Sodium and potassium conductance changes during a membrane action potential.

PubMed

Bezanilla, F; Rojas, E; Taylor, R E

1970-12-01

1. A method for turning a membrane potential control system on and off in less than 10 musec is described. This method was used to record membrane currents in perfused giant axons from Dosidicus gigas and Loligo forbesi after turning on the voltage clamp system at various times during the course of a membrane action potential.2. The membrane current measured just after the capacity charging transient was found to have an almost linear relation to the controlled membrane potential.3. The total membrane conductance taken from these current-voltage curves was found to have a time course during the action potential similar to that found by Cole & Curtis (1939).4. The instantaneous current voltage curves were linear enough to make it possible to obtain a good estimate of the individual sodium and potassium channel conductances, either algebraically or by clamping to the sodium, or potassium, reversal potentials. Good general agreement was obtained with the predictions of the Hodgkin-Huxley equations.5. We consider these results to constitute the first direct experimental demonstration of the conductance changes to sodium and potassium during the course of an action potential.

Empowering potential: a theory of wellness motivation.

PubMed

Fleury, J D

1991-01-01

Data were collected from 29 individuals who were attempting to initiate and sustain programs of cardiac risk factor modification. Data were analyzed through the technique of constant comparative analysis. Empowering potential, the basic social process identified from the data, explained individual motivation to initiate and sustain cardiovascular health behavior. Empowering potential was a continuous process of individual growth and development which facilitated the emergence of new and positive health patterns. Within the process of empowering potential, individuals use a variety of strategies which guide the initiation and maintenance of health-related change. The process of empowering potential consists of three stages: appraising readiness, changing, and integrating change. Two categories occurred throughout the process of empowering potential: imaging and social support systems. These findings provide a better understanding of how motivated action is initiated and reinitiated over time.

Modulation of hERG potassium channel gating normalizes action potential duration prolonged by dysfunctional KCNQ1 potassium channel

PubMed Central

Zhang, Hongkang; Zou, Beiyan; Yu, Haibo; Moretti, Alessandra; Wang, Xiaoying; Yan, Wei; Babcock, Joseph J.; Bellin, Milena; McManus, Owen B.; Tomaselli, Gordon; Nan, Fajun; Laugwitz, Karl-Ludwig; Li, Min

2012-01-01

Long QT syndrome (LQTS) is a genetic disease characterized by a prolonged QT interval in an electrocardiogram (ECG), leading to higher risk of sudden cardiac death. Among the 12 identified genes causal to heritable LQTS, ∼90% of affected individuals harbor mutations in either KCNQ1 or human ether-a-go-go related genes (hERG), which encode two repolarizing potassium currents known as IKs and IKr. The ability to quantitatively assess contributions of different current components is therefore important for investigating disease phenotypes and testing effectiveness of pharmacological modulation. Here we report a quantitative analysis by simulating cardiac action potentials of cultured human cardiomyocytes to match the experimental waveforms of both healthy control and LQT syndrome type 1 (LQT1) action potentials. The quantitative evaluation suggests that elevation of IKr by reducing voltage sensitivity of inactivation, not via slowing of deactivation, could more effectively restore normal QT duration if IKs is reduced. Using a unique specific chemical activator for IKr that has a primary effect of causing a right shift of V1/2 for inactivation, we then examined the duration changes of autonomous action potentials from differentiated human cardiomyocytes. Indeed, this activator causes dose-dependent shortening of the action potential durations and is able to normalize action potentials of cells of patients with LQT1. In contrast, an IKr chemical activator of primary effects in slowing channel deactivation was not effective in modulating action potential durations. Our studies provide both the theoretical basis and experimental support for compensatory normalization of action potential duration by a pharmacological agent. PMID:22745159

Citizen's actions

NASA Technical Reports Server (NTRS)

1975-01-01

The role played by individual citizens as consumers of energy was examined, with emphasis on studying ways in which their action could result in energy conservation. It was shown that there are ways that energy can be conserved in this way, with citizens acting either individually or in groups. The potential savings are significant, but the actual savings may be quite small. The citizens need to be motivated to save and to believe in a conservation ethic; developing such an ethic is difficult, and perhaps not responsive to the shotgun approach now being attempted. The true course of action may be to synthesize new societal structures that provide the maximum evolution of culture within the limitation of scarce energy resources.

Using Arrays of Microelectrodes Implanted in Residual Peripheral Nerves to Provide Dexterous Control of, and Modulated Sensory Feedback from, a Hand Prosthesis

DTIC Science & Technology

2016-10-01

isolated action potentials or multi-action potential activity from residual peripheral nerve while patient intends movements of amputated hand/arm...Subtask 3.1: Mapping of neural activity (Months 4 – 36) • Patients will be asked to intend a number of individual finger and multiple finger flexion...during these intended movements. We will map the different intended movements onto the neural activity recorded on the electrodes of the micro-electrode

[Functional organization and structure of the serotonergic neuronal network of terrestrial snail].

PubMed

Nikitin, E S; Balaban, P M

2011-01-01

The extension of knowledge how the brain works requires permanent improvement of methods of recording of neuronal activity and increase in the number of neurons recorded simultaneously to better understand the collective work of neuronal networks and assemblies. Conventional methods allow simultaneous intracellular recording up to 2-5 neurons and their membrane potentials, currents or monosynaptic connections or observation of spiking of neuronal groups with subsequent discrimination of individual spikes with loss of details of the dynamics of membrane potential. We recorded activity of a compact group of serotonergic neurons (up to 56 simultaneously) in the ganglion of a terrestrial mollusk using the method of optical recording of membrane potential that allowed to record individual action potentials in details with action potential parameters and to reveal morphology of the neurons rcorded. We demonstrated clear clustering in the group in relation with the dynamics of action potentials and phasic or tonic components in the neuronal responses to external electrophysiological and tactile stimuli. Also, we showed that identified neuron Pd2 could induce activation of a significant number of neurons in the group whereas neuron Pd4 did not induce any activation. However, its activation is delayed with regard to activation of the reacting group of neurons. Our data strongly support the concept of possible delegation of the integrative function by the network to a single neuron.

Action Learning: The Possibility of Differing Hierarchies in Learning Sets

ERIC Educational Resources Information Center

Yeadon-Lee, Annie

2013-01-01

This paper presents the proposition that a variety of differing hierarchies exist in an action learning set at any one time, and each hierarchy has the potential to affect an individual's behaviour within the set. An interpretivist philosophy underpins the research framework adopted in this paper. Data were captured by means of 11 in-depth…

Sodium and potassium conductance changes during a membrane action potential

PubMed Central

Bezanilla, Francisco; Rojas, Eduardo; Taylor, Robert E.

1970-01-01

1. A method for turning a membrane potential control system on and off in less than 10 μsec is described. This method was used to record membrane currents in perfused giant axons from Dosidicus gigas and Loligo forbesi after turning on the voltage clamp system at various times during the course of a membrane action potential. 2. The membrane current measured just after the capacity charging transient was found to have an almost linear relation to the controlled membrane potential. 3. The total membrane conductance taken from these current—voltage curves was found to have a time course during the action potential similar to that found by Cole & Curtis (1939). 4. The instantaneous current voltage curves were linear enough to make it possible to obtain a good estimate of the individual sodium and potassium channel conductances, either algebraically or by clamping to the sodium, or potassium, reversal potentials. Good general agreement was obtained with the predictions of the Hodgkin—Huxley equations. 5. We consider these results to constitute the first direct experimental demonstration of the conductance changes to sodium and potassium during the course of an action potential. PMID:5505231

Neuronal representation of individual heroin choices in the orbitofrontal cortex.

PubMed

Guillem, Karine; Brenot, Viridiana; Durand, Audrey; Ahmed, Serge H

2018-05-01

Drug addiction is a harmful preference for drug use over and at the expense of other non-drug-related activities. We previously identified in the rat orbitofrontal cortex (OFC) a mechanism that influences individual preferences between cocaine use and an alternative action rewarded by a non-drug reward (i.e. sweet water). Here, we sought to test the generality of this mechanism to a different addictive drug, heroin. OFC neuronal activity was recorded while rats responded for heroin or the alternative non-drug reward separately or while they chose between the two. First, we found that heroin-rewarded and sweet water-rewarded actions were encoded by two non-overlapping OFC neuronal populations and that the relative size of the heroin population represented individual drug choices. Second, OFC neurons encoding the preferred action-which was the non-drug action in the large majority of individuals-progressively fired more than non-preferred action-coding neurons 1 second after the onset of choice trials and around 1 second before the preferred action was actually chosen, suggesting a pre-choice neuronal competition for action selection. Together with a previous study on cocaine choice, the present study on heroin choice reveals important commonalities in how OFC neurons encode individual drug choices and preferences across different classes of drugs. It also reveals some drug-specific differences in OFC encoding activity. Notably, the proportion of neurons that non-selectively encode both the drug and the non-drug reward was higher when the drug was heroin (present study) than when it was cocaine (previous study). We will discuss the potential functional significance of these commonalities and differences in OFC neuronal activity across different drugs for understanding drug choice. © 2017 Society for the Study of Addiction.

Sub-millisecond closed-loop feedback stimulation between arbitrary sets of individual neurons

PubMed Central

Müller, Jan; Bakkum, Douglas J.; Hierlemann, Andreas

2012-01-01

We present a system to artificially correlate the spike timing between sets of arbitrary neurons that were interfaced to a complementary metal–oxide–semiconductor (CMOS) high-density microelectrode array (MEA). The system features a novel reprogrammable and flexible event engine unit to detect arbitrary spatio-temporal patterns of recorded action potentials and is capable of delivering sub-millisecond closed-loop feedback of electrical stimulation upon trigger events in real-time. The relative timing between action potentials of individual neurons as well as the temporal pattern among multiple neurons, or neuronal assemblies, is considered an important factor governing memory and learning in the brain. Artificially changing timings between arbitrary sets of spiking neurons with our system could provide a “knob” to tune information processing in the network. PMID:23335887

Random laser action in bovine semen

NASA Astrophysics Data System (ADS)

Smuk, Andrei; Lazaro, Edgar; Olson, Leif P.; Lawandy, N. M.

2011-03-01

Experiments using bovine semen reveal that the addition of a high-gain water soluble dye results in random laser action when excited by a Q-switched, frequency doubled, Nd:Yag laser. The data shows that the linewidth collapse of the emission is correlated to the sperm count of the individual samples, potentially making this a rapid, low sample volume approach to count determination.

Experiential knowledge of expert coaches can help identify informational constraints on performance of dynamic interceptive actions.

PubMed

Greenwood, Daniel; Davids, Keith; Renshaw, Ian

2014-01-01

Coordination of dynamic interceptive movements is predicated on cyclical relations between an individual's actions and information sources from the performance environment. To identify dynamic informational constraints, which are interwoven with individual and task constraints, coaches' experiential knowledge provides a complementary source to support empirical understanding of performance in sport. In this study, 15 expert coaches from 3 sports (track and field, gymnastics and cricket) participated in a semi-structured interview process to identify potential informational constraints which they perceived to regulate action during run-up performance. Expert coaches' experiential knowledge revealed multiple information sources which may constrain performance adaptations in such locomotor pointing tasks. In addition to the locomotor pointing target, coaches' knowledge highlighted two other key informational constraints: vertical reference points located near the locomotor pointing target and a check mark located prior to the locomotor pointing target. This study highlights opportunities for broadening the understanding of perception and action coupling processes, and the identified information sources warrant further empirical investigation as potential constraints on athletic performance. Integration of experiential knowledge of expert coaches with theoretically driven empirical knowledge represents a promising avenue to drive future applied science research and pedagogical practice.

Reconstruction of the action potential of ventricular myocardial fibres

PubMed Central

Beeler, G. W.; Reuter, H.

1977-01-01

1. A mathematical model of membrane action potentials of mammalian ventricular myocardial fibres is described. The reconstruction model is based as closely as possible on ionic currents which have been measured by the voltage-clamp method. 2. Four individual components of ionic current were formulated mathematically in terms of Hodgkin—Huxley type equations. The model incorporates two voltage- and time-dependent inward currents, the excitatory inward sodium current, iNa, and a secondary or slow inward current, is, primarily carried by calcium ions. A time-independent outward potassium current, iK1, exhibiting inward-going rectification, and a voltage- and time-dependent outward current, ix1, primarily carried by potassium ions, are further elements of the model. 3. The iNa is primarily responsible for the rapid upstroke of the action potential, while the other current components determine the configuration of the plateau of the action potential and the re-polarization phase. The relative importance of inactivation of is and of activation of ix1 for termination of the plateau is evaluated by the model. 4. Experimental phenomena like slow recovery of the sodium system from inactivation, frequency dependence of the action potential duration, all-or-nothing re-polarization, membrane oscillations are adequately described by the model. 5. Possible inadequacies and shortcomings of the model are discussed. PMID:874889

Distinctive laterality of neural networks supporting action understanding in left- and right-handed individuals: An EEG coherence study.

PubMed

Kelly, Rachel; Mizelle, J C; Wheaton, Lewis A

2015-08-01

Prior work has demonstrated that perspective and handedness of observed actions can affect action understanding differently in right and left-handed persons, suggesting potential differences in the neural networks underlying action understanding between right and left-handed individuals. We sought to evaluate potential differences in these neural networks using electroencephalography (EEG). Right- and left-handed participants observed images of tool-use actions from egocentric and allocentric perspectives, with right- and left-handed actors performing the actions. Participants judged the outcome of the observed actions, and response accuracy and latency were recorded. Behaviorally, the highest accuracy and shortest latency was found in the egocentric perspective for right- and left-handed observers. Handedness of subject showed an effect on accuracy and latency also, where right-handed observers were faster to respond than left-handed observers, but on average were less accurate. Mu band (8-10 Hz) cortico-cortical coherence analysis indicated that right-handed observers have coherence in the motor dominant left parietal-premotor networks when looking at an egocentric right or allocentric left hands. When looking in an egocentric perspective at a left hand or allocentric right hand, coherence was lateralized to right parietal-premotor areas. In left-handed observers, bilateral parietal-premotor coherence patterns were observed regardless of actor handedness. These findings suggest that the cortical networks involved in understanding action outcomes are dependent on hand dominance, and notably right handed participants seem to utilize motor systems based on the limb seen performing the action. The decreased accuracy for right-handed participants on allocentric images could be due to asymmetrical lateralization of encoding action and motoric dominance, which may interfere with translating allocentric limb action outcomes. Further neurophysiological studies will determine the specific processes of how left- and right-handed participants understand actions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Building Warmth Sculpture in the Student-Teacher Relationship: Goethean Observation and Contemplative Practice in an Action Research Inquiry

ERIC Educational Resources Information Center

Kresin-Price, Nancy

2013-01-01

Through an action research approach, this dissertation focuses on the central role of interpersonal warmth in the teacher and student relationship. The heart of its inquiry is based on data gathered by a set of teachers working collaboratively as co-researchers in their own classrooms. These individuals inquired into the potential of the teacher…

The Challenge for Female Educational Leaders: An Examination of the Problem and Proposed Solutions through Educational and Social Change Strategies.

ERIC Educational Resources Information Center

Brathwaite, Frank

Despite the current need for strong leadership skills to facilitate task achievement, individual development, and social action in an increasingly complex society, women are failing to make significant headway in educational administration. Lack of leadership opportunities for women limits both individual and organizational potential. The problem…

The Ontario Food and Nutrition Strategy: identifying indicators of food access and food literacy for early monitoring of the food environment.

PubMed

Boucher, Beatrice A; Manafò, Elizabeth; Boddy, Meaghan R; Roblin, Lynn; Truscott, Rebecca

2017-09-01

To address challenges Canadians face within their food environments, a comprehensive, multistakeholder, intergovernmental approach to policy development is essential. Food environment indicators are needed to assess population status and change. The Ontario Food and Nutrition Strategy (OFNS) integrates the food, agriculture and nutrition sectors, and aims to improve the health of Ontarians through actions that promote healthy food systems and environments. This report describes the process of identifying indicators for 11 OFNS action areas in two strategic directions (SDs): Healthy Food Access, and Food Literacy and Skills. The OFNS Indicators Advisory Group used a five-step process to select indicators: (1) potential indicators from national and provincial data sources were identified; (2) indicators were organized by SD, action area and data type; (3) selection criteria were identified, pilot tested and finalized; (4) final criteria were applied to refine the indicator list; and (5) indicators were prioritized after reapplication of selection criteria. Sixty-nine potential indicators were initially identified; however, many were individual-level rather than system-level measures. After final application of the selection criteria, one individual-level indicator and six system-level indicators were prioritized in five action areas; for six of the action areas, no indicators were available. Data limitations suggest that available data may not measure important aspects of the food environment, highlighting the need for action and resources to improve system-level indicators and support monitoring of the food environment and health in Ontario and across Canada.

Integrating big data and actionable health coaching to optimize wellness.

PubMed

Hood, Leroy; Lovejoy, Jennifer C; Price, Nathan D

2015-01-09

The Hundred Person Wellness Project (HPWP) is a 10-month pilot study of 100 'well' individuals where integrated data from whole-genome sequencing, gut microbiome, clinical laboratory tests and quantified self measures from each individual are used to provide actionable results for health coaching with the goal of optimizing wellness and minimizing disease. In a commentary in BMC Medicine, Diamandis argues that HPWP and similar projects will likely result in 'unnecessary and potential harmful over-testing'. We argue that this new approach will ultimately lead to lower costs, better healthcare, innovation and economic growth. The central points of the HPWP are: 1) it is focused on optimizing wellness through longitudinal data collection, integration and mining of individual data clouds, enabling development of predictive models of wellness and disease that will reveal actionable possibilities; and 2) by extending this study to 100,000 well people, we will establish multiparameter, quantifiable wellness metrics and identify markers for wellness to early disease transitions for most common diseases, which will ultimately allow earlier disease intervention, eventually transitioning the individual early on from a disease back to a wellness trajectory.

Rapid Ca2+ flux through the transverse tubular membrane, activated by individual action potentials in mammalian skeletal muscle

PubMed Central

Launikonis, Bradley S; Stephenson, D George; Friedrich, Oliver

2009-01-01

Periods of low frequency stimulation are known to increase the net Ca2+ uptake in skeletal muscle but the mechanism responsible for this Ca2+ entry is not known. In this study a novel high-resolution fluorescence microscopy approach allowed the detection of an action potential-induced Ca2+ flux across the tubular (t-) system of rat extensor digitorum longus muscle fibres that appears to be responsible for the net uptake of Ca2+ in working muscle. Action potentials were triggered in the t-system of mechanically skinned fibres from rat by brief field stimulation and t-system [Ca2+] ([Ca2+]t-sys) and cytoplasmic [Ca2+] ([Ca2+]cyto) were simultaneously resolved on a confocal microscope. When initial [Ca2+]t-sys was ≥ 0.2 mm a Ca2+ flux from t-system to the cytoplasm was observed following a single action potential. The action potential-induced Ca2+ flux and associated t-system Ca2+ permeability decayed exponentially and displayed inactivation characteristics such that further Ca2+ entry across the t-system could not be observed after 2–3 action potentials at 10 Hz stimulation rate. When [Ca2+]t-sys was closer to 0.1 mm, a transient rise in [Ca2+]t-sys was observed almost concurrently with the increase in [Ca2+]cyto following the action potential. The change in direction of Ca2+ flux was consistent with changes in the direction of the driving force for Ca2+. This is the first demonstration of a rapid t-system Ca2+ flux associated with a single action potential in mammalian skeletal muscle. The properties of this channel are inconsistent with a flux through the L-type Ca2+ channel suggesting that an as yet unidentified t-system protein is conducting this current. This action potential-activated Ca2+ flux provides an explanation for the previously described Ca2+ entry and accumulation observed with prolonged, intermittent muscle activity. PMID:19332499

78 FR 79076 - Currently Approved Information Collection: Comment Request for Generic Clearance for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-27

... and efficiency of existing products and services; to obtain knowledge about the potential public... audiences and customers. Current Actions: None. Type of Review: Extension. Affected Public: Individuals or...

Action principle for Coulomb collisions in plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hirvijoki, Eero

In this study, an action principle for Coulomb collisions in plasmas is proposed. Although no natural Lagrangian exists for the Landau-Fokker-Planck equation, an Eulerian variational formulation is found considering the system of partial differential equations that couple the distribution function and the Rosenbluth-MacDonald-Judd potentials. Conservation laws are derived after generalizing the energy-momentum stress tensor for second order Lagrangians and, in the case of a test-particle population in a given plasma background, the action principle is shown to correspond to the Langevin equation for individual particles.

Action principle for Coulomb collisions in plasmas

DOE PAGES

Hirvijoki, Eero

2016-09-14

In this study, an action principle for Coulomb collisions in plasmas is proposed. Although no natural Lagrangian exists for the Landau-Fokker-Planck equation, an Eulerian variational formulation is found considering the system of partial differential equations that couple the distribution function and the Rosenbluth-MacDonald-Judd potentials. Conservation laws are derived after generalizing the energy-momentum stress tensor for second order Lagrangians and, in the case of a test-particle population in a given plasma background, the action principle is shown to correspond to the Langevin equation for individual particles.

Optimization Methods for Spiking Neurons and Networks

PubMed Central

Russell, Alexander; Orchard, Garrick; Dong, Yi; Mihalaş, Ştefan; Niebur, Ernst; Tapson, Jonathan; Etienne-Cummings, Ralph

2011-01-01

Spiking neurons and spiking neural circuits are finding uses in a multitude of tasks such as robotic locomotion control, neuroprosthetics, visual sensory processing, and audition. The desired neural output is achieved through the use of complex neuron models, or by combining multiple simple neurons into a network. In either case, a means for configuring the neuron or neural circuit is required. Manual manipulation of parameters is both time consuming and non-intuitive due to the nonlinear relationship between parameters and the neuron’s output. The complexity rises even further as the neurons are networked and the systems often become mathematically intractable. In large circuits, the desired behavior and timing of action potential trains may be known but the timing of the individual action potentials is unknown and unimportant, whereas in single neuron systems the timing of individual action potentials is critical. In this paper, we automate the process of finding parameters. To configure a single neuron we derive a maximum likelihood method for configuring a neuron model, specifically the Mihalas–Niebur Neuron. Similarly, to configure neural circuits, we show how we use genetic algorithms (GAs) to configure parameters for a network of simple integrate and fire with adaptation neurons. The GA approach is demonstrated both in software simulation and hardware implementation on a reconfigurable custom very large scale integration chip. PMID:20959265

Motor unit recruitment and bursts of activity in the surface electromyogram during a sustained contraction.

PubMed

Riley, Zachary A; Terry, Mary E; Mendez-Villanueva, Alberto; Litsey, Jane C; Enoka, Roger M

2008-06-01

Bursts of activity in the surface electromyogram (EMG) during a sustained contraction have been interpreted as corresponding to the transient recruitment of motor units, but this association has never been confirmed. The current study compared the timing of trains of action potentials discharged by single motor units during a sustained contraction with the bursts of activity detected in the surface EMG signal. The 20 motor units from 6 subjects [recruitment threshold, 35.3 +/- 11.3% maximal voluntary contraction (MVC) force] that were detected with fine wire electrodes discharged 2-9 trains of action potentials (7.2 +/- 5.6 s in duration) when recruited during a contraction that was sustained at a force below its recruitment threshold (target force, 25.4 +/- 10.6% MVC force). High-pass filtering the bipolar surface EMG signal improved its correlation with the single motor unit signal. An algorithm applied to the surface EMG was able to detect 75% of the trains of motor unit action potentials. The results indicate that bursts of activity in the surface EMG during a constant-force contraction correspond to the transient recruitment of higher-threshold motor units in healthy individuals, and these results could assist in the diagnosis and design of treatment in individuals who demonstrate deficits in motor unit activation.

Ionic mechanisms and Ca2+ dynamics underlying the glucose response of pancreatic β cells: a simulation study

PubMed Central

Cha, Chae Young; Nakamura, Yasuhiko; Himeno, Yukiko; Wang, JianWu; Fujimoto, Shinpei; Inagaki, Nobuya; Earm, Yung E

2011-01-01

To clarify the mechanisms underlying the pancreatic β-cell response to varying glucose concentrations ([G]), electrophysiological findings were integrated into a mathematical cell model. The Ca2+ dynamics of the endoplasmic reticulum (ER) were also improved. The model was validated by demonstrating quiescent potential, burst–interburst electrical events accompanied by Ca2+ transients, and continuous firing of action potentials over [G] ranges of 0–6, 7–18, and >19 mM, respectively. These responses to glucose were completely reversible. The action potential, input impedance, and Ca2+ transients were in good agreement with experimental measurements. The ionic mechanisms underlying the burst–interburst rhythm were investigated by lead potential analysis, which quantified the contributions of individual current components. This analysis demonstrated that slow potential changes during the interburst period were attributable to modifications of ion channels or transporters by intracellular ions and/or metabolites to different degrees depending on [G]. The predominant role of adenosine triphosphate–sensitive K+ current in switching on and off the repetitive firing of action potentials at 8 mM [G] was taken over at a higher [G] by Ca2+- or Na+-dependent currents, which were generated by the plasma membrane Ca2+ pump, Na+/K+ pump, Na+/Ca2+ exchanger, and TRPM channel. Accumulation and release of Ca2+ by the ER also had a strong influence on the slow electrical rhythm. We conclude that the present mathematical model is useful for quantifying the role of individual functional components in the whole cell responses based on experimental findings. PMID:21708953

Tracking individual action potentials throughout mammalian axonal arbors.

PubMed

Radivojevic, Milos; Franke, Felix; Altermatt, Michael; Müller, Jan; Hierlemann, Andreas; Bakkum, Douglas J

2017-10-09

Axons are neuronal processes specialized for conduction of action potentials (APs). The timing and temporal precision of APs when they reach each of the synapses are fundamentally important for information processing in the brain. Due to small diameters of axons, direct recording of single AP transmission is challenging. Consequently, most knowledge about axonal conductance derives from modeling studies or indirect measurements. We demonstrate a method to noninvasively and directly record individual APs propagating along millimeter-length axonal arbors in cortical cultures with hundreds of microelectrodes at microsecond temporal resolution. We find that cortical axons conduct single APs with high temporal precision (~100 µs arrival time jitter per mm length) and reliability: in more than 8,000,000 recorded APs, we did not observe any conduction or branch-point failures. Upon high-frequency stimulation at 100 Hz, successive became slower, and their arrival time precision decreased by 20% and 12% for the 100th AP, respectively.

Attribution of movement: Potential links between subjective reports of agency and output monitoring.

PubMed

Sugimori, Eriko; Asai, Tomohisa

2015-01-01

According to agency memory theory, individuals decide whether "I did it" based on a memory trace of "I am doing it". The purpose of this study was to validate the agency memory theory. To this end, several hand actions were individually presented as samples, and participants were asked to perform the sample action, observe the performance of that action by another person, or imagine performing the action. Online feedback received by the participants during the action was manipulated among the different conditions, and output monitoring, in which participants were asked whether they had performed each hand action, was conducted. The rate at which respondents thought that they themselves had performed the action was higher when visual feedback was unaltered than when it was altered (Experiment 1A), and this tendency was observed across all types of altered feedback (Experiment 1B). The observation of an action performed by the hand of another person did not increase the rate at which respondents thought that they themselves had performed the action unless the participants actually did perform the action (Experiments 2A and 2B). In Experiment 3, a relationship was observed between the subjective feeling that "I am the one who is causing an action" and the memory that "I did perform the action". These experiments support the hypothesis that qualitative information and sense of "self" are tagged in a memory trace and that such tags can be used as cues for judgements when the memory is related to the "self".

Private behaviors for the public good: Citizens' actions and U.S. energy conservation

NASA Astrophysics Data System (ADS)

Bolsen, Toby

Why and when do individuals take political actions? Why do some, but not all, citizens make sacrifices for the sake of the public good? Outside of work on participation, political scientists have paid little attention to these questions. I seek to fill this gap by exploring the factors that drive political behaviors. I focus specifically on an important class of behaviors: actions regarding the consumption of energy. I begin by developing a theory that brings together the potentially interactive effects of individual and environmental factors that shape individuals' decisions to take action. I test predictions generated by my theory in three empirical chapters: a media content analysis, laboratory experiment, and survey experiment. The content analysis allows me to assess frames in a communication toward energy consumption, which I examine later in terms of effects. I use the theory and experiments to evaluate the impact of competing forces on attitudes toward energy conservation, willingness to pay for energy saving devices, and actual behavior (e.g., a purchasing decision and financial contribution). My results suggest a primacy of norms, which is fascinating because the impact of norms is under-studied relative to research evaluating the impact of political communications.

Cooperative Drought Adaptation: Integrating Infrastructure Development, Conservation, and Water Transfers into Adaptive Policy Pathways

NASA Astrophysics Data System (ADS)

Zeff, H. B.; Characklis, G. W.; Reed, P. M.; Herman, J. D.

2015-12-01

Water supply policies that integrate portfolios of short-term management decisions with long-term infrastructure development enable utilities to adapt to a range of future scenarios. An effective mix of short-term management actions can augment existing infrastructure, potentially forestalling new development. Likewise, coordinated expansion of infrastructure such as regional interconnections and shared treatment capacity can increase the effectiveness of some management actions like water transfers. Highly adaptable decision pathways that mix long-term infrastructure options and short-term management actions require decision triggers capable of incorporating the impact of these time-evolving decisions on growing water supply needs. Here, we adapt risk-based triggers to sequence a set of potential infrastructure options in combination with utility-specific conservation actions and inter-utility water transfers. Individual infrastructure pathways can be augmented with conservation or water transfers to reduce the cost of meeting utility objectives, but they can also include cooperatively developed, shared infrastructure that expands regional capacity to transfer water. This analysis explores the role of cooperation among four water utilities in the 'Research Triangle' region of North Carolina by formulating three distinct categories of adaptive policy pathways: independent action (utility-specific conservation and supply infrastructure only), weak cooperation (utility-specific conservation and infrastructure development with regional transfers), and strong cooperation (utility specific conservation and jointly developed of regional infrastructure that supports transfers). Results suggest that strong cooperation aids the utilities in meeting their individual objections at substantially lower costs and with fewer irreversible infrastructure options.

Spatial variability in T-tubule and electrical remodeling of left ventricular epicardium in mouse hearts with transgenic Gαq overexpression-induced pathological hypertrophy

PubMed Central

Tao, Wen; Shi, Jianjian; Dorn, Gerald W.; Wei, Lei; Rubart, Michael

2012-01-01

Pathological left ventricular hypertrophy (LVH) is consistently associated with prolongation of the ventricular action potentials. A number of previous studies, employing various experimental models of hypertrophy, have revealed marked differences in the effects of hypertrophy on action potential duration (APD) between myocytes from endocardial and epicardial layers of the LV free wall. It is not known, however, whether pathological LVH is also accompanied by redistribution of APD among myocytes from the same layer in the LV free wall. In the experiments here, LV epicardial action potential remodeling was examined in a mouse model of decompensated LVH, produced by cardiac-restricted transgenic Gαq overexpression. Confocal linescanning-based optical recordings of propagated action potentials from individual in situ cardiomyocytes across the outer layer of the anterior LV epicardium demonstrated spatially non-uniform action potential prolongation in transgenic hearts, giving rise to alterations in spatial dispersion of epicardial repolarization. Local density and distribution of anti-Cx43 mmune reactivity in Gαq hearts were unchanged compared to wild-type hearts, suggesting preservation of intercellular coupling. Confocal microscopy also revealed heterogeneous disorganization of T-tubules in epicardial cardiomyocytes in situ. These data provide evidence of the existence of significant electrical and structural heterogeneity within the LV epicardial layer of hearts with transgenic Gαq overexpression-induced hypertrophy, and further support the notion that a small portion of electrically well connected LV tissue can maintain dispersion of action potential duration through heterogeneity in the activities of sarcolemmal ionic currents that control repolarization. It remains to be examined whether other experimental models of pathological LVH, including pressure overload LVH, similarly exhibit alterations in T-tubule organization and/or dispersion of repolarization within distinct layers of LV myocardium. PMID:22728217

Reliability of directional information in unsorted spikes and local field potentials recorded in human motor cortex.

PubMed

Perge, János A; Zhang, Shaomin; Malik, Wasim Q; Homer, Mark L; Cash, Sydney; Friehs, Gerhard; Eskandar, Emad N; Donoghue, John P; Hochberg, Leigh R

2014-08-01

Action potentials and local field potentials (LFPs) recorded in primary motor cortex contain information about the direction of movement. LFPs are assumed to be more robust to signal instabilities than action potentials, which makes LFPs, along with action potentials, a promising signal source for brain-computer interface applications. Still, relatively little research has directly compared the utility of LFPs to action potentials in decoding movement direction in human motor cortex. We conducted intracortical multi-electrode recordings in motor cortex of two persons (T2 and [S3]) as they performed a motor imagery task. We then compared the offline decoding performance of LFPs and spiking extracted from the same data recorded across a one-year period in each participant. We obtained offline prediction accuracy of movement direction and endpoint velocity in multiple LFP bands, with the best performance in the highest (200-400 Hz) LFP frequency band, presumably also containing low-pass filtered action potentials. Cross-frequency correlations of preferred directions and directional modulation index showed high similarity of directional information between action potential firing rates (spiking) and high frequency LFPs (70-400 Hz), and increasing disparity with lower frequency bands (0-7, 10-40 and 50-65 Hz). Spikes predicted the direction of intended movement more accurately than any individual LFP band, however combined decoding of all LFPs was statistically indistinguishable from spike-based performance. As the quality of spiking signals (i.e. signal amplitude) and the number of significantly modulated spiking units decreased, the offline decoding performance decreased 3.6[5.65]%/month (for T2 and [S3] respectively). The decrease in the number of significantly modulated LFP signals and their decoding accuracy followed a similar trend (2.4[2.85]%/month, ANCOVA, p = 0.27[0.03]). Field potentials provided comparable offline decoding performance to unsorted spikes. Thus, LFPs may provide useful external device control using current human intracortical recording technology. ( NCT00912041.).

Responding to Information Needs in the 1980s.

ERIC Educational Resources Information Center

McGraw, Harold W., Jr.

1979-01-01

Argues that technological developments in cable television, computers, and telecommunications could decentralize power and put the resources of the new technology more broadly at the command of individuals and small groups, but that this potential requires action to be realized. (Author)

Perceptual and Cognitive Impairments and Driving

PubMed Central

Korner-Bitensky, Nicol; Coopersmith, Henry; Mayo, Nancy; Leblanc, Ginette; Kaizer, Franceen

1990-01-01

Perceptual and cognitive disorders that frequently accompany stroke and head injury influence an individual's ability to drive a motor vehicle. Canadian physicians are legally responsible for identifying patients who are potentially unsafe to drive and, if they fail to do so, may be held liable in a civil action suit. The authors review the guidelines for physicians evaluating a patient's fitness to drive after brain injury. They also examine the actions a physician should take when a patient with perceptual and cognitive problems wants to drive. Ultimately, by taking these actions, physicians will help to prevent driving accidents. PMID:21234047

The Role of Embodiment and Individual Empathy Levels in Gesture Comprehension.

PubMed

Jospe, Karine; Flöel, Agnes; Lavidor, Michal

2017-01-01

Research suggests that the action-observation network is involved in both emotional-embodiment (empathy) and action-embodiment (imitation) mechanisms. Here we tested whether empathy modulates action-embodiment, hypothesizing that restricting imitation abilities will impair performance in a hand gesture comprehension task. Moreover, we hypothesized that empathy levels will modulate the imitation restriction effect. One hundred twenty participants with a range of empathy scores performed gesture comprehension under restricted and unrestricted hand conditions. Empathetic participants performed better under the unrestricted compared to the restricted condition, and compared to the low empathy participants. Remarkably however, the latter showed the exactly opposite pattern and performed better under the restricted condition. This pattern was not found in a facial expression recognition task. The selective interaction of embodiment restriction and empathy suggests that empathy modulates the way people employ embodiment in gesture comprehension. We discuss the potential of embodiment-induced therapy to improve empathetic abilities in individuals with low empathy.

The effects of an action video game on visual and affective information processing.

PubMed

Bailey, Kira; West, Robert

2013-04-04

Playing action video games can have beneficial effects on visuospatial cognition and negative effects on social information processing. However, these two effects have not been demonstrated in the same individuals in a single study. The current study used event-related brain potentials (ERPs) to examine the effects of playing an action or non-action video game on the processing of emotion in facial expression. The data revealed that 10h of playing an action or non-action video game had differential effects on the ERPs relative to a no-contact control group. Playing an action game resulted in two effects: one that reflected an increase in the amplitude of the ERPs following training over the right frontal and posterior regions that was similar for angry, happy, and neutral faces; and one that reflected a reduction in the allocation of attention to happy faces. In contrast, playing a non-action game resulted in changes in slow wave activity over the central-parietal and frontal regions that were greater for targets (i.e., angry and happy faces) than for non-targets (i.e., neutral faces). These data demonstrate that the contrasting effects of action video games on visuospatial and emotion processing occur in the same individuals following the same level of gaming experience. This observation leads to the suggestion that caution should be exercised when using action video games to modify visual processing, as this experience could also have unintended effects on emotion processing. Published by Elsevier B.V.

Don't Think, Just Feel the Music: Individuals with Strong Pavlovian-to-Instrumental Transfer Effects Rely Less on Model-based Reinforcement Learning.

PubMed

Sebold, Miriam; Schad, Daniel J; Nebe, Stephan; Garbusow, Maria; Jünger, Elisabeth; Kroemer, Nils B; Kathmann, Norbert; Zimmermann, Ulrich S; Smolka, Michael N; Rapp, Michael A; Heinz, Andreas; Huys, Quentin J M

2016-07-01

Behavioral choice can be characterized along two axes. One axis distinguishes reflexive, model-free systems that slowly accumulate values through experience and a model-based system that uses knowledge to reason prospectively. The second axis distinguishes Pavlovian valuation of stimuli from instrumental valuation of actions or stimulus-action pairs. This results in four values and many possible interactions between them, with important consequences for accounts of individual variation. We here explored whether individual variation along one axis was related to individual variation along the other. Specifically, we asked whether individuals' balance between model-based and model-free learning was related to their tendency to show Pavlovian interferences with instrumental decisions. In two independent samples with a total of 243 participants, Pavlovian-instrumental transfer effects were negatively correlated with the strength of model-based reasoning in a two-step task. This suggests a potential common underlying substrate predisposing individuals to both have strong Pavlovian interference and be less model-based and provides a framework within which to interpret the observation of both effects in addiction.

The faces of pain: a cluster analysis of individual differences in facial activity patterns of pain.

PubMed

Kunz, M; Lautenbacher, S

2014-07-01

There is general agreement that facial activity during pain conveys pain-specific information but is nevertheless characterized by substantial inter-individual differences. With the present study we aim to investigate whether these differences represent idiosyncratic variations or whether they can be clustered into distinct facial activity patterns. Facial actions during heat pain were assessed in two samples of pain-free individuals (n = 128; n = 112) and were later analysed using the Facial Action Coding System. Hierarchical cluster analyses were used to look for combinations of single facial actions in episodes of pain. The stability/replicability of facial activity patterns was determined across samples as well as across different basic social situations. Cluster analyses revealed four distinct activity patterns during pain, which stably occurred across samples and situations: (I) narrowed eyes with furrowed brows and wrinkled nose; (II) opened mouth with narrowed eyes; (III) raised eyebrows; and (IV) furrowed brows with narrowed eyes. In addition, a considerable number of participants were facially completely unresponsive during pain induction (stoic cluster). These activity patterns seem to be reaction stereotypies in the majority of individuals (in nearly two-thirds), whereas a minority displayed varying clusters across situations. These findings suggest that there is no uniform set of facial actions but instead there are at least four different facial activity patterns occurring during pain that are composed of different configurations of facial actions. Raising awareness about these different 'faces of pain' might hold the potential of improving the detection and, thereby, the communication of pain. © 2013 European Pain Federation - EFIC®

Analysis of requirements for accelerating the development of geothermal energy resources in California

NASA Technical Reports Server (NTRS)

Fredrickson, C. D.

1978-01-01

Various resource data are presented showing that geothermal energy has the potential of satisfying a singificant part of California's increasing energy needs. General factors slowing the development of geothermal energy in California are discussed and required actions to accelerate its progress are presented. Finally, scenarios for developing the most promising prospects in the state directed at timely on-line power are given. Specific actions required to realize each of these individual scenarios are identified.

The impact of using old germplasm on genetic merit and diversity-A cattle breed case study.

PubMed

Eynard, Sonia E; Windig, Jack J; Hulsegge, Ina; Hiemstra, Sipke-Joost; Calus, Mario P L

2018-05-29

Artificial selection and high genetic gains in livestock breeds led to a loss of genetic diversity. Current genetic diversity conservation actions focus on long-term maintenance of breeds under selection. Gene banks play a role in such actions by storing genetic materials for future use and the recent development of genomic information is facilitating characterization of gene bank material for better use. Using the Meuse-Rhine-Issel Dutch cattle breed as a case study, we inferred the potential role of germplasm of old individuals for genetic diversity conservation of the current population. First, we described the evolution of genetic merit and diversity over time and then we applied the optimal contribution (OC) strategy to select individuals for maximizing genetic diversity, or maximizing genetic merit while constraining loss of genetic diversity. In the past decades, genetic merit increased while genetic diversity decreased. Genetic merit and diversity were both higher in an OC scenario restricting the rate of inbreeding when old individuals were considered for selection, compared to considering only animals from the current population. Thus, our study shows that gene bank material, in the form of old individuals, has the potential to support long-term maintenance and selection of breeds. © 2018 The Authors. Journal of Animal Breeding and Genetics Published by Blackwell Verlag GmbH.

Spontaneous and evoked release are independently regulated at individual active zones.

PubMed

Melom, Jan E; Akbergenova, Yulia; Gavornik, Jeffrey P; Littleton, J Troy

2013-10-30

Neurotransmitter release from synaptic vesicle fusion is the fundamental mechanism for neuronal communication at synapses. Evoked release following an action potential has been well characterized for its function in activating the postsynaptic cell, but the significance of spontaneous release is less clear. Using transgenic tools to image single synaptic vesicle fusion events at individual release sites (active zones) in Drosophila, we characterized the spatial and temporal dynamics of exocytotic events that occur spontaneously or in response to an action potential. We also analyzed the relationship between these two modes of fusion at single release sites. A majority of active zones participate in both modes of fusion, although release probability is not correlated between the two modes of release and is highly variable across the population. A subset of active zones is specifically dedicated to spontaneous release, indicating a population of postsynaptic receptors is uniquely activated by this mode of vesicle fusion. Imaging synaptic transmission at individual release sites also revealed general rules for spontaneous and evoked release, and indicate that active zones with similar release probability can cluster spatially within individual synaptic boutons. These findings suggest neuronal connections contain two information channels that can be spatially segregated and independently regulated to transmit evoked or spontaneous fusion signals.

Occlusion of LTP-Like Plasticity in Human Primary Motor Cortex by Action Observation

PubMed Central

Lepage, Jean-François; Morin-Moncet, Olivier; Beaulé, Vincent; de Beaumont, Louis; Champoux, Francois; Théoret, Hugo

2012-01-01

Passive observation of motor actions induces cortical activity in the primary motor cortex (M1) of the onlooker, which could potentially contribute to motor learning. While recent studies report modulation of motor performance following action observation, the neurophysiological mechanism supporting these behavioral changes remains to be specifically defined. Here, we assessed whether the observation of a repetitive thumb movement – similarly to active motor practice – would inhibit subsequent long-term potentiation-like (LTP) plasticity induced by paired-associative stimulation (PAS). Before undergoing PAS, participants were asked to either 1) perform abductions of the right thumb as fast as possible; 2) passively observe someone else perform thumb abductions; or 3) passively observe a moving dot mimicking thumb movements. Motor evoked potentials (MEP) were used to assess cortical excitability before and after motor practice (or observation) and at two time points following PAS. Results show that, similarly to participants in the motor practice group, individuals observing repeated motor actions showed marked inhibition of PAS-induced LTP, while the “moving dot” group displayed the expected increase in MEP amplitude, despite differences in baseline excitability. Interestingly, LTP occlusion in the action-observation group was present even if no increase in cortical excitability or movement speed was observed following observation. These results suggest that mere observation of repeated hand actions is sufficient to induce LTP, despite the absence of motor learning. PMID:22701704

Measuring Environmental Health Perception among College Students

ERIC Educational Resources Information Center

Ratnapradipa, Dhitinut; Brown, Stephen L.; Middleton, Wendi K.; Wodika, Alicia B.

2011-01-01

One's knowledge, perception, and attitude are fundamental in determining how one behaves regarding environmental hazards. While science has made great strides in promoting environmental health, threats still exist, largely due to individual actions in response to potential health hazards. Undergraduate students (n = 395) enrolled in an…

Who will attack the competitors? How political parties resolve strategic and collective action dilemmas in negative campaigning

PubMed Central

Dolezal, Martin; Müller, Wolfgang C

2015-01-01

Negative campaigning presents parties with a collective action problem. While parties would prefer to have their competitors attacked, potential backlash effects from negative messages mean that individual politicians typically lack the incentives to carry out such attacks. We theorize that parties solve this problem by implementing a division of labour that takes into account the incentives of individual office holders, their availability for campaign activity, and media relevance. Drawing on these arguments we expect that holders of high public office and party leaders are less likely to issue attacks, leaving the bulk of the ‘dirty work’ to be carried out by party floor leaders and general secretaries. Examining almost 8000 press releases issued by over 600 individual politicians during four election campaigns in Austria, we find strong support for our theoretical expectations. PMID:28989298

Principles of Lifeworld Led Public Health Practice in the UK and Sweden: Reducing Health Inequalities.

PubMed

Hemingway, Ann; Norton, Liz; Aarts, Clara

2015-01-01

The purpose of this paper is to consider the role of the lifeworld perspective in reducing inequalities in health and we explain how the public health practitioner can use this perspective to address public health issues with individuals and groups. We offer ideas for public health actions that are based on and deal with the lifeworld context of individual people or families. Each of the dimensions of the lifeworld temporality, spatiality, intersubjectivity, embodiment and mood are outlined and their significance explained in relation to health inequalities. Suggestions for action to reduce health inequalities are made and overall principles of lifeworld led public health practice are proposed by way of conclusion. The principles comprise understanding the community members' lifeworld view, understanding their view of their potential, offering resources and facilitating empowerment, and sharing lifeworld case studies and lobbying to influence local and national policy in relation to both the individual and communities.

How to think about your drink: Action-identification and the relation between mindfulness and dyscontrolled drinking.

PubMed

Schellhas, Laura; Ostafin, Brian D; Palfai, Tibor P; de Jong, Peter J

2016-05-01

Cross-sectional and intervention research have shown that mindfulness is inversely associated with difficulties in controlling alcohol use. However, little is known regarding the mechanisms through which mindfulness is related to increased control over drinking. One potential mechanism consists of the way individuals represent their drinking behaviour. Action identification theory proposes that self-control of behaviour is improved by shifting from high-level representations regarding the meaning of a behaviour to lower-level representations regarding "how-to" aspects of a behaviour. Because mindfulness involves present-moment awareness, it may help to facilitate such shifts. We hypothesized that an inverse relation between mindfulness and dyscontrolled drinking would be partially accounted for by the way individuals mentally represent their drinking behaviour - i.e., reduced levels of high-level action identification and increased levels of low-level action identification. One hundred and twenty five undergraduate psychology students completed self-report measures of mindful awareness, action identification of alcohol use, and difficulty in controlling alcohol use. Results supported the hypothesis that high-level action identification partially mediates the relation between mindfulness and dyscontrolled drinking but did not support a mediating role for low-level action identification. These results suggest that mindfulness can improve self-control of alcohol by changing the way we think about our drinking behaviour. Copyright © 2016. Published by Elsevier Ltd.

34 CFR 361.19 - Affirmative action for individuals with disabilities.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 2 2010-07-01 2010-07-01 false Affirmative action for individuals with disabilities... Administration § 361.19 Affirmative action for individuals with disabilities. The State plan must assure that the State agency takes affirmative action to employ and advance in employment qualified individuals with...

34 CFR 361.19 - Affirmative action for individuals with disabilities.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 34 Education 2 2011-07-01 2010-07-01 true Affirmative action for individuals with disabilities... Administration § 361.19 Affirmative action for individuals with disabilities. The State plan must assure that the State agency takes affirmative action to employ and advance in employment qualified individuals with...

On the continuous differentiability of inter-spike intervals of synaptically connected cortical spiking neurons in a neuronal network.

PubMed

Kumar, Gautam; Kothare, Mayuresh V

2013-12-01

We derive conditions for continuous differentiability of inter-spike intervals (ISIs) of spiking neurons with respect to parameters (decision variables) of an external stimulating input current that drives a recurrent network of synaptically connected neurons. The dynamical behavior of individual neurons is represented by a class of discontinuous single-neuron models. We report here that ISIs of neurons in the network are continuously differentiable with respect to decision variables if (1) a continuously differentiable trajectory of the membrane potential exists between consecutive action potentials with respect to time and decision variables and (2) the partial derivative of the membrane potential of spiking neurons with respect to time is not equal to the partial derivative of their firing threshold with respect to time at the time of action potentials. Our theoretical results are supported by showing fulfillment of these conditions for a class of known bidimensional spiking neuron models.

Age factors potentiating drug toxicity in the reproductive axis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walker, R.F.

Traditionally, the drug toxicity in the reproductive system has been a concern only as it affects fertility and fecundity in young individuals. The purpose of this report is to address the potential problem of synergy between drug actions and abnormal secretion of reproductive hormones that together produce disease in older individuals. Thus, reproductive toxicity has different, but no less serious implications in aging individuals. During aging, the coordinated function of elements within the reproductive neuroendocrine axis degrades. This change promotes atypical secretion of hormones producing abnormal responses in target organs and thus creates a condition with pathogenic potential. Certain drugsmore » may contribute to reproductive toxicity in aging individuals either by accelerating the process of dysregulation and/or by synergizing with hormones to stimulate pathologic changes in target tissues. The geriatric population or the world is increasing, and since it consumes a proportionately larger percentage of drugs than younger groups, this novel form of reproductive toxicity may represent a problem in drug safety that warrants serious consideration.« less

Comparing sequencing assays and human-machine analyses in actionable genomics for glioblastoma.

PubMed

Wrzeszczynski, Kazimierz O; Frank, Mayu O; Koyama, Takahiko; Rhrissorrakrai, Kahn; Robine, Nicolas; Utro, Filippo; Emde, Anne-Katrin; Chen, Bo-Juen; Arora, Kanika; Shah, Minita; Vacic, Vladimir; Norel, Raquel; Bilal, Erhan; Bergmann, Ewa A; Moore Vogel, Julia L; Bruce, Jeffrey N; Lassman, Andrew B; Canoll, Peter; Grommes, Christian; Harvey, Steve; Parida, Laxmi; Michelini, Vanessa V; Zody, Michael C; Jobanputra, Vaidehi; Royyuru, Ajay K; Darnell, Robert B

2017-08-01

To analyze a glioblastoma tumor specimen with 3 different platforms and compare potentially actionable calls from each. Tumor DNA was analyzed by a commercial targeted panel. In addition, tumor-normal DNA was analyzed by whole-genome sequencing (WGS) and tumor RNA was analyzed by RNA sequencing (RNA-seq). The WGS and RNA-seq data were analyzed by a team of bioinformaticians and cancer oncologists, and separately by IBM Watson Genomic Analytics (WGA), an automated system for prioritizing somatic variants and identifying drugs. More variants were identified by WGS/RNA analysis than by targeted panels. WGA completed a comparable analysis in a fraction of the time required by the human analysts. The development of an effective human-machine interface in the analysis of deep cancer genomic datasets may provide potentially clinically actionable calls for individual patients in a more timely and efficient manner than currently possible. NCT02725684.

Hearing loss and perceptions of noise in the workplace among rural Australians.

PubMed

Williams, Warwick; Purdy, Suzanne; Murray, Narelle; LePage, Eric; Challinor, Kathy

2004-06-01

To compare measured hearing levels of individuals regularly exposed to noise in their workplace to self-reported and family-reported hearing loss. To compare the attitudes and preventative actions adopted by individuals who are more aware of the potential for hearing loss to less aware individuals. The project examined the perceptions of rural workers concerning noise, noise exposure and hearing. The subjects completed a 'Noise at Work' questionnaire and some demographic data at the time of audiometric testing. The subjects were recruited when attending their rural health clinic for audiometric testing. Participants comprised 113 men and 23 women (20-65 years, mean = 39.6, SD = 11.4) working across a range of activities at different levels in their workplaces. The range in current employment was from 0.5 to 45 years (mean = 13.8, SD = 10.7). Hearing tests were compared with perceptions of noise annoyance, hearing damage risk and preventative action. Self- and family-reported hearing loss and conversational difficulties in noise correlated well with measured audiograms. Perceptions of workplace noise tended to be more positive if people felt they had hearing problems. There was no difference in preventative action between those who did and did not feel they had hearing problems. Both groups rated barriers to action and lack of self-efficacy in a similar negative way. There is a need for specific training to ensure that rural workers have skills to take more positive action in reducing noise exposure at work.

13 CFR 400.206 - Environmental requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... “normally” is stressed; there may be individual cases in which specific factors require contrary action. (ii... other cases, potentially affect: (A) A floodplain; (B) A wetland; (C) Important farmlands, or prime... supportive studies have been conducted to assure that such studies are objective and comprehensive in scope...

13 CFR 400.206 - Environmental requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... “normally” is stressed; there may be individual cases in which specific factors require contrary action. (ii... other cases, potentially affect: (A) A floodplain; (B) A wetland; (C) Important farmlands, or prime... supportive studies have been conducted to assure that such studies are objective and comprehensive in scope...

13 CFR 400.206 - Environmental requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... “normally” is stressed; there may be individual cases in which specific factors require contrary action. (ii... other cases, potentially affect: (A) A floodplain; (B) A wetland; (C) Important farmlands, or prime... supportive studies have been conducted to assure that such studies are objective and comprehensive in scope...

APPROACHES TO EXTRAPOLATING EFFECTS OF EDCS ACROSS BIOLOGICAL LEVELS OF ORGANIZATION IN FISH

EPA Science Inventory

A challenge in ecological risk assessments is to obtain, in a resource-effective manner, information that provides insight both into chemical mode/mechanism of action (MOA) and adverse effects in individual animals, which are indicative of potential population-level responses. T...

Reliability of directional information in unsorted spikes and local field potentials recorded in human motor cortex

PubMed Central

Perge, János A.; Zhang, Shaomin; Malik, Wasim Q.; Homer, Mark L.; Cash, Sydney; Friehs, Gerhard; Eskandar, Emad N.; Donoghue, John P.; Hochberg, Leigh R.

2014-01-01

Objective Action potentials and local field potentials (LFPs) recorded in primary motor cortex contain information about the direction of movement. LFPs are assumed to be more robust to signal instabilities than action potentials, which makes LFPs along with action potentials a promising signal source for brain-computer interface applications. Still, relatively little research has directly compared the utility of LFPs to action potentials in decoding movement direction in human motor cortex. Approach We conducted intracortical multielectrode recordings in motor cortex of two persons (T2 and [S3]) as they performed a motor imagery task. We then compared the offline decoding performance of LFPs and spiking extracted from the same data recorded across a one-year period in each participant. Main results We obtained offline prediction accuracy of movement direction and endpoint velocity in multiple LFP bands, with the best performance in the highest (200–400Hz) LFP frequency band, presumably also containing low-pass filtered action potentials. Cross-frequency correlations of preferred directions and directional modulation index showed high similarity of directional information between action potential firing rates (spiking) and high frequency LFPs (70–400Hz), and increasing disparity with lower frequency bands (0–7, 10–40 and 50–65Hz). Spikes predicted the direction of intended movement more accurately than any individual LFP band, however combined decoding of all LFPs was statistically indistinguishable from spike based performance. As the quality of spiking signals (i.e. signal amplitude) and the number of significantly modulated spiking units decreased, the offline decoding performance decreased 3.6[5.65]%/month (for T2 and [S3] respectively). The decrease in the number of significantly modulated LFP signals and their decoding accuracy followed a similar trend (2.4[2.85]%/month, ANCOVA, p=0.27[0.03]). Significance Field potentials provided comparable offline decoding performance to unsorted spikes. Thus, LFPs may provide useful external device control using current human intracortical recording technology. (Clinical trial registration number: NCT00912041) PMID:24921388

Transforming Constructivist Learning into Action: Design Thinking in Education

ERIC Educational Resources Information Center

Scheer, Andrea; Noweski, Christine; Meinel, Christoph

2012-01-01

In an ever changing society of the 21st century, there is a demand to equip students with meta competences going beyond cognitive knowledge. Education, therefore, needs a transition from transferring knowledge to developing individual potentials with the help of constructivist learning. Advantages of constructivist learning, and criteria for its…

The Effect of Hierarchical Task Representations on Task Selection in Voluntary Task Switching

ERIC Educational Resources Information Center

Weaver, Starla M.; Arrington, Catherine M.

2013-01-01

The current study explored the potential for hierarchical representations to influence action selection during voluntary task switching. Participants switched between 4 individual task elements. In Experiment 1, participants were encouraged to represent the task elements as grouped within a hierarchy based on experimental manipulations of varying…

75 FR 12688 - Safety Zone; Gallants Channel, Beaufort, NC

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-17

... immediate action is needed to ensure the safety of human life and property from the hazards of falling... life and property on navigable waters and due to the hazards associated with potential falling debris... which do not individually or cumulatively have a significant effect on the human environment. This rule...

The Discourse of Pauli Murray: Rhetoric of Process.

ERIC Educational Resources Information Center

Foss, Sonja K.

The purposes of black feminist Pauli Murray in her feminist discourse are to help individuals gain self-awareness about their personal and social histories and about their potential for action, and to direct the energies of all oppressed people toward working together against oppression. Murray's discourse is addressed to successful professional…

Limiting climate change: what’s most worth doing?

NASA Astrophysics Data System (ADS)

Stern, Paul C.; Wolske, Kimberly S.

2017-09-01

Wynes and Nicholas (2017 Environ. Res. Lett. 12 074024) claim that some of the most important actions individuals can take to mitigate climate change have been overlooked, particularly in educational messages for adolescents, and estimate the potential impact of some of these, including having fewer children and living car free. These estimates raise questions that deserve serious analysis, but they are based only on the technical potential of the actions and do not consider the plasticity of the behaviors and the feasibility of policies to support them. The actions identified as having the greatest potential are lifestyle changes that accrue benefits over a lifetime or longer, so are not realistic alternatives to actions that can be enacted immediately. But presenting lifestyle choices and the relative impacts of different actions as discussion starters for adolescents could be promising, especially if the discussions highlight issues of behavioral plasticity, policy plasticity, and time scale. Research has identified design principles for interventions to achieve the strongest emissions reductions at time scales up to the decadal. Design principles for achieving longer-lasting changes deserve careful analytic attention, as well as a stronger focus in adolescent textbooks and messages to the general population. Both adolescents and researchers would do well to think carefully about what could promote the generational changes needed to reach a climate change target such as ‘well below 2 °C’.

BETWEEN KNOWING AND BELIEVING: SALVAGING ILLUSION'S RIGHTFUL PLACE IN PSYCHOANALYSIS.

PubMed

Tuch, Richard

2016-01-01

Illusion has historically received insufficient psychoanalytic attention, even though it plays an indispensable and adaptive role that helps protect individuals from becoming traumatized by the most psychically noxious aspects of reality. Trauma is mitigated by an individual's knowing about the existence of such realities yet simultaneously believing them non-existent, with neither position granted exclusivity. Psychoanalytic theory is surprisingly predicated on the employment of illusions that picture an individual capable of controlling the potentially traumatic actions of others, just so long as the individual effectively manages his own intrapsychic processes (wishes, fantasies, impulses, etc.). The role of illusion in everyday life is highlighted. © 2016 The Psychoanalytic Quarterly, Inc.

Real-time estimation and biofeedback of single-neuron firing rates using local field potentials

PubMed Central

Hall, Thomas M.; Nazarpour, Kianoush; Jackson, Andrew

2014-01-01

The long-term stability and low-frequency composition of local field potentials (LFPs) offer important advantages for robust and efficient neuroprostheses. However, cortical LFPs recorded by multi-electrode arrays are often assumed to contain only redundant information arising from the activity of large neuronal populations. Here we show that multichannel LFPs in monkey motor cortex each contain a slightly different mixture of distinctive slow potentials that accompany neuronal firing. As a result, the firing rates of individual neurons can be estimated with surprising accuracy. We implemented this method in a real-time biofeedback brain–machine interface, and found that monkeys could learn to modulate the activity of arbitrary neurons using feedback derived solely from LFPs. These findings provide a principled method for monitoring individual neurons without long-term recording of action potentials. PMID:25394574

Upper stimulation threshold for retinal ganglion cell activation.

PubMed

Meng, Kevin; Fellner, Andreas; Rattay, Frank; Ghezzi, Diego; Meffin, Hamish; Ibbotson, Michael R; Kameneva, Tatiana

2018-08-01

The existence of an upper threshold in electrically stimulated retinal ganglion cells (RGCs) is of interest because of its relevance to the development of visual prosthetic devices, which are designed to restore partial sight to blind patients. The upper threshold is defined as the stimulation level above which no action potentials (direct spikes) can be elicited in electrically stimulated retina. We collected and analyzed in vitro recordings from rat RGCs in response to extracellular biphasic (anodic-cathodic) pulse stimulation of varying amplitudes and pulse durations. Such responses were also simulated using a multicompartment model. We identified the individual cell variability in response to stimulation and the phenomenon known as upper threshold in all but one of the recorded cells (n  =  20/21). We found that the latencies of spike responses relative to stimulus amplitude had a characteristic U-shape. In silico, we showed that the upper threshold phenomenon was observed only in the soma. For all tested biphasic pulse durations, electrode positions, and pulse amplitudes above lower threshold, a propagating action potential was observed in the distal axon. For amplitudes above the somatic upper threshold, the axonal action potential back-propagated in the direction of the soma, but the soma's low level of hyperpolarization prevented action potential generation in the soma itself. An upper threshold observed in the soma does not prevent spike conductance in the axon.

Collaboration in Action: Office of Research and Development ...

EPA Pesticide Factsheets

The "Collaboration in Action: US EPA's Office of Research and Develop - Current Wildfire Research Program" was invited by the USDA's US Forest Service's Scientific Executive Committee to provide USFS scientific leadership active and potential future opportunities for cooperation/collaboration. Health impacts of wildfire smoke merit the attention and action of the US EPA and current research is supported in the ACE and SHC Research Programs. Wildland fire smoke research has taken on greater importance because the 1) contribution of wildland fire PM emissions relative to total US PM emissions is increasing, 2) the population health impacts are measurable and costly, 3) vulnerable and sensitive populations at-risk are increasing attendant to our aging U.S. population and the increasing area of the wildland-urban interface, and 4) health impacts of smoke could be minimized by identifying at-risk individuals and reducing their exposures. Examples are provided. The "Collaboration in Action: US EPA's Office of Research and Develop - Current Wildfire Research Program" was invited by the USDA's US Forest Service's Scientific Executive Committee to provide USFS scientific leadership active and potential future opportunities for cooperation/collaboration.

Decreased afferent excitability contributes to synaptic depression during high-frequency stimulation in hippocampal area CA1

PubMed Central

Kim, Eunyoung; Owen, Benjamin; Holmes, William R.

2012-01-01

Long-term potentiation (LTP) is often induced experimentally by continuous high-frequency afferent stimulation (HFS), typically at 100 Hz for 1 s. Induction of LTP requires postsynaptic depolarization and voltage-dependent calcium influx. Induction is more effective if the same number of stimuli are given as a series of short bursts rather than as continuous HFS, in part because excitatory postsynaptic potentials (EPSPs) become strongly depressed during HFS, reducing postsynaptic depolarization. In this study, we examined mechanisms of EPSP depression during HFS in area CA1 of rat hippocampal brain slices. We tested for presynaptic terminal vesicle depletion by examining minimal stimulation-evoked excitatory postsynaptic currents (EPSCs) during 100-Hz HFS. While transmission failures increased, consistent with vesicle depletion, EPSC latencies also increased during HFS, suggesting a decrease in afferent excitability. Extracellular recordings of Schaffer collateral fiber volleys confirmed a decrease in afferent excitability, with decreased fiber volley amplitudes and increased latencies during HFS. To determine the mechanism responsible for fiber volley changes, we recorded antidromic action potentials in single CA3 pyramidal neurons evoked by stimulating Schaffer collateral axons. During HFS, individual action potentials decreased in amplitude and increased in latency, and these changes were accompanied by a large increase in the probability of action potential failure. Time derivative and phase-plane analyses indicated decreases in both axon initial segment and somato-dendritic components of CA3 neuron action potentials. Our results indicate that decreased presynaptic axon excitability contributes to depression of excitatory synaptic transmission during HFS at synapses between Schaffer collaterals and CA1 pyramidal neurons. PMID:22773781

Disability, disparate impact, and class actions.

PubMed

Stein, Michael Ashley; Waterstone, Michael E

2006-12-01

Following Title VII's enactment, group-based employment discrimination actions flourished due to disparate impact theory and the class action device. Courts recognized that subordination that defined a group's social identity was also sufficient legally to bind members together, even when relief had to be issued individually. Woven through these cases was a notion of panethnicity that united inherently unrelated groups into a common identity, for example, Asian Americans. Stringent judicial interpretation subsequently eroded both legal frameworks and it has become increasingly difficult to assert collective employment actions, even against discriminatory practices affecting an entire group. This deconstruction has immensely disadvantaged persons with disabilities. Under the Americans with Disabilities Act (ADA), individual employee claims to accommodate specific impairments, such as whether to install ramps or replace computer screens, have all but eclipsed a coherent theory of disability-based disparate impact law. Moreover, the class action device has been virtually nonexistent in disability discrimination employment cases. The absence of collective action has been especially harmful because the realm of the workplace is precisely where group-based remedies are needed most. Specifically, a crucial but overlooked issue in disability integration is the harder-to-reach embedded norms that require job and policy modifications. The Article argues that pandisability theory serves as an analogue to earlier notions of panethnicity and provides an equally compelling heuristic for determining class identity. It shows that pandisability undergirds ADA public service and public accommodation class actions in which individualized remedy assessments have been accepted as part of group-based challenges to social exclusion. The Article also demonstrates that this broader vision of collective action is consistent with the history underlying the class action device. Taking advantage of the relatively blank slate of writing on group-based disability discrimination, it offers an intrepid vision of the ADA's potential for transforming workplace environments. In advocating for a return to an earlier paradigm of collective action in the disability context, the Article also provides some thoughts on challenging race- and sex-based discrimination. Future workplace policies should plan for "all jobs to include some physical activity" unrelated to job qualifications in order to "dissuade unhealthy people from coming to work at Wal-Mart."

Predicting individual differences in decision-making process from signature movement styles: an illustrative study of leaders.

PubMed

Connors, Brenda L; Rende, Richard; Colton, Timothy J

2013-01-01

There has been a surge of interest in examining the utility of methods for capturing individual differences in decision-making style. We illustrate the potential offered by Movement Pattern Analysis (MPA), an observational methodology that has been used in business and by the US Department of Defense to record body movements that provide predictive insight into individual differences in decision-making motivations and actions. Twelve military officers participated in an intensive 2-h interview that permitted detailed and fine-grained observation and coding of signature movements by trained practitioners using MPA. Three months later, these subjects completed four hypothetical decision-making tasks in which the amount of information sought out before coming to a decision, as well as the time spent on the tasks, were under the partial control of the subject. A composite MPA indicator of how a person allocates decision-making actions and motivations to balance both Assertion (exertion of tangible movement effort on the environment to make something occur) and Perspective (through movements that support shaping in the body to perceive and create a suitable viewpoint for action) was highly correlated with the total number of information draws and total response time-individuals high on Assertion reached for less information and had faster response times than those high on Perspective. Discussion focuses on the utility of using movement-based observational measures to capture individual differences in decision-making style and the implications for application in applied settings geared toward investigations of experienced leaders and world statesmen where individuality rules the day.

Predicting individual differences in decision-making process from signature movement styles: an illustrative study of leaders

PubMed Central

Connors, Brenda L.; Rende, Richard; Colton, Timothy J.

2013-01-01

There has been a surge of interest in examining the utility of methods for capturing individual differences in decision-making style. We illustrate the potential offered by Movement Pattern Analysis (MPA), an observational methodology that has been used in business and by the US Department of Defense to record body movements that provide predictive insight into individual differences in decision-making motivations and actions. Twelve military officers participated in an intensive 2-h interview that permitted detailed and fine-grained observation and coding of signature movements by trained practitioners using MPA. Three months later, these subjects completed four hypothetical decision-making tasks in which the amount of information sought out before coming to a decision, as well as the time spent on the tasks, were under the partial control of the subject. A composite MPA indicator of how a person allocates decision-making actions and motivations to balance both Assertion (exertion of tangible movement effort on the environment to make something occur) and Perspective (through movements that support shaping in the body to perceive and create a suitable viewpoint for action) was highly correlated with the total number of information draws and total response time—individuals high on Assertion reached for less information and had faster response times than those high on Perspective. Discussion focuses on the utility of using movement-based observational measures to capture individual differences in decision-making style and the implications for application in applied settings geared toward investigations of experienced leaders and world statesmen where individuality rules the day. PMID:24069012

Bidirectional transfer between joint and individual actions in a task of discrete force production.

PubMed

Masumoto, Junya; Inui, Nobuyuki

2017-07-01

The present study examined bidirectional learning transfer between joint and individual actions involving discrete isometric force production with the right index finger. To examine the effects of practice of joint action on performance of the individual action, participants performed a pre-test (individual condition), practice blocks (joint condition), and a post-test (individual condition) (IJI task). To examine the effects of practice of the individual action on performance during the joint action, the participants performed a pre-test (joint condition), practice blocks (individual condition), and a post-test (joint condition) (JIJ task). Whereas one participant made pressing movements with a target peak force of 10% maximum voluntary contraction (MVC) in the individual condition, two participants produced the target force of the sum of 10% MVC produced by each of them in the joint condition. In both the IJI and JIJ tasks, absolute errors and standard deviations of peak force were smaller post-test than pre-test, indicating bidirectional transfer between individual and joint conditions for force accuracy and variability. Although the negative correlation between forces produced by two participants (complementary force production) became stronger with practice blocks in the IJI task, there was no difference between the pre- and post-tests for the negative correlation in the JIJ task. In the JIJ task, the decrease in force accuracy and variability during the individual action did not facilitate complementary force production during the joint action. This indicates that practice performed by two people is essential for complementary force production in joint action.

Empowering social action through narratives of identity and culture.

PubMed

Williams, Lewis; Labonte, Ronald; O'Brien, Mike

2003-03-01

Concern at widening health and wealth inequities between communities accompanying processes of globalization in recent years are reflected in contemporary definitions of health promotion, premised on the stratagem of individuals and communities increasing control over factors that determine health, thereby improving their health status. Such community empowerment practice is commonly accepted within the health promotion literature as encompassing intrapersonal, interpersonal and socio-political elements. Less articulated and understood, however, are the processes whereby the identities and cultures of marginalized communities intersect with and reverberate through these levels of action. The potential of identity and culture as important individual and community resources within social action takes on further significance within global-ized contexts, which simultaneously expose marginalized communities to dominant cultural power relations while affording members new avenues for cultural expression. In this paper we highlight culture and identity as important aspects of the empowerment process, drawing on the experiences of migrant Tongan and Samoan women throughout a social action process in Aotearoa/New Zealand. In particular, narratives of identity and culture within storytelling as an empowerment practice are explicated, as is the articulation of identity and culture within more structurally orientated power relations throughout subsequent activities related to policy advocacy.

Space for action: How practitioners influence environmental assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kågström, Mari, E-mail: mari.kagstrom@slu.se; Richardson, Tim, E-mail: tim.richardson@nmbu.no

2015-09-15

Highlights: • The concept of ‘space for action’ offers an important new lens on EA practice. • Focuses on the relation between practitioner's understanding and their actions • Environmental assessment practice is decisively shaped by practitioners. • Practitioners may underestimate their potential to make a difference. • Contributes to understanding change in the environmental assessment field. This article contributes to understanding of how change occurs in the field of environmental assessment (EA). It argues that the integration of new issues in EA, such as human health, is significantly influenced by how practitioners' understandings shape their actions, and by what happensmore » when those, possibly different, interpretations of appropriate action are acted out. The concept of space for action is developed as a means of investigating this relation between understanding and action. Frame theory is also used, to develop a sharper focus on how ‘potential spaces for action’ are created, what these imply for (individuals') preferred choices and actions in certain situations, and what happens in practice when these are acted out and ‘actual spaces for action’ are created. This novel approach is then applied in a Swedish case study of transport planning. The analysis reveals the important work done by practitioners, revealing just how EA practice is decisively shaped by practitioners. Analysis of practice using the lens of spaces for action offers an important new perspective in understanding how the field adapts to new challenges.« less

Effects of action video game training on visual working memory.

PubMed

Blacker, Kara J; Curby, Kim M; Klobusicky, Elizabeth; Chein, Jason M

2014-10-01

The ability to hold visual information in mind over a brief delay is critical for acquiring information and navigating a complex visual world. Despite the ubiquitous nature of visual working memory (VWM) in our everyday lives, this system is fundamentally limited in capacity. Therefore, the potential to improve VWM through training is a growing area of research. An emerging body of literature suggests that extensive experience playing action video games yields a myriad of perceptual and attentional benefits. Several lines of converging work suggest that action video game play may influence VWM as well. The current study utilized a training paradigm to examine whether action video games cause improvements to the quantity and/or the quality of information stored in VWM. The results suggest that VWM capacity, as measured by a change detection task, is increased after action video game training, as compared with training on a control game, and that some improvement to VWM precision occurs with action game training as well. However, these findings do not appear to extend to a complex span measure of VWM, which is often thought to tap into higher-order executive skills. The VWM improvements seen in individuals trained on an action video game cannot be accounted for by differences in motivation or engagement, differential expectations, or baseline differences in demographics as compared with the control group used. In sum, action video game training represents a potentially unique and engaging platform by which this severely capacity-limited VWM system might be enhanced.

Neuroticism and attitudes toward action in 19 countries.

PubMed

Ireland, Molly E; Hepler, Justin; Li, Hong; Albarracín, Dolores

2015-06-01

Although individuals scoring high on Neuroticism tend to avoid taking action when faced with challenges, Neuroticism is also characterized by impulsivity. To explore cognitive biases related to this costly behavior pattern, we tested whether individuals who rated themselves as higher in Neuroticism would evaluate the general concepts of action and inaction as, respectively, more negative and positive. We further investigated whether anxiety and depression would mediate and individualism-collectivism would moderate these relations in a large international sample. Participants (N = 3,827 college students; 69% female) from 19 countries completed surveys measuring Neuroticism, attitudes toward action and inaction, depression, anxiety, and individualism-collectivism. Hierarchical linear models tested the above predictions. Neuroticism negatively correlated with attitudes toward action and positively correlated with attitudes toward inaction. Furthermore, anxiety was primarily responsible for emotionally unstable individuals' less positive attitudes toward action, and individuals who endorsed more collectivistic than individualistic beliefs showed a stronger negative association between Neuroticism and attitudes toward action. Researchers and practitioners interested in understanding and remediating the negative consequences of Neuroticism should pay greater attention to attitudes toward action and inaction, particularly focusing on their links with anxiety and individualism-collectivism. © 2014 Wiley Periodicals, Inc.

Goal Disengagement in Emerging Adulthood: The Adaptive Potential of Action Crises

ERIC Educational Resources Information Center

Brandstätter, Veronika; Herrmann, Marcel

2016-01-01

In emerging adulthood, being committed to and making progress on important personal goals constitutes a source of identity and well-being. Goal striving, however, does not always go without problems. Even though highly committed to a goal, individuals may experience recurring setbacks and, consequently, increasing doubts about the goal that might…

The Farther Reaches of Gestalt Therapy: A Conversation with George Brown

ERIC Educational Resources Information Center

Carter, Betsie; Vargiu, Susan

1977-01-01

This interview evokes much of the essential spirit of Gestalt Therapy and some of its techniques. Gestalt is a method of growth for developing the potential of the healthy individual. It emphasizes acquiring awareness of the existential moment, integrating unconscious aspects of self, and taking responsibility for one's actions. (Author/BP)

Enhancing Elementary-School Mathematics Teachers' Efficacy Beliefs: A Qualitative Action Research

ERIC Educational Resources Information Center

Katz, Sara; Stupel, Moshe

2016-01-01

Individuals and societies that can use mathematics effectively in this period of rapid changes will have a voice on increasing the opportunities and potentials which can shape their future. This has brought affective characteristics, such as self-efficacy, that affect mathematics achievement into focus of the research. Teacher efficacy refers to…

Harm avoiders suppress motor resonance to observed immoral actions

PubMed Central

Candidi, Matteo; Sforza, Anna Laura; Aglioti, Salvatore Maria

2015-01-01

Motor resonance (MR) contingent upon action observation is thought to occur largely automatically. Although recent studies suggest that this process is not completely impervious to top-down modulations, much less is known on the possible role of the moral connotation of observed action goal in modulating MR. Here, we explored whether observing actions with different moral connotations modulates MR and whether any modulation depends on the onlookers’ personality. To this aim, we recorded motor potentials evoked by single-pulse transcranial magnetic stimulation from hand muscles of participants who were watching images of a model performing hand actions with the same postures and low-level goals (i.e. grasping an object) but with different moral connotations (‘stealing a wallet’ vs ‘picking up a notepaper’). Participants’ personality traits were measured using the temperament and character inventory. Results show a selective suppression of corticospinal excitability during observation of immoral actions in individuals with high scores in harm avoidance, a personality trait characterized by excessive worrying and fearfulness. Thus, a combination of dispositional (personality traits) and situational (morality of an action) variables appears to influence MR with the observed actions. PMID:24526183

Principles of Lifeworld Led Public Health Practice in the UK and Sweden: Reducing Health Inequalities

PubMed Central

Hemingway, Ann; Norton, Liz; Aarts, Clara

2015-01-01

The purpose of this paper is to consider the role of the lifeworld perspective in reducing inequalities in health and we explain how the public health practitioner can use this perspective to address public health issues with individuals and groups. We offer ideas for public health actions that are based on and deal with the lifeworld context of individual people or families. Each of the dimensions of the lifeworld temporality, spatiality, intersubjectivity, embodiment and mood are outlined and their significance explained in relation to health inequalities. Suggestions for action to reduce health inequalities are made and overall principles of lifeworld led public health practice are proposed by way of conclusion. The principles comprise understanding the community members' lifeworld view, understanding their view of their potential, offering resources and facilitating empowerment, and sharing lifeworld case studies and lobbying to influence local and national policy in relation to both the individual and communities. PMID:25642346

What can individuals do to reduce personal health risks from air pollution?

PubMed Central

Laumbach, Robert; Meng, Qingyu

2015-01-01

In many areas of the world, concentrations of ambient air pollutants exceed levels associated with increased risk of acute and chronic health problems. While effective policies to reduce emissions at their sources are clearly preferable, some evidence supports the effectiveness of individual actions to reduce exposure and health risks. Personal exposure to ambient air pollution can be reduced on high air pollution days by staying indoors, reducing outdoor air infiltration to indoors, cleaning indoor air with air filters, and limiting physical exertion, especially outdoors and near air pollution sources. Limited evidence suggests that the use of respirators may be effective in some circumstances. Awareness of air pollution levels is facilitated by a growing number of public air quality alert systems. Avoiding exposure to air pollutants is especially important for susceptible individuals with chronic cardiovascular or pulmonary disease, children, and the elderly. Research on mechanisms underlying the adverse health effects of air pollution have suggested potential pharmaceutical or chemopreventive interventions, such as antioxidant or antithrombotic agents, but in the absence of data on health outcomes, no sound recommendations can be made for primary prevention. Health care providers and their patients should carefully consider individual circumstances related to outdoor and indoor air pollutant exposure levels and susceptibility to those air pollutants when deciding on a course of action to reduce personal exposure and health risks from ambient air pollutants. Careful consideration is especially warranted when interventions may have unintended negative consequences, such as when efforts to avoid exposure to air pollutants lead to reduced physical activity or when there is evidence that dietary supplements, such as antioxidants, have potential adverse health effects. These potential complications of partially effective personal interventions to reduce exposure or risk highlight the primary importance of reducing emissions of air pollutants at their sources. PMID:25694820

What can individuals do to reduce personal health risks from air pollution?

PubMed

Laumbach, Robert; Meng, Qingyu; Kipen, Howard

2015-01-01

In many areas of the world, concentrations of ambient air pollutants exceed levels associated with increased risk of acute and chronic health problems. While effective policies to reduce emissions at their sources are clearly preferable, some evidence supports the effectiveness of individual actions to reduce exposure and health risks. Personal exposure to ambient air pollution can be reduced on high air pollution days by staying indoors, reducing outdoor air infiltration to indoors, cleaning indoor air with air filters, and limiting physical exertion, especially outdoors and near air pollution sources. Limited evidence suggests that the use of respirators may be effective in some circumstances. Awareness of air pollution levels is facilitated by a growing number of public air quality alert systems. Avoiding exposure to air pollutants is especially important for susceptible individuals with chronic cardiovascular or pulmonary disease, children, and the elderly. Research on mechanisms underlying the adverse health effects of air pollution have suggested potential pharmaceutical or chemopreventive interventions, such as antioxidant or antithrombotic agents, but in the absence of data on health outcomes, no sound recommendations can be made for primary prevention. Health care providers and their patients should carefully consider individual circumstances related to outdoor and indoor air pollutant exposure levels and susceptibility to those air pollutants when deciding on a course of action to reduce personal exposure and health risks from ambient air pollutants. Careful consideration is especially warranted when interventions may have unintended negative consequences, such as when efforts to avoid exposure to air pollutants lead to reduced physical activity or when there is evidence that dietary supplements, such as antioxidants, have potential adverse health effects. These potential complications of partially effective personal interventions to reduce exposure or risk highlight the primary importance of reducing emissions of air pollutants at their sources.

Understanding the impact of accreditation on quality in healthcare: A grounded theory approach.

PubMed

Desveaux, L; Mitchell, J I; Shaw, J; Ivers, N M

2017-11-01

To explore how organizations respond to and interact with the accreditation process and the actual and potential mechanisms through which accreditation may influence quality. Qualitative grounded theory study. Organizations who had participated in Accreditation Canada's Qmentum program during January 2014-June 2016. Individuals who had coordinated the accreditation process or were involved in managing or promoting quality. The accreditation process is largely viewed as a quality assurance process, which often feeds in to quality improvement activities if the feedback aligns with organizational priorities. Three key stages are required for accreditation to impact quality: coherence, organizational buy-in and organizational action. These stages map to constructs outlined in Normalization Process Theory. Coherence is established when an organization and its staff perceive that accreditation aligns with the organization's beliefs, context and model of service delivery. Organizational buy-in is established when there is both a conceptual champion and an operational champion, and is influenced by both internal and external contextual factors. Quality improvement action occurs when organizations take purposeful action in response to observations, feedback or self-reflection resulting from the accreditation process. The accreditation process has the potential to influence quality through a series of three mechanisms: coherence, organizational buy-in and collective quality improvement action. Internal and external contextual factors, including individual characteristics, influence an organization's experience of accreditation. © The Author 2017. Published by Oxford University Press in association with the International Society for Quality in Health Care. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Emg Signal Analysis of Healthy and Neuropathic Individuals

NASA Astrophysics Data System (ADS)

Gupta, Ashutosh; Sayed, Tabassum; Garg, Ridhi; Shreyam, Richa

2017-08-01

Electromyography is a method to evaluate levels of muscle activity. When a muscle contracts, an action potential is generated and this circulates along the muscular fibers. In electromyography, electrodes are connected to the skin and the electrical activity of muscles is measured and graph is plotted. The surface EMG signals picked up during the muscular activity are interfaced with a system. The EMG signals from individual suffering from Neuropathy and healthy individual, so obtained, are processed and analyzed using signal processing techniques. This project includes the investigation and interpretation of EMG signals of healthy and Neuropathic individuals using MATLAB. The prospective use of this study is in developing the prosthetic device for the people with Neuropathic disability.

Psychotic Depression and Suicidal Behavior.

PubMed

Fredriksen, Kristin J; Schoeyen, Helle K; Johannessen, Jan O; Walby, Fredrik A; Davidson, Larry; Schaufel, Margrethe A

2017-01-01

This study investigated how severely depressed individuals experienced the relationship between psychotic symptoms and suicidal ideation and behavior. Semi-structured qualitative interviews were conducted with a purposive sample of nine inpatients from a psychiatric university hospital between September 2012 and May 2013 fulfilling diagnostic criteria for a psychotic depressive episode as part of a unipolar or bipolar disorder. Analysis was conducted using systematic text condensation. Participants experienced (1) being directed to perform impulsive potentially fatal actions, (2) feeling hounded to death, (3) becoming trapped in an inescapable darkness, and (4) being left bereft of mental control. They described how impulsivity directed by delusions and hallucinations resulted in unpredictable actions with only moments from decision to conduct. Suicide was seen as an escape not only from life problems but also from psychotic experiences and intense anxiety. Participants reported being in a chaotic state, unable to think rationally or anticipate the consequences of their actions. Their ability to identify and communicate psychotic symptoms and suicidal ideation and behavior was compromised, leaving them to struggle alone with these terrifying experiences. Suicide risk assessments based on verbal reports from individuals with psychotic depression may not always be valid due to potential impulsivity and underreporting of suicidal ideation. It may be important for clinicians to explore the delusional content of such patients' experiences to assess the possibility of suicide as a result of shame, guilt, remorse, or altruistic intentions to save others from harm.

Comparing sequencing assays and human-machine analyses in actionable genomics for glioblastoma

PubMed Central

Wrzeszczynski, Kazimierz O.; Frank, Mayu O.; Koyama, Takahiko; Rhrissorrakrai, Kahn; Robine, Nicolas; Utro, Filippo; Emde, Anne-Katrin; Chen, Bo-Juen; Arora, Kanika; Shah, Minita; Vacic, Vladimir; Norel, Raquel; Bilal, Erhan; Bergmann, Ewa A.; Moore Vogel, Julia L.; Bruce, Jeffrey N.; Lassman, Andrew B.; Canoll, Peter; Grommes, Christian; Harvey, Steve; Parida, Laxmi; Michelini, Vanessa V.; Zody, Michael C.; Jobanputra, Vaidehi; Royyuru, Ajay K.

2017-01-01

Objective: To analyze a glioblastoma tumor specimen with 3 different platforms and compare potentially actionable calls from each. Methods: Tumor DNA was analyzed by a commercial targeted panel. In addition, tumor-normal DNA was analyzed by whole-genome sequencing (WGS) and tumor RNA was analyzed by RNA sequencing (RNA-seq). The WGS and RNA-seq data were analyzed by a team of bioinformaticians and cancer oncologists, and separately by IBM Watson Genomic Analytics (WGA), an automated system for prioritizing somatic variants and identifying drugs. Results: More variants were identified by WGS/RNA analysis than by targeted panels. WGA completed a comparable analysis in a fraction of the time required by the human analysts. Conclusions: The development of an effective human-machine interface in the analysis of deep cancer genomic datasets may provide potentially clinically actionable calls for individual patients in a more timely and efficient manner than currently possible. ClinicalTrials.gov identifier: NCT02725684. PMID:28740869

Distinct Olfactory Cross-Modal Effects on the Human Motor System

PubMed Central

Rossi, Simone; De Capua, Alberto; Pasqualetti, Patrizio; Ulivelli, Monica; Falzarano, Vincenzo; Bartalini, Sabina; Passero, Stefano; Nuti, Daniele

2008-01-01

Background Converging evidence indicates that action observation and action-related sounds activate cross-modally the human motor system. Since olfaction, the most ancestral sense, may have behavioural consequences on human activities, we causally investigated by transcranial magnetic stimulation (TMS) whether food odour could additionally facilitate the human motor system during the observation of grasping objects with alimentary valence, and the degree of specificity of these effects. Methodology/Principal Findings In a repeated-measure block design, carried out on 24 healthy individuals participating to three different experiments, we show that sniffing alimentary odorants immediately increases the motor potentials evoked in hand muscles by TMS of the motor cortex. This effect was odorant-specific and was absent when subjects were presented with odorants including a potentially noxious trigeminal component. The smell-induced corticospinal facilitation of hand muscles during observation of grasping was an additive effect which superimposed to that induced by the mere observation of grasping actions for food or non-food objects. The odour-induced motor facilitation took place only in case of congruence between the sniffed odour and the observed grasped food, and specifically involved the muscle acting as prime mover for hand/fingers shaping in the observed action. Conclusions/Significance Complex olfactory cross-modal effects on the human corticospinal system are physiologically demonstrable. They are odorant-specific and, depending on the experimental context, muscle- and action-specific as well. This finding implies potential new diagnostic and rehabilitative applications. PMID:18301777

The pacemaker activity generating the intrinsic myogenic contraction of the dorsal vessel of Tenebrio molitor (Coleoptera).

PubMed

Markou, T; Theophilidis, G

2000-11-01

Combined intracellular and extracellular recordings from various parts of the isolated dorsal vessel of Tenebrio molitor revealed some of the following electrophysiological properties of the heart and the aorta. (i) The wave of depolarization causing forward pulsation of the dorsal vessel was always transmitted from posterior to anterior, with a conduction velocity of 0.014 m s(-1) in the heart and 0.001 m s(-1) in the aorta when the heart rate was 60 beats min(-1). (ii) There was no pacemaker activity in the aorta. (iii) The duration of the compound action potential in the aortic muscle depended on the duration of the pacemaker action potential generated in the heart. (iv) Isolated parts of the heart continued to contract rhythmically for hours, indicating powerful pacemaker activity in individual cardiac segments. (v) There was a direct relationship between action potential duration and the length of the preceding diastolic interval. (vi) The rhythmic wave of depolarization was dependent on the influx of Ca(2+). (vii) The recovery of the electrical properties of myocardial cells that had been disrupted by sectioning was rapid. (viii) In hearts sectioned into two halves, the rhythmic pacemaker action potentials recorded simultaneously from the two isolated halves eventually drifted out of phase, but they had the same intrinsic frequency. In the light of these data, we discuss two alternative models for the generation of spontaneous rhythmic pumping movements of the heart and aorta.

Solving the puzzle of collective action through inter-individual differences

PubMed Central

von Rueden, Chris; Gavrilets, Sergey; Glowacki, Luke

2015-01-01

Models of collective action infrequently account for differences across individuals beyond a limited set of strategies, ignoring variation in endowment (e.g. physical condition, wealth, knowledge, personality, support), individual costs of effort, or expected gains from cooperation. However, behavioural research indicates these inter-individual differences can have significant effects on the dynamics of collective action. The papers contributed to this theme issue evaluate how individual differences affect the propensity to cooperate, and how they can catalyse others’ likelihood of cooperation (e.g. via leadership). Many of the papers emphasize the relationship between individual decisions and socio-ecological context, particularly the effect of group size. All together, the papers in this theme issue provide a more complete picture of collective action, by embracing the reality of inter-individual variation and its multiple roles in the success or failure of collective action. PMID:26503677

Do Low Income Youth of Color See "The Bigger Picture" When Discussing Type 2 Diabetes: A Qualitative Evaluation of a Public Health Literacy Campaign.

PubMed

Schillinger, Dean; Tran, Jessica; Fine, Sarah

2018-04-24

As Type 2 diabetes spikes among minority and low-income youth, there is an urgent need to tackle the drivers of this preventable disease. The Bigger Picture (TBP) is a counter-marketing campaign using youth-created, spoken-word public service announcements (PSAs) to reframe the epidemic as a socio-environmental phenomenon requiring communal action, civic engagement and norm change. We examined whether and how TBP PSAs advance health literacy among low-income, minority youth. We showed nine PSAs, asking individuals open-ended questions via questionnaire, then facilitating a focus group to reflect upon the PSAs. Questionnaire responses revealed a balance between individual vs. public health literacy. Some focused on individual responsibility and behaviors, while others described socio-environmental forces underlying risk. The focus group generated a preponderance of public health literacy responses, emphasizing future action. Striking sociopolitical themes emerged, reflecting tensions minority and low-income youth experience, such as entrapment vs. liberation. Our findings speak to the structural barriers and complexities underlying diabetes risk, and the ability of spoken word medium to make these challenges visible and motivate action. Delivering TBP content to promote interactive reflection has potential to change behavioral norms and build capacity to confront the social, economic and structural factors that influence behaviors.

PREFACE TO: "PHARMACEUTICALS AND PERSONAL ...

EPA Pesticide Factsheets

Often overlooked in our daily lives are the inescapable, intimate, and immediate connections between our personal activities and the environment in which we live. This is especially true with regard to the use and disposal of consumer chemicals. A significant aspect of our global society that illustrates the potential impact of our lives on the environment is the widespread and escalating use of pharmaceuticals and personal care products - simply referred to as PPCPS. Many of these chemicals are specifically designed to elicit potent pharmacological or toxicological effects. In distinct contrast to nearly all agro/industrial chemicals, which are often used on large, relatively confined scales, the end use for PPCPs is highly dispersed and centered around the activities and actions of the individual. PPCPs enjoy worldwide usage and attendant discharge or inadvertent release to the environment. Their introduction to the environment has no geographic boundaries or climatic-use limitations as do many other synthetic chemicals - they are discharged to the environment wherever people live or visit, regardless of the time of year. It is difficult for the individual to perceive their small-scale activities as having any measurable impact on the larger environment - personal actions are often deemed minuscule or inconsequential in the larger scheme. Yet it is the combined actions and activities of individuals that indeed can significantly impact the environment in a myri

Neuroticism and Attitudes Toward Action in 19 Countries

PubMed Central

Ireland, Molly E.; Hepler, Justin; Li, Hong; Albarracín, Dolores

2018-01-01

Although individuals scoring high on Neuroticism tend to avoid taking action when faced with challenges, Neuroticism is also characterized by impulsivity. To explore cognitive biases related to this costly behavior pattern, we tested whether individuals who rated themselves as higher in Neuroticism would evaluate the general concepts of action and inaction as, respectively, more negative and positive. We further investigated whether anxiety and depression would mediate and individualism-collectivism would moderate these relations in a large international sample. Participants (N = 3,827 college students; 69% female) from 19 countries completed surveys measuring Neuroticism, attitudes toward action and inaction, depression, anxiety, and individualism-collectivism. Hierarchical linear models tested the above predictions. Neuroticism negatively correlated with attitudes toward action and positively correlated with attitudes toward inaction. Furthermore, anxiety was primarily responsible for emotionally unstable individuals’ less positive attitudes toward action, and individuals who endorsed more collectivistic than individualistic beliefs showed a stronger negative association between Neuroticism and attitudes toward action. Researchers and practitioners interested in understanding and remediating the negative consequences of Neuroticism should pay greater attention to attitudes toward action and inaction, particularly focusing on their links with anxiety and individualism-collectivism. PMID:24684688

Putting program evaluation to work: a framework for creating actionable knowledge for suicide prevention practice.

PubMed

Wilkins, Natalie; Thigpen, Sally; Lockman, Jennifer; Mackin, Juliette; Madden, Mary; Perkins, Tamara; Schut, James; Van Regenmorter, Christina; Williams, Lygia; Donovan, John

2013-06-01

The economic and human cost of suicidal behavior to individuals, families, communities, and society makes suicide a serious public health concern, both in the US and around the world. As research and evaluation continue to identify strategies that have the potential to reduce or ultimately prevent suicidal behavior, the need for translating these findings into practice grows. The development of actionable knowledge is an emerging process for translating important research and evaluation findings into action to benefit practice settings. In an effort to apply evaluation findings to strengthen suicide prevention practice, the Centers for Disease Control and Prevention (CDC) and the Substance Abuse and Mental Health Services Administration (SAMHSA) supported the development of three actionable knowledge products that make key findings and lessons learned from youth suicide prevention program evaluations accessible and useable for action. This paper describes the actionable knowledge framework (adapted from the knowledge transfer literature), the three products that resulted, and recommendations for further research into this emerging method for translating research and evaluation findings and bridging the knowledge-action gap.

Community-Based English Clubs: English Practice and Social Change outside the Classroom

ERIC Educational Resources Information Center

Malu, Kathleen F.; Smedley, Bryce

2016-01-01

This article defines and provides a rationale for the creation of community-based English clubs. We offer strategies that individuals can use to create and sustain English clubs, and we suggest meeting activities that will engage members in conversations and potential community action on a range of topics such as democracy, gender equality, and…

Fuels planning: science synthesis and integration; social issues fact sheet 11: Challenges to collaboration

Treesearch

Christine Esposito

2006-01-01

Bringing the right people into a collaborative process can be difficult. Potential collaborators must all feel they have something to gain to justify investing resources, sharing knowledge, and perhaps compromising on goals and actions. This fact sheet discusses some of the common challenges that individuals, communities, and institutions face in collaboration.

Academics' Perceptions of the Benefits and Challenges of Self and Peer Assessment in Higher Education

ERIC Educational Resources Information Center

Adachi, Chie; Tai, Joanna Hong-Meng; Dawson, Phillip

2018-01-01

Despite compelling evidence of its potential effectiveness, uptake of self and peer assessment in higher education has been slower than expected. As with other assessment practices, self and peer assessment is ultimately enabled, or inhibited, by the actions of individual academics. This paper explores what academics see as the benefits and…

Predicting global population connectivity and targeting conservation action for snow leopard across its range

Treesearch

Philip Riordan; Samuel A. Cushman; David Mallon; Kun Shi; Joelene Hughes

2016-01-01

Movements of individuals within and among populations help to maintain genetic variability and population viability. Therefore, understanding landscape connectivity is vital for effective species conservation. The snow leopard is endemic to mountainous areas of central Asia and occurs within 12 countries. We assess potential connectivity across the species’...

Using Arrays of Microelectrodes Implanted in Residual Peripheral Nerves to Provide Dexterous Control of, and Modulated Sensory Feedback from, a Hand Prosthesis

DTIC Science & Technology

2017-10-01

potentials or multi-action potential activity from residual peripheral nerve while patient intends movements of amputated hand/arm Subtask 3.1: Mapping of...neural activity (Months 4 – 36) • Patients will be asked to intend a number of individual finger and multiple finger flexion, extension, adduction...intended movements. We will map the different intended movements onto the neural activity recorded on the electrodes of the micro-electrode array

The actions of the social insurance agency regarding long-term sickness absentees before and after a medical assessment--a study of 384 case files.

PubMed

Marklund, Staffan; Lundh, Göran; Gustafsson, Klas; Linder, Jürgen; Svedberg, Pia; Alexanderson, Kristina

2015-01-01

The purpose of this article is to investigate actions taken by the Social Insurance Agency (SIA) for long-term sickness absentees and possible associations of this with future sick leave or disability pension. For 384 long-term sickness absentees who had had a multidisciplinary medical assessment (MMA) during 2001-2006, three types of data were obtained: (1) case file information about SIA actions, (2) suggested rehabilitation measures from the MMA and (3) sickness absence and disability pension data. Most individuals had been subject to a range of actions by the SIA. Sixty percent had been invited to a coordination meeting, and half of those who assessed by the MMA for vocational rehabilitation were approved to get it by the SIA. Few SIA actions were associated with full or partial return to work. Although the studied individuals had been on sick leave for a long time, the number of SIA actions related to vocational rehabilitation was limited and came late in the sick-leave spell. The information from the MMA was often not used as a basis for further SIA action and seldom resulted in return to work. The positive MMA views on the potential of vocational rehabilitation were not met by SIA actions. Suggestions on vocational rehabilitation from a medical assessment was in many cases not used by the social insurance agency in relationship to long-term sickness absentees. Active rehabilitation measures by the social insurance agency were few and came late in the sickness absence process. Few of the activities taken by the social insurance agency enhanced return to work.

Learning by observation: insights from Williams syndrome.

PubMed

Foti, Francesca; Menghini, Deny; Mandolesi, Laura; Federico, Francesca; Vicari, Stefano; Petrosini, Laura

2013-01-01

Observing another person performing a complex action accelerates the observer's acquisition of the same action and limits the time-consuming process of learning by trial and error. Observational learning makes an interesting and potentially important topic in the developmental domain, especially when disorders are considered. The implications of studies aimed at clarifying whether and how this form of learning is spared by pathology are manifold. We focused on a specific population with learning and intellectual disabilities, the individuals with Williams syndrome. The performance of twenty-eight individuals with Williams syndrome was compared with that of mental age- and gender-matched thirty-two typically developing children on tasks of learning of a visuo-motor sequence by observation or by trial and error. Regardless of the learning modality, acquiring the correct sequence involved three main phases: a detection phase, in which participants discovered the correct sequence and learned how to perform the task; an exercise phase, in which they reproduced the sequence until performance was error-free; an automatization phase, in which by repeating the error-free sequence they became accurate and speedy. Participants with Williams syndrome beneficiated of observational training (in which they observed an actor detecting the visuo-motor sequence) in the detection phase, while they performed worse than typically developing children in the exercise and automatization phases. Thus, by exploiting competencies learned by observation, individuals with Williams syndrome detected the visuo-motor sequence, putting into action the appropriate procedural strategies. Conversely, their impaired performances in the exercise phases appeared linked to impaired spatial working memory, while their deficits in automatization phases to deficits in processes increasing efficiency and speed of the response. Overall, observational experience was advantageous for acquiring competencies, since it primed subjects' interest in the actions to be performed and functioned as a catalyst for executed action.

Tagging insulin in microgravity

NASA Technical Reports Server (NTRS)

Dobeck, Michael; Nelson, Ronald S.

1992-01-01

Knowing the exact subcellular sites of action of insulin in the body has the potential to give basic science investigators a basis from which a cause and cure for this disease can be approached. The goal of this project is to create a test reagent that can be used to visualize these subcellular sites. The unique microgravity environment of the Shuttle will allow the creation of a reagent that has the possibility of elucidating the subcellular sites of action of insulin. Several techniques have been used in an attempt to isolate the sites of action of items such as insulin. One of these is autoradiography in which the test item is obtained from animals fed radioactive materials. What is clearly needed is to visualize individual insulin molecules at their sites of action. The insulin tagging process to be used on G-399 involves the conjugation of insulin molecules with ferritin molecules to create a reagent that will be used back on Earth in an attempt to elucidate the sites of action of insulin.

Parallel, but Dissociable, Processing in Discrete Corticostriatal Inputs Encodes Skill Learning.

PubMed

Kupferschmidt, David A; Juczewski, Konrad; Cui, Guohong; Johnson, Kari A; Lovinger, David M

2017-10-11

Changes in cortical and striatal function underlie the transition from novel actions to refined motor skills. How discrete, anatomically defined corticostriatal projections function in vivo to encode skill learning remains unclear. Using novel fiber photometry approaches to assess real-time activity of associative inputs from medial prefrontal cortex to dorsomedial striatum and sensorimotor inputs from motor cortex to dorsolateral striatum, we show that associative and sensorimotor inputs co-engage early in action learning and disengage in a dissociable manner as actions are refined. Disengagement of associative, but not sensorimotor, inputs predicts individual differences in subsequent skill learning. Divergent somatic and presynaptic engagement in both projections during early action learning suggests potential learning-related in vivo modulation of presynaptic corticostriatal function. These findings reveal parallel processing within associative and sensorimotor circuits that challenges and refines existing views of corticostriatal function and expose neuronal projection- and compartment-specific activity dynamics that encode and predict action learning. Published by Elsevier Inc.

Double Stimulation in the Waiting Experiment with Collectives: Testing a Vygotskian Model of the Emergence of Volitional Action.

PubMed

Sannino, Annalisa

2016-03-01

This study explores what human conduct looks like when research embraces uncertainty and distance itself from the dominant methodological demands of control and predictability. The context is the waiting experiment originally designed in Kurt Lewin's research group, discussed by Vygotsky as an instance among a range of experiments related to his notion of double stimulation. Little attention has been paid to this experiment, despite its great heuristic potential for charting the terrain of uncertainty and agency in experimental settings. Behind the notion of double stimulation lays Vygotsky's distinctive view of human beings' ability to intentionally shape their actions. Accordingly, human beings in situations of uncertainty and cognitive incongruity can rely on artifacts which serve the function of auxiliary motives and which help them undertake volitional actions. A double stimulation model depicting how such actions emerge is tested in a waiting experiment conducted with collectives, in contrast with a previous waiting experiment conducted with individuals. The model, validated in the waiting experiment with individual participants, applies only to a limited extent to the collectives. The analysis shows the extent to which double stimulation takes place in the waiting experiment with collectives, the differences between the two experiments, and what implications can be drawn for an expanded view on experiments.

Interpersonal motor resonance in autism spectrum disorder: evidence against a global "mirror system" deficit.

PubMed

Enticott, Peter G; Kennedy, Hayley A; Rinehart, Nicole J; Bradshaw, John L; Tonge, Bruce J; Daskalakis, Zafiris J; Fitzgerald, Paul B

2013-01-01

The mirror neuron hypothesis of autism is highly controversial, in part because there are conflicting reports as to whether putative indices of mirror system activity are actually deficient in autism spectrum disorder (ASD). Recent evidence suggests that a typical putative mirror system response may be seen in people with an ASD when there is a degree of social relevance to the visual stimuli used to elicit that response. Individuals with ASD (n = 32) and matched neurotypical controls (n = 32) completed a transcranial magnetic stimulation (TMS) experiment in which the left primary motor cortex (M1) was stimulated during the observation of static hands, individual (i.e., one person) hand actions, and interactive (i.e., two person) hand actions. Motor-evoked potentials (MEP) were recorded from the contralateral first dorsal interosseous, and used to generate an index of interpersonal motor resonance (IMR; a putative measure of mirror system activity) during action observation. There was no difference between ASD and NT groups in the level of IMR during the observation of these actions. These findings provide evidence against a global mirror system deficit in ASD, and this evidence appears to extend beyond stimuli that have social relevance. Attentional and visual processing influences may be important for understanding the apparent role of IMR in the pathophysiology of ASD.

Achieving the Framework Convention on Tobacco Control's potential by investing in national capacity.

PubMed

Wipfli, H; Stillman, F; Tamplin, S; da Costa e Silva, V Luiza; Yach, D; Samet, J

2004-12-01

May 2003 marked a critical achievement in efforts to stem the global tobacco epidemic, as the member states of the World Health Organization unanimously endorsed the Framework Convention on Tobacco Control (FCTC). However, the adoption of the FCTC signifies only the end of the beginning of effective global action to control tobacco. Over the next several years the utility of the FCTC process and the treaty itself will be tested as individual countries seek to ratify and implement the treaty's obligations. Significant barriers to the treaty's long term success exist in many countries. It is crucial that the international tobacco control community now refocuses its efforts on national capacity building and ensures that individual countries have the knowledge, tools, data, people, and organisations needed to implement the convention and develop sustained tobacco control programmes. This paper provides a model of national tobacco control capacity and offers a prioritised agenda for action.

Efforts to monitor Global progress on individual and community demand for immunization: Development of definitions and indicators for the Global Vaccine Action Plan Strategic Objective 2.

PubMed

Hickler, Benjamin; MacDonald, Noni E; Senouci, Kamel; Schuh, Holly B

2017-06-16

The Second Strategic Objective of the Global Vaccine Action Plan, "individuals and communities understand the value of vaccines and demand immunization as both their right and responsibility", differs from the other five in that it does not focus on supply-side aspects of immunization programs but rather on public demand for vaccines and immunization services. This commentary summarizes the work (literature review, consultations with experts, and with potential users) and findings of the UNICEF/World Health Organization Strategic Objective 2 informal Working Group on Vaccine Demand, which developed a definition for demand and indicators related to Strategic Objective 2. Demand for vaccines and vaccination is a complex concept that is not external to supply systems but rather encompasses the interaction between human behaviors and system structure and dynamics. Copyright © 2017. Published by Elsevier Ltd.

Double-dealing behavior potentially promotes cooperation in evolutionary prisoner's dilemma games

NASA Astrophysics Data System (ADS)

Dai, Qionglin; Li, Haihong; Cheng, Hongyan; Li, Yuting; Yang, Junzhong

2010-11-01

We investigate the effects of double-dealing behavior on cooperation in evolutionary games. Each individual in a population has two attributes: character and action. One's action may be consistent with one's character or not. We provide analytical results by a mean-field description of evolutionary prisoner's dilemma games (PDGs). Moreover, we give numerical results on different networks, ranging from square lattices to scale-free networks (SFNs). Two important conclusions have been drawn from the results on SFNs. Firstly, if only non-influential individuals (those with low degrees) have chances of becoming double-dealers, cooperation is certain to deteriorate. Secondly, when influential individuals (those with high degrees) adopt double-dealing behavior moderately, cooperation would be enhanced, which is in opposition to the traditional belief. These results help us to understand better the social phenomenon of the existence of double-dealers. In addition to the PDG, other types of games including the snowdrift game, the stag-hunt game and the harmony game have also been studied on our model. The results for these three games are also presented, which are consistent with the results for the PDG qualitatively. Furthermore, we consider our model under the co-evolution framework, in which the probability of an individual changing into a double-dealer and the individual strategy both could evolve during the evolutionary process.

At Least I Tried: The Relationship between Regulatory Focus and Regret Following Action vs. Inaction

PubMed Central

Itzkin, Adi; Van Dijk, Dina; Azar, Ofer H.

2016-01-01

Regret is an unpleasant feeling that may arise following decisions that ended poorly, and may affect the decision-maker's well-being and future decision making. Some studies show that a decision to act leads to greater regret than a decision not to act when both resulted in failure, because the latter is usually the norm. In some cases, when the norm is to act, this pattern is reversed. We suggest that the decision maker's regulatory focus, affects regret after action or inaction. Specifically, promotion-focused individuals, who tend to be more proactive, view action as more normal than prevention-focused individuals, and therefore experience regulatory fit when an action decision is made. Hence, we hypothesized that promotion-focused individuals will feel less regret than prevention-focused individuals when a decision to act ended poorly. In addition, we hypothesized that a trigger for change implied in the situation, decreases the level of regret following action. We tested our hypotheses on a sample of 330 participants enrolled in an online survey. The participants received six decision scenarios, in which they were asked to evaluate the level of regret following action and inaction. Individual regulatory focus was measured by two different scales. Promotion-focused individuals attributed less regret than prevention-focused individuals to action decisions. Regret following inaction was not affected by regulatory focus. In addition, a trigger for change decreases regret following action. Orthodox people tend to attribute more regret than non-orthodox to a person who made an action decision. The results contribute to the literature by showing that not only the situation but also the decision maker's orientation affects the regret after action vs. inaction. PMID:27833581

N-hexane neuropathy in offset printers.

PubMed Central

Chang, C M; Yu, C W; Fong, K Y; Leung, S Y; Tsin, T W; Yu, Y L; Cheung, T F; Chan, S Y

1993-01-01

In an offset printing factory with 56 workers, 20 (36%) developed symptomatic peripheral neuropathy due to exposure to n-hexane. Another 26 workers (46%) were found to have subclinical neuropathy. The initial change in the nerve conduction study was reduced amplitude of the sensory action potentials, followed by reduced amplitude of the motor action potentials, reduction in motor conduction velocities and increase in distal latencies. These changes indicate primary axonal degeneration with secondary demyelination. Sural nerve biopsy in a severe case showed giant axonal swellings due to accumulation of 10nm neurofilaments, myelin sheath attenuation and widening of nodal gaps. The development of neuropathy bore no direct relationship to the duration of exposure, hence factors such as individual susceptibility may be important. Optic neuropathy and CNS involvement were uncommon and autonomic neuropathy was not encountered. Images PMID:8505647

The Clifton Youth StrengthsExplorer Assessment: Identifying the Talents of Today's Youth

ERIC Educational Resources Information Center

Educational Horizons, 2006

2006-01-01

The aim of many educators is to help youth reach their maximum potential. The Clifton Youth StrengthsExplorer gives teachers a tool to help identify the talents of their students, as well as actionable suggestions for utilizing those talents. Such information can help teachers to individualize the ways in which they respond to youths, and the…

When Does the "Duty to Protect" Apply with a Client Who has Anorexia Nervosa?

ERIC Educational Resources Information Center

Werth, James L., Jr.; Wright, Kimberly S.; Archambault, Rita J.; Bardash, Rebekah, J.

2003-01-01

Individuals with eating disorders, especially those with anorexia nervosa, have the potential to experience significant harm and even death as a result of behaviors related to their condition. Because of this risk, the authors argue that there is a duty to protect (i.e., an obligation to take some action when a person is engaging or considering…

Memory for Self-Performed Actions in Individuals with Asperger Syndrome

PubMed Central

Zalla, Tiziana; Daprati, Elena; Sav, Anca-Maria; Chaste, Pauline; Nico, Daniele; Leboyer, Marion

2010-01-01

Memory for action is enhanced if individuals are allowed to perform the corresponding movements, compared to when they simply listen to them (enactment effect). Previous studies have shown that individuals with Autism Spectrum Disorders (ASD) have difficulties with processes involving the self, such as autobiographical memories and self performed actions. The present study aimed at assessing memory for action in Asperger Syndrome (AS). We investigated whether adults with AS would benefit from the enactment effect when recalling a list of previously performed items vs. items that were only visually and verbally experienced through three experimental tasks (Free Recall, Old/New Recognition and Source Memory). The results showed that while performance on Recognition and Source Memory tasks was preserved in individuals with AS, the enactment effect for self-performed actions was not consistently present, as revealed by the lower number of performed actions being recalled on the Free Recall test, as compared to adults with typical development. Subtle difficulties in encoding specific motor and proprioceptive signals during action execution in individuals with AS might affect retrieval of relevant personal episodic information. These disturbances might be associated to an impaired action monitoring system. PMID:20967277

Memory for self-performed actions in individuals with Asperger syndrome.

PubMed

Zalla, Tiziana; Daprati, Elena; Sav, Anca-Maria; Chaste, Pauline; Nico, Daniele; Leboyer, Marion

2010-10-12

Memory for action is enhanced if individuals are allowed to perform the corresponding movements, compared to when they simply listen to them (enactment effect). Previous studies have shown that individuals with Autism Spectrum Disorders (ASD) have difficulties with processes involving the self, such as autobiographical memories and self performed actions. The present study aimed at assessing memory for action in Asperger Syndrome (AS). We investigated whether adults with AS would benefit from the enactment effect when recalling a list of previously performed items vs. items that were only visually and verbally experienced through three experimental tasks (Free Recall, Old/New Recognition and Source Memory). The results showed that while performance on Recognition and Source Memory tasks was preserved in individuals with AS, the enactment effect for self-performed actions was not consistently present, as revealed by the lower number of performed actions being recalled on the Free Recall test, as compared to adults with typical development. Subtle difficulties in encoding specific motor and proprioceptive signals during action execution in individuals with AS might affect retrieval of relevant personal episodic information. These disturbances might be associated to an impaired action monitoring system.

CORRECTIVE ACTION DECISION DOCUMENT FOR AREA 9 UXO LANDFILL, TONOPAH TEST RNGE, CAU 453, REVISION 0, MARCH 1998

DOE Office of Scientific and Technical Information (OSTI.GOV)

none

1998-03-01

This Corrective Action Decision Document (CADD) has been prepared for the Area 9 Unexploded Ordnance (UXO) Landfill (Corrective Action Unit [CAU] 453) in accordance with the Federal Facility Agreement and Consent Order (FFACO) of 1996. Corrective Action Unit 453 is located at the Tonopah Test Range (TTR), Nevada, and is comprised of three individual landfill cells located northwest of Area 9. The cells are listed as one Corrective Action Site (CAS) 09-55-001-0952. The landfill cells have been designated as: � Cell A9-1 � Cell A9-2 � Cell A9-3 The purpose of this CADD is to identify and provide a rationalemore » for the selection of a recommended corrective action alternative for CAU 453. The scope of this CADD consists of the following tasks: � Develop corrective action objectives. � Identify corrective action alternative screening criteria. � Develop corrective action alternatives. � Perform detailed and comparative evaluations of the corrective action alternatives in relation to the corrective action objectives and screening criteria. � Recommend and justify a preferred corrective action alternative for the CAU. In June and July 1997, a corrective action investigation was performed that consisted of activities set forth in the Corrective Action Investigation Plan (CAIP) (DOE/NV, 1997). Subsurface investigation of the soils surrounding the cells revealed no contaminants of concern (COCs) above preliminary action levels. The cell contents were not investigated due to the potential for live UXO. Details concerning the analytical and investigation results can be found in Appendix A of this CADD. Based on the potential exposure pathways, the following corrective action objectives have been identified for CAU 453: � Prevent or mitigate human exposure to subsurface soils containing COCs, solid waste, and/or UXO. � Prevent adverse impacts to groundwater quality. Based on the review of existing data, future land use, and current operations at the TTR, the following alternatives have been developed for consideration at the Area 9 UXO Landfill CAU: � Alternative 1 - No Further Action � Alternative 2 - Closure in Place by Administrative Controls � Alternative 3 - Closure in Place by Capping � Alternative 4 - Clean Closure by Removal The corrective action alternatives were evaluated based on four general corrective action standards and five remedy selection decision factors. Based on the results of this evaluation, Alternative 2, Closure in Place by Administrative Controls, was selected as the preferred corrective action alternative. The preferred corrective action alternative was evaluated on its technical merits, focusing on performance, reliability, feasibility, and safety. The alternative was judged to meet all requirements for the technical components evaluated and to represent the most cost-effective corrective action. The alternative meets all applicable state and federal regulations for closure of the site and will reduce potential future exposure pathways to the contents of the landfill. During corrective action implementation, this alternative will present minimal potential threat to site workers. However, appropriate health and safety procedures will be developed and implemented.« less

Joint Action Coordination in 2½- and 3-Year-Old Children

PubMed Central

Meyer, Marlene; Bekkering, Harold; Paulus, Markus; Hunnius, Sabine

2010-01-01

When acting jointly with others, adults can be as proficient as when acting individually. However, how young children coordinate their actions with another person and how their action coordination develops during early childhood is not well understood. By means of a sequential button-pressing game, which could be played jointly or individually, the action coordination of 2½- and 3-year-old children was examined. Performance accuracy and variability of response timing were taken as indicators of coordination ability. Results showed substantial improvement in joint action coordination between the age of 2½ and 3, but both age groups performed equally well when acting individually. Interestingly, 3-year-olds performed equally well in the joint and the individual condition, whereas 2½-year-olds did not yet show this adult-like pattern as indicated by less accurate performance in the joint action. The findings suggest that in contrast to 3-year-olds, 2½-year-olds still have difficulties in establishing well-coordinated joint action with an adult partner. Possible underlying cognitive abilities such as action planning and action control are discussed. PMID:21165176

Minimum separation distances for natural gas pipeline and boilers in the 300 area, Hanford Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daling, P.M.; Graham, T.M.

1997-08-01

The U.S. Department of Energy (DOE) is proposing actions to reduce energy expenditures and improve energy system reliability at the 300 Area of the Hanford Site. These actions include replacing the centralized heating system with heating units for individual buildings or groups of buildings, constructing a new natural gas distribution system to provide a fuel source for many of these units, and constructing a central control building to operate and maintain the system. The individual heating units will include steam boilers that are to be housed in individual annex buildings located at some distance away from nearby 300 Area nuclearmore » facilities. This analysis develops the basis for siting the package boilers and natural gas distribution systems to be used to supply steam to 300 Area nuclear facilities. The effects of four potential fire and explosion scenarios involving the boiler and natural gas pipeline were quantified to determine minimum separation distances that would reduce the risks to nearby nuclear facilities. The resulting minimum separation distances are shown in Table ES.1.« less

Factors Motivating and Hindering Information and Communication Technologies Action Competence

ERIC Educational Resources Information Center

Kurt, Adile Askim; Akbulut, Yavuz; Odabasi, H. Ferhan; Ceylan, Beril; Kuzu, Elif Bugra; Donmez, Onur; Izmirli, Ozden Sahin

2013-01-01

Information and Communication Technologies Action Competence (ICTAC) can be defined as "individuals' motivation and capacity to voluntarily employ their ICT skills for initiating or taking part in civic actions". Since academic staff and teachers in ICT related fields have crucial roles in training action-competent individuals, this…

Conflicting and complementary ethics of animal welfare considerations in reintroductions.

PubMed

Harrington, Lauren A; Moehrenschlager, Axel; Gelling, Merryl; Atkinson, Rob P D; Hughes, Joelene; Macdonald, David W

2013-06-01

Despite differences in focus, goals, and strategies between conservation biology and animal welfare, both are inextricably linked in many ways, and greater consideration of animal welfare, although important in its own right, also has considerable potential to contribute to conservation success. Nevertheless, animal welfare and animal ethics are not always considered explicitly within conservation practice. We systematically reviewed the recent scientific peer-reviewed and online gray literature on reintroductions of captive-bred and wild-caught animals (mammals, birds, amphibians, and reptiles) to quantify the occurrence of animal welfare issues. We considered monitoring that could be indicative of the animal's welfare status and supportive management actions that could improve animal welfare (regardless of whether the aim was explicitly animal-welfare orientated). Potential welfare issues (of variable nature and extent) were recorded in 67% of 199 projects reviewed; the most common were mortality >50%, dispersal or loss of animals, disease, and human conflict. Most (>70%) projects monitored survival, 18% assessed body condition, and 2% monitored stress levels. Animal welfare, explicitly, was referred to in 6% of projects. Supportive actions, most commonly use of on-site prerelease pens and provision of supplemental food or water, were implemented in 79% of projects, although the extent and duration of support varied. Practitioners can address animal-welfare issues in reintroductions by considering the potential implications for individual animals at all stages of the release process using the decision tree presented. We urge practitioners to report potential animal-welfare issues, describe mitigation actions, and evaluate their efficacy to facilitate transparent evaluation of common moral dilemmas and to advance communal strategies for dealing with them. Currently, comparative mortality rates, health risks, postrelease stress, effectiveness of supportive measures, and behavior of individuals warrant further research to improve animal welfare in reintroductions and to increase success of such projects. © 2013 Society for Conservation Biology.

'Health should not have to be a problem': talking health and accountability in an internet forum on veganism.

PubMed

Sneijder, Petra; te Molder, Hedwig F M

2004-07-01

This article draws upon insights from discursive psychology to examine how participants in an Internet forum on veganism orient to the relationship between food choice, health and accountability. First, we explore the ways in which participants ascribe responsibility for health problems like vitamin deficiency to individual recipients. By suggesting individual practices as a cause for problems, speakers undermine the notion that problems arise through veganism as a matter of principle. Second, we show how participants construct solutions to individual health problems as involving mundane and simple actions. Both discursive procedures enable speakers to resist negative assumptions about the potentially complicated nature of veganism in relation to health protection.

Error-Induced Learning as a Resource-Adaptive Process in Young and Elderly Individuals

NASA Astrophysics Data System (ADS)

Ferdinand, Nicola K.; Weiten, Anja; Mecklinger, Axel; Kray, Jutta

Thorndike described in his law of effect [44] that actions followed by positive events are more likely to be repeated in the future, whereas actions that are followed by negative outcomes are less likely to be repeated. This implies that behavior is evaluated in the light of its potential consequences, and non-reward events (i.e., errors) must be detected for reinforcement learning to take place. In short, humans have to monitor their performance in order to detect and correct errors, and this allows them to successfully adapt their behavior to changing environmental demands and acquire new behavior, i.e., to learn.

Motivational Text Message Intervention for Eating Disorders: A Single-Case Alternating Treatment Design Using Ecological Momentary Assessment.

PubMed

Shingleton, Rebecca M; Pratt, Elizabeth M; Gorman, Bernard; Barlow, David H; Palfai, Tibor P; Thompson-Brenner, Heather

2016-05-01

This study tested a motivational text message treatment adjunct for individuals with eating disorders (EDs) who exhibited high dietary restraint/restriction. A replicated single-case alternating treatment design was used to examine (a) the feasibility of combining a brief motivational interview with subsequent text messages and (b) the influence of the text messages on eating behaviors and motivation to change in individuals with EDs (N=12). The protocol was 8weeks and the text messages were adjunctive to cognitive-behavioral therapy. The intervention was well accepted (mean rating=7/10) and feasible within the context of monetary compensation (mean daily monitoring compliance =91%). Text messages did not impact behavioral outcomes: dietary restraint and kilocalorie intake. They had mixed effects on motivation to change dietary restraint, measured by the Readiness and Motivation Questionnaire (RMQ). When receiving text messages, RMQ precontemplation scores (desire to restrict) significantly increased, indicating decreased motivation; however, action scores (effort toward reducing dietary restraint) significantly increased, indicating increased motivation. These effects were moderated by weight status. Underweight individuals (n=4; body mass index [BMI]<19.0) reported increased ambivalence-that is, an increased desire to restrict and increased action toward reducing restriction-in response to the text messages. Normal weight participants (n=8; BMI>19.0) reported only increased action toward reducing restriction in response to the text messages. These data demonstrate text messages are a potentially feasible and acceptable treatment adjunct and may be effective at increasing motivation to change for normal weight individuals, while their influence on underweight patients is more complex. These findings provide a foundation for future research in technology-based motivational interventions for EDs and offer preliminary evidence for using these methods among normal weight individuals. Copyright © 2016. Published by Elsevier Ltd.

Feedback of Individual Genetic Results to Research Participants: Is It Feasible in Europe?

PubMed Central

Mascalzoni, Deborah; Soini, Sirpa; Machado, Helena; Kaye, Jane; Bentzen, Heidi Beate; Rial-Sebbag, Emmanuelle; D'Abramo, Flavio; Witt, Michał; Schamps, Geneviève; Katić, Višnja; Krajnovic, Dusanca; Harris, Jennifer R.

2016-01-01

Background: There is growing consensus that individual genetic research results that are scientifically robust, analytically valid, and clinically actionable should be offered to research participants. However, the general practice in European research projects is that results are usually not provided to research participants for many reasons. This article reports on the views of European experts and scholars who are members of the European COST Action CHIP ME IS1303 (Citizen's Health through public-private Initiatives: Public health, Market and Ethical perspectives) regarding challenges to the feedback of individual genetic results to research participants in Europe and potential strategies to address these challenges. Materials and Methods: A consultation of the COST Action members was conducted through an email survey and a workshop. The results from the consultation were analyzed following a conventional content analysis approach. Results: Legal frameworks, professional guidelines, and financial, organizational, and human resources to support the feedback of results are largely missing in Europe. Necessary steps to facilitate the feedback process include clarifying legal requirements to the feedback of results, developing harmonized European best practices, promoting interdisciplinary and cross-institutional collaboration, designing educational programs and cost-efficient IT-based platforms, involving research ethics committees, and documenting the health benefits and risks of the feedback process. Conclusions: Coordinated efforts at pan-European level are needed to enable equitable, scientifically sound, and socially robust feedback of results to research participants. PMID:27082461

Do Low Income Youth of Color See “The Bigger Picture” When Discussing Type 2 Diabetes: A Qualitative Evaluation of a Public Health Literacy Campaign

PubMed Central

Schillinger, Dean; Tran, Jessica; Fine, Sarah

2018-01-01

As Type 2 diabetes spikes among minority and low-income youth, there is an urgent need to tackle the drivers of this preventable disease. The Bigger Picture (TBP) is a counter-marketing campaign using youth-created, spoken-word public service announcements (PSAs) to reframe the epidemic as a socio-environmental phenomenon requiring communal action, civic engagement and norm change. Methods: We examined whether and how TBP PSAs advance health literacy among low-income, minority youth. We showed nine PSAs, asking individuals open-ended questions via questionnaire, then facilitating a focus group to reflect upon the PSAs. Results: Questionnaire responses revealed a balance between individual vs. public health literacy. Some focused on individual responsibility and behaviors, while others described socio-environmental forces underlying risk. The focus group generated a preponderance of public health literacy responses, emphasizing future action. Striking sociopolitical themes emerged, reflecting tensions minority and low-income youth experience, such as entrapment vs. liberation. Conclusion: Our findings speak to the structural barriers and complexities underlying diabetes risk, and the ability of spoken word medium to make these challenges visible and motivate action. Practice Implications: Delivering TBP content to promote interactive reflection has potential to change behavioral norms and build capacity to confront the social, economic and structural factors that influence behaviors. PMID:29695114

Can persuasive messages encourage individuals to create action plans for physical activity?

PubMed

Sweet, Shane N; Brawley, Lawrence R; Hatchell, Alexandra; Gainforth, Heather L; Latimer-Cheung, Amy E

2014-08-01

Given the positive influence of action planning on physical activity, persuasive messages could be designed to promote action planning. The purpose of this paper was to test action planning messages in two studies. Participants were allocated to one of two message groups, reading either a physical activity only or physical activity plus action planning message (Study 1) and either a gain-framed or loss-framed action planning message (Study 2). The percent of individuals who created an action plan and the quality of the plans were evaluated. In Study 1, individuals in the physical activity plus action planning group created as many action plans as the physical activity only group, but their plans were higher quality. In Study 2, Week 2 differences between the gain- and loss-framed message groups were found for action planning. To our knowledge, these studies were the first to investigate message-induced action planning as a behavior. More research is needed to optimize these messages.

Your own actions influence how you perceive other people: A misattribution of action appraisals

PubMed Central

Tipper, Steven P.; Bach, Patric

2008-01-01

The attribution of personal traits to other persons depends on the actions the observer performs at the same time (Bach & Tipper, 2007). Here, we show that the effect reflects a misattribution of appraisals of the observers’ own actions to the actions of others. We exploited spatial compatibility effects to manipulate how fluently—how fast and how accurately—participants identified two individuals performing sporty or academic actions. The traits attributed to each person in a subsequent rating task depended on the fluency of participants’ responses in a specific manner. An individual more fluently identified while performing the academic action appeared more academic and less sporty. An individual more fluently identified while performing the sporty action appeared sportier. Thus, social perception is—at least partially—embodied. The ease of our own responses can be misattributed to the actions of others, affecting which personal traits are attributed to them. PMID:21633518

Predictive gaze during observation of irrational actions in adults with autism spectrum conditions.

PubMed

Marsh, L E; Pearson, A; Ropar, D; Hamilton, A F de C

2015-01-01

Understanding irrational actions may require the observer to make mental state inferences about why an action was performed. Individuals with autism spectrum conditions (ASC) have well documented difficulties with mentalizing; however, the degree to which rationality understanding is impaired in autism is not yet clear. The present study uses eye-tracking to measure online understanding of action rationality in individuals with ASC. Twenty adults with ASC and 20 typically developing controls, matched for age and IQ watched movies of rational and irrational actions while their eye movements were recorded. Measures of looking time, scan path and saccade latency were calculated. Results from looking time and scan path analyses demonstrate that participants with ASC have reduced visual attention to salient action features such as the action goal and the hand performing the action, regardless of action rationality. However, when participants with ASC do attend to these features, they are able to make anticipatory goal saccades as quickly as typically developing controls. Taken together these results indicate that individuals with autism have reduced attention to observed actions, but when attention is maintained, goal prediction is typical. We conclude that the basic mechanisms of action understanding are intact in individuals with ASC although there may be impairment in the top-down, social modulation of eye movements.

A market survey of geothermal wellhead power generation systems

NASA Technical Reports Server (NTRS)

Leeds, M. W.

1978-01-01

The market potential for a portable geothermal wellhead power conversion device is assessed. Major study objectives included identifying the most promising applications for such a system, the potential impediments confronting their industrialization, and the various government actions needed to overcome these impediments. The heart of the study was a series of structured interviews with key decision-making individual in the various disciplines of the geothermal community. In addition, some technical and economic analyses of a candidate system were performed to support the feasibility of the basic concept.

Interest and Identity Convergence for Equitable Mathematics' Teaching: Reflections on the Interplay of the Institutional and Individual on Teacher Development and Action

ERIC Educational Resources Information Center

Meister, Tara

2017-01-01

Propelled by Maxine Greene's (1988) continuum of freedom from normative structures to critical consciousness and action, I illuminate the institutional and individual influences on teacher development and action in mathematics teaching. I focus on the question: What barriers and openings, both individually and institutionally, spur teachers to…

Financial Literacy and Education as an Asset Development Strategy: The Potential of IDA Saving Clubs at Community Action Agencies

ERIC Educational Resources Information Center

Parker, Jonas

2010-01-01

In the past two decades, the financial education movement has rapidly grown into a set of policies and programs that aims to empower individuals and families with financial literacy--the attitudes, knowledge, and skills necessary to make and act on informed financial decisions. For low- and moderate-income families in the U.S., this development…

Principles and Application of Hydrotherapy for Equine Athletes.

PubMed

King, Melissa R

2016-04-01

Hydrotherapy has become a key element within equine rehabilitation protocols and is used to address range of motion, proprioception, strength, neuromotor control, pain, and inflammation. Various forms of hydrotherapy can be tailored to the individual's injury and the expected return to athletic performance. This article describes the mechanisms of action of hydrotherapies and potential use in the clinical management of equine musculoskeletal injuries. Published by Elsevier Inc.

Facilitation and refractoriness of the electrically evoked compound action potential.

PubMed

Hey, Matthias; Müller-Deile, Joachim; Hessel, Horst; Killian, Matthijs

2017-11-01

In this study we aim to resolve the contributions of facilitation and refractoriness at very short pulse intervals. Measurements of the refractory properties of the electrically evoked compound action potential (ECAP) of the auditory nerve in cochlear implant (CI) users at inter pulse intervals below 300 μs are influenced by facilitation and recovery effects. ECAPs were recorded using masker pulses with a wide range of current levels relative to the probe pulse levels, for three suprathreshold probe levels and pulse intervals from 13 to 200 μs. Evoked potentials were measured for 21 CI patients by using the masked response extraction artifact cancellation procedure. During analysis of the measurements the stimulation current was not used as absolute value, but in relation to the patient's individual ECAP threshold. This enabled a more general approach to describe facilitation as a probe level independent effect. Maximum facilitation was found for all tested inter pulse intervals at masker levels near patient's individual ECAP threshold, independent from probe level. For short inter pulse intervals an increased N 1 P 1 amplitude was measured for subthreshold masker levels down to 120 CL below patient's individual ECAP threshold in contrast to the recreated state. ECAPs recorded with inter pulse intervals up to 200 μs are influenced by facilitation and recovery. Facilitation effects are most pronounced for masker levels at or below ECAP threshold, while recovery effects increase with higher masker levels above ECAP threshold. The local maximum of the ECAP amplitude for masker levels around ECAP threshold can be explained by the mutual influence of maximum facilitation and minimal refractoriness. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Evidence that monkeys (Macaca tonkeana and Sapajus apella) read moves, but no evidence that they read goals.

PubMed

Costes-Thiré, Morgane; Levé, Marine; Uhlrich, Pierre; Pasquaretta, Cristian; De Marco, Arianna; Thierry, Bernard

2015-08-01

Whereas most experiments indicate that monkeys have no theory of mind, a study carried out by Wood and collaborators (2007) claimed that they can make inferences about the intentions of another individual. We applied the experimental procedure devised by these authors to investigate whether monkeys can recognize goal-directed actions. We tested 16 Tonkean macaques (Macaca tonkeana) and 12 tufted capuchin monkeys (Sapajus apella). Each subject was submitted to 24 trials in randomized order. The experimenter presented 2 containers, 1 of which was potentially baited with a food reward. After the experimenter had either intentionally or accidentally made an action on 1 of the containers, the subject was asked to select 1 of them. We found that individuals in both species failed to distinguish between accidental and intentional actions. However, they displayed a significant preference for the container touched by the experimenter in the hand conditions, and not in the elbow conditions. These results do not support those reported by Wood and collaborators, but they are consistent with other studies concluding that monkeys are not capable of mind reading. (c) 2015 APA, all rights reserved).

Forecasting the effects of land-use and climate change on wildlife communities and habitats in the lower Mississippi Valley

USGS Publications Warehouse

Faulkner, Stephen P.

2010-01-01

Landscape patterns and processes reflect both natural ecosystem attributes and the policy and management decisions of individual Federal, State, county, and private organizations. Land-use regulation, water management, and habitat conservation and restoration efforts increasingly rely on landscape-level approaches that incorporate scientific information into the decision-making process. Since management actions are implemented to affect future conditions, decision-support models are necessary to forecast potential future conditions resulting from these decisions. Spatially explicit modeling approaches enable testing of different scenarios and help evaluate potential outcomes of management actions in conjunction with natural processes such as climate change. The ability to forecast the effects of changing land use and climate is critically important to land and resource managers since their work is inherently site specific, yet conservation strategies and practices are expressed at higher spatial and temporal scales that must be considered in the decisionmaking process.

Fast, temperature-sensitive and clathrin-independent endocytosis at central synapses

PubMed Central

Delvendahl, Igor; Vyleta, Nicholas P.; von Gersdorff, Henrique; Hallermann, Stefan

2016-01-01

The fusion of neurotransmitter-filled vesicles during synaptic transmission is balanced by endocytotic membrane retrieval. Despite extensive research, the speed and mechanisms of synaptic vesicle endocytosis have remained controversial. Here, we establish low-noise time-resolved membrane capacitance measurements that allow monitoring changes in surface membrane area elicited by single action potentials and stronger stimuli with high-temporal resolution at physiological temperature in individual bonafide mature central synapses. We show that single action potentials trigger very rapid endocytosis, retrieving presynaptic membrane with a time constant of 470 ms. This fast endocytosis is independent of clathrin, but mediated by dynamin and actin. In contrast, stronger stimuli evoke a slower mode of endocytosis that is clathrin-, dynamin-, and actin-dependent. Furthermore, the speed of endocytosis is highly temperature-dependent with a Q10 of ~3.5. These results demonstrate that distinct molecular modes of endocytosis with markedly different kinetics operate at central synapses. PMID:27146271

Complex adaptive systems and game theory: An unlikely union

USGS Publications Warehouse

Hadzikadic, M.; Carmichael, T.; Curtin, C.

2010-01-01

A Complex Adaptive System is a collection of autonomous, heterogeneous agents, whose behavior is defined with a limited number of rules. A Game Theory is a mathematical construct that assumes a small number of rational players who have a limited number of actions or strategies available to them. The CAS method has the potential to alleviate some of the shortcomings of GT. On the other hand, CAS researchers are always looking for a realistic way to define interactions among agents. GT offers an attractive option for defining the rules of such interactions in a way that is both potentially consistent with observed real-world behavior and subject to mathematical interpretation. This article reports on the results of an effort to build a CAS system that utilizes GT for determining the actions of individual agents. ?? 2009 Wiley Periodicals, Inc. Complexity, 16,24-42, 2010.

Model-based estimators of density and connectivity to inform conservation of spatially structured populations

USGS Publications Warehouse

Morin, Dana J.; Fuller, Angela K.; Royle, J. Andrew; Sutherland, Chris

2017-01-01

Conservation and management of spatially structured populations is challenging because solutions must consider where individuals are located, but also differential individual space use as a result of landscape heterogeneity. A recent extension of spatial capture–recapture (SCR) models, the ecological distance model, uses spatial encounter histories of individuals (e.g., a record of where individuals are detected across space, often sequenced over multiple sampling occasions), to estimate the relationship between space use and characteristics of a landscape, allowing simultaneous estimation of both local densities of individuals across space and connectivity at the scale of individual movement. We developed two model-based estimators derived from the SCR ecological distance model to quantify connectivity over a continuous surface: (1) potential connectivity—a metric of the connectivity of areas based on resistance to individual movement; and (2) density-weighted connectivity (DWC)—potential connectivity weighted by estimated density. Estimates of potential connectivity and DWC can provide spatial representations of areas that are most important for the conservation of threatened species, or management of abundant populations (i.e., areas with high density and landscape connectivity), and thus generate predictions that have great potential to inform conservation and management actions. We used a simulation study with a stationary trap design across a range of landscape resistance scenarios to evaluate how well our model estimates resistance, potential connectivity, and DWC. Correlation between true and estimated potential connectivity was high, and there was positive correlation and high spatial accuracy between estimated DWC and true DWC. We applied our approach to data collected from a population of black bears in New York, and found that forested areas represented low levels of resistance for black bears. We demonstrate that formal inference about measures of landscape connectivity can be achieved from standard methods of studying animal populations which yield individual encounter history data such as camera trapping. Resulting biological parameters including resistance, potential connectivity, and DWC estimate the spatial distribution and connectivity of the population within a statistical framework, and we outline applications to many possible conservation and management problems.

Analysis of Enzymatic Degradation of Cellulose Microfibrils using Quantitative Surface Plasmon Resonance Imaging

NASA Astrophysics Data System (ADS)

Reiter, Kyle; Raegen, Adam; Allen, Scott; Quirk, Amanda; Clarke, Anthony; Lipkowski, Jacek; Dutcher, John

2013-03-01

Cellulose is the largest component of biomass on Earth and, as a result, is a significant potential energy source. The production of cellulosic ethanol as a fuel source requires conversion of cellulose fibers into fermentable sugars. Increasing our understanding of the action of cellulose enzymes (cellulases) on cellulose microfibrils is an important step in developing more efficient industrial processes for the production of cellulosic ethanol. We have used a custom designed Surface Plasmon Resonance imaging (SPRi) device to study the action of cellulases from the Hypocrea jecorinasecretome on bacterial cellulose microfibrils. This has allowed us to determine the rates of action and extent of degradation of cellulose microfibrils on exposure to both individual cellulases and combinations of different classes of cellulases, which has allowed us to investigate synergistic interactions between the cellulases.

Surface Plasmon Resonance Imaging of the Enzymatic Degradation of Cellulose Microfibrils

NASA Astrophysics Data System (ADS)

Reiter, Kyle; Raegen, Adam; Clarke, Anthony; Lipkowski, Jacek; Dutcher, John

2012-02-01

As the largest component of biomass on Earth, cellulose represents a significant potential energy reservoir. Enzymatic hydrolysis of cellulose into fermentable sugars, an integral step in the production of biofuel, is a challenging problem on an industrial scale. More efficient conversion processes may be developed by an increased understanding of the action of the cellulolytic enzymes involved in cellulose degradation. We have used our recently developed quantitative, angle-scanning surface plasmon resonance imaging (SPRi) device to study the degradation of cellulose microfibrils upon exposure to cellulosic enzymes. In particular, we have studied the action of individual enzymes, and combinations of enzymes, from the Hypocrea Jecorina cellulase system on heterogeneous, industrially-relevant cellulose substrates. This has allowed us to define a characteristic time of action for the enzymes for different degrees of surface coverage of the cellulose microfibrils.

Action potentials reliably invade axonal arbors of rat neocortical neurons

PubMed Central

Cox, Charles L.; Denk, Winfried; Tank, David W.; Svoboda, Karel

2000-01-01

Neocortical pyramidal neurons have extensive axonal arborizations that make thousands of synapses. Action potentials can invade these arbors and cause calcium influx that is required for neurotransmitter release and excitation of postsynaptic targets. Thus, the regulation of action potential invasion in axonal branches might shape the spread of excitation in cortical neural networks. To measure the reliability and extent of action potential invasion into axonal arbors, we have used two-photon excitation laser scanning microscopy to directly image action-potential-mediated calcium influx in single varicosities of layer 2/3 pyramidal neurons in acute brain slices. Our data show that single action potentials or bursts of action potentials reliably invade axonal arbors over a range of developmental ages (postnatal 10–24 days) and temperatures (24°C-30°C). Hyperpolarizing current steps preceding action potential initiation, protocols that had previously been observed to produce failures of action potential propagation in cultured preparations, were ineffective in modulating the spread of action potentials in acute slices. Our data show that action potentials reliably invade the axonal arbors of neocortical pyramidal neurons. Failures in synaptic transmission must therefore originate downstream of action potential invasion. We also explored the function of modulators that inhibit presynaptic calcium influx. Consistent with previous studies, we find that adenosine reduces action-potential-mediated calcium influx in presynaptic terminals. This reduction was observed in all terminals tested, suggesting that some modulatory systems are expressed homogeneously in most terminals of the same neuron. PMID:10931955

Naïve Definitions of Action and Inaction: The Continuum, Spread, and Valence of Behaviors

PubMed Central

McCulloch, Kathleen C.; Li, Hong; Hong, Sungjin; Albarracin, Dolores

2011-01-01

The cohesiveness of a society depends, in part, on how its individual members manage their daily activities with respect to the goals of that society. Hence, there should be a degree of social agreement on what constitutes action and what constitutes inaction. The present research investigated the structure of action and inaction definitions, the evaluation of action versus inaction, and individual differences in these evaluations. Action-inaction ratings of behaviors and states showed more social agreement at the ends of the inaction-action continuum than at the middle, suggesting a socially shared construal of this definition. Action-inaction ratings were also shown to correlate with the valence of the rated behaviors, such that the more active the behavior the more positive its valence. Lastly, individual differences in locomotion, need for closure, and Christian religious beliefs correlated positively with a preference for action. PMID:23487013

Interpersonal motor resonance in autism spectrum disorder: evidence against a global “mirror system” deficit

PubMed Central

Enticott, Peter G.; Kennedy, Hayley A.; Rinehart, Nicole J.; Bradshaw, John L.; Tonge, Bruce J.; Daskalakis, Zafiris J.; Fitzgerald, Paul B.

2013-01-01

The mirror neuron hypothesis of autism is highly controversial, in part because there are conflicting reports as to whether putative indices of mirror system activity are actually deficient in autism spectrum disorder (ASD). Recent evidence suggests that a typical putative mirror system response may be seen in people with an ASD when there is a degree of social relevance to the visual stimuli used to elicit that response. Individuals with ASD (n = 32) and matched neurotypical controls (n = 32) completed a transcranial magnetic stimulation (TMS) experiment in which the left primary motor cortex (M1) was stimulated during the observation of static hands, individual (i.e., one person) hand actions, and interactive (i.e., two person) hand actions. Motor-evoked potentials (MEP) were recorded from the contralateral first dorsal interosseous, and used to generate an index of interpersonal motor resonance (IMR; a putative measure of mirror system activity) during action observation. There was no difference between ASD and NT groups in the level of IMR during the observation of these actions. These findings provide evidence against a global mirror system deficit in ASD, and this evidence appears to extend beyond stimuli that have social relevance. Attentional and visual processing influences may be important for understanding the apparent role of IMR in the pathophysiology of ASD. PMID:23734121

The action of ether and methoxyflurane on synaptic transmission in isolated preparations of the mammalian cortex.

PubMed Central

Richards, C D; Russell, W J; Smaje, J C

1975-01-01

1. The actions of ether and methoxyflurane on the evoked potentials of in vitro preparations of the guinea-pig olfactory cortex were studied. Following stimulation of the lateral olfactory tract (l.o.t.) evoked potentials could be recorded from the cortical surface; these potentials consisted of an initial wave (the compound action potential of the l.o.t.) followed by a negative field potential which was associated with the synchronous excitation of many superficial excitatory synapses (population e.p.s.p.). Superimposed on the population e.p.s.p. was a number of positive peaks. These positive peaks reflect the synchronous discharge of many neurones and so have been called population spikes. 2. When ether or methoxyflurane was added to the gas stream that superfused the surface of the preparations, the population e.p.s.p.s. and population spikes were depressed at lower concentrations than those required to depress the compound action potential of the afferent fibres. 3. The evoked activity of individual cells in the cortex was depressed by ether and methoxyflurane. However, five of the twelve cells tested in ether showed an increase in their evoked activity at concentrations below 4-5%, but at higher concentrations these cells also became depressed. 4. Both ether and methoxyflurane depressed the sensitivity of cortical neurones to iontophoretically applied L-glutamate and may similarly depress the sensitivity of the post-synaptic membrane to the released transmitter substance. 5. Neither anaesthetic appeared to increase the threshold depolarization required for nerve impulse generation. Thus, the decrease of the discharge of the post-synaptic cells was primarily caused by a depression of chemical transmission. 6. Ether caused some cells in the cortex to alter their normal pattern of synaptically evoked discharge and both anaesthetics induced similar changes during excitation by glutamate. PMID:168356

The role of health promotion: between global thinking and local action.

PubMed

King, Lesley

2006-12-01

The persistence of health inequities provides an ongoing challenge for health promotion. The dictum 'think globally, act locally' fails to recognise the significance of infrastructure and policy in linking global issues and local practices as a means of addressing health inequities. Commentary and opinion. Through analytic tools and methods, health promotion has much to contribute to facilitating health-improving changes in social, economic and physical environments. Local actions provide excellent illustrations of organisational change and intersectoral action, and present the possibility that such actions could be widely implemented. While this has occurred on some issues, this is not usually the case. Political support, policy and infrastructure are required to link global ideas and local actions and overcome the impasse. Media advocacy is one example of an approach with potential to make these links and mobilise political support. Reframing media and political discussion, away from the dichotomy of individual responsibility and government intervention and towards acknowledging the social context of human behaviour, could contribute to policy and social environments with greater capacity to address inequities.

Assessing the Electrode-Neuron Interface with the Electrically Evoked Compound Action Potential, Electrode Position, and Behavioral Thresholds.

PubMed

DeVries, Lindsay; Scheperle, Rachel; Bierer, Julie Arenberg

2016-06-01

Variability in speech perception scores among cochlear implant listeners may largely reflect the variable efficacy of implant electrodes to convey stimulus information to the auditory nerve. In the present study, three metrics were applied to assess the quality of the electrode-neuron interface of individual cochlear implant channels: the electrically evoked compound action potential (ECAP), the estimation of electrode position using computerized tomography (CT), and behavioral thresholds using focused stimulation. The primary motivation of this approach is to evaluate the ECAP as a site-specific measure of the electrode-neuron interface in the context of two peripheral factors that likely contribute to degraded perception: large electrode-to-modiolus distance and reduced neural density. Ten unilaterally implanted adults with Advanced Bionics HiRes90k devices participated. ECAPs were elicited with monopolar stimulation within a forward-masking paradigm to construct channel interaction functions (CIF), behavioral thresholds were obtained with quadrupolar (sQP) stimulation, and data from imaging provided estimates of electrode-to-modiolus distance and scalar location (scala tympani (ST), intermediate, or scala vestibuli (SV)) for each electrode. The width of the ECAP CIF was positively correlated with electrode-to-modiolus distance; both of these measures were also influenced by scalar position. The ECAP peak amplitude was negatively correlated with behavioral thresholds. Moreover, subjects with low behavioral thresholds and large ECAP amplitudes, averaged across electrodes, tended to have higher speech perception scores. These results suggest a potential clinical role for the ECAP in the objective assessment of individual cochlear implant channels, with the potential to improve speech perception outcomes.

12 CFR 268.105 - Individual complaints.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Individual complaints. 268.105 Section 268.105... RULES REGARDING EQUAL OPPORTUNITY Board Program To Promote Equal Opportunity § 268.105 Individual... individual and the Board and to describe generally the action(s) or practice(s) that form the basis of the...

29 CFR 1614.106 - Individual complaints.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 4 2010-07-01 2010-07-01 false Individual complaints. 1614.106 Section 1614.106 Labor... EMPLOYMENT OPPORTUNITY Agency Program To Promote Equal Employment Opportunity § 1614.106 Individual... individual and the agency and to describe generally the action(s) or practice(s) that form the basis of the...

Perceiving Goals and Actions in Individuals with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Zalla, Tiziana; Labruyère, Nelly; Georgieff, Nicolas

2013-01-01

In the present study, we investigated the ability to parse familiar sequences of action into meaningful events in young individuals with autism spectrum disorders (ASDs), as compared to young individuals with typical development (TD) and young individuals with moderate mental retardation or learning disabilities (MLDs). While viewing two…

Caring Across the Continuum: A Call to Nurse Leaders to Manifest Values Through Action With Community Outreach.

PubMed

Dyess, Susan MacLeod; Opalinski, Andra; Saiswick, Kim; Fox, Valerie

2016-01-01

As health reform continues to advance, there is a need for nurse leaders to broaden their perspective related to possible nursing practice models and potential community partners in order to successfully address caring, accomplish the triple aim mandate, and achieve suitable metrics for maximum reimbursement. Intentional efforts must be made by nurse leaders to maximize caring and ensure that professional nurses are responding to the key drivers shifting health care delivery in the 21st century. Academic-practice collaboration (APC) and community-based participatory action research (CBPAR) align well. Together, they provide an ideal mechanism to pursue endeavors that extend evidence for caring services across the health care continuum. One APC/CBPAR model for community outreach that can maximize individual and population health outcomes is highlighted in this article. Furthermore, useful action steps are offered that could be taken by a nurse leader to develop and maintain any form of APC/CBPAR in order to manifest values through caring action across the health care continuum.

A case study of the development of environmental action projects from the framework of participatory action research within two middle school classrooms

NASA Astrophysics Data System (ADS)

Charmatz, Kim

The purpose of this study was to understand student and teacher empowerment through a socially critical environmental education perspective. The main research question guiding this study was: How do participants make sense of a learning experience in which students design and carry out an environmental action project in their community? This study used participatory action research and critical theory as practical and theoretical frameworks. These frameworks were relevant as this study sought to examine social change, power, and relationships through participants' experiences. The context of this study was within one seventh and one eighth grade classroom participating in environmental projects. The study was conducted in spring 2005 with an additional follow-up data collection period during spring 2006. The school was located in a densely populated metropolitan suburb. Fifty-three students, a teacher researcher, and three science teachers participated. Data sources were written surveys, scores on Middle School Environmental Literacy Survey Instrument (MSELI), observations, interviews, and student work. This study used a mixed methodological approach. Quantitative data analysis involved dependent samples t-test scores on the MSELI before and after the completion of the projects. Qualitative data were analyzed using an inductive analysis approach. This study has implications for educators interested in democratic education. Environmental action projects provide a context for students and teachers to learn interdisciplinary content knowledge, develop personal beliefs, and learn ways to take action in their communities. This pedagogy has the potential to increase cooperation, communication, and tensions within school communities. Students' participation in the development of environmental action projects may lead to feelings of empowerment or being able to make a difference in their community, as an individual or member of a group. Future research is needed to discern why participants experience this type of educational experience differently, for example, how does the type of environmental action project influence individual and group empowerment?

Impulsive action and motivation.

PubMed

Frijda, Nico H

2010-07-01

This paper explores the way in which emotions are causal determinants of action. It argues that emotional events, as appraised by the individual, elicit changes in motive states (called states of action readiness), which in turn may (or may not) cause action. Actions can be elicited automatically, without prior intention (called impulsive actions), or intentionally. Impulsive actions reflect the simplest and biologically most general form in which emotions can cause action, since they require no reflection, no foresight, and no planning. Impulsive actions are determined conjointly by the nature of action readiness, the affordances perceived in the eliciting event as appraised, and the individual's action repertoire. Those actions from one's repertoire are performed that both match the perceived affordances and the aim of the state of action readiness. Copyright © 2010 Elsevier B.V. All rights reserved.

The SAM framework: modeling the effects of management factors on human behavior in risk analysis.

PubMed

Murphy, D M; Paté-Cornell, M E

1996-08-01

Complex engineered systems, such as nuclear reactors and chemical plants, have the potential for catastrophic failure with disastrous consequences. In recent years, human and management factors have been recognized as frequent root causes of major failures in such systems. However, classical probabilistic risk analysis (PRA) techniques do not account for the underlying causes of these errors because they focus on the physical system and do not explicitly address the link between components' performance and organizational factors. This paper describes a general approach for addressing the human and management causes of system failure, called the SAM (System-Action-Management) framework. Beginning with a quantitative risk model of the physical system, SAM expands the scope of analysis to incorporate first the decisions and actions of individuals that affect the physical system. SAM then links management factors (incentives, training, policies and procedures, selection criteria, etc.) to those decisions and actions. The focus of this paper is on four quantitative models of action that describe this last relationship. These models address the formation of intentions for action and their execution as a function of the organizational environment. Intention formation is described by three alternative models: a rational model, a bounded rationality model, and a rule-based model. The execution of intentions is then modeled separately. These four models are designed to assess the probabilities of individual actions from the perspective of management, thus reflecting the uncertainties inherent to human behavior. The SAM framework is illustrated for a hypothetical case of hazardous materials transportation. This framework can be used as a tool to increase the safety and reliability of complex technical systems by modifying the organization, rather than, or in addition to, re-designing the physical system.

Non-conscious visual cues related to affect and action alter perception of effort and endurance performance

PubMed Central

Blanchfield, Anthony; Hardy, James; Marcora, Samuele

2014-01-01

The psychobiological model of endurance performance proposes that endurance performance is determined by a decision-making process based on perception of effort and potential motivation. Recent research has reported that effort-based decision-making during cognitive tasks can be altered by non-conscious visual cues relating to affect and action. The effects of these non-conscious visual cues on effort and performance during physical tasks are however unknown. We report two experiments investigating the effects of subliminal priming with visual cues related to affect and action on perception of effort and endurance performance. In Experiment 1 thirteen individuals were subliminally primed with happy or sad faces as they cycled to exhaustion in a counterbalanced and randomized crossover design. A paired t-test (happy vs. sad faces) revealed that individuals cycled significantly longer (178 s, p = 0.04) when subliminally primed with happy faces. A 2 × 5 (condition × iso-time) ANOVA also revealed a significant main effect of condition on rating of perceived exertion (RPE) during the time to exhaustion (TTE) test with lower RPE when subjects were subliminally primed with happy faces (p = 0.04). In Experiment 2, a single-subject randomization tests design found that subliminal priming with action words facilitated a significantly longer TTE (399 s, p = 0.04) in comparison to inaction words. Like Experiment 1, this greater TTE was accompanied by a significantly lower RPE (p = 0.03). These experiments are the first to show that subliminal visual cues relating to affect and action can alter perception of effort and endurance performance. Non-conscious visual cues may therefore influence the effort-based decision-making process that is proposed to determine endurance performance. Accordingly, the findings raise notable implications for individuals who may encounter such visual cues during endurance competitions, training, or health related exercise. PMID:25566014

Attribution of Mild Cognitive Impairment Etiology in Patients and Their Care-Partners

PubMed Central

Rodakowski, Juleen; Schulz, Richard; Gentry, Amanda; Garand, Linda; Lingler, Jennifer Hagerty

2013-01-01

Objective This study examined the attribution of MCI etiology assigned by individuals with MCI and their care-partners, and the extent to which the dyads agreed on the attribution of MCI etiology. Methods We conducted secondary analyses of cross-sectional data from a cohort of individuals with MCI (n=60) and their care-partners (n=60). The mean age of the individuals with MCI was 71.0±9.4 and of care-partners 64.2±11.0 years. The primary outcome was attribution assigned to memory deficits on the Illness Perception Questionnaire. We categorized the attribution of MCI etiology as either potentially controllable or uncontrollable factors. We described the distribution of MCI etiology with descriptive and contingency tables. We determined the odds of a patient or care-partner choosing one type of MCI etiology over another. Results Although individuals with MCI and their care-partners most frequently attributed MCI to uncontrollable factors (81.7% and 61.0%, respectively), care-partners were 28.41 [95% CI, 1.26 to 645.48] times more likely to attribute MCI etiology to potentially controllable factors than individuals with MCI. No significant associations between demographic factors and attribution of MCI etiology were found for the individuals with MCI or the care-partners. Conclusion Findings demonstrated that members of the dyad attributed MCI etiology to different causes. Attributions of MCI etiology should be explored by professionals to clarify misconceptions and potentially improve subsequent voluntary actions intended to assist oneself or others. PMID:24123240

[Patterns of action potential firing in cortical neurons of neonatal mice and their electrophysiological property].

PubMed

Furong, Liu; Shengtian, L I

2016-05-25

To investigate patterns of action potential firing in cortical heurons of neonatal mice and their electrophysiological properties. The passive and active membrane properties of cortical neurons from 3-d neonatal mice were observed by whole-cell patch clamp with different voltage and current mode. Three patterns of action potential firing were identified in response to depolarized current injection. The effects of action potential firing patterns on voltage-dependent inward and outward current were found. Neurons with three different firing patterns had different thresholds of depolarized current. In the morphology analysis of action potential, the three type neurons were different in rise time, duration, amplitude and threshold of the first action potential evoked by 80 pA current injection. The passive properties were similar in three patterns of action potential firing. These results indicate that newborn cortical neurons exhibit different patterns of action potential firing with different action potential parameters such as shape and threshold.

Environmental Assessment for the Transfer of 1100 AREA, Southern Rail Connection and Rolling Stock, Hanford Site, Richland, Washington

DOE Office of Scientific and Technical Information (OSTI.GOV)

N /A

This environmental assessment (EA) has been prepared to assess potential environmental impacts associated with the U.S. Department of Energy's proposed action: the transfer of the 1100 Area, southern rail connection and rolling stock to a non-federal entity. Impact information contained herein will be used by the U.S. Department of Energy, Richland Operations Office Manager, to determine if the proposed action is a major federal action significantly affecting the quality of the human environment. If the proposed action is determined to be major and significant, an environmental impact statement will be prepared. If the proposed action is determined not to bemore » major and significant, a Finding of No Significant Impact (FONSI) will be issued and the action can proceed. Criteria used to evaluate significance can be found in Title 40, Code of Federal Regulations (CFR) 1508.27. This EA was prepared in compliance with the ''National Environmental Policy Act'' (NEPA) of 1969, as amended, the Council on Environmental Quality (CEQ) Regulations for Implementing the Procedural Provisions of NEPA (40 CFR 1500-1508), and the U.S. Department of Energy Implementing Procedures for NEPA (10 CFR 1021). The following is a description of each section of the EA. (1) Purpose and Need for Action. This provides a brief statement concerning the problem or opportunity the U.S. Department of Energy is addressing with the proposed action. As necessary, background information is provided. (2) Description of the Proposed Action. A description with sufficient detail to identify potential environmental impacts is provided. (3) Alternatives to the Proposed Action. Reasonable alternative actions, which would address the Purpose and Need, are described. A no action alternative, as required by 10 CFR 1021, also is described. (4) Affected Environment. This provides a brief description of the locale in which the proposed action takes place, and which may be environmentally impacted. (5) Environmental Impacts. The range of environmental impacts, beneficial and adverse, are described for the proposed action. Impacts of alternatives briefly are discussed. (6) Permits and Regulatory Requirements. A brief description of permits and regulatory requirements for the proposed action is provided. (7) Organizations Consulted. Any outside agencies, groups, or individuals contacted as part of environmental assessment documentation preparation are listed. (8) References. Documents used to provide information or data are listed. The appendices contain additional information necessary to support an understanding of the proposed action, alternatives, and potential impacts is provided. Comments resulting from review of the environmental assessment by states and tribes or other stakeholders and the response to those comments will be included in the appendices.« less

75 FR 36654 - Petition from Pesticide Poisoning Victims United; Notice of Availability; Extension of Comment...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-28

...EPA issued a notice in the Federal Register of April 28, 2010, concerning a petition from Pesticide Poisoning Victims United that asks the Agency to undertake a number of actions to protect potentially affected individuals in Lane County, OR from pesticides applied to surrounding forestlands. This document extends the comment period for 45 days, from June 28, 2010, to August 12, 2010.

Suicide prevention by online support groups: an action theory-based model of emotional first aid.

PubMed

Gilat, Itzhak; Shahar, Golan

2009-01-01

In the last two decades, online support groups have become a valuable source of help for individuals in suicidal crisis. Their attractiveness is attributed to features that enhance help-seeking and self-disclosure such as availability, anonymity, and use of written communication. However, online support groups also suffer from limitations and potential risks as agents of suicide prevention. The Israeli Association for Emotional First Aid (ERAN) has developed a practical model that seeks to maximize the benefits and minimize the risks of online suicide prevention. The model applies the Action Theory concepts whereby individuals shape their own environment. The present paper presents the model, which is based on an online support group combined with personal chat and a telephonic help line. The online support group is moderated by paraprofessionals who function as both process regulators and support providers. The principles and practice of the model are described, the theoretical rationale is presented, and directions for future research are suggested.

Probabilistic measures of climate change vulnerability, adaptation action benefits, and related uncertainty from maximum temperature metric selection.

PubMed

DeWeber, Jefferson T; Wagner, Tyler

2018-06-01

Predictions of the projected changes in species distributions and potential adaptation action benefits can help guide conservation actions. There is substantial uncertainty in projecting species distributions into an unknown future, however, which can undermine confidence in predictions or misdirect conservation actions if not properly considered. Recent studies have shown that the selection of alternative climate metrics describing very different climatic aspects (e.g., mean air temperature vs. mean precipitation) can be a substantial source of projection uncertainty. It is unclear, however, how much projection uncertainty might stem from selecting among highly correlated, ecologically similar climate metrics (e.g., maximum temperature in July, maximum 30-day temperature) describing the same climatic aspect (e.g., maximum temperatures) known to limit a species' distribution. It is also unclear how projection uncertainty might propagate into predictions of the potential benefits of adaptation actions that might lessen climate change effects. We provide probabilistic measures of climate change vulnerability, adaptation action benefits, and related uncertainty stemming from the selection of four maximum temperature metrics for brook trout (Salvelinus fontinalis), a cold-water salmonid of conservation concern in the eastern United States. Projected losses in suitable stream length varied by as much as 20% among alternative maximum temperature metrics for mid-century climate projections, which was similar to variation among three climate models. Similarly, the regional average predicted increase in brook trout occurrence probability under an adaptation action scenario of full riparian forest restoration varied by as much as .2 among metrics. Our use of Bayesian inference provides probabilistic measures of vulnerability and adaptation action benefits for individual stream reaches that properly address statistical uncertainty and can help guide conservation actions. Our study demonstrates that even relatively small differences in the definitions of climate metrics can result in very different projections and reveal high uncertainty in predicted climate change effects. © 2018 John Wiley & Sons Ltd.

Probabilistic measures of climate change vulnerability, adaptation action benefits, and related uncertainty from maximum temperature metric selection

USGS Publications Warehouse

DeWeber, Jefferson T.; Wagner, Tyler

2018-01-01

Predictions of the projected changes in species distributions and potential adaptation action benefits can help guide conservation actions. There is substantial uncertainty in projecting species distributions into an unknown future, however, which can undermine confidence in predictions or misdirect conservation actions if not properly considered. Recent studies have shown that the selection of alternative climate metrics describing very different climatic aspects (e.g., mean air temperature vs. mean precipitation) can be a substantial source of projection uncertainty. It is unclear, however, how much projection uncertainty might stem from selecting among highly correlated, ecologically similar climate metrics (e.g., maximum temperature in July, maximum 30‐day temperature) describing the same climatic aspect (e.g., maximum temperatures) known to limit a species’ distribution. It is also unclear how projection uncertainty might propagate into predictions of the potential benefits of adaptation actions that might lessen climate change effects. We provide probabilistic measures of climate change vulnerability, adaptation action benefits, and related uncertainty stemming from the selection of four maximum temperature metrics for brook trout (Salvelinus fontinalis), a cold‐water salmonid of conservation concern in the eastern United States. Projected losses in suitable stream length varied by as much as 20% among alternative maximum temperature metrics for mid‐century climate projections, which was similar to variation among three climate models. Similarly, the regional average predicted increase in brook trout occurrence probability under an adaptation action scenario of full riparian forest restoration varied by as much as .2 among metrics. Our use of Bayesian inference provides probabilistic measures of vulnerability and adaptation action benefits for individual stream reaches that properly address statistical uncertainty and can help guide conservation actions. Our study demonstrates that even relatively small differences in the definitions of climate metrics can result in very different projections and reveal high uncertainty in predicted climate change effects.

INCENTIVES TO IDENTIFY: RACIAL IDENTITY IN THE AGE OF AFFIRMATIVE ACTION

PubMed Central

Antman, Francisca; Duncan, Brian

2016-01-01

We link data on racial self-identification with changes in state-level affirmative action policies to ask whether racial self-identification responds to economic incentives. We find that after a state bans affirmative action, multiracial individuals who face an incentive to identify under affirmative action are about 30 percent less likely to identify with their minority groups. In contrast, multiracial individuals who face a disincentive to identify under affirmative action are roughly 20 percent more likely to identify with their minority groups once affirmative action policies are banned. PMID:27635103

INCENTIVES TO IDENTIFY: RACIAL IDENTITY IN THE AGE OF AFFIRMATIVE ACTION.

PubMed

Antman, Francisca; Duncan, Brian

2015-07-01

We link data on racial self-identification with changes in state-level affirmative action policies to ask whether racial self-identification responds to economic incentives. We find that after a state bans affirmative action, multiracial individuals who face an incentive to identify under affirmative action are about 30 percent less likely to identify with their minority groups. In contrast, multiracial individuals who face a disincentive to identify under affirmative action are roughly 20 percent more likely to identify with their minority groups once affirmative action policies are banned.

Role of action potential configuration and the contribution of Ca2+ and K+ currents to isoprenaline-induced changes in canine ventricular cells

PubMed Central

Szentandrássy, N; Farkas, V; Bárándi, L; Hegyi, B; Ruzsnavszky, F; Horváth, B; Bányász, T; Magyar, J; Márton, I; Nánási, PP

2012-01-01

BACKGROUND AND PURPOSE Although isoprenaline (ISO) is known to activate several ion currents in mammalian myocardium, little is known about the role of action potential morphology in the ISO-induced changes in ion currents. Therefore, the effects of ISO on action potential configuration, L-type Ca2+ current (ICa), slow delayed rectifier K+ current (IKs) and fast delayed rectifier K+ current (IKr) were studied and compared in a frequency-dependent manner using canine isolated ventricular myocytes from various transmural locations. EXPERIMENTAL APPROACH Action potentials were recorded with conventional sharp microelectrodes; ion currents were measured using conventional and action potential voltage clamp techniques. KEY RESULTS In myocytes displaying a spike-and-dome action potential configuration (epicardial and midmyocardial cells), ISO caused reversible shortening of action potentials accompanied by elevation of the plateau. ISO-induced action potential shortening was absent in endocardial cells and in myocytes pretreated with 4-aminopyridine. Application of the IKr blocker E-4031 failed to modify the ISO effect, while action potentials were lengthened by ISO in the presence of the IKs blocker HMR-1556. Both action potential shortening and elevation of the plateau were prevented by pretreatment with the ICa blocker nisoldipine. Action potential voltage clamp experiments revealed a prominent slowly inactivating ICa followed by a rise in IKs, both currents increased with increasing the cycle length. CONCLUSIONS AND IMPLICATIONS The effect of ISO in canine ventricular cells depends critically on action potential configuration, and the ISO-induced activation of IKs– but not IKr– may be responsible for the observed shortening of action potentials. PMID:22563726

Role of action potential configuration and the contribution of C²⁺a and K⁺ currents to isoprenaline-induced changes in canine ventricular cells.

PubMed

Szentandrássy, N; Farkas, V; Bárándi, L; Hegyi, B; Ruzsnavszky, F; Horváth, B; Bányász, T; Magyar, J; Márton, I; Nánási, P P

2012-10-01

Although isoprenaline (ISO) is known to activate several ion currents in mammalian myocardium, little is known about the role of action potential morphology in the ISO-induced changes in ion currents. Therefore, the effects of ISO on action potential configuration, L-type Ca²⁺ current (I(Ca)), slow delayed rectifier K⁺ current (I(Ks)) and fast delayed rectifier K⁺ current (I(Kr)) were studied and compared in a frequency-dependent manner using canine isolated ventricular myocytes from various transmural locations. Action potentials were recorded with conventional sharp microelectrodes; ion currents were measured using conventional and action potential voltage clamp techniques. In myocytes displaying a spike-and-dome action potential configuration (epicardial and midmyocardial cells), ISO caused reversible shortening of action potentials accompanied by elevation of the plateau. ISO-induced action potential shortening was absent in endocardial cells and in myocytes pretreated with 4-aminopyridine. Application of the I(Kr) blocker E-4031 failed to modify the ISO effect, while action potentials were lengthened by ISO in the presence of the I(Ks) blocker HMR-1556. Both action potential shortening and elevation of the plateau were prevented by pretreatment with the I(Ca) blocker nisoldipine. Action potential voltage clamp experiments revealed a prominent slowly inactivating I(Ca) followed by a rise in I(Ks) , both currents increased with increasing the cycle length. The effect of ISO in canine ventricular cells depends critically on action potential configuration, and the ISO-induced activation of I(Ks) - but not I(Kr) - may be responsible for the observed shortening of action potentials. © 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.

Handbook for Ecology Action.

ERIC Educational Resources Information Center

Eber, Ronald

This handbook has been compiled to aid concerned individuals and ecology groups more adequately define their goals, initiate good programs, and take effective action. It examines the ways a group of working individuals can become involved in action programs for ecological change. Part 1 deals with organization, preliminary organizing, structuring,…

Improving Separation Assurance Stability Through Trajectory Flexibility Preservation

NASA Technical Reports Server (NTRS)

Idris, Husni; Shen, Ni; Wing, David J.

2010-01-01

New information and automation technologies are enabling the distribution of tasks and decisions from the service providers to the users of the air traffic system, with potential capacity and cost benefits. This distribution of tasks and decisions raises the concern that independent user actions will decrease the predictability and increase the complexity of the traffic system, hence inhibiting and possibly reversing any potential benefits. One such concern is the adverse impact of uncoordinated actions by individual aircraft on the stability of separation assurance. For example, individual aircraft performing self-separation may resolve predicted losses of separation or conflicts with some traffic, only to result in secondary conflicts with other traffic or with the same traffic later in time. In answer to this concern, this paper proposes metrics for preserving user trajectory flexibility to be used in self-separation along with other objectives. The hypothesis is that preserving trajectory flexibility will naturally reduce the creation of secondary conflicts by bringing about implicit coordination between aircraft. The impact of using these metrics on improving self-separation stability is investigated by measuring the impact on secondary conflicts. The scenarios analyzed include aircraft in en route airspace with each aircraft meeting a required time of arrival in a twenty minute time horizon while maintaining separation from the surrounding traffic and using trajectory flexibility metrics to mitigate the risk of secondary conflicts. Preliminary experiments showed promising results in that the trajectory flexibility preservation reduced the potential for secondary conflicts.

Characteristics of action potentials and their underlying outward currents in rat taste receptor cells.

PubMed

Chen, Y; Sun, X D; Herness, S

1996-02-01

1. Taste receptor cells produce action potentials as a result of transduction mechanisms that occur when these cells are stimulated with tastants. These action potentials are thought to be key signaling events in relaying information to the central nervous system. We explored the ionic basis of action potentials from dissociated posterior rat taste cells using the patch-clamp recording technique in both voltage-clamp and current-clamp modes. 2. Action potentials were evoked by intracellular injection of depolarizing current pulses from a holding potential of -80 mV. The threshold potential for firing of action potentials was approximately -35 mV; the input resistance of these cells averaged 6.9 G omega. With long depolarizing pulses, two or three action potentials could be elicited with successive attenuation of the spike height. Afterhyperpolarizations were observed often. 3. Both sodium and calcium currents contribute to depolarizing phases of the action potential. Action potentials were blocked completely in the presence of the sodium channel blocker tetrodotoxin. Calcium contributions could be visualized as prolonged calcium plateaus when repolarizing potassium currents were blocked and barium was used as a charge carrier. 4. Outward currents were composed of sustained delayed rectifier current, transient potassium current, and calcium-activated potassium current. Transient and sustained potassium currents activated close to -30 mV and increased monotonically with further depolarization. Up to half the outward current inactivated with decay constants on the order of seconds. Sustained and transient currents displayed steep voltage dependence in conductance and inactivation curves. Half inactivation occurred at -20 +/- 3.1 mV (mean +/- SE) with a decrease of 11.2 +/- 0.5 mV per e-fold. Half maximal conductance occurred at 3.6 +/- 1.8 mV and increased 12.2 +/- 0.6 mV per e-fold. Calcium-activated potassium current was evidenced by application of apamin and the use of calcium-free bathing solution. It was most obvious at more depolarized holding potentials that inactivated much of the transient and sustained outward currents. 5. Potassium currents contribute to both the repolarization and afterhyperpolarization phases of the action potential. These currents were blocked by bath application of tetraethylammonium, which also substantially broadened the action potential. Application of 4-aminopyridine was able to selectively block transient potassium currents without affecting sustained currents. This also broadened the action potential as well as eliminated the afterhyperpolarization. 6. A second type of action potential was observed that differed in duration. These slow action potentials had t1/2 durations of 9.6 ms compared with 1.4 ms for fast action potentials. Input resistances of the two groups were indistinguishable. Approximately one-fourth of the cells eliciting action potentials were of the slow type. 7. Cells eliciting fast action potentials had large outward currents capable of producing a quick repolarization, whereas cells with slow action potentials had small outward currents by comparison. The average values of fast cells were 2,563 pA and 1.4 ms compared with 373 pA and 9.6 ms for slow cells. Current and duration values were related exponentially. No significant difference was noted for inward currents. 8. These results suggest that many taste receptor cells conduct action potentials, which may be classified broadly into two groups on the basis of action potential duration and potassium current magnitude. These groups may be related to cell turnover. The physiological role of action potentials remains to be elucidated but may be important for communication within the taste bud as well as to the afferent nerve.

Social construction: vistas in clinical child and adolescent psychology.

PubMed

Gergen, Kenneth J; Lightfoot, Cynthia; Sydow, Lisa

2004-06-01

We explore here the potentials of a social constructionist orientation to knowledge for research and clinical practice. Dialogues on social construction emphasize the communal origins of knowledge. They stress the cultural basis of knowledge claims, the significance of language, the value saturation of all knowledge, and the significance of relationships as opposed to individuals. An initial illustration of constructionism in action centers on adolescent risk behavior. Such behavior is often constructed negatively within popular writings and the social science and thus ignores the meaning of such actions to the adolescents themselves. Discourse analysis indicates that for adolescents risky behavior serves important functions of enhancing group solidarity and establishing positive identity. A second illustration, exploring the implications of constructionism for therapy, places a strong emphasis on the therapist as a collaborator in the building of meaning. Traditional investments in diagnosis and treatment are replaced with the collaborative creation of new possibilities for action.

Vicarious Neural Processing of Outcomes during Observational Learning

PubMed Central

Monfardini, Elisabetta; Gazzola, Valeria; Boussaoud, Driss

2013-01-01

Learning what behaviour is appropriate in a specific context by observing the actions of others and their outcomes is a key constituent of human cognition, because it saves time and energy and reduces exposure to potentially dangerous situations. Observational learning of associative rules relies on the ability to map the actions of others onto our own, process outcomes, and combine these sources of information. Here, we combined newly developed experimental tasks and functional magnetic resonance imaging (fMRI) to investigate the neural mechanisms that govern such observational learning. Results show that the neural systems involved in individual trial-and-error learning and in action observation and execution both participate in observational learning. In addition, we identified brain areas that specifically activate for others’ incorrect outcomes during learning in the posterior medial frontal cortex (pMFC), the anterior insula and the posterior superior temporal sulcus (pSTS). PMID:24040104

Combination of High-density Microelectrode Array and Patch Clamp Recordings to Enable Studies of Multisynaptic Integration.

PubMed

Jäckel, David; Bakkum, Douglas J; Russell, Thomas L; Müller, Jan; Radivojevic, Milos; Frey, Urs; Franke, Felix; Hierlemann, Andreas

2017-04-20

We present a novel, all-electric approach to record and to precisely control the activity of tens of individual presynaptic neurons. The method allows for parallel mapping of the efficacy of multiple synapses and of the resulting dynamics of postsynaptic neurons in a cortical culture. For the measurements, we combine an extracellular high-density microelectrode array, featuring 11'000 electrodes for extracellular recording and stimulation, with intracellular patch-clamp recording. We are able to identify the contributions of individual presynaptic neurons - including inhibitory and excitatory synaptic inputs - to postsynaptic potentials, which enables us to study dendritic integration. Since the electrical stimuli can be controlled at microsecond resolution, our method enables to evoke action potentials at tens of presynaptic cells in precisely orchestrated sequences of high reliability and minimum jitter. We demonstrate the potential of this method by evoking short- and long-term synaptic plasticity through manipulation of multiple synaptic inputs to a specific neuron.

Enforcement actions: Significant actions resolved. Volume 14, No. 2, Part 1: Individual actions. Quarterly progress report, April--June 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-09-01

This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (April--June 1995) and includes copies of Orders sent by the Nuclear Regulatory Commission to individuals with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC. The Commission believes this information may be useful to licensees in making employment decisions.

Enforcement actions: Significant actions resolved individuals actions. Semiannual progress report, July--December 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This compilation summarizes significant enforcement actions that have been resolved during the period (July - December 1996) and includes copies of Orders and Notices of Violation sent by the Nuclear Regulatory Commission to individuals with respect to-these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC. The Commission believes this information may be useful to licensees in making employment decisions.

Enforcement actions: Significant actions resolved individual actions. Semiannual progress report, January 1997--June 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This compilation summarizes significant enforcement actions that have been resolved during the period (January - June 1997) and includes copies of Orders and Notices of Violation sent by the Nuclear Regulatory Commission to individuals with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC. The Commission believes this information may be useful to licensees in making employment decisions.

Sleep and metabolic control: waking to a problem?

PubMed

Trenell, Michael I; Marshall, Nathaniel S; Rogers, Naomi L

2007-01-01

1. The aim of the present review is to outline: (i) the association between sleep and metabolism; (ii) how sleep duration influences the development of disease; and (iii) how sex differences, ageing and obesity may potentially influence the relationship between sleep, metabolic control and subsequent disease. 2. Sleep is associated with a number of endocrine changes, including a change in insulin action in healthy young individuals. Sleep duration shows a prospective U-shaped relationship with all-cause mortality, cardiovascular disease and Type 2 diabetes. 3. Chronic sleep restriction is becoming more common. Experimental sleep restriction impedes daytime glucose control and increases appetite. 4. The sex hormones oestrogen and testosterone influence sleep duration and quality and may account for sex differences in the prevalence of sleep-related disorders. 5. Ageing is associated with a decreased sleep duration, decreased muscle mass and impaired insulin action. 6. Obesity impairs insulin action and is associated with the incidence and severity of obstructive sleep apnoea. 7. Sleep plays an integral role in metabolic control. Consequently, insufficient sleep may represent a modifiable risk factor for the development of Type 2 diabetes. The challenge ahead is to identify how sex differences, ageing and obesity could potentially influence the relationship between sleep and metabolism.

Non-invasive assessment of skeletal muscle activity

NASA Astrophysics Data System (ADS)

Merletti, Roberto; Orizio, Claudio; di Prampero, Pietro E.; Tesch, Per

2005-10-01

After the first 3 years (2002-2005), the MAP project has made available: - systems fo electrodes, signal conditioning and digital processing for multichannel simultaneously-detected EMG and MMG as well as for simultaneous electrical stimulation and EMG detection with artifact cancellation. - innovative non-invasive techniques for the extraction of individual motor unit action potentials (MUAPS) and individual motor and MMG contributions from the surface EMG interference signal and the MMG signal. - processing techniques for extractions of indicators of progressive fatigue from the electrically-elicited (M-wave) EMG signal. - techniques for the analysis of dynamic multichannel EMG during cyclic or explosive exercise (in collaboration with project EXER/MAP-MED-027).

State and location dependence of action potential metabolic cost in cortical pyramidal neurons.

PubMed

Hallermann, Stefan; de Kock, Christiaan P J; Stuart, Greg J; Kole, Maarten H P

2012-06-03

Action potential generation and conduction requires large quantities of energy to restore Na(+) and K(+) ion gradients. We investigated the subcellular location and voltage dependence of this metabolic cost in rat neocortical pyramidal neurons. Using Na(+)/K(+) charge overlap as a measure of action potential energy efficiency, we found that action potential initiation in the axon initial segment (AIS) and forward propagation into the axon were energetically inefficient, depending on the resting membrane potential. In contrast, action potential backpropagation into dendrites was efficient. Computer simulations predicted that, although the AIS and nodes of Ranvier had the highest metabolic cost per membrane area, action potential backpropagation into the dendrites and forward propagation into axon collaterals dominated energy consumption in cortical pyramidal neurons. Finally, we found that the high metabolic cost of action potential initiation and propagation down the axon is a trade-off between energy minimization and maximization of the conduction reliability of high-frequency action potentials.

Two Equals One: Two Human Actions During Social Interaction Are Grouped as One Unit in Working Memory.

PubMed

Ding, Xiaowei; Gao, Zaifeng; Shen, Mowei

2017-09-01

Every day, people perceive other people performing interactive actions. Retaining these actions of human agents in working memory (WM) plays a pivotal role in a normal social life. However, whether the semantic knowledge embedded in the interactive actions has a pervasive impact on the storage of the actions in WM remains unknown. In the current study, we investigated two opposing hypotheses: (a) that WM stores the interactions individually (the individual-storage hypothesis) and (b) that WM stores the interactions as chunks (the chunk-storage hypothesis). We required participants to memorize a set of individual actions while ignoring the underlying social interactions. We found that although the social-interaction aspect was task irrelevant, the interactive actions were stored in WM as chunks that were not affected by memory load (Experiments 1 and 2); however, inverting the human actions vertically abolished this chunking effect (Experiment 3). These results suggest that WM automatically and efficiently used semantic knowledge about interactive actions to store them and support the chunk-storage hypothesis.

Action learning across the decades.

PubMed

Eason, Ken

2017-05-02

Purpose The purpose of this paper is to explore how action learning concepts were used in two healthcare projects undertaken many decades apart. The specific purpose in both cases was to examine how action learning can contribute to shared learning across key stakeholders in a complex socio-technical system. In each case study, action learning supported joint design programmes and the sharing of perspectives about the complex system under investigation. Design/methodology/approach Two action learning projects are described: first, the Hospital Internal Communications (HIC) project led by Reg Revans in the 1960s. Senior staff in ten London hospitals formed action learning teams to address communication issues. Second, in the Better Outcomes for People with Learning Disabilities: Transforming Care (BOLDTC) project, videoconferencing equipment enabled people with learning disabilities to increase their opportunities to communicate. A mutual learning process was established to enable stakeholders to explore the potential of the technical system to improve individual care. Findings The HIC project demonstrated the importance of evidence being shared between team members and that action had to engage the larger healthcare system outside the hospital. The BOLDTC project confirmed the continuing relevance of action learning to healthcare today. Mutual learning was achieved between health and social care specialists and technologists. Originality/value This work draws together the socio-technical systems tradition (considering both social and technical issues in organisations) and action learning to demonstrate that complex systems development needs to be undertaken as a learning process in which action provides the fuel for learning and design.

The potential for multi-disciplinary primary health care services to take action on the social determinants of health: actions and constraints

PubMed Central

2013-01-01

Background The Commission on the Social Determinants of Health and the World Health Organization have called for action to address the social determinants of health. This paper considers the extent to which primary health care services in Australia are able to respond to this call. We report on interview data from an empirical study of primary health care centres in Adelaide and Alice Springs, Australia. Methods Sixty-eight interviews were held with staff and managers at six case study primary health care services, regional health executives, and departmental funders to explore how their work responded to the social determinants of health and the dilemmas in doing so. The six case study sites included an Aboriginal Community Controlled Organisation, a sexual health non-government organisation, and four services funded and managed by the South Australian government. Results While respondents varied in the extent to which they exhibited an understanding of social determinants most were reflexive about the constraints on their ability to take action. Services’ responses to social determinants included delivering services in a way that takes account of the limitations individuals face from their life circumstances, and physical spaces in the primary health care services being designed to do more than simply deliver services to individuals. The services also undertake advocacy for policies that create healthier communities but note barriers to them doing this work. Our findings suggest that primary health care workers are required to transverse “dilemmatic space” in their work. Conclusions The absence of systematic supportive policy, frameworks and structure means that it is hard for PHC services to act on the Commission on the Social Determinants of Health’s recommendations. Our study does, however, provide evidence of the potential for PHC services to be more responsive to social determinants given more support and by building alliances with communities and social movements. Further research on the value of community control of PHC services and the types of policy, resource and managerial environments that support action on social determinants is warranted by this study’s findings. PMID:23663304

The potential for multi-disciplinary primary health care services to take action on the social determinants of health: actions and constraints.

PubMed

Baum, Frances E; Legge, David G; Freeman, Toby; Lawless, Angela; Labonté, Ronald; Jolley, Gwyneth M

2013-05-10

The Commission on the Social Determinants of Health and the World Health Organization have called for action to address the social determinants of health. This paper considers the extent to which primary health care services in Australia are able to respond to this call. We report on interview data from an empirical study of primary health care centres in Adelaide and Alice Springs, Australia. Sixty-eight interviews were held with staff and managers at six case study primary health care services, regional health executives, and departmental funders to explore how their work responded to the social determinants of health and the dilemmas in doing so. The six case study sites included an Aboriginal Community Controlled Organisation, a sexual health non-government organisation, and four services funded and managed by the South Australian government. While respondents varied in the extent to which they exhibited an understanding of social determinants most were reflexive about the constraints on their ability to take action. Services' responses to social determinants included delivering services in a way that takes account of the limitations individuals face from their life circumstances, and physical spaces in the primary health care services being designed to do more than simply deliver services to individuals. The services also undertake advocacy for policies that create healthier communities but note barriers to them doing this work. Our findings suggest that primary health care workers are required to transverse "dilemmatic space" in their work. The absence of systematic supportive policy, frameworks and structure means that it is hard for PHC services to act on the Commission on the Social Determinants of Health's recommendations. Our study does, however, provide evidence of the potential for PHC services to be more responsive to social determinants given more support and by building alliances with communities and social movements. Further research on the value of community control of PHC services and the types of policy, resource and managerial environments that support action on social determinants is warranted by this study's findings.

Upregulation of K(2P)3.1 K+ Current Causes Action Potential Shortening in Patients With Chronic Atrial Fibrillation.

PubMed

Schmidt, Constanze; Wiedmann, Felix; Voigt, Niels; Zhou, Xiao-Bo; Heijman, Jordi; Lang, Siegfried; Albert, Virginia; Kallenberger, Stefan; Ruhparwar, Arjang; Szabó, Gábor; Kallenbach, Klaus; Karck, Matthias; Borggrefe, Martin; Biliczki, Peter; Ehrlich, Joachim R; Baczkó, István; Lugenbiel, Patrick; Schweizer, Patrick A; Donner, Birgit C; Katus, Hugo A; Dobrev, Dobromir; Thomas, Dierk

2015-07-14

Antiarrhythmic management of atrial fibrillation (AF) remains a major clinical challenge. Mechanism-based approaches to AF therapy are sought to increase effectiveness and to provide individualized patient care. K(2P)3.1 (TASK-1 [tandem of P domains in a weak inward-rectifying K+ channel-related acid-sensitive K+ channel-1]) 2-pore-domain K+ (K(2P)) channels have been implicated in action potential regulation in animal models. However, their role in the pathophysiology and treatment of paroxysmal and chronic patients with AF is unknown. Right and left atrial tissue was obtained from patients with paroxysmal or chronic AF and from control subjects in sinus rhythm. Ion channel expression was analyzed by quantitative real-time polymerase chain reaction and Western blot. Membrane currents and action potentials were recorded using voltage- and current-clamp techniques. K(2P)3.1 subunits exhibited predominantly atrial expression, and atrial K(2P)3.1 transcript levels were highest among functional K(2P) channels. K(2P)3.1 mRNA and protein levels were increased in chronic AF. Enhancement of corresponding currents in the right atrium resulted in shortened action potential duration at 90% of repolarization (APD90) compared with patients in sinus rhythm. In contrast, K(2P)3.1 expression was not significantly affected in subjects with paroxysmal AF. Pharmacological K(2P)3.1 inhibition prolonged APD90 in atrial myocytes from patients with chronic AF to values observed among control subjects in sinus rhythm. Enhancement of atrium-selective K(2P)3.1 currents contributes to APD shortening in patients with chronic AF, and K(2P)3.1 channel inhibition reverses AF-related APD shortening. These results highlight the potential of K(2P)3.1 as a novel drug target for mechanism-based AF therapy. © 2015 American Heart Association, Inc.

The effect of recording site on extracted features of motor unit action potential.

PubMed

Artuğ, N Tuğrul; Goker, Imran; Bolat, Bülent; Osman, Onur; Kocasoy Orhan, Elif; Baslo, M Baris

2016-06-01

Motor unit action potential (MUAP), which consists of individual muscle fiber action potentials (MFAPs), represents the electrical activity of the motor unit. The values of the MUAP features are changed by denervation and reinnervation in neurogenic involvement as well as muscle fiber loss with increased diameter variability in myopathic diseases. The present study is designed to investigate how increased muscle fiber diameter variability affects MUAP parameters in simulated motor units. In order to detect this variation, simulated MUAPs were calculated both at the innervation zone where the MFAPs are more synchronized, and near the tendon, where they show increased temporal dispersion. Reinnervation in neurogenic state increases MUAP amplitude for the recordings at both the innervation zone and near the tendon. However, MUAP duration and the number of peaks significantly increased in a case of myopathy for recordings near the tendon. Furthermore, of the new features, "number of peaks×spike duration" was found as the strongest indicator of MFAP dispersion in myopathy. MUAPs were also recorded from healthy participants in order to investigate the biological counterpart of the simulation data. MUAPs which were recorded near to tendon revealed significantly prolonged duration and decreased amplitude. Although the number of peaks was increased by moving the needle near to tendon, this was not significant. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Voltage-gated sodium channel expression and action potential generation in differentiated NG108-15 cells.

PubMed

Liu, Jinxu; Tu, Huiyin; Zhang, Dongze; Zheng, Hong; Li, Yu-Long

2012-10-25

The generation of action potential is required for stimulus-evoked neurotransmitter release in most neurons. Although various voltage-gated ion channels are involved in action potential production, the initiation of the action potential is mainly mediated by voltage-gated Na+ channels. In the present study, differentiation-induced changes of mRNA and protein expression of Na+ channels, Na+ currents, and cell membrane excitability were investigated in NG108-15 cells. Whole-cell patch-clamp results showed that differentiation (9 days) didn't change cell membrane excitability, compared to undifferentiated state. But differentiation (21 days) induced the action potential generation in 45.5% of NG108-15 cells (25/55 cells). In 9-day-differentiated cells, Na+ currents were mildly increased, which was also found in 21-day differentiated cells without action potential. In 21-day differentiated cells with action potential, Na+ currents were significantly enhanced. Western blot data showed that the expression of Na+ channels was increased with differentiated-time dependent manner. Single-cell real-time PCR data demonstrated that the expression of Na+ channel mRNA was increased by 21 days of differentiation in NG108-15 cells. More importantly, the mRNA level of Na+ channels in cells with action potential was higher than that in cells without action potential. Differentiation induces expression of voltage-gated Na+ channels and action potential generation in NG108-15 cells. A high level of the Na+ channel density is required for differentiation-triggered action potential generation.

CORRRECTIVE ACTION DECISION DOCUMENT FOR CORRECTIVE ACTION UNIT 427: AREA 3 SEPTIC WASTE SYSTEMS 2 AND 6, TONOPAH TEST RANGE, NEVADA, REVISION 0, JUNE 1998

DOE Office of Scientific and Technical Information (OSTI.GOV)

ITLV.

1998-06-01

This Corrective Action Decision Document has been prepared for the Area 3 Septic Waste Systems 2 and 6 (Corrective Action Unit 427) in accordance with the Federal Facility Agreement and Consent Order of 1996 (FFACO, 1996). Corrective Action Unit 427 is located at the Tonopah Test Range, Nevada, and is comprised of the following Corrective Action Sites, each an individual septic waste system (DOE/NV, 1996a): Septic Waste System 2 is Corrective Action Site Number 03-05-002-SW02. Septic Waste System 6 is Corrective Action Site Number 03-05-002-SW06. The purpose of this Corrective Action Decision Document is to identify and provide a rationalemore » for the selection of a recommended corrective action alternative for each Corrective Action Site. The scope of this Correction Action Decision Document consists of the following tasks: Develop corrective action objectives. Identify corrective action alternative screening criteria. Develop corrective action alternatives. Perform detailed and comparative evaluations of the corrective action alternatives in relation to the corrective action objectives and screening criteria. Recommend and justify a preferred corrective action alternative for each CAS. From November 1997 through January 1998, a corrective action investigation was performed as set forth in the Corrective Action Investigation Plan for Corrective Action Unit No. 427: Area 3 Septic Waste System Numbers 2 and 6, Tonopah Test Range, Nevada (DOE/NV, 1997b). Details can be found in Appendix A of this document. The results indicated that contamination is present in some portions of the CAU and not in others as described in Table ES-1 and shown in Figure A.2-2 of Appendix A. Based on the potential exposure pathways, the following corrective action objectives have been identified for Corrective Action Unit 427: Prevent or mitigate human exposure to subsurface soils containing TPH at concentrations greater than 100 milligrams per kilogram (NAC, 1996b). Close Septic Tank 33-5 in accordance with Nevada Administrative Code 459 (NAC, 1996c). Prevent adverse impacts to groundwater quality. Based on the review of existing data, future land use, and current operations at the Tonopah Test Range, the following alternatives were developed for consideration at the Area 3 Septic Waste Systems 2 and 6: Alternative 1 - No Further Action Alternative 2 - Closure of Septic Tank 33-5 and Administrative Controls Alternative 3 - Closure of Septic Tank 33-5, Excavation, and Disposal The corrective action alternatives were evaluated based on four general corrective action standards and five remedy selection decision factors. Based on the results of this evaluation, the preferred alternative for Corrective Action Unit 427 is Alternative 2, Closure of Septic Tank 33-5 and Administrative Controls. The preferred corrective action alternative was evaluated on technical merit, focusing on performance, reliability, feasibility, and safety. The alternative was judged to meet all requirements for the technical components evaluated. The alternative meets all applicable state and federal regulations for closure of the site and will reduce potential future exposure pathways to the contaminated soils. During corrective action implementation, this alternative will present minimal potential threat to site workers who come in contact with the waste. However, procedures will be developed and implemented to ensure worker health and safety.« less

Vortex transmutation.

PubMed

Ferrando, Albert; Zacarés, Mario; García-March, Miguel-Angel; Monsoriu, Juan A; de Córdoba, Pedro Fernández

2005-09-16

Using group theory arguments and numerical simulations, we demonstrate the possibility of changing the vorticity or topological charge of an individual vortex by means of the action of a system possessing a discrete rotational symmetry of finite order. We establish on theoretical grounds a "transmutation pass" determining the conditions for this phenomenon to occur and numerically analyze it in the context of two-dimensional optical lattices. An analogous approach is applicable to the problems of Bose-Einstein condensates in periodic potentials.

Transdisciplinary breastfeeding support: Creating program and policy synergy across the reproductive continuum

PubMed Central

Labbok, Miriam H

2008-01-01

This paper was presented at the symposium on Breastfeeding and Feminism: A Focus on Reproductive Health, Rights and Justice. It underscores the power and potential of synergy between and among organizations and individuals supporting breastfeeding, the mother-child dyad, and reproductive health to increase sustainable breastfeeding support. These concepts were brought together to lay the groundwork for working group discussions of synergy in program and policy actions. PMID:18680583

Emotion-Based Dispositions to Rash Action: Positive and Negative Urgency

ERIC Educational Resources Information Center

Cyders, Melissa A.; Smith, Gregory T.

2008-01-01

Under heightened emotional states, individuals are more inclined to engage in ill-considered or rash actions than at other times. The authors present evidence for the existence of 2 related traits called positive and negative urgency. The traits refer to individual differences in the disposition to engage in rash action when experiencing extreme…

Uniform and Complementary Social Interaction: Distinct Pathways to Solidarity

PubMed Central

Koudenburg, Namkje; Postmes, Tom; Gordijn, Ernestine H.; van Mourik Broekman, Aafke

2015-01-01

We examine how different forms of co-action give rise to feelings of solidarity. We propose that (a) coordinated action elicits a sense of solidarity, and (b) the process through which such solidarity emerges differs for different forms of co-action. We suggest that whether solidarity within groups emerges from uniform action (e.g. synchronizing, as when people speak in unison) or from more complementary forms of action (e.g. alternating, when speaking in turns) has important consequences for the emergent position of individuals within the group. Uniform action relies on commonality, leaving little scope for individuality. In complementary action each individual makes a distinctive contribution to the group, thereby increasing a sense of personal value to the group, which should contribute to the emergence of solidarity. The predictions receive support from five studies, in which we study groups in laboratory and field settings. Results show that both complementary and uniform co-action increase a sense of solidarity compared to control conditions. However, in the complementary action condition, but not in the uniform action (or synchrony) condition, the effect on feelings of solidarity is mediated by a sense of personal value to the group. PMID:26047131

Uniform and Complementary Social Interaction: Distinct Pathways to Solidarity.

PubMed

Koudenburg, Namkje; Postmes, Tom; Gordijn, Ernestine H; van Mourik Broekman, Aafke

2015-01-01

We examine how different forms of co-action give rise to feelings of solidarity. We propose that (a) coordinated action elicits a sense of solidarity, and (b) the process through which such solidarity emerges differs for different forms of co-action. We suggest that whether solidarity within groups emerges from uniform action (e.g. synchronizing, as when people speak in unison) or from more complementary forms of action (e.g. alternating, when speaking in turns) has important consequences for the emergent position of individuals within the group. Uniform action relies on commonality, leaving little scope for individuality. In complementary action each individual makes a distinctive contribution to the group, thereby increasing a sense of personal value to the group, which should contribute to the emergence of solidarity. The predictions receive support from five studies, in which we study groups in laboratory and field settings. Results show that both complementary and uniform co-action increase a sense of solidarity compared to control conditions. However, in the complementary action condition, but not in the uniform action (or synchrony) condition, the effect on feelings of solidarity is mediated by a sense of personal value to the group.

Effects of premature stimulation on HERG K+ channels

PubMed Central

Lu, Yu; Mahaut-Smith, Martyn P; Varghese, Anthony; Huang, Christopher L-H; Kemp, Paul R; Vandenberg, Jamie I

2001-01-01

The unusual kinetics of human ether-à-go-go-related gene (HERG) K+ channels are consistent with a role in the suppression of arrhythmias initiated by premature beats. Action potential clamp protocols were used to investigate the effect of premature stimulation on HERG K+ channels, transfected in Chinese hamster ovary cells, at 37 °C. HERG K+ channel currents peaked during the terminal repolarization phase of normally paced action potential waveforms. However, the magnitude of the current and the time point at which conductance was maximal depended on the type of action potential waveform used (epicardial, endocardial, Purkinje fibre or atrial). HERG K+ channel currents recorded during premature action potentials consisted of an early transient outward current followed by a sustained outward current. The magnitude of the transient current component showed a biphasic dependence on the coupling interval between the normally paced and premature action potentials and was maximal at a coupling interval equivalent to 90% repolarization (APD90) for ventricular action potentials. The largest transient current response occurred at shorter coupling intervals for Purkinje fibre (APD90– 20 ms) and atrial (APD90– 30 ms) action potentials. The magnitude of the sustained current response following premature stimulation was similar to that recorded during the first action potential for ventricular action potential waveforms. However, for Purkinje and atrial action potentials the sustained current response was significantly larger during the premature action potential than during the normally paced action potential. A Markov model that included three closed states, one open and one inactivated state with transitions permitted between the pre-open closed state and the inactivated state, successfully reproduced our results for the effects of premature stimuli, both during square pulse and action potential clamp waveforms. These properties of HERG K+ channels may help to suppress arrhythmias initiated by early afterdepolarizations and premature beats in the ventricles, Purkinje fibres or atria. PMID:11744759

Effective Disengagement: Insecure People Are More Likely to Disengage From an Ongoing Task and Take Effective Action When Facing Danger.

PubMed

Ein-Dor, Tsachi; Perry-Paldi, Adi; Merrin, Jenna; Efrati, Yaniv; Hirschberger, Gilad

2018-04-01

People believe that they can respond effectively to threats, but actually they experience difficulties in disengaging from ongoing tasks and shifting their attention to life-threatening events. We contend that this tendency is especially true for secure people with respect to their worldview and perception of others and not for insecure individuals. In Study 1 (N = 290), we examined individuals' reactions to various threat scenarios. In Study 2 (N = 65), we examined these reactions using a behavioral design high in ecological validity. In Study 3 (N = 78), we examined group-level benefits for the actions of insecure individuals by manipulating asocial behavior in response to an emergency. Study 1 indicated that anxiously attached individuals stayed away from threats and sought help; avoidant people tended to take action by either assessing the risk of the event and/or enacting an asocial action such as fight or flight. Study 2 added ecological validity to these findings, and Study 3 showed that priming asocial behavior responses promoted actions that increased group members' chances of survival. Results validate the central tenets of social defense theory and indicate that actions that are deemed asocial may paradoxically promote the survival of individuals and groups. © 2017 Wiley Periodicals, Inc.

Enforcement actions: Significant actions resolved individual actions. Volume 14, Nos. 3 and 4, Part 1. Semiannual progress report, July--December 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-02-01

This compilation summarizes significant enforcement actions that have been resolved during the period (July - December 1995) and includes copies of Orders and Notices of Violation sent by the Nuclear Regulatory Commission to individuals with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC. The Commission believes this information may be useful to licensees in making employment decisions.

Enforcement actions: Significant actions resolved -- individual actions. Semiannual progress report, July--December 1997; Volume 16, Number 2, Part 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This compilation summarizes significant enforcement actions that have been resolved during the period (July--December 1997) and includes copies of Orders and Notices of Violation sent by the Nuclear Regulatory Commission to individuals with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC. The Commission believes this information may be useful to licensees in making employment decisions.

Electrophysiology of neurones of the inferior mesenteric ganglion of the cat.

PubMed Central

Julé, Y; Szurszewski, J H

1983-01-01

Intracellular recordings were obtained from cells in vitro in the inferior mesenteric ganglia of the cat. Neurones could be classified into three types: non-spontaneous, irregular discharging and regular discharging neurones. Non-spontaneous neurones had a stable resting membrane potential and responded with action potentials to indirect preganglionic nerve stimulation and to intracellular injection of depolarizing current. Irregular discharging neurones were characterized by a discharge of excitatory post-synaptic potentials (e.p.s.p.s.) which sometimes gave rise to action potentials. This activity was abolished by hexamethonium bromide, chlorisondamine and d-tubocurarine chloride. Tetrodotoxin and a low Ca2+ -high Mg2+ solution also blocked on-going activity in irregular discharging neurones. Regular discharging neurones were characterized by a rhythmic discharge of action potentials. Each action potential was preceded by a gradual depolarization of the intracellularly recorded membrane potential. Intracellular injection of hyperpolarizing current abolished the regular discharge of action potential. No synaptic potentials were observed during hyperpolarization of the membrane potential. Nicotinic, muscarinic and adrenergic receptor blocking drugs did not modify the discharge of action potentials in regular discharging neurones. A low Ca2+ -high Mg2+ solution also had no effect on the regular discharge of action potentials. Interpolation of an action potential between spontaneous action potentials in regular discharging neurones reset the rhythm of discharge. It is suggested that regular discharging neurones were endogenously active and that these neurones provided synaptic input to irregular discharging neurones. PMID:6140310

Electrophysiology of neurones of the inferior mesenteric ganglion of the cat.

PubMed

Julé, Y; Szurszewski, J H

1983-11-01

Intracellular recordings were obtained from cells in vitro in the inferior mesenteric ganglia of the cat. Neurones could be classified into three types: non-spontaneous, irregular discharging and regular discharging neurones. Non-spontaneous neurones had a stable resting membrane potential and responded with action potentials to indirect preganglionic nerve stimulation and to intracellular injection of depolarizing current. Irregular discharging neurones were characterized by a discharge of excitatory post-synaptic potentials (e.p.s.p.s.) which sometimes gave rise to action potentials. This activity was abolished by hexamethonium bromide, chlorisondamine and d-tubocurarine chloride. Tetrodotoxin and a low Ca2+ -high Mg2+ solution also blocked on-going activity in irregular discharging neurones. Regular discharging neurones were characterized by a rhythmic discharge of action potentials. Each action potential was preceded by a gradual depolarization of the intracellularly recorded membrane potential. Intracellular injection of hyperpolarizing current abolished the regular discharge of action potential. No synaptic potentials were observed during hyperpolarization of the membrane potential. Nicotinic, muscarinic and adrenergic receptor blocking drugs did not modify the discharge of action potentials in regular discharging neurones. A low Ca2+ -high Mg2+ solution also had no effect on the regular discharge of action potentials. Interpolation of an action potential between spontaneous action potentials in regular discharging neurones reset the rhythm of discharge. It is suggested that regular discharging neurones were endogenously active and that these neurones provided synaptic input to irregular discharging neurones.

Dynamics of action potential initiation in the GABAergic thalamic reticular nucleus in vivo.

PubMed

Muñoz, Fabián; Fuentealba, Pablo

2012-01-01

Understanding the neural mechanisms of action potential generation is critical to establish the way neural circuits generate and coordinate activity. Accordingly, we investigated the dynamics of action potential initiation in the GABAergic thalamic reticular nucleus (TRN) using in vivo intracellular recordings in cats in order to preserve anatomically-intact axo-dendritic distributions and naturally-occurring spatiotemporal patterns of synaptic activity in this structure that regulates the thalamic relay to neocortex. We found a wide operational range of voltage thresholds for action potentials, mostly due to intrinsic voltage-gated conductances and not synaptic activity driven by network oscillations. Varying levels of synchronous synaptic inputs produced fast rates of membrane potential depolarization preceding the action potential onset that were associated with lower thresholds and increased excitability, consistent with TRN neurons performing as coincidence detectors. On the other hand the presence of action potentials preceding any given spike was associated with more depolarized thresholds. The phase-plane trajectory of the action potential showed somato-dendritic propagation, but no obvious axon initial segment component, prominent in other neuronal classes and allegedly responsible for the high onset speed. Overall, our results suggest that TRN neurons could flexibly integrate synaptic inputs to discharge action potentials over wide voltage ranges, and perform as coincidence detectors and temporal integrators, supported by a dynamic action potential threshold.

Mechanisms for greater insulin-stimulated glucose uptake in normal and insulin-resistant skeletal muscle after acute exercise

PubMed Central

2015-01-01

Enhanced skeletal muscle and whole body insulin sensitivity can persist for up to 24–48 h after one exercise session. This review focuses on potential mechanisms for greater postexercise and insulin-stimulated glucose uptake (ISGU) by muscle in individuals with normal or reduced insulin sensitivity. A model is proposed for the processes underlying this improvement; i.e., triggers initiate events that activate subsequent memory elements, which store information that is relayed to mediators, which translate memory into action by controlling an end effector that directly executes increased insulin-stimulated glucose transport. Several candidates are potential triggers or memory elements, but none have been conclusively verified. Regarding potential mediators in both normal and insulin-resistant individuals, elevated postexercise ISGU with a physiological insulin dose coincides with greater Akt substrate of 160 kDa (AS160) phosphorylation without improved proximal insulin signaling at steps from insulin receptor binding to Akt activity. Causality remains to be established between greater AS160 phosphorylation and improved ISGU. The end effector for normal individuals is increased GLUT4 translocation, but this remains untested for insulin-resistant individuals postexercise. Following exercise, insulin-resistant individuals can attain ISGU values similar to nonexercising healthy controls, but after a comparable exercise protocol performed by both groups, ISGU for the insulin-resistant group has been consistently reported to be below postexercise values for the healthy group. Further research is required to fully understand the mechanisms underlying the improved postexercise ISGU in individuals with normal or subnormal insulin sensitivity and to explain the disparity between these groups after similar exercise. PMID:26487009

Attribution of mild cognitive impairment etiology in patients and their care partners.

PubMed

Rodakowski, Juleen; Schulz, Richard; Gentry, Amanda; Garand, Linda; Lingler, Jennifer Hagerty

2014-05-01

This study examined the attribution of mild cognitive impairment (MCI) etiology assigned by individuals with MCI and their care partners, and the extent to which the dyads agreed on the attribution of MCI etiology. We conducted secondary analyses of cross-sectional data from a cohort of individuals with MCI (n = 60) and their care partners (n = 60). The mean age of the individuals with MCI was 71.0 ± 9.4 years and of care partners 64.2 ± 11.0 years. The primary outcome was attribution assigned to memory deficits on the Illness Perception Questionnaire. We categorized the attribution of MCI etiology as either potentially controllable or uncontrollable factors. We described the distribution of MCI etiology with descriptive and contingency tables. We determined the odds of a patient or care partner choosing one type of MCI etiology over another. Although individuals with MCI and their care partners most frequently attributed MCI to uncontrollable factors (81.7% and 61.0%, respectively), care partners were 28.41 (95% CI, 1.26 to 645.48) times more likely to attribute MCI etiology to potentially controllable factors than individuals with MCI. No significant associations between demographic factors and attribution of MCI etiology were found for the individuals with MCI or the care partners. Findings demonstrated that members of the dyad attributed MCI etiology to different causes. Attributions of MCI etiology should be explored by professionals to clarify misconceptions and potentially improve subsequent voluntary actions intended to assist oneself or others. Copyright © 2013 John Wiley & Sons, Ltd.

Toward citizenship science education: what students do to make the world a better place?

NASA Astrophysics Data System (ADS)

Vesterinen, Veli-Matti; Tolppanen, Sakari; Aksela, Maija

2016-01-01

With increased focus on sustainability and socioscientific issues, dealing with issues related to citizenship is now seen as an important element of science education. However, in order to make the world a better place, mere understanding about socioscientific issues is not enough. Action must also be taken. In this study, 35 international gifted students-potential scientists-aged 15-19 were interviewed to investigate what they were doing to make the world a better place. The interviews were analyzed using qualitative content analysis with focus on students' actions toward a better world, their rationalizations for such actions, and the role of science in the rationalizations. The analysis shows that students consciously take a wide range of actions, and that they see citizenship as a process of constant self-development. The three categories created to highlight the variation in the ways students take action were personally responsible actions, participatory actions, and preparing for future. Although many students saw that science and scientists play a big role in solving especially the environmental problems, most of them also discussed the structural causes for problems, as well as the interplay of social, economic, and political forces. The results indicate that citizenship science education should take the variety of students' actions into consideration, give students the possibility to take individual and participatory action, as well as give students opportunities to get to know and discuss the ways a career in science or engineering can contribute to saving the world.

Corticospinal excitability during the observation of social behavior.

PubMed

Bucchioni, Giulia; Cavallo, Andrea; Ippolito, Davide; Marton, Gianluca; Castiello, Umberto

2013-03-01

Evidence suggests that the observation of an action induces in the observers an enhancement of motor evoked potentials (MEPs) recorded by the observer's muscles corresponding to those involved in the observed action. Although this is a well-studied phenomenon, it remains still unclear how the viewer's motor facilitation is influenced by the social content characterizing the observed scene. In the present study we investigated the facilitation of the corticospinal system during the observation of either an action that does not imply a social interaction (i.e., an actor throwing a ball against a wall), or an action which implies a social interaction (i.e., an actor passing a ball to a partner). Results indicate that MEPs amplitude is enhanced during the observation of a social rather than an individual action. We contend that the increase in MEPs activation might reflect an enhancement of the simulative activity stemming from the mirror system during the observation of social interactions. Altogether these findings show that the human corticospinal system is sensitive to social interactions and may support the role of the mirror neurons system in social cognition. Copyright © 2012 Elsevier Inc. All rights reserved.

Treatment with a Clinically-Relevant Dose of Methylphenidate Alters NMDA Receptor Composition and Synaptic Plasticity in the Juvenile Rat Prefrontal Cortex

PubMed Central

Urban, Kimberly R.; Li, Yan-Chun; Gao, Wen-Jun

2013-01-01

Methylphenidate (Ritalin, MPH) is the most commonly prescribed psychoactive drug for children. Used to treat attention-deficit/hyperactivity disorder (ADHD) and for cognitive enhancement in healthy individuals, its cellular mechanisms of action and potential long-term effects are poorly understood. We recently reported that a clinically relevant (1 mg/kg i.p., single injection) dose of MPH significantly decreased neuronal excitability in the juvenile rat prefrontal cortical neurons. Here we further explore the actions of acute treatment with MPH on the level of NMDA receptor subunits and NMDA receptor-mediated short- and long-term synaptic plasticity in the juvenile rat prefrontal cortical neurons. We found that a single dose of MPH treatment (1 mg/kg, intraperitoneal) significantly decreased the surface and total protein levels of NMDA receptor subunits NR1 and NR2B, but not NR2A, in the juvenile prefrontal cortex. In addition, the amplitude, decay time and charge transfer of NMDA receptor-mediated EPSCs were significantly decreased whereas the amplitude and short-term depression of AMPA receptor-mediated EPSCs were significantly increased in the prefrontal neurons. Furthermore, MPH treatment also significantly increased the probability and magnitude of LTP induction, but had only a small effect on LTD induction in juvenile rat prefrontal cortical neurons. Our data thus present a novel mechanism of action of MPH, i.e., changes in glutamatergic receptor-mediated synaptic plasticity following early-life treatment. Furthermore, since a single dosage resulted in significant changes in NMDA receptors, off-label usage by healthy individuals, especially children and adolescents, may result in altered potential for plastic learning. PMID:23333502

Recognition Memory and Source Memory in Autism Spectrum Disorder: A Study of the Intention Superiority and Enactment Effects

ERIC Educational Resources Information Center

Grainger, Catherine; Williams, David M.; Lind, Sophie E.

2017-01-01

It is well established that neurotypical individuals generally show better memory for actions they have performed than actions they have observed others perform or merely read about, a so-called "enactment effect." Strikingly, research has also shown that neurotypical individuals demonstrate superior memory for actions they…

Dietary nitrite and nitrate: a review of potential mechanisms of cardiovascular benefits

PubMed Central

Machha, Ajay

2012-01-01

Purpose In the last decade, a growing scientific and medical interest has emerged toward cardiovascular effects of dietary nitrite and nitrate; however, many questions concerning their mode of action(s) remain unanswered. In this review, we focus on multiple mechanisms that might account for potential cardiovascular beneficial effects of dietary nitrite and nitrate. Results Beneficial changes to cardiovascular health from dietary nitrite and nitrate might result from several mechanism(s) including their reduction into nitric oxide, improvement in endothelial function, vascular relaxation, and/or inhibition of the platelet aggregation. From recently obtained evidence, it appears that the longstanding concerns about the toxicity of oral nitrite or nitrate are overstated. Conclusion Dietary nitrite and nitrate may have cardiovascular protective effects in both healthy individuals and also those with cardiovascular disease conditions. A role for nitrite and nitrate in nitric oxide biosynthesis and/or in improving nitric oxide bioavailability may eventually provide a rationale for using dietary nitrite and nitrate supplementation in the treatment and prevention of cardiovascular diseases. PMID:21626413

Dopamine modulates an intrinsic mGluR5-mediated depolarization underlying prefrontal persistent activity

PubMed Central

Sidiropoulou, Kyriaki; Lu, Fang-Min; Fowler, Melissa A.; Xiao, Rui; Phillips, Christopher; Ozkan, Emin D.; Zhu, Michael X.; White, Francis J.; Cooper, Donald C.

2009-01-01

Intrinsic properties of neurons that enable them to maintain depolarized, persistently activated states in the absence of sustained input are poorly understood. In short-term memory tasks, individual prefrontal cortical (PFC) neurons are capable of maintaining persistent action potential output during delay periods between informative cues and behavioral responses. Dopamine and drugs of abuse alter PFC function and working memory possibly by modulating intrinsic neuronal properties. Here we use patch-clamp recording of layer 5 PFC pyramidal neurons to identify an action potential burst-evoked intrinsic mGluR5-mediated postsynaptic depolarization that initiates an activated state. Depolarization occurs in the absence of recurrent synaptic activity and is reduced by a postsynaptic dopamine D1/5 receptor pathway. The depolarization is substantially diminished following behavioral sensitization to cocaine; moreover the D1/5 receptor modulation is lost. We propose the burst-evoked intrinsic depolarization to be a novel form of short-term cellular memory that is modulated by dopamine and cocaine experience. PMID:19169252

Fast, Temperature-Sensitive and Clathrin-Independent Endocytosis at Central Synapses.

PubMed

Delvendahl, Igor; Vyleta, Nicholas P; von Gersdorff, Henrique; Hallermann, Stefan

2016-05-04

The fusion of neurotransmitter-filled vesicles during synaptic transmission is balanced by endocytotic membrane retrieval. Despite extensive research, the speed and mechanisms of synaptic vesicle endocytosis have remained controversial. Here, we establish low-noise time-resolved membrane capacitance measurements that allow monitoring changes in surface membrane area elicited by single action potentials and stronger stimuli with high-temporal resolution at physiological temperature in individual bona-fide mature central synapses. We show that single action potentials trigger very rapid endocytosis, retrieving presynaptic membrane with a time constant of 470 ms. This fast endocytosis is independent of clathrin but mediated by dynamin and actin. In contrast, stronger stimuli evoke a slower mode of endocytosis that is clathrin, dynamin, and actin dependent. Furthermore, the speed of endocytosis is highly temperature dependent with a Q10 of ∼3.5. These results demonstrate that distinct molecular modes of endocytosis with markedly different kinetics operate at central synapses. Copyright © 2016 Elsevier Inc. All rights reserved.

Mechanisms and consequences of action potential burst firing in rat neocortical pyramidal neurons

PubMed Central

Williams, Stephen R; Stuart, Greg J

1999-01-01

Electrophysiological recordings and pharmacological manipulations were used to investigate the mechanisms underlying the generation of action potential burst firing and its postsynaptic consequences in visually identified rat layer 5 pyramidal neurons in vitro.Based upon repetitive firing properties and subthreshold membrane characteristics, layer 5 pyramidal neurons were separated into three classes: regular firing and weak and strong intrinsically burst firing.High frequency (330 ± 10 Hz) action potential burst firing was abolished or greatly weakened by the removal of Ca2+ (n = 5) from, or by the addition of the Ca2+ channel antagonist Ni2+ (250–500 μm; n = 8) to, the perfusion medium.The blockade of apical dendritic sodium channels by the local dendritic application of TTX (100 nm; n = 5) abolished or greatly weakened action potential burst firing, as did the local apical dendritic application of Ni2+ (1 mm; n = 5).Apical dendritic depolarisation resulted in low frequency (157 ± 26 Hz; n = 6) action potential burst firing in regular firing neurons, as classified by somatic current injection. The intensity of action potential burst discharges in intrinsically burst firing neurons was facilitated by dendritic depolarisation (n = 11).Action potential amplitude decreased throughout a burst when recorded somatically, suggesting that later action potentials may fail to propagate axonally. Axonal recordings demonstrated that each action potential in a burst is axonally initiated and that no decrement in action potential amplitude is apparent in the axon > 30 μm from the soma.Paired recordings (n = 16) from synaptically coupled neurons indicated that each action potential in a burst could cause transmitter release. EPSPs or EPSCs evoked by a presynaptic burst of action potentials showed use-dependent synaptic depression.A postsynaptic, TTX-sensitive voltage-dependent amplification process ensured that later EPSPs in a burst were amplified when generated from membrane potentials positive to -60 mV, providing a postsynaptic mechanism that counteracts use-dependent depression at synapses between layer 5 pyramidal neurons. PMID:10581316

Assessing the Effects of Information About Global Population Growth on Risk Perceptions and Support for Mitigation and Prevention Strategies.

PubMed

Dawson, Ian G J

2018-05-16

The human population is forecast to increase by 3-4 billion people during this century and many scientists have expressed concerns that this could increase the likelihood of certain adverse events (e.g., climate change and resource shortages). Recent research shows that these concerns are mirrored in public risk perceptions and that these perceptions correlate with a willingness to adopt mitigation behaviors (e.g., reduce resource consumption) and preventative actions (e.g., support actions to limit growth). However, little research has assessed the factors that influence risk perceptions of global population growth (GPG). To contribute to this important goal, this article presents three studies that examined how risk perceptions of GPG might be influenced by textual-visual representations (like those in media and Internet articles) of the potential effects of GPG. Study 1 found that a textual narrative that highlighted the potential negative (cf. positive) consequences of GPG led to higher perceived risk and greater willingness to adopt mitigation behaviors, but not to support preventative actions. Notably, the influence of the narratives on perceived risk was largely moderated by the participant's prior knowledge and perceptions of GPG. Contrary to expectations, studies 2 and 3 revealed, respectively, that photographs depicting GPG-related imagery and graphs depicting GPG rates had no significant effect on the perceived risk of GPG or the willingness to embrace mitigation or preventative actions. However, study 3 found that individuals with higher "graph literacy" perceived GPG as a higher risk and were more willing to adopt mitigation behaviors and support preventative actions. © 2018 Society for Risk Analysis.

49 CFR 451.16 - Action by approval authority-individual approval.

Code of Federal Regulations, 2013 CFR

2013-10-01

... GUARD, DEPARTMENT OF HOMELAND SECURITY SAFETY APPROVAL OF CARGO CONTAINERS TESTING AND APPROVAL OF CONTAINERS Approval of New Containers § 451.16 Action by approval authority-individual approval. (a) The...

49 CFR 451.16 - Action by approval authority-individual approval.

Code of Federal Regulations, 2011 CFR

2011-10-01

... GUARD, DEPARTMENT OF HOMELAND SECURITY SAFETY APPROVAL OF CARGO CONTAINERS TESTING AND APPROVAL OF CONTAINERS Approval of New Containers § 451.16 Action by approval authority-individual approval. (a) The...

49 CFR 451.16 - Action by approval authority-individual approval.

Code of Federal Regulations, 2012 CFR

2012-10-01

... GUARD, DEPARTMENT OF HOMELAND SECURITY SAFETY APPROVAL OF CARGO CONTAINERS TESTING AND APPROVAL OF CONTAINERS Approval of New Containers § 451.16 Action by approval authority-individual approval. (a) The...

49 CFR 451.16 - Action by approval authority-individual approval.

Code of Federal Regulations, 2010 CFR

2010-10-01

... GUARD, DEPARTMENT OF HOMELAND SECURITY SAFETY APPROVAL OF CARGO CONTAINERS TESTING AND APPROVAL OF CONTAINERS Approval of New Containers § 451.16 Action by approval authority-individual approval. (a) The...

49 CFR 451.16 - Action by approval authority-individual approval.

Code of Federal Regulations, 2014 CFR

2014-10-01

... GUARD, DEPARTMENT OF HOMELAND SECURITY SAFETY APPROVAL OF CARGO CONTAINERS TESTING AND APPROVAL OF CONTAINERS Approval of New Containers § 451.16 Action by approval authority-individual approval. (a) The...

From recording discrete actions to studying continuous goal-directed behaviours in team sports.

PubMed

Correia, Vanda; Araújo, Duarte; Vilar, Luís; Davids, Keith

2013-01-01

This paper highlights the importance of examining interpersonal interactions in performance analysis of team sports, predicated on the relationship between perception and action, compared to the traditional cataloguing of actions by individual performers. We discuss how ecological dynamics may provide a potential unifying theoretical and empirical framework to achieve this re-emphasis in research. With reference to data from illustrative studies on performance analysis and sport expertise, we critically evaluate some of the main assumptions and methodological approaches with regard to understanding how information influences action and decision-making during team sports performance. Current data demonstrate how the understanding of performance behaviours in team sports by sport scientists and practitioners may be enhanced with a re-emphasis in research on the dynamics of emergent ongoing interactions. Ecological dynamics provides formal and theoretically grounded descriptions of player-environment interactions with respect to key performance goals and the unfolding information of competitive performance. Developing these formal descriptions and explanations of sport performance may provide a significant contribution to the field of performance analysis, supporting design and intervention in both research and practice.

An Implementation of the Action Space Concept in Behavioral Analysis.

ERIC Educational Resources Information Center

Higgs, Gary K.

The Contact Action Space (CAS) of an individual, or group of individuals, has a significant impact on the location of activities and the organization of the use of space. Beginning with the most basic components of a CAS, the individual behavior pattern element is developed, and operational variations affecting alignment and configuration are…

Corrective action investigation plan for Corrective Action Unit 340, Pesticide Release Sites, Nevada Test Site, Nye County, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This Correction Action Investigation Plan (CAIP) has been developed in accordance with the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the US Department of Energy, Nevada Operations Office (DOE/NV); the State of Nevada Division of Environmental Protection (NDEP); and the US Department of Defense. As required by the FFACO (1996), this document provides or references all of the specific information for planning investigation activities associated with three Corrective Action Sites (CASs) located at the Nevada Test Site (NTS). These CASs are collectively known as Corrective Action Unit (CAU) 340, Pesticide Release Sites. According to themore » FFACO, CASs are sites that may require corrective action(s) and may include solid waste management units or individual disposal or release sites. These sites are CAS 23-21-01, Area 23 Quonset Hut 800 (Q800) Pesticide Release Ditch; CAS 23-18-03, Area 23 Skid Huts Pesticide Storage; and CAS 15-18-02, Area 15 Quonset Hut 15-11 Pesticide Storage (Q15-11). The purpose of this CAIP for CAU 340 is to direct and guide the investigation for the evaluation of the nature and extent of pesticides, herbicides, and other contaminants of potential concern (COPCs) that were stored, mixed, and/or disposed of at each of the CASs.« less

The human ether-a-go-go-related gene (hERG) current inhibition selectively prolongs action potential of midmyocardial cells to augment transmural dispersion.

PubMed

Yasuda, C; Yasuda, S; Yamashita, H; Okada, J; Hisada, T; Sugiura, S

2015-08-01

The majority of drug induced arrhythmias are related to the prolongation of action potential duration following inhibition of rapidly activating delayed rectifier potassium current (I(Kr)) mediated by the hERG channel. However, for arrhythmias to develop and be sustained, not only the prolongation of action potential duration but also its transmural dispersion are required. Herein, we evaluated the effect of hERG inhibition on transmural dispersion of action potential duration using the action potential clamp technique that combined an in silico myocyte model with the actual I(Kr) measurement. Whole cell I(Kr) current was measured in Chinese hamster ovary cells stably expressing the hERG channel. The measured current was coupled with models of ventricular endocardial, M-, and epicardial cells to calculate the action potentials. Action potentials were evaluated under control condition and in the presence of 1, 10, or 100 μM disopyramide, an hERG inhibitor. Disopyramide dose-dependently increased the action potential durations of the three cell types. However, action potential duration of M-cells increased disproportionately at higher doses, and was significantly different from that of epicardial and endocardial cells (dispersion of repolarization). By contrast, the effects of disopyramide on peak I(Kr) and instantaneous current-voltage relation were similar in all cell types. Simulation study suggested that the reduced repolarization reserve of M-cell with smaller amount of slowly activating delayed rectifier potassium current levels off at longer action potential duration to make such differences. The action potential clamp technique is useful for studying the mechanism of arrhythmogenesis by hERG inhibition through the transmural dispersion of repolarization.

Perceiving goals and actions in individuals with autism spectrum disorders.

PubMed

Zalla, Tiziana; Labruyère, Nelly; Georgieff, Nicolas

2013-10-01

In the present study, we investigated the ability to parse familiar sequences of action into meaningful events in young individuals with autism spectrum disorders (ASDs), as compared to young individuals with typical development (TD) and young individuals with moderate mental retardation or learning disabilities (MLDs). While viewing two videotaped movies, participants were requested to detect the boundary transitions between component events at both fine and coarse levels of the action hierarchical structure. Overall, reduced accuracy for event detection was found in participants with ASDs, relative to participants with TD, at both levels of action segmentation. The performance was, however, equally diminished in participants with ASDs and MLDs under the course-grained segmentation suggesting that difficulties to detect fine-grained events in ASDs cannot be explained by a general intellectual dysfunction. Reduced accuracy for event detection was related to diminished event recall, memory for event sequence and Theory of Mind abilities. We hypothesized that difficulties with event detection result from a deficit disrupting the on-line processing of kinematic features and physical changes of dynamic human actions. An impairment at the earlier stages of the event encoding process might contribute to deficits in episodic memory and social functioning in individuals with ASDs.

Action potential amplitude as a noninvasive indicator of motor unit-specific hypertrophy.

PubMed

Pope, Zachary K; Hester, Garrett M; Benik, Franklin M; DeFreitas, Jason M

2016-05-01

Skeletal muscle fibers hypertrophy in response to strength training, with type II fibers generally demonstrating the greatest plasticity in regards to cross-sectional area (CSA). However, assessing fiber type-specific CSA in humans requires invasive muscle biopsies. With advancements in the decomposition of surface electromyographic (sEMG) signals recorded using multichannel electrode arrays, the firing properties of individual motor units (MUs) can now be detected noninvasively. Since action potential amplitude (APSIZE) has a documented relationship with muscle fiber size, as well as with its parent MU's recruitment threshold (RT) force, our purpose was to examine if MU APSIZE, as a function of its RT (i.e., the size principle), could potentially be used as a longitudinal indicator of MU-specific hypertrophy. By decomposing the sEMG signals from the vastus lateralis muscle of 10 subjects during maximal voluntary knee extensions, we noninvasively assessed the relationship between MU APSIZE and RT before and immediately after an 8-wk strength training intervention. In addition to significant increases in muscle size and strength (P < 0.02), our data show that training elicited an increase in MU APSIZE of high-threshold MUs. Additionally, a large portion of the variance (83.6%) in the change in each individual's relationship between MU APSIZE and RT was explained by training-induced changes in whole muscle CSA (obtained via ultrasonography). Our findings suggest that the noninvasive, electrophysiological assessment of longitudinal changes to MU APSIZE appears to reflect hypertrophy specific to MUs across the RT continuum. Copyright © 2016 the American Physiological Society.

Enterprise Management Network Architecture Distributed Knowledge Base Support

DTIC Science & Technology

1990-11-01

Advantages Potentially, this makes a distributed system more powerful than a conventional, centralized one in two ways: " First, it can be more reliable...does not completely apply [35]. The grain size of the processors measures the individual problem-solving power of the agents. In this definition...problem-solving power amounts to the conceptual size of a single action taken by an agent visible to the other agents in the system. If the grain is coarse

Health-Associated Niche Inhabitants as Oral Probiotics: The Case of Streptococcus dentisani

PubMed Central

López-López, Arantxa; Camelo-Castillo, Anny; Ferrer, María D.; Simon-Soro, Áurea; Mira, Alex

2017-01-01

Oral diseases, including dental caries and periodontitis, are among the most prevalent diseases worldwide and develop as a consequence of a microbial dysbiosis. Several bacterial strains are being tested as potential oral health-promoting organisms, but usually they are species isolated from niches other than the site where they must exert its probiotic action, typically from fecal samples. We hypothesize that oral inhabitants associated to health conditions will be more effective than traditional, gut-associated probiotic species in key aspects such as colonization of the oral site where disease takes place or the possession of oral health promoting functions, as well as more practical issues like safety and toxicity, and establishing proper doses for administration. As an example of these active colonizers, we describe the case of Streptococcus dentisani, a new streptococcal species isolated from dental plaque of caries-free individuals. We have detected it in 98% of dental plaque samples from healthy individuals and, as expected, it does not produce any toxic secondary metabolite and does not survive a simulated stomach digestion, preventing potential secondary effects. Besides, this species has a double probiotic action, as it inhibits the growth of major oral pathogens through the production of bacteriocins, and also buffers acidic pH (the primary cause of dental caries) through an arginolytic pathway. We propose the use of S. dentisani as a promising probiotic against tooth decay. PMID:28344574

Dynamics of Action Potential Initiation in the GABAergic Thalamic Reticular Nucleus In Vivo

PubMed Central

Muñoz, Fabián; Fuentealba, Pablo

2012-01-01

Understanding the neural mechanisms of action potential generation is critical to establish the way neural circuits generate and coordinate activity. Accordingly, we investigated the dynamics of action potential initiation in the GABAergic thalamic reticular nucleus (TRN) using in vivo intracellular recordings in cats in order to preserve anatomically-intact axo-dendritic distributions and naturally-occurring spatiotemporal patterns of synaptic activity in this structure that regulates the thalamic relay to neocortex. We found a wide operational range of voltage thresholds for action potentials, mostly due to intrinsic voltage-gated conductances and not synaptic activity driven by network oscillations. Varying levels of synchronous synaptic inputs produced fast rates of membrane potential depolarization preceding the action potential onset that were associated with lower thresholds and increased excitability, consistent with TRN neurons performing as coincidence detectors. On the other hand the presence of action potentials preceding any given spike was associated with more depolarized thresholds. The phase-plane trajectory of the action potential showed somato-dendritic propagation, but no obvious axon initial segment component, prominent in other neuronal classes and allegedly responsible for the high onset speed. Overall, our results suggest that TRN neurons could flexibly integrate synaptic inputs to discharge action potentials over wide voltage ranges, and perform as coincidence detectors and temporal integrators, supported by a dynamic action potential threshold. PMID:22279567

Decision making and action implementation: evidence for an early visually triggered motor activation specific to potential actions.

PubMed

Tandonnet, Christophe; Garry, Michael I; Summers, Jeffery J

2013-07-01

To make a decision may rely on accumulating evidence in favor of one alternative until a threshold is reached. Sequential-sampling models differ by the way of accumulating evidence and the link with action implementation. Here, we tested a model's prediction of an early action implementation specific to potential actions. We assessed the dynamics of action implementation in go/no-go and between-hand choice tasks by transcranial magnetic stimulation of the motor cortex (single- or paired-pulse TMS; 3-ms interstimulus interval). Prior to implementation of the selected action, the amplitude of the motor evoked potential first increased whatever the visual stimulus but only for the hand potentially involved in the to-be-produced action. These findings suggest that visual stimuli can trigger an early motor activation specific to potential actions, consistent with race-like models with continuous transmission between decision making and action implementation. Copyright © 2013 Society for Psychophysiological Research.

Social Capital and Fear of Crime in Adolescence: A Multilevel Study.

PubMed

Vieno, Alessio; Lenzi, Michela; Roccato, Michele; Russo, Silvia; Monaci, Maria Grazia; Scacchi, Luca

2016-09-01

Hierarchical linear modeling was used to examine the relationships between social capital (at the individual, the neighborhood, and the regional levels) and adolescents' fear of crime, while controlling for the main individual (sociodemographics, television viewing, and bullying victimization), neighborhood (neighborhood size and aggregated victimization), and regional (crime rate and level of urbanization) variables. Data were analyzed using a three-level model based on 22,639 15.7-year-old (SD = 0.67) students nested within 1081 neighborhoods and 19 Italian regions. The findings revealed that individual and contextual measures of social capital, modeled at the individual, neighborhood, and regional levels simultaneously, showed negative associations with adolescents' fear of crime. Males and participants with higher family affluence were less likely to feel fear of crime, whereas victimization, both at the individual and neighborhood levels, had a positive association with fear of crime. Strengths, limitations, and potential applications of the study are discussed. © Society for Community Research and Action 2016.

The Action Observation System when Observing Hand Actions in Autism and Typical Development.

PubMed

Pokorny, Jennifer J; Hatt, Naomi V; Colombi, Costanza; Vivanti, Giacomo; Rogers, Sally J; Rivera, Susan M

2015-06-01

Social impairments in individuals with autism spectrum disorders (ASD) may be in part due to difficulty perceiving and recognizing the actions of others. Evidence from imitation studies, which involves both observation and execution of an action, suggests differences, in individuals with ASD, between the ability to imitate goal-directed actions involving objects (transitive actions) and the ability to imitate actions that do not involve objects (intransitive actions). In the present study, we examined whether there were differences in how ASD adolescents encoded transitive and intransitive actions compared to typically developing (TD) adolescents, by having participants view videos of a hand reaching across a screen toward an object or to where an object would be while functional magnetic resonance images were collected. Analyses focused on areas within the action observation network (AON), which is activated during the observation of actions performed by others. We hypothesized that the AON would differentiate transitive from intransitive actions only in the ASD group. However, results revealed that object presence modulated activity in the right inferior frontal gyrus and supramarginal gyrus of the TD group, a differentiation that was not seen in the ASD group. Furthermore, there were no significant group differences between the TD and ASD groups in any of the conditions. This suggests that there is not a global deficit of the AON in individuals with ASD while observing transitive and intransitive actions. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

The effects of saxitoxin and tetrodotoxin on nerve conduction in the presence of lithium ions and of magnesium ions

PubMed Central

Evans, M. H.

1969-01-01

1. It has been shown that nerve fibres from rat cauda equina will conduct action potentials after immersion in saline in which lithium chloride is substituted for sodium chloride. 2. Both saxitoxin and tetrodotoxin inhibit lithium-generated action potentials. The concentration of toxin needed to inhibit the lithium-generated action potentials is similar to that needed to inhibit sodium-generated action potentials. 3. If magnesium chloride is added to the saline to give a concentration of 10-15 mM there is usually a slight fall in amplitude of the compound action potential. Saxitoxin and tetrodotoxin now inhibit the action potential to a greater degree than in the absence of magnesium ions. PMID:5789802

Actions and mechanisms of action of novel analogues of sotalol on guinea-pig and rabbit ventricular cells.

PubMed Central

Connors, S. P.; Gill, E. W.; Terrar, D. A.

1992-01-01

1. The actions and mechanisms of action of novel analogues of sotalol which prolong cardiac action potentials were investigated in guinea-pig and rabbit isolated ventricular cells. 2. In guinea-pig and rabbit cells the compounds significantly prolonged action potential duration at 20% and 90% repolarization levels without affecting resting membrane potential. In guinea-pig but not rabbit cells there was an increase in action potential amplitude and in rabbit cells there was no change in the shape or position of the 'notch' in the action potential. 3. Possible mechanisms of action were studied in more detail in the case of compound II (1-(4-methanesulphonamidophenoxy)-3-(N-methyl 3,4 dichlorophenylethylamino)-2-propanol). Prolongation of action potential duration continued to occur in the presence of nisoldipine, and calcium currents recorded under voltage-clamp conditions were not reduced by compound II (1 microM). Action potential prolongation by compound II was also unaffected in the presence of 10 microM tetrodotoxin. 4. Compound II (1 microM) did not influence IK1 assessed from the current during ramp changes in membrane potential (20 mV s-1) over the range -90 to -10 mV. 5. Compound II (1 microM) blocked time-dependent delayed rectifier potassium current (IK) activated by step depolarizations and recorded as an outward tail following repolarization. When a submaximal concentration (50 nM) was applied there was no change in the apparent reversal potential of IK.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1393293

Variability of acute extracellular action potential measurements with multisite silicon probes

PubMed Central

Scott, Kimberly M.; Du, Jiangang; Lester, Henry A.; Masmanidis, Sotiris C.

2012-01-01

Device miniaturization technologies have led to significant advances in sensors for extracellular measurements of electrical activity in the brain. Multisite, silicon-based probes containing implantable electrode arrays afford greater coverage of neuronal activity than single electrodes and therefore potentially offer a more complete view of how neuronal ensembles encode information. However, scaling up the number of sites is not sufficient to ensure capture of multiple neurons, as action potential signals from extracellular electrodes may vary due to numerous factors. In order to understand the large-scale recording capabilities and potential limitations of multisite probes, it is important to quantify this variability, and to determine whether certain key device parameters influence the recordings. Here we investigate the effect of four parameters, namely, electrode surface, width of the structural support shafts, shaft number, and position of the recording site relative to the shaft tip. This study employs acutely implanted silicon probes containing up to 64 recording sites, whose performance is evaluated by the metrics of noise, spike amplitude, and spike detection probability. On average, we find no significant effect of device geometry on spike amplitude and detection probability but we find significant differences among individual experiments, with the likelihood of detecting spikes varying by a factor of approximately three across trials. PMID:22971352

Estimating costs and potentials of different methods to reduce the Swedish phosphorus load from agriculture to surface water.

PubMed

Malmaeus, J M; Karlsson, O M

2010-01-01

This paper reviews 17 measures to reduce phosphorus leakage from Swedish agriculture to surface waters. Our aim is to evaluate the possible contribution from agriculture to achieve environmental goals including the Baltic Sea Action Plan. Using a regional approach integrating the variability in field specific characteristics, typical costs and national potential for the included measures may be estimated without identifying, e.g., suitable individual fields for implementation. The result may be helpful to select suitable measures but may also influence the design of environmental targets before they are determined. We find that the cheapest measures are reduced phosphorus content in animal food and fertilizer application supervision in pig farms, both measures with annual potentials of around 50t each, and costs of euro7 to euro11 kg(-1)yr(-1). The total potential of the listed measures is an annual phosphorus reduction to surface waters of 242t. If the most expensive measures are excluded (>euro1000 kg(-1)yr(-1)) and including retention in lakes the phosphorus transport to the sea could be reduced by 165 t yr(-1). This amount can be compared with the Swedish commitment in the Baltic Sea Action Plan (BSAP) to reduce input to the Baltic Proper by 290 t yr(-1).

The effect of facial expressions on peripersonal and interpersonal spaces.

PubMed

Ruggiero, Gennaro; Frassinetti, Francesca; Coello, Yann; Rapuano, Mariachiara; di Cola, Armando Schiano; Iachini, Tina

2017-11-01

Identifying individuals' intent through the emotional valence conveyed by their facial expression influences our capacity to approach-avoid these individuals during social interactions. Here, we explore if and how the emotional valence of others' facial expressiveness modulates peripersonal-action and interpersonal-social spaces. Through Immersive Virtual Reality, participants determined reachability-distance (for peripersonal space) and comfort-distance (for interpersonal space) from male/female virtual confederates exhibiting happy, angry and neutral facial expressions while being approached by (passive-approach) or walking toward (active-approach) them. Results showed an increase of distance when seeing angry rather than happy confederates in both approach conditions of comfort-distance. The effect also appeared in reachability-distance, but only in the passive-approach. Anger prompts avoidant behaviors, and thus an expansion of distance, particularly with a potential violation of near body space by an intruder. Overall, the findings suggest that peripersonal-action space, in comparison with interpersonal-social space, is similarly sensitive to the emotional valence of stimuli. We propose that this similarity could reflect a common adaptive mechanism shared by these spaces, presumably at different degrees, for ensuring self-protection functions.

48 CFR 501.404-70 - Contract action.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Contract action. 501.404... Contract action. Contract action. A contract action, for the purpose of determining whether an individual or class deviation is appropriate, has the same meaning as that used for reporting contract actions...

Learning as discourse change: A sociocultural mechanism

NASA Astrophysics Data System (ADS)

Wickman, Per-Olof; Östman, Leif

2002-09-01

This paper deals with a theoretical mechanism for learning and a methodological approach for analyzing meaning making in classroom talk and action. It examines the potential of the approach for illuminating learning on a discursive level, i.e., how discourses change and how individuals become participants of new practices. Our approach involves a high-resolution analysis of how meaningful relations are built in encounters between individuals and between individuals and the world. The approach is based mainly on the work of the later Wittgenstein, but also on pragmatism and sociocultural research. To demonstrate how our approach can be used, we analyze what university students learn during a practical on insects. We specifically demonstrate how the encounters with physical pinned insects contribute to the meaning students make and how these encounters interact with other experiences during laboratory work.

Adaptivity in Agent-Based Routing for Data Networks

NASA Technical Reports Server (NTRS)

Wolpert, David H.; Kirshner, Sergey; Merz, Chris J.; Turner, Kagan

2000-01-01

Adaptivity, both of the individual agents and of the interaction structure among the agents, seems indispensable for scaling up multi-agent systems (MAS s) in noisy environments. One important consideration in designing adaptive agents is choosing their action spaces to be as amenable as possible to machine learning techniques, especially to reinforcement learning (RL) techniques. One important way to have the interaction structure connecting agents itself be adaptive is to have the intentions and/or actions of the agents be in the input spaces of the other agents, much as in Stackelberg games. We consider both kinds of adaptivity in the design of a MAS to control network packet routing. We demonstrate on the OPNET event-driven network simulator the perhaps surprising fact that simply changing the action space of the agents to be better suited to RL can result in very large improvements in their potential performance: at their best settings, our learning-amenable router agents achieve throughputs up to three and one half times better than that of the standard Bellman-Ford routing algorithm, even when the Bellman-Ford protocol traffic is maintained. We then demonstrate that much of that potential improvement can be realized by having the agents learn their settings when the agent interaction structure is itself adaptive.

Group augmentation, collective action, and territorial boundary patrols by male chimpanzees

PubMed Central

Langergraber, Kevin E.; Watts, David P.; Mitani, John C.

2017-01-01

How can collective action evolve when individuals benefit from cooperation regardless of whether they pay its participation costs? According to one influential perspective, collective action problems are common, especially when groups are large, but may be solved when individuals who have more to gain from the collective good or can produce it at low costs provide it to others as a byproduct. Several results from a 20-y study of one of the most striking examples of collective action in nonhuman animals, territorial boundary patrolling by male chimpanzees, are consistent with these ideas. Individuals were more likely to patrol when (i) they had more to gain because they had many offspring in the group; (ii) they incurred relatively low costs because of their high dominance rank and superior physical condition; and (iii) the group size was relatively small. However, several other findings were better explained by group augmentation theory, which proposes that individuals should bear the short-term costs of collective action even when they have little to gain immediately if such action leads to increases in group size and long-term increases in reproductive success. In support of this theory, (i) individual patrolling effort was higher and less variable than participation in intergroup aggression in other primate species; (ii) males often patrolled when they had no offspring or maternal relatives in the group; and (iii) the aggregate patrolling effort of the group did not decrease with group size. We propose that group augmentation theory deserves more consideration in research on collective action. PMID:28630310

Alteration of neural action potential patterns by axonal stimulation: the importance of stimulus location.

PubMed

Crago, Patrick E; Makowski, Nathaniel S

2014-10-01

Stimulation of peripheral nerves is often superimposed on ongoing motor and sensory activity in the same axons, without a quantitative model of the net action potential train at the axon endpoint. We develop a model of action potential patterns elicited by superimposing constant frequency axonal stimulation on the action potentials arriving from a physiologically activated neural source. The model includes interactions due to collision block, resetting of the neural impulse generator, and the refractory period of the axon at the point of stimulation. Both the mean endpoint firing rate and the probability distribution of the action potential firing periods depend strongly on the relative firing rates of the two sources and the intersite conduction time between them. When the stimulus rate exceeds the neural rate, neural action potentials do not reach the endpoint and the rate of endpoint action potentials is the same as the stimulus rate, regardless of the intersite conduction time. However, when the stimulus rate is less than the neural rate, and the intersite conduction time is short, the two rates partially sum. Increases in stimulus rate produce non-monotonic increases in endpoint rate and continuously increasing block of neurally generated action potentials. Rate summation is reduced and more neural action potentials are blocked as the intersite conduction time increases. At long intersite conduction times, the endpoint rate simplifies to being the maximum of either the neural or the stimulus rate. This study highlights the potential of increasing the endpoint action potential rate and preserving neural information transmission by low rate stimulation with short intersite conduction times. Intersite conduction times can be decreased with proximal stimulation sites for muscles and distal stimulation sites for sensory endings. The model provides a basis for optimizing experiments and designing neuroprosthetic interventions involving motor or sensory stimulation.

The role of Na-Ca exchange current in the cardiac action potential.

PubMed

Janvier, N C; Boyett, M R

1996-07-01

Since 1981, when Mullins published his provocative book proposing that the Na-Ca exchanger is electrogenic, it has been shown, first by computer simulation by Noble and later by experiment by various investigators, that inward iNaCa triggered by the Ca2+ transient is responsible for the low plateau of the atrial action potential and contributes to the high plateau of the ventricular action potential. Reduction or complete block of inward iNaCa by buffering intracellular Ca2+ with EGTA or BAPTA, by blocking SR Ca2+ release or by substituting extracellular Na+ with Li+ can result in a shortening of the action potential. The effect of block of outward iNaCa or complete block of both inward and outward iNaCa on the action potential has not been investigated experimentally, because of the lack of a suitable blocker, and remains a goal for the future. An increase in the intracellular Na+ concentration (after the application of cardiac glycoside or an increase in heart rate) or an increase in extracellular Ca2+ are believed to lead to an outward shift in iNaCa at plateau potentials and a shortening of the action potential. Changes in the Ca2+ transient are expected to result in changes in inward iNaCa and thus the action potential. This may explain the shortening of the premature action potential as well as the prolongation of the action potential when a muscle is allowed to shorten during the action potential. Inward iNaCa may play an important role in both normal and abnormal pacemaker activity in the heart.

Review article: potential mechanisms of action of rifaximin in the management of irritable bowel syndrome with diarrhoea.

PubMed

Pimentel, M

2016-01-01

The role of gut microbiota in the pathophysiology of irritable bowel syndrome (IBS) is supported by various lines of evidence, including differences in mucosal and faecal microbiota between patients with IBS and healthy individuals, development of post-infectious IBS, and the efficacy of some probiotics and nonsystemic antibiotics (e.g. rifaximin). To review the literature regarding the role of rifaximin in IBS and its potential mechanism(s) of action. A literature search was conducted using the terms 'rifaximin', 'irritable bowel syndrome' and 'mechanism of action'. Rifaximin was approved in 2015 for the treatment of IBS with diarrhoea. In contrast to other currently available IBS therapies that require daily administration to maintain efficacy, 2-week rifaximin treatment achieved symptom improvement that persisted ≥12 weeks post-treatment. The mechanisms of action of rifaximin, therefore, may extend beyond direct bactericidal effects. Data suggest that rifaximin may decrease host proinflammatory responses to bacterial products in patients with IBS. In some cases, small intestinal bacterial overgrowth (SIBO) may play a role in the clinical symptoms of IBS. Because of the high level of solubility of rifaximin in the small intestine, rifaximin may reset microbial diversity in this environment. Consistent with this hypothesis, rifaximin has antibiotic efficacy against isolates derived from patients with SIBO. Resetting microbial diversity via rifaximin use may lead to a decrease in bacterial fermentation and a reduction in the clinical symptoms of IBS. © 2015 John Wiley & Sons Ltd.

Everyday action in schizophrenia: performance patterns and underlying cognitive mechanisms.

PubMed

Kessler, Rachel K; Giovannetti, Tania; MacMullen, Laura R

2007-07-01

Everyday action is impaired among individuals with schizophrenia, yet few studies have characterized the nature of this deficit using performance-based measures. This study examined the performance of 20 individuals with schizophrenia or schizoaffective disorder on the Naturalistic Action Test (M. F. Schwartz, L. J. Buxbaum, M. Ferraro, T. Veramonti, & M. Segal, 2003). Performance was coded to examine overall impairment, task accomplishment, and error patterns and was compared with that of healthy controls (n = 28) and individuals with mild dementia (n = 23). Additionally, 2 competing accounts of everyday action deficits, the resource theory and an executive account, were evaluated. When compared with controls, the participants with schizophrenia demonstrated impaired performance. Relative to dementia patients, participants with schizophrenia obtained higher accomplishment scores but committed comparable rates of errors. Moreover, distributions of error types for the 2 groups differed, with the participants with schizophrenia demonstrating greater proportions of errors associated with executive dysfunction. This is the 1st study to show different Naturalistic Action Test performance patterns between 2 neurologically impaired populations. The distinct performance pattern demonstrated by individuals with schizophrenia reflects specific deficits in executive function.

Simulation of action potential propagation in plants.

PubMed

Sukhov, Vladimir; Nerush, Vladimir; Orlova, Lyubov; Vodeneev, Vladimir

2011-12-21

Action potential is considered to be one of the primary responses of a plant to action of various environmental factors. Understanding plant action potential propagation mechanisms requires experimental investigation and simulation; however, a detailed mathematical model of plant electrical signal transmission is absent. Here, the mathematical model of action potential propagation in plants has been worked out. The model is a two-dimensional system of excitable cells; each of them is electrically coupled with four neighboring ones. Ion diffusion between excitable cell apoplast areas is also taken into account. The action potential generation in a single cell has been described on the basis of our previous model. The model simulates active and passive signal transmission well enough. It has been used to analyze theoretically the influence of cell to cell electrical conductivity and H(+)-ATPase activity on the signal transmission in plants. An increase in cell to cell electrical conductivity has been shown to stimulate an increase in the length constant, the action potential propagation velocity and the temperature threshold, while the membrane potential threshold being weakly changed. The growth of H(+)-ATPase activity has been found to induce the increase of temperature and membrane potential thresholds and the reduction of the length constant and the action potential propagation velocity. Copyright © 2011 Elsevier Ltd. All rights reserved.

Prospective memory in an air traffic control simulation: External aids that signal when to act

PubMed Central

Loft, Shayne; Smith, Rebekah E.; Bhaskara, Adella

2011-01-01

At work and in our personal life we often need to remember to perform intended actions at some point in the future, referred to as Prospective Memory. Individuals sometimes forget to perform intentions in safety-critical work contexts. Holding intentions can also interfere with ongoing tasks. We applied theories and methods from the experimental literature to test the effectiveness of external aids in reducing prospective memory error and costs to ongoing tasks in an air traffic control simulation. Participants were trained to accept and hand-off aircraft, and to detect aircraft conflicts. For the prospective memory task participants were required to substitute alternative actions for routine actions when accepting target aircraft. Across two experiments, external display aids were provided that presented the details of target aircraft and associated intended actions. We predicted that aids would only be effective if they provided information that was diagnostic of target occurrence and in this study we examined the utility of aids that directly cued participants when to allocate attention to the prospective memory task. When aids were set to flash when the prospective memory target aircraft needed to be accepted, prospective memory error and costs to ongoing tasks of aircraft acceptance and conflict detection were reduced. In contrast, aids that did not alert participants specifically when the target aircraft were present provided no advantage compared to when no aids we used. These findings have practical implications for the potential relative utility of automated external aids for occupations where individuals monitor multi-item dynamic displays. PMID:21443381

Prospective memory in an air traffic control simulation: external aids that signal when to act.

PubMed

Loft, Shayne; Smith, Rebekah E; Bhaskara, Adella

2011-03-01

At work and in our personal life we often need to remember to perform intended actions at some point in the future, referred to as Prospective Memory. Individuals sometimes forget to perform intentions in safety-critical work contexts. Holding intentions can also interfere with ongoing tasks. We applied theories and methods from the experimental literature to test the effectiveness of external aids in reducing prospective memory error and costs to ongoing tasks in an air traffic control simulation. Participants were trained to accept and hand-off aircraft and to detect aircraft conflicts. For the prospective memory task, participants were required to substitute alternative actions for routine actions when accepting target aircraft. Across two experiments, external display aids were provided that presented the details of target aircraft and associated intended actions. We predicted that aids would only be effective if they provided information that was diagnostic of target occurrence, and in this study, we examined the utility of aids that directly cued participants when to allocate attention to the prospective memory task. When aids were set to flash when the prospective memory target aircraft needed to be accepted, prospective memory error and costs to ongoing tasks of aircraft acceptance and conflict detection were reduced. In contrast, aids that did not alert participants specifically when the target aircraft were present provided no advantage compared to when no aids were used. These findings have practical implications for the potential relative utility of automated external aids for occupations where individuals monitor multi-item dynamic displays.

Ethics and data protection in human biomarker studies in environmental health.

PubMed

Casteleyn, Ludwine; Dumez, Birgit; Van Damme, Karel; Anwar, Wagida A

2013-08-01

Human biomarker studies in environmental health are essential tools to study the relationship between health and environment. They should ultimately contribute to a better understanding of environmentally induced adverse health effects and to appropriate preventive actions. To ensure the protection of the rights and dignity of study participants a complex legal and ethical framework is applied, consisting of several international directives, conventions, and guidelines, whether or not translated in domestic laws. Main characteristics of ethics and data protection in studies using biomarkers in the field of environmental health are summarized and current discussions on related questions and bottlenecks highlighted. In the current regulatory context, dominated by the protection of the individual study participant, difficulties are reported due to the different interpretation and implementation of the regulations of concern within and across borders. Advancement of consistency and compatibility is recommended and efforts are ongoing. An increasing demand for secondary use of data and samples poses additional challenges in finding a right balance between the individual rights of the study participants on the one hand and the common interest of, and potential benefit for the public or community at large on the other. Ethics committees could play a key role in assessing problems originating from the sometimes competing needs at individual and societal level. Building trust in science amongst (potential) study participants and within the community allows the inclusion of arguments from the societal perspective. This requires increased attention for respectful communication efforts. Striving for public participation in decision making processes may promote policy relevant research and the related translation of study results into action. Copyright © 2013 Elsevier GmbH. All rights reserved.

Visual perception and regulatory conflict: motivation and physiology influence distance perception.

PubMed

Cole, Shana; Balcetis, Emily; Zhang, Sam

2013-02-01

Regulatory conflict can emerge when people experience a strong motivation to act on goals but a conflicting inclination to withhold action because physical resources available, or physiological potentials, are low. This study demonstrated that distance perception is biased in ways that theory suggests assists in managing this conflict. Participants estimated the distance to a target location. Individual differences in physiological potential measured via waist-to-hip ratio interacted with manipulated motivational states to predict visual perception. Among people low in physiological potential and likely to experience regulatory conflict, the environment appeared easier to traverse when motivation was strong compared with weak. Among people high in potential and less likely to experience conflict, perception was not predicted by motivational strength. The role of motivated distance perception in self-regulation is discussed. 2013 APA, all rights reserved

Non-Genomic Effects of Xenoestrogen Mixtures

PubMed Central

Viñas, René; Jeng, Yow-Jiun; Watson, Cheryl S.

2012-01-01

Xenoestrogens (XEs) are chemicals derived from a variety of natural and anthropogenic sources that can interfere with endogenous estrogens by either mimicking or blocking their responses via non-genomic and/or genomic signaling mechanisms. Disruption of estrogens’ actions through the less-studied non-genomic pathway can alter such functional end points as cell proliferation, peptide hormone release, catecholamine transport, and apoptosis, among others. Studies of potentially adverse effects due to mixtures and to low doses of endocrine-disrupting chemicals have recently become more feasible, though few so far have included actions via the non-genomic pathway. Physiologic estrogens and XEs evoke non-monotonic dose responses, with different compounds having different patterns of actions dependent on concentration and time, making mixture assessments all the more challenging. In order to understand the spectrum of toxicities and their mechanisms, future work should focus on carefully studying individual and mixture components across a range of concentrations and cellular pathways in a variety of tissue types. PMID:23066391

41 CFR 60-741.43 - Affirmative action policy.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 41 Public Contracts and Property Management 1 2011-07-01 2009-07-01 true Affirmative action policy... OF LABOR 741-AFFIRMATIVE ACTION AND NONDISCRIMINATION OBLIGATIONS OF CONTRACTORS AND SUBCONTRACTORS REGARDING INDIVIDUALS WITH DISABILITIES Affirmative Action Program § 60-741.43 Affirmative action policy...

41 CFR 60-741.43 - Affirmative action policy.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Affirmative action policy... OF LABOR 741-AFFIRMATIVE ACTION AND NONDISCRIMINATION OBLIGATIONS OF CONTRACTORS AND SUBCONTRACTORS REGARDING INDIVIDUALS WITH DISABILITIES Affirmative Action Program § 60-741.43 Affirmative action policy...

[Loudness optimized registration of compound action potential in cochlear implant recipients].

PubMed

Berger, Klaus; Hocke, Thomas; Hessel, Horst

2017-11-01

Background Postoperative measurements of compound action potentials are not always possible due to the insufficient acceptance of the CI-recipients. This study investigated the impact of different parameters on the acceptance of the measurements. Methods Compound action potentials of 16 CI recipients were measured with different pulse-widths. Recipients performed a loudness rating at the potential thresholds with the different sequences. Results Compound action potentials obtained with higher pulse-widths were rated softer than those obtained with smaller pulse-widths. Conclusions Compound action potentials measured with higher pulse-widths generate a gap between loudest acceptable presentation level and potential threshold. This gap contributes to a higher acceptance of postoperative measurements. Georg Thieme Verlag KG Stuttgart · New York.

Naltrexone for the treatment of alcoholism: clinical findings, mechanisms of action, and pharmacogenetics.

PubMed

Ray, Lara A; Chin, Pauline F; Miotto, Karen

2010-03-01

Naltrexone is an opioid receptor antagonist with established efficacy, albeit moderate, for the treatment of alcohol dependence. This manuscript provides a critical review of the literature on naltrexone as a pharmacotherapy for alcoholism by covering the following areas: (a) clinical findings from treatment studies; (b) pharmacokinetics and safety data; (c) medication compliance and persistence; and (d) neurobiological and biobehavioral mechanisms of action of naltrexone for the indication of alcohol dependence. This review will then focus on the emerging literature on naltrexone pharmacogenetics, which has the potential to identify responders on the basis of genetic variation and to use genetic tools to individualize the use of this medication. Limitations and future directions in the research and practice of naltrexone for alcoholism are also outlined.

Intracellular calcium movements during excitation–contraction coupling in mammalian slow-twitch and fast-twitch muscle fibers

PubMed Central

Hollingworth, Stephen

2012-01-01

In skeletal muscle fibers, action potentials elicit contractions by releasing calcium ions (Ca2+) from the sarcoplasmic reticulum. Experiments on individual mouse muscle fibers micro-injected with a rapidly responding fluorescent Ca2+ indicator dye reveal that the amount of Ca2+ released is three- to fourfold larger in fast-twitch fibers than in slow-twitch fibers, and the proportion of the released Ca2+ that binds to troponin to activate contraction is substantially smaller. PMID:22450485

The Pharmacogenomics Research Network Translational Pharmacogenetics Program: Overcoming Challenges of Real-World Implementation

PubMed Central

Shuldiner, AR; Relling, MV; Peterson, JF; Hicks, JK; Freimuth, RR; Sadee, W; Pereira, NL; Roden, DM; Johnson, JA; Klein, TE

2013-01-01

The pace of discovery of potentially actionable pharmacogenetic variants has increased dramatically in recent years. However, the implementation of this new knowledge for individualized patient care has been slow. The Pharmacogenomics Research Network (PGRN) Translational Pharmacogenetics Program seeks to identify barriers and develop real-world solutions to implementation of evidence-based pharmacogenetic tests in diverse health-care settings. Dissemination of the resulting toolbox of “implementation best practices” will prove useful to a broad audience. PMID:23588301

Estimating Individual Influences of Behavioral Intentions: An Application of Random-Effects Modeling to the Theory of Reasoned Action.

ERIC Educational Resources Information Center

Hedeker, Donald; And Others

1996-01-01

Methods are proposed and described for estimating the degree to which relations among variables vary at the individual level. As an example, M. Fishbein and I. Ajzen's theory of reasoned action is examined. This article illustrates the use of empirical Bayes methods based on a random-effects regression model to estimate individual influences…

40 CFR 141.563 - What follow-up action is my system required to take based on continuous turbidity monitoring?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Individual Filter Turbidity Requirements § 141.563 What follow-up action is my system required to take based...: If * * * Your system must * * * (a) The turbidity of an individual filter (or the turbidity of combined filter effluent (CFE) for systems with 2 filters that monitor CFE in lieu of individual filters...

40 CFR 141.563 - What follow-up action is my system required to take based on continuous turbidity monitoring?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Individual Filter Turbidity Requirements § 141.563 What follow-up action is my system required to take based...: If * * * Your system must * * * (a) The turbidity of an individual filter (or the turbidity of combined filter effluent (CFE) for systems with 2 filters that monitor CFE in lieu of individual filters...

40 CFR 141.563 - What follow-up action is my system required to take based on continuous turbidity monitoring?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Individual Filter Turbidity Requirements § 141.563 What follow-up action is my system required to take based...: If * * * Your system must * * * (a) The turbidity of an individual filter (or the turbidity of combined filter effluent (CFE) for systems with 2 filters that monitor CFE in lieu of individual filters...

40 CFR 141.563 - What follow-up action is my system required to take based on continuous turbidity monitoring?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Individual Filter Turbidity Requirements § 141.563 What follow-up action is my system required to take based...: If * * * Your system must * * * (a) The turbidity of an individual filter (or the turbidity of combined filter effluent (CFE) for systems with 2 filters that monitor CFE in lieu of individual filters...

40 CFR 141.563 - What follow-up action is my system required to take based on continuous turbidity monitoring?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Individual Filter Turbidity Requirements § 141.563 What follow-up action is my system required to take based...: If * * * Your system must * * * (a) The turbidity of an individual filter (or the turbidity of combined filter effluent (CFE) for systems with 2 filters that monitor CFE in lieu of individual filters...

Right external globus pallidus changes are associated with altered causal awareness in youth with depression

PubMed Central

Griffiths, K R; Lagopoulos, J; Hermens, D F; Hickie, I B; Balleine, B W

2015-01-01

Cognitive impairment is a functionally disabling feature of depression contributing to maladaptive decision-making, a loss of behavioral control and an increased disease burden. The ability to calculate the causal efficacy of ones actions in achieving specific goals is critical to normal decision-making and, in this study, we combined voxel-based morphometry (VBM), shape analysis and diffusion tensor tractography to investigate the relationship between cortical–basal ganglia structural integrity and such causal awareness in 43 young subjects with depression and 21 demographically similar healthy controls. Volumetric analysis determined a relationship between right pallidal size and sensitivity to the causal status of specific actions. More specifically, shape analysis identified dorsolateral surface vertices where an inward location was correlated with reduced levels of causal awareness. Probabilistic tractography revealed that affected parts of the pallidum were primarily connected with the striatum, dorsal thalamus and hippocampus. VBM did not reveal any whole-brain gray matter regions that correlated with causal awareness. We conclude that volumetric reduction within the indirect pathway involving the right dorsolateral pallidum is associated with reduced awareness of the causal efficacy of goal-directed actions in young depressed individuals. This causal awareness task allows for the identification of a functionally and biologically relevant subgroup to which more targeted cognitive interventions could be applied, potentially enhancing the long-term outcomes for these individuals. PMID:26440541

Inducing repetitive action potential firing in neurons via synthesized photoresponsive nanoscale cellular prostheses.

PubMed

Lu, Siyuan; Madhukar, Anupam

2013-02-01

Recently we reported an analysis that examined the potential of synthesized photovoltaic functional abiotic nanosystems (PVFANs) to modulate membrane potential and activate action potential firing in neurons. Here we extend the analysis to delineate the requirements on the electronic energy levels and the attendant photophysical properties of the PVFANs to induce repetitive action potential under continuous light, a capability essential for the proposed potential application of PVFANs as retinal cellular prostheses to compensate for loss of photoreceptors. We find that repetitive action potential firing demands two basic characteristics in the electronic response of the PVFANs: an exponential dependence of the PVFAN excited state decay rate on the membrane potential and a three-state system such that, following photon absorption, the electron decay from the excited state to the ground state is via intermediate state(s) whose lifetime is comparable to the refractory time following an action potential. In this study, the potential of synthetic photovoltaic functional abiotic nanosystems (PVFANs) is examined under continuous light to modulate membrane potential and activate action potential firing in neurons with the proposed potential application of PVFANs as retinal cellular prostheses. Copyright © 2013 Elsevier Inc. All rights reserved.

Effects of K(+) channel openers on spontaneous action potentials in detrusor smooth muscle of the guinea-pig urinary bladder.

PubMed

Takagi, Hiroaki; Hashitani, Hikaru

2016-10-15

The modulation of spontaneous excitability in detrusor smooth muscle (DSM) upon the pharmacological activation of different populations of K(+) channels was investigated. Effects of distinct K(+) channel openers on spontaneous action potentials in DSM of the guinea-pig bladder were examined using intracellular microelectrode techniques. NS1619 (10μM), a large conductance Ca(2+)-activated K(+) (BK) channel opener, transiently increased action potential frequency and then prevented their generation without hyperpolarizing the membrane in a manner sensitive to iberiotoxin (IbTX, 100nM). A higher concentration of NS1619 (30μM) hyperpolarized the membrane and abolished action potential firing. NS309 (10μM) and SKA31 (100μM), small conductance Ca(2+)-activated K(+) (SK) channel openers, dramatically increased the duration of the after-hyperpolarization and then abolished action potential firing in an apamin (100nM)-sensitive manner. Flupirtine (10μM), a Kv7 channel opener, inhibited action potential firing without hyperpolarizing the membrane in a manner sensitive to XE991 (10μM), a Kv7 channel blocker. BRL37344 (10μM), a β3-adrenceptor agonist, or rolipram (10nM), a phosphodiesterase 4 inhibitor, also inhibited action potential firing. A higher concentration of rolipram (100nM) hyperpolarized the DSM and abolished the action potentials. IbTX (100nM) prevented the rolipram-induced blockade of action potentials but not the hyperpolarization. BK and Kv7 channels appear to predominantly contribute to the stabilization of DSM excitability. Spare SK channels could be pharmacologically activated to suppress DSM excitability. BK channels appear to be involved in the cyclic AMP-induced inhibition of action potentials but not the membrane hyperpolarization. Copyright © 2016 Elsevier B.V. All rights reserved.

Imaging Action Potential in Single Mammalian Neurons by Tracking the Accompanying Sub-Nanometer Mechanical Motion.

PubMed

Yang, Yunze; Liu, Xian-Wei; Wang, Hui; Yu, Hui; Guan, Yan; Wang, Shaopeng; Tao, Nongjian

2018-03-28

Action potentials in neurons have been studied traditionally by intracellular electrophysiological recordings and more recently by the fluorescence detection methods. Here we describe a label-free optical imaging method that can measure mechanical motion in single cells with a sub-nanometer detection limit. Using the method, we have observed sub-nanometer mechanical motion accompanying the action potential in single mammalian neurons by averaging the repeated action potential spikes. The shape and width of the transient displacement are similar to those of the electrically recorded action potential, but the amplitude varies from neuron to neuron, and from one region of a neuron to another, ranging from 0.2-0.4 nm. The work indicates that action potentials may be studied noninvasively in single mammalian neurons by label-free imaging of the accompanying sub-nanometer mechanical motion.

Pathological prolongation of action potential duration as a cause of the reduced alpha-adrenoceptor-mediated negative inotropy in streptozotocin-induced diabetic mice myocardium.

PubMed

Kanae, Haruna; Hamaguchi, Shogo; Wakasugi, Yumi; Kusakabe, Taichi; Kato, Keisuke; Namekata, Iyuki; Tanaka, Hikaru

2017-11-01

Effect of pathological prolongation of action potential duration on the α-adrenoceptor-mediated negative inotropy was studied in streptozotocin-induced diabetic mice myocardium. In streptozotocin-treated mouse ventricular myocardium, which had longer duration of action potential than that in control mice, the negative inotropic response induced by phenylephrine was smaller than that in control mice. 4-Aminopyridine prolonged the action potential duration and decreased the negative inotropy in control mice. Cromakalim shortened the action potential duration and increased the negative inotropy in streptozotocin-treated mice. These results suggest that the reduced α-adrenoceptor-mediated inotropy in the diabetic mouse myocardium is partly due to its prolonged action potential. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Determination of cable parameters in skeletal muscle fibres during repetitive firing of action potentials.

PubMed

Riisager, Anders; Duehmke, Rudy; Nielsen, Ole Bækgaard; Huang, Christopher L; Pedersen, Thomas Holm

2014-10-15

Recent studies in rat muscle fibres show that repetitive firing of action potentials causes changes in fibre resting membrane conductance (Gm) that reflect regulation of ClC-1 Cl(-) and KATP K(+) ion channels. Methodologically, these findings were obtained by inserting two microelectrodes at close proximity in the same fibres enabling measurements of fibre input resistance (Rin) in between action potential trains. Since the fibre length constant (λ) could not be determined, however, the calculation of Gm relied on the assumptions that the specific cytosolic resistivity (Ri) and muscle fibre volume remained constant during the repeated action potential firing. Here we present a three-microelectrode technique that enables determinations of multiple cable parameters in action potential-firing fibres including Rin and λ as well as waveform and conduction velocities of fully propagating action potentials. It is shown that in both rat and mouse extensor digitorum longus (EDL) fibres, action potential firing leads to substantial changes in both muscle fibre volume and Ri. The analysis also showed, however, that regardless of these changes, rat and mouse EDL fibres both exhibited initial decreases in Gm that were eventually followed by a ∼3-fold, fully reversible increase in Gm after the firing of 1450-1800 action potentials. Using this three-electrode method we further show that the latter rise in Gm was closely associated with excitation failures and loss of action potential signal above -20 mV. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

Determination of cable parameters in skeletal muscle fibres during repetitive firing of action potentials

PubMed Central

Riisager, Anders; Duehmke, Rudy; Nielsen, Ole Bækgaard; Huang, Christopher L; Pedersen, Thomas Holm

2014-01-01

Recent studies in rat muscle fibres show that repetitive firing of action potentials causes changes in fibre resting membrane conductance (Gm) that reflect regulation of ClC-1 Cl− and KATP K+ ion channels. Methodologically, these findings were obtained by inserting two microelectrodes at close proximity in the same fibres enabling measurements of fibre input resistance (Rin) in between action potential trains. Since the fibre length constant (λ) could not be determined, however, the calculation of Gm relied on the assumptions that the specific cytosolic resistivity (Ri) and muscle fibre volume remained constant during the repeated action potential firing. Here we present a three-microelectrode technique that enables determinations of multiple cable parameters in action potential-firing fibres including Rin and λ as well as waveform and conduction velocities of fully propagating action potentials. It is shown that in both rat and mouse extensor digitorum longus (EDL) fibres, action potential firing leads to substantial changes in both muscle fibre volume and Ri. The analysis also showed, however, that regardless of these changes, rat and mouse EDL fibres both exhibited initial decreases in Gm that were eventually followed by a ∼3-fold, fully reversible increase in Gm after the firing of 1450–1800 action potentials. Using this three-electrode method we further show that the latter rise in Gm was closely associated with excitation failures and loss of action potential signal above −20 mV. PMID:25128573

Action adaptation during natural unfolding social scenes influences action recognition and inferences made about actor beliefs.

PubMed

Keefe, Bruce D; Wincenciak, Joanna; Jellema, Tjeerd; Ward, James W; Barraclough, Nick E

2016-07-01

When observing another individual's actions, we can both recognize their actions and infer their beliefs concerning the physical and social environment. The extent to which visual adaptation influences action recognition and conceptually later stages of processing involved in deriving the belief state of the actor remains unknown. To explore this we used virtual reality (life-size photorealistic actors presented in stereoscopic three dimensions) to see how visual adaptation influences the perception of individuals in naturally unfolding social scenes at increasingly higher levels of action understanding. We presented scenes in which one actor picked up boxes (of varying number and weight), after which a second actor picked up a single box. Adaptation to the first actor's behavior systematically changed perception of the second actor. Aftereffects increased with the duration of the first actor's behavior, declined exponentially over time, and were independent of view direction. Inferences about the second actor's expectation of box weight were also distorted by adaptation to the first actor. Distortions in action recognition and actor expectations did not, however, extend across different actions, indicating that adaptation is not acting at an action-independent abstract level but rather at an action-dependent level. We conclude that although adaptation influences more complex inferences about belief states of individuals, this is likely to be a result of adaptation at an earlier action recognition stage rather than adaptation operating at a higher, more abstract level in mentalizing or simulation systems.

Synaptic depolarization is more effective than back-propagating action potentials during induction of associative long-term potentiation in hippocampal pyramidal neurons.

PubMed

Hardie, Jason; Spruston, Nelson

2009-03-11

Long-term potentiation (LTP) requires postsynaptic depolarization that can result from EPSPs paired with action potentials or larger EPSPs that trigger dendritic spikes. We explored the relative contribution of these sources of depolarization to LTP induction during synaptically driven action potential firing in hippocampal CA1 pyramidal neurons. Pairing of a weak test input with a strong input resulted in large LTP (approximately 75% increase) when the weak and strong inputs were both located in the apical dendrites. This form of LTP did not require somatic action potentials. When the strong input was located in the basal dendrites, the resulting LTP was smaller (< or =25% increase). Pairing the test input with somatically evoked action potentials mimicked this form of LTP. Thus, back-propagating action potentials may contribute to modest LTP, but local synaptic depolarization and/or dendritic spikes mediate a stronger form of LTP that requires spatial proximity of the associated synaptic inputs.

New insights into the acute actions from a high dosage of fluoxetine on neuronal and cardiac function: Drosophila, crayfish and rodent models.

PubMed

Majeed, Zana R; Ritter, Kyle; Robinson, Jonathan; Blümich, Sandra L E; Brailoiu, Eugen; Cooper, Robin L

2015-01-01

The commonly used mood altering drug fluoxetine (Prozac) in humans has a low occurrence in reports of harmful effects from overdose; however, individuals with altered metabolism of the drug and accidental overdose have led to critical conditions and even death. We addressed direct actions of high concentrations on synaptic transmission at neuromuscular junctions (NMJs), neural properties, and cardiac function unrelated to fluoxetine's action as a selective 5-HT reuptake inhibitor. There appears to be action in blocking action potentials in crayfish axons, enhanced occurrences of spontaneous synaptic vesicle fusion events in the presynaptic terminals at NMJs of both Drosophila and crayfish. In rodent neurons, cytoplasmic Ca(2+) rises by fluoxetine and is thapsigargin dependent. The Drosophila larval heart showed a dose dependent effect in cardiac arrest. Acute paralytic behavior in crayfish occurred at a systemic concentration of 2mM. A high percentage of death as well as slowed development occurred in Drosophila larvae consuming food containing 100μM fluoxetine. The release of Ca(2+) from the endoplasmic reticulum in neurons and the cardiac tissue as well as blockage of voltage-gated Na(+) channels in neurons could explain the effects on the whole animal as well as the isolated tissues. The use of various animal models in demonstrating the potential mechanisms for the toxic effects with high doses of fluoxetine maybe beneficial for acute treatments in humans. Future studies in determining how fluoxetine is internalized in cells and if there are subtle effects of these mentioned mechanisms presented with chronic therapeutic doses are of general interest. Copyright © 2015 Elsevier Inc. All rights reserved.

Cardiac action potential imaging

NASA Astrophysics Data System (ADS)

Tian, Qinghai; Lipp, Peter; Kaestner, Lars

2013-06-01

Action potentials in cardiac myocytes have durations in the order of magnitude of 100 milliseconds. In biomedical investigations the documentation of the occurrence of action potentials is often not sufficient, but a recording of the shape of an action potential allows a functional estimation of several molecular players. Therefore a temporal resolution of around 500 images per second is compulsory. In the past such measurements have been performed with photometric approaches limiting the measurement to one cell at a time. In contrast, imaging allows reading out several cells at a time with additional spatial information. Recent developments in camera technologies allow the acquisition with the required speed and sensitivity. We performed action potential imaging on isolated adult cardiomyocytes of guinea pigs utilizing the fluorescent membrane potential sensor di-8-ANEPPS and latest electron-multiplication CCD as well as scientific CMOS cameras of several manufacturers. Furthermore, we characterized the signal to noise ratio of action potential signals of varying sets of cameras, dye concentrations and objective lenses. We ensured that di-8-ANEPPS itself did not alter action potentials by avoiding concentrations above 5 μM. Based on these results we can conclude that imaging is a reliable method to read out action potentials. Compared to conventional current-clamp experiments, this optical approach allows a much higher throughput and due to its contact free concept leaving the cell to a much higher degree undisturbed. Action potential imaging based on isolated adult cardiomyocytes can be utilized in pharmacological cardiac safety screens bearing numerous advantages over approaches based on heterologous expression of hERG channels in cell lines.

Reduced cortico-motor facilitation in a normal sample with high traits of autism.

PubMed

Puzzo, Ignazio; Cooper, Nicholas R; Vetter, Petra; Russo, Riccardo; Fitzgerald, Paul B

2009-12-25

Recent research in social neuroscience proposes a link between mirror neuron system (MNS) and social cognition. The MNS has been proposed to be the neural mechanism underlying action recognition and intention understanding and more broadly social cognition. Pre-motor MNS has been suggested to modulate the motor cortex during action observation. This modulation results in an enhanced cortico-motor excitability reflected in increased motor evoked potentials (MEPs) at the muscle of interest during action observation. Anomalous MNS activity has been reported in the autistic population whose social skills are notably impaired. It is still an open question whether traits of autism in the normal population are linked to the MNS functioning. We measured TMS-induced MEPs in normal individuals with high and low traits of autism as measured by the autistic quotient (AQ), while observing videos of hand or mouth actions, static images of a hand or mouth or a blank screen. No differences were observed between the two while they observed a blank screen. However participants with low traits of autism showed significantly greater MEP amplitudes during observation of hand/mouth actions relative to static hand/mouth stimuli. In contrast, participants with high traits of autism did not show such a MEP amplitude difference between observation of actions and static stimuli. These results are discussed with reference to MNS functioning.

A simple model for the generation of the vestibular evoked myogenic potential (VEMP).

PubMed

Wit, Hero P; Kingma, Charlotte M

2006-06-01

To describe the mechanism by which the vestibular evoked myogenic potential is generated. Vestibular evoked myogenic potential generation is modeled by adding a large number of muscle motor unit action potentials. These action potentials occur randomly in time along a 100 ms long time axis. But because between approximately 15 and 20 ms after a loud short sound stimulus (almost) no action potentials are generated during VEMP measurements in human subjects, no action potentials are present in the model during this time. The evoked potential is the result of the lack of amplitude cancellation in the averaged surface electromyogram at the edges of this 5 ms long time interval. The relatively simple model describes generation and some properties of the vestibular evoked myogenic potential very well. It is shown that, in contrast with other evoked potentials (BAEPs, VERs), the vestibular evoked myogenic potential is the result of an interruption of activity and not that of summed synchronized neural action potentials.

The thalamic low-threshold Ca2+ potential: a key determinant of the local and global dynamics of the slow (<1 Hz) sleep oscillation in thalamocortical networks

PubMed Central

Crunelli, Vincenzo; Errington, Adam C.; Hughes, Stuart W.; Tóth, Tibor I.

2011-01-01

During non-rapid eye movement sleep and certain types of anaesthesia, neurons in the neocortex and thalamus exhibit a distinctive slow (<1 Hz) oscillation that consists of alternating UP and DOWN membrane potential states and which correlates with a pronounced slow (<1 Hz) rhythm in the electroencephalogram. While several studies have claimed that the slow oscillation is generated exclusively in neocortical networks and then transmitted to other brain areas, substantial evidence exists to suggest that the full expression of the slow oscillation in an intact thalamocortical (TC) network requires the balanced interaction of oscillator systems in both the neocortex and thalamus. Within such a scenario, we have previously argued that the powerful low-threshold Ca2+ potential (LTCP)-mediated burst of action potentials that initiates the UP states in individual TC neurons may be a vital signal for instigating UP states in related cortical areas. To investigate these issues we constructed a computational model of the TC network which encompasses the important known aspects of the slow oscillation that have been garnered from earlier in vivo and in vitro experiments. Using this model we confirm that the overall expression of the slow oscillation is intricately reliant on intact connections between the thalamus and the cortex. In particular, we demonstrate that UP state-related LTCP-mediated bursts in TC neurons are proficient in triggering synchronous UP states in cortical networks, thereby bringing about a synchronous slow oscillation in the whole network. The importance of LTCP-mediated action potential bursts in the slow oscillation is also underlined by the observation that their associated dendritic Ca2+ signals are the only ones that inform corticothalamic synapses of the TC neuron output, since they, but not those elicited by tonic action potential firing, reach the distal dendritic sites where these synapses are located. PMID:21893530

A rabbit ventricular action potential model replicating cardiac dynamics at rapid heart rates.

PubMed

Mahajan, Aman; Shiferaw, Yohannes; Sato, Daisuke; Baher, Ali; Olcese, Riccardo; Xie, Lai-Hua; Yang, Ming-Jim; Chen, Peng-Sheng; Restrepo, Juan G; Karma, Alain; Garfinkel, Alan; Qu, Zhilin; Weiss, James N

2008-01-15

Mathematical modeling of the cardiac action potential has proven to be a powerful tool for illuminating various aspects of cardiac function, including cardiac arrhythmias. However, no currently available detailed action potential model accurately reproduces the dynamics of the cardiac action potential and intracellular calcium (Ca(i)) cycling at rapid heart rates relevant to ventricular tachycardia and fibrillation. The aim of this study was to develop such a model. Using an existing rabbit ventricular action potential model, we modified the L-type calcium (Ca) current (I(Ca,L)) and Ca(i) cycling formulations based on new experimental patch-clamp data obtained in isolated rabbit ventricular myocytes, using the perforated patch configuration at 35-37 degrees C. Incorporating a minimal seven-state Markovian model of I(Ca,L) that reproduced Ca- and voltage-dependent kinetics in combination with our previously published dynamic Ca(i) cycling model, the new model replicates experimentally observed action potential duration and Ca(i) transient alternans at rapid heart rates, and accurately reproduces experimental action potential duration restitution curves obtained by either dynamic or S1S2 pacing.

Emotion-modulated startle in psychopathy: Clarifying familiar effects

PubMed Central

Baskin-Sommers, Arielle R.; Curtin, John J.; Newman, Joseph P.

2012-01-01

The behavior of psychopathic individuals is thought to reflect a core fear deficit that prevents these individuals from appreciating the consequences of their choices and actions. However, growing evidence suggests that psychopathy-related emotion deficits are moderated by attention and, thus, may not reflect a reduced capacity for emotion responding. The present study attempts to reconcile this attention perspective with one of the most cited findings in psychopathy, which reports emotion-modulated startle deficits among psychopathic individuals during picture viewing. In this study, we evaluate the potential effects of a putative attention bottleneck on the emotion processing of psychopathic offenders during picture viewing by manipulating picture familiarity and examining emotion-modulated startle and late positive potential (LPP). As predicted, psychopathic individuals displayed the classic deficit in emotion-modulated startle during novel pictures, but they showed no deficit in emotion-modulated startle during familiar pictures. Conversely, results for LPP responses revealed psychopathy-related differences during familiar pictures and no psychopathy-related differences during novel pictures. Important differences related to the two Factors of psychopathy are also discussed. Overall, the results of this study not only highlight the differential importance of perceptual load on emotion processing in psychopathy, but also raise interesting questions about the varied effects of attention on psychopathy-related emotion deficits. PMID:23356218

The Role of the Food Industry in Obesity Prevention.

PubMed

Binks, Martin

2016-06-01

Obesity is a complex disease of diverse etiology. Among the potential influences in the development of obesity, the food supply chain remains an important influence. We provide a conceptual overview related to the food industry's role in obesity prevention. We first discuss some limitations of current public health efforts. We then describe how a model that attends to personal autonomy in the context of supportive policy intervention can empower individuals in their efforts to navigate the food supply chain. We then provide an evidence informed overview of key areas where continued efforts to collaboratively engage the food industry, through solution-focused dialogue and action, have the potential to contribute to obesity prevention. While challenging, appropriately transparent, well-governed public-private partnerships have the demonstrated potential to benefit the communities we serve.

Spectral action models of gravity on packed swiss cheese cosmology

NASA Astrophysics Data System (ADS)

Ball, Adam; Marcolli, Matilde

2016-06-01

We present a model of (modified) gravity on spacetimes with fractal structure based on packing of spheres, which are (Euclidean) variants of the packed swiss cheese cosmology models. As the action functional for gravity we consider the spectral action of noncommutative geometry, and we compute its expansion on a space obtained as an Apollonian packing of three-dimensional spheres inside a four-dimensional ball. Using information from the zeta function of the Dirac operator of the spectral triple, we compute the leading terms in the asymptotic expansion of the spectral action. They consist of a zeta regularization of the divergent sum of the leading terms of the spectral actions of the individual spheres in the packing. This accounts for the contribution of points 1 and 3 in the dimension spectrum (as in the case of a 3-sphere). There is an additional term coming from the residue at the additional point in the real dimension spectrum that corresponds to the packing constant, as well as a series of fluctuations coming from log-periodic oscillations, created by the points of the dimension spectrum that are off the real line. These terms detect the fractality of the residue set of the sphere packing. We show that the presence of fractality influences the shape of the slow-roll potential for inflation, obtained from the spectral action. We also discuss the effect of truncating the fractal structure at a certain scale related to the energy scale in the spectral action.

Simulations of the cardiac action potential based on the Hodgkin-Huxley kinetics with the use of Microsoft Excel spreadsheets.

PubMed

Wu, Sheng-Nan

2004-03-31

The purpose of this study was to develop a method to simulate the cardiac action potential using a Microsoft Excel spreadsheet. The mathematical model contained voltage-gated ionic currents that were modeled using either Beeler-Reuter (B-R) or Luo-Rudy (L-R) phase 1 kinetics. The simulation protocol involves the use of in-cell formulas directly typed into a spreadsheet. The capability of spreadsheet iteration was used in these simulations. It does not require any prior knowledge of computer programming, although the use of the macro language can speed up the calculation. The normal configuration of the cardiac ventricular action potential can be well simulated in the B-R model that is defined by four individual ionic currents, each representing the diffusion of ions through channels in the membrane. The contribution of Na+ inward current to the rate of depolarization is reproduced in this model. After removal of Na+ current from the model, a constant current stimulus elicits an oscillatory change in membrane potential. In the L-R phase 1 model where six types of ionic currents were defined, the effect of extracellular K+ concentration on changes both in the time course of repolarization and in the time-independent K+ current can be demonstrated, when the solutions are implemented in Excel. Using the simulation protocols described here, the users can readily study and graphically display the underlying properties of ionic currents to see how changes in these properties determine the behavior of the heart cell. The method employed in these simulation protocols may also be extended or modified to other biological simulation programs.

Perceived Punishment and Reward Values Assigned to Supervisor Actions.

DTIC Science & Technology

1982-04-01

be viewed differently by different individuals. For example, Tornow (1971) noted that one employee might feel rewarded by an assignment to a... Tornow , 1971), many of these items reflected actions that might be viewed as affecting job demands and challenge. Factor Analyses To investigate more...individuals. While earlier research (Hackman & Lawler, 1971; Tornow , 1971) has demonstrated that individual differences in personality and need strength

Environmental Assessment and Finding of No Significant Impact: Widening Trench 36 of the 218-E-12B Low-Level Burial Ground, Hanford Site, Richland, Washington

DOE Office of Scientific and Technical Information (OSTI.GOV)

N /A

1999-02-11

This environmental assessment was prepared to assess potential environmental impacts associated with the proposed action to widen and operate unused Trench 36 in the 218-E-12B Low-Level Burial Ground for disposal of low-level waste. Information contained herein will be used by the Manager, U.S. Department of Energy, Richland Operations Office, to determine if the Proposed Action is a major federal action significantly affecting the quality of the human environment. If the Proposed Action is determined to be major and significant, an environmental impact statement will be prepared. If the Proposed Action is determined not to be major and significant, a Findingmore » of No Significant Impact will be issued and the action may proceed. Criteria used to evaluate significance can be found in Title 40, Code of Federal Regulations 1508.27. This environmental assessment was prepared in compliance with the ''National Environmental Policy Act of1969'', as amended, the Council on Environmental Quality Regulations for Implementing the Procedural Provisions of ''National Environmental Policy Act'' (Title 40, Code of Federal Regulations 1500-1508), and the U.S. Department of Energy Implementing Procedures for ''National Environmental Polio Act'' (Title 10, Code of Federal Regulations 1021). The following is a description of each section of this environmental assessment. (1) Purpose and Need for Action. This section provides a brief statement concerning the problem or opportunity the U.S, Department of Energy is addressing with the Proposed Action. Background information is provided. (2) Description of the Proposed Action. This section provides a description of the Proposed Action with sufficient detail to identify potential environmental impacts. (3) Alternatives to the Proposed Action. This section describes reasonable,alternative actions to the Proposed Action, which addresses the Purpose and Need. A No Action Alternative, as required by Title 10, Code of Federal Regulations 1021, also is described. (4) Affected Environment. This section provides a brief description of the locale in which the Proposed Action would take place. (5) Environmental Impacts. This section describes the range of environmental impacts, beneficial and adverse, of the Proposed Action. Impacts of alternatives briefly are discussed. (6) Permits and Regulatory Requirements. This section provides a brief description of permits and regulatory requirements for the Proposed Action. (7) Organizations Consulted. This section lists any outside groups, agencies, or individuals contacted as part of the environmental assessment preparation and/or review. (8) References. This section provides a list of documents used to contribute information or data in preparation of this environmental assessment.« less

Worker piping triggers hissing for coordinated colony defence in the dwarf honeybee Apis florea.

PubMed

Sen Sarma, Moushumi; Fuchs, Stefan; Werber, Christian; Tautz, Jürgen

2002-01-01

Defending a large social insect colony containing several thousands of workers requires the simultaneous action of many individuals. Ideally this action involves communication between the workers, enabling coordinated action and a fast response. The Asian dwarf honeybee, Apis florea, is a small honeybee with an open nesting habit and a comparatively small colony size, features that leave them particularly exposed to predators. We describe here a novel defence response of these bees in which the emission of an initial warning signal from one individual ("piping") is followed 0.3 to 0.7 seconds later by a general response from a large number of bees ("hissing"). Piping is audible to the human ear, with a fundamental frequency of 384 +/- 31Hz and lasting for 0.82 +/- 0.35 seconds. Hissing is a broad band, noisy signal, clearly audible to the human observer and produced by slight but visible movements of the bees' wings. Hissing begins in individuals close to the piping bee, spreads rapidly to neighbours and results in an impressive coordinated crescendo occasionally involving the entire colony. Piping and hissing are accompanied by a marked decrease, or even cessation, of worker activities such as forager dancing and departures from the colony. We show that whereas hissing of the colony can be elicited without piping, the sequential and correlated piping and hissing response is specific to the presence of potential predators close to the colony. We suggest that the combined audio-visual effect of the hissing might deter small predators, while the cessation of flight activity could decrease the risk of predation by birds and insects which prey selectively on flying bees.

Releasing Effect of Individual Potential: Formation of Productive Collective and Children's Self-Transcendence in a Chinese School.

PubMed

Wu, Aruna; Li, Xiao-Wen; Zhang, Qian

2017-09-01

We describe the intricate relations between social demand structures and their role in facilitation of individual development of children and teachers in a Chinese classroom. The relationship of an individual to the immediate social group is further qualified by the inclusion in a collective which enables the participants to transform their individual self-structures through taking on social roles in everyday collective activities, which release further potential for their individual development. We describe that releasing effect in the case of an intervention program in a Chinese school for the children of rural migrants re-settled in a city, demonstrating gradually how the inter-individual competitive orientation promoted by autocratic teaching style becomes transformed into collective good oriented joint actions towards excellence in educational endeavors (Jiti). The productive nature of the Jiti makes an ecology with multiple nested and open systems, in which every group and student is producer and consumer of each other, and personal self-transcendence is actualized in the process. The releasing effect is demonstrated through observing the co-emergence of new forms of progressive conduct and new problems, presented in pupils' positive participation in activities. The description of the intervention in a Chinese school provides us with insight on how concrete social inclusion frameworks with the underpinning Chinese philosophy of "acting up to trends" can prevent the emergence of direct animosities and lead to new integration of self and society.

The integration and interpretation of pharmacogenomics - a comparative study between the United States of America and Europe: towards better health care.

PubMed

Bartlett, Mark J; Shephard, Elizabeth A

2016-06-01

The study of pharmacogenomics has, by harnessing sequence information from human genomes, the potential to lead to novel approaches in drug discovery, an individualized application of drug therapy, and new insights into disease prevention. For this potential to be realized results need to be interpreted to the prescriber into a format which dictates an action. This mini review briefly describes the history, the regulatory environment, opinions towards, and implementation, integration and interpretation of pharmacogenomics in the United States of America and Europe. The article discusses also how interpretation of pharmacogenomics could move forward to better implementation in health care.

From Power to Inaction.

PubMed

Durso, Geoffrey R O; Briñol, Pablo; Petty, Richard E

2016-12-01

Research has shown that people who feel powerful are more likely to act than those who feel powerless, whereas people who feel ambivalent are less likely to act than those whose reactions are univalent (entirely positive or entirely negative). But what happens when powerful people also are ambivalent? On the basis of the self-validation theory of judgment, we hypothesized that power and ambivalence would interact to predict individuals' action. Because power can validate individuals' reactions, we reasoned that feeling powerful strengthens whatever reactions people have during a decision. It can strengthen univalent reactions and increase action orientation, as shown in past research. Among people who hold an ambivalent judgment, however, those who feel powerful would be less action oriented than those who feel powerless. Two experiments provide evidence for this hypothesized interactive effect of power and ambivalence on individuals' action tendencies during both positive decisions (promoting an employee; Experiment 1) and negative decisions (firing an employee; Experiment 2). In summary, when individuals' reactions are ambivalent, power increases the likelihood of inaction.

Alteration of neural action potential patterns by axonal stimulation: the importance of stimulus location

PubMed Central

Crago, Patrick E; Makowski, Nathan S

2014-01-01

Objective Stimulation of peripheral nerves is often superimposed on ongoing motor and sensory activity in the same axons, without a quantitative model of the net action potential train at the axon endpoint. Approach We develop a model of action potential patterns elicited by superimposing constant frequency axonal stimulation on the action potentials arriving from a physiologically activated neural source. The model includes interactions due to collision block, resetting of the neural impulse generator, and the refractory period of the axon at the point of stimulation. Main Results Both the mean endpoint firing rate and the probability distribution of the action potential firing periods depend strongly on the relative firing rates of the two sources and the intersite conduction time between them. When the stimulus rate exceeds the neural rate, neural action potentials do not reach the endpoint and the rate of endpoint action potentials is the same as the stimulus rate, regardless of the intersite conduction time. However, when the stimulus rate is less than the neural rate, and the intersite conduction time is short, the two rates partially sum. Increases in stimulus rate produce non-monotonic increases in endpoint rate and continuously increasing block of neurally generated action potentials. Rate summation is reduced and more neural action potentials are blocked as the intersite conduction time increases.. At long intersite conduction times, the endpoint rate simplifies to being the maximum of either the neural or the stimulus rate. Significance This study highlights the potential of increasing the endpoint action potential rate and preserving neural information transmission by low rate stimulation with short intersite conduction times. Intersite conduction times can be decreased with proximal stimulation sites for muscles and distal stimulation sites for sensory endings. The model provides a basis for optimizing experiments and designing neuroprosthetic interventions involving motor or sensory stimulation. PMID:25161163

Alteration of neural action potential patterns by axonal stimulation: the importance of stimulus location

NASA Astrophysics Data System (ADS)

Crago, Patrick E.; Makowski, Nathaniel S.

2014-10-01

Objective. Stimulation of peripheral nerves is often superimposed on ongoing motor and sensory activity in the same axons, without a quantitative model of the net action potential train at the axon endpoint. Approach. We develop a model of action potential patterns elicited by superimposing constant frequency axonal stimulation on the action potentials arriving from a physiologically activated neural source. The model includes interactions due to collision block, resetting of the neural impulse generator, and the refractory period of the axon at the point of stimulation. Main results. Both the mean endpoint firing rate and the probability distribution of the action potential firing periods depend strongly on the relative firing rates of the two sources and the intersite conduction time between them. When the stimulus rate exceeds the neural rate, neural action potentials do not reach the endpoint and the rate of endpoint action potentials is the same as the stimulus rate, regardless of the intersite conduction time. However, when the stimulus rate is less than the neural rate, and the intersite conduction time is short, the two rates partially sum. Increases in stimulus rate produce non-monotonic increases in endpoint rate and continuously increasing block of neurally generated action potentials. Rate summation is reduced and more neural action potentials are blocked as the intersite conduction time increases. At long intersite conduction times, the endpoint rate simplifies to being the maximum of either the neural or the stimulus rate. Significance. This study highlights the potential of increasing the endpoint action potential rate and preserving neural information transmission by low rate stimulation with short intersite conduction times. Intersite conduction times can be decreased with proximal stimulation sites for muscles and distal stimulation sites for sensory endings. The model provides a basis for optimizing experiments and designing neuroprosthetic interventions involving motor or sensory stimulation.

Improving Disclosure and Consent

PubMed Central

Brody, Julia Green; Morello-Frosch, Rachel; Brown, Phil; Rudel, Ruthann A.; Altman, Rebecca Gasior; Frye, Margaret; Osimo, Cheryl A.; Pérez, Carla; Seryak, Liesel M.

2007-01-01

The recent flood of research concerning pollutants in personal environmental and biological samples—blood, urine, breastmilk, household dust and air, umbilical cord blood, and other media—raises questions about whether and how to report results to individual study participants. Clinical medicine provides an expert-driven framework, whereas community-based participatory research emphasizes participants’ right to know and the potential to inform action even when health effects are uncertain. Activist efforts offer other models. We consider ethical issues involved in the decision to report individual results in exposure studies and what information should be included. Our discussion is informed by our experience with 120 women in a study of 89 pollutants in homes and by interviews with other researchers and institutional review board staff. PMID:17666695

A Framework for Public Health Action: The Health Impact Pyramid

PubMed Central

2010-01-01

A 5-tier pyramid best describes the impact of different types of public health interventions and provides a framework to improve health. At the base of this pyramid, indicating interventions with the greatest potential impact, are efforts to address socioeconomic determinants of health. In ascending order are interventions that change the context to make individuals' default decisions healthy, clinical interventions that require limited contact but confer long-term protection, ongoing direct clinical care, and health education and counseling. Interventions focusing on lower levels of the pyramid tend to be more effective because they reach broader segments of society and require less individual effort. Implementing interventions at each of the levels can achieve the maximum possible sustained public health benefit. PMID:20167880

The Relative Importance of Language in Guiding Social Preferences Through Development

PubMed Central

Esseily, Rana; Somogyi, Eszter; Guellai, Bahia

2016-01-01

In this paper, we review evidence from infants, toddlers, and preschoolers to tackle the question of how individuals orient preferences and actions toward social partners and how these preferences change over development. We aim at emphasizing the importance of language in guiding categorization relatively to other cues such as age, race and gender. We discuss the importance of language as part of a communication system that orients infants and older children’s attention toward relevant information in their environment and toward affiliated social partners who are potential sources of knowledge. We argue that other cues (visually perceptible features) are less reliable in informing individuals whether others share a common knowledge and whether they can be source of information. PMID:27812345

The Relative Importance of Language in Guiding Social Preferences Through Development.

PubMed

Esseily, Rana; Somogyi, Eszter; Guellai, Bahia

2016-01-01

In this paper, we review evidence from infants, toddlers, and preschoolers to tackle the question of how individuals orient preferences and actions toward social partners and how these preferences change over development. We aim at emphasizing the importance of language in guiding categorization relatively to other cues such as age, race and gender. We discuss the importance of language as part of a communication system that orients infants and older children's attention toward relevant information in their environment and toward affiliated social partners who are potential sources of knowledge. We argue that other cues (visually perceptible features) are less reliable in informing individuals whether others share a common knowledge and whether they can be source of information.

45 CFR 689.3 - Actions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 3 2011-10-01 2011-10-01 false Actions. 689.3 Section 689.3 Public Welfare... Actions. (a) Possible final actions listed in this paragraph (a) for guidance range from minimal... include possible criminal sanctions. (1) Group I actions. (i) Send a letter of reprimand to the individual...

45 CFR 689.3 - Actions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 3 2010-10-01 2010-10-01 false Actions. 689.3 Section 689.3 Public Welfare... Actions. (a) Possible final actions listed in this paragraph (a) for guidance range from minimal... include possible criminal sanctions. (1) Group I actions. (i) Send a letter of reprimand to the individual...

Effect of an educational game on university students' learning about action potentials.

PubMed

Luchi, Kelly Cristina Gaviao; Montrezor, Luís Henrique; Marcondes, Fernanda K

2017-06-01

The aim of this study was to evaluate the effect of an educational game that is used for teaching the mechanisms of the action potentials in cell membranes. The game was composed of pieces representing the intracellular and extracellular environments, ions, ion channels, and the Na + -K + -ATPase pump. During the game activity, the students arranged the pieces to demonstrate how the ions move through the membrane in a resting state and during an action potential, linking the ion movement with a graph of the action potential. To test the effect of the game activity on student understanding, first-year dental students were given the game to play at different times in a series of classes teaching resting membrane potential and action potentials. In all experiments, students who played the game performed better in assessments. According to 98% of the students, the game supported the learning process. The data confirm the students' perception, indicating that the educational game improved their understanding about action potentials. Copyright © 2017 the American Physiological Society.

Understanding the electrical behavior of the action potential in terms of elementary electrical sources.

PubMed

Rodriguez-Falces, Javier

2015-03-01

A concept of major importance in human electrophysiology studies is the process by which activation of an excitable cell results in a rapid rise and fall of the electrical membrane potential, the so-called action potential. Hodgkin and Huxley proposed a model to explain the ionic mechanisms underlying the formation of action potentials. However, this model is unsuitably complex for teaching purposes. In addition, the Hodgkin and Huxley approach describes the shape of the action potential only in terms of ionic currents, i.e., it is unable to explain the electrical significance of the action potential or describe the electrical field arising from this source using basic concepts of electromagnetic theory. The goal of the present report was to propose a new model to describe the electrical behaviour of the action potential in terms of elementary electrical sources (in particular, dipoles). The efficacy of this model was tested through a closed-book written exam. The proposed model increased the ability of students to appreciate the distributed character of the action potential and also to recognize that this source spreads out along the fiber as function of space. In addition, the new approach allowed students to realize that the amplitude and sign of the extracellular electrical potential arising from the action potential are determined by the spatial derivative of this intracellular source. The proposed model, which incorporates intuitive graphical representations, has improved students' understanding of the electrical potentials generated by bioelectrical sources and has heightened their interest in bioelectricity. Copyright © 2015 The American Physiological Society.

Schooling and Labor Market Effects of Temporary Authorization: Evidence from DACA

PubMed Central

Amuedo-Dorantes, Catalina

2017-01-01

This paper explores the labor market and schooling effects of the Deferred Action for Childhood Arrivals (DACA) initiative, which provides work authorization to eligible immigrants along with a temporary reprieve from deportation. The analysis relies on a difference-in-differences approach that exploits the discontinuity in program rules to compare eligible individuals to ineligible, likely undocumented immigrants before and after the program went into effect. To address potential endogeneity concerns, we focus on youths that likely met DACA’s schooling requirement when the program was announced. We find that DACA reduced the probability of school enrollment of eligible higher-educated individuals, as well as some evidence that it increased the employment likelihood of men, in particular. Together, these findings suggest that a lack of authorization may lead individuals to enroll in school when working is not a viable option. Thus, once employment restrictions are relaxed and the opportunity costs of higher-education rise, eligible individuals may reduce investments in schooling. PMID:28690364

Schooling and Labor Market Effects of Temporary Authorization: Evidence from DACA.

PubMed

Amuedo-Dorantes, Catalina; Antman, Francisca

2017-01-01

This paper explores the labor market and schooling effects of the Deferred Action for Childhood Arrivals (DACA) initiative, which provides work authorization to eligible immigrants along with a temporary reprieve from deportation. The analysis relies on a difference-in-differences approach that exploits the discontinuity in program rules to compare eligible individuals to ineligible, likely undocumented immigrants before and after the program went into effect. To address potential endogeneity concerns, we focus on youths that likely met DACA's schooling requirement when the program was announced. We find that DACA reduced the probability of school enrollment of eligible higher-educated individuals, as well as some evidence that it increased the employment likelihood of men, in particular. Together, these findings suggest that a lack of authorization may lead individuals to enroll in school when working is not a viable option. Thus, once employment restrictions are relaxed and the opportunity costs of higher-education rise, eligible individuals may reduce investments in schooling.

Enhanced visual short-term memory in action video game players.

PubMed

Blacker, Kara J; Curby, Kim M

2013-08-01

Visual short-term memory (VSTM) is critical for acquiring visual knowledge and shows marked individual variability. Previous work has illustrated a VSTM advantage among action video game players (Boot et al. Acta Psychologica 129:387-398, 2008). A growing body of literature has suggested that action video game playing can bolster visual cognitive abilities in a domain-general manner, including abilities related to visual attention and the speed of processing, providing some potential bases for this VSTM advantage. In the present study, we investigated the VSTM advantage among video game players and assessed whether enhanced processing speed can account for this advantage. Experiment 1, using simple colored stimuli, revealed that action video game players demonstrate a similar VSTM advantage over nongamers, regardless of whether they are given limited or ample time to encode items into memory. Experiment 2, using complex shapes as the stimuli to increase the processing demands of the task, replicated this VSTM advantage, irrespective of encoding duration. These findings are inconsistent with a speed-of-processing account of this advantage. An alternative, attentional account, grounded in the existing literature on the visuo-cognitive consequences of video game play, is discussed.

Integrative clinical sequencing in the management of children and young adults with refractory or relapsed cancer

PubMed Central

Mody, Rajen J.; Wu, Yi-Mi; Lonigro, Robert J.; Cao, Xuhong; Roychowdhury, Sameek; Vats, Pankaj; Frank, Kevin M.; Prensner, John R.; Asangani, Irfan; Palanisamy, Nallasivam; Dillman, Jonathan R.; Rabah, Raja M.; Kunju, Laxmi Priya; Everett, Jessica; Raymond, Victoria M.; Ning, Yu; Su, Fengyun; Wang, Rui; Stoffel, Elena M.; Innis, Jeffrey W.; Roberts, J. Scott; Robertson, Patricia L.; Yanik, Gregory; Chamdin, Aghiad; Connelly, James A.; Choi, Sung; Harris, Andrew C.; Kitko, Carrie; Rao, Rama Jasty; Levine, John E.; Castle, Valerie P.; Hutchinson, Raymond J.; Talpaz, Moshe; Robinson, Dan R.; Chinnaiyan, Arul M.

2016-01-01

Importance Cancer is caused by a diverse array of somatic and germline genomic aberrations. Advances in genomic sequencing technologies have improved the ability to detect these molecular aberrations with greater sensitivity. However, integrating them into clinical management in an individualized manner has proven challenging. Objective To evaluate the use of integrative clinical sequencing and genetic counseling in the assessment and treatment of children and young adults with cancer. Design, Settings and Participants An observational, consecutive case series (May 2012–October 2014) of 102 children and young adults (mean age, 10.6; median age, 11.5, range: 0–22 years) with relapsed, refractory, or rare cancer at a single major academic medical center. Exposures Each participant underwent integrative clinical exome (tumor and germline DNA) and transcriptome (tumor RNA) sequencing along with genetic counseling. Results were discussed in a multi-disciplinary Precision Medicine Tumor Board (PMTB) and recommendations were reported to treating physicians and families. Main Outcomes and Measures Proportion of patients with potentially actionable findings (PAF), results of clinical actions based on integrative clinical sequencing (ICS), and estimated proportion of patients or their families at risk for future cancer. PAF was defined as any genomic findings discovered during sequencing analysis that could lead to a 1) change in patient management by providing a targetable molecular aberration, 2) change in diagnosis or risk stratification or 3) provides cancer-related germline findings, which inform patients/families about a potential future risk of various cancers; Results We screened 104 patients and enrolled 102 patients of which 91 (89%) had adequate tumor tissue available to complete sequencing and only these patients were included in all subsequent calculations, including 28 (31%) with hematological malignancies and 63 (69%) with solid tumors. Overall, 42 (46%) patients had PAFs which changed patient management including, 54% (15/28) with hematological malignancies and 43% (27/63) with solid tumors. Overall, individualized actions were taken in 23 of the 91 (25%) patients and families based on actionable ICS findings, including change in treatment in 14 (15%) and genetic counseling for future cancer risk in 9 (10%) patients. 9/91 (10%) of these personalized clinical interventions resulted in ongoing partial clinical remission of 8–16 months duration or help sustain complete clinical remission of 6–21 months duration. All 9 (10%) patients and families with actionable incidental genetic findings agreed to formal genetic counseling and screening. Conclusions and Relevance In this single center case series of children and young adults with relapsed or refractory cancer, incorporation of data from integrative clinical sequencing into clinical management was feasible, revealed potentially actionable findings in 46% of patients, and was associated with change in treatment and family genetic counseling in a small proportion of patients. The lack of a control group limited our ability to judge whether better clinical outcomes were achieved compared to standard care. PMID:26325560

Selective activation of heteromeric SK channels contributes to action potential repolarization in mouse atrial myocytes.

PubMed

Hancock, Jane M; Weatherall, Kate L; Choisy, Stéphanie C; James, Andrew F; Hancox, Jules C; Marrion, Neil V

2015-05-01

Activation of small conductance calcium-activated potassium (SK) channels is proposed to contribute to repolarization of the action potential in atrial myocytes. This role is controversial, as these cardiac SK channels appear to exhibit an uncharacteristic pharmacology. The objectives of this study were to resolve whether activation of SK channels contributes to atrial action potential repolarization and to determine the likely subunit composition of the channel. The effect of 2 SK channel inhibitors was assessed on outward current evoked in voltage clamp and on action potential duration in perforated patch and whole-cell current clamp recording from acutely isolated mouse atrial myocytes. The presence of SK channel subunits was assessed using immunocytochemistry. A significant component of outward current was reduced by the SK channel blockers apamin and UCL1684. Block by apamin displayed a sensitivity indicating that this current was carried by homomeric SK2 channels. Action potential duration was significantly prolonged by UCL1684, but not by apamin. This effect was accompanied by an increase in beat-to-beat variability and action potential triangulation. This pharmacology was matched by that of expressed heteromeric SK2-SK3 channels in HEK293 cells. Immunocytochemistry showed that atrial myocytes express both SK2 and SK3 channels with an overlapping expression pattern. Only proposed heteromeric SK2-SK3 channels are physiologically activated to contribute to action potential repolarization, which is indicated by the difference in pharmacology of evoked outward current and prolongation of atrial action potential duration. The effect of blocking this channel on the action potential suggests that SK channel inhibition during cardiac function has the potential to be proarrhythmic. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Urocortin2 prolongs action potential duration and modulates potassium currents in guinea pig myocytes and HEK293 cells.

PubMed

Yang, Li-Zhen; Zhu, Yi-Chun

2015-07-05

We previously reported that activation of corticotropin releasing factor receptor type 2 by urocortin2 up-regulates both L-type Ca(2+) channels and intracellular Ca(2+) concentration in ventricular myocytes and plays an important role in cardiac contractility and arrhythmogenesis. This study goal was to further test the hypothesis that urocortin2 may modulate action potentials as well as rapidly and slowly activating delayed rectifier potassium currents. With whole cell patch-clamp techniques, action potentials and slowly activating delayed rectifier potassium currents were recorded in isolated guinea pig ventricular myocytes, respectively. And rapidly activating delayed rectifier potassium currents were tested in hERG-HEK293 cells. Urocortin2 produced a time- and concentration-dependent prolongation of action potential duration. The EC50 values of action potential duration and action potential duration at 90% of repolarization were 14.73 and 24.3nM respectively. The prolongation of action potential duration of urocortin2 was almost completely or partly abolished by H-89 (protein kinase A inhibitor) or KB-R7943 (Na(+)/Ca(2+) exchange inhibitor) pretreatment respectively. And urocortin2 caused reduction of rapidly activating delayed rectifier potassium currents in hERG-HEK293 cells. In addition, urocortin2 slowed the rate of slowly activating delayed rectifier potassium channel activation, and rightward shifted the threshold of slowly activating delayed rectifier potassium currents to more positive potentials. Urocortin2 prolonged action potential duration via activation of protein kinase A and Na(+)/ Ca(2+) exchange in isolated guinea pig ventricular myocytes in a time- and concentration- dependent manner. In hERG-HEK293 cells, urocortin2 reduced rapidly activating delayed rectifier potassium current density which may contribute to action potential duration prolongation. Copyright © 2015 Elsevier B.V. All rights reserved.

Population of computational rabbit-specific ventricular action potential models for investigating sources of variability in cellular repolarisation.

PubMed

Gemmell, Philip; Burrage, Kevin; Rodriguez, Blanca; Quinn, T Alexander

2014-01-01

Variability is observed at all levels of cardiac electrophysiology. Yet, the underlying causes and importance of this variability are generally unknown, and difficult to investigate with current experimental techniques. The aim of the present study was to generate populations of computational ventricular action potential models that reproduce experimentally observed intercellular variability of repolarisation (represented by action potential duration) and to identify its potential causes. A systematic exploration of the effects of simultaneously varying the magnitude of six transmembrane current conductances (transient outward, rapid and slow delayed rectifier K(+), inward rectifying K(+), L-type Ca(2+), and Na(+)/K(+) pump currents) in two rabbit-specific ventricular action potential models (Shannon et al. and Mahajan et al.) at multiple cycle lengths (400, 600, 1,000 ms) was performed. This was accomplished with distributed computing software specialised for multi-dimensional parameter sweeps and grid execution. An initial population of 15,625 parameter sets was generated for both models at each cycle length. Action potential durations of these populations were compared to experimentally derived ranges for rabbit ventricular myocytes. 1,352 parameter sets for the Shannon model and 779 parameter sets for the Mahajan model yielded action potential duration within the experimental range, demonstrating that a wide array of ionic conductance values can be used to simulate a physiological rabbit ventricular action potential. Furthermore, by using clutter-based dimension reordering, a technique that allows visualisation of multi-dimensional spaces in two dimensions, the interaction of current conductances and their relative importance to the ventricular action potential at different cycle lengths were revealed. Overall, this work represents an important step towards a better understanding of the role that variability in current conductances may play in experimentally observed intercellular variability of rabbit ventricular action potential repolarisation.

Population of Computational Rabbit-Specific Ventricular Action Potential Models for Investigating Sources of Variability in Cellular Repolarisation

PubMed Central

Gemmell, Philip; Burrage, Kevin; Rodriguez, Blanca; Quinn, T. Alexander

2014-01-01

Variability is observed at all levels of cardiac electrophysiology. Yet, the underlying causes and importance of this variability are generally unknown, and difficult to investigate with current experimental techniques. The aim of the present study was to generate populations of computational ventricular action potential models that reproduce experimentally observed intercellular variability of repolarisation (represented by action potential duration) and to identify its potential causes. A systematic exploration of the effects of simultaneously varying the magnitude of six transmembrane current conductances (transient outward, rapid and slow delayed rectifier K+, inward rectifying K+, L-type Ca2+, and Na+/K+ pump currents) in two rabbit-specific ventricular action potential models (Shannon et al. and Mahajan et al.) at multiple cycle lengths (400, 600, 1,000 ms) was performed. This was accomplished with distributed computing software specialised for multi-dimensional parameter sweeps and grid execution. An initial population of 15,625 parameter sets was generated for both models at each cycle length. Action potential durations of these populations were compared to experimentally derived ranges for rabbit ventricular myocytes. 1,352 parameter sets for the Shannon model and 779 parameter sets for the Mahajan model yielded action potential duration within the experimental range, demonstrating that a wide array of ionic conductance values can be used to simulate a physiological rabbit ventricular action potential. Furthermore, by using clutter-based dimension reordering, a technique that allows visualisation of multi-dimensional spaces in two dimensions, the interaction of current conductances and their relative importance to the ventricular action potential at different cycle lengths were revealed. Overall, this work represents an important step towards a better understanding of the role that variability in current conductances may play in experimentally observed intercellular variability of rabbit ventricular action potential repolarisation. PMID:24587229

Unsustainable human-induced injuries to the Critically Endangered Taiwanese humpback dolphins (Sousa chinensis taiwanensis).

PubMed

Wang, John Y; Riehl, Kimberly N; Yang, Shih Chu; Araújo-Wang, Claryana

2017-03-15

The Critically Endangered Taiwanese humpback dolphin (Sousa chinensis taiwanensis) is endemic to inshore and estuarine waters of central western Taiwan. It numbers fewer than 75 individuals, is declining and faces a myriad of human threats. Data from a long-term photo-identification program on these dolphins allowed major injuries to be examined quantitatively. A large proportion (57.7%) of individuals had suffered major human-induced injuries that likely compromised their health, survivorship or reproductive potential and thus, the future of this subspecies. Considering major injuries as "takes", the injury rate (1.13 dolphins/year) for the population was 8-8.5 times higher than its Potential Biological Removal rate. Observations of new injuries and fishing gear entanglements on several dolphins showed that fisheries continue to be the predominant cause of these major injuries. Unless immediate action is taken to reduce harmful fisheries, extinction is imminent for Taiwan's only endemic dolphin. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mapping the Social World of Classrooms: A Multi-Level, Multi-Reporter Approach to Social Processes and Behavioral Engagement.

PubMed

Kim, Ha Yeon; Cappella, Elise

2016-03-01

Understanding the social context of classrooms has been a central goal of research focused on the promotion of academic development. Building on the current literature on classroom social settings and guided by a risk and protection framework, this study examines the unique and combined contribution of individual relationships and quality of classroom interactions on behavioral engagement among low-income Latino students in kindergarten to fifth grade (N = 111). Findings indicate that individual relationships with teachers and peers and classroom quality, each independently predicted behavioral engagement. Moreover, high-quality classrooms buffered the negative influence of students' difficulties in individual relationships on behavioral engagement. Findings illuminate the need to consider multiple layers of social classroom relationships and interactions and suggest the potential benefit of targeting classroom quality as a mechanism for improving behavioral engagement in urban elementary schools. © Society for Community Research and Action 2016.

The effect of genetic test-based risk information on behavioral outcomes: A critical examination of failed trials and a call to action.

PubMed

Austin, Jehannine

2015-12-01

Encouraging individuals at risk for common complex disease like heart disease, cancer, and diabetes to adopt lifestyle changes (e.g., smoking cessation, exercise, proper nutrition, increased screening) could be powerful public health tools to decrease the enormous personal and economic burden of these conditions. Theoretically, genetic risk information appears to be a compelling tool that could be used to provoke at-risk individuals to adopt these lifestyle changes. Unfortunately, however, numerous studies now have shown that providing individuals with genetic test-based risk information has little to no impact on their behavior. In this article (a commentary not a systematic review), the failed trials in which genetic information has been used as a tool to induce behavior change will be critically examined in order to identify new and potentially more effective ways forward. © 2015 Wiley Periodicals, Inc.

Development and Validation of the Transgender Inclusive Behavior Scale (TIBS).

PubMed

Kattari, Shanna K; O'Connor, Ashley A; Kattari, Leonardo

2018-01-01

Transgender-inclusive behaviors are actions and communication supporting transgender individuals. Examples include using language not reinforcing the gender binary, asking for and using correct pronouns, creation of spaces that welcome members of the transgender community, and acknowledging cisgender (non-transgender) privilege. A survey was developed measuring this behavior in individuals to examine the impact of transgender-inclusive behavior and the potential effect of interventions on promoting inclusive behavior. Data were collected utilizing an online survey (N = 1,051). The sample was split in half to run two sets of cases in a principal components analysis. Analysis of the full sample showed Cronbach's alpha to be .93 (n = 918). Findings suggest that the Transgender Inclusive Behavior Scale (TIBS) may be a useful instrument for identifying behaviors related to being inclusive of transgender individuals, groups, and communities. It may also be used to measure behavior change before and after transgender-specific educational and behavioral interventions.

Intention Seekers: Conspiracist Ideation and Biased Attributions of Intentionality

PubMed Central

2015-01-01

Conspiracist beliefs are widespread and potentially hazardous. A growing body of research suggests that cognitive biases may play a role in endorsement of conspiracy theories. The current research examines the novel hypothesis that individuals who are biased towards inferring intentional explanations for ambiguous actions are more likely to endorse conspiracy theories, which portray events as the exclusive product of intentional agency. Study 1 replicated a previously observed relationship between conspiracist ideation and individual differences in anthropomorphisation. Studies 2 and 3 report a relationship between conspiracism and inferences of intentionality for imagined ambiguous events. Additionally, Study 3 again found conspiracist ideation to be predicted by individual differences in anthropomorphism. Contrary to expectations, however, the relationship was not mediated by the intentionality bias. The findings are discussed in terms of a domain-general intentionality bias making conspiracy theories appear particularly plausible. Alternative explanations are suggested for the association between conspiracism and anthropomorphism. PMID:25970175

A Case for Pharmacogenomics in Management of Cardiac Arrhythmias

PubMed Central

Kandoi, Gaurav; Nanda, Anjali; Scaria, Vinod; Sivasubbu, Sridhar

2012-01-01

Disorders of the cardiac rhythm are quite prevalent in clinical practice. Though the variability in drug response between individuals has been extensively studied, this information has not been widely used in clinical practice. Rapid advances in the field of pharmacogenomics have provided us with crucial insights on inter-individual genetic variability and its impact on drug metabolism and action. Technologies for faster and cheaper genetic testing and even personal genome sequencing would enable clinicians to optimize prescription based on the genetic makeup of the individual, which would open up new avenues in the area of personalized medicine. We have systematically looked at literature evidence on pharmacogenomics markers for anti-arrhythmic agents from the OpenPGx consortium collection and reason the applicability of genetics in the management of arrhythmia. We also discuss potential issues that need to be resolved before personalized pharmacogenomics becomes a reality in regular clinical practice. PMID:22557843

Action potential propagation: ion current or intramembrane electric field?

PubMed

Martí, Albert; Pérez, Juan J; Madrenas, Jordi

2018-01-01

The established action potential propagation mechanisms do not satisfactorily explain propagation on myelinated axons given the current knowledge of biological channels and membranes. The flow across ion channels presents two possible effects: the electric potential variations across the lipid bilayers (action potential) and the propagation of an electric field through the membrane inner part. The proposed mechanism is based on intra-membrane electric field propagation, this propagation can explain the action potential saltatory propagation and its constant delay independent of distance between Ranvier nodes in myelinated axons.

Antidromic propagation of action potentials in branched axons: implications for the mechanisms of action of deep brain stimulation.

PubMed

Grill, Warren M; Cantrell, Meredith B; Robertson, Matthew S

2008-02-01

Electrical stimulation of the central nervous system creates both orthodromically propagating action potentials, by stimulation of local cells and passing axons, and antidromically propagating action potentials, by stimulation of presynaptic axons and terminals. Our aim was to understand how antidromic action potentials navigate through complex arborizations, such as those of thalamic and basal ganglia afferents-sites of electrical activation during deep brain stimulation. We developed computational models to study the propagation of antidromic action potentials past the bifurcation in branched axons. In both unmyelinated and myelinated branched axons, when the diameters of each axon branch remained under a specific threshold (set by the antidromic geometric ratio), antidromic propagation occurred robustly; action potentials traveled both antidromically into the primary segment as well as "re-orthodromically" into the terminal secondary segment. Propagation occurred across a broad range of stimulation frequencies, axon segment geometries, and concentrations of extracellular potassium, but was strongly dependent on the geometry of the node of Ranvier at the axonal bifurcation. Thus, antidromic activation of axon terminals can, through axon collaterals, lead to widespread activation or inhibition of targets remote from the site of stimulation. These effects should be included when interpreting the results of functional imaging or evoked potential studies on the mechanisms of action of DBS.

Rutin hydrate ameliorates cadmium chloride-induced spatial memory loss and neural apoptosis in rats by enhancing levels of acetylcholine, inhibiting JNK and ERK1/2 activation and activating mTOR signalling.

PubMed

Abdel-Aleem, Ghada A; Khaleel, Eman F

2017-12-07

This study aimed at studying the potential neuroprotective effect of Rutin hydrate (RH) alone or in conjugation with α-tocopherol against cadmium chloride (CdCl 2 )-induced neurotoxicity and cognitive impairment in rats and to investigate the mechanisms of action. Rats intoxicated with CdCl 2 were treated with the vehicle, RH, α-tocopherol or combined treatment were examined, and compared to control rats received vehicle or individual doses of either drug. Data confirmed that RH improves spatial memory function by increasing acetylcholine availability, boosting endogenous antioxidant potential, activating cell survival and inhibiting apoptotic pathways, an effect that is more effective when RH was conjugated with α-tocopherol. Mechanism of RH action includes activation of PP2A mediated inhibiting of ERK1/2 and JNK apoptotic pathways and inhibition of PTEN mediated activation of mTOR survival pathway. In conclusion, RH affords a potent neuroprotection against CdCl 2 -induced brain damage and memory dysfunction and co-administration of α-tocopherol enhances its activity.

Motor control by precisely timed spike patterns

PubMed Central

Srivastava, Kyle H.; Holmes, Caroline M.; Vellema, Michiel; Pack, Andrea R.; Elemans, Coen P. H.; Nemenman, Ilya; Sober, Samuel J.

2017-01-01

A fundamental problem in neuroscience is understanding how sequences of action potentials (“spikes”) encode information about sensory signals and motor outputs. Although traditional theories assume that this information is conveyed by the total number of spikes fired within a specified time interval (spike rate), recent studies have shown that additional information is carried by the millisecond-scale timing patterns of action potentials (spike timing). However, it is unknown whether or how subtle differences in spike timing drive differences in perception or behavior, leaving it unclear whether the information in spike timing actually plays a role in brain function. By examining the activity of individual motor units (the muscle fibers innervated by a single motor neuron) and manipulating patterns of activation of these neurons, we provide both correlative and causal evidence that the nervous system uses millisecond-scale variations in the timing of spikes within multispike patterns to control a vertebrate behavior—namely, respiration in the Bengalese finch, a songbird. These findings suggest that a fundamental assumption of current theories of motor coding requires revision. PMID:28100491

The Right Network for the Right Problem

ERIC Educational Resources Information Center

Gomez, Louis M.; Russell, Jennifer L.; Bryk, Anthony S.; LeMahieu, Paul G.; Mejia, Eva M.

2016-01-01

Educators are realizing that individuals working in isolation can't adequately address the teaching and learning problems that face us today. Collective action networks are needed. Sharing networks use collective energy to support individual action and agency, whereas execution networks typically address complex problems that require sustained…

Minocycline inhibits D-amphetamine-elicited action potential bursts in a central snail neuron.

PubMed

Chen, Y-H; Lin, P-L; Wong, R-W; Wu, Y-T; Hsu, H-Y; Tsai, M-C; Lin, M-J; Hsu, Y-C; Lin, C-H

2012-10-25

Minocycline is a second-generation tetracycline that has been reported to have powerful neuroprotective properties. In our previous studies, we found that d-amphetamine (AMPH) elicited action potential bursts in an identifiable RP4 neuron of the African snail, Achatina fulica Ferussac. This study sought to determine the effects of minocycline on the AMPH-elicited action potential pattern changes in the central snail neuron, using the two-electrode voltage clamping method. Extracellular application of AMPH at 300 μM elicited action potential bursts in the RP4 neuron. Minocycline dose-dependently (300-900 μM) inhibited the action potential bursts elicited by AMPH. The inhibitory effects of minocycline on AMPH-elicited action potential bursts were restored by forskolin (50 μM), an adenylate cyclase activator, and by dibutyryl cAMP (N(6),2'-O-Dibutyryladenosine 3',5'-cyclic monophosphate; 1mM), a membrane-permeable cAMP analog. Co-administration of forskolin (50 μM) plus tetraethylammonium chloride (TEA; 5mM) or co-administration of TEA (5mM) plus dibutyryl cAMP (1mM) also elicited action potential bursts, which were prevented and inhibited by minocycline. In addition, minocycline prevented and inhibited forskolin (100 μM)-elicited action potential bursts. Notably, TEA (50mM)-elicited action potential bursts in the RP4 neuron were not affected by minocycline. Minocycline did not affect steady-state outward currents of the RP4 neuron. However, minocycline did decrease the AMPH-elicited steady-state current changes. Similarly, minocycline decreased the effects of forskolin-elicited steady-state current changes. Pretreatment with H89 (N-[2-(p-Bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide dihydrochloride; 10 μM), a protein kinase A inhibitor, inhibited AMPH-elicited action potential bursts and decreased AMPH-elicited steady-state current changes. These results suggest that the cAMP-protein kinase A signaling pathway and the steady-state current are involved in the inhibitory effects of minocycline upon AMPH-elicited action potential bursts. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

The functional role of the parieto-frontal mirror circuit: interpretations and misinterpretations.

PubMed

Rizzolatti, Giacomo; Sinigaglia, Corrado

2010-04-01

The parieto-frontal cortical circuit that is active during action observation is the circuit with mirror properties that has been most extensively studied. Yet, there remains controversy on its role in social cognition and its contribution to understanding the actions and intentions of other individuals. Recent studies in monkeys and humans have shed light on what the parieto-frontal cortical circuit encodes and its possible functional relevance for cognition. We conclude that, although there are several mechanisms through which one can understand the behaviour of other individuals, the parieto-frontal mechanism is the only one that allows an individual to understand the action of others 'from the inside' and gives the observer a first-person grasp of the motor goals and intentions of other individuals.

Action perception in individuals with congenital blindness or deafness: how does the loss of a sensory modality from birth affect perception-induced motor facilitation?

PubMed

Alaerts, Kaat; Swinnen, Stephan P; Wenderoth, Nicole

2011-05-01

Seeing or hearing manual actions activates the mirror neuron system, that is, specialized neurons within motor areas which fire when an action is performed but also when it is passively perceived. Using TMS, it was shown that motor cortex of typically developed subjects becomes facilitated not only from seeing others' actions, but also from merely hearing action-related sounds. In the present study, TMS was used for the first time to explore the "auditory" and "visual" responsiveness of motor cortex in individuals with congenital blindness or deafness. TMS was applied over left primary motor cortex (M1) to measure cortico-motor facilitation while subjects passively perceived manual actions (either visually or aurally). Although largely unexpected, congenitally blind or deaf subjects displayed substantially lower resonant motor facilitation upon action perception compared to seeing/hearing control subjects. Moreover, muscle-specific changes in cortico-motor excitability within M1 appeared to be absent in individuals with profound blindness or deafness. Overall, these findings strongly argue against the hypothesis that an increased reliance on the remaining sensory modality in blind or deaf subjects is accompanied by an increased responsiveness of the "auditory" or "visual" perceptual-motor "mirror" system, respectively. Moreover, the apparent lack of resonant motor facilitation for the blind and deaf subjects may challenge the hypothesis of a unitary mirror system underlying human action recognition and may suggest that action perception in blind and deaf subjects engages a mode of action processing that is different from the human action recognition system recruited in typically developed subjects.

Concern and Helplessness: Citizens' Assessments of Individual and Collective Action on the Provision of Environmental Public Goods in a Coastal City at Risk of Inundation.

PubMed

Bunyan, Sabrina; Collins, Alan; Duffy, David

2016-09-01

Survey data from a representative sample of 1005 households in the UK coastal city of Portsmouth are examined to discern commonalities and contrasts in their assessment of actions to address the related environmental threats of climate change and flooding. The city of Portsmouth is at risk of inundation from rising sea levels and the city has recent experience of flooding. A simple local and global public good framework is used to organize the understanding of reported attitudes and their determinants. The findings show that it is not always the same individuals who express concern about both climate change and flooding. Investigation into perceptions of helplessness in tackling climate change indicates that individuals more often perceived themselves to be helpless in tackling climate but perceived local collective action to be more effective. Individuals considered local collective action to be more effective in tackling climate change. Perceptions of individual helplessness are in turn related to reported concern. Several socioeconomic characteristics of individuals are shown to be useful in explaining the determinants of concern and perceptions of helplessness among respondents. As other cities face climate change-related challenges, the empirical findings, based upon attitudes from an alert urban population, are informative to policy design.

Concern and Helplessness: Citizens' Assessments of Individual and Collective Action on the Provision of Environmental Public Goods in a Coastal City at Risk of Inundation

NASA Astrophysics Data System (ADS)

Bunyan, Sabrina; Collins, Alan; Duffy, David

2016-09-01

Survey data from a representative sample of 1005 households in the UK coastal city of Portsmouth are examined to discern commonalities and contrasts in their assessment of actions to address the related environmental threats of climate change and flooding. The city of Portsmouth is at risk of inundation from rising sea levels and the city has recent experience of flooding. A simple local and global public good framework is used to organize the understanding of reported attitudes and their determinants. The findings show that it is not always the same individuals who express concern about both climate change and flooding. Investigation into perceptions of helplessness in tackling climate change indicates that individuals more often perceived themselves to be helpless in tackling climate but perceived local collective action to be more effective. Individuals considered local collective action to be more effective in tackling climate change. Perceptions of individual helplessness are in turn related to reported concern. Several socioeconomic characteristics of individuals are shown to be useful in explaining the determinants of concern and perceptions of helplessness among respondents. As other cities face climate change-related challenges, the empirical findings, based upon attitudes from an alert urban population, are informative to policy design.

Selective effects of an octopus toxin on action potentials

PubMed Central

Dulhunty, Angela; Gage, Peter W.

1971-01-01

1. A lethal, water soluble toxin (Maculotoxin, MTX) with a molecular weight less than 540, can be extracted from the salivary glands of an octopus (Hapalochlaena maculosa). 2. MTX blocks action potentials in sartorius muscle fibres of toads without affecting the membrane potential. Delayed rectification is not inhibited by the toxin. 3. At low concentrations (10-6-10-5 g/ml.) MTX blocks action potentials only after a certain number have been elicited. The number of action potentials, which can be defined accurately, depends on the concentration of MTX and the concentration of sodium ions in the extracellular solution. 4. The toxin has no post-synaptic effect at the neuromuscular junction and it is concluded that it blocks neuromuscular transmission by inhibiting action potentials in motor nerve terminals. PMID:4330930

Unbroken mirror neurons in autism spectrum disorders.

PubMed

Fan, Yang-Teng; Decety, Jean; Yang, Chia-Yen; Liu, Ji-Lin; Cheng, Yawei

2010-09-01

The 'broken mirror' theory of autism, which proposes that a dysfunction of the human mirror neuron system (MNS) is responsible for the core social and cognitive deficits in individuals with autism spectrum disorders (ASD), has received considerable attention despite weak empirical evidence. In this electroencephalographic study, we examined mu suppression, as an indicator of sensorimotor resonance, concurrent with oculomotor performance while individuals (n = 20) with ASD and control participants (n = 20) either executed hand actions or observed hand actions or a moving dot. No difference in visual attention between groups was found as indicated by fixation duration and normalized fixation number on the presented stimuli. The mu suppression over the sensorimotor cortex was significantly affected by experimental conditions, but not by group membership, nor by the interaction between groups and conditions. Individuals with ASD, similar to the controls, exhibited stronger mu suppression when watching hand actions relative to a moving dot. Notably, participants with ASD failed to imitate the observed actions while their mu suppression indicating the MNS activity was intact. In addition, the mu suppression during the observation of hand actions was positively associated with the communication competence of individuals with ASD. Our study clearly challenges the broken mirror theory of autism. The functioning of the mirror neuron system might be preserved in individuals with ASD to a certain degree. Less mu suppression to action observation coupled with more communicational severity can reflect the symptom heterogeneity of ASD. Additional research needs to be done, and more caution should be used when reaching out to the media.

Automatic classification of visual evoked potentials based on wavelet decomposition

NASA Astrophysics Data System (ADS)

Stasiakiewicz, Paweł; Dobrowolski, Andrzej P.; Tomczykiewicz, Kazimierz

2017-04-01

Diagnosis of part of the visual system, that is responsible for conducting compound action potential, is generally based on visual evoked potentials generated as a result of stimulation of the eye by external light source. The condition of patient's visual path is assessed by set of parameters that describe the time domain characteristic extremes called waves. The decision process is compound therefore diagnosis significantly depends on experience of a doctor. The authors developed a procedure - based on wavelet decomposition and linear discriminant analysis - that ensures automatic classification of visual evoked potentials. The algorithm enables to assign individual case to normal or pathological class. The proposed classifier has a 96,4% sensitivity at 10,4% probability of false alarm in a group of 220 cases and area under curve ROC equals to 0,96 which, from the medical point of view, is a very good result.

Neurons as sensors: individual and cascaded chemical sensing.

PubMed

Prasad, Shalini; Zhang, Xuan; Yang, Mo; Ozkan, Cengiz S; Ozkan, Mihrimah

2004-07-15

A single neuron sensor has been developed based on the interaction of gradient electric fields and the cell membrane. Single neurons are rapidly positioned over individual microelectrodes using positive dielectrophoretic traps. This enables the continuous extracellular electrophysiological measurements from individual neurons. The sensor developed using this technique provides the first experimental method for determining single cell sensitivity; the speed of response and the associated physiological changes to a broad spectrum of chemical agents. Binding of specific chemical agents to a specific combination of receptors induces changes to the extracellular membrane potential of a single neuron, which can be translated into unique "signature patterns" (SP), which function as identification tags. Signature patterns are derived using Fast Fourier Transformation (FFT) analysis and Wavelet Transformation (WT) analysis of the modified extracellular action potential. The validity and the sensitivity of the system are demonstrated for a variety of chemical agents ranging from behavior altering chemicals (ethanol), environmentally hazardous agents (hydrogen peroxide, EDTA) to physiologically harmful agents (pyrethroids) at pico- and femto-molar concentrations. The ability of a single neuron to selectively identify specific chemical agents when injected in a serial manner is demonstrated in "cascaded sensing".

Improving Measures via Examining the Behavior of Distractors in Multiple-Choice Tests

PubMed Central

Sideridis, Georgios; Tsaousis, Ioannis; Al Harbi, Khaleel

2017-01-01

The purpose of the present article was to illustrate, using an example from a national assessment, the value from analyzing the behavior of distractors in measures that engage the multiple-choice format. A secondary purpose of the present article was to illustrate four remedial actions that can potentially improve the measurement of the construct(s) under study. Participants were 2,248 individuals who took a national examination of chemistry. The behavior of the distractors was analyzed by modeling their behavior within the Rasch model. Potentially informative distractors were (a) further modeled using the partial credit model, (b) split onto separate items and retested for model fit and parsimony, (c) combined to form a “super” item or testlet, and (d) reexamined after deleting low-ability individuals who likely guessed on those informative, albeit erroneous, distractors. Results indicated that all but the item split strategies were associated with better model fit compared with the original model. The best fitted model, however, involved modeling and crediting informative distractors via the partial credit model or eliminating the responses of low-ability individuals who likely guessed on informative distractors. The implications, advantages, and disadvantages of modeling informative distractors for measurement purposes are discussed. PMID:29795904

Mimicking and anticipating others’ actions is linked to Social Information Processing

PubMed Central

Klomfar, Sophie; d’Haene, Ine; Brass, Marcel

2018-01-01

It is widely known that individuals frequently imitate each other in social situations and that such mimicry fulfills an important social role in the sense that it functions as a social glue. With reference to the anticipated action effect, it has recently been demonstrated that individuals do not only imitate others, but also engage in anticipated action before the observed person starts engaging in that action. Interestingly, both phenomena (i.e., mimicry and anticipated action) rely on tracking others’ social behavior. Therefore, in the present research we investigated whether mimicry and anticipated action are related to social abilities as indicated by measures of social intelligence. The results demonstrate for the first time that mimicry as well as anticipated action is correlated with an important aspect of social intelligence—namely the ability to process social information. Theoretical implications and limitations are discussed. PMID:29590127

Virtual morality: emotion and action in a simulated three-dimensional "trolley problem".

PubMed

Navarrete, C David; McDonald, Melissa M; Mott, Michael L; Asher, Benjamin

2012-04-01

Experimentally investigating the relationship between moral judgment and action is difficult when the action of interest entails harming others. We adopt a new approach to this problem by placing subjects in an immersive, virtual reality environment that simulates the classic "trolley problem." In this moral dilemma, the majority of research participants behaved as "moral utilitarians," either (a) acting to cause the death of one individual in order to save the lives of five others, or (b) abstaining from action, when that action would have caused five deaths versus one. Confirming the emotional distinction between moral actions and omissions, autonomic arousal was greater when the utilitarian outcome required action, and increased arousal was associated with a decreased likelihood of utilitarian-biased behavior. This pattern of results held across individuals of different gender, age, and race. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

Mimicking and anticipating others' actions is linked to Social Information Processing.

PubMed

Genschow, Oliver; Klomfar, Sophie; d'Haene, Ine; Brass, Marcel

2018-01-01

It is widely known that individuals frequently imitate each other in social situations and that such mimicry fulfills an important social role in the sense that it functions as a social glue. With reference to the anticipated action effect, it has recently been demonstrated that individuals do not only imitate others, but also engage in anticipated action before the observed person starts engaging in that action. Interestingly, both phenomena (i.e., mimicry and anticipated action) rely on tracking others' social behavior. Therefore, in the present research we investigated whether mimicry and anticipated action are related to social abilities as indicated by measures of social intelligence. The results demonstrate for the first time that mimicry as well as anticipated action is correlated with an important aspect of social intelligence-namely the ability to process social information. Theoretical implications and limitations are discussed.

Relationship between size and latency of action potentials in human muscle sympathetic nerve activity.

PubMed

Salmanpour, Aryan; Brown, Lyndon J; Steinback, Craig D; Usselman, Charlotte W; Goswami, Ruma; Shoemaker, J Kevin

2011-06-01

We employed a novel action potential detection and classification technique to study the relationship between the recruitment of sympathetic action potentials (i.e., neurons) and the size of integrated sympathetic bursts in human muscle sympathetic nerve activity (MSNA). Multifiber postganglionic sympathetic nerve activity from the common fibular nerve was collected using microneurography in 10 healthy subjects at rest and during activation of sympathetic outflow using lower body negative pressure (LBNP). Burst occurrence increased with LBNP. Integrated burst strength (size) varied from 0.22 ± 0.07 V at rest to 0.28 ± 0.09 V during LBNP. Sympathetic burst size (i.e., peak height) was directly related to the number of action potentials within a sympathetic burst both at baseline (r = 0.75 ± 0.13; P < 0.001) and LBNP (r = 0.75 ± 0.12; P < 0.001). Also, the amplitude of detected action potentials within sympathetic bursts was directly related to the increased burst size at both baseline (r = 0.59 ± 0.16; P < 0.001) and LBNP (r = 0.61 ± 0.12; P < 0.001). In addition, the number of detected action potentials and the number of distinct action potential clusters within a given sympathetic burst were correlated at baseline (r = 0.7 ± 0.1; P < 0.001) and during LBNP (r = 0.74 ± 0.03; P < 0.001). Furthermore, action potential latency (i.e., an inverse index of neural conduction velocity) was decreased as a function of action potential size at baseline and LBNP. LBNP did not change the number of action potentials and unique clusters per sympathetic burst. It was concluded that there exists a hierarchical pattern of recruitment of additional faster conducting neurons of larger amplitude as the sympathetic bursts become stronger (i.e., larger amplitude bursts). This fundamental pattern was evident at rest and was not altered by the level of baroreceptor unloading applied in this study.

All optical experimental design for neuron excitation, inhibition, and action potential detection

NASA Astrophysics Data System (ADS)

Walsh, Alex J.; Tolstykh, Gleb; Martens, Stacey; Sedelnikova, Anna; Ibey, Bennett L.; Beier, Hope T.

2016-03-01

Recently, infrared light has been shown to both stimulate and inhibit excitatory cells. However, studies of infrared light for excitatory cell inhibition have been constrained by the use of invasive and cumbersome electrodes for cell excitation and action potential recording. Here, we present an all optical experimental design for neuronal excitation, inhibition, and action potential detection. Primary rat neurons were transfected with plasmids containing the light sensitive ion channel CheRiff. CheRiff has a peak excitation around 450 nm, allowing excitation of transfected neurons with pulsed blue light. Additionally, primary neurons were transfected with QuasAr2, a fast and sensitive fluorescent voltage indicator. QuasAr2 is excited with yellow or red light and therefore does not spectrally overlap CheRiff, enabling imaging and action potential activation, simultaneously. Using an optic fiber, neurons were exposed to blue light sequentially to generate controlled action potentials. A second optic fiber delivered a single pulse of 1869nm light to the neuron causing inhibition of the evoked action potentials (by the blue light). When used in concert, these optical techniques enable electrode free neuron excitation, inhibition, and action potential recording, allowing research into neuronal behaviors with high spatial fidelity.

Habitual action video game playing is associated with caudate nucleus-dependent navigational strategies.

PubMed

West, Greg L; Drisdelle, Brandi Lee; Konishi, Kyoko; Jackson, Jonathan; Jolicoeur, Pierre; Bohbot, Veronique D

2015-06-07

The habitual playing of video games is associated with increased grey matter and activity in the striatum. Studies in humans and rodents have shown an inverse relationship between grey matter in the striatum and hippocampus. We investigated whether action video game playing is also associated with increased use of response learning strategies during navigation, known to be dependent on the caudate nucleus of the striatum, when presented in a dual solution task. We tested 26 action video game players (actionVGPs) and 33 non-action video game players (nonVGPs) on the 4-on-8 virtual maze and a visual attention event-related potential (ERP) task, which elicits a robust N-2-posterior-controlateral (N2pc) component. We found that actionVGPs had a significantly higher likelihood of using a response learning strategy (80.76%) compared to nonVGPs (42.42%). Consistent with previous evidence, actionVGPs and nonVGPs differed in the way they deployed visual attention to central and peripheral targets as observed in the elicited N2pc component during an ERP visual attention task. Increased use of the response strategy in actionVGPs is consistent with previously observed increases in striatal volume in video game players (VGPs). Using response strategies is associated with decreased grey matter in the hippocampus. Previous studies have shown that decreased volume in the hippocampus precedes the onset of many neurological and psychiatric disorders. If actionVGPs have lower grey matter in the hippocampus, as response learners normally do, then these individuals could be at increased risk of developing neurological and psychiatric disorders during their lifetime. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Habitual action video game playing is associated with caudate nucleus-dependent navigational strategies

PubMed Central

West, Greg L.; Drisdelle, Brandi Lee; Konishi, Kyoko; Jackson, Jonathan; Jolicoeur, Pierre; Bohbot, Veronique D.

2015-01-01

The habitual playing of video games is associated with increased grey matter and activity in the striatum. Studies in humans and rodents have shown an inverse relationship between grey matter in the striatum and hippocampus. We investigated whether action video game playing is also associated with increased use of response learning strategies during navigation, known to be dependent on the caudate nucleus of the striatum, when presented in a dual solution task. We tested 26 action video game players (actionVGPs) and 33 non-action video game players (nonVGPs) on the 4-on-8 virtual maze and a visual attention event-related potential (ERP) task, which elicits a robust N-2-posterior-controlateral (N2pc) component. We found that actionVGPs had a significantly higher likelihood of using a response learning strategy (80.76%) compared to nonVGPs (42.42%). Consistent with previous evidence, actionVGPs and nonVGPs differed in the way they deployed visual attention to central and peripheral targets as observed in the elicited N2pc component during an ERP visual attention task. Increased use of the response strategy in actionVGPs is consistent with previously observed increases in striatal volume in video game players (VGPs). Using response strategies is associated with decreased grey matter in the hippocampus. Previous studies have shown that decreased volume in the hippocampus precedes the onset of many neurological and psychiatric disorders. If actionVGPs have lower grey matter in the hippocampus, as response learners normally do, then these individuals could be at increased risk of developing neurological and psychiatric disorders during their lifetime. PMID:25994669

4 CFR 28.98 - Individual charges in EEO cases.

Code of Federal Regulations, 2013 CFR

2013-01-01

... complaint process. (d) Special rules for RIF based actions. An individual alleging discrimination issues in connection with a RIF-based separation may follow the procedures outlined above in paragraph (c) of this.... (2) A charging party challenging a RIF action by filing directly with the PAB shall follow the...

4 CFR 28.98 - Individual charges in EEO cases.

Code of Federal Regulations, 2012 CFR

2012-01-01

... complaint process. (d) Special rules for RIF based actions. An individual alleging discrimination issues in connection with a RIF-based separation may follow the procedures outlined above in paragraph (c) of this.... (2) A charging party challenging a RIF action by filing directly with the PAB shall follow the...

4 CFR 28.98 - Individual charges in EEO cases.

Code of Federal Regulations, 2014 CFR

2014-01-01

... complaint process. (d) Special rules for RIF based actions. An individual alleging discrimination issues in connection with a RIF-based separation may follow the procedures outlined above in paragraph (c) of this.... (2) A charging party challenging a RIF action by filing directly with the PAB shall follow the...

The DiabetAction Program: Implementation in Community-Based Settings

ERIC Educational Resources Information Center

Mathieu, Marie-Eve; Brochu, Martin; Beliveau, Louise

2009-01-01

Developed for specialists who want to increase the physical activity (PA) level of type 2 diabetic and at-risk individuals, the 10-week DiabetAction program introduced participants to a wide variety of cardiovascular, resistance, balance, and flexibility exercises. Thirty-three of 48 individuals completed the intervention in community-based…

The Emergence of Personality: Dynamic Foundations of Individual Variation

ERIC Educational Resources Information Center

Nowak, Aandrzej; Vallacher, Robin R.; Zochowski, Michal

2005-01-01

We conceptualize personality and individual variation from the perspective of dynamical systems. People's thoughts, feelings, and predispositions for action are inherently dynamic, displaying constant change due to internal mechanisms and external forces, but over time the flow of thought and action converges on a narrow range of states--a…

Involving Stakeholders in Determining Professional Development Center Attendance Policies.

ERIC Educational Resources Information Center

Good, Jennifer

2003-01-01

This action research project targeted teacher absenteeism at professional development events, findings no significant patterns in time of day, location, workshop topic, and teaching level. Instead, a pattern of chronic absenteeism for some individuals was noted. An action plan included increased marketing, communication with individual no-show…

10 CFR 26.77 - Management actions regarding possible impairment.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Section 26.77 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Management Actions and... competently perform his or her duties. (b) If an individual appears to be impaired or the individual's fitness... perform drug and alcohol tests or implement the determination of fitness process otherwise required by...

10 CFR 26.77 - Management actions regarding possible impairment.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Section 26.77 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Management Actions and... competently perform his or her duties. (b) If an individual appears to be impaired or the individual's fitness... perform drug and alcohol tests or implement the determination of fitness process otherwise required by...

10 CFR 26.77 - Management actions regarding possible impairment.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Section 26.77 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Management Actions and... competently perform his or her duties. (b) If an individual appears to be impaired or the individual's fitness... perform drug and alcohol tests or implement the determination of fitness process otherwise required by...

10 CFR 26.77 - Management actions regarding possible impairment.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Section 26.77 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Management Actions and... competently perform his or her duties. (b) If an individual appears to be impaired or the individual's fitness... perform drug and alcohol tests or implement the determination of fitness process otherwise required by...

10 CFR 26.77 - Management actions regarding possible impairment.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Section 26.77 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Management Actions and... competently perform his or her duties. (b) If an individual appears to be impaired or the individual's fitness... perform drug and alcohol tests or implement the determination of fitness process otherwise required by...

20 CFR 438.110 - Certification and disclosure.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 438.110 Employees' Benefits SOCIAL SECURITY ADMINISTRATION RESTRICTIONS ON LOBBYING General § 438.110... influence a covered Federal action; or (2) A change in the person(s) or individual(s) influencing or attempting to influence a covered Federal action; or, (3) A change in the officer(s), employee(s), or Member...

20 CFR 438.110 - Certification and disclosure.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 438.110 Employees' Benefits SOCIAL SECURITY ADMINISTRATION RESTRICTIONS ON LOBBYING General § 438.110... influence a covered Federal action; or (2) A change in the person(s) or individual(s) influencing or attempting to influence a covered Federal action; or, (3) A change in the officer(s), employee(s), or Member...

Online Action Monitoring and Memory for Self-Performed Actions in Autism Spectrum Disorder

ERIC Educational Resources Information Center

Grainger, Catherine; Williams, David M.; Lind, Sophie E.

2014-01-01

This study explored whether individuals with autism spectrum disorder (ASD) experience difficulties with action monitoring. Two experimental tasks examined whether adults with ASD are able to monitor their own actions online, and whether they also show a typical enactment effects in memory (enhanced memory for actions they have performed compared…

Assessing anesthetic activity through modulation of the membrane dipole potential.

PubMed

Davis, Benjamin Michael; Brenton, Jonathan; Davis, Sterenn; Shamsher, Ehtesham; Sisa, Claudia; Grgic, Ljuban; Cordeiro, M Francesca

2017-10-01

There is great individual variation in response to general anesthetics (GAs) leading to difficulties in optimal dosing and sometimes even accidental awareness during general anesthesia (AAGA). AAGA is a rare, but potentially devastating, complication affecting between 0.1% and 2% of patients undergoing surgery. The development of novel personalized screening techniques to accurately predict a patient's response to GAs and the risk of AAGA remains an unmet clinical need. In the present study, we demonstrate the principle of using a fluorescent reporter of the membrane dipole potential, di-8-ANEPPs, as a novel method to monitor anesthetic activity using a well-described inducer/noninducer pair. The membrane dipole potential has previously been suggested to contribute a novel mechanism of anesthetic action. We show that the fluorescence ratio of di-8-ANEPPs changed in response to physiological concentrations of the anesthetic, 1-chloro-1,2,2-trifluorocyclobutane (F 3 ), but not the structurally similar noninducer, 1,2-dichlorohexafluorocyclobutane (F 6 ), to artificial membranes and in vitro retinal cell systems. Modulation of the membrane dipole provides an explanation to overcome the limitations associated with the alternative membrane-mediated mechanisms of GA action. Furthermore, by combining this technique with noninvasive retinal imaging technologies, we propose that this technique could provide a novel and noninvasive technique to monitor GA susceptibility and identify patients at risk of AAGA. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

Cannabidiol as a Potential New Type of an Antipsychotic. A Critical Review of the Evidence.

PubMed

Rohleder, Cathrin; Müller, Juliane K; Lange, Bettina; Leweke, F M

2016-01-01

There is urgent need for the development of mechanistically different and less side-effect prone antipsychotic compounds. The endocannabinoid system has been suggested to represent a potential new target in this indication. While the chronic use of cannabis itself has been considered a risk factor contributing to the development of schizophrenia, triggered by the phytocannabinoid delta-9-tetrahydrocannabinol (Δ 9 -THC), cannabidiol, the second most important phytocannabinoid, appears to have no psychotomimetic potential. Although, results from animal studies are inconsistent to a certain extent and seem to depend on behavioral paradigms, treatment duration and experimental conditions applied, cannabidiol has shown antipsychotic properties in both rodents and rhesus monkeys. After some individual treatment attempts, the first randomized, double-blind controlled clinical trial demonstrated that in acute schizophrenia cannabidiol exerts antipsychotic properties comparable to the antipsychotic drug amisulpride while being accompanied by a superior, placebo-like side effect profile. As the clinical improvement by cannabidiol was significantly associated with elevated anandamide levels, it appears likely that its antipsychotic action is based on mechanisms associated with increased anandamide concentrations. Although, a plethora of mechanisms of action has been suggested, their potential relevance for the antipsychotic effects of cannabidiol still needs to be investigated. The clarification of these mechanisms as well as the establishment of cannabidiol's antipsychotic efficacy and its hopefully benign side-effect profile remains the subject of a number of previously started clinical trials.

Dismembering the ethical physician

PubMed Central

Genuis, S J

2006-01-01

Physicians may experience ethical distress when they are caught in difficult clinical situations that demand ethical decision making, particularly when their preferred action may contravene the expectations of patients and established authorities. When principled and competent doctors succumb to patient wishes or establishment guidelines and participate in actions they perceive to be ethically inappropriate, or agree to refrain from interventions they believe to be in the best interests of patients, individual professional integrity may be diminished, and ethical reliability is potentially compromised. In a climate of ever‐proliferating ethical quandaries, it is essential for the medical community, health institutions, and governing bodies to pursue a judicious tension between the indispensable regulation of physicians necessary to maintain professional standards and preserve public safety, and the support for “freedom of conscience” that principled physicians require to practise medicine in keeping with their personal ethical orientation. PMID:16597808

Cortical Action Potential Backpropagation Explains Spike Threshold Variability and Rapid-Onset Kinetics

PubMed Central

Yu, Yuguo; Shu, Yousheng; McCormick, David A.

2008-01-01

Neocortical action potential responses in vivo are characterized by considerable threshold variability, and thus timing and rate variability, even under seemingly identical conditions. This finding suggests that cortical ensembles are required for accurate sensorimotor integration and processing. Intracellularly, trial-to-trial variability results not only from variation in synaptic activities, but also in the transformation of these into patterns of action potentials. Through simultaneous axonal and somatic recordings and computational simulations, we demonstrate that the initiation of action potentials in the axon initial segment followed by backpropagation of these spikes throughout the neuron results in a distortion of the relationship between the timing of synaptic and action potential events. In addition, this backpropagation also results in an unusually high rate of rise of membrane potential at the foot of the action potential. The distortion of the relationship between the amplitude time course of synaptic inputs and action potential output caused by spike back-propagation results in the appearance of high spike threshold variability at the level of the soma. At the point of spike initiation, the axon initial segment, threshold variability is considerably less. Our results indicate that spike generation in cortical neurons is largely as expected by Hodgkin—Huxley theory and is more precise than previously thought. PMID:18632930

Axonal propagation of simple and complex spikes in cerebellar Purkinje neurons.

PubMed

Khaliq, Zayd M; Raman, Indira M

2005-01-12

In cerebellar Purkinje neurons, the reliability of propagation of high-frequency simple spikes and spikelets of complex spikes is likely to regulate inhibition of Purkinje target neurons. To test the extent to which a one-to-one correspondence exists between somatic and axonal spikes, we made dual somatic and axonal recordings from Purkinje neurons in mouse cerebellar slices. Somatic action potentials were recorded with a whole-cell pipette, and the corresponding axonal signals were recorded extracellularly with a loose-patch pipette. Propagation of spontaneous and evoked simple spikes was highly reliable. At somatic firing rates of approximately 200 spikes/sec, <10% of spikes failed to propagate, with failures becoming more frequent only at maximal somatic firing rates (approximately 260 spikes/sec). Complex spikes were elicited by climbing fiber stimulation, and their somatic waveforms were modulated by tonic current injection, as well as by paired stimulation to depress the underlying EPSCs. Across conditions, the mean number of propagating action potentials remained just above two spikes per climbing fiber stimulation, but the instantaneous frequency of the propagating spikes changed, from approximately 375 Hz during somatic hyperpolarizations that silenced spontaneous firing to approximately 150 Hz during spontaneous activity. The probability of propagation of individual spikelets could be described quantitatively as a saturating function of spikelet amplitude, rate of rise, or preceding interspike interval. The results suggest that ion channels of Purkinje axons are adapted to produce extremely short refractory periods and that brief bursts of forward-propagating action potentials generated by complex spikes may contribute transiently to inhibition of postsynaptic neurons.

Distinct Neural Properties in the Low-Frequency Region of the Chicken Cochlear Nucleus Magnocellularis

PubMed Central

2017-01-01

Abstract Topography in the avian cochlear nucleus magnocellularis (NM) is represented as gradually increasing characteristic frequency (CF) along the caudolateral-to-rostromedial axis. In this study, we characterized the organization and cell biophysics of the caudolateral NM (NMc) in chickens (Gallus gallus). Examination of cellular and dendritic architecture first revealed that NMc contains small neurons and extensive dendritic processes, in contrast to adendritic, large neurons located more rostromedially. Individual dye-filling study further demonstrated that NMc is divided into two subregions, with NMc2 neurons having larger and more complex dendritic fields than NMc1. Axonal tract tracing studies confirmed that NMc1 and NMc2 neurons receive afferent inputs from the auditory nerve and the superior olivary nucleus, similar to the adendritic NM. However, the auditory axons synapse with NMc neurons via small bouton-like terminals, unlike the large end bulb synapses on adendritic NM neurons. Immunocytochemistry demonstrated that most NMc2 neurons express cholecystokinin but not calretinin, distinct from NMc1 and adendritic NM neurons that are cholecystokinin negative and mostly calretinin positive. Finally, whole-cell current clamp recordings revealed that NMc neurons require significantly lower threshold current for action potential generation than adendritic NM neurons. Moreover, in contrast to adendritic NM neurons that generate a single-onset action potential, NMc neurons generate multiple action potentials to suprathreshold sustained depolarization. Taken together, our data indicate that NMc contains multiple neuron types that are structurally, connectively, molecularly, and physiologically different from traditionally defined NM neurons, emphasizing specialized neural properties for processing low-frequency sounds. PMID:28413822

Development of hypersynchrony in the cortical network during chemoconvulsant-induced epileptic seizures in vivo.

PubMed

Cymerblit-Sabba, Adi; Schiller, Yitzhak

2012-03-01

The prevailing view of epileptic seizures is that they are caused by increased hypersynchronous activity in the cortical network. However, this view is based mostly on electroencephalography (EEG) recordings that do not directly monitor neuronal synchronization of action potential firing. In this study, we used multielectrode single-unit recordings from the hippocampus to investigate firing of individual CA1 neurons and directly monitor synchronization of action potential firing between neurons during the different ictal phases of chemoconvulsant-induced epileptic seizures in vivo. During the early phase of seizures manifesting as low-amplitude rhythmic β-electrocorticography (ECoG) activity, the firing frequency of most neurons markedly increased. To our surprise, the average overall neuronal synchronization as measured by the cross-correlation function was reduced compared with control conditions with ~60% of neuronal pairs showing no significant correlated firing. However, correlated firing was not uniform and a minority of neuronal pairs showed a high degree of correlated firing. Moreover, during the early phase of seizures, correlated firing between 9.8 ± 5.1% of all stably recorded pairs increased compared with control conditions. As seizures progressed and high-frequency ECoG polyspikes developed, the firing frequency of neurons further increased and enhanced correlated firing was observed between virtually all neuronal pairs. These findings indicated that epileptic seizures represented a hyperactive state with widespread increase in action potential firing. Hypersynchrony also characterized seizures. However, it initially developed in a small subset of neurons and gradually spread to involve the entire cortical network only in the later more intense ictal phases.

Median and ulnar muscle and sensory evoked potentials.

PubMed

Felsenthal, G

1978-08-01

The medical literature was reviewed to find suggested clinical applications of the study of the amplitude of evoked muscle action potentials (MAP) and sensory action potentials (SAP). In addition, the literature was reviewed to ascertain the normal amplitude and duration of the evoked MAP and SAP as well as the factors affecting the amplitude: age, sex, temperature, ischemia. The present study determined the normal amplitude and duration of the median and ulnar MAP and SAP in fifty normal subjects. The amplitude of evoked muscle or sensory action potentials depends on multiple factors. Increased skin resistance, capacitance, and impedance at the surface of the recording electrode diminishes the amplitude. Similarly, increased distance from the source of the action potential diminishes its amplitude. Increased interelectrode distance increases the amplitude of the bipolarly recorded sensory action potential until a certain interelectrode distance is exceeded and the diphasic response becomes tri- or tetraphasic. Artifact or poor technique may reduce the potential difference between the recording electrodes or obscure the late positive phase of the action potential and thus diminish the peak to peak amplitude measurement. Intraindividual comparison indicated a marked difference of amplitude in opposite hands. The range of the MAP of the abductor pollicis brevis in one hand was 40.0--100% of the response in the opposite hand. For the abductor digiti minimi, the MAP was 58.5--100% of the response of the opposite hand. The median and ulnar SAP was between 50--100% of the opposite SAP. Consequent to these findings the effect of hand dominance on the amplitude of median and ulnar evoked muscle and sensory action potentials was studied in 41 right handed volunteers. The amplitudes of the median muscle action potential (p less than 0.02) and the median and ulnar sensory action potentials (p less than 0.001) were significantly less in the dominant hand. There was no significant difference between the ulnar muscle action potentials or for the median and ulnar distal motor and sensory latencies in the right and left hands of this group of volunteers.

Ionotropic glutamate receptor GluA4 and T-type calcium channel Cav 3.1 subunits control key aspects of synaptic transmission at the mouse L5B-POm giant synapse.

PubMed

Seol, Min; Kuner, Thomas

2015-12-01

The properties and molecular determinants of synaptic transmission at giant synapses connecting layer 5B (L5B) neurons of the somatosensory cortex (S1) with relay neurons of the posteriomedial nucleus (POm) of the thalamus have not been investigated in mice. We addressed this by using direct electrical stimulation of fluorescently labelled single corticothalamic terminals combined with molecular perturbations and whole-cell recordings from POm relay neurons. Consistent with their function as drivers, we found large-amplitude excitatory postsynaptic currents (EPSCs) and multiple postsynaptic action potentials triggered by a single presynaptic action potential. To study the molecular basis of these two features, ionotropic glutamate receptors and low voltage-gated T-type calcium channels were probed by virus-mediated genetic perturbation. Loss of GluA4 almost abolished the EPSC amplitude, strongly delaying the onset of action potential generation, but maintaining the number of action potentials generated per presynaptic action potential. In contrast, knockdown of the Cav 3.1 subunit abrogated the driver function of the synapse at a typical resting membrane potential of -70 mV. However, when depolarizing the membrane potential to -60 mV, the synapse relayed single action potentials. Hence, GluA4 subunits are required to produce an EPSC sufficiently large to trigger postsynaptic action potentials within a defined time window after the presynaptic action potential, while Cav 3.1 expression is essential to establish the driver function of L5B-POm synapses at hyperpolarized membrane potentials. © 2015 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Low concentrations of procaine and diethylaminoethanol reduce the excitability but not the action potential amplitude of hippocampal pyramidal cells.

PubMed

Butterworth, J F; Cole, L R

1990-10-01

To determine whether concentrations of diethylaminoethanol (DEAE) and procaine below those that reduce the amplitude of action potentials might alter the excitability of brain cells, a single microelectrode intracellular recording technique was used to measure firing threshold and action potential amplitude of pyramidal cells in rat hippocampal slices. At low concentrations of both DEAE (less than or equal to 5 mM) and procaine (less than or equal to 0.5 mM), firing threshold was significantly increased (P less than 0.01), whereas action potential spike amplitude was minimally altered. At higher concentrations, both drugs significantly decreased action potential spike amplitude (P less than 0.025) as well as increased firing threshold (P less than 0.001). Diethylaminoethanol tended to increase threshold relatively more than procaine, when drug concentrations that similarly reduced action potential amplitude were compared. All actions of DEAE and procaine were reversible. Inhibition of action potentials by DEAE and procaine was clearly concentration-dependent (P less than or equal to 0.015). Diethylaminoethanol effects on threshold were marginally concentration-dependent (P = 0.08); procaine did not demonstrate clear concentration-dependent effects (P = 0.33) over the concentrations tested in this study. These similar actions of procaine and DEAE on brain cells suggest a mechanism by which intravenous local anesthetics may contribute to the general anesthetic state. Moreover, it appears possible that procaine metabolism and DEAE accumulation may underlie the prolonged effects sometimes seen after intravenous procaine administration.

From Movements to Actions: Two Mechanisms for Learning Action Sequences

ERIC Educational Resources Information Center

Endress, Ansgar D.; Wood, Justin N.

2011-01-01

When other individuals move, we interpret their movements as discrete, hierarchically-organized, goal-directed actions. However, the mechanisms that integrate visible movement features into actions are poorly understood. Here, we consider two sequence learning mechanisms--transitional probability-based (TP) and position-based encoding…

41 CFR 60-741.41 - Availability of affirmative action program.

Code of Federal Regulations, 2010 CFR

2010-07-01

... affirmative action program. 60-741.41 Section 60-741.41 Public Contracts and Property Management Other... OPPORTUNITY, DEPARTMENT OF LABOR 741-AFFIRMATIVE ACTION AND NONDISCRIMINATION OBLIGATIONS OF CONTRACTORS AND SUBCONTRACTORS REGARDING INDIVIDUALS WITH DISABILITIES Affirmative Action Program § 60-741.41 Availability of...

41 CFR 60-741.41 - Availability of affirmative action program.

Code of Federal Regulations, 2011 CFR

2011-07-01

... affirmative action program. 60-741.41 Section 60-741.41 Public Contracts and Property Management Other... OPPORTUNITY, DEPARTMENT OF LABOR 741-AFFIRMATIVE ACTION AND NONDISCRIMINATION OBLIGATIONS OF CONTRACTORS AND SUBCONTRACTORS REGARDING INDIVIDUALS WITH DISABILITIES Affirmative Action Program § 60-741.41 Availability of...

The Birth of Social Intelligence

PubMed Central

Henderson, Annette M. E.; Gerson, Sarah; Woodward, Amanda L.

2013-01-01

The ability to make sense out of the actions of others is critical to people’s daily functioning. Adults are social experts: They understand that people’s actions are directed at goals and are driven by intentions. In this article, the authors highlight key findings from studies examining infants’ understanding of human action. These findings suggest that infants come to understand that intentions and attention guide human action within the first few months of their lives. By 13 months, infants understand that intentions are specific to individuals, yet there are some actions that are shared by all individuals within a group. Taken together, the evidence suggests that infants are well on their way to becoming social experts by their second birthdays. PMID:25278644

78 FR 34031 - Burned Area Emergency Response, Forest Service

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-06

...) Evaluate potential threats to critical values; (2) determine the risk level for each threat; (3) identify... actions that meet the objectives; (6) evaluate potential response actions on likelihood for timely... stabilization actions. Improved the descriptive guidelines for employing response actions involving...

Conduction velocity of action potentials measured from unidimensional latency-topography in human and frog skeletal muscle fibers.

PubMed

Homma, S; Nakajima, Y; Hayashi, K; Toma, S

1986-01-01

Conduction of an action potential along skeletal muscle fibers was graphically displayed by unidimensional latency-topography, UDLT. Since the slopes of the equipotential line were linear and the width of the line was constant, it was possible to calculate conduction velocity from the slope. To determine conduction direction of the muscle action potential elicited by electric stimulation applied directly to the muscle, surface recording electrodes were placed on a two-dimensional plane over a human muscle. Thus a bi-dimensional topography was obtained. Then, twelve or sixteen surface electrodes were placed linearly along the longitudinal direction of the action potential conduction which was disclosed by the bi-dimensional topography. Thus conduction velocity of muscle action potential in man, calculated from the slope, was for m. brachioradialis, 3.9 +/- 0.4 m/s; for m. biceps brachii, 3.6 +/- 0.2 m/s; for m. sternocleidomastoideus, 3.6 +/- 0.4 m/s. By using a tungsten microelectrode to stimulate the motor axons, a convex-like equipotential line of an action potential in UDLT was obtained from human muscle fibers. Since a similar pattern of UDLT was obtained from experiments on isolated frog muscles, in which the muscle action potential was elicited by stimulating the motor axon, it was assumed that the maximum of the curve corresponds to the end-plate region, and that the slopes on both sides indicate bi-directional conduction of the action potential.

Active action potential propagation but not initiation in thalamic interneuron dendrites

PubMed Central

Casale, Amanda E.; McCormick, David A.

2012-01-01

Inhibitory interneurons of the dorsal lateral geniculate nucleus of the thalamus modulate the activity of thalamocortical cells in response to excitatory input through the release of inhibitory neurotransmitter from both axons and dendrites. The exact mechanisms by which release can occur from dendrites are, however, not well understood. Recent experiments using calcium imaging have suggested that Na/K based action potentials can evoke calcium transients in dendrites via local active conductances, making the back-propagating action potential a candidate for dendritic neurotransmitter release. In this study, we employed high temporal and spatial resolution voltage-sensitive dye imaging to assess the characteristics of dendritic voltage deflections in response to Na/K action potentials in interneurons of the mouse dorsal lateral geniculate nucleus. We found that trains or single action potentials elicited by somatic current injection or local synaptic stimulation led to action potentials that rapidly and actively back-propagated throughout the entire dendritic arbor and into the fine filiform dendritic appendages known to release GABAergic vesicles. Action potentials always appeared first in the soma or proximal dendrite in response to somatic current injection or local synaptic stimulation, and the rapid back-propagation into the dendritic arbor depended upon voltage-gated sodium and TEA-sensitive potassium channels. Our results indicate that thalamic interneuron dendrites integrate synaptic inputs that initiate action potentials, most likely in the axon initial segment, that then back-propagate with high-fidelity into the dendrites, resulting in a nearly synchronous release of GABA from both axonal and dendritic compartments. PMID:22171033

Critical dialogical approach: A methodological direction for occupation-based social transformative work.

PubMed

Farias, Lisette; Laliberte Rudman, Debbie; Pollard, Nick; Schiller, Sandra; Serrata Malfitano, Ana Paula; Thomas, Kerry; van Bruggen, Hanneke

2018-05-03

Calls for embracing the potential and responsibility of occupational therapy to address socio-political conditions that perpetuate occupational injustices have materialized in the literature. However, to reach beyond traditional frameworks informing practices, this social agenda requires the incorporation of diverse epistemological and methodological approaches to support action commensurate with social transformative goals. Our intent is to present a methodological approach that can help extend the ways of thinking or frameworks used in occupational therapy and science to support the ongoing development of practices with and for individuals and collectives affected by marginalizing conditions. We describe the epistemological and theoretical underpinnings of a methodological approach drawing on Freire and Bakhtin's work. Integrating our shared experience taking part in an example study, we discuss the unique advantages of co-generating data using two methods aligned with this approach; dialogical interviews and critical reflexivity. Key considerations when employing this approach are presented, based on its proposed epistemological and theoretical stance and our shared experiences engaging in it. A critical dialogical approach offers one way forward in expanding occupational therapy and science scholarship by promoting collaborative knowledge generation and examination of taken-for-granted understandings that shape individuals assumptions and actions.

Tonic and Phasic Receptor Neurons in the Vertebrate Olfactory Epithelium

PubMed Central

Madrid, Rodolfo; Sanhueza, Magdalena; Alvarez, Osvaldo; Bacigalupo, Juan

2003-01-01

Olfactory receptor neurons (ORNs) respond to odorants with characteristic patterns of action potentials that are relevant for odor coding. Prolonged odorant exposures revealed three populations of dissociated toad ORNs, which were mimicked by depolarizing currents: tonic (TN, displaying sustained firing, 49% of 102 cells), phasic (PN, exhibiting brief action potential trains, 36%) and intermediate neurons (IN, generating trains longer than PN, 15%). We studied the biophysical properties underlying the differences between TNs and PNs, the most extreme cases among ORNs. TNs and PNs possessed similar membrane capacitances (∼4 pF), but they differed in resting potential (−82 versus −64 mV), input resistance (4.2 versus 2.9 GΩ) and unspecific current, Iu (TNs: 0 < Iu ≤ 1 pA/pF; and PNs: Iu > 1 pA/pF). Firing behavior did not correlate with differences in voltage-gated conductances. We developed a mathematical model that accurately simulates tonic and phasic patterns. Whole cell recordings from rat ORNs in fragments (∼4 mm2) of olfactory epithelium showed that such a tissue normally contains tonic and phasic receptor neurons, suggesting that this feature is common across a wide range of vertebrates. Our findings show that the individual passive electrical properties can govern the firing patterns of ORNs. PMID:12770919

Event-Related Potentials Discriminate Familiar and Unusual Goal Outcomes in 5-Month-Olds and Adults

ERIC Educational Resources Information Center

Michel, Christine; Kaduk, Katharina; Ní Choisdealbha, Áine; Reid, Vincent M.

2017-01-01

Previous event-related potential (ERP) work has indicated that the neural processing of action sequences develops with age. Although adults and 9-month-olds use a semantic processing system, perceiving actions activates attentional processes in 7-month-olds. However, presenting a sequence of action context, action execution and action conclusion…

Empowering people to be healthier: public health nutrition through the Ottawa Charter.

PubMed

Flynn, Mary A T

2015-08-01

The WHO's Ottawa Charter highlights five priority areas for taking action in public health. Only one of them is at the individual level as action at more upstream intervention levels, such as community or policy levels, is critical for enabling individuals to succeed. The objective of the present paper is to give insight into the many complex processes involved in public health nutrition by describing the Ottawa Charter's five priority areas for taking action using public health nutrition initiatives I have been involved in. Evidence-based guidelines for healthy eating and infant feeding provide an essential basis for individuals to 'develop personal skills' (Action Area 1). 'Re-orienting health services' (Action Area 2) can address the needs of vulnerable population subgroups, such as the culturally sensitive diabetes prevention programme established for an Indo-Asian community in Canada. Identifying geographic areas at high risk of childhood obesity enables better strategic planning and targeting of resources to 'strengthen community action' (Action Area 3). Calorie menu labelling can 'create supportive environments' (Action Area 4) through encouraging a demand for less energy-dense, healthier food options. 'Building healthy public policy' (Action Area 5) to implement mandatory folic acid food fortification for prevention of birth defects has many advantages over a voluntary approach. In conclusion, evaluation and evidence-based decision-making needs to take account of different strategies used to take action in each of these priority areas. For this, the randomised control trial needs adaptation to determine the best practice in public health nutrition where interventions play out in real life with all its confounding factors.

Intervention strategies to improve nutrition and health behaviours before conception.

PubMed

Barker, Mary; Dombrowski, Stephan U; Colbourn, Tim; Fall, Caroline H D; Kriznik, Natasha M; Lawrence, Wendy T; Norris, Shane A; Ngaiza, Gloria; Patel, Dilisha; Skordis-Worrall, Jolene; Sniehotta, Falko F; Steegers-Theunissen, Régine; Vogel, Christina; Woods-Townsend, Kathryn; Stephenson, Judith

2018-05-05

The nutritional status of both women and men before conception has profound implications for the growth, development, and long-term health of their offspring. Evidence of the effectiveness of preconception interventions for improving outcomes for mothers and babies is scarce. However, given the large potential health return, and relatively low costs and risk of harm, research into potential interventions is warranted. We identified three promising strategies for intervention that are likely to be scalable and have positive effects on a range of health outcomes: supplementation and fortification; cash transfers and incentives; and behaviour change interventions. On the basis of these strategies, we suggest a model specifying pathways to effect. Pathways are incorporated into a life-course framework using individual motivation and receptiveness at different preconception action phases, to guide design and targeting of preconception interventions. Interventions for individuals not planning immediate pregnancy take advantage of settings and implementation platforms outside the maternal and child health arena, since this group is unlikely to be engaged with maternal health services. Interventions to improve women's nutritional status and health behaviours at all preconception action phases should consider social and environmental determinants, to avoid exacerbating health and gender inequalities, and be underpinned by a social movement that touches the whole population. We propose a dual strategy that targets specific groups actively planning a pregnancy, while improving the health of the population more broadly. Modern marketing techniques could be used to promote a social movement based on an emotional and symbolic connection between improved preconception maternal health and nutrition, and offspring health. We suggest that speedy and scalable benefits to public health might be achieved through strategic engagement with the private sector. Political theory supports the development of an advocacy coalition of groups interested in preconception health, to harness the political will and leadership necessary to turn high-level policy into effective coordinated action. Copyright © 2018 Elsevier Ltd. All rights reserved.

Individual differences in personality profiles among potential living kidney transplant donors

PubMed Central

Rodríguez-Marín, Jesús; Martínez-Zaragoza, Fermín; de Santiago-Guervós, Carlos

2013-01-01

Background: Although the psychological assessment of potential living kidney donors (PLKD) is part of the recommendations for action for any transplant coordination, there are not many studies that provide data about the importance of selecting donors for improving transplant outcomes. This work aims to raise awareness of potential kidney donors by designing methods for early detection of potential problems after the transplant, as well as by selecting the most suitable donors. Methods: This is a study of 25 PLKD drawn from the General University Hospital of Alicante. Participants completed the Millon Clinical Multiaxial Inventory (MCMI-III) for the study of personality characteristics. Results: Women scored higher than men in the compulsive personality scale, and individuals with a genetic link with the recipient scored higher on depressive and dependent scales than did those with other relationships (emotional or altruistic). Conclusions: Women showed a pattern of significantly more compulsive personality traits (cautious, controlled, perfectionist) within a non-pathological style. Among the PLKD, there were significantly more women, which is contrary to what typically happens with donations from cadavers. Genetically related subjects scored higher on depression than did those that were emotionally related. The personality assessment of candidates for PLKD can help with developing a post-transplant follow-up regimen for an improved quality of life. PMID:24892237

41 CFR 60-741.44 - Required contents of affirmative action programs.

Code of Federal Regulations, 2011 CFR

2011-07-01

... affirmative action programs. 60-741.44 Section 60-741.44 Public Contracts and Property Management Other... OPPORTUNITY, DEPARTMENT OF LABOR 741-AFFIRMATIVE ACTION AND NONDISCRIMINATION OBLIGATIONS OF CONTRACTORS AND SUBCONTRACTORS REGARDING INDIVIDUALS WITH DISABILITIES Affirmative Action Program § 60-741.44 Required contents...

41 CFR 60-741.40 - Applicability of the affirmative action program requirement.

Code of Federal Regulations, 2011 CFR

2011-07-01

... affirmative action program requirement. 60-741.40 Section 60-741.40 Public Contracts and Property Management... EMPLOYMENT OPPORTUNITY, DEPARTMENT OF LABOR 741-AFFIRMATIVE ACTION AND NONDISCRIMINATION OBLIGATIONS OF CONTRACTORS AND SUBCONTRACTORS REGARDING INDIVIDUALS WITH DISABILITIES Affirmative Action Program § 60-741.40...

41 CFR 60-741.40 - Applicability of the affirmative action program requirement.

Code of Federal Regulations, 2010 CFR

2010-07-01

... affirmative action program requirement. 60-741.40 Section 60-741.40 Public Contracts and Property Management... EMPLOYMENT OPPORTUNITY, DEPARTMENT OF LABOR 741-AFFIRMATIVE ACTION AND NONDISCRIMINATION OBLIGATIONS OF CONTRACTORS AND SUBCONTRACTORS REGARDING INDIVIDUALS WITH DISABILITIES Affirmative Action Program § 60-741.40...

Parental Involvement in the Habilitation Process Following Children's Cochlear Implantation: An Action Theory Perspective

ERIC Educational Resources Information Center

Zaidman-Zait, Anat; Young, Richard A.

2008-01-01

Action theory and the qualitative action-project method are used in this study to address and illustrate the complexity of parenting children who have received cochlear implants (CIs) as well as the intentionality of parents engaged in that process. "Action" refers to individual and joint goal-directed and intentional behaviors. Action theory has…

Cellular resolution circuit mapping with temporal-focused excitation of soma-targeted channelrhodopsin

PubMed Central

Baker, Christopher A; Elyada, Yishai M; Parra, Andres; Bolton, M McLean

2016-01-01

We describe refinements in optogenetic methods for circuit mapping that enable measurements of functional synaptic connectivity with single-neuron resolution. By expanding a two-photon beam in the imaging plane using the temporal focusing method and restricting channelrhodopsin to the soma and proximal dendrites, we are able to reliably evoke action potentials in individual neurons, verify spike generation with GCaMP6s, and determine the presence or absence of synaptic connections with patch-clamp electrophysiological recording. DOI: http://dx.doi.org/10.7554/eLife.14193.001 PMID:27525487

Toward a More Efficient Implementation of Antifibrillation Pacing

PubMed Central

Wilson, Dan; Moehlis, Jeff

2016-01-01

We devise a methodology to determine an optimal pattern of inputs to synchronize firing patterns of cardiac cells which only requires the ability to measure action potential durations in individual cells. In numerical bidomain simulations, the resulting synchronizing inputs are shown to terminate spiral waves with a higher probability than comparable inputs that do not synchronize the cells as strongly. These results suggest that designing stimuli which promote synchronization in cardiac tissue could improve the success rate of defibrillation, and point towards novel strategies for optimizing antifibrillation pacing. PMID:27391010

Understanding the Electrical Behavior of the Action Potential in Terms of Elementary Electrical Sources

ERIC Educational Resources Information Center

Rodriguez-Falces, Javier

2015-01-01

A concept of major importance in human electrophysiology studies is the process by which activation of an excitable cell results in a rapid rise and fall of the electrical membrane potential, the so-called action potential. Hodgkin and Huxley proposed a model to explain the ionic mechanisms underlying the formation of action potentials. However,…

Detachable glass microelectrodes for recording action potentials in active moving organs.

PubMed

Barbic, Mladen; Moreno, Angel; Harris, Tim D; Kay, Matthew W

2017-06-01

Here, we describe new detachable floating glass micropipette electrode devices that provide targeted action potential recordings in active moving organs without requiring constant mechanical constraint or pharmacological inhibition of tissue motion. The technology is based on the concept of a glass micropipette electrode that is held firmly during cell targeting and intracellular insertion, after which a 100-µg glass microelectrode, a "microdevice," is gently released to remain within the moving organ. The microdevices provide long-term recordings of action potentials, even during millimeter-scale movement of tissue in which the device is embedded. We demonstrate two different glass micropipette electrode holding and detachment designs appropriate for the heart (sharp glass microdevices for cardiac myocytes in rats, guinea pigs, and humans) and the brain (patch glass microdevices for neurons in rats). We explain how microdevices enable measurements of multiple cells within a moving organ that are typically difficult with other technologies. Using sharp microdevices, action potential duration was monitored continuously for 15 min in unconstrained perfused hearts during global ischemia-reperfusion, providing beat-to-beat measurements of changes in action potential duration. Action potentials from neurons in the hippocampus of anesthetized rats were measured with patch microdevices, which provided stable base potentials during long-term recordings. Our results demonstrate that detachable microdevices are an elegant and robust tool to record electrical activity with high temporal resolution and cellular level localization without disturbing the physiological working conditions of the organ. NEW & NOTEWORTHY Cellular action potential measurements within tissue using glass micropipette electrodes usually require tissue immobilization, potentially influencing the physiological relevance of the measurement. Here, we addressed this limitation with novel 100-µg detachable glass microelectrodes that can be precisely positioned to provide long-term measurements of action potential duration during unconstrained tissue movement. Copyright © 2017 the American Physiological Society.

Collective Action Problem in Heterogeneous Groups with Punishment and Foresight

NASA Astrophysics Data System (ADS)

Perry, Logan; Shrestha, Mahendra Duwal; Vose, Michael D.; Gavrilets, Sergey

2018-03-01

The collective action problem can easily undermine cooperation in groups. Recent work has shown that within-group heterogeneity can under some conditions promote voluntary provisioning of collective goods. Here we generalize this work for the case when individuals can not only contribute to the production of collective goods, but also punish free-riders. To do this, we extend the standard theory by allowing individuals to have limited foresight so they can anticipate actions of their group-mates. For humans, this is a realistic assumption because we possess a "theory of mind". We use agent-based simulations to study collective actions that aim to overcome challenges from nature or win competition with neighboring groups. We contrast the dynamics of collective action in egalitarian and hierarchical groups. We show that foresight allows groups to overcome both the first- and second-order free-rider problems. While foresight increases cooperation, it does not necessarily result in higher payoffs. We show that while between-group conflicts promotes within-group cooperation, the effects of cultural group selection on cooperation are relatively small. Our models predict the emergence of a division of labor in which more powerful individuals specialize in punishment while less powerful individuals mostly contribute to the production of collective goods.

Reafferent copies of imitated actions in the right superior temporal cortex

PubMed Central

Iacoboni, Marco; Koski, Lisa M.; Brass, Marcel; Bekkering, Harold; Woods, Roger P.; Dubeau, Marie-Charlotte; Mazziotta, John C.; Rizzolatti, Giacomo

2001-01-01

Imitation is a complex phenomenon, the neural mechanisms of which are still largely unknown. When individuals imitate an action that already is present in their motor repertoire, a mechanism matching the observed action onto an internal motor representation of that action should suffice for the purpose. When one has to copy a new action, however, or to adjust an action present in one's motor repertoire to a different observed action, an additional mechanism is needed that allows the observer to compare the action made by another individual with the sensory consequences of the same action made by himself. Previous experiments have shown that a mechanism that directly matches observed actions on their motor counterparts exists in the premotor cortex of monkeys and humans. Here we report the results of functional magnetic resonance experiments, suggesting that in the superior temporal sulcus, a higher order visual region, there is a sector that becomes active both during hand action observation and during imitation even in the absence of direct vision of the imitator's hand. The motor-related activity is greater during imitation than during control motor tasks. This newly identified region has all the requisites for being the region at which the observed actions, and the reafferent motor-related copies of actions made by the imitator, interact. PMID:11717457

The Economics and Sociology of Religious Giving: Instrumental Rationality or Communal Bonding?

ERIC Educational Resources Information Center

Peifer, Jared L.

2010-01-01

Religious individuals commonly make sizable monetary sacrifices by contributing to their congregations. This social action resides in the overlap of religious and economic realms of behavior, creating a certain tension. Following a Weberian approach to social inquiry, I treat religious giving as social action whereby individuals direct their…

Thought-action fusion in individuals with OCD symptoms.

PubMed

Amir, N; Freshman, M; Ramsey, B; Neary, E; Brigidi, B

2001-07-01

Rachman (Rachman, S. (1993). Obsessions, responsibility, and guilt. Behaviour Research and Therapy, 31, 149-154) suggested that patients with OCD may interpret thoughts as having special importance, thus experiencing thought-action fusion (TAF). Shafran, Thordarson and Rachman (Shafran, R., Thordarson, D. S. & Rachman, S. (1996). Thought-action fusion in obsessive compulsive disorder. Journal of Anxiety Disorders, 710, 379-391) developed a questionnaire (TAF) and found that obsessives scored higher than non-obsessives on the measure. In the current study, we modified the TAF to include a scale that assessed the "likelihood of events happening to others" as well as ratings of the responsibility and cost for having these thoughts. Replicating previous findings, we found that individuals with OC symptoms gave higher ratings to the likelihood of negative events happening as a result of their negative thoughts. Individuals with OC symptoms also rated the likelihood that they would prevent harm by their positive thoughts higher than did individuals without OC symptoms. These results suggest that the role of thought-action fusion in OCs may extend to exaggerated beliefs about thoughts regarding the reduction of harm.

Quadratic adaptive algorithm for solving cardiac action potential models.

PubMed

Chen, Min-Hung; Chen, Po-Yuan; Luo, Ching-Hsing

2016-10-01

An adaptive integration method is proposed for computing cardiac action potential models accurately and efficiently. Time steps are adaptively chosen by solving a quadratic formula involving the first and second derivatives of the membrane action potential. To improve the numerical accuracy, we devise an extremum-locator (el) function to predict the local extremum when approaching the peak amplitude of the action potential. In addition, the time step restriction (tsr) technique is designed to limit the increase in time steps, and thus prevent the membrane potential from changing abruptly. The performance of the proposed method is tested using the Luo-Rudy phase 1 (LR1), dynamic (LR2), and human O'Hara-Rudy dynamic (ORd) ventricular action potential models, and the Courtemanche atrial model incorporating a Markov sodium channel model. Numerical experiments demonstrate that the action potential generated using the proposed method is more accurate than that using the traditional Hybrid method, especially near the peak region. The traditional Hybrid method may choose large time steps near to the peak region, and sometimes causes the action potential to become distorted. In contrast, the proposed new method chooses very fine time steps in the peak region, but large time steps in the smooth region, and the profiles are smoother and closer to the reference solution. In the test on the stiff Markov ionic channel model, the Hybrid blows up if the allowable time step is set to be greater than 0.1ms. In contrast, our method can adjust the time step size automatically, and is stable. Overall, the proposed method is more accurate than and as efficient as the traditional Hybrid method, especially for the human ORd model. The proposed method shows improvement for action potentials with a non-smooth morphology, and it needs further investigation to determine whether the method is helpful during propagation of the action potential. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modulation of mu suppression in children with autism spectrum disorders in response to familiar or unfamiliar stimuli: the mirror neuron hypothesis.

PubMed

Oberman, Lindsay M; Ramachandran, Vilayanur S; Pineda, Jaime A

2008-04-01

In an early description of the mu rhythm, Gastaut and Bert [Gastaut, H. J., & Bert, J. (1954). EEG changes during cinematographic presentation. Clinical Neurophysiology, 6, 433-444] noted that it was blocked when an individual identified himself with an active person on the screen, suggesting that it may be modulated by the degree to which the individual can relate to the observed action. Additionally, multiple recent studies suggest that the mirror neurons system (MNS) is impaired in individuals with autism spectrum disorders (ASD), which may affect their ability to relate to others. The current study aimed to investigate MNS sensitivity by examining mu suppression to familiarity, i.e., the degree to which the observer is able to identify with the actor on the screen by using familiar versus unfamiliar actors. The participants viewed four 80s videos that included: (1) stranger: an unfamiliar hand performing a grasping action; (2) familiar: the child's guardian or sibling's hand performing the same action; (3) own: the participant's own hand performing the same action; (4) bouncing balls: two balls moving vertically toward and away from each other. The study revealed that mu suppression was sensitive to degree of familiarity. Both typically developing participants and those with ASD showed greater suppression to familiar hands compared to those of strangers. These findings suggest that the MNS responds to observed actions in individuals with ASD, but only when individuals can identify in some personal way with the stimuli.

Active Videogaming for Individuals with Severe Movement Disorders: Results from a Community Study.

PubMed

Chung, Peter J; Vanderbilt, Douglas L; Schrager, Sheree M; Nguyen, Eugene; Fowler, Eileen

2015-06-01

Active videogaming (AVG) has potential to provide positive health outcomes for individuals with cerebral palsy (CP), but their use for individuals with severe motor impairments is limited. Our objective was to evaluate the accessibility and enjoyment of videogames using the Kinect™ (Microsoft, Redmond, WA) with the Flexible Action and Articulated Skeleton Toolkit (FAAST) system (University of Southern California Institute for Creative Technologies, Los Angeles, CA) for individuals with severely limiting CP. A videogaming system was installed in a community center serving adults with CP, and a staff member was instructed in its use. Participants completed a baseline survey assessing demographics, mobility, and prior videogame experience; they then used the FAAST system with Kinect and completed a 5-point Likert survey to assess their experience. Descriptive statistics assessed overall enjoyment of the system, and Mann-Whitney U tests were conducted to determine whether responses differed by demographic factors, mobility, or prior videogame experience. Twenty-two subjects were recruited. The enjoyment scale demonstrated high internal consistency (Cronbach's alpha=0.88). The mean total enjoyment score was 4.24 out of 5. Median scores did not significantly differ by ethnicity, gender, CP severity, or previous videogame exposure. The FAAST with Kinect is a low-cost system that engages individuals with severe movement disorders across a wide range of physical ability and videogame experience. Further research should be conducted on in-home use, therapeutic applications, and potential benefits for socialization.

36 CFR 905.735-108 - Remedial and disciplinary action.

Code of Federal Regulations, 2010 CFR

2010-07-01

... DEVELOPMENT CORPORATION STANDARDS OF CONDUCT General Provisions § 905.735-108 Remedial and disciplinary action... assignment; (3) Changes in the assigned duties of the individual; or (4) Disciplinary action. (b) Where the situation warrants some form of disciplinary action, the Chairman may choose from a wide range including a...

34 CFR 364.31 - What are the affirmative action requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 34 Education 2 2011-07-01 2010-07-01 true What are the affirmative action requirements? 364.31... Requirements? § 364.31 What are the affirmative action requirements? The State plan must include satisfactory... Act will take affirmative action to employ and advance in employment qualified individuals with...

34 CFR 369.43 - What are the affirmative action plan requirements affecting grantees?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 2 2010-07-01 2010-07-01 false What are the affirmative action plan requirements... affirmative action plan requirements affecting grantees? A recipient of Federal assistance must develop and implement an affirmative action plan to employ and advance in employment qualified individuals with...

34 CFR 369.43 - What are the affirmative action plan requirements affecting grantees?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 34 Education 2 2011-07-01 2010-07-01 true What are the affirmative action plan requirements... affirmative action plan requirements affecting grantees? A recipient of Federal assistance must develop and implement an affirmative action plan to employ and advance in employment qualified individuals with...

34 CFR 364.31 - What are the affirmative action requirements?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 2 2010-07-01 2010-07-01 false What are the affirmative action requirements? 364.31... Requirements? § 364.31 What are the affirmative action requirements? The State plan must include satisfactory... Act will take affirmative action to employ and advance in employment qualified individuals with...

Comparative antibacterial activity of hexachlorophane in different formulations used for skin disinfection

PubMed Central

Gibson, J. W.

1969-01-01

Two formulations of hexachlorophane have been compared for their antibacterial effects in respect of skin disinfection. It was found that the activity of hexachlorophane is dependent upon its vehicle of formulation. A 2·5% soap gel possesses broad-spectrum bactericidal activity with remarkable speed of kill, whereas a 3% detergent formulation has no bactericidal action against Gram-negative bacteria and only a very slow action against Gram-positive bacteria. In practice the rapid action of the 2·5% soap gel against both Gram-negative and Gram-positive transient skin bacteria can be achieved by correctly applying the preparation directly to the dry hands. It appears that the 2·5% soap gel does not need to rely on mechanical removal of transient organisms as does the 3% detergent. The 2·5% soap gel is more dependable in its action on the resident bacteria than the 3% detergent. It controlled the resident flora in the skin of all subjects tested whereas the latter appeared to be potentiated on the skin of certain individuals only. It has been possible to distinguish between the antibacterial effect on the resident organisms and the mere removal of transient bacteria by mechanical action of the 3% detergent as opposed to antibacterial effect on residents and rapid antibacterial effect on transients by the 2·5% soap gel. PMID:5784696

Legal liability in bisphosphonate-related osteonecrosis of the jaw.

PubMed

Lo Russo, L; Ciavarella, D; Buccelli, C; Di Fede, O; Campisi, G; Lo Muzio, L; Pellegrino, G; Di Lorenzo, P

2014-09-01

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is an adverse reaction that may occur in patients administered with bisphosphonates (BP). This condition can cause high morbidity and hinder quality of life. Its treatment is complex and often unsatisfactory, and prevention strategies may have limited effectiveness, if any. Thus, managing patients treated with BP may result in exposure of the practitioner to legal liability or malpractice claims: legal actions pursuant to BRONJ are reported to be underway on three continents. Nonetheless, the attribution of liability, if any, is a complex process requiring, on the basis of current knowledge, a robust and pragmatic approach to the facts, which must be identified from the point of view of the time, place and individuals involved. This means a comprehensive consideration of the sequence of actions from bisphosphonates prescription to BRONJ occurrence (as well as immediately after, and any action potentially related to its causation or worsening) is required in order to determine if a breach in informing, diagnosing, managing or referring the patient took place, as well as determining if the patient was compliant in attending to prescriptions and follow-up programmes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walker, Heidi, E-mail: heidi.mwalker@yahoo.ca; Sinclair, A. John, E-mail: john.sinclair@ad.umanitoba.ca; Spaling, Harry, E-mail: harry.spaling@kingsu.ca

Meaningful public engagement is a challenging, but promising, feature of strategic environmental assessment (SEA) due to its potential for integrating sustainability principles into policies, plans and programs in developing countries such as Kenya. This research examined two selected SEA case studies to identify the extent of participation, learning outcomes attributable to participation, and if any learning outcomes led to social action for sustainability at the community level. Strengths across the two cases were the inclusion of marginalized populations and consideration of socio-economic concerns. Consistent weaknesses included inadequate notice, document inaccessibility, lack of feedback and communication, and late analysis of alternatives.more » Despite some learning conditions being unfulfilled, examples of instrumental, communicative, and transformative learning were identified through a focus group and semi-structured interviews with community participants and public officials. Some of these learning outcomes led to individual and social actions that contribute to sustainability. -- Highlights: • The strengths and weaknesses of Kenyan SEA public participation processes were identified. • Multiple deficiencies in the SEA process likely frustrate meaningful public engagement. • Participant learning was observed despite process weaknesses. • Participant learning can lead to action for sustainability at the community level.« less

Towards autonomous fuzzy control

NASA Technical Reports Server (NTRS)

Shenoi, Sujeet; Ramer, Arthur

1993-01-01

The efficient implementation of on-line adaptation in real time is an important research problem in fuzzy control. The goal is to develop autonomous self-organizing controllers employing system-independent control meta-knowledge which enables them to adjust their control policies depending on the systems they control and the environments in which they operate. An autonomous fuzzy controller would continuously observe system behavior while implementing its control actions and would use the outcomes of these actions to refine its control policy. It could be designed to lie dormant when its control actions give rise to adequate performance characteristics but could rapidly and autonomously initiate real-time adaptation whenever its performance degrades. Such an autonomous fuzzy controller would have immense practical value. It could accommodate individual variations in system characteristics and also compensate for degradations in system characteristics caused by wear and tear. It could also potentially deal with black-box systems and control scenarios. On-going research in autonomous fuzzy control is reported. The ultimate research objective is to develop robust and relatively inexpensive autonomous fuzzy control hardware suitable for use in real time environments.

How parents process child health and nutrition information: A grounded theory model.

PubMed

Lovell, Jennifer L

2016-02-01

The aim of the present study was to investigate low-income parents' experiences receiving, making meaning of, and applying sociocultural messages about childhood health and nutrition. Semi-structured interviews were conducted with parents from 16 low-income Early Head Start families. Verbatim interview transcripts, observations, field notes, documentary evidence, and follow-up participant checks were used during grounded theory analysis of the data. Data yielded a potential theoretical model of parental movement toward action involving (a) the culture and context influencing parents, (b) parents' sources of social and cultural messages, (c) parental values and engagement, (d) parental motivation for action, (e) intervening conditions impacting motivation and application, and (f) parent action taken on the individual and social levels. Parent characteristics greatly impacted the ways in which parents understood and applied health and nutrition information. Among other implications, it is recommended that educators and providers focus on a parent's beliefs, values, and cultural preferences regarding food and health behaviors as well as his/her personal/family definition of "health" when framing recommendations and developing interventions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Community gardening: a parsimonious path to individual, community, and environmental resilience.

PubMed

Okvat, Heather A; Zautra, Alex J

2011-06-01

The goal of this paper is to introduce community gardening as a promising method of furthering well-being and resilience on multiple levels: individual, social group, and natural environment. We examine empirical evidence for the benefits of gardening, and we advocate the development and testing of social ecological models of community resilience through examination of the impact of community gardens, especially in urban areas. The definition of community is extended beyond human social ties to include connections with other species and the earth itself, what Berry (1988) has called an Earth community. We discuss the potential contribution of an extensive network of community gardens to easing the global climate change crisis and address the role of community psychologists in community gardening research and policy-oriented action.

Improving disclosure and consent: "is it safe?": new ethics for reporting personal exposures to environmental chemicals.

PubMed

Brody, Julia Green; Morello-Frosch, Rachel; Brown, Phil; Rudel, Ruthann A; Altman, Rebecca Gasior; Frye, Margaret; Osimo, Cheryl A; Pérez, Carla; Seryak, Liesel M

2007-09-01

The recent flood of research concerning pollutants in personal environmental and biological samples-blood, urine, breastmilk, household dust and air, umbilical cord blood, and other media-raises questions about whether and how to report results to individual study participants. Clinical medicine provides an expert-driven framework, whereas community-based participatory research emphasizes participants' right to know and the potential to inform action even when health effects are uncertain. Activist efforts offer other models. We consider ethical issues involved in the decision to report individual results in exposure studies and what information should be included. Our discussion is informed by our experience with 120 women in a study of 89 pollutants in homes and by interviews with other researchers and institutional review board staff.

[The harm to health of the under-age individuals as an objective criterion for the differentiation of criminal responsibilities for committing non-violent sexual offence against them].

PubMed

Bimbinov, A A

2016-01-01

The present publication is devoted to the search for the objective criterion for the differentiation of criminal responsibilities for committing non-violent sexual offence against the juveniles under the age of 16 years. It has been shown that the current version of articles 134 and 135 of the criminal code of the Russian Federation does not adequately reflect the true character and the social danger of such actions. The formal methods of the legal, logical, and concrete sociological analysis were employed to substantiate the necessity of differentiation of criminal liability for the non-violent sexual abuse depending on the degree of potential harm to the health of the under-age individuals.

Managing Multiple Chronic Conditions: A Strategic Framework for Improving Health Outcomes and Quality of Life

PubMed Central

Parekh, Anand K.; Goodman, Richard A.; Gordon, Catherine; Koh, Howard K.

2011-01-01

The escalating problem of multiple chronic conditions (MCC) among Americans is now a major public health and medical challenge, associated with suboptimal health outcomes and rising health-care expenses. Despite this problem's growth, the delivery of health services has continued to employ outmoded “siloed” approaches that focus on individual chronic diseases. We describe an action-oriented framework—developed by the U.S. Department of Health and Human Services with additional input provided by stakeholder organizations—that outlines national strategies for maximizing care coordination and for improving health and quality of life for individuals with MCC. We note how the framework's potential can be optimized through some of the provisions of the new Patient Protection and Affordable Care Act, and through public-private partnerships. PMID:21800741

Partnering With Community-Dwelling Individuals With Diabetes for Health Behavior Change Using Action Plans: An Innovation in Health Professionals Education and Practice.

PubMed

Barry Hultquist, Teresa; Brown, Sara Goomis; Geske, Jenenne; Kaiser, Katherine Laux; Waibel-Rycek, Denise

2015-11-01

Health care practitioners support or hinder an individual's attempts to self-manage health behavior. Practitioners must understand an individual's health needs and goals to effectively partner for behavior change. Self-management support (SMS) promote efforts toward positive health behavior change. Practitioners need training to provide effective SMS, beginning with their formal education. The purpose of this educational practice project was to integrate an evidence-based intervention (SMS using action plans) into a nursing curriculum. Three sequential steps included (1) providing foundational SMS education, (2) SMS application with students' personal action plans, and (3) implementing SMS with community-dwelling individuals with diabetes. Students (n = 130) partnered with participants (n = 85), developing short- (n = 240) and long-term (n = 99) action plans during home visits. The average baseline Diabetes Empowerment Scale score measuring participant's perceived psychosocial diabetes management self-efficacy was 4.3 (1-5 scale, SD = 0.51, n = 83). Most common short-term actions related to physical activity (n = 100, 42%) and healthy eating (n = 61, 25%). Average participant confidence level was 7.7 (SD = 1.9, 0-10 scale). Short-term goal evaluation (n = 209) revealed 66% (n = 137) were met more than 50% of the time. Both participants (99%) and students (99%) expressed satisfaction with home visit and action plan experiences. This teaching-learning experience is replicable and applicable to any professional health care student. © 2015 Society for Public Health Education.

Sodium Channel Nav1.8 Underlies TTX-Resistant Axonal Action Potential Conduction in Somatosensory C-Fibers of Distal Cutaneous Nerves.

PubMed

Klein, Amanda H; Vyshnevska, Alina; Hartke, Timothy V; De Col, Roberto; Mankowski, Joseph L; Turnquist, Brian; Bosmans, Frank; Reeh, Peter W; Schmelz, Martin; Carr, Richard W; Ringkamp, Matthias

2017-05-17

Voltage-gated sodium (Na V ) channels are responsible for the initiation and conduction of action potentials within primary afferents. The nine Na V channel isoforms recognized in mammals are often functionally divided into tetrodotoxin (TTX)-sensitive (TTX-s) channels (Na V 1.1-Na V 1.4, Na V 1.6-Na V 1.7) that are blocked by nanomolar concentrations and TTX-resistant (TTX-r) channels (Na V 1.8 and Na V 1.9) inhibited by millimolar concentrations, with Na V 1.5 having an intermediate toxin sensitivity. For small-diameter primary afferent neurons, it is unclear to what extent different Na V channel isoforms are distributed along the peripheral and central branches of their bifurcated axons. To determine the relative contribution of TTX-s and TTX-r channels to action potential conduction in different axonal compartments, we investigated the effects of TTX on C-fiber-mediated compound action potentials (C-CAPs) of proximal and distal peripheral nerve segments and dorsal roots from mice and pigtail monkeys ( Macaca nemestrina ). In the dorsal roots and proximal peripheral nerves of mice and nonhuman primates, TTX reduced the C-CAP amplitude to 16% of the baseline. In contrast, >30% of the C-CAP was resistant to TTX in distal peripheral branches of monkeys and WT and Na V 1.9 -/- mice. In nerves from Na V 1.8 -/- mice, TTX-r C-CAPs could not be detected. These data indicate that Na V 1.8 is the primary isoform underlying TTX-r conduction in distal axons of somatosensory C-fibers. Furthermore, there is a differential spatial distribution of Na V 1.8 within C-fiber axons, being functionally more prominent in the most distal axons and terminal regions. The enrichment of Na V 1.8 in distal axons may provide a useful target in the treatment of pain of peripheral origin. SIGNIFICANCE STATEMENT It is unclear whether individual sodium channel isoforms exert differential roles in action potential conduction along the axonal membrane of nociceptive, unmyelinated peripheral nerve fibers, but clarifying the role of sodium channel subtypes in different axonal segments may be useful for the development of novel analgesic strategies. Here, we provide evidence from mice and nonhuman primates that a substantial portion of the C-fiber compound action potential in distal peripheral nerves, but not proximal nerves or dorsal roots, is resistant to tetrodotoxin and that, in mice, this effect is mediated solely by voltage-gated sodium channel 1.8 (Na V 1.8). The functional prominence of Na V 1.8 within the axonal compartment immediately proximal to its termination may affect strategies targeting pain of peripheral origin. Copyright © 2017 the authors 0270-6474/17/375205-11$15.00/0.

Effects of tacrolimus on action potential configuration and transmembrane ion currents in canine ventricular cells.

PubMed

Szabó, László; Szentandrássy, Norbert; Kistamás, Kornél; Hegyi, Bence; Ruzsnavszky, Ferenc; Váczi, Krisztina; Horváth, Balázs; Magyar, János; Bányász, Tamás; Pál, Balázs; Nánási, Péter P

2013-03-01

Tacrolimus is a commonly used immunosuppressive agent which causes cardiovascular complications, e.g., hypertension and hypertrophic cardiomyopathy. In spite of it, there is little information on the cellular cardiac effects of the immunosuppressive agent tacrolimus in larger mammals. In the present study, therefore, the concentration-dependent effects of tacrolimus on action potential morphology and the underlying ion currents were studied in canine ventricular cardiomyocytes. Standard microelectrode, conventional whole cell patch clamp, and action potential voltage clamp techniques were applied in myocytes enzymatically dispersed from canine ventricular myocardium. Tacrolimus (3-30 μM) caused a concentration-dependent reduction of maximum velocity of depolarization and repolarization, action potential amplitude, phase-1 repolarization, action potential duration, and plateau potential, while no significant change in the resting membrane potential was observed. Conventional voltage clamp experiments revealed that tacrolimus concentrations ≥3 μM blocked a variety of ion currents, including I(Ca), I(to), I(K1), I(Kr), and I(Ks). Similar results were obtained under action potential voltage clamp conditions. These effects of tacrolimus developed rapidly and were fully reversible upon washout. The blockade of inward currents with the concomitant shortening of action potential duration in canine myocytes is the opposite of those observed previously with tacrolimus in small rodents. It is concluded that although tacrolimus blocks several ion channels at higher concentrations, there is no risk of direct interaction with cardiac ion channels when applying tacrolimus in therapeutic concentrations.

TRPM4 non-selective cation channels influence action potentials in rabbit Purkinje fibres.

PubMed

Hof, Thomas; Sallé, Laurent; Coulbault, Laurent; Richer, Romain; Alexandre, Joachim; Rouet, René; Manrique, Alain; Guinamard, Romain

2016-01-15

The transient receptor potential melastatin 4 (TRPM4) inhibitor 9-phenanthrol reduces action potential duration in rabbit Purkinje fibres but not in ventricle. TRPM4-like single channel activity is observed in isolated rabbit Purkinje cells but not in ventricular cells. The TRPM4-like current develops during the notch and early repolarization phases of the action potential in Purkinje cells. Transient receptor potential melastatin 4 (TRPM4) Ca(2+)-activated non-selective cation channel activity has been recorded in cardiomyocytes and sinus node cells from mammals. In addition, TRPM4 gene mutations are associated with human diseases of cardiac conduction, suggesting that TRPM4 plays a role in this aspect of cardiac function. Here we evaluate the TRPM4 contribution to cardiac electrophysiology of Purkinje fibres. Ventricular strips with Purkinje fibres were isolated from rabbit hearts. Intracellular microelectrodes recorded Purkinje fibre activity and the TRPM4 inhibitor 9-phenanthrol was applied to unmask potential TRPM4 contributions to the action potential. 9-Phenanthrol reduced action potential duration measured at the point of 50 and 90% repolarization with an EC50 of 32.8 and 36.1×10(-6) mol l(-1), respectively, but did not modulate ventricular action potentials. Inside-out patch-clamp recordings were used to monitor TRPM4 activity in isolated Purkinje cells. TRPM4-like single channel activity (conductance = 23.8 pS; equal permeability for Na(+) and K(+); sensitivity to voltage, Ca(2+) and 9-phenanthrol) was observed in 43% of patches from Purkinje cells but not from ventricular cells (0/16). Action potential clamp experiments performed in the whole-cell configuration revealed a transient inward 9-phenanthrol-sensitive current (peak density = -0.65 ± 0.15 pA pF(-1); n = 5) during the plateau phases of the Purkinje fibre action potential. These results show that TRPM4 influences action potential characteristics in rabbit Purkinje fibres and thus could modulate cardiac conduction and be involved in triggering arrhythmias. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

14 CFR 1216.306 - Actions normally requiring an EIS.

Code of Federal Regulations, 2013 CFR

2013-01-01

... normally requiring an EIS. (a) NASA will prepare an EIS for actions with the potential to significantly... action or mitigation of its potentially significant impacts. (b) Typical NASA actions normally requiring... material greater than the quantity for which the NASA Nuclear Flight Safety Assurance Manager may grant...

Rhythm in joint action: psychological and neurophysiological mechanisms for real-time interpersonal coordination

PubMed Central

Keller, Peter E.; Novembre, Giacomo; Hove, Michael J.

2014-01-01

Human interaction often requires simultaneous precision and flexibility in the coordination of rhythmic behaviour between individuals engaged in joint activity, for example, playing a musical duet or dancing with a partner. This review article addresses the psychological processes and brain mechanisms that enable such rhythmic interpersonal coordination. First, an overview is given of research on the cognitive-motor processes that enable individuals to represent joint action goals and to anticipate, attend and adapt to other's actions in real time. Second, the neurophysiological mechanisms that underpin rhythmic interpersonal coordination are sought in studies of sensorimotor and cognitive processes that play a role in the representation and integration of self- and other-related actions within and between individuals' brains. Finally, relationships between social–psychological factors and rhythmic interpersonal coordination are considered from two perspectives, one concerning how social-cognitive tendencies (e.g. empathy) affect coordination, and the other concerning how coordination affects interpersonal affiliation, trust and prosocial behaviour. Our review highlights musical ensemble performance as an ecologically valid yet readily controlled domain for investigating rhythm in joint action. PMID:25385772

The perception of rational, goal-directed action in nonhuman primates.

PubMed

Wood, Justin N; Glynn, David D; Phillips, Brenda C; Hauser, Marc D

2007-09-07

Humans are capable of making inferences about other individuals' intentions and goals by evaluating their actions in relation to the constraints imposed by the environment. This capacity enables humans to go beyond the surface appearance of behavior to draw inferences about an individual's mental states. Presently unclear is whether this capacity is uniquely human or is shared with other animals. We show that cotton-top tamarins, rhesus macaques, and chimpanzees all make spontaneous inferences about a human experimenter's goal by attending to the environmental constraints that guide rational action. These findings rule out simple associative accounts of action perception and show that our capacity to infer rational, goal-directed action likely arose at least as far back as the New World monkeys, some 40 million years ago.

Cell-type-dependent action potentials and voltage-gated currents in mouse fungiform taste buds.

PubMed

Kimura, Kenji; Ohtubo, Yoshitaka; Tateno, Katsumi; Takeuchi, Keita; Kumazawa, Takashi; Yoshii, Kiyonori

2014-01-01

Taste receptor cells fire action potentials in response to taste substances to trigger non-exocytotic neurotransmitter release in type II cells and exocytotic release in type III cells. We investigated possible differences between these action potentials fired by mouse taste receptor cells using in situ whole-cell recordings, and subsequently we identified their cell types immunologically with cell-type markers, an IP3 receptor (IP3 R3) for type II cells and a SNARE protein (SNAP-25) for type III cells. Cells not immunoreactive to these antibodies were examined as non-IRCs. Here, we show that type II cells and type III cells fire action potentials using different ionic mechanisms, and that non-IRCs also fire action potentials with either of the ionic mechanisms. The width of action potentials was significantly narrower and their afterhyperpolarization was deeper in type III cells than in type II cells. Na(+) current density was similar in type II cells and type III cells, but it was significantly smaller in non-IRCs than in the others. Although outwardly rectifying current density was similar between type II cells and type III cells, tetraethylammonium (TEA) preferentially suppressed the density in type III cells and the majority of non-IRCs. Our mathematical model revealed that the shape of action potentials depended on the ratio of TEA-sensitive current density and TEA-insensitive current one. The action potentials of type II cells and type III cells under physiological conditions are discussed. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

The optimal distance between two electrode tips during recording of compound nerve action potentials in the rat median nerve

PubMed Central

Li, Yongping; Lao, Jie; Zhao, Xin; Tian, Dong; Zhu, Yi; Wei, Xiaochun

2014-01-01

The distance between the two electrode tips can greatly influence the parameters used for recording compound nerve action potentials. To investigate the optimal parameters for these recordings in the rat median nerve, we dissociated the nerve using different methods and compound nerve action potentials were orthodromically or antidromically recorded with different electrode spacings. Compound nerve action potentials could be consistently recorded using a method in which the middle part of the median nerve was intact, with both ends dissociated from the surrounding fascia and a ground wire inserted into the muscle close to the intact part. When the distance between two stimulating electrode tips was increased, the threshold and supramaximal stimulating intensity of compound nerve action potentials were gradually decreased, but the amplitude was not changed significantly. When the distance between two recording electrode tips was increased, the amplitude was gradually increased, but the threshold and supramaximal stimulating intensity exhibited no significant change. Different distances between recording and stimulating sites did not produce significant effects on the aforementioned parameters. A distance of 5 mm between recording and stimulating electrodes and a distance of 10 mm between recording and stimulating sites were found to be optimal for compound nerve action potential recording in the rat median nerve. In addition, the orthodromic compound action potential, with a biphasic waveform that was more stable and displayed less interference (however also required a higher threshold and higher supramaximal stimulus), was found to be superior to the antidromic compound action potential. PMID:25206798

Short infrared laser pulses block action potentials in neurons

NASA Astrophysics Data System (ADS)

Walsh, Alex J.; Tolstykh, Gleb P.; Martens, Stacey L.; Ibey, Bennett L.; Beier, Hope T.

2017-02-01

Short infrared laser pulses have many physiological effects on cells including the ability to stimulate action potentials in neurons. Here we show that short infrared laser pulses can also reversibly block action potentials. Primary rat hippocampal neurons were transfected with the Optopatch2 plasmid, which contains both a blue-light activated channel rhodopsin (CheRiff) and a red-light fluorescent membrane voltage reporter (QuasAr2). This optogenetic platform allows robust stimulation and recording of action potential activity in neurons in a non-contact, low noise manner. For all experiments, QuasAr2 was imaged continuously on a wide-field fluorescent microscope using a Krypton laser (647 nm) as the excitation source and an EMCCD camera operating at 1000 Hz to collect emitted fluorescence. A co-aligned Argon laser (488 nm, 5 ms at 10Hz) provided activation light for CheRiff. A 200 mm fiber delivered infrared light locally to the target neuron. Reversible action potential block in neurons was observed following a short infrared laser pulse (0.26-0.96 J/cm2; 1.37-5.01 ms; 1869 nm), with the block persisting for more than 1 s with exposures greater than 0.69 J/cm2. Action potential block was sustained for 30 s with the short infrared laser pulsed at 1-7 Hz. Full recovery of neuronal activity was observed 5-30s post-infrared exposure. These results indicate that optogenetics provides a robust platform for the study of action potential block and that short infrared laser pulses can be used for non-contact, reversible action potential block.

Action potentials and ion conductances in wild-type and CALHM1-knockout type II taste cells

PubMed Central

Saung, Wint Thu; Foskett, J. Kevin

2017-01-01

Taste bud type II cells fire action potentials in response to tastants, triggering nonvesicular ATP release to gustatory neurons via voltage-gated CALHM1-associated ion channels. Whereas CALHM1 regulates mouse cortical neuron excitability, its roles in regulating type II cell excitability are unknown. In this study, we compared membrane conductances and action potentials in single identified TRPM5-GFP-expressing circumvallate papillae type II cells acutely isolated from wild-type (WT) and Calhm1 knockout (KO) mice. The activation kinetics of large voltage-gated outward currents were accelerated in cells from Calhm1 KO mice, and their associated nonselective tail currents, previously shown to be highly correlated with ATP release, were completely absent in Calhm1 KO cells, suggesting that CALHM1 contributes to all of these currents. Calhm1 deletion did not significantly alter resting membrane potential or input resistance, the amplitudes and kinetics of Na+ currents either estimated from action potentials or recorded from steady-state voltage pulses, or action potential threshold, overshoot peak, afterhyperpolarization, and firing frequency. However, Calhm1 deletion reduced the half-widths of action potentials and accelerated the deactivation kinetics of transient outward currents, suggesting that the CALHM1-associated conductance becomes activated during the repolarization phase of action potentials. NEW & NOTEWORTHY CALHM1 is an essential ion channel component of the ATP neurotransmitter release mechanism in type II taste bud cells. Its contribution to type II cell resting membrane properties and excitability is unknown. Nonselective voltage-gated currents, previously associated with ATP release, were absent in cells lacking CALHM1. Calhm1 deletion was without effects on resting membrane properties or voltage-gated Na+ and K+ channels but contributed modestly to the kinetics of action potentials. PMID:28202574

Somatic spikes regulate dendritic signaling in small neurons in the absence of backpropagating action potentials.

PubMed

Myoga, Michael H; Beierlein, Michael; Regehr, Wade G

2009-06-17

Somatic spiking is known to regulate dendritic signaling and associative synaptic plasticity in many types of large neurons, but it is unclear whether somatic action potentials play similar roles in small neurons. Here we ask whether somatic action potentials can also influence dendritic signaling in an electrically compact neuron, the cerebellar stellate cell (SC). Experiments were conducted in rat brain slices using a combination of imaging and electrophysiology. We find that somatic action potentials elevate dendritic calcium levels in SCs. There was little attenuation of calcium signals with distance from the soma in SCs from postnatal day 17 (P17)-P19 rats, which had dendrites that averaged 60 microm in length, and in short SC dendrites from P30-P33 rats. Somatic action potentials evoke dendritic calcium increases that are not affected by blocking dendritic sodium channels. This indicates that dendritic signals in SCs do not rely on dendritic sodium channels, which differs from many types of large neurons, in which dendritic sodium channels and backpropagating action potentials allow somatic spikes to control dendritic calcium signaling. Despite the lack of active backpropagating action potentials, we find that trains of somatic action potentials elevate dendritic calcium sufficiently to release endocannabinoids and retrogradely suppress parallel fiber to SC synapses in P17-P19 rats. Prolonged SC firing at physiologically realistic frequencies produces retrograde suppression when combined with low-level group I metabotropic glutamate receptor activation. Somatic spiking also interacts with synaptic stimulation to promote associative plasticity. These findings indicate that in small neurons the passive spread of potential within dendrites can allow somatic spiking to regulate dendritic calcium signaling and synaptic plasticity.

Action potentials and ion conductances in wild-type and CALHM1-knockout type II taste cells.

PubMed

Ma, Zhongming; Saung, Wint Thu; Foskett, J Kevin

2017-05-01

Taste bud type II cells fire action potentials in response to tastants, triggering nonvesicular ATP release to gustatory neurons via voltage-gated CALHM1-associated ion channels. Whereas CALHM1 regulates mouse cortical neuron excitability, its roles in regulating type II cell excitability are unknown. In this study, we compared membrane conductances and action potentials in single identified TRPM5-GFP-expressing circumvallate papillae type II cells acutely isolated from wild-type (WT) and Calhm1 knockout (KO) mice. The activation kinetics of large voltage-gated outward currents were accelerated in cells from Calhm1 KO mice, and their associated nonselective tail currents, previously shown to be highly correlated with ATP release, were completely absent in Calhm1 KO cells, suggesting that CALHM1 contributes to all of these currents. Calhm1 deletion did not significantly alter resting membrane potential or input resistance, the amplitudes and kinetics of Na + currents either estimated from action potentials or recorded from steady-state voltage pulses, or action potential threshold, overshoot peak, afterhyperpolarization, and firing frequency. However, Calhm1 deletion reduced the half-widths of action potentials and accelerated the deactivation kinetics of transient outward currents, suggesting that the CALHM1-associated conductance becomes activated during the repolarization phase of action potentials. NEW & NOTEWORTHY CALHM1 is an essential ion channel component of the ATP neurotransmitter release mechanism in type II taste bud cells. Its contribution to type II cell resting membrane properties and excitability is unknown. Nonselective voltage-gated currents, previously associated with ATP release, were absent in cells lacking CALHM1. Calhm1 deletion was without effects on resting membrane properties or voltage-gated Na + and K + channels but contributed modestly to the kinetics of action potentials. Copyright © 2017 the American Physiological Society.

Why Culture Matters in Health Interventions: Lessons from HIV/AIDS Stigma and NCDs

ERIC Educational Resources Information Center

Airhihenbuwa, Collins O.; Ford, Chandra L.; Iwelunmor, Juliet I.

2014-01-01

Theories about health behavior are commonly used in public health and often frame problems as ascribed or related to individuals' actions or inaction. This framing suggests that poor health occurs because individuals are unable or unwilling to heed preventive messages or recommended treatment actions. The recent United Nations call for…

The Law's Understanding of Intellectual Disability as a Disability

ERIC Educational Resources Information Center

Ellis, James W.

2013-01-01

Intellectual disability (ID) is differently yet validly described by different professions. Legal professionals find it most useful to consider ID as a disability rather than a disorder. Because the law regulates the actions of individuals in a society and the actions of society on an individual, the law's concern in dealing with a person with ID…

Leading the Process of Reculturing: Roles and Actions of School Leaders

ERIC Educational Resources Information Center

Geijsel, Femke; Meijers, Frans; Wardekker, Wim

2007-01-01

In this article, we focus on the role and actions of individual school leaders in initiating and governing the process of reculturing. First, we elaborate on the core elements of the process of reculturing, referring to a complex learning process of finding a new balance between cognitions and emotions both individually and collectively. We then…

Nash Equilibria in Theory of Reasoned Action

NASA Astrophysics Data System (ADS)

Almeida, Leando; Cruz, José; Ferreira, Helena; Pinto, Alberto Adrego

2009-08-01

Game theory and Decision Theory have been applied to many different areas such as Physics, Economics, Biology, etc. In its application to Psychology, we introduce, in the literature, a Game Theoretical Model of Planned Behavior or Reasoned Action by establishing an analogy between two specific theories. In this study we take in account that individual decision-making is an outcome of a process where group decisions can determine individual probabilistic behavior. Using Game Theory concepts, we describe how intentions can be transformed in behavior and according to the Nash Equilibrium, this process will correspond to the best individual decision/response taking in account the collective response. This analysis can be extended to several examples based in the Game Theoretical Model of Planned Behavior or Reasoned Action.

Extraction of honey from underground bee nests by central African chimpanzees (Pan troglodytes troglodytes) in Loango National Park, Gabon: Techniques and individual differences.

PubMed

Estienne, Vittoria; Stephens, Colleen; Boesch, Christophe

2017-08-01

A detailed analysis of tool use behaviors can disclose the underlying cognitive traits of the users. We investigated the technique used by wild chimpanzees to extract the underground nests of stingless bees (Meliplebeia lendliana), which represent a hard-to-reach resource given their highly undetectable location. Using remote-sensor camera trap footage, we analyzed 151 visits to 50 different bee nests by 18 adult chimpanzees of both sexes. We quantified the degree of complexity and flexibility of this technique by looking at the behavioral repertoire and at its structural organization. We used Generalized Linear Mixed Models to test whether individuals differed in their action repertoire sizes and in their action sequencing patterns, as well as in their preferences of use of different behavioral elements (namely, actions, and grip types). We found that subjects showed non-randomly organized sequences of actions and that the occurrence of certain actions was predicted by the type of the previous action in the sequences. Subjects did not differ in their repertoire sizes, and all used extractive actions involving tools more often than manual digging. As for the type of grip employed, the grip involving the coordinated use of hands and feet together was most frequently used by all subjects when perforating, and we detected significant individual preferences in this domain. Overall, we describe a highly complex and flexible extractive technique, and propose the existence of inter-individual variation in it. We discuss our results in the light of the evolution of higher cognitive abilities in the human lineage. © 2017 Wiley Periodicals, Inc.

[Factors behind action, emotion, and decision making].

PubMed

Watanabe, Katsumi

2009-12-01

Human actions, emotions, and decision making are products of complex interactions between explicit and implicit processes at various levels of spatial and temporal scales. Although it may not be possible to obtain to experimental data for all the complexity of human behavioral and emotional processes in our everyday life, recent studies have investigated the effects of social contexts on actions, emotions, and decision making; these studies include those in the fields of experimental psychology, cognitive science, and neuroscience. In this paper, we review several empirical studies that exemplify how our actions, social emotions, and decision making are influenced by the presence of implicit external, rather than internal factors, particularly by presence of other individuals. The following are the main principles identified. (1) Unconscious behavioral contagion: Individuals tend to mimic others' actions. This tendency occurs unconsciously even when the observed and the to-be-executed movements are unrelated at various levels and aspects of behaviors (e. g., behavioral tempo and speed). (2) Neural substrates of social emotions: Various social emotions, including admiration, compassion, envy, and schadenfreude, are represented in neuronal networks that are similar to those of basic emotional processes. (3) Evasive nature of human decision making: Individuals tend to overrate their own subjective impression of and emotional reaction in forecasting affective reaction to events in the future, even though the predictive power of information from peer group is much larger in this regard. Individuals are seldom aware of the dissociation between their intended choice and excuted actions and are willing to give elaborate explanations for the choices they, in fact, did not make. Using these empirical examples, I will illustrate the considerable influences of implicit, unconscious processes on human actions, emotions, and decision making.

Mentoring, coaching and action learning: interventions in a national clinical leadership development programme.

PubMed

McNamara, Martin S; Fealy, Gerard M; Casey, Mary; O'Connor, Tom; Patton, Declan; Doyle, Louise; Quinlan, Christina

2014-09-01

To evaluate mentoring, coaching and action learning interventions used to develop nurses' and midwives' clinical leadership competencies and to describe the programme participants' experiences of the interventions. Mentoring, coaching and action learning are effective interventions in clinical leadership development and were used in a new national clinical leadership development programme, introduced in Ireland in 2011. An evaluation of the programme focused on how participants experienced the interventions. A qualitative design, using multiple data sources and multiple data collection methods. Methods used to generate data on participant experiences of individual interventions included focus groups, individual interviews and nonparticipant observation. Seventy participants, including 50 programme participants and those providing the interventions, contributed to the data collection. Mentoring, coaching and action learning were positively experienced by participants and contributed to the development of clinical leadership competencies, as attested to by the programme participants and intervention facilitators. The use of interventions that are action-oriented and focused on service development, such as mentoring, coaching and action learning, should be supported in clinical leadership development programmes. Being quite different to short attendance courses, these interventions require longer-term commitment on the part of both individuals and their organisations. In using mentoring, coaching and action learning interventions, the focus should be on each participant's current role and everyday practice and on helping the participant to develop and demonstrate clinical leadership skills in these contexts. © 2014 John Wiley & Sons Ltd.

The activity of spontaneous action potentials in developing hair cells is regulated by Ca(2+)-dependence of a transient K+ current.

PubMed

Levic, Snezana; Lv, Ping; Yamoah, Ebenezer N

2011-01-01

Spontaneous action potentials have been described in developing sensory systems. These rhythmic activities may have instructional roles for the functional development of synaptic connections. The importance of spontaneous action potentials in the developing auditory system is underpinned by the stark correlation between the time of auditory system functional maturity, and the cessation of spontaneous action potentials. A prominent K(+) current that regulates patterning of action potentials is I(A). This current undergoes marked changes in expression during chicken hair cell development. Although the properties of I(A) are not normally classified as Ca(2+)-dependent, we demonstrate that throughout the development of chicken hair cells, I(A) is greatly reduced by acute alterations of intracellular Ca(2+). As determinants of spike timing and firing frequency, intracellular Ca(2+) buffers shift the activation and inactivation properties of the current to more positive potentials. Our findings provide evidence to demonstrate that the kinetics and functional expression of I(A) are tightly regulated by intracellular Ca(2+). Such feedback mechanism between the functional expression of I(A) and intracellular Ca(2+) may shape the activity of spontaneous action potentials, thus potentially sculpting synaptic connections in an activity-dependent manner in the developing cochlea. © 2011 Levic et al.

Radioprotective activity of Gentiana lutea extract and mangiferin.

PubMed

Menkovic, Nebojsa; Juranic, Zorica; Stanojkovic, Tatjana; Raonic-Stevanovic, Tatjana; Savikin, Katarina; Zdunić, Gordana; Borojevic, Nenad

2010-11-01

Radioprotective/sensitizing actions of Gentiana lutea aqueous-ethanol extract and mangiferin on radiation-induced effects on different types of cells were investigated. The study focused on the decreasing survival of normal human immunocompetent cells, the survival of the malignant cells in vitro, and the survival of ex vivo irradiated cells before and after consumption of the extract by healthy volunteers. The in vitro experiments showed that mangiferin could inhibit cytotoxic action of ionizing irradiation (doses of 6 and 8 Gy) only on normal resting human PBMC, not stimulated for proliferation. Orally consumed G. lutea extract showed the potential to reduce the cytotoxic effect of x-ray irradiation on normal human immunocompetent cells PBMC of some healthy people, without changing the susceptibility of malignant cells to be destroyed by irradiation. Since the radioprotective effect was individually dependent, further clinical studies are needed. Copyright © 2010 John Wiley & Sons, Ltd.

The orbitofrontal oracle: cortical mechanisms for the prediction and evaluation of specific behavioral outcomes.

PubMed

Rudebeck, Peter H; Murray, Elisabeth A

2014-12-17

The orbitofrontal cortex (OFC) has long been associated with the flexible control of behavior and concepts such as behavioral inhibition, self-control, and emotional regulation. These ideas emphasize the suppression of behaviors and emotions, but OFC's affirmative functions have remained enigmatic. Here we review recent work that has advanced our understanding of this prefrontal area and how its functions are shaped through interaction with subcortical structures such as the amygdala. Recent findings have overturned theories emphasizing behavioral inhibition as OFC's fundamental function. Instead, new findings indicate that OFC provides predictions about specific outcomes associated with stimuli, choices, and actions, especially their moment-to-moment value based on current internal states. OFC function thereby encompasses a broad representation or model of an individual's sensory milieu and potential actions, along with their relationship to likely behavioral outcomes. Copyright © 2014 Elsevier Inc. All rights reserved.

Oleoresin capsicum (Cap-Stun) toxicity from aerosol exposure.

PubMed

Watson, W A; Stremel, K R; Westdorp, E J

1996-01-01

To describe the clinical toxicity caused by oleoresin capsicum (OC) spray during law-enforcement action. A medical record review. Emergency department (ED), Truman Medical Center, Kansas City, MO. Consecutive patients who presented to the ED after OC-spray exposure from law-enforcement action between June 1991 and June 1994. Patient presentation and symptoms at presentation, evaluation, and treatment during ED stay. Eighty-one ED patients, approximately 10% of all individuals sprayed by police officers, presented after exposure to OC. Ocular burning and redness were the most common presenting symptoms. None of the patients required hospitalization due to OC toxicity. Corneal abrasions and respiratory symptoms occurred in 7 and 6 patients, respectively. The need for ED evaluation and treatment was infrequent after exposure to OC. A transient burning sensation, erythema, and localized irritation were the most common findings. While no patients had adverse outcomes attributed to OC exposure, practitioners assessing exposure should consider the potential for pulmonary and ocular toxicity.

Suicide and murder-suicide involving automobiles.

PubMed

Pridmore, Saxby; Varbanov, Svetlin; Sale, Ian

2017-02-01

We aim to explore the phenomenon of suicide by driving one vehicle into another, and draw attention to the cost to occupants of targeted vehicles. We examined academic literature, court and newspaper reports, and online sources. Driver suicide may be achieved by colliding with a fixed object or another vehicle. When a second vehicle is targeted, the occupants of that vehicle experience property loss, and potentially physical and psychiatric injury, or death. Driver suicides are associated with death of another person, in 11.3% of cases. Some suicidal individuals are able to act with great consideration for the consequences of their actions. Every effort must be made to help suicidal people with mental disorders or other predicaments. There is a need for public discussion of suicide by targeting an oncoming vehicle. It is less likely that suicide drivers who target other vehicles are unable to choose and more likely they have not considered the consequences of their actions.

Cyber safety for adolescent girls: bullying, harassment, sexting, pornography, and solicitation.

PubMed

Smith, Peter K; Thompson, Fran; Davidson, Julia

2014-10-01

To examine cyber safety for adolescent girls, specifically issues around the definition, measurement, prevalence, and impact of cyberbullying, harassment, sexting, pornography, and solicitation. Despite some continuing disagreements about definition, especially around cyberbullying and cyber harassment, and about measurement, it is clear that a significant minority of adolescents have potentially or actually harmful experiences on the Internet. There are important sex differences, and those exploited by pornography are mainly women. On some measures, these dangers have increased in recent years, although the extent can be exaggerated. The nature of Internet grooming appears to be changing. Negative effects are well documented in a range of domains, although more longitudinal studies are needed. Individual coping strategies, family and school-based support, and legal actions, all have a role to play in minimizing these dangers. Cyber safety is an important issue. More research and action is needed, and interventions need to be evaluated for their effectiveness.

Vaccinium corymbosum L. (blueberry) extracts exhibit protective action against cadmium toxicity in Saccharomyces cerevisiae cells.

PubMed

Oprea, Eliza; Ruta, Lavinia L; Nicolau, Ioana; Popa, Claudia V; Neagoe, Aurora D; Farcasanu, Ileana C

2014-01-01

Blueberries (Vaccinium corymbosum L.) are a rich source of antioxidants and their consumption is believed to contribute to food-related protection against oxidative stress. In the present study, the chemoprotective action of blueberry extracts against cadmium toxicity was investigated using a cadmium-hypersensitive strain of Saccharomyces cerevisiae. Four varieties of blueberries were used in the study, and it was found that the extracts with high content of total anthocyanidins exhibited significant protective effect against the toxicity of cadmium and H2O2. Both the blueberry extracts and pure cyanidin exhibited protective effects against cadmium in a dose-dependent manner, but without significantly interfering with the cadmium accumulation by the yeast cells. The results imply that the blueberry extracts might be a potentially valuable food supplement for individuals exposed to high cadmium. Copyright © 2013 Elsevier Ltd. All rights reserved.

Lengthening our perspective: morphological, cellular, and molecular responses to eccentric exercise.

PubMed

Hyldahl, Robert D; Hubal, Monica J

2014-02-01

The response of skeletal muscle to unaccustomed eccentric exercise has been studied widely, yet it is incompletely understood. This review is intended to provide an up-to-date overview of our understanding of how skeletal muscle responds to eccentric actions, with particular emphasis on the underlying molecular and cellular mechanisms of damage and recovery. This review begins by addressing the question of whether eccentric actions result in physical damage to muscle fibers and/or connective tissue. We next review the symptomatic manifestations of eccentric exercise (i.e., indirect damage markers, such as delayed onset muscle soreness), with emphasis on their relatively poorly understood molecular underpinnings. We then highlight factors that potentially modify the muscle damage response following eccentric exercise. Finally, we explore the utility of using eccentric training to improve muscle function in populations of healthy and aging individuals, as well as those living with neuromuscular disorders. Copyright © 2013 Wiley Periodicals, Inc.

The Communities Advancing Resilience Toolkit (CART): an intervention to build community resilience to disasters.

PubMed

Pfefferbaum, Rose L; Pfefferbaum, Betty; Van Horn, Richard L; Klomp, Richard W; Norris, Fran H; Reissman, Dori B

2013-01-01

Community resilience has emerged as a construct to support and foster healthy individual, family, and community adaptation to mass casualty incidents. The Communities Advancing Resilience Toolkit (CART) is a publicly available theory-based and evidence-informed community intervention designed to enhance community resilience by bringing stakeholders together to address community issues in a process that includes assessment, feedback, planning, and action. Tools include a field-tested community resilience survey and other assessment and analytical instruments. The CART process encourages public engagement in problem solving and the development and use of local assets to address community needs. CART recognizes 4 interrelated domains that contribute to community resilience: connection and caring, resources, transformative potential, and disaster management. The primary value of CART is its contribution to community participation, communication, self-awareness, cooperation, and critical reflection and its ability to stimulate analysis, collaboration, skill building, resource sharing, and purposeful action.

Effects of fatigue on motor unit firing rate versus recruitment threshold relationships.

PubMed

Stock, Matt S; Beck, Travis W; Defreitas, Jason M

2012-01-01

The purpose of this study was to examine the influence of fatigue on the average firing rate versus recruitment threshold relationships for the vastus lateralis (VL) and vastus medialis. Nineteen subjects performed ten maximum voluntary contractions of the dominant leg extensors. Before and after this fatiguing protocol, the subjects performed a trapezoid isometric muscle action of the leg extensors, and bipolar surface electromyographic signals were detected from both muscles. These signals were then decomposed into individual motor unit action potential trains. For each subject and muscle, the relationship between average firing rate and recruitment threshold was examined using linear regression analyses. For the VL, the linear slope coefficients and y-intercepts for these relationships increased and decreased, respectively, after fatigue. For both muscles, many of the motor units decreased their firing rates. With fatigue, recruitment of higher threshold motor units resulted in an increase in slope for the VL. Copyright © 2011 Wiley Periodicals, Inc.

A Participatory Action Research Study of Nature Education in Nature: Towards Community-Based Eco-Pedagogy

ERIC Educational Resources Information Center

Eryaman, Mustafa Yunus; Yalcin-Ozdilek, Sukran; Okur, Emel; Cetinkaya, Zeynep; Uygun, Selcuk

2010-01-01

Contemporary nature education is exploring different ways to develop awareness for change and initiate action. Such educational activities go beyond creating understanding and awareness in order to develop a sense of commitment for individual and collective action. This participatory action research study aimed to improve teachers' sensitiveness…

"Practical Action": Its Centrality in Producing and Reproducing the Formal Structure of School Organization.

ERIC Educational Resources Information Center

Cabraal, Liyana M. C.

The behaviorist world view, influential in many social-science disciplines, is challenged by theories of action. With steady developments in nonbehaviorist thinking and related social-action conceptions, the study of school organizational structure can be transformed into a field centered about the dynamics of individuals' practical actions. This…

Transitioning to a More Sustainable Society: Unpacking the Role of the Learning-Action Nexus

ERIC Educational Resources Information Center

Moyer, Joanne M.; Sinclair, A. John; Quinn, Lisa

2016-01-01

In recent years, action on sustainability has been highly influential around the globe and many now recognize the importance of individual and social learning for inspiring action and achieving sustainability outcomes. Transformative learning theory has been criticized, however, for insufficient development of the link between learning and action.…

Culture and Commitment: The Key to the Creation of an Action Learning Organization

ERIC Educational Resources Information Center

Hind, Matthew; Koenigsberger, John

2007-01-01

This article examines the introduction and practice of action learning into a highly volatile, commercial environment. During nine years of action learning projects, the impact on individuals, the action learning sets into which they were formed, the organization and its structure and the organizational culture were evaluated. The article…

Preparing Palestinian Reflective English Language Teachers through Classroom Based Action Research

ERIC Educational Resources Information Center

Dajani, Majida "Mohammed Yousef "

2015-01-01

This study aimed to describe the implementation of individual action research projects among some forty English language teachers distributed in thirty Palestinian schools in Ramallah and Qabatya districts-Palestine. It aimed to analyze the outcomes of the teachers' action research as part of a broader participatory action research project that is…

78 FR 23740 - Notice of Availability of a Swine Brucellosis and Pseudorabies Proposed Action Plan

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-22

...] Notice of Availability of a Swine Brucellosis and Pseudorabies Proposed Action Plan AGENCY: Animal and... proposed action plan describing a potential new approach to managing swine brucellosis and pseudorabies...-0086) a notice that made a proposed action plan describing a potential new approach to managing swine...

An investigative framework to facilitate epidemiological thinking during herd problem-solving.

PubMed

More, Simon J; Doherty, Michael L; O'Grady, Luke

2017-01-01

Veterinary clinicians and students commonly use diagnostic approaches appropriate for individual cases when conducting herd problem-solving. However, these approaches can be problematic, in part because they make limited use of epidemiological principles and methods, which has clear application during the investigation of herd problems. In this paper, we provide an overview of diagnostic approaches that are used when investigating individual animal cases, and the challenges faced when these approaches are directly translated from the individual to the herd. Further, we propose an investigative framework to facilitate epidemiological thinking during herd problem-solving. A number of different approaches are used when making a diagnosis on an individual animal, including pattern recognition, hypothetico-deductive reasoning, and the key abnormality method. Methods commonly applied to individuals are often adapted for herd problem-solving: 'comparison with best practice' being a herd-level adaptation of pattern recognition, and 'differential diagnoses' a herd-level adaptation of hypothetico-deductive reasoning. These approaches can be effective, however, challenges can arise. Herds are complex; a collection of individual cows, but also additional layers relating to environment, management, feeding etc. It is unrealistic to expect seamless translation of diagnostic approaches from the individual to the herd. Comparison with best practice is time-consuming and prioritisation of actions can be problematic, whereas differential diagnoses can lead to 'pathogen hunting', particularly in complex cases. Epidemiology is the science of understanding disease in populations. The focus is on the population, underpinned by principles and utilising methods that seek to allow us to generate solid conclusions from apparently uncontrolled situations. In this paper, we argue for the inclusion of epidemiological principles and methods as an additional tool for herd problem-solving, and outline an investigative framework, with examples, to effectively incorporate these principles and methods with other diagnostic approaches during herd problem-solving. Relevant measures of performance are identified, and measures of case frequencies are calculated and compared across time, in space and among animal groupings, to identify patterns, clues and plausible hypotheses, consistent with potential biological processes. With this knowledge, the subsequent investigation (relevant on-farm activities, diagnostic testing and other examinations) can be focused, and actions prioritised (specifically, those actions that are likely to make the greatest difference in addressing the problem if enacted). In our experience, this investigative framework is an effective teaching tool, facilitating epidemiological thinking among students during herd problem-solving. It is a generic and robust process, suited to many herd-based problems.

Modulating anosognosia for hemiplegia: The role of dangerous actions in emergent awareness.

PubMed

D'Imperio, Daniela; Bulgarelli, Cristina; Bertagnoli, Sara; Avesani, Renato; Moro, Valentina

2017-07-01

Anosognosia for hemiplegia is a lack of awareness of motor deficits following a right hemisphere lesion. Residual forms of awareness co-occur with an explicit denial of hemiplegia. The term emergent awareness refers to a condition in which awareness of motor deficits is reported verbally during the actual performance of an action involving the affected body part. In this study, two tasks were used to explore the potential effects of i) attempting actions which are impossible for sufferers of hemiplegia and ii) attempting actions which are potentially dangerous. Sixteen hemiplegic patients (8 anosognosic, and 8 non-anosognosic) were asked to perform both potentially dangerous and neutral actions. Our results confirm an increase in emergent awareness in anosognosic patients during the execution of both of these types of action. Moreover, actions that are potentially dangerous improved the degree of awareness. However, lesions in the fronto-temporal areas appear to be associated with a reduced effect of action execution (emergent awareness) while lesions in the basal ganglia and amygdale and the white matter underlying the insula and fronto-temporal areas are associated with a lesser degree of improvement resulting from attempting to perform dangerous actions. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Cardiovascular disease prevention and health promotion in the French speaking community of Belgium].

PubMed

Coppieters, Y; Béduwé, C; Collignon, J L; Hubens, V; Levêque, A

2010-01-01

Cardiovascular diseases remain the first cause of mortality in Belgium and are a priority for the Five-year program of health promotion in the French speaking Community. It is declined in operational programs by priority thematics, including the heart health. With this framework, it appeared necessary to operationalize cardiovascular priorities. A process of systemic and participative planning was set up in order to seek operational strategies and actions, and to cover the whole population and actors concerned with these health problems. The various cardiovascular risk factors, which potentiate one another, are approached together and in a global way. Upstream to the risk factors, social health determinants play an important role in cardiovascular diseases and others diseases like cancers. Tracking cardiovascular risk factors among people 30 to 75 years is also proposed. It makes it possible to identify people at risk and to put forward individual and adapted measures. The plan integrates actions of health promotion (acting on the health determinants and factors which influence them) as well as actions aiming at improving tracking and the accompaniment of the patients in secondary and tertiary prevention. Actions on health determinants and the factors influencing them present moreover the advantage of being often common to many chronic diseases.

Development and Pilot Testing of a Decision Aid for Genomic Research Participants Notified of Clinically Actionable Research Findings for Cancer Risk.

PubMed

Willis, Amanda M; Smith, Sian K; Meiser, Bettina; Ballinger, Mandy L; Thomas, David M; Tattersall, Martin; Young, Mary-Anne

2018-02-17

Germline genomic testing is increasingly used in research to identify genetic causes of disease, including cancer. However, there is evidence that individuals who are notified of clinically actionable research findings have difficulty making informed decisions regarding uptake of genetic counseling for these findings. This study aimed to produce and pilot test a decision aid to assist participants in genomic research studies who are notified of clinically actionable research findings to make informed choices regarding uptake of genetic counseling. Development was guided by published literature, the International Patient Decision Aid Standards, and the expertise of a steering committee of clinicians, researchers, and consumers. Decision aid acceptability was assessed by self-report questionnaire. All 19 participants stated that the decision aid was easy to read, clearly presented, increased their understanding of the implications of taking up research findings, and would be helpful in decision-making. While low to moderate levels of distress/worry were reported after reading the booklet, a majority of participants also reported feeling reassured. All participants would recommend the booklet to others considering uptake of clinically actionable research findings. Results indicate the decision aid is acceptable to the target audience, with potential as a useful decision support tool for genomic research participants.

[Effect of pulse magnetic field on distribution of neuronal action potential].

PubMed

Zheng, Yu; Cai, Di; Wang, Jin-Hai; Li, Gang; Lin, Ling

2014-08-25

The biological effect on the organism generated by magnetic field is widely studied. The present study was aimed to observe the change of sodium channel under magnetic field in neurons. Cortical neurons of Kunming mice were isolated, subjected to 15 Hz, 1 mT pulse magnetic stimulation, and then the currents of neurons were recorded by whole-cell patch clamp. The results showed that, under magnetic stimulation, the activation process of Na(+) channel was delayed, and the inactivation process was accelerated. Given the classic three-layer model, the polarization diagram of cell membrane potential distribution under pulse magnetic field was simulated, and it was found that the membrane potential induced was associated with the frequency and intensity of magnetic field. Also the effect of magnetic field-induced current on action potential was simulated by Hodgkin-Huxley (H-H) model. The result showed that the generation of action potential was delayed, and frequency and the amplitudes were decreased when working current was between -1.32 μA and 0 μA. When the working current was higher than 0 μA, the generation frequency of action potential was increased, and the change of amplitudes was not obvious, and when the working current was lower than -1.32 μA, the time of rising edge and amplitudes of action potential were decreased drastically, and the action potential was unable to generate. These results suggest that the magnetic field simulation can affect the distribution frequency and amplitude of action potential of neuron via sodium channel mediation.

Human Reliability Assessments: Using the Past (Shuttle) to Predict the Future (ORION)

NASA Technical Reports Server (NTRS)

Mott, Diana L.; Bigler, Mark A.

2017-01-01

NASA uses two HRA assessment methodologies. The first is a simplified method which is based on how much time is available to complete the action, with consideration included for environmental and personal factors that could influence the human's reliability. This method is expected to provide a conservative value or placeholder as a preliminary estimate. This preliminary estimate is used to determine which placeholder needs a more detailed assessment. The second methodology is used to develop a more detailed human reliability assessment on the performance of critical human actions. This assessment needs to consider more than the time available, this would include factors such as: the importance of the action, the context, environmental factors, potential human stresses, previous experience, training, physical design interfaces, available procedures/checklists and internal human stresses. The more detailed assessment is still expected to be more realistic than that based primarily on time available. When performing an HRA on a system or process that has an operational history, we have information specific to the task based on this history and experience. In the case of a PRA model that is based on a new design and has no operational history, providing a "reasonable" assessment of potential crew actions becomes more problematic. In order to determine what is expected of future operational parameters, the experience from individuals who had relevant experience and were familiar with the system and process previously implemented by NASA was used to provide the "best" available data. Personnel from Flight Operations, Flight Directors, Launch Test Directors, Control Room Console Operators and Astronauts were all interviewed to provide a comprehensive picture of previous NASA operations. Verification of the assumptions and expectations expressed in the assessments will be needed when the procedures, flight rules and operational requirements are developed and then finalized.

Vascular targets for cannabinoids: animal and human studies

PubMed Central

Stanley, Christopher; O'Sullivan, Saoirse E

2014-01-01

Application of cannabinoids and endocannabinoids to perfused vascular beds or individual isolated arteries results in changes in vascular resistance. In most cases, the result is vasorelaxation, although vasoconstrictor responses are also observed. Cannabinoids also modulate the actions of vasoactive compounds including acetylcholine, methoxamine, angiotensin II and U46619 (thromboxane mimetic). Numerous mechanisms of action have been proposed including receptor activation, potassium channel activation, calcium channel inhibition and the production of vasoactive mediators such as calcitonin gene-related peptide, prostanoids, NO, endothelial-derived hyperpolarizing factor and hydrogen peroxide. The purpose of this review is to examine the evidence for the range of receptors now known to be activated by cannabinoids. Direct activation by cannabinoids of CB1, CBe, TRPV1 (and potentially other TRP channels) and PPARs in the vasculature has been observed. A potential role for CB2, GPR55 and 5-HT1A has also been identified in some studies. Indirectly, activation of prostanoid receptors (TP, IP, EP1 and EP4) and the CGRP receptor is involved in the vascular responses to cannabinoids. The majority of this evidence has been obtained through animal research, but recent work has confirmed some of these targets in human arteries. Vascular responses to cannabinoids are enhanced in hypertension and cirrhosis, but are reduced in obesity and diabetes, both due to changes in the target sites of action. Much further work is required to establish the extent of vascular actions of cannabinoids and the application of this research in physiological and pathophysiological situations. Linked ArticlesThis article is part of a themed section on Cannabinoids 2013. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-6 PMID:24329566

5 CFR 1209.1 - Scope.

Code of Federal Regulations, 2010 CFR

2010-01-01

... APPEALS AND STAY REQUESTS OF PERSONNEL ACTIONS ALLEGEDLY BASED ON WHISTLEBLOWING Jurisdiction and... whistleblowing activities. Included are individual right of action appeals authorized by 5 U.S.C. 1221(a), appeals of otherwise appealable actions allegedly based on the appellant's whistleblowing activities, and...

Gesture Based Control and EMG Decomposition

NASA Technical Reports Server (NTRS)

Wheeler, Kevin R.; Chang, Mindy H.; Knuth, Kevin H.

2005-01-01

This paper presents two probabilistic developments for use with Electromyograms (EMG). First described is a new-electric interface for virtual device control based on gesture recognition. The second development is a Bayesian method for decomposing EMG into individual motor unit action potentials. This more complex technique will then allow for higher resolution in separating muscle groups for gesture recognition. All examples presented rely upon sampling EMG data from a subject's forearm. The gesture based recognition uses pattern recognition software that has been trained to identify gestures from among a given set of gestures. The pattern recognition software consists of hidden Markov models which are used to recognize the gestures as they are being performed in real-time from moving averages of EMG. Two experiments were conducted to examine the feasibility of this interface technology. The first replicated a virtual joystick interface, and the second replicated a keyboard. Moving averages of EMG do not provide easy distinction between fine muscle groups. To better distinguish between different fine motor skill muscle groups we present a Bayesian algorithm to separate surface EMG into representative motor unit action potentials. The algorithm is based upon differential Variable Component Analysis (dVCA) [l], [2] which was originally developed for Electroencephalograms. The algorithm uses a simple forward model representing a mixture of motor unit action potentials as seen across multiple channels. The parameters of this model are iteratively optimized for each component. Results are presented on both synthetic and experimental EMG data. The synthetic case has additive white noise and is compared with known components. The experimental EMG data was obtained using a custom linear electrode array designed for this study.

Intracellular recording of action potentials by nanopillar electroporation.

PubMed

Xie, Chong; Lin, Ziliang; Hanson, Lindsey; Cui, Yi; Cui, Bianxiao

2012-02-12

Action potentials have a central role in the nervous system and in many cellular processes, notably those involving ion channels. The accurate measurement of action potentials requires efficient coupling between the cell membrane and the measuring electrodes. Intracellular recording methods such as patch clamping involve measuring the voltage or current across the cell membrane by accessing the cell interior with an electrode, allowing both the amplitude and shape of the action potentials to be recorded faithfully with high signal-to-noise ratios. However, the invasive nature of intracellular methods usually limits the recording time to a few hours, and their complexity makes it difficult to simultaneously record more than a few cells. Extracellular recording methods, such as multielectrode arrays and multitransistor arrays, are non-invasive and allow long-term and multiplexed measurements. However, extracellular recording sacrifices the one-to-one correspondence between the cells and electrodes, and also suffers from significantly reduced signal strength and quality. Extracellular techniques are not, therefore, able to record action potentials with the accuracy needed to explore the properties of ion channels. As a result, the pharmacological screening of ion-channel drugs is usually performed by low-throughput intracellular recording methods. The use of nanowire transistors, nanotube-coupled transistors and micro gold-spine and related electrodes can significantly improve the signal strength of recorded action potentials. Here, we show that vertical nanopillar electrodes can record both the extracellular and intracellular action potentials of cultured cardiomyocytes over a long period of time with excellent signal strength and quality. Moreover, it is possible to repeatedly switch between extracellular and intracellular recording by nanoscale electroporation and resealing processes. Furthermore, vertical nanopillar electrodes can detect subtle changes in action potentials induced by drugs that target ion channels.

Intracellular recording of action potentials by nanopillar electroporation

NASA Astrophysics Data System (ADS)

Xie, Chong; Lin, Ziliang; Hanson, Lindsey; Cui, Yi; Cui, Bianxiao

2012-03-01

Action potentials have a central role in the nervous system and in many cellular processes, notably those involving ion channels. The accurate measurement of action potentials requires efficient coupling between the cell membrane and the measuring electrodes. Intracellular recording methods such as patch clamping involve measuring the voltage or current across the cell membrane by accessing the cell interior with an electrode, allowing both the amplitude and shape of the action potentials to be recorded faithfully with high signal-to-noise ratios. However, the invasive nature of intracellular methods usually limits the recording time to a few hours, and their complexity makes it difficult to simultaneously record more than a few cells. Extracellular recording methods, such as multielectrode arrays and multitransistor arrays, are non-invasive and allow long-term and multiplexed measurements. However, extracellular recording sacrifices the one-to-one correspondence between the cells and electrodes, and also suffers from significantly reduced signal strength and quality. Extracellular techniques are not, therefore, able to record action potentials with the accuracy needed to explore the properties of ion channels. As a result, the pharmacological screening of ion-channel drugs is usually performed by low-throughput intracellular recording methods. The use of nanowire transistors, nanotube-coupled transistors and micro gold-spine and related electrodes can significantly improve the signal strength of recorded action potentials. Here, we show that vertical nanopillar electrodes can record both the extracellular and intracellular action potentials of cultured cardiomyocytes over a long period of time with excellent signal strength and quality. Moreover, it is possible to repeatedly switch between extracellular and intracellular recording by nanoscale electroporation and resealing processes. Furthermore, vertical nanopillar electrodes can detect subtle changes in action potentials induced by drugs that target ion channels.

Action potential bursts in central snail neurons elicited by paeonol: roles of ionic currents

PubMed Central

Chen, Yi-hung; Lin, Pei-lin; Hsu, Hui-yu; Wu, Ya-ting; Yang, Han-yin; Lu, Dah-yuu; Huang, Shiang-suo; Hsieh, Ching-liang; Lin, Jaung-geng

2010-01-01

Aim: To investigate the effects of 2′-hydroxy-4′-methoxyacetophenone (paeonol) on the electrophysiological behavior of a central neuron (right parietal 4; RP4) of the giant African snail (Achatina fulica Ferussac). Methods: Intracellular recordings and the two-electrode voltage clamp method were used to study the effects of paeonol on the RP4 neuron. Results: The RP4 neuron generated spontaneous action potentials. Bath application of paeonol at a concentration of ≥500 μmol/L reversibly elicited action potential bursts in a concentration-dependent manner. Immersing the neurons in Co2+-substituted Ca2+-free solution did not block paeonol-elicited bursting. Pretreatment with the protein kinase A (PKA) inhibitor KT-5720 or the protein kinase C (PKC) inhibitor Ro 31-8220 did not affect the action potential bursts. Voltage-clamp studies revealed that paeonol at a concentration of 500 μmol/L had no remarkable effects on the total inward currents, whereas paeonol decreased the delayed rectifying K+ current (IKD) and the fast-inactivating K+ current (IA). Application of 4-aminopyridine (4-AP 5 mmol/L), an inhibitor of IA, or charybdotoxin 250 nmol/L, an inhibitor of the Ca2+-activated K+ current (IK(Ca)), failed to elicit action potential bursts, whereas tetraethylammonium chloride (TEA 50 mmol/L), an IKD blocker, successfully elicited action potential bursts. At a lower concentration of 5 mmol/L, TEA facilitated the induction of action potential bursts elicited by paeonol. Conclusion: Paeonol elicited a bursting firing pattern of action potentials in the RP4 neuron and this activity relates closely to the inhibitory effects of paeonol on the IKD. PMID:21042287

The Activation of the Mirror Neuron System during Action Observation and Action Execution with Mirror Visual Feedback in Stroke: A Systematic Review

PubMed Central

Zhang, Jack J. Q.; Welage, Nandana

2018-01-01

Objective To evaluate the concurrent and training effects of action observation (AO) and action execution with mirror visual feedback (MVF) on the activation of the mirror neuron system (MNS) and its relationship with the activation of the motor cortex in stroke individuals. Methods A literature search using CINAHL, PubMed, PsycINFO, Medline, Web of Science, and SCOPUS to find relevant studies was performed. Results A total of 19 articles were included. Two functional magnetic resonance imaging (fMRI) studies reported that MVF could activate the ipsilesional primary motor cortex as well as the MNS in stroke individuals, whereas two other fMRI studies found that the MNS was not activated by MVF in stroke individuals. Two clinical trials reported that long-term action execution with MVF induced a shift of activation toward the ipsilesional hemisphere. Five fMRI studies showed that AO activated the MNS, of which, three found the activation of movement-related areas. Five electroencephalography (EEG) studies demonstrated that AO or MVF enhanced mu suppression over the sensorimotor cortex. Conclusions MVF may contribute to stroke recovery by revising the interhemispheric imbalance caused by stroke due to the activation of the MNS. AO may also promote motor relearning in stroke individuals by activating the MNS and motor cortex. PMID:29853839

Consequences of converting graded to action potentials upon neural information coding and energy efficiency.

PubMed

Sengupta, Biswa; Laughlin, Simon Barry; Niven, Jeremy Edward

2014-01-01

Information is encoded in neural circuits using both graded and action potentials, converting between them within single neurons and successive processing layers. This conversion is accompanied by information loss and a drop in energy efficiency. We investigate the biophysical causes of this loss of information and efficiency by comparing spiking neuron models, containing stochastic voltage-gated Na(+) and K(+) channels, with generator potential and graded potential models lacking voltage-gated Na(+) channels. We identify three causes of information loss in the generator potential that are the by-product of action potential generation: (1) the voltage-gated Na(+) channels necessary for action potential generation increase intrinsic noise and (2) introduce non-linearities, and (3) the finite duration of the action potential creates a 'footprint' in the generator potential that obscures incoming signals. These three processes reduce information rates by ∼50% in generator potentials, to ∼3 times that of spike trains. Both generator potentials and graded potentials consume almost an order of magnitude less energy per second than spike trains. Because of the lower information rates of generator potentials they are substantially less energy efficient than graded potentials. However, both are an order of magnitude more efficient than spike trains due to the higher energy costs and low information content of spikes, emphasizing that there is a two-fold cost of converting analogue to digital; information loss and cost inflation.

Consequences of Converting Graded to Action Potentials upon Neural Information Coding and Energy Efficiency

PubMed Central

Sengupta, Biswa; Laughlin, Simon Barry; Niven, Jeremy Edward

2014-01-01

Information is encoded in neural circuits using both graded and action potentials, converting between them within single neurons and successive processing layers. This conversion is accompanied by information loss and a drop in energy efficiency. We investigate the biophysical causes of this loss of information and efficiency by comparing spiking neuron models, containing stochastic voltage-gated Na+ and K+ channels, with generator potential and graded potential models lacking voltage-gated Na+ channels. We identify three causes of information loss in the generator potential that are the by-product of action potential generation: (1) the voltage-gated Na+ channels necessary for action potential generation increase intrinsic noise and (2) introduce non-linearities, and (3) the finite duration of the action potential creates a ‘footprint’ in the generator potential that obscures incoming signals. These three processes reduce information rates by ∼50% in generator potentials, to ∼3 times that of spike trains. Both generator potentials and graded potentials consume almost an order of magnitude less energy per second than spike trains. Because of the lower information rates of generator potentials they are substantially less energy efficient than graded potentials. However, both are an order of magnitude more efficient than spike trains due to the higher energy costs and low information content of spikes, emphasizing that there is a two-fold cost of converting analogue to digital; information loss and cost inflation. PMID:24465197

Millisecond infrared laser pulses depolarize and elicit action potentials on in-vitro dorsal root ganglion neurons

PubMed Central

Paris, Lambert; Marc, Isabelle; Charlot, Benoit; Dumas, Michel; Valmier, Jean; Bardin, Fabrice

2017-01-01

This work focuses on the optical stimulation of dorsal root ganglion (DRG) neurons through infrared laser light stimulation. We show that a few millisecond laser pulse at 1875 nm induces a membrane depolarization, which was observed by the patch-clamp technique. This stimulation led to action potentials firing on a minority of neurons beyond an energy threshold. A depolarization without action potential was observed for the majority of DRG neurons, even beyond the action potential energy threshold. The use of ruthenium red, a thermal channel blocker, stops the action potential generation, but has no effects on membrane depolarization. Local temperature measurements reveal that the depolarization amplitude is sensitive to the amplitude of the temperature rise as well as to the time rate of change of temperature, but in a way which may not fully follow a photothermal capacitive mechanism, suggesting that more complex mechanisms are involved. PMID:29082085

[Effects of dauricine on action potentials and slow inward currents of guinea pig ventricular papillary muscles].

PubMed

Li, S N; Zhang, K Y

1992-11-01

Effects of dauricine (Dau) on the action potentials (AP), the slow action potentials (SAP), and the slow inward currents (Isi) of guinea pig ventricular papillary muscles were observed by means of intracellular microelectrode and single sucrose gap voltage clamp technique. In the early stage, Dau shortened action potential duration 100 (APD100) and effective refractory period (ERP) (ERP/APD < 1; P < 0.01), but did not affect APD20 and other parameters. In the late stage, Dau prolonged APD100, ERP, and APD20, significantly decreased action potential amplitude (APA), maximum velocity (Vmax), and overshot (OS) (ERP/APD > 1; P < 0.01), greatly diminished APA and OS of SAP induced by isoprenaline (P < 0.01), and remarkably inhibited Isi (P < 0.01). The results suggested that Dau exerted an inhibitory effect on Na+, Ca2+, and K+ channels.

Simulation of axonal excitability using a Spreadsheet template created in Microsoft Excel.

PubMed

Brown, A M

2000-08-01

The objective of this present study was to implement an established simulation protocol (A.M. Brown, A methodology for simulating biological systems using Microsoft Excel, Comp. Methods Prog. Biomed. 58 (1999) 181-90) to model axonal excitability. The simulation protocol involves the use of in-cell formulas directly typed into a spreadsheet and does not require any programming skills or use of the macro language. Once the initial spreadsheet template has been set up the simulations described in this paper can be executed with a few simple keystrokes. The model axon contained voltage-gated ion channels that were modeled using Hodgkin Huxley style kinetics. The basic properties of axonal excitability modeled were: (1) threshold of action potential firing, demonstrating that not only are the stimulus amplitude and duration critical in the generation of an action potential, but also the resting membrane potential; (2) refractoriness, the phenomenon of reduced excitability immediately following an action potential. The difference between the absolute refractory period, when no amount of stimulus will elicit an action potential, and relative refractory period, when an action potential may be generated by applying increased stimulus, was demonstrated with regard to the underlying state of the Na(+) and K(+) channels; (3) temporal summation, a process by which two sub-threshold stimuli can unite to elicit an action potential was shown to be due to conductance changes outlasting the first stimulus and summing with the second stimulus-induced conductance changes to drive the membrane potential past threshold; (4) anode break excitation, where membrane hyperpolarization was shown to produce an action potential by removing Na(+) channel inactivation that is present at resting membrane potential. The simulations described in this paper provide insights into mechanisms of axonal excitation that can be carried out by following an easily understood protocol.

Individuals' decisions affecting radiation exposure after a nuclear explosion.

PubMed

Florig, H Keith; Fischhoff, Baruch

2007-05-01

In the aftermath of a nuclear attack, shelters can offer potentially important protection. How well they fill that role depends on a set of interdependent decisions made by the individuals and organizations that must prepare and use them. We look at three such decisions. For each, we begin with formal analysis of the consequences expected from different possible actions. Those analyses are, then, reviewed in terms of how individuals facing these choices will perceive them, given the information that they are likely to have. The first example suggests that preparing a home shelter according to guidelines from the Department of Homeland Security may not pass a cost-benefit test. The second example explores the use of readily available information about a blast to infer how urgently shelter should be sought. The third example considers when shelters should be left, suggesting that individuals with the best shelters and slowest evacuation speeds should evacuate last, if they have the provisions needed to remain. In each case, helping people to protect themselves requires prior risk analyses and communication development.

Working Towards Open and Inclusive Support of Mental Health in Academia

NASA Astrophysics Data System (ADS)

Black, T. E.

2017-12-01

Mental health issues among academics have historically been dismissed as being inherent to the academic culture. While this culture is starting to shift toward more open recognition of these issues, progress toward addressing them lags. I will share a graduate student-focused perspective on some causes and effects of mental health issues in academia, and offer some actionable ideas for improvement. The stereotypical graduate school experience is conducive to the development of mental health issues. Financial stresses, balancing research, teaching, and degree commitments, and managing significant non-academic life events can be detrimental to student health without an adequate system of support. The limited recognition of and support for mental health issues in academia comes at great cost not only to individual health, but to the scientific community. Who do we exclude when we do not fully support individuals with mental health concerns? There are many anecdotes of scientists leaving academia for the sake of their mental health; it is plausible that many, anticipating potential mental health concerns or the factors that drive them, do not pursue academia at all. How can we support those in academia who experience mental health concerns? We can start by ensuring that everyone in our community has access to appropriate resources. This may look like providing new community members with clear information about the mental health services and resources that are available to the community, or advocating for better resources where they are lacking. It is important, however, to address the potential causes of mental health issues as well as the symptoms. While exact factors depend strongly on individuals, we should work to establish more flexible community standards and protocols that can accommodate the various life circumstances that we may encounter. Such actions would help to drive a broader culture shift toward recognizing and destigmatizing mental health issues.

Optical mapping of optogenetically shaped cardiac action potentials.

PubMed

Park, Sarah A; Lee, Shin-Rong; Tung, Leslie; Yue, David T

2014-08-19

Light-mediated silencing and stimulation of cardiac excitability, an important complement to electrical stimulation, promises important discoveries and therapies. To date, cardiac optogenetics has been studied with patch-clamp, multielectrode arrays, video microscopy, and an all-optical system measuring calcium transients. The future lies in achieving simultaneous optical acquisition of excitability signals and optogenetic control, both with high spatio-temporal resolution. Here, we make progress by combining optical mapping of action potentials with concurrent activation of channelrhodopsin-2 (ChR2) or halorhodopsin (eNpHR3.0), via an all-optical system applied to monolayers of neonatal rat ventricular myocytes (NRVM). Additionally, we explore the capability of ChR2 and eNpHR3.0 to shape action-potential waveforms, potentially aiding the study of short/long QT syndromes that result from abnormal changes in action potential duration (APD). These results show the promise of an all-optical system to acquire action potentials with precise temporal optogenetics control, achieving a long-sought flexibility beyond the means of conventional electrical stimulation.

Optical mapping of optogenetically shaped cardiac action potentials

PubMed Central

Park, Sarah A.; Lee, Shin-Rong; Tung, Leslie; Yue, David T.

2014-01-01

Light-mediated silencing and stimulation of cardiac excitability, an important complement to electrical stimulation, promises important discoveries and therapies. To date, cardiac optogenetics has been studied with patch-clamp, multielectrode arrays, video microscopy, and an all-optical system measuring calcium transients. The future lies in achieving simultaneous optical acquisition of excitability signals and optogenetic control, both with high spatio-temporal resolution. Here, we make progress by combining optical mapping of action potentials with concurrent activation of channelrhodopsin-2 (ChR2) or halorhodopsin (eNpHR3.0), via an all-optical system applied to monolayers of neonatal rat ventricular myocytes (NRVM). Additionally, we explore the capability of ChR2 and eNpHR3.0 to shape action-potential waveforms, potentially aiding the study of short/long QT syndromes that result from abnormal changes in action potential duration (APD). These results show the promise of an all-optical system to acquire action potentials with precise temporal optogenetics control, achieving a long-sought flexibility beyond the means of conventional electrical stimulation. PMID:25135113

Building a multiple modality, theory-based physical activity intervention: The development of CardiACTION!

PubMed

Estabrooks, Paul A; Glasgow, Russ E; Xu, Stan; Dzewaltowski, David A; Lee, Rebecca E; Thomas, Deborah; Almeida, Fabio A; Thayer, Amy N; Smith-Ray, Renae L

2011-01-01

OBJECTIVES: Despite the widely acknowledged benefits of regular physical activity (PA), specific goals for increased population levels of PA, and strongly recommended strategies to promote PA, there is no evidence suggesting that the prevalence of PA is improving. If PA intervention research is to be improved, theory should be used as the basis for intervention development, participant context or environment should be considered in the process, and intervention characteristics that will heighten the likelihood of translation into practice should be implemented (e.g., ease of implementation, low human resource costs). The purpose of this paper is to describe the implementation of the aforementioned concepts within the intervention development process associated with CardiACTION an ongoing randomized 2 × 2 factorial trial. METHODS: The Ecological Model of Physical Activity integrated with Protection Motivation Theory was used to inform the design of the interventions. This integrated model was selected to allow for the development of theory-based individual, environmental, and individually + environmentally targeted physical activity interventions. All intervention strategies were matched to proposed mediators of behavior change. Strategies were then matched to the most appropriate interactive technology (i.e., interactive computer session, automated telephone counseling, and tailored mailings) delivery channel. CONCLUSIONS: The potential implications of this study include determining the independent and combined influence of individual and environment mechanisms of behavior change on intervention effectiveness. In addition, all intervention models are developed to be scalable and disseminable to a broad audience at a low cost.

Describing patterns of weight changes using principal components analysis: results from the Action for Health in Diabetes (Look AHEAD) research group.

PubMed

Espeland, Mark A; Bray, George A; Neiberg, Rebecca; Rejeski, W Jack; Knowler, William C; Lang, Wei; Cheskin, Lawrence J; Williamson, Don; Lewis, C Beth; Wing, Rena

2009-10-01

To demonstrate how principal components analysis can be used to describe patterns of weight changes in response to an intensive lifestyle intervention. Principal components analysis was applied to monthly percent weight changes measured on 2,485 individuals enrolled in the lifestyle arm of the Action for Health in Diabetes (Look AHEAD) clinical trial. These individuals were 45 to 75 years of age, with type 2 diabetes and body mass indices greater than 25 kg/m(2). Associations between baseline characteristics and weight loss patterns were described using analyses of variance. Three components collectively accounted for 97.0% of total intrasubject variance: a gradually decelerating weight loss (88.8%), early versus late weight loss (6.6%), and a mid-year trough (1.6%). In agreement with previous reports, each of the baseline characteristics we examined had statistically significant relationships with weight loss patterns. As examples, males tended to have a steeper trajectory of percent weight loss and to lose weight more quickly than women. Individuals with higher hemoglobin A(1c) (glycosylated hemoglobin; HbA(1c)) tended to have a flatter trajectory of percent weight loss and to have mid-year troughs in weight loss compared to those with lower HbA(1c). Principal components analysis provided a coherent description of characteristic patterns of weight changes and is a useful vehicle for identifying their correlates and potentially for predicting weight control outcomes.

An Extension of the Theory of Reasoned Action in Ethical Decision Contexts: The Role of Normative Influence and Ethical Judgment

ERIC Educational Resources Information Center

Celuch, Kevin; Dill, Andy

2011-01-01

The moral conduct of organizations is ultimately dependent on the discrete actions of individuals. The authors address the scholarly and managerial imperative of how individuals combine various cognitions in their ethical decision making. The study extends the understanding of ethical decision making by exploring relationships among Theory of…

Injury risk associated with playing actions during competitive soccer

PubMed Central

Rahnama, N; Reilly, T; Lees, A

2002-01-01

Objective: To assess the exposure of players to injury risk during English Premier League soccer matches in relation to selected factors. Methods: Injury risk was assessed by rating the injury potential of playing actions during competition with respect to (a) type of playing action, (b) period of the game, (c) zone of the pitch, and (d) playing either at home or away. In all, 10 games from the English Premier League 1999–2000 were chosen for analysis. A notation system was used whereby 16 soccer specific playing actions were classified into three categories: those inducing actual injury, those with a potential for injury (graded as mild, moderate, or high), and those deemed to have no potential for injury. The pitch was divided into 18 zones, and the position of each event was recorded along with time elapsed in the game, enabling six 15 minute periods to be defined. Results: Close to 18 000 actions were notated. On average (mean (SD)), 1788 (73) events (one every three seconds), 767 (99) events with injury potential (one every six seconds), and 2 (1) injuries (one every 45 minutes) per game were recorded. An overall injury incidence of 53 per 1000 playing hours was calculated. Receiving a tackle, receiving a "charge", and making a tackle were categorised as having a substantial injury risk, and goal catch, goal punch, kicking the ball, shot on goal, set kick, and heading the ball were all categorised as having a significant injury risk. All other actions were deemed low in risk. The first 15 minutes of each half contained the highest number of actions with mild injury potential, the last 15 minutes having the highest number of actions with moderate injury potential (p<0.01). The first and last 15 minutes of the game had the highest number of actions with high injury potential, although not significant. More actions with mild injury potential occurred in the goal area, and more actions with moderate and high injury potential occurred in the zone adjacent to the goal area (p<0.001). There was no significant difference between home and away with regard to injury potential. Conclusions: Playing actions with high injury risk were linked to contesting possession. Injury risk was highest in the first and last 15 minutes of the game, reflecting the intense engagements in the opening period and the possible effect of fatigue in the closing period. Injury risk was concentrated in the areas of the pitch where possession of the ball is most vigorously contested, which were specific attacking and defending zones close to the goal. Injury potential was no greater in away matches than at home. PMID:12351333

Moral responsibility, technology, and experiences of the tragic: from Kierkegaard to offshore engineering.

PubMed

Coeckelbergh, Mark

2012-03-01

The standard response to engineering disasters like the Deepwater Horizon case is to ascribe full moral responsibility to individuals and to collectives treated as individuals. However, this approach is inappropriate since concrete action and experience in engineering contexts seldom meets the criteria of our traditional moral theories. Technological action is often distributed rather than individual or collective, we lack full control of the technology and its consequences, and we lack knowledge and are uncertain about these consequences. In this paper, I analyse these problems by employing Kierkegaardian notions of tragedy and moral responsibility in order to account for experiences of the tragic in technological action. I argue that ascription of responsibility in engineering contexts should be sensitive to personal experiences of lack of control, uncertainty, role conflicts, social dependence, and tragic choice. I conclude that this does not justify evading individual and corporate responsibility, but inspires practices of responsibility ascription that are less 'harsh' on those directly involved in technological action, that listen to their personal experiences, and that encourage them to gain more knowledge about what they are doing. © The Author(s) 2010. This article is published with open access at Springerlink.com

Climate change helplessness and the (de)moralization of individual energy behavior.

PubMed

Salomon, Erika; Preston, Jesse L; Tannenbaum, Melanie B

2017-03-01

Although most people understand the threat of climate change, they do little to modify their own energy conservation behavior. One reason for this gap between belief and behavior may be that individual actions seem unimpactful and therefore are not morally relevant. This research investigates how climate change helplessness-belief that one's actions cannot affect climate change-can undermine the moralization of climate change and personal energy conservation. In Study 1, climate change efficacy predicted both moralization of energy use and energy conservation intentions beyond individual belief in climate change. In Studies 2 and 3, participants read information about climate change that varied in efficacy message, that is, whether individual actions (e.g., using less water, turning down heat) make a difference in the environment. Participants who read that their behavior made no meaningful impact reported weaker moralization and intentions (Study 2), and reported more energy consumption 1 week later (Study 3). Moreover, effects on intentions and actions were mediated by changes in moralization. We discuss ways to improve climate change messages to foster environmental efficacy and moralization of personal energy use. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Evil games.

PubMed

Chambers, David W

2010-01-01

A defining characteristic of humans is our capacity to create a better world through mutual action. Traditional ethics attempts to define and impose the one or several things we should all want. The alternative argued here is that we can retain our individual definitions of what matters and still work together for mutual improvement. Agreeing on common ethical principles is not a precondition for an effective moral life. This approach to morality is based on game theory, which holds that in purposely social interactions: (a) there are basic understandings, (b) individuals pursue their own interests, (c) we can judge others' interests, and (d) the distribution of benefits and burdens depends on the joint action of individuals, not on the action of individuals in isolation. In this view, immorality becomes a matter of cheating in the game of life. The three primary forms of cheating are deception (misleading others into thinking they are playing a game other than the one that is to their advantage to play), coercion (blocking courses of action others would normally be entitled to), and reneging (playing the game and then dodging the payoff if one does not like the outcome). These three evils are illustrated by Shakespeare's plays Othello, Richard III, and Antony and Cleopatra.

A preliminary evaluation of bardoxolone methyl for the treatment of diabetic nephropathy.

PubMed

Thomas, Merlin

2012-08-01

The coordinated activation of Nrf-2-dependent signaling pathway is currently being investigated in a range of chronic diseases. Bardoxolone methyl is a potent, orally bioavailable Nrf-2 agonist. In a recent 52-week study, treatment with bardoxolone methyl improved renal function in patients with chronic kidney disease (CKD) and type 2 diabetes. This improvement was sustained for the duration of the treatment. Such agonists potentially offer new options for the complex management of renal impairment. A literature search was performed to analyze the pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of bardoxolone methyl in both healthy volunteers and patients. Updated information about bardoxolone methyl, either after single administration or after chronic administration is also included. A special focus has been put on the putative mechanisms of action and potential toxicity profiles as well as an ongoing trials in patients with CKD and type 2 diabetes. The development of an agent that leads to sustained improvement in renal function comes as a welcome relief to the millions of individuals with diabetes and CKD. However, much remains to be established regarding its actions in a complex and pleiotropic signalling cascade. Other triterpenoids with different PK/PD profiles are currently under development.

Linking the Heart and the Head: Humanism and Professionalism in Medical Education and Practice.

PubMed

Montgomery, Lynda; Loue, Sana; Stange, Kurt C

2017-05-01

This paper articulates a practical interpretive framework for understanding humanism in medicine through the lens of how it is taught and learned. Beginning with a search for key tensions and relevant insights in the literature on humanism in health professions education, we synthesized a conceptual model designed to foster reflection and action to realize humanistic principles in medical education and practice. The resulting model centers on the interaction between the heart and the head. The heart represents the emotive domains of empathy, compassion, and connectedness. The head represents the cognitive domains of knowledge, attitudes, and beliefs. The cognitive domains often are associated with professionalism, and the emotive domains with humanism, but it is the connection between the two that is vital to humanistic education and practice. The connection between the heart and the head is nurtured by critical reflection and conscious awareness. Four provinces of experience nurture humanism: (1) personal reflection, (2) action, (3) system support, and (4) collective reflection. These domains represent potential levers for developing humanism. Critical reflection and conscious awareness between the heart and head through personal reflection, individual and collective behavior, and supportive systems has potential to foster humanistic development toward healing and health.

Metabolomic profiling to identify potential serum biomarkers for schizophrenia and risperidone action.

PubMed

Xuan, Jiekun; Pan, Guihua; Qiu, Yunping; Yang, Lun; Su, Mingming; Liu, Yumin; Chen, Jian; Feng, Guoyin; Fang, Yiru; Jia, Wei; Xing, Qinghe; He, Lin

2011-12-02

Despite recent advances in understanding the pathophysiology of schizophrenia and the mechanisms of antipsychotic drug action, the development of biomarkers for diagnosis and therapeutic monitoring in schizophrenia remains challenging. Metabolomics provides a powerful approach to discover diagnostic and therapeutic biomarkers by analyzing global changes in an individual's metabolic profile in response to pathophysiological stimuli or drug intervention. In this study, we performed gas chromatography-mass spectrometry based metabolomic profiling in serum of unmedicated schizophrenic patients before and after an 8-week risperidone monotherapy, to detect potential biomarkers associated with schizophrenia and risperidone treatment. Twenty-two marker metabolites contributing to the complete separation of schizophrenic patients from matched healthy controls were identified, with citrate, palmitic acid, myo-inositol, and allantoin exhibiting the best combined classification performance. Twenty marker metabolites contributing to the complete separation between posttreatment and pretreatment patients were identified, with myo-inositol, uric acid, and tryptophan showing the maximum combined classification performance. Metabolic pathways including energy metabolism, antioxidant defense systems, neurotransmitter metabolism, fatty acid biosynthesis, and phospholipid metabolism were found to be disturbed in schizophrenic patients and partially normalized following risperidone therapy. Further study of these metabolites may facilitate the development of noninvasive biomarkers and more efficient therapeutic strategies for schizophrenia.

Multidrug-Resistant TB

PubMed Central

Cox, Helen; Coomans, Fons

2016-01-01

Abstract The right to enjoy the benefits of scientific progress (REBSP) is a little-known but potentially valuable right that can contribute to rights-based approaches to addressing multidrug-resistant TB (MDR-TB). We argue that better understanding of the REBSP may help to advance legal and civil society action for health rights. While the REBSP does not provide an individual entitlement to have a new drug developed for MDR-TB, it sets up entitlements to expect a state to establish a legislative and policy framework aimed at developing scientific capacity to address the most important health issues and at disseminating the outcomes of scientific research. By making scientific findings available and accessible, people can be enabled to claim the use of science for social benefits. Inasmuch as the market fails to address neglected diseases such as MDR-TB, the REBSP provides a potential counterbalance to frame a positive obligation on states to both marshal their own resources and to coordinate the actions of multiple other actors towards this goal, including non-state actors. While the latter do not hold the same level of accountability as states, the REBSP can still enable the recognition of obligations at a level of “soft law” responsibilities. PMID:27780997

Quantifying carbon footprint reduction opportunities for U.S. households and communities.

PubMed

Jones, Christopher M; Kammen, Daniel M

2011-05-01

Carbon management is of increasing interest to individuals, households, and communities. In order to effectively assess and manage their climate impacts, individuals need information on the financial and greenhouse gas benefits of effective mitigation opportunities. We use consumption-based life cycle accounting techniques to quantify the carbon footprints of typical U.S. households in 28 cities for 6 household sizes and 12 income brackets. The model includes emissions embodied in transportation, energy, water, waste, food, goods, and services. We further quantify greenhouse gas and financial savings from 13 potential mitigation actions across all household types. The model suggests that the size and composition of carbon footprints vary dramatically between geographic regions and within regions based on basic demographic characteristics. Despite these differences, large cash-positive carbon footprint reductions are evident across all household types and locations; however, realizing this potential may require tailoring policies and programs to different population segments with very different carbon footprint profiles. The results of this model have been incorporated into an open access online carbon footprint management tool designed to enable behavior change at the household level through personalized feedback.

Determination of the motor unit behavior of lumbar erector spinae muscles through surface EMG decomposition technology in healthy female subjects.

PubMed

Silva, Mariana Felipe; Dias, Josilainne Marcelino; Pereira, Ligia Maxwell; Mazuquin, Bruno Fles; Lindley, Steven; Richards, Jim; Cardoso, Jefferson Rosa

2017-01-01

The aims of this study were to determine the motor unit behavior of the erector spinae muscles and to assess whether differences exist between the dominant/nondominant sides of the back muscles. Nine healthy women, aged 21.7 years (SD = 0.7), performed a back extension test. Surface electromyographic decomposition data were collected from both sides of the erector spinae and decomposed into individual motor unit action potential trains. The mean firing rate for each motor unit was calculated, and a regression analysis was performed against the corresponding recruitment thresholds. The mean firing rate ranged from 15.9 to 23.9 pps and 15.8 to 20.6 pps on the dominant and nondominant sides, respectively. However, the early motor unit potentials of the nondominant lumbar erector spinae muscles were recruited at a lower firing rate. This technique may further our understanding of individuals with back pain and other underlying neuromuscular diseases. Muscle Nerve 55: 28-34, 2017. © 2016 Wiley Periodicals, Inc.

Can the use of humor in psychotherapy be taught?

PubMed

Valentine, Lisa; Gabbard, Glen O

2014-02-01

Despite an abundance of literature detailing the potential benefits of the use of humor in therapy, humor is rarely taught to psychiatric residents as a method of therapeutic intervention. This communication attempts to explain how current understanding of attachment theory and neuroscience may assist psychiatric faculty and supervisors in their teaching of humorous therapeutic interventions. This article reviews and synthesizes the extant literature on the use of humor, as well as recent work in neuroscience, attachment theory, and mentalization. Humor can be conceptualized as an instance of implicit relational knowing and may thus contribute significantly to the therapeutic action of psychotherapy as a subcategory of "moments of meeting" between therapist and patient. However, training residents to use humor in psychotherapy requires more individualized attention in supervision and classroom seminars. Factors such as individual proclivities for humorous repartee, mentalizing capacity, and an authentic interest in adding humor to the session may be necessary to incorporate spontaneous humor into one's technique. New findings from the areas of attachment theory, neuroscience, and right-hemisphere learning are providing potential opportunities for sophisticated teaching of the use of humor in psychotherapy.

Cognitive strategies take advantage of the cooperative potential of heterogeneous networks

NASA Astrophysics Data System (ADS)

Vukov, Jeromos; Santos, Francisco C.; Pacheco, Jorge M.

2012-06-01

Understanding the emergence and maintenance of cooperation is one of the most challenging topics of our time. Evolutionary game theory offers a very flexible framework within which to address this challenge. Here we use the prisoner's dilemma game to investigate the performance of individuals who are capable of adopting reactive strategies in communities structurally organized by means of Barabási-Albert scale-free networks. We find that basic cognitive abilities, such as the capability to distinguish their partners and act according to their previous actions, enable cooperation to thrive. This result is particularly significant whenever fear is the leading social tension, as this fosters retaliation, thus enforcing and sustaining cooperation. Being able to simultaneously reward fellow cooperators and punish defectors proves instrumental in achieving cooperation and the welfare of the community. As a result, central individuals can successfully lead the community and turn defective players into cooperative ones. Finally, even when participation costs—known to be detrimental to cooperation in scale-free networks—are explicitly included, we find that basic cognitive abilities have enough potential to help cooperation to prevail.

The Challenge of Evaluating Action Learning

ERIC Educational Resources Information Center

Edmonstone, John

2015-01-01

The paper examines the benefits claimed for action learning at individual, organisational and inter-organisational levels. It goes on to identify both generic difficulties in evaluating development programmes and action learning specifically. The distinction between formative and summative evaluation is considered and a summative evaluation…

Action Learning.

ERIC Educational Resources Information Center

1996

These four papers were presented at a symposium on action learning moderated by Lex Dilworth at the 1996 conference of the Academy of Human Resource Development. "Developing an Infrastructure for Individual and Organizational Change: Transfer of Learning from an Action Reflection Learning (ARL) Program" (ARL Inquiry) reports findings…

The Mirror Neuron System and Action Recognition

ERIC Educational Resources Information Center

Buccino, Giovanni; Binkofski, Ferdinand; Riggio, Lucia

2004-01-01

Mirror neurons, first described in the rostral part of monkey ventral premotor cortex (area F5), discharge both when the animal performs a goal-directed hand action and when it observes another individual performing the same or a similar action. More recently, in the same area mirror neurons responding to the observation of mouth actions have been…

Deactivation in the Sensorimotor Area during Observation of a Human Agent Performing Robotic Actions

ERIC Educational Resources Information Center

Shimada, Sotaro

2010-01-01

It is well established that several motor areas, called the mirror-neuron system (MNS), are activated when an individual observes other's actions. However, whether the MNS responds similarly to robotic actions compared with human actions is still controversial. The present study investigated whether and how the motor area activity is influenced by…

Detecting Threat-Related Intentional Actions of Others: Effects of Image Quality, Response Mode, and Target Cuing on Vigilance

ERIC Educational Resources Information Center

Parasuraman, Raja; de Visser, Ewart; Clarke, Ellen; McGarry, W. Ryan; Hussey, Elizabeth; Shaw, Tyler; Thompson, James C.

2009-01-01

Three experiments examined the vigilance performance of participants watching videos depicting intentional actions of an individual's hand reaching for and grasping an object--involving transporting or using either a gun or a hairdryer--in order to detect infrequent threat-related actions. Participants indicated detection of target actions either…

Interaction of insulin with prokinetic drugs in STZ-induced diabetic mice

PubMed Central

Shalaby, Mohamed A Fouad; Latif, Hekma A Abd El; Sayed, Mostafa E El

2013-01-01

AIM: To study the possible interactions of metoclopramide, domperidone and erythromycin in streptozotocin-induced diabetic mice treated with insulin by various parameters. METHODS: Effects of the individual as well as combined drugs were studied in diabetic mice via estimation of the blood glucose and serum insulin levels, small intestinal transit (SIT), gastric emptying (GE), xylose absorption and glucose tolerance tests. Groups were given insulin 2 IU/kg s.c., metoclopramide 20 mg/kg p.o., domperidone 20 mg/kg p.o. and erythromycin 6 mg/kg p.o. individually and in combination. There were also normal and diabetic control groups. The first set of experiments was carried out to investigate the subchronic effect on blood glucose and serum insulin levels in diabetic mice of one week of daily dose administration of the tested drugs individually as well as the combination of insulin with each prokinetic drug. The other five sets of experiments were carried out to investigate the acute effect of a single dose of each drug individually and in combination on blood glucose and serum insulin levels, SIT, GE, oral xylose absorption and glucose tolerance tests. RESULTS: The study included the prokinetic drugs metoclopramide (20 mg/kg), domperidone (20 mg/kg) and erythromycin (6 mg/kg), as well as insulin (2 IU/kg), which was individually effective in decreasing SIT, enhancing GE and increasing xylose absorption significantly in diabetic mice. Erythromycin tended to decrease blood glucose level and increase serum insulin level after 1 wk of daily administration in diabetic mice. Erythromycin potentiated the effect of insulin on blood glucose level and serum insulin level whereas other prokinetic agents failed to do so after repeated dose administration in diabetic mice. Metoclopramide or erythromycin in combination with insulin significantly decreased SIT, in diabetic mice, to lower levels than with insulin alone. Administration of prokinetic drugs along with insulin antagonized the action of insulin on xylose absorption. These combinations also increased the rate of glucose absorption from the gut. CONCLUSION: The present study suggests that prokinetic drugs could potentially improve glycemic control in diabetic gastroparesis by allowing a more predictable absorption of nutrients, matched to the action of exogenous insulin. The use of prokinetics, such as erythromycin, may be interesting in the clinic in decreasing the need for insulin in diabetic patients. The dose of insulin may be safely decreased with erythromycin in chronic treatments. PMID:23667771

Spontaneous action potentials and neural coding in unmyelinated axons.

PubMed

O'Donnell, Cian; van Rossum, Mark C W

2015-04-01

The voltage-gated Na and K channels in neurons are responsible for action potential generation. Because ion channels open and close in a stochastic fashion, spontaneous (ectopic) action potentials can result even in the absence of stimulation. While spontaneous action potentials have been studied in detail in single-compartment models, studies on spatially extended processes have been limited. The simulations and analysis presented here show that spontaneous rate in unmyelinated axon depends nonmonotonically on the length of the axon, that the spontaneous activity has sub-Poisson statistics, and that neural coding can be hampered by the spontaneous spikes by reducing the probability of transmitting the first spike in a train.

Improving Cardiac Action Potential Measurements: 2D and 3D Cell Culture.

PubMed

Daily, Neil J; Yin, Yue; Kemanli, Pinar; Ip, Brian; Wakatsuki, Tetsuro

2015-11-01

Progress in the development of assays for measuring cardiac action potential is crucial for the discovery of drugs for treating cardiac disease and assessing cardiotoxicity. Recently, high-throughput methods for assessing action potential using induced pluripotent stem cell (iPSC) derived cardiomyocytes in both two-dimensional monolayer cultures and three-dimensional tissues have been developed. We describe an improved method for assessing cardiac action potential using an ultra-fast cost-effective plate reader with commercially available dyes. Our methods improve dramatically the detection of the fluorescence signal from these dyes and make way for the development of more high-throughput methods for cardiac drug discovery and cardiotoxicity.

Action potentials contribute to epileptic high-frequency oscillations recorded with electrodes remote from neurons.

PubMed

Kobayashi, Katsuhiro; Akiyama, Tomoyuki; Ohmori, Iori; Yoshinaga, Harumi; Gotman, Jean

2015-05-01

The importance of epileptic high-frequency oscillations (HFOs) in electroencephalogram (EEG) is growing. Action potentials generating some HFOs are observed in the vicinity of neurons in experimental animals. However electrodes that are remote from neurons, as in case of clinical situations, should not record action potentials. We propose to resolve this question by a realistic simulation of epileptic neuronal network. The rat dentate gyrus with sclerosis was simulated in silico. We computed the current dipole moment generated by each granule cell and the field potentials in a measurement area far from neurons. The dentate gyrus was stimulated through synaptic input to evoke discharges resembling interictal epileptiform discharges, which had superimposed HFOs⩽295Hz that were recordable with remote electrodes and represented bursts of action potentials of granule cells. The increase in power of HFOs was associated with the progression of sclerosis, the reduction of GABAergic inhibition, and the increase in cell connectivity. Spectral frequency of HFOs had similar tendencies. HFOs recorded with electrodes remote from neurons could actually be generated by clusters of action potentials. The phenomenon of action potentials recorded with remote electrodes can possibly extend the clinical meaning of EEG. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

A physical action potential generator: design, implementation and evaluation.

PubMed

Latorre, Malcolm A; Chan, Adrian D C; Wårdell, Karin

2015-01-01

The objective was to develop a physical action potential generator (Paxon) with the ability to generate a stable, repeatable, programmable, and physiological-like action potential. The Paxon has an equivalent of 40 nodes of Ranvier that were mimicked using resin embedded gold wires (Ø = 20 μm). These nodes were software controlled and the action potentials were initiated by a start trigger. Clinically used Ag-AgCl electrodes were coupled to the Paxon for functional testing. The Paxon's action potential parameters were tunable using a second order mathematical equation to generate physiologically relevant output, which was accomplished by varying the number of nodes involved (1-40 in incremental steps of 1) and the node drive potential (0-2.8 V in 0.7 mV steps), while keeping a fixed inter-nodal timing and test electrode configuration. A system noise floor of 0.07 ± 0.01 μV was calculated over 50 runs. A differential test electrode recorded a peak positive amplitude of 1.5 ± 0.05 mV (gain of 40x) at time 196.4 ± 0.06 ms, including a post trigger delay. The Paxon's programmable action potential like signal has the possibility to be used as a validation test platform for medical surface electrodes and their attached systems.

Peripheral μ-opioid receptor mediated inhibition of calcium signaling and action potential-evoked calcium fluorescent transients in primary afferent CGRP nociceptive terminals.

PubMed

Baillie, Landon D; Schmidhammer, Helmut; Mulligan, Sean J

2015-06-01

While μ-opioid receptor (MOR) agonists remain the most powerful analgesics for the treatment of severe pain, serious adverse side effects that are secondary to their central nervous system actions pose substantial barriers to therapeutic use. Preclinical and clinical evidence suggest that peripheral MORs play an important role in opioid analgesia, particularly under inflammatory conditions. However, the mechanisms of peripheral MOR signaling in primary afferent pain fibres remain to be established. We have recently introduced a novel ex vivo optical imaging approach that, for the first time, allows the study of physiological functioning within individual peripheral nociceptive fibre free nerve endings in mice. In the present study, we found that MOR activation in selectively identified, primary afferent CGRP nociceptive terminals caused inhibition of N-type Ca(2+) channel signaling and suppression of action potential-evoked Ca(2+) fluorescent transients mediated by 'big conductance' Ca(2+)-activated K(+) channels (BKCa). In the live animal, we showed that the peripherally acting MOR agonist HS-731 produced analgesia and that BKCa channels were the major effectors of the peripheral MOR signaling. We have identified two key molecular transducers of MOR activation that mediate significant inhibition of nociceptive signaling in primary afferent terminals. Understanding the mechanisms of peripheral MOR signaling may promote the development of pathway selective μ-opioid drugs that offer improved therapeutic profiles for achieving potent analgesia while avoiding serious adverse central side effects. Copyright © 2015 Elsevier Ltd. All rights reserved.

Implementation of Mass Cytometry as a Tool for Mechanism of Action Studies in Inflammatory Bowel Disease.

PubMed

Tyler, Christopher J; Pérez-Jeldres, Tamara; Ehinger, Erik; Capaldo, Brian; Karuppuchamy, Thangaraj; Boyer, Joshua D; Patel, Derek; Dulai, Parambir; Boland, Brigid S; Lannigan, Joanne; Eckmann, Lars; Ernst, Peter B; Sandborn, William J; Ho, Samuel B; Rivera-Nieves, Jesús

2018-06-08

Novel therapeutics for inflammatory bowel disease (IBD) are under development, yet mechanistic readouts at the tissue level are lacking. Techniques to assess intestinal immune composition could represent a valuable tool for mechanism of action (MOA) studies of novel drugs. Mass cytometry enables analysis of intestinal inflammatory cell infiltrate and corresponding molecular fingerprints with unprecedented resolution. Here, we aimed to optimize the methodology for isolation and cryopreservation of cells from intestinal tissue to allow for the potential implementation of mass cytometry in MOA studies. We investigated key technical issues, including minimal tissue requirements, cell isolation protocols, and cell storage, using intestinal biopsies and peripheral blood from healthy individuals. High-dimensional mass cytometry was employed for the analyses of biopsy-derived intestinal cellular subsets. Dithiothreitol and mechanical dissociation decreased epithelial cell contamination and allowed for isolation of adequate cell numbers from 2 to 4 colonic or ileal biopsies (6 × 104±2 × 104) after a 20-minute collagenase digestion, allowing for reliable detection of most major immune cell subsets. Biopsies and antibody-labeled mononuclear cells could be cryopreserved for later processing and acquisition (viability > 70%; P < 0.05). Mass cytometry represents a unique tool for deep immunophenotyping intestinal cell composition. This technique has the potential to facilitate analysis of drug actions at the target tissue by identifying specific cellular subsets and their molecular signatures. Its widespread implementation may impact not only IBD research but also other gastrointestinal conditions where inflammatory cells play a role in pathogenesis.

Factors influencing private and public environmental protection behaviors: results from a survey of residents in Shaanxi, China.

PubMed

Feng, Wang; Reisner, Ann

2011-03-01

Currently one of the largest and most rapidly developing countries, China also has some of the world's most severe environmental problems. China will most likely need to use all of the potential major strategies currently available to solve the country's huge environmental challenges, including promoting individual conservation behavior through educational campaigns and encouraging public environmental advocacy. This paper summarized the findings of a survey of 347 residents of Shaanxi province on environmental attitudes and behaviors. The survey found generally high levels of environmental knowledge and high recognition of the seriousness of environmental issues, moderate levels of individual actions supporting environmental resource conservation and low levels of public environmental behaviors, particularly for organized public advocacy. Further analysis indicated that the perceived importance of environmental protection is the most important factor influencing individual environmental resource conservation, but not public advocacy behaviors. Implications for environmental campaigns are discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

The neural correlates of ‘vitality form’ recognition: an fMRI study

PubMed Central

Di Cesare, Giuseppe; Di Dio, Cinzia; Rochat, Magali J.; Sinigaglia, Corrado; Bruschweiler-Stern, Nadia; Stern, Daniel N.

2014-01-01

The observation of goal-directed actions performed by another individual allows one to understand what that individual is doing and why he/she is doing it. Important information about others’ behaviour is also carried out by the dynamics of the observed action. Action dynamics characterize the ‘vitality form’ of an action describing the cognitive and affective relation between the performing agent and the action recipient. Here, using the fMRI technique, we assessed the neural correlates of vitality form recognition presenting participants with videos showing two actors executing actions with different vitality forms: energetic and gentle. The participants viewed the actions in two tasks. In one task (what), they had to focus on the goal of the presented action; in the other task (how), they had to focus on the vitality form. For both tasks, activations were found in the action observation/execution circuit. Most interestingly, the contrast how vs what revealed activation in right dorso-central insula, highlighting the involvement, in the recognition of vitality form, of an anatomical region connecting somatosensory areas with the medial temporal region and, in particular, with the hippocampus. This somatosensory-insular-limbic circuit could underlie the observers’ capacity to understand the vitality forms conveyed by the observed action. PMID:23740868

The relationship between muscle action and repetition maximum on the squat and bench press in men and women.

PubMed

Flanagan, Shawn D; Mills, Matthew D; Sterczala, Adam J; Mala, Jesse; Comstock, Brett A; Szivak, Tunde K; DuPont, William H; Looney, David P; McDermott, Danielle M; Hooper, David R; White, Mark T; Dunn-Lewis, Courtenay; Volek, Jeff S; Maresh, Carl M; Kraemer, William J

2014-09-01

The relationship between muscle action and fatigue is not well understood, especially in terms of potential sex-specific differences. The purpose of this investigation was to determine whether a different number of repetitions could be performed on the individual muscle actions of the bench press and squat in men and women. Ten resistance-trained men (n = 10; age, 25.2 ± 1.2 years; height, 178.6 ± 8.8 cm; weight, 91.4 ± 18.1 kg; body fat, 12.7 ± 3.6%) and women (n = 10; age, 25.4 ± 2.4 years; height, 164 ± 4.0 cm; weight, 58.45 ± 3.3 kg; body fat, 20.8 ± 1.5%) participated in this balanced and randomized within-group study. Using 85% of a 1 repetition maximum, over the course of 3 visits, subjects performed 1 eccentric (ECC), concentric (CON), or combined (COMB) set to failure on the squat and bench press. Differences in muscle action and sex-specific number of repetitions to failure were compared on the squat and bench press, where significance was p ≤ 0.05. Across both exercises and sex, we observed significant differences between each of the 3 muscle actions, where the number of repetitions decreased from ECC to COMB to CON. While no sex-specific differences were observed in the squat, women performed significantly more repetitions on the ECC and CON muscle actions of the bench press. Men performed more combined repetitions, however, indicating a greater reliance on the stretch-shortening cycle. Different muscle actions contribute uniquely to the successful performance of a lift and fatigue. These contributions appear to differ in men and women.

Decoding of intentional actions from scalp electroencephalography (EEG) in freely-behaving infants.

PubMed

Hernandez, Zachery R; Cruz-Garza, Jesus; Tse, Teresa; Contreras-Vidal, Jose L

2014-01-01

The mirror neuron system (MNS) in humans is thought to enable an individual's understanding of the meaning of actions performed by others and the potential imitation and learning of those actions. In humans, electroencephalographic (EEG) changes in sensorimotor a-band at central electrodes, which desynchronizes both during execution and observation of goal-directed actions (i.e., μ suppression), have been considered an analog to MNS function. However, methodological and developmental issues, as well as the nature of generalized μ suppression to imagined, observed, and performed actions, have yet to provide a mechanistic relationship between EEG μ-rhythm and MNS function, and the extent to which EEG can be used to infer intent during MNS tasks remains unknown. In this study we present a novel methodology using active EEG and inertial sensors to record brain activity and behavioral actions from freely-behaving infants during exploration, imitation, attentive rest, pointing, reaching and grasping, and interaction with an actor. We used 5-band (1-4Hz) EEG as input to a dimensionality reduction algorithm (locality-preserving Fisher's discriminant analysis, LFDA) followed by a neural classifier (Gaussian mixture models, GMMs) to decode the each MNS task performed by freely-behaving 6-24 month old infants during interaction with an adult actor. Here, we present results from a 20-month male infant to illustrate our approach and show the feasibility of EEG-based classification of freely occurring MNS behaviors displayed by an infant. These results, which provide an alternative to the μ-rhythm theory of MNS function, indicate the informative nature of EEG in relation to intentionality (goal) for MNS tasks which may support action-understanding and thus bear implications for advancing the understanding of MNS function.

Convergent mechanisms underlying rapid antidepressant action

PubMed Central

Zanos, Panos; Thompson, Scott M.; Duman, Ronald S.; Zarate, Carlos A.; Gould, Todd D.

2018-01-01

Traditional pharmacological treatments for depression have a delayed therapeutic onset, ranging from several weeks to months, and there is a high percentage of individuals who never respond to treatment. In contrast, ketamine produces rapid-onset antidepressant, anti-suicidal and anti-anhedonic actions following a single administration to depressed patients. Proposed mechanisms of ketamine’s antidepressant action include N-methyl-D-aspartate receptor (NMDAR) modulation, GABAergic interneuron disinhibition, and direct actions of its hydroxynorketamine (HNK) metabolites. Downstream actions include activation of mechanistic target of rapamycin (mTOR), deactivation of glycogen synthase kinase-3 and eukaryotic elongation factor 2 (eEF2), enhanced brain-derived neurotrophic factor (BDNF) signaling, and activation of α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors (AMPARs). These putative mechanisms of ketamine action are not mutually exclusive and may complement each other to induce potentiation of excitatory synapses in affective-regulating brain circuits, which results in amelioration of depression symptoms. We review these proposed mechanisms of ketamine action in the context of how such mechanisms are informing the development of novel putative rapid-acting antidepressant drugs. Such drugs that have undergoing pre-clinical, and in some cases clinical, testing include the muscarinic acetylcholine receptor antagonist scopolamine, GluN2B-NMDAR antagonists (i.e., CP-101,606, MK-0657), (2R,6R)-HNK, NMDAR glycine site modulators (i.e., 4-chlorokynurenine - pro-drug of the glycineB NMDAR antagonist 7-chlorokynurenic acid), NMDAR agonists (i.e. GLYX-13 (rapastinel)), metabotropic glutamate receptor 2/3 (mGluR2/3) antagonists, GABAA receptor modulators, and drugs acting on various serotonin receptor subtypes. These ongoing studies suggest that the future acute treatment of depression will typically occur within hours, rather than months, of treatment initiation. PMID:29516301