Here we make a significant addition to this repertoire through the design of a semi-automated microfluidic device, NeuroChip, which has been optimised for selecting worms based on the electrophysiological features of the pharyngeal neural network. We demonstrate this device has the capability to sort mutant from wild-type worms based on high definition extracellular electrophysiological recordings. NeuroChip resolves discrete differences in excitatory, inhibitory and neuromodulatory components of the neural network from individual animals. Worms may be fed into the device consecutively from a reservoir and recovered unharmed. It combines microfluidics with integrated electrode recording for sequential trapping, restraining, recording, releasing and recovering of C. elegans. Thus mutant worms may be selected, recovered and propagated enabling mutagenesis screens based on an electrophysiological phenotype. Drugs may be rapidly applied during the recording thus permitting compound screening. For toxicology, this analysis can provide a precise description of sub-lethal effects on neural function. The chamber has been modified to accommodate L2 larval stages showing applicability for small size nematodes including parasitic species which otherwise are not tractable to this experimental approach. We also combine NeuroChip with optogenetics for targeted interrogation of the function of the neural circuit. NeuroChip thus adds a new tool for exploitation of C. elegans and has applications in neurogenetics, drug discovery and neurotoxicology. PMID:23717588

  14. CONTRACTING AND ERUPTING COMPONENTS OF SIGMOIDAL ACTIVE REGIONS

    SciTech Connect

    Liu Rui; Wang Yuming; Liu Chang; Wang Haimin; Toeroek, Tibor

    2012-10-01

    It has recently been noted that solar eruptions can be associated with the contraction of coronal loops that are not involved in magnetic reconnection processes. In this paper, we investigate five coronal eruptions originating from four sigmoidal active regions, using high-cadence, high-resolution narrowband EUV images obtained by the Solar Dynamic Observatory (SDO). The magnitudes of the flares associated with the eruptions range from GOES class B to class X. Owing to the high-sensitivity and broad temperature coverage of the Atmospheric Imaging Assembly (AIA) on board SDO, we are able to identify both the contracting and erupting components of the eruptions: the former is observed in cold AIA channels as the contracting coronal loops overlying the elbows of the sigmoid, and the latter is preferentially observed in warm/hot AIA channels as an expanding bubble originating from the center of the sigmoid. The initiation of eruption always precedes the contraction, and in the energetically mild events (B- and C-flares), it also precedes the increase in GOES soft X-ray fluxes. In the more energetic events, the eruption is simultaneous with the impulsive phase of the nonthermal hard X-ray emission. These observations confirm that loop contraction is an integrated process in eruptions with partially opened arcades. The consequence of contraction is a new equilibrium with reduced magnetic energy, as the contracting loops never regain their original positions. The contracting process is a direct consequence of flare energy release, as evidenced by the strong correlation of the maximal contracting speed, and strong anti-correlation of the time delay of contraction relative to expansion, with the peak soft X-ray flux. This is also implied by the relationship between contraction and expansion, i.e., their timing and speed.

  15. [Collective versus selective contracts from a legal point of view].

    PubMed

    Schirmer, Horst Dieter

    2006-01-01

    The historically proven organisational model of service relations between sickness funds and healthcare providers are collective contracts. A collective contract as a standards treaty ("Normenvertrag") is particularly pronounced concerning the panel doctor law ("Vertragsarztrecht") defining medical care on the basis of the principle of benefits in kind governing benefit claims of the insured in case of illness. The collective contract is a suitable instrument for ensuring both consistent and exhaustive provision of care and for organising the conditions of care, especially the quality and reimbursement of professional medical services. For several years the legislator has been "experimenting" with parallel contract design patterns such as the contract of integrated care in the form of selective contracts between health insurances or their associations and healthcare providers or groups of healthcare providers. More recently, allowances for conclusion of such contracts have been supposed to lead to competition between the contractual systems. It is doubtful whether this "push-start" will contribute to overcoming the systematic legal disadvantages of selective contracting as an organisational model for the provision of healthcare services to the insured.

  16. TraceContract

    NASA Technical Reports Server (NTRS)

    Kavelund, Klaus; Barringer, Howard

    2012-01-01

    TraceContract is an API (Application Programming Interface) for trace analysis. A trace is a sequence of events, and can, for example, be generated by a running program, instrumented appropriately to generate events. An event can be any data object. An example of a trace is a log file containing events that a programmer has found important to record during a program execution. Trace - Contract takes as input such a trace together with a specification formulated using the API and reports on any violations of the specification, potentially calling code (reactions) to be executed when violations are detected. The software is developed as an internal DSL (Domain Specific Language) in the Scala programming language. Scala is a relatively new programming language that is specifically convenient for defining such internal DSLs due to a number of language characteristics. This includes Scala s elegant combination of object-oriented and functional programming, a succinct notation, and an advanced type system. The DSL offers a combination of data-parameterized state machines and temporal logic, which is novel. As an extension of Scala, it is a very expressive and convenient log file analysis framework.

  17. Which managed care contract(s) should you sign?

    PubMed

    Biddinger, D

    2001-01-01

    Contracts are a basic responsibility in running a medical practice--so much so that it's inappropriate to pass those responsibilities to someone else. Managers must at least understand the basic terms and conditions of the contract and the reimbursement their practices will receive. This article is written from the perspective of a privately owned medical practice and addresses only discounted, fee-for-service managed care contracts.

  18. 48 CFR 935.071 - Contract clause.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clause. 935.071... CONTRACTING RESEARCH AND DEVELOPMENT CONTRACTING 935.071 Contract clause. The contracting officer must insert the clause at 952.235-71, Research Misconduct, in contracts, including management and...

  19. 48 CFR 1316.406 - Contract clauses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clauses. 1316.406 Section 1316.406 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Incentive Contracts 1316.406 Contract clauses. Insert a...

  20. 48 CFR 937.7040 - Contract clauses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clauses. 937.7040... CONTRACTING SERVICE CONTRACTING Protective Services Contracting 937.7040 Contract clauses. The contracting officer shall insert the clause at 952.237-70 entitled “Collective bargaining...

  1. 48 CFR 1517.204 - Contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Contracts. 1517.204 Section 1517.204 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 1517.204 Contracts. The SCM may approve a contract...

  2. 48 CFR 1846.470 - Contract clause.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CONTRACT MANAGEMENT QUALITY ASSURANCE Government Contract Quality Assurance 1846.470 Contract clause. The contracting officer may insert a clause substantially as stated at 1852.246-71, Government Contract Quality Assurance Functions, in solicitations and contracts to specify the location(s) of quality...

  3. 48 CFR 316.307 - Contract clauses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Contract clauses. 316.307 Section 316.307 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Cost-reimbursement Contracts 316.307 Contract clauses. (a) If a...

  4. 48 CFR 2442.1107 - Contract clause.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... value of $500,000 or less. (d) The clause shall not be used in contracts for information technology... CONTRACT MANAGEMENT CONTRACT ADMINISTRATION Production Surveillance and Reporting 2442.1107 Contract clause..., Contract Management System, in solicitations and contracts when all of the following conditions apply:...

  5. 48 CFR 2442.1107 - Contract clause.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... value of $500,000 or less. (d) The clause shall not be used in contracts for information technology... CONTRACT MANAGEMENT CONTRACT ADMINISTRATION Production Surveillance and Reporting 2442.1107 Contract clause..., Contract Management System, in solicitations and contracts when all of the following conditions apply:...

  6. 48 CFR 3416.307 - Contract clauses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Cost-Reimbursement Contracts 3416.307 Contract... solicitations of and resultant cost-reimbursement contracts with nonprofit organizations other than educational institutional, hospitals, or organizations listed in Attachment C to Office of Management and Budget Circular...

  7. 48 CFR 3417.204 - Contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 7 2011-10-01 2011-10-01 false Contracts. 3417.204... CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 3417.204 Contracts. (e) Except as otherwise provided by law, contract periods that exceed the five-year limitation specified in FAR...

  8. 48 CFR 716.406 - Contract clauses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clauses. 716.406 Section 716.406 Federal Acquisition Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Cost Reimbursement Contracts 716.406 Contract clauses....

  9. 48 CFR 2417.204 - Contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Contracts. 2417.204... CONTRACTING METHODS AND CONTRACTING TYPES SPECIAL CONTRACTING METHODS Options 2417.204 Contracts. (e) The Senior Procurement Executive shall approve any solicitation or contract which exceeds the five (5)...

  10. 48 CFR 4.103 - Contract clause.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Contract clause. 4.103... MATTERS Contract Execution 4.103 Contract clause. The contracting officer shall insert the clause at 52.204-1, Approval of Contract, in solicitations and contracts if required by agency procedures....

  11. 48 CFR 3417.204 - Contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 7 2012-10-01 2012-10-01 false Contracts. 3417.204... CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 3417.204 Contracts. (e) Except as otherwise provided by law, contract periods that exceed the five-year limitation specified in FAR...

  12. 48 CFR 3016.603 - Letter contracts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Letter contracts. 3016.603... ACQUISITION REGULATION (HSAR) CONTRACT METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Time-and-Materials, Labor-Hour, and Letter Contracts 3016.603 Letter contracts....

  13. 48 CFR 2017.204 - Contracts

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Contracts 2017.204 Section 2017.204 Federal Acquisition Regulations System NUCLEAR REGULATORY COMMISSION CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 2017.204 Contracts (a) The contracting officer...

  14. 48 CFR 1817.204 - Contracts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false Contracts. 1817.204... CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 1817.204 Contracts. (e)(i) The 5-year limitation (basic plus option periods) applies to all NASA contracts regardless of type and...

  15. 48 CFR 916.307 - Contract clauses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clauses. 916.307 Section 916.307 Federal Acquisition Regulations System DEPARTMENT OF ENERGY CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Cost-Reimbursement Contracts 916.307 Contract clauses. (g) Insert...

  16. 48 CFR 817.204 - Contracts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Contracts. 817.204 Section 817.204 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 817.204 Contracts. (a) The contracting officer...

  17. 48 CFR 1817.204 - Contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Contracts. 1817.204... CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 1817.204 Contracts. (e)(i) The 5-year limitation (basic plus option periods) applies to all NASA contracts regardless of type and...

  18. 48 CFR 817.204 - Contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Contracts. 817.204 Section 817.204 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 817.204 Contracts. (a) The contracting officer...

  19. 48 CFR 1817.204 - Contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Contracts. 1817.204... CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 1817.204 Contracts. (e)(i) The 5-year limitation (basic plus option periods) applies to all NASA contracts regardless of type and...

  20. 24 CFR 883.602 - The contract.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 4 2014-04-01 2014-04-01 false The contract. 883.602 Section 883... Contract § 883.602 The contract. (a) Contract. The Housing Assistance Payments Contract sets forth rights... payments. (b) Housing Assistance Payments to Owners under the Contract. The Housing Assistance...

  1. 48 CFR 2017.204 - Contracts

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false Contracts 2017.204 Section 2017.204 Federal Acquisition Regulations System NUCLEAR REGULATORY COMMISSION CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 2017.204 Contracts (a) The contracting officer...

  2. 48 CFR 817.204 - Contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Contracts. 817.204 Section 817.204 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 817.204 Contracts. (a) The contracting officer...

  3. 48 CFR 2017.204 - Contracts

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Contracts 2017.204 Section 2017.204 Federal Acquisition Regulations System NUCLEAR REGULATORY COMMISSION CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 2017.204 Contracts (a) The contracting officer...

  4. 48 CFR 2417.204 - Contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Contracts. 2417.204... CONTRACTING METHODS AND CONTRACTING TYPES SPECIAL CONTRACTING METHODS Options 2417.204 Contracts. (e) The Senior Procurement Executive shall approve any solicitation or contract which exceeds the five (5)...

  5. 48 CFR 1817.204 - Contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Contracts. 1817.204... CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 1817.204 Contracts. (e)(i) The 5-year limitation (basic plus option periods) applies to all NASA contracts regardless of type and...

  6. 48 CFR 2417.204 - Contracts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false Contracts. 2417.204... CONTRACTING METHODS AND CONTRACTING TYPES SPECIAL CONTRACTING METHODS Options 2417.204 Contracts. (e)(1) The Senior Procurement Executive (SPE) is authorized to approve contract periods for other than...

  7. 48 CFR 3416.603 - Letter contracts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Letter contracts. 3416.603... CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Time-and-Materials, Labor-Hour, and Letter Contracts 3416.603 Letter contracts....

  8. 24 CFR 880.501 - The contract.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 4 2014-04-01 2014-04-01 false The contract. 880.501 Section 880... Contract § 880.501 The contract. (a) Contract. The Housing Assistance Payments Contract sets forth rights and duties of the owner and the contract administrator with respect to the project and the...

  9. 48 CFR 16.302 - Cost contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Cost contracts. 16.302 Section 16.302 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Cost-Reimbursement Contracts 16.302 Cost contracts....

  10. 48 CFR 17.204 - Contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Contracts. 17.204 Section 17.204 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 17.204 Contracts. (a) The contract shall specify...

  11. 48 CFR 817.204 - Contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contracts. 817.204 Section 817.204 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 817.204 Contracts. (a) The contracting officer...

  12. 48 CFR 417.204 - Contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 4 2014-10-01 2014-10-01 false Contracts. 417.204 Section 417.204 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 417.204 Contracts. The head of the contracting...

  13. 48 CFR 3042.7000 - Contract clause.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Contract clause. 3042.7000... SECURITY ACQUISITION REGULATION (HSAR) CONTRACT MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Contracting Officer's Technical Representative 3042.7000 Contract clause. The contracting officer shall...

  14. 48 CFR 3417.204 - Contracts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Contracts. 3417.204 Section... CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 3417.204 Contracts. (e) Except as otherwise provided by law, contract periods that exceed the five-year limitation specified in FAR...

  15. 48 CFR 16.307 - Contract clauses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Contract clauses. 16.307 Section 16.307 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Cost-Reimbursement Contracts 16.307 Contract clauses. (a)(1)...

  16. 48 CFR 17.204 - Contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Contracts. 17.204 Section 17.204 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 17.204 Contracts. (a) The contract shall specify...

  17. 48 CFR 817.204 - Contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Contracts. 817.204 Section 817.204 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 817.204 Contracts. (a) The contracting officer...

  18. 48 CFR 716.406 - Contract clauses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Contract clauses. 716.406 Section 716.406 Federal Acquisition Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Cost Reimbursement Contracts 716.406 Contract clauses....

  19. 48 CFR 3417.204 - Contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 7 2014-10-01 2014-10-01 false Contracts. 3417.204... CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 3417.204 Contracts. (e) Except as otherwise provided by law, contract periods that exceed the five-year limitation specified in FAR...

  20. 48 CFR 417.204 - Contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Contracts. 417.204 Section 417.204 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 417.204 Contracts. The head of the contracting...

  1. 48 CFR 1416.405 - Contract clauses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clauses. 1416.405 Section 1416.405 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Incentive Contracts 1416.405 Contract clauses. The BPC, without the...

  2. 48 CFR 2417.204 - Contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Contracts. 2417.204... CONTRACTING METHODS AND CONTRACTING TYPES SPECIAL CONTRACTING METHODS Options 2417.204 Contracts. (e)(1) The Senior Procurement Executive (SPE) is authorized to approve contract periods for other than...

  3. 48 CFR 2017.204 - Contracts

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Contracts 2017.204 Section 2017.204 Federal Acquisition Regulations System NUCLEAR REGULATORY COMMISSION CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 2017.204 Contracts (a) The contracting officer...

  4. 48 CFR 417.204 - Contracts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 4 2013-10-01 2013-10-01 false Contracts. 417.204 Section 417.204 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 417.204 Contracts. The head of the contracting...

  5. 48 CFR 417.204 - Contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Contracts. 417.204 Section 417.204 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 417.204 Contracts. The head of the contracting...

  6. 48 CFR 16.406 - Contract clauses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Contract clauses. 16.406 Section 16.406 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Incentive Contracts 16.406 Contract clauses. (a) Insert...

  7. 48 CFR 732.111 - Contract clauses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Contract clauses. 732.111... CONTRACTING REQUIREMENTS CONTRACT FINANCING General 732.111 Contract clauses. (a) (b) USAID may obtain short... indefinite quantity contracts that are a combination of contract types. Rather than using the...

  8. 48 CFR 1817.204 - Contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Contracts. 1817.204 Section... CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 1817.204 Contracts. (e)(i) The 5-year limitation (basic plus option periods) applies to all NASA contracts regardless of type and...

  9. 48 CFR 3417.70 - Modular contracting.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Modular contracting. 3417... REGULATION CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Modular Contracting 3417.70 Modular contracting. (a) FSA—May incrementally conduct successive procurements of modules of...

  10. 48 CFR 417.204 - Contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 4 2012-10-01 2012-10-01 false Contracts. 417.204 Section 417.204 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 417.204 Contracts. The head of the contracting...

  11. 48 CFR 17.204 - Contracts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Contracts. 17.204 Section 17.204 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 17.204 Contracts. (a) The contract shall specify...

  12. 48 CFR 17.204 - Contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Contracts. 17.204 Section 17.204 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 17.204 Contracts. (a) The contract shall specify...

  13. 48 CFR 2017.204 - Contracts

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Contracts 2017.204 Section 2017.204 Federal Acquisition Regulations System NUCLEAR REGULATORY COMMISSION CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 2017.204 Contracts (a) The contracting officer...

  14. 48 CFR 17.204 - Contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Contracts. 17.204 Section 17.204 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 17.204 Contracts. (a) The contract shall specify...

  15. 24 CFR 881.501 - The contract.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 4 2014-04-01 2014-04-01 false The contract. 881.501 Section 881... Payments Contract § 881.501 The contract. (a) Contract. The Housing Assistance Payments Contract sets forth rights and duties of the owner and the contract administrator with respect to the project and the...

  16. 48 CFR 732.111 - Contract clauses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clauses. 732.111... CONTRACTING REQUIREMENTS CONTRACT FINANCING General 732.111 Contract clauses. (a) (b) USAID may obtain short... indefinite quantity contracts that are a combination of contract types. Rather than using the...

  17. 48 CFR 17.109 - Contract clauses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Contract clauses. 17.109 Section 17.109 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Multiyear Contracting 17.109 Contract clauses. (a)...

  18. 48 CFR 3437.670 - Contract type.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Contract type. 3437.670... SPECIAL CATEGORIES OF CONTRACTING SERVICE CONTRACTING Performance-Based Acquisition 3437.670 Contract type. Award-term contracting may be used for performance-based contracts and task orders that...

  19. 48 CFR 916.307 - Contract clauses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Contract clauses. 916.307 Section 916.307 Federal Acquisition Regulations System DEPARTMENT OF ENERGY CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Cost-Reimbursement Contracts 916.307 Contract clauses. (a)...

  20. 48 CFR 916.307 - Contract clauses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Contract clauses. 916.307 Section 916.307 Federal Acquisition Regulations System DEPARTMENT OF ENERGY CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Cost-Reimbursement Contracts 916.307 Contract clauses. (a)...

  1. 48 CFR 916.307 - Contract clauses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Contract clauses. 916.307 Section 916.307 Federal Acquisition Regulations System DEPARTMENT OF ENERGY CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Cost-Reimbursement Contracts 916.307 Contract clauses. (a)...

  2. 48 CFR 916.307 - Contract clauses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Contract clauses. 916.307 Section 916.307 Federal Acquisition Regulations System DEPARTMENT OF ENERGY CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Cost-Reimbursement Contracts 916.307 Contract clauses. (a)...

  3. 48 CFR 2442.1107 - Contract clause.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., Contract Management System, in solicitations and contracts when all of the following conditions apply: (1... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Contract clause. 2442.1107... CONTRACT MANAGEMENT CONTRACT ADMINISTRATION Production Surveillance and Reporting 2442.1107 Contract...

  4. 48 CFR 4.802 - Contract files.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Contract files. 4.802... MATTERS Government Contract Files 4.802 Contract files. (a) A contract file should generally consist of— (1) The contracting office contract file, that documents the basis for the acquisition and the...

  5. Computational modeling of the human atrial anatomy and electrophysiology.

    PubMed

    Dössel, Olaf; Krueger, Martin W; Weber, Frank M; Wilhelms, Mathias; Seemann, Gunnar

    2012-08-01

    This review article gives a comprehensive survey of the progress made in computational modeling of the human atria during the last 10 years. Modeling the anatomy has emerged from simple "peanut"-like structures to very detailed models including atrial wall and fiber direction. Electrophysiological models started with just two cellular models in 1998. Today, five models exist considering e.g. details of intracellular compartments and atrial heterogeneity. On the pathological side, modeling atrial remodeling and fibrotic tissue are the other important aspects. The bridge to data that are measured in the catheter laboratory and on the body surface (ECG) is under construction. Every measurement can be used either for model personalization or for validation. Potential clinical applications are briefly outlined and future research perspectives are suggested.

  6. Electrophysiological correlates of language switching in second language learners.

    PubMed

    Van Der Meij, Maartje; Cuetos, Fernando; Carreiras, Manuel; Barber, Horacio A

    2011-01-01

    This study analyzed the electrophysiological correlates of language switching in second language learners. Participants were native Spanish speakers classified in two groups according to English proficiency (high and low). Event-related potentials (ERPs) were recorded while they read English sentences, half of which contained an adjective in Spanish in the middle of the sentence. The ERP results show the time-course of language switch processing for both groups: an initial detection of the switch driven by language-specific orthography (left-occipital N250) followed by costs at the level of the lexico-semantic system (N400), and finally a late updating or reanalysis process (LPC). In the high proficiency group, effects in the N400 time window extended to left anterior electrodes and were followed by larger LPC amplitudes at posterior sites. These differences suggest that proficiency modulates the different processes triggered by language switches.

  7. Electrophysiological assessment of amiodarone in treatment of resistant supraventricular arrhythmias.

    PubMed Central

    Rowland, E; Krikler, D M

    1980-01-01

    Oral amiodarone has been used to treat 21 patients with various supraventricular arrhythmias; 13 had Wolff-Parkinson-White syndrome, which was complicated by atrial fibrillation and re-entry atrioventricular tachycardia in four, and re-entry tachycardia alone in the other nine. The remaining eight patients had paroxysmal atrial fibrillation or flutter without pre-excitation. All were refractory to conventional treatment and had undergone intracardiac electrophysiological study. Fifteen have been controlled with amiodarone, this treatment proving most effective in atrial fibrillation or flutter with or without pre-excitation. Amiodarone was successful in only four of the nine patients with re-entry atrioventricular tachycardia. In two patients who responded well the drug had to be discontinued because of side effects. Images PMID:7426165

  8. The sense of smell in Odonata: an electrophysiological screening.

    PubMed

    Piersanti, Silvana; Frati, Francesca; Conti, Eric; Rebora, Manuela; Salerno, Gianandrea

    2014-11-01

    Volatile chemicals mediate a great range of intra- and interspecific signalling and information in insects. Olfaction has been widely investigated mostly in Neoptera while the knowledge of this sense in most basal insects such as Paleoptera (Odonata and Ephemeroptera) is still poor. In the present study we show the results of an electrophysiological screening on two model species, Libellula depressa (Libellulidae) and Ischnura elegans (Coenagrionidae), representatives of the two Odonata suborders Anisoptera and Zygoptera, with the aim to deep the knowledge on the sense of smell of this insect order. The antennal olfactory sensory neurons (OSNs) of these two species responded to the same 22 compounds (out of 48 chemicals belonging to different functional groups) encompassing mostly amines, carboxylic acids or aldehydes and belonging to green leaf volatiles, vertebrate related volatiles and volatiles emitted by standing waters bacteria. The properties of Odonata OSNs are very similar to those of ionotropic receptors (IRs) expressing OSNs in other insects.

  9. Affective Priming by Eye Gaze Stimuli: Behavioral and Electrophysiological Evidence

    PubMed Central

    Chen, Tingji; Peltola, Mikko J.; Ranta, Lotta J.; Hietanen, Jari K.

    2016-01-01

    The present study employed the affective priming paradigm and measurements of event-related potentials (ERPs) to investigate implicit affective reactions elicited by gaze stimuli. Participants categorized positive and negative words primed by direct gaze, averted gaze and closed eyes. The behavioral response time (RT) results indicated that direct gaze implicitly elicited more positive affective reactions than did closed eyes. Analyses of the ERP responses to the target words revealed a priming effect on the N170 and an interaction on late positive potential (LPP) responses, and congruently with the behavioral results, suggested that, compared to closed eyes, direct gaze was affectively more congruent with positive words and more incongruent with negative words. The priming effect on the N170 response indicated that gaze stimuli influenced the subsequent affective word processing at an early stage of information processing. In conclusion, the present behavioral and electrophysiological evidence suggests that direct gaze automatically activates more positive affective reactions than closed eyes. PMID:28003803

  10. Electrophysiological ratio markers for the balance between reward and punishment.

    PubMed

    Schutter, Dennis J L G; Van Honk, Jack

    2005-08-01

    It has been argued that prototypical forms of psychopathology result from an imbalance in reward and punishment systems. Recent studies suggest that the ratios between slower and faster waves of the electroencephalogram (EEG) index this motivational balance and might therefore have diagnostic value for psychopathology. To scrutinize this notion, the present study investigated whether resting state EEG ratios would predict decision making on the Iowa gambling task (Iowa-GT), a well-known marker for motivational imbalance. A resting state EEG recording was acquired followed by the Iowa-GT in twenty-eight healthy right-handed volunteers. Results showed that higher versus lower EEG ratios were associated with disadvantageous versus advantageous decision making strategies indicating motivational imbalances in reward- and punishment-driven behavior, respectively. This finding provides the first direct evidence that the electrophysiologically derived EEG ratios can serve as biological markers for balance and imbalance in motivation.

  11. Reentry confined to the atrioventricular node: electrophysiologic and anatomic findings.

    PubMed

    Sheinman, M M; Gonzalez, R; Thomas, A; Ullyot, D; Bharati, S; Lev, M

    1982-05-01

    A patient with recurrent disabling, paroxysmal supraventricular tachycardia refractory to drug treatment underwent electrophysiologic studies. The paroxysmal supraventricular tachycardia was found to be due to atrioventricular (A-V) nodal reentry. The patient died shortly after surgical His bundle section and detailed anatomic studies were performed. These showed fatty infiltration of the approaches to the sinoatrial node, atrial preferential pathways, and A-V node and common bundle. The A-V node was mechanically damaged and the common His bundle was completely severed. These abnormalities were clearly delineated and there was no evidence of an atrio-His bundle bypass tract to an accessory A-V node. Specifically, the central fibrous body and pars membranacea were defined and no atrial muscular fibers pierced these structures to joint the A-V bundle. It is concluded that paroxysmal supraventricular tachycardia due to A-V nodal reentry can be confined to the A-V node.

  12. Low-energy x-ray irradiation for electrophysiological studies

    SciTech Connect

    Schauer, D.A.; Zeman, G.H.; Pellmar, T.C.

    1989-01-01

    High-dose-rate acute whole-body exposures have been the main focus of radiobiology research conducted at the Armed Forces Radiobiology Research Institute (AFRRI) for many years. Extensive quantitative studies have been conducted analyzing behavioral effects, radiation-induced syndromes, and combined injury phenomena. Tolliver and Pellmar initiated a study to evaluate radiation damage to brain neurophysiology. A 50-kVp molybdenum target/filter x-ray tube was installed inside a lead-shielded Faraday cage. High-dose rates of up to 1.54 Gy/min (17.4-keV weighted average photons) were used to conduct local in vitro irradiations of the hippocampal region of guinea pig brains. Electrophysiological recordings of subtle changes in neuronal activity indicate this system is suitable for this application.

  13. Electrophysiological assessment of brain function in severe malnutrition.

    PubMed

    Robinson, S; Young, R E; Golden, M H

    1995-11-01

    Brain function in 10 severely malnourished children and matched controls was assessed using spectral analysis of electroencephalographic responses to photic driving during slow-wave sleep. The percentage power in the classical EEG broad-band domains was derived from temporo-occipital records. The malnourished group (5-23 months old; z-score height-for-age -3.2 +/- 0.3, weight-for-height -2.5 +/- 0.3) were tested on admission and on discharge from hospital. No significant differences were found between admission and discharge. Significant differences were found between malnourished and control groups, in the alpha 1 band in the undriven EEG, and in the alpha/beta 1 power ratio while driving at 8 Hz. These electrophysiological abnormalities, persisting despite somatic rehabilitation, must be associated with the chronic rather than the acute aspects of malnutrition, and can index the deviation of brain function from normality.

  14. Characteristics of the electrophysiological activity of muscles attached to the transverse carpal ligament in carpal tunnel syndrome.

    PubMed

    Horiguchi, Gen; Aoki, Takafumi; Ito, Hiromoto

    2011-01-01

    The main cause of carpal tunnel syndrome (CTS) remains unknown. Stiffness of the subcutaneous area of the volar aspect of the carpal tunnel is present in many patients and suggests that the stiffness of muscles attached to the transverse carpal ligament is increased. We performed an electrophysiological study to investigate muscle activities and to clarify whether the stiffness of muscles attached to the transverse carpal ligament is involved in the pathogenesis of CTS. The subjects of this study included 16 patients with early CTS showing no motor dysfunction. Both thenar muscles (opponens pollicis, abductor pollicis brevis, and flexor pollicis brevis) and hypothenar muscles (opponens digiti minimi, abductor digiti minimi, flexor digiti minimi brevis) were investigated. Surface electrodes were placed on each muscle, and maximum voluntary contractions with the thumb and little finger in opposition were maintained for 3 seconds in all patients and in 7 control subjects. Electromyographs were subjected to fast Fourier transform analysis, and the root mean square (RMS) and the mean power frequency (MPF) were determined for each muscle. The RMS of the opponens pollicis was significantly less in hands affected by CTS (292.8 µV) than in healthy hands (405.9 µV). The RMS did not differ between affected hands and healthy hands for the other 2 thenar muscles but did differ significantly for the hypothenar muscles. The MPF did not differ between affected hands and healthy hands for any muscle. The results show that electrophysiological differences are present among muscles innervated by the median nerve and that hypothenar muscles originally unrelated to median nerve dysfunction are also affected in early CTS. These results suggest that modulation of muscles attached to the transverse carpal ligament is involved in the pathogenesis of CTS.

  15. Analysis of multiple sclerosis patients with electrophysiological and structural tests.

    PubMed

    Hamurcu, Mualla; Orhan, Gürdal; Sarıcaoğlu, Murat Sinan; Mungan, Semra; Duru, Zeynep

    2016-08-18

    We aimed to analyze the effects of progressive myelin loss and neurodegeneration seen in patients with multiple sclerosis (MS) on visual tract with electrophysiological and structural tests. Fifty-one patients diagnosed with MS in the Neurology Department were followed up in neuro-ophthalmology outpatient clinic irrespective of their visual symptoms, and were included in our study. The patients were classified as the ones with the history of optic neuritis (group II) and ones without the history (group I) of optic neuritis. The data, including clinical presentation, retinal nerve fiber layer thickness (RNFLT) measurements, pattern visual evoked potential (pVEP) and flash electro retino grams (ERG) test results, were recorded. In our study, comparison of pVEP test latencies of groups I and II with each other, and with those of healthy subjects revealed statistically significant differences (p < 0.05). The analysis of rod functions on ERG did not show any significant changes (p > 0.05). However, both groups showed significantly decreased cone b-wave amplitudes, elongation of latencies, and decreased flicker amplitudes on cone and flicker potentials obtained after light adaptation (p < 0.05). There was significant thinning in RNFLT of the both groups when compared to the normal standards. The difference between two groups was statistically significant (p < 0.05). Axon loss is seen in the optic nerve with subclinical or acute optic neuritis in patients with MS. RNFLT analysis and electrophysiological tests are of great importance in diagnosis of MS, as well as to determine progression and to direct neuroprotective therapy in patients diagnosed with MS. Objective analysis methods gain more importance in the diagnosis and follow-up of MS patients, parallel to technological advancements.

  16. Electrophysiological evaluation of oropharyngeal swallowing in myotonic dystrophy

    PubMed Central

    Ertekin, C; Yuceyar, N; Aydogdu, I; Karasoy, H

    2001-01-01

    OBJECTIVE—Oropharyngeal dysphagia is a common feature of patients with myotonic dystrophy and is not usually perceived due to their emotional deficits and lack of interest. The aim was to show the existence and frequency of subclinical electrophysiological abnormalities in oropharyngeal swallowing and to clarify the mechanisms of dysphagia in myotonic dystrophy.
METHODS—Eighteen patients with myotonic dystrophy were examined for oropharyngeal phase of swallowing by clinical and electrophysiological methods. Ten patients had dysphagia whereas 11 patients had signs and symptoms reflecting CNS involvement. Four patients with myotonia congenita and 30 healthy volunteers served as controls. Laryngeal movements were detected by means of a piezoelectric sensor. EMG activities of the submental muscle (SM-EMG) and needle EMG of the cricopharyngeal muscle of the upper eosophageal sphincter (CP-EMG) were also recorded during swallowing.
RESULTS—In about 70% of the patients with myotonic dystrophy, the existence of oropharyngeal dysphagia was indicated objectively by means of the technique of "dysphagia limit" and by clinical evaluation. Duration of the swallowing reflex as defined by the laryngeal relocation time (0-2 time interval) and submental muscle excitation as a part of the swallowing reflex (A-C interval) were significantly prolonged in patients with myotonic dystrophy, especially in dysphagic patients. Triggering time of the swallowing reflex (A-0 interval) also showed significant prolongation, especially in the patients having both dysphagia and CNS involvement. During swallowing, CP muscle activity was abnormal in 40% of the patients with myotonic dystrophy.
CONCLUSION—Both myopathic weakness and myotonia encountered in oropharyngeal muscles play an important part in the oral and the pharyngeal phases of swallowing dysfunction in myotonic dystrophy. It was also suggested that CNS involvement might contribute to the delay of the triggering of the

  17. Ganzfeld-induced hallucinatory experience, its phenomenology and cerebral electrophysiology.

    PubMed

    Wackermann, Jirí; Pütz, Peter; Allefeld, Carsten

    2008-01-01

    Ganzfeld, i.e., exposure to an unstructured, uniform stimulation field, elicits in most observers pseudo-hallucinatory percepts, and may even induce global functional state changes ('altered states of consciousness'). The present paper gives a comprehensive overview of the phenomenology of subjective experience in the ganzfeld and its electrophysiological correlates. Laboratory techniques for visual or multi-modal ganzfeld induction are explained. The spectrum of ganzfeld-induced phenomena, ranging from elementary percepts to complex, vivid, dream-like imagery is described, and the latter illustrated by transcripts of subjects' reports. Similarities and differences to related sensory/perceptual phenomena are also discussed. Earlier findings on electrophysiological correlates of the ganzfeld are reviewed. Our own studies of electroencephalographic (EEG) activity in the ganzfeld are presented in some detail, and a re-analysis of data on EEG correlates of hallucinatory percepts in statu nascendi is reported. The results do not support the hypothesis of the hypnagogic origin of the percepts; the ganzfeld-induced steady-state is an activated state, and the spectral EEG dynamics in the alpha frequency range reveals processes of attention shifts and percept formation. The final section is devoted to the controversial topic of allegedly anomalous communication between human subjects ('ganzfeld telepathy'). It is shown that the use of ganzfeld in this research field relies partly on unsupported hypotheses concerning ganzfeld-induced states, partly on a weak conceptual background of the experimental procedure. The rôle of a particular belief system shared by the participants and experimenters is critically discussed.

  18. Impact of ionic current variability on human ventricular cellular electrophysiology.

    PubMed

    Romero, Lucía; Pueyo, Esther; Fink, Martin; Rodríguez, Blanca

    2009-10-01

    Abnormalities in repolarization and its rate dependence are known to be related to increased proarrhythmic risk. A number of repolarization-related electrophysiological properties are commonly used as preclinical biomarkers of arrhythmic risk. However, the variability and complexity of repolarization mechanisms make the use of cellular biomarkers to predict arrhythmic risk preclinically challenging. Our goal is to investigate the role of ionic current properties and their variability in modulating cellular biomarkers of arrhythmic risk to improve risk stratification and identification in humans. A systematic investigation into the sensitivity of the main preclinical biomarkers of arrhythmic risk to changes in ionic current conductances and kinetics was performed using computer simulations. Four stimulation protocols were applied to the ten Tusscher and Panfilov human ventricular model to quantify the impact of +/-15 and +/-30% variations in key model parameters on action potential (AP) properties, Ca(2+) and Na(+) dynamics, and their rate dependence. Simulations show that, in humans, AP duration is moderately sensitive to changes in all repolarization current conductances and in L-type Ca(2+) current (I(CaL)) and slow component of the delayed rectifier current (I(Ks)) inactivation kinetics. AP triangulation, however, is strongly dependent only on inward rectifier K(+) current (I(K1)) and delayed rectifier current (I(Kr)) conductances. Furthermore, AP rate dependence (i.e., AP duration rate adaptation and restitution properties) and intracellular Ca(2+) and Na(+) levels are highly sensitive to both I(CaL) and Na(+)/K(+) pump current (I(NaK)) properties. This study provides quantitative insights into the sensitivity of preclinical biomarkers of arrhythmic risk to variations in ionic current properties in humans. The results show the importance of sensitivity analysis as a powerful method for the in-depth validation of mathematical models in cardiac electrophysiology.

  19. [Oral propranolol in Wolff-Parkinson-White syndrome. Electrophysiological data].

    PubMed

    Dolla, E; Levy, S; Cointe, R; Moyal, C; Bru, P; Rossi, P; Gérard, R

    1991-07-01

    The effects of oral propranolol were studied in 24 patients with the WPW syndrome. The average daily dose of propranolol was 130 +/- 24 mg administered in 3 doses over a period of 48 to 72 hours. Endocavitary electrophysiological study was performed 2 to 4 hours after the last dose. The effective anterograde refractory periods (EARP) of the accessory and normal pathways were measured before and after propranolol (and, in both studies, before and after isoproterenol). The EARP of the accessory pathway was not affected by the propranolol. However, in the 9 patients in whom its value was less than 270 ms, it increased significantly (p = 0.01). The EARP of the accessory pathway measured after administration of isoproterenol increased significantly in all patients with oral propranolol (p = 0.001). Sustained reciprocating tachycardia could be induced in 19 patients and non-sustained reciprocating tachycardia in 5 other patients during base line electrophysiological study. Oral propranolol prevented the induction of the tachycardias in 18 patients (75%), even after isoproterenol. The shortest R-R interval between two pre-excited complexes in atrial fibrillation increased after propranolol (283 +/- 45 to 343 +/- 95 ms). These results show that oral propranolol increases the EARP of the accessory pathway and the shortest R-R interval between two pre-excited complexes in atrial fibrillation in patients with short anterograde refractory periods of their accessory pathways, and is effective in preventing reciprocating tachycardia. Oral propranolol may be useful and can be used safely in patients with the Wolff-Parkinson-White syndrome.

  20. A Wireless Headstage for Combined Optogenetics and Multichannel Electrophysiological Recording.

    PubMed

    Gagnon-Turcotte, Gabriel; LeChasseur, Yoan; Bories, Cyril; Messaddeq, Younes; De Koninck, Yves; Gosselin, Benoit

    2017-02-01

    This paper presents a wireless headstage with real-time spike detection and data compression for combined optogenetics and multichannel electrophysiological recording. The proposed headstage, which is intended to perform both optical stimulation and electrophysiological recordings simultaneously in freely moving transgenic rodents, is entirely built with commercial off-the-shelf components, and includes 32 recording channels and 32 optical stimulation channels. It can detect, compress and transmit full action potential waveforms over 32 channels in parallel and in real time using an embedded digital signal processor based on a low-power field programmable gate array and a Microblaze microprocessor softcore. Such a processor implements a complete digital spike detector featuring a novel adaptive threshold based on a Sigma-delta control loop, and a wavelet data compression module using a new dynamic coefficient re-quantization technique achieving large compression ratios with higher signal quality. Simultaneous optical stimulation and recording have been performed in-vivo using an optrode featuring 8 microelectrodes and 1 implantable fiber coupled to a 465-nm LED, in the somatosensory cortex and the Hippocampus of a transgenic mouse expressing ChannelRhodospin (Thy1::ChR2-YFP line 4) under anesthetized conditions. Experimental results show that the proposed headstage can trigger neuron activity while collecting, detecting and compressing single cell microvolt amplitude activity from multiple channels in parallel while achieving overall compression ratios above 500. This is the first reported high-channel count wireless optogenetic device providing simultaneous optical stimulation and recording. Measured characteristics show that the proposed headstage can achieve up to 100% of true positive detection rate for signal-to-noise ratio (SNR) down to 15 dB, while achieving up to 97.28% at SNR as low as 5 dB. The implemented prototype features a lifespan of up to 105

  1. The antiarrhythmic and cardiac electrophysiological effects of buprenorphine.

    PubMed Central

    Boachie-Ansah, G.; Sitsapesan, R.; Kane, K. A.; Parratt, J. R.

    1989-01-01

    1. The effects of buprenorphine, given intravenously, on the incidence and severity of early acute coronary artery occlusion-induced arrhythmias were examined in anaesthetised rats. The electrophysiological effects of buprenorphine were also examined in sheep Purkinje fibres and rat papillary muscles, superfused in vitro with either a normal or a hypoxic, hyperkalaemic and acidotic physiological salt solution (PSS). 2. In anaesthetised rats subjected to acute coronary artery occlusion, pretreatment with buprenorphine (1 mg kg-1 i.v.) markedly reduced the incidence of ventricular extra-systoles during the initial 30 min post-occlusion period. The incidence of ventricular fibrillation (VF) was also significantly reduced from 56% to 10%. 3. At the antiarrhythmic dose (1 mg kg -1), buprenorphine also attenuated the sudden fall in systemic arterial blood pressure induced by acute coronary artery ligation. 4. In normal sheep Purkinje fibres and rat papillary muscles, buprenorphine (10(-6)-10(-5) M) significantly reduced the action potential height and maximum rate of depolarisation of phase zero (MRD) and prolonged the duration of the action potential. 5. Superfusion of sheep Purkinje fibres and rat papillary muscles with a hypoxic, hyperkalaemic and acidotic PSS resulted in marked reductions in resting membrane potential, upstroke and duration of the action potential. 6. In the presence of the modified compared with normal PSS, buprenorphine reduced the action potential height and MRD of both sheep Purkinje fibres and rat papillary muscles to a greater extent, although its ability to prolong the action potential duration was attenuated. 7. The antiarrhythmic effects of buprenorphine observed in vivo may be explained by its direct cardiac electrophysiological effects.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2758241

  2. Simultaneous FMRI and electrophysiology in the rodent brain.

    PubMed

    Pan, Wen-ju; Thompson, Garth; Magnuson, Matthew; Majeed, Waqas; Jaeger, Dieter; Keilholz, Shella

    2010-08-19

    To examine the neural basis of the blood oxygenation level dependent (BOLD) magnetic resonance imaging (MRI) signal, we have developed a rodent model in which functional MRI data and in vivo intracortical recording can be performed simultaneously. The combination of MRI and electrical recording is technically challenging because the electrodes used for recording distort the MRI images and the MRI acquisition induces noise in the electrical recording. To minimize the mutual interference of the two modalities, glass microelectrodes were used rather than metal and a noise removal algorithm was implemented for the electrophysiology data. In our studies, two microelectrodes were separately implanted in bilateral primary somatosensory cortices (SI) of the rat and fixed in place. One coronal slice covering the electrode tips was selected for functional MRI. Electrode shafts and fixation positions were not included in the image slice to avoid imaging artifacts. The removed scalp was replaced with toothpaste to reduce susceptibility mismatch and prevent Gibbs ringing artifacts in the images. The artifact structure induced in the electrical recordings by the rapidly-switching magnetic fields during image acquisition was characterized by averaging all cycles of scans for each run. The noise structure during imaging was then subtracted from original recordings. The denoised time courses were then used for further analysis in combination with the fMRI data. As an example, the simultaneous acquisition was used to determine the relationship between spontaneous fMRI BOLD signals and band-limited intracortical electrical activity. Simultaneous fMRI and electrophysiological recording in the rodent will provide a platform for many exciting applications in neuroscience in addition to elucidating the relationship between the fMRI BOLD signal and neuronal activity.

  3. Health contract in the classroom.

    PubMed

    Haber, David

    2007-01-01

    A health contract is a technique used by health professionals to help clients achieve a health goal. This article describes a course, "Changing Health Behaviors," in which a health contract strategy is taught and practiced with older adults. The health contract can also be included as a smaller educational component within a gerontology course that covers risk factors such as sedentary behavior or nutritional deficiency, counseling or health education techniques, or program development. Gerontology students who complete a degree or certificate program may enter a variety of venues in which a health contract can be a useful tool with older clients.

  4. Uterine Contraction Modeling and Simulation

    NASA Technical Reports Server (NTRS)

    Liu, Miao; Belfore, Lee A.; Shen, Yuzhong; Scerbo, Mark W.

    2010-01-01

    Building a training system for medical personnel to properly interpret fetal heart rate tracing requires developing accurate models that can relate various signal patterns to certain pathologies. In addition to modeling the fetal heart rate signal itself, the change of uterine pressure that bears strong relation to fetal heart rate and provides indications of maternal and fetal status should also be considered. In this work, we have developed a group of parametric models to simulate uterine contractions during labor and delivery. Through analysis of real patient records, we propose to model uterine contraction signals by three major components: regular contractions, impulsive noise caused by fetal movements, and low amplitude noise invoked by maternal breathing and measuring apparatus. The regular contractions are modeled by an asymmetric generalized Gaussian function and least squares estimation is used to compute the parameter values of the asymmetric generalized Gaussian function based on uterine contractions of real patients. Regular contractions are detected based on thresholding and derivative analysis of uterine contractions. Impulsive noise caused by fetal movements and low amplitude noise by maternal breathing and measuring apparatus are modeled by rational polynomial functions and Perlin noise, respectively. Experiment results show the synthesized uterine contractions can mimic the real uterine contractions realistically, demonstrating the effectiveness of the proposed algorithm.

  5. Convergence of circuit dysfunction in ASD: a common bridge between diverse genetic and environmental risk factors and common clinical electrophysiology

    PubMed Central

    Port, Russell G.; Gandal, Michael J.; Roberts, Timothy P. L.; Siegel, Steven J.; Carlson, Gregory C.

    2014-01-01

    Most recent estimates indicate that 1 in 68 children are affected by an autism spectrum disorder (ASD). Though decades of research have uncovered much about these disorders, the pathological mechanism remains unknown. Hampering efforts is the seeming inability to integrate findings over the micro to macro scales of study, from changes in molecular, synaptic and cellular function to large-scale brain dysfunction impacting sensory, communicative, motor and cognitive activity. In this review, we describe how studies focusing on neuronal circuit function provide unique context for identifying common neurobiological disease mechanisms of ASD. We discuss how recent EEG and MEG studies in subjects with ASD have repeatedly shown alterations in ensemble population recordings (both in simple evoked related potential latencies and specific frequency subcomponents). Because these disease-associated electrophysiological abnormalities have been recapitulated in rodent models, studying circuit differences in these models may provide access to abnormal circuit function found in ASD. We then identify emerging in vivo and ex vivo techniques, focusing on how these assays can characterize circuit level dysfunction and determine if these abnormalities underlie abnormal clinical electrophysiology. Such circuit level study in animal models may help us understand how diverse genetic and environmental risks can produce a common set of EEG, MEG and anatomical abnormalities found in ASD. PMID:25538564

  6. Convergence of circuit dysfunction in ASD: a common bridge between diverse genetic and environmental risk factors and common clinical electrophysiology.

    PubMed

    Port, Russell G; Gandal, Michael J; Roberts, Timothy P L; Siegel, Steven J; Carlson, Gregory C

    2014-01-01

    Most recent estimates indicate that 1 in 68 children are affected by an autism spectrum disorder (ASD). Though decades of research have uncovered much about these disorders, the pathological mechanism remains unknown. Hampering efforts is the seeming inability to integrate findings over the micro to macro scales of study, from changes in molecular, synaptic and cellular function to large-scale brain dysfunction impacting sensory, communicative, motor and cognitive activity. In this review, we describe how studies focusing on neuronal circuit function provide unique context for identifying common neurobiological disease mechanisms of ASD. We discuss how recent EEG and MEG studies in subjects with ASD have repeatedly shown alterations in ensemble population recordings (both in simple evoked related potential latencies and specific frequency subcomponents). Because these disease-associated electrophysiological abnormalities have been recapitulated in rodent models, studying circuit differences in these models may provide access to abnormal circuit function found in ASD. We then identify emerging in vivo and ex vivo techniques, focusing on how these assays can characterize circuit level dysfunction and determine if these abnormalities underlie abnormal clinical electrophysiology. Such circuit level study in animal models may help us understand how diverse genetic and environmental risks can produce a common set of EEG, MEG and anatomical abnormalities found in ASD.

  7. Cloudwave: Distributed Processing of “Big Data” from Electrophysiological Recordings for Epilepsy Clinical Research Using Hadoop

    PubMed Central

    Jayapandian, Catherine P.; Chen, Chien-Hung; Bozorgi, Alireza; Lhatoo, Samden D.; Zhang, Guo-Qiang; Sahoo, Satya S.

    2013-01-01

    Epilepsy is the most common serious neurological disorder affecting 50–60 million persons worldwide. Multi-modal electrophysiological data, such as electroencephalography (EEG) and electrocardiography (EKG), are central to effective patient care and clinical research in epilepsy. Electrophysiological data is an example of clinical “big data” consisting of more than 100 multi-channel signals with recordings from each patient generating 5–10GB of data. Current approaches to store and analyze signal data using standalone tools, such as Nihon Kohden neurology software, are inadequate to meet the growing volume of data and the need for supporting multi-center collaborative studies with real time and interactive access. We introduce the Cloudwave platform in this paper that features a Web-based intuitive signal analysis interface integrated with a Hadoop-based data processing module implemented on clinical data stored in a “private cloud”. Cloudwave has been developed as part of the National Institute of Neurological Disorders and Strokes (NINDS) funded multi-center Prevention and Risk Identification of SUDEP Mortality (PRISM) project. The Cloudwave visualization interface provides real-time rendering of multi-modal signals with “montages” for EEG feature characterization over 2TB of patient data generated at the Case University Hospital Epilepsy Monitoring Unit. Results from performance evaluation of the Cloudwave Hadoop data processing module demonstrate one order of magnitude improvement in performance over 77GB of patient data. (Cloudwave project: http://prism.case.edu/prism/index.php/Cloudwave) PMID:24551370

  8. AN ELECTROPHYSIOLOGICAL INVESTIGATION OF NEUROMUSCULAR TRANSMISSION IN MYASTHENIA GRAVIS,

    DTIC Science & Technology

    with myasthenia gravis . With repetitive nerve stimulation at frequencies above 2/sec, only the first few stimuli elicited muscle contractions in most...It is tentatively concluded that in myasthenia gravis there is a deficiency in the amount of ACh in the quanta of transmitter released from the motor nerve terminals. (Author)

  9. Performance Problems in Service Contracting

    DTIC Science & Technology

    1988-01-01

    technical manual for the U.S. Army. Contract types have run the gamut from firm fixed price to various forms of cost plus arrangements, and award has been...in a National Forest to producing a technical manual for the U.S. Army. Contract types have run the gamut from firm fixed price to various forms of

  10. Profitability Implications of Sustainable Contracting

    DTIC Science & Technology

    2006-08-01

    PROFITABILITY IFUCATIONS OF SUSTAINABLE CONTRACTING BY Dude L Underwood LT, CEC, USN DISTRIBUTION STATEMEMT A Approved for Public Release...Lafayette, Indiana 47907-2051 PROFITABILITY IMPLICATIONS OF SUSTAINABLE CONTRACTING An Independent Research Study Submitted to the Faculty of Purdue...27 iv 4.2. Business Ratio Com parison ................................................................. 27 4.3. Net Profit M argin Com parison

  11. Policing Mechanisms in Agricultural Contracts

    ERIC Educational Resources Information Center

    Wolf, Steven; Hueth, Brent; Ligon, Ethan

    2001-01-01

    In this paper we focus on mechanisms of coordination in agricultural contracts. Our approach is intended to advance understanding of social relations of production and distribution of power in agrofood systems. Through an analysis of contracts between farmers and intermediaries (e.g., processors, shippers, consignment agents) for California fruits…

  12. Two Views on Performance Contracting.

    ERIC Educational Resources Information Center

    Lurie, Sylvia; Smith, Kenneth

    1996-01-01

    North Chicago, Illinois, District 187, received a districtwide overhaul of lighting, heating, ventilation, and security systems through a 10-year performance contract with the Honeywell Corporation. The Briarcliff Manor Union-Free School District, New York, has a contract with Johnson Controls that guarantees a portion of the energy savings…

  13. Contract Education: A Background Paper.

    ERIC Educational Resources Information Center

    California Community Colleges, Sacramento. Academic Senate.

    Today contract education is generally thought of as a program or course for which an employer is paying the full cost of instruction for customized training. Contract education can help faculty remain current, encourage industry to make equipment available to the college that might otherwise be too expensive, and provide employment opportunities…

  14. Neural control of lengthening contractions.

    PubMed

    Duchateau, Jacques; Enoka, Roger M

    2016-01-01

    A number of studies over the last few decades have established that the control strategy employed by the nervous system during lengthening (eccentric) differs from those used during shortening (concentric) and isometric contractions. The purpose of this review is to summarize current knowledge on the neural control of lengthening contractions. After a brief discussion of methodological issues that can confound the comparison between lengthening and shortening actions, the review provides evidence that untrained individuals are usually unable to fully activate their muscles during a maximal lengthening contraction and that motor unit activity during submaximal lengthening actions differs from that during shortening actions. Contrary to common knowledge, however, more recent studies have found that the recruitment order of motor units is similar during submaximal shortening and lengthening contractions, but that discharge rate is systematically lower during lengthening actions. Subsequently, the review examines the mechanisms responsible for the specific control of maximal and submaximal lengthening contractions as reported by recent studies on the modulation of cortical and spinal excitability. As similar modulation has been observed regardless of contraction intensity, it appears that spinal and corticospinal excitability are reduced during lengthening compared with shortening and isometric contractions. Nonetheless, the modulation observed during lengthening contractions is mainly attributable to inhibition at the spinal level.

  15. CONTRACT ADMINISTRATIVE TRACKING SYSTEM (CATS)

    EPA Science Inventory

    The Contract Administrative Tracking System (CATS) was developed in response to an ORD NHEERL, Mid-Continent Ecology Division (MED)-recognized need for an automated tracking and retrieval system for Cost Reimbursable Level of Effort (CR/LOE) Contracts. CATS is an Oracle-based app...

  16. A scalable neuroinformatics data flow for electrophysiological signals using MapReduce.

    PubMed

    Jayapandian, Catherine; Wei, Annan; Ramesh, Priya; Zonjy, Bilal; Lhatoo, Samden D; Loparo, Kenneth; Zhang, Guo-Qiang; Sahoo, Satya S

    2015-01-01

    Data-driven neuroscience research is providing new insights in progression of neurological disorders and supporting the development of improved treatment approaches. However, the volume, velocity, and variety of neuroscience data generated from sophisticated recording instruments and acquisition methods have exacerbated the limited scalability of existing neuroinformatics tools. This makes it difficult for neuroscience researchers to effectively leverage the growing multi-modal neuroscience data to advance research in serious neurological disorders, such as epilepsy. We describe the development of the Cloudwave data flow that uses new data partitioning techniques to store and analyze electrophysiological signal in distributed computing infrastructure. The Cloudwave data flow uses MapReduce parallel programming algorithm to implement an integrated signal data processing pipeline that scales with large volume of data generated at high velocity. Using an epilepsy domain ontology together with an epilepsy focused extensible data representation format called Cloudwave Signal Format (CSF), the data flow addresses the challenge of data heterogeneity and is interoperable with existing neuroinformatics data representation formats, such as HDF5. The scalability of the Cloudwave data flow is evaluated using a 30-node cluster installed with the open source Hadoop software stack. The results demonstrate that the Cloudwave data flow can process increasing volume of signal data by leveraging Hadoop Data Nodes to reduce the total data processing time. The Cloudwave data flow is a template for developing highly scalable neuroscience data processing pipelines using MapReduce algorithms to support a variety of user applications.

  17. Creating a movement heuristic for voluntary action: electrophysiological correlates of movement-outcome learning.

    PubMed

    Bednark, Jeffery G; Reynolds, John N J; Stafford, Tom; Redgrave, Peter; Franz, Elizabeth A

    2013-03-01

    Performance of voluntary behavior requires the selection of appropriate movements to attain a desired goal. We propose that the selection of voluntary movements is often contingent on the formation of a movement heuristic or set of internal rules governing movement selection. We used event-related potentials (ERPs) to identify the electrophysiological correlates of the formation of movement heuristics during movement-outcome learning. In two experiments, ERPs from non-learning control tasks were compared to a movement-learning task in which a movement heuristic was formed. We found that novelty P3 amplitude was negatively correlated with improved performance in the movement-learning task. Additionally, enhancement of novelty P3 amplitude was observed during learning even after controlling for memory, attentional and inter-stimulus interval parameters. The feedback correct-related positivity (fCRP) was only elicited by sensory effects following intentional movements. These findings extend previous studies demonstrating the role of the fCRP in performance monitoring and the role of the P3 in learning. In particular, the present study highlights an integrative role of the fCRP and the novelty P3 for the acquisition of movement heuristics. While the fCRP indicates that the goal of intentional movements has been attained, the novelty P3 engages stimulus-driven attentional mechanisms to determine the primary aspects of movement and context required to elicit the sensory effect.

  18. Electrophysiological characterization of granule cells in the dentate gyrus immediately after birth

    PubMed Central

    Pedroni, Andrea; Minh, Do Duc; Mallamaci, Antonello; Cherubini, Enrico

    2014-01-01

    Granule cells (GCs) in the dentate gyrus are generated mainly postnatally. Between embryonic day 10 and 14, neural precursors migrate from the primary dentate matrix to the dentate gyrus where they differentiate into neurons. Neurogenesis reaches a peak at the end of the first postnatal week and it is completed at the end of the first postnatal month. This process continues at a reduced rate throughout life. Interestingly, immediately after birth, GCs exhibit a clear GABAergic phenotype. Only later they integrate the classical glutamatergic trisynaptic hippocampal circuit. Here, whole cell patch clamp recordings, in current clamp mode, were performed from immature GCs, intracellularly loaded with biocytin (in hippocampal slices from P0 to P3 old rats) in order to compare their morphological characteristics with their electrophysiological properties. The vast majority of GCs were very immature with small somata, few dendritic branches terminating with small varicosities and growth cones. In spite of their immaturity their axons reached often the cornu ammonis 3 area. Immature GCs generated, upon membrane depolarization, either rudimentary sodium spikes or more clear overshooting action potentials that fired repetitively. They exhibited also low threshold calcium spikes. In addition, most spiking neurons showed spontaneous synchronized network activity, reminiscent of giant depolarizing potentials (GDPs) generated in the hippocampus by the synergistic action of glutamate and GABA, both depolarizing and excitatory. This early synchronized activity, absent during adult neurogenesis, may play a crucial role in the refinement of local neuronal circuits within the developing dentate gyrus. PMID:24592213

  19. Closed-Loop, Multichannel Experimentation Using the Open-Source NeuroRighter Electrophysiology Platform

    PubMed Central

    Newman, Jonathan P.; Zeller-Townson, Riley; Fong, Ming-Fai; Arcot Desai, Sharanya; Gross, Robert E.; Potter, Steve M.

    2013-01-01

    Single neuron feedback control techniques, such as voltage clamp and dynamic clamp, have enabled numerous advances in our understanding of ion channels, electrochemical signaling, and neural dynamics. Although commercially available multichannel recording and stimulation systems are commonly used for studying neural processing at the network level, they provide little native support for real-time feedback. We developed the open-source NeuroRighter multichannel electrophysiology hardware and software platform for closed-loop multichannel control with a focus on accessibility and low cost. NeuroRighter allows 64 channels of stimulation and recording for around US $10,000, along with the ability to integrate with other software and hardware. Here, we present substantial enhancements to the NeuroRighter platform, including a redesigned desktop application, a new stimulation subsystem allowing arbitrary stimulation patterns, low-latency data servers for accessing data streams, and a new application programming interface (API) for creating closed-loop protocols that can be inserted into NeuroRighter as plugin programs. This greatly simplifies the design of sophisticated real-time experiments without sacrificing the power and speed of a compiled programming language. Here we present a detailed description of NeuroRighter as a stand-alone application, its plugin API, and an extensive set of case studies that highlight the system’s abilities for conducting closed-loop, multichannel interfacing experiments. PMID:23346047

  20. Auditory Cortical Maturation in a Child with Cochlear Implant: Analysis of Electrophysiological and Behavioral Measures

    PubMed Central

    Silva, Liliane Aparecida Fagundes; Couto, Maria Inês Vieira; Tsuji, Robinson Koji; Bento, Ricardo Ferreira; de Carvalho, Ana Claudia Martinho; Matas, Carla Gentile

    2015-01-01

    The purpose of this study was to longitudinally assess the behavioral and electrophysiological hearing changes of a girl inserted in a CI program, who had bilateral profound sensorineural hearing loss and underwent surgery of cochlear implantation with electrode activation at 21 months of age. She was evaluated using the P1 component of Long Latency Auditory Evoked Potential (LLAEP); speech perception tests of the Glendonald Auditory Screening Procedure (GASP); Infant Toddler Meaningful Auditory Integration Scale (IT-MAIS); and Meaningful Use of Speech Scales (MUSS). The study was conducted prior to activation and after three, nine, and 18 months of cochlear implant activation. The results of the LLAEP were compared with data from a hearing child matched by gender and chronological age. The results of the LLAEP of the child with cochlear implant showed gradual decrease in latency of the P1 component after auditory stimulation (172 ms–134 ms). In the GASP, IT-MAIS, and MUSS, gradual development of listening skills and oral language was observed. The values of the LLAEP of the hearing child were expected for chronological age (132 ms–128 ms). The use of different clinical instruments allow a better understanding of the auditory habilitation and rehabilitation process via CI. PMID:26881163

  1. Materials for Multifunctional Balloon Catheters With Capabilities in Cardiac Electrophysiological Mapping and Ablation Therapy

    PubMed Central

    Kim, Dae-Hyeong; Lu, Nanshu; Ghaffari, Roozbeh; Kim, Yun-Soung; Lee, Stephen P.; Xu, Lizhi; Wu, Jian; Kim, Rak-Hwan; Song, Jizhou; Liu, Zhuangjian; Viventi, Jonathan; de Graff, Bassel; Elolampi, Brian; Mansour, Moussa; Slepian, Marvin J.; Hwang, Sukwon; Moss, Joshua D.; Won, Sang-Min; Huang, Younggang; Litt, Brian; Rogers, John A.

    2011-01-01

    Development of advanced surgical tools for minimally invasive procedures represents an activity of central importance to improvements in human health. A key materials challenge is in the realization of bio-compatible interfaces between the classes of semiconductor and sensor technologies that might be most useful in this context and the soft, curvilinear surfaces of the body. This paper describes a solution based on biocompatible materials and devices that integrate directly with the thin elastic membranes of otherwise conventional balloon catheters, to provide multimodal functionality suitable for clinical use. We present sensors for measuring temperature, flow, tactile, optical and electrophysiological data, together with radio frequency (RF) electrodes for controlled, local ablation of tissue. These components connect together in arrayed layouts designed to decouple their operation from large strain deformations associated with deployment and repeated inflation/deflation. Use of such ‘instrumented’ balloon catheter devices in live animal models and in vitro tests illustrates their operation in cardiac ablation therapy. These concepts have the potential for application in surgical systems of the future, not only those based on catheters but also on other platforms, such as surgical gloves. PMID:21378969

  2. Spatial attention facilitates assembly of the briefest percepts: Electrophysiological evidence from color fusion.

    PubMed

    Akyürek, Elkan G; van Asselt, E Manon

    2015-12-01

    When two different color stimuli are presented in rapid succession, the resulting percept is sometimes that of a mixture of both colors, due to a perceptual process called color fusion. Although color fusion might seem to occur very early in the visual pathway, and only happens across the briefest of stimulus presentation intervals (< 50 ms), the present study showed that spatial attention can alter the fusion process. In a series of experiments, spatial cues were presented that either validly indicated the location of a pair of (different) color stimuli in successive stimulus arrays, or did not, pointing toward isoluminant gray distractors in the other visual hemifield. Increased color fusion was observed for valid cues across a range of stimulus durations, at the expense of individual color reports. By contrast, perception of repeated, same-color stimulus pairs did not change, suggesting that the enhancement was specific to fusion, not color discrimination per se. Electrophysiological measures furthermore showed that the amplitude of the N1, N2pc, and P3 components of the ERP were differentially modulated during the perception of individual and fused colors, as a function of cueing and stimulus duration. Fusion itself, collapsed across cueing conditions, was reflected uniquely in N1 amplitude. Overall, the results suggest that spatial attention enhances color fusion and decreases competition between stimuli, constituting an adaptive slowdown in service of temporal integration.

  3. Strategies and Lessons-Learned for the Successful Alignment of Contract Cost with the Contract Budget Base (CBB) within the First Year of Contract Award - 13154

    SciTech Connect

    Mullis, Jay; Rueter, Ken

    2013-07-01

    In order to provide a sound basis and foundation for integrated Project and Contract change management, it is imperative to ensure the alignment of the Negotiated Contract Costs (NCC) with the Contract Budget Base (CBB), where CBB is defined as the Performance Measurement Baseline (PMB) plus Management Reserve (MR). The achievement of this alignment assures customer and contractor agreement on scope, requirements, quantities, schedule and cost, which facilitates the identification of change conditions and ultimate agreement on the value of changes to the NCC and the CBB. Delays in contract/CBB true up/reconciliation can negatively effect measurement of project progress, limiting owner understanding of liability, and may result in increased contract disagreements and potential claims. The Department of Energy Oak Ridge Office of Environmental Management (OR-EM) and URS - CH2M Oak Ridge LLC (UCOR) achieved alignment of the NCC with the CBB within 10 months of UCOR taking over work on the East Tennessee Technology Park (ETTP) cleanup contract by: 1. Managing as a discrete project; 2. Establishing expectations and setting tone of interactions; 3. Using personnel experienced with Federal Acquisition Regulation (FAR); 4. Partnering; 5. Establishing ombudsmen. (authors)

  4. Intrinsic Signal Imaging of Deprivation-Induced Contraction of Whisker Representations in Rat Somatosensory Cortex

    PubMed Central

    Drew, Patrick J.

    2009-01-01

    In classical sensory cortical map plasticity, the representation of deprived or underused inputs contracts within cortical sensory maps, whereas spared inputs expand. Expansion of spared inputs occurs preferentially into nearby cortical columns representing temporally correlated spared inputs, suggesting that expansion involves correlation-based learning rules at cross-columnar synapses. It is unknown whether deprived representations contract in a similar anisotropic manner, which would implicate similar learning rules and sites of plasticity. We briefly deprived D-row whiskers in 20-day-old rats, so that each deprived whisker had deprived (D-row) and spared (C- and E-row) neighbors. Intrinsic signal optical imaging revealed that D-row deprivation weakened and contracted the functional representation of deprived D-row whiskers in L2/3 of somatosensory (S1) cortex. Spared whisker representations did not strengthen or expand, indicating that D-row deprivation selectively engages the depression component of map plasticity. Contraction of deprived whisker representations was spatially uniform, with equal withdrawal from spared and deprived neighbors. Single-unit electrophysiological recordings confirmed these results, and showed substantial weakening of responses to deprived whiskers in layer 2/3 of S1, and modest weakening in L4. The observed isotropic contraction of deprived whisker representations during D-row deprivation is consistent with plasticity at intracolumnar, rather than cross-columnar, synapses. PMID:18515797

  5. Effect of phenylephrine infusion on atrial electrophysiological properties.

    PubMed Central

    Leitch, J. W.; Basta, M.; Fletcher, P. J.

    1997-01-01

    OBJECTIVE: To determine the effect of changes in autonomic tone induced by phenylephrine infusion on atrial refractoriness and conduction. DESIGN: Left and right atrial electrophysiological properties were measured before and after a constant phenylephrine infusion designed to increase sinus cycle length by 25%. SUBJECTS: 20 patients, aged 53 (SD 6) years, undergoing electrophysiological study for investigation of idiopathic paroxysmal atrial fibrillation (seven patients) or for routine follow up after successful catheter ablation of supraventricular tachycardia (13 patients). MAIN OUTCOME MEASURES: Changes in left and right atrial effective refractory periods, atrial activation times, and frequency of induction of atrial fibrillation. RESULTS: Phenylephrine (mean dose 69 (SD 18) mg/min) increased mean blood pressure by 22 (12) mm Hg (range 7 to 44) and lengthened sinus cycle length by 223 (94) ms (20 to 430). Left atrial effective refractory period lengthened following phenylephrine infusion from 250 (25) to 264 (21) ms (P < 0.001) but there was no significant change in right atrial effective refractory period: 200 (20) v 206 (29), P = 0.11. There was a significant relation between the effect of phenylephrine on sinus cycle length and on right atrial refractoriness (r = 0.6, P = 0.005) with shortening of right atrial refractoriness in patients with the greatest prolongation in sinus cycle length. During phenylephrine infusion, the right atrial stimulus to left atrial activation time at the basic pacing cycle length of 600 ms was unchanged, at 130 (18) v 131 (17) ms, but activation delay with a premature extrastimulus increased: 212 (28) v 227 (38) ms, P = 0.002. Atrial fibrillation was induced by two of 58 refractory period measurements at baseline and by 12 of 61 measurements during phenylephrine infusion (P < 0.01). Phenylephrine increased the difference between left and right atrial refractory periods by 22.8 (19.4) ms in the five patients with induced atrial

  6. Electrophysiology of regular firing cells in the rat perirhinal cortex.

    PubMed

    D'Antuono, M; Biagini, G; Tancredi, V; Avoli, M

    2001-01-01

    The electrophysiological properties of neurons in the rat perirhinal cortex were analyzed with intracellular recordings in an in vitro slice preparation. Cells included in this study (n = 59) had resting membrane potential (RMP) = -73.9 +/- 8.5 mV (mean +/- SD), action potential amplitude = 95.5 +/- 10.4 mV, input resistance = 36.1 +/- v 15.7 M omega, and time constant = 13.9 +/- 3.4 ms. When filled with neurobiotin (n = 27) they displayed a pyramidal shape with an apical dendrite and extensive basal dendritic tree. Injection of intracellular current pulses revealed: 1) a tetrodotoxin (TTX, 1 microM)-sensitive, inward rectification in the depolarizing direction (n = 6), and 2) a time- and voltage-dependent hyperpolarizing sag that was blocked by extracellular Cs+ (3 mM, n = 5) application. Prolonged (up to 3 s) depolarizing pulses made perirhinal cells discharge regular firing of fast action potentials that diminished over time in frequency and reached a steady level (i.e., adapted). Repetitive firing was followed by an afterhyperpolarization that was decreased, along with firing adaptation, by the Ca(2+)-channel blocker Co2+ (2 mM, n = 6). Action potential broadening became evident during repetitive firing. This behavior, which was more pronounced when larger pulses of depolarizing current were injected (and thus when repetitive firing attained higher rates), was markedly decreased by Co2+ application. Subthreshold membrane oscillations at 5-12 Hz became apparent when cells were depolarized by 10-20 mV from RMP, and action potential clusters appeared with further depolarization. Application of glutamatergic and GABAA receptor antagonists (n = 4), CO2+ (n = 6), or Cs+ (n = 5) did not prevent the occurrence of these oscillations that were abolished by TTX (n = 6). Our results show that pyramidal-like neurons in the perirhinal cortex are regular firing cells with electrophysiological features resembling those of other cortical pyramidal elements. The ability to

  7. Active sodium transport and the electrophysiology of rabbit colon.

    PubMed

    Schultz, S G; Frizzell, R A; Nellans, H N

    1977-05-12

    The electrophysiologic properties of rabbit colonic epithelial cells were investigated employing microelectrode techniques. Under open-circuit conditions, the transepithelial electrical potential difference (PD) averaged 20 mV, serosa positive, and the intracellular electrical potential (psimc) averaged -32 mV, cell interior negative with respect to the mucosal solution; under short-circuit conditions, psimc averaged -46 mV. The addition of amiloride to the mucosal solution abolishes the transepithelial PD and active Na transport, and psimc is hyperpolarized to an average value of -53 mV. These results indicate that Na entry into the mucosal cell is a conductive process which, normally, depolarized psimc. The data obtained were interpreted using a double-membrane equivalent electrical circuit model of the "active Na transport pathway" involving two voltage-independent electromotive forces (emf's) and two voltage-independent resistances arrayed in series. Our observations are consistent with the notions that: (a) The emf's and resistances across the mucosal and baso-lateral membranes are determined predominantly by the emf (64 mV) and resistance of the Na entry process and the emf (53 mV) and resistance of the process responsible for active Na extrusion across the baso-lateral membranes: that is, the electrophysiological properties of the cell appear to be determined solely by the properties and processes responsible for transcellular active Na transport. The emf of the Na entry process is consistent with the notion that the Na activity in the intracellular transport pool is approximately one-tenth that in the mucosal solution or about 14 mM. (b) In the presence of amiloride, the transcellular conductance is essentially abolished and the total tissue conductance is the result of ionic diffusion through paracellular pathways. (c) The negative intracellular potential (with respect to the mucosal solution) is due primarily to the presence of a low resistance

  8. Electrophysiological characteristics of enteric neurons isolated from the Immortomouse

    PubMed Central

    Hawkins, Edward G.; Dewey, William L.; Anitha, Mallappa; Srinivasan, Shanthi; Grider, John R.; Akbarali, Hamid I.

    2013-01-01

    Background Recently two enteric neuronal cell lines, one fetal (IM-FEN) and the other post-natal (IM-PEN), have been developed from the H-2Kb-tsA58 transgenic mouse (immortomouse). However, their electrophysiological properties are not known. The goal of this study was to determine the electrical excitability and ionic conductance of the immortalized postnatal enteric neuronal (IM-PEN) cell line. Methods Whole cell patch clamp studies, immunohistochemistry and RT-PCR were performed on differentiated IM-PEN cells following propagation at 33°C and differentiation at 37°C. Results Differentiated IM-PEN cells stained positively for the neuron specific markers βIII-tubulin and PGP9.5. The mRNA for several ion channels expressed in enteric neurons were detected by RT-PCR. In current clamp, the resting membrane potential was −24.6 ± 2.1mV (n=6) for IM-FEN and −29.8 ± 0.9mV (n=30) for IM-PEN. Current injections from Vh −80 mV, resulted in passive responses but not action potentials. Depolarizing pulses in the whole cell voltage clamp configuration from Vh −80 mV elicited small nifedipine-sensitive inward currents. Additionally, outward currents with slow deactivating tail currents were blocked by niflumic acid and low chloride solution. A volume-regulated anion current was elicited by hypo-osmotic solution and inhibited by 10μM DCPIB. Growth with rabbit gastrointestinal smooth muscle did not yield significant differences in the active properties of the IM-PEN cell line. Transient expression of L-type Ca2+ channels produced large inward currents demonstrating a working mechanism for protein folding and transport. Conclusion The electrophysiological characteristics of IM-PEN cells suggest that chloride channels in IM-PEN cells play an important role in their resting state and membrane trafficking of some of the ion channels may preclude their electrical excitability. PMID:23371009

  9. INFINITY construction contract signed

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Key state and community leaders celebrated April 6 with the signing of a construction contract for the state-of-the-art INFINITY Science Center planned near John C. Stennis Space Center in south Mississippi. Gulfport Mayor George Schloegel (l to r), chair of non-profit INFINITY Science Center Inc., was joined for the signing ceremony at the Hancock Bank in Gulfport by Virginia Wagner, sister of late Hancock Bank President Leo Seal Jr.; and Roy Anderson III, president and CEO of Roy Anderson Corp. Seal was the first chair of INFINITY Science Center Inc., which has led in development of the project. Roy Anderson Corp. plans to begin construction on the 72,000-square-foot, $28 million science and education center in May. The Mississippi Department of Transportation (MDOT) also is set to begin construction of a $2 million access road to the new center. The April 6 ceremony was attended by numerous officials, including former Stennis Space Center Directors Jerry Hlass and Roy Estess; Mississippi Senate President Pro Tempore Billy Hewes, R-Gulfport; Mississippi Rep. Diane Peranich, D-Pass Christian; and MDOT Southern District Commissioner Wayne Brown.

  10. [Contracts including performance and management of uncertainty].

    PubMed

    Duru, G; Garassus, P; Auray, J-P

    2013-09-01

    Since many decades in France, the most important part of ambulatory health care expenditure is represented by drug consumption. By the fact, French patient is indeed the greatest world consumer of pharmaceuticals treatments. Therefore, the regulation authorities by successive strategies, attempt to limit or even restrict market access for new drugs in the health care sector secured by public social insurance coverage. Common objectives are to assess the reimbursement to scientific studies and to fix the price of therapeutics at an acceptable level for both industries and government. New trends try then to determine recently the drug price in a dual approach, as a component of global and effective contract, including performance and outcome. The first diffusion authorization is diffusion concerned, but this concept takes into account the eventual success of new produces in long-term survey. Signed for a fixed period as reciprocal partnership between regulation authorities and pharmaceutics industries, the contract integrates two dimensions of incertitude. The first one is represented by the strategy of new treatments development according to efficacy and adapted price, and the second one is linked to the result of diffusion and determines adapted rules if eventual non-respects of the previous engagement are registered. This paper discusses problems related to this new dimension of incertitude affected by conditional drug prices in market access strategy and the adapted follow-up of new treatment diffusion fixed by "outcome" contract between French regulation administration and pharmaceutics industries in our recent economic context.

  11. Cartographic services contract...for everything geographic

    USGS Publications Warehouse

    ,

    2003-01-01

    The U.S. Geological Survey's (USGS) Cartographic Services Contract (CSC) is used to award work for photogrammetric and mapping services under the umbrella of Architect-Engineer (A&E) contracting. The A&E contract is broad in scope and can accommodate any activity related to standard, nonstandard, graphic, and digital cartographic products. Services provided may include, but are not limited to, photogrammetric mapping and aerotriangulation; orthophotography; thematic mapping (for example, land characterization); analog and digital imagery applications; geographic information systems development; surveying and control acquisition, including ground-based and airborne Global Positioning System; analog and digital image manipulation, analysis, and interpretation; raster and vector map digitizing; data manipulations (for example, transformations, conversions, generalization, integration, and conflation); primary and ancillary data acquisition (for example, aerial photography, satellite imagery, multispectral, multitemporal, and hyperspectral data); image scanning and processing; metadata production, revision, and creation; and production or revision of standard USGS products defined by formal and informal specification and standards, such as those for digital line graphs, digital elevation models, digital orthophoto quadrangles, and digital raster graphics.

  12. 48 CFR 1204.103 - Contract clause.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clause. 1204.103... ADMINISTRATIVE MATTERS Contract Execution 1204.103 Contract clause. The contracting officer shall insert the clause at (FAR) 48 CFR 52.204-1, Approval of Contract, filled in as appropriate, in solicitations...

  13. 48 CFR 1242.7000 - Contract clauses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clauses. 1242... MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Contract Administration Clauses 1242.7000 Contract clauses. (a) The contracting officer may use the clause at (TAR) 48 CFR 1252.242-70, Dissemination...

  14. 48 CFR 1316.307 - Contract clauses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clauses. 1316.307... CONTRACT TYPES TYPES OF CONTRACTS Cost-Reimbursement Contracts 1316.307 Contract clauses. (a) Insert a clause that is substantially the same as 1352.216-70, Estimated and Allowable Costs, in all...

  15. 48 CFR 2035.70 - Contract clauses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Contract clauses. 2035.70 Section 2035.70 Federal Acquisition Regulations System NUCLEAR REGULATORY COMMISSION SPECIAL CATEGORIES OF CONTRACTING RESEARCH AND DEVELOPMENT CONTRACTING 2035.70 Contract clauses. (a) The contracting officer...

  16. 48 CFR 2035.70 - Contract clauses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Contract clauses. 2035.70 Section 2035.70 Federal Acquisition Regulations System NUCLEAR REGULATORY COMMISSION SPECIAL CATEGORIES OF CONTRACTING RESEARCH AND DEVELOPMENT CONTRACTING 2035.70 Contract clauses. (a) The contracting officer...

  17. 48 CFR 2035.70 - Contract clauses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Contract clauses. 2035.70 Section 2035.70 Federal Acquisition Regulations System NUCLEAR REGULATORY COMMISSION SPECIAL CATEGORIES OF CONTRACTING RESEARCH AND DEVELOPMENT CONTRACTING 2035.70 Contract clauses. (a) The contracting officer...

  18. 48 CFR 2035.70 - Contract clauses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false Contract clauses. 2035.70 Section 2035.70 Federal Acquisition Regulations System NUCLEAR REGULATORY COMMISSION SPECIAL CATEGORIES OF CONTRACTING RESEARCH AND DEVELOPMENT CONTRACTING 2035.70 Contract clauses. (a) The contracting officer...

  19. 48 CFR 2035.70 - Contract clauses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Contract clauses. 2035.70 Section 2035.70 Federal Acquisition Regulations System NUCLEAR REGULATORY COMMISSION SPECIAL CATEGORIES OF CONTRACTING RESEARCH AND DEVELOPMENT CONTRACTING 2035.70 Contract clauses. (a) The contracting officer...

  20. 48 CFR 316.603 - Letter contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Letter contracts. 316.603 Section 316.603 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Time-and-Materials, Labor-Hour, and Letter Contracts 316.603...

  1. 25 CFR 502.15 - Management contract.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Management contract. 502.15 Section 502.15 Indians... CHAPTER § 502.15 Management contract. Management contract means any contract, subcontract, or collateral... contract or agreement provides for the management of all or part of a gaming operation....

  2. 25 CFR 502.15 - Management contract.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Management contract. 502.15 Section 502.15 Indians... CHAPTER § 502.15 Management contract. Management contract means any contract, subcontract, or collateral... contract or agreement provides for the management of all or part of a gaming operation....

  3. 25 CFR 502.15 - Management contract.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Management contract. 502.15 Section 502.15 Indians... CHAPTER § 502.15 Management contract. Management contract means any contract, subcontract, or collateral... contract or agreement provides for the management of all or part of a gaming operation....

  4. 48 CFR 43.205 - Contract clauses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Section 43.205 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACT MANAGEMENT CONTRACT MODIFICATIONS Change Orders 43.205 Contract clauses. (a)(1) The contracting officer shall insert the clause at 52.243-1, Changes—Fixed-Price, in solicitations and contracts when a...

  5. 48 CFR 43.205 - Contract clauses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Section 43.205 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACT MANAGEMENT CONTRACT MODIFICATIONS Change Orders 43.205 Contract clauses. (a)(1) The contracting officer shall insert the clause at 52.243-1, Changes—Fixed-Price, in solicitations and contracts when a...

  6. 48 CFR 543.205 - Contract clauses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Section 543.205 Federal Acquisition Regulations System GENERAL SERVICES ADMINISTRATION CONTRACT MANAGEMENT CONTRACT MODIFICATIONS Change Orders 543.205 Contract clauses. The contracting officer shall insert 552.243-71, Equitable Adjustments, in solicitations and contracts containing FAR 52.243-4, Changes....

  7. 48 CFR 543.205 - Contract clauses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Section 543.205 Federal Acquisition Regulations System GENERAL SERVICES ADMINISTRATION CONTRACT MANAGEMENT CONTRACT MODIFICATIONS Change Orders 543.205 Contract clauses. The contracting officer shall insert 552.243-71, Equitable Adjustments, in solicitations and contracts containing FAR 52.243-4, Changes....

  8. 48 CFR 42.401 - Contract correspondence.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Contract correspondence... MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Correspondence and Visits 42.401 Contract correspondence. (a) The contracting officer (or other contracting agency personnel) normally shall (1)...

  9. 48 CFR 42.401 - Contract correspondence.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Contract correspondence... MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Correspondence and Visits 42.401 Contract correspondence. (a) The contracting officer (or other contracting agency personnel) normally shall (1)...

  10. 48 CFR 42.401 - Contract correspondence.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Contract correspondence... MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Correspondence and Visits 42.401 Contract correspondence. (a) The contracting officer (or other contracting agency personnel) normally shall (1)...

  11. 48 CFR 42.401 - Contract correspondence.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Contract correspondence... MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Correspondence and Visits 42.401 Contract correspondence. (a) The contracting officer (or other contracting agency personnel) normally shall (1)...

  12. 48 CFR 42.401 - Contract correspondence.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Contract correspondence... MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Correspondence and Visits 42.401 Contract correspondence. (a) The contracting officer (or other contracting agency personnel) normally shall (1)...

  13. 48 CFR 846.312 - Construction contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Construction contracts. 846.312 Section 846.312 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CONTRACT MANAGEMENT QUALITY ASSURANCE Contract Clauses 846.312 Construction contracts. The contracting officer...

  14. 48 CFR 16.603 - Letter contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Letter contracts. 16.603 Section 16.603 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Time-and-Materials, Labor-Hour, and Letter Contracts...

  15. 48 CFR 1517.204 - Contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Contracts. 1517.204 Section 1517.204 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 1517.204 Contracts. The SCM may approve...

  16. 48 CFR 317.204 - Contracts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 4 2013-10-01 2013-10-01 false Contracts. 317.204 Section 317.204 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 317.204 Contracts. (e) The total of the basic and...

  17. 7 CFR 631.10 - Contracts.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Contracts. 631.10 Section 631.10 Agriculture... AGRICULTURE LONG TERM CONTRACTING GREAT PLAINS CONSERVATION PROGRAM Contracts § 631.10 Contracts. (a) To participate in the program, an applicant must enter into a contract agreeing to implement a conservation...

  18. 24 CFR 232.605 - Contract requirements.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 2 2012-04-01 2012-04-01 false Contract requirements. 232.605... Fire Safety Equipment Form of Contract § 232.605 Contract requirements. (a) The contract between the mortgagor and the general contractor may be in the form of either a lump sum contract or a cost...

  19. 48 CFR 837.403 - Contract clause.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract clause. 837.403... OF CONTRACTING SERVICE CONTRACTING Nonpersonal Health Care Services 837.403 Contract clause. The contracting officer shall insert the clause at 852.237-7, Indemnification and medical liability insurance,...

  20. 48 CFR 217.204 - Contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Contracts. 217.204 Section... DEFENSE CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 217.204 Contracts. (e)(i) Notwithstanding FAR 17.204(e), the ordering period of a task order or delivery order...

  1. 48 CFR 811.503 - Contract clause.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Contract clause. 811.503... ACQUISITION PLANNING DESCRIBING AGENCY NEEDS Liquidated Damages 811.503 Contract clause. When the contracting... contracting officer must include the clause in 852.211-74, Liquidated damages, in the contract....

  2. 48 CFR 617.204 - Contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 4 2014-10-01 2014-10-01 false Contracts. 617.204 Section 617.204 Federal Acquisition Regulations System DEPARTMENT OF STATE CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 617.204 Contracts. (e) The Procurement Executive shall...

  3. 48 CFR 217.204 - Contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Contracts. 217.204 Section... DEFENSE CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 217.204 Contracts. (e)(i) Notwithstanding FAR 17.204(e), the ordering period of a task order or delivery order...

  4. 48 CFR 317.204 - Contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Contracts. 317.204 Section 317.204 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 317.204 Contracts. (e) The total of the basic and...

  5. 48 CFR 846.312 - Construction contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Construction contracts. 846.312 Section 846.312 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CONTRACT MANAGEMENT QUALITY ASSURANCE Contract Clauses 846.312 Construction contracts. The contracting officer...

  6. 7 CFR 632.22 - Contracts.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Contracts. 632.22 Section 632.22 Agriculture... AGRICULTURE LONG TERM CONTRACTING RURAL ABANDONED MINE PROGRAM Participation § 632.22 Contracts. (a) Cost-sharing contracts. A land user who has an approved reclamation plan may enter into a contract with NRCS...

  7. 43 CFR 2.228 - Government contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Government contracts. 2.228 Section 2.228... TESTIMONY Privacy Act § 2.228 Government contracts. (a) Required contract provisions. When a contract... Department function, the contract shall, consistent with the Department's authority, cause the...

  8. 48 CFR 217.204 - Contracts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Contracts. 217.204 Section... DEFENSE CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 217.204 Contracts. (e)(i) Notwithstanding FAR 17.204(e), the ordering period of a task order or delivery order...

  9. 48 CFR 16.503 - Requirements contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Requirements contracts. 16.503 Section 16.503 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Indefinite-Delivery Contracts 16.503 Requirements...

  10. 48 CFR 1517.204 - Contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Contracts. 1517.204 Section 1517.204 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 1517.204 Contracts. The SCM may approve...

  11. 7 CFR 634.25 - Contracting.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Contracting. 634.25 Section 634.25 Agriculture... AGRICULTURE LONG TERM CONTRACTING RURAL CLEAN WATER PROGRAM Participant RCWP Contracts § 634.25 Contracting. (a) To participate in RCWP, a landowner or operator must enter into a contract in which he or...

  12. 48 CFR 617.204 - Contracts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 4 2013-10-01 2013-10-01 false Contracts. 617.204 Section 617.204 Federal Acquisition Regulations System DEPARTMENT OF STATE CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 617.204 Contracts. (e) The Procurement Executive shall...

  13. 7 CFR 800.198 - Contracts.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 7 2012-01-01 2012-01-01 false Contracts. 800.198 Section 800.198 Agriculture..., Designations, Approvals, Contracts, and Conflicts of Interest § 800.198 Contracts. (a) Services contracted and who may apply. The Service may enter into a contract with any person, State, or governmental agency...

  14. 48 CFR 3432.705 - Contract clauses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Contract clauses. 3432.705 Section 3432.705 Federal Acquisition Regulations System DEPARTMENT OF EDUCATION ACQUISITION REGULATION GENERAL CONTRACTING REQUIREMENTS CONTRACT FINANCING Contract Funding 3432.705 Contract clauses....

  15. 7 CFR 634.25 - Contracting.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Contracting. 634.25 Section 634.25 Agriculture... AGRICULTURE LONG TERM CONTRACTING RURAL CLEAN WATER PROGRAM Participant RCWP Contracts § 634.25 Contracting. (a) To participate in RCWP, a landowner or operator must enter into a contract in which he or...

  16. 48 CFR 317.204 - Contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 4 2012-10-01 2012-10-01 false Contracts. 317.204 Section 317.204 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 317.204 Contracts. (e) The total of the basic and...

  17. 7 CFR 631.10 - Contracts.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Contracts. 631.10 Section 631.10 Agriculture... AGRICULTURE LONG TERM CONTRACTING GREAT PLAINS CONSERVATION PROGRAM Contracts § 631.10 Contracts. (a) To participate in the program, an applicant must enter into a contract agreeing to implement a conservation...

  18. 48 CFR 617.204 - Contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 4 2012-10-01 2012-10-01 false Contracts. 617.204 Section 617.204 Federal Acquisition Regulations System DEPARTMENT OF STATE CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 617.204 Contracts. (e) The Procurement Executive shall...

  19. 48 CFR 617.204 - Contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Contracts. 617.204 Section 617.204 Federal Acquisition Regulations System DEPARTMENT OF STATE CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 617.204 Contracts. (e) The Procurement Executive shall...

  20. 7 CFR 634.25 - Contracting.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Contracting. 634.25 Section 634.25 Agriculture... AGRICULTURE LONG TERM CONTRACTING RURAL CLEAN WATER PROGRAM Participant RCWP Contracts § 634.25 Contracting. (a) To participate in RCWP, a landowner or operator must enter into a contract in which he or...