Sample records for gain control circuitry

  1. Controlling gain one photon at a time

    PubMed Central

    Schwartz, Gregory W; Rieke, Fred

    2013-01-01

    Adaptation is a salient property of sensory processing. All adaptational or gain control mechanisms face the challenge of obtaining a reliable estimate of the property of the input to be adapted to and obtaining this estimate sufficiently rapidly to be useful. Here, we explore how the primate retina balances the need to change gain rapidly and reliably when photons arrive rarely at individual rod photoreceptors. We find that the weakest backgrounds that decrease the gain of the retinal output signals are similar to those that increase human behavioral threshold, and identify a novel site of gain control in the retinal circuitry. Thus, surprisingly, the gain of retinal signals begins to decrease essentially as soon as background lights are detectable; under these conditions, gain control does not rely on a highly averaged estimate of the photon count, but instead signals from individual photon absorptions trigger changes in gain. DOI: http://dx.doi.org/10.7554/eLife.00467.001 PMID:23682314

  2. Light-controlled resistors provide quadrature signal rejection for high-gain servo systems

    NASA Technical Reports Server (NTRS)

    Mc Cauley, D. D.

    1967-01-01

    Servo amplifier feedback system, in which the phase sensitive detection, low pass filtering, and multiplication functions required for quadrature rejection, are preformed by light-controlled photoresistors, eliminates complex circuitry. System increases gain, improves signal-to-noise ratio, and eliminates the necessity for compensation.

  3. A digitally controlled AGC loop circuitry for GNSS receiver chip with a binary weighted accurate dB-linear PGA

    NASA Astrophysics Data System (ADS)

    Gang, Jin; Yiqi, Zhuang; Yue, Yin; Miao, Cui

    2015-03-01

    A novel digitally controlled automatic gain control (AGC) loop circuitry for the global navigation satellite system (GNSS) receiver chip is presented. The entire AGC loop contains a programmable gain amplifier (PGA), an AGC circuit and an analog-to-digital converter (ADC), which is implemented in a 0.18 μm complementary metal-oxide-semiconductor (CMOS) process and measured. A binary-weighted approach is proposed in the PGA to achieve wide dB-linear gain control with small gain error. With binary-weighted cascaded amplifiers for coarse gain control, and parallel binary-weighted trans-conductance amplifier array for fine gain control, the PGA can provide a 64 dB dynamic range from -4 to 60 dB in 1.14 dB gain steps with a less than 0.15 dB gain error. Based on the Gaussian noise statistic characteristic of the GNSS signal, a digital AGC circuit is also proposed with low area and fast settling. The feed-backward AGC loop occupies an area of 0.27 mm2 and settles within less than 165 μs while consuming an average current of 1.92 mA at 1.8 V.

  4. Automatic quadrature control and measuring system. [using optical coupling circuitry

    NASA Technical Reports Server (NTRS)

    Hamlet, J. F. (Inventor)

    1974-01-01

    A quadrature component cancellation and measuring system comprising a detection system for detecting the quadrature component from a primary signal, including reference circuitry to define the phase of the quadrature component for detection is described. A Raysistor optical coupling control device connects an output from the detection system to a circuit driven by a signal based upon the primary signal. Combining circuitry connects the primary signal and the circuit controlled by the Raysistor device to subtract quadrature components. A known current through the optically sensitive element produces a signal defining the magnitude of the quadrature component.

  5. Subtractive, divisive and non-monotonic gain control in feedforward nets linearized by noise and delays.

    PubMed

    Mejias, Jorge F; Payeur, Alexandre; Selin, Erik; Maler, Leonard; Longtin, André

    2014-01-01

    The control of input-to-output mappings, or gain control, is one of the main strategies used by neural networks for the processing and gating of information. Using a spiking neural network model, we studied the gain control induced by a form of inhibitory feedforward circuitry-also known as "open-loop feedback"-, which has been experimentally observed in a cerebellum-like structure in weakly electric fish. We found, both analytically and numerically, that this network displays three different regimes of gain control: subtractive, divisive, and non-monotonic. Subtractive gain control was obtained when noise is very low in the network. Also, it was possible to change from divisive to non-monotonic gain control by simply modulating the strength of the feedforward inhibition, which may be achieved via long-term synaptic plasticity. The particular case of divisive gain control has been previously observed in vivo in weakly electric fish. These gain control regimes were robust to the presence of temporal delays in the inhibitory feedforward pathway, which were found to linearize the input-to-output mappings (or f-I curves) via a novel variability-increasing mechanism. Our findings highlight the feedforward-induced gain control analyzed here as a highly versatile mechanism of information gating in the brain.

  6. The architecture and conservation pattern of whole-cell control circuitry.

    PubMed

    McAdams, Harley H; Shapiro, Lucy

    2011-05-27

    The control circuitry that directs and paces Caulobacter cell cycle progression involves the entire cell operating as an integrated system. This control circuitry monitors the environment and the internal state of the cell, including the cell topology, as it orchestrates orderly activation of cell cycle subsystems and Caulobacter's asymmetric cell division. The proteins of the Caulobacter cell cycle control system and its internal organization are co-conserved across many alphaproteobacteria species, but there are great differences in the regulatory apparatus' functionality and peripheral connectivity to other cellular subsystems from species to species. This pattern is similar to that observed for the "kernels" of the regulatory networks that regulate development of metazoan body plans. The Caulobacter cell cycle control system has been exquisitely optimized as a total system for robust operation in the face of internal stochastic noise and environmental uncertainty. When sufficient details accumulate, as for Caulobacter cell cycle regulation, the system design has been found to be eminently rational and indeed consistent with good design practices for human-designed asynchronous control systems. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. The Development of Micromachined Gyroscope Structure and Circuitry Technology

    PubMed Central

    Xia, Dunzhu; Yu, Cheng; Kong, Lun

    2014-01-01

    This review surveys micromachined gyroscope structure and circuitry technology. The principle of micromachined gyroscopes is first introduced. Then, different kinds of MEMS gyroscope structures, materials and fabrication technologies are illustrated. Micromachined gyroscopes are mainly categorized into micromachined vibrating gyroscopes (MVGs), piezoelectric vibrating gyroscopes (PVGs), surface acoustic wave (SAW) gyroscopes, bulk acoustic wave (BAW) gyroscopes, micromachined electrostatically suspended gyroscopes (MESGs), magnetically suspended gyroscopes (MSGs), micro fiber optic gyroscopes (MFOGs), micro fluid gyroscopes (MFGs), micro atom gyroscopes (MAGs), and special micromachined gyroscopes. Next, the control electronics of micromachined gyroscopes are analyzed. The control circuits are categorized into typical circuitry and special circuitry technologies. The typical circuitry technologies include typical analog circuitry and digital circuitry, while the special circuitry consists of sigma delta, mode matching, temperature/quadrature compensation and novel special technologies. Finally, the characteristics of various typical gyroscopes and their development tendency are discussed and investigated in detail. PMID:24424468

  8. Altered emotional interference processing in affective and cognitive-control brain circuitry in major depression

    PubMed Central

    Fales, Christina L.; Barch, Deanna M.; Rundle, Melissa M.; Mintun, Mark A.; Snyder, Abraham Z.; Cohen, Jonathan D.; Mathews, Jose; Sheline, Yvette I.

    2008-01-01

    Background Major depression is characterized by a negativity bias: an enhanced responsiveness to, and memory for, affectively negative stimuli. However it is not yet clear whether this bias represents (1) impaired top-down cognitive control over affective responses, potentially linked to deficits in dorsolateral prefrontal cortex function; or (2) enhanced bottom-up responses to affectively-laden stimuli that dysregulate cognitive control mechanisms, potentially linked to deficits in amygdala and anterior cingulate function. Methods We used an attentional interference task using emotional distracters to test for top-down versus bottom-up dysfunction in the interaction of cognitive-control circuitry and emotion-processing circuitry. A total of 27 patients with major depression and 24 controls were tested. Event-related functional magnetic resonance imaging was carried out as participants directly attended to, or attempted to ignore, fear-related stimuli. Results Compared to controls, patients with depression showed an enhanced amygdala response to unattended fear-related stimuli (relative to unattended neutral). By contrast, control participants showed increased activity in right dorsolateral prefrontal cortex (Brodmann areas 46/9) when ignoring fear stimuli (relative to neutral), which the patients with depression did not. In addition, the depressed participants failed to show evidence of error-related cognitive adjustments (increased activity in bilateral dorsolateral prefrontal cortex on post-error trials), but the control group did show them. Conclusions These results suggest multiple sources of dysregulation in emotional and cognitive control circuitry in depression, implicating both top-down and bottom-up dysfunction. PMID:17719567

  9. The inhibitory microcircuit of the substantia nigra provides feedback gain control of the basal ganglia output

    PubMed Central

    Brown, Jennifer; Pan, Wei-Xing; Dudman, Joshua Tate

    2014-01-01

    Dysfunction of the basal ganglia produces severe deficits in the timing, initiation, and vigor of movement. These diverse impairments suggest a control system gone awry. In engineered systems, feedback is critical for control. By contrast, models of the basal ganglia highlight feedforward circuitry and ignore intrinsic feedback circuits. In this study, we show that feedback via axon collaterals of substantia nigra projection neurons control the gain of the basal ganglia output. Through a combination of physiology, optogenetics, anatomy, and circuit mapping, we elaborate a general circuit mechanism for gain control in a microcircuit lacking interneurons. Our data suggest that diverse tonic firing rates, weak unitary connections and a spatially diffuse collateral circuit with distinct topography and kinetics from feedforward input is sufficient to implement divisive feedback inhibition. The importance of feedback for engineered systems implies that the intranigral microcircuit, despite its absence from canonical models, could be essential to basal ganglia function. DOI: http://dx.doi.org/10.7554/eLife.02397.001 PMID:24849626

  10. The Impact of Emotional States on Cognitive Control Circuitry and Function.

    PubMed

    Cohen, Alexandra O; Dellarco, Danielle V; Breiner, Kaitlyn; Helion, Chelsea; Heller, Aaron S; Rahdar, Ahrareh; Pedersen, Gloria; Chein, Jason; Dyke, Jonathan P; Galvan, Adriana; Casey, B J

    2016-03-01

    Typically in the laboratory, cognitive and emotional processes are studied separately or as a stream of fleeting emotional stimuli embedded within a cognitive task. Yet in life, thoughts and actions often occur in more lasting emotional states of arousal. The current study examines the impact of emotions on actions using a novel behavioral paradigm and functional neuroimaging to assess cognitive control under sustained states of threat (anticipation of an aversive noise) and excitement (anticipation of winning money). Thirty-eight healthy adult participants were scanned while performing an emotional go/no-go task with positive (happy faces), negative (fearful faces), and neutral (calm faces) emotional cues, under threat or excitement. Cognitive control performance was enhanced during the excited state relative to a nonarousing control condition. This enhanced performance was paralleled by heightened activity of frontoparietal and frontostriatal circuitry. In contrast, under persistent threat, cognitive control was diminished when the valence of the emotional cue conflicted with the emotional state. Successful task performance in this conflicting emotional condition was associated with increased activity in the posterior cingulate cortex, a default mode network region implicated in complex processes such as processing emotions in the context of self and monitoring performance. This region showed positive coupling with frontoparietal circuitry implicated in cognitive control, providing support for a role of the posterior cingulate cortex in mobilizing cognitive resources to improve performance. These findings suggest that emotional states of arousal differentially modulate cognitive control and point to the potential utility of this paradigm for understanding effects of situational and pathological states of arousal on behavior.

  11. Singing modulates parvalbumin interneurons throughout songbird forebrain vocal control circuitry

    PubMed Central

    Zengin-Toktas, Yildiz

    2017-01-01

    Across species, the performance of vocal signals can be modulated by the social environment. Zebra finches, for example, adjust their song performance when singing to females (‘female-directed’ or FD song) compared to when singing in isolation (‘undirected’ or UD song). These changes are salient, as females prefer the FD song over the UD song. Despite the importance of these performance changes, the neural mechanisms underlying this social modulation remain poorly understood. Previous work in finches has established that expression of the immediate early gene EGR1 is increased during singing and modulated by social context within the vocal control circuitry. Here, we examined whether particular neural subpopulations within those vocal control regions exhibit similar modulations of EGR1 expression. We compared EGR1 expression in neurons expressing parvalbumin (PV), a calcium buffer that modulates network plasticity and homeostasis, among males that performed FD song, males that produced UD song, or males that did not sing. We found that, overall, singing but not social context significantly affected EGR1 expression in PV neurons throughout the vocal control nuclei. We observed differences in EGR1 expression between two classes of PV interneurons in the basal ganglia nucleus Area X. Additionally, we found that singing altered the amount of PV expression in neurons in HVC and Area X and that distinct PV interneuron types in Area X exhibited different patterns of modulation by singing. These data indicate that throughout the vocal control circuitry the singing-related regulation of EGR1 expression in PV neurons may be less influenced by social context than in other neuron types and raise the possibility of cell-type specific differences in plasticity and calcium buffering. PMID:28235074

  12. The inhibitory microcircuit of the substantia nigra provides feedback gain control of the basal ganglia output.

    PubMed

    Brown, Jennifer; Pan, Wei-Xing; Dudman, Joshua Tate

    2014-05-21

    Dysfunction of the basal ganglia produces severe deficits in the timing, initiation, and vigor of movement. These diverse impairments suggest a control system gone awry. In engineered systems, feedback is critical for control. By contrast, models of the basal ganglia highlight feedforward circuitry and ignore intrinsic feedback circuits. In this study, we show that feedback via axon collaterals of substantia nigra projection neurons control the gain of the basal ganglia output. Through a combination of physiology, optogenetics, anatomy, and circuit mapping, we elaborate a general circuit mechanism for gain control in a microcircuit lacking interneurons. Our data suggest that diverse tonic firing rates, weak unitary connections and a spatially diffuse collateral circuit with distinct topography and kinetics from feedforward input is sufficient to implement divisive feedback inhibition. The importance of feedback for engineered systems implies that the intranigral microcircuit, despite its absence from canonical models, could be essential to basal ganglia function. DOI: http://dx.doi.org/10.7554/eLife.02397.001. Copyright © 2014, Brown et al.

  13. Asthma Triggers: Gain Control

    MedlinePlus

    ... Centers Asthma Contact Us Share Asthma Triggers: Gain Control Breathing Freely: Controlling Asthma Triggers This video features ... Air Quality: Biological Pollutants Help Your Child Gain Control Over Asthma Top of Page Molds About Molds ...

  14. Central Brain Circuitry for Color-Vision-Modulated Behaviors.

    PubMed

    Longden, Kit D

    2016-10-24

    Color is famous for not existing in the external world: our brains create the perception of color from the spatial and temporal patterns of the wavelength and intensity of light. For an intangible quality, we have detailed knowledge of its origins and consequences. Much is known about the organization and evolution of the first phases of color processing, the filtering of light in the eye and processing in the retina, and about the final phases, the roles of color in behavior and natural selection. To understand how color processing in the central brain has evolved, we need well-defined pathways or circuitry where we can gauge how color contributes to the computations involved in specific behaviors. Examples of such pathways or circuitry that are dedicated to processing color cues are rare, despite the separation of color and luminance pathways early in the visual system of many species, and despite the traditional definition of color as being independent of luminance. This minireview presents examples in which color vision contributes to behaviors dominated by other visual modalities, examples that are not part of the canon of color vision circuitry. The pathways and circuitry process a range of chromatic properties of objects and their illumination, and are taken from a variety of species. By considering how color processing complements luminance processing, rather than being independent of it, we gain an additional way to account for the diversity of color coding in the central brain, its consequences for specific behaviors and ultimately the evolution of color vision. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Optogenetic dissection of medial prefrontal cortex circuitry

    PubMed Central

    Riga, Danai; Matos, Mariana R.; Glas, Annet; Smit, August B.; Spijker, Sabine; Van den Oever, Michel C.

    2014-01-01

    The medial prefrontal cortex (mPFC) is critically involved in numerous cognitive functions, including attention, inhibitory control, habit formation, working memory and long-term memory. Moreover, through its dense interconnectivity with subcortical regions (e.g., thalamus, striatum, amygdala and hippocampus), the mPFC is thought to exert top-down executive control over the processing of aversive and appetitive stimuli. Because the mPFC has been implicated in the processing of a wide range of cognitive and emotional stimuli, it is thought to function as a central hub in the brain circuitry mediating symptoms of psychiatric disorders. New optogenetics technology enables anatomical and functional dissection of mPFC circuitry with unprecedented spatial and temporal resolution. This provides important novel insights in the contribution of specific neuronal subpopulations and their connectivity to mPFC function in health and disease states. In this review, we present the current knowledge obtained with optogenetic methods concerning mPFC function and dysfunction and integrate this with findings from traditional intervention approaches used to investigate the mPFC circuitry in animal models of cognitive processing and psychiatric disorders. PMID:25538574

  16. Optogenetic dissection of medial prefrontal cortex circuitry.

    PubMed

    Riga, Danai; Matos, Mariana R; Glas, Annet; Smit, August B; Spijker, Sabine; Van den Oever, Michel C

    2014-01-01

    The medial prefrontal cortex (mPFC) is critically involved in numerous cognitive functions, including attention, inhibitory control, habit formation, working memory and long-term memory. Moreover, through its dense interconnectivity with subcortical regions (e.g., thalamus, striatum, amygdala and hippocampus), the mPFC is thought to exert top-down executive control over the processing of aversive and appetitive stimuli. Because the mPFC has been implicated in the processing of a wide range of cognitive and emotional stimuli, it is thought to function as a central hub in the brain circuitry mediating symptoms of psychiatric disorders. New optogenetics technology enables anatomical and functional dissection of mPFC circuitry with unprecedented spatial and temporal resolution. This provides important novel insights in the contribution of specific neuronal subpopulations and their connectivity to mPFC function in health and disease states. In this review, we present the current knowledge obtained with optogenetic methods concerning mPFC function and dysfunction and integrate this with findings from traditional intervention approaches used to investigate the mPFC circuitry in animal models of cognitive processing and psychiatric disorders.

  17. Optogenetic mapping of brain circuitry

    NASA Astrophysics Data System (ADS)

    Augustine, George J.; Berglund, Ken; Gill, Harin; Hoffmann, Carolin; Katarya, Malvika; Kim, Jinsook; Kudolo, John; Lee, Li M.; Lee, Molly; Lo, Daniel; Nakajima, Ryuichi; Park, Min Yoon; Tan, Gregory; Tang, Yanxia; Teo, Peggy; Tsuda, Sachiko; Wen, Lei; Yoon, Su-In

    2012-10-01

    Studies of the brain promise to be revolutionized by new experimental strategies that harness the combined power of optical techniques and genetics. We have mapped the circuitry of the mouse brain by using both optogenetic actuators that control neuronal activity and optogenetic sensors that detect neuronal activity. Using the light-activated cation channel, channelrhodopsin-2, to locally photostimulate neurons allows high-speed mapping of local and long-range circuitry. For example, with this approach we have mapped local circuits in the cerebral cortex, cerebellum and many other brain regions. Using the fluorescent sensor for chloride ions, Clomeleon, allows imaging of the spatial and temporal dimensions of inhibitory circuits in the brain. This approach allows imaging of both conventional "phasic" synaptic inhibition as well as unconventional "tonic" inhibition. The combined use of light to both control and monitor neural activity creates unprecedented opportunities to explore brain function, screen pharmaceutical agents, and potentially to use light to ameliorate psychiatric and neurological disorders.

  18. A neural circuitry that emphasizes spinal feedback generates diverse behaviours of human locomotion

    PubMed Central

    Song, Seungmoon; Geyer, Hartmut

    2015-01-01

    Neural networks along the spinal cord contribute substantially to generating locomotion behaviours in humans and other legged animals. However, the neural circuitry involved in this spinal control remains unclear. We here propose a specific circuitry that emphasizes feedback integration over central pattern generation. The circuitry is based on neurophysiologically plausible muscle-reflex pathways that are organized in 10 spinal modules realizing limb functions essential to legged systems in stance and swing. These modules are combined with a supraspinal control layer that adjusts the desired foot placements and selects the leg that is to transition into swing control during double support. Using physics-based simulation, we test the proposed circuitry in a neuromuscular human model that includes neural transmission delays, musculotendon dynamics and compliant foot–ground contacts. We find that the control network is sufficient to compose steady and transitional 3-D locomotion behaviours including walking and running, acceleration and deceleration, slope and stair negotiation, turning, and deliberate obstacle avoidance. The results suggest feedback integration to be functionally more important than central pattern generation in human locomotion across behaviours. In addition, the proposed control architecture may serve as a guide in the search for the neurophysiological origin and circuitry of spinal control in humans. PMID:25920414

  19. CHARACTERIZATION OF OZONE EMISSIONS FROM AIR CLEANERS EQUIPPED WITH OZONE GENERATORS AND SENSOR AND FEEDBACK CONTROL CIRCUITRY

    EPA Science Inventory

    The paper give results of a characterization of ozone emissions from air cleaners equipped with ozone generators and sensor and feedback control circuitry. Ozone emission rates of several consumer appliances, marketed as indoor air treatment or air purification systems, were det...

  20. Input-dependent modulation of MEG gamma oscillations reflects gain control in the visual cortex.

    PubMed

    Orekhova, Elena V; Sysoeva, Olga V; Schneiderman, Justin F; Lundström, Sebastian; Galuta, Ilia A; Goiaeva, Dzerasa E; Prokofyev, Andrey O; Riaz, Bushra; Keeler, Courtney; Hadjikhani, Nouchine; Gillberg, Christopher; Stroganova, Tatiana A

    2018-05-31

    Gamma-band oscillations arise from the interplay between neural excitation (E) and inhibition (I) and may provide a non-invasive window into the state of cortical circuitry. A bell-shaped modulation of gamma response power by increasing the intensity of sensory input was observed in animals and is thought to reflect neural gain control. Here we sought to find a similar input-output relationship in humans with MEG via modulating the intensity of a visual stimulation by changing the velocity/temporal-frequency of visual motion. In the first experiment, adult participants observed static and moving gratings. The frequency of the MEG gamma response monotonically increased with motion velocity whereas power followed a bell-shape. In the second experiment, on a large group of children and adults, we found that despite drastic developmental changes in frequency and power of gamma oscillations, the relative suppression at high motion velocities was scaled to the same range of values across the life-span. In light of animal and modeling studies, the modulation of gamma power and frequency at high stimulation intensities characterizes the capacity of inhibitory neurons to counterbalance increasing excitation in visual networks. Gamma suppression may thus provide a non-invasive measure of inhibitory-based gain control in the healthy and diseased brain.

  1. Histones: Controlling Tumor Signaling Circuitry

    PubMed Central

    Martins, Manoela D.; Castilho, Rogerio M.

    2014-01-01

    Epigenetic modifications constitute the next frontier in tumor biology research. Post-translation modification of histones dynamically influences gene expression independent of alterations to the DNA sequence. These mechanisms are often mediated by histone linkers or by proteins associated with the recruitment of DNA-binding proteins, HDAC I and II interacting proteins and transcriptional activators, coactivators or corepressors. Early evidence suggested that histones and their modifiers are involved in sophisticated processes that modulate tumor behavior and cellular phenotype. In this review, we discuss how recent discoveries about chromatin modifications, particularly histone acetylation, are shaping our knowledge of cell biology and our understanding of the molecular circuitry governing tumor progression and consider whether recent insights may extend to novel therapeutic approaches. Furthermore, we discuss the latest oncogenomic findings in Head and Neck Squamous Cell Carcinoma (HNSCC) from studies using Next Generation Sequencing (NGS) technology and highlight the impact of mutations identified in histones and their modifiers. PMID:25177526

  2. Optimization of control gain by operator adjustment

    NASA Technical Reports Server (NTRS)

    Kruse, W.; Rothbauer, G.

    1973-01-01

    An optimal gain was established by measuring errors at 5 discrete control gain settings in an experimental set-up consisting of a 2-dimensional, first-order pursuit tracking task performed by subjects (S's). No significant experience effect on optimum gain setting was found in the first experiment. During the second experiment, in which control gain was continuously adjustable, high experienced S's tended to reach the previously determined optimum gain quite accurately and quickly. Less experienced S's tended to select a marginally optimum gain either below or above the experimentally determined optimum depending on initial control gain setting, although mean settings of both groups were equal. This quick and simple method is recommended for selecting control gains for different control systems and forcing functions.

  3. Neural circuitry coordinating male copulation

    PubMed Central

    Pavlou, Hania J; Lin, Andrew C; Neville, Megan C; Nojima, Tetsuya; Diao, Fengqiu; Chen, Brian E; White, Benjamin H; Goodwin, Stephen F

    2016-01-01

    Copulation is the goal of the courtship process, crucial to reproductive success and evolutionary fitness. Identifying the circuitry underlying copulation is a necessary step towards understanding universal principles of circuit operation, and how circuit elements are recruited into the production of ordered action sequences. Here, we identify key sex-specific neurons that mediate copulation in Drosophila, and define a sexually dimorphic motor circuit in the male abdominal ganglion that mediates the action sequence of initiating and terminating copulation. This sexually dimorphic circuit composed of three neuronal classes – motor neurons, interneurons and mechanosensory neurons – controls the mechanics of copulation. By correlating the connectivity, function and activity of these neurons we have determined the logic for how this circuitry is coordinated to generate this male-specific behavior, and sets the stage for a circuit-level dissection of active sensing and modulation of copulatory behavior. DOI: http://dx.doi.org/10.7554/eLife.20713.001 PMID:27855059

  4. LPV Controller Interpolation for Improved Gain-Scheduling Control Performance

    NASA Technical Reports Server (NTRS)

    Wu, Fen; Kim, SungWan

    2002-01-01

    In this paper, a new gain-scheduling control design approach is proposed by combining LPV (linear parameter-varying) control theory with interpolation techniques. The improvement of gain-scheduled controllers can be achieved from local synthesis of Lyapunov functions and continuous construction of a global Lyapunov function by interpolation. It has been shown that this combined LPV control design scheme is capable of improving closed-loop performance derived from local performance improvement. The gain of the LPV controller will also change continuously across parameter space. The advantages of the newly proposed LPV control is demonstrated through a detailed AMB controller design example.

  5. Method for integrating microelectromechanical devices with electronic circuitry

    DOEpatents

    Montague, Stephen; Smith, James H.; Sniegowski, Jeffry J.; McWhorter, Paul J.

    1998-01-01

    A method for integrating one or more microelectromechanical (MEM) devices with electronic circuitry. The method comprises the steps of forming each MEM device within a cavity below a device surface of the substrate; encapsulating the MEM device prior to forming electronic circuitry on the substrate; and releasing the MEM device for operation after fabrication of the electronic circuitry. Planarization of the encapsulated MEM device prior to formation of the electronic circuitry allows the use of standard processing steps for fabrication of the electronic circuitry.

  6. Method for integrating microelectromechanical devices with electronic circuitry

    DOEpatents

    Montague, S.; Smith, J.H.; Sniegowski, J.J.; McWhorter, P.J.

    1998-08-25

    A method is disclosed for integrating one or more microelectromechanical (MEM) devices with electronic circuitry. The method comprises the steps of forming each MEM device within a cavity below a device surface of the substrate; encapsulating the MEM device prior to forming electronic circuitry on the substrate; and releasing the MEM device for operation after fabrication of the electronic circuitry. Planarization of the encapsulated MEM device prior to formation of the electronic circuitry allows the use of standard processing steps for fabrication of the electronic circuitry. 13 figs.

  7. Neural alterations of fronto-striatal circuitry during reward anticipation in euthymic bipolar disorder.

    PubMed

    Schreiter, S; Spengler, S; Willert, A; Mohnke, S; Herold, D; Erk, S; Romanczuk-Seiferth, N; Quinlivan, E; Hindi-Attar, C; Banzhaf, C; Wackerhagen, C; Romund, L; Garbusow, M; Stamm, T; Heinz, A; Walter, H; Bermpohl, F

    2016-11-01

    Bipolar disorder (BD), with the hallmark symptoms of elevated and depressed mood, is thought to be characterized by underlying alterations in reward-processing networks. However, to date the neural circuitry underlying abnormal responses during reward processing in BD remains largely unexplored. The aim of this study was to investigate whether euthymic BD is characterized by aberrant ventral striatal (VS) activation patterns and altered connectivity with the prefrontal cortex in response to monetary gains and losses. During functional magnetic resonance imaging 20 euthymic BD patients and 20 age-, gender- and intelligence quotient-matched healthy controls completed a monetary incentive delay paradigm, to examine neural processing of reward and loss anticipation. A priori defined regions of interest (ROIs) included the VS and the anterior prefrontal cortex (aPFC). Psychophysiological interactions (PPIs) between these ROIs were estimated and tested for group differences for reward and loss anticipation separately. BD participants, relative to healthy controls, displayed decreased activation selectively in the left and right VS during anticipation of reward, but not during loss anticipation. PPI analyses showed decreased functional connectivity between the left VS and aPFC in BD patients compared with healthy controls during reward anticipation. This is the first study showing decreased VS activity and aberrant connectivity in the reward-processing circuitry in euthymic, medicated BD patients during reward anticipation. Our findings contrast with research supporting a reward hypersensitivity model of BD, and add to the body of literature suggesting that blunted activation of reward processing circuits may be a vulnerability factor for mood disorders.

  8. A variable-gain output feedback control design methodology

    NASA Technical Reports Server (NTRS)

    Halyo, Nesim; Moerder, Daniel D.; Broussard, John R.; Taylor, Deborah B.

    1989-01-01

    A digital control system design technique is developed in which the control system gain matrix varies with the plant operating point parameters. The design technique is obtained by formulating the problem as an optimal stochastic output feedback control law with variable gains. This approach provides a control theory framework within which the operating range of a control law can be significantly extended. Furthermore, the approach avoids the major shortcomings of the conventional gain-scheduling techniques. The optimal variable gain output feedback control problem is solved by embedding the Multi-Configuration Control (MCC) problem, previously solved at ICS. An algorithm to compute the optimal variable gain output feedback control gain matrices is developed. The algorithm is a modified version of the MCC algorithm improved so as to handle the large dimensionality which arises particularly in variable-gain control problems. The design methodology developed is applied to a reconfigurable aircraft control problem. A variable-gain output feedback control problem was formulated to design a flight control law for an AFTI F-16 aircraft which can automatically reconfigure its control strategy to accommodate failures in the horizontal tail control surface. Simulations of the closed-loop reconfigurable system show that the approach produces a control design which can accommodate such failures with relative ease. The technique can be applied to many other problems including sensor failure accommodation, mode switching control laws and super agility.

  9. Variable gain for a wind turbine pitch control

    NASA Technical Reports Server (NTRS)

    Seidel, R. C.; Birchenough, A. G.

    1981-01-01

    The gain variation is made in the software logic of the pitch angle controller. The gain level is changed depending upon the level of power error. The control uses low gain for low pitch activity the majority of the time. If the power exceeds ten percent offset above rated, the gain is increased to a higher gain to more effectively limit power. A variable gain control functioned well in tests on the Mod-0 wind turbine.

  10. New modules are added to vibrissal premotor circuitry with the emergence of exploratory whisking

    PubMed Central

    Takatoh, Jun; Nelson, Anders; Zhou, Xiang; Bolton, M. McLean; Ehlers, Michael D.; Arenkiel, Benjamin R.; Mooney, Richard; Wang, Fan

    2012-01-01

    SUMMARY Rodents begin to use bilaterally coordinated, rhythmic sweeping of their vibrissae (“whisking”) for environmental exploration around two weeks after birth. Whether and how vibrissal control circuitry changes after birth is unknown, and relevant premotor circuitry remains poorly characterized. Using a modified rabies virus transsynaptic tracing strategy, we labeled neurons synapsing directly onto vibrissa facial motor neurons (vFMNs). Sources of potential excitatory, inhibitory, and modulatory vFMN premotor neurons, and differences between the premotor circuitry for vFMNs innervating intrinsic versus extrinsic vibrissal muscles, were systematically characterized. The emergence of whisking is accompanied by the addition of “new” sets of bilateral excitatory inputs to vFMNs from neurons in the lateral paragigantocellularis (LPGi). Furthermore, descending axons from the motor cortex directly innervate LPGi premotor neurons. Thus, neural modules well suited to facilitate the bilateral coordination and cortical control of whisking are added to premotor circuitry in parallel with the emergence of this exploratory behavior. PMID:23352170

  11. Interface Electronic Circuitry for an Electronic Tongue

    NASA Technical Reports Server (NTRS)

    Keymeulen, Didier; Buehler, Martin

    2007-01-01

    Electronic circuitry has been developed to serve as an interface between an electronic tongue and digital input/output boards in a laptop computer that is used to control the tongue and process its readings. Electronic tongues can be used for a variety of purposes, including evaluating water quality, analyzing biochemicals, analyzing biofilms, and measuring electrical conductivities of soils.

  12. The heterogeneous integration of single-walled carbon nanotubes onto complementary metal oxide semiconductor circuitry for sensing applications.

    PubMed

    Chen, Chia-Ling; Agarwal, Vinay; Sonkusale, Sameer; Dokmeci, Mehmet R

    2009-06-03

    A simple methodology for integrating single-walled carbon nanotubes (SWNTs) onto complementary metal oxide semiconductor (CMOS) circuitry is presented. The SWNTs were incorporated onto the CMOS chip as the feedback resistor of a two-stage Miller compensated operational amplifier utilizing dielectrophoretic assembly. The measured electrical properties from the integrated SWNTs yield ohmic behavior with a two-terminal resistance of approximately 37.5 kOmega and the measured small signal ac gain (-2) from the inverting amplifier confirmed successful integration of carbon nanotubes onto the CMOS circuitry. Furthermore, the temperature response of the SWNTs integrated onto CMOS circuitry has been measured and had a thermal coefficient of resistance (TCR) of -0.4% degrees C(-1). This methodology, demonstrated for the integration of SWNTs onto CMOS technology, is versatile, high yield and paves the way for the realization of novel miniature carbon-nanotube-based sensor systems.

  13. Apparatus, system and method for providing cryptographic key information with physically unclonable function circuitry

    DOEpatents

    Areno, Matthew

    2015-12-08

    Techniques and mechanisms for providing a value from physically unclonable function (PUF) circuitry for a cryptographic operation of a security module. In an embodiment, a cryptographic engine receives a value from PUF circuitry and based on the value, outputs a result of a cryptographic operation to a bus of the security module. The bus couples the cryptographic engine to control logic or interface logic of the security module. In another embodiment, the value is provided to the cryptographic engine from the PUF circuitry via a signal line which is distinct from the bus, where any exchange of the value by either of the cryptographic engine and the PUF circuitry is for communication of the first value independent of the bus.

  14. A variable-gain output feedback control design approach

    NASA Technical Reports Server (NTRS)

    Haylo, Nesim

    1989-01-01

    A multi-model design technique to find a variable-gain control law defined over the whole operating range is proposed. The design is formulated as an optimal control problem which minimizes a cost function weighing the performance at many operating points. The solution is obtained by embedding into the Multi-Configuration Control (MCC) problem, a multi-model robust control design technique. In contrast to conventional gain scheduling which uses a curve fit of single model designs, the optimal variable-gain control law stabilizes the plant at every operating point included in the design. An iterative algorithm to compute the optimal control gains is presented. The methodology has been successfully applied to reconfigurable aircraft flight control and to nonlinear flight control systems.

  15. Lighting up the brain's reward circuitry.

    PubMed

    Lobo, Mary Kay

    2012-07-01

    The brain's reward circuit is critical for mediating natural reward behaviors including food, sex, and social interaction. Drugs of abuse take over this circuit and produce persistent molecular and cellular alterations in the brain regions and their neural circuitry that make up the reward pathway. Recent use of optogenetic technologies has provided novel insights into the functional and molecular role of the circuitry and cell subtypes within these circuits that constitute this pathway. This perspective will address the current and future use of light-activated proteins, including those involved in modulating neuronal activity, cellular signaling, and molecular properties in the neural circuitry mediating rewarding stimuli and maladaptive responses to drugs of abuse. © 2012 New York Academy of Sciences.

  16. Linear-parameter-varying gain-scheduled control of aerospace systems

    NASA Astrophysics Data System (ADS)

    Barker, Jeffrey Michael

    The dynamics of many aerospace systems vary significantly as a function of flight condition. Robust control provides methods of guaranteeing performance and stability goals across flight conditions. In mu-syntthesis, changes to the dynamical system are primarily treated as uncertainty. This method has been successfully applied to many control problems, and here is applied to flutter control. More recently, two techniques for generating robust gain-scheduled controller have been developed. Linear fractional transformation (LFT) gain-scheduled control is an extension of mu-synthesis in which the plant and controller are explicit functions of parameters measurable in real-time. This LFT gain-scheduled control technique is applied to the Benchmark Active Control Technology (BACT) wing, and compared with mu-synthesis control. Linear parameter-varying (LPV) gain-scheduled control is an extension of Hinfinity control to parameter varying systems. LPV gain-scheduled control directly incorporates bounds on the rate of change of the scheduling parameters, and often reduces conservatism inherent in LFT gain-scheduled control. Gain-scheduled LPV control of the BACT wing compares very favorably with the LFT controller. Gain-scheduled LPV controllers are generated for the lateral-directional and longitudinal axes of the Innovative Control Effectors (ICE) aircraft and implemented in nonlinear simulations and real-time piloted nonlinear simulations. Cooper-Harper and pilot-induced oscillation ratings were obtained for an initial design, a reference aircraft and a redesign. Piloted simulation results for the initial LPV gain-scheduled control of the ICE aircraft are compared with results for a conventional fighter aircraft in discrete pitch and roll angle tracking tasks. The results for the redesigned controller are significantly better than both the previous LPV controller and the conventional aircraft.

  17. Contrast Gain Control in Auditory Cortex

    PubMed Central

    Rabinowitz, Neil C.; Willmore, Ben D.B.; Schnupp, Jan W.H.; King, Andrew J.

    2011-01-01

    Summary The auditory system must represent sounds with a wide range of statistical properties. One important property is the spectrotemporal contrast in the acoustic environment: the variation in sound pressure in each frequency band, relative to the mean pressure. We show that neurons in ferret auditory cortex rescale their gain to partially compensate for the spectrotemporal contrast of recent stimulation. When contrast is low, neurons increase their gain, becoming more sensitive to small changes in the stimulus, although the effectiveness of contrast gain control is reduced at low mean levels. Gain is primarily determined by contrast near each neuron's preferred frequency, but there is also a contribution from contrast in more distant frequency bands. Neural responses are modulated by contrast over timescales of ∼100 ms. By using contrast gain control to expand or compress the representation of its inputs, the auditory system may be seeking an efficient coding of natural sounds. PMID:21689603

  18. Target-matched insertion gain derived from three different hearing aid selection procedures.

    PubMed

    Punch, J L; Shovels, A H; Dickinson, W W; Calder, J H; Snead, C

    1995-11-01

    Three hearing aid selection procedures were compared to determine if any one was superior in producing prescribed real-ear insertion gain. For each of three subject groups, 12 in-the-ear style hearing aids with Class D circuitry and similar dispenser controls were ordered from one of three manufacturers. Subject groups were classified based on the type of information included on the hearing aid order form: (1) the subject's audiogram, (2) a three-part matrix specifying the desired maximum output, full-on gain, and frequency response slope of the hearing aid, or (3) the desired 2-cc coupler full-in grain of the hearing aid, based on real-ear coupler difference (RECD) measurements. Following electroacoustic adjustments aimed at approximating a commonly used target insertion gain formula, results revealed no significant differences among any of the three selection procedures with respect to obtaining acceptable insertion gain values.

  19. Brain serotonergic circuitries

    PubMed Central

    Charnay, Yves; Leger, Lucienne

    2010-01-01

    Brain serotonergic circuitries interact with other neurotransmitter systems on a multitude of different molecular levels. In humans, as in other mammalian species, serotonin (5-HT) plays a modulatory role in almost every physiological function. Furthermore, serotonergic dysfunction is thought to be implicated in several psychiatric and neurodegenerative disorders. We describe the neuroanatomy and neurochemistry of brain serotonergic circuitries. The contribution of emergent in vivo imaging methods to the regional localization of binding site receptors and certain aspects of their functional connectivity in correlation to behavior is also discussed. 5-HT cell bodies, mainly localized in the raphe nuclei, send axons to almost every brain region. It is argued that the specificity of the local chemocommunication between 5-HT and other neuronal elements mainly depends on mechanisms regulating the extracellular concentration of 5-HT, the diversity of high-affinity membrane receptors, and their specific transduction modalities. PMID:21319493

  20. Compensated gain control circuit for buck regulator command charge circuit

    DOEpatents

    Barrett, David M.

    1996-01-01

    A buck regulator command charge circuit includes a compensated-gain control signal for compensating for changes in the component values in order to achieve optimal voltage regulation. The compensated-gain control circuit includes an automatic-gain control circuit for generating a variable-gain control signal. The automatic-gain control circuit is formed of a precision rectifier circuit, a filter network, an error amplifier, and an integrator circuit.

  1. Compensated gain control circuit for buck regulator command charge circuit

    DOEpatents

    Barrett, D.M.

    1996-11-05

    A buck regulator command charge circuit includes a compensated-gain control signal for compensating for changes in the component values in order to achieve optimal voltage regulation. The compensated-gain control circuit includes an automatic-gain control circuit for generating a variable-gain control signal. The automatic-gain control circuit is formed of a precision rectifier circuit, a filter network, an error amplifier, and an integrator circuit. 5 figs.

  2. Method for integrating microelectromechanical devices with electronic circuitry

    DOEpatents

    Barron, Carole C.; Fleming, James G.; Montague, Stephen

    1999-01-01

    A method is disclosed for integrating one or more microelectromechanical (MEM) devices with electronic circuitry on a common substrate. The MEM device can be fabricated within a substrate cavity and encapsulated with a sacrificial material. This allows the MEM device to be annealed and the substrate planarized prior to forming electronic circuitry on the substrate using a series of standard processing steps. After fabrication of the electronic circuitry, the electronic circuitry can be protected by a two-ply protection layer of titanium nitride (TiN) and tungsten (W) during an etch release process whereby the MEM device is released for operation by etching away a portion of a sacrificial material (e.g. silicon dioxide or a silicate glass) that encapsulates the MEM device. The etch release process is preferably performed using a mixture of hydrofluoric acid (HF) and hydrochloric acid (HCI) which reduces the time for releasing the MEM device compared to use of a buffered oxide etchant. After release of the MEM device, the TiN:W protection layer can be removed with a peroxide-based etchant without damaging the electronic circuitry.

  3. A novel digital image sensor with row wise gain compensation for Hyper Spectral Imager (HySI) application

    NASA Astrophysics Data System (ADS)

    Lin, Shengmin; Lin, Chi-Pin; Wang, Weng-Lyang; Hsiao, Feng-Ke; Sikora, Robert

    2009-08-01

    A 256x512 element digital image sensor has been developed which has a large pixel size, slow scan and low power consumption for Hyper Spectral Imager (HySI) applications. The device is a mixed mode, silicon on chip (SOC) IC. It combines analog circuitry, digital circuitry and optical sensor circuitry into a single chip. This chip integrates a 256x512 active pixel sensor array, a programming gain amplifier (PGA) for row wise gain setting, I2C interface, SRAM, 12 bit analog to digital convertor (ADC), voltage regulator, low voltage differential signal (LVDS) and timing generator. The device can be used for 256 pixels of spatial resolution and 512 bands of spectral resolution ranged from 400 nm to 950 nm in wavelength. In row wise gain readout mode, one can set a different gain on each row of the photo detector by storing the gain setting data on the SRAM thru the I2C interface. This unique row wise gain setting can be used to compensate the silicon spectral response non-uniformity problem. Due to this unique function, the device is suitable for hyper-spectral imager applications. The HySI camera located on-board the Chandrayaan-1 satellite, was successfully launched to the moon on Oct. 22, 2008. The device is currently mapping the moon and sending back excellent images of the moon surface. The device design and the moon image data will be presented in the paper.

  4. Reward Circuitry in Addiction.

    PubMed

    Cooper, Sarah; Robison, A J; Mazei-Robison, Michelle S

    2017-07-01

    Understanding the brain circuitry that underlies reward is critical to improve treatment for many common health issues, including obesity, depression, and addiction. Here we focus on insights into the organization and function of reward circuitry and its synaptic and structural adaptations in response to cocaine exposure. While the importance of certain circuits, such as the mesocorticolimbic dopamine pathway, are well established in drug reward, recent studies using genetics-based tools have revealed functional changes throughout the reward circuitry that contribute to different facets of addiction, such as relapse and craving. The ability to observe and manipulate neuronal activity within specific cell types and circuits has led to new insight into not only the basic connections between brain regions, but also the molecular changes within these specific microcircuits, such as neurotrophic factor and GTPase signaling or α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor function, that underlie synaptic and structural plasticity evoked by drugs of abuse. Excitingly, these insights from preclinical rodent work are now being translated into the clinic, where transcranial magnetic simulation and deep brain stimulation therapies are being piloted in human cocaine dependence. Thus, this review seeks to summarize current understanding of the major brain regions implicated in drug-related behaviors and the molecular mechanisms that contribute to altered connectivity between these regions, with the postulation that increased knowledge of the plasticity within the drug reward circuit will lead to new and improved treatments for addiction.

  5. Serotonin Affects Movement Gain Control in the Spinal Cord

    PubMed Central

    Glaser, Joshua I.; Deng, Linna; Thompson, Christopher K.; Stevenson, Ian H.; Wang, Qining; Hornby, Thomas George; Heckman, Charles J.; Kording, Konrad P.

    2014-01-01

    A fundamental challenge for the nervous system is to encode signals spanning many orders of magnitude with neurons of limited bandwidth. To meet this challenge, perceptual systems use gain control. However, whether the motor system uses an analogous mechanism is essentially unknown. Neuromodulators, such as serotonin, are prime candidates for gain control signals during force production. Serotonergic neurons project diffusely to motor pools, and, therefore, force production by one muscle should change the gain of others. Here we present behavioral and pharmaceutical evidence that serotonin modulates the input–output gain of motoneurons in humans. By selectively changing the efficacy of serotonin with drugs, we systematically modulated the amplitude of spinal reflexes. More importantly, force production in different limbs interacts systematically, as predicted by a spinal gain control mechanism. Psychophysics and pharmacology suggest that the motor system adopts gain control mechanisms, and serotonin is a primary driver for their implementation in force production. PMID:25232107

  6. Loop gain stabilizing with an all-digital automatic-gain-control method for high-precision fiber-optic gyroscope.

    PubMed

    Zheng, Yue; Zhang, Chunxi; Li, Lijing; Song, Lailiang; Chen, Wen

    2016-06-10

    For a fiber-optic gyroscope (FOG) using electronic dithers to suppress the dead zone, without a fixed loop gain, the deterministic compensation for the dither signals in the control loop of the FOG cannot remain accurate, resulting in the dither residuals in the FOG rotation rate output and the navigation errors in the inertial navigation system. An all-digital automatic-gain-control method for stabilizing the loop gain of the FOG is proposed. By using a perturbation square wave to measure the loop gain of the FOG and adding an automatic gain control loop in the conventional control loop of the FOG, we successfully obtain the actual loop gain and make the loop gain converge to the reference value. The experimental results show that in the case of 20% variation in the loop gain, the dither residuals are successfully eliminated and the standard deviation of the FOG sampling outputs is decreased from 2.00  deg/h to 0.62  deg/h (sampling period 2.5 ms, 10 points smoothing). With this method, the loop gain of the FOG can be stabilized over the operation temperature range and in the long-time application, which provides a solid foundation for the engineering applications of the high-precision FOG.

  7. Additional Drive Circuitry for Piezoelectric Screw Motors

    NASA Technical Reports Server (NTRS)

    Smythe, Robert; Palmer, Dean; Gursel, Yekta; Reder, Leonard; Savedra, Raymond

    2004-01-01

    Modules of additional drive circuitry have been developed to enhance the functionality of a family of commercially available positioning motors (Picomotor . or equivalent) that provide linear motion controllable, in principle, to within increments .30 nm. A motor of this type includes a piezoelectric actuator that turns a screw. Unlike traditional piezoelectrically actuated mechanisms, a motor of this type does not rely on the piezoelectric transducer to hold position: the screw does not turn except when the drive signal is applied to the actuator.

  8. Functional dysconnectivity of corticostriatal circuitry as a risk phenotype for psychosis.

    PubMed

    Fornito, Alex; Harrison, Ben J; Goodby, Emmeline; Dean, Anna; Ooi, Cinly; Nathan, Pradeep J; Lennox, Belinda R; Jones, Peter B; Suckling, John; Bullmore, Edward T

    2013-11-01

    Dysregulation of corticostriatal circuitry has long been thought to be critical in the etiology of psychotic disorders, although the differential roles played by dorsal and ventral systems in mediating risk for psychosis have been contentious. To use resting-state functional magnetic resonance imaging to characterize disease-related, risk-related, and symptom-related changes of corticostriatal functional circuitry in patients with first-episode psychosis and their unaffected first-degree relatives. This case-control cross-sectional study was conducted at a specialist early psychosis clinic, GlaxoSmithKline Clinical Unit, and magnetic resonance imaging facility. Nineteen patients with first-episode psychosis, 25 of their unaffected first-degree relatives, and 26 healthy control subjects were included in this study. Voxelwise statistical parametric maps testing differences in the strength of functional connectivity between 6 striatal seed regions of interest (3 caudate and 3 putamen) per hemisphere and all other brain regions. Disease-related changes, reflecting differences between patients and control subjects, involved widespread dysregulation of corticostriatal systems characterized most prominently by a dorsal-to-ventral gradient of hypoconnectivity to hyperconnectivity between striatal and prefrontal regions. A similar gradient was evident in comparisons between relatives and control subjects, identifying it as a genetically inherited risk phenotype. In patients, functional connectivity in risk-affected and disease-affected dorsal frontostriatal circuitry correlated with the severity of both positive and negative symptoms. First-episode psychosis is associated with pronounced dysregulation of corticostriatal systems, characterized most prominently by hypoconnectivity of dorsal and hyperconnectivity of ventral frontostriatal circuits. These changes correlate with symptom severity and are also apparent in unaffected first-degree relatives, suggesting that they

  9. Processing circuitry for single channel radiation detector

    NASA Technical Reports Server (NTRS)

    Holland, Samuel D. (Inventor); Delaune, Paul B. (Inventor); Turner, Kathryn M. (Inventor)

    2009-01-01

    Processing circuitry is provided for a high voltage operated radiation detector. An event detector utilizes a comparator configured to produce an event signal based on a leading edge threshold value. A preferred event detector does not produce another event signal until a trailing edge threshold value is satisfied. The event signal can be utilized for counting the number of particle hits and also for controlling data collection operation for a peak detect circuit and timer. The leading edge threshold value is programmable such that it can be reprogrammed by a remote computer. A digital high voltage control is preferably operable to monitor and adjust high voltage for the detector.

  10. Finding Optimal Gains In Linear-Quadratic Control Problems

    NASA Technical Reports Server (NTRS)

    Milman, Mark H.; Scheid, Robert E., Jr.

    1990-01-01

    Analytical method based on Volterra factorization leads to new approximations for optimal control gains in finite-time linear-quadratic control problem of system having infinite number of dimensions. Circumvents need to analyze and solve Riccati equations and provides more transparent connection between dynamics of system and optimal gain.

  11. Activation of Corticostriatal Circuitry Relieves Chronic Neuropathic Pain

    PubMed Central

    Lee, Michelle; Manders, Toby R.; Eberle, Sarah E.; Su, Chen; D'amour, James; Yang, Runtao; Lin, Hau Yueh; Deisseroth, Karl; Froemke, Robert C.

    2015-01-01

    Neural circuits that determine the perception and modulation of pain remain poorly understood. The prefrontal cortex (PFC) provides top-down control of sensory and affective processes. While animal and human imaging studies have shown that the PFC is involved in pain regulation, its exact role in pain states remains incompletely understood. A key output target for the PFC is the nucleus accumbens (NAc), an important component of the reward circuitry. Interestingly, recent human imaging studies suggest that the projection from the PFC to the NAc is altered in chronic pain. The function of this corticostriatal projection in pain states, however, is not known. Here we show that optogenetic activation of the PFC produces strong antinociceptive effects in a rat model (spared nerve injury model) of persistent neuropathic pain. PFC activation also reduces the affective symptoms of pain. Furthermore, we show that this pain-relieving function of the PFC is likely mediated by projections to the NAc. Thus, our results support a novel role for corticostriatal circuitry in pain regulation. PMID:25834050

  12. Science and Teachers: Cardboard Circuitry

    ERIC Educational Resources Information Center

    Science and Children, 1977

    1977-01-01

    Diagrams a quick, improvised cardboard circuitry for battery holder, bulb socket, and switches. Materials include corrugated cardboard, paper clips, and rubber bands. Assembly useful in determining the electrical conductivity of substances. (CS)

  13. Commutated automatic gain control system

    NASA Technical Reports Server (NTRS)

    Yost, S. R.

    1982-01-01

    The commutated automatic gain control (AGC) system was designed and built for the prototype Loran-C receiver is discussed. The current version of the prototype receiver, the Mini L-80, was tested initially in 1980. The receiver uses a super jolt microcomputer to control a memory aided phase loop (MAPLL). The microcomputer also controls the input/output, latitude/longitude conversion, and the recently added AGC system. The AGC control adjusts the level of each station signal, such that the early portion of each envelope rise is about at the same amplitude in the receiver envelope detector.

  14. Robust Optimal Adaptive Control Method with Large Adaptive Gain

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.

    2009-01-01

    In the presence of large uncertainties, a control system needs to be able to adapt rapidly to regain performance. Fast adaptation is referred to the implementation of adaptive control with a large adaptive gain to reduce the tracking error rapidly. However, a large adaptive gain can lead to high-frequency oscillations which can adversely affect robustness of an adaptive control law. A new adaptive control modification is presented that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. The modification is based on the minimization of the Y2 norm of the tracking error, which is formulated as an optimal control problem. The optimality condition is used to derive the modification using the gradient method. The optimal control modification results in a stable adaptation and allows a large adaptive gain to be used for better tracking while providing sufficient stability robustness. Simulations were conducted for a damaged generic transport aircraft with both standard adaptive control and the adaptive optimal control modification technique. The results demonstrate the effectiveness of the proposed modification in tracking a reference model while maintaining a sufficient time delay margin.

  15. Impulsivity and Aggression in Schizophrenia: A Neural Circuitry Perspective with Implications for Treatment

    PubMed Central

    Hoptman, Matthew J.

    2015-01-01

    Elevations of impulsive behavior have been observed in a number of serious mental illnesses. These phenomena can lead to harmful behaviors, including violence, and thus represent a serious public health concern. Such violence is often a reason for psychiatric hospitalization, and it often leads to prolonged hospital stays, suffering by patients and their victims, and increased stigmatization. Despite the attention paid to violence, little is understood about its neural basis in schizophrenia. On a psychological level, aggression in schizophrenia has been primarily attributed to psychotic symptoms, desires for instrumental gain, or impulsive responses to perceived personal slights. Often multiple attributions can coexist during a single aggressive incident. In this review, I will discuss the neural circuitry associated with impulsivity and aggression in schizophrenia, with an emphasis on implications for treatment. Impulsivity appears to account for a great deal of aggression in schizophrenia, especially in inpatient settings. Urgency, defined as impulsivity in the context of strong emotion, is the primary focus of this article. It is elevated in several psychiatric disorders, and in schizophrenia, it has been related to aggression. Many studies have implicated dysfunctional frontotemporal circuitry in impulsivity and aggression in schizophrenia, and pharmacological treatments may act via that circuitry to reduce urgency and aggressive behaviors, but more mechanistic studies are critically needed. Recent studies point toward manipulable neurobehavioral targets and suggest that cognitive, pharmacological, neuromodulatory, and neurofeedback treatment approaches can be developed to ameliorate urgency and aggression in schizophrenia. It is hoped that these approaches will improve treatment efficacy. PMID:25900066

  16. Nonreciprocal gain control for ring laser

    NASA Technical Reports Server (NTRS)

    Dueker, G.; Lee, P.

    1967-01-01

    Nonreciprocal gain control is used in a ring laser where the two contracirculating beams may have differing intensities because of the residual Faraday rotation and other secondary nonreciprocal effects.

  17. Automatic Gain Control in Compact Spectrometers.

    PubMed

    Protopopov, Vladimir

    2016-03-01

    An image intensifier installed in the optical path of a compact spectrometer may act not only as a fast gating unit, which is widely used for time-resolved measurements, but also as a variable attenuator-amplifier in a continuous wave mode. This opens the possibility of an automatic gain control, a new feature in spectroscopy. With it, the user is relieved from the necessity to manually adjust signal level at a certain value that it is done automatically by means of an electronic feedback loop. It is even more important that automatic gain control is done without changing exposure time, which is an additional benefit in time-resolved experiments. The concept, algorithm, design considerations, and experimental results are presented. © The Author(s) 2016.

  18. Online contributions of auditory feedback to neural activity in avian song control circuitry

    PubMed Central

    Sakata, Jon T.; Brainard, Michael S.

    2008-01-01

    Birdsong, like human speech, relies critically on auditory feedback to provide information about the quality of vocalizations. Although the importance of auditory feedback to vocal learning is well established, whether and how feedback signals influence vocal premotor circuitry has remained obscure. Previous studies in singing birds have not detected changes to vocal premotor activity following perturbations of auditory feedback, leading to the hypothesis that contributions of feedback to vocal plasticity might rely on ‘offline’ processing. Here, we recorded single and multi-unit activity in the premotor nucleus HVC of singing Bengalese finches in response to feedback perturbations that are known to drive plastic changes in song. We found that transient feedback perturbation caused reliable decreases in HVC activity at short latencies (20-80 ms). Similar changes to HVC activity occurred in awake, non-singing finches when the bird’s own song was played back with auditory perturbations that simulated those experienced by singing birds. These data indicate that neurons in avian vocal premotor circuitry are rapidly influenced by perturbations of auditory feedback and support the possibility that feedback information in HVC contributes online to the production and plasticity of vocalizations. PMID:18971480

  19. Circuitry, systems and methods for detecting magnetic fields

    DOEpatents

    Kotter, Dale K [Shelley, ID; Spencer, David F [Idaho Falls, ID; Roybal, Lyle G [Idaho Falls, ID; Rohrbaugh, David T [Idaho Falls, ID

    2010-09-14

    Circuitry for detecting magnetic fields includes a first magnetoresistive sensor and a second magnetoresistive sensor configured to form a gradiometer. The circuitry includes a digital signal processor and a first feedback loop coupled between the first magnetoresistive sensor and the digital signal processor. A second feedback loop which is discrete from the first feedback loop is coupled between the second magnetoresistive sensor and the digital signal processor.

  20. Transitional circuitry for studying the properties of DNA

    NASA Astrophysics Data System (ADS)

    Trubochkina, N.

    2018-01-01

    The article is devoted to a new view of the structure of DNA as an intellectual scheme possessing the properties of logic and memory. The theory of transient circuitry, developed by the author for optimal computer circuits, revealed an amazing structural similarity between mathematical models of transition silicon elements and logic and memory circuits of solid state transient circuitry and atomic models of parts of DNA.

  1. Gain Scheduling for the Orion Launch Abort Vehicle Controller

    NASA Technical Reports Server (NTRS)

    McNamara, Sara J.; Restrepo, Carolina I.; Madsen, Jennifer M.; Medina, Edgar A.; Proud, Ryan W.; Whitley, Ryan J.

    2011-01-01

    One of NASAs challenges for the Orion vehicle is the control system design for the Launch Abort Vehicle (LAV), which is required to abort safely at any time during the atmospheric ascent portion of ight. The focus of this paper is the gain design and scheduling process for a controller that covers the wide range of vehicle configurations and flight conditions experienced during the full envelope of potential abort trajectories from the pad to exo-atmospheric flight. Several factors are taken into account in the automation process for tuning the gains including the abort effectors, the environmental changes and the autopilot modes. Gain scheduling is accomplished using a linear quadratic regulator (LQR) approach for the decoupled, simplified linear model throughout the operational envelope in time, altitude and Mach number. The derived gains are then implemented into the full linear model for controller requirement validation. Finally, the gains are tested and evaluated in a non-linear simulation using the vehicles ight software to ensure performance requirements are met. An overview of the LAV controller design and a description of the linear plant models are presented. Examples of the most significant challenges with the automation of the gain tuning process are then discussed. In conclusion, the paper will consider the lessons learned through out the process, especially in regards to automation, and examine the usefulness of the gain scheduling tool and process developed as applicable to non-Orion vehicles.

  2. Commutated automatic gain control system

    NASA Technical Reports Server (NTRS)

    Yost, S. R.

    1982-01-01

    A commutated automatic gain control (AGC) system was designed and built for a prototype Loran C receiver. The receiver uses a microcomputer to control a memory aided phase-locked loop (MAPLL). The microcomputer also controls the input/output, latitude/longitude conversion, and the recently added AGC system. The circuit designed for the AGC is described, and bench and flight test results are presented. The AGC circuit described actually samples starting at a point 40 microseconds after a zero crossing determined by the software lock pulse ultimately generated by a 30 microsecond delay and add network in the receiver front end envelope detector.

  3. Reading acceleration training changes brain circuitry in children with reading difficulties

    PubMed Central

    Horowitz-Kraus, Tzipi; Vannest, Jennifer J; Kadis, Darren; Cicchino, Nicole; Wang, Yingying Y; Holland, Scott K

    2014-01-01

    Introduction Dyslexia is characterized by slow, inaccurate reading. Previous studies have shown that the Reading Acceleration Program (RAP) improves reading speed and accuracy in children and adults with dyslexia and in typical readers across different orthographies. However, the effect of the RAP on the neural circuitry of reading has not been established. In the current study, we examined the effect of the RAP training on regions of interest in the neural circuitry for reading using a lexical decision task during fMRI in children with reading difficulties and typical readers. Methods Children (8–12 years old) with reading difficulties and typical readers were studied before and after 4 weeks of training with the RAP in both groups. Results In addition to improvements in oral and silent contextual reading speed, training-related gains were associated with increased activation of the left hemisphere in both children with reading difficulties and typical readers. However, only children with reading difficulties showed improvements in reading comprehension, which were associated with significant increases in right frontal lobe activation. Conclusions Our results demonstrate differential effects of the RAP on neural circuits supporting reading in both children with reading difficulties and typical readers and suggest that the intervention may stimulate use of typical neural circuits for reading and engage compensatory pathways to support reading in the developing brain of children with reading difficulties. PMID:25365797

  4. Conic section function neural network circuitry for offline signature recognition.

    PubMed

    Erkmen, Burcu; Kahraman, Nihan; Vural, Revna A; Yildirim, Tulay

    2010-04-01

    In this brief, conic section function neural network (CSFNN) circuitry was designed for offline signature recognition. CSFNN is a unified framework for multilayer perceptron (MLP) and radial basis function (RBF) networks to make simultaneous use of advantages of both. The CSFNN circuitry architecture was developed using a mixed mode circuit implementation. The designed circuit system is problem independent. Hence, the general purpose neural network circuit system could be applied to various pattern recognition problems with different network sizes on condition with the maximum network size of 16-16-8. In this brief, CSFNN circuitry system has been applied to two different signature recognition problems. CSFNN circuitry was trained with chip-in-the-loop learning technique in order to compensate typical analog process variations. CSFNN hardware achieved highly comparable computational performances with CSFNN software for nonlinear signature recognition problems.

  5. Thin Film Transistor Control Circuitry for MEMS Acoustic Transducers

    NASA Astrophysics Data System (ADS)

    Daugherty, Robin

    This work seeks to develop a practical solution for short range ultrasonic communications and produce an integrated array of acoustic transmitters on a flexible substrate. This is done using flexible thin film transistor (TFT) and micro electromechanical systems (MEMS). The goal is to develop a flexible system capable of communicating in the ultrasonic frequency range at a distance of 10-100 meters. This requires a great deal of innovation on the part of the FDC team developing the TFT driving circuitry and the MEMS team adapting the technology for fabrication on a flexible substrate. The technologies required for this research are independently developed. The TFT development is driven primarily by research into flexible displays. The MEMS development is driving by research in biosensors and micro actuators. This project involves the integration of TFT flexible circuit capabilities with MEMS micro actuators in the novel area of flexible acoustic transmitter arrays. This thesis focuses on the design, testing and analysis of the circuit components required for this project.

  6. Method for passively compensating for temperature coefficient of gain in silicon photomultipliers and similar devices

    DOEpatents

    McKisson, John E.; Barbosa, Fernando

    2015-09-01

    A method for designing a completely passive bias compensation circuit to stabilize the gain of multiple pixel avalanche photo detector devices. The method includes determining circuitry design and component values to achieve a desired precision of gain stability. The method can be used with any temperature sensitive device with a nominally linear coefficient of voltage dependent parameter that must be stabilized. The circuitry design includes a negative temperature coefficient resistor in thermal contact with the photomultiplier device to provide a varying resistance and a second fixed resistor to form a voltage divider that can be chosen to set the desired slope and intercept for the characteristic with a specific voltage source value. The addition of a third resistor to the divider network provides a solution set for a set of SiPM devices that requires only a single stabilized voltage source value.

  7. Adaptive gain and filtering circuit for a sound reproduction system

    NASA Technical Reports Server (NTRS)

    Engebretson, A. Maynard (Inventor); O'Connell, Michael P. (Inventor)

    1998-01-01

    Adaptive compressive gain and level dependent spectral shaping circuitry for a hearing aid include a microphone to produce an input signal and a plurality of channels connected to a common circuit output. Each channel has a preset frequency response. Each channel includes a filter with a preset frequency response to receive the input signal and to produce a filtered signal, a channel amplifier to amplify the filtered signal to produce a channel output signal, a threshold register to establish a channel threshold level, and a gain circuit. The gain circuit increases the gain of the channel amplifier when the channel output signal falls below the channel threshold level and decreases the gain of the channel amplifier when the channel output signal rises above the channel threshold level. A transducer produces sound in response to the signal passed by the common circuit output.

  8. Contrast gain control in first- and second-order motion perception.

    PubMed

    Lu, Z L; Sperling, G

    1996-12-01

    A novel pedestal-plus-test paradigm is used to determine the nonlinear gain-control properties of the first-order (luminance) and the second-order (texture-contrast) motion systems, that is, how these systems' responses to motion stimuli are reduced by pedestals and other masking stimuli. Motion-direction thresholds were measured for test stimuli consisting of drifting luminance and texture-contrast-modulation stimuli superimposed on pedestals of various amplitudes. (A pedestal is a static sine-wave grating of the same type and same spatial frequency as the moving test grating.) It was found that first-order motion-direction thresholds are unaffected by small pedestals, but at pedestal contrasts above 1-2% (5-10 x pedestal threshold), motion thresholds increase proportionally to pedestal amplitude (a Weber law). For first-order stimuli, pedestal masking is specific to the spatial frequency of the test. On the other hand, motion-direction thresholds for texture-contrast stimuli are independent of pedestal amplitude (no gain control whatever) throughout the accessible pedestal amplitude range (from 0 to 40%). However, when baseline carrier contrast increases (with constant pedestal modulation amplitude), motion thresholds increase, showing that gain control in second-order motion is determined not by the modulator (as in first-order motion) but by the carrier. Note that baseline contrast of the carrier is inherently independent of spatial frequency of the modulator. The drastically different gain-control properties of the two motion systems and prior observations of motion masking and motion saturation are all encompassed in a functional theory. The stimulus inputs to both first- and second-order motion process are normalized by feedforward, shunting gain control. The different properties arise because the modulator is used to control the first-order gain and the carrier is used to control the second-order gain.

  9. Vehicle yaw stability control via H∞ gain scheduling

    NASA Astrophysics Data System (ADS)

    Zhang, Jinhua; Sun, Weichao; Feng, Zhiguang

    2018-06-01

    Yaw stability control (YSC) is rather significant in a vehicle lateral motion, since it can considerably reduce casualties caused by vehicle instability. Nevertheless with the vehicle running, the parameters, such as vehicle mass and moment of inertial, can be perturbed because of variation of capacity, loadage and consumption of fuel, hence some of nominal controllers cannot always work satisfactorily. To overcome the aforementioned deficiency, a gain scheduled H∞ YSC controller is developed in this paper, taking the vehicle mass and moment of inertial as the scheduled variables, now that the gain scheduled H∞ controller can guarantee both the robustness against parameter perturbation and the adjustability of tracking accuracy. Then the constructed controller is verified via numerical simulation and MATLAB-CarSim coalition simulation. The simulation results indicate that the designed controller can indeed improve the vehicle handing performance under circumstance of lateral stability.

  10. Nuclear receptor/microRNA circuitry links muscle fiber type to energy metabolism.

    PubMed

    Gan, Zhenji; Rumsey, John; Hazen, Bethany C; Lai, Ling; Leone, Teresa C; Vega, Rick B; Xie, Hui; Conley, Kevin E; Auwerx, Johan; Smith, Steven R; Olson, Eric N; Kralli, Anastasia; Kelly, Daniel P

    2013-06-01

    The mechanisms involved in the coordinate regulation of the metabolic and structural programs controlling muscle fitness and endurance are unknown. Recently, the nuclear receptor PPARβ/δ was shown to activate muscle endurance programs in transgenic mice. In contrast, muscle-specific transgenic overexpression of the related nuclear receptor, PPARα, results in reduced capacity for endurance exercise. We took advantage of the divergent actions of PPARβ/δ and PPARα to explore the downstream regulatory circuitry that orchestrates the programs linking muscle fiber type with energy metabolism. Our results indicate that, in addition to the well-established role in transcriptional control of muscle metabolic genes, PPARβ/δ and PPARα participate in programs that exert opposing actions upon the type I fiber program through a distinct muscle microRNA (miRNA) network, dependent on the actions of another nuclear receptor, estrogen-related receptor γ (ERRγ). Gain-of-function and loss-of-function strategies in mice, together with assessment of muscle biopsies from humans, demonstrated that type I muscle fiber proportion is increased via the stimulatory actions of ERRγ on the expression of miR-499 and miR-208b. This nuclear receptor/miRNA regulatory circuit shows promise for the identification of therapeutic targets aimed at maintaining muscle fitness in a variety of chronic disease states, such as obesity, skeletal myopathies, and heart failure.

  11. Contrast gain control: a bilinear model for chromatic selectivity.

    PubMed

    Singer, B; D'Zmura, M

    1995-04-01

    We report the results of psychophysical experiments on color contrast induction. In earlier work [Vision Res. 34, 3111 (1994)], we showed that modulating the spatial contrast of an annulus in time induces an apparent modulation of the contrast of a central disk, at isoluminance. Here we vary the chromatic properties of disk and annulus systematically in a study of the interactions among the luminance and the color-opponent channels. Results show that induced contrast depends linearly on both disk and annulus contrast, at low and moderate contrast levels. This dependence leads us to propose a bilinear model for color contrast gain control. The model predicts the magnitude and the chromatic properties of induced contrast. In agreement with experimental results, the model displays chromatic selectivity in contrast gain control and a negligible effect of contrast modulation at isoluminance on the appearance of achromatic contrast. We show that the bilinear model for chromatic selectivity may be realized as a feed-forward multiplicative gain control. Data collected at high contrast levels are fit by embellishing the model with saturating nonlinearities in the contrast gain control of each color channel.

  12. Mapping the brain's metaphor circuitry: metaphorical thought in everyday reason

    PubMed Central

    Lakoff, George

    2014-01-01

    An overview of the basics of metaphorical thought and language from the perspective of Neurocognition, the integrated interdisciplinary study of how conceptual thought and language work in the brain. The paper outlines a theory of metaphor circuitry and discusses how everyday reason makes use of embodied metaphor circuitry. PMID:25566012

  13. Dynamics of cochlear nonlinearity: Automatic gain control or instantaneous damping?

    PubMed

    Altoè, Alessandro; Charaziak, Karolina K; Shera, Christopher A

    2017-12-01

    Measurements of basilar-membrane (BM) motion show that the compressive nonlinearity of cochlear mechanical responses is not an instantaneous phenomenon. For this reason, the cochlear amplifier has been thought to incorporate an automatic gain control (AGC) mechanism characterized by a finite reaction time. This paper studies the effect of instantaneous nonlinear damping on the responses of oscillatory systems. The principal results are that (i) instantaneous nonlinear damping produces a noninstantaneous gain control that differs markedly from typical AGC strategies; (ii) the kinetics of compressive nonlinearity implied by the finite reaction time of an AGC system appear inconsistent with the nonlinear dynamics measured on the gerbil basilar membrane; and (iii) conversely, those nonlinear dynamics can be reproduced using an harmonic oscillator with instantaneous nonlinear damping. Furthermore, existing cochlear models that include instantaneous gain-control mechanisms capture the principal kinetics of BM nonlinearity. Thus, an AGC system with finite reaction time appears neither necessary nor sufficient to explain nonlinear gain control in the cochlea.

  14. Sex Differences in Stress Response Circuitry Activation Dependent on Female Hormonal Cycle

    PubMed Central

    Goldstein, Jill M.; Jerram, Matthew; Abbs, Brandon; Whitfield-Gabrieli, Susan; Makris, Nikos

    2010-01-01

    Understanding sex differences in stress regulation has important implications for understanding basic physiological differences in the male and female brain and their impact on vulnerability to sex differences in chronic medical disorders associated with stress response circuitry. In this fMRI study, we demonstrated that significant sex differences in brain activity in stress response circuitry were dependent on women's menstrual cycle phase. Twelve healthy Caucasian premenopausal women were compared to a group of healthy men from the same population, based on age, ethnicity, education, and right-handedness. Subjects were scanned using negative valence/high arousal versus neutral visual stimuli that we demonstrated activated stress response circuitry (amygdala, hypothalamus, hippocampus, brainstem, orbitofrontal and medial prefrontal cortices (OFC and mPFC), and anterior cingulate gyrus (ACG). Women were scanned twice based on normal variation in menstrual cycle hormones (i.e., early follicular (EF) compared with late follicular-midcycle menstrual phases (LF/MC)). Using SPM8b, there were few significant differences in BOLD signal changes in men compared to EF women, except ventromedial (VMN) and lateral (LHA) hypothalamus, left amygdala, and ACG. In contrast, men exhibited significantly greater BOLD signal changes compared to LF/MC women on bilateral ACG and OFC, mPFC, LHA, VMN, hippocampus, and periaqueductal gray, with largest effect sizes in mPFC and OFC. Findings suggest that sex differences in stress response circuitry are hormonally regulated via the impact of subcortical brain activity on the cortical control of arousal, and demonstrate that females have been endowed with a natural hormonal capacity to regulate the stress response that differs from males. PMID:20071507

  15. Sex differences in stress response circuitry activation dependent on female hormonal cycle.

    PubMed

    Goldstein, Jill M; Jerram, Matthew; Abbs, Brandon; Whitfield-Gabrieli, Susan; Makris, Nikos

    2010-01-13

    Understanding sex differences in stress regulation has important implications for understanding basic physiological differences in the male and female brain and their impact on vulnerability to sex differences in chronic medical disorders associated with stress response circuitry. In this functional magnetic resonance imaging study, we demonstrated that significant sex differences in brain activity in stress response circuitry were dependent on women's menstrual cycle phase. Twelve healthy Caucasian premenopausal women were compared to a group of healthy men from the same population, based on age, ethnicity, education, and right handedness. Subjects were scanned using negative valence/high arousal versus neutral visual stimuli that we demonstrated activated stress response circuitry [amygdala, hypothalamus, hippocampus, brainstem, orbitofrontal cortex (OFC), medial prefrontal cortex (mPFC), and anterior cingulate gyrus (ACG)]. Women were scanned twice based on normal variation in menstrual cycle hormones [i.e., early follicular (EF) compared with late follicular-midcycle (LF/MC) menstrual phases]. Using SPM8b, there were few significant differences in blood oxygenation level-dependent (BOLD) signal changes in men compared to EF women, except ventromedial nucleus (VMN), lateral hypothalamic area (LHA), left amygdala, and ACG. In contrast, men exhibited significantly greater BOLD signal changes compared to LF/MC women on bilateral ACG and OFC, mPFC, LHA, VMN, hippocampus, and periaqueductal gray, with largest effect sizes in mPFC and OFC. Findings suggest that sex differences in stress response circuitry are hormonally regulated via the impact of subcortical brain activity on the cortical control of arousal, and demonstrate that females have been endowed with a natural hormonal capacity to regulate the stress response that differs from males.

  16. Neural Circuitry of Impaired Emotion Regulation in Substance Use Disorders.

    PubMed

    Wilcox, Claire E; Pommy, Jessica M; Adinoff, Bryon

    2016-04-01

    Impaired emotion regulation contributes to the development and severity of substance use disorders (substance disorders). This review summarizes the literature on alterations in emotion regulation neural circuitry in substance disorders, particularly in relation to disorders of negative affect (without substance disorder), and it presents promising areas of future research. Emotion regulation paradigms during functional magnetic resonance imaging are conceptualized into four dimensions: affect intensity and reactivity, affective modulation, cognitive modulation, and behavioral control. The neural circuitry associated with impaired emotion regulation is compared in individuals with and without substance disorders, with a focus on amygdala, insula, and prefrontal cortex activation and their functional and structural connectivity. Hypoactivation of the rostral anterior cingulate cortex/ventromedial prefrontal cortex (rACC/vmPFC) is the most consistent finding across studies, dimensions, and clinical populations (individuals with and without substance disorders). The same pattern is evident for regions in the cognitive control network (anterior cingulate and dorsal and ventrolateral prefrontal cortices) during cognitive modulation and behavioral control. These congruent findings are possibly related to attenuated functional and/or structural connectivity between the amygdala and insula and between the rACC/vmPFC and cognitive control network. Although increased amygdala and insula activation is associated with impaired emotion regulation in individuals without substance disorders, it is not consistently observed in substance disorders. Emotion regulation disturbances in substance disorders may therefore stem from impairments in prefrontal functioning, rather than excessive reactivity to emotional stimuli. Treatments for emotion regulation in individuals without substance disorders that normalize prefrontal functioning may offer greater efficacy for substance disorders

  17. Control Circuitry for High Speed VLSI (Very Large Scale Integration) Winograd Fourier Transform Processors.

    DTIC Science & Technology

    1985-12-01

    Office of Scientific Research , and Air Force Space Division are sponsoring research for the development of a high speed DFT processor. This DFT...to the arithmetic circuitry through a master/slave 11-15 %v OPR ONESHOT OUTPUT OUTPUT .., ~ INITIALIZATION COLUMN’ 00 N DONE CUTRPLANE PLAtNE Figure...Since the TSP is an NP-complete problem, many mathematicians, operations researchers , computer scientists and the like have proposed heuristic

  18. Importance of reward and prefrontal circuitry in hunger and satiety: Prader-Willi syndrome vs simple obesity.

    PubMed

    Holsen, L M; Savage, C R; Martin, L E; Bruce, A S; Lepping, R J; Ko, E; Brooks, W M; Butler, M G; Zarcone, J R; Goldstein, J M

    2012-05-01

    The majority of research on obesity (OB) has focused primarily on clinical features (eating behavior, adiposity measures) or peripheral appetite-regulatory peptides (leptin, ghrelin). However, recent functional neuroimaging studies have demonstrated that some reward circuitry regions that are associated with appetite-regulatory hormones are also involved in the development and maintenance of OB. Prader-Willi syndrome (PWS), characterized by hyperphagia and hyperghrelinemia reflecting multi-system dysfunction in inhibitory and satiety mechanisms, serves as an extreme model of genetic OB. Simple (non-PWS) OB represents an OB-control state. This study investigated subcortical food motivation circuitry and prefrontal inhibitory circuitry functioning in response to food stimuli before and after eating in individuals with PWS compared with OB. We hypothesized that groups would differ in limbic regions (that is, hypothalamus, amygdala) and prefrontal regions associated with cognitive control (that is, dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC) after eating. A total of 14 individuals with PWS, 14 BMI- and age-matched individuals with OB, and 15 age-matched healthy-weight controls viewed food and non-food images while undergoing functional MRI before (pre-meal) and after (post-meal) eating. Using SPM8, group contrasts were tested for hypothesized regions: hypothalamus, nucleus accumbens (NAc), amygdala, hippocampus, OFC, medial PFC and DLPFC. Compared with OB and HWC, PWS demonstrated higher activity in reward/limbic regions (NAc, amygdala) and lower activity in the hypothalamus and hippocampus in response to food (vs non-food) images pre-meal. Post meal, PWS exhibited higher subcortical activation (hypothalamus, amygdala, hippocampus) compared with OB and HWC. OB showed significantly higher activity versus PWS and HWC in cortical regions (DLPFC, OFC) associated with inhibitory control. In PWS, compared with OB per se, results suggest

  19. Importance of Reward and Prefrontal Circuitry in Hunger and Satiety: Prader-Willi Syndrome vs. Simple Obesity

    PubMed Central

    Holsen, Laura M.; Savage, Cary R.; Martin, Laura E.; Bruce, Amanda S.; Lepping, Rebecca J.; Ko, Eunice; Brooks, William M.; Butler, Merlin G.; Zarcone, Jennifer R.; Goldstein, Jill M.

    2011-01-01

    Background The majority of research on obesity has focused primarily on clinical features (eating behavior, adiposity measures), or peripheral appetite-regulatory peptides (leptin, ghrelin). However, recent functional neuroimaging studies have demonstrated that some reward circuitry regions which are associated with appetite-regulatory hormones are also involved in the development and maintenance of obesity. Prader-Willi syndrome (PWS), characterized by hyperphagia and hyperghrelinemia reflecting multi-system dysfunction in inhibitory and satiety mechanisms, serves as an extreme model of genetic obesity. Simple (non-PWS) obesity (OB) represents an obesity control state. Objective This study investigated subcortical food motivation circuitry and prefrontal inhibitory circuitry functioning in response to food stimuli before and after eating in individuals with PWS compared with OB. We hypothesized that groups would differ in limbic regions (i.e., hypothalamus, amygdala) and prefrontal regions associated with cognitive control [i.e., dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC)] after eating. Design and Participants Fourteen individuals with PWS, 14 BMI- and age-matched individuals with OB, and 15 age-matched healthy-weight controls (HWC) viewed food and non-food images while undergoing functional MRI before (pre-meal) and after (post-meal) eating. Using SPM8, group contrasts were tested for hypothesized regions: hypothalamus, nucleus accumbens (NAc), amygdala, hippocampus, OFC, medial PFC, and DLPFC. Results Compared with OB and HWC, PWS demonstrated higher activity in reward/limbic regions (NAc, amygdala) and lower activity in hypothalamus and hippocampus, in response to food (vs. non-food) images pre-meal. Post-meal, PWS exhibited higher subcortical activation (hypothalamus, amygdala, hippocampus) compared to OB and HWC. OB showed significantly higher activity versus PWS and HWC in cortical regions (DLPFC, OFC) associated with inhibitory

  20. Testing the connections within face processing circuitry in Capgras delusion with diffusion imaging tractography

    PubMed Central

    Bobes, Maria A.; Góngora, Daylin; Valdes, Annette; Santos, Yusniel; Acosta, Yanely; Fernandez Garcia, Yuriem; Lage, Agustin; Valdés-Sosa, Mitchell

    2016-01-01

    Although Capgras delusion (CD) patients are capable of recognizing familiar faces, they present a delusional belief that some relatives have been replaced by impostors. CD has been explained as a selective disruption of a pathway processing affective values of familiar faces. To test the integrity of connections within face processing circuitry, diffusion tensor imaging was performed in a CD patient and 10 age-matched controls. Voxel-based morphometry indicated gray matter damage in right frontal areas. Tractography was used to examine two important tracts of the face processing circuitry: the inferior fronto-occipital fasciculus (IFOF) and the inferior longitudinal (ILF). The superior longitudinal fasciculus (SLF) and commissural tracts were also assessed. CD patient did not differ from controls in the commissural fibers, or the SLF. Right and left ILF, and right IFOF were also equivalent to those of controls. However, the left IFOF was significantly reduced respect to controls, also showing a significant dissociation with the ILF, which represents a selective impairment in the fiber-tract connecting occipital and frontal areas. This suggests a possible involvement of the IFOF in affective processing of faces in typical observers and in covert recognition in some cases with prosopagnosia. PMID:26909325

  1. Determining resistivity of a geological formation using circuitry located within a borehole casing

    DOEpatents

    Vail III, William Banning

    2006-01-17

    Geological formation resistivity is determined. Circuitry is located within the borehole casing that is adjacent to the geological formation. The circuitry can measure one or more voltages across two or more voltage measurement electrodes associated with the borehole casing. The measured voltages are used by a processor to determine the resistivity of the geological formation. A common mode signal can also be reduced using the circuitry.

  2. Contrast Gain Control Model Fits Masking Data

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.; Solomon, Joshua A.; Null, Cynthia H. (Technical Monitor)

    1994-01-01

    We studied the fit of a contrast gain control model to data of Foley (JOSA 1994), consisting of thresholds for a Gabor patch masked by gratings of various orientations, or by compounds of two orientations. Our general model includes models of Foley and Teo & Heeger (IEEE 1994). Our specific model used a bank of Gabor filters with octave bandwidths at 8 orientations. Excitatory and inhibitory nonlinearities were power functions with exponents of 2.4 and 2. Inhibitory pooling was broad in orientation, but narrow in spatial frequency and space. Minkowski pooling used an exponent of 4. All of the data for observer KMF were well fit by the model. We have developed a contrast gain control model that fits masking data. Unlike Foley's, our model accepts images as inputs. Unlike Teo & Heeger's, our model did not require multiple channels for different dynamic ranges.

  3. Electro-active sensor, method for constructing the same; apparatus and circuitry for detection of electro-active species

    NASA Technical Reports Server (NTRS)

    Buehler, Martin (Inventor)

    2009-01-01

    An electro-active sensor includes a nonconductive platform with a first electrode set attached with a first side of a nonconductive platform. The first electrode set serves as an electrochemical cell that may be utilized to detect electro-active species in solution. A plurality of electrode sets and a variety of additional electrochemical cells and sensors may be attached with the nonconductive platform. The present invention also includes a method for constructing the aforementioned electro-active sensor. Additionally, an apparatus for detection and observation is disclosed, where the apparatus includes a sealable chamber for insertion of a portion of an electro-active sensor. The apparatus allows for monitoring and detection activities. Allowing for control of attached cells and sensors, a dual-mode circuitry is also disclosed. The dual-mode circuitry includes a switch, allowing the circuitry to be switched from a potentiostat to a galvanostat mode.

  4. Neural Circuitry of Impaired Emotion Regulation in Substance Use Disorders

    PubMed Central

    Wilcox, Claire E.; Pommy, Jessica M.; Adinoff, Bryon

    2016-01-01

    Impaired emotion regulation contributes to the development and severity of substance use disorders (substance disorders). This review summarizes the literature on alterations in emotion regulation neural circuitry in substance disorders, particularly in relation to disorders of negative affect (without substance disorder), and it presents promising areas of future research. Emotion regulation paradigms during functional magnetic resonance imaging are conceptualized into four dimensions: affect intensity and reactivity, affective modulation, cognitive modulation, and behavioral control. The neural circuitry associated with impaired emotion regulation is compared in individuals with and without substance disorders, with a focus on amygdala, insula, and prefrontal cortex activation and their functional and structural connectivity. Hypoactivation of the rostral anterior cingulate cortex/ventromedial prefrontal cortex (rACC/vmPFC) is the most consistent finding across studies, dimensions, and clinical populations (individuals with and without substance disorders). The same pattern is evident for regions in the cognitive control network (anterior cingulate and dorsal and ventrolateral prefrontal cortices) during cognitive modulation and behavioral control. These congruent findings are possibly related to attenuated functional and/or structural connectivity between the amygdala and insula and between the rACC/vmPFC and cognitive control network. Although increased amygdala and insula activation is associated with impaired emotion regulation in individuals without substance disorders, it is not consistently observed in substance disorders. Emotion regulation disturbances in substance disorders may therefore stem from impairments in prefrontal functioning, rather than excessive reactivity to emotional stimuli. Treatments for emotion regulation in individuals without substance disorders that normalize prefrontal functioning may offer greater efficacy for substance disorders

  5. Hearing in noisy environments: noise invariance and contrast gain control

    PubMed Central

    Willmore, Ben D B; Cooke, James E; King, Andrew J

    2014-01-01

    Contrast gain control has recently been identified as a fundamental property of the auditory system. Electrophysiological recordings in ferrets have shown that neurons continuously adjust their gain (their sensitivity to change in sound level) in response to the contrast of sounds that are heard. At the level of the auditory cortex, these gain changes partly compensate for changes in sound contrast. This means that sounds which are structurally similar, but have different contrasts, have similar neuronal representations in the auditory cortex. As a result, the cortical representation is relatively invariant to stimulus contrast and robust to the presence of noise in the stimulus. In the inferior colliculus (an important subcortical auditory structure), gain changes are less reliably compensatory, suggesting that contrast- and noise-invariant representations are constructed gradually as one ascends the auditory pathway. In addition to noise invariance, contrast gain control provides a variety of computational advantages over static neuronal representations; it makes efficient use of neuronal dynamic range, may contribute to redundancy-reducing, sparse codes for sound and allows for simpler decoding of population responses. The circuits underlying auditory contrast gain control are still under investigation. As in the visual system, these circuits may be modulated by factors other than stimulus contrast, forming a potential neural substrate for mediating the effects of attention as well as interactions between the senses. PMID:24907308

  6. Time Difference Amplifier with Robust Gain Using Closed-Loop Control

    NASA Astrophysics Data System (ADS)

    Nakura, Toru; Mandai, Shingo; Ikeda, Makoto; Asada, Kunihiro

    This paper presents a Time Difference Amplifier (TDA) that amplifies the input time difference into the output time difference. Cross coupled chains of variable delay cells with the same number of stages are applicable for TDA, and the gain is adjusted via the closed-loop control. The TDA was fabricated using 65nm CMOS and the measurement results show that the time difference gain is 4.78 at a nominal power supply while the designed gain is 4.0. The gain is stable enough to be less than 1.4% gain shift under ±10% power supply voltage fluctuation.

  7. Automatic gain control in the echolocation system of dolphins

    NASA Astrophysics Data System (ADS)

    Au, Whitlow W. L.; Benoit-Bird, Kelly J.

    2003-06-01

    In bats and technological sonars, the gain of the receiver is progressively increased with time after the transmission of a signal to compensate for acoustic propagation loss. The current understanding of dolphin echolocation indicates that automatic gain control is not a part of their sonar system. In order to test this understanding, we have performed field measurements of free-ranging echolocating dolphins. Here we show that dolphins do possess an automatic gain control mechanism, but that it is implemented in the transmission phase rather than the receiving phase of a sonar cycle. We find that the amplitude of the dolphins' echolocation signals are highly range dependent; this amplitude increases with increasing target range, R, in a 20log(R) fashion to compensate for propagation loss. If the echolocation target is a fish school with many sound scatterers, the echoes from the school will remain nearly constant with range as the dolphin closes in on it. This characteristic has the same effect as time-varying gain in bats and technological sonar when considered from a sonar system perspective.

  8. Optically-programmable nonlinear photonic component for dielectric-loaded plasmonic circuitry.

    PubMed

    Krasavin, Alexey V; Randhawa, Sukanya; Bouillard, Jean-Sebastien; Renger, Jan; Quidant, Romain; Zayats, Anatoly V

    2011-12-05

    We demonstrate both experimentally and numerically a compact and efficient, optically tuneable plasmonic component utilizing a surface plasmon polariton ring resonator with nonlinearity based on trans-cis isomerization in a polymer material. We observe more than 3-fold change between high and low transmission states of the device at milliwatt control powers (∼100 W/cm2 by intensity), with the performance limited by switching speed of the material. Such plasmonic components can be employed in optically programmable and reconfigurable integrated photonic circuitry.

  9. Individual differences in frontolimbic circuitry and anxiety emerge with adolescent changes in endocannabinoid signaling across species.

    PubMed

    Gee, Dylan G; Fetcho, Robert N; Jing, Deqiang; Li, Anfei; Glatt, Charles E; Drysdale, Andrew T; Cohen, Alexandra O; Dellarco, Danielle V; Yang, Rui R; Dale, Anders M; Jernigan, Terry L; Lee, Francis S; Casey, B J

    2016-04-19

    Anxiety disorders peak in incidence during adolescence, a developmental window that is marked by dynamic changes in gene expression, endocannabinoid signaling, and frontolimbic circuitry. We tested whether genetic alterations in endocannabinoid signaling related to a common polymorphism in fatty acid amide hydrolase (FAAH), which alters endocannabinoid anandamide (AEA) levels, would impact the development of frontolimbic circuitry implicated in anxiety disorders. In a pediatric imaging sample of over 1,000 3- to 21-y-olds, we show effects of the FAAH genotype specific to frontolimbic connectivity that emerge by ∼12 y of age and are paralleled by changes in anxiety-related behavior. Using a knock-in mouse model of the FAAH polymorphism that controls for genetic and environmental backgrounds, we confirm phenotypic differences in frontoamygdala circuitry and anxiety-related behavior by postnatal day 45 (P45), when AEA levels begin to decrease, and also, at P75 but not before. These results, which converge across species and level of analysis, highlight the importance of underlying developmental neurobiology in the emergence of genetic effects on brain circuitry and function. Moreover, the results have important implications for the identification of risk for disease and precise targeting of treatments to the biological state of the developing brain as a function of developmental changes in gene expression and neural circuit maturation.

  10. Application of gain scheduling to the control of batch bioreactors

    NASA Technical Reports Server (NTRS)

    Cardello, Ralph; San, Ka-Yiu

    1987-01-01

    The implementation of control algorithms to batch bioreactors is often complicated by the inherent variations in process dynamics during the course of fermentation. Such a wide operating range may render the performance of fixed gain PID controllers unsatisfactory. In this work, a detailed study on the control of batch fermentation is performed. Furthermore, a simple batch controller design is proposed which incorporates the concept of gain-scheduling, a subclass of adaptive control, with oxygen uptake rate as an auxiliary variable. The control of oxygen tension in the biorector is used as a vehicle to convey the proposed idea, analysis and results. Simulation experiments indicate significant improvement in controller performance can be achieved by the proposed approach even in the presence of measurement noise.

  11. Fixed gain and adaptive techniques for rotorcraft vibration control

    NASA Technical Reports Server (NTRS)

    Roy, R. H.; Saberi, H. A.; Walker, R. A.

    1985-01-01

    The results of an analysis effort performed to demonstrate the feasibility of employing approximate dynamical models and frequency shaped cost functional control law desgin techniques for helicopter vibration suppression are presented. Both fixed gain and adaptive control designs based on linear second order dynamical models were implemented in a detailed Rotor Systems Research Aircraft (RSRA) simulation to validate these active vibration suppression control laws. Approximate models of fuselage flexibility were included in the RSRA simulation in order to more accurately characterize the structural dynamics. The results for both the fixed gain and adaptive approaches are promising and provide a foundation for pursuing further validation in more extensive simulation studies and in wind tunnel and/or flight tests.

  12. Mechanisms of Gain Control by Voltage-Gated Channels in Intrinsically-Firing Neurons

    PubMed Central

    Patel, Ameera X.; Burdakov, Denis

    2015-01-01

    Gain modulation is a key feature of neural information processing, but underlying mechanisms remain unclear. In single neurons, gain can be measured as the slope of the current-frequency (input-output) relationship over any given range of inputs. While much work has focused on the control of basal firing rates and spike rate adaptation, gain control has been relatively unstudied. Of the limited studies on gain control, some have examined the roles of synaptic noise and passive somatic currents, but the roles of voltage-gated channels present ubiquitously in neurons have been less explored. Here, we systematically examined the relationship between gain and voltage-gated ion channels in a conductance-based, tonically-active, model neuron. Changes in expression (conductance density) of voltage-gated channels increased (Ca2+ channel), reduced (K+ channels), or produced little effect (h-type channel) on gain. We found that the gain-controlling ability of channels increased exponentially with the steepness of their activation within the dynamic voltage window (voltage range associated with firing). For depolarization-activated channels, this produced a greater channel current per action potential at higher firing rates. This allowed these channels to modulate gain by contributing to firing preferentially at states of higher excitation. A finer analysis of the current-voltage relationship during tonic firing identified narrow voltage windows at which the gain-modulating channels exerted their effects. As a proof of concept, we show that h-type channels can be tuned to modulate gain by changing the steepness of their activation within the dynamic voltage window. These results show how the impact of an ion channel on gain can be predicted from the relationship between channel kinetics and the membrane potential during firing. This is potentially relevant to understanding input-output scaling in a wide class of neurons found throughout the brain and other nervous systems

  13. PI controller design for indirect vector controlled induction motor: A decoupling approach.

    PubMed

    Jain, Jitendra Kr; Ghosh, Sandip; Maity, Somnath; Dworak, Pawel

    2017-09-01

    Decoupling of the stator currents is important for smoother torque response of indirect vector controlled induction motors. Typically, feedforward decoupling is used to take care of current coupling that requires exact knowledge of motor parameters, additional circuitry and signal processing. In this paper, a method is proposed to design the regulating proportional-integral gains that minimize coupling without any requirement of the additional decoupler. The variation of the coupling terms for change in load torque is considered as the performance measure. An iterative linear matrix inequality based H ∞ control design approach is used to obtain the controller gains. A comparison between the feedforward and the proposed decoupling schemes is presented through simulation and experimental results. The results show that the proposed scheme is simple yet effective even without additional block or burden on signal processing. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  14. Two stage dual gate MESFET monolithic gain control amplifier for Ka-band

    NASA Technical Reports Server (NTRS)

    Sokolov, V.; Geddes, J.; Contolatis, A.

    1987-01-01

    A monolithic two stage gain control amplifier has been developed using submicron gate length dual gate MESFETs fabricated on ion implanted material. The amplifier has a gain of 12 dB at 30 GHz with a gain control range of over 30 dB. This ion implanted monolithic IC is readily integrable with other phased array receiver functions such as low noise amplifiers and phase shifters.

  15. A Developmental Shift from Positive to Negative Connectivity in Human Amygdala-Prefrontal Circuitry

    PubMed Central

    Gee, Dylan G.; Humphreys, Kathryn L.; Flannery, Jessica; Goff, Bonnie; Telzer, Eva H.; Shapiro, Mor; Hare, Todd A.; Bookheimer, Susan Y.; Tottenham, Nim

    2013-01-01

    Recent human imaging and animal studies highlight the importance of frontoamygdala circuitry in the regulation of emotional behavior and its disruption in anxiety-related disorders. While tracing studies have suggested changes in amygdala-cortical connectivity through the adolescent period in rodents, less is known about the reciprocal connections within this circuitry across human development, when these circuits are being fine-tuned and substantial changes in emotional control are observed. The present study examined developmental changes in amygdala-prefrontal circuitry across the ages of 4 to 22 years using task-based functional magnetic resonance imaging (fMRI). Results suggest positive amygdala-prefrontal connectivity in early childhood that switches to negative functional connectivity during the transition to adolescence. Amygdala-mPFC functional connectivity was significantly positive (greater than zero) among participants younger than ten, whereas functional connectivity was significantly negative (less than zero) among participants ten years and older, over and above the effect of amygdala reactivity. The developmental switch in functional connectivity was paralleled by a steady decline in amygdala reactivity. Moreover, the valence switch might explain age-related improvement in task performance and a developmentally normative decline in anxiety. Initial positive connectivity followed by a valence shift to negative connectivity provides a neurobiological basis for regulatory development and may present novel insight into a more general process of developing regulatory connections. PMID:23467374

  16. Progress toward the maintenance and repair of degenerating retinal circuitry.

    PubMed

    Vugler, Anthony A

    2010-01-01

    Retinal diseases such as age-related macular degeneration and retinitis pigmentosa remain major causes of severe vision loss in humans. Clinical trials for treatment of retinal degenerations are underway and advancements in our understanding of retinal biology in health/disease have implications for novel therapies. A review of retinal biology is used to inform a discussion of current strategies to maintain/repair neural circuitry in age-related macular degeneration, retinitis pigmentosa, and Type 2 Leber congenital amaurosis. In age-related macular degeneration/retinitis pigmentosa, a progressive loss of rods/cones results in corruption of bipolar cell circuitry, although retinal output neurons/photoreceptive melanopsin cells survive. Visual function can be stabilized/enhanced after treatment in age-related macular degeneration, but in advanced degenerations, reorganization of retinal circuitry may preclude attempts to restore cone function. In Type 2 Leber congenital amaurosis, useful vision can be restored by gene therapy where central cones survive. Remarkable progress has been made in restoring vision to rodents using light-responsive ion channels inserted into bipolar cells/retinal ganglion cells. Advances in genetic, cellular, and prosthetic therapies show varying degrees of promise for treating retinal degenerations. While functional benefits can be obtained after early therapeutic interventions, efforts should be made to minimize circuitry changes as soon as possible after rod/cone loss. Advances in retinal anatomy/physiology and genetic technologies should allow refinement of future reparative strategies.

  17. Intergenerational Neuroimaging of Human Brain Circuitry

    PubMed Central

    Ho, Tiffany C.; Sanders, Stephan J.; Gotlib, Ian H.; Hoeft, Fumiko

    2016-01-01

    Neuroscientists are increasingly using advanced neuroimaging methods to elucidate the intergenerational transmission of human brain circuitry. This new line of work promises to shed insight into the ontogeny of complex behavioral traits, including psychiatric disorders, and possible mechanisms of transmission. Here, we highlight recent intergenerational neuroimaging studies and provide recommendations for future work. PMID:27623194

  18. LNA with wide range of gain control and wideband interference rejection

    NASA Astrophysics Data System (ADS)

    Wang, Jhen-Ji; Chen, Duan-Yu

    2016-10-01

    This work presents a low-noise amplifier (LNA) design with a wide-range gain control characteristic that integrates adjustable current distribution and output impedance techniques. For a given gain characteristic, the proposed LNA provides better wideband interference rejection performance than conventional LNA. Moreover, the proposed LNA also has a wider gain control range than conventional LNA. Therefore, it is suitable for satellite communications systems. The simulation results demonstrate that the voltage gain control range is between 14.5 and 34.2 dB for such applications (2600 MHz); the input reflection coefficient is less than -18.9 dB; the noise figure (NF) is 1.25 dB; and the third-order intercept point (IIP3) is 4.52 dBm. The proposed LNA consumes 23.85-28.17 mW at a supply voltage of 1.8 V. It is implemented by using TSMC 0.18-um RF CMOS process technology.

  19. Stitching Codeable Circuits: High School Students' Learning About Circuitry and Coding with Electronic Textiles

    NASA Astrophysics Data System (ADS)

    Litts, Breanne K.; Kafai, Yasmin B.; Lui, Debora A.; Walker, Justice T.; Widman, Sari A.

    2017-10-01

    Learning about circuitry by connecting a battery, light bulb, and wires is a common activity in many science classrooms. In this paper, we expand students' learning about circuitry with electronic textiles, which use conductive thread instead of wires and sewable LEDs instead of lightbulbs, by integrating programming sensor inputs and light outputs and examining how the two domains interact. We implemented an electronic textiles unit with 23 high school students ages 16-17 years who learned how to craft and code circuits with the LilyPad Arduino, an electronic textile construction kit. Our analyses not only confirm significant increases in students' understanding of functional circuits but also showcase students' ability in designing and remixing program code for controlling circuits. In our discussion, we address opportunities and challenges of introducing codeable circuit design for integrating maker activities that include engineering and computing into classrooms.

  20. Dynamic neural network models of the premotoneuronal circuitry controlling wrist movements in primates.

    PubMed

    Maier, M A; Shupe, L E; Fetz, E E

    2005-10-01

    Dynamic recurrent neural networks were derived to simulate neuronal populations generating bidirectional wrist movements in the monkey. The models incorporate anatomical connections of cortical and rubral neurons, muscle afferents, segmental interneurons and motoneurons; they also incorporate the response profiles of four populations of neurons observed in behaving monkeys. The networks were derived by gradient descent algorithms to generate the eight characteristic patterns of motor unit activations observed during alternating flexion-extension wrist movements. The resulting model generated the appropriate input-output transforms and developed connection strengths resembling those in physiological pathways. We found that this network could be further trained to simulate additional tasks, such as experimentally observed reflex responses to limb perturbations that stretched or shortened the active muscles, and scaling of response amplitudes in proportion to inputs. In the final comprehensive network, motor units are driven by the combined activity of cortical, rubral, spinal and afferent units during step tracking and perturbations. The model displayed many emergent properties corresponding to physiological characteristics. The resulting neural network provides a working model of premotoneuronal circuitry and elucidates the neural mechanisms controlling motoneuron activity. It also predicts several features to be experimentally tested, for example the consequences of eliminating inhibitory connections in cortex and red nucleus. It also reveals that co-contraction can be achieved by simultaneous activation of the flexor and extensor circuits without invoking features specific to co-contraction.

  1. Gain control in the sonar of odontocetes.

    PubMed

    Ya Supin, Alexander; Nachtigall, Paul E

    2013-06-01

    The sonar of odontocetes processes echo-signals within a wide range of echo levels. The level of echoes varies widely by tens of decibels depending on the level of the emitted sonar pulse, the target strength, the distance to the target, and the sound absorption by the water media. The auditory system of odontocetes must be capable of effective perception, analysis, and discrimination of echo-signals within all this variability. The sonar of odontocetes has several mechanisms to compensate for the echo-level variation (gain control). To date, several mechanisms of the biosonar gain control have been revealed in odontocetes: (1) adjustment of emitted sonar pulse levels (the longer the distance to the target, the higher the level of the emitted pulse), (2) short-term variation of hearing sensitivity based on forward masking of the echo by the preceding self-heard emitted pulse and subsequent release from the masking, and (3) active long-term control of hearing sensitivity. Recent investigations with the use of the auditory evoked-potential technique have demonstrated that these mechanisms effectively minimize the variation of the response to the echo when either the emitted sonar pulse level, or the target distance, or both vary within a wide range. A short review of these data is presented herein.

  2. Coherence and interlimb force control: Effects of visual gain.

    PubMed

    Kang, Nyeonju; Cauraugh, James H

    2018-03-06

    Neural coupling across hemispheres and homologous muscles often appears during bimanual motor control. Force coupling in a specific frequency domain may indicate specific bimanual force coordination patterns. This study investigated coherence on pairs of bimanual isometric index finger force while manipulating visual gain and task asymmetry conditions. We used two visual gain conditions (low and high gain = 8 and 512 pixels/N), and created task asymmetry by manipulating coefficient ratios imposed on the left and right index finger forces (0.4:1.6; 1:1; 1.6:0.4, respectively). Unequal coefficient ratios required different contributions from each hand to the bimanual force task resulting in force asymmetry. Fourteen healthy young adults performed bimanual isometric force control at 20% of their maximal level of the summed force of both fingers. We quantified peak coherence and relative phase angle between hands at 0-4, 4-8, and 8-12 Hz, and estimated a signal-to-noise ratio of bimanual forces. The findings revealed higher peak coherence and relative phase angle at 0-4 Hz than at 4-8 and 8-12 Hz for both visual gain conditions. Further, peak coherence and relative phase angle values at 0-4 Hz were larger at the high gain than at the low gain. At the high gain, higher peak coherence at 0-4 Hz collapsed across task asymmetry conditions significantly predicted greater signal-to-noise ratio. These findings indicate that a greater level of visual information facilitates bimanual force coupling at a specific frequency range related to sensorimotor processing. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Altered functioning of reward circuitry in youth offspring of parents with bipolar disorder.

    PubMed

    Manelis, A; Ladouceur, C D; Graur, S; Monk, K; Bonar, L K; Hickey, M B; Dwojak, A C; Axelson, D; Goldstein, B I; Goldstein, T R; Bebko, G; Bertocci, M A; Gill, M K; Birmaher, B; Phillips, M L

    2016-01-01

    Offspring of parents with bipolar disorder (BD) (BO) are at higher risk of BD than offspring of parents with non-BD psychopathology (NBO), although both groups are at higher risk than offspring of psychiatrically healthy parents (HC) for other affective and psychiatric disorders. Abnormal functioning in reward circuitry has been demonstrated previously in individuals with BD. We aimed to determine whether activation and functional connectivity in this circuitry during risky decision-making differentiated BO, NBO and HC. BO (n = 29; mean age = 13.8 years; 14 female), NBO (n = 28; mean age = 13.9 years; 12 female) and HC (n = 23; mean age = 13.7 years; 11 female) were scanned while performing a number-guessing reward task. Of the participants, 11 BO and 12 NBO had current non-BD psychopathology; five BO and four NBO were taking psychotropic medications. A 3 (group) × 2 (conditions: win-control/loss-control) analysis of variance revealed a main effect of group on right frontal pole activation: BO showed significantly greater activation than HC. There was a significant main effect of group on functional connectivity between the bilateral ventral striatum and the right ventrolateral prefrontal cortex (Z > 3.09, cluster-p < 0.05): BO showed significantly greater negative functional connectivity than other participants. These between-group differences remained after removing youth with psychiatric disorders and psychotropic medications from analyses. This is the first study to demonstrate that reward circuitry activation and functional connectivity distinguish BO from NBO and HC. The fact that the pattern of findings remained when comparing healthy BO v. healthy NBO v. HC suggests that these neuroimaging measures may represent trait-level neurobiological markers conferring either risk for, or protection against, BD in youth.

  4. Targeting Lumbar Spinal Neural Circuitry by Epidural Stimulation to Restore Motor Function After Spinal Cord Injury.

    PubMed

    Minassian, Karen; McKay, W Barry; Binder, Heinrich; Hofstoetter, Ursula S

    2016-04-01

    Epidural spinal cord stimulation has a long history of application for improving motor control in spinal cord injury. This review focuses on its resurgence following the progress made in understanding the underlying neurophysiological mechanisms and on recent reports of its augmentative effects upon otherwise subfunctional volitional motor control. Early work revealed that the spinal circuitry involved in lower-limb motor control can be accessed by stimulating through electrodes placed epidurally over the posterior aspect of the lumbar spinal cord below a paralyzing injury. Current understanding is that such stimulation activates large-to-medium-diameter sensory fibers within the posterior roots. Those fibers then trans-synaptically activate various spinal reflex circuits and plurisegmentally organized interneuronal networks that control more complex contraction and relaxation patterns involving multiple muscles. The induced change in responsiveness of this spinal motor circuitry to any residual supraspinal input via clinically silent translesional neural connections that have survived the injury may be a likely explanation for rudimentary volitional control enabled by epidural stimulation in otherwise paralyzed muscles. Technological developments that allow dynamic control of stimulation parameters and the potential for activity-dependent beneficial plasticity may further unveil the remarkable capacity of spinal motor processing that remains even after severe spinal cord injuries.

  5. Subtractive, divisive and non-monotonic gain control in feedforward nets linearized by noise and delays

    PubMed Central

    Mejias, Jorge F.; Payeur, Alexandre; Selin, Erik; Maler, Leonard; Longtin, André

    2014-01-01

    The control of input-to-output mappings, or gain control, is one of the main strategies used by neural networks for the processing and gating of information. Using a spiking neural network model, we studied the gain control induced by a form of inhibitory feedforward circuitry—also known as “open-loop feedback”—, which has been experimentally observed in a cerebellum-like structure in weakly electric fish. We found, both analytically and numerically, that this network displays three different regimes of gain control: subtractive, divisive, and non-monotonic. Subtractive gain control was obtained when noise is very low in the network. Also, it was possible to change from divisive to non-monotonic gain control by simply modulating the strength of the feedforward inhibition, which may be achieved via long-term synaptic plasticity. The particular case of divisive gain control has been previously observed in vivo in weakly electric fish. These gain control regimes were robust to the presence of temporal delays in the inhibitory feedforward pathway, which were found to linearize the input-to-output mappings (or f-I curves) via a novel variability-increasing mechanism. Our findings highlight the feedforward-induced gain control analyzed here as a highly versatile mechanism of information gating in the brain. PMID:24616694

  6. Synthesis of Optimal Constant-Gain Positive-Real Controllers for Passive Systems

    NASA Technical Reports Server (NTRS)

    Mao, Y.; Kelkar, A. G.; Joshi, S. M.

    1999-01-01

    This paper presents synthesis methods for the design of constant-gain positive real controllers for passive systems. The results presented in this paper, in conjunction with the previous work by the authors on passification of non-passive systems, offer a useful synthesis tool for the design of passivity-based robust controllers for non-passive systems as well. Two synthesis approaches are given for minimizing an LQ-type performance index, resulting in optimal controller gains. Two separate algorithms, one for each of these approaches, are given. The synthesis techniques are demonstrated using two numerical examples: control of a flexible structure and longitudinal control of a fighter aircraft.

  7. Stress, trauma and PTSD: translational insights into the core synaptic circuitry and its modulation.

    PubMed

    Bennett, Maxwell R; Hatton, Sean N; Lagopoulos, Jim

    2016-06-01

    Evidence is considered as to whether behavioral criteria for diagnosis of post-traumatic stress disorder (PTSD) are applicable to that of traumatized animals and whether the phenomena of acquisition, extinction and reactivation of fear behavior in animals are also successfully applicable to humans. This evidence suggests an affirmative answer in both cases. Furthermore, the deficits in gray matter found in PTSD, determined with magnetic resonance imaging, are also observed in traumatized animals, lending neuropsychological support to the use of animals to probe what has gone awry in PTSD. Such animal experiments indicate that the core synaptic circuitry mediating behavior following trauma consists of the amygdala, ventral-medial prefrontal cortex and hippocampus, all of which are modulated by the basal ganglia. It is not clear if this is the case in PTSD as the observations using fMRI are equivocal and open to technical objections. Nevertheless, the effects of the basal ganglia in controlling glutamatergic synaptic transmission through dopaminergic and serotonergic synaptic mechanisms in the core synaptic circuitry provides a ready explanation for why modifying these mechanisms delays extinction in animal models and predisposes towards PTSD. In addition, changes of brain-derived neurotrophic factor (BDNF) in the core synaptic circuitry have significant effects on acquisition and extinction in animal experiments with single nucleotide polymorphisms in the BDNF gene predisposing to PTSD.

  8. Gain control of photomultiplier tubes used in detecting differential absorption lidar returns

    NASA Technical Reports Server (NTRS)

    Allen, Robert J. (Inventor)

    1989-01-01

    A technique for controlling the gain of a photomultiplier tube (PMT) 20. A voltage divider (resistors 45-49 in FIG. 1 and zener diodes 60-65 in FIG. 3) is used to control the potentials on dynodes 5, 7, and 9 of PMT 20. Transistor switches 53 and 58 provide the control of the voltage divider in FIG. 1 and photodiodes 66, 67 and 70 provide the control in FIG. 3. The gain control of PMT 20 is in the range from 100% to less than 0.001% (100,000 to 1).

  9. DNA decorated carbon nanotube sensors on CMOS circuitry for environmental monitoring

    NASA Astrophysics Data System (ADS)

    Liu, Yu; Chen, Chia-Ling; Agarwal, V.; Li, Xinghui; Sonkusale, S.; Dokmeci, Mehmet R.; Wang, Ming L.

    2010-04-01

    Single-walled carbon nanotubes (SWNTs) with their large surface area, high aspect ratio are one of the novel materials which have numerous attractive features amenable for high sensitivity sensors. Several nanotube based sensors including, gas, chemical and biosensors have been demonstrated. Moreover, most of these sensors require off chip components to detect the variations in the signals making them complicated and hard to commercialize. Here we present a novel complementary metal oxide semiconductor (CMOS) integrated carbon nanotube sensors for portable high sensitivity chemical sensing applications. Multiple zincation steps have been developed to ascertain proper electrical connectivity between the carbon nanotubes and the foundry made CMOS circuitry. The SWNTs have been integrated onto (CMOS) circuitry as the feedback resistor of a Miller compensated operational amplifier utilizing low temperature Dielectrophoretic (DEP) assembly process which has been tailored to be compatible with the post-CMOS integration at the die level. Building nanotube sensors directly on commercial CMOS circuitry allows single chip solutions eliminating the need for long parasitic lines and numerous wire bonds. The carbon nanotube sensors realized on CMOS circuitry show strong response to various vapors including Dimethyl methylphosphonate and Dinitrotoluene. The remarkable set of attributes of the SWNTs realized on CMOS electronic chips provides an attractive platform for high sensitivity portable nanotube based bio and chemical sensors.

  10. The control gain region for synchronization in non-diffusively coupled complex networks

    NASA Astrophysics Data System (ADS)

    Gequn, Liu; Wenhui, Li; Huijie, Yang; Knowles, Gareth

    2014-07-01

    The control gain region for synchronization of non-diffusively coupled networks was studied with respect to three conditions: synchronization, synchronization in finite time, and synchronization in the minimum time. Based on cancellation control methodology and master stability function formalism, we found that a complete feasible control gain region may be bounded, unbounded, empty or a union of several bounded and unbounded regions, with a similar shape to the synchronized region. An interesting possibility emerged that a network could be synchronized by both negative and positive feedback control simultaneously. By bridging synchronizability and synchronizing response speeds with a settling time index, we have developed timed synchronized region (TSR) as a substitute for the classical synchronized region to study finite time synchronization. As for the last condition, a graphical method was developed to estimate control gain with the minimum synchronization time (CGMST). Each condition has examples provided for illustration and verification.

  11. Electronic circuitry development in a micropyrotechnic system for micropropulsion applications

    NASA Astrophysics Data System (ADS)

    Puig-Vidal, Manuel; Lopez, Jaime; Miribel, Pere; Montane, Enric; Lopez-Villegas, Jose M.; Samitier, Josep; Rossi, Carole; Camps, Thierry; Dumonteuil, Maxime

    2003-04-01

    An electronic circuitry is proposed and implemented to optimize the ignition process and the robustness of a microthruster. The principle is based on the integration of propellant material within a micromachined system. The operational concept is simply based on the combustion of an energetic propellant stored in a micromachined chamber. Each thruster contains three parts (heater, chamber, nozzle). Due to the one shot characteristic, microthrusters are fabricated in 2D array configuration. For the functioning of this kind of system, one critical point is the optimization of the ignition process as a function of the power schedule delivered by electronic devices. One particular attention has been paid on the design and implementation of an electronic chip to control and optimize the system ignition. Ignition process is triggered by electrical power delivered to a polysilicon resistance in contact with the propellant. The resistance is used to sense the temperature on the propellant which is in contact. Temperature of the microthruster node before the ignition is monitored via the electronic circuitry. A pre-heating process before ignition seems to be a good methodology to optimize the ignition process. Pre-heating temperature and pre-heating time are critical parameters to be adjusted. Simulation and experimental results will deeply contribute to improve the micropyrotechnic system. This paper will discuss all these point.

  12. L∞-gain adaptive fuzzy fault accommodation control design for nonlinear time-delay systems.

    PubMed

    Wu, Huai-Ning; Qiang, Xiao-Hong; Guo, Lei

    2011-06-01

    In this paper, an adaptive fuzzy fault accommodation (FA) control design with a guaranteed L(∞)-gain performance is developed for a class of nonlinear time-delay systems with persistent bounded disturbances. Using the Lyapunov technique and the Razumikhin-type lemma, the existence condition of the L(∞) -gain adaptive fuzzy FA controllers is provided in terms of linear matrix inequalities (LMIs). In the proposed FA scheme, a fuzzy logic system is employed to approximate the unknown term in the derivative of the Lyapunov function due to the unknown fault function; a continuous-state feedback control strategy is adopted for the control design to avoid the undesirable chattering phenomenon. The resulting FA controllers can ensure that every response of the closed-loop system is uniformly ultimately bounded with a guaranteed L(∞)-gain performance in the presence of a fault. Moreover, by the existing LMI optimization technique, a suboptimal controller is obtained in the sense of minimizing an upper bound of the L(∞)-gain. Finally, the achieved simulation results on the FA control of a continuous stirred tank reactor (CSTR) show the effectiveness of the proposed design procedure.

  13. Kids, Candy, Brain and Behavior: Age Differences in Responses to Candy Gains and Losses

    PubMed Central

    Luking, Katherine R; Luby, Joan; Barch, Deanna M

    2014-01-01

    The development of reward-related neural systems, from adolescence through adulthood, has received much recent attention in the developmental neuroimaging literature. However, few studies have investigated behavioral and neural responses to both gains and losses in pre-pubertal child populations. To address this gap in the literature, in the present study healthy children aged 7–11 years and young-adults completed an fMRI card-guessing game using candy pieces delivered post-scan as an incentive. Age differences in behavioral and neural responses to candy gains/losses were investigated. Adults and children displayed similar responses to gains, but robust age differences were observed following candy losses within the caudate, thalamus, insula, and hippocampus. Interestingly, when task behavior was included as a factor in post-hoc mediation analyses, activation following loss within the caudate/thalamus related to task behavior and relationships with age were no longer significant. Conversely, relationships between response to loss and age within the hippocampus and insula remained significant even when controlling for behavior, with children showing heightened loss responses within the dorsal/posterior insula. These results suggest that both age and task behavior influence responses within the extended reward circuitry, and that children seem to be more sensitive than adults to loss feedback particularly within the dorsal/posterior insula. PMID:24534632

  14. Sensitive Periods of Emotion Regulation: Influences of Parental Care on Frontoamygdala Circuitry and Plasticity

    ERIC Educational Resources Information Center

    Gee, Dylan G.

    2016-01-01

    Early caregiving experiences play a central role in shaping emotional development, stress physiology, and refinement of limbic circuitry. Converging evidence across species delineates a sensitive period of heightened neuroplasticity when frontoamygdala circuitry is especially amenable to caregiver inputs early in life. During this period, parental…

  15. Model of visual contrast gain control and pattern masking

    NASA Technical Reports Server (NTRS)

    Watson, A. B.; Solomon, J. A.

    1997-01-01

    We have implemented a model of contrast gain and control in human vision that incorporates a number of key features, including a contrast sensitivity function, multiple oriented bandpass channels, accelerating nonlinearities, and a devisive inhibitory gain control pool. The parameters of this model have been optimized through a fit to the recent data that describe masking of a Gabor function by cosine and Gabor masks [J. M. Foley, "Human luminance pattern mechanisms: masking experiments require a new model," J. Opt. Soc. Am. A 11, 1710 (1994)]. The model achieves a good fit to the data. We also demonstrate how the concept of recruitment may accommodate a variant of this model in which excitatory and inhibitory paths have a common accelerating nonlinearity, but which include multiple channels tuned to different levels of contrast.

  16. Learning to walk with an adaptive gain proportional myoelectric controller for a robotic ankle exoskeleton.

    PubMed

    Koller, Jeffrey R; Jacobs, Daniel A; Ferris, Daniel P; Remy, C David

    2015-11-04

    Robotic ankle exoskeletons can provide assistance to users and reduce metabolic power during walking. Our research group has investigated the use of proportional myoelectric control for controlling robotic ankle exoskeletons. Previously, these controllers have relied on a constant gain to map user's muscle activity to actuation control signals. A constant gain may act as a constraint on the user, so we designed a controller that dynamically adapts the gain to the user's myoelectric amplitude. We hypothesized that an adaptive gain proportional myoelectric controller would reduce metabolic energy expenditure compared to walking with the ankle exoskeleton unpowered because users could choose their preferred control gain. We tested eight healthy subjects walking with the adaptive gain proportional myoelectric controller with bilateral ankle exoskeletons. The adaptive gain was updated each stride such that on average the user's peak muscle activity was mapped to maximal power output of the exoskeleton. All subjects participated in three identical training sessions where they walked on a treadmill for 50 minutes (30 minutes of which the exoskeleton was powered) at 1.2 ms(-1). We calculated and analyzed metabolic energy consumption, muscle recruitment, inverse kinematics, inverse dynamics, and exoskeleton mechanics. Using our controller, subjects achieved a metabolic reduction similar to that seen in previous work in about a third of the training time. The resulting controller gain was lower than that seen in previous work (β=1.50±0.14 versus a constant β=2). The adapted gain allowed users more total ankle joint power than that of unassisted walking, increasing ankle power in exchange for a decrease in hip power. Our findings indicate that humans prefer to walk with greater ankle mechanical power output than their unassisted gait when provided with an ankle exoskeleton using an adaptive controller. This suggests that robotic assistance from an exoskeleton can allow

  17. Abnormalities of neural circuitry in Alzheimer's disease: hippocampus and cortical cholinergic innervation.

    PubMed

    Geula, C

    1998-07-01

    Severe pathology in Alzheimer's disease (AD) results in marked disruption of cortical circuitry. Formation of neurofibrillary tangles, neuronal loss, decrease in dendritic extent, and synaptic depletion combine to halt communication among various cortical areas, resulting in anatomic isolation and fragmentation of many cortical zones. The clinical manifestation of this disruption is severe and debilitating cognitive dysfunction, often accompanied by psychiatric and behavioral disturbances and a diminished ability to perform activities of daily living. However, different cortical circuits are not equally vulnerable to AD pathology. In particular, two cortical systems that appear to be involved in the neural processing of memory are selectively vulnerable to degeneration in AD. One consists of connections between the hippocampus and its neighboring cortical structures within the temporal lobe. The second is the cortical cholinergic system that originates in neurons within the basal forebrain and innervates the entire cortical mantle. The circuitry in these systems shows early and severe degenerative changes in the course of AD. The selective vulnerability of these circuits is the probable reason for the early and marked loss of memory observed in these patients. This review presents current knowledge of the general pattern of cortical circuitry, followed by a summary of abnormalities of this circuitry in AD. The cortical circuits that exhibit selective pathology in AD are described in greater detail. Therapeutic implications of the abnormal circuitry in AD are also discussed. For therapies to be effective, early diagnosis of AD is necessary. Future efforts at AD therapy must be combined with an equally intense effort to develop tools capable of early diagnosis of AD, preferably at a preclinical stage before the onset of cognitive symptoms.

  18. Design of optimally normal minimum gain controllers by continuation method

    NASA Technical Reports Server (NTRS)

    Lim, K. B.; Juang, J.-N.; Kim, Z. C.

    1989-01-01

    A measure of the departure from normality is investigated for system robustness. An attractive feature of the normality index is its simplicity for pole placement designs. To allow a tradeoff between system robustness and control effort, a cost function consisting of the sum of a norm of weighted gain matrix and a normality index is minimized. First- and second-order necessary conditions for the constrained optimization problem are derived and solved by a Newton-Raphson algorithm imbedded into a one-parameter family of neighboring zero problems. The method presented allows the direct computation of optimal gains in terms of robustness and control effort for pole placement problems.

  19. Flexible Contrast Gain Control in the Right Hemisphere

    ERIC Educational Resources Information Center

    Okubo, Matia; Nicholls, Michael E. R.

    2005-01-01

    This study investigates whether the right hemisphere has more flexible contrast gain control settings for the identification of spatial frequency. Right-handed participants identified 1 and 9 cycles per degree sinusoidal gratings presented either to the left visual field-right hemisphere (LVF-RH) or the right visual field-left hemisphere (RVF-LH).…

  20. PV source based high voltage gain current fed converter

    NASA Astrophysics Data System (ADS)

    Saha, Soumya; Poddar, Sahityika; Chimonyo, Kudzai B.; Arunkumar, G.; Elangovan, D.

    2017-11-01

    This work involves designing and simulation of a PV source based high voltage gain, current fed converter. It deals with an isolated DC-DC converter which utilizes boost converter topology. The proposed converter is capable of high voltage gain and above all have very high efficiency levels as proved by the simulation results. The project intends to produce an output of 800 V dc from a 48 V dc input. The simulation results obtained from PSIM application interface were used to analyze the performance of the proposed converter. Transformer used in the circuit steps up the voltage as well as to provide electrical isolation between the low voltage and high voltage side. Since the converter involves high switching frequency of 100 kHz, ultrafast recovery diodes are employed in the circuitry. The major application of the project is for future modeling of solar powered electric hybrid cars.

  1. Hormonal gain control of a medial preoptic area social reward circuit

    PubMed Central

    McHenry, Jenna A.; Otis, James M.; Rossi, Mark A.; Robinson, J. Elliott; Kosyk, Oksana; Miller, Noah W.; McElligott, Zoe A.; Budygin, Evgeny A.; Rubinow, David R.; Stuber, Garret D.

    2017-01-01

    Neural networks that control reproduction must integrate social and hormonal signals, tune motivation, and invigorate social interactions. However, the neurocircuit mechanisms for these processes remain unresolved. The medial preoptic area (mPOA), an essential node for social behaviors and is comprised of molecularly-diverse neurons with widespread projections. Here, we identify a steroid-responsive subset of neurotensin (Nts) expressing mPOA neurons that interface with the ventral tegmental area (VTA) to form a socially-engaged reward circuit. Using in vivo 2-photon imaging in female mice, we show that mPOANts neurons preferentially encode attractive male cues compared to non-social appetitive stimuli. Ovarian hormone signals regulate both the physiological and cue encoding properties of these cells. Furthermore, optogenetic stimulation of mPOANts-VTA circuitry promotes rewarding phenotypes, social approach, and striatal dopamine release. Collectively, these data demonstrate that steroid-sensitive mPOA neurons encode ethologically-relevant stimuli and co-opt midbrain reward circuits to promote prosocial behavior critical for species survival. PMID:28135243

  2. Crystal oscillators using negative voltage gain, single pole response amplifiers

    NASA Technical Reports Server (NTRS)

    Kleinberg, Leonard L. (Inventor)

    1989-01-01

    A simple and inexpensive crystal oscillator is provided which employs negative voltage gain, single pole response amplifiers. The amplifiers may include such configurations as gate inverters, operational amplifiers and conventional bipolar transistor amplifiers, all of which operate at a frequency which is on the roll-off portion of their gain versus frequency curve. Several amplifier feedback circuit variations are employed to set desired bias levels and to allow the oscillator to operate at the crystal's fundamental frequency or at an overtone of the fundamental frequency. The oscillator is made less expensive than comparable oscillators by employing relatively low frequency amplifiers and operating them at roll-off, at frequencies beyond which they are customarily used. Simplicity is provided because operation at roll-off eliminates components ordinarily required in similar circuits to provide sufficient phase-shift in the feedback circuitry for oscillation to occur.

  3. Dynamic modulation of visual and electrosensory gains for locomotor control

    PubMed Central

    Sutton, Erin E.; Demir, Alican; Stamper, Sarah A.; Fortune, Eric S.; Cowan, Noah J.

    2016-01-01

    Animal nervous systems resolve sensory conflict for the control of movement. For example, the glass knifefish, Eigenmannia virescens, relies on visual and electrosensory feedback as it swims to maintain position within a moving refuge. To study how signals from these two parallel sensory streams are used in refuge tracking, we constructed a novel augmented reality apparatus that enables the independent manipulation of visual and electrosensory cues to freely swimming fish (n = 5). We evaluated the linearity of multisensory integration, the change to the relative perceptual weights given to vision and electrosense in relation to sensory salience, and the effect of the magnitude of sensory conflict on sensorimotor gain. First, we found that tracking behaviour obeys superposition of the sensory inputs, suggesting linear sensorimotor integration. In addition, fish rely more on vision when electrosensory salience is reduced, suggesting that fish dynamically alter sensorimotor gains in a manner consistent with Bayesian integration. However, the magnitude of sensory conflict did not significantly affect sensorimotor gain. These studies lay the theoretical and experimental groundwork for future work investigating multisensory control of locomotion. PMID:27170650

  4. HPA-Axis Hormone Modulation of Stress Response Circuitry Activity in Women with Remitted Major Depression

    PubMed Central

    Holsen, Laura M.; Lancaster, Katie; Klibanski, Anne; Whitfield-Gabrieli, Susan; Cherkerzian, Sara; Buka, Stephen; Goldstein, Jill M.

    2013-01-01

    Decades of clinical and basic research indicate significant links between altered hypothalamic-pituitary-adrenal (HPA)-axis hormone dynamics and major depressive disorder (MDD). Recent neuroimaging studies of MDD highlight abnormalities in stress response circuitry regions which play a role in the regulation of the HPA-axes. However, there is a dearth of research examining these systems in parallel, especially as related to potential trait characteristics. The current study addresses this gap by investigating neural responses to a mild visual stress challenge with real-time assessment of adrenal hormones in women with MDD in remission and controls. 15 women with recurrent MDD in remission (rMDD) and 15 healthy control women were scanned on a 3T Siemens MR scanner while viewing neutral and negative (stress-evoking) stimuli. Blood samples were obtained before, during, and after scanning for measurement of HPA-axis hormone levels. Compared to controls, rMDD women demonstrated higher anxiety ratings, increased cortisol levels, and hyperactivation in the amygdala and hippocampus, p<0.05, FWE-corrected in response to the stress challenge. Among rMDD women, amygdala activation was negatively related to cortisol changes and positively associated with duration of remission. Findings presented here provide evidence for differential effects of altered HPA-axis hormone dynamics on hyperactivity in stress response circuitry regions elicited by a well-validated stress paradigm in women with recurrent MDD in remission. PMID:23891965

  5. Reduced neural activity of the prefrontal cognitive control circuitry during response inhibition to negative words in people with schizophrenia

    PubMed Central

    Vercammen, Ans; Morris, Richard; Green, Melissa J.; Lenroot, Rhoshel; Kulkarni, Jayashri; Carr, Vaughan J.; Weickert, Cynthia Shannon; Weickert, Thomas W.

    2012-01-01

    Background Schizophrenia is characterized by deficits in executive control and impairments in emotion processing. This study assessed the nature and extent of potential alterations in the neural substrates supporting the interaction between cognitive control mechanisms and emotion attribution processes in people with schizophrenia. Methods Functional magnetic resonance imaging was performed during a verbal emotional go/no-go task. People with schizophrenia and healthy controls responded to word stimuli of a prespecified emotional valence (positive, negative or neutral) while inhibiting responses to stimuli of a different valence. Results We enrolled 20 people with schizophrenia and 23 controls in the study. Healthy controls activated an extensive dorsal prefrontal–parietal network while inhibiting responses to negative words compared to neutral words, but showed deactivation of the midcingulate cortex while inhibiting responses to positive words compared to neutral words. People with schizophrenia failed to activate this network during response inhibition to negative words, whereas during response inhibition to positive words they did not deactivate the cingulate, but showed increased responsivity in the frontal cortex. Limitations Sample heterogeneity is characteristic of studies of schizophrenia and may have contributed to more variable neural responses in the patient sample despite the care taken to control for potentially confounding variables. Conclusion Our results showed that schizophrenia is associated with aberrant modulation of neural responses during the interaction between cognitive control and emotion processing. Failure of the frontal circuitry to regulate goal-directed behaviour based on emotion attributions may contribute to deficits in psychosocial functioning in daily life. PMID:22617625

  6. Power inverter implementing phase skipping control

    DOEpatents

    Somani, Utsav; Amirahmadi, Ahmadreza; Jourdan, Charles; Batarseh, Issa

    2016-10-18

    A power inverter includes a DC/AC inverter having first, second and third phase circuitry coupled to receive power from a power source. A controller is coupled to a driver for each of the first, second and third phase circuitry (control input drivers). The controller includes an associated memory storing a phase skipping control algorithm, wherein the controller is coupled to receive updating information including a power level generated by the power source. The drivers are coupled to control inputs of the first, second and third phase circuitry, where the drivers are configured for receiving phase skipping control signals from the controller and outputting mode selection signals configured to dynamically select an operating mode for the DC/AC inverter from a Normal Control operation and a Phase Skipping Control operation which have different power injection patterns through the first, second and third phase circuitry depending upon the power level.

  7. Method, apparatus and system to compensate for drift by physically unclonable function circuitry

    DOEpatents

    Hamlet, Jason

    2016-11-22

    Techniques and mechanisms to detect and compensate for drift by a physically uncloneable function (PUF) circuit. In an embodiment, first state information is registered as reference information to be made available for subsequent evaluation of whether drift by PUF circuitry has occurred. The first state information is associated with a first error correction strength. The first state information is generated based on a first PUF value output by the PUF circuitry. In another embodiment, second state information is determined based on a second PUF value that is output by the PUF circuitry. An evaluation of whether drift has occurred is performed based on the first state information and the second state information, the evaluation including determining whether a threshold error correction strength is exceeded concurrent with a magnitude of error being less than the first error correction strength.

  8. Analysis and design of gain scheduled control systems. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Shamma, Jeff S.

    1988-01-01

    Gain scheduling, as an idea, is to construct a global feedback control system for a time varying and/or nonlinear plant from a collection of local time invariant designs. However in the absence of a sound analysis, these designs come with no guarantees on the robustness, performance, or even nominal stability of the overall gain schedule design. Such an analysis is presented for three types of gain scheduling situations: (1) a linear parameter varying plant scheduling on its exogenous parameters, (2) a nonlinear plant scheduling on a prescribed reference trajectory, and (3) a nonlinear plant scheduling on the current plant output. Conditions are given which guarantee that the stability, robustness, and performance properties of the fixed operating point designs carry over to the global gain scheduled designs, such as the scheduling variable should vary slowly and capture the plants nonlinearities. Finally, an alternate design framework is proposed which removes the slowing varying restriction or gain scheduled systems. This framework addresses some fundamental feedback issues previously ignored in standard gain.

  9. Kids, candy, brain and behavior: age differences in responses to candy gains and losses.

    PubMed

    Luking, Katherine R; Luby, Joan L; Barch, Deanna M

    2014-07-01

    The development of reward-related neural systems, from adolescence through adulthood, has received much recent attention in the developmental neuroimaging literature. However, few studies have investigated behavioral and neural responses to both gains and losses in pre-pubertal child populations. To address this gap in the literature, in the present study healthy children aged 7-11 years and young-adults completed an fMRI card-guessing game using candy pieces delivered post-scan as an incentive. Age differences in behavioral and neural responses to candy gains/losses were investigated. Adults and children displayed similar responses to gains, but robust age differences were observed following candy losses within the caudate, thalamus, insula, and hippocampus. Interestingly, when task behavior was included as a factor in post hoc mediation analyses, activation following loss within the caudate/thalamus related to task behavior and relationships with age were no longer significant. Conversely, relationships between response to loss and age within the hippocampus and insula remained significant even when controlling for behavior, with children showing heightened loss responses within the dorsal/posterior insula. These results suggest that both age and task behavior influence responses within the extended reward circuitry, and that children seem to be more sensitive than adults to loss feedback particularly within the dorsal/posterior insula. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Stitching Codeable Circuits: High School Students' Learning about Circuitry and Coding with Electronic Textiles

    ERIC Educational Resources Information Center

    Litts, Breanne K.; Kafai, Yasmin B.; Lui, Debora A.; Walker, Justice T.; Widman, Sari A.

    2017-01-01

    Learning about circuitry by connecting a battery, light bulb, and wires is a common activity in many science classrooms. In this paper, we expand students' learning about circuitry with electronic textiles, which use conductive thread instead of wires and sewable LEDs instead of lightbulbs, by integrating programming sensor inputs and light…

  11. Neural circuitry and immunity

    PubMed Central

    Pavlov, Valentin A.; Tracey, Kevin J.

    2015-01-01

    Research during the last decade has significantly advanced our understanding of the molecular mechanisms at the interface between the nervous system and the immune system. Insight into bidirectional neuroimmune communication has characterized the nervous system as an important partner of the immune system in the regulation of inflammation. Neuronal pathways, including the vagus nerve-based inflammatory reflex are physiological regulators of immune function and inflammation. In parallel, neuronal function is altered in conditions characterized by immune dysregulation and inflammation. Here, we review these regulatory mechanisms and describe the neural circuitry modulating immunity. Understanding these mechanisms reveals possibilities to use targeted neuromodulation as a therapeutic approach for inflammatory and autoimmune disorders. These findings and current clinical exploration of neuromodulation in the treatment of inflammatory diseases defines the emerging field of Bioelectronic Medicine. PMID:26512000

  12. Advanced Data Acquisition Systems with Self-Healing Circuitry

    NASA Technical Reports Server (NTRS)

    Larson, William E.; Ihlefeld, Curtis M.; Medelius, Pedro J.; Delgado, H. (Technical Monitor)

    2001-01-01

    Kennedy Space Center's Spaceport Engineering & Technology Directorate has developed a data acquisition system that will help drive down the cost of ground launch operations. This system automates both the physical measurement set-up function as well as configuration management documentation. The key element of the system is a self-configuring, self-calibrating, signal-conditioning amplifier that automatically adapts to any sensor to which it is connected. This paper will describe the core technology behind this device and the automated data system in which it has been integrated. The paper will also describe the revolutionary enhancements that are planned for this innovative measurement technology. All measurement electronics devices contain circuitry that, if it fails or degrades, requires the unit to be replaced, adding to the cost of operations. Kennedy Space Center is now developing analog circuits that will be able to detect their own failure and dynamically reconfigure their circuitry to restore themselves to normal operation. This technology will have wide ranging application in all electronic devices used in space and ground systems.

  13. DNA-based random number generation in security circuitry.

    PubMed

    Gearheart, Christy M; Arazi, Benjamin; Rouchka, Eric C

    2010-06-01

    DNA-based circuit design is an area of research in which traditional silicon-based technologies are replaced by naturally occurring phenomena taken from biochemistry and molecular biology. This research focuses on further developing DNA-based methodologies to mimic digital data manipulation. While exhibiting fundamental principles, this work was done in conjunction with the vision that DNA-based circuitry, when the technology matures, will form the basis for a tamper-proof security module, revolutionizing the meaning and concept of tamper-proofing and possibly preventing it altogether based on accurate scientific observations. A paramount part of such a solution would be self-generation of random numbers. A novel prototype schema employs solid phase synthesis of oligonucleotides for random construction of DNA sequences; temporary storage and retrieval is achieved through plasmid vectors. A discussion of how to evaluate sequence randomness is included, as well as how these techniques are applied to a simulation of the random number generation circuitry. Simulation results show generated sequences successfully pass three selected NIST random number generation tests specified for security applications.

  14. Tuning and performance evaluation of PID controller for superheater steam temperature control of 200 MW boiler using gain phase assignment algorithm

    NASA Astrophysics Data System (ADS)

    Begum, A. Yasmine; Gireesh, N.

    2018-04-01

    In superheater, steam temperature is controlled in a cascade control loop. The cascade control loop consists of PI and PID controllers. To improve the superheater steam temperature control the controller's gains in a cascade control loop has to be tuned efficiently. The mathematical model of the superheater is derived by sets of nonlinear partial differential equations. The tuning methods taken for study here are designed for delay plus first order transfer function model. Hence from the dynamical model of the superheater, a FOPTD model is derived using frequency response method. Then by using Chien-Hrones-Reswick Tuning Algorithm and Gain-Phase Assignment Algorithm optimum controller gains has been found out based on the least value of integral time weighted absolute error.

  15. External locus of control contributes to racial disparities in memory and reasoning training gains in ACTIVE

    PubMed Central

    Zahodne, Laura B.; Meyer, Oanh L.; Choi, Eunhee; Thomas, Michael L.; Willis, Sherry L.; Marsiske, Michael; Gross, Alden L.; Rebok, George W.; Parisi, Jeanine M.

    2015-01-01

    Racial disparities in cognitive outcomes may be partly explained by differences in locus of control. African Americans report more external locus of control than non-Hispanic Whites, and external locus of control is associated with poorer health and cognition. The aims of this study were to compare cognitive training gains between African American and non-Hispanic White participants in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study and determine whether racial differences in training gains are mediated by locus of control. The sample comprised 2,062 (26% African American) adults aged 65 and older who participated in memory, reasoning, or speed training. Latent growth curve models evaluated predictors of 10-year cognitive trajectories separately by training group. Multiple group modeling examined associations between training gains and locus of control across racial groups. Compared to non-Hispanic Whites, African Americans evidenced less improvement in memory and reasoning performance after training. These effects were partially mediated by locus of control, controlling for age, sex, education, health, depression, testing site, and initial cognitive ability. African Americans reported more external locus of control, which was associated with smaller training gains. External locus of control also had a stronger negative association with reasoning training gain for African Americans than for Whites. No racial difference in training gain was identified for speed training. Future intervention research with African Americans should test whether explicitly targeting external locus of control leads to greater cognitive improvement following cognitive training. PMID:26237116

  16. Functional Maps of Neocortical Local Circuitry

    PubMed Central

    Thomson, Alex M.; Lamy, Christophe

    2007-01-01

    This review aims to summarize data obtained with different techniques to provide a functional map of the local circuit connections made by neocortical neurones, a reference for those interested in cortical circuitry and the numerical information required by those wishing to model the circuit. A brief description of the main techniques used to study circuitry is followed by outline descriptions of the major classes of neocortical excitatory and inhibitory neurones and the connections that each layer makes with other cortical and subcortical regions. Maps summarizing the projection patterns of each class of neurone within the local circuit and tables of the properties of these local circuit connections are provided. This review relies primarily on anatomical studies that have identified the classes of neurones and their local and long distance connections and on paired intracellular and whole-cell recordings which have documented the properties of the connections between them. A large number of different types of synaptic connections have been described, but for some there are only a few published examples and for others the details that can only be obtained with paired recordings and dye-filling are lacking. A further complication is provided by the range of species, technical approaches and age groups used in these studies. Wherever possible the range of available data are summarised and compared. To fill some of the more obvious gaps for the less well-documented cases, data obtained with other methods are also summarized. PMID:18982117

  17. Redesign of a Variable-Gain Output Feedback Longitudinal Controller Flown on the High-Alpha Research Vehicle (HARV)

    NASA Technical Reports Server (NTRS)

    Ostroff, Aaron J.

    1998-01-01

    This paper describes a redesigned longitudinal controller that flew on the High-Alpha Research Vehicle (HARV) during calendar years (CY) 1995 and 1996. Linear models are developed for both the modified controller and a baseline controller that was flown in CY 1994. The modified controller was developed with three gain sets for flight evaluation, and several linear analysis results are shown comparing the gain sets. A Neal-Smith flying qualities analysis shows that performance for the low- and medium-gain sets is near the level 1 boundary, depending upon the bandwidth assumed, whereas the high-gain set indicates a sensitivity problem. A newly developed high-alpha Bode envelope criterion indicates that the control system gains may be slightly high, even for the low-gain set. A large motion-base simulator in the United Kingdom was used to evaluate the various controllers. Desired performance, which appeared to be satisfactory for flight, was generally met with both the low- and medium-gain sets. Both the high-gain set and the baseline controller were very sensitive, and it was easy to generate pilot-induced oscillation (PIO) in some of the target-tracking maneuvers. Flight target-tracking results varied from level 1 to level 3 and from no sensitivity to PIO. These results were related to pilot technique and whether actuator rate saturation was encountered.

  18. Perceptual alternation in obsessive compulsive disorder--implications for a role of the cortico-striatal circuitry in mediating awareness.

    PubMed

    Li, C S; Chen, M C; Yang, Y Y; Chang, H L; Liu, C Y; Shen, S; Chen, C Y

    2000-06-15

    Mounting evidence suggests that obsessive compulsive disorder (OCD) results from functional aberrations of the fronto-striatal circuitry. However, empirical studies of the behavioral manifestations of OCD have been relatively lacking. The present study employs a behavioral task that allows a quantitative measure of how alternative percepts are formed from one moment to another, a process mimicking the brain state in which different thoughts and imageries compete for access to awareness. Eighteen patients with OCD, 12 with generalized anxiety disorder, and 18 normal subjects participated in the experiment, in which they viewed one of the three Schröder staircases and responded by pressing a key to each perceptual reversal. The results demonstrate that the patients with OCD have a higher perceptual alternation rate than the normal controls. Moreover, the frequency of perceptual alternation is significantly correlated with the Yale-Brown obsessive compulsive and the Hamilton anxiety scores. The increase in the frequency of perceptual reversals cannot easily be accounted for by learning or by different patterns of eye fixations on the task. These results provide further evidence that an impairment of the inhibitory function of the cortico-striatal circuitry might underlie the etiology of OCD. The implications of the results for a general role of the cortico-striatal circuitry in mediating awareness are discussed.

  19. Gain-Scheduled Fault Tolerance Control Under False Identification

    NASA Technical Reports Server (NTRS)

    Shin, Jong-Yeob; Belcastro, Christine (Technical Monitor)

    2006-01-01

    An active fault tolerant control (FTC) law is generally sensitive to false identification since the control gain is reconfigured for fault occurrence. In the conventional FTC law design procedure, dynamic variations due to false identification are not considered. In this paper, an FTC synthesis method is developed in order to consider possible variations of closed-loop dynamics under false identification into the control design procedure. An active FTC synthesis problem is formulated into an LMI optimization problem to minimize the upper bound of the induced-L2 norm which can represent the worst-case performance degradation due to false identification. The developed synthesis method is applied for control of the longitudinal motions of FASER (Free-flying Airplane for Subscale Experimental Research). The designed FTC law of the airplane is simulated for pitch angle command tracking under a false identification case.

  20. Reliable gain-scheduled control of discrete-time systems and its application to CSTR model

    NASA Astrophysics Data System (ADS)

    Sakthivel, R.; Selvi, S.; Mathiyalagan, K.; Shi, Y.

    2016-10-01

    This paper is focused on reliable gain-scheduled controller design for a class of discrete-time systems with randomly occurring nonlinearities and actuator fault. Further, the nonlinearity in the system model is assumed to occur randomly according to a Bernoulli distribution with measurable time-varying probability in real time. The main purpose of this paper is to design a gain-scheduled controller by implementing a probability-dependent Lyapunov function and linear matrix inequality (LMI) approach such that the closed-loop discrete-time system is stochastically stable for all admissible randomly occurring nonlinearities. The existence conditions for the reliable controller is formulated in terms of LMI constraints. Finally, the proposed reliable gain-scheduled control scheme is applied on continuously stirred tank reactor model to demonstrate the effectiveness and applicability of the proposed design technique.

  1. External locus of control contributes to racial disparities in memory and reasoning training gains in ACTIVE.

    PubMed

    Zahodne, Laura B; Meyer, Oanh L; Choi, Eunhee; Thomas, Michael L; Willis, Sherry L; Marsiske, Michael; Gross, Alden L; Rebok, George W; Parisi, Jeanine M

    2015-09-01

    Racial disparities in cognitive outcomes may be partly explained by differences in locus of control. African Americans report more external locus of control than non-Hispanic Whites, and external locus of control is associated with poorer health and cognition. The aims of this study were to compare cognitive training gains between African American and non-Hispanic White participants in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study and determine whether racial differences in training gains are mediated by locus of control. The sample comprised 2,062 (26% African American) adults aged 65 and older who participated in memory, reasoning, or speed training. Latent growth curve models evaluated predictors of 10-year cognitive trajectories separately by training group. Multiple group modeling examined associations between training gains and locus of control across racial groups. Compared to non-Hispanic Whites, African Americans evidenced less improvement in memory and reasoning performance after training. These effects were partially mediated by locus of control, controlling for age, sex, education, health, depression, testing site, and initial cognitive ability. African Americans reported more external locus of control, which was associated with smaller training gains. External locus of control also had a stronger negative association with reasoning training gain for African Americans than for Whites. No racial difference in training gain was identified for speed training. Future intervention research with African Americans should test whether explicitly targeting external locus of control leads to greater cognitive improvement following cognitive training. (c) 2015 APA, all rights reserved).

  2. Musicianship enhances ipsilateral and contralateral efferent gain control to the cochlea.

    PubMed

    Bidelman, Gavin M; Schneider, Amy D; Heitzmann, Victoria R; Bhagat, Shaum P

    2017-02-01

    Human hearing sensitivity is easily compromised with overexposure to excessively loud sounds, leading to permanent hearing damage. Consequently, finding activities and/or experiential factors that distinguish "tender" from "tough" ears (i.e., acoustic vulnerability) would be important for identifying people at higher risk for hearing damage. To regulate sound transmission and protect the inner ear against acoustic trauma, the auditory system modulates gain control to the cochlea via biological feedback of the medial olivocochlear (MOC) efferents, a neuronal pathway linking the lower brainstem and cochlear outer hair cells. We hypothesized that a salient form of auditory experience shown to have pervasive neuroplastic benefits, namely musical training, might act to fortify hearing through tonic engagement of these reflexive pathways. By measuring MOC efferent feedback via otoacoustic emissions (cochlear emitted sounds), we show that dynamic ipsilateral and contralateral cochlear gain control is enhanced in musically-trained individuals. Across all participants, MOC strength was correlated with the years of listeners' training suggested that efferent gain control is experience dependent. Our data provide new evidence that intensive listening experience(s) (e.g., musicianship) can strengthen the ipsi/contralateral MOC efferent system and sound regulation to the inner ear. Implications for reducing acoustic vulnerability to damaging sounds are discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Application of variable-gain output feedback for high-alpha control

    NASA Technical Reports Server (NTRS)

    Ostroff, Aaron J.

    1990-01-01

    A variable-gain, optimal, discrete, output feedback design approach that is applied to a nonlinear flight regime is described. The flight regime covers a wide angle-of-attack range that includes stall and post stall. The paper includes brief descriptions of the variable-gain formulation, the discrete-control structure and flight equations used to apply the design approach, and the high performance airplane model used in the application. Both linear and nonlinear analysis are shown for a longitudinal four-model design case with angles of attack of 5, 15, 35, and 60 deg. Linear and nonlinear simulations are compared for a single-point longitudinal design at 60 deg angle of attack. Nonlinear simulations for the four-model, multi-mode, variable-gain design include a longitudinal pitch-up and pitch-down maneuver and high angle-of-attack regulation during a lateral maneuver.

  4. A Presynaptic Gain Control Mechanism Fine-Tunes Olfactory Behavior

    PubMed Central

    Root, Cory M.; Masuyama, Kaoru; Green, David S.; Enell, Lina E.; Nässel, Dick R.; Lee, Chi-Hon; Wang, Jing W.

    2008-01-01

    Early sensory processing can play a critical role in sensing environmental cues. We have investigated the physiological and behavioral function of gain control at the first synapse of olfactory processing in Drosophila. We report that olfactory receptor neurons (ORNs) express the GABAB receptor (GABABR) and its expression expands the dynamic range of ORN synaptic transmission that is preserved in projection neuron responses. Strikingly, we find that different ORN channels have unique baseline levels of GABABR expression. ORNs that sense the aversive odorant CO2 do not express GABABRs nor exhibit any presynaptic inhibition. In contrast, pheromone-sensing ORNs express a high level of GABABRs and exhibit strong presynaptic inhibition. Furthermore, a behavioral significance of presynaptic inhibition was revealed by a courtship behavior in which pheromone-dependent mate localization is impaired in flies that lack GABABRs in specific ORNs. Together, these findings indicate that different olfactory receptor channels may employ heterogeneous presynaptic gain control as a mechanism to allow an animal’s innate behavioral responses to match its ecological needs. PMID:18667158

  5. Post-Stall Aerodynamic Modeling and Gain-Scheduled Control Design

    NASA Technical Reports Server (NTRS)

    Wu, Fen; Gopalarathnam, Ashok; Kim, Sungwan

    2005-01-01

    A multidisciplinary research e.ort that combines aerodynamic modeling and gain-scheduled control design for aircraft flight at post-stall conditions is described. The aerodynamic modeling uses a decambering approach for rapid prediction of post-stall aerodynamic characteristics of multiple-wing con.gurations using known section data. The approach is successful in bringing to light multiple solutions at post-stall angles of attack right during the iteration process. The predictions agree fairly well with experimental results from wind tunnel tests. The control research was focused on actuator saturation and .ight transition between low and high angles of attack regions for near- and post-stall aircraft using advanced LPV control techniques. The new control approaches maintain adequate control capability to handle high angle of attack aircraft control with stability and performance guarantee.

  6. Digitally gain controlled linear high voltage amplifier for laboratory applications.

    PubMed

    Koçum, C

    2011-08-01

    The design of a digitally gain controlled high-voltage non-inverting bipolar linear amplifier is presented. This cost efficient and relatively simple circuit has stable operation range from dc to 90 kHz under the load of 10 kΩ and 39 pF. The amplifier can swing up to 360 V(pp) under these conditions and it has 2.5 μs rise time. The gain can be changed by the aid of JFETs. The amplifiers have been realized using a combination of operational amplifiers and high-voltage discrete bipolar junction transistors. The circuit details and performance characteristics are discussed.

  7. Adaptive fuzzy dynamic surface control for the chaotic permanent magnet synchronous motor using Nussbaum gain

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

    Luo, Shaohua

    This paper is concerned with the problem of adaptive fuzzy dynamic surface control (DSC) for the permanent magnet synchronous motor (PMSM) system with chaotic behavior, disturbance and unknown control gain and parameters. Nussbaum gain is adopted to cope with the situation that the control gain is unknown. And the unknown items can be estimated by fuzzy logic system. The proposed controller guarantees that all the signals in the closed-loop system are bounded and the system output eventually converges to a small neighborhood of the desired reference signal. Finally, the numerical simulations indicate that the proposed scheme can suppress the chaosmore » of PMSM and show the effectiveness and robustness of the proposed method.« less

  8. Adaptive fuzzy dynamic surface control for the chaotic permanent magnet synchronous motor using Nussbaum gain.

    PubMed

    Luo, Shaohua

    2014-09-01

    This paper is concerned with the problem of adaptive fuzzy dynamic surface control (DSC) for the permanent magnet synchronous motor (PMSM) system with chaotic behavior, disturbance and unknown control gain and parameters. Nussbaum gain is adopted to cope with the situation that the control gain is unknown. And the unknown items can be estimated by fuzzy logic system. The proposed controller guarantees that all the signals in the closed-loop system are bounded and the system output eventually converges to a small neighborhood of the desired reference signal. Finally, the numerical simulations indicate that the proposed scheme can suppress the chaos of PMSM and show the effectiveness and robustness of the proposed method.

  9. Use of tear ring permits repair of sealed module circuitry

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Improved packaging technique for modular electronic circuitry utilizes a tear ring which may be removed for repair and resealed. The tear ring is put over the container and header to which the electronic circuit assembly has been attached.

  10. Reward Circuitry Plasticity in Pain Perception and Modulation

    PubMed Central

    DosSantos, Marcos F.; Moura, Brenda de Souza; DaSilva, Alexandre F.

    2017-01-01

    Although pain is a widely known phenomenon and an important clinical symptom that occurs in numerous diseases, its mechanisms are still barely understood. Owing to the scarce information concerning its pathophysiology, particularly what is involved in the transition from an acute state to a chronic condition, pain treatment is frequently unsatisfactory, therefore contributing to the amplification of the chronic pain burden. In fact, pain is an extremely complex experience that demands the recruitment of an intricate set of central nervous system components. This includes cortical and subcortical areas involved in interpretation of the general characteristics of noxious stimuli. It also comprises neural circuits that process the motivational-affective dimension of pain. Hence, the reward circuitry represents a vital element for pain experience and modulation. This review article focuses on the interpretation of the extensive data available connecting the major components of the reward circuitry to pain suffering, including the nucleus accumbens, ventral tegmental area, and the medial prefrontal cortex; with especial attention dedicated to the evaluation of neuroplastic changes affecting these structures found in chronic pain syndromes, such as migraine, trigeminal neuropathic pain, chronic back pain, and fibromyalgia. PMID:29209204

  11. Rugged microelectronic module package supports circuitry on heat sink

    NASA Technical Reports Server (NTRS)

    Johnson, A. L.

    1966-01-01

    Rugged module package for thin film hybrid microcircuits incorporated a rigid, thermally conductive support structure, which serves as a heat sink, and a lead wire block in which T-shaped electrical connectors are potted. It protects the circuitry from shock and vibration loads, dissipates internal heat, and simplifies electrical connections between adjacent modules.

  12. Female-Specific Intergenerational Transmission Patterns of the Human Corticolimbic Circuitry

    PubMed Central

    Yamagata, Bun; Murayama, Kou; Black, Jessica M.; Hancock, Roeland; Mimura, Masaru; Yang, Tony T.; Reiss, Allan L.

    2016-01-01

    Parents have large genetic and environmental influences on offspring's cognition, behavior, and brain. These intergenerational effects are observed in mood disorders, with particularly robust association in depression between mothers and daughters. No studies have thus far examined the neural bases of these intergenerational effects in humans. Corticolimbic circuitry is known to be highly relevant in a wide range of processes, including mood regulation and depression. These findings suggest that corticolimbic circuitry may also show matrilineal transmission patterns. Therefore, we examined human parent–offspring association in this neurocircuitry and investigated the degree of association in gray matter volume between parent and offspring. We used voxelwise correlation analysis in a total of 35 healthy families, consisting of parents and their biological offspring. We found positive associations of regional gray matter volume in the corticolimbic circuit, including the amygdala, hippocampus, anterior cingulate cortex, and ventromedial prefrontal cortex between biological mothers and daughters. This association was significantly greater than mother–son, father–daughter, and father–son associations. The current study suggests that the corticolimbic circuitry, which has been implicated in mood regulation, shows a matrilineal-specific transmission patterns. Our preliminary findings are consistent with what has been found behaviorally in depression and may have clinical implications for disorders known to have dysfunction in mood regulation such as depression. Studies such as ours will likely bridge animal work examining gene expression in the brains and clinical symptom-based observations and provide promising ways to investigate intergenerational transmission patterns in the human brain. SIGNIFICANCE STATEMENT Parents have large genetic and environmental influences on the offspring, known as intergenerational effects. Specifically, depression has been shown to

  13. Parametric instabilities and their control in multidimensional nonuniform gain media

    NASA Astrophysics Data System (ADS)

    Charbonneau-Lefort, Mathieu; Afeyan, Bedros; Fejer, Martin

    2007-11-01

    In order to control parametric instabilities in large scale long pulse laser produced plasmas, optical mixing techniques seem most promising [1]. We examine ways of controlling the growth of some modes while creating other unstable ones in nonuniform gain media, including the effects of transverse localization of the pump wave. We show that multidimensional effects are essential to understand laser-gain medium interactions [2] and that one dimensional models such as the celebrated Rosenbluth result [3] can be misleading [4]. These findings are verified in experiments carried out in a chirped quasi-phase-matched gratings in optical parametric amplifiers where thousands of shots can be taken and statistically significant and stable results obtained. [1] B. Afeyan, et al., IFSA Proceedings, 2003. [2] M. M. Sushchik and G. I. Freidman, Radiofizika 13, 1354 (1970). [3] M. N. Rosenbluth, Phys. Rev. Lett. 29, 565 (1972). [4] M. Charbonneau-Lefort, PhD thesis, Stanford University, 2007.

  14. Reward value-based gain control: divisive normalization in parietal cortex.

    PubMed

    Louie, Kenway; Grattan, Lauren E; Glimcher, Paul W

    2011-07-20

    The representation of value is a critical component of decision making. Rational choice theory assumes that options are assigned absolute values, independent of the value or existence of other alternatives. However, context-dependent choice behavior in both animals and humans violates this assumption, suggesting that biological decision processes rely on comparative evaluation. Here we show that neurons in the monkey lateral intraparietal cortex encode a relative form of saccadic value, explicitly dependent on the values of the other available alternatives. Analogous to extra-classical receptive field effects in visual cortex, this relative representation incorporates target values outside the response field and is observed in both stimulus-driven activity and baseline firing rates. This context-dependent modulation is precisely described by divisive normalization, indicating that this standard form of sensory gain control may be a general mechanism of cortical computation. Such normalization in decision circuits effectively implements an adaptive gain control for value coding and provides a possible mechanistic basis for behavioral context-dependent violations of rationality.

  15. Separate Circuitries Encode the Hedonic and Nutritional Values of Sugar

    PubMed Central

    Tellez, Luis A.; Han, Wenfei; Zhang, Xiaobing; Ferreira, Tatiana L.; Perez, Isaac O.; Shammah-Lagnado, Sara J.; van den Pol, Anthony N.; de Araujo, Ivan E.

    2016-01-01

    Sugar exerts its potent reinforcing effects via both gustatory and post-ingestive pathways. It is however unknown if sweetness and nutritional signals engage segregated brain networks to motivate ingestion. We show in mice that separate basal ganglia circuitries mediate the hedonic and nutritional actions of sugar. We found that, during sugar intake, suppressing hedonic value inhibited dopamine release in ventral but not dorsal striatum, whereas suppressing nutritional value inhibited dopamine release in dorsal but not ventral striatum. Consistently, cell-specific ablation of dopamine-excitable cells in dorsal, but not ventral, striatum inhibited sugar’s ability to drive the ingestion of unpalatable solutions. Conversely, optogenetic stimulation of dopamine-excitable cells in dorsal, but not ventral, striatum substituted for sugar in its ability to drive the ingestion of unpalatable solutions. Our data demonstrate that sugar recruits a distributed dopamine-excitable striatal circuitry that acts to prioritize energy seeking over taste quality. PMID:26807950

  16. Separate circuitries encode the hedonic and nutritional values of sugar.

    PubMed

    Tellez, Luis A; Han, Wenfei; Zhang, Xiaobing; Ferreira, Tatiana L; Perez, Isaac O; Shammah-Lagnado, Sara J; van den Pol, Anthony N; de Araujo, Ivan E

    2016-03-01

    Sugar exerts its potent reinforcing effects via both gustatory and post-ingestive pathways. It is, however, unknown whether sweetness and nutritional signals engage segregated brain networks to motivate ingestion. We found in mice that separate basal ganglia circuitries mediated the hedonic and nutritional actions of sugar. During sugar intake, suppressing hedonic value inhibited dopamine release in ventral, but not dorsal, striatum, whereas suppressing nutritional value inhibited dopamine release in dorsal, but not ventral, striatum. Consistently, cell-specific ablation of dopamine-excitable cells in dorsal, but not ventral, striatum inhibited sugar's ability to drive the ingestion of unpalatable solutions. Conversely, optogenetic stimulation of dopamine-excitable cells in dorsal, but not ventral, striatum substituted for sugar in its ability to drive the ingestion of unpalatable solutions. Our data indicate that sugar recruits a distributed dopamine-excitable striatal circuitry that acts to prioritize energy-seeking over taste quality.

  17. Gain control by layer six in cortical circuits of vision.

    PubMed

    Olsen, Shawn R; Bortone, Dante S; Adesnik, Hillel; Scanziani, Massimo

    2012-02-22

    After entering the cerebral cortex, sensory information spreads through six different horizontal neuronal layers that are interconnected by vertical axonal projections. It is believed that through these projections layers can influence each other's response to sensory stimuli, but the specific role that each layer has in cortical processing is still poorly understood. Here we show that layer six in the primary visual cortex of the mouse has a crucial role in controlling the gain of visually evoked activity in neurons of the upper layers without changing their tuning to orientation. This gain modulation results from the coordinated action of layer six intracortical projections to superficial layers and deep projections to the thalamus, with a substantial role of the intracortical circuit. This study establishes layer six as a major mediator of cortical gain modulation and suggests that it could be a node through which convergent inputs from several brain areas can regulate the earliest steps of cortical visual processing.

  18. Presynaptic gain control by endogenous cotransmission of dopamine and GABA in the olfactory bulb.

    PubMed

    Vaaga, Christopher E; Yorgason, Jordan T; Williams, John T; Westbrook, Gary L

    2017-03-01

    In the olfactory bulb, lateral inhibition mediated by local juxtaglomerular interneurons has been proposed as a gain control mechanism, important for decorrelating odorant responses. Among juxtaglomerular interneurons, short axon cells are unique as dual-transmitter neurons that release dopamine and GABA. To examine their intraglomerular function, we expressed channelrhodopsin under control of the DAT-cre promoter and activated olfactory afferents within individual glomeruli. Optical stimulation of labeled cells triggered endogenous dopamine release as measured by cyclic voltammetry and GABA release as measured by whole cell GABA A receptor currents. Activation of short axon cells reduced the afferent presynaptic release probability via D 2 and GABA B receptor activation, resulting in reduced spiking in both mitral and external tufted cells. Our results suggest that short axon cells influence glomerular activity not only by direct inhibition of external tufted cells but also by inhibition of afferent inputs to external tufted and mitral cells. NEW & NOTEWORTHY Sensory systems, including the olfactory system, encode information across a large dynamic range, making synaptic mechanisms of gain control critical to proper function. Here we demonstrate that a dual-transmitter interneuron in the olfactory bulb controls the gain of intraglomerular afferent input via two distinct mechanisms, presynaptic inhibition as well as inhibition of a principal neuron subtype, and thereby potently controls the synaptic gain of afferent inputs. Copyright © 2017 the American Physiological Society.

  19. A new adjustable gains for second order sliding mode control of saturated DFIG-based wind turbine

    NASA Astrophysics Data System (ADS)

    Bounadja, E.; Djahbar, A.; Taleb, R.; Boudjema, Z.

    2017-02-01

    The control of Doubly-Fed induction generator (DFIG), used in wind energy conversion, has been given a great deal of interest. Frequently, this control has been dealt with ignoring the magnetic saturation effect in the DFIG model. The aim of the present work is twofold: firstly, the magnetic saturation effect is accounted in the control design model; secondly, a new second order sliding mode control scheme using adjustable-gains (AG-SOSMC) is proposed to control the DFIG via its rotor side converter. This scheme allows the independent control of the generated active and reactive power. Conventionally, the second order sliding mode control (SOSMC) applied to the DFIG, utilize the super-twisting algorithm with fixed gains. In the proposed AG-SOSMC, a simple means by which the controller can adjust its behavior is used. For that, a linear function is used to represent the variation in gain as a function of the absolute value of the discrepancy between the reference rotor current and its measured value. The transient DFIG speed response using the aforementioned characteristic is compared with the one determined by using the conventional SOSMC controller with fixed gains. Simulation results show, accurate dynamic performances, quicker transient response and more accurate control are achieved for different operating conditions.

  20. Transfer Function Control for Biometric Monitoring System

    NASA Technical Reports Server (NTRS)

    Chmiel, Alan J. (Inventor); Grodinsky, Carlos M. (Inventor); Humphreys, Bradley T. (Inventor)

    2015-01-01

    A modular apparatus for acquiring biometric data may include circuitry operative to receive an input signal indicative of a biometric condition, the circuitry being configured to process the input signal according to a transfer function thereof and to provide a corresponding processed input signal. A controller is configured to provide at least one control signal to the circuitry to programmatically modify the transfer function of the modular system to facilitate acquisition of the biometric data.

  1. Neuro-adaptive backstepping control of SISO non-affine systems with unknown gain sign.

    PubMed

    Ramezani, Zahra; Arefi, Mohammad Mehdi; Zargarzadeh, Hassan; Jahed-Motlagh, Mohammad Reza

    2016-11-01

    This paper presents two neuro-adaptive controllers for a class of uncertain single-input, single-output (SISO) nonlinear non-affine systems with unknown gain sign. The first approach is state feedback controller, so that a neuro-adaptive state-feedback controller is constructed based on the backstepping technique. The second approach is an observer-based controller and K-filters are designed to estimate the system states. The proposed method relaxes a priori knowledge of control gain sign and therefore by utilizing the Nussbaum-type functions this problem is addressed. In these methods, neural networks are employed to approximate the unknown nonlinear functions. The proposed adaptive control schemes guarantee that all the closed-loop signals are semi-globally uniformly ultimately bounded (SGUUB). Finally, the theoretical results are numerically verified through simulation examples. Simulation results show the effectiveness of the proposed methods. Copyright © 2016 ISA. All rights reserved.

  2. The effects of control-display gain on performance of race car drivers in an isometric braking task.

    PubMed

    de Winter, J C F; de Groot, S

    2012-12-01

    To minimise lap times during car racing, it is important to build up brake forces rapidly and maintain precise control. We examined the effect of the amplification factor (gain) between brake pedal force and a visually represented output value on a driver's ability to track a target value. The test setup was a formula racing car cockpit fitted with an isometric brake pedal. Thirteen racing drivers performed tracking tasks with four control-display gains and two target functions: a step function (35 trials per gain) and a multisine function (15 trials per gain). The control-display gain had only minor effects on root mean-squared error between output value and target value, but it had large effects on build-up speed, overshoot, within-participants variability, and self-reported physical load. The results confirm the hypothesis that choosing an optimum gain involves balancing stability against physical effort.

  3. Reward Circuitry Function in Autism during Face Anticipation and Outcomes

    ERIC Educational Resources Information Center

    Dichter, Gabriel S.; Richey, J. Anthony; Rittenberg, Alison M.; Sabatino, Antoinette; Bodfish, James W.

    2012-01-01

    The aim of this study was to investigate reward circuitry responses in autism during reward anticipation and outcomes for monetary and social rewards. During monetary anticipation, participants with autism spectrum disorders (ASDs) showed hypoactivation in right nucleus accumbens and hyperactivation in right hippocampus, whereas during monetary…

  4. Association between subthalamic nucleus deep brain stimulation and weight gain: Results of a case-control study.

    PubMed

    Strowd, Roy E; Herco, Maja; Passmore-Griffin, Leah; Avery, Bradley; Haq, Ihtsham; Tatter, Stephen B; Tate, Jessica; Siddiqui, Mustafa S

    2016-01-01

    To evaluate whether weight change in patients with Parkinson's disease (PD) is different in those undergoing deep brain stimulation (DBS) of the subthalamic nucleus (STN) compared to those not undergoing DBS. A retrospective case-control study was performed in PD patients who had undergone STN DBS (cases) compared to matched PD patients without DBS (controls). Demographic and clinical data including Unified Parkinson's Disease Rating Scale (UPDRS) motor scores were collected. Repeated measures mixed model regression was used to identify variables associated with weight gain. Thirty-five cases and 34 controls were identified. Baseline age, gender, diagnosis and weight were similar. Duration of diagnosis was longer in cases (6.3 vs 4.9 years, p=0.0015). At 21.3 months, cases gained 2.9 kg (+4.65%) while controls lost 1.8 kg (-3.05%, p<0.02). Postoperative UPDRS motor scores improved by 49% indicating surgical efficacy. Only younger age (p=0.0002) and DBS (p=0.008) were significantly associated with weight gain. In this case-control study, PD patients undergoing STN DBS experienced post-operative weight gain that was significantly different from the weight loss observed in non-DBS PD controls. Patients, especially overweight individuals, should be informed that STN DBS can result in weight gain. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Heterogeneity of neuroblastoma cell identity defined by transcriptional circuitries.

    PubMed

    Boeva, Valentina; Louis-Brennetot, Caroline; Peltier, Agathe; Durand, Simon; Pierre-Eugène, Cécile; Raynal, Virginie; Etchevers, Heather C; Thomas, Sophie; Lermine, Alban; Daudigeos-Dubus, Estelle; Geoerger, Birgit; Orth, Martin F; Grünewald, Thomas G P; Diaz, Elise; Ducos, Bertrand; Surdez, Didier; Carcaboso, Angel M; Medvedeva, Irina; Deller, Thomas; Combaret, Valérie; Lapouble, Eve; Pierron, Gaelle; Grossetête-Lalami, Sandrine; Baulande, Sylvain; Schleiermacher, Gudrun; Barillot, Emmanuel; Rohrer, Hermann; Delattre, Olivier; Janoueix-Lerosey, Isabelle

    2017-09-01

    Neuroblastoma is a tumor of the peripheral sympathetic nervous system, derived from multipotent neural crest cells (NCCs). To define core regulatory circuitries (CRCs) controlling the gene expression program of neuroblastoma, we established and analyzed the neuroblastoma super-enhancer landscape. We discovered three types of identity in neuroblastoma cell lines: a sympathetic noradrenergic identity, defined by a CRC module including the PHOX2B, HAND2 and GATA3 transcription factors (TFs); an NCC-like identity, driven by a CRC module containing AP-1 TFs; and a mixed type, further deconvoluted at the single-cell level. Treatment of the mixed type with chemotherapeutic agents resulted in enrichment of NCC-like cells. The noradrenergic module was validated by ChIP-seq. Functional studies demonstrated dependency of neuroblastoma with noradrenergic identity on PHOX2B, evocative of lineage addiction. Most neuroblastoma primary tumors express TFs from the noradrenergic and NCC-like modules. Our data demonstrate a previously unknown aspect of tumor heterogeneity relevant for neuroblastoma treatment strategies.

  6. Controlled mass pollination in loblolly pine to increase genetic gains

    Treesearch

    F.E. Bridgwater; D.L. Bramlett; T.D. Byram; W.J. Lowe

    1998-01-01

    Controlled mass pollination (CMP) is one way to increase genetic gains from traditional wind-pollinated seed orchards. Methodology is under development by several forestry companies in the southern USA. Costs of CMP depend on the efficient installation, pollination, and removal of inexpensive paper bags. Even in pilot-scale studies these costs seem reasonable. Net...

  7. Switched Fuzzy-PD Control of Contact Forces in Robotic Microbiomanipulation.

    PubMed

    Zhang, Weize; Dong, Xianke; Liu, Xinyu

    2017-05-01

    Force sensing and control are of paramount importance in robotic micromanipulation. A contact force regulator capable of accurately applying mechanical stimuli to a live Drosophila larva could greatly facilitate mechanobiology research on Drosophila and may eventually lead to novel discoveries in mechanotransduction mechanisms of neuronal circuitries. In this paper, we present a novel contact force control scheme implemented in an automated Drosophila larvae micromanipulation system, featuring a switched fuzzy to proportional-differential (PD) controller and a noise-insensitive extended high gain observer (EHGO). The switched fuzzy-PD control law inherits the fast convergence of fuzzy control and overcomes its drawbacks such as large overshoot and steady-state oscillation. The noise-insensitive EHGO can reliably estimate system modeling errors and is robust to force measurement noises, which is advantageous over conventional high gain observers (sensitive to signal noises). Force control experiments show that, compared to a proportional-integral-differential (PID) controller, this new force control scheme significantly enhances the system dynamic performance in terms of rising time, overshoot, and oscillation. The developed robotic system and the force control scheme will be applied to mechanical stimulation and fluorescence imaging of Drosophila larvae for identifying new mechanotransduction mechanisms.

  8. Controlling the gain contribution of background emitters in few-quantum-dot microlasers

    NASA Astrophysics Data System (ADS)

    Gericke, F.; Segnon, M.; von Helversen, M.; Hopfmann, C.; Heindel, T.; Schneider, C.; Höfling, S.; Kamp, M.; Musiał, A.; Porte, X.; Gies, C.; Reitzenstein, S.

    2018-02-01

    We provide experimental and theoretical insight into single-emitter lasing effects in a quantum dot (QD)-microlaser under controlled variation of background gain provided by off-resonant discrete gain centers. For that purpose, we apply an advanced two-color excitation concept where the background gain contribution of off-resonant QDs can be continuously tuned by precisely balancing the relative excitation power of two lasers emitting at different wavelengths. In this way, by selectively exciting a single resonant QD and off-resonant QDs, we identify distinct single-QD signatures in the lasing characteristics and distinguish between gain contributions of a single resonant emitter and a countable number of off-resonant background emitters to the optical output of the microlaser. Our work addresses the important question whether single-QD lasing is feasible in experimentally accessible systems and shows that, for the investigated microlaser, the single-QD gain needs to be supported by the background gain contribution of off-resonant QDs to reach the transition to lasing. Interestingly, while a single QD cannot drive the investigated micropillar into lasing, its relative contribution to the emission can be as high as 70% and it dominates the statistics of emitted photons in the intermediate excitation regime below threshold.

  9. Switched-Observer-Based Adaptive Neural Control of MIMO Switched Nonlinear Systems With Unknown Control Gains.

    PubMed

    Long, Lijun; Zhao, Jun

    2017-07-01

    In this paper, the problem of adaptive neural output-feedback control is addressed for a class of multi-input multioutput (MIMO) switched uncertain nonlinear systems with unknown control gains. Neural networks (NNs) are used to approximate unknown nonlinear functions. In order to avoid the conservativeness caused by adoption of a common observer for all subsystems, an MIMO NN switched observer is designed to estimate unmeasurable states. A new switched observer-based adaptive neural control technique for the problem studied is then provided by exploiting the classical average dwell time (ADT) method and the backstepping method and the Nussbaum gain technique. It effectively handles the obstacle about the coexistence of multiple Nussbaum-type function terms, and improves the classical ADT method, since the exponential decline property of Lyapunov functions for individual subsystems is no longer satisfied. It is shown that the technique proposed is able to guarantee semiglobal uniformly ultimately boundedness of all the signals in the closed-loop system under a class of switching signals with ADT, and the tracking errors converge to a small neighborhood of the origin. The effectiveness of the approach proposed is illustrated by its application to a two inverted pendulum system.

  10. Modeling lateral geniculate nucleus response with contrast gain control. Part 2: Analysis

    PubMed Central

    Cope, Davis; Blakeslee, Barbara; McCourt, Mark E.

    2014-01-01

    Cope, Blakeslee and McCourt (2013) proposed a class of models for LGN ON-cell behavior consisting of a linear response with divisive normalization by local stimulus contrast. Here we analyze a specific model with the linear response defined by a difference-of-Gaussians filter and a circular Gaussian for the gain pool weighting function. For sinusoidal grating stimuli, the parameter region for band-pass behavior of the linear response is determined, the gain control response is shown to act as a switch (changing from “off” to “on” with increasing spatial frequency), and it is shown that large gain pools stabilize the optimal spatial frequency of the total nonlinear response at a fixed value independent of contrast and stimulus magnitude. Under- and super-saturation as well as contrast saturation occur as typical effects of stimulus magnitude. For circular spot stimuli, it is shown that large gain pools stabilize the spot size that yields the maximum response. PMID:24562034

  11. Robust Gain-Scheduled Fault Tolerant Control for a Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Shin, Jong-Yeob; Gregory, Irene

    2007-01-01

    This paper presents an application of robust gain-scheduled control concepts using a linear parameter-varying (LPV) control synthesis method to design fault tolerant controllers for a civil transport aircraft. To apply the robust LPV control synthesis method, the nonlinear dynamics must be represented by an LPV model, which is developed using the function substitution method over the entire flight envelope. The developed LPV model associated with the aerodynamic coefficient uncertainties represents nonlinear dynamics including those outside the equilibrium manifold. Passive and active fault tolerant controllers (FTC) are designed for the longitudinal dynamics of the Boeing 747-100/200 aircraft in the presence of elevator failure. Both FTC laws are evaluated in the full nonlinear aircraft simulation in the presence of the elevator fault and the results are compared to show pros and cons of each control law.

  12. Caenorhabditis elegans Male Copulation Circuitry Incorporates Sex-Shared Defecation Components To Promote Intromission and Sperm Transfer

    PubMed Central

    LeBoeuf, Brigitte; Garcia, L. Rene

    2016-01-01

    Sexual dimorphism can be achieved using a variety of mechanisms, including sex-specific circuits and sex-specific function of shared circuits, though how these work together to produce sexually dimorphic behaviors requires further investigation. Here, we explore how components of the sex-shared defecation circuitry are incorporated into the sex-specific male mating circuitry in Caenorhabditis elegans to produce successful copulation. Using behavioral studies, calcium imaging, and genetic manipulation, we show that aspects of the defecation system are coopted by the male copulatory circuitry to facilitate intromission and ejaculation. Similar to hermaphrodites, male defecation is initiated by an intestinal calcium wave, but circuit activity is coordinated differently during mating. In hermaphrodites, the tail neuron DVB promotes expulsion of gut contents through the release of the neurotransmitter GABA onto the anal depressor muscle. However, in the male, both neuron and muscle take on modified functions to promote successful copulation. Males require calcium-dependent activator protein for secretion (CAPS)/unc-31, a dense core vesicle exocytosis activator protein, in the DVB to regulate copulatory spicule insertion, while the anal depressor is remodeled to promote release of sperm into the hermaphrodite. This work shows how sex-shared circuitry is modified in multiple ways to contribute to sex-specific mating. PMID:28031243

  13. A Wirelessly Powered Smart Contact Lens with Reconfigurable Wide Range and Tunable Sensitivity Sensor Readout Circuitry

    PubMed Central

    Chiou, Jin-Chern; Hsu, Shun-Hsi; Huang, Yu-Chieh; Yeh, Guan-Ting; Liou, Wei-Ting; Kuei, Cheng-Kai

    2017-01-01

    This study presented a wireless smart contact lens system that was composed of a reconfigurable capacitive sensor interface circuitry and wirelessly powered radio-frequency identification (RFID) addressable system for sensor control and data communication. In order to improve compliance and reduce user discomfort, a capacitive sensor was embedded on a soft contact lens of 200 μm thickness using commercially available bio-compatible lens material and a standard manufacturing process. The results indicated that the reconfigurable sensor interface achieved sensitivity and baseline tuning up to 120 pF while consuming only 110 μW power. The range and sensitivity tuning of the readout circuitry ensured a reliable operation with respect to sensor fabrication variations and independent calibration of the sensor baseline for individuals. The on-chip voltage scaling allowed the further extension of the detection range and prevented the implementation of large on-chip elements. The on-lens system enabled the detection of capacitive variation caused by pressure changes in the range of 2.25 to 30 mmHg and hydration level variation from a distance of 1 cm using incident power from an RFID reader at 26.5 dBm. PMID:28067859

  14. Motivation by potential gains and losses affects control processes via different mechanisms in the attentional network.

    PubMed

    Paschke, Lena M; Walter, Henrik; Steimke, Rosa; Ludwig, Vera U; Gaschler, Robert; Schubert, Torsten; Stelzel, Christine

    2015-05-01

    Attentional control in demanding cognitive tasks can be improved by manipulating the motivational state. Motivation to obtain gains and motivation to avoid losses both usually result in faster reaction times and stronger activation in relevant brain areas such as the prefrontal cortex, but little is known about differences in the underlying neurocognitive mechanisms of these types of motivation in an attentional control context. In the present functional magnetic resonance imaging (fMRI) study, we tested whether potential gain and loss as motivating incentives lead to overlapping or distinct neural effects in the attentional network, and whether one of these conditions is more effective than the other. A Flanker task with word stimuli as targets and distracters was performed by 115 healthy participants. Using a mixed blocked and event-related design allowed us to investigate transient and sustained motivation-related effects. Participants could either gain money (potential gain) or avoid losing money (potential loss) in different task blocks. Participants showed a congruency effect with increased reaction times for incongruent compared to congruent trials. Potential gain led to generally faster responses compared to the neutral condition and to stronger improvements than potential loss. Potential loss also led to shorter response times compared to the neutral condition, but participants improved mainly during incongruent and not during congruent trials. The event-related fMRI data revealed a main effect of congruency with increased activity in the left inferior frontal gyrus (IFG) and inferior frontal junction area (IFJ), the pre-supplementary motor area (pre-SMA), bilateral insula, intraparietal sulcus (IPS) and visual word form area (VWFA). While potential gain led to increased activity in a cluster of the IFJ and the VWFA only during incongruent trials, potential loss was linked to activity increases in these regions during incongruent and congruent trials. The

  15. Elearning approaches to prevent weight gain in young adults: A randomized controlled study.

    PubMed

    Nikolaou, Charoula Konstantia; Hankey, Catherine Ruth; Lean, Michael Ernest John

    2015-12-01

    Preventing obesity among young adults should be a preferred public health approach given the limited efficacy of treatment interventions. This study examined whether weight gain can be prevented by online approaches using two different behavioral models, one overtly directed at obesity and the other covertly. A three-group parallel randomized controlled intervention was conducted in 2012-2013; 20,975 young adults were allocated a priori to one control and two "treatment" groups. Two treatment groups were offered online courses over 19 weeks on (1) personal weight control ("Not the Ice Cream Van," NTICV) and, (2) political, environmental, and social issues around food ("Goddess Demetra," "GD"). Control group received no contact. The primary outcome was weight change over 40 weeks. Within-group 40-week weight changes were different between groups (P < 0.001): Control (n = 2,134): +2.0 kg (95% CI = 1.5, 2.3 kg); NTICV (n = 1,810): -1.0 kg (95% CI = -1.3, -0.5); and GD (n = 2,057): -1.35 kg (95% CI = -1.4 to -0.7). Relative risks for weight gain vs. NTICV = 0.13 kg (95% CI = 0.10, 0.15), P < 0.0001; GD = 0.07 kg (95% CI = 0.05, 0.10), P < 0.0001. Both interventions were associated with prevention of the weight gain observed among control subjects. This low-cost intervention could be widely transferable as one tool against the obesity epidemic. Outside the randomized controlled trial setting, it could be enhanced using supporting advertising and social media. © 2015 The Obesity Society.

  16. Neuroimaging in attention-deficit hyperactivity disorder: beyond the frontostriatal circuitry.

    PubMed

    Cherkasova, Mariya V; Hechtman, Lily

    2009-10-01

    To review the findings of structural and functional neuroimaging studies in attention-deficit hyperactivity disorder (ADHD), with a focus on abnormalities reported in brain regions that lie outside the frontostriatal circuitry, which is currently believed to play a central role in the pathophysiology of ADHD. Relevant publications were found primarily by searching the MEDLINE and PubMed databases using the keywords ADHD and the abbreviations of magnetic resonance imaging (MRI), functional MRI, positron emission tomography, and single photon emission computed tomography. The reference lists of the articles found through the databases were then reviewed for the purpose of finding additional articles. There is now substantial evidence of structural and functional alterations in regions outside the frontostriatal circuitry in ADHD, most notably in the cerebellum and the parietal lobes. Although there is compelling evidence suggesting that frontostriatal dysfunction may be central to the pathophysiology of ADHD, the neuroimaging findings point to distributed neural substrates rather than a single one. More research is needed to elucidate the nature of contributions of nonfrontostriatal regions to the pathophysiology of ADHD.

  17. Inhibitory control gains from higher-order cognitive strategy training.

    PubMed

    Motes, Michael A; Gamino, Jacquelyn F; Chapman, Sandra B; Rao, Neena K; Maguire, Mandy J; Brier, Matthew R; Kraut, Michael A; Hart, John

    2014-02-01

    The present study examined the transfer of higher-order cognitive strategy training to inhibitory control. Middle school students enrolled in a comprehension- and reasoning-focused cognitive strategy training program and passive controls participated. The training program taught students a set of steps for inferring essential gist or themes from materials. Both before and after training or a comparable duration in the case of the passive controls, participants completed a semantically cued Go/No-Go task that was designed to assess the effects of depth of semantic processing on response inhibition and components of event-related potentials (ERP) related to response inhibition. Depth of semantic processing was manipulated by varying the level of semantic categorization required for response selection and inhibition. The SMART-trained group showed inhibitory control gains and changes in fronto-central P3 ERP amplitudes on inhibition trials; whereas, the control group did not. The results provide evidence of the transfer of higher-order cognitive strategy training to inhibitory control and modulation of ERPs associated with semantically cued inhibitory control. The findings are discussed in terms of implications for cognitive strategy training, models of cognitive abilities, and education. Published by Elsevier Inc.

  18. Binocular contrast-gain control for natural scenes: Image structure and phase alignment.

    PubMed

    Huang, Pi-Chun; Dai, Yu-Ming

    2018-05-01

    In the context of natural scenes, we applied the pattern-masking paradigm to investigate how image structure and phase alignment affect contrast-gain control in binocular vision. We measured the discrimination thresholds of bandpass-filtered natural-scene images (targets) under various types of pedestals. Our first experiment had four pedestal types: bandpass-filtered pedestals, unfiltered pedestals, notch-filtered pedestals (which enabled removal of the spatial frequency), and misaligned pedestals (which involved rotation of unfiltered pedestals). Our second experiment featured six types of pedestals: bandpass-filtered, unfiltered, and notch-filtered pedestals, and the corresponding phase-scrambled pedestals. The thresholds were compared for monocular, binocular, and dichoptic viewing configurations. The bandpass-filtered pedestal and unfiltered pedestals showed classic dipper shapes; the dipper shapes of the notch-filtered, misaligned, and phase-scrambled pedestals were weak. We adopted a two-stage binocular contrast-gain control model to describe our results. We deduced that the phase-alignment information influenced the contrast-gain control mechanism before the binocular summation stage and that the phase-alignment information and structural misalignment information caused relatively strong divisive inhibition in the monocular and interocular suppression stages. When the pedestals were phase-scrambled, the elimination of the interocular suppression processing was the most convincing explanation of the results. Thus, our results indicated that both phase-alignment information and similar image structures cause strong interocular suppression. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Gain dynamics of clad-pumped Yb-fiber amplifier and intensity noise control.

    PubMed

    Zhao, Jian; Guiraud, Germain; Floissat, Florian; Gouhier, Benoit; Rota-Rodrigo, Sergio; Traynor, Nicholas; Santarelli, Giorgio

    2017-01-09

    Gain dynamics study provides an attractive method to understand the intensity noise behavior in fiber amplifiers. Here, the gain dynamics of a medium power (5 W) clad-pumped Yb-fiber amplifier is experimentally evaluated by measuring the frequency domain transfer functions for the input seed and pump lasers from 10 Hz to 1 MHz. We study gain dynamic behavior of the fiber amplifier in the presence of significant residual pump power (compared to the seed power), showing that the seed transfer function is strongly saturated at low Fourier frequencies while the pump power modulation transfer function is nearly unaffected. The characterization of relative intensity noise (RIN) of the fiber amplifier is well explained by the gain dynamics analysis. Finally, a 600 kHz bandwidth feedback loop using an acoustic-optical modulator (AOM) controlling the seed intensity is successfully demonstrated to suppress the broadband laser intensity noise. A maximum noise reduction of about 30 dB is achieved leading to a RIN of -152 dBc/Hz (~1 kHz-10 MHz) at 2.5 W output power.

  20. HIV-1 proteins dysregulate motivational processes and dopamine circuitry.

    PubMed

    Bertrand, Sarah J; Mactutus, Charles F; Harrod, Steven B; Moran, Landhing M; Booze, Rosemarie M

    2018-05-18

    Motivational alterations, such as apathy, in HIV-1+ individuals are associated with decreased performance on tasks involving frontal-subcortical circuitry. We used the HIV-1 transgenic (Tg) rat to assess effect of long-term HIV-1 protein exposure on motivated behavior using sucrose (1-30%, w/v) and cocaine (0.01-1.0 mg/kg/infusion) maintained responding with fixed-ratio (FR) and progressive-ratio (PR) schedules of reinforcement. For sucrose-reinforced responding, HIV-1 Tg rats displayed no change in EC 50 relative to controls, suggesting no change in sucrose reinforcement but had a downward shifted concentration-response curves, suggesting a decrease in response vigor. Cocaine-maintained responding was attenuated in HIV-1 Tg rats (FR1 0.33 mg/kg/infusion and PR 1.0 mg/kg/infusion). Dose-response tests (PR) revealed that HIV-1 Tg animals responded significantly less than F344 control rats and failed to earn significantly more infusions of cocaine as the unit dose increased. When choosing between cocaine and sucrose, control rats initially chose sucrose but with time shifted to a cocaine preference. In contrast, HIV-1 disrupted choice behaviors. DAT function was altered in the striatum of HIV-1 Tg rats; however, prior cocaine self-administration produced a unique effect on dopamine homeostasis in the HIV-1 Tg striatum. These findings of altered goal directed behaviors may determine neurobiological mechanisms of apathy in HIV-1+ patients.

  1. Mechanisms of Long Non-Coding RNAs in the Assembly and Plasticity of Neural Circuitry.

    PubMed

    Wang, Andi; Wang, Junbao; Liu, Ying; Zhou, Yan

    2017-01-01

    The mechanisms underlying development processes and functional dynamics of neural circuits are far from understood. Long non-coding RNAs (lncRNAs) have emerged as essential players in defining identities of neural cells, and in modulating neural activities. In this review, we summarized latest advances concerning roles and mechanisms of lncRNAs in assembly, maintenance and plasticity of neural circuitry, as well as lncRNAs' implications in neurological disorders. We also discussed technical advances and challenges in studying functions and mechanisms of lncRNAs in neural circuitry. Finally, we proposed that lncRNA studies would advance our understanding on how neural circuits develop and function in physiology and disease conditions.

  2. Cognitive Control of Eating: the Role of Memory in Appetite and Weight Gain.

    PubMed

    Higgs, Suzanne; Spetter, Maartje S

    2018-03-01

    The present review organises the recent literature on the role of memory in eating behaviours and provides an overview of the current evidence relating to the associations between memory and weight gain. Research over the last few years has highlighted working memory as an important cognitive process that underpins many aspects of appetite control. Recent work on episodic memory and appetite has replicated work showing that manipulating memory for recent eating affects later consumption and extended this work to examine associations between individual differences in memory and eating behaviours. Poorer episodic memory ability is related to a reduced sensitivity to internal states of hunger and satiety and a tendency towards uncontrolled eating. There is also recent evidence to suggest that working memory and episodic memory impairments are related to weight gain and high BMI. Working memory and episodic memory are core cognitive processes that are critical for food-related decision-making, and disruption to these processes contributes to problems with appetite control and weight gain, which suggests that weight loss programmes might be improved by the addition of cognitive training.

  3. Application of automatic gain control for radiometer diagnostic in SST-1 tokamak.

    PubMed

    Makwana, Foram R; Siju, Varsha; Edappala, Praveenlal; Pathak, S K

    2017-12-01

    This paper describes the characterisation of a negative feedback type of automatic gain control (AGC) circuit that will be an integral part of the heterodyne radiometer system operating at a frequency range of 75-86 GHz at SST-1 tokamak. The developed AGC circuit is a combination of variable gain amplifier and log amplifier which provides both gain and attenuation typically up to 15 dB and 45 dB, respectively, at a fixed set point voltage and it has been explored for the first time in tokamak radiometry application. The other important characteristics are that it exhibits a very fast response time of 390 ns to understand the fast dynamics of electron cyclotron emission and can operate at very wide input RF power dynamic range of around 60 dB that ensures signal level within the dynamic range of the detection system.

  4. Reduced state feedback gain computation. [optimization and control theory for aircraft control

    NASA Technical Reports Server (NTRS)

    Kaufman, H.

    1976-01-01

    Because application of conventional optimal linear regulator theory to flight controller design requires the capability of measuring and/or estimating the entire state vector, it is of interest to consider procedures for computing controls which are restricted to be linear feedback functions of a lower dimensional output vector and which take into account the presence of measurement noise and process uncertainty. Therefore, a stochastic linear model that was developed is presented which accounts for aircraft parameter and initial uncertainty, measurement noise, turbulence, pilot command and a restricted number of measurable outputs. Optimization with respect to the corresponding output feedback gains was performed for both finite and infinite time performance indices without gradient computation by using Zangwill's modification of a procedure originally proposed by Powell. Results using a seventh order process show the proposed procedures to be very effective.

  5. Reward circuitry dysfunction in psychiatric and neurodevelopmental disorders and genetic syndromes: animal models and clinical findings.

    PubMed

    Dichter, Gabriel S; Damiano, Cara A; Allen, John A

    2012-07-06

    This review summarizes evidence of dysregulated reward circuitry function in a range of neurodevelopmental and psychiatric disorders and genetic syndromes. First, the contribution of identifying a core mechanistic process across disparate disorders to disease classification is discussed, followed by a review of the neurobiology of reward circuitry. We next consider preclinical animal models and clinical evidence of reward-pathway dysfunction in a range of disorders, including psychiatric disorders (i.e., substance-use disorders, affective disorders, eating disorders, and obsessive compulsive disorders), neurodevelopmental disorders (i.e., schizophrenia, attention-deficit/hyperactivity disorder, autism spectrum disorders, Tourette's syndrome, conduct disorder/oppositional defiant disorder), and genetic syndromes (i.e., Fragile X syndrome, Prader-Willi syndrome, Williams syndrome, Angelman syndrome, and Rett syndrome). We also provide brief overviews of effective psychopharmacologic agents that have an effect on the dopamine system in these disorders. This review concludes with methodological considerations for future research designed to more clearly probe reward-circuitry dysfunction, with the ultimate goal of improved intervention strategies.

  6. Reward circuitry dysfunction in psychiatric and neurodevelopmental disorders and genetic syndromes: animal models and clinical findings

    PubMed Central

    2012-01-01

    This review summarizes evidence of dysregulated reward circuitry function in a range of neurodevelopmental and psychiatric disorders and genetic syndromes. First, the contribution of identifying a core mechanistic process across disparate disorders to disease classification is discussed, followed by a review of the neurobiology of reward circuitry. We next consider preclinical animal models and clinical evidence of reward-pathway dysfunction in a range of disorders, including psychiatric disorders (i.e., substance-use disorders, affective disorders, eating disorders, and obsessive compulsive disorders), neurodevelopmental disorders (i.e., schizophrenia, attention-deficit/hyperactivity disorder, autism spectrum disorders, Tourette’s syndrome, conduct disorder/oppositional defiant disorder), and genetic syndromes (i.e., Fragile X syndrome, Prader–Willi syndrome, Williams syndrome, Angelman syndrome, and Rett syndrome). We also provide brief overviews of effective psychopharmacologic agents that have an effect on the dopamine system in these disorders. This review concludes with methodological considerations for future research designed to more clearly probe reward-circuitry dysfunction, with the ultimate goal of improved intervention strategies. PMID:22958744

  7. Spaceflight induces changes in the synaptic circuitry of the postnatal developing neocortex

    NASA Technical Reports Server (NTRS)

    DeFelipe, J.; Arellano, J. I.; Merchan-Perez, A.; Gonzalez-Albo, M. C.; Walton, K.; Llinas, R.

    2002-01-01

    The establishment of the adult pattern of neocortical circuitry depends on various intrinsic and extrinsic factors, whose modification during development can lead to alterations in cortical organization and function. We report the effect of 16 days of spaceflight [Neurolab mission; from postnatal day 14 (P14) to P30] on the neocortical representation of the hindlimb synaptic circuitry in rats. As a result, we show, for the first time, that development in microgravity leads to changes in the number and morphology of cortical synapses in a laminar-specific manner. In the layers II/III and Va, the synaptic cross-sectional lengths were significantly larger in flight animals than in ground control animals. Flight animals also showed significantly lower synaptic densities in layers II/III, IV and Va. The greatest difference was found in layer II/III, where there was a difference of 344 million synapses per mm(3) (15.6% decrease). Furthermore, after a 4 month period of re-adaptation to terrestrial gravity, some changes disappeared (i.e. the alterations were transient), while conversely, some new differences also appeared. For example, significant differences in synaptic density in layers II/III and Va after re-adaptation were no longer observed, whereas in layer IV the density of synapses increased notably in flight animals (a difference of 185 million synapses per mm(3) or 13.4%). In addition, all the changes observed only affected asymmetrical synapses, which are known to be excitatory. These results indicates that terrestrial gravity is a necessary environmental parameter for normal cortical synaptogenesis. These findings are fundamental in planning future long-term spaceflights.

  8. Automatic gain control of neural coupling during cooperative hand movements.

    PubMed

    Thomas, F A; Dietz, V; Schrafl-Altermatt, M

    2018-04-13

    Cooperative hand movements (e.g. opening a bottle) are controlled by a task-specific neural coupling, reflected in EMG reflex responses contralateral to the stimulation site. In this study the contralateral reflex responses in forearm extensor muscles to ipsilateral ulnar nerve stimulation was analyzed at various resistance and velocities of cooperative hand movements. The size of contralateral reflex responses was closely related to the level of forearm muscle activation required to accomplish the various cooperative hand movement tasks. This indicates an automatic gain control of neural coupling that allows a rapid matching of corrective forces exerted at both sides of an object with the goal 'two hands one action'.

  9. Determinants of weight gain in the action to control cardiovascular risk in diabetes trial.

    PubMed

    Fonseca, Vivian; McDuffie, Roberta; Calles, Jorge; Cohen, Robert M; Feeney, Patricia; Feinglos, Mark; Gerstein, Hertzel C; Ismail-Beigi, Faramarz; Morgan, Timothy M; Pop-Busui, Rodica; Riddle, Matthew C

    2013-08-01

    Identify determinants of weight gain in people with type 2 diabetes mellitus (T2DM) allocated to intensive versus standard glycemic control in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial. We studied determinants of weight gain over 2 years in 8,929 participants (4,425 intensive arm and 4,504 standard arm) with T2DM in the ACCORD trial. We used general linear models to examine the association between each baseline characteristic and weight change at the 2-year visit. We fit a linear regression of change in weight and A1C and used general linear models to examine the association between each medication at baseline and weight change at the 2-year visit, stratified by glycemia allocation. There was significantly more weight gain in the intensive glycemia arm of the trial compared with the standard arm (3.0 ± 7.0 vs. 0.3 ± 6.3 kg). On multivariate analysis, younger age, male sex, Asian race, no smoking history, high A1C, baseline BMI of 25-35, high waist circumference, baseline insulin use, and baseline metformin use were independently associated with weight gain over 2 years. Reduction of A1C from baseline was consistently associated with weight gain only when baseline A1C was elevated. Medication usage accounted for <15% of the variability of weight change, with initiation of thiazolidinedione (TZD) use the most prominent factor. Intensive participants who never took insulin or a TZD had an average weight loss of 2.9 kg during the first 2 years of the trial. In contrast, intensive participants who had never previously used insulin or TZD but began this combination after enrolling in the ACCORD trial had a weight gain of 4.6-5.3 kg at 2 years. Weight gain in ACCORD was greater with intensive than with standard treatment and generally associated with reduction of A1C from elevated baseline values. Initiation of TZD and/or insulin therapy was the most important medication-related factor associated with weight gain.

  10. Sensory gain control (amplification) as a mechanism of selective attention: electrophysiological and neuroimaging evidence.

    PubMed Central

    Hillyard, S A; Vogel, E K; Luck, S J

    1998-01-01

    Both physiological and behavioral studies have suggested that stimulus-driven neural activity in the sensory pathways can be modulated in amplitude during selective attention. Recordings of event-related brain potentials indicate that such sensory gain control or amplification processes play an important role in visual-spatial attention. Combined event-related brain potential and neuroimaging experiments provide strong evidence that attentional gain control operates at an early stage of visual processing in extrastriate cortical areas. These data support early selection theories of attention and provide a basis for distinguishing between separate mechanisms of attentional suppression (of unattended inputs) and attentional facilitation (of attended inputs). PMID:9770220

  11. Integrating DNA strand displacement circuitry to the nonlinear hybridization chain reaction.

    PubMed

    Zhang, Zhuo; Fan, Tsz Wing; Hsing, I-Ming

    2017-02-23

    Programmable and modular attributes of DNA molecules allow one to develop versatile sensing platforms that can be operated isothermally and enzyme-free. In this work, we present an approach to integrate upstream DNA strand displacement circuits that can be turned on by a sequence-specific microRNA analyte with a downstream nonlinear hybridization chain reaction for a cascading hyperbranched nucleic acid assembly. This system provides a two-step amplification strategy for highly sensitive detection of the miRNA analyte, conducive for multiplexed detection. Multiple miRNA analytes were tested with our integrated circuitry using the same downstream signal amplification setting, showing the decoupling of nonlinear self-assembly with the analyte sequence. Compared with the reported methods, our signal amplification approach provides an additional control module for higher-order DNA self-assembly and could be developed into a promising platform for the detection of critical nucleic-acid based biomarkers.

  12. Interdisciplinary Approaches of Transcranial Magnetic Stimulation Applied to a Respiratory Neuronal Circuitry Model

    PubMed Central

    Vinit, Stéphane; Keomani, Emilie; Deramaudt, Thérèse B.; Spruance, Victoria M.; Bezdudnaya, Tatiana; Lane, Michael A.

    2014-01-01

    Respiratory related diseases associated with the neuronal control of breathing represent life-threatening issues and to date, no effective therapeutics are available to enhance the impaired function. The aim of this study was to determine whether a preclinical respiratory model could be used for further studies to develop a non-invasive therapeutic tool applied to rat diaphragmatic neuronal circuitry. Transcranial magnetic stimulation (TMS) was performed on adult male Sprague-Dawley rats using a human figure-of-eight coil. The largest diaphragmatic motor evoked potentials (MEPdia) were recorded when the center of the coil was positioned 6 mm caudal from Bregma, involving a stimulation of respiratory supraspinal pathways. Magnetic shielding of the coil with mu metal reduced magnetic field intensities and improved focality with increased motor threshold and lower amplitude recruitment curve. Moreover, transynaptic neuroanatomical tracing with pseudorabies virus (applied to the diaphragm) suggest that connections exist between the motor cortex, the periaqueductal grey cell regions, several brainstem neurons and spinal phrenic motoneurons (distributed in the C3-4 spinal cord). These results reveal the anatomical substrate through which supraspinal stimulation can convey descending action potential volleys to the spinal motoneurons (directly or indirectly). We conclude that MEPdia following a single pulse of TMS can be successfully recorded in the rat and may be used in the assessment of respiratory supraspinal plasticity. Supraspinal non-invasive stimulations aimed to neuromodulate respiratory circuitry will enable new avenues of research into neuroplasticity and the development of therapies for respiratory dysfunction associated with neural injury and disease (e.g. spinal cord injury, amyotrophic lateral sclerosis). PMID:25406091

  13. Contribution of olivofloccular circuitry developmental defects to atypical gaze in autism

    PubMed Central

    Wegiel, Jerzy; Kuchna, Izabela; Nowicki, Krzysztof; Imaki, Humi; Wegiel, Jarek; Ma, Shuang Yong; Azmitia, Efrain C.; Banerjee, Probal; Flory, Michael; Cohen, Ira L.; London, Eric; Brown, W. Ted; Hare, Carolyn Komich; Wisniewski, Thomas

    2014-01-01

    Individuals with autism demonstrate atypical gaze, impairments in smooth pursuit, altered movement perception and deficits in facial perception. The olivofloccular neuronal circuit is a major contributor to eye movement control. This study of the cerebellum in 12 autistic and 10 control subjects revealed dysplastic changes in the flocculus of eight autistic (67%) and two control (20%) subjects. Defects of the oculomotor system, including avoidance of eye contact and poor or no eye contact, were reported in 88% of autistic subjects with postmortem-detected floccular dysplasia. Focal disorganization of the flocculus cytoarchitecture with deficit, altered morphology, and spatial disorientation of Purkinje cells (PCs); deficit and abnormalities of granule, basket, stellate and unipolar brush cells; and structural defects and abnormal orientation of Bergmann glia are indicators of profound disruption of flocculus circuitry in a dysplastic area. The average volume of PCs was 26% less in the dysplastic region than in the unaffected region of the flocculus (p<0.01) in autistic subjects. Moreover, the average volume of PCs in the entire cerebellum was 25% less in the autistic subjects than in the control subjects (p<0.001). Findings from this study and a parallel study of the inferior olive (IO) suggest that focal floccular dysplasia combined with IO neurons and PC developmental defects may contribute to oculomotor system dysfunction and atypical gaze in autistic subjects. PMID:23558308

  14. Catecholaminergic connectivity to the inner ear, central auditory and vocal motor circuitry in the plainfin midshipman fish, Porichthys notatus

    PubMed Central

    Forlano, Paul M.; Kim, Spencer D.; Krzyminska, Zuzanna M.; Sisneros, Joseph A.

    2014-01-01

    Although the neuroanatomical distribution of catecholaminergic (CA) neurons has been well documented across all vertebrate classes, few studies have examined CA connectivity to physiologically and anatomically identified neural circuitry that controls behavior. The goal of this study was to characterize CA distribution in the brain and inner ear of the plainfin midshipman fish (Porichthys notatus) with particular emphasis on their relationship with anatomically labeled circuitry that both produces and encodes social acoustic signals in this species. Neurobiotin labeling of the main auditory endorgan, the saccule, combined with tyrosine hydroxylase immunofluorescence (TH-ir) revealed a strong CA innervation of both the peripheral and central auditory system. Diencephalic TH-ir neurons in the periventricular posterior tuberculum, known to be dopaminergic, send ascending projections to the ventral telencephalon and prominent descending projections to vocal-acoustic integration sites, notably the hindbrain octavolateralis efferent nucleus, as well as onto the base of hair cells in the saccule via nerve VIII. Neurobiotin backfills of the vocal nerve in combination with TH-ir revealed CA terminals on all components of the vocal pattern generator which appears to largely originate from local TH-ir neurons but may include diencephalic projections as well. This study provides strong evidence for catecholamines as important neuromodulators of both auditory and vocal circuitry and acoustic-driven social behavior in midshipman fish. This first demonstration of TH-ir terminals in the main endorgan of hearing in a non-mammalian vertebrate suggests a conserved and important anatomical and functional role for dopamine in normal audition. PMID:24715479

  15. Gain-scheduling multivariable LPV control of an irrigation canal system.

    PubMed

    Bolea, Yolanda; Puig, Vicenç

    2016-07-01

    The purpose of this paper is to present a multivariable linear parameter varying (LPV) controller with a gain scheduling Smith Predictor (SP) scheme applicable to open-flow canal systems. This LPV controller based on SP is designed taking into account the uncertainty in the estimation of delay and the variation of plant parameters according to the operating point. This new methodology can be applied to a class of delay systems that can be represented by a set of models that can be factorized into a rational multivariable model in series with left/right diagonal (multiple) delays, such as, the case of irrigation canals. A multiple pool canal system is used to test and validate the proposed control approach. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  16. A Technology-Mediated Behavioral Weight Gain Prevention Intervention for College Students: Controlled, Quasi-Experimental Study

    PubMed Central

    Monroe, Courtney M; Turner-McGrievy, Gabrielle; Sundstrom, Beth; Larsen, Chelsea; Magradey, Karen; Wilcox, Sara; Brandt, Heather M

    2016-01-01

    Background Both men and women are vulnerable to weight gain during the college years, and this phenomenon is linked to an increased risk of several chronic diseases and mortality. Technology represents an attractive medium for the delivery of weight control interventions focused on college students, given its reach and appeal among this population. However, few technology-mediated weight gain prevention interventions have been evaluated for college students. Objective This study examined a new technology-based, social media-facilitated weight gain prevention intervention for college students. Methods Undergraduates (n =58) in two sections of a public university course were allocated to either a behavioral weight gain prevention intervention (Healthy Weight, HW; N=29) or a human papillomavirus (HPV) vaccination awareness intervention (control; N=29). All students were enrolled, regardless of initial body weight or expressed interest in weight management. The interventions delivered 8 lessons via electronic newsletters and Facebook postings over 9 weeks, which were designed to foster social support and introduce relevant educational content. The HW intervention targeted behavioral strategies to prevent weight gain and provided participants with a Wi-Fi-enabled scale and an electronic physical activity tracker to facilitate weight regulation. A repeated-measures analysis of variance was conducted to examine within- and between-group differences in measures of self-reported weight control practices and objectively measured weight. Use of each intervention medium and device was objectively tracked, and intervention satisfaction measures were obtained. Results Students remained weight stable (HW: −0.48+1.9 kg; control: −0.45+1.4 kg), with no significant difference between groups over 9 weeks (P =.94). However, HW students reported a significantly greater increase in the number of appropriate weight control strategies than did controls (2.1+4.5 vs −1

  17. A Technology-Mediated Behavioral Weight Gain Prevention Intervention for College Students: Controlled, Quasi-Experimental Study.

    PubMed

    West, Delia Smith; Monroe, Courtney M; Turner-McGrievy, Gabrielle; Sundstrom, Beth; Larsen, Chelsea; Magradey, Karen; Wilcox, Sara; Brandt, Heather M

    2016-06-13

    Both men and women are vulnerable to weight gain during the college years, and this phenomenon is linked to an increased risk of several chronic diseases and mortality. Technology represents an attractive medium for the delivery of weight control interventions focused on college students, given its reach and appeal among this population. However, few technology-mediated weight gain prevention interventions have been evaluated for college students. This study examined a new technology-based, social media-facilitated weight gain prevention intervention for college students. Undergraduates (n =58) in two sections of a public university course were allocated to either a behavioral weight gain prevention intervention (Healthy Weight, HW; N=29) or a human papillomavirus (HPV) vaccination awareness intervention (control; N=29). All students were enrolled, regardless of initial body weight or expressed interest in weight management. The interventions delivered 8 lessons via electronic newsletters and Facebook postings over 9 weeks, which were designed to foster social support and introduce relevant educational content. The HW intervention targeted behavioral strategies to prevent weight gain and provided participants with a Wi-Fi-enabled scale and an electronic physical activity tracker to facilitate weight regulation. A repeated-measures analysis of variance was conducted to examine within- and between-group differences in measures of self-reported weight control practices and objectively measured weight. Use of each intervention medium and device was objectively tracked, and intervention satisfaction measures were obtained. Students remained weight stable (HW: -0.48+1.9 kg; control: -0.45+1.4 kg), with no significant difference between groups over 9 weeks (P =.94). However, HW students reported a significantly greater increase in the number of appropriate weight control strategies than did controls (2.1+4.5 vs -1.1+3.4, respectively; P =.003) and there was no increase in

  18. Functional mapping of the neural circuitry of rat maternal motivation: effects of site-specific transient neural inactivation

    PubMed Central

    Pereira, Mariana; Morrell, Joan I.

    2011-01-01

    The present review focuses on recent studies from our laboratory examining the neural circuitry subserving rat maternal motivation across postpartum. We employed a site-specific neural inactivation method by infusion of bupivacaine to map the maternal motivation circuitry using two complementary behavioral approaches: unconditioned maternal responsiveness and choice of pup- over cocaine-conditioned incentives in a concurrent pup/cocaine choice conditioned place preference task. Our findings revealed that during the early postpartum period, distinct brain structures, including the medial preoptic area, ventral tegmental area and medial prefrontal cortex infralimbic and anterior cingulate subregions, contribute a pup-specific bias to the motivational circuitry. As the postpartum period progresses and the pups grow older, our findings further revealed that maternal responsiveness becomes progressively less dependent on medial preoptic area and medial prefrontal cortex infralimbic activity, and more distributed in the maternal circuitry, such that additional network components, including the medial prefrontal cortex prelimbic subregion, are recruited with maternal experience, and contribute to the expression of late postpartum maternal behavior. Collectively, our findings provide strong evidence that the remarkable ability of postpartum females to successfully care for their developing infants is subserved by a distributed neural network that carries out efficient and dynamic processing of complex, constantly changing incoming environmental and pup-related stimuli, ultimately allowing the progression of appropriate expression and waning of maternal responsiveness across the postpartum period. PMID:21815954

  19. The Brain Reward Circuitry in Mood Disorders

    PubMed Central

    Russo, Scott J.; Nestler, Eric J.

    2013-01-01

    Mood disorders are common and debilitating conditions characterized in part by profound deficits in reward-related behavioral domains. A recent literature has identified important structural and functional alterations within the brain’s reward circuitry —particularly in the ventral tegmental area to nucleus accumbens pathway — that are associated with symptoms such as anhedonia and aberrant reward-associated perception and memory. This review synthesizes recent data from human and rodent studies from which emerges a circuit-level framework for understanding reward deficits in depression. We also discuss some of the molecular and cellular underpinnings of this framework, ranging from adaptations in glutamatergic synapses and neurotrophic factors to transcriptional and epigenetic mechanisms. PMID:23942470

  20. Neuronal Circuitry Mechanisms Regulating Adult Mammalian Neurogenesis

    PubMed Central

    Song, Juan; Olsen, Reid H.J.; Sun, Jiaqi; Ming, Guo-li; Song, Hongjun

    2017-01-01

    The adult mammalian brain is a dynamic structure, capable of remodeling in response to various physiological and pathological stimuli. One dramatic example of brain plasticity is the birth and subsequent integration of newborn neurons into the existing circuitry. This process, termed adult neurogenesis, recapitulates neural developmental events in two specialized adult brain regions: the lateral ventricles of the forebrain. Recent studies have begun to delineate how the existing neuronal circuits influence the dynamic process of adult neurogenesis, from activation of quiescent neural stem cells (NSCs) to the integration and survival of newborn neurons. Here, we review recent progress toward understanding the circuit-based regulation of adult neurogenesis in the hippocampus and olfactory bulb. PMID:27143698

  1. Interaural Level Difference Dependent Gain Control and Synaptic Scaling Underlying Binaural Computation

    PubMed Central

    Xiong, Xiaorui R.; Liang, Feixue; Li, Haifu; Mesik, Lukas; Zhang, Ke K.; Polley, Daniel B.; Tao, Huizhong W.; Xiao, Zhongju; Zhang, Li I.

    2013-01-01

    Binaural integration in the central nucleus of inferior colliculus (ICC) plays a critical role in sound localization. However, its arithmetic nature and underlying synaptic mechanisms remain unclear. Here, we showed in mouse ICC neurons that the contralateral dominance is created by a “push-pull”-like mechanism, with contralaterally dominant excitation and more bilaterally balanced inhibition. Importantly, binaural spiking response is generated apparently from an ipsilaterally-mediated scaling of contralateral response, leaving frequency tuning unchanged. This scaling effect is attributed to a divisive attenuation of contralaterally-evoked synaptic excitation onto ICC neurons with their inhibition largely unaffected. Thus, a gain control mediates the linear transformation from monaural to binaural spike responses. The gain value is modulated by interaural level difference (ILD) primarily through scaling excitation to different levels. The ILD-dependent synaptic scaling and gain adjustment allow ICC neurons to dynamically encode interaural sound localization cues while maintaining an invariant representation of other independent sound attributes. PMID:23972599

  2. Brain signatures of monetary loss and gain: outcome-related potentials in a single outcome gambling task

    PubMed Central

    Kamarajan, Chella; Porjesz, Bernice; Rangaswamy, Madhavi; Tang, Yongqiang; Chorlian, David B.; Padmanabhapillai, Ajayan; Saunders, Ramotse; Pandey, Ashwini K.; Roopesh, Bangalore N.; Manz, Niklas; Stimus, Arthur T.; Begleiter, Henri

    2009-01-01

    This study evaluates the event-related potential (ERP) components in a single outcome gambling task that involved monetary losses and gains. The participants were 50 healthy young volunteers (25 males and 25 females). The gambling task involved valence (loss and gain) and amount (50¢ and 10¢) as outcomes. The outcome-related negativity (ORN/N2) and outcome-related positivity (ORP/P3) were analyzed and compared across conditions and gender. Monetary gain (compared to loss) and higher amount (50¢ compared to 10¢) produced higher amplitudes and shorter latencies in both ORN and ORP components. Difference wave plots showed that earlier processing (200-400 ms) is dominated by the valence (loss/gain) while later processing (after 400 ms) is marked by the amount (50¢/10¢). Functional mapping using Low Resolution Electromagnetic Tomography (LORETA) indicated that the ORN separated the loss against gain in both genders, while the ORP activity distinguished the 50¢ against 10¢ in males. This study further strengthens the view that separate brain processes/circuitry may mediate loss and gain. Although there were no gender differences in behavioral and impulsivity scores, ORN and ORP measures for different task conditions had significant correlations with behavioral scores. This gambling paradigm may potentially offer valuable indicators to study outcome processing and impulsivity in normals as well as in clinical populations. PMID:18775749

  3. LPV gain-scheduled control of SCR aftertreatment systems

    NASA Astrophysics Data System (ADS)

    Meisami-Azad, Mona; Mohammadpour, Javad; Grigoriadis, Karolos M.; Harold, Michael P.; Franchek, Matthew A.

    2012-01-01

    Hydrocarbons, carbon monoxide and some of other polluting emissions produced by diesel engines are usually lower than those produced by gasoline engines. While great strides have been made in the exhaust aftertreatment of vehicular pollutants, the elimination of nitrogen oxide (NO x ) from diesel vehicles is still a challenge. The primary reason is that diesel combustion is a fuel-lean process, and hence there is significant unreacted oxygen in the exhaust. Selective catalytic reduction (SCR) is a well-developed technology for power plants and has been recently employed for reducing NO x emissions from automotive sources and in particular, heavy-duty diesel engines. In this article, we develop a linear parameter-varying (LPV) feedforward/feedback control design method for the SCR aftertreatment system to decrease NO x emissions while keeping ammonia slippage to a desired low level downstream the catalyst. The performance of the closed-loop system obtained from the interconnection of the SCR system and the output feedback LPV control strategy is then compared with other control design methods including sliding mode, and observer-based static state-feedback parameter-varying control. To reduce the computational complexity involved in the control design process, the number of LPV parameters in the developed quasi-LPV (qLPV) model is reduced by applying the principal component analysis technique. An LPV feedback/feedforward controller is then designed for the qLPV model with reduced number of scheduling parameters. The designed full-order controller is further simplified to a first-order transfer function with a parameter-varying gain and pole. Finally, simulation results using both a low-order model and a high-fidelity and high-order model of SCR reactions in GT-POWER interfaced with MATLAB/SIMULINK illustrate the high NO x conversion efficiency of the closed-loop SCR system using the proposed parameter-varying control law.

  4. The LIM protein complex establishes a retinal circuitry of visual adaptation by regulating Pax6 α-enhancer activity

    PubMed Central

    Kim, Yeha; Lim, Soyeon; Ha, Taejeong; Song, You-Hyang; Sohn, Young-In; Park, Dae-Jin; Paik, Sun-Sook; Kim-Kaneyama, Joo-ri; Song, Mi-Ryoung; Leung, Amanda; Levine, Edward M; Kim, In-Beom; Goo, Yong Sook; Lee, Seung-Hee; Kang, Kyung Hwa; Kim, Jin Woo

    2017-01-01

    The visual responses of vertebrates are sensitive to the overall composition of retinal interneurons including amacrine cells, which tune the activity of the retinal circuitry. The expression of Paired-homeobox 6 (PAX6) is regulated by multiple cis-DNA elements including the intronic α-enhancer, which is active in GABAergic amacrine cell subsets. Here, we report that the transforming growth factor ß1-induced transcript 1 protein (Tgfb1i1) interacts with the LIM domain transcription factors Lhx3 and Isl1 to inhibit the α-enhancer in the post-natal mouse retina. Tgfb1i1-/- mice show elevated α-enhancer activity leading to overproduction of Pax6ΔPD isoform that supports the GABAergic amacrine cell fate maintenance. Consequently, the Tgfb1i1-/- mouse retinas show a sustained light response, which becomes more transient in mice with the auto-stimulation-defective Pax6ΔPBS/ΔPBS mutation. Together, we show the antagonistic regulation of the α-enhancer activity by Pax6 and the LIM protein complex is necessary for the establishment of an inner retinal circuitry, which controls visual adaptation. DOI: http://dx.doi.org/10.7554/eLife.21303.001 PMID:28139974

  5. Lateral hypothalamus, nucleus accumbens, and ventral pallidum roles in eating and hunger: interactions between homeostatic and reward circuitry

    PubMed Central

    Castro, Daniel C.; Cole, Shannon L.; Berridge, Kent C.

    2015-01-01

    The study of the neural bases of eating behavior, hunger, and reward has consistently implicated the lateral hypothalamus (LH) and its interactions with mesocorticolimbic circuitry, such as mesolimbic dopamine projections to nucleus accumbens (NAc) and ventral pallidum (VP), in controlling motivation to eat. The NAc and VP play special roles in mediating the hedonic impact (“liking”) and motivational incentive salience (“wanting”) of food rewards, and their interactions with LH help permit regulatory hunger/satiety modulation of food motivation and reward. Here, we review some progress that has been made regarding this circuitry and its functions: the identification of localized anatomical hedonic hotspots within NAc and VP for enhancing hedonic impact; interactions of NAc/VP hedonic hotspots with specific LH signals such as orexin; an anterior-posterior gradient of sites in NAc shell for producing intense appetitive eating vs. intense fearful reactions; and anatomically distributed appetitive functions of dopamine and mu opioid signals in NAc shell and related structures. Such findings help improve our understanding of NAc, VP, and LH interactions in mediating affective and motivation functions, including “liking” and “wanting” for food rewards. PMID:26124708

  6. Switch Box For Controlling Flows Of Four Gases

    NASA Technical Reports Server (NTRS)

    Wishard, James R.; Lamb, James L.

    1995-01-01

    Switch box designed for use in simultaneously controlling flows of as many as four out of total of six available gases into semiconductor-processing chamber. Contains switches, relays, logic circuitry, display devices, and other circuitry for connecting each of as many as four gas controllers to any one of as many as six available mass-flow controllers. Front panel of switch box apprises technician of statuses of flows of various gases.

  7. PROJECT SUCCESS: Electricity. (Pre-post Tests, Vocabulary Lists, Beginning Circuitry, Intermediate Projects).

    ERIC Educational Resources Information Center

    James, Sally

    Four packets comprise the electricity component of an enrichment program for gifted elementary students. Provided in the introductory packet are sample pre- and posttests for the unit. Remaining packets present vocabulary lists, student worksheets on beginning circuitry, and suggestions for student projects (such as making a battery, constructing…

  8. Oxytonergic circuitry sustains and enables creative cognition in humans

    PubMed Central

    Baas, Matthijs; Roskes, Marieke; Sligte, Daniel J.; Ebstein, Richard P.; Chew, Soo Hong; Tong, Terry; Jiang, Yushi; Mayseless, Naama; Shamay-Tsoory, Simone G.

    2014-01-01

    Creativity enables humans to adapt flexibly to changing circumstances, to manage complex social relations and to survive and prosper through social, technological and medical innovations. In humans, chronic, trait-based as well as temporary, state-based approach orientation has been linked to increased capacity for divergent rather than convergent thinking, to more global and holistic processing styles and to more original ideation and creative problem solving. Here, we link creative cognition to oxytocin, a hypothalamic neuropeptide known to up-regulate approach orientation in both animals and humans. Study 1 (N = 492) showed that plasma oxytocin predicts novelty-seeking temperament. Study 2 (N = 110) revealed that genotype differences in a polymorphism in the oxytocin receptor gene rs1042778 predicted creative ideation, with GG/GT-carriers being more original than TT-carriers. Using double-blind placebo-controlled between-subjects designs, Studies 3–6 (N = 191) finally showed that intranasal oxytocin (vs matching placebo) reduced analytical reasoning, and increased holistic processing, divergent thinking and creative performance. We conclude that the oxytonergic circuitry sustains and enables the day-to-day creativity humans need for survival and prosperity and discuss implications. PMID:23863476

  9. Hybrid zero-voltage switching (ZVS) control for power inverters

    DOEpatents

    Amirahmadi, Ahmadreza; Hu, Haibing; Batarseh, Issa

    2016-11-01

    A power inverter combination includes a half-bridge power inverter including first and second semiconductor power switches receiving input power having an intermediate node therebetween providing an inductor current through an inductor. A controller includes input comparison circuitry receiving the inductor current having outputs coupled to first inputs of pulse width modulation (PWM) generation circuitry, and a predictive control block having an output coupled to second inputs of the PWM generation circuitry. The predictive control block is coupled to receive a measure of Vin and an output voltage at a grid connection point. A memory stores a current control algorithm configured for resetting a PWM period for a switching signal applied to control nodes of the first and second power switch whenever the inductor current reaches a predetermined upper limit or a predetermined lower limit.

  10. Role of Basal Ganglia in Sleep–Wake Regulation: Neural Circuitry and Clinical Significance

    PubMed Central

    Vetrivelan, Ramalingam; Qiu, Mei-Hong; Chang, Celene; Lu, Jun

    2010-01-01

    Researchers over the last decade have made substantial progress toward understanding the roles of dopamine and the basal ganglia (BG) in the control of sleep–wake behavior. In this review, we outline recent advancements regarding dopaminergic modulation of sleep through the BG and extra-BG sites. Our main hypothesis is that dopamine promotes sleep by its action on the D2 receptors in the BG and promotes wakefulness by its action on D1 and D2 receptors in the extra-BG sites. This hypothesis implicates dopamine depletion in the BG (such as in Parkinson's disease) in causing frequent nighttime arousal and overall insomnia. Furthermore, the arousal effects of psychostimulants (methamphetamine, cocaine, and modafinil) may be linked to the ventral periaquductal gray (vPAG) dopaminergic circuitry targeting the extra-BG sleep–wake network. PMID:21151379

  11. Design and testing of an advanced implantable neuroprosthesis with myoelectric control.

    PubMed

    Hart, Ronald L; Bhadra, Niloy; Montague, Fred W; Kilgore, Kevin L; Peckham, P Hunter

    2011-02-01

    An implantable stimulator-telemeter (IST-12) was developed for applications in neuroprosthetic restoration of limb function in paralyzed individuals. The IST-12 provides 12 stimulation channels and two myoelectric signal (MES) channels. The MES circuitry includes a two-channel multiplexer, preamplifier, variable gain amplifier/bandpass filter, full-wave rectifier, and bin integrator. Power and control signals are transmitted from an external control unit to the IST-12 through an inductive link. Recorded MES signals are telemetered back to the external control unit through the same inductive link. Following bench testing, one device was implanted chronically in a dog for 15 months and evaluated. Conditions were identified in which MES could be recorded with minimal stimulus artifact. The ability to record MES in the presence of stimulation was verified, confirming the potential of the IST-12 to be used as a myoelectric controlled neuroprosthesis.

  12. Integrator Circuitry for Single Channel Radiation Detector

    NASA Technical Reports Server (NTRS)

    Holland, Samuel D. (Inventor); Delaune, Paul B. (Inventor); Turner, Kathryn M. (Inventor)

    2008-01-01

    Input circuitry is provided for a high voltage operated radiation detector to receive pulses from the detector having a rise time in the range of from about one nanosecond to about ten nanoseconds. An integrator circuit, which utilizes current feedback, receives the incoming charge from the radiation detector and creates voltage by integrating across a small capacitor. The integrator utilizes an amplifier which closely follows the voltage across the capacitor to produce an integrator output pulse with a peak value which may be used to determine the energy which produced the pulse. The pulse width of the output is stretched to approximately 50 to 300 nanoseconds for use by subsequent circuits which may then use amplifiers with lower slew rates.

  13. High Efficiency Automatic-Power-Controlled and Gain-Clamped EDFA for Broadband Passive Optical Networking Systems

    NASA Astrophysics Data System (ADS)

    Shen, Jyi-Lai; Wei, Shui-Ken; Lin, Chin-Yuan; Iong Li, Ssu; Huang, Chih-Chuan

    2010-04-01

    The configuration of a simple improved high efficiency automatic-power-controlled and gain-clamped EDFA (APC-GC-EDFA) for broadband passive optical networking systems (BPON) is presented here. In order to compensate the phase and amplitude variation due to the different distance between the optical line terminal (OLT) and optical network units (ONU), the APC-GC-EDFA need to be employed. A single 980 nm laser module is employed as the primary pump. To extend the bandwidth, all C-band ASE is recycled as the secondary pump to enhance the gain efficiency. An electrical feedback circuit is used as a multi-wavelength channel transmitter monitor for the automatic power control to improve the gain-flattened flatness for stable amplification. The experimental results prove that the EDFA system can provide flatter clamped gain in both C-band and L-band configurations. The gain flatness wavelength ranging from 1530 to 1610 nm is within 32.83 ± 0.64 dB, i.e. below 1.95 %. The gains are clamped at 33.85 ± 0.65 dB for the input signal power of -40 dBm to -10 dBm. The range of noise figure is between 6.37 and 6.56, which is slightly lower compared to that of unclamped amplifiers. This will be very useful for measuring the gain flatness of APC-GC-EDFA. Finally, we have also demonstrated the records of the overall simultaneous dynamics measurements for the new system stabilization. The carrier to noise ratio (CNR) is 49.5 to 50.8 dBc which is above the National Television System Committee (NTSC) standard of 43 dBc, and both composite second order (CSO) 69.2 to 71.5 dBc and composite triple beat (CTB) of 69.8 to 72.2 dBc are above 53 dBc. The recorded corresponding rise-time of 1.087 ms indicates that the system does not exhibit any overshoot of gain or ASE variation due to the signal at the beginning of the pulse.

  14. Synaptic plasticity in drug reward circuitry.

    PubMed

    Winder, Danny G; Egli, Regula E; Schramm, Nicole L; Matthews, Robert T

    2002-11-01

    Drug addiction is a major public health issue worldwide. The persistence of drug craving coupled with the known recruitment of learning and memory centers in the brain has led investigators to hypothesize that the alterations in glutamatergic synaptic efficacy brought on by synaptic plasticity may play key roles in the addiction process. Here we review the present literature, examining the properties of synaptic plasticity within drug reward circuitry, and the effects that drugs of abuse have on these forms of plasticity. Interestingly, multiple forms of synaptic plasticity can be induced at glutamatergic synapses within the dorsal striatum, its ventral extension the nucleus accumbens, and the ventral tegmental area, and at least some of these forms of plasticity are regulated by behaviorally meaningful administration of cocaine and/or amphetamine. Thus, the present data suggest that regulation of synaptic plasticity in reward circuits is a tractable candidate mechanism underlying aspects of addiction.

  15. Exercise-enhanced Neuroplasticity Targeting Motor and Cognitive Circuitry in Parkinson’s Disease

    PubMed Central

    Petzinger, G. M.; Fisher, B. E.; McEwen, S.; Beeler, J. A.; Walsh, J. P.; Jakowec, M. W.

    2013-01-01

    The purpose of this review is to highlight the potential role of exercise in promoting neuroplasticity and repair in Parkinson’s disease (PD). Exercise interventions in individuals with PD incorporate goal-based motor skill training in order to engage cognitive circuitry important in motor learning. Using this exercise approach, physical therapy facilitates learning through instruction and feedback (reinforcement), and encouragement to perform beyond self-perceived capability. Individuals with PD become more cognitively engaged with the practice and learning of movements and skills that were previously automatic and unconscious. Studies that have incorporated both goal-based training and aerobic exercise have supported the potential for improving both cognitive and automatic components of motor control. Utilizing animal models, basic research is beginning to reveal exercise-induced effects on neuroplasticity. Since neuroplasticity occurs at the level of circuits and synaptic connections, we examine the effects of exercise from this perspective. PMID:23769598

  16. An optimal output feedback gain variation scheme for the control of plants exhibiting gross parameter changes

    NASA Technical Reports Server (NTRS)

    Moerder, Daniel D.

    1987-01-01

    A concept for optimally designing output feedback controllers for plants whose dynamics exhibit gross changes over their operating regimes was developed. This was to formulate the design problem in such a way that the implemented feedback gains vary as the output of a dynamical system whose independent variable is a scalar parameterization of the plant operating point. The results of this effort include derivation of necessary conditions for optimality for the general problem formulation, and for several simplified cases. The question of existence of a solution to the design problem was also examined, and it was shown that the class of gain variation schemes developed are capable of achieving gain variation histories which are arbitrarily close to the unconstrained gain solution for each point in the plant operating range. The theory was implemented in a feedback design algorithm, which was exercised in a numerical example. The results are applicable to the design of practical high-performance feedback controllers for plants whose dynamics vary significanly during operation. Many aerospace systems fall into this category.

  17. What happens in the thymus does not stay in the thymus: how T cells recycle the CD4+-CD8+ lineage commitment transcriptional circuitry to control their function

    PubMed Central

    Vacchio, Melanie S.; Bosselut, Rémy

    2016-01-01

    MHC-restricted CD4+ and CD8+ T cell are at the core of most adaptive immune responses. Although these cells carry distinct functions, they arise from a common precursor during thymic differentiation, in a developmental sequence that matches CD4 and CD8 expression and functional potential with MHC restriction. While the transcriptional control of CD4+-CD8+ lineage choice in the thymus is now better understood, less was known about what maintains the CD4+- and CD8+-lineage integrity of mature T cells. In this review, we discuss the mechanisms that establish in the thymus, and maintain in post-thymic cells, the separation of these lineages. We focus on recent studies that address the mechanisms of epigenetic control of Cd4 expression and emphasize how maintaining a transcriptional circuitry nucleated around Thpok and Runx proteins, the key architects of CD4+-CD8+ lineage commitment in the thymus, is critical for CD4+ T cell helper functions. PMID:27260768

  18. Design and evaluation of controls for drift, video gain, and color balance in spaceborne facsimile cameras

    NASA Technical Reports Server (NTRS)

    Katzberg, S. J.; Kelly, W. L., IV; Rowland, C. W.; Burcher, E. E.

    1973-01-01

    The facsimile camera is an optical-mechanical scanning device which has become an attractive candidate as an imaging system for planetary landers and rovers. This paper presents electronic techniques which permit the acquisition and reconstruction of high quality images with this device, even under varying lighting conditions. These techniques include a control for low frequency noise and drift, an automatic gain control, a pulse-duration light modulation scheme, and a relative spectral gain control. Taken together, these techniques allow the reconstruction of radiometrically accurate and properly balanced color images from facsimile camera video data. These techniques have been incorporated into a facsimile camera and reproduction system, and experimental results are presented for each technique and for the complete system.

  19. Toward DNA-based Security Circuitry: First Step - Random Number Generation.

    PubMed

    Bogard, Christy M; Arazi, Benjamin; Rouchka, Eric C

    2008-08-10

    DNA-based circuit design is an area of research in which traditional silicon-based technologies are replaced by naturally occurring phenomena taken from biochemistry and molecular biology. Our team investigates the implications of DNA-based circuit design in serving security applications. As an initial step we develop a random number generation circuitry. A novel prototype schema employs solid-phase synthesis of oligonucleotides for random construction of DNA sequences. Temporary storage and retrieval is achieved through plasmid vectors.

  20. Floating-point scaling technique for sources separation automatic gain control

    NASA Astrophysics Data System (ADS)

    Fermas, A.; Belouchrani, A.; Ait-Mohamed, O.

    2012-07-01

    Based on the floating-point representation and taking advantage of scaling factor indetermination in blind source separation (BSS) processing, we propose a scaling technique applied to the separation matrix, to avoid the saturation or the weakness in the recovered source signals. This technique performs an automatic gain control in an on-line BSS environment. We demonstrate the effectiveness of this technique by using the implementation of a division-free BSS algorithm with two inputs, two outputs. The proposed technique is computationally cheaper and efficient for a hardware implementation compared to the Euclidean normalisation.

  1. Visual signal detection in structured backgrounds. II. Effects of contrast gain control, background variations, and white noise

    NASA Technical Reports Server (NTRS)

    Eckstein, M. P.; Ahumada, A. J. Jr; Watson, A. B.

    1997-01-01

    Studies of visual detection of a signal superimposed on one of two identical backgrounds show performance degradation when the background has high contrast and is similar in spatial frequency and/or orientation to the signal. To account for this finding, models include a contrast gain control mechanism that pools activity across spatial frequency, orientation and space to inhibit (divisively) the response of the receptor sensitive to the signal. In tasks in which the observer has to detect a known signal added to one of M different backgrounds grounds due to added visual noise, the main sources of degradation are the stochastic noise in the image and the suboptimal visual processing. We investigate how these two sources of degradation (contrast gain control and variations in the background) interact in a task in which the signal is embedded in one of M locations in a complex spatially varying background (structured background). We use backgrounds extracted from patient digital medical images. To isolate effects of the fixed deterministic background (the contrast gain control) from the effects of the background variations, we conduct detection experiments with three different background conditions: (1) uniform background, (2) a repeated sample of structured background, and (3) different samples of structured background. Results show that human visual detection degrades from the uniform background condition to the repeated background condition and degrades even further in the different backgrounds condition. These results suggest that both the contrast gain control mechanism and the background random variations degrade human performance in detection of a signal in a complex, spatially varying background. A filter model and added white noise are used to generate estimates of sampling efficiencies, an equivalent internal noise, an equivalent contrast-gain-control-induced noise, and an equivalent noise due to the variations in the structured background.

  2. A critical appraisal of neuroimaging studies of bipolar disorder: toward a new conceptualization of underlying neural circuitry and roadmap for future research

    PubMed Central

    Phillips, Mary L; Swartz, Holly A.

    2014-01-01

    Objective This critical review appraises neuroimaging findings in bipolar disorder in emotion processing, emotion regulation, and reward processing neural circuitry, to synthesize current knowledge of the neural underpinnings of bipolar disorder, and provide a neuroimaging research “roadmap” for future studies. Method We examined findings from all major studies in bipolar disorder that used fMRI, volumetric analyses, diffusion imaging, and resting state techniques, to inform current conceptual models of larger-scale neural circuitry abnormalities in bipolar disorder Results Bipolar disorder can be conceptualized in neural circuitry terms as parallel dysfunction in bilateral prefrontal cortical (especially ventrolateral prefrontal cortical)-hippocampal-amygdala emotion processing and emotion regulation neural circuitries, together with an “overactive” left-sided ventral striatal-ventrolateral and orbitofrontal cortical reward processing circuitry, that result in characteristic behavioral abnormalities associated with bipolar disorder: emotional lability, emotional dysregulation and heightened reward sensitivity. A potential structural basis for these functional abnormalities are gray matter decreases in prefrontal and temporal cortices, amygdala and hippocampus, and fractional anisotropy decreases in white matter tracts connecting prefrontal and subcortical regions. Conclusion Neuroimaging studies of bipolar disorder clearly demonstrate abnormalities in neural circuitries supporting emotion processing, emotion regulation and reward processing, although there are several limitations to these studies. Future neuroimaging research in bipolar disorder should include studies adopting dimensional approaches; larger studies examining neurodevelopmental trajectories in bipolar disorder and at-risk youth; multimodal neuroimaging studies using integrated systems approaches; and studies using pattern recognition approaches to provide clinically useful, individual

  3. Micromachined Silicon Stimulating Probes with CMOS Circuitry for Use in the Central Nervous System

    NASA Astrophysics Data System (ADS)

    Tanghe, Steven John

    1992-01-01

    Electrical stimulation in the central nervous system is a valuable technique for studying neural systems and is a key element in the development of prostheses for deafness and other disorders. This thesis presents a family of multielectrode probe structures, fulfilling the need for chronic multipoint stimulation tools essential for interfacing to the highly complex neural networks in the brain. These probes are batch-fabricated on silicon wafers, employing photoengraving techniques to precisely control the electrode site and array geometries and to allow the integration of on-chip CMOS circuitry for signal multiplexing and stimulus current generation. Silicon micromachining is used to define the probe shapes, which have typical shank dimensions of 3 mm in length by 100 mu m in width by 15 μm in thickness. Each shank supports up to eight planar iridium oxide electrode sites capable of delivering charge densities in excess of 3 mC/cm^2 during current pulse stimulation. Three active probe circuits have been designed with varied complexity and capability. All three can deliver biphasic stimulus currents through 16 sites using only 5 external leads, and they are all compatible with the same external control system. The most complex design interprets site addresses and stimulus current amplitudes from 16-bit words shifted into the probe at 4 MHz. Sixteen on-chip, biphasic, 8-bit digital-to-analog converters deliver analog stimulus currents in the range of +/- 254 muA to any combination of electrode sites. These DACs exhibit full-scale internal linearity to better than +/-1/2 LSB and can be calibrated by varying the positive power supply voltage. The entire probe circuit dissipates only 80 muW from +/-5 V supplies when not delivering stimulus currents, it includes several safety features, and is testable from the input pads. Test results from the fabricated circuits indicate that they all function properly at clocking frequencies as high as 10 MHz, meeting or exceeding

  4. Voluntary Fasting to Control Post-Ramadan Weight Gain among Overweight and Obese Women

    PubMed Central

    Ismail, Suriani; Shamsuddin, Khadijah; Latiff, Khalib A.; Saad, Hazizi A.; Majid, Latifah A.; Othman, Fadlan M.

    2015-01-01

    Objectives: This study aimed to examine the effectiveness of an Islamic voluntary fasting intervention to control post-Ramadan weight gain. Methods: This study was conducted between July and November 2011. Two weight loss intervention programmes were developed and implemented among groups of overweight or obese Malay women living in the Malaysian cities of Putrajaya and Seremban: a standard programme promoting control of food intake according to national dietary guidelines (group B) and a faith-based programme promoting voluntary fasting in addition to the standard programme (group A). Participants’ dietary practices (i.e., voluntary fasting practices, frequency of fruit/vegetable consumption per week and quantity of carbohydrates/protein consumed per day), body mass index (BMI), blood pressure, fasting blood high-density lipoprotein cholesterol (HDL-C) and total cholesterol (TC):HDL-C ratio were assessed before Ramadan and three months post-Ramadan. Results: Voluntary fasting practices increased only in group A (P <0.01). Additionally, the quantity of protein/carbohydrates consumed per day, mean diastolic pressure and TC:HDL-C ratio decreased only in group A (P <0.01, 0.05, 0.02 and <0.01, respectively). Frequency of fruit/vegetable consumption per week, as well as HDL-C levels, increased only in group A (P = 0.03 and <0.01, respectively). Although changes in BMI between the groups was not significant (P = 0.08), BMI decrease among participants in group A was significant (P <0.01). Conclusion: Control of post-Ramadan weight gain was more evident in the faith-based intervention group. Healthcare providers should consider faith-based interventions to encourage weight loss during Ramadan and to prevent post-Ramadan weight gain among patients. PMID:25685394

  5. Disturbance in the neural circuitry underlying positive emotional processing in post-traumatic stress disorder (PTSD). An fMRI study.

    PubMed

    Jatzko, Alexander; Schmitt, Andrea; Demirakca, Traute; Weimer, Erik; Braus, Dieter F

    2006-03-01

    This study was designed to investigate the circuitry underlying movie-induced positive emotional processing in subjects with chronic PTSD. Ten male subjects with chronic PTSD and ten matched controls were studied. In an fMRI-paradigm a sequence of a wellknown Walt Disney cartoon with positive emotional valence was shown. PTSD subjects showed an increased activation in the right posterior temporal, precentral and superior frontal cortex. Controls recruited more emotion-related regions bilateral in the temporal pole and areas of the left fusiform and parahippocampal gyrus. This pilot study is the first to reveal alterations in the processing of positive emotions in PTSD possibly reflecting a neuronal correlate of the symptom of emotional numbness in PTSD.

  6. Oxytonergic circuitry sustains and enables creative cognition in humans.

    PubMed

    De Dreu, Carsten K W; Baas, Matthijs; Roskes, Marieke; Sligte, Daniel J; Ebstein, Richard P; Chew, Soo Hong; Tong, Terry; Jiang, Yushi; Mayseless, Naama; Shamay-Tsoory, Simone G

    2014-08-01

    Creativity enables humans to adapt flexibly to changing circumstances, to manage complex social relations and to survive and prosper through social, technological and medical innovations. In humans, chronic, trait-based as well as temporary, state-based approach orientation has been linked to increased capacity for divergent rather than convergent thinking, to more global and holistic processing styles and to more original ideation and creative problem solving. Here, we link creative cognition to oxytocin, a hypothalamic neuropeptide known to up-regulate approach orientation in both animals and humans. Study 1 (N = 492) showed that plasma oxytocin predicts novelty-seeking temperament. Study 2 (N = 110) revealed that genotype differences in a polymorphism in the oxytocin receptor gene rs1042778 predicted creative ideation, with GG/GT-carriers being more original than TT-carriers. Using double-blind placebo-controlled between-subjects designs, Studies 3-6 (N = 191) finally showed that intranasal oxytocin (vs matching placebo) reduced analytical reasoning, and increased holistic processing, divergent thinking and creative performance. We conclude that the oxytonergic circuitry sustains and enables the day-to-day creativity humans need for survival and prosperity and discuss implications. © The Author (2013). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  7. Silent Synapse-Based Circuitry Remodeling in Drug Addiction.

    PubMed

    Dong, Yan

    2016-05-01

    Exposure to cocaine, and likely other drugs of abuse, generates α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor-silent glutamatergic synapses in the nucleus accumbens. These immature synaptic contacts evolve after drug withdrawal to redefine the neurocircuital properties. These results raise at least three critical questions: (1) what are the molecular and cellular mechanisms that mediate drug-induced generation of silent synapses; (2) how are neurocircuits remodeled upon generation and evolution of drug-generated silent synapses; and (3) what behavioral consequences are produced by silent synapse-based circuitry remodeling? This short review analyzes related experimental results, and extends them to some speculations. © The Author 2015. Published by Oxford University Press on behalf of CINP.

  8. Maternal Locus of Control and Developmental Gain Demonstrated by High Risk Infants: A Longitudinal Analysis.

    ERIC Educational Resources Information Center

    Maisto, Albert A.; German, Michael L.

    1981-01-01

    Short- and long-term effects of a parent-infant training program for biologically handicapped infants was evaluated in terms of maternal locus of control. Results indicated that maternal locus of control accounted for a substantial portion of the variance in the infants' developmental gains following the program intervention period. (Author/RH)

  9. Dual Tasking and Working Memory in Alcoholism: Relation to Frontocerebellar Circuitry

    PubMed Central

    Chanraud, Sandra; Pitel, Anne-Lise; Rohlfing, Torsten; Pfefferbaum, Adolf; Sullivan, Edith V

    2010-01-01

    Controversy exists regarding the role of cerebellar systems in cognition and whether working memory compromise commonly marking alcoholism can be explained by compromise of nodes of corticocerebellar circuitry. We tested 17 alcoholics and 31 age-matched controls with dual-task, working memory paradigms. Interference tasks competed with verbal and spatial working memory tasks using low (three item) or high (six item) memory loads. Participants also underwent structural MRI to obtain volumes of nodes of the frontocerebellar system. On the verbal working memory task, both groups performed equally. On the spatial working memory with the high-load task, the alcoholic group was disproportionately more affected by the arithmetic distractor than were controls. In alcoholics, volumes of the left thalamus and left cerebellar Crus I volumes were more robust predictors of performance in the spatial working memory task with the arithmetic distractor than the left frontal superior cortex. In controls, volumes of the right middle frontal gyrus and right cerebellar Crus I were independent predictors over the left cerebellar Crus I, left thalamus, right superior parietal cortex, or left middle frontal gyrus of spatial working memory performance with tracking interference. The brain–behavior correlations suggest that alcoholics and controls relied on the integrity of certain nodes of corticocerebellar systems to perform these verbal and spatial working memory tasks, but that the specific pattern of relationships differed by group. The resulting brain structure–function patterns provide correlational support that components of this corticocerebellar system not typically related to normal performance in dual-task conditions may be available to augment otherwise dampened performance by alcoholics. PMID:20410871

  10. Impact of Sex and Menopausal Status on Episodic Memory Circuitry in Early Midlife.

    PubMed

    Jacobs, Emily G; Weiss, Blair K; Makris, Nikos; Whitfield-Gabrieli, Sue; Buka, Stephen L; Klibanski, Anne; Goldstein, Jill M

    2016-09-28

    Cognitive neuroscience of aging studies traditionally target participants age 65 and older. However, epidemiological surveys show that many women report increased forgetfulness earlier in the aging process, as they transition to menopause. In this population-based fMRI study, we stepped back by over a decade to characterize the changes in memory circuitry that occur in early midlife, as a function of sex and women's reproductive stage. Participants (N = 200; age range, 45-55) performed a verbal encoding task during fMRI scanning. Reproductive histories and serologic evaluations were used to determine menopausal status. Results revealed a pronounced impact of reproductive stage on task-evoked hippocampal responses, despite minimal difference in chronological age. Next, we examined the impact of sex and reproductive stage on functional connectivity across task-related brain regions. Postmenopausal women showed enhanced bilateral hippocampal connectivity relative to premenopausal and perimenopausal women. Across women, lower 17β-estradiol concentrations were related to more pronounced alterations in hippocampal connectivity and poorer performance on a subsequent memory retrieval task, strongly implicating sex steroids in the regulation of this circuitry. Finally, subgroup analyses revealed that high-performing postmenopausal women (relative to low and middle performers) exhibited a pattern of brain activity akin to premenopausal women. Together, these findings underscore the importance of considering reproductive stage, not simply chronological age, to identify neuronal and cognitive changes that unfold in the middle decades of life. In keeping with preclinical studies, these human findings suggest that the decline in ovarian estradiol production during menopause plays a significant role in shaping memory circuitry. Maintaining intact memory function with age is one of the greatest public health challenges of our time, and women have an increased risk for memory

  11. Adaptive control and noise suppression by a variable-gain gradient algorithm

    NASA Technical Reports Server (NTRS)

    Merhav, S. J.; Mehta, R. S.

    1987-01-01

    An adaptive control system based on normalized LMS filters is investigated. The finite impulse response of the nonparametric controller is adaptively estimated using a given reference model. Specifically, the following issues are addressed: The stability of the closed loop system is analyzed and heuristically established. Next, the adaptation process is studied for piecewise constant plant parameters. It is shown that by introducing a variable-gain in the gradient algorithm, a substantial reduction in the LMS adaptation rate can be achieved. Finally, process noise at the plant output generally causes a biased estimate of the controller. By introducing a noise suppression scheme, this bias can be substantially reduced and the response of the adapted system becomes very close to that of the reference model. Extensive computer simulations validate these and demonstrate assertions that the system can rapidly adapt to random jumps in plant parameters.

  12. Pathological anxiety and function/dysfunction in the brain's fear/defense circuitry.

    PubMed

    Lang, Peter J; McTeague, Lisa M; Bradley, Margaret M

    2014-01-01

    Research from the University of Florida Center for the Study of Emotion and Attention aims to develop neurobiological measures that objectively discriminate among symptom patterns in patients with anxiety disorders. From this perspective, anxiety and mood pathologies are considered to be brain disorders, resulting from dysfunction and maladaptive plasticity in the neural circuits that determine fearful/defensive and appetitive/reward behavior (Insel et al., 2010). We review recent studies indicating that an enhanced probe startle reflex during the processing of fear memory cues (mediated by cortico-limbic circuitry and thus indicative of plastic brain changes), varies systematically in strength over a spectrum-wide dimension of anxiety pathology-across and within diagnoses-extending from strong focal fear reactions to a consistently blunted reaction in patients with more generalized anxiety and comorbid mood disorders. Preliminary studies with functional magnetic resonance imaging (fMRI) encourage the hypothesis that fear/defense circuit dysfunction covaries with this same dimension of psychopathology. Plans are described for an extended study of the brain's motivation circuitry in anxiety spectrum patients, with the aim of defining the specifics of circuit dysfunction in severe disorders. A sub-project explores the use of real-time fMRI feedback in circuit analysis and as a modality to up-regulate circuit function in the context of blunted affect.

  13. An enhanced velocity-based algorithm for safe implementations of gain-scheduled controllers

    NASA Astrophysics Data System (ADS)

    Lhachemi, H.; Saussié, D.; Zhu, G.

    2017-09-01

    This paper presents an enhanced velocity-based algorithm to implement gain-scheduled controllers for nonlinear and parameter-dependent systems. A new scheme including pre- and post-filtering is proposed with the assumption that the time-derivative of the controller inputs is not available for feedback control. It is shown that the proposed control structure can preserve the input-output properties of the linearised closed-loop system in the neighbourhood of each equilibrium point, avoiding the emergence of the so-called hidden coupling terms. Moreover, it is guaranteed that this implementation will not introduce unobservable or uncontrollable unstable modes, and hence the internal stability will not be affected. A case study dealing with the design of a pitch-axis missile autopilot is carried out and the numerical simulation results confirm the validity of the proposed approach.

  14. Dynamic Feed Control For Injection Molding

    DOEpatents

    Kazmer, David O.

    1996-09-17

    The invention provides methods and apparatus in which mold material flows through a gate into a mold cavity that defines the shape of a desired part. An adjustable valve is provided that is operable to change dynamically the effective size of the gate to control the flow of mold material through the gate. The valve is adjustable while the mold material is flowing through the gate into the mold cavity. A sensor is provided for sensing a process condition while the part is being molded. During molding, the valve is adjusted based at least in part on information from the sensor. In the preferred embodiment, the adjustable valve is controlled by a digital computer, which includes circuitry for acquiring data from the sensor, processing circuitry for computing a desired position of the valve based on the data from the sensor and a control data file containing target process conditions, and control circuitry for generating signals to control a valve driver to adjust the position of the valve. More complex embodiments include a plurality of gates, sensors, and controllable valves. Each valve is individually controllable so that process conditions corresponding to each gate can be adjusted independently. This allows for great flexibility in the control of injection molding to produce complex, high-quality parts.

  15. A novel heart rate control model provides insights linking LF-HRV behavior to the open-loop gain.

    PubMed

    Dvir, Hila; Bobrovsky, Ben Zion; Gabbay, Uri

    2013-09-20

    Low-frequency heart rate variability (LF-HRV) at rest has already been successfully modeled as self-sustained oscillations in a nonlinear control loop, but these models fail to simulate LF-HRV decreases either during aerobic exercise or in heart failure patients. Following control engineering practices, we assume the existence of a biological excitation (dither) within the heart rate control loop that softens the nonlinearity and studied LF-HRV behavior in a dither-embedded model. We adopted the Ottesen model with some revisions and induced a dither of high-frequency stochastic perturbations. We simulated scenarios of a healthy subject at rest and during aerobic exercise (by decreasing peripheral vascular resistance) and a heart failure patient (by decreasing stroke volume). The simulations resembled physiological LF-HRV behavior, i.e., LF-HRV decreased during aerobic exercise and in the heart failure patient. The simulations exhibited LF-HRV dependency on the open-loop gain, which is related to the product of the feedback gain and the feed forward gain. We are the first to demonstrate that LF-HRV may be dependent on the open-loop gain. Accordingly, reduced open-loop gain results in decreased LF-HRV, and vice versa. Our findings explain a well-known but unexplained observed phenomenon of reduced LF-HRV both in heart failure patients and in healthy subjects performing aerobic exercise. These findings have implications on how changes in LF-HRV can be interpreted physiologically, a necessary step towards the clinical utilization of LF-HRV. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  16. Continuous higher-order sliding mode control with time-varying gain for a class of uncertain nonlinear systems.

    PubMed

    Han, Yaozhen; Liu, Xiangjie

    2016-05-01

    This paper presents a continuous higher-order sliding mode (HOSM) control scheme with time-varying gain for a class of uncertain nonlinear systems. The proposed controller is derived from the concept of geometric homogeneity and super-twisting algorithm, and includes two parts, the first part of which achieves smooth finite time stabilization of pure integrator chains. The second part conquers the twice differentiable uncertainty and realizes system robustness by employing super-twisting algorithm. Particularly, time-varying switching control gain is constructed to reduce the switching control action magnitude to the minimum possible value while keeping the property of finite time convergence. Examples concerning the perturbed triple integrator chains and excitation control for single-machine infinite bus power system are simulated respectively to demonstrate the effectiveness and applicability of the proposed approach. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Adaptive-gain fast super-twisting sliding mode fault tolerant control for a reusable launch vehicle in reentry phase.

    PubMed

    Zhang, Yao; Tang, Shengjing; Guo, Jie

    2017-11-01

    In this paper, a novel adaptive-gain fast super-twisting (AGFST) sliding mode attitude control synthesis is carried out for a reusable launch vehicle subject to actuator faults and unknown disturbances. According to the fast nonsingular terminal sliding mode surface (FNTSMS) and adaptive-gain fast super-twisting algorithm, an adaptive fault tolerant control law for the attitude stabilization is derived to protect against the actuator faults and unknown uncertainties. Firstly, a second-order nonlinear control-oriented model for the RLV is established by feedback linearization method. And on the basis a fast nonsingular terminal sliding mode (FNTSM) manifold is designed, which provides fast finite-time global convergence and avoids singularity problem as well as chattering phenomenon. Based on the merits of the standard super-twisting (ST) algorithm and fast reaching law with adaption, a novel adaptive-gain fast super-twisting (AGFST) algorithm is proposed for the finite-time fault tolerant attitude control problem of the RLV without any knowledge of the bounds of uncertainties and actuator faults. The important feature of the AGFST algorithm includes non-overestimating the values of the control gains and faster convergence speed than the standard ST algorithm. A formal proof of the finite-time stability of the closed-loop system is derived using the Lyapunov function technique. An estimation of the convergence time and accurate expression of convergence region are also provided. Finally, simulations are presented to illustrate the effectiveness and superiority of the proposed control scheme. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  18. Attentional Gain Control of Ongoing Cortical Speech Representations in a “Cocktail Party”

    PubMed Central

    Kerlin, Jess R.; Shahin, Antoine J.; Miller, Lee M.

    2010-01-01

    Normal listeners possess the remarkable perceptual ability to select a single speech stream among many competing talkers. However, few studies of selective attention have addressed the unique nature of speech as a temporally extended and complex auditory object. We hypothesized that sustained selective attention to speech in a multi-talker environment would act as gain control on the early auditory cortical representations of speech. Using high-density electroencephalography and a template-matching analysis method, we found selective gain to the continuous speech content of an attended talker, greatest at a frequency of 4–8 Hz, in auditory cortex. In addition, the difference in alpha power (8–12 Hz) at parietal sites across hemispheres indicated the direction of auditory attention to speech, as has been previously found in visual tasks. The strength of this hemispheric alpha lateralization, in turn, predicted an individual’s attentional gain of the cortical speech signal. These results support a model of spatial speech stream segregation, mediated by a supramodal attention mechanism, enabling selection of the attended representation in auditory cortex. PMID:20071526

  19. System and Method for Fabricating Super Conducting Circuitry on Both Sides of an Ultra-Thin Layer

    NASA Technical Reports Server (NTRS)

    Brown, Ari D. (Inventor); Mikula, Vilem (Inventor)

    2017-01-01

    A method of fabricating circuitry in a wafer includes depositing a superconducting metal on a silicon on insulator wafer having a handle wafer, coating the wafer with a sacrificial layer and bonding the wafer to a thermally oxide silicon wafer with a first epoxy. The method includes flipping the wafer, thinning the flipped wafer by removing a handle wafer, etching a buried oxide layer, depositing a superconducting layer, bonding the wafer to a thermally oxidized silicon wafer having a handle wafer using an epoxy, flipping the wafer again, thinning the flipped wafer, etching a buried oxide layer from the wafer and etching the sacrificial layer from the wafer. The result is a wafer having superconductive circuitry on both sides of an ultra-thin silicon layer.

  20. Assembly of the Auditory Circuitry by a Hox Genetic Network in the Mouse Brainstem

    PubMed Central

    Di Bonito, Maria; Narita, Yuichi; Avallone, Bice; Sequino, Luigi; Mancuso, Marta; Andolfi, Gennaro; Franzè, Anna Maria; Puelles, Luis; Rijli, Filippo M.; Studer, Michèle

    2013-01-01

    Rhombomeres (r) contribute to brainstem auditory nuclei during development. Hox genes are determinants of rhombomere-derived fate and neuronal connectivity. Little is known about the contribution of individual rhombomeres and their associated Hox codes to auditory sensorimotor circuitry. Here, we show that r4 contributes to functionally linked sensory and motor components, including the ventral nucleus of lateral lemniscus, posterior ventral cochlear nuclei (VCN), and motor olivocochlear neurons. Assembly of the r4-derived auditory components is involved in sound perception and depends on regulatory interactions between Hoxb1 and Hoxb2. Indeed, in Hoxb1 and Hoxb2 mutant mice the transmission of low-level auditory stimuli is lost, resulting in hearing impairments. On the other hand, Hoxa2 regulates the Rig1 axon guidance receptor and controls contralateral projections from the anterior VCN to the medial nucleus of the trapezoid body, a circuit involved in sound localization. Thus, individual rhombomeres and their associated Hox codes control the assembly of distinct functionally segregated sub-circuits in the developing auditory brainstem. PMID:23408898

  1. Assembly of the auditory circuitry by a Hox genetic network in the mouse brainstem.

    PubMed

    Di Bonito, Maria; Narita, Yuichi; Avallone, Bice; Sequino, Luigi; Mancuso, Marta; Andolfi, Gennaro; Franzè, Anna Maria; Puelles, Luis; Rijli, Filippo M; Studer, Michèle

    2013-01-01

    Rhombomeres (r) contribute to brainstem auditory nuclei during development. Hox genes are determinants of rhombomere-derived fate and neuronal connectivity. Little is known about the contribution of individual rhombomeres and their associated Hox codes to auditory sensorimotor circuitry. Here, we show that r4 contributes to functionally linked sensory and motor components, including the ventral nucleus of lateral lemniscus, posterior ventral cochlear nuclei (VCN), and motor olivocochlear neurons. Assembly of the r4-derived auditory components is involved in sound perception and depends on regulatory interactions between Hoxb1 and Hoxb2. Indeed, in Hoxb1 and Hoxb2 mutant mice the transmission of low-level auditory stimuli is lost, resulting in hearing impairments. On the other hand, Hoxa2 regulates the Rig1 axon guidance receptor and controls contralateral projections from the anterior VCN to the medial nucleus of the trapezoid body, a circuit involved in sound localization. Thus, individual rhombomeres and their associated Hox codes control the assembly of distinct functionally segregated sub-circuits in the developing auditory brainstem.

  2. Microencapsulation of gallium-indium (Ga-In) liquid metal for self-healing applications.

    PubMed

    Blaiszik, B J; Jones, A R; Sottos, N R; White, S R

    2014-01-01

    Microcapsules containing a liquid metal alloy core of gallium-indium (Ga-In) are prepared via in situ urea-formaldehyde (UF) microencapsulation. The capsule size, shape, thermal properties, and shell wall thickness are investigated. We prepare ellipsoidal capsules with major and minor diameter aspect ratios ranging from 1.64 to 1.08 and with major diameters ranging from 245 µm to 3 µm. We observe that as the capsule major diameter decreases, the aspect ratio approaches 1. The thermal properties of the prepared microcapsules are investigated by thermogravimetric (TGA) and differential scanning calorimetry (DSC). Microcapsules are shown to survive incorporation into an epoxy matrix and to trigger via mechanical damage to the cured matrix. Microcapsules containing liquid metal cores may have diverse applications ranging from self-healing to contrast enhancement or the demonstration of mechano-adaptive circuitry.

  3. GD SDR Automatic Gain Control Characterization Testing

    NASA Technical Reports Server (NTRS)

    Nappier, Jennifer M.; Briones, Janette C.

    2013-01-01

    The General Dynamics (GD) S-Band software defined radio (SDR) in the Space Communications and Navigation (SCAN) Testbed on the International Space Station (ISS) will provide experimenters an opportunity to develop and demonstrate experimental waveforms in space. The GD SDR platform and initial waveform were characterized on the ground before launch and the data will be compared to the data that will be collected during on-orbit operations. A desired function of the SDR is to estimate the received signal to noise ratio (SNR), which would enable experimenters to better determine on-orbit link conditions. The GD SDR does not have an SNR estimator, but it does have an analog and a digital automatic gain control (AGC). The AGCs can be used to estimate the SDR input power which can be converted into a SNR. Tests were conducted to characterize the AGC response to changes in SDR input power and temperature. This purpose of this paper is to describe the tests that were conducted, discuss the results showi ng how the AGCs relate to the SDR input power, and provide recommendations for AGC testing and characterization.

  4. GD SDR Automatic Gain Control Characterization Testing

    NASA Technical Reports Server (NTRS)

    Nappier, Jennifer M.; Briones, Janette C.

    2013-01-01

    The General Dynamics (GD) S-Band software defined radio (SDR) in the Space Communications and Navigation (SCAN) Testbed on the International Space Station (ISS) will provide experimenters an opportunity to develop and demonstrate experimental waveforms in space. The GD SDR platform and initial waveform were characterized on the ground before launch and the data will be compared to the data that will be collected during on-orbit operations. A desired function of the SDR is to estimate the received signal to noise ratio (SNR), which would enable experimenters to better determine on-orbit link conditions. The GD SDR does not have an SNR estimator, but it does have an analog and a digital automatic gain control (AGC). The AGCs can be used to estimate the SDR input power which can be converted into a SNR. Tests were conducted to characterize the AGC response to changes in SDR input power and temperature. This purpose of this paper is to describe the tests that were conducted, discuss the results showing how the AGCs relate to the SDR input power, and provide recommendations for AGC testing and characterization.

  5. Experimental Demonstration and Circuitry for a Very Compact Coil-Only Pulse Echo EMAT

    PubMed Central

    Rueter, Dirk

    2017-01-01

    This experimental study demonstrates for the first time a solid-state circuitry and design for a simple compact copper coil (without an additional bulky permanent magnet or bulky electromagnet) as a contactless electromagnetic acoustic transducer (EMAT) for pulse echo operation at MHz frequencies. A pulsed ultrasound emission into a metallic test object is electromagnetically excited by an intense MHz burst at up to 500 A through the 0.15 mm filaments of the transducer. Immediately thereafter, a smoother and quasi “DC-like” current of 100 A is applied for about 1 ms and allows an echo detection. The ultrasonic pulse echo operation for a simple, compact, non-contacting copper coil is new. Application scenarios for compact transducer techniques include very narrow and hostile environments, in which, e.g., quickly moving metal parts must be tested with only one, non-contacting ultrasound shot. The small transducer coil can be operated remotely with a cable connection, separate from the much bulkier supply circuitry. Several options for more technical and fundamental progress are discussed. PMID:28441722

  6. Regulating Critical Period Plasticity: Insight from the Visual System to Fear Circuitry for Therapeutic Interventions

    PubMed Central

    Nabel, Elisa M.; Morishita, Hirofumi

    2013-01-01

    Early temporary windows of heightened brain plasticity called critical periods developmentally sculpt neural circuits and contribute to adult behavior. Regulatory mechanisms of visual cortex development – the preeminent model of experience-dependent critical period plasticity-actively limit adult plasticity and have proved fruitful therapeutic targets to reopen plasticity and rewire faulty visual system connections later in life. Interestingly, these molecular mechanisms have been implicated in the regulation of plasticity in other functions beyond vision. Applying mechanistic understandings of critical period plasticity in the visual cortex to fear circuitry may provide a conceptual framework for developing novel therapeutic tools to mitigate aberrant fear responses in post traumatic stress disorder. In this review, we turn to the model of experience-dependent visual plasticity to provide novel insights for the mechanisms regulating plasticity in the fear system. Fear circuitry, particularly fear memory erasure, also undergoes age-related changes in experience-dependent plasticity. We consider the contributions of molecular brakes that halt visual critical period plasticity to circuitry underlying fear memory erasure. A major molecular brake in the visual cortex, perineuronal net formation, recently has been identified in the development of fear systems that are resilient to fear memory erasure. The roles of other molecular brakes, myelin-related Nogo receptor signaling and Lynx family proteins – endogenous inhibitors for nicotinic acetylcholine receptor, are explored in the context of fear memory plasticity. Such fear plasticity regulators, including epigenetic effects, provide promising targets for therapeutic interventions. PMID:24273519

  7. Current control circuitry

    DOEpatents

    Taubman, Matthew S [Richland, WA

    2005-03-15

    Among the embodiments of the present invention is an apparatus that includes a transistor (30), a servo device (40), and a current source (50). The servo device (40) is operable to provide a common base mode of operation of the transistor (30) by maintaining an approximately constant voltage level at the transistor base (32b). The current source (150) is operable to provide a bias current to the transistor (30). A first device (24) provides an input signal to an electrical node (70) positioned between the emitter (32e) of the transistor (30) and the current source (50). A second device (26) receives an output signal from the collector (32c) of the transistor (30).

  8. Placebo neural systems: nitric oxide, morphine and the dopamine brain reward and motivation circuitries.

    PubMed

    Fricchione, Gregory; Stefano, George B

    2005-05-01

    Evidence suggests that the placebo response is related to the tonic effects of constitutive nitric oxide in neural, vascular and immune tissues. Constitutive nitric oxide levels play a role in the modulation of dopamine outflow in the nigrostriatal movement and the mesolimbic and mesocortical reward and motivation circuitries. Endogenous morphine, which stimulates constitutive nitric oxide, may be an important signal molecule working at mu receptors on gamma aminobutyric acid B interneurons to disinhibit nigral and tegmental dopamine output. We surmise that placebo induced belief will activate the prefrontal cortex with downstream stimulatory effects on these dopamine systems as well as on periaqueductal grey opioid output neurons. Placebo responses in Parkinson's disease, depression and pain disorder may result. In addition, mesolimbic/mesocortical control of the stress response systems may provide a way for the placebo response to benefit other medical conditions.

  9. Weight gain in preterm infants following parent-administered Vimala massage: a randomized controlled trial.

    PubMed

    Gonzalez, Alma Patricia; Vasquez-Mendoza, Guadalupe; García-Vela, Alfonso; Guzmán-Ramirez, Andres; Salazar-Torres, Marcos; Romero-Gutierrez, Gustavo

    2009-04-01

    Massage has been proposed as a way of facilitating development and growth of newborns through its effects on increasing blood flow, heart rate, digestion, and immunity. Massage might increase basal metabolism and nutrient absorption through endocrine effects such as increase in insulin and adrenaline and decrease in cortisol. Preliminary studies have suggested significant impact on weight gain with shortening of in-hospital stays of up to 6 days. We compared weight gain among preterm infants receiving Vimala massage plus usual care versus usual care alone. A randomized controlled trial was conducted. Sixty clinically stable preterm newborns with a corrected gestational age of 30 to 35 weeks receiving enteral nutrition in the hospital nursery were included. Half of them were assigned at random to receive Vimala massage twice daily for 10 days plus usual nursery care; the others received usual nursery care. Weight, head circumference, caloric intake, and nutritional method were recorded daily. Group characteristics were compared with analysis of variance, T test, and chi (2) test as appropriate. There were no differences between groups in gender, gestational age, initial weight, head circumference, and caloric intake and type of nutrition at baseline. Infants receiving massage had a larger weight gain versus the control group since the third day (188.2 +/- 41.20 g/kg versus 146.7 +/- 56.43 g/kg, P < 0.001). Hospital stay was shorter in infants receiving massage and usual nursery care (15.63 +/- 5.41 days versus 19.33 +/- 7.92 days, P = 0.03). The addition of parent-administered Vimala massage to usual nursery care resulted in increased weight gain and shorter hospital stay among clinically stable preterm newborns.

  10. Olfactory receptor neurons use gain control and complementary kinetics to encode intermittent odorant stimuli

    PubMed Central

    Gorur-Shandilya, Srinivas; Demir, Mahmut; Long, Junjiajia; Clark, Damon A; Emonet, Thierry

    2017-01-01

    Insects find food and mates by navigating odorant plumes that can be highly intermittent, with intensities and durations that vary rapidly over orders of magnitude. Much is known about olfactory responses to pulses and steps, but it remains unclear how olfactory receptor neurons (ORNs) detect the intensity and timing of natural stimuli, where the absence of scale in the signal makes detection a formidable olfactory task. By stimulating Drosophila ORNs in vivo with naturalistic and Gaussian stimuli, we show that ORNs adapt to stimulus mean and variance, and that adaptation and saturation contribute to naturalistic sensing. Mean-dependent gain control followed the Weber-Fechner relation and occurred primarily at odor transduction, while variance-dependent gain control occurred at both transduction and spiking. Transduction and spike generation possessed complementary kinetic properties, that together preserved the timing of odorant encounters in ORN spiking, regardless of intensity. Such scale-invariance could be critical during odor plume navigation. DOI: http://dx.doi.org/10.7554/eLife.27670.001 PMID:28653907

  11. Food motivation circuitry hypoactivation related to hedonic and nonhedonic aspects of hunger and satiety in women with active anorexia nervosa and weight-restored women with anorexia nervosa.

    PubMed

    Holsen, Laura M; Lawson, Elizabeth A; Blum, Justine; Ko, Eunice; Makris, Nikos; Fazeli, Pouneh K; Klibanski, Anne; Goldstein, Jill M

    2012-09-01

    Previous studies have provided evidence of food motivation circuitry dysfunction in individuals with anorexia nervosa. However, methodological limitations present challenges to the development of a cohesive neurobiological model of anorexia nervosa. Our goal was to investigate the neural circuitry of appetite dysregulation across states of hunger and satiety in active and weight-restored phases of anorexia nervosa using robust methodology to advance our understanding of potential neural circuitry abnormalities related to hedonic and nonhedonic state and trait. We scanned women with active anorexia nervosa, weight-restored women with anorexia nervosa and healthy-weight controls on a 3-T Siemens magnetic resonance scanner while they viewed images of high- and low-calorie foods and objects before (premeal) and after (postmeal) eating a 400 kcal meal. We enrolled 12 women with active disease, 10 weight-restored women with anorexia nervosa and 11 controls in our study. Compared with controls, both weight-restored women and those with active disease demonstrated hypoactivity premeal in the hypothalamus, amygdala and anterior insula in response to high-calorie foods (v. objects). Postmeal, hypoactivation in the anterior insula persisted in women with active disease. Percent signal change in the anterior insula was positively correlated with food stimuli ratings and hedonic and nonhedonic appetite ratings in controls, but not women with active disease. Our findings are limited by a relatively small sample size, which prevented the use of an analysis of variance model and exploration of interaction effects, although our substantial effect sizes of between-group differences suggest adequate power for our statistical analysis approach. Participants taking psychotropic medications were included. Our data provide evidence of potential state and trait hypoactivations in food motivation regions involved in the assessment of food's reward value and integration of these with

  12. Flight of frigatebirds inside clouds - energy gain, stability and control.

    PubMed

    Sachs, Gottfried; Weimerskirch, Henri

    2018-07-07

    Investigating the unique ability of frigatebirds of flying inside clouds, it is shown that they achieve a large energy gain by ascents to high altitudes in strong updrafts of trade cumulus clouds. Frigatebirds often perform that kind of flight, at daytime as well as in the night. This suggests that they are capable of flying inside clouds in a controlled and stabilized manner. The control requirements for ascents in terms of a circling flight in updrafts of trade cumulus clouds are analyzed, and the necessary aerodynamic control moments are determined. Based on a stability investigation, it is shown that there are restoring effects which act against disturbances causing possible deviations from the circling flight condition. The aerodynamic moments which effectuate that stabilization are identified. Furthermore, the problem of neutral azimuth stability which generally exists in the flight of birds and which is the reason for continually increasing deviations from the course is dealt with. It is shown for the circling flight mode of frigatebirds inside clouds that, here, deviations are small and remain constant, suggesting that a corrective control action is not required. This is particularly important for circling flight in conditions without a visual reference, like inside clouds. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Clock Controller For Ac Self-Timing Analysis Of Logic System

    DOEpatents

    Lo, Tinchee; Flanagan, John D.

    2004-05-18

    A clock controller and clock generating method are provided for AC self-test timing analysis of a logic system. The controller includes latch circuitry which receives a DC input signal at a data input, and a pair of continuous out-of-phase clock signals at capture and launch clock inputs thereof. The latch circuitry outputs two overlapping pulses responsive to the DC input signal going high. The two overlapping pulses are provided to waveform shaper circuitry which produces therefrom two non-overlapping pulses at clock speed of the logic system to be tested. The two non-overlapping pulses are a single pair of clock pulses which facilitate AC self-test timing analysis of the logic system.

  14. System-Level Integrated Circuit (SLIC) Technology Development for Phased Array Antenna Applications

    NASA Technical Reports Server (NTRS)

    Windyka, John A.; Zablocki, Ed G.

    1997-01-01

    This report documents the efforts and progress in developing a 'system-level' integrated circuit, or SLIC, for application in advanced phased array antenna systems. The SLIC combines radio-frequency (RF) microelectronics, digital and analog support circuitry, and photonic interfaces into a single micro-hybrid assembly. Together, these technologies provide not only the amplitude and phase control necessary for electronic beam steering in the phased array, but also add thermally-compensated automatic gain control, health and status feedback, bias regulation, and reduced interconnect complexity. All circuitry is integrated into a compact, multilayer structure configured for use as a two-by-four element phased array module, operating at 20 Gigahertz, using a Microwave High-Density Interconnect (MHDI) process. The resultant hardware is constructed without conventional wirebonds, maintains tight inter-element spacing, and leads toward low-cost mass production. The measured performances and development issues associated with both the two-by-four element module and the constituent elements are presented. Additionally, a section of the report describes alternative architectures and applications supported by the SLIC electronics. Test results show excellent yield and performance of RF circuitry and full automatic gain control for multiple, independent channels. Digital control function, while suffering from lower manufacturing yield, also proved successful.

  15. Evolution of the circuitry for conscious color vision in primates

    PubMed Central

    Neitz, J; Neitz, M

    2017-01-01

    There are many ganglion cell types and subtypes in our retina that carry color information. These have appeared at different times over the history of the evolution of the vertebrate visual system. They project to several different places in the brain and serve a variety of purposes allowing wavelength information to contribute to diverse visual functions. These include circadian photoentrainment, regulation of sleep and mood, guidance of orienting movements, detection and segmentation of objects. Predecessors to some of the circuits serving these purposes presumably arose before mammals evolved and different functions are represented by distinct ganglion cell types. However, while other animals use color information to elicit motor movements and regulate activity rhythms, as do humans, using phylogenetically ancient circuitry, the ability to appreciate color appearance may have been refined in ancestors to primates, mediated by a special set of ganglion cells that serve only that purpose. Understanding the circuitry for color vision has implications for the possibility of treating color blindness using gene therapy by recapitulating evolution. In addition, understanding how color is encoded, including how chromatic and achromatic percepts are separated is a step toward developing a complete picture of the diversity of ganglion cell types and their functions. Such knowledge could be useful in developing therapeutic strategies for blinding eye disorders that rely on stimulating elements in the retina, where more than 50 different neuron types are organized into circuits that transform signals from photoreceptors into specialized detectors many of which are not directly involved in conscious vision. PMID:27935605

  16. Evolution of the circuitry for conscious color vision in primates.

    PubMed

    Neitz, J; Neitz, M

    2017-02-01

    There are many ganglion cell types and subtypes in our retina that carry color information. These have appeared at different times over the history of the evolution of the vertebrate visual system. They project to several different places in the brain and serve a variety of purposes allowing wavelength information to contribute to diverse visual functions. These include circadian photoentrainment, regulation of sleep and mood, guidance of orienting movements, detection and segmentation of objects. Predecessors to some of the circuits serving these purposes presumably arose before mammals evolved and different functions are represented by distinct ganglion cell types. However, while other animals use color information to elicit motor movements and regulate activity rhythms, as do humans, using phylogenetically ancient circuitry, the ability to appreciate color appearance may have been refined in ancestors to primates, mediated by a special set of ganglion cells that serve only that purpose. Understanding the circuitry for color vision has implications for the possibility of treating color blindness using gene therapy by recapitulating evolution. In addition, understanding how color is encoded, including how chromatic and achromatic percepts are separated is a step toward developing a complete picture of the diversity of ganglion cell types and their functions. Such knowledge could be useful in developing therapeutic strategies for blinding eye disorders that rely on stimulating elements in the retina, where more than 50 different neuron types are organized into circuits that transform signals from photoreceptors into specialized detectors many of which are not directly involved in conscious vision.

  17. Nanowire active-matrix circuitry for low-voltage macroscale artificial skin.

    PubMed

    Takei, Kuniharu; Takahashi, Toshitake; Ho, Johnny C; Ko, Hyunhyub; Gillies, Andrew G; Leu, Paul W; Fearing, Ronald S; Javey, Ali

    2010-10-01

    Large-scale integration of high-performance electronic components on mechanically flexible substrates may enable new applications in electronics, sensing and energy. Over the past several years, tremendous progress in the printing and transfer of single-crystalline, inorganic micro- and nanostructures on plastic substrates has been achieved through various process schemes. For instance, contact printing of parallel arrays of semiconductor nanowires (NWs) has been explored as a versatile route to enable fabrication of high-performance, bendable transistors and sensors. However, truly macroscale integration of ordered NW circuitry has not yet been demonstrated, with the largest-scale active systems being of the order of 1 cm(2) (refs 11,15). This limitation is in part due to assembly- and processing-related obstacles, although larger-scale integration has been demonstrated for randomly oriented NWs (ref. 16). Driven by this challenge, here we demonstrate macroscale (7×7 cm(2)) integration of parallel NW arrays as the active-matrix backplane of a flexible pressure-sensor array (18×19 pixels). The integrated sensor array effectively functions as an artificial electronic skin, capable of monitoring applied pressure profiles with high spatial resolution. The active-matrix circuitry operates at a low operating voltage of less than 5 V and exhibits superb mechanical robustness and reliability, without performance degradation on bending to small radii of curvature (2.5 mm) for over 2,000 bending cycles. This work presents the largest integration of ordered NW-array active components, and demonstrates a model platform for future integration of nanomaterials for practical applications.

  18. Optimal PID gain schedule for hydrogenerators

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

    Orelind, G.; Wozniak, L.; Medanic, J.

    1989-09-01

    This paper describes the development and testing of a digital gain switching governor for hydrogenerators. Optimal gains were found at different load points by minimizing a quadratic performance criterion prior to controller operating. During operation, the gain sets are switched in depending on the gate position and speed error magnitude. With gain switching operating, the digital governor was shown to have a substantial reduction of noise on the command signal and up to 42% faster responses to power requests. Non-linear control strategies enabled the digital governor to have a 2.5% to 2% reduction in speed overshoot on startups, and anmore » 8% to 1% reduction in undershoot on load rejections as compared to the analog.« less

  19. Function and Dysfunction of Prefrontal Brain Circuitry in Alcoholic Korsakoff’s Syndrome

    PubMed Central

    Oscar-Berman, Marlene

    2013-01-01

    The signature symptom of alcohol-induced persisting amnestic disorder, more commonly referred to as alcoholic Korsakoff’s syndrome (KS), is anterograde amnesia, or memory loss for recent events, and until the mid 20th Century, the putative brain damage was considered to be in diencephalic and medial temporal lobe structures. Overall intelligence, as measured by standardized IQ tests, usually remains intact. Preservation of IQ occurs because memories formed before the onset of prolonged heavy drinking — the types of information and abilities tapped by intelligence tests — remain relatively well preserved compared with memories recently acquired. However, clinical and experimental evidence has shown that neurobehavioral dysfunction in alcoholic patients with KS does include nonmnemonic abilities, and further brain damage involves extensive frontal and limbic circuitries. Among the abnormalities are confabulation, disruption of elements of executive functioning and cognitive control, and emotional impairments. Here, we discuss the relationship between neurobehavioral impairments in KS and alcoholism-related brain damage. More specifically, we examine the role of damage to prefrontal brain systems in the neuropsychological profile of alcoholic KS. PMID:22538385

  20. Gain-scheduled {{\\mathscr{H}}}_{\\infty } buckling control of a circular beam-column subject to time-varying axial loads

    NASA Astrophysics Data System (ADS)

    Schaeffner, Maximilian; Platz, Roland

    2018-06-01

    For slender beam-columns loaded by axial compressive forces, active buckling control provides a possibility to increase the maximum bearable axial load above that of a purely passive structure. In this paper, an approach for gain-scheduled {{\\mathscr{H}}}∞ buckling control of a slender beam-column with circular cross-section subject to time-varying axial loads is investigated experimentally. Piezo-elastic supports with integrated piezoelectric stack actuators at the beam-column ends allow an active stabilization in arbitrary lateral directions. The axial loads on the beam-column influence its lateral dynamic behavior and, eventually, cause the beam-column to buckle. A reduced modal model of the beam-column subject to axial loads including the dynamics of the electrical components is set up and calibrated with experimental data. Particularly, the linear parameter-varying open-loop plant is used to design a model-based gain-scheduled {{\\mathscr{H}}}∞ buckling control that is implemented in an experimental test setup. The beam-column is loaded by ramp- and step-shaped time-varying axial compressive loads that result in a lateral deformation of the beam-column due to imperfections, such as predeformation, eccentric loading or clamping moments. The lateral deformations and the maximum bearable loads of the beam-column are analyzed and compared for the beam-column with and without gain-scheduled {{\\mathscr{H}}}∞ buckling control or, respectively, active and passive configuration. With the proposed gain-scheduled {{\\mathscr{H}}}∞ buckling control it is possible to increase the maximum bearable load of the active beam-column by 19% for ramp-shaped axial loads and to significantly reduce the beam-column deformations for step-shaped axial loads compared to the passive structure.

  1. System and circuitry to provide stable transconductance for biasing

    NASA Technical Reports Server (NTRS)

    Garverick, Steven L. (Inventor); Yu, Xinyu (Inventor)

    2012-01-01

    An amplifier system can include an input amplifier configured to receive an analog input signal and provide an amplified signal corresponding to the analog input signal. A tracking loop is configured to employ delta modulation for tracking the amplified signal, the tracking loop providing a corresponding output signal. A biasing circuit is configured to adjust a bias current to maintain stable transconductance over temperature variations, the biasing circuit providing at least one bias signal for biasing at least one of the input amplifier and the tracking loop, whereby the circuitry receiving the at least one bias signal exhibits stable performance over the temperature variations. In another embodiment the biasing circuit can be utilized in other applications.

  2. Programming Arduino to Control Bias Voltages to Temperature-Depedndent Gamma-ray Detectors aboard TRYAD Mission

    NASA Astrophysics Data System (ADS)

    Stevons, C. E.; Jenke, P.; Briggs, M. S.

    2016-12-01

    Terrestrial Gamma-ray Flashes (TGFs) are sub-millisecond gamma-ray flashes that are correlated with lightning have been observed with numerous satellites since their discovery in the early 1990s. Although substantial research has been conducted on TGFs, puzzling questions regarding their origin are still left unanswered. Consequently, the Terrestrial RaYs Analysis and Detection (TRYAD) mission is designed to solve many issues about TGFs by measuring the beam profile and orientation of TGFs in low Earth orbit. This project consists of sending two CubeSats into low-Earth orbit where they will independently sample TGF beams. Both of the TRYAD CubeSats will contain a gamma-ray detector composed of lead doped plastic scintillator coupled to silicon photomultiplier (SiPM) arrays. The gain readings of the SiPMs vary with temperature and the bias voltage must be corrected to compensate. Using an Arduino micro-controller, circuitry and software was developed to control the gain in response to the resistance of a thermistor. I will present the difficulties involved with this project along with our solutions.

  3. Device for self-verifying temperature measurement and control

    DOEpatents

    Watkins, Arthur D.; Cannon, Collins P.; Tolle, Charles R.

    2004-08-03

    A measuring instrument includes a first temperature sensor, a second temperature sensor and circuitry. The first and second temperature sensors each generate a signal indicative of the temperature of a medium being detected. The circuitry is configured to activate verification of temperature being sensed with the first sensor. According to one construction, the first temperature sensor comprises at least one thermocouple temperature sensor and the second temperature sensor comprises an optical temperature sensor, each sensor measuring temperature over the same range of temperature, but using a different physical phenomena. Also according to one construction, the circuitry comprises a computer configured to detect failure of one of the thermocouples by comparing temperature of the optical temperature sensor with each of the thermocouple temperature sensors. Even further, an output control signal is generated via a fuzzy inference machine and control apparatus.

  4. Microwave remediation of electronic circuitry waste and the resulting gaseous emissions

    NASA Astrophysics Data System (ADS)

    Schulz, Rebecca L.

    The global community has become increasingly dependent on computer and electronic technology. As a result, society is faced with an increasing amount of obsolete equipment and electronic circuitry waste. Electronic waste is generally disposed of in landfills. While convenient, this action causes a substantial loss of finite resources and poses an environmental threat as the circuit board components breakdown and are exposed to the elements. Hazardous compounds such as lead, mercury and cadmium may leach from the circuitry and find their way into the groundwater supply. For this dissertation, a microwave waste remediation system was developed. The system was designed to remove the organic components from a wide variety of electronic circuitry. Upon additional heating of the resulting ash material in an industrial microwave, a glass and metal product can be recovered. Analysis of the metal reveals the presence of precious metals (gold, silver) that can be sold to provide a return on investment. a glass and metal product can be recovered. Analysis of the metal reveals the presence of precious metals (gold, silver) that can be sold to provide a return on investment. Gaseous organic compounds that were generated as a result of organic removal were treated in a microwave off gas system that effectively reduced the concentration of the products emitted by several orders of magnitude, and in some cases completely destroying the waste gas. Upon further heating in an industrial microwave, a glass and metal product were recovered. In order to better understand the effects of processing parameters on the efficiency of the off-gas system, a parametric study was developed. The study tested the microwave system at 3 flow rates (10, 30, and 50 ft 3/min) and three temperatures (400, 700 and 1000°C. In order to test the effects of microwave energy, the experiments were repeated using a conventional furnace. While microwave energy is widely used, the mechanisms of interaction with

  5. Cortical circuitry implementing graphical models.

    PubMed

    Litvak, Shai; Ullman, Shimon

    2009-11-01

    In this letter, we develop and simulate a large-scale network of spiking neurons that approximates the inference computations performed by graphical models. Unlike previous related schemes, which used sum and product operations in either the log or linear domains, the current model uses an inference scheme based on the sum and maximization operations in the log domain. Simulations show that using these operations, a large-scale circuit, which combines populations of spiking neurons as basic building blocks, is capable of finding close approximations to the full mathematical computations performed by graphical models within a few hundred milliseconds. The circuit is general in the sense that it can be wired for any graph structure, it supports multistate variables, and it uses standard leaky integrate-and-fire neuronal units. Following previous work, which proposed relations between graphical models and the large-scale cortical anatomy, we focus on the cortical microcircuitry and propose how anatomical and physiological aspects of the local circuitry may map onto elements of the graphical model implementation. We discuss in particular the roles of three major types of inhibitory neurons (small fast-spiking basket cells, large layer 2/3 basket cells, and double-bouquet neurons), subpopulations of strongly interconnected neurons with their unique connectivity patterns in different cortical layers, and the possible role of minicolumns in the realization of the population-based maximum operation.

  6. Multi-objective optimization of piezoelectric circuitry network for mode delocalization and suppression of bladed disk

    NASA Astrophysics Data System (ADS)

    Yoo, David; Tang, J.

    2017-04-01

    Since weakly-coupled bladed disks are highly sensitive to the presence of uncertainties, they can easily undergo vibration localization. When vibration localization occurs, vibration modes of bladed disk become dramatically different from those under the perfectly periodic condition, and the dynamic response under engine-order excitation is drastically amplified. In previous studies, it is investigated that amplified vibration response can be suppressed by connecting piezoelectric circuitry into individual blades to induce the damped absorber effect, and localized vibration modes can be alleviated by integrating piezoelectric circuitry network. Delocalization of vibration modes and vibration suppression of bladed disk, however, require different optimal set of circuit parameters. In this research, multi-objective optimization approach is developed to enable finding the best circuit parameters, simultaneously achieving both objectives. In this way, the robustness and reliability in bladed disk can be ensured. Gradient-based optimizations are individually developed for mode delocalization and vibration suppression, which are then integrated into multi-objective optimization framework.

  7. Oxytocin Treatment, Circuitry, and Autism: A Critical Review of the Literature Placing Oxytocin Into the Autism Context.

    PubMed

    Guastella, Adam J; Hickie, Ian B

    2016-02-01

    Observed impairment in reciprocal social interaction is a diagnostic hallmark of autism spectrum disorders. There is no effective medical treatment for these problems. Psychological treatments remain costly, time intensive, and developmentally sensitive for efficacy. In this review, we explore the potential of oxytocin-based therapies for social impairments in autism. Evidence shows that acute oxytocin administration improves numerous markers critical to the social circuitry underlying social deficits in autism. Oxytocin may optimize these circuits and enhance reward, motivation, and learning to improve therapeutic outcomes. Despite this, the current evidence of therapeutic benefit from extended oxytocin treatment remains very limited. We highlight complexity in crossing from the laboratory to the autism clinical setting in evaluation of this therapeutic. We discuss a clinical trial approach that provides optimal opportunity for therapeutic response by using personalized methods that better target specific circuitry to define who will obtain benefit, at what stage of development, and the optimal delivery approach for circuitry manipulation. For the autism field, the therapeutic challenges will be resolved by a range of treatment strategies, including greater focus on specific interventions, such as oxytocin, that have a strong basis in the fundamental neurobiology of social behavior. More sophisticated and targeted clinical trials utilizing such approaches are now required, placing oxytocin into the autism context. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  8. Reason's Enemy Is Not Emotion: Engagement of Cognitive Control Networks Explains Biases in Gain/Loss Framing

    PubMed Central

    2017-01-01

    In the classic gain/loss framing effect, describing a gamble as a potential gain or loss biases people to make risk-averse or risk-seeking decisions, respectively. The canonical explanation for this effect is that frames differentially modulate emotional processes, which in turn leads to irrational choice behavior. Here, we evaluate the source of framing biases by integrating functional magnetic resonance imaging data from 143 human participants performing a gain/loss framing task with meta-analytic data from >8000 neuroimaging studies. We found that activation during choices consistent with the framing effect were most correlated with activation associated with the resting or default brain, while activation during choices inconsistent with the framing effect was most correlated with the task-engaged brain. Our findings argue against the common interpretation of gain/loss framing as a competition between emotion and control. Instead, our study indicates that this effect results from differential cognitive engagement across decision frames. SIGNIFICANCE STATEMENT The biases frequently exhibited by human decision makers have often been attributed to the presence of emotion. Using a large fMRI sample and analysis of whole-brain networks defined with the meta-analytic tool Neurosynth, we find that neural activity during frame-biased decisions was more significantly associated with default behaviors (and the absence of executive control) than with emotion. These findings point to a role for neuroscience in shaping long-standing psychological theories in decision science. PMID:28264981

  9. Reason's Enemy Is Not Emotion: Engagement of Cognitive Control Networks Explains Biases in Gain/Loss Framing.

    PubMed

    Li, Rosa; Smith, David V; Clithero, John A; Venkatraman, Vinod; Carter, R McKell; Huettel, Scott A

    2017-03-29

    In the classic gain/loss framing effect, describing a gamble as a potential gain or loss biases people to make risk-averse or risk-seeking decisions, respectively. The canonical explanation for this effect is that frames differentially modulate emotional processes, which in turn leads to irrational choice behavior. Here, we evaluate the source of framing biases by integrating functional magnetic resonance imaging data from 143 human participants performing a gain/loss framing task with meta-analytic data from >8000 neuroimaging studies. We found that activation during choices consistent with the framing effect were most correlated with activation associated with the resting or default brain, while activation during choices inconsistent with the framing effect was most correlated with the task-engaged brain. Our findings argue against the common interpretation of gain/loss framing as a competition between emotion and control. Instead, our study indicates that this effect results from differential cognitive engagement across decision frames. SIGNIFICANCE STATEMENT The biases frequently exhibited by human decision makers have often been attributed to the presence of emotion. Using a large fMRI sample and analysis of whole-brain networks defined with the meta-analytic tool Neurosynth, we find that neural activity during frame-biased decisions was more significantly associated with default behaviors (and the absence of executive control) than with emotion. These findings point to a role for neuroscience in shaping long-standing psychological theories in decision science. Copyright © 2017 the authors 0270-6474/17/373588-11$15.00/0.

  10. Control systems engineering for optimizing a prenatal weight gain intervention to regulate infant birth weight.

    PubMed

    Savage, Jennifer S; Downs, Danielle Symons; Dong, Yuwen; Rivera, Daniel E

    2014-07-01

    We used dynamical systems modeling to describe how a prenatal behavioral intervention that adapts to the needs of each pregnant woman may help manage gestational weight gain and alter the obesogenic intrauterine environment to regulate infant birth weight. This approach relies on integrating mechanistic energy balance, theory of planned behavior, and self-regulation models to describe how internal processes can be impacted by intervention dosages, and reinforce positive outcomes (e.g., healthy eating and physical activity) to moderate gestational weight gain and affect birth weight. A simulated hypothetical case study from MATLAB with Simulink showed how, in response to our adaptive intervention, self-regulation helps adjust perceived behavioral control. This, in turn, changes the woman's intention and behavior with respect to healthy eating and physical activity during pregnancy, affecting gestational weight gain and infant birth weight. This article demonstrates the potential for real-world applications of an adaptive intervention to manage gestational weight gain and moderate infant birth weight. This model could be expanded to examine the long-term sustainable impacts of an intervention that varies according to the participant's needs on maternal postpartum weight retention and child postnatal eating behavior.

  11. 78 FR 24234 - Certain Semiconductor Chips With DRAM Circuitry, and Modules and Products Containing Same; Notice...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-24

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-819] Certain Semiconductor Chips With DRAM Circuitry, and Modules and Products Containing Same; Notice of Request for Statements on the... order barring the entry of unlicensed DRAM semiconductor chips manufactured by Nanya Technology...

  12. Neural Encoding and Integration of Learned Probabilistic Sequences in Avian Sensory-Motor Circuitry

    PubMed Central

    Brainard, Michael S.

    2013-01-01

    Many complex behaviors, such as human speech and birdsong, reflect a set of categorical actions that can be flexibly organized into variable sequences. However, little is known about how the brain encodes the probabilities of such sequences. Behavioral sequences are typically characterized by the probability of transitioning from a given action to any subsequent action (which we term “divergence probability”). In contrast, we hypothesized that neural circuits might encode the probability of transitioning to a given action from any preceding action (which we term “convergence probability”). The convergence probability of repeatedly experienced sequences could naturally become encoded by Hebbian plasticity operating on the patterns of neural activity associated with those sequences. To determine whether convergence probability is encoded in the nervous system, we investigated how auditory-motor neurons in vocal premotor nucleus HVC of songbirds encode different probabilistic characterizations of produced syllable sequences. We recorded responses to auditory playback of pseudorandomly sequenced syllables from the bird's repertoire, and found that variations in responses to a given syllable could be explained by a positive linear dependence on the convergence probability of preceding sequences. Furthermore, convergence probability accounted for more response variation than other probabilistic characterizations, including divergence probability. Finally, we found that responses integrated over >7–10 syllables (∼700–1000 ms) with the sign, gain, and temporal extent of integration depending on convergence probability. Our results demonstrate that convergence probability is encoded in sensory-motor circuitry of the song-system, and suggest that encoding of convergence probability is a general feature of sensory-motor circuits. PMID:24198363

  13. Robust control for spacecraft rendezvous system with actuator unsymmetrical saturation: a gain scheduling approach

    NASA Astrophysics Data System (ADS)

    Wang, Qian; Xue, Anke

    2018-06-01

    This paper has proposed a robust control for the spacecraft rendezvous system by considering the parameter uncertainties and actuator unsymmetrical saturation based on the discrete gain scheduling approach. By changing of variables, we transform the actuator unsymmetrical saturation control problem into a symmetrical one. The main advantage of the proposed method is improving the dynamic performance of the closed-loop system with a region of attraction as large as possible. By the Lyapunov approach and the scheduling technology, the existence conditions for the admissible controller are formulated in the form of linear matrix inequalities. The numerical simulation illustrates the effectiveness of the proposed method.

  14. Adjustment of Adaptive Gain with Bounded Linear Stability Analysis to Improve Time-Delay Margin for Metrics-Driven Adaptive Control

    NASA Technical Reports Server (NTRS)

    Bakhtiari-Nejad, Maryam; Nguyen, Nhan T.; Krishnakumar, Kalmanje Srinvas

    2009-01-01

    This paper presents the application of Bounded Linear Stability Analysis (BLSA) method for metrics driven adaptive control. The bounded linear stability analysis method is used for analyzing stability of adaptive control models, without linearizing the adaptive laws. Metrics-driven adaptive control introduces a notion that adaptation should be driven by some stability metrics to achieve robustness. By the application of bounded linear stability analysis method the adaptive gain is adjusted during the adaptation in order to meet certain phase margin requirements. Analysis of metrics-driven adaptive control is evaluated for a linear damaged twin-engine generic transport model of aircraft. The analysis shows that the system with the adjusted adaptive gain becomes more robust to unmodeled dynamics or time delay.

  15. Controlling slow and fast light and dynamic pulse-splitting with tunable optical gain in a whispering-gallery-mode microcavity

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

    Asano, M.; Ikuta, R.; Imoto, N.

    We report controllable manipulation of slow and fast light in a whispering-gallery-mode microtoroid resonator fabricated from Erbium (Er{sup 3+}) doped silica. We observe continuous transition of the coupling between the fiber-taper waveguide and the microresonator from undercoupling to critical coupling and then to overcoupling regimes by increasing the pump power even though the spatial distance between the resonator and the waveguide was kept fixed. This, in turn, enables switching from fast to slow light and vice versa just by increasing the optical gain. An enhancement of delay of two-fold over the passive silica resonator (no optical gain) was observed inmore » the slow light regime. Moreover, we show dynamic pulse splitting and its control in slow/fast light systems using optical gain.« less

  16. High-speed low-power photonic transistor devices based on optically-controlled gain or absorption to affect optical interference.

    PubMed

    Huang, Yingyan; Ho, Seng-Tiong

    2008-10-13

    We show that a photonic transistor device can be realized via the manipulation of optical interference by optically controlled gain or absorption in novel ways, resulting in efficient transistor signal gain and switching action. Exemplary devices illustrate two complementary device types with high operating speed, microm size, microW switching power, and switching gain. They can act in tandem to provide a wide variety of operations including wavelength conversion, pulse regeneration, and logical operations. These devices could have a Transistor Figure-of-Merits >10(5) times higher than current chi((3)) approaches and are highly attractive.

  17. Adaptive Robust Output Feedback Control for a Marine Dynamic Positioning System Based on a High-Gain Observer.

    PubMed

    Du, Jialu; Hu, Xin; Liu, Hongbo; Chen, C L Philip

    2015-11-01

    This paper develops an adaptive robust output feedback control scheme for dynamically positioned ships with unavailable velocities and unknown dynamic parameters in an unknown time-variant disturbance environment. The controller is designed by incorporating the high-gain observer and radial basis function (RBF) neural networks in vectorial backstepping method. The high-gain observer provides the estimations of the ship position and heading as well as velocities. The RBF neural networks are employed to compensate for the uncertainties of ship dynamics. The adaptive laws incorporating a leakage term are designed to estimate the weights of RBF neural networks and the bounds of unknown time-variant environmental disturbances. In contrast to the existing results of dynamic positioning (DP) controllers, the proposed control scheme relies only on the ship position and heading measurements and does not require a priori knowledge of the ship dynamics and external disturbances. By means of Lyapunov functions, it is theoretically proved that our output feedback controller can control a ship's position and heading to the arbitrarily small neighborhood of the desired target values while guaranteeing that all signals in the closed-loop DP control system are uniformly ultimately bounded. Finally, simulations involving two ships are carried out, and simulation results demonstrate the effectiveness of the proposed control scheme.

  18. Self-assembled DNA tetrahedral optofluidic lasers with precise and tunable gain control.

    PubMed

    Chen, Qiushu; Liu, Huajie; Lee, Wonsuk; Sun, Yuze; Zhu, Dan; Pei, Hao; Fan, Chunhai; Fan, Xudong

    2013-09-07

    We have applied self-assembled DNA tetrahedral nanostructures for the precise and tunable control of the gain in an optofluidic fluorescence resonance energy transfer (FRET) laser. By adjusting the ratio of the donor and the acceptor attached to the tetrahedral vertices, 3.8 times reduction in the lasing threshold and 28-fold enhancement in the lasing efficiency were demonstrated. This work takes advantage of the self-recognition and self-assembly capabilities of biomolecules with well-defined structures and addressability, enabling nano-engineering of the laser down to the molecular level.

  19. Training the emotional brain: improving affective control through emotional working memory training.

    PubMed

    Schweizer, Susanne; Grahn, Jessica; Hampshire, Adam; Mobbs, Dean; Dalgleish, Tim

    2013-03-20

    Affective cognitive control capacity (e.g., the ability to regulate emotions or manipulate emotional material in the service of task goals) is associated with professional and interpersonal success. Impoverished affective control, by contrast, characterizes many neuropsychiatric disorders. Insights from neuroscience indicate that affective cognitive control relies on the same frontoparietal neural circuitry as working memory (WM) tasks, which suggests that systematic WM training, performed in an emotional context, has the potential to augment affective control. Here we show, using behavioral and fMRI measures, that 20 d of training on a novel emotional WM protocol successfully enhanced the efficiency of this frontoparietal demand network. Critically, compared with placebo training, emotional WM training also accrued transfer benefits to a "gold standard" measure of affective cognitive control-emotion regulation. These emotion regulation gains were associated with greater activity in the targeted frontoparietal demand network along with other brain regions implicated in affective control, notably the subgenual anterior cingulate cortex. The results have important implications for the utility of WM training in clinical, prevention, and occupational settings.

  20. Food motivation circuitry hypoactivation related to hedonic and nonhedonic aspects of hunger and satiety in women with active anorexia nervosa and weight-restored women with anorexia nervosa

    PubMed Central

    Holsen, Laura M.; Lawson, Elizabeth A.; Blum, Justine; Ko, Eunice; Makris, Nikos; Fazeli, Pouneh K.; Klibanski, Anne; Goldstein, Jill M.

    2012-01-01

    Background Previous studies have provided evidence of food motivation circuitry dysfunction in individuals with anorexia nervosa. However, methodological limitations present challenges to the development of a cohesive neurobiological model of anorexia nervosa. Our goal was to investigate the neural circuitry of appetite dysregulation across states of hunger and satiety in active and weight-restored phases of anorexia nervosa using robust methodology to advance our understanding of potential neural circuitry abnormalities related to hedonic and nonhedonic state and trait. Methods We scanned women with active anorexia nervosa, weight-restored women with anorexia nervosa and healthy-weight controls on a 3-T Siemens magnetic resonance scanner while they viewed images of high- and low-calorie foods and objects before (premeal) and after (postmeal) eating a 400 kcal meal. Results We enrolled 12 women with active disease, 10 weight-restored women with anorexia nervosa and 11 controls in our study. Compared with controls, both weight-restored women and those with active disease demonstrated hypoactivity premeal in the hypothalamus, amygdala and anterior insula in response to high-calorie foods (v. objects). Postmeal, hypoactivation in the anterior insula persisted in women with active disease. Percent signal change in the anterior insula was positively correlated with food stimuli ratings and hedonic and nonhedonic appetite ratings in controls, but not women with active disease. Limitations Our findings are limited by a relatively small sample size, which prevented the use of an analysis of variance model and exploration of interaction effects, although our substantial effect sizes of between-group differences suggest adequate power for our statistical analysis approach. Participants taking psychotropic medications were included. Conclusion Our data provide evidence of potential state and trait hypoactivations in food motivation regions involved in the assessment of food

  1. Almost output regulation of LFT systems via gain-scheduling control

    NASA Astrophysics Data System (ADS)

    Yuan, Chengzhi; Duan, Chang; Wu, Fen

    2018-05-01

    Output regulation of general uncertain systems is a meaningful yet challenging problem. In spite of the rich literature in the field, the problem has not yet been addressed adequately due to the lack of an effective design mechanism. In this paper, we propose a new design framework for almost output regulation of uncertain systems described in the general form of linear fractional transformation (LFT) with time-varying parametric uncertainties and unknown external perturbations. A novel semi-LFT gain-scheduling output regulator structure is proposed, such that the associated control synthesis conditions guaranteeing both output regulation and ? disturbance attenuation performance are formulated as a set of linear matrix inequalities (LMIs) plus parameter-dependent linear matrix equations, which can be solved separately. A numerical example has been used to demonstrate the effectiveness of the proposed approach.

  2. Understanding efficiency limits of dielectric elastomer driver circuitry

    NASA Astrophysics Data System (ADS)

    Lo, Ho Cheong; Calius, Emilio; Anderson, Iain

    2013-04-01

    Dielectric elastomers (DEs) can theoretically operate at efficiencies greater than that of electromagnetics. This is due to their unique mode of operation which involves charging and discharging a capacitive load at a few kilovolts (typically 1kV-4kV). Efficient recovery of the electrical energy stored in the capacitance of the DE is essential in achieving favourable efficiencies as actuators or generators. This is not a trivial problem because the DE acts as a voltage source with a low capacity and a large output resistance. These properties are not ideal for a power source, and will reduce the performance of any power conditioning circuit utilizing inductors or transformers. This paper briefly explores how circuit parameters affect the performance of a simple inductor circuit used to transfer energy from a DE to another capacitor. These parameters must be taken into account when designing the driving circuitry to maximize performance.

  3. Optimizing Gestational Weight Gain With the Eating4Two Smartphone App: Protocol for a Randomized Controlled Trial.

    PubMed

    Davis, Deborah; Davey, Rachel; Williams, Lauren T; Foureur, Maralyn; Nohr, Ellen; Knight-Agarwal, Catherine; Lawlis, Tanya; Oats, Jeremy; Skouteris, Helen; Fuller-Tyszkiewicz, Matthew

    2018-05-30

    Approximately 50% of women gain excessive weight in pregnancy. Optimizing gestational weight gain is important for the short- and long-term health of the childbearing woman and her baby. Despite this, there is no recommendation for routine weighing in pregnancy, and weight is a topic that many maternity care providers avoid. Resource-intensive interventions have mainly targeted overweight and obese women with variable results. Few studies have examined the way that socioeconomic status might influence the effectiveness or acceptability of an intervention to participants. Given the scale of the problem of maternal weight gain, maternity services will be unlikely to sustain resource intensive interventions; therefore, innovative strategies are required to assist women to manage weight gain in pregnancy. The primary aim of the trial was to examine the effectiveness of the Eating4Two smartphone app in assisting women of all body mass index categories to optimize gestational weight gain. Secondary aims include comparing childbirth outcomes and satisfaction with antenatal care and examining the way that relative advantage and disadvantage might influence engagement with and acceptability of the intervention. This randomized controlled trial will randomize 1330 women to control or intervention groups in 3 regions of different socioeconomic status. Women will be recruited from clinical and social media sites. The intervention group will be provided with access to the Eating4Two mobile phone app which provides nutrition and dietary information specifically tailored for pregnancy, advice on food serving sizes, and a graph that illustrates women's weight change in relation to the range recommended by the Institute of Medicine. Women will be encouraged to use the app to prompt conversations with their maternity care providers about weight gain in pregnancy. The control group will receive routine antenatal care. Recruitment has commenced though the recruitment rate is slower

  4. Fail-safe numerical control

    NASA Technical Reports Server (NTRS)

    Thompson, G. A.

    1970-01-01

    System provides duplicate set of control logic circuitry. Comparators insure that the same data is present in both circuits. If any discrepancy is found, the machine is automatically stopped, before damage can occur.

  5. A novel transdermal nanoethosomal gel of betahistine dihydrochloride for weight gain control: in-vitro and in-vivo characterization

    PubMed Central

    El-Menshawe, Shahira F; Ali, Adel Ahmed; Halawa, Abdelkhalk Ali; Srag El-Din, Ahmed SG

    2017-01-01

    Background Betahistine dihydrochloride (BDH) is a histamine analog used to control weight gain, with short elimination half-life and gastric irritation as side effects. Objective The aim of the current investigation is to formulate and optimize a topical BDH ethosomal gel for weight gain control. Materials and methods Box–Behnken design was applied to study the effect of independent variables: phosphatidylcholine (PC), propylene glycol (PG), and ethanol on vesicle size; entrapment efficiency; % drug release; and flux. The morphology and zeta potential of the optimized formulation were evaluated. The % drug release, flux, and pharmacodynamics of the optimized formulation gel were studied. Results The size and entrapment efficiency percent had a direct positive relationship with the concentration of PC and negative relationship with ethanol and PG. The % drug release and flux decreased with increasing PC and PG, while ethanol enhanced both responses. Regression modeling indicated a good correlation between dependent and independent variables, where F16 was chosen as the optimized formulation. F16 showed well-defined spherical vesicles and zeta potential of −24 mV, and % release from the gel exceeded 99.5% over 16 h with the flux of 0.28 mg/cm2/h. Food intake and weight gain of rats were significantly decreased after transdermal application of the BDH ethosomal gel when compared with control, placebo, and BDH gel. The histopathological findings proved the absence of inflammation and decrease in adipose tissue. Conclusion Results obtained showed a significant, sustained transdermal absorption of BDH ethosomal gel and, consequently, a decrease in food intake and weight gain. PMID:29238164

  6. Focusing on optic tectum circuitry through the lens of genetics.

    PubMed

    Nevin, Linda M; Robles, Estuardo; Baier, Herwig; Scott, Ethan K

    2010-09-28

    The visual pathway is tasked with processing incoming signals from the retina and converting this information into adaptive behavior. Recent studies of the larval zebrafish tectum have begun to clarify how the 'micro-circuitry' of this highly organized midbrain structure filters visual input, which arrives in the superficial layers and directs motor output through efferent projections from its deep layers. The new emphasis has been on the specific function of neuronal cell types, which can now be reproducibly labeled, imaged and manipulated using genetic and optical techniques. Here, we discuss recent advances and emerging experimental approaches for studying tectal circuits as models for visual processing and sensorimotor transformation by the vertebrate brain.

  7. Device and method for self-verifying temperature measurement and control

    DOEpatents

    Watkins, Arthur D.; Cannon, Collins P.; Tolle, Charles R.

    2002-10-29

    A measuring instrument includes a first temperature sensor, a second temperature sensor and circuitry. The first and second temperature sensors each generate a signal indicative of the temperature of a medium being detected. The circuitry is configured to activate verification of temperature being sensed with the first sensor. According to one construction, the first temperature sensor comprises at least one thermocouple temperature sensor and the second temperature sensor comprises an optical temperature sensor, each sensor measuring temperature over the same range of temperature, but using a different physical phenomena. Also according to one construction, the circuitry comprises a computer configured to detect failure of one of the thermocouples by comparing temperature of the optical temperature sensor with each of the thermocouple temperature sensors. Even further, an output control signal is generated via a fuzzy inference machine and control apparatus.

  8. Analysis of sensorless control of brushless DC motor using unknown input observer with different gains

    NASA Astrophysics Data System (ADS)

    Astik, Mitesh B.; Bhatt, Praghnesh; Bhalja, Bhavesh R.

    2017-03-01

    A sensorless control scheme based on an unknown input observer is presented in this paper in which back EMF of the Brushless DC Motor (BLDC) is continuously estimated from available line voltages and currents. During negative rotation of motor, actual and estimated speed fail to track the reference speed and if the corrective action is not taken by the observer, the motor goes into saturation. To overcome this problem, the speed estimation algorithm has been implemented in this paper to control the dynamic behavior of the motor during negative rotation. The Ackermans method was used to calculate the gains of an unknown input observer which is based on the appropriate choice of the eigenvalues in advance. The criteria to choose eigenvalue is to obtain a balance between faster convergence rate and the least noise level. Simulations have been carried out for different disturbances such as step changes in motor reference speed and load torque. The comparative simulation results clearly depict that the disturbance effects in actual and estimated responses minimizes as observer gain setting increases.

  9. Modification of saccadic gain by reinforcement

    PubMed Central

    Paeye, Céline; Wallman, Josh

    2011-01-01

    Control of saccadic gain is often viewed as a simple compensatory process in which gain is adjusted over many trials by the postsaccadic retinal error, thereby maintaining saccadic accuracy. Here, we propose that gain might also be changed by a reinforcement process not requiring a visual error. To test this hypothesis, we used experimental paradigms in which retinal error was removed by extinguishing the target at the start of each saccade and either an auditory tone or the vision of the target on the fovea was provided as reinforcement after those saccades that met an amplitude criterion. These reinforcement procedures caused a progressive change in saccade amplitude in nearly all subjects, although the rate of adaptation differed greatly among subjects. When we reversed the contingencies and reinforced those saccades landing closer to the original target location, saccade gain changed back toward normal gain in most subjects. When subjects had saccades adapted first by reinforcement and a week later by conventional intrasaccadic step adaptation, both paradigms yielded similar degrees of gain changes and similar transfer to new amplitudes and to new starting positions of the target step as well as comparable rates of recovery. We interpret these changes in saccadic gain in the absence of postsaccadic retinal error as showing that saccade adaptation is not controlled by a single error signal. More generally, our findings suggest that normal saccade adaptation might involve general learning mechanisms rather than only specialized mechanisms for motor calibration. PMID:21525366

  10. Waveguide metatronics: Lumped circuitry based on structural dispersion.

    PubMed

    Li, Yue; Liberal, Iñigo; Della Giovampaola, Cristian; Engheta, Nader

    2016-06-01

    Engineering optical nanocircuits by exploiting modularization concepts and methods inherited from electronics may lead to multiple innovations in optical information processing at the nanoscale. We introduce the concept of "waveguide metatronics," an advanced form of optical metatronics that uses structural dispersion in waveguides to obtain the materials and structures required to construct this class of circuitry. Using numerical simulations, we demonstrate that the design of a metatronic circuit can be carried out by using a waveguide filled with materials with positive permittivity. This includes the implementation of all "lumped" circuit elements and their assembly in a single circuit board. In doing so, we extend the concepts of optical metatronics to frequency ranges where there are no natural plasmonic materials available. The proposed methodology could be exploited as a platform to experimentally validate optical metatronic circuits in other frequency regimes, such as microwave frequency setups, and/or to provide a new route to design optical nanocircuitry.

  11. Waveguide metatronics: Lumped circuitry based on structural dispersion

    PubMed Central

    Li, Yue; Liberal, Iñigo; Della Giovampaola, Cristian; Engheta, Nader

    2016-01-01

    Engineering optical nanocircuits by exploiting modularization concepts and methods inherited from electronics may lead to multiple innovations in optical information processing at the nanoscale. We introduce the concept of “waveguide metatronics,” an advanced form of optical metatronics that uses structural dispersion in waveguides to obtain the materials and structures required to construct this class of circuitry. Using numerical simulations, we demonstrate that the design of a metatronic circuit can be carried out by using a waveguide filled with materials with positive permittivity. This includes the implementation of all “lumped” circuit elements and their assembly in a single circuit board. In doing so, we extend the concepts of optical metatronics to frequency ranges where there are no natural plasmonic materials available. The proposed methodology could be exploited as a platform to experimentally validate optical metatronic circuits in other frequency regimes, such as microwave frequency setups, and/or to provide a new route to design optical nanocircuitry. PMID:27386566

  12. Electron tunneling infrared sensor module with integrated control circuitry

    NASA Technical Reports Server (NTRS)

    Boyadzhyan-Sevak, Vardkes V. (Inventor)

    2001-01-01

    In an integrated electron tunneling sensor, an automatic tunneling control circuit varies a high voltage bias applied to the sensor deflection electrode in response to changes in sensor output to maintain the proper gap between the sensor tip and membrane. The control circuit ensures stable tunneling activity in the presence of large signals and other disturbances to the sensor. Output signals from the module may be derived from the amplified sensor output. The integrated sensor module is particularly well adapted for use in blood glucose measurement and monitoring system.

  13. Extended Horizon Liftings for Periodic Gain Adjustments in Control Systems, and for Equalization of Communication Channels

    NASA Technical Reports Server (NTRS)

    Bayard, David S. (Inventor)

    1996-01-01

    Periodic gain adjustment in plants of irreducible order, n, or for equalization of communications channels is effected in such a way that the plant (system) appears to be minimum phase by choosing a horizon time N greater then n of liftings in periodic input and output windows Pu and Py, respectively, where N is an integer chosen to define the extent (length) of each of the windows Pu and Py, and n is the order of an irreducible input/output plant. The plant may be an electrical, mechanical or chemical system, in which case output tracking (OT) is carried out for feedback control or a communication channel, in which case input tracking (IT) is carried out. Conditions for OT are distinct from IT in terms of zero annihilation, namely for OT and of IT, where the OT conditions are intended for gain adjustments in the control system, and IT conditions are intended for equalization for communication channels.

  14. Experimental knee joint pain during strength training and muscle strength gain in healthy subjects: a randomized controlled trial.

    PubMed

    Sørensen, T J; Langberg, H; Hodges, P W; Bliddal, H; Henriksen, M

    2012-01-01

    Knee joint pain and reduced quadriceps strength are cardinal symptoms in many knee pathologies. In people with painful knee pathologies, quadriceps exercise reduces pain, improves physical function, and increases muscle strength. A general assumption is that pain compromises muscle function and thus may prevent effective rehabilitation. This study evaluated the effects of experimental knee joint pain during quadriceps strength training on muscle strength gain in healthy individuals. Twenty-seven healthy untrained volunteers participated in a randomized controlled trial of quadriceps strengthening (3 times per week for 8 weeks). Participants were randomized to perform resistance training either during pain induced by injections of painful hypertonic saline (pain group, n = 13) or during a nonpainful control condition with injection of isotonic saline (control group, n = 14) into the infrapatellar fat pad. The primary outcome measure was change in maximal isokinetic muscle strength in knee extension/flexion (60, 120, and 180 degrees/second). The group who exercised with pain had a significantly larger improvement in isokinetic muscle strength at all angular velocities of knee extension compared to the control group. In knee flexion there were improvements in isokinetic muscle strength in both groups with no between-group differences. Experimental knee joint pain improved the training-induced gain in muscle strength following 8 weeks of quadriceps training. It remains to be studied whether knee joint pain has a positive effect on strength gain in patients with knee pathology. Copyright © 2012 by the American College of Rheumatology.

  15. Effect of intermittent kangaroo mother care on weight gain of low birth weight neonates with delayed weight gain.

    PubMed

    Samra, Nashwa M; Taweel, Amal El; Cadwell, Karin

    2013-01-01

    To evaluate intermittent Kangaroo Mother Care (KMC) with additional opportunities to breastfeed on weight gain of low birth weight (LBW) neonates with delayed weight gain. 40 LBW neonates were followed to see whether KMC with additional opportunities to breastfeed improved weight gain. In the KMC group, the mean age of regaining birth weight was significantly less (15.68 vs. 24.56 days) and the average daily weight gain was significantly higher (22.09 vs. 10.39 g, p < .001) than controls. KMC with additional opportunities to breastfeed was found to be an effective intervention for LBWs with delayed weight gain and should be considered to be an effective strategy.

  16. Stepping motor controller

    DOEpatents

    Bourret, S.C.; Swansen, J.E.

    1982-07-02

    A stepping motor is microprocessor controlled by digital circuitry which monitors the output of a shaft encoder adjustably secured to the stepping motor and generates a subsequent stepping pulse only after the preceding step has occurred and a fixed delay has expired. The fixed delay is variable on a real-time basis to provide for smooth and controlled deceleration.

  17. Differences in brain circuitry for appetitive and reactive aggression as revealed by realistic auditory scripts

    PubMed Central

    Moran, James K.; Weierstall, Roland; Elbert, Thomas

    2014-01-01

    Aggressive behavior is thought to divide into two motivational elements: The first being a self-defensively motivated aggression against threat and a second, hedonically motivated “appetitive” aggression. Appetitive aggression is the less understood of the two, often only researched within abnormal psychology. Our approach is to understand it as a universal and adaptive response, and examine the functional neural activity of ordinary men (N = 50) presented with an imaginative listening task involving a murderer describing a kill. We manipulated motivational context in a between-subjects design to evoke appetitive or reactive aggression, against a neutral control, measuring activity with Magnetoencephalography (MEG). Results show differences in left frontal regions in delta (2–5 Hz) and alpha band (8–12 Hz) for aggressive conditions and right parietal delta activity differentiating appetitive and reactive aggression. These results validate the distinction of reward-driven appetitive aggression from reactive aggression in ordinary populations at the level of functional neural brain circuitry. PMID:25538590

  18. Vehicle dynamics control of four in-wheel motor drive electric vehicle using gain scheduling based on tyre cornering stiffness estimation

    NASA Astrophysics Data System (ADS)

    Xiong, Lu; Yu, Zhuoping; Wang, Yang; Yang, Chen; Meng, Yufeng

    2012-06-01

    This paper focuses on the vehicle dynamic control system for a four in-wheel motor drive electric vehicle, aiming at improving vehicle stability under critical driving conditions. The vehicle dynamics controller is composed of three modules, i.e. motion following control, control allocation and vehicle state estimation. Considering the strong nonlinearity of the tyres under critical driving conditions, the yaw motion of the vehicle is regulated by gain scheduling control based on the linear quadratic regulator theory. The feed-forward and feedback gains of the controller are updated in real-time by online estimation of the tyre cornering stiffness, so as to ensure the control robustness against environmental disturbances as well as parameter uncertainty. The control allocation module allocates the calculated generalised force requirements to each in-wheel motor based on quadratic programming theory while taking the tyre longitudinal/lateral force coupling characteristic into consideration. Simulations under a variety of driving conditions are carried out to verify the control algorithm. Simulation results indicate that the proposed vehicle stability controller can effectively stabilise the vehicle motion under critical driving conditions.

  19. Compact vehicle drive module having improved thermal control

    DOEpatents

    Meyer, Andreas A.; Radosevich, Lawrence D.; Beihoff, Bruce C.; Kehl, Dennis L.; Kannenberg, Daniel G.

    2006-01-03

    An electric vehicle drive includes a thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support, which may be controlled in a closed-loop manner. Interfacing between circuits, circuit mounting structure, and the support provide for greatly enhanced cooling. The support may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

  20. An analytical fuzzy-based approach to ?-gain optimal control of input-affine nonlinear systems using Newton-type algorithm

    NASA Astrophysics Data System (ADS)

    Milic, Vladimir; Kasac, Josip; Novakovic, Branko

    2015-10-01

    This paper is concerned with ?-gain optimisation of input-affine nonlinear systems controlled by analytic fuzzy logic system. Unlike the conventional fuzzy-based strategies, the non-conventional analytic fuzzy control method does not require an explicit fuzzy rule base. As the first contribution of this paper, we prove, by using the Stone-Weierstrass theorem, that the proposed fuzzy system without rule base is universal approximator. The second contribution of this paper is an algorithm for solving a finite-horizon minimax problem for ?-gain optimisation. The proposed algorithm consists of recursive chain rule for first- and second-order derivatives, Newton's method, multi-step Adams method and automatic differentiation. Finally, the results of this paper are evaluated on a second-order nonlinear system.

  1. Adaptive Piezoelectric Circuitry Sensor Network with High-Frequency Harmonics Interrogation for Structural Damage Detection

    DTIC Science & Technology

    2014-09-17

    AFRL-OSR-VA-TR-2014-0255 ADAPTIVE PIEZOELECTRIC CIRCUITRY SENSOR NETWORK KON -WELL WANG MICHIGAN UNIV ANN ARBOR Final Report 09/17/2014 DISTRIBUTION A...Harmonics Interrogation for Structural Damage Detection FA9550-11-1-0072 Kon -Well Wang and Jiong Tang The Regents of the University of Michigan, 3003...mechanism. These efforts have yielded a complete methodology of adaptive high-frequency piezoelectric self-sensing interrogation. None None None SAR Kon

  2. Effects of Device on Video Head Impulse Test (vHIT) Gain.

    PubMed

    Janky, Kristen L; Patterson, Jessie N; Shepard, Neil T; Thomas, Megan L A; Honaker, Julie A

    2017-10-01

    Numerous video head impulse test (vHIT) devices are available commercially; however, gain is not calculated uniformly. An evaluation of these devices/algorithms in healthy controls and patients with vestibular loss is necessary for comparing and synthesizing work that utilizes different devices and gain calculations. Using three commercially available vHIT devices/algorithms, the purpose of the present study was to compare: (1) horizontal canal vHIT gain among devices/algorithms in normal control subjects; (2) the effects of age on vHIT gain for each device/algorithm in normal control subjects; and (3) the clinical performance of horizontal canal vHIT gain between devices/algorithms for differentiating normal versus abnormal vestibular function. Prospective. Sixty-one normal control adult subjects (range 20-78) and eleven adults with unilateral or bilateral vestibular loss (range 32-79). vHIT was administered using three different devices/algorithms, randomized in order, for each subject on the same day: (1) Impulse (Otometrics, Schaumberg, IL; monocular eye recording, right eye only; using area under the curve gain), (2) EyeSeeCam (Interacoustics, Denmark; monocular eye recording, left eye only; using instantaneous gain), and (3) VisualEyes (MicroMedical, Chatham, IL, binocular eye recording; using position gain). There was a significant mean difference in vHIT gain among devices/algorithms for both the normal control and vestibular loss groups. vHIT gain was significantly larger in the ipsilateral direction of the eye used to measure gain; however, in spite of the significant mean differences in vHIT gain among devices/algorithms and the significant directional bias, classification of "normal" versus "abnormal" gain is consistent across all compared devices/algorithms, with the exception of instantaneous gain at 40 msec. There was not an effect of age on vHIT gain up to 78 years regardless of the device/algorithm. These findings support that vHIT gain is

  3. Integrated-Circuit Controller For Brushless dc Motor

    NASA Technical Reports Server (NTRS)

    Le, Dong Tuan

    1994-01-01

    Generic circuit performs commutation-logic and power-switching functions for control of brushless dc motor. Controller includes commutation-logic and associated control circuitry, power supply, and inverters containing power transistors. Major advantages of controller are size, weight, and power consumption can be made less than other brushless-dc-motor controllers.

  4. Gain scheduling - Potential hazards and possible remedies

    NASA Technical Reports Server (NTRS)

    Shamma, Jeff S.; Athans, Michael

    1991-01-01

    A common gain scheduling rule-of-thumb is to schedule on a slow variable. In this work, it is shown how current gain scheduling practice is necessarily limited to slow variations in the scheduling variable. These limitations are revealed to be consequences of fundamental control concepts. Furthermore, it is shown how a formulation of the gain scheduling procedure can lead toward ultimately removing these restrictions.

  5. Parallel-Processing CMOS Circuitry for M-QAM and 8PSK TCM

    NASA Technical Reports Server (NTRS)

    Gray, Andrew; Lee, Dennis; Hoy, Scott; Fisher, Dave; Fong, Wai; Ghuman, Parminder

    2009-01-01

    There has been some additional development of parts reported in "Multi-Modulator for Bandwidth-Efficient Communication" (NPO-40807), NASA Tech Briefs, Vol. 32, No. 6 (June 2009), page 34. The focus was on 1) The generation of M-order quadrature amplitude modulation (M-QAM) and octonary-phase-shift-keying, trellis-coded modulation (8PSK TCM), 2) The use of square-root raised-cosine pulse-shaping filters, 3) A parallel-processing architecture that enables low-speed [complementary metal oxide/semiconductor (CMOS)] circuitry to perform the coding, modulation, and pulse-shaping computations at a high rate; and 4) Implementation of the architecture in a CMOS field-programmable gate array.

  6. Gain-Compensating Circuit For NDE and Ultrasonics

    NASA Technical Reports Server (NTRS)

    Kushnick, Peter W.

    1987-01-01

    High-frequency gain-compensating circuit designed for general use in nondestructive evaluation and ultrasonic measurements. Controls gain of ultrasonic receiver as function of time to aid in measuring attenuation of samples with high losses; for example, human skin and graphite/epoxy composites. Features high signal-to-noise ratio, large signal bandwidth and large dynamic range. Control bandwidth of 5 MHz ensures accuracy of control signal. Currently being used for retrieval of more information from ultrasonic signals sent through composite materials that have high losses, and to measure skin-burn depth in humans.

  7. Integrated circuit electrometer and sweep circuitry for an atmospheric probe

    NASA Technical Reports Server (NTRS)

    Zimmerman, L. E.

    1971-01-01

    The design of electrometer circuitry using an integrated circuit operational amplifier with a MOSFET input is described. Input protection against static voltages is provided by a dual ultra low leakage diode or a neon lamp. Factors affecting frequency response leakage resistance, and current stability are discussed, and methods are suggested for increasing response speed and for eliminating leakage resistance and current instabilities. Based on the above, two practical circuits, one having a linear response and the other a logarithmic response, were designed and evaluated experimentally. The design of a sweep circuit to implement mobility measurements using atmospheric probes is presented. A triangular voltage waveform is generated and shaped to contain a step in voltage from zero volts in both positive and negative directions.

  8. Alternative neural circuitry that might be impaired in the development of Alzheimer disease.

    PubMed

    Avila, Jesus; Perry, George; Strange, Bryan A; Hernandez, Felix

    2015-01-01

    It is well established that some individuals with normal cognitive capacity have abundant senile plaques in their brains. It has been proposed that those individuals are resilient or have compensation factors to prevent cognitive decline. In this comment, we explore an alternative mechanism through which cognitive capacity is maintained. This mechanism could involve the impairment of alternative neural circuitry. Also, the proportion of molecules such as Aβ or tau protein present in different areas of the brain could be important.

  9. Taste Reward Circuitry Related Brain Structures Characterize Ill and Recovered Anorexia Nervosa and Bulimia Nervosa

    PubMed Central

    Frank, Guido K.; Shott, Megan E.; Hagman, Jennifer O.; Mittal, Vijay A.

    2013-01-01

    Objective The pathophysiology of the eating disorder anorexia nervosa remains obscure, but structural brain alterations could be functionally important biomarkers. Here we assessed taste pleasantness and reward sensitivity in relation to brain structure, which might be related to food avoidance commonly seen in eating disorders. Method We used structural magnetic resonance brain imaging to study gray and white matter volumes in individuals with restricting type currently ill (n = 19) or recovered-anorexia nervosa (n = 24), bulimia nervosa (n= 19) and healthy control women (n=24). Results All eating disorder groups showed increased gray matter volume of the medial orbitofrontal cortex (gyrus rectus). Manually tracing confirmed larger gyrus rectus volume, and predicted taste pleasantness across all groups. The analyses also indicated other morphological differences between diagnostic categories: Ill and recovered-anorexia nervosa had increased right, while bulimia nervosa had increased left antero-ventral insula gray matter volumes compared to controls. Furthermore, dorsal striatum volumes were reduced in recovered-anorexia and bulimia nervosa, and predicted sensitivity to reward in the eating disorder groups. The eating disorder groups also showed reduced white matter in right temporal and parietal areas when compared to healthy controls. Notably, the results held when controlling for a range of covariates (e.g., age, depression, anxiety, medications). Conclusion Brain structure in medial orbitofrontal cortex, insula and striatum is altered in eating disorders and suggests altered brain circuitry that has been associated with taste pleasantness and reward value. PMID:23680873

  10. Effect of Intermittent Kangaroo Mother Care on Weight Gain of Low Birth Weight Neonates With Delayed Weight Gain

    PubMed Central

    Samra, Nashwa M.; Taweel, Amal El; Cadwell, Karin

    2013-01-01

    Objective: To evaluate intermittent Kangaroo Mother Care (KMC) with additional opportunities to breastfeed on weight gain of low birth weight (LBW) neonates with delayed weight gain. Methods: 40 LBW neonates were followed to see whether KMC with additional opportunities to breastfeed improved weight gain. Results: In the KMC group, the mean age of regaining birth weight was significantly less (15.68 vs. 24.56 days) and the average daily weight gain was significantly higher (22.09 vs. 10.39 g, p < .001) than controls. Conclusion: KMC with additional opportunities to breastfeed was found to be an effective intervention for LBWs with delayed weight gain and should be considered to be an effective strategy. PMID:24868132

  11. Circuitry and plasticity of the dorsal horn--toward a better understanding of neuropathic pain.

    PubMed

    West, S J; Bannister, K; Dickenson, A H; Bennett, D L

    2015-08-06

    Maladaptive plasticity within the dorsal horn (DH) of the spinal cord is a key substrate for development of neuropathic pain following peripheral nerve injury. Advances in genetic engineering, tracing techniques and opto-genetics are leading to a much better understanding of the complex circuitry of the spinal DH and the radical changes evoked in such circuitry by nerve injury. These changes can be viewed at multiple levels including: synaptic remodeling including enhanced excitatory and reduced inhibitory drive, morphological and electrophysiological changes which are observed both to primary afferent inputs as well as DH neurons, and ultimately circuit-level rewiring which leads to altered connectivity and aberrant processing of sensory inputs in the DH. The DH should not be seen in isolation but is subject to important descending modulation from the brainstem, which is further dysregulated by nerve injury. Understanding which changes relate to specific disease-states is essential, and recent work has aimed to stratify patient populations in a mechanistic fashion. In this review we will discuss how such pathophysiological mechanisms may lead to the distressing sensory phenomena experienced by patients suffering neuropathic pain, and the relationship of such mechanisms to current and potential future treatment modalities. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  12. Compact, Reliable EEPROM Controller

    NASA Technical Reports Server (NTRS)

    Katz, Richard; Kleyner, Igor

    2010-01-01

    A compact, reliable controller for an electrically erasable, programmable read-only memory (EEPROM) has been developed specifically for a space-flight application. The design may be adaptable to other applications in which there are requirements for reliability in general and, in particular, for prevention of inadvertent writing of data in EEPROM cells. Inadvertent writes pose risks of loss of reliability in the original space-flight application and could pose such risks in other applications. Prior EEPROM controllers are large and complex and do not provide all reasonable protections (in many cases, few or no protections) against inadvertent writes. In contrast, the present controller provides several layers of protection against inadvertent writes. The controller also incorporates a write-time monitor, enabling determination of trends in the performance of an EEPROM through all phases of testing. The controller has been designed as an integral subsystem of a system that includes not only the controller and the controlled EEPROM aboard a spacecraft but also computers in a ground control station, relatively simple onboard support circuitry, and an onboard communication subsystem that utilizes the MIL-STD-1553B protocol. (MIL-STD-1553B is a military standard that encompasses a method of communication and electrical-interface requirements for digital electronic subsystems connected to a data bus. MIL-STD- 1553B is commonly used in defense and space applications.) The intent was to both maximize reliability while minimizing the size and complexity of onboard circuitry. In operation, control of the EEPROM is effected via the ground computers, the MIL-STD-1553B communication subsystem, and the onboard support circuitry, all of which, in combination, provide the multiple layers of protection against inadvertent writes. There is no controller software, unlike in many prior EEPROM controllers; software can be a major contributor to unreliability, particularly in fault

  13. The Neural Basis of and a Common Neural Circuitry in Different Types of Pro-social Behavior

    PubMed Central

    Luo, Jun

    2018-01-01

    Pro-social behaviors are voluntary behaviors that benefit other people or society as a whole, such as charitable donations, cooperation, trust, altruistic punishment, and fairness. These behaviors have been widely described through non self-interest decision-making in behavioral experimental studies and are thought to be increased by social preference motives. Importantly, recent studies using a combination of neuroimaging and brain stimulation, designed to reveal the neural mechanisms of pro-social behaviors, have found that a wide range of brain areas, specifically the prefrontal cortex, anterior insula, anterior cingulate cortex, and amygdala, are correlated or causally related with pro-social behaviors. In this review, we summarize the research on the neural basis of various kinds of pro-social behaviors and describe a common shared neural circuitry of these pro-social behaviors. We introduce several general ways in which experimental economics and neuroscience can be combined to develop important contributions to understanding social decision-making and pro-social behaviors. Future research should attempt to explore the neural circuitry between the frontal lobes and deeper brain areas. PMID:29922197

  14. Changes in neural circuitry associated with depression at pre-clinical, pre-motor and early motor phases of Parkinson's disease.

    PubMed

    Borgonovo, Janina; Allende-Castro, Camilo; Laliena, Almudena; Guerrero, Néstor; Silva, Hernán; Concha, Miguel L

    2017-02-01

    Although Parkinson's Disease (PD) is mostly considered a motor disorder, it can present at early stages as a non-motor pathology. Among the non-motor clinical manifestations, depression shows a high prevalence and can be one of the first clinical signs to appear, even a decade before the onset of motor symptoms. Here, we review the evidence of early dysfunction in neural circuitry associated with depression in the context of PD, focusing on pre-clinical, pre-motor and early motor phases of the disease. In the pre-clinical phase, structural and functional changes in the substantia nigra, basal ganglia and limbic structures are already observed. Some of these changes are linked to motor compensation mechanisms while others correspond to pathological processes common to PD and depression and thus could underlie the appearance of depressive symptoms during the pre-motor phase. Studies of the early motor phase (less than five years post diagnosis) reveal an association between the extent of damage in different monoaminergic systems and the appearance of emotional disorders. We propose that the limbic loop of the basal ganglia and the lateral habenula play key roles in the early genesis of depression in PD. Alterations in the neural circuitry linked with emotional control might be sensitive markers of the ongoing neurodegenerative process and thus may serve to facilitate an early diagnosis of this disease. To take advantage of this, we need to improve the clinical criteria and develop biomarkers to identify depression, which could be used to determine individuals at risk to develop PD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. The Impact of Weight Gain on Motivation, Compliance, and Metabolic Control in Patients with Type 2 Diabetes Mellitus

    PubMed Central

    Pi-Sunyer, F. Xavier

    2010-01-01

    Patients with type 2 diabetes, approximately 85% of whom are overweight or obese, often have an increased incidence of cardiovascular disease (CVD) risk factors such as hypertension and dyslipidemia. Both type 2 diabetes and obesity are independent risk factors for CVD. Unfortunately, many therapies aimed at maintaining and improving glucose control are associated with weight gain. Among the older antidiabetes agents, most, including the insulin secretagogues and sensitizers, can lead to weight gain, except for metformin, which is weight-neutral. Among the newer agents, the dipeptidyl peptidase-4 inhibitors generally are weight-neutral in addition to lowering glucose, while the glucagon-like peptide–1 receptor agonists lead to weight reduction. Patients with type 2 diabetes are at an increased risk for both diabetes-and CV-related outcomes, and weight reduction is an important component of diabetes management. Weight gain in patients with type 2 diabetes can contribute to patient frustration and may negatively impact their compliance to therapeutic regimens. The selection of antidiabetes agents that not only improve glucose control but reduce or have a neutral effect on weight with beneficial effects on lipids are ideal options for managing patients with type 2 diabetes. PMID:19820278

  16. DC motor proportional control system for orthotic devices

    NASA Technical Reports Server (NTRS)

    Blaise, H. T.; Allen, J. R.

    1972-01-01

    Multi-channel proportional control system for operation of dc motors for use with externally-powered orthotic arm braces is described. Components of circuitry and principles of operation are described. Schematic diagram of control circuit is provided.

  17. Sex differences, hormones, and fMRI stress response circuitry deficits in psychoses.

    PubMed

    Goldstein, Jill M; Lancaster, Katie; Longenecker, Julia M; Abbs, Brandon; Holsen, Laura M; Cherkerzian, Sara; Whitfield-Gabrieli, Susan; Makris, Nicolas; Tsuang, Ming T; Buka, Stephen L; Seidman, Larry J; Klibanski, Anne

    2015-06-30

    Response to stress is dysregulated in psychosis (PSY). fMRI studies showed hyperactivity in hypothalamus (HYPO), hippocampus (HIPP), amygdala (AMYG), anterior cingulate (ACC), orbital and medial prefrontal (OFC; mPFC) cortices, with some studies reporting sex differences. We predicted abnormal steroid hormone levels in PSY would be associated with sex differences in hyperactivity in HYPO, AMYG, and HIPP, and hypoactivity in PFC and ACC, with more severe deficits in men. We studied 32 PSY cases (50.0% women) and 39 controls (43.6% women) using a novel visual stress challenge while collecting blood. PSY males showed BOLD hyperactivity across all hypothesized regions, including HYPO and ACC by FWE-correction. Females showed hyperactivity in HIPP and AMYG and hypoactivity in OFC and mPFC, the latter FWE-corrected. Interaction of group by sex was significant in mPFC (F = 7.00, p = 0.01), with PSY females exhibiting the lowest activity. Male hyperactivity in HYPO and ACC was significantly associated with hypercortisolemia post-stress challenge, and mPFC with low androgens. Steroid hormones and neural activity were dissociated in PSY women. Findings suggest disruptions in neural circuitry-hormone associations in response to stress are sex-dependent in psychosis, particularly in prefrontal cortex. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  18. System for controlling apnea

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

    Holzrichter, John F

    2015-05-05

    An implanted stimulation device or air control device are activated by an external radar-like sensor for controlling apnea. The radar-like sensor senses the closure of the air flow cavity, and associated control circuitry signals (1) a stimulator to cause muscles to open the air passage way that is closing or closed or (2) an air control device to open the air passage way that is closing or closed.

  19. Age and gender modulate the neural circuitry supporting facial emotion processing in adults with major depressive disorder.

    PubMed

    Briceño, Emily M; Rapport, Lisa J; Kassel, Michelle T; Bieliauskas, Linas A; Zubieta, Jon-Kar; Weisenbach, Sara L; Langenecker, Scott A

    2015-03-01

    Emotion processing, supported by frontolimbic circuitry known to be sensitive to the effects of aging, is a relatively understudied cognitive-emotional domain in geriatric depression. Some evidence suggests that the neurophysiological disruption observed in emotion processing among adults with major depressive disorder (MDD) may be modulated by both gender and age. Therefore, the present study investigated the effects of gender and age on the neural circuitry supporting emotion processing in MDD. Cross-sectional comparison of fMRI signal during performance of an emotion processing task. Outpatient university setting. One hundred adults recruited by MDD status, gender, and age. Participants underwent fMRI while completing the Facial Emotion Perception Test. They viewed photographs of faces and categorized the emotion perceived. Contrast for fMRI was of face perception minus animal identification blocks. Effects of depression were observed in precuneus and effects of age in a number of frontolimbic regions. Three-way interactions were present between MDD status, gender, and age in regions pertinent to emotion processing, including frontal, limbic, and basal ganglia. Young women with MDD and older men with MDD exhibited hyperactivation in these regions compared with their respective same-gender healthy comparison (HC) counterparts. In contrast, older women and younger men with MDD exhibited hypoactivation compared to their respective same-gender HC counterparts. This the first study to report gender- and age-specific differences in emotion processing circuitry in MDD. Gender-differential mechanisms may underlie cognitive-emotional disruption in older adults with MDD. The present findings have implications for improved probes into the heterogeneity of the MDD syndrome. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

  20. [Body weight gain after radioiodine therapy in hyperthyroidism].

    PubMed

    Scheidhauer, K; Odatzidu, L; Kiencke, P; Schicha, H

    2002-02-01

    Analysis and follow up of body weight after radioiodine therapy (RITh) of hyperthyroidism, since excessive weight gain is a common complaint among these patients. Therapy and body weight related data of 100 consecutive RITh-patients were retrospectively analysed from the time before up to three years after RITh. All patients suffered from hyperthyroidism (Graves' disease or autonomy), but were adjusted to euthyroid levels after RITh. Patients' data were compared to a control group of 48 euthyroid patients out of the same ambulance and during the same time scale. All patients (RITh and controls) gained weight over the time. There was no statistically significant difference in BMI development over three years between RITh-patients and controls (5.5% resp. 4.9% increase). In the first year after RITh, weight gain of the RITh patients was higher indeed, but lower in the follow up, resulting in the same range of weight gain after three years as the controls. Besides that women showed a slightly higher increase of BMI than men, and so did younger patients compared to elder as well as patients with overweight already before RITh. An initially distinct increase of body weight after RITh of hyperthyroidism is mainly a compensation of pretherapeutic weight loss due to hyperthyroidism. Presupposing adequate euthyroid adjustment of thyroid metabolism after therapy, RITh is not responsible for later weight gain and adipositas.

  1. Pharmacological Modulation of Noradrenergic Arousal Circuitry Disrupts Functional Connectivity of the Locus Ceruleus in Humans

    PubMed Central

    Song, Andrew H.

    2017-01-01

    State-dependent activity of locus ceruleus (LC) neurons has long suggested a role for noradrenergic modulation of arousal. However, in vivo insights into noradrenergic arousal circuitry have been constrained by the fundamental inaccessibility of the human brain for invasive studies. Functional magnetic resonance imaging (fMRI) studies performed during site-specific pharmacological manipulations of arousal levels may be used to study brain arousal circuitry. Dexmedetomidine is an anesthetic that alters the level of arousal by selectively targeting α2 adrenergic receptors on LC neurons, resulting in reduced firing rate and norepinephrine release. Thus, we hypothesized that dexmedetomidine-induced altered arousal would manifest with reduced functional connectivity between the LC and key brain regions involved in the regulation of arousal. To test this hypothesis, we acquired resting-state fMRI data in right-handed healthy volunteers 18–36 years of age (n = 15, 6 males) at baseline, during dexmedetomidine-induced altered arousal, and recovery states. As previously reported, seed-based resting-state fMRI analyses revealed that the LC was functionally connected to a broad network of regions including the reticular formation, basal ganglia, thalamus, posterior cingulate cortex (PCC), precuneus, and cerebellum. Functional connectivity of the LC to only a subset of these regions (PCC, thalamus, and caudate nucleus) covaried with the level of arousal. Functional connectivity of the PCC to the ventral tegmental area/pontine reticular formation and thalamus, in addition to the LC, also covaried with the level of arousal. We propose a framework in which the LC, PCC, thalamus, and basal ganglia comprise a functional arousal circuitry. SIGNIFICANCE STATEMENT Electrophysiological studies of locus ceruleus (LC) neurons have long suggested a role for noradrenergic mechanisms in mediating arousal. However, the fundamental inaccessibility of the human brain for invasive studies has

  2. Preventing weight gain: a population cohort study of the nature and effectiveness of mid-age women's weight control practices.

    PubMed

    Williams, L; Germov, J; Young, A

    2007-06-01

    To examine women's weight control practices and their effectiveness in preventing weight gain. Retrospective cohort study of weight control practices and 2-year weight change among mid-age women participating in the Australian Longitudinal Study on Women's Health (ALSWH). 11,589 Australian women (aged 47-52 years). The prevalence and types of self-reported weight control practices used were assessed by a nine-item instrument. Two-year weight change was self-reported and adjusted for baseline body mass index (BMI) and other potential confounders. Seventy-four per cent of the cohort (N=8556) reported actively trying to control their weight. Dietary modification was used more frequently than exercise. Two-thirds of the weight-controlling women used a combination of practices, the two most common being 'decreased food quantity, cut down on fats/sugars and exercise' (32%, baseline BMI 25.87(0.10)), and 'decreased food quantity and cut down on fats/sugars without exercise' (15.6%, baseline BMI 27.04(0.14)). Potentially health-damaging practices (smoking, laxatives, fasting) were relatively uncommon, at 7.9%. Only one combination of practices (decreased food quantity, cut down on fats/sugars, use of a commercial weight loss programme and exercise) prevented mean weight gain (-0.03 kg), whereas the mean (s.d.) weight of the cohort increased (+1.19(4.78)) over the 2-year period. The majority of mid-age women attempting weight control used practices consistent with public health messages. Despite their efforts, the group was mostly unsuccessful in preventing weight gain. Public health authorities and health practitioners may need to make more quantitative recommendations and emphasize the importance of balancing physical activity with dietary intake to achieve successful weight control for women at this life stage.

  3. Extended horizon lifting for periodic gain adjustment in control systems, and for equalization of communication channels

    NASA Technical Reports Server (NTRS)

    Bayard, David S. (Inventor)

    1994-01-01

    Periodic gain adjustment in plants of irreducible order, n, or for equalization of communications channels is effected in such a way that the plant (system) appears to be minimum phase by choosing a horizon time N is greater than n of liftings in periodic input and output windows rho sub u and rho sub y, respectively, where N is an integer chosen to define the extent (length) of each of the windows rho sub u and rho sub y, and n is the order of an irreducible input/output plant. The plant may be an electrical, mechanical, or chemical system, in which case output tracking (OT) is carried out for feedback control or a communication channel, in which case input tracking (IT) is performed. Conditions for OT are distinct from IT in terms of zero annihilation, namely H(sub s)H(sub s)(sup +) = I for OT and H(sub s)H(sub s)(sup +) = I of IT, where the OT conditions are intended for gain adjustments in the control system, and IT conditions are intended for equalization for communication channels.

  4. Parafoveal Target Detectability Reversal Predicted by Local Luminance and Contrast Gain Control

    NASA Technical Reports Server (NTRS)

    Ahumada, Albert J., Jr.; Beard, Bettina L.; Null, Cynthia H. (Technical Monitor)

    1996-01-01

    This project is part of a program to develop image discrimination models for the prediction of the detectability of objects in a range of backgrounds. We wanted to see if the models could predict parafoveal object detection as well as they predict detection in foveal vision. We also wanted to make our simplified models more general by local computation of luminance and contrast gain control. A signal image (0.78 x 0.17 deg) was made by subtracting a simulated airport runway scene background image (2.7 deg square) from the same scene containing an obstructing aircraft. Signal visibility contrast thresholds were measured in a fully crossed factorial design with three factors: eccentricity (0 deg or 4 deg), background (uniform or runway scene background), and fixed-pattern white noise contrast (0%, 5%, or 10%). Three experienced observers responded to three repetitions of 60 2IFC trials in each condition and thresholds were estimated by maximum likelihood probit analysis. In the fovea the average detection contrast threshold was 4 dB lower for the runway background than for the uniform background, but in the parafovea, the average threshold was 6 dB higher for the runway background than for the uniform background. This interaction was similar across the different noise levels and for all three observers. A likely reason for the runway background giving a lower threshold in the fovea is the low luminance near the signal in that scene. In our model, the local luminance computation is controlled by a spatial spread parameter. When this parameter and a corresponding parameter for the spatial spread of contrast gain were increased for the parafoveal predictions, the model predicts the interaction of background with eccentricity.

  5. Electric field induced needle-pulsed arc discharge carbon nanotube production apparatus: circuitry and mechanical design.

    PubMed

    Kia, Kaveh Kazemi; Bonabi, Fahimeh

    2012-12-01

    A simple and low cost apparatus is reported to produce multiwall carbon nanotubes and carbon nano-onions by a low power short pulsed arc discharge reactor. The electric circuitry and the mechanical design details and a micro-filtering assembly are described. The pulsed-plasma is generated and applied between two graphite electrodes. The pulse width is 0.3 μs. A strong dc electric field is established along side the electrodes. The repetitive discharges occur in less than 1 mm distance between a sharp tip graphite rod as anode, and a tubular graphite as cathode. A hydrocarbon vapor, as carbon source, is introduced through the graphite nozzle in the cathode assembly. The pressure of the chamber is controlled by a vacuum pump. A magnetic field, perpendicular to the plasma path, is provided. The results show that the synergetic use of a pulsed-current and a dc power supply enables us to synthesize carbon nanoparticles with short pulsed plasma. The simplicity and inexpensiveness of this plan is noticeable. Pulsed nature of plasma provides some extra degrees of freedom that make the production more controllable. Effects of some design parameters such as electric field, pulse frequency, and cathode shape are discussed. The products are examined using scanning probe microscopy techniques.

  6. Electric field induced needle-pulsed arc discharge carbon nanotube production apparatus: Circuitry and mechanical design

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

    Kia, Kaveh Kazemi; Bonabi, Fahimeh

    A simple and low cost apparatus is reported to produce multiwall carbon nanotubes and carbon nano-onions by a low power short pulsed arc discharge reactor. The electric circuitry and the mechanical design details and a micro-filtering assembly are described. The pulsed-plasma is generated and applied between two graphite electrodes. The pulse width is 0.3 {mu}s. A strong dc electric field is established along side the electrodes. The repetitive discharges occur in less than 1 mm distance between a sharp tip graphite rod as anode, and a tubular graphite as cathode. A hydrocarbon vapor, as carbon source, is introduced through themore » graphite nozzle in the cathode assembly. The pressure of the chamber is controlled by a vacuum pump. A magnetic field, perpendicular to the plasma path, is provided. The results show that the synergetic use of a pulsed-current and a dc power supply enables us to synthesize carbon nanoparticles with short pulsed plasma. The simplicity and inexpensiveness of this plan is noticeable. Pulsed nature of plasma provides some extra degrees of freedom that make the production more controllable. Effects of some design parameters such as electric field, pulse frequency, and cathode shape are discussed. The products are examined using scanning probe microscopy techniques.« less

  7. Electric field induced needle-pulsed arc discharge carbon nanotube production apparatus: Circuitry and mechanical design

    NASA Astrophysics Data System (ADS)

    Kia, Kaveh Kazemi; Bonabi, Fahimeh

    2012-12-01

    A simple and low cost apparatus is reported to produce multiwall carbon nanotubes and carbon nano-onions by a low power short pulsed arc discharge reactor. The electric circuitry and the mechanical design details and a micro-filtering assembly are described. The pulsed-plasma is generated and applied between two graphite electrodes. The pulse width is 0.3 μs. A strong dc electric field is established along side the electrodes. The repetitive discharges occur in less than 1 mm distance between a sharp tip graphite rod as anode, and a tubular graphite as cathode. A hydrocarbon vapor, as carbon source, is introduced through the graphite nozzle in the cathode assembly. The pressure of the chamber is controlled by a vacuum pump. A magnetic field, perpendicular to the plasma path, is provided. The results show that the synergetic use of a pulsed-current and a dc power supply enables us to synthesize carbon nanoparticles with short pulsed plasma. The simplicity and inexpensiveness of this plan is noticeable. Pulsed nature of plasma provides some extra degrees of freedom that make the production more controllable. Effects of some design parameters such as electric field, pulse frequency, and cathode shape are discussed. The products are examined using scanning probe microscopy techniques.

  8. Controlling morphology and chain aggregation in semiconducting conjugated polymers: the role of solvent on optical gain in MEH-PPV.

    PubMed

    Lampert, Zach E; Reynolds, C Lewis; Papanikolas, John M; Aboelfotoh, M Osama

    2012-10-25

    We report the results of a detailed investigation that addresses the influence of polymer morphology and chain aggregation, as controlled by the chemical nature of the solvent, on the optical gain properties of the conjugated polymer poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV). Using the variable stripe length technique in the picosecond regime, we have extensively studied the optical gain performance of asymmetric planar waveguides formed with thin MEH-PPV films spin-cast from concentrated chlorobenzene (CB) and tetrahydrofuran (THF) solutions onto thermally oxidized silicon substrates. CB and THF solvents were chosen based on their known ability to promote and effectively limit aggregate formation, respectively. Very large net gain coefficients are demonstrated, reaching values of 330 and 365 cm(-1), respectively, when optically pumping the waveguides with a maximum energy density of 85 μJ/cm(2). Our results clearly demonstrate that polymer morphology, and hence, the chain conformation dependence of the degree of aggregation in the films as controlled by the solvent, has minimal impact on the net gain. Moreover, the waveguides exhibit low loss coefficients of 10-20 cm(-1) at the ASE wavelength. These results question the importance of polymer morphology and aggregate formation in polymer-based optical devices operating at high excitation densities in the stimulated emission regime as would be characteristic of lasers and optical amplifiers.

  9. Engineering studies related to Skylab program. [assessment of automatic gain control data

    NASA Technical Reports Server (NTRS)

    Hayne, G. S.

    1973-01-01

    The relationship between the S-193 Automatic Gain Control data and the magnitude of received signal power was studied in order to characterize performance parameters for Skylab equipment. The r-factor was used for the assessment and is defined to be less than unity, and a function of off-nadir angle, ocean surface roughness, and receiver signal to noise ratio. A digital computer simulation was also used to assess to additive receiver, or white noise. The system model for the digital simulation is described, along with intermediate frequency and video impulse response functions used, details of the input waveforms, and results to date. Specific discussion of the digital computer programs used is also provided.

  10. Reorganization of Functional Networks in Verbal Working Memory Circuitry in Early Midlife: The Impact of Sex and Menopausal Status.

    PubMed

    Jacobs, Emily G; Weiss, Blair; Makris, Nikos; Whitfield-Gabrieli, Sue; Buka, Stephen L; Klibanski, Anne; Goldstein, Jill M

    2017-05-01

    Converging preclinical and human evidence indicates that the decline in ovarian estradiol production during the menopausal transition may play a mechanistic role in the neuronal changes that occur early in the aging process. Here, we present findings from a population-based fMRI study characterizing regional and network-level differences in working memory (WM) circuitry in midlife men and women (N = 142; age range 46-53), as a function of sex and reproductive stage. Reproductive histories and hormonal evaluations were used to determine menopausal status. Participants performed a verbal WM task during fMRI scanning. Results revealed robust differences in task-evoked responses in dorsolateral prefrontal cortex and hippocampus as a function of women's reproductive stage, despite minimal variance in chronological age. Sex differences in regional activity and functional connectivity that were pronounced between men and premenopausal women were diminished for postmenopausal women. Critically, analyzing data without regard to sex or reproductive status obscured group differences in the circuit-level neural strategies associated with successful working memory performance. These findings underscore the importance of reproductive age and hormonal status, over and above chronological age, for understanding sex differences in the aging of memory circuitry. Further, these findings suggest that early changes in working memory circuitry are evident decades before the age range typically targeted in cognitive aging studies. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  11. Modeling and distributed gain scheduling strategy for load frequency control in smart grids with communication topology changes.

    PubMed

    Liu, Shichao; Liu, Xiaoping P; El Saddik, Abdulmotaleb

    2014-03-01

    In this paper, we investigate the modeling and distributed control problems for the load frequency control (LFC) in a smart grid. In contrast with existing works, we consider more practical and real scenarios, where the communication topology of the smart grid changes because of either link failures or packet losses. These topology changes are modeled as a time-varying communication topology matrix. By using this matrix, a new closed-loop power system model is proposed to integrate the communication topology changes into the dynamics of a physical power system. The globally asymptotical stability of this closed-loop power system is analyzed. A distributed gain scheduling LFC strategy is proposed to compensate for the potential degradation of dynamic performance (mean square errors of state vectors) of the power system under communication topology changes. In comparison to conventional centralized control approaches, the proposed method can improve the robustness of the smart grid to the variation of the communication network as well as to reduce computation load. Simulation results show that the proposed distributed gain scheduling approach is capable to improve the robustness of the smart grid to communication topology changes. © 2013 ISA. Published by ISA. All rights reserved.

  12. Reward circuitry in resilience to severe trauma: An fMRI investigation of resilient special forces soldiers

    PubMed Central

    Vythilingam, Meena; Nelson, Eric E.; Scaramozza, Matthew; Waldeck, Tracy; Hazlett, Gary; Southwick, Steven M.; Pine, Daniel S.; Drevets, Wayne; Charney, Dennis S.; Ernst, Monique

    2008-01-01

    Enhanced brain reward function could contribute to resilience to trauma. Reward circuitry in active duty, resilient special forces (SF) soldiers was evaluated using fMRI during a monetary incentive delay task. Findings in this group of resilient individuals revealed unique patterns of activation during expectation of reward in the subgenual prefrontal cortex and nucleus accumbens area; regions pivotal to reward processes. PMID:19243926

  13. ACCELERATOR TARGET POSITIONER AND CONTROL CIRCUIT THEREFOR

    DOEpatents

    Stone, K.F.; Force, R.J.; Olson, W.W.; Cagle, D.S.

    1959-12-15

    An apparatus is described for inserting and retracting a target material with respect to the internal beam of a charged particle accelerator and to circuitry for controlling the timing and motion of the target placement. Two drive coils are mounted on the shaft of a target holder arm and disposed within the accelerator magnetic field with one coil at right angles to the other. Control circuitry alternately connects each coil to a current source and to a varying shorting resistance whereby the coils interchangeably produce driving and braking forces which swing the target arm within a ninety degree arc. The target is thus moved into the beam and away from it at high speeds and is brought to rest after each movement without whiplash or vibration.

  14. Cortical influences on brainstem circuitry responsible for conditioned pain modulation in humans.

    PubMed

    Youssef, Andrew M; Macefield, Vaughan G; Henderson, Luke A

    2016-07-01

    Conditioned pain modulation (CPM) is a powerful endogenous analgesic mechanism which can completely inhibit incoming nociceptor signals at the primary synapse. The circuitry responsible for CPM lies within the brainstem and involves the subnucleus reticularis dorsalis (SRD). While the brainstem is critical for CPM, the cortex can significantly modulate its expression, likely via the brainstem circuitry critical for CPM. Since higher cortical regions such as the anterior, mid-cingulate, and dorsolateral prefrontal cortices are activated by noxious stimuli and show reduced activations during other analgesic responses, we hypothesized that these regions would display reduced responses during CPM analgesia. Furthermore, we hypothesized that functional connectivity strength between these cortical regions and the SRD would be stronger in those that express CPM analgesia compared with those that do not. We used functional magnetic resonance imaging to determine sites recruited during CPM expression and their influence on the SRD. A lack of CPM analgesia was associated with greater signal intensity increases during each test stimulus in the presence of the conditioning stimulus compared to test stimuli alone in the mid-cingulate and dorsolateral prefrontal cortices and increased functional connectivity with the SRD. In contrast, those subjects exhibiting CPM analgesia showed no change in the magnitude of signal intensity increases in these cortical regions or strength of functional connectivity with the SRD. These data suggest that during multiple or widespread painful stimuli, engagement of the prefrontal and cingulate cortices prevents the generation of CPM analgesia, raising the possibility altered responsiveness in these cortical regions underlie the reduced CPM observed in individuals with chronic pain. Hum Brain Mapp 37:2630-2644, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  15. Corticostriatal circuitry in regulating diseases characterized by intrusive thinking

    PubMed Central

    Kalivas, Benjamin C.; Kalivas, Peter W.

    2016-01-01

    Intrusive thinking triggers clinical symptoms in many neuropsychiatric disorders. Using drug addiction as an exemplar disorder sustained in part by intrusive thinking, we explore studies demonstrating that impairments in corticostriatal circuitry strongly contribute to intrusive thinking. Neuroimaging studies have long implicated this projection in cue-induced craving to use drugs, and preclinical models show that marked changes are produced at corticostriatal synapses in the nucleus accumbens during a relapse episode. We delineate an accumbens microcircuit that mediates cue-induced drug seeking becoming an intrusive event. This microcircuit harbors many potential therapeutic targets. We focus on preclinical and clinical studies, showing that administering N-acetylcysteine restores uptake of synaptic glutamate by astroglial glutamate transporters and thereby inhibits intrusive thinking. We posit that because intrusive thinking is a shared endophenotype in many disorders, N-acetylcysteine has positive effects in clinical trials for a variety of neuropsychiatric disorders, including drug addiction, gambling, trichotillomania, and depression. PMID:27069381

  16. Corticostriatal circuitry in regulating diseases characterized by intrusive thinking.

    PubMed

    Kalivas, Benjamin C; Kalivas, Peter W

    2016-03-01

    Intrusive thinking triggers clinical symptoms in many neuropsychiatric disorders. Using drug addiction as an exemplar disorder sustained in part by intrusive thinking, we explore studies demonstrating that impairments in corticostriatal circuitry strongly contribute to intrusive thinking. Neuroimaging studies have long implicated this projection in cue-induced craving to use drugs, and preclinical models show that marked changes are produced at corticostriatal synapses in the nucleus accumbens during a relapse episode. We delineate an accumbens microcircuit that mediates cue-induced drug seeking becoming an intrusive event. This microcircuit harbors many potential therapeutic targets. We focus on preclinical and clinical studies, showing that administering N-acetylcysteine restores uptake of synaptic glutamate by astroglial glutamate transporters and thereby inhibits intrusive thinking. We posit that because intrusive thinking is a shared endophenotype in many disorders, N-acetylcysteine has positive effects in clinical trials for a variety of neuropsychiatric disorders, including drug addiction, gambling, trichotillomania, and depression.

  17. Controlling suspended samplers by programmable calculator and interface circuitry

    Treesearch

    Rand E. Eads; Mark R. Boolootian

    1985-01-01

    A programmable calculator connected to an interface circuit can control automatic samplers and record streamflow data. The circuit converts a voltage representing water stage to a digital signal. The sampling program logs streamflow data when there is a predefined deviation from a linear trend in the water elevation. The calculator estimates suspended sediment...

  18. Metal Chelation as a Powerful Strategy to Probe Cellular Circuitry Governing Fungal Drug Resistance and Morphogenesis

    PubMed Central

    Averette, Anna F.; Lee, Soo Chan; Kim, Taeyup; Bahn, Yong-Sun; Robbins, Nicole; Heitman, Joseph; Cowen, Leah E.

    2016-01-01

    Fungal pathogens have evolved diverse strategies to sense host-relevant cues and coordinate cellular responses, which enable virulence and drug resistance. Defining circuitry controlling these traits opens new opportunities for chemical diversity in therapeutics, as the cognate inhibitors are rarely explored by conventional screening approaches. This has great potential to address the pressing need for new therapeutic strategies for invasive fungal infections, which have a staggering impact on human health. To explore this approach, we focused on a leading human fungal pathogen, Candida albicans, and screened 1,280 pharmacologically active compounds to identify those that potentiate the activity of echinocandins, which are front-line therapeutics that target fungal cell wall synthesis. We identified 19 compounds that enhance activity of the echinocandin caspofungin against an echinocandin-resistant clinical isolate, with the broad-spectrum chelator DTPA demonstrating the greatest synergistic activity. We found that DTPA increases susceptibility to echinocandins via chelation of magnesium. Whole genome sequencing of mutants resistant to the combination of DTPA and caspofungin identified mutations in the histidine kinase gene NIK1 that confer resistance to the combination. Functional analyses demonstrated that DTPA activates the mitogen-activated protein kinase Hog1, and that NIK1 mutations block Hog1 activation in response to both caspofungin and DTPA. The combination has therapeutic relevance as DTPA enhanced the efficacy of caspofungin in a mouse model of echinocandin-resistant candidiasis. We found that DTPA not only reduces drug resistance but also modulates morphogenesis, a key virulence trait that is normally regulated by environmental cues. DTPA induced filamentation via depletion of zinc, in a manner that is contingent upon Ras1-PKA signaling, as well as the transcription factors Brg1 and Rob1. Thus, we establish a new mechanism by which metal chelation

  19. Metal Chelation as a Powerful Strategy to Probe Cellular Circuitry Governing Fungal Drug Resistance and Morphogenesis.

    PubMed

    Polvi, Elizabeth J; Averette, Anna F; Lee, Soo Chan; Kim, Taeyup; Bahn, Yong-Sun; Veri, Amanda O; Robbins, Nicole; Heitman, Joseph; Cowen, Leah E

    2016-10-01

    Fungal pathogens have evolved diverse strategies to sense host-relevant cues and coordinate cellular responses, which enable virulence and drug resistance. Defining circuitry controlling these traits opens new opportunities for chemical diversity in therapeutics, as the cognate inhibitors are rarely explored by conventional screening approaches. This has great potential to address the pressing need for new therapeutic strategies for invasive fungal infections, which have a staggering impact on human health. To explore this approach, we focused on a leading human fungal pathogen, Candida albicans, and screened 1,280 pharmacologically active compounds to identify those that potentiate the activity of echinocandins, which are front-line therapeutics that target fungal cell wall synthesis. We identified 19 compounds that enhance activity of the echinocandin caspofungin against an echinocandin-resistant clinical isolate, with the broad-spectrum chelator DTPA demonstrating the greatest synergistic activity. We found that DTPA increases susceptibility to echinocandins via chelation of magnesium. Whole genome sequencing of mutants resistant to the combination of DTPA and caspofungin identified mutations in the histidine kinase gene NIK1 that confer resistance to the combination. Functional analyses demonstrated that DTPA activates the mitogen-activated protein kinase Hog1, and that NIK1 mutations block Hog1 activation in response to both caspofungin and DTPA. The combination has therapeutic relevance as DTPA enhanced the efficacy of caspofungin in a mouse model of echinocandin-resistant candidiasis. We found that DTPA not only reduces drug resistance but also modulates morphogenesis, a key virulence trait that is normally regulated by environmental cues. DTPA induced filamentation via depletion of zinc, in a manner that is contingent upon Ras1-PKA signaling, as well as the transcription factors Brg1 and Rob1. Thus, we establish a new mechanism by which metal chelation

  20. Local Circuit Inhibition in the Cerebral Cortex as the source of Gain Control and Untuned Suppression

    PubMed Central

    Shapley, Robert M.; Xing, Dajun

    2012-01-01

    Theoretical considerations have led to the concept that the cerebral cortex is operating in a balanced state in which synaptic excitation is approximately balanced by synaptic inhibition from the local cortical circuit. This paper is about the functional consequences of the balanced state in sensory cortex. One consequence is gain control: there is experimental evidence and theoretical support for the idea that local circuit inhibition acts as a local automatic gain control throughout the cortex. Second, inhibition increases cortical feature selectivity: many studies of different sensory cortical areas have reported that suppressive mechanisms contribute to feature selectivity. Synaptic inhibition from the local microcircuit should be untuned (or broadly tuned) for stimulus features because of the microarchitecture of the cortical microcircuit. Untuned inhibition probably is the source of Untuned Suppression that enhances feature selectivity. We studied inhibition’s function in our experiments, guided by a neuronal network model, on orientation selectivity in the primary visual cortex, V1, of the Macaque monkey. Our results revealed that Untuned Suppression, generated by local circuit inhibition, is crucial for the generation of highly orientation-selective cells in V1 cortex. PMID:23036513

  1. Preliminary investigation of the relationships between sleep duration, reward circuitry function, and mood dysregulation in youth offspring of parents with bipolar disorder.

    PubMed

    Soehner, Adriane M; Bertocci, Michele A; Manelis, Anna; Bebko, Genna; Ladouceur, Cecile D; Graur, Simona; Monk, Kelly; Bonar, Lisa K; Hickey, Mary Beth; Axelson, David; Goldstein, Benjamin I; Goldstein, Tina R; Birmaher, Boris; Phillips, Mary L

    2016-11-15

    Altered reward circuitry function is observed in individuals with bipolar disorder (BD) and their unaffected offspring (OBP). While OBP are at elevated risk for BD, modifiable risk factors that may exacerbate neural vulnerabilities in OBP remain under-characterized. As sleep loss is strongly linked to mania in BD, this study tested associations between sleep duration, reward circuitry function, and mood dysregulation in OBP. Two groups of youth unaffected with BD (9-17yr) completed a number-guessing fMRI reward paradigm: 25 OBP and 21 age-sex-IQ-matched offspring of control parents with non-BD psychopathology (OCP), to differentiate risk for BD from risk for psychopathology more broadly. Regressions tested effects of group status, self-reported past-week sleep duration, and their interaction on neural activity and bilateral ventral striatum (VS) functional connectivity to win>control. Correlations with parent-reported mood dysregulation were assessed. Group effects were observed for right posterior insula activity (OCP>OBP) and VS-left posterior insula connectivity (OBP>OCP). Group ⁎ sleep duration interactions were observed for left dorsal anterior-mid-cingulate (daMCC) activity and VS-left anterior insula/ventrolateral prefrontal cortex (VLPFC) connectivity. Specifically, sleep duration and daMCC activity were positively related in OBP, but negatively related in OCP and sleep duration and VS-left anterior insula/VLPFC connectivity were negatively related in OBP, but positively in OCP. Additionally, increased VS-left posterior insula connectivity and VS-left anterior insula/VLPFC connectivity were associated with greater mood dysregulation in OBP only. Cross-sectional design and small sample size. Altered reward-related VS-insula connectivity could represent a neural pathway underpinning mood dysregulation in OBP, and may be modulated by shortened sleep duration. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. A randomized, placebo-controlled study of zonisamide to prevent olanzapine-associated weight gain.

    PubMed

    McElroy, Susan L; Winstanley, Erin; Mori, Nicole; Martens, Brian; McCoy, Jessica; Moeller, Dianna; Guerdjikova, Anna I; Keck, Paul E

    2012-04-01

    Weight gain is commonly observed with olanzapine treatment. Zonisamide is an antiepileptic drug associated with weight loss. This study examined the effectiveness of zonisamide in preventing weight gain in 42 patients beginning olanzapine for bipolar disorder or schizophrenia. Each patient had a body mass index of 22 mg/kg or greater and was randomized to taking olanzapine with either zonisamide (n = 20) or placebo (n = 22) for 16 weeks. The primary outcome measure was change in body weight in kilograms from baseline. In the primary analysis using longitudinal regression, patients who received zonisamide had a significantly slower rate of weight gain and increase in body mass index than those who received placebo. The patients treated with zonisamide gained a mean (SD) of 0.9 (3.3) kg, whereas those treated with placebo gained a mean (SD) of 5.0 (5.5) kg; P = 0.01. None of the patients in the zonisamide group, compared with 7 patients (33%) in the placebo group, gained 7% of body weight or greater from baseline (Fisher exact test, P = 0.009). The zonisamide group, however, reported significantly more cognitive impairment as an adverse event than the placebo group (25% vs 0, respectively; P = 0.02). Zonisamide was effective for mitigating weight gain in patients with bipolar disorder or schizophrenia initiating treatment with olanzapine but was associated with cognitive impairment as an adverse event.

  3. Mode control in a high-gain relativistic klystron amplifier

    NASA Astrophysics Data System (ADS)

    Li, Zheng-Hong; Zhang, Hong; Ju, Bing-Quan; Su, Chang; Wu, Yang

    2010-05-01

    Middle cavities between the input and output cavity can be used to decrease the required input RF power for the relativistic klystron amplifier. Meanwhile higher modes, which affect the working mode, are also easy to excite in a device with more middle cavities. In order for the positive feedback process for higher modes to be excited, a special measure is taken to increase the threshold current for such modes. Higher modes' excitation will be avoided when the threshold current is significantly larger than the beam current. So a high-gain S-band relativistic klystron amplifier is designed for the beam of current 5 kA and beam voltage 600 kV. Particle in cell simulations show that the gain is 1.6 × 105 with the input RF power of 6.8 kW, and that the output RF power reaches 1.1 GW.

  4. The 40-Something randomized controlled trial to prevent weight gain in mid-age women.

    PubMed

    Williams, Lauren T; Hollis, Jenna L; Collins, Clare E; Morgan, Philip J

    2013-10-25

    Obesity prevention is a major public health priority. Despite the health risks associated with weight gain, there has been a distinct lack of research into effective interventions to prevent, rather than treat, obesity particularly at high risk life stages such as menopause in women. This paper describes the rationale for and design of a 2-year randomized controlled trial (RCT) (the 40-Something Study) aimed at testing the feasibility and efficacy of a relatively low intensity intervention designed to achieve weight control in non-obese women about to enter the menopause transition. The study is a parallel-group RCT consisting of 12 months of intervention (Phase 1) and 12 months of monitoring (Phase 2). Non-obese pre-menopausal healthy females 44-50 years of age were screened, stratified according to Body Mass Index (BMI) category (18.5-24.9 and 25-29.9 kg/m²) and randomly assigned to one of two groups: motivational interviewing (MI) intervention (n = 28), or a self-directed intervention (SDI) (control) (n = 26). The MI intervention consisted of five consultations with health professionals (four with a Dietitian and one with an Exercise Physiologist) who applied components of MI counselling to consultations with the women over a 12 month period. The SDI was developed as a control and these participants received print materials only. Outcome measures were collected at baseline, three, 12, 18 and 24 months and included weight (primary outcome), waist circumference, body composition, blood pressure, plasma markers of metabolic syndrome risk, dietary intake, physical activity and quality of life. Analysis of covariance will be used to investigate outcomes according to intervention type and duration (comparing baseline, 12 and 24 months). The 40-Something study is the first RCT aimed at preventing menopausal weight gain in Australian women. Importantly, this paper describes the methods used to evaluate whether a relatively low intensity, health professional led

  5. MOS Circuitry Would Detect Low-Energy Charged Particles

    NASA Technical Reports Server (NTRS)

    Sinha, Mahadeva; Wadsworth, Mark

    2003-01-01

    Metal oxide semiconductor (MOS) circuits for measuring spatially varying intensities of beams of low-energy charged particles have been developed. These circuits are intended especially for use in measuring fluxes of ions with spatial resolution along the focal planes of mass spectrometers. Unlike prior mass spectrometer focal-plane detectors, these MOS circuits would not be based on ion-induced generation of electrons, and photons; instead, they would be based on direct detection of the electric charges of the ions. Hence, there would be no need for microchannel plates (for ion-to-electron conversion), phosphors (for electron-to-photon conversion), and photodetectors (for final detection) -- components that degrade spatial resolution and contribute to complexity and size. The developmental circuits are based on linear arrays of charge-coupled devices (CCDs) with associated readout circuitry (see figure). They resemble linear CCD photodetector arrays, except that instead of a photodetector, each pixel contains a capacitive charge sensor. The capacitor in each sensor comprises two electrodes (typically made of aluminum) separated by a layer of insulating material. The exposed electrode captures ions and accumulates their electric charges during signal-integration periods.

  6. Topology and Control of the Cell-Cycle-Regulated Transcriptional Circuitry

    PubMed Central

    Haase, Steven B.; Wittenberg, Curt

    2014-01-01

    Nearly 20% of the budding yeast genome is transcribed periodically during the cell division cycle. The precise temporal execution of this large transcriptional program is controlled by a large interacting network of transcriptional regulators, kinases, and ubiquitin ligases. Historically, this network has been viewed as a collection of four coregulated gene clusters that are associated with each phase of the cell cycle. Although the broad outlines of these gene clusters were described nearly 20 years ago, new technologies have enabled major advances in our understanding of the genes comprising those clusters, their regulation, and the complex regulatory interplay between clusters. More recently, advances are being made in understanding the roles of chromatin in the control of the transcriptional program. We are also beginning to discover important regulatory interactions between the cell-cycle transcriptional program and other cell-cycle regulatory mechanisms such as checkpoints and metabolic networks. Here we review recent advances and contemporary models of the transcriptional network and consider these models in the context of eukaryotic cell-cycle controls. PMID:24395825

  7. Synaptic reorganization of inhibitory hilar interneuron circuitry after traumatic brain injury in mice

    PubMed Central

    Hunt, Robert F.; Scheff, Stephen W.; Smith, Bret N.

    2011-01-01

    Functional plasticity of synaptic networks in the dentate gyrus has been implicated in the development of posttraumatic epilepsy and in cognitive dysfunction after traumatic brain injury, but little is known about potentially pathogenic changes in inhibitory circuits. We examined synaptic inhibition of dentate granule cells and excitability of surviving GABAergic hilar interneurons 8–13 weeks after cortical contusion brain injury in transgenic mice that express enhanced green fluorescent protein in a subpopulation of inhibitory neurons. Whole-cell voltage-clamp recordings in granule cells revealed a reduction in spontaneous and miniature IPSC frequency after head injury; no concurrent change in paired-pulse ratio was found in granule cells after paired electrical stimulation of the hilus. Despite reduced inhibitory input to granule cells, action potential and EPSC frequencies were increased in hilar GABA neurons from slices ipsilateral to the injury, versus those from control or contralateral slices. Further, increased excitatory synaptic activity was detected in hilar GABA neurons ipsilateral to the injury after glutamate photostimulation of either the granule cell or CA3 pyramidal cell layers. Together, these findings suggest that excitatory drive to surviving hilar GABA neurons is enhanced by convergent input from both pyramidal and granule cells, but synaptic inhibition of granule cells is not fully restored after injury. This rewiring of circuitry regulating hilar inhibitory neurons may reflect an important compensatory mechanism, but it may also contribute to network destabilization by increasing the relative impact of surviving individual interneurons in controlling granule cell excitability in the posttraumatic dentate gyrus. PMID:21543618

  8. Remote temperature-set-point controller

    DOEpatents

    Burke, W.F.; Winiecki, A.L.

    1984-10-17

    An instrument is described for carrying out mechanical strain tests on metallic samples with the addition of means for varying the temperature with strain. The instrument includes opposing arms and associated equipment for holding a sample and varying the mechanical strain on the sample through a plurality of cycles of increasing and decreasing strain within predetermined limits, circuitry for producing an output signal representative of the strain during the tests, apparatus including a a set point and a coil about the sample for providing a controlled temperature in the sample, and circuitry interconnected between the strain output signal and set point for varying the temperature of the sample linearly with strain during the tests.

  9. Remote temperature-set-point controller

    DOEpatents

    Burke, William F.; Winiecki, Alan L.

    1986-01-01

    An instrument for carrying out mechanical strain tests on metallic samples with the addition of an electrical system for varying the temperature with strain, the instrument including opposing arms and associated equipment for holding a sample and varying the mechanical strain on the sample through a plurality of cycles of increasing and decreasing strain within predetermined limits, circuitry for producing an output signal representative of the strain during the tests, apparatus including a set point and a coil about the sample for providing a controlled temperature in the sample, and circuitry interconnected between the strain output signal and set point for varying the temperature of the sample linearly with strain during the tests.

  10. Longitudinal relationships among activity in attention redirection neural circuitry and symptom severity in youth.

    PubMed

    Bertocci, Michele A; Bebko, Genna; Dwojak, Amanda; Iyengar, Satish; Ladouceur, Cecile D; Fournier, Jay C; Versace, Amelia; Perlman, Susan B; Almeida, Jorge R C; Travis, Michael J; Gill, Mary Kay; Bonar, Lisa; Schirda, Claudiu; Diwadkar, Vaibhav A; Sunshine, Jeffrey L; Holland, Scott K; Kowatch, Robert A; Birmaher, Boris; Axelson, David; Horwitz, Sarah M; Frazier, Thomas; Arnold, L Eugene; Fristad, Mary A; Youngstrom, Eric A; Findling, Robert L; Phillips, Mary L

    2017-05-01

    Changes in neural circuitry function may be associated with longitudinal changes in psychiatric symptom severity. Identification of these relationships may aid in elucidating the neural basis of psychiatric symptom evolution over time. We aimed to distinguish these relationships using data from the Longitudinal Assessment of Manic Symptoms (LAMS) cohort. Forty-one youth completed two study visits (mean=21.3 months). Elastic-net regression (Multiple response Gaussian family) identified emotional regulation neural circuitry that changed in association with changes in depression, mania, anxiety, affect lability, and positive mood and energy dysregulation, accounting for clinical and demographic variables. Non-zero coefficients between change in the above symptom measures and change in activity over the inter-scan interval were identified in right amygdala and left ventrolateral prefrontal cortex. Differing patterns of neural activity change were associated with changes in each of the above symptoms over time. Specifically, from Scan1 to Scan2, worsening affective lability and depression severity were associated with increased right amygdala and left ventrolateral prefrontal cortical activity. Worsening anxiety and positive mood and energy dysregulation were associated with decreased right amygdala and increased left ventrolateral prefrontal cortical activity. Worsening mania was associated with increased right amygdala and decreased left ventrolateral prefrontal cortical activity. These changes in neural activity between scans accounted for 13.6% of the variance; that is 25% of the total explained variance (39.6%) in these measures. Distinct neural mechanisms underlie changes in different mood and anxiety symptoms overtime.

  11. Determining productivity gains from herbaceous vegetation management with 'age-shift' calculations

    Treesearch

    David B. South; James H. Miller; Mark O. Kimberley; Curtis L. Vanderschaaf

    2006-01-01

    Gains in stand volume that result from competition control and fertilization are sometimes reported as 'percentage gains'. Because percentage gains arithmetically decline over time asstand volume increases, plantation managers have difficultyin using percentage gains to project growth and revenues. The 'age-shift' method quantifies the year...

  12. How does a specific learning and memory system in the mammalian brain gain control of behavior?

    PubMed

    McDonald, Robert J; Hong, Nancy S

    2013-11-01

    This review addresses a fundamental, yet poorly understood set of issues in systems neuroscience. The issues revolve around conceptualizations of the organization of learning and memory in the mammalian brain. One intriguing, and somewhat popular, conceptualization is the idea that there are multiple learning and memory systems in the mammalian brain and they interact in different ways to influence and/or control behavior. This approach has generated interesting empirical and theoretical work supporting this view. One issue that needs to be addressed is how these systems influence or gain control of voluntary behavior. To address this issue, we clearly specify what we mean by a learning and memory system. We then review two types of processes that might influence which memory system gains control of behavior. One set of processes are external factors that can affect which system controls behavior in a given situation including task parameters like the kind of information available to the subject, types of training experience, and amount of training. The second set of processes are brain mechanisms that might influence what memory system controls behavior in a given situation including executive functions mediated by the prefrontal cortex; switching mechanisms mediated by ascending neurotransmitter systems, the unique role of the hippocampus during learning. The issue of trait differences in control of different learning and memory systems will also be considered in which trait differences in learning and memory function are thought to potentially emerge from differences in level of prefrontal influence, differences in plasticity processes, differences in ascending neurotransmitter control, differential access to effector systems like motivational and motor systems. Finally, we present scenarios in which different mechanisms might interact. This review was conceived to become a jumping off point for new work directed at understanding these issues. The outcome of

  13. Hippo-independent activation of YAP by the GNAQ uveal melanoma oncogene through a trio-regulated rho GTPase signaling circuitry.

    PubMed

    Feng, Xiaodong; Degese, Maria Sol; Iglesias-Bartolome, Ramiro; Vaque, Jose P; Molinolo, Alfredo A; Rodrigues, Murilo; Zaidi, M Raza; Ksander, Bruce R; Merlino, Glenn; Sodhi, Akrit; Chen, Qianming; Gutkind, J Silvio

    2014-06-16

    Mutually exclusive activating mutations in the GNAQ and GNA11 oncogenes, encoding heterotrimeric Gαq family members, have been identified in ∼ 83% and ∼ 6% of uveal and skin melanomas, respectively. However, the molecular events underlying these GNAQ-driven malignancies are not yet defined, thus limiting the ability to develop cancer-targeted therapies. Here, we focused on the transcriptional coactivator YAP, a critical component of the Hippo signaling pathway that controls organ size. We found that Gαq stimulates YAP through a Trio-Rho/Rac signaling circuitry promoting actin polymerization, independently of phospholipase Cβ and the canonical Hippo pathway. Furthermore, we show that Gαq promotes the YAP-dependent growth of uveal melanoma cells, thereby identifying YAP as a suitable therapeutic target in uveal melanoma, a GNAQ/GNA11-initiated human malignancy. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Hybrid Nanowire Ion-to-Electron Transducers for Integrated Bioelectronic Circuitry.

    PubMed

    Carrad, D J; Mostert, A B; Ullah, A R; Burke, A M; Joyce, H J; Tan, H H; Jagadish, C; Krogstrup, P; Nygård, J; Meredith, P; Micolich, A P

    2017-02-08

    A key task in the emerging field of bioelectronics is the transduction between ionic/protonic and electronic signals at high fidelity. This is a considerable challenge since the two carrier types exhibit intrinsically different physics and are best supported by very different materials types-electronic signals in inorganic semiconductors and ionic/protonic signals in organic or bio-organic polymers, gels, or electrolytes. Here we demonstrate a new class of organic-inorganic transducing interface featuring semiconducting nanowires electrostatically gated using a solid proton-transporting hygroscopic polymer. This model platform allows us to study the basic transducing mechanisms as well as deliver high fidelity signal conversion by tapping into and drawing together the best candidates from traditionally disparate realms of electronic materials research. By combining complementary n- and p-type transducers we demonstrate functional logic with significant potential for scaling toward high-density integrated bioelectronic circuitry.

  15. Stretchable biocompatible electronics by embedding electrical circuitry in biocompatible elastomers.

    PubMed

    Jahanshahi, Amir; Salvo, Pietro; Vanfleteren, Jan

    2012-01-01

    Stretchable and curvilinear electronics has been used recently for the fabrication of micro systems interacting with the human body. The applications range from different kinds of implantable sensors inside the body to conformable electrodes and artificial skins. One of the key parameters in biocompatible stretchable electronics is the fabrication of reliable electrical interconnects. Although very recent literature has reported on the reliability of stretchable interconnects by cyclic loading, work still needs to be done on the integration of electrical circuitry composed of rigid components and stretchable interconnects in a biological environment. In this work, the feasibility of a developed technology to fabricate simple electrical circuits with meander shaped stretchable interconnects is presented. Stretchable interconnects are 200 nm thin Au layer supported with polyimide (PI). A stretchable array of light emitting diodes (LEDs) is embedded in biocompatible elastomer using this technology platform and it features a 50% total elongation.

  16. Gaining control: reform, reimbursement and politics in New York's community hospitals, 1890--1915.

    PubMed Central

    Rosner, D

    1980-01-01

    This is an historical study of an early twentieth century political struggle regarding hospital reimbursement in New York City. During a period called the "Progressive Era" (1895--1915), administrators in the City's Comptroller's office sought to gain control over small, locally run community hospitals by dismantling the long-standing practice of flat-grant payments to institutions. Central office planners felt that these payments gave too much control to trustees. In its place, the Comptroller initiated a system of per-capita, per-diem reimbursement. Inspectors now judged for the institutions which services and which clients were appropriate for municipal reimbursement. From the perspective of the Comptroller's office, this change was an attempt to put rationality into the system of municipal support for charitable institutions. From the perspective of trustees and community representatives, however, this change was a political attack on the rights of institutions and local communities to control their own fate. Within the context of the larger Progressive Era "good government" movement to centralize decision-making in the hands of experts who believed strongly in the efficiency of larger institutions, it was generally the smallest, most financially troubled community institutions which felt the brunt of these changes. PMID:6990801

  17. Weight Gain Prevention among Midlife Women: A Randomized Controlled Trial to Address Needs Related to the Physical and Social Environment.

    PubMed

    Perry, Courtney D; Degeneffe, Dennis; Davey, Cynthia; Kollannoor-Samuel, Grace; Reicks, Marla

    2016-05-25

    Women tend to gain weight at midlife (40-60 years) increasing risk of obesity-related chronic diseases. Within specific eating occasions, needs related to the physical and social environment may result in less healthy eating behavior, which can lead to weight gain over time. The purpose of this study was to determine if a dietitian-delivered nutrition counseling intervention tailored to eating occasion needs could improve diet and prevent weight gain among midlife women over two years. A randomized controlled trial was conducted with healthy midlife women (n = 354) in one U.S. metropolitan area. The intervention group (n = 185) received ten hours of individual nutrition counseling from dietitians over six months, while women in a control group (n = 169) received no counseling. Measured height, weight and waist circumference, and dietary intakes were collected at baseline and every six months over two years. Mixed linear models were used to test for intervention effect on change in outcome variables over time. Dietary intakes of fruit, reduced/low-fat dairy foods and refined grains were significantly improved over time in the intervention compared to control group. However, the intervention had no effect on weight over time (p = 0.48). Nutrition counseling tailored to address eating occasion needs improved self-reported diet but did not significantly affect weight change.

  18. Double-differential recording and AGC using microcontrolled variable gain ASIC.

    PubMed

    Rieger, Robert; Deng, Shin-Liang

    2013-01-01

    Low-power wearable recording of biopotentials requires acquisition front-ends with high common-mode rejection for interference suppression and adjustable gain to provide an optimum signal range to a cascading analogue-to-digital stage. A microcontroller operated double-differential (DD) recording setup and automatic gain control circuit (AGC) are discussed which reject common-mode interference and provide tunable gain, thus compensating for imbalance and variation in electrode interface impedance. Custom-designed variable gain amplifiers (ASIC) are used as part of the recording setup. The circuit gain and balance is set by the timing of microcontroller generated clock signals. Measured results are presented which confirm that improved common-mode rejection is achieved compared to a single differential amplifier in the presence of input network imbalance. Practical measured examples further validate gain control suitable for biopotential recording and power-line rejection for wearable ECG and EMG recording. The prototype front-end consumes 318 μW including amplifiers and microcontroller.

  19. Childhood maltreatment is associated with altered fear circuitry and increased internalizing symptoms by late adolescence

    PubMed Central

    Herringa, Ryan J.; Birn, Rasmus M.; Ruttle, Paula L.; Burghy, Cory A.; Stodola, Diane E.; Davidson, Richard J.; Essex, Marilyn J.

    2013-01-01

    Maltreatment during childhood is a major risk factor for anxiety and depression, which are major public health problems. However, the underlying brain mechanism linking maltreatment and internalizing disorders remains poorly understood. Maltreatment may alter the activation of fear circuitry, but little is known about its impact on the connectivity of this circuitry in adolescence and whether such brain changes actually lead to internalizing symptoms. We examined the associations between experiences of maltreatment during childhood, resting-state functional brain connectivity (rs-FC) of the amygdala and hippocampus, and internalizing symptoms in 64 adolescents participating in a longitudinal community study. Childhood experiences of maltreatment were associated with lower hippocampus–subgenual cingulate rs-FC in both adolescent females and males and lower amygdala–subgenual cingulate rs-FC in females only. Furthermore, rs-FC mediated the association of maltreatment during childhood with adolescent internalizing symptoms. Thus, maltreatment in childhood, even at the lower severity levels found in a community sample, may alter the regulatory capacity of the brain’s fear circuit, leading to increased internalizing symptoms by late adolescence. These findings highlight the importance of fronto–hippocampal connectivity for both sexes in internalizing symptoms following maltreatment in childhood. Furthermore, the impact of maltreatment during childhood on both fronto–amygdala and –hippocampal connectivity in females may help explain their higher risk for internalizing disorders such as anxiety and depression. PMID:24191026

  20. An analysis of the circuitry of the visual pathway of the lateral eye of limullus

    NASA Technical Reports Server (NTRS)

    Sjoestrand, F. S.

    1970-01-01

    The methodology is discussed for three-dimensional analysis of the nervous system on the basis of electron micrographs of serial sections. An analysis is presented of a part of the circuitry of the rabbit retina. In addition, some exploratory work is reported with respect to the visual cortex of the cat brain. A proper technique for preservation of the visual cortex was worked out and a technique to localize microelectrode tips in the tissue in connection with electron microscopy was partially worked out.

  1. Effects of internal gain assumptions in building energy calculations

    NASA Astrophysics Data System (ADS)

    Christensen, C.; Perkins, R.

    1981-01-01

    The utilization of direct solar gains in buildings can be affected by operating profiles, such as schedules for internal gains, thermostat controls, and ventilation rates. Building energy analysis methods use various assumptions about these profiles. The effects of typical internal gain assumptions in energy calculations are described. Heating and cooling loads from simulations using the DOE 2.1 computer code are compared for various internal gain inputs: typical hourly profiles, constant average profiles, and zero gain profiles. Prototype single-family-detached and multifamily-attached residential units are studied with various levels of insulation and infiltration. Small detached commercial buildings and attached zones in large commercial buildings are studied with various levels of internal gains. The results indicate that calculations of annual heating and cooling loads are sensitive to internal gains, but in most cases are relatively insensitive to hourly variations in internal gains.

  2. Neural Control of the Lower Urinary Tract

    PubMed Central

    de Groat, William C.; Griffiths, Derek; Yoshimura, Naoki

    2015-01-01

    This article summarizes anatomical, neurophysiological, pharmacological, and brain imaging studies in humans and animals that have provided insights into the neural circuitry and neurotransmitter mechanisms controlling the lower urinary tract. The functions of the lower urinary tract to store and periodically eliminate urine are regulated by a complex neural control system in the brain, spinal cord, and peripheral autonomic ganglia that coordinates the activity of smooth and striated muscles of the bladder and urethral outlet. The neural control of micturition is organized as a hierarchical system in which spinal storage mechanisms are in turn regulated by circuitry in the rostral brain stem that initiates reflex voiding. Input from the forebrain triggers voluntary voiding by modulating the brain stem circuitry. Many neural circuits controlling the lower urinary tract exhibit switch-like patterns of activity that turn on and off in an all-or-none manner. The major component of the micturition switching circuit is a spinobulbospinal parasympathetic reflex pathway that has essential connections in the periaqueductal gray and pontine micturition center. A computer model of this circuit that mimics the switching functions of the bladder and urethra at the onset of micturition is described. Micturition occurs involuntarily in infants and young children until the age of 3 to 5 years, after which it is regulated voluntarily. Diseases or injuries of the nervous system in adults can cause the re-emergence of involuntary micturition, leading to urinary incontinence. Neuroplasticity underlying these developmental and pathological changes in voiding function is discussed. PMID:25589273

  3. Sympathetic baroreflex gain in normotensive pregnant women

    PubMed Central

    Usselman, Charlotte W.; Skow, Rachel J.; Matenchuk, Brittany A.; Chari, Radha S.; Julian, Colleen G.; Stickland, Michael K.; Davenport, Margie H.

    2015-01-01

    Muscle sympathetic nerve activity is increased during normotensive pregnancy while mean arterial pressure is maintained or reduced, suggesting baroreflex resetting. We hypothesized spontaneous sympathetic baroreflex gain would be reduced in normotensive pregnant women relative to nonpregnant matched controls. Integrated muscle sympathetic burst incidence and total sympathetic activity (microneurography), blood pressure (Finometer), and R-R interval (ECG) were assessed at rest in 11 pregnant women (33 ± 1 wk gestation, 31 ± 1 yr, prepregnancy BMI: 23.5 ± 0.9 kg/m2) and 11 nonpregnant controls (29 ± 1 yr; BMI: 25.2 ± 1.7 kg/m2). Pregnant women had elevated baseline sympathetic burst incidence (43 ± 2 vs. 33 ± 2 bursts/100 heart beats, P = 0.01) and total sympathetic activity (1,811 ± 148 vs. 1,140 ± 55 au, P < 0.01) relative to controls. Both mean (88 ± 3 vs. 91 ± 2 mmHg, P = 0.4) and diastolic (DBP) (72 ± 3 vs. 73 ± 2 mmHg, P = 0.7) pressures were similar between pregnant and nonpregnant women, respectively, indicating an upward resetting of the baroreflex set point with pregnancy. Baroreflex gain, calculated as the linear relationship between sympathetic burst incidence and DBP, was reduced in pregnant women relative to controls (−3.7 ± 0.5 vs. −5.4 ± 0.5 bursts·100 heart beats−1·mmHg−1, P = 0.03), as was baroreflex gain calculated with total sympathetic activity (−294 ± 24 vs. −210 ± 24 au·100 heart beats−1·mmHg−1; P = 0.03). Cardiovagal baroreflex gain (sequence method) was not different between nonpregnant controls and pregnant women (49 ± 8 vs. 36 ± 8 ms/mmHg; P = 0.2). However, sympathetic (burst incidence) and cardiovagal gains were negatively correlated in pregnant women (R = −0.7; P = 0.02). Together, these data indicate that the influence of the sympathetic nervous system over arterial blood pressure is reduced in normotensive pregnancy, in terms of both long-term and beat-to-beat regulation of arterial pressure

  4. Water heater control module

    DOEpatents

    Hammerstrom, Donald J

    2013-11-26

    An advanced electric water heater control system that interfaces with a high temperature cut-off thermostat and an upper regulating thermostat. The system includes a control module that is electrically connected to the high-temperature cut-off thermostat and the upper regulating thermostat. The control module includes a switch to open or close the high-temperature cut-off thermostat and the upper regulating thermostat. The control module further includes circuitry configured to control said switch in response to a signal selected from the group of an autonomous signal, a communicated signal, and combinations thereof.

  5. Σ-Δ modulator for a programmable gain, low-power, high-linearity automotive sensor interface

    NASA Astrophysics Data System (ADS)

    de la Rosa, Jose M.; Medeiro, Fernando; Perez-Verdu, Belen; del Rio, Rocio; Rodriguez-Vazquez, Angel

    2003-04-01

    Smart sensors play a critical role in modern automotive electronic systems, covering a wide range of data capturing functions and operating under adverse environmental conditions - temperature range of [-40¦C,175¦C]. In such sensors, the signal provided by transducers is composed of an offset voltage, which depends on the manufacturing process, and a low-frequency signal carrying the information. In practice, the offset voltage is subject to temperature variations, thus causing a shifting of the signal range to be measured. Therefore, the measuring circuit driving the sensor, normally formed by a low-noise preamplifier and an Analog-to-Digital Converter (ADC), must accommodate the complete range of possible offsets and real signals. In this scenario, the use of ADCs based on Sigma-Delta Modulators (SDMs) is convenient for several reasons. On the one hand, the noise-shaping performed by SDMs allows to achieve high resolution (16-17bits), in the band of interest (10-20kHz), with less power consumption than full Nyquist ADCs. On the other hand, the action of feedback renders SDMs very linear, and high-linearity is a must for automotive applications. Last but not least, the robustness of SDMs with respect to circuit imperfections make them suitable to include programmable gain without significant performance degradation. This feature allows to accommodate the complete range of possible offsets and information signals in a sensor interface with relaxed specifications for the preamplifier circuitry. This paper describes the design and implementation of a third-order cascade (2-1) SDM with programmable gain in a 0.35mm CMOS technology - the type of technology commonly employed for automotive applications (deep submicron is mostly employed for telecom). It is capable of handling signals up to 20-kHz bandwidth with 17-bit resolution. The programmable gain is implemented by a capacitor array whose unitary capacitors are connected or disconnected depending on the value of

  6. Perturbation of Serotonin Homeostasis during Adulthood Affects Serotonergic Neuronal Circuitry.

    PubMed

    Pratelli, Marta; Migliarini, Sara; Pelosi, Barbara; Napolitano, Francesco; Usiello, Alessandro; Pasqualetti, Massimo

    2017-01-01

    Growing evidence shows that the neurotransmitter serotonin (5-HT) modulates the fine-tuning of neuron development and the establishment of wiring patterns in the brain. However, whether serotonin is involved in the maintenance of neuronal circuitry in the adult brain remains elusive. Here, we use a Tph2 fl ° x conditional knockout (cKO) mouse line to assess the impact of serotonin depletion during adulthood on serotonergic system organization. Data show that the density of serotonergic fibers is increased in the hippocampus and decreased in the thalamic paraventricular nucleus (PVN) as a consequence of brain serotonin depletion. Strikingly, these defects are rescued following reestablishment of brain 5-HT signaling via administration of the serotonin precursor 5-hydroxytryptophan (5-HTP). Finally, 3D reconstruction of serotonergic fibers reveals that changes in serotonin homeostasis affect axonal branching complexity. These data demonstrate that maintaining proper serotonin homeostasis in the adult brain is crucial to preserve the correct serotonergic axonal wiring.

  7. Ultralow-Noise Atomic-Scale Structures for Quantum Circuitry in Silicon.

    PubMed

    Shamim, Saquib; Weber, Bent; Thompson, Daniel W; Simmons, Michelle Y; Ghosh, Arindam

    2016-09-14

    The atomically precise doping of silicon with phosphorus (Si:P) using scanning tunneling microscopy (STM) promises ultimate miniaturization of field effect transistors. The one-dimensional (1D) Si:P nanowires are of particular interest, retaining exceptional conductivity down to the atomic scale, and are predicted as interconnects for a scalable silicon-based quantum computer. Here, we show that ultrathin Si:P nanowires form one of the most-stable electrical conductors, with the phenomenological Hooge parameter of low-frequency noise being as low as ≈10(-8) at 4.2 K, nearly 3 orders of magnitude lower than even carbon-nanotube-based 1D conductors. A in-built isolation from the surface charge fluctuations due to encapsulation of the wires within the epitaxial Si matrix is the dominant cause for the observed suppression of noise. Apart from quantum information technology, our results confirm the promising prospects for precision-doped Si:P structures in atomic-scale circuitry for the 11 nm technology node and beyond.

  8. Radiation-Hardened Circuitry Using Mask-Programmable Analog Arrays. Final Report

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

    Britton, Jr., Charles L.; Ericson, Milton Nance; Bobrek, Miljko

    As the recent accident at Fukushima Daiichi so vividly demonstrated, telerobotic technologies capable of withstanding high radiation environments need to be readily available to enable operations, repair, and recovery under severe accident scenarios where human entry is extremely dangerous or not possible. Telerobotic technologies that enable remote operation in high dose rate environments have undergone revolutionary improvement over the past few decades. However, much of this technology cannot be employed in nuclear power environments due the radiation sensitivity of the electronics and the organic insulator materials currently in use. This is the final report of the activities involving the NEETmore » 2 project Radiation Hardened Circuitry Using Mask-Programmable Analog Arrays. We present a detailed functional block diagram of the proposed data acquisition system, the thought process leading to technical decisions, the implemented system, and the tested results from the systems. This system will be capable of monitoring at least three parameters of importance to nuclear reactor monitoring: temperature, radiation level, and pressure.« less

  9. The 40-Something randomized controlled trial to prevent weight gain in mid-age women

    PubMed Central

    2013-01-01

    Background Obesity prevention is a major public health priority. Despite the health risks associated with weight gain, there has been a distinct lack of research into effective interventions to prevent, rather than treat, obesity particularly at high risk life stages such as menopause in women. This paper describes the rationale for and design of a 2-year randomized controlled trial (RCT) (the 40-Something Study) aimed at testing the feasibility and efficacy of a relatively low intensity intervention designed to achieve weight control in non-obese women about to enter the menopause transition. Methods and design The study is a parallel-group RCT consisting of 12 months of intervention (Phase 1) and 12 months of monitoring (Phase 2). Non-obese pre-menopausal healthy females 44–50 years of age were screened, stratified according to Body Mass Index (BMI) category (18.5-24.9 and 25–29.9 kg/m2) and randomly assigned to one of two groups: motivational interviewing (MI) intervention (n = 28), or a self-directed intervention (SDI) (control) (n = 26). The MI intervention consisted of five consultations with health professionals (four with a Dietitian and one with an Exercise Physiologist) who applied components of MI counselling to consultations with the women over a 12 month period. The SDI was developed as a control and these participants received print materials only. Outcome measures were collected at baseline, three, 12, 18 and 24 months and included weight (primary outcome), waist circumference, body composition, blood pressure, plasma markers of metabolic syndrome risk, dietary intake, physical activity and quality of life. Analysis of covariance will be used to investigate outcomes according to intervention type and duration (comparing baseline, 12 and 24 months). Discussion The 40-Something study is the first RCT aimed at preventing menopausal weight gain in Australian women. Importantly, this paper describes the methods used to evaluate whether

  10. Control of a solar-energy-supplied electrical-power system without intermediate circuitry

    NASA Astrophysics Data System (ADS)

    Leistner, K.

    A computer control system is developed for electric-power systems comprising solar cells and small numbers of users with individual centrally controlled converters (and storage facilities when needed). Typical system structures are reviewed; the advantages of systems without an intermediate network are outlined; the demands on a control system in such a network (optimizing generator working point and power distribution) are defined; and a flexible modular prototype system is described in detail. A charging station for lead batteries used in electric automobiles is analyzed as an example. The power requirements of the control system (30 W for generator control and 50 W for communications and distribution control) are found to limit its use to larger networks.

  11. Concerted Efforts to Control or Eliminate Neglected Tropical Diseases: How Much Health Will Be Gained?

    PubMed Central

    Hontelez, Jan A. C.; Bakker, Roel; Blok, David J.; Cai, Rui; Houweling, Tanja A. J.; Kulik, Margarete C.; Lenk, Edeltraud J.; Luyendijk, Marianne; Matthijsse, Suzette M.; Redekop, William K.; Wagenaar, Inge; Jacobson, Julie; Nagelkerke, Nico J. D.; Richardus, Jan H.

    2016-01-01

    Background The London Declaration (2012) was formulated to support and focus the control and elimination of ten neglected tropical diseases (NTDs), with targets for 2020 as formulated by the WHO Roadmap. Five NTDs (lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminths and trachoma) are to be controlled by preventive chemotherapy (PCT), and four (Chagas’ disease, human African trypanosomiasis, leprosy and visceral leishmaniasis) by innovative and intensified disease management (IDM). Guinea worm, virtually eradicated, is not considered here. We aim to estimate the global health impact of meeting these targets in terms of averted morbidity, mortality, and disability adjusted life years (DALYs). Methods The Global Burden of Disease (GBD) 2010 study provides prevalence and burden estimates for all nine NTDs in 1990 and 2010, by country, age and sex, which were taken as the basis for our calculations. Estimates for other years were obtained by interpolating between 1990 (or the start-year of large-scale control efforts) and 2010, and further extrapolating until 2030, such that the 2020 targets were met. The NTD disease manifestations considered in the GBD study were analyzed as either reversible or irreversible. Health impacts were assessed by comparing the results of achieving the targets with the counterfactual, construed as the health burden had the 1990 (or 2010 if higher) situation continued unabated. Principle Findings/Conclusions Our calculations show that meeting the targets will lead to about 600 million averted DALYs in the period 2011–2030, nearly equally distributed between PCT and IDM-NTDs, with the health gain amongst PCT-NTDs mostly (96%) due to averted disability and amongst IDM-NTDs largely (95%) from averted mortality. These health gains include about 150 million averted irreversible disease manifestations (e.g. blindness) and 5 million averted deaths. Control of soil-transmitted helminths accounts for one third of all

  12. Control of linear modes in cylindrical resistive magnetohydrodynamics with a resistive wall, plasma rotation, and complex gain

    NASA Astrophysics Data System (ADS)

    Brennan, D. P.; Finn, J. M.

    2014-10-01

    Feedback stabilization of magnetohydrodynamic (MHD) modes in a tokamak is studied in a cylindrical model with a resistive wall, plasma resistivity, viscosity, and toroidal rotation. The control is based on a linear combination of the normal and tangential components of the magnetic field just inside the resistive wall. The feedback includes complex gain, for both the normal and for the tangential components, and it is known that the imaginary part of the feedback for the former is equivalent to plasma rotation [J. M. Finn and L. Chacon, Phys. Plasmas 11, 1866 (2004)]. The work includes (1) analysis with a reduced resistive MHD model for a tokamak with finite β and with stepfunction current density and pressure profiles, and (2) computations with a full compressible visco-resistive MHD model with smooth decreasing profiles of current density and pressure. The equilibria are stable for β = 0 and the marginal stability values βrp,rw < βrp,iw < βip,rw < βip,iw (resistive plasma, resistive wall; resistive plasma, ideal wall; ideal plasma, resistive wall; and ideal plasma, ideal wall) are computed for both models. The main results are: (a) imaginary gain with normal sensors or plasma rotation stabilizes below βrp,iw because rotation suppresses the diffusion of flux from the plasma out through the wall and, more surprisingly, (b) rotation or imaginary gain with normal sensors destabilizes above βrp,iw because it prevents the feedback flux from entering the plasma through the resistive wall to form a virtual wall. A method of using complex gain Gi to optimize in the presence of rotation in this regime with β > βrp,iw is presented. The effect of imaginary gain with tangential sensors is more complicated but essentially destabilizes above and below βrp,iw.

  13. Motor and non-motor circuitry activation induced by subthalamic nucleus deep brain stimulation (STN DBS) in Parkinson’s disease patients: Intraoperative fMRI for DBS

    PubMed Central

    Knight, Emily J.; Testini, Paola; Min, Hoon-Ki; Gibson, William S.; Gorny, Krzysztof R.; Favazza, Christopher P.; Felmlee, Joel P.; Kim, Inyong; Welker, Kirk M.; Clayton, Daniel A.; Klassen, Bryan T.; Chang, Su-youne; Lee, Kendall H.

    2015-01-01

    Objective To test the hypothesis suggested by previous studies that subthalamic nucleus (STN) deep brain stimulation (DBS) in patients with PD would affect the activity of both motor and non-motor networks, we applied intraoperative fMRI to patients receiving DBS. Patients and Methods Ten patients receiving STN DBS for PD underwent intraoperative 1.5T fMRI during high frequency stimulation delivered via an external pulse generator. The study was conducted between the dates of January 1, 2013 and September 30, 2014. Results We observed blood oxygen level dependent (BOLD) signal changes (FDR<.001) in the motor circuitry, including primary motor, premotor, and supplementary motor cortices, thalamus, pedunculopontine nucleus (PPN), and cerebellum, as well as in the limbic circuitry, including cingulate and insular cortices. Activation of the motor network was observed also after applying a Bonferroni correction (p<.001) to our dataset, suggesting that, across subjects, BOLD changes in the motor circuitry are more consistent compared to those occurring in the non-motor network. Conclusions These findings support the modulatory role of STN DBS on the activity of motor and non-motor networks, and suggest complex mechanisms at the basis of the efficacy of this treatment modality. Furthermore, these results suggest that, across subjects, BOLD changes in the motor circuitry are more consistent compared to those occurring in the non-motor network. With further studies combining the use of real time intraoperative fMRI with clinical outcomes in patients treated with DBS, functional imaging techniques have the potential not only to elucidate the mechanisms of DBS functioning, but also to guide and assist in the surgical treatment of patients affected by movement and neuropsychiatric disorders. PMID:26046412

  14. Altered behavioral and neural responsiveness to counterfactual gains in the elderly.

    PubMed

    Tobia, Michael J; Guo, Rong; Gläscher, Jan; Schwarze, Ulrike; Brassen, Stefanie; Büchel, Christian; Obermayer, Klaus; Sommer, Tobias

    2016-06-01

    Counterfactual information processing refers to the consideration of events that did not occur in comparison to those actually experienced, in order to determine optimal actions, and can be formulated as computational learning signals, referred to as fictive prediction errors. Decision making and the neural circuitry for counterfactual processing are altered in healthy elderly adults. This experiment investigated age differences in neural systems for decision making with knowledge of counterfactual outcomes. Two groups of healthy adult participants, young (N = 30; ages 19-30 years) and elderly (N = 19; ages 65-80 years), were scanned with fMRI during 240 trials of a strategic sequential investment task in which a particular strategy of differentially weighting counterfactual gains and losses during valuation is associated with more optimal performance. Elderly participants earned significantly less than young adults, differently weighted counterfactual consequences and exploited task knowledge, and exhibited altered activity in a fronto-striatal circuit while making choices, compared to young adults. The degree to which task knowledge was exploited was positively correlated with modulation of neural activity by expected value in the vmPFC for young adults, but not in the elderly. These findings demonstrate that elderly participants' poor task performance may be related to different counterfactual processing.

  15. Neural circuitry of abdominal pain-related fear learning and reinstatement in irritable bowel syndrome.

    PubMed

    Icenhour, A; Langhorst, J; Benson, S; Schlamann, M; Hampel, S; Engler, H; Forsting, M; Elsenbruch, S

    2015-01-01

    Altered pain anticipation likely contributes to disturbed central pain processing in chronic pain conditions like irritable bowel syndrome (IBS), but the learning processes shaping the expectation of pain remain poorly understood. We assessed the neural circuitry mediating the formation, extinction, and reactivation of abdominal pain-related memories in IBS patients compared to healthy controls (HC) in a differential fear conditioning paradigm. During fear acquisition, predictive visual cues (CS(+)) were paired with rectal distensions (US), while control cues (CS(-)) were presented unpaired. During extinction, only CSs were presented. Subsequently, memory reactivation was assessed with a reinstatement procedure involving unexpected USs. Using functional magnetic resonance imaging, group differences in neural activation to CS(+) vs CS(-) were analyzed, along with skin conductance responses (SCR), CS valence, CS-US contingency, state anxiety, salivary cortisol, and alpha-amylase activity. The contribution of anxiety symptoms was addressed in covariance analyses. Fear acquisition was altered in IBS, as indicated by more accurate contingency awareness, greater CS-related valence change, and enhanced CS(+)-induced differential activation of prefrontal cortex and amygdala. IBS patients further revealed enhanced differential cingulate activation during extinction and greater differential hippocampal activation during reinstatement. Anxiety affected neural responses during memory formation and reinstatement. Abdominal pain-related fear learning and memory processes are altered in IBS, mediated by amygdala, cingulate cortex, prefrontal areas, and hippocampus. Enhanced reinstatement may contribute to hypervigilance and central pain amplification, especially in anxious patients. Preventing a 'relapse' of learned fear utilizing extinction-based interventions may be a promising treatment goal in IBS. © 2014 John Wiley & Sons Ltd.

  16. Intake of Sweets, Snacks and Soft Drinks Predicts Weight Gain in Obese Pregnant Women: Detailed Analysis of the Results of a Randomised Controlled Trial

    PubMed Central

    Renault, Kristina M.; Carlsen, Emma M.; Nørgaard, Kirsten; Nilas, Lisbeth; Pryds, Ole; Secher, Niels J.; Olsen, Sjurdur F.; Halldorsson, Thorhallur I.

    2015-01-01

    Background Lifestyle interventions targeting obese pregnant women often result in modest reduction in gestational weight gain, pregnancy complications and related risk factors. Examining adherence to the intervention can, however, provide valuable information on the importance of the different factors targeted. Objective To evaluate improvements and relevance of different dietary factors targeted with respect to gestational weight gain in a 3-arm Randomised Controlled Trial (n=342) among obese pregnant women with BMI≥30 kg/m2. Methods Randomisation 1:1:1 to either hypocaloric Mediterranean type of diet and physical activity intervention (D+PA); physical activity intervention alone (PA); or control (C). Diet was assessed at baseline (weeks 11–14) and endpoint (weeks 36–37) using a validated food frequency questionnaire. Results During the intervention women in the D+PA group significantly lowered their intakes of added sugars and saturated fat and increased their protein intake by ~1% of total energy compared to controls. Of these dietary variables only intakes of added sugar appeared to be related to GWG, while no association was observed for saturated fat or protein. Further analyses revealed that foods that contributed to intake of added sugars, including sweets, snacks, cakes, and soft drinks were strongly associated with weight gain, with women consuming sweets ≥2/day having 5.4 kg (95% CI 2.1-8.7) greater weight gain than those with a low (<1wk) intake. The results for soft drinks were more conflicting, as women with high weight gain tended to favour artificially sweetened soft drinks. Conclusion In our sample of obese pregnant women, craving for sweets, snacks, and soft drinks strongly predicts GWG. Emphasis on reducing intakes of these foods may be more relevant for limiting gestational weight gain than encouraging strict compliance to more specific diets. Trial Registration ClinicalTrials.gov NCT01345149 PMID:26192183

  17. Intake of Sweets, Snacks and Soft Drinks Predicts Weight Gain in Obese Pregnant Women: Detailed Analysis of the Results of a Randomised Controlled Trial.

    PubMed

    Renault, Kristina M; Carlsen, Emma M; Nørgaard, Kirsten; Nilas, Lisbeth; Pryds, Ole; Secher, Niels J; Olsen, Sjurdur F; Halldorsson, Thorhallur I

    2015-01-01

    Lifestyle interventions targeting obese pregnant women often result in modest reduction in gestational weight gain, pregnancy complications and related risk factors. Examining adherence to the intervention can, however, provide valuable information on the importance of the different factors targeted. To evaluate improvements and relevance of different dietary factors targeted with respect to gestational weight gain in a 3-arm Randomised Controlled Trial (n=342) among obese pregnant women with BMI≥30 kg/m2. Randomisation 1:1:1 to either hypocaloric Mediterranean type of diet and physical activity intervention (D+PA); physical activity intervention alone (PA); or control (C). Diet was assessed at baseline (weeks 11-14) and endpoint (weeks 36-37) using a validated food frequency questionnaire. During the intervention women in the D+PA group significantly lowered their intakes of added sugars and saturated fat and increased their protein intake by ~1% of total energy compared to controls. Of these dietary variables only intakes of added sugar appeared to be related to GWG, while no association was observed for saturated fat or protein. Further analyses revealed that foods that contributed to intake of added sugars, including sweets, snacks, cakes, and soft drinks were strongly associated with weight gain, with women consuming sweets ≥2/day having 5.4 kg (95% CI 2.1-8.7) greater weight gain than those with a low (<1wk) intake. The results for soft drinks were more conflicting, as women with high weight gain tended to favour artificially sweetened soft drinks. In our sample of obese pregnant women, craving for sweets, snacks, and soft drinks strongly predicts GWG. Emphasis on reducing intakes of these foods may be more relevant for limiting gestational weight gain than encouraging strict compliance to more specific diets. ClinicalTrials.gov NCT01345149.

  18. Reduced Activation in Lateral Prefrontal Cortex and Anterior Cingulate during Attention and Cognitive Control Functions in Medication-Naive Adolescents with Depression Compared to Controls

    ERIC Educational Resources Information Center

    Halari, Rozmin; Simic, Mima; Pariante, Carmine M.; Papadopoulos, Andrew; Cleare, Anthony; Brammer, Michael; Fombonne, Eric; Rubia, Katya

    2009-01-01

    Background: There is increasing recognition of major depressive disorder (MDD) in adolescence. In adult MDD, abnormalities of fronto-striatal and fronto-cingulate circuitries mediating cognitive control functions have been implicated in the pathogenesis and been related to problems with controlling negative thoughts. No neuroimaging studies of…

  19. Tbr2 Deficiency in Mitral and Tufted Cells Disrupts Excitatory–Inhibitory Balance of Neural Circuitry in the Mouse Olfactory Bulb

    PubMed Central

    Mizuguchi, Rumiko; Naritsuka, Hiromi; Mori, Kensaku; Mao, Chai-An; Klein, William H.; Yoshihara, Yoshihiro

    2013-01-01

    The olfactory bulb (OB) is the first relay station in the brain where odor information from the olfactory epithelium is integrated, processed through its intrinsic neural circuitry, and conveyed to higher olfactory centers. Compared with profound mechanistic insights into olfactory axon wiring from the nose to the OB, little is known about the molecular mechanisms underlying the formation of functional neural circuitry among various types of neurons inside the OB. T-box transcription factor Tbr2 is expressed in various types of glutamatergic excitatory neurons in the brain including the OB projection neurons, mitral and tufted cells. Here we generated conditional knockout mice in which the Tbr2 gene is inactivated specifically in mitral and tufted cells from late embryonic stages. Tbr2 deficiency caused cell-autonomous changes in molecular expression including a compensatory increase of another T-box member, Tbr1, and a concomitant shift of vesicular glutamate transporter (VGluT) subtypes from VGluT1 to VGluT2. Tbr2-deficient mitral and tufted cells also exhibited anatomical abnormalities in their dendritic morphology and projection patterns. Additionally, several non-cell-autonomous phenotypes were observed in parvalbumin-, calbindin-, and 5T4-positive GABAergic interneurons. Furthermore, the number of dendrodendritic reciprocal synapses between mitral/tufted cells and GABAergic interneurons was significantly reduced. Upon stimulation with odorants, larger numbers of mitral and tufted cells were activated in Tbr2 conditional knockout mice. These results suggest that Tbr2 is required for not only the proper differentiation of mitral and tufted cells, but also for the establishment of functional neuronal circuitry in the OB and maintenance of excitatory–inhibitory balance crucial for odor information processing. PMID:22745484

  20. Tbr2 deficiency in mitral and tufted cells disrupts excitatory-inhibitory balance of neural circuitry in the mouse olfactory bulb.

    PubMed

    Mizuguchi, Rumiko; Naritsuka, Hiromi; Mori, Kensaku; Mao, Chai-An; Klein, William H; Yoshihara, Yoshihiro

    2012-06-27

    The olfactory bulb (OB) is the first relay station in the brain where odor information from the olfactory epithelium is integrated, processed through its intrinsic neural circuitry, and conveyed to higher olfactory centers. Compared with profound mechanistic insights into olfactory axon wiring from the nose to the OB, little is known about the molecular mechanisms underlying the formation of functional neural circuitry among various types of neurons inside the OB. T-box transcription factor Tbr2 is expressed in various types of glutamatergic excitatory neurons in the brain including the OB projection neurons, mitral and tufted cells. Here we generated conditional knockout mice in which the Tbr2 gene is inactivated specifically in mitral and tufted cells from late embryonic stages. Tbr2 deficiency caused cell-autonomous changes in molecular expression including a compensatory increase of another T-box member, Tbr1, and a concomitant shift of vesicular glutamate transporter (VGluT) subtypes from VGluT1 to VGluT2. Tbr2-deficient mitral and tufted cells also exhibited anatomical abnormalities in their dendritic morphology and projection patterns. Additionally, several non-cell-autonomous phenotypes were observed in parvalbumin-, calbindin-, and 5T4-positive GABAergic interneurons. Furthermore, the number of dendrodendritic reciprocal synapses between mitral/tufted cells and GABAergic interneurons was significantly reduced. Upon stimulation with odorants, larger numbers of mitral and tufted cells were activated in Tbr2 conditional knockout mice. These results suggest that Tbr2 is required for not only the proper differentiation of mitral and tufted cells, but also for the establishment of functional neuronal circuitry in the OB and maintenance of excitatory-inhibitory balance crucial for odor information processing.

  1. Forward-masking based gain control in odontocete biosonar: an evoked-potential study.

    PubMed

    Supin, Alexander Ya; Nachtigall, Paul E; Breese, Marlee

    2009-04-01

    Auditory evoked potentials (AEPs) were recorded during echolocation in a false killer whale Pseudorca crassidens. An electronically synthesized and played-back ("phantom") echo was used. Each electronic echo was triggered by an emitted biosonar pulse. The echo had a spectrum similar to that of the emitted biosonar clicks, and its intensity was proportional to that of the emitted click. The attenuation of the echo relative to the emitted click and its delay was controlled by the experimenter. Four combinations of echo attenuation and delay were tested (-31 dB, 2 ms), (-40 dB, 4 ms), (-49 dB, 8 ms), and (-58 dB, 16 ms); thus, attenuation and delay were associated with a rate of 9 dB of increased attenuation per delay doubling. AEPs related to emitted clicks displayed a regular amplitude dependence on the click level. Echo-related AEPs did not feature amplitude dependence on echo attenuation or emitted click levels, except in a few combinations of the lowest values of these two variables. The results are explained by a hypothesis that partial forward masking of the echoes by the preceding emitted sonar pulses serves as a kind of automatic gain control in the auditory system of echolocating odontocetes.

  2. Subwavelength atom localization via coherent manipulation of the Raman gain process

    NASA Astrophysics Data System (ADS)

    Qamar, Sajid; Mehmood, Asad; Qamar, Shahid

    2009-03-01

    We present a simple scheme of atom localization in a subwavelength domain via manipulation of Raman gain process. We consider a four-level system with a pump and a weak probe field. In addition, we apply a coherent field to control the gain process. The system is similar to the one used by Agarwal and Dasgupta [Phys. Rev. A 70, 023802 (2004)] for the superluminal pulse propagation through Raman gain medium. For atom localization, we consider both pump and control fields to be the standing-wave fields of the cavity. We show that a much precise position of an atom passing through the standing-wave fields can be determined by measuring the gain spectrum of the probe field.

  3. Attenuating effect of reboxetine on appetite and weight gain in olanzapine-treated schizophrenia patients: a double-blind placebo-controlled study.

    PubMed

    Poyurovsky, Michael; Fuchs, Camil; Pashinian, Artashez; Levi, Aya; Faragian, Sarit; Maayan, Rachel; Gil-Ad, Irit

    2007-06-01

    Search for safe and effective strategies to diminish weight gain associated with second generation antipsychotics (SGAs) is imperative. In the present study, we sought to replicate our preliminary findings, which indicated that coadministration of the selective norepinephrine reuptake inhibitor reboxetine attenuates olanzapine-induced weight gain. Fifty-nine patients hospitalized for first-episode DSM-IV schizophrenic disorder participated in this randomized double-blind study. Reboxetine (4 mg/day; 31 patients) or placebo (29 patients) was coadministered with olanzapine (10 mg/day) for 6 weeks. Analysis was by intention-to-treat. Nine patients in each group prematurely discontinued the trial. Olanzapine/reboxetine-treated patients showed a significantly lower increase in body weight (mean = 3.31 kg, SD = 2.73) than their olanzapine/placebo-treated counterparts (mean = 4.91 kg, SD = 2.45). Significantly fewer olanzapine/reboxetine-treated patients gained at least 7% of their initial weight, the cutoff for clinically significant weight gain (6 [19.4%] of 31 patients vs 13 [46.4%] of 28 patients). Seven (22.6%) olanzapine/reboxetine-treated patients compared to only one patient (3.6%) in the olanzapine/placebo group revealed no weight change or even modest weight loss. Appetite increase was significantly lower in the olanzapine/reboxetine than olanzapine/placebo group and was correlated with attenuation of weight gain. Reboxetine addition was safe and well tolerated. The results confirm that coadministration of reboxetine promotes a clinically meaningful attenuation of olanzapine-induced weight gain in schizophrenia patients. If substantiated in long-term studies, along with behavioral management and diet counseling, reboxetine may have a clinical utility in controlling SGA-induced weight gain.

  4. Adaptation without parameter change: Dynamic gain control in motion detection

    PubMed Central

    Borst, Alexander; Flanagin, Virginia L.; Sompolinsky, Haim

    2005-01-01

    Many sensory systems adapt their input-output relationship to changes in the statistics of the ambient stimulus. Such adaptive behavior has been measured in a motion detection sensitive neuron of the fly visual system, H1. The rapid adaptation of the velocity response gain has been interpreted as evidence of optimal matching of the H1 response to the dynamic range of the stimulus, thereby maximizing its information transmission. Here, we show that correlation-type motion detectors, which are commonly thought to underlie fly motion vision, intrinsically possess adaptive properties. Increasing the amplitude of the velocity fluctuations leads to a decrease of the effective gain and the time constant of the velocity response without any change in the parameters of these detectors. The seemingly complex property of this adaptation turns out to be a straightforward consequence of the multidimensionality of the stimulus and the nonlinear nature of the system. PMID:15833815

  5. Regulation of Blood Glucose Concentration in Type 1 Diabetics Using Single Order Sliding Mode Control Combined with Fuzzy On-line Tunable Gain, a Simulation Study

    PubMed Central

    Dinani, Soudabeh Taghian; Zekri, Maryam; Kamali, Marzieh

    2015-01-01

    Diabetes is considered as a global affecting disease with an increasing contribution to both mortality rate and cost damage in the society. Therefore, tight control of blood glucose levels has gained significant attention over the decades. This paper proposes a method for blood glucose level regulation in type 1 diabetics. The control strategy is based on combining the fuzzy logic theory and single order sliding mode control (SOSMC) to improve the properties of sliding mode control method and to alleviate its drawbacks. The aim of the proposed controller that is called SOSMC combined with fuzzy on-line tunable gain is to tune the gain of the controller adaptively. This merit causes a less amount of control effort, which is the rate of insulin delivered to the patient body. As a result, this method can decline the risk of hypoglycemia, a lethal phenomenon in regulating blood glucose level in diabetics caused by a low blood glucose level. Moreover, it attenuates the chattering observed in SOSMC significantly. It is worth noting that in this approach, a mathematical model called minimal model is applied instead of the intravenously infused insulin–blood glucose dynamics. The simulation results demonstrate a good performance of the proposed controller in meal disturbance rejection and robustness against parameter changes. In addition, this method is compared to fuzzy high-order sliding mode control (FHOSMC) and the superiority of the new method compared to FHOSMC is shown in the results. PMID:26284169

  6. Regulation of Blood Glucose Concentration in Type 1 Diabetics Using Single Order Sliding Mode Control Combined with Fuzzy On-line Tunable Gain, a Simulation Study.

    PubMed

    Dinani, Soudabeh Taghian; Zekri, Maryam; Kamali, Marzieh

    2015-01-01

    Diabetes is considered as a global affecting disease with an increasing contribution to both mortality rate and cost damage in the society. Therefore, tight control of blood glucose levels has gained significant attention over the decades. This paper proposes a method for blood glucose level regulation in type 1 diabetics. The control strategy is based on combining the fuzzy logic theory and single order sliding mode control (SOSMC) to improve the properties of sliding mode control method and to alleviate its drawbacks. The aim of the proposed controller that is called SOSMC combined with fuzzy on-line tunable gain is to tune the gain of the controller adaptively. This merit causes a less amount of control effort, which is the rate of insulin delivered to the patient body. As a result, this method can decline the risk of hypoglycemia, a lethal phenomenon in regulating blood glucose level in diabetics caused by a low blood glucose level. Moreover, it attenuates the chattering observed in SOSMC significantly. It is worth noting that in this approach, a mathematical model called minimal model is applied instead of the intravenously infused insulin-blood glucose dynamics. The simulation results demonstrate a good performance of the proposed controller in meal disturbance rejection and robustness against parameter changes. In addition, this method is compared to fuzzy high-order sliding mode control (FHOSMC) and the superiority of the new method compared to FHOSMC is shown in the results.

  7. Controlling suspended sediment samplers by programmable calculator and interface circuitry

    Treesearch

    Rand E. Eads; Mark R. Boolootian

    1985-01-01

    A programmable calculator connected to an interface circuit can control automatic samplers and record streamflow data. The circuit converts a voltage representing water stage to a digital signal. The sampling program logs streamflow data when there is a predefined deviation from a linear trend in the water elevation. The calculator estimates suspended sediment...

  8. Neural circuitry and plasticity mechanisms underlying delay eyeblink conditioning

    PubMed Central

    Freeman, John H.; Steinmetz, Adam B.

    2011-01-01

    Pavlovian eyeblink conditioning has been used extensively as a model system for examining the neural mechanisms underlying associative learning. Delay eyeblink conditioning depends on the intermediate cerebellum ipsilateral to the conditioned eye. Evidence favors a two-site plasticity model within the cerebellum with long-term depression of parallel fiber synapses on Purkinje cells and long-term potentiation of mossy fiber synapses on neurons in the anterior interpositus nucleus. Conditioned stimulus and unconditioned stimulus inputs arise from the pontine nuclei and inferior olive, respectively, converging in the cerebellar cortex and deep nuclei. Projections from subcortical sensory nuclei to the pontine nuclei that are necessary for eyeblink conditioning are beginning to be identified, and recent studies indicate that there are dynamic interactions between sensory thalamic nuclei and the cerebellum during eyeblink conditioning. Cerebellar output is projected to the magnocellular red nucleus and then to the motor nuclei that generate the blink response(s). Tremendous progress has been made toward determining the neural mechanisms of delay eyeblink conditioning but there are still significant gaps in our understanding of the necessary neural circuitry and plasticity mechanisms underlying cerebellar learning. PMID:21969489

  9. A model-based gain scheduling approach for controlling the common-rail system for GDI engines

    NASA Astrophysics Data System (ADS)

    di Gaeta, Alessandro; Montanaro, Umberto; Fiengo, Giovanni; Palladino, Angelo; Giglio, Veniero

    2012-04-01

    The progressive reduction in vehicle emission requirements have forced the automotive industry to invest in research for developing alternative and more efficient control strategies. All control features and resources are permanently active in an electronic control unit (ECU), ensuring the best performance with respect to emissions, fuel economy, driveability and diagnostics, independently from engine working point. In this article, a considerable step forward has been achieved by the common-rail technology which has made possible to vary the injection pressure over the entire engine speed range. As a consequence, the injection of a fixed amount of fuel is more precise and multiple injections in a combustion cycle can be made. In this article, a novel gain scheduling pressure controller for gasoline direct injection (GDI) engine is designed to stabilise the mean fuel pressure into the rail and to track demanded pressure trajectories. By exploiting a simple control-oriented model describing the mean pressure dynamics in the rail, the control structure turns to be simple enough to be effectively implemented in commercial ECUs. Experimental results in a wide range of operating points confirm the effectiveness of the proposed control method to tame efficiently the mean value pressure dynamics of the plant showing a good accuracy and robustness with respect to unavoidable parameters uncertainties, unmodelled dynamics, and hidden coupling terms.

  10. Performance bounds for nonlinear systems with a nonlinear ℒ2-gain property

    NASA Astrophysics Data System (ADS)

    Zhang, Huan; Dower, Peter M.

    2012-09-01

    Nonlinear ℒ2-gain is a finite gain concept that generalises the notion of conventional (linear) finite ℒ2-gain to admit the application of ℒ2-gain analysis tools of a broader class of nonlinear systems. The computation of tight comparison function bounds for this nonlinear ℒ2-gain property is important in applications such as small gain design. This article presents an approximation framework for these comparison function bounds through the formulation and solution of an optimal control problem. Key to the solution of this problem is the lifting of an ℒ2-norm input constraint, which is facilitated via the introduction of an energy saturation operator. This admits the solution of the optimal control problem of interest via dynamic programming and associated numerical methods, leading to the computation of the proposed bounds. Two examples are presented to demonstrate this approach.

  11. Engineering nucleic acid structures for programmable molecular circuitry and intracellular biocomputation

    NASA Astrophysics Data System (ADS)

    Li, Jiang; Green, Alexander A.; Yan, Hao; Fan, Chunhai

    2017-11-01

    Nucleic acids have attracted widespread attention due to the simplicity with which they can be designed to form discrete structures and programmed to perform specific functions at the nanoscale. The advantages of DNA/RNA nanotechnology offer numerous opportunities for in-cell and in-vivo applications, and the technology holds great promise to advance the growing field of synthetic biology. Many elegant examples have revealed the potential in integrating nucleic acid nanostructures in cells and in vivo where they can perform important physiological functions. In this Review, we summarize the current abilities of DNA/RNA nanotechnology to realize applications in live cells and then discuss the key problems that must be solved to fully exploit the useful properties of nanostructures. Finally, we provide viewpoints on how to integrate the tools provided by DNA/RNA nanotechnology and related new technologies to construct nucleic acid nanostructure-based molecular circuitry for synthetic biology.

  12. Psychosocial working conditions and weight gain among employees.

    PubMed

    Lallukka, T; Laaksonen, M; Martikainen, P; Sarlio-Lähteenkorva, S; Lahelma, E

    2005-08-01

    To study the associations between psychosocial working conditions and weight gain. Data from postal questionnaires (response rate 67%) sent to 40- to 60-y-old women (n=7093) and men (n=1799) employed by the City of Helsinki in 2000-2002 were analysed. Weight gain during the previous 12 months was the outcome variable in logistic regression analyses. Independent variables included Karasek's job demands and job control, work fatigue, working overtime, work-related mental strain, social support and the work-home interface. The final models were adjusted for age, education, marital status, physical strain and body mass index. In the previous 12 months, 25% of women and 19% of men reported weight gain. Work fatigue and working overtime were associated with weight gain in both sexes. Women who were dissatisfied with combining paid work and family life were more likely to have gained weight. Men with low job demands were less likely to have gained weight. All of these associations were independent of each other. Few work-related factors were associated with weight gain. However, our study suggests that work fatigue and working overtime are potential risk factors for weight gain. These findings need to be confirmed in prospective studies.

  13. Interventions for preventing excessive weight gain during pregnancy

    PubMed Central

    Muktabhant, Benja; Lumbiganon, Pisake; Ngamjarus, Chetta; Dowswell, Therese

    2014-01-01

    Background Excessive weight gain during pregnancy is associated with multiple maternal and neonatal complications. However, interventions to prevent excessive weight gain during pregnancy have not been adequately evaluated. Objectives To evaluate the effectiveness of interventions for preventing excessive weight gain during pregnancy and associated pregnancy complications. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (20 October 2011) and MEDLINE (1966 to 20 October 2011). Selection criteria All randomised controlled trials and quasi-randomised trials of interventions for preventing excessive weight gain during pregnancy. Data collection and analysis We assessed for inclusion all potential studies we identified as a result of the search strategy. At least two review authors independently assessed trial quality and extracted data. We resolved discrepancies through discussion. We have presented results using risk ratio (RR) for categorical data and mean difference for continuous data. We analysed data using a fixed-effect model. Main results We included 28 studies involving 3976 women; 27 of these studies with 3964 women contributed data to the analyses. Interventions focused on a broad range of interventions. However, for most outcomes we could not combine data in a meta-analysis, and where we did pool data, no more than two or three studies could be combined for a particular intervention and outcome. Overall, results from this review were mainly not statistically significant, and where there did appear to be differences between intervention and control groups, results were not consistent. For women in general clinic populations one (behavioural counselling versus standard care) of three interventions examined was associated with a reduction in the rate of excessive weight gain (RR 0.72, 95% confidence interval 0.54 to 0.95); for women in high-risk groups no intervention appeared to reduce excess weight gain. There were

  14. Cybernetic Control of an Electrochemical Repertoire.

    ERIC Educational Resources Information Center

    He, Peixin; And Others

    1982-01-01

    Describes major features of a computer-operated, cybernetic potentiostat and the development, design, and operation of the software in ROM. The instrument contains control circuitry and software making it compatible with the static mercury drop electrode produced by EG&G Princeton Applied Research Corporation. Sample results using the…

  15. Employment, work hours and weight gain among middle-aged women.

    PubMed

    Au, N; Hauck, K; Hollingsworth, B

    2013-05-01

    To investigate the influence of employment and work hours on weight gain and weight loss among middle-aged women. Quantile regression techniques were used to estimate the influence of employment and hours worked on percentage weight change over 2 years across the entire distribution of weight change in a cohort of middle-aged women. A range of controls was included in the models to isolate the effect of work status. A total of 9276 women aged 45-50 years at baseline who were present in both the 1996 and 1998 surveys of the Australian Longitudinal Study of Women's Health. The women were a representative sample of the Australian population. Being out of the labour force or unemployed was associated with lower weight gain and higher weight loss than being employed. The association was stronger at low to moderate levels of weight gain. Among employed women, working regular (35-40), long (41-48) or very long (49+) hours was associated with increasingly higher levels of weight gain compared with working part-time hours. The association was stronger for women with greater weight gain overall. The association between unemployment and weight change became insignificant when health status was controlled for. Employment was associated with more weight gain and less weight loss. Among the employed, working longer hours was associated with more weight gain, especially at the higher levels of weight gain where the health consequences are more serious. These findings suggest that as women work longer hours they are more likely to make lifestyle choices that are associated with weight gain.

  16. A Microcomputer Interface for External Circuit Control.

    ERIC Educational Resources Information Center

    Gorham, D. A.

    1983-01-01

    Describes an interface designed to meet the requirements of an instrumentation teaching laboratory, particularly to develop computer-controlled digital circuitry while exploiting electrical drive properties of common transistor-transistor logic (TTL) devices, minimizing cost/number of components. Discusses decoding for Pet, switches, lights, and…

  17. Preventing weight gain in adults: the pound of prevention study.

    PubMed Central

    Jeffery, R W; French, S A

    1999-01-01

    OBJECTIVES: This study examined whether weight gain with age could be prevented through the use of a low-intensity intervention. METHODS: Participants, 228 men and 998 women recruited from diverse sources, were randomized to one of the following groups: (1) no-contact control, (2) education through monthly newsletters, or (3) education plus incentives for participation. All participants were weighed and completed questionnaires about behaviors and attitudes related to weight at baseline and annually for 3 years thereafter. RESULTS: Individuals in intervention groups reported favorable changes over time in frequency of weighting and healthy dieting practices relative to those in the control group. These behavior changes were in turn related to a reduced rate of weight gain over time. However, weight gain over 3 years did not differ significantly by treatment group. CONCLUSIONS: This low-intensity educational approach to weight gain prevention sustained interest over a lengthy time period and was associated positively with behavior change, but it was not strong enough to significantly reduce weight gain with age. PMID:10224988

  18. Stable Short-Term Frequency Support Using Adaptive Gains for a DFIG-Based Wind Power Plant

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

    Lee, Jinsik; Jang, Gilsoo; Muljadi, Eduard

    For the fixed-gain inertial control of wind power plants (WPPs), a large gain setting provides a large contribution to supporting system frequency control, but it may cause over-deceleration for a wind turbine generator that has a small amount of kinetic energy (KE). Further, if the wind speed decreases during inertial control, even a small gain may cause over-deceleration. This paper proposes a stable inertial control scheme using adaptive gains for a doubly fed induction generator (DFIG)-based WPP. The scheme aims to improve the frequency nadir (FN) while ensuring stable operation of all DFIGs, particularly when the wind speed decreases duringmore » inertial control. In this scheme, adaptive gains are set to be proportional to the KE stored in DFIGs, which is spatially and temporally dependent. To improve the FN, upon detecting an event, large gains are set to be proportional to the KE of DFIGs; to ensure stable operation, the gains decrease with the declining KE. The simulation results demonstrate that the scheme improves the FN while ensuring stable operation of all DFIGs in various wind and system conditions. Further, it prevents over-deceleration even when the wind speed decreases during inertial control.« less

  19. Training Children in Pedestrian Safety: Distinguishing Gains in Knowledge from Gains in Safe Behavior

    PubMed Central

    McClure, Leslie A.

    2014-01-01

    Pedestrian injuries contribute greatly to child morbidity and mortality. Recent evidence suggests that training within virtual pedestrian environments may improve children’s street crossing skills, but may not convey knowledge about safety in street environments. We hypothesized that (a) children will gain pedestrian safety knowledge via videos/software/internet websites, but not when trained by virtual pedestrian environment or other strategies; (b) pedestrian safety knowledge will be associated with safe pedestrian behavior both before and after training; and (c) increases in knowledge will be associated with increases in safe behavior among children trained individually at streetside locations, but not those trained by means of other strategies. We analyzed data from a randomized controlled trial evaluating pedestrian safety training. We randomly assigned 240 children ages 7–8 to one of four training conditions: videos/software/internet, virtual reality (VR), individualized streetside instruction, or a no-contact control. Both virtual and field simulations of street crossing at 2-lane bi-directional mid-block locations assessed pedestrian behavior at baseline, post-training, and 6-month follow-up. Pedestrian knowledge was assessed orally on all three occasions. Children trained by videos/software/internet, and those trained individually, showed increased knowledge following training relative to children in the other groups (ps < 0.01). Correlations between pedestrian safety knowledge and pedestrian behavior were mostly non-significant. Correlations between change in knowledge and change in behavior from pre- to post-intervention also were non-significant, both for the full sample and within conditions. Children trained using videos/software/internet gained knowledge but did not change their behavior. Children trained individually gained in both knowledge and safer behavior. Children trained virtually gained in safer behavior but not knowledge. If VR is used

  20. Optomechanical transistor with mechanical gain

    NASA Astrophysics Data System (ADS)

    Zhang, X. Z.; Tian, Lin; Li, Yong

    2018-04-01

    We study an optomechanical transistor, where an input field can be transferred and amplified unidirectionally in a cyclic three-mode optomechanical system. In this system, the mechanical resonator is coupled simultaneously to two cavity modes. We show that it only requires a finite mechanical gain to achieve the nonreciprocal amplification. Here the nonreciprocity is caused by the phase difference between the linearized optomechanical couplings that breaks the time-reversal symmetry of this system. The amplification arises from the mechanical gain, which provides an effective phonon bath that pumps the mechanical mode coherently. This effect is analogous to the stimulated emission of atoms, where the probe field can be amplified when its frequency is in resonance with that of the anti-Stokes transition. We show that by choosing optimal parameters, this optomechanical transistor can reach perfect unidirectionality accompanied with strong amplification. In addition, the presence of the mechanical gain can result in ultralong delay in the phase of the probe field, which provides an alternative to controlling light transport in optomechanical systems.

  1. Genomic Circuitry Underlying Immunological Response to Pediatric Acute Respiratory Infection.

    PubMed

    Henrickson, Sarah E; Manne, Sasikanth; Dolfi, Douglas V; Mansfield, Kathleen D; Parkhouse, Kaela; Mistry, Rakesh D; Alpern, Elizabeth R; Hensley, Scott E; Sullivan, Kathleen E; Coffin, Susan E; Wherry, E John

    2018-01-09

    Acute respiratory tract viral infections (ARTIs) cause significant morbidity and mortality. CD8 T cells are fundamental to host responses, but transcriptional alterations underlying anti-viral mechanisms and links to clinical characteristics remain unclear. CD8 T cell transcriptional circuitry in acutely ill pediatric patients with influenza-like illness was distinct for different viral pathogens. Although changes included expected upregulation of interferon-stimulated genes (ISGs), transcriptional downregulation was prominent upon exposure to innate immune signals in early IFV infection. Network analysis linked changes to severity of infection, asthma, sex, and age. An influenza pediatric signature (IPS) distinguished acute influenza from other ARTIs and outperformed other influenza prediction gene lists. The IPS allowed a deeper investigation of the connection between transcriptional alterations and clinical characteristics of acute illness, including age-based differences in circuits connecting the STAT1/2 pathway to ISGs. A CD8 T cell-focused systems immunology approach in pediatrics identified age-based alterations in ARTI host response pathways. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  2. Control of linear modes in cylindrical resistive magnetohydrodynamics with a resistive wall, plasma rotation, and complex gain

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

    Brennan, D. P.; Finn, J. M.

    2014-10-15

    Feedback stabilization of magnetohydrodynamic (MHD) modes in a tokamak is studied in a cylindrical model with a resistive wall, plasma resistivity, viscosity, and toroidal rotation. The control is based on a linear combination of the normal and tangential components of the magnetic field just inside the resistive wall. The feedback includes complex gain, for both the normal and for the tangential components, and it is known that the imaginary part of the feedback for the former is equivalent to plasma rotation [J. M. Finn and L. Chacon, Phys. Plasmas 11, 1866 (2004)]. The work includes (1) analysis with a reducedmore » resistive MHD model for a tokamak with finite β and with stepfunction current density and pressure profiles, and (2) computations with a full compressible visco-resistive MHD model with smooth decreasing profiles of current density and pressure. The equilibria are stable for β = 0 and the marginal stability values β{sub rp,rw} < β{sub rp,iw} < β{sub ip,rw} < β{sub ip,iw} (resistive plasma, resistive wall; resistive plasma, ideal wall; ideal plasma, resistive wall; and ideal plasma, ideal wall) are computed for both models. The main results are: (a) imaginary gain with normal sensors or plasma rotation stabilizes below β{sub rp,iw} because rotation suppresses the diffusion of flux from the plasma out through the wall and, more surprisingly, (b) rotation or imaginary gain with normal sensors destabilizes above β{sub rp,iw} because it prevents the feedback flux from entering the plasma through the resistive wall to form a virtual wall. A method of using complex gain G{sub i} to optimize in the presence of rotation in this regime with β > β{sub rp,iw} is presented. The effect of imaginary gain with tangential sensors is more complicated but essentially destabilizes above and below β{sub rp,iw}.« less

  3. Low speed phaselock speed control system. [for brushless dc motor

    NASA Technical Reports Server (NTRS)

    Fulcher, R. W.; Sudey, J. (Inventor)

    1975-01-01

    A motor speed control system for an electronically commutated brushless dc motor is provided which includes a phaselock loop with bidirectional torque control for locking the frequency output of a high density encoder, responsive to actual speed conditions, to a reference frequency signal, corresponding to the desired speed. The system includes a phase comparator, which produces an output in accordance with the difference in phase between the reference and encoder frequency signals, and an integrator-digital-to-analog converter unit, which converts the comparator output into an analog error signal voltage. Compensation circuitry, including a biasing means, is provided to convert the analog error signal voltage to a bidirectional error signal voltage which is utilized by an absolute value amplifier, rotational decoder, power amplifier-commutators, and an arrangement of commutation circuitry.

  4. Energy expenditure, spontaneous physical activity and with weight gain in kidney transplant recipients.

    PubMed

    Heng, Anne-Elisabeth; Montaurier, Christophe; Cano, Noël; Caillot, Nicolas; Blot, A; Meunier, Nathalie; Pereira, Bruno; Marceau, Geoffroy; Sapin, Vincent; Jouve, Christelle; Boirie, Yves; Deteix, Patrice; Morio, Beatrice

    2015-06-01

    Alterations in energy metabolism could trigger weight gain after renal transplantation. Nineteen transplanted non-diabetic men, 53 ± 1.6 years old, receiving calcineurin inhibitors but no corticosteroids were studied. They were compared with nine healthy men matched for height, age and lean body mass. Daily energy expenditure and its components (sleeping, basal and absorptive metabolic rates) were analyzed for 24 h in calorimetric chambers and for 4 days in free living conditions using calibrated accelerometry. Other variables known to influence energy expenditure were assessed: body composition, physical activity, 4-day food intake, drug consumption, serum C-reactive protein, interleukin-6, thyroid and parathyroid hormones, and epinephrine. Transplant recipients who gained more than 5% body weight after transplantation (n = 11, +11.0 ± 1.5 kg) were compared with those who did not (n = 8) and with the controls. Weight gain compared with non-weight gain patients and controls exhibited higher fat mass without change in lean body mass. Daily, sleeping and resting energy expenditure adjusted for lean body mass was significantly higher in non-weight gain (167.1 ± 4.2 kJ/kg/lean body mass/24 h, P < 0.05) compared with weight gain patients (147.4 ± 3.6) and controls (146.1 ± 4.6). Weight gain compared with controls and non-weight gain subjects had lower free living physical activity and a higher consumption of antihypertensive drugs and β-blockers. After kidney transplantation, weight gain patients were characterized by lower adjusted energy expenditure, reduced spontaneous physical activity but a more sedentary life style and a trend toward a higher energy intake explaining the reason they gained weight. The nWG KTR had increased resting and sleeping EE which protected them from weight gain. Such hypermetabolism was also observed in 24-h EE measurements. By comparison with the nWG patients, the WG transplant recipients were characterized by higher

  5. Contributions of Low and High Spatial Frequency Processing to Impaired Object Recognition Circuitry in Schizophrenia

    PubMed Central

    Calderone, Daniel J.; Hoptman, Matthew J.; Martínez, Antígona; Nair-Collins, Sangeeta; Mauro, Cristina J.; Bar, Moshe; Javitt, Daniel C.; Butler, Pamela D.

    2013-01-01

    Patients with schizophrenia exhibit cognitive and sensory impairment, and object recognition deficits have been linked to sensory deficits. The “frame and fill” model of object recognition posits that low spatial frequency (LSF) information rapidly reaches the prefrontal cortex (PFC) and creates a general shape of an object that feeds back to the ventral temporal cortex to assist object recognition. Visual dysfunction findings in schizophrenia suggest a preferential loss of LSF information. This study used functional magnetic resonance imaging (fMRI) and resting state functional connectivity (RSFC) to investigate the contribution of visual deficits to impaired object “framing” circuitry in schizophrenia. Participants were shown object stimuli that were intact or contained only LSF or high spatial frequency (HSF) information. For controls, fMRI revealed preferential activation to LSF information in precuneus, superior temporal, and medial and dorsolateral PFC areas, whereas patients showed a preference for HSF information or no preference. RSFC revealed a lack of connectivity between early visual areas and PFC for patients. These results demonstrate impaired processing of LSF information during object recognition in schizophrenia, with patients instead displaying increased processing of HSF information. This is consistent with findings of a preference for local over global visual information in schizophrenia. PMID:22735157

  6. Intranasal insulin modulates intrinsic reward and prefrontal circuitry of the human brain in lean women.

    PubMed

    Kullmann, Stephanie; Frank, Sabine; Heni, Martin; Ketterer, Caroline; Veit, Ralf; Häring, Hans-Ulrich; Fritsche, Andreas; Preissl, Hubert

    2013-01-01

    There is accumulating evidence that food consumption is controlled by a wide range of brain circuits outside of the homeostatic system. Activation in these brain circuits may override the homeostatic system and also contribute to the enormous increase of obesity. However, little is known about the influence of hormonal signals on the brain's non-homeostatic system. Thus, selective insulin action in the brain was investigated by using intranasal application. We performed 'resting-state' functional magnetic resonance imaging in 17 healthy lean female subjects to assess intrinsic brain activity by fractional amplitude of low-frequency fluctuations (fALFF) before, 30 and 90 min after application of intranasal insulin. Here, we showed that insulin modulates intrinsic brain activity in the hypothalamus and orbitofrontal cortex. Furthermore, we could show that the prefrontal and anterior cingulate cortex response to insulin is associated with body mass index. This demonstrates that hormonal signals as insulin may reduce food intake by modifying the reward and prefrontal circuitry of the human brain, thereby potentially decreasing the rewarding properties of food. Due to the alarming increase in obesity worldwide, it is of great importance to identify neural mechanisms of interaction between the homeostatic and non-homeostatic system to generate new targets for obesity therapy. Copyright © 2012 S. Karger AG, Basel.

  7. Within-session effect of repeated stress exposure on extinction circuitry function in social anxiety disorder.

    PubMed

    Åhs, Fredrik; Gingnell, Malin; Furmark, Tomas; Fredrikson, Mats

    2017-03-30

    Anxiety reduction following repeated exposure to stressful experiences is generally held to depend on neural processes involved in extinction of conditioned fear. We predicted that repeated exposure to stressful experiences would change activity throughout the circuitry serving extinction, including ventromedial prefrontal cortex (vmPFC), the hippocampus and the amygdala. To test this prediction, 36 participants diagnosed with SAD performed two successive speeches in front of an observing audience while regional cerebral blood flow (rCBF) was recorded using positron emission tomography. To control for non-anxiolytic effects of repeated exposure, rCBF was also measured during repeated presentations of neutral and angry facial expressions. Results showed that anxiety ratings and heart rate decreased from the first to the second speech, indicating an anxiolytic effect of repeated exposure. Exposure attenuated rCBF in the amygdala whereas no change in rCBF was observed in the vmPFC or hippocampus. The rCBF-reductions in the amygdala were greater following repetition of the speech task than repetition of face exposure indicating that they were specific to anxiety attenuation and not due to a reduced novelty. Our findings suggest that amygdala-related attenuation processes are key to understanding the working mechanisms of exposure therapy. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  8. Generation of Hermite-Gaussian modes and vortex arrays based on two-dimensional gain distribution controlled microchip laser.

    PubMed

    Kong, Weipeng; Sugita, Atsushi; Taira, Takunori

    2012-07-01

    We have demonstrated high-order Hermite-Gaussian (HG) mode generation based on 2D gain distribution control edge-pumped, composite all-ceramic Yb:YAG/YAG microchip lasers using a V-type cavity. Several hundred milliwatts to several watts HG(mn) modes are achieved. We also generated different kinds of vortex arrays directly from the oscillator with the same power level. In addition, a more than 7 W doughnut-shape mode can be generated in the same cavity.

  9. A double-blind, placebo-controlled trial of sibutramine for clozapine-associated weight gain.

    PubMed

    Henderson, D C; Fan, X; Copeland, P M; Borba, C P; Daley, T B; Nguyen, D D; Zhang, H; Hayden, D; Freudenreich, O; Cather, C; Evins, A E; Goff, D C

    2007-02-01

    This study sought to examine the effectiveness of sibutramine, a weight loss agent, on clozapine-associated weight gain. This was a 12-week double-blind, placebo controlled, randomized trial of sibutramine for weight loss in obese clozapine-treated schizophrenia or schizoaffective disorder subjects. Ten patients were enrolled into the placebo group and 11 patients into the sibutramine group. There were no significant baseline differences between the two groups on age, gender, education, ethnicity, diagnosis, weight, body mass index (BMI), and blood pressure. At week 12, there were no significant differences in changes in weight, BMI, abdominal and waist circumferences, Hba1c, fasting glucose, or cholesterol levels. Sibutramine treatment did not show significant weight loss compared with placebo in clozapine-treated patients with schizophrenia or schizoaffective disorder. Further research with a larger sample size and longer follow-up duration is warranted.

  10. The emotional power of poetry: neural circuitry, psychophysiology and compositional principles

    PubMed Central

    Koelsch, Stefan; Wagner, Valentin; Jacobsen, Thomas; Menninghaus, Winfried

    2017-01-01

    Abstract It is a common experience—and well established experimentally—that music can engage us emotionally in a compelling manner. The mechanisms underlying these experiences are receiving increasing scrutiny. However, the extent to which other domains of aesthetic experience can similarly elicit strong emotions is unknown. Using psychophysiology, neuroimaging and behavioral responses, we show that recited poetry can act as a powerful stimulus for eliciting peak emotional responses, including chills and objectively measurable goosebumps that engage the primary reward circuitry. Importantly, while these responses to poetry are largely analogous to those found for music, their neural underpinnings show important differences, specifically with regard to the crucial role of the nucleus accumbens. We also go beyond replicating previous music-related studies by showing that peak aesthetic pleasure can co-occur with physiological markers of negative affect. Finally, the distribution of chills across the trajectory of poems provides insight into compositional principles of poetry. PMID:28460078

  11. Parental Body Mass Index, Gestational Weight Gain, and Risk of Macrosomia: a Population-Based Case-Control Study in China.

    PubMed

    Yang, Shaoping; Zhou, Aifen; Xiong, Chao; Yang, Rong; Bassig, Bryan A; Hu, Ronghua; Zhang, Yiming; Yao, Cong; Zhang, Yaqi; Qiu, Lin; Qian, Zhengmin; Trevathan, Edwin; Flick, Louise; Xu, Shunqing; Wang, Youjie; Xia, Wei; Zheng, Tongzhang; Zhang, Bin

    2015-09-01

    The prevalence of macrosomia has risen markedly worldwide, including in China, during the past two decades. Few epidemiological studies, however, have investigated the risk factors for macrosomia in China. This study was designed to investigate the associations between parental anthropometric characteristics, gestational weight gain (GWG), and risk of macrosomia in China. This population-based, case-control study in Wuhan, China, included a total of 6341 subjects (870 cases and 5471 controls). Multivariable logistic regression was conducted to calculate odds ratios (OR) and 95% confidence intervals (CI). Mothers or fathers who were overweight or obese before pregnancy had an elevated risk of giving birth to a macrosomic infant compared with their normal weight counterparts. Women with GWG above the Institute of Medicine (IOM) recommendation had an adjusted OR of 6.09 [95% CI 5.04, 7.35] for delivering a macrosomic infant compared with women who had GWG within the IOM recommendation. When stratified by maternal pre-pregnancy body mass index (BMI), women who were underweight or normal weight before pregnancy were observed to have a higher risk of macrosomia birth associated with greater GWG. Parental pre-pregnancy overweight/obesity and excessive GWG during pregnancy were highly associated with macrosomia. The association with GWG was most pronounced in mothers who had a normal or underweight pre-pregnancy BMI. Weight control efforts before pregnancy for mothers and fathers as well as control of maternal gain during pregnancy may reduce the risk of macrosomia. © 2015 John Wiley & Sons Ltd.

  12. Thermal energy storage apparatus, controllers and thermal energy storage control methods

    DOEpatents

    Hammerstrom, Donald J.

    2016-05-03

    Thermal energy storage apparatus, controllers and thermal energy storage control methods are described. According to one aspect, a thermal energy storage apparatus controller includes processing circuitry configured to access first information which is indicative of surpluses and deficiencies of electrical energy upon an electrical power system at a plurality of moments in time, access second information which is indicative of temperature of a thermal energy storage medium at a plurality of moments in time, and use the first and second information to control an amount of electrical energy which is utilized by a heating element to heat the thermal energy storage medium at a plurality of moments in time.

  13. Motor and Nonmotor Circuitry Activation Induced by Subthalamic Nucleus Deep Brain Stimulation in Patients With Parkinson Disease: Intraoperative Functional Magnetic Resonance Imaging for Deep Brain Stimulation.

    PubMed

    Knight, Emily J; Testini, Paola; Min, Hoon-Ki; Gibson, William S; Gorny, Krzysztof R; Favazza, Christopher P; Felmlee, Joel P; Kim, Inyong; Welker, Kirk M; Clayton, Daniel A; Klassen, Bryan T; Chang, Su-youne; Lee, Kendall H

    2015-06-01

    To test the hypothesis suggested by previous studies that subthalamic nucleus (STN) deep brain stimulation (DBS) in patients with Parkinson disease would affect the activity of motor and nonmotor networks, we applied intraoperative functional magnetic resonance imaging (fMRI) to patients receiving DBS. Ten patients receiving STN DBS for Parkinson disease underwent intraoperative 1.5-T fMRI during high-frequency stimulation delivered via an external pulse generator. The study was conducted between January 1, 2013, and September 30, 2014. We observed blood oxygen level-dependent (BOLD) signal changes (false discovery rate <0.001) in the motor circuitry (including the primary motor, premotor, and supplementary motor cortices; thalamus; pedunculopontine nucleus; and cerebellum) and in the limbic circuitry (including the cingulate and insular cortices). Activation of the motor network was observed also after applying a Bonferroni correction (P<.001) to the data set, suggesting that across patients, BOLD changes in the motor circuitry are more consistent compared with those occurring in the nonmotor network. These findings support the modulatory role of STN DBS on the activity of motor and nonmotor networks and suggest complex mechanisms as the basis of the efficacy of this treatment modality. Furthermore, these results suggest that across patients, BOLD changes in the motor circuitry are more consistent than those in the nonmotor network. With further studies combining the use of real-time intraoperative fMRI with clinical outcomes in patients treated with DBS, functional imaging techniques have the potential not only to elucidate the mechanisms of DBS functioning but also to guide and assist in the surgical treatment of patients affected by movement and neuropsychiatric disorders. clinicaltrials.gov Identifier: NCT01809613. Copyright © 2015 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  14. Risperidone and Divalproex Differentially Engage the Fronto-Striato-Temporal Circuitry in Pediatric Mania: A Pharmacological Functional Magnetic Resonance Imaging Study

    ERIC Educational Resources Information Center

    Pavuluri, Mani N.; Passarotti, Alessandra M.; Fitzgerald, Jacklynn M.; Wegbreit, Ezra; Sweeney, John A.

    2012-01-01

    Objective: The current study examined the impact of risperidone and divalproex on affective and working memory circuitry in patients with pediatric bipolar disorder (PBD). Method: This was a six-week, double-blind, randomized trial of risperidone plus placebo versus divalproex plus placebo for patients with mania (n = 21; 13.6 [plus or minus] 2.5…

  15. Salicylic acid potentiates an agonist-dependent gain control that amplifies pathogen signals in the activation of defense mechanisms.

    PubMed

    Shirasu, K; Nakajima, H; Rajasekhar, V K; Dixon, R A; Lamb, C

    1997-02-01

    The phenylpropanoid-derived natural product salicylic acid (SA) plays a key role in disease resistance. However, SA administered in the absence of a pathogen is a paradoxically weak inductive signal, often requiring concentrations of 0.5 to 5 mM to induce acquired resistance or related defense mechanisms or to precondition signal systems. In contrast, endogenous SA accumulates to concentrations of < 70 microM at the site of attempted infection. Here, we show that although 10 to 100 microM SA had negligible effects when administered to soybean cell suspensions in the absence of a pathogen, physiological concentrations of SA markedly enhanced the induction of defense gene transcripts, H2O2 accumulation, and hypersensitive cell death by an avirulent strain of Pseudomonas syringae pv glycinea, with optimal effects being at approximately 50 microM. SA also synergistically enhanced H2O2 accumulation in response to the protein phosphatase type 2A inhibitor cantharidin in the absence of a pathogen. The synergistic effect of SA was potent, rapid, and insensitive to the protein synthesis inhibitor cycloheximide, and we conclude that SA stimulates an agonist-dependent gain control operating at an early step in the signal pathway for induction of the hypersensitive response. This fine control mechanism differs from previously described time-dependent, inductive coarse control mechanisms for SA action in the absence of a pathogen. Induction of H2O2 accumulation and hypersensitive cell death by avirulent P. s. glycinea was blocked by the phenylpropanoid synthesis inhibitor alpha-aminooxy-beta-phenylpropionic acid, and these responses could be rescued by exogenous SA. Because the agonist-dependent gain control operates at physiological levels of SA, we propose that rapid fine control signal amplification makes an important contribution to SA function in the induction of disease resistance mechanisms.

  16. Gain stabilization control system of the upgraded magnetic proton recoil neutron spectrometer at JET.

    PubMed

    Sjöstrand, Henrik; Andersson Sundén, E; Conroy, S; Ericsson, G; Gatu Johnson, M; Giacomelli, L; Gorini, G; Hellesen, C; Hjalmarsson, A; Popovichev, S; Ronchi, E; Tardocchi, M; Weiszflog, M

    2009-06-01

    Burning plasma experiments such as ITER and DEMO require diagnostics capable of withstanding the harsh environment generated by the intense neutron flux and to maintain stable operating conditions for times longer than present day systems. For these reasons, advanced control and monitoring (CM) systems will be necessary for the reliable operation of diagnostics. This paper describes the CM system of the upgraded magnetic proton recoil neutron spectrometer installed at the Joint European Torus focusing in particular on a technique for the stabilization of the gain of the photomultipliers coupled to the neutron detectors. The results presented here show that this technique provides good results over long time scales. The technique is of general interest for all diagnostics that employ scintillators coupled to photomultiplier tubes.

  17. Nucleus accumbens response to gains in reputation for the self relative to gains for others predicts social media use

    PubMed Central

    Meshi, Dar; Morawetz, Carmen; Heekeren, Hauke R.

    2013-01-01

    Our reputation is important to us; we've experienced natural selection to care about our reputation. Recently, the neural processing of gains in reputation (positive social feedback concerning one's character) has been shown to occur in the human ventral striatum. It is still unclear, however, how individual differences in the processing of gains in reputation may lead to individual differences in real-world behavior. For example, in the real-world, one way that people currently maintain their reputation is by using social media websites, like Facebook. Furthermore, Facebook use consists of a social comparison component, where users observe others' behavior and can compare it to their own. Therefore, we hypothesized a relationship between the way the brain processes specifically self-relevant gains in reputation and one's degree of Facebook use. We recorded functional neuroimaging data while participants received gains in reputation, observed the gains in reputation of another person, or received monetary reward. We demonstrate that across participants, when responding to gains in reputation for the self, relative to observing gains for others, reward-related activity in the left nucleus accumbens predicts Facebook use. However, nucleus accumbens activity in response to monetary reward did not predict Facebook use. Finally, a control step-wise regression analysis showed that Facebook use primarily explains our results in the nucleus accumbens. Overall, our results demonstrate how individual sensitivity of the nucleus accumbens to the receipt of self-relevant social information leads to differences in real-world behavior. PMID:24009567

  18. Nucleus accumbens response to gains in reputation for the self relative to gains for others predicts social media use.

    PubMed

    Meshi, Dar; Morawetz, Carmen; Heekeren, Hauke R

    2013-01-01

    Our reputation is important to us; we've experienced natural selection to care about our reputation. Recently, the neural processing of gains in reputation (positive social feedback concerning one's character) has been shown to occur in the human ventral striatum. It is still unclear, however, how individual differences in the processing of gains in reputation may lead to individual differences in real-world behavior. For example, in the real-world, one way that people currently maintain their reputation is by using social media websites, like Facebook. Furthermore, Facebook use consists of a social comparison component, where users observe others' behavior and can compare it to their own. Therefore, we hypothesized a relationship between the way the brain processes specifically self-relevant gains in reputation and one's degree of Facebook use. We recorded functional neuroimaging data while participants received gains in reputation, observed the gains in reputation of another person, or received monetary reward. We demonstrate that across participants, when responding to gains in reputation for the self, relative to observing gains for others, reward-related activity in the left nucleus accumbens predicts Facebook use. However, nucleus accumbens activity in response to monetary reward did not predict Facebook use. Finally, a control step-wise regression analysis showed that Facebook use primarily explains our results in the nucleus accumbens. Overall, our results demonstrate how individual sensitivity of the nucleus accumbens to the receipt of self-relevant social information leads to differences in real-world behavior.

  19. On-Chip AC self-test controller

    DOEpatents

    Flanagan, John D [Rhinebeck, NY; Herring, Jay R [Poughkeepsie, NY; Lo, Tin-Chee [Fishkill, NY

    2009-09-29

    A system for performing AC self-test on an integrated circuit that includes a system clock for normal operation is provided. The system includes the system clock, self-test circuitry, a first and second test register to capture and launch test data in response to a sequence of data pulses, and a logic circuit to be tested. The self-test circuitry includes an AC self-test controller and a clock splitter. The clock splitter generates the sequence of data pulses including a long data capture pulse followed by an at speed data launch pulse and an at speed data capture pulse followed by a long data launch pulse. The at speed data launch pulse and the at speed data capture pulse are generated for a common cycle of the system clock.

  20. Forebrain networks and the control of feeding by environmental learned cues

    PubMed Central

    Petrovich, Gorica D.

    2013-01-01

    The motivation to eat is driven by a complex sum of physiological and non-physiological influences computed by the brain. Physiological signals that inform the brain about energy and nutrient needs are the primary drivers, but environmental signals unrelated to energy balance also control appetite and eating. The two components could act in concert to support the homeostatic regulation of food intake. Often, however, environmental influences rival physiological control and stimulate eating irrespective of satiety, or inhibit eating irrespective of hunger. If persistent, such maladaptive challenges to the physiological system could lead to dysregulated eating and ultimately to eating disorders. Nevertheless, the brain mechanisms underlying environmental contribution in the control of food intake are poorly understood. This paper provides an overview in recent advances in deciphering the critical brain systems using rodent models for environmental control by learned cues. These models use associative learning to compete with the physiological control, and in one preparation food cues stimulate a meal despite satiety, while in another preparation fear cues stop a meal despite hunger. Thus far, four forebrain regions have been identified as part of the essential cue induced feeding circuitry. These are telencephalic areas critical for associative learning, memory encoding, and decision making, the amygdala, hippocampus and prefrontal cortex and the lateral hypothalamus, which functions to integrate feeding, reward, and motivation. This circuitry also engages two orexigenic peptides, ghrelin and orexin. A parallel amygdalar circuitry supports fear cue cessation of feeding. These findings illuminate the brain mechanisms underlying environmental control of food intake and might be also relevant to aspects of human appetite and maladaptive overeating and undereating. PMID:23562305

  1. Apollo experience report: Detection and minimization of ignition hazards from water/glycol contamination of silver-clad electrical circuitry

    NASA Technical Reports Server (NTRS)

    Downs, W. R.

    1976-01-01

    The potential flammability hazard when a water/glycol solution contacts defectively insulated silver-clad copper circuitry or electrical components carrying a direct current is described. The chemical reactions and means for detecting them are explained. Methods for detecting and cleaning contaminated areas and the use of inhibitors to arrest chemical reactivity are also explained. Preventive measures to minimize hazards are given. Photomicrographs of the chemical reactions occurring on silver clad wires are also included.

  2. Cost-benefit decision circuitry: proposed modulatory role for acetylcholine.

    PubMed

    Fobbs, Wambura C; Mizumori, Sheri J Y

    2014-01-01

    In order to select which action should be taken, an animal must weigh the costs and benefits of possible outcomes associate with each action. Such decisions, called cost-benefit decisions, likely involve several cognitive processes (including memory) and a vast neural circuitry. Rodent models have allowed research to begin to probe the neural basis of three forms of cost-benefit decision making: effort-, delay-, and risk-based decision making. In this review, we detail the current understanding of the functional circuits that subserve each form of decision making. We highlight the extensive literature by detailing the ability of dopamine to influence decisions by modulating structures within these circuits. Since acetylcholine projects to all of the same important structures, we propose several ways in which the cholinergic system may play a local modulatory role that will allow it to shape these behaviors. A greater understanding of the contribution of the cholinergic system to cost-benefit decisions will permit us to better link the decision and memory processes, and this will help us to better understand and/or treat individuals with deficits in a number of higher cognitive functions including decision making, learning, memory, and language. © 2014 Elsevier Inc. All rights reserved.

  3. The role of a personalized dietary intervention in managing gestational weight gain: a prospective, controlled study in a low-risk antenatal population.

    PubMed

    Di Carlo, Costantino; Iannotti, Giuseppina; Sparice, Stefania; Chiacchio, Maria Pia; Greco, Elena; Tommaselli, Giovanni Antonio; Nappi, Carmine

    2014-04-01

    To compare the efficacy of a personal dietary intervention on gestational weight gain control with a general intervention promoting healthy eating. Prospective, controlled study including 154 low-risk pregnant women randomly allocated to two groups: 77 receiving a personalized diet plan and a close follow-up by a dietician (intervention group), 77 receiving standard dietary care by means of a brochure on healthy eating during pregnancy (control group). Pre-pregnancy weight, gestational age, height, weight and BMI at baseline, weight at term, gestational age at delivery and newborn weight were recorded for all participants. The primary end-point was the difference in body weight between baseline and term. Secondary end-points were the difference in body weight between pre-pregnancy and term and in newborn weights. Maternal weight gain at term was significantly lower both as compared to pre-pregnancy weight (8.2 ± 4.0 vs. 13.4 ± 4.2 kg; p < 0.001) and to weight at baseline (7.7 ± 3.8 vs. 13.7 ± 4.3 kg; p < 0.001) in the intervention group as compared to controls. A positive, significant correlation between the delta weight between baseline and term and newborn weight was observed in both groups, but stronger in patients from the intervention group (intervention group R = 0.76, p < 0.001; control group R = 0.35, p = 0.01). This study suggests that a personalized nutritional intervention, in which the dietician plays an active role within the obstetric team, may represent a successful approach in limiting weight gain in pregnant women.

  4. Goals-feedback conditions and episodic memory: Mechanisms for memory gains in older and younger adults.

    PubMed

    West, Robin L; Dark-Freudeman, Alissa; Bagwell, Dana K

    2009-02-01

    Research has established that challenging memory goals always lead to score increases for younger adults, and can increase older adults' scores under supportive conditions. This study examined beliefs and on-task effort as potential mechanisms for these self-regulatory gains, in particular to learn whether episodic memory gains across multiple trials of shopping list recall are controlled by the same factors for young and old people. Goals with feedback led to higher recall and strategic categorisation than a control condition. Strategy usage was the strongest predictor of gains over trials for both age groups. Age, goal condition, and effort also predicted scores across the entire sample. Older adults' gains, but not younger adults' gains, were affected significantly by the interaction of self-efficacy beliefs and goal condition, and condition interacted with locus of control to predict younger adult gains. These results emphasise the importance of self-regulatory effort and positive beliefs for facilitating goal-related memory gains.

  5. Closed Loop solar array-ion thruster system with power control circuitry

    NASA Technical Reports Server (NTRS)

    Gruber, R. P. (Inventor)

    1979-01-01

    A power control circuit connected between a solar array and an ion thruster receives voltage and current signals from the solar array. The control circuit multiplies the voltage and current signals together to produce a power signal which is differentiated with respect to time. The differentiator output is detected by a zero crossing detector and, after suitable shaping, the detector output is phase compared with a clock in a phase demodulator. An integrator receives no output from the phase demodulator when the operating point is at the maximum power but is driven toward the maximum power point for non-optimum operation. A ramp generator provides minor variations in the beam current reference signal produced by the integrator in order to obtain the first derivative of power.

  6. New LMI based gain-scheduling control for recovering contact-free operation of a magnetically levitated rotor

    NASA Astrophysics Data System (ADS)

    Wang, M.; Cole, M. O. T.; Keogh, P. S.

    2017-11-01

    A new approach for the recovery of contact-free levitation of a rotor supported by active magnetic bearings (AMB) is assessed through control strategy design, system modelling and experimental verification. The rotor is considered to make contact with a touchdown bearing (TDB), which may lead to entrapment in a bi-stable nonlinear response. A linear matrix inequality (LMI) based gain-scheduling H∞ control technique is introduced to recover the rotor to a contact-free state. The controller formulation involves a time-varying effective stiffness parameter, which can be evaluated in terms of forces transmitted through the TDB. Rather than measuring these forces directly, an observer is introduced with a model of the base structure to transform base acceleration signals using polytopic coordinates for controller adjustment. Force transmission to the supporting base structure will occur either through an AMB alone without contact, or through the AMB and TDB with contact and this must be accounted for in the observer design. The controller is verified experimentally in terms of (a) non-contact robust stability and vibration suppression performance; (b) control action for contact-free recovery at typical running speeds with various unbalance and TDB misalignment conditions; and (c) coast-down experimental tests. The results demonstrate the effectiveness of the AMB control action whenever it operates within its dynamic load capacity.

  7. Accelerometer Method and Apparatus for Integral Display and Control Functions

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1996-01-01

    Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto. Art accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.

  8. Accelerometer Method and Apparatus for Integral Display and Control Functions

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1998-01-01

    Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto is discussed. An accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.

  9. Using Unconstrained Tongue Motion as an Alternative Control Mechanism for Wheeled Mobility

    PubMed Central

    Huo, Xueliang; Ghovanloo, Maysam

    2015-01-01

    Tongue drive system (TDS) is a tongue-operated, minimally invasive, unobtrusive, noncontact, and wireless assistive technology that infers users’ intentions by detecting and classifying their voluntary tongue motions, and translating them to user-defined commands. We have developed customized interface circuitry between an external TDS (eTDS) prototype and a commercial powered wheelchair (PWC) as well as three control strategies to evaluate the tongue motion as an alternative control input for wheeled mobility. We tested the eTDS performance in driving PWCs on 12 able-bodied human subjects, of which 11 were novice. The results showed that all subjects could complete navigation tasks by operating the PWC using their tongue motions. Despite little prior experience, the average time using the eTDS and the tongue was only approximately three times longer than using a joystick and the fingers. Navigation time was strongly dependant on the number of issued commands, which reduced by gaining experience. Particularly, the unintended issued commands (the Midas touch problem) were rare, demonstrating the effectiveness of the tongue tracking and external magnetic field cancellation algorithms as well as the safety of the TDS for wheeled mobility. PMID:19362901

  10. Using unconstrained tongue motion as an alternative control mechanism for wheeled mobility.

    PubMed

    Huo, Xueliang; Ghovanloo, Maysam

    2009-06-01

    Tongue drive system (TDS) is a tongue-operated, minimally invasive, unobtrusive, noncontact, and wireless assistive technology that infers users' intentions by detecting and classifying their voluntary tongue motions, and translating them to user-defined commands. We have developed customized interface circuitry between an external TDS (eTDS) prototype and a commercial powered wheelchair (PWC) as well as three control strategies to evaluate the tongue motion as an alternative control input for wheeled mobility. We tested the eTDS performance in driving PWCs on 12 able-bodied human subjects, of which 11 were novice. The results showed that all subjects could complete navigation tasks by operating the PWC using their tongue motions. Despite little prior experience, the average time using the eTDS and the tongue was only approximately three times longer than using a joystick and the fingers. Navigation time was strongly dependant on the number of issued commands, which reduced by gaining experience. Particularly, the unintended issued commands (the Midas touch problem) were rare, demonstrating the effectiveness of the tongue tracking and external magnetic field cancellation algorithms as well as the safety of the TDS for wheeled mobility.

  11. Understanding Overbidding: Using the Neural Circuitry of Reward to Design Economic Auctions

    PubMed Central

    Delgado, Mauricio R.; Schotter, Andrew; Ozbay, Erkut Y.; Phelps, Elizabeth A.

    2011-01-01

    We take advantage of our knowledge of the neural circuitry of reward to investigate a puzzling economic phenomenon: Why do people overbid in auctions? Using functional magnetic resonance imaging (fMRI), we observed that the social competition inherent in an auction results in a more pronounced blood oxygen level–dependent (BOLD) response to loss in the striatum, with greater overbidding correlated with the magnitude of this response. Leveraging these neuroimaging results, we design a behavioral experiment that demonstrates that framing an experimental auction to emphasize loss increases overbidding. These results highlight a role for the contemplation of loss in understanding the tendency to bid “too high.” Current economic theories suggest overbidding may result from either “joy of winning” or risk aversion. By combining neuroeconomic and behavioral economic techniques, we find that another factor, namely loss contemplation in a social context, may mediate overbidding in auctions. PMID:18818362

  12. Understanding overbidding: using the neural circuitry of reward to design economic auctions.

    PubMed

    Delgado, Mauricio R; Schotter, Andrew; Ozbay, Erkut Y; Phelps, Elizabeth A

    2008-09-26

    We take advantage of our knowledge of the neural circuitry of reward to investigate a puzzling economic phenomenon: Why do people overbid in auctions? Using functional magnetic resonance imaging (fMRI), we observed that the social competition inherent in an auction results in a more pronounced blood oxygen level-dependent (BOLD) response to loss in the striatum, with greater overbidding correlated with the magnitude of this response. Leveraging these neuroimaging results, we design a behavioral experiment that demonstrates that framing an experimental auction to emphasize loss increases overbidding. These results highlight a role for the contemplation of loss in understanding the tendency to bid "too high." Current economic theories suggest overbidding may result from either "joy of winning" or risk aversion. By combining neuroeconomic and behavioral economic techniques, we find that another factor, namely loss contemplation in a social context, may mediate overbidding in auctions.

  13. An analog neural hardware implementation using charge-injection multipliers and neutron-specific gain control.

    PubMed

    Massengill, L W; Mundie, D B

    1992-01-01

    A neural network IC based on a dynamic charge injection is described. The hardware design is space and power efficient, and achieves massive parallelism of analog inner products via charge-based multipliers and spatially distributed summing buses. Basic synaptic cells are constructed of exponential pulse-decay modulation (EPDM) dynamic injection multipliers operating sequentially on propagating signal vectors and locally stored analog weights. Individually adjustable gain controls on each neutron reduce the effects of limited weight dynamic range. A hardware simulator/trainer has been developed which incorporates the physical (nonideal) characteristics of actual circuit components into the training process, thus absorbing nonlinearities and parametric deviations into the macroscopic performance of the network. Results show that charge-based techniques may achieve a high degree of neural density and throughput using standard CMOS processes.

  14. Simplified microprocessor design for VLSI control applications

    NASA Technical Reports Server (NTRS)

    Cameron, K.

    1991-01-01

    A design technique for microprocessors combining the simplicity of reduced instruction set computers (RISC's) with the richer instruction sets of complex instruction set computers (CISC's) is presented. They utilize the pipelined instruction decode and datapaths common to RISC's. Instruction invariant data processing sequences which transparently support complex addressing modes permit the formulation of simple control circuitry. Compact implementations are possible since neither complicated controllers nor large register sets are required.

  15. "Liking" and "wanting" linked to Reward Deficiency Syndrome (RDS): hypothesizing differential responsivity in brain reward circuitry.

    PubMed

    Blum, Kenneth; Gardner, Eliot; Oscar-Berman, Marlene; Gold, Mark

    2012-01-01

    In an attempt to resolve controversy regarding the causal contributions of mesolimbic dopamine (DA) systems to reward, we evaluate the three main competing explanatory categories: "liking,"learning," and "wanting" [1]. That is, DA may mediate (a) the hedonic impact of reward (liking), (b) learned predictions about rewarding effects (learning), or (c) the pursuit of rewards by attributing incentive salience to reward-related stimuli (wanting). We evaluate these hypotheses, especially as they relate to the Reward Deficiency Syndrome (RDS), and we find that the incentive salience or "wanting" hypothesis of DA function is supported by a majority of the evidence. Neuroimaging studies have shown that drugs of abuse, palatable foods, and anticipated behaviors such as sex and gaming affect brain regions involving reward circuitry, and may not be unidirectional. Drugs of abuse enhance DA signaling and sensitize mesolimbic mechanisms that evolved to attribute incentive salience to rewards. Addictive drugs have in common that they are voluntarily selfadministered, they enhance (directly or indirectly) dopaminergic synaptic function in the nucleus accumbens (NAC), and they stimulate the functioning of brain reward circuitry (producing the "high" that drug users seek). Although originally believed simply to encode the set point of hedonic tone, these circuits now are believed to be functionally more complex, also encoding attention, reward expectancy, disconfirmation of reward expectancy, and incentive motivation. Elevated stress levels, together with polymorphisms of dopaminergic genes and other neurotransmitter genetic variants, may have a cumulative effect on vulnerability to addiction. The RDS model of etiology holds very well for a variety of chemical and behavioral addictions.

  16. Gain optimization with non-linear controls

    NASA Technical Reports Server (NTRS)

    Slater, G. L.; Kandadai, R. D.

    1984-01-01

    An algorithm has been developed for the analysis and design of controls for non-linear systems. The technical approach is to use statistical linearization to model the non-linear dynamics of a system by a quasi-Gaussian model. A covariance analysis is performed to determine the behavior of the dynamical system and a quadratic cost function. Expressions for the cost function and its derivatives are determined so that numerical optimization techniques can be applied to determine optimal feedback laws. The primary application for this paper is centered about the design of controls for nominally linear systems but where the controls are saturated or limited by fixed constraints. The analysis is general, however, and numerical computation requires only that the specific non-linearity be considered in the analysis.

  17. Gain Coupling of Class A Semiconductor Lasers (Postprint)

    DTIC Science & Technology

    2010-09-01

    Circuits (Wiley, 1995). 15. SimuLase Version 1.4.0.0 by Nonlinear Control Strategies, Inc. (2009). 16. A. Siegman , Lasers (University Science, 1986). 3062 OPTICS LETTERS / Vol. 35, No. 18 / September 15, 2010 3 ...AFRL-RY-WP-TP-2010-1250 GAIN COUPLING OF CLASS A SEMICONDUCTOR LASERS (POSTPRINT) Chris Hessenius, Mahmoud Fallahi, and Jerome Moloney...June 2010 4. TITLE AND SUBTITLE GAIN COUPLING OF CLASS A SEMICONDUCTOR LASERS (POSTPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c

  18. Automatic Gain Control in Mass Spectrometry using a Jet Disrupter Electrode in an Electrodynamic Ion Funnel

    PubMed Central

    Page, Jason S.; Bogdanov, Bogdan; Vilkov, Andrey N.; Prior, David C.; Buschbach, Michael A.; Tang, Keqi; Smith, Richard D.

    2007-01-01

    We report on the use of a jet disrupter electrode in an electrodynamic ion funnel as an electronic valve to regulate the intensity of the ion beam transmitted through the interface of a mass spectrometer in order to perform automatic gain control (AGC). The ion flux is determined by either directly detecting the ion current on the conductance limiting orifice of the ion funnel or using a short mass spectrometry acquisition. Based upon the ion flux intensity, the voltage of the jet disrupter is adjusted to alter the transmission efficiency of the ion funnel to provide a desired ion population to the mass analyzer. Ion beam regulation by an ion funnel is shown to provide control to within a few percent of a targeted ion intensity or abundance. The utility of ion funnel AGC was evaluated using a protein tryptic digest analyzed with liquid chromatography Fourier transform ion cyclotron resonance (LC-FTICR) mass spectrometry. The ion population in the ICR cell was accurately controlled to selected levels, which improved data quality and provided better mass measurement accuracy. PMID:15694774

  19. Cross-entropy optimization for neuromodulation.

    PubMed

    Brar, Harleen K; Yunpeng Pan; Mahmoudi, Babak; Theodorou, Evangelos A

    2016-08-01

    This study presents a reinforcement learning approach for the optimization of the proportional-integral gains of the feedback controller represented in a computational model of epilepsy. The chaotic oscillator model provides a feedback control systems view of the dynamics of an epileptic brain with an internal feedback controller representative of the natural seizure suppression mechanism within the brain circuitry. Normal and pathological brain activity is simulated in this model by adjusting the feedback gain values of the internal controller. With insufficient gains, the internal controller cannot provide enough feedback to the brain dynamics causing an increase in correlation between different brain sites. This increase in synchronization results in the destabilization of the brain dynamics, which is representative of an epileptic seizure. To provide compensation for an insufficient internal controller an external controller is designed using proportional-integral feedback control strategy. A cross-entropy optimization algorithm is applied to the chaotic oscillator network model to learn the optimal feedback gains for the external controller instead of hand-tuning the gains to provide sufficient control to the pathological brain and prevent seizure generation. The correlation between the dynamics of neural activity within different brain sites is calculated for experimental data to show similar dynamics of epileptic neural activity as simulated by the network of chaotic oscillators.

  20. Inspection criteria ensure quality control of parallel gap soldering

    NASA Technical Reports Server (NTRS)

    Burka, J. A.

    1968-01-01

    Investigation of parallel gap soldering of electrical leads resulted in recommendation on material preparation, equipment, process control, and visual inspection criteria to ensure reliable solder joints. The recommendations will minimize problems in heat-dwell time, amount of solder, bridging conductors, and damage of circuitry.

  1. Pro-Dopamine Regulator – (KB220) to Balance Brain Reward Circuitry in Reward Deficiency Syndrome (RDS)

    PubMed Central

    Blum, Kenneth; Febo, Marcelo; Fried, Lyle; Baron, David; Braverman, Eric R.; Dushaj, Kristina; Li, Mona; Demetrovics, Zsolt; Badgaiyan, Rajendra D.

    2017-01-01

    We are faced with a worldwide opiate/opioid epidemic that is devastating. According to the Centers for Disease Control and Prevention (CDC), at least 127 people, young and old, are dying every day in America due to narcotic overdose. The Food and Drug Administration (FDA) has approved Medication-Assisted Treatments (MATs) for opiate/opioids as well as alcohol and nicotine. The mechanism of action of most MATS favors either blocking of dopaminergic function or a form of Opiate Substitution Therapy (OST). These treatment options are adequate for short-term treatment of the symptoms of addiction and harm reduction but fail long-term to deal with the cause or lead to recovery. There is a need to continue to seek better treatment options. This mini-review is the history of the development of one such treatment; a glutaminergic-dopaminergic optimization complex called KB220. Growing evidence indicates that brain reward circuitry controls drug addiction, in conjunction with “anti-reward systems” as the “anti-reward systems” can be affected by both glutaminergic and dopaminergic transmission. KB220 may likely alter the function of these regions and provide for the possible eventual balancing the brain reward system and the induction of “dopamine homeostasis.” Many of these concepts have been reported elsewhere and have become an integral part of the addiction science literature. However, the concise review may encourage readership to reconsider these facts and stimulate further research focused on the impact that the induction of “dopamine homeostasis” may have on recovery and relapse prevention. PMID:28804788

  2. Lessons from sleeping flies: insights from Drosophila melanogaster on the neuronal circuitry and importance of sleep.

    PubMed

    Potdar, Sheetal; Sheeba, Vasu

    2013-06-01

    Sleep is a highly conserved behavior whose role is as yet unknown, although it is widely acknowledged as being important. Here we provide an overview of many vital questions regarding this behavior, that have been addressed in recent years using the genetically tractable model organism Drosophila melanogaster in several laboratories around the world. Rest in D. melanogaster has been compared to mammalian sleep and its homeostatic and circadian regulation have been shown to be controlled by intricate neuronal circuitry involving circadian clock neurons, mushroom bodies, and pars intercerebralis, although their exact roles are not entirely clear. We draw attention to the yet unanswered questions and contradictions regarding the nature of the interactions between the brain regions implicated in the control of sleep. Dopamine, octopamine, γ-aminobutyric acid (GABA), and serotonin are the chief neurotransmitters identified as functioning in different limbs of this circuit, either promoting arousal or sleep by modulating membrane excitability of underlying neurons. Some studies have suggested that certain brain areas may contribute towards both sleep and arousal depending on activation of specific subsets of neurons. Signaling pathways implicated in the sleep circuit include cyclic adenosine monophosphate (cAMP) and epidermal growth factor receptor-extracellular signal-regulated kinase (EGFR-ERK) signaling pathways that operate on different neural substrates. Thus, this field of research appears to be on the cusp of many new and exciting findings that may eventually help in understanding how this complex physiological phenomenon is modulated by various neuronal circuits in the brain. Finally, some efforts to approach the "Holy Grail" of why we sleep have been summarized.

  3. Training feed-forward neural networks with gain constraints

    PubMed

    Hartman

    2000-04-01

    Inaccurate input-output gains (partial derivatives of outputs with respect to inputs) are common in neural network models when input variables are correlated or when data are incomplete or inaccurate. Accurate gains are essential for optimization, control, and other purposes. We develop and explore a method for training feedforward neural networks subject to inequality or equality-bound constraints on the gains of the learned mapping. Gain constraints are implemented as penalty terms added to the objective function, and training is done using gradient descent. Adaptive and robust procedures are devised for balancing the relative strengths of the various terms in the objective function, which is essential when the constraints are inconsistent with the data. The approach has the virtue that the model domain of validity can be extended via extrapolation training, which can dramatically improve generalization. The algorithm is demonstrated here on artificial and real-world problems with very good results and has been advantageously applied to dozens of models currently in commercial use.

  4. Genetic Gains Through Testing and Crossing Longleaf Pine Plus Trees

    Treesearch

    Calvin F. Bey; E. Bayne Snyder

    1978-01-01

    A progeny test of 226 superior tree selections from nine geographic sources across the South confirmed earlier results that showed the Gulf Coast source superior in survival and growth. Family variation within a region was large and provided additional genetic gain. Control-pollinated tests of elite x elite trees yielded even more gains. Progeny of the elite x elite...

  5. A phosphorylation-and-ubiquitylation circuitry driving ATR activation and homologous recombination

    PubMed Central

    Dubois, Jean-Christophe; Yates, Maïlyn; Gaudreau-Lapierre, Antoine; Clément, Geneviève; Cappadocia, Laurent; Gaudreau, Luc

    2017-01-01

    Abstract RPA-coated single-stranded DNA (RPA–ssDNA), a nucleoprotein structure induced by DNA damage, promotes ATR activation and homologous recombination (HR). RPA is hyper-phosphorylated and ubiquitylated after DNA damage. The ubiquitylation of RPA by PRP19 and RFWD3 facilitates ATR activation and HR, but how it is stimulated by DNA damage is still unclear. Here, we show that RFWD3 binds RPA constitutively, whereas PRP19 recognizes RPA after DNA damage. The recruitment of PRP19 by RPA depends on PIKK-mediated RPA phosphorylation and a positively charged pocket in PRP19. An RPA32 mutant lacking phosphorylation sites fails to recruit PRP19 and support RPA ubiquitylation. PRP19 mutants unable to bind RPA or lacking ubiquitin ligase activity also fail to support RPA ubiquitylation and HR. These results suggest that RPA phosphorylation enhances the recruitment of PRP19 to RPA–ssDNA and stimulates RPA ubiquitylation through a process requiring both PRP19 and RFWD3, thereby triggering a phosphorylation-ubiquitylation circuitry that promotes ATR activation and HR. PMID:28666352

  6. Distributed cerebellar plasticity implements adaptable gain control in a manipulation task: a closed-loop robotic simulation

    PubMed Central

    Garrido, Jesús A.; Luque, Niceto R.; D'Angelo, Egidio; Ros, Eduardo

    2013-01-01

    Adaptable gain regulation is at the core of the forward controller operation performed by the cerebro-cerebellar loops and it allows the intensity of motor acts to be finely tuned in a predictive manner. In order to learn and store information about body-object dynamics and to generate an internal model of movement, the cerebellum is thought to employ long-term synaptic plasticity. LTD at the PF-PC synapse has classically been assumed to subserve this function (Marr, 1969). However, this plasticity alone cannot account for the broad dynamic ranges and time scales of cerebellar adaptation. We therefore tested the role of plasticity distributed over multiple synaptic sites (Hansel et al., 2001; Gao et al., 2012) by generating an analog cerebellar model embedded into a control loop connected to a robotic simulator. The robot used a three-joint arm and performed repetitive fast manipulations with different masses along an 8-shape trajectory. In accordance with biological evidence, the cerebellum model was endowed with both LTD and LTP at the PF-PC, MF-DCN and PC-DCN synapses. This resulted in a network scheme whose effectiveness was extended considerably compared to one including just PF-PC synaptic plasticity. Indeed, the system including distributed plasticity reliably self-adapted to manipulate different masses and to learn the arm-object dynamics over a time course that included fast learning and consolidation, along the lines of what has been observed in behavioral tests. In particular, PF-PC plasticity operated as a time correlator between the actual input state and the system error, while MF-DCN and PC-DCN plasticity played a key role in generating the gain controller. This model suggests that distributed synaptic plasticity allows generation of the complex learning properties of the cerebellum. The incorporation of further plasticity mechanisms and of spiking signal processing will allow this concept to be extended in a more realistic computational scenario

  7. Fractional-N phase-locked loop for split and direct automatic frequency control in A-GPS

    NASA Astrophysics Data System (ADS)

    Park, Chester Sungchung; Park, Sungkyung

    2018-07-01

    A low-power mixed-signal phase-locked loop (PLL) is modelled and designed for the DigRF interface between the RF chip and the modem chip. An assisted-GPS or A-GPS multi-standard system includes the DigRF interface and uses the split automatic frequency control (AFC) technique. The PLL circuitry uses the direct AFC technique and is based on the fractional-N architecture using a digital delta-sigma modulator along with a digital counter, fulfilling simple ultra-high-resolution AFC with robust digital circuitry and its timing. Relative to the output frequency, the measured AFC resolution or accuracy is <5 parts per billion (ppb) or on the order of a Hertz. The cycle-to-cycle rms jitter is <6 ps and the typical settling time is <30 μs. A spur reduction technique is adopted and implemented as well, demonstrating spur reduction without employing dithering. The proposed PLL includes a low-leakage phase-frequency detector, a low-drop-out regulator, power-on-reset circuitry and precharge circuitry. The PLL is implemented in a 90-nm CMOS process technology with 1.2 V single supply. The overall PLL draws about 1.1 mA from the supply.

  8. How Pregnant African-American Women View Pregnancy Weight Gain

    PubMed Central

    Groth, Susan W.; Morrison-Beedy, Dianne; Meng, Ying

    2012-01-01

    Objective To gain insight into how low-income, pregnant African-American women viewed their weight gain while pregnant and how they managed their weight during pregnancy. Design Descriptive study using three focus groups. Setting Women were recruited from urban prenatal care sites and the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) services in a medium-sized urban Northeastern city. Participants Twenty-six adult, low-income, pregnant African-American women, aged 18–39; the majority were within the first 20 weeks of pregnancy. Methods Three focus groups were conducted utilizing open-ended questions related to pregnancy weight gain. Content analysis was used to analyze the verbatim transcripts. Analysis focused on meaning, intention and context. Groups were compared and contrasted at the within and between group levels to identify themes. Results Four themes were identified that provided insight into how women viewed their pregnancy weight gain and managed weight gain during pregnancy: (a) pregnancy weight gain: no matter how much means a healthy baby; (b) weight retention: it happens; (c) there is a limit: weight gain impact on appearance; and (d) watching and waiting: plans for controlling weight. Conclusion Low-income African-American women, though cognizant of the likelihood of retention of weight following pregnancy, are not focused on limiting their gestational weight gain. The cultural acceptance of a larger body size along with the belief that gaining more weight is indicative of a healthy infant present challenges for interventions to limit excessive gestational weight gain. PMID:22789036

  9. Sudden gains in cognitive therapy and interpersonal therapy for social anxiety disorder.

    PubMed

    Bohn, Christiane; Aderka, Idan M; Schreiber, Franziska; Stangier, Ulrich; Hofmann, Stefan G

    2013-02-01

    The present study examined the effects of sudden gains on treatment outcome in a randomized controlled trial including individual cognitive therapy (CT) and interpersonal therapy (IPT) for social anxiety disorder (SAD). Participants were 67 individuals with SAD who received 16 treatment sessions. Symptom severity at each session was assessed using the Social Phobia Weekly Summary Scale (Clark et al., 2003). Results indicate that 22.4% of participants experienced a sudden gain during treatment. Individuals with sudden gains had significantly lower social anxiety symptoms at post-treatment and follow-up compared to individuals without sudden gains. Sudden gains in CT and IPT had similar magnitudes, frequencies, and timings. However, sudden gains resulted in lower levels of post-treatment symptoms in CT compared to IPT. Cognitive changes did not precede sudden gains, but sudden gains resulted in cognitive changes. Sudden gains in CT and IPT for SAD are predictive of long-term outcome. In addition, the effect of sudden gains may be greater in CT compared to IPT.

  10. Differential neural circuitry and self-interest in real vs hypothetical moral decisions

    PubMed Central

    Dalgleish, Tim; Thompson, Russell; Evans, Davy; Schweizer, Susanne; Mobbs, Dean

    2012-01-01

    Classic social psychology studies demonstrate that people can behave in ways that contradict their intentions—especially within the moral domain. We measured brain activity while subjects decided between financial self-benefit (earning money) and preventing physical harm (applying an electric shock) to a confederate under both real and hypothetical conditions. We found a shared neural network associated with empathic concern for both types of decisions. However, hypothetical and real moral decisions also recruited distinct neural circuitry: hypothetical moral decisions mapped closely onto the imagination network, while real moral decisions elicited activity in the bilateral amygdala and anterior cingulate—areas essential for social and affective processes. Moreover, during real moral decision-making, distinct regions of the prefrontal cortex (PFC) determined whether subjects make selfish or pro-social moral choices. Together, these results reveal not only differential neural mechanisms for real and hypothetical moral decisions but also that the nature of real moral decisions can be predicted by dissociable networks within the PFC. PMID:22711879

  11. Radiating dipole model of interference induced in spacecraft circuitry by surface discharges

    NASA Technical Reports Server (NTRS)

    Metz, R. N.

    1984-01-01

    Spacecraft in geosynchronous orbit can be charged electrically to high voltages by interaction with the space plasma. Differential charging of spacecraft surfaces leads to arc and blowoff discharging. The discharges are thought to upset interior, computer-level circuitry. In addition to capacitive or electrostatic effects, significant inductive and less significant radiative effects of these discharges exist and can be modeled in a dipole approximation. Flight measurements suggest source frequencies of 5 to 50 MHz. Laboratory tests indicate source current strengths of several amperes. Electrical and magnetic fields at distances of many centimeters from such sources can be as large as tens of volts per meter and meter squared, respectively. Estimates of field attenuation by spacecraft walls and structures suggest that interior fields may be appreciable if electromagnetic shielding is much thinner than about 0.025 mm (1 mil). Pickup of such fields by wires and cables interconnecting circuit components could be a source of interference signals of several volts amplitude.

  12. Gain scheduled linear quadratic control for quadcopter

    NASA Astrophysics Data System (ADS)

    Okasha, M.; Shah, J.; Fauzi, W.; Hanouf, Z.

    2017-12-01

    This study exploits the dynamics and control of quadcopters using Linear Quadratic Regulator (LQR) control approach. The quadcopter’s mathematical model is derived using the Newton-Euler method. It is a highly manoeuvrable, nonlinear, coupled with six degrees of freedom (DOF) model, which includes aerodynamics and detailed gyroscopic moments that are often ignored in many literatures. The linearized model is obtained and characterized by the heading angle (i.e. yaw angle) of the quadcopter. The adopted control approach utilizes LQR method to track several reference trajectories including circle and helix curves with significant variation in the yaw angle. The controller is modified to overcome difficulties related to the continuous changes in the operating points and eliminate chattering and discontinuity that is observed in the control input signal. Numerical non-linear simulations are performed using MATLAB and Simulink to illustrate to accuracy and effectiveness of the proposed controller.

  13. Central circuitries for body temperature regulation and fever.

    PubMed

    Nakamura, Kazuhiro

    2011-11-01

    Body temperature regulation is a fundamental homeostatic function that is governed by the central nervous system in homeothermic animals, including humans. The central thermoregulatory system also functions for host defense from invading pathogens by elevating body core temperature, a response known as fever. Thermoregulation and fever involve a variety of involuntary effector responses, and this review summarizes the current understandings of the central circuitry mechanisms that underlie nonshivering thermogenesis in brown adipose tissue, shivering thermogenesis in skeletal muscles, thermoregulatory cardiac regulation, heat-loss regulation through cutaneous vasomotion, and ACTH release. To defend thermal homeostasis from environmental thermal challenges, feedforward thermosensory information on environmental temperature sensed by skin thermoreceptors ascends through the spinal cord and lateral parabrachial nucleus to the preoptic area (POA). The POA also receives feedback signals from local thermosensitive neurons, as well as pyrogenic signals of prostaglandin E(2) produced in response to infection. These afferent signals are integrated and affect the activity of GABAergic inhibitory projection neurons descending from the POA to the dorsomedial hypothalamus (DMH) or to the rostral medullary raphe region (rMR). Attenuation of the descending inhibition by cooling or pyrogenic signals leads to disinhibition of thermogenic neurons in the DMH and sympathetic and somatic premotor neurons in the rMR, which then drive spinal motor output mechanisms to elicit thermogenesis, tachycardia, and cutaneous vasoconstriction. Warming signals enhance the descending inhibition from the POA to inhibit the motor outputs, resulting in cutaneous vasodilation and inhibited thermogenesis. This central thermoregulatory mechanism also functions for metabolic regulation and stress-induced hyperthermia.

  14. Design and Flight Tests of an Adaptive Control System Employing Normal-Acceleration Command

    NASA Technical Reports Server (NTRS)

    McNeill, Water E.; McLean, John D.; Hegarty, Daniel M.; Heinle, Donovan R.

    1961-01-01

    An adaptive control system employing normal-acceleration command has been designed with the aid of an analog computer and has been flight tested. The design of the system was based on the concept of using a mathematical model in combination with a high gain and a limiter. The study was undertaken to investigate the application of a system of this type to the task of maintaining nearly constant dynamic longitudinal response of a piloted airplane over the flight envelope without relying on air data measurements for gain adjustment. The range of flight conditions investigated was between Mach numbers of 0.36 and 1.15 and altitudes of 10,000 and 40,000 feet. The final adaptive system configuration was derived from analog computer tests, in which the physical airplane control system and much of the control circuitry were included in the loop. The method employed to generate the feedback signals resulted in a model whose characteristics varied somewhat with changes in flight condition. Flight results showed that the system limited the variation in longitudinal natural frequency of the adaptive airplane to about half that of the basic airplane and that, for the subsonic cases, the damping ratio was maintained between 0.56 and 0.69. The system also automatically compensated for the transonic trim change. Objectionable features of the system were an exaggerated sensitivity of pitch attitude to gust disturbances, abnormally large pitch attitude response for a given pilot input at low speeds, and an initial delay in normal-acceleration response to pilot control at all flight conditions. The adaptive system chatter of +/-0.05 to +/-0.10 of elevon at about 9 cycles per second (resulting in a maximum airplane normal-acceleration response of from +/-0.025 g to +/- 0.035 g) was considered by the pilots to be mildly objectionable but tolerable.

  15. Gain statistics of a fiber optical parametric amplifier with a temporally incoherent pump.

    PubMed

    Xu, Y Q; Murdoch, S G

    2010-03-15

    We present an investigation of the statistics of the gain fluctuations of a fiber optical parametric amplifier pumped with a temporally incoherent pump. We derive a simple expression for the probability distribution of the gain of the amplified optical signal. The gain statistics are shown to be a strong function of the signal detuning and allow the possibility of generating optical gain distributions with controllable long-tails. Very good agreement is found between this theory and the experimentally measured gain distributions of an incoherently pumped amplifier.

  16. Enhanced Master Controller Unit Tester

    NASA Technical Reports Server (NTRS)

    Benson, Patricia; Johnson, Yvette; Johnson, Brian; Williams, Philip; Burton, Geoffrey; McCoy, Anthony

    2007-01-01

    The Enhanced Master Controller Unit Tester (EMUT) software is a tool for development and testing of software for a master controller (MC) flight computer. The primary function of the EMUT software is to simulate interfaces between the MC computer and external analog and digital circuitry (including other computers) in a rack of equipment to be used in scientific experiments. The simulations span the range of nominal, off-nominal, and erroneous operational conditions, enabling the testing of MC software before all the equipment becomes available.

  17. Pursuit gain and saccadic intrusions in first-degree relatives of probands with schizophrenia.

    PubMed

    Clementz, B A; Sweeney, J A; Hirt, M; Haas, G

    1990-11-01

    Oculomotor functioning of 26 probands with schizophrenia, 12 spectrum and 46 nonspectrum first-degree relatives, and 38 nonpsychiatric control subjects was evaluated. Spectrum relatives had more anticipatory saccades (ASs) and lower pursuit gain than nonspectrum relatives, who had more ASs and lower pursuit gain than control subjects. Probands also had lower pursuit gain than nonspectrum relatives and control subjects but did not differ from other groups on AS frequency. Control subjects had more globally accurate pursuit tracking (root mean square [RMS] error deviation) than both relative groups, whereas probands had the poorest RMS scores. Square wave jerk frequency did not differentiate the groups. Attention enhancement affected the frequency of ASs but did not affect either the other intrusive saccadic event or RMS scores. These results offer evidence that eye-movement dysfunction may serve as a biological marker for schizophrenia.

  18. A Gain-Programmable Transit-Time-Stable and Temperature-Stable PMT Voltage Divider

    NASA Astrophysics Data System (ADS)

    Liu, Yaqiang; Li, Hongdi; Wang, Yu; Xing, Tao; Xie, Shuping; Uribe, J.; Baghaei, H.; Ramirez, R.; Kim, Soonseok; Wong, Wai-Hoi

    2004-10-01

    A gain-programmable, transit-time-stable, temperature-stable photomultiplier (PMT) voltage divider design is described in this paper. The signal-to-noise ratio can be increased by changing a PMT gain directly instead of adjusting the gain of the preamplifier. PMT gain can be changed only by adjusting the voltages for the dynodes instead of changing the total high voltage between the anode and the photocathode, which can cause a significant signal transit-time variation that cannot be accepted by an application with a critical timing requirement, such as positron emission tomography (PET) or time-of-flight (TOF) detection/PET. The dynode voltage can be controlled by a digital analog converter isolated with a linear optocoupler. The optocoupler consists of an infrared light emission diode (LED) optically coupled with two phototransistors, and one is used in a servo feedback circuit to control the LED drive current for compensating temperature characteristics. The results showed that a six times gain range could be achieved; the gain drift was <0.5% over a 20/spl deg/C temperature range; 250 ps transit-time variation was measured over the entire gain range. A compact print circuit board (PCB) for the voltage divider integrated with a fixed-gain preamplifier has been designed and constructed. It can save about $30 per PMT channel compared with a commercial PMT voltage divider along with a variable gain amplifier. The preamplifier can be totally disabled, therefore in a system with a large amount of PMTs, only one channel can be enabled for calibrating the PMT gain. This new PMT voltage divider design is being applied to our animal PET camera and TOF/PET research.

  19. Effectiveness of a mHealth Lifestyle Program With Telephone Support (TXT2BFiT) to Prevent Unhealthy Weight Gain in Young Adults: Randomized Controlled Trial.

    PubMed

    Partridge, Stephanie R; McGeechan, Kevin; Hebden, Lana; Balestracci, Kate; Wong, Annette Ty; Denney-Wilson, Elizabeth; Harris, Mark F; Phongsavan, Philayrath; Bauman, Adrian; Allman-Farinelli, Margaret

    2015-06-15

    Weight gained in young adulthood often persists throughout later life with associated chronic disease risk. Despite this, current population prevention strategies are not specifically designed for young adults. We designed and assessed the efficacy of an mHealth prevention program, TXT2BFiT, in preventing excess weight gain and improving dietary and physical activity behaviors in young adults at increased risk of obesity and unhealthy lifestyle choices. A two-arm, parallel-group randomized controlled trial was conducted. Subjects and analyzing researchers were blinded. A total of 250 18- to 35-year-olds with a high risk of weight gain, a body mass index (BMI) of 23.0 to 24.9 kg/m(2) with at least 2 kg of weight gain in the previous 12 months, or a BMI of 25.0 to 31.9 kg/m(2) were randomized to the intervention or control group. In the 12-week intervention period, the intervention group received 8 text messages weekly based on the transtheoretical model of behavior change, 1 email weekly, 5 personalized coaching calls, a diet booklet, and access to resources and mobile phone apps on a website. Control group participants received only 4 text messages and printed dietary and physical activity guidelines. Measured body weight and height were collected at baseline and at 12 weeks. Outcomes were assessed via online surveys at baseline and at 12 weeks, including self-reported weight and dietary and physical activity measures. A total of 214 participants-110 intervention and 104 control-completed the 12-week intervention period. A total of 10 participants out of 250 (4.0%)-10 intervention and 0 control-dropped out, and 26 participants (10.4%)-5 intervention and 21 control-did not complete postintervention online surveys. Adherence to coaching calls and delivery of text messages was over 90%. At 12 weeks, the intervention group were 2.2 kg (95% CI 0.8-3.6) lighter than controls (P=.005). Intervention participants consumed more vegetables (P=.009), fewer sugary soft drinks

  20. [Neuronal control of posture and locomotion in decerebrated and spinalized animals].

    PubMed

    Musienko, P E; Gorskiĭ, O V; Kilimnik, V A; Kozlovskaia, I B; Courtine, G; Edgerton, V R; Gerasimenko, Iu P

    2013-03-01

    We have found that the brainstem-spinal cord circuitry of decerebrated cats actively maintain the equilibrium during standing, walking and imposed mechanical perturbations similar to that observed in intact animals. The corrective hindlimb motor responses during standing included redistribution of the extensor activity ipsilateral and contralateral to perturbation. The postural corrections in walking cats were due to considerable modification of EMG pattern in the limbs as well as changing of the swing-stance phases of the step cycle and ground reaction forces depending of perturbation side. Thus the basic mechanisms for balance control of decerebrated animals in these two forms of motor behavior are different. Balance-related adjustments relied entirely on the integration of somatosensory information arising from the moving hindquarters because of the suppression of vestibular, visual, and head-neck-trunk sensory input. We propose that the somatosensory input from the hindquarters in concert with the lumbosacral spinal circuitry can control the dynamics of the hindquarters sufficient to sustain balance. We found that, after isolation from the brainstem or forebrain, lumbosacral circuits receiving tonic epidural electrical stimulation can effectively control equilibrium during standing and stepping. Detailed analyses of the relationships among muscle activity, trunk kinematics, and limb kinetics indicate that spinal motor systems utilize a combination of feedback and feedforward strategies to maintain dynamic equilibrium during walking. The unexpected ability of spinal circuitries to exert efficient postural control in the presence of epidural electrical stimulation in decerebrated and spinal cats have significant implications for the potential of humans with a severe spinal cord injury to regain a significant level of functional standing and walking capacities.

  1. Low Voltage Current-Reused Pseudo-Differential Programmable Gain Amplifier

    NASA Astrophysics Data System (ADS)

    Nguyen, Huy-Hieu; Lee, Jeong-Seon; Lee, Sang-Gug

    This paper reports a current-reused pseudo-differential (CRPD) programmable gain amplifier (PGA) that demonstrates small size, low power, wide band, low noise, and high linearity operation with 4 control bits. Implemented in 0.18um CMOS technology, the PGA shows the gain range from -9.9 to 8.3dB with gain error of less than ±0.38dB. The IIP3, P1dB, and smallest 3-dB bandwidth are 10.5 to 27dBm, -9 to 9.5dBm, and 250MHz, respectively. The PGA occupies the chip area of 0.04mm2 and consumes only 460 µA from a 1.2V supply.

  2. Electrical energy consumption control apparatuses and electrical energy consumption control methods

    DOEpatents

    Hammerstrom, Donald J.

    2012-09-04

    Electrical energy consumption control apparatuses and electrical energy consumption control methods are described. According to one aspect, an electrical energy consumption control apparatus includes processing circuitry configured to receive a signal which is indicative of current of electrical energy which is consumed by a plurality of loads at a site, to compare the signal which is indicative of current of electrical energy which is consumed by the plurality of loads at the site with a desired substantially sinusoidal waveform of current of electrical energy which is received at the site from an electrical power system, and to use the comparison to control an amount of the electrical energy which is consumed by at least one of the loads of the site.

  3. First principles view on chemical compound space: Gaining rigorous atomistic control of molecular properties

    DOE PAGES

    von Lilienfeld, O. Anatole

    2013-02-26

    A well-defined notion of chemical compound space (CCS) is essential for gaining rigorous control of properties through variation of elemental composition and atomic configurations. Here, we give an introduction to an atomistic first principles perspective on CCS. First, CCS is discussed in terms of variational nuclear charges in the context of conceptual density functional and molecular grand-canonical ensemble theory. Thereafter, we revisit the notion of compound pairs, related to each other via “alchemical” interpolations involving fractional nuclear charges in the electronic Hamiltonian. We address Taylor expansions in CCS, property nonlinearity, improved predictions using reference compound pairs, and the ounce-of-gold prizemore » challenge to linearize CCS. Finally, we turn to machine learning of analytical structure property relationships in CCS. Here, these relationships correspond to inferred, rather than derived through variational principle, solutions of the electronic Schrödinger equation.« less

  4. Random Photon Absorption Model Elucidates How Early Gain Control in Fly Photoreceptors Arises from Quantal Sampling

    PubMed Central

    Song, Zhuoyi; Zhou, Yu; Juusola, Mikko

    2016-01-01

    Many diurnal photoreceptors encode vast real-world light changes effectively, but how this performance originates from photon sampling is unclear. A 4-module biophysically-realistic fly photoreceptor model, in which information capture is limited by the number of its sampling units (microvilli) and their photon-hit recovery time (refractoriness), can accurately simulate real recordings and their information content. However, sublinear summation in quantum bump production (quantum-gain-nonlinearity) may also cause adaptation by reducing the bump/photon gain when multiple photons hit the same microvillus simultaneously. Here, we use a Random Photon Absorption Model (RandPAM), which is the 1st module of the 4-module fly photoreceptor model, to quantify the contribution of quantum-gain-nonlinearity in light adaptation. We show how quantum-gain-nonlinearity already results from photon sampling alone. In the extreme case, when two or more simultaneous photon-hits reduce to a single sublinear value, quantum-gain-nonlinearity is preset before the phototransduction reactions adapt the quantum bump waveform. However, the contribution of quantum-gain-nonlinearity in light adaptation depends upon the likelihood of multi-photon-hits, which is strictly determined by the number of microvilli and light intensity. Specifically, its contribution to light-adaptation is marginal (≤ 1%) in fly photoreceptors with many thousands of microvilli, because the probability of simultaneous multi-photon-hits on any one microvillus is low even during daylight conditions. However, in cells with fewer sampling units, the impact of quantum-gain-nonlinearity increases with brightening light. PMID:27445779

  5. Network analysis reveals disrupted functional brain circuitry in drug-naive social anxiety disorder.

    PubMed

    Yang, Xun; Liu, Jin; Meng, Yajing; Xia, Mingrui; Cui, Zaixu; Wu, Xi; Hu, Xinyu; Zhang, Wei; Gong, Gaolang; Gong, Qiyong; Sweeney, John A; He, Yong

    2017-12-07

    Social anxiety disorder (SAD) is a common and disabling condition characterized by excessive fear and avoidance of public scrutiny. Psychoradiology studies have suggested that the emotional and behavior deficits in SAD are associated with abnormalities in regional brain function and functional connectivity. However, little is known about whether intrinsic functional brain networks in patients with SAD are topologically disrupted. Here, we collected resting-state fMRI data from 33 drug-naive patients with SAD and 32 healthy controls (HC), constructed functional networks with 34 predefined regions based on previous meta-analytic research with task-based fMRI in SAD, and performed network-based statistic and graph-theory analyses. The network-based statistic analysis revealed a single connected abnormal circuitry including the frontolimbic circuit (termed the "fear circuit", including the dorsolateral prefrontal cortex, ventral medial prefrontal cortex and insula) and posterior cingulate/occipital areas supporting perceptual processing. In this single altered network, patients with SAD had higher functional connectivity than HC. At the global level, graph-theory analysis revealed that the patients exhibited a lower normalized characteristic path length than HC, which suggests a disorder-related shift of network topology toward randomized configurations. SAD-related deficits in nodal degree, efficiency and participation coefficient were detected in the parahippocampal gyrus, posterior cingulate cortex, dorsolateral prefrontal cortex, insula and the calcarine sulcus. Aspects of abnormal connectivity were associated with anxiety symptoms. These findings highlight the aberrant topological organization of functional brain network organization in SAD, which provides insights into the neural mechanisms underlying excessive fear and avoidance of social interactions in patients with debilitating social anxiety. Copyright © 2017. Published by Elsevier Inc.

  6. An Examination of Executive Dysfunction Associated with Frontostriatal Circuitry in Parkinson’s Disease

    PubMed Central

    ZGALJARDIC, DENNIS J.; BOROD, JOAN C.; FOLDI, NANCY S.; MATTIS, PAUL J.; GORDON, MARK F.; FEIGIN, ANDREW; EIDELBERG, DAVID

    2015-01-01

    Parkinson’s disease (PD) is a neurodegenerative movement disorder presenting with subcortical pathology and characterized by motor deficits. However, as is frequently reported in the literature, patients with PD can also exhibit cognitive and behavioral (i.e., nonmotor) impairments, cognitive executive deficits and depression being the most prominent. Considerable attention has addressed the role that disruption to frontostriatal circuitry can play in mediating nonmotor dysfunction in PD. The three nonmotor frontostriatal circuits, which connect frontal cortical regions to the basal ganglia, originate from the dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), and orbitofrontal cortex (OFC). The objective of the current study was to use our understanding of frontostriatal circuit function (via literature review) to categorize neuropsychological measures of cognitive and behavioral executive functions by circuit. To our knowledge, such an approach has not been previously attempted in the study of executive dysfunction in PD. Neuropsychological measures of executive functions and self-report behavioral inventories, categorized by circuit function, were administered to 32 nondemented patients with Parkinson’s disease (NDPD) and to 29 demographically matched, healthy normal control participants (NC). Our findings revealed significant group differences for each circuit, with the PD group performing worse than the NC group. Among the patients with PD, indices of impairment were greater for tasks associated with DLPFC function than with OFC function. Further, only an index of DLPFC test performance was demonstrated to significantly discriminate individuals with and without PD. In conclusion, our findings suggest that nondemented patients with PD exhibit greater impairment on neuropsychological measures associated with DLPFC than with ACC or OFC circuit function. PMID:16840240

  7. Developmental gains in visuospatial memory predict gains in mathematics achievement.

    PubMed

    Li, Yaoran; Geary, David C

    2013-01-01

    Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusive, and their working memory capacity and processing speed in first and fifth grade. Intelligence was assessed in first grade and their second to fourth grade teachers reported on their in-class attentive behavior. Developmental gains in visuospatial memory span (d = 2.4) were larger than gains in the capacity of the central executive (d = 1.6) that in turn were larger than gains in phonological memory span (d = 1.1). First to fifth grade gains in visuospatial memory and in speed of numeral processing predicted end of fifth grade mathematics achievement, as did first grade central executive scores, intelligence, and in-class attentive behavior. The results suggest there are important individual differences in the rate of growth of visuospatial memory during childhood and that these differences become increasingly important for mathematics learning.

  8. Developmental Gains in Visuospatial Memory Predict Gains in Mathematics Achievement

    PubMed Central

    Li, Yaoran; Geary, David C.

    2013-01-01

    Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusive, and their working memory capacity and processing speed in first and fifth grade. Intelligence was assessed in first grade and their second to fourth grade teachers reported on their in-class attentive behavior. Developmental gains in visuospatial memory span (d = 2.4) were larger than gains in the capacity of the central executive (d = 1.6) that in turn were larger than gains in phonological memory span (d = 1.1). First to fifth grade gains in visuospatial memory and in speed of numeral processing predicted end of fifth grade mathematics achievement, as did first grade central executive scores, intelligence, and in-class attentive behavior. The results suggest there are important individual differences in the rate of growth of visuospatial memory during childhood and that these differences become increasingly important for mathematics learning. PMID:23936154

  9. Metformin for treatment of antipsychotic-induced weight gain: a randomized, placebo-controlled study.

    PubMed

    Wang, Man; Tong, Jian-hua; Zhu, Gang; Liang, Guang-ming; Yan, Hong-fei; Wang, Xiu-zhen

    2012-06-01

    To evaluate the efficacy of metformin for treatment of antipsychotic-induced weight gain. Seventy-two patients with first-episode schizophrenia who gained more than 7% of their predrug weight were randomly assigned to receive 1000 mg/d of metformin or placebo in addition to their ongoing treatment for 12 weeks using a double-blind study design. The primary outcome was change in body weight. The secondary outcomes included changes in body mass index, fasting glucose and insulin, and insulin resistance index. Of the 72 patients who were randomly assigned, 66 (91.6%) completed treatments. The body weight, body mass index, fasting insulin and insulin resistance index decreased significantly in the metformin group, but increased in the placebo group during the 12-week follow-up period. Significantly more patients in the metformin group lost their baseline weight by more than 7%, which was the cutoff for clinically meaningful weight loss. Metformin was tolerated well by majority patients. Metformin was effective and safe in attenuating antipsychotic-induced weight gain and insulin resistance in first-episode schizophrenia patients. Patients displayed good adherence to metformin. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Quest for the basic plan of nervous system circuitry

    PubMed Central

    Swanson, Larry W.

    2007-01-01

    The basic plan of nervous system organization has been investigated since classical antiquity. The first model centered on pneumas pumped from sensory nerves through the ventricular system and out motor nerves to muscles. It was popular well into the seventeenth century and diverted attention from the organization of brain parenchyma itself. Willis focused on gray matter production and white matter conduction of pneumas in 1664, and by the late nineteenth century a clear cellular model of nervous system organization based on sensory, motor, and association neuron classes transmitting nerve impulses was elaborated by Cajal and his contemporaries. Today, revolutionary advances in experimental pathway tracing methods, molecular genetics, and computer science inspire systems neuroscience. Seven minimal requirements are outlined for knowledge management systems capable of describing, analyzing, and modeling the basic plan of nervous system circuitry in general, and the plan evolved for vertebrates, for mammals, and ultimately for humans in particular. The goal remains a relatively simple, easy to understand model analogous to the one Harvey elaborated in 1628 for circulation in the cardiovascular system. As Cajal wrote in 1909, “To extend our understanding of neural function to the most complex human physiological and psychological activities, it is essential that we first generate a clear and accurate view of the structure of the relevant centers, and of the human brain itself, so that the basic plan—the overview—can be grasped in the blink of an eye.” PMID:17267046

  11. Antipsychotic induced weight gain in schizophrenia:mechanisms and management.

    PubMed

    Rege, Sanil

    2008-05-01

    The aim of the present paper was to describe the mechanisms and management of antipsychotic-induced weight gain in schizophrenia patients. A comprehensive literature review of all available articles on the mechanisms and management of antipsychotic-induced weight gain was done by searching databases PsychINFO and PubMed. A summary of the available guidelines for monitoring of antipsychotic-induced weight gain and metabolic syndrome is also provided. There has been a substantial increase in the number of studies investigating the mechanisms and management of antipsychotic-induced weight gain after 2002. These include advances in the understanding of pharmacogenomics of weight gain and several randomized controlled trials (RCTs) evaluating pharmacological and psychological treatments to promote weight loss. The most effective strategy for prevention of weight gain is the choice of antipsychotic medication with low weight gain potential. In individuals with established weight gain and metabolic issues, switching to an antipsychotic agent with lower weight gain potential and/or lifestyle modifications with physical activity are most effective in promoting weight loss. Pharmacological agents such as orlistat and sibutramine are effective in general obesity but have not been sufficiently evaluated in antipsychotic-induced weight gain. The case to prescribe routine pharmacological treatment to promote weight loss is weak. Long-term, pragmatic studies are required to inform clinical practice. Weight gain in schizophrenia is associated with significant physical and psychological morbidity. Achieving an optimal trade-off between effectiveness and side-effects of antipsychotic agents, although difficult, is achievable. This should be based on three main principles: (i) a shared decision-making model between the patient, clinician and carer(s) when choosing an antipsychotic; (ii) a commitment to baseline and follow-up monitoring with explicit identification of the responsible

  12. Additive effects of oxytocin receptor gene polymorphisms on reward circuitry in youth with autism.

    PubMed

    Hernandez, L M; Krasileva, K; Green, S A; Sherman, L E; Ponting, C; McCarron, R; Lowe, J K; Geschwind, D H; Bookheimer, S Y; Dapretto, M

    2017-08-01

    Several common alleles in the oxytocin receptor gene (OXTR) are associated with altered brain function in reward circuitry in neurotypical adults and may increase risk for autism spectrum disorders (ASD). Yet, it is currently unknown how variation in the OXTR relates to brain functioning in individuals with ASD, and, critically, whether neural endophenotypes vary as a function of aggregate genetic risk. Here, for we believe the first time, we use a multi-locus approach to examine how genetic variation across several OXTR single-nucleotide polymorphisms (SNPs) affect functional connectivity of the brain's reward network. Using data from 41 children with ASD and 41 neurotypical children, we examined functional connectivity of the nucleus accumbens (NAcc) - a hub of the reward network - focusing on how connectivity varies with OXTR risk-allele dosage. Youth with ASD showed reduced NAcc connectivity with other areas in the reward circuit as a function of increased OXTR risk-allele dosage, as well as a positive association between risk-allele dosage and symptom severity, whereas neurotypical youth showed increased NAcc connectivity with frontal brain regions involved in mentalizing. In addition, we found that increased NAcc-frontal cortex connectivity in typically developing youth was related to better scores on a standardized measure of social functioning. Our results indicate that cumulative genetic variation on the OXTR impacts reward system connectivity in both youth with ASD and neurotypical controls. By showing differential genetic effects on neuroendophenotypes, these pathways elucidate mechanisms of vulnerability versus resilience in carriers of disease-associated risk alleles.

  13. A microprogrammable radar controller

    NASA Technical Reports Server (NTRS)

    Law, D. C.

    1986-01-01

    The Wave Propagation Lab. has completed the design and construction of a microprogrammable radar controller for atmospheric wind profiling. Unlike some radar controllers using state machines or hardwired logic for radar timing, this design is a high speed programmable sequencer with signal processing resources. A block diagram of the device is shown. The device is a single 8 1/2 inch by 10 1/2 inch printed circuit board and consists of three main subsections: (1) the host computer interface; (2) the microprogram sequencer; and (3) the signal processing circuitry. Each of these subsections are described in detail.

  14. Gain weighted eigenspace assignment

    NASA Technical Reports Server (NTRS)

    Davidson, John B.; Andrisani, Dominick, II

    1994-01-01

    This report presents the development of the gain weighted eigenspace assignment methodology. This provides a designer with a systematic methodology for trading off eigenvector placement versus gain magnitudes, while still maintaining desired closed-loop eigenvalue locations. This is accomplished by forming a cost function composed of a scalar measure of error between desired and achievable eigenvectors and a scalar measure of gain magnitude, determining analytical expressions for the gradients, and solving for the optimal solution by numerical iteration. For this development the scalar measure of gain magnitude is chosen to be a weighted sum of the squares of all the individual elements of the feedback gain matrix. An example is presented to demonstrate the method. In this example, solutions yielding achievable eigenvectors close to the desired eigenvectors are obtained with significant reductions in gain magnitude compared to a solution obtained using a previously developed eigenspace (eigenstructure) assignment method.

  15. Monolithic optical integrated control circuitry for GaAs MMIC-based phased arrays

    NASA Technical Reports Server (NTRS)

    Bhasin, K. B.; Ponchak, G. E.; Kascak, T. J.

    1985-01-01

    Gallium arsenide (GaAs) monolithic microwave integrated circuits (MMIC's) show promise in phased-array antenna applications for future space communications systems. Their efficient usage will depend on the control of amplitude and phase signals for each MMIC element in the phased array and in the low-loss radiofrequency feed. For a phased array contining several MMIC elements a complex system is required to control and feed each element. The characteristics of GaAs MMIC's for 20/30-GHz phased-array systems are discussed. The optical/MMIC interface and the desired characteristics of optical integrated circuits (OIC's) for such an interface are described. Anticipated fabrication considerations for eventual full monolithic integration of optical integrated circuits with MMIC's on a GaAs substrate are presented.

  16. AUTOMATIC LIGHT CONTROL

    DOEpatents

    Artzt, M.

    1957-08-27

    A control system for a projection kinescope used in a facsimile scanning system and, in particular, meams for maintaining substantially constant the light emanating from the flying spot on the face of the kinescope are described. In general, the invention provides a feeler member disposed in such a position with respect to a projecting lens as to intercept a portion of the light striking the lens. Suitable circuitry in conjunction with a photomultiplier tube provides a signal proportional to the light intensity of the flying spot. The grid bias on the kinescope is controlled by this signal to maintain the intensity of the spot substantially constant.

  17. A description of model 3B of the multipurpose ventricular actuating system. [providing controlled driving pressures

    NASA Technical Reports Server (NTRS)

    Webb, J. A., Jr.

    1974-01-01

    The multipurpose ventricular actuating system is a pneumatic signal generating device that provides controlled driving pressures for actuating pulsatile blood pumps. Overall system capabilities, the timing circuitry, and calibration instruction are included.

  18. It's all about gains: Risk preferences in problem gambling.

    PubMed

    Ring, Patrick; Probst, Catharina C; Neyse, Levent; Wolff, Stephan; Kaernbach, Christian; van Eimeren, Thilo; Camerer, Colin F; Schmidt, Ulrich

    2018-06-07

    Problem gambling is a serious socioeconomic problem involving high individual and social costs. In this article, we study risk preferences of problem gamblers including their risk attitudes in the gain and loss domains, their weighting of probabilities, and their degree of loss aversion. Our findings indicate that problem gamblers are systematically more risk taking and less sensitive toward changes in probabilities in the gain domain only. Neither their risk attitudes in the loss domain nor their degree of loss aversion are significantly different from the controls. Additional evidence for a similar degree of sensitivity toward negative outcomes is gained from skin conductance data-a psychophysiological marker for emotional arousal-in a threat-of-shock task. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  19. Generation of Quality Pulses for Control of Qubit/Quantum Memory Spin States: Experimental and Simulation

    DTIC Science & Technology

    2016-09-01

    TECHNICAL REPORT 3046 September 2016 GENERATION OF QUALITY PULSES FOR CONTROL OF QUBIT/QUANTUM MEMORY SPIN STATES: EXPERIMENTAL AND SIMULATION...control circuitry for control of electron/ nuclear spin states of qubits/quantum memory applicable to semiconductor, superconductor, ionic, and...coherence time of the qubit/ memory , we present as an example the integration of cryogenic superconductor components, including filters and

  20. Image intensifier gain uniformity improvements in sealed tubes by selective scrubbing

    DOEpatents

    Thomas, S.W.

    1995-04-18

    The gain uniformity of sealed microchannel plate image intensifiers (MCPIs) is improved by selectively scrubbing the high gain sections with a controlled bright light source. Using the premise that ions returning to the cathode from the microchannel plate (MCP) damage the cathode and reduce its sensitivity, a HeNe laser beam light source is raster scanned across the cathode of a microchannel plate image intensifier (MCPI) tube. Cathode current is monitored and when it exceeds a preset threshold, the sweep rate is decreased 1000 times, giving 1000 times the exposure to cathode areas with sensitivity greater than the threshold. The threshold is set at the cathode current corresponding to the lowest sensitivity in the active cathode area so that sensitivity of the entire cathode is reduced to this level. This process reduces tube gain by between 10% and 30% in the high gain areas while gain reduction in low gain areas is negligible. 4 figs.

  1. Image intensifier gain uniformity improvements in sealed tubes by selective scrubbing

    DOEpatents

    Thomas, Stanley W.

    1995-01-01

    The gain uniformity of sealed microchannel plate image intensifiers (MCPIs) is improved by selectively scrubbing the high gain sections with a controlled bright light source. Using the premise that ions returning to the cathode from the microchannel plate (MCP) damage the cathode and reduce its sensitivity, a HeNe laser beam light source is raster scanned across the cathode of a microchannel plate image intensifier (MCPI) tube. Cathode current is monitored and when it exceeds a preset threshold, the sweep rate is decreased 1000 times, giving 1000 times the exposure to cathode areas with sensitivity greater than the threshold. The threshold is set at the cathode current corresponding to the lowest sensitivity in the active cathode area so that sensitivity of the entire cathode is reduced to this level. This process reduces tube gain by between 10% and 30% in the high gain areas while gain reduction in low gain areas is negligible.

  2. Enhanced Control of Attention by Stimulating Mesolimbic-Corticopetal Cholinergic Circuitry

    PubMed Central

    St. Peters, Megan; Demeter, Elise; Lustig, Cindy; Bruno, John P.; Sarter, Martin

    2011-01-01

    Sustaining and recovering attentional performance requires interactions between the brain’s motivation and attention systems. The first experiment demonstrated that in rats performing a sustained attention task (SAT), presentation of a distractor (dSAT) augmented performance-associated increases in cholinergic neurotransmission in prefrontal cortex (PFC). Because stimulation of NMDA receptors in the shell of the nucleus accumbens (NAC) activates PFC cholinergic neurotransmission, a second experiment demonstrated that bilateral infusions of NMDA into the NAC shell, but not core, improved dSAT-performance to levels observed in the absence of a distractor. A third experiment demonstrated that removal of prefrontal or posterior parietal cholinergic inputs, by intra-cortical infusions of the cholinotoxin 192 IgG saporin, attenuated the beneficial effects of NMDA on dSAT perfomance. Mesolimbic activation of cholinergic projections to the cortex benefits the cognitive control of attentional performance by enhancing the detection of cues and the filtering of distractors. PMID:21715641

  3. Multimodal gain control at the hippocampal Schaffer collateral-CA1 synapse.

    PubMed

    Lange-Asschenfeldt, Christian; Schipke, Carola G; Riepe, Matthias W

    2007-04-06

    Information processing at central nervous system synapses is shaped by long-lasting modifications, such as long-term potentiation and short-lived and putatively synapse-specific modifications by various forms of short-term plasticity, such as facilitation, potentiation, and depression. Using an extracellular paired-pulse facilitation (PPF) protocol at the Schaffer collateral-CA1 (SC) connection in acute hippocampal slices in mice, we extend previous reports of optimal signal gain at intermediate interpulse intervals obtained at single SC synapses to the network level. Moreover, maximum signal gain changed when the input intensity was altered. We found further that facilitation decreased with increasing stimulus amplitude and duration in an exact exponential fashion when varied at a fixed interpulse interval. Variation of these intensity parameters accounted for significant changes in PPF adding a spatial dimension to time-based synaptic filter characteristics. Thus, this synapse functions as an amplitude window discriminator with a low-level aperture in combination with a band-pass frequency filter. By providing mathematical functions for the characteristic presynaptic parameters frequency, stimulus amplitude, and pulse duration at the network level our results lay ground for future studies on pharmacologically, genetically, or otherwise altered animal models.

  4. Multimodal Pilot Behavior in Multi-Axis Tracking Tasks with Time-Varying Motion Cueing Gains

    NASA Technical Reports Server (NTRS)

    Zaal, P. M. T; Pool, D. M.

    2014-01-01

    In a large number of motion-base simulators, adaptive motion filters are utilized to maximize the use of the available motion envelope of the motion system. However, not much is known about how the time-varying characteristics of such adaptive filters affect pilots when performing manual aircraft control. This paper presents the results of a study investigating the effects of time-varying motion filter gains on pilot control behavior and performance. An experiment was performed in a motion-base simulator where participants performed a simultaneous roll and pitch tracking task, while the roll and/or pitch motion filter gains changed over time. Results indicate that performance increases over time with increasing motion gains. This increase is a result of a time-varying adaptation of pilots' equalization dynamics, characterized by increased visual and motion response gains and decreased visual lead time constants. Opposite trends are found for decreasing motion filter gains. Even though the trends in both controlled axes are found to be largely the same, effects are less significant in roll. In addition, results indicate minor cross-coupling effects between pitch and roll, where a cueing variation in one axis affects the behavior adopted in the other axis.

  5. Interventions to reduce weight gain in schizophrenia.

    PubMed

    Faulkner, G; Cohn, T; Remington, G

    2007-01-24

    Weight gain is common for people with schizophrenia and this has serious implications for health and well being. To determine the effects of both pharmacological (excluding medication switching) and non pharmacological strategies for reducing or preventing weight gain in people with schizophrenia. We searched key databases and the Cochrane Schizophrenia Group's trials register (April 2006), reference sections within relevant papers, hand searched key journals, and contacted the first author of each relevant study and other experts to collect further information. We included all clinical randomised controlled trials comparing any pharmacological or non pharmacological intervention for weight gain (diet and exercise counselling) with standard care or other treatments for people with schizophrenia or schizophrenia-like illnesses. We reliably selected, quality assessed and extracted data from studies. As weight is a continuous outcome measurement, weighted mean differences (WMD) of the change from baseline were calculated. The primary outcome measure was weight loss. Twenty-three randomised controlled trials met the inclusion criteria for this review. Five trials assessed a cognitive/behavioural intervention and eighteen assessed a pharmacological adjunct. In terms of prevention, two cognitive/behavioural trials showed significant treatment effect (mean weight change) at end of treatment (n=104, 2 RCTs, WMD -3.38 kg CI -4.2 to -2.0). Pharmacological adjunct treatments were significant with a modest prevention of weight gain (n=274, 6 RCTs, WMD - 1.16 kg CI -1.9 to -0.4). In terms of treatments for weight loss, we found significantly greater weight reduction in the cognitive behavioural intervention group (n=129, 3 RCTs, WMD -1.69 kg CI -2.8 to -0.6) compared with standard care. Modest weight loss can be achieved with selective pharmacological and non pharmacological interventions. However, interpretation is limited by the small number of studies, small sample size

  6. Coplanar semiconductor-metal circuitry defined on few-layer MoTe2 via polymorphic heteroepitaxy

    NASA Astrophysics Data System (ADS)

    Sung, Ji Ho; Heo, Hoseok; Si, Saerom; Kim, Yong Hyeon; Noh, Hyeong Rae; Song, Kyung; Kim, Juho; Lee, Chang-Soo; Seo, Seung-Young; Kim, Dong-Hwi; Kim, Hyoung Kug; Yeom, Han Woong; Kim, Tae-Hwan; Choi, Si-Young; Kim, Jun Sung; Jo, Moon-Ho

    2017-11-01

    Crystal polymorphism selectively stabilizes the electronic phase of atomically thin transition-metal dichalcogenides (TMDCs) as metallic or semiconducting, suggesting the potential to integrate these polymorphs as circuit components in two-dimensional electronic circuitry. Developing a selective and sequential growth strategy for such two-dimensional polymorphs in the vapour phase is a critical step in this endeavour. Here, we report on the polymorphic integration of distinct metallic (1T‧) and semiconducting (2H) MoTe2 crystals within the same atomic planes by heteroepitaxy. The realized polymorphic coplanar contact is atomically coherent, and its barrier potential is spatially tight-confined over a length of only a few nanometres, with a lowest contact barrier height of ∼25 meV. We also demonstrate the generality of our synthetic integration approach for other TMDC polymorph films with large areas.

  7. Stress effects on framed decisions: there are differences for gains and losses.

    PubMed

    Pabst, Stephan; Brand, Matthias; Wolf, Oliver T

    2013-01-01

    Recent studies have shown that acute stress can lead to riskier decision making. Yet, the underlying mechanisms of the stress effects on decisions under risk remain poorly understood. To gain a better understanding of decision-making processes and potential strategy application under stress, we investigated decision making in pure gain and loss domains with unequal expected values (EVs) across alternatives. We conducted an experimental study with a 2 × 2 design (stress vs. no stress and gain domain vs. loss domain). The Trier Social Stress Test (TSST) was utilized to induce acute stress. Controls performed the placebo-TSST (p-TSST). To validate the stress response we measured salivary cortisol and alpha-amylase concentrations. We used a modified version of the Game of Dice Task (GDT) to assess decision-making performance in a gain and a loss domain. Results showed that non-stressed participants made less risky decisions in the gain domain compared to those of the loss domain. This behavior is in accordance with previous studies and indicates the stability of the framing effect in even more complex tasks with changing EVs across alternatives. Stress did not alter risk taking behavior in the gain domain. Yet, in the loss domain stressed participants made less risky decisions compared to controls. Additionally, the data support earlier findings of longer reaction times in loss compared to gain domains due to higher cognitive effort for loss-framed decisions. It is discussed that stress may lead to reduced amygdala activation, which has been found to reduce riskier decisions in a loss domain. With respect to earlier results of riskier decisions in tasks that unite both gain and loss domains, it is discussed whether stress leads to a stronger evaluation of high gains and a neglect of losses.

  8. Effect of body weight gain on insulin sensitivity after retirement from exercise training

    NASA Technical Reports Server (NTRS)

    Dolkas, Constantine B.; Rodnick, Kenneth J.; Mondon, Carl E.

    1990-01-01

    The effect of the body-weight gain after retirement from an exercise-training program on the retained increase in insulin sensitivity elicited by the training was investigated in exercise-trained (ET) rats. Insulin sensitivity was assessed by oral glucose tolerance and insulin suppression tests immediately after training and during retirement. Results show that, compared with sedentary controls, exercise training enhanced insulin-induced glucose uptake, but the enhanced sensitivity was gradually lost with the end of running activity until after seven days of retirement, when it became equal to that of controls. This loss of enhanced sensitivity to insulin was associated with an accelerated gain in body weight beginning one day after the start of retirement. However, those animals that gained weight only at rates similar to those of control rats, retained their enhanced sensitivity to insulin.

  9. Optofluidic lasers with a single molecular layer of gain

    PubMed Central

    Chen, Qiushu; Ritt, Michael; Sivaramakrishnan, Sivaraj; Sun, Yuze; Fan, Xudong

    2014-01-01

    We achieve optofluidic lasers with a single molecular layer of gain, in which green fluorescent protein, dye-labeled bovine serum albumin, and dye-labeled DNA are respectively used as the gain medium and attached to the surface of a ring resonator via surface immobilization biochemical methods. It is estimated that the surface density of the gain molecules is on the order of 1012/cm2, sufficient for lasing under pulsed optical excitation. It is further shown that the optofluidic laser can be tuned by energy transfer mechanisms through biomolecular interactions. This work not only opens a door to novel photonic devices that can be controlled at the level of a single molecular layer, but also provides a promising sensing platform to analyze biochemical processes at the solid-liquid interface. PMID:25312306

  10. Computer simulation of space station computer steered high gain antenna

    NASA Technical Reports Server (NTRS)

    Beach, S. W.

    1973-01-01

    The mathematical modeling and programming of a complete simulation program for a space station computer-steered high gain antenna are described. The program provides for reading input data cards, numerically integrating up to 50 first order differential equations, and monitoring up to 48 variables on printed output and on plots. The program system consists of a high gain antenna, an antenna gimbal control system, an on board computer, and the environment in which all are to operate.

  11. Coaxial GaAs-AlGaAs core-multishell nanowire lasers with epitaxial gain control

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

    Stettner, T., E-mail: Thomas.Stettner@wsi.tum.de, E-mail: Gregor.Koblmueller@wsi.tum.de, E-mail: Jonathan.Finley@wsi.tum.de; Zimmermann, P.; Loitsch, B.

    2016-01-04

    We demonstrate the growth and single-mode lasing operation of GaAs-AlGaAs core-multishell nanowires (NW) with radial single and multiple GaAs quantum wells (QWs) as active gain media. When subject to optical pumping lasing emission with distinct s-shaped input-output characteristics, linewidth narrowing and emission energies associated with the confined QWs are observed. Comparing the low temperature performance of QW NW laser structures having 7 coaxial QWs with a nominally identical structure having only a single QW shows that the threshold power density reduces several-fold, down to values as low as ∼2.4 kW/cm{sup 2} for the multiple QW NW laser. This confirms that themore » individual radial QWs are electronically weakly coupled and that epitaxial design can be used to optimize the gain characteristics of the devices. Temperature-dependent investigations show that lasing prevails up to 300 K, opening promising new avenues for efficient III–V semiconductor NW lasers with embedded low-dimensional gain media.« less

  12. Genetic subtype differences in neural circuitry of food motivation in Prader-Willi syndrome.

    PubMed

    Holsen, L M; Zarcone, J R; Chambers, R; Butler, M G; Bittel, D C; Brooks, W M; Thompson, T I; Savage, C R

    2009-02-01

    Differences in behavioral phenotypes between the two most common subtypes of Prader-Willi syndrome (PWS) (chromosome 15q deletions and maternal uniparental disomy 15 (UPD) indicate that distinct neural networks may be affected. Though both subtypes display hyperphagia, the deletion subgroup shows reduced behavioral inhibition around food, whereas those with UPD are generally more able to maintain cognitive control over food intake impulses. To examine the neural basis of phenotypic differences to better understand relationships between genetic subtypes and behavioral outcomes. We predicted greater food motivation circuitry activity in the deletion subtype and greater activity in higher order cognitive regions in the UPD group, especially after eating. Nine individuals with PWS due to UPD and nine individuals with PWS due to (type 2) deletion, matched for age, gender and body mass index, underwent functional magnetic resonance imaging (fMRI) while viewing food images during two food motivation states: one before (pre-meal) and one after (post-meal) eating a standardized 500 kcal meal. Both PWS subgroups showed greater activity in response to food pre- and post-meal compared with the healthy-weight group. Compared with UPD, the deletion subtype showed increased food motivation network activation both pre- and post-meal, especially in the medial prefrontal cortex (mPFC) and amygdala. In contrast, the UPD group showed greater activation than the deletion subtype post-meal in the dorsolateral prefrontal cortex (DLPFC) and parahippocampal gyrus (PHG). These preliminary findings are the first functional neuroimaging findings to support divergent neural mechanisms associated with behavioral phenotypes in genetic subtypes of PWS. Results are discussed within the framework of genetic mechanisms such as haploinsufficiency and gene dosage effects and their differential influence on deletion and UPD subtypes, respectively.

  13. Hardware Evolution of Closed-Loop Controller Designs

    NASA Technical Reports Server (NTRS)

    Gwaltney, David; Ferguson, Ian

    2002-01-01

    Poster presentation will outline on-going efforts at NASA, MSFC to employ various Evolvable Hardware experimental platforms in the evolution of digital and analog circuitry for application to automatic control. Included will be information concerning the application of commercially available hardware and software along with the use of the JPL developed FPTA2 integrated circuit and supporting JPL developed software. Results to date will be presented.

  14. A Role for the Lateral Dorsal Tegmentum in Memory and Decision Neural Circuitry

    PubMed Central

    Redila, Van; Kinzel, Chantelle; Jo, Yong Sang; Puryear, Corey B.; Mizumori, Sheri J.Y.

    2017-01-01

    A role for the hippocampus in memory is clear, although the mechanism for its contribution remains a matter of debate. Converging evidence suggests that hippocampus evaluates the extent to which context-defining features of events occur as expected. The consequence of mismatches, or prediction error, signals from hippocampus is discussed in terms of its impact on neural circuitry that evaluates the significance of prediction errors: Ventral tegmental area (VTA) dopamine cells burst fire to rewards or cues that predict rewards (Schultz et al., 1997). Although the lateral dorsal tegmentum (LDTg) importantly controls dopamine cell burst firing (Lodge & Grace, 2006) the behavioral significance of the LDTg control is not known. Therefore, we evaluated LDTg functional activity as rats performed a spatial memory task that generates task-dependent reward codes in VTA (Jo et al., 2013; Puryear et al., 2010) and another VTA afferent, the pedunculopontine nucleus (PPTg, Norton et al., 2011). Reversible inactivation of the LDTg significantly impaired choice accuracy. LDTg neurons coded primarily egocentric information in the form of movement velocity, turning behaviors, and behaviors leading up to expected reward locations. A subset of the velocity-tuned LDTg cells also showed high frequency bursts shortly before or after reward encounters, after which they showed tonic elevated firing during consumption of small, but not large, rewards. Cells that fired before reward encounters showed stronger correlations with velocity as rats moved toward, rather than away from, rewarded sites. LDTg neural activity was more strongly regulated by egocentric behaviors than that observed for PPTg or VTA cells that were recorded by Puryear et al. and Norton et al. While PPTg activity was uniquely sensitive to ongoing sensory input, all three regions encoded reward magnitude (although in different ways), reward expectation, and reward encounters. Only VTA encoded reward prediction errors. LDTg

  15. Neurocognitive and electrophysiological evidence of altered face processing in parents of children with autism: implications for a model of abnormal development of social brain circuitry in autism.

    PubMed

    Dawson, Geraldine; Webb, Sara Jane; Wijsman, Ellen; Schellenberg, Gerard; Estes, Annette; Munson, Jeffrey; Faja, Susan

    2005-01-01

    Neuroimaging and behavioral studies have shown that children and adults with autism have impaired face recognition. Individuals with autism also exhibit atypical event-related brain potentials to faces, characterized by a failure to show a negative component (N170) latency advantage to face compared to nonface stimuli and a bilateral, rather than right lateralized, pattern of N170 distribution. In this report, performance by 143 parents of children with autism on standardized verbal, visual-spatial, and face recognition tasks was examined. It was found that parents of children with autism exhibited a significant decrement in face recognition ability relative to their verbal and visual spatial abilities. Event-related brain potentials to face and nonface stimuli were examined in 21 parents of children with autism and 21 control adults. Parents of children with autism showed an atypical event-related potential response to faces, which mirrored the pattern shown by children and adults with autism. These results raise the possibility that face processing might be a functional trait marker of genetic susceptibility to autism. Discussion focuses on hypotheses regarding the neurodevelopmental and genetic basis of altered face processing in autism. A general model of the normal emergence of social brain circuitry in the first year of life is proposed, followed by a discussion of how the trajectory of normal development of social brain circuitry, including cortical specialization for face processing, is altered in individuals with autism. The hypothesis that genetic-mediated dysfunction of the dopamine reward system, especially its functioning in social contexts, might account for altered face processing in individuals with autism and their relatives is discussed.

  16. Effects of lifestyle intervention on dietary intake, physical activity level, and gestational weight gain in pregnant women with different pre-pregnancy Body Mass Index in a randomized control trial.

    PubMed

    Hui, Amy Leung; Back, Lisa; Ludwig, Sora; Gardiner, Phillip; Sevenhuysen, Gustaaf; Dean, Heather J; Sellers, Elisabeth; McGavock, Jonathan; Morris, Margaret; Jiang, Depeng; Shen, Garry X

    2014-09-24

    The objectives of this study were to assess the efficacy of lifestyle intervention on gestational weight gain in pregnant women with normal and above normal body mass index (BMI) in a randomized controlled trial. A total of 116 pregnant women (<20 weeks of pregnancy) without diabetes were enrolled and 113 pregnant women completed the program. Participants were randomized into intervention and control groups. Women in the intervention group received weekly trainer-led group exercise sessions, instructed home exercise for 3-5-times/week during 20-36 weeks of gestation, and dietary counseling twice during pregnancy. Participants in the control group did not receive the intervention. All participants completed a physical activity questionnaire and a 3-day food record at enrolment and 2 months after enrolment. The participants in the intervention group with normal pre-pregnancy BMI (≤24.9 kg/M2, n = 30) had lower gestational weight gain (GWG), offspring birth weight and excessive gestational weight gain (EGWG) on pregnancy weight gain compared to the control group (n = 27, p < 0.05). Those weight related-changes were not detected between the intervention (n = 27) and control group (n = 29) in the above normal pre-pregnancy BMI participants. Intervention reduced total calorie, total fat, saturated fat and cholesterol intake were detected in women with normal or above normal pre-pregnancy BMI compared to the control group (p < 0.05 or 0.01). Increased physical activity and reduced carbohydrate intake were detected in women with normal (p < 0.05), but not above normal, pre-pregnancy BMI at 2 months after the onset of the intervention compared to the control group. The results of the present study demonstrated that the lifestyle intervention program decreased EGWG, GWG, offspring birth weight in pregnant women with normal, but not above normal, pre-pregnancy BMI, which was associated with increased physical activity and decreased carbohydrate intake. NCT00486629.

  17. Comparing gains and losses.

    PubMed

    McGraw, A Peter; Larsen, Jeff T; Kahneman, Daniel; Schkade, David

    2010-10-01

    Loss aversion in choice is commonly assumed to arise from the anticipation that losses have a greater effect on feelings than gains, but evidence for this assumption in research on judged feelings is mixed. We argue that loss aversion is present in judged feelings when people compare gains and losses and assess them on a common scale. But many situations in which people judge and express their feelings lack these features. When judging their feelings about an outcome, people naturally consider a context of similar outcomes for comparison (e.g., they consider losses against other losses). This process permits gains and losses to be normed separately and produces psychological scale units that may not be the same in size or meaning for gains and losses. Our experiments show loss aversion in judged feelings for tasks that encourage gain-loss comparisons, but not tasks that discourage them, particularly those using bipolar scales.

  18. Feed Your Head: Neurodevelopmental Control of Feeding and Metabolism

    PubMed Central

    Lee, Daniel A.; Blackshaw, Seth

    2014-01-01

    During critical periods of development early in life, excessive or scarce nutritional environments can disrupt the development of central feeding and metabolic neural circuitry, leading to obesity and metabolic disorders in adulthood. A better understanding of the genetic networks that control the development of feeding and metabolic neural circuits, along with knowledge of how and where dietary signals disrupt this process, can serve as the basis for future therapies aimed at reversing the public health crisis that is now building as a result of the global obesity epidemic. This review of animal and human studies highlights recent insights into the molecular mechanisms that regulate the development of central feeding circuitries, the mechanisms by which gestational and early postnatal nutritional status affects this process, and approaches aimed at counteracting the deleterious effects of early over- and underfeeding. PMID:24274739

  19. An interglomerular circuit gates glomerular output and implements gain control in the mouse olfactory bulb

    PubMed Central

    Banerjee, Arkarup; Marbach, Fred; Anselmi, Francesca; Koh, Matthew S.; Davis, Martin B.; da Silva, Pedro Garcia; Delevich, Kristen; Oyibo, Hassana K.; Gupta, Priyanka; Li, Bo; Albeanu, Dinu F.

    2015-01-01

    Summary Odors elicit distributed activation of glomeruli in the olfactory bulb (OB). Crosstalk between co-active glomeruli has been proposed to perform a variety of computations, facilitating efficient extraction of sensory information by the cortex. Dopaminergic/GABAergic cells in the OB, which can be identified by their expression of the dopamine transporter (DAT), provide the earliest opportunity for such crosstalk. Here we show in mice that DAT+ cells carry concentration dependent odor signals and broadcast focal glomerular inputs throughout the OB to cause suppression of mitral/tufted (M/T) cell firing, an effect that is mediated by the external tufted (ET) cells coupled to DAT+ cells via chemical and electrical synapses. We find that DAT+ cells implement gain control and decorrelate odor representations in the M/T cell population. Our results further indicate that ET cells are gatekeepers of glomerular output and prime determinants of M/T responsiveness. PMID:26139373

  20. Mapping Compulsivity in the DSM-5 Obsessive Compulsive and Related Disorders: Cognitive Domains, Neural Circuitry, and Treatment

    PubMed Central

    Apergis-Schoute, Annemieke M; Vaghi, Matilde M; Banca, Paula; Gillan, Claire M; Voon, Valerie; Chamberlain, Samuel R; Cinosi, Eduardo; Reid, Jemma; Shahper, Sonia; Bullmore, Edward T; Sahakian, Barbara J; Robbins, Trevor W

    2018-01-01

    Abstract Compulsions are repetitive, stereotyped thoughts and behaviors designed to reduce harm. Growing evidence suggests that the neurocognitive mechanisms mediating behavioral inhibition (motor inhibition, cognitive inflexibility) reversal learning and habit formation (shift from goal-directed to habitual responding) contribute toward compulsive activity in a broad range of disorders. In obsessive compulsive disorder, distributed network perturbation appears focused around the prefrontal cortex, caudate, putamen, and associated neuro-circuitry. Obsessive compulsive disorder-related attentional set-shifting deficits correlated with reduced resting state functional connectivity between the dorsal caudate and the ventrolateral prefrontal cortex on neuroimaging. In contrast, experimental provocation of obsessive compulsive disorder symptoms reduced neural activation in brain regions implicated in goal-directed behavioral control (ventromedial prefrontal cortex, caudate) with concordant increased activation in regions implicated in habit learning (presupplementary motor area, putamen). The ventromedial prefrontal cortex plays a multifaceted role, integrating affective evaluative processes, flexible behavior, and fear learning. Findings from a neuroimaging study of Pavlovian fear reversal, in which obsessive compulsive disorder patients failed to flexibly update fear responses despite normal initial fear conditioning, suggest there is an absence of ventromedial prefrontal cortex safety signaling in obsessive compulsive disorder, which potentially undermines explicit contingency knowledge and may help to explain the link between cognitive inflexibility, fear, and anxiety processing in compulsive disorders such as obsessive compulsive disorder. PMID:29036632